article stringlengths 0 826k | abstract stringlengths 174 4.34k |
|---|---|
it is chronic , progressive , and costly , and creates several complications . for individuals with diabetes
it is difficult to accept these threads which may change their lifestyle . in most cases it will not be weird to see mood disorders such as depression in these individuals ( 1 ) .
depression has a two - way relationship with diabetes and has been proposed as a risk factor for it .
depression is a debilitating and highly morbid disease with a higher prevalence ( estimated to be about 33 percent ) in diabetic patients than in general population ( 8 to 20% ) ( 2 ) .
depression is a mood disorder characterized by the symptoms of low mood , reduction of energy and interest , feeling of guilt , difficulty in concentration , loss of appetite , thoughts of death and suicide , chronic daily stress , lower levels of psychological well - being and consequent low quality of life , insomnia or hypersomnia , significant loss of weight , and dysfunction ( 4 ) .
the other variable studied is the feeling of guilt which is defined as a violation of norms and values taught by ancestors and eradicates self - confidence of the person .
in fact , feeling of guilt affects the individual s performance by anxiety and fear in the workplace and makes him fail in adjusting with different environments ( 5 ) .
because of the need for self - care , and in most cases , care by family members , diabetic children may feel themselves as a burden on families , compared to children of the same age .
the way of interpreting the annoying thoughts is an important factor in determining the severity of the discomfort and anxiety caused by the consequence of this opinion , such as being an extra member in family , because of raising financial burden on the family , ascribing any action to himself in the family , so that the interpretation of thoughts can be influenced by cognitive biases .
failure to express emotions , or anxiety and worry which leads sometimes to feelings of guilt ( 6 ) . this feeling may be incompatible with excitement which is not easily amendable and brings stress , inhibition and psychological damage and severe intellectual ruminations occur .
individual s sense may be relieved by compensatory works , partly , but it does not go away completely and can cause mental disorders in diabetic children with feeling of loneliness and alienation , because they assume themselves to be intruders in the family ( 7 ) .
the aim of diabetes treatment is prevention of its complications and in addition , maintaining optimal psychological well - being of the patients . in the past
it was thought that doctors were able to provide favorable conditions for individuals by doing effective treatment and control of disease symptoms , but the evidence suggests that psychological well - being and in wider context quality of life , is something that does not concern only controlling symptoms ; when it has special relevance in treating a chronic disease such as diabetes , in addition to controlling symptoms , it has to improve psychological well - being and process of patient s life ( 8) . psychological well - being is the psychological part of the quality of life structure and is defined as understanding people from living in the area of emotional behaviors , psychological functions and dimensions of mental health ( 9 ) .
diabetic children do not have appropriate emotional responses and are experiencing lower psychological well - being due to the difficulties imposed by diabetes such as dietary , activity limitation , invasive monitoring of blood glucose , daily insulin injections , physical chronic complications , hospitalizations , and shortened life expectancy ( 10 ) .
the prevalence of negative psychological outcomes among people with diabetes especially children and adolescents , and their frustration toward the process of medical treatment has implications for the intention of developing psychological interventions in the field of clinical and health psychology .
publicly health instructions for diabetics have always been given based on teaching of self - care .
acceptance and commitment therapy is different from the traditional cognitive behavioral therapy ( cbt ) .
act has two major goals : ( a ) , and ( b ) commitment and action toward living a life according to one s chosen values ( 11 ) .
this treatment is trying to increase person s psychological acceptance in the case of subjective experiences ( thoughts and emotions ) and reduce ineffective control measures mutually and add to the psychological awareness in the present moment ( 12 ) .
there are numerous psychological therapies for the treatment of depression and psychological consequences associated with it in diabetic patients .
some researchers believe that applying this method can increase effectiveness beside reducing disease symptoms , due to its underlying mechanism such as acceptance , awareness raising , desensitization , living in the present moment , observing without judgment , confrontation , and release ( 13 ) .
results of previous studies showed that the use of mindfulness method will cause a decrease in depressive attacks ( 3 , 14 ) .
boey showed that acceptance of diabetes and its related cognitions significantly associated with lower values of hba1c and also decreased depression in patients simultaneously .
many of these studies included hba1c , the primary marker of glycemic control , as an indicator of disease management ( 15 , 16 ) . despite many words very little
this study seeks to answer the question of whether acceptance and commitment therapy ( act ) is effective for depression , psychological well - being and feeling of guilt in 7 - 15 years old diabetic children ?
the present study is a clinical trial with control group along with random assignment and pre - test -post - test .
the study population included 34 participants out of all 7 - 15 years old patients referred to the diabetes association in tabriz , iran , of whom 40 participants were selected using convenient sampling .
the experimental group participated in therapy sessions and the control group did not receive any interventions .
entry criteria for this study included : age less than 15 years , having diabetes for at least one year without having major psychiatric disorder .
exclusion criteria , determined by treating physician in most cases , included : needing significant change in the dose of insulin administered during the research , acute or chronic medical illness that makes problems in venesection or intolerance in long sessions , cinching up severe medical complications of diabetes , receiving psychiatric treatment or use of psychotropic drugs and drug abuse during the study period .
following the research , in order to obey research ethics in addition to obtaining written consent of the children and their parents to participate in research , the evaluations of pre - test were also conducted .
three members of the experimental group and 3 patients of the control group were excluded for various reasons , including being absent in more than three sessions , not participating in pro - test , disease and change of residence city .
finally 17 patients in the experimental group and 17 patients in the control group were randomly settled . for data collection ,
the following tools were used : the rcds is a 30-item self - report measure of depressive symptoms developed by reynolds ( 17 ) .
the items assess symptoms of depression from the criteria listed in major depression and dysthymia in the diagnostic and statistical manual of mental disorders - third edition - revised ( dsm - iii - r ; american psychiatric association ) .
all but one of the items assesses clinically relevant depressive symptoms on a 4-point likert - type scale , ranging from 1 almost never to 4 all the time .
items 1 , 5 , 10 , 12 , 23 , 25 , and 30 were reversed scored so that higher scores on each item reflect higher levels of depressive symptoms . the total score of the rcds can range between 30 and 121 points .
internal - consistency reliabilities were upper 0.80 seconds , lower 0.90 seconds within and across grades , gender , ethnic groups , and for a subset of learning disabled students .
validity studies support the test based on its congruence with diagnostic systems ( in the time ) , correlations with other established measures ( mid 0.70 seconds ) , and convergent and divergent studies yielded predictable results ( 17 ) .
this test consists of 30 items and with a scoring range of 0 and 1 .
asgari ( 18 ) to assess the reliability of this questionnaire made use of cronbach s alpha and bisection and for each one achieved the coefficients of 0.67 and 0.68 to arrange . to assess its validity , correlated its score with criterion question score and it was determined that there is a significant relationship between questionnaire scores and criterion question ( p < 0.001 and r = 0.28 ) . to measure psychological ( 19 ) well - being ,
a questionnaire was used which has been introduced by diener , emmons , larsen and griffin , having 5-item answering seven degree scale ( 1 = completely disagree to 7 = strongly agree ) .
park et al . ( 20 ) to determine the reliability of psychological well - being scale obtained a significant negative correlation between the scale and the beck depression test scores .
( 21 ) reported the validity of psychological well - being scale by using cronbach s alpha coefficient for samples of american , german , japanese , mexican and chinese , 0.90 , 0.82 , 0.79 , 0.76 , and 0.61 , respectively .
schimmack and associates also found a significant correlation between scores on psychological well - being scale with extraversion ( 0.46 ) and neuroticism ( 0.48 ) scores .
the topics for each session included : 1 ) building the therapeutic contract and functional analysis ; 2 ) creative hopelessness : the man in the cave and the farmer and the donkey
metaphors ; 3 ) values clarification and building a commitment , the funeral exercise .
metaphor : eat the whole apple ; 4 ) control as the problem : the rule of 95 - 5% and control as the problem : pink elephants and what s the name of your mother ? exercises ; 5 ) the alternative to control , be willing as a possibility , acceptance exercises : eyes on exercise ; 6 ) cognitive defusion : the ride with posters
, milk , milk , milk exercises and establishing language conventions : i m having the thought that i m failure instead of saying
i m a failure ; 7 ) self as context : metaphor : chessboard , and screening for barriers and strengthening values : metaphors : the journey and welcome to all and the rude ; 8) acceptance and commitment , fear of commitment : metaphor : now you know how to drive ; 9 ) remember session , internal dialogue : this is nt working , it s always the same , and i thought it was o.k . , but it is nt ... metaphor : the rider ; 10 ) remember session and relapse prevention . after 10 sessions of intervention for the experimental group only
all assessments of participants were conducted by a psychologist who was not the therapist and who was blind to subject s treatment . due to the illiteracy in some subjects ,
the data were collected orally for them . in accordance with the code of ethics ,
we performed a descriptive study of the dependent variables of interest ( means and standard deviations ) .
data analysis was performed with the spss statistical package ( v. 19.0 ) and a 5% a priori type i error .
the rcds is a 30-item self - report measure of depressive symptoms developed by reynolds ( 17 ) .
the items assess symptoms of depression from the criteria listed in major depression and dysthymia in the diagnostic and statistical manual of mental disorders - third edition - revised ( dsm - iii - r ; american psychiatric association ) .
all but one of the items assesses clinically relevant depressive symptoms on a 4-point likert - type scale , ranging from 1 almost never to 4 all the time .
items 1 , 5 , 10 , 12 , 23 , 25 , and 30 were reversed scored so that higher scores on each item reflect higher levels of depressive symptoms .
internal - consistency reliabilities were upper 0.80 seconds , lower 0.90 seconds within and across grades , gender , ethnic groups , and for a subset of learning disabled students .
validity studies support the test based on its congruence with diagnostic systems ( in the time ) , correlations with other established measures ( mid 0.70 seconds ) , and convergent and divergent studies yielded predictable results ( 17 ) .
this test consists of 30 items and with a scoring range of 0 and 1 .
asgari ( 18 ) to assess the reliability of this questionnaire made use of cronbach s alpha and bisection and for each one achieved the coefficients of 0.67 and 0.68 to arrange . to assess its validity , correlated its score with criterion question score and it was determined that there is a significant relationship between questionnaire scores and criterion question ( p < 0.001 and r = 0.28 ) .
to measure psychological ( 19 ) well - being , a questionnaire was used which has been introduced by diener , emmons , larsen and griffin , having 5-item answering seven degree scale ( 1 = completely disagree to 7 = strongly agree ) .
park et al . ( 20 ) to determine the reliability of psychological well - being scale obtained a significant negative correlation between the scale and the beck depression test scores .
( 21 ) reported the validity of psychological well - being scale by using cronbach s alpha coefficient for samples of american , german , japanese , mexican and chinese , 0.90 , 0.82 , 0.79 , 0.76 , and 0.61 , respectively .
schimmack and associates also found a significant correlation between scores on psychological well - being scale with extraversion ( 0.46 ) and neuroticism ( 0.48 ) scores .
the topics for each session included : 1 ) building the therapeutic contract and functional analysis ; 2 ) creative hopelessness : the man in the cave and the farmer and the donkey metaphors ; 3 ) values clarification and building a commitment , the funeral exercise .
metaphor : eat the whole apple ; 4 ) control as the problem : the rule of 95 - 5% and control as the problem : pink elephants and what s the name of your mother ? exercises ; 5 ) the alternative to control , be willing as a possibility , acceptance exercises : eyes on exercise ; 6 ) cognitive defusion : the ride with posters
i m a failure ; 7 ) self as context : metaphor : chessboard , and screening for barriers and strengthening values : metaphors : the journey and welcome to all and the rude ; 8) acceptance and commitment , fear of commitment : metaphor : now you know how to drive ; 9 ) remember session , internal dialogue : this is nt working , it s always the same , and i thought it was o.k . , but it is nt ... metaphor : the rider ; 10 ) remember session and relapse prevention .
after 10 sessions of intervention for the experimental group only , the post - test was performed on both groups .
all assessments of participants were conducted by a psychologist who was not the therapist and who was blind to subject s treatment . due to the illiteracy in some subjects ,
the data were collected orally for them . in accordance with the code of ethics ,
we performed a descriptive study of the dependent variables of interest ( means and standard deviations ) .
data analysis was performed with the spss statistical package ( v. 19.0 ) and a 5% a priori type i error .
table 2 shows mean and standard deviation of variables depression , psychological well - being , and feeling of guilt in the experimental and control group .
values are presented as mean sd . to measure the equality of variances , data were evaluated
with levine s test of homogeneity of variance .
the results showed that variances of the experimental and control group for depression ( f = 0.712 , p = 0.405 ) , psychological well - being ( f = 3.07 , p = 0.089 ) and feeling of guilt ( f = 1.93 , p = 0.174 ) were equal .
the results showed significant homogeneity using mancova tests including pillai s trace , wilks lambda , hotelling s trace and roy s largest root .
experimental and control group differ from each other , at least in two dependent variables .
mancova results on the variables of depression , psychological well - being , and feeling of guilt in both control and experimental group after controlling the pre - test are shown in table 3 .
this analysis shows that the two groups are different from each other in three investigated variables according to the means presented in table 2 .
furthermore , an increase in psychological well - being and a decrease in depression and feeling of guilt scores were observed in the experimental group as compared with the control group .
the results showed that acceptance and commitment therapy ( act ) is effective on reducing depression and feeling of guilt , and increasing the psychological well - being of diabetic children .
( 3 ) , kaviani et al . ( 23 ) and hayes et al . ( 24 ) .
they believe that applying this method can increase effectiveness besides reducing disease symptoms , due to its underlying mechanism such as acceptance , awareness raising , desensitization , living in the present moment , observing without judgment , confrontation and release ( 13 ) . it should be noted that this treatment modality is a short - term and structured intervention and like traditional cognitive therapy , the purpose of mental care education , is not to change the content of the thoughts , rather the aim is to create an attitude or a different relationship with the thoughts , feelings and emotions which includes maintaining full attention with an attitude of acceptance and away from the judgment ( 25 ) . the focus of this act process is to develop and enhance clients willingness to have and accept their private experiences .
treatment involves exploring the futility of emotional control and avoidance , which can often paradoxically increase individuals level of distress and deter them from engaging in purposeful and vital , value driven behavior .
instead , individuals are encouraged to accept their private experiences , doing so helps them engage in valued behavior .
based on acceptance and commitment therapy , the concept of interlinking or emotional defusion is the impact rate that a thought has on behavior ; such as the effects of subjective interpretation on the children s feeling of guilt .
context - dependent behavior and think dependent behaviors are placed on the continuum between interlinking or emotional defusion . when a person blends with his thoughts , he does not distinguish his own subjective judgment from reality ( 24 , 26 ) . thus increasing psychological flexibility of pediatric patients in acceptance and commitment therapy and creating
a thinking based on mindfulness can increase the patient s ability to cope with symptoms of disease , following the prescribed diet and some family adversity .
naturally , improvement of symptoms depression and individual commitment to carry out some behaviors in the long term would increase psychological well - being of the child .
limitation of study population and scarecity of similar studies in iran and elsewhere can be regarded as a limitation to this study .
it is recommended to consider this treatment as a new psychological and supportive treatment in diabetic patients .
it can also be useful in other groups of patients such as aids , cancer and patients with depression and its relined variables .
it is recommended to consider this treatment as a new psychological and supportive treatment in diabetic patients .
it can also be useful in other groups of patients such as aids , cancer and patients with depression and its relined variables . | background : diabetes imposes restrictions on physical , emotional , and social functioning of children and adolescents.objectives:the aim of this study was to determine effectiveness of acceptance and commitment therapy ( act ) for depression , psychological well - being and feeling of guilt in 7 - 15 years old diabetic children.patients and methods : this was a clinical trial with pre - test and post - test design with control group .
the study population consisted of 34 participants selected using convenient sampling out of all 7 - 15 years old patients that referred to the diabetes association of tabriz .
they were randomly allocated into two equal groups ( experimental and control ) .
the experimental group participated in therapy sessions and the control group did not receive any intervention .
the research instruments were reynolds child depression scale ( rcds ) , eysenck feelings of guilt scale and satisfaction with life scale ( swls).results : multivariate covariance analysis ( mancova ) showed that the treatment was effective on variables of depression , psychological well - being and feeling guilty in 7 - 15 years old diabetic children ( p < 0.001).conclusions : the aforementioned treatment is effective and suggested to be used in other psychosomatic diseases of children . |
nonalcoholic fatty liver disease ( nafld ) is one of the most common chronic liver diseases worldwide and occurs predominantly in obese , sedentary people and patients with type ii diabetes ( 1 ) .
nafld includes a wide variety of liver disorders from simple steatosis to hepatic fibrosis and cirrhosis ( 2 ) .
it is usually associated with metabolic disorders such as obesity , insulin resistance ( 3 ) , hypertension , dyslipidemia and impaired fat metabolism ( 4 ) , and it can increase mortality risk due to the associated cardiovascular disease ( 5 ) . although there is no proven treatment for this disorder ,
researchers have suggested a combination of modified diet and exercise for treatment ( 6 ) .
previous studies have shown that a diet rich in antioxidants and anti - inflammatory agents can be effective in the treatment of nafld ( 7 ) .
ginger is the root of zingiber officinale and is one of the most used spices in many countries .
ginger contains active ingredients such as gingerol , shogaol , zingerone and -bisabolene ( 8) . in ancient medical practice , ginger was used for treatment of various disorders such as rheumatoid arthritis , neurodegenerative diseases , inflammation and asthma ( 9 ) .
previous studies have shown that ginger and its active compounds can exhibit anti - diabetes , anti - cancer and anti - inflammatory properties ( 10 , 11 ) .
it has been shown that ginger extract can exhibit antioxidant activity and reduce the levels of pro - inflammatory biomarkers ( 12 ) .
moreover , recent studies on patients with type ii diabetes and hyperlipidemia have shown that ginger can reduce insulin resistance and serum triglyceride concentration ( 13 , 14 ) .
accordingly , the hypothesis of this study was that ginger supplementation can be introduced as a new therapeutic strategy for nafld by improving the body s antioxidant activity , and reducing levels of inflammation and insulin resistance .
a randomized double - blind study was designed to evaluate this hypothesis in order to examine the effectiveness of ginger supplementation in patients with nafld .
inclusion criteria included the presence of steatosis on fibroscan ( cap score > 270 ) and a high concentration of liver enzyme ( alanine aminotransferase ( alt ) greater than 1.5 times the upper limit of the normal range ) at the time of randomization .
exclusion criteria included chronic liver diseases such as various types of hepatitis , diabetes mellitus , cancer , inherited disorders affecting the liver condition ( storage disorders of iron , copper , and others ) , non - treated hypothyroidism , as well as , alcohol use , taking any medications , weight loss surgery in the last year or strict diets to lose weight in the past three months , pregnancy , lactation , autoimmune diseases , weight loss more than ten percent of initial body weight during the intervention , unwillingness to continue the study protocol , and not taking more than ten percent of supplements in any follow - up visit .
eligible patients with nafld were invited to participate in this study . at first , all participants were informed about the study protocol by being given a complete description of the objectives , benefits and potential harms of the study .
the study was approved by the ethics committee of tehran university of medical sciences and informed consent was received from the participants who elected to participate in the study .
participants were randomly allocated based on age , sex and severity of steatosis into two groups .
randomization lists were computer - generated by a statistician and participants , project managers and employees at the clinic were completely unaware ( blind ) about the intervention and control groups . at the first visit , baseline data were gathered and patients were advised to consume two capsules , each containing 500 mg of ginger ( green plants of life pharmaceutics co. , iran ) or identical placebos ( starch ) one hour after breakfast and two capsules after dinner for 12 weeks . for all patients ,
capsules were given in the first week for three weeks , and in each visit a new series of supplements were prescribed .
in both groups , patients were advised to follow a modified diet and physical activity plan , according to the clinical guidelines on the identification , evaluation , and treatment of overweight and obesity in adults from the national institutes for health ( nih ) and the north american association for the study of obesity ( 15 ) . according to these groups , less than 30% of energy from lipids ( 10% from sfas , 15% from mufas and 5% from pufas ) ,
15% to 18% of energy from proteins and 52% to 55% of energy from carbohydrates were provided .
also , patients were advised to limit their dietary cholesterol intake to less than 300 mg per day and consume 20 to 30 grams of fiber per day .
all patients were advised to exercise 30 min , three times per week . to remind the participants about supplement consumption phone calls
for all patients , anthropometric parameters , including weight , height , waist and hip circumference , were measured at the beginning ( week 0 ) and the end ( week 12 ) of the study .
body mass index ( bmi ) was calculated by dividing weight to height squared ( m ) , and waist to hip ratio ( whr ) was calculated by dividing the waist to hip circumference .
all the measurements were made by one person in order to reduce measurement errors . to assess food intake , all participants of the study
were asked to complete a three - day food record at the beginning and at the end of the study .
blood samples were received from all patients after 10 to 12 hours of fasting at the beginning ( week 0 ) and the end ( week 12 ) of the study .
g - glutamyltransferase ( ggt ) was measured using an enzymatic colorimetric assay ( parsazmoun ) .
alt and aspartate aminotransferase ( ast ) concentrations were measured using a photometric assay ( parsazmoun ) .
the concentration of tnf- was measured using an elisa kit ( ebioscience , inc . , san diego , ca , usa , cat no : 109957025 ) and high - sensitivity c - reactive protein concentration was also measured by elisa kit ( parsazmun co. , tehran , iran , cat no : 93001 ) .
insulin resistance was measured by the homeostasis model formula ( homa - ir - ir ) as follows : homa - ir = [ fasting insulin ( mu / l ) 3 fasting blood glucose ( mg / dl)]/405 ( 16 ) .
the steatosis and hepatic fibrosis in patients was measured using ultrasound elastography at the beginning and the end of the study .
the physical activity of patients was measured by the metabolic equivalent of task ( met ) questionnaire at the beginning and the end of the study .
normal distribution of data was assured using the kolmogorov - smirnov and shapiro - wilk tests .
baseline characteristics of variables were compared among the two groups using independent sample t - test , mann - whitney u test and chi - square test .
within - group comparisons , before and after the intervention , were made with the student s t - test or wilcoxon . in order to eliminate the effects of confounding factors ,
all ancova models were adjusted for the baseline value of each variable and mean changes in bmi , whr , met and energy .
inclusion criteria included the presence of steatosis on fibroscan ( cap score > 270 ) and a high concentration of liver enzyme ( alanine aminotransferase ( alt ) greater than 1.5 times the upper limit of the normal range ) at the time of randomization .
exclusion criteria included chronic liver diseases such as various types of hepatitis , diabetes mellitus , cancer , inherited disorders affecting the liver condition ( storage disorders of iron , copper , and others ) , non - treated hypothyroidism , as well as , alcohol use , taking any medications , weight loss surgery in the last year or strict diets to lose weight in the past three months , pregnancy , lactation , autoimmune diseases , weight loss more than ten percent of initial body weight during the intervention , unwillingness to continue the study protocol , and not taking more than ten percent of supplements in any follow - up visit .
eligible patients with nafld were invited to participate in this study . at first , all participants were informed about the study protocol by being given a complete description of the objectives , benefits and potential harms of the study .
the study was approved by the ethics committee of tehran university of medical sciences and informed consent was received from the participants who elected to participate in the study . eventually 50 patients who met the inclusion criteria were selected .
participants were randomly allocated based on age , sex and severity of steatosis into two groups .
randomization lists were computer - generated by a statistician and participants , project managers and employees at the clinic were completely unaware ( blind ) about the intervention and control groups . at the first visit , baseline data were gathered and patients were advised to consume two capsules , each containing 500 mg of ginger ( green plants of life pharmaceutics co. , iran ) or identical placebos ( starch ) one hour after breakfast and two capsules after dinner for 12 weeks . for all patients ,
capsules were given in the first week for three weeks , and in each visit a new series of supplements were prescribed .
in both groups , patients were advised to follow a modified diet and physical activity plan , according to the clinical guidelines on the identification , evaluation , and treatment of overweight and obesity in adults from the national institutes for health ( nih ) and the north american association for the study of obesity ( 15 ) . according to these groups , less than 30% of energy from lipids ( 10% from sfas , 15% from mufas and 5% from pufas ) ,
15% to 18% of energy from proteins and 52% to 55% of energy from carbohydrates were provided .
also , patients were advised to limit their dietary cholesterol intake to less than 300 mg per day and consume 20 to 30 grams of fiber per day .
all patients were advised to exercise 30 min , three times per week . to remind the participants about supplement consumption phone calls
for all patients , anthropometric parameters , including weight , height , waist and hip circumference , were measured at the beginning ( week 0 ) and the end ( week 12 ) of the study .
body mass index ( bmi ) was calculated by dividing weight to height squared ( m ) , and waist to hip ratio ( whr ) was calculated by dividing the waist to hip circumference .
all the measurements were made by one person in order to reduce measurement errors . to assess food intake , all participants of the study
were asked to complete a three - day food record at the beginning and at the end of the study .
blood samples were received from all patients after 10 to 12 hours of fasting at the beginning ( week 0 ) and the end ( week 12 ) of the study .
g - glutamyltransferase ( ggt ) was measured using an enzymatic colorimetric assay ( parsazmoun ) .
alt and aspartate aminotransferase ( ast ) concentrations were measured using a photometric assay ( parsazmoun ) .
, san diego , ca , usa , cat no : 109957025 ) and high - sensitivity c - reactive protein concentration was also measured by elisa kit ( parsazmun co. , tehran , iran , cat no : 93001 ) .
insulin resistance was measured by the homeostasis model formula ( homa - ir - ir ) as follows : homa - ir = [ fasting insulin ( mu / l ) 3 fasting blood glucose ( mg / dl)]/405 ( 16 ) .
the steatosis and hepatic fibrosis in patients was measured using ultrasound elastography at the beginning and the end of the study .
the physical activity of patients was measured by the metabolic equivalent of task ( met ) questionnaire at the beginning and the end of the study .
normal distribution of data was assured using the kolmogorov - smirnov and shapiro - wilk tests .
baseline characteristics of variables were compared among the two groups using independent sample t - test , mann - whitney u test and chi - square test .
within - group comparisons , before and after the intervention , were made with the student s t - test or wilcoxon . in order to eliminate the effects of confounding factors ,
all ancova models were adjusted for the baseline value of each variable and mean changes in bmi , whr , met and energy .
fifty patients were included in the study and were randomly assigned to take either two grams of ginger ( n = 25 ) or the identical placebo ( n = 25 ) .
two patients in the ginger group ( due to unwillingness to continue ) and four patients in the control group ( two persons due to immigration and two persons due to unwillingness to continue ) were excluded , and 44 people , including 23 patients in the ginger group and 21 patients in the control group were entered into the final analysis .
eighty - eight percent of patients in the study successfully completed 12 weeks of treatment .
no significant difference was found between demographic index levels , weight , bmi , nutritional intake ( energy , selenium , vitamin d , vitamin e , vitamin c , omega-3 and omega-6 ) , physical activity , and especially , the steatosis degree and liver fibrosis between the two groups at baseline . however , there was a significant difference between the two groups in levels of hs - crp and ast liver enzyme at the beginning of the study .
abbreviations : bmi , body mass index ; met , metabolic equivalent of task ; whr , waist to hip ratio .
serum levels of the alt in both groups had a significant reduction ( p < 0.05 ) , but it declined significantly more in the ginger group compared with the placebo group ( p = 0.02 ) ( table 2 ) .
also , it remained significant after adjusting the results for the energy , physical activity , whr and bmi variables ( p = 0.045 ) ( table 3 ) .
abbreviations : alt , alanine aminotransferase ; ast , aspartate aminotransferase ; ggt , -glutamyl transferase ; homa - ir , homeostasis model formula for insulin resistance ; hs - crp , high - sensitivity c - reactive protein ; tnf- , tumor necrosis factor alpha .
p1 and p2 value , difference compared with the value at the beginning of the study within groups ( paired t - test ) .
pt value , mean difference of changes between the two groups ( independent t - test ) .
abbreviations : alt , alanine aminotransferase ; ast , aspartate aminotransferase ; ggt , -glutamyl transferase ; homa - ir , homeostasis model formula for insulin resistance ; hs - crp , high - sensitivity c - reactive protein ; tnf- , tumor necrosis factor alpha .
anthropometric measures , including weight , bmi , waist circumference , hip circumference and waist - to - hip ratio , decreased significantly in both groups at the end of study , but this reduction was not significantly different between the two groups except for hip circumference , which reduced significantly more in the ginger group in comparison to the placebo group ( p = 0.015 ) .
improvements in serum levels of ast and ggt were observed in both groups ; however , this reduction was significant only in the ginger group .
after adjusting the results for baseline values , this reduction was significant only for ggt ( p < 0.01 ) , and ast changes between the two groups was not significant ( p = 0.886 ) . a substantial improvement in most liver indicators was observed within each group and between the two groups before and after the adjustment for confounder variables .
patients taking ginger capsules compared to the placebo group had a significantly greater decrease in the steatosis score ( p < 0.001 ) , but the difference in fibrosis score between the two groups was not significant ( p = 0.39 ) . at the end of the study , there was a significant reduction in levels of tnf- and hs - crp in both groups , but the decline was greater in the ginger group ( 0.01 and 0.016 , respectively ) .
furthermore , the ginger supplement compared to the placebo caused greater reduction in the levels of insulin resistance index ( homa - ir ) ( p = 0.022 ) .
no severe effects were reported due to the ginger or placebo supplementation by the patients .
only one patient complained of mild headache and one of heartburn caused by the ginger supplements , both of which were resolved by recommendations of the nutritional consultants .
fifty patients were included in the study and were randomly assigned to take either two grams of ginger ( n = 25 ) or the identical placebo ( n = 25 ) .
two patients in the ginger group ( due to unwillingness to continue ) and four patients in the control group ( two persons due to immigration and two persons due to unwillingness to continue ) were excluded , and 44 people , including 23 patients in the ginger group and 21 patients in the control group were entered into the final analysis .
eighty - eight percent of patients in the study successfully completed 12 weeks of treatment .
no significant difference was found between demographic index levels , weight , bmi , nutritional intake ( energy , selenium , vitamin d , vitamin e , vitamin c , omega-3 and omega-6 ) , physical activity , and especially , the steatosis degree and liver fibrosis between the two groups at baseline . however , there was a significant difference between the two groups in levels of hs - crp and ast liver enzyme at the beginning of the study .
abbreviations : bmi , body mass index ; met , metabolic equivalent of task ; whr , waist to hip ratio .
serum levels of the alt in both groups had a significant reduction ( p < 0.05 ) , but it declined significantly more in the ginger group compared with the placebo group ( p = 0.02 ) ( table 2 ) .
also , it remained significant after adjusting the results for the energy , physical activity , whr and bmi variables ( p = 0.045 ) ( table 3 ) .
abbreviations : alt , alanine aminotransferase ; ast , aspartate aminotransferase ; ggt , -glutamyl transferase ; homa - ir , homeostasis model formula for insulin resistance ; hs - crp , high - sensitivity c - reactive protein ; tnf- , tumor necrosis factor alpha .
p1 and p2 value , difference compared with the value at the beginning of the study within groups ( paired t - test ) .
pt value , mean difference of changes between the two groups ( independent t - test ) .
abbreviations : alt , alanine aminotransferase ; ast , aspartate aminotransferase ; ggt , -glutamyl transferase ; homa - ir , homeostasis model formula for insulin resistance ; hs - crp , high - sensitivity c - reactive protein ; tnf- , tumor necrosis factor alpha .
anthropometric measures , including weight , bmi , waist circumference , hip circumference and waist - to - hip ratio , decreased significantly in both groups at the end of study , but this reduction was not significantly different between the two groups except for hip circumference , which reduced significantly more in the ginger group in comparison to the placebo group ( p = 0.015 ) .
improvements in serum levels of ast and ggt were observed in both groups ; however , this reduction was significant only in the ginger group .
after adjusting the results for baseline values , this reduction was significant only for ggt ( p < 0.01 ) , and ast changes between the two groups was not significant ( p = 0.886 ) . a substantial improvement in most liver indicators was observed within each group and between the two groups before and after the adjustment for confounder variables .
patients taking ginger capsules compared to the placebo group had a significantly greater decrease in the steatosis score ( p < 0.001 ) , but the difference in fibrosis score between the two groups was not significant ( p = 0.39 ) . at the end of the study
, there was a significant reduction in levels of tnf- and hs - crp in both groups , but the decline was greater in the ginger group ( 0.01 and 0.016 , respectively ) .
furthermore , the ginger supplement compared to the placebo caused greater reduction in the levels of insulin resistance index ( homa - ir ) ( p = 0.022 ) .
no severe effects were reported due to the ginger or placebo supplementation by the patients .
only one patient complained of mild headache and one of heartburn caused by the ginger supplements , both of which were resolved by recommendations of the nutritional consultants .
to our knowledge , this is the first randomized , double - blind clinical trial study that examined the effects of ginger supplementation with lifestyle intervention on liver enzymes , inflammatory markers , steatosis and hepatic fibrosis scores in patients with nonalcoholic fatty liver disease ( nafld ) . in this study ,
daily consumption of two grams of ginger supplement for 12 weeks resulted in a significant decrease in inflammatory marker levels , alt and ggt liver enzymes and liver steatosis .
insulin resistance is one of the major risk factors in the pathogenesis of nafld ( 16 ) .
our study has shown that ginger supplementation reduces insulin resistance , which is in line with previous studies .
have shown that ginger supplementation can ameliorate levels of insulin resistance markers ( 14 ) .
furthermore , mozaffari et al . showed that a daily intake of three grams of ginger powder for eight weeks resulted in a significant reduction in fasting blood sugar levels and insulin resistance ( 17 ) .
thus , our study confirmed these previous studies , and showed that as little as two grams / day of ginger can reduce insulin resistance . according to the other studies , inflammatory agents play an important role in the pathogenesis of nafld .
some studies have shown that in patients with nafld , polymorphisms of tnf- promoter , at positions 238 ( tnfa ) and 308 ( tnf2 ) , are common and its expression increases ( 18 ) .
tnf - a plays a critical role in both insulin resistance and liver fibrosis and increases fatty acids oxidation ( 19 , 20 ) .
so , reduction of tnf- and other inflammatory factors can improve the treatment of nafld . in this study
, it was shown that ginger supplementation caused a significant decrease in serum levels of tnf- and hs - crp , which is consistent with previous studies such as those by lee et al .
the hepatic steatosis score in the group receiving ginger supplements reduced significantly more than the control group , while liver fibrosis showed no significant difference between the two groups .
hepatic steatosis is characterized by overload of triglycerides in hepatocytes that can injure the liver ( 23 ) .
animal studies have shown that the active compounds in ginger can enhance the antioxidant defense systems , such as glutathione peroxidase and glutathione s - transferase , and reduce levels of malondialdehyde ( mda ) and hepatic steatosis ( 24 , 25 ) .
it seems that one of the main reasons for this protective feature is the effect of ginger on the expression of proliferating cell nuclear antigen ( pcna ) .
pcna is a nuclear protein that is involved in regulating cell proliferation . in liver disorders such as nafld and cirrhosis , the expression of pcna
is increased , which ultimately can result in excessive and uncontrolled proliferation of tissue to replace the damaged tissue and causes liver fibrosis progression .
previous studies have shown that ginger supplementation can reduce the expression of pcna and prevent the intensification of liver fibrosis ( 26 ) . in this study ,
no significant decrease was observed in liver fibrosis score in the ginger group compared to the placebo group .
this can be due to the short - term of the intervention , because it takes a long time for regeneration of hepatic tissue and reduction of fibrotic tissue .
the lack of using liver biopsy to derive a pathology score of disease was one of the limitations of this study .
researchers were not able to use this method in this study due to its invasive nature , however , we evaluated the hepatic steatosis and fibrosis with transient elastography , which provides quantitative , noninvasive results .
the advantage of this study was that it is the first study evaluating the effects of ginger supplementation on nafld . in conclusion ,
this randomized controlled clinical trial found some evidence that ginger supplementation could increase the effectiveness of lifestyle interventions ( diet modification and physical activity ) compared with lifestyle interventions alone for treatment of nafld .
whether these effects will be sustained and/or augmented with longer treatment durations remains to be determined . | background : nonalcoholic fatty liver disease ( nafld ) is one of the most common chronic liver diseases worldwide .
the pathogenesis of this disease is closely associated with obesity and insulin resistance .
ginger can have hypolipidemic and antioxidant effects , and act as an insulinsensitizer.objectives:the aim of this study was to evaluate the effects of ginger supplementation in nafld management.patients and methods : in a randomized , double - blind , placebo - controlled clinical trial , 44 patients with nafld were assigned to take either two grams per day of a ginger supplement or the identical placebo , for 12 weeks . in both groups , patients were advised to follow a modified diet and physical activity program .
the metabolic parameters and indicators of liver damage were measured at study baseline and after the 12 week intervention.results:ginger supplementation resulted in a significant reduction in alanine aminotransferase , -glutamyl transferase , inflammatory cytokines , as well as the insulin resistance index and hepatic steatosis grade in comparison to the placebo .
we did not find any significant effect of taking ginger supplements on hepatic fibrosis and aspartate aminotransferase.conclusions:twelve weeks of two grams of ginger supplementation showed beneficial effects on some nafld characteristics .
further studies are recommended to assess the long - term supplementation effects . |
it is thought to be secondary to the seeding and subsequent growth of splenic cells within the peritoneal cavity and , less commonly , within extraperitoneal locations.13 given that splenosis is usually asymptomatic , its true incidence is unknown.4 the diagnosis of splenosis is usually made incidentally on imaging or at laparotomy , masquerading as benign or malignant tumors or other pathological conditions , such as endometriosis.5 it is uncommonly of clinical significance and despite the extent of neovascularization which occurs as the splenic tissue grows , major bleeding complications are rare.6 the following report describes a rare case of massive gastrointestinal bleeding secondary to perigastric splenosis that was treated successfully with transarterial embolization .
a 52-year - old male with no previous history of gastrointestinal bleeding presented to the emergency department with chest pain and solid food dysphagia .
his medical history included atrial fibrillation , hypertension , obstructive sleep apnea , asthma , and splenectomy at age 14 following a traumatic splenic rupture after being kicked by a horse .
initial cardiac workup was negative and he was discharged home with an outpatient follow - up appointment with gastroenterology .
his medications included dabigatran , diltiazem , irbesartan , montelukast , budesonide / formeterol , fluticasone / salmeterol , and salbutamol .
outpatient upper endoscopy identified a schatzki s ring at the esophageal gastric junction as well as several small clean - based ulcers at the prepyloric region on a duodenum hiatus hernia .
he was placed on a proton - pump inhibitor and sent home following the procedure .
four days later he re - presented to the emergency department with multiple episodes of melena , light - headedness , progressive shortness of breath on exertion , and rapid atrial fibrillation ( heart rate ~130 bpm , normotensive ) .
g / l ) , mean corpuscular volume 83.8 fl , platelets 31210/l , creatinine 79 mol / l , urea 10.8 mmol / l , international normalized ratio 1.2 , partial thromboplastin time 28 , and normal liver function tests .
he was given 1 l of crystalloid , placed on a pantoprazole infusion , and his dabigatran was held .
urgent upper endoscopy revealed stigmata of recent hemorrhage from recent biopsy sites , the previously observed clean - based ulcers , and a submucosal lesion in the third part of the duodenum , which was not bleeding .
the biopsy sites were cauterized with a gold - probe and he was admitted for observation . on post - admit day 2 , the patient had a syncopal episode associated with melena and a hemoglobin decline of 30
repeat endoscopy revealed only a large adherent clot in the fundus , which could not be aspirated .
the patient s melena persisted and hemoglobin continued to fall prompting another upper endoscopy that demonstrated a small pouch in the gastric fundus without any stigmata of recent hemorrhage , but concerning for either a diverticulum or fistula .
a subsequent upper gastrointestinal series confirmed a mild focal out - pouching of the gastric fundus without any evidence of a fistula or leak .
a computed tomography ( ct ) scan was performed and revealed replacement of the spleen by multiple soft tissue nodules consistent with splenosis , but could not identify a clear source of bleeding due to retained oral contrast within the stomach from the prior upper gastrointestinal series . on post - admit day 8 ,
the patient had a repeat ct scan which revealed a previously unidentified 1.3 cm perigastric lesion with moderate vascularity within the gastric fundus .
an endoscopic ultrasound was performed , which did not reveal any large varices , but did confirm a number of smaller perforating vessels within the fundal lesion , as well as several perigastric lesions , which were later identified as perigastric splenosis .
endoscopic ultrasound - assisted fine - needle aspiration of one of the perigastric lesions revealed a mixed population of lymphocytes , plasma cells , neutrophils , and eosinophils favoring a reactive lymph node , thus , nondiagnostic .
the patient continued to have melena stool and a subsequent ct angiogram was acquired revealing an extensive network of enlarged arteries within the wall of the gastric fundus that were supplying a grouping of splenosis along the posterior aspect of the gastric fundus ( figure 1 ) .
the dominant arterial supply was localized to a branch of the left inferior phrenic artery , which underwent successful transarterial coil embolization that was confirmed on a follow - up ct scan ( figures 1 and 2 ) .
the patient clinically improved , his hemoglobin stabilized , and he was ultimately discharged home .
follow - up imaging 2 months later revealed further interval decrease in the size of the intramural gastric arterial collaterals perfusing the perigastric splenules .
as of the most recent follow - up appointment 8 months following the patients initial presentation , there was no further bleeding .
verbal consent was provided by the patient to have his data used in this study .
residual viable splenic tissue can autotransplant throughout the peritoneal cavity and elsewhere , deriving its blood supply from adjacent tissues and organs.5 the splenic implants are commonly found within the greater omentum due to its vascularity , which provides an ideal environment for regeneration and neovascularization .
additional potential sites of implantation include ( in order of frequency ) : the serosal surface of the small bowel , parietal peritoneum , mesentery , diaphragm , intrahepatic , and intrathoracic.68 although splenosis has been implicated in intestinal obstruction , gastrointestinal bleeding , and relapse of hematological diseases , patients are usually asymptomatic and the diagnosis is typically made incidentally on imaging or at laparotomy.3 as the ectopic splenic tissue may provide a degree of normal splenic function , asymptomatic splenosis is managed conservatively and resection is unnecessary.3,5,9 diagnosing splenosis can be challenging given the extent and varied potential sites for autotransplantation as well as its relatively nonspecific appearance on conventional imaging modalities ( ultrasound , ct , magnetic resonance imaging ) . as such , splenosis has been mistakenly reported as renal , adrenal , or abdominal tumors , metastases , lymphoma , endometriosis , and ectopic testicles.6 the diagnosis of splenosis can be confirmed by scintigraphy with technetium tc 99m - labeled red blood cells.10,11 biopsies taken from the splenic tissue of splenosis generally display characteristics consistent with splenic tissue , such as red and white pulp and marginal zones.5 gastrointestinal bleeding secondary to splenosis is rare and usually occult.5,6 to our knowledge , three cases of massive upper gastrointestinal bleeding secondary to splenosis have been reported in the literature .
all cases required surgical resection for definitive management ( table 1).3,6,11 this is the first case of massive upper gastrointestinal bleeding secondary to splenosis involving the gastric fundus successfully managed through endovascular embolization .
the anchoring heuristic implies relying on initial impressions to answer a clinical question.12 in our case report , the patient initially presented with a massive gastrointestinal bleed shortly following upper endoscopy and gastric biopsy . despite the rarity of massive bleeding following routine endoscopic gastric biopsy ,
this became the initial working diagnosis.13 following an additional episode of bleeding , a repeat upper endoscopy suggested the bleeding to be secondary to a gastric diverticulum , a more common cause than gastric splenosis .
the disposition to consider a diagnosis as being more likely after being previously exposed to such a diagnosis defines the availability heuristic.12 as a consequence , arriving at the patient s true diagnosis was delayed .
finally , a ct scan demonstrated a perigastric vascular lesion , considered at one point to be a potential gastric varix with therapeutic endoscopic injection of cyanoacrylate considered , further exemplifying the availability heuristic .
fortunately , the patient s underlying history was reconsidered and an endoscopic ultrasound performed ruling out gastric varices .
subsequent consultation with an interventional radiologist and acquisition of a triphasic ct scan ultimately uncovered the correct diagnosis and led to successful embolization of an enlarged branch of the left inferior phrenic artery perfusing a grouping or perigastric splenosis .
interobserver variability may have played a role in delaying the diagnosis of the fundal lesion as well . a study conducted by lau
et al found the level of agreement between experts assessing the severity of bleeding peptic ulcers using video endoscopy was poor in more than a third of occasions.14 in our case report , each endoscopy was performed by a different gastroenterologist . within large tertiary care facilities , it is unlikely an emergent procedure will be performed by the same interventionist on the same patient . as a result
although the pathology was nondiagnostic and scintigraphy with technetium tc 99m - labeled red blood cells was not performed , given the patient s course and findings on imaging , a diagnosis of splenosis was made and treated successfully .
thus , we suggest considering splenosis in the main differential diagnoses in patients presenting with upper gastrointestinal bleeding and a history of prior splenic trauma . | splenosis , the autotransplantation of splenic tissue following splenic trauma , is uncommonly clinically significant .
splenosis is typically diagnosed incidentally on imaging or at laparotomy and has been mistakenly attributed to various malignancies and pathological conditions . on the rare occasion when splenosis plays a causative role in a pathological condition
, a diagnostic challenge may ensue that can lead to a delay in both diagnosis and treatment .
the following case report describes a patient presenting with a massive upper gastrointestinal bleed resulting from arterial enlargement within the gastric fundus secondary to perigastric splenosis .
the cause of the bleeding was initially elusive and this case highlights the importance of a thorough clinical history when faced with a diagnostic challenge .
treatment options , including the successful use of transarterial embolization in this case , are also presented . |
gitelman 's syndrome ( gs ) is an autosomal recessive tubular disorder characterized by hypokalemic alkalosis , hypomagnesemia , and hypocalciuria .
hypopituitarism can have varied etiologies including tumor in hypothalamo - pituitary region or its treatment , inflammatory , genetic , trauma , and hemorrhage , and can result in a host of hormonal and electrolyte abnormalities .
both these disorders can cause significant morbidity and a combination of both can be potentially devastating .
a few case reports are emerging which show a combination of inherited tubular disorders with pituitary abnormalities on imaging , but with normal hormonal profile .
we report the first case of a post - menopausal lady who had a combination of gitelman 's syndrome with multiple pituitary hormone deficiencies ( mphd ) and was treated successfully by replacement of hormones and electrolytes .
a 57-year - old lady , a known case of hypothyroidism for 7 years on levothyroxine replacement , presented with complaints of generalized weakness , postural giddiness , and intermittent episodes of spontaneous carpopedal spasms for past 9 months and was bedridden for past 1 month .
she used to consume approximately 250 ml of milk products per day and had sunlight exposure for 10 minutes per week .
there was no history of diuretic use , protracted vomiting or diarrhea , polydipsia , or polyuria .
she was noted to have hypotension on several occasions over the past 9 months for which she was treated with intravenous fluids .
she has three children ( last child birth 21 years back ) and there was no history of lactation failure .
she attained menopause at the age of 47 years , prior to which her periods were regular .
clinically , she was obese ( bmi 34.13 kg / m ) , and had supine hypotension ( bp 70/50 mmhg ) , pallor , bilateral non - pitting edema , acanthosis nigricans , and skin tags . trousseaus and chvosteks 's signs were positive .
there was no goiter , deep tendon jerks were normal , and rest of the examination was normal .
investigations revealed anemia ( hb 10.3 gm% ) , hyponatremia , hypokalemia , hypomagnesemia , hypocalcemia , hypophosphatemia , hypochloremia , and metabolic alkalosis [ table 1 ] .
her serum 25-hydroxy vitamin d3level was 11.89 ng / ml and intact parathyroid hormone ( pth ) was 249 pg / ml ( 10.065.0 ) .
urinary spot sodium ( 180 meq / l ) , potassium ( 13 meq / l ) , and chloride ( 161
24-hour urinary calcium [ 127 mg ( normal < 200 mg ) ] , phosphorus [ 412 mg ( normal < 1200 mg ) ] , and copper [ 8.3 g / d ( normal < 60 g / d ) ] excretion were normal .
plasma renin activity 4.4 ng / ml / h ( 0.13.1 ) and plasma aldosterone 38.1 ng / dl ( 316 ) levels were high .
plasma glucose levels ( ogtt ) , and renal and liver function tests were normal .
qualitative test for urinary amino acids , hiv and antinuclear antibody ( ana ) serologies were negative .
biochemical parameters pre- and postpresentation ( at 6-month follow - up ) thyroid profile at baseline was suggestive of hypothyroidism [ low t4 , thyroid stimulating hormone ( tsh ) 9.06 u / l ] , whereas it was normal at presentation .
there was hypocortisolism ( random plasma cortisol : 164 nmol / l and peak cortisol during insulin - induced hypoglycemia : 453.2 nmol / l ) , relatively normal adrenocorticotropic hormone ( acth ) 11.6 pg / ml ( 7.263.3 ) , and low gonadotropins [ luteinizing hormone ( lh ) 1.36 miu / ml , follicle stimulating hormone ( fsh ) 4.00 miu / ml ]
. serum prolactin [ 5.8 ng/ ml ( 525 ) ] and serum insulin - like growth factor 1 ( igf-1 ) [ 156 ng / ml ( 66310 ) ] were low normal .
peak growth hormone level after iih was 5.6 ng / ml . anti - thyroid peroxide antibody levels were normal .
mri sella showed loss of posterior pituitary bright spot [ figure 1 ] ; however , anterior pituitary was normal . in view of the above , a diagnosis of gitelman 's syndrome with mphd was made .
she was treated with levothyroxine , hydrocortisone , and supplementation with vitamin d , sodium , potassium , magnesium , calcium , and chloride .
she showed global improvement in symptoms , her carpopedal spasms resolved , blood pressure normalized , and biochemical parameters improved which are enumerated in table 1 .
bartter 's and gitelman 's syndrome are two ends of a spectrum of inherited renal tubulopathies that are characterized by renal salt wasting , hypokalemic metabolic alkalosis , hyperreninemic - hyperaldosteronism with normal blood pressure , and hyperplasia of juxtaglomerular apparatus .
gitelman 's syndrome ( gs ) , in addition , also exhibits hypomagnesemia and hypocalciuria . bartter 's syndrome is the more severe of two and presents in antenatal period or early childhood , whereas gitelman 's syndrome presents later in life and adult cases have also been described .
our patient presented with nonspecific features of generalized weakness that can be explained on the basis of severe dyselectrolytemia and hypopituitarism .
postural giddiness can be a manifestation of gitelman 's syndrome per se or that of hypotension that our patient had .
loss of fluid and electrolytes leads to activation of renin angiotensin aldosterone system ( ras ) resulting in hyperaldosteronism on one hand and renal release of vasodilator prostaglandins ( pge2 and prostacyclins ) on the other .
hence , blood pressure remains normal despite hyperaldosteronism as prostaglandin - induced vasodilatation counters the hypertensive effects of overactive ras .
association of conn 's syndrome that results in hyporeninemic - hyperaldosteronism has also been recently reported with gs .
our patient , however , had hyperreninemic - hyperaldosteronism and normal adrenals on mri , hence such an association is ruled out .
hypokalemic metabolic alkalosis occurs due to hyperreninemic - hyperaldosteronism leading to increased potassium and hydrogen ion secretion in the collecting tubules .
magnesium wasting in distal convoluted tubules as a result of inhibition of its uptake in the presence of hypokalemia and metabolic alkalosis leads to hypomagnesemia in gitelman 's syndrome , as was seen in our case .
hypochloridemia with increased urinary chlorine excretion is also a feature of bartter 's syndrome and an overlap of both the conditions can not be denied in our case .
hypocalcemia in our patient is thought to have occurred due to poor oral intake of milk products ; vitamin d deficiency , and possibly reduction in 1-hydroxylase activity .
an overlap with bartter 's syndrome is seen in many patients and this could also possibly have worsened hypocalcemia .
hypophosphatemia in our patient can be explained by poor oral intake , hypovitaminosis d , and secondary hyperparathyroidism .
panhypopituitarism , on the other hand , refers to total or partial loss of pituitary hormone secretion as a result of pituitary or hypothalamic dysfunction resulting in loss of anterior pituitary hormones with or without loss of antidiuretic hormone .
our patient had low lh , fsh levels despite having attained menopause ; acth was relatively normal in spite of low cortisol and stimulated cortisol level was suggestive of compensated adrenal insufficiency .
her tsh value was mildly elevated despite low total t4 that is seen in subclinical hypothyroidism , but can also occur in secondary hypothyroidism . due to the presence of above combination of hormonal profile and abnormality in pituitary on imaging , a diagnosis of pituitary failure was made . diuretic use and protracted vomiting or diarrhea as a possible cause of hyokalemia was were excluded by history taking .
secondary causes for tubulopathy were excluded including fanconi 's syndrome , renal tubular acidosis , systemic lupus erythematosus , wilson 's disease , and hiv . in the light of above
, we diagnosed our patient to be suffering from gitelman 's syndrome though she had some overlapping features of bartter 's syndrome as well .
both these syndromes are autosomal recessive disorders caused by an inactivating mutation of the thiazide - sensitive sodium - chloride cotransporter in the loop of henle and distal renal tubule , namely slc12a3 and clcnkb genes , encoding the chloride channel .
mphd can be due to tumor or its treatment in the hypothalamo - pituitary region , which was ruled out by history and imaging .
autoimmune etiology is another important factor ; however , surrogate antibodies ( anti - tpo and ana ) were negative in our patient to rule out autoimmune disrorder . also , there was no history of lactation failure to suggest sheehan 's syndrome as a possible cause . barring these , inherited causes can give rise to mphd which could be a causative factor in our patient .
the tubular defect in bartter 's or gitelman 's syndrome can not be corrected and lifelong magnesium and potassium supplementation is required , whereas treatment of mphd is replacement of deficient hormones , as was done in our patient .
the combination of nonsteroidal anti - inflammatory drugs ( nsaids ) to reduce renal pg synthesis and a potassium - sparing diuretic to raise the plasma potassium concentration toward normal partially reverses the metabolic alkalosis and corrects the hypomagnesemia .
to conclude , gitelman 's syndrome is an often overlooked cause of hypokalemia and hypomagnesemia in adults .
hence , a clinician should be alert to such a possibility as the outcome can be rewarding .
it remains to be seen , however , whether association of gitelman 's syndrome with pituitary abnormalities with or without mphd is just a chance association or there is a common genetic link . | gitelman 's syndrome is an inherited tubulopathy affecting thiazide - sensitive sodium chloride cotransporter , which manifests with hypokalemic alkalosis , hypomagnesemia , and hypocalciuria .
recently few cases have been described having an association of gitelman 's syndrome with pituitary abnormalities on imaging , though with normal hormonal status .
we describe the first case of an adult patient having gitelman 's syndrome and hypopituitarism with abnormal pituitary imaging .
she presented to us with hypotension , hypokalemia , hypomagnesemia with alkalosis , hypothyroidism , hypocortisolism , and hypogonadism .
she was treated with replacement of electrolytes and hormones , to which she showed an excellent response . |
gastric cancer is a universally common cancer and the second most common cause of cancer related death .
lymph node metastasis is reported to be one of the most important prognostic factors for gastric carcinoma .
the tumor - node - metastasis staging method ( tnm ) staging system is a widely accepted method for the determination of prognosis and therapeutic plan .
this system has been affected by increase of lymph node dissection and the pathologist 's accuracy in finding the number of lymph nodes in the gastrectomy specimen .
furthermore , extended lymphadenectomy can cause stage migration due to increase in the number of metastatic lymph nodes .
many authors suggest that the lymph node staging system based on tnm classification will not be affected by the extent of lymph node dissection .
some authors have shown that staging based on the metastatic lymph node ratio ( n ratio ) , which is calculated by dividing the number of metastatic lymph nodes by the total number of nodes is an independent and easy - to - assess prognostic factor for patients with gastric cancer .
recent findings about esophageal and colon cancer patients suggest that largest involved lymph node size is a more important prognostic factor in these patients than the number of lymph nodes involved ; but in the case of gastric carcinoma there is a little evidence to show that lymph node size and metastatic nest size are prognostic factors . in this study , we compare five methods of n classification of gastric carcinoma including tnm , n ratio , largest involved lymph node size , largest metastatic nest size , and the largest metastatic nest to lymph node size ratio for the prediction of survival and disease free survival time ( dfs ) .
this multicentric historical cohort study was conducted on 148 patients with m0 gastric adenocarcinoma who underwent surgery during 2002 - 2010 : in valiasr , emam khomeini , ghods ( arak , iran ) , alzahra ( isfahan , iran ) and emam - reza hospitals ( mashhad , iran ) .
all patients were included if they underwent curative total or partial gastrectomy for m0 primary gastric adenocarcinoma .
they were excluded if they had undergone surgery for lymphoma , gastrointestinal stromal tumor , peptic ulcer , and other diseases .
patients without lymph node metastasis and patients who had distant or peritoneal metastasis were also excluded . in all cases ,
all dissected lymph nodes cut along their longest axis and fixed in formalin , embedded in paraffin , three micron section were prepared and the slides were stained with hematoxyl in and eosin .
all the slides were reviewed by two pathologists and a consensus meeting was held in case of discrepancy .
these pathologists had no information regarding the patients prognosis ( including survival or recurrence ) .
important microscopic features were recorded , these include : type of adenocarcinoma ( signet , intestinal ) , grade ( poorly , moderately , and well - differentiated ) , stage , number of dissected and involved lymph nodes , largest size of involved the lymph nodes , largest metastatic nest diameter , and largest metastatic nest to lymph node diameter ratio .
the five systems were explained as bellow ; first : the node ratio ( n ratio ) ; the ratio of the number of involved lymph node to the total number of harvesting lymph nodes .
second : the largest involve lymph node size ; among involve lymph node the size of largest one was selected .
third : the largest metastatic nest size ; involve lymph nodes nest were mark under 40 magnifications .
then by microscopic ruler the size was measured and the largest one was selected . in case of multiple nests in one lymph node the sum of diameter of all were considered .
forth : the largest metastatic nest to lymph node size ratio ; for every involved lymph node the ratio of metastatic nest size to diameter of lymph node was calculated then among them the biggest ratio was selected .
methods of lymph node status classification then , the survival rate and recurrence rate and disease free survival period of patients were determined .
these patients were visited by an oncologist or surgeon and survival and recurrence rates were determined .
then , we determined the optimal cut off points of the n ratio , the largest involved lymph node size , the largest metastatic nest size and the largest metastatic nest to lymph node size ratio , which can predict prognosis ( including survival time and dfs ) .
the k - s and levene 's test were applied to verify normal distribution and equality of variances . according to the results of the tests , mentioned above
, we used the student t - test or mann withney u test for the comparison of the quantitative data in grouping variables . the chi square test was used to find the relationship between the qualitative data .
receiver operating characteristic curves and sensitivity analysis were used to determine the optimal cut - off value of the n ratio , largest involved lymph node size , largest metastatic nest size , largest metastatic to lymph node size ratio .
all procedures were performed according to the principle of the ethical standards committee of arak ( iran ) university of medical sciences .
a total of 148 cases of gastric cancer in the time interval ranging from 2002 to 2010 reported in five hospitals in iran were evaluated .
( 77.02% ) the number of dissected lymph nodes per patient varied widely ( 1 - 48 ) , with mean of 9.26 .
the 5-year overall survival rate was 16% [ figure 1 ] and the median of overall survival time were 16 months .
the results of the comparative analysis of demographics clinical and pathological features are shown in table 2 .
survival function of all cases of gastric carcinoma comparative analysis of demographic , clinical and pathological features in - patient with gastric carcinoma median survival times were not significantly different between the subgroups of the clinicopathological parameters including sex , age , and site of tumor , type of gastrectomy , histological type , and grade of adenocarcinoma .
the comparative analysis of survival and dfs in each nodal group according to the five nodal classification systems is presented in table 4 and figures 26 .
number of patient in each nodal group according to five staging system ( n=148 ) result analysis of survival and dfs between subgroups of each n classification system survival functions of gastric carcinoma according to ii ratio classification survival functions of gastric carcinoma according to largest lymph node size classification survival functions of gastric carcinoma according to the largest metastatic nest size survival functions of gastric carcinoma according to largest metastatic nest to lymph node size ratio survival functions of gastric carcinoma according to tnm classification
lymph node metastasis is one of the most important prognostic factors of gastric cancer . at present , the classification of lymph node involvement in gastric cancer is still under extensive evaluation ; there are some objectives for tumor staging : assisting in the definition of clinical treatment , simplicity , surgical applicability , and providing some prognostic information for patients . to accomplish these objectives ,
every lymph node metastasis classification system should be simple , accurate , reproducible and prognostic relevance without stage migration .
reproducibility is crucial for post - treatment pathological classification , inter , and intra observer variability has to be low . according to each lymph node metastasis classification , the prognosis can be estimated and determine the therapeutic strategy planning .
it has been suggested that the number of metastasis lymph nodes ( tnm staging ) is a widely accepted , convenience , reproducible method with good assessing potential for the prognosis of gastric cancer .
this staging system is influenced by the number of the resected and examined lymph node .
although n classification is recommended the 15 or more lymph nodes should be examined for accurate staging of gastric carcinoma , the number of metastatic lymph nodes increases in proportion to the number of dissected nodes , suggesting that the patient classified as n1 after limited lymph node dissection may be classified as n2 or n3 after extensive lymphadenectomy . on the other hand , the n classification may be changed by adding or reducing one or more positive lymph nodes .
stage migration occurs in 5 - 15% of gastric cancer cases , after extensive lymphadenectomy .
in addition , when fewer than 15 lymph nodes are detected , the probability of stage migration rises .
another method for n classification in gastric cancer is n ratio , which is calculated by dividing the number of metastatic lymph nodes by the total number of nodes harvested .
this factor reflects both tumor characteristics : the number of metastatic lymph nodes and the extent of lymphadenectomy .
this system is convenient , reproducible and has surgical applicability , high ability to predict survival and reduced stage migration .
in addition , the n ratio system is applicable in patients when fewer than 15 lymph nodes are dissected .
there has been no consensus about n ratio cut - off value for the classification of the n status in gastric carcinoma and the definition of the significant prognostic cut - off point varies .
many authors have shown a significant deterioration in prognosis when 25% of the removed lymph nodes were positive and in some studies three ( < 10% , 10 - 25% , > 25% ) or four ( 0 ,
< 10% , 10 - 25% , > 25% ) subgroups of cases with different survival time were identified . in the present study , four subgroups of patients with remarkably different median survival time
were identified : 0 , < 15% , 15 - 40% and > 40% . we also tried to analyze the median of survival time and dfs of our cases and classify them with other cut - off points including 10% and 25% , but in the present study cut off points of 0 , 15% , and 40% have the best significant different median of survival time between the subgroups .
lim et al . in the same study reported a significantly difference in survival rate when more than 40% of removed lymph nodes were invaded .
persiani et al . reported three subgroups of patients with significantly different 5-year survival rates by 2 cut - off points 15 and 40% ( n1 : ratio < 15% , n2 : ratio 15 - 40% , n3 : ratio >
40% ) we stratified the patients into four n ratio groups with three cut - off points ( 0 , 15 , 40% ) rather than three n ratio groups with two cut - off points ( 15 and 40% ) ; based on the hypothesis that gastric cancer with no nodal involvement should not be grouped with gastric cancer with nodal involvement .
the cut - off point of zero was determined in the present study . in the literature review ,
the n ratio system for the classification of gastric cancer n staging is a simple , accurate and reproducible method , but routine hematoxylin and eosin staining may not exactly reflect the lymph node metastasis due to lymph node micro - metastasis .
others methods examined in this study for n classification of gastric cancer depend on the size of the lymph node and metastatic nest .
there are several reports that the largest involved lymph node size may be useful for n classification in esophageal and colon cancer ; however , attention to the largest involved lymph node size in n classification of gastric carcinoma has been rare .
two previous study divided patients into two groups : lymph node size < 2 cm , > = 2 cm and found that this method was an independent prognostic factor .
dhar et al . in another study suggested a 7 mm or less cut - off point in the n classification of a number of patients who were then assigned to group n1 , a second group that is group n2 had a8 mm or more cut - off point . these above methods stratified patients into three groups ( n0 , n1 , n2 ) with 2 cut- off points ( 7 , 20 mm ) , but we stratified patients into 4 groups ( n0 , n1 , n2 , n3 ) with three cut - off points ( 0 , 5 , 11 mm ) .
since our classification is divided into four groups , this method is comparable with other classifications .
furthermore , it seems that both the size of lymph node and the size of the metastatic nest have theoretical value in the classification of n groups .
our study showed that the largest metastatic nest size was an independent prognostic factor in terms of overall and dfs .
it seems , in a theoretical approach , two factors that is metastatic nest size and lymph node size are important in the n classification of gastric carcinoma according to size ; we described a factor for the classification of gastric cancer n groups according to the above two factors , we named this factor the largest metastatic nest to lymph node size ratio ( mls ratio ) . in this study , metastatic nest to lymph node diameter ratio
mls ratio is an independent prognostic factor in terms of overall and disease free survival rate .
this method for gastric cancer n classification is a simple technique and needs only a standard microscopic ruler .
this method is applicable especially in patients with fewer than 15 lymph nodes removed during surgery .
from among the n staging system we recommend the metastatic lymph node ratio and the largest metastatic nest to lymph node size systems , since they are reproducible , simple , have good survival applicability , have prognostic value and include less stage migration specially in patients whom fewer than 15 lymph nodes are dissected . | background : the presence of metastatic lymph nodes is the most important prognostic factor for gastric carcinoma ; however , the optimal system for the accurate staging of lymph node metastasis for patients with gastric cancer remains controversial .
this study was designed to compare five systems in relation to the n classification of gastric carcinoma.materials and methods : this multicentric historical cohort study was conducted on 148 patients with m0 gastric adenocarcinoma who underwent gastrectomy in , five referral hospitals in iran .
lymph nodes were sectioned , stained with hematoxyl in and eosin .
the lymph node status was classified according to the five systems which are : the number of involved lymph nodes ( tnm staging ) , metastatic lymph node ratio ( n ratio ) , and the largest involved lymph node size , largest metastatic nest size and largest metastatic nest to lymph node size ratio.results:patients were classified into significant prognostic groups by the five n classification method including the tnm method , n ratio ( 0 , 0.15 , 0.15 - 0.4 , > 0.4 ) , largest involved lymph node size ( 0 , 5 , 5 - 11 , > 11 mm ) , largest metastatic nest size ( 1 , 1 - 7.5 , > 7.5 mm ) and largest metastatic nest to lymph node size ratio ( 0.3 , 0.3 - 0.9 , > 0.9 ) .
all of the above systems remained as independently significant prognostic factors in terms of overall and disease free survival time.conclusion:among the n staging systems we recommend the metastatic lymph node ratio and largest metastatic nest to lymph node size systems , since they are reproducible , simple , have good survival applicability , have prognostic value and include less stage migration especially in patients whom fewer than 15 lymph nodes are dissected . |
stroke is the third cause of mortality and the first
cause of disability in adults [ 1 , 2 ] . as cerebral ischemia can not be predicted , timely
imaging and accurate interpretation are required to identify patients who might
benefit from more aggressive therapy .
although computed tomography ( ct ) and
magnetic resonance imaging ( mri ) have been important and widely used clinical
imaging techniques , there are some shortcomings in the imaging of acute stroke ,
such as the limited brain coverage .
however , up to now , the markers of
cerebral ischemia were scarce [ 2 , 3 ] .
the ideal cerebral ischemia markers should not only per - meate
across the bbb but also accumulate in the brain ischemia . recently , mathis et al . synthesized a series of thio - flavin - t
derivatives , which had the benzothiazole - aniline backbone and showed good
permeation across the bbb [ 46 ] .
also it is well known that
the nitroimidazole derivatives can selectively accumulate in hypoxic tissue and
be used to image tumor hypoxia [ 79 ] and cerebral ischemia [ 10 , 11 ] . in our previous study , three
nitroimidazole - based thioflavin - t derivatives were synthesized and radiolabeled
with iodine-131 ( see figure 1 ) : n -[4-(benzothiazol-2-yl)-phenyl]-3-(2-nitroimidazole-1-yl )
propanamide ( 2npbta ) , n-[4-(benzothiazol-2-yl)phenyl]-3-(4-nitroimidazole-1-yl)-propanamide
( 4npbta ) , and n-[4-(benzothiazol-2-yl )
phe - nyl]-3-(4-nitroimidazole-1-yl)-n - methylpropanamide
( 4n - pbta-1 ) . in vitro and in vivo results showed that they could bind to viable
hypoxic tumor cells . in this paper ,
their permeability across the bbb
into the normal brain and in vivo evaluation in the gerbil cerebral
ischemia models were investigated .
no - carrier - added na[i ] ( aqueous solution ) was
obtained from china institute of atomic energy .
2npbta , 4npbta , and 4npbta-1
were synthesized and radiolabeled with iodine-131 in our laboratory .
kunming mice were obtained from breeding center of the
institute of zoology and adult mongolian gerbils from breeding center of
capital university of medical sciences .
all experiments were carried out
following the principles of laboratory animal care and the china law on the
protection of animals .
radioactivity in the brain of the animals was assayed
using a cobra ii series auto - gamma counting system ( packard ) .
brain uptake and clearance were performed using normal
kunming mice ( males , 20 g ) .
each
mouse received a 0.1 ml ( 2 ci , mbq ) dose
of [ i]2npbta , [ ] 4npbta , or [ i]4npbta-1 by tail vein injection .
such injection solution ( 0.1 ml ) was taken as standard for calculating the
percent injected dose per gram of tissue , that is , % id / g . at 2 and 30 minutes
postinjection , mice were killed without anesthesia by cervical dislocation in
groups of five .
the brain uptake
( the percent injected dose per gram of tissue , % id / g ) was calculated .
the
2-to-30 minutes ratios of % id / g of the brain were calculated .
the final results
were expressed as mean standard
deviation ( sd ) .
adult mongolian gerbils ( males , 100 g ) were
used for cerebral ischemia models .
a right common carotid artery ligation was
performed to produce cerebral hypoxia - ischemia ( hi ) as initially described by
levine and payan .
gerbils were anesthetized intraperitoneally ( i.p . ) with 3.5% chloral hydrate ( 1
ml ) , and the four limbs were fixed .
a midline anterior incision was made , the
right common carotid artery was isolated and ligated with 60 surgical sutures
distally and proximally .
thereafter , the incision was closed , and the gerbils were allowed to awake .
gerbils were ranked by the modified stroke index ( si ) described by ohno et al . .
[ i]2npbta , [ i]4npbta , or [ i]4npbta-1 ( 0.5 ml , 10 ci , mbq ) was
injected i.p . into the gerbils .
such injection solution ( 0.5 ml ) was taken as
standard for calculating the percent injected dose per gram of tissue , that is ,
% id / g .
the gerbils were sacrificed without
anesthesia by cervical dislocation in groups of three at 4 , 8 , and 12 hours
after injection .
the whole brain was removed , placed on dry ice for about 2
minutes , and then cut in half along the cerebral longitudinal fissure .
the right / left hemispheral
uptake ratios , that is , the ratios of ischemic brain to normal brain , were also
calculated .
the final results were expressed as mean standard
deviation ( sd ) . the observed significance level ( p value )
[ ] 2npbta ( 0.1 ml , 2 ci ) was
injected intraperitoneally ( i.p . ) into the gerbils subjected to right common
carotid artery ligation at 0 , 60 , 120 , 180 , and 240 minutes .
such injection
solution ( 0.1 ml ) was taken as standard for calculating the percent injected
dose per gram of tissue , that is , % id / g . before sacrifice ,
gerbils were sacrificed ( no anesthesia ) by cervical dislocation 120
minutes after the final injection .
the whole brain was removed , blotted free of
excess blood , placed on dry ice for about 2 minutes , and then sliced coronally
at approximately 3-mm intervals , yielding a total of five coronal slices ,
designated a
each slice was then cut in half
at the midsagittal plane , and the right and left halves were weighed and
radioactivity counted .
high brain uptake and low nonspecific binding , as measured
by the ratio of brain uptake at 2 and 30 minutes , will generally improve the
quality of brain tomographic studies .
it can be seen from table 1 that the brain uptake of
the three compounds was high at 2 minutes , and low binding at 30 minutes . as a
result ,
the ratio of brain uptake at 2 and 30 minutes for [ i]2npbta , [ i]4npbta , and [ i]4npbta-1 reached 6.2 , 9.7 ,
and 5.4 , correspondingly .
thus , these compounds showed not only good permeation
across the bbb into the brain at the early stage postinjection but also fast
clearance from the normal brain tissue soon , making them worthy of further
study as brain ischemia markers .
the uptake of [ i]2npbta , [ i]4npbta , and [ i]4n - pbta-1 in the ischemic brain hemisphere
( right ) and normal brain hemisphere ( left ) at 4 , 8 , and 12 hours after
administration is presented in table 2 .
the right / left ( ischemic / normal )
hemispheral uptake ratios were also calculated .
the uptake in the right
hemisphere was higher than that in the left at 4 , 8 , and 12 hours postinjection
for [ i]2npbta .
this indicated that
the clearance from ischemic brain tissue was slower than that from normal brain
tissue .
this was attributed to the selective accumulation of 2-nitroimidazole
in hypoxic or ischemic conditions [ 15 , 16 ] .
the right / left uptake ratios , that is , the uptake
ratios of ischemic to normal brain tissues were gradually increasing for [ i]2npbta , from 1.18 at 4 hours
to 1.76 at 12 hours .
similar to the finding of read et al . that 30% of penumbral tissue of ischemic
stroke was present at an average of approximately 20 hours using the hypoxia
marker f - labeled fluoromisonidazole
,
as for [ i]2npbta , the difference
between the uptake of the right hemisphere and the left hemisphere was
significant ( .05 > p > .01 ) at 12 hours , and the difference of the right / left
uptake ratios between 12 hours and 4 hours was very significant ( p < .01 ) . unfortunately , as for [ i]4npbta and [ i]4npbta-1 , the differences
between ischemic and normal brain tissues were not significant among all groups
( p > .05 ) .
figure 2 shows the uptake of [ i]2npbta in coronal brain
slices from 4 gerbils subjected to right common carotid ligation after multiple
injections .
the brain of
each gerbil was divided into five 3-mm coronal sections , designated a
the stroke indices ranging from 0 to 13 were indicated
above the histograms for each animal . increased uptake of [ i]2npbta in ischemic
hemispheres was found .
the right / left hemisphere uptake ratios were 1.1 , 0.9 ,
0.9 , 1.1 , and 0.9 from a to e for stroke index = 0 and 1.2 , 1.2 , 1.1 , 1.3 , 1.1
for stroke index = 4 . for stroke indices = 11 and 13 , they were 1.5 , 2.0 , 1.8 ,
1.7 , 1.5 and 1.3 , 2.4 , 2.2 , 2.0 , 1.4 . in the gerbil with no evidence of
ischemia ( stroke index 0 )
, there was no evident right / left difference in any
coronal sections . in the gerbil with a stroke index of 4
the gerbils with markedly symptomatic ischemia ( stroke
indices 11 or 13 ) showed a 2-fold or 2.4-fold higher uptake in the midparietal
region of the right hemisphere compared with the left .
this confirmed that
there was greater uptake of [ i]2npbta in the right
hemisphere compared with the left and verified that there was a trend for
increased uptake with increasing stroke index .
our data supported the result
reported by hoffman et al . through the study of
[ h]misonidazole that the right / left
hemisphere uptake ratios correlated positively with the severity of the stroke .
for the gerbils with stroke index 11 or 13 , the
right / left hemisphere uptake ratios were modest at the most anterior coronal
sections , that is , section a , the rostral end .
the two anterior cerebral arteries
of the gerbils fuse in the interhemispheric fissure to form a single
pericallosal artery [ 1820 ] .
ischemia may be developed
in the anterior brain regions on the nonligated side following the loss of the
contributing anterior cerebral flow from the opposite internal carotid
circulation .
thus , the rostral end of the left brain of the most symptomatic gerbil also
showed an increase in uptake , compared with the corresponding coronal section
in gerbil with very low stroke index .
the gerbil has an incomplete circle of
willis and , after carotid ligation , may develop severe ischemia in the
forebrain .
the cerebellum and brain stem , which are supplied by the vertebral
arteries , are included in the posterior sections of the brain .
thus , the right / left difference was also
modest at the caudal end , that is , the section e , and the coronal brain
sections consistently showed a decreasing rostal - to - caudal binding of [ i]2npbta , from b to e.
different from the result of hoffman et al . that there was no difference between right and left
at
the caudal ends , ours also showed difference at slice e , they were 1.5 fold
and 1.4 fold for stroke indices = 11 and 13 .
the unique anatomical feature of the gerbil made them
widely used as a model in global ischemia [ 18 , 19 , 21 ] .
unlike rats
, gerbils do not have a posterior communicating artery , that is , the
circle of willis is incomplete and there is incomplete anastomosis of the
anterior cerebral arteries .
therefore , the blood supply of each hemisphere is
isolated from the contralateral carotid and basilar arteries . thus , global
cerebral ischemia in gerbils can be induced by bilateral common carotid artery
occlusion or unilateral common carotid occlusion .
ligation of one carotid
artery causes ischemia in the ipsilateral hemisphere , while the other side is
unaffected , providing neighboring normal tissue as an internal control .
many
investigators have demonstrated that unilateral carotid occulation produces
homolateral ischemia and/or infarction in approximately 3050% of adult male
gerbils [ 1820 ] .
this study indicated that [ i]2npbta , [ i]4npbta , and [ i]4npbta-1 showed good
permeation across the bbb into the brain and fast washout from the normal brain
tissue .
this study also demonstrated a specific location of [ i]2npbta in the cerebral
ischemic tissue .
these results represented a first step toward cerebral
ischemia markers of 2npbta and made it worthy of further investigation . | timely imaging and accurate interpretation of cerebral ischemia are required to
identify patients who might benefit from more aggressive therapy , and nuclear medicine
offers a noninvasive method for demonstrating cerebral ischemia .
three
nitroimidazole - based thioflavin - t derivatives , n-[4-(benzothiazol-2-yl)phenyl]-3-(4-nitroimidazole-1-yl ) propanamide ( 4npbta ) , n-[4-(benzothiazol-2-yl)phenyl]-3-(4-nitroimidazole-1-yl)-n - methylpropanamide ( 4npbta-1 ) , and
n-[4-(benzothiazol-2-yl)phenyl]-3-(2-nitroimidazole-1-yl ) propanamide ( 2npbta ) , were
radioiodinated and evaluated as possible cerebral ischemia markers . in normal mice ,
these compounds showed good permeation of the intact blood - brain barrier ( bbb ) , high
initial brain uptake , and rapid washout . in gerbil stroke models that had been subjected
to right common carotid artery ligation to produce cerebral ischemia , [ 131i]2npbta ,
uptake in the right cerebral hemisphere decreased more slowly than that of the left , and
the right / left hemisphere uptake ratios increased with time . also , the right / left
hemisphere uptake ratios correlated positively with the severity of the stroke .
the results showed that
[ 131i]2npbta had a specific location in the cerebral ischemic tissue .
this represented a first step in finding new drugs and might provide a possible cerebral
ischemic marker . |
could there possibly have been some influence from the old world on the group of people you mentioned deep in the amazon ?
varisco s response : some people think that perhaps the phoenicians came over here very early . [ that ] would be an old world influence .
it is the kind of thing that if one steps back , it makes sense .
i know that sounds crazy , but we are so used to thinking that the way we think about treating the dead is the normal way of doing it .
when you understand their logic , you say , wow , that is interesting .
i do not think that was in ancient phoenicia but it is an interesting historical question . | all known human societies have a worldview that deserves to be called religion ; all religions must explain death .
anthropologists study the diversity of religious systems , present and past , in order to understand what is common to humanity . rather than starting from the view of a particular revelation or set of doctrines , the anthropologist tries to step outside his or her own subjective worldview and identify patterns in the evolution of human thinking about the reality of physical death .
are humans the only animals that are conscious of death , or do we share sentiments observable in our closest living relatives , the chimpanzees ? at what point in history
did the concept of an afterlife , life in some spiritual sense after physical death , appear ? is the religious explanation of life and death a mere reflection of a communal social fact , as the sociologist emil durkheim suggested , or a shared psychological trait , as more recent scholars assert ?
can and should the modern scientist make a definitive statement about the finality of death and human consciousness ? |
during the past 50 years , the number of women enrolling in medical school has increased almost nine - fold . in particular , the figures published by the association of medical colleges showed that , in 2005 , women in the united states ( us ) represented 49% of all medical students , compared to 6% in 1960 . similarly in the united kingdom ( uk ) , women composed 59% of the yearly intake of medical schools in 2009 , in contrast to 32% in 1977 . despite this encouraging influx , there is considerable evidence that women are still under - represented in the higher echelons of academic medicine [ 3 - 5 ] .
studies on surrogate markers of academic productivity , like the authorship of scientific publications and the presence on the editorial board of biomedical journals , clearly demonstrate that female representation in these areas is still scanty despite recent increases .
the lowest numbers are recorded in the specialty journals of surgery and orthopaedics ( where the proportion of female first authors is only 16.7% and 6.5% , respectively ) , while in obstetric and paediatric journals the percentage is closer to 40% .
this inequality between the two genders is also evident in other fields of academic medicine , such as rank attainment , leadership roles and salaries .
the percentage of female principal investigators for the national institute of health ( nih ) was 24.6% in 2003 , with female investigators achieving , on average , smaller grants .
only 12% of department chairs , 17% of full professors and 11% of medical school deans in the us are female . in the uk , the council of heads of medical schools annual census
has shown that , in 2006 , female doctors accounted for only 11% of all professorships and only 36% of clinical lecturers ' posts .
interestingly , the proportion of women steadily decreases as they progress from assistant to associate and full professor both in ' traditionally male ' ( 21% , 12% , 6% in surgery ) and ' traditionally female ' ( 53% , 40% , 22% in paediatrics ) specialties .
could this kind of disparity exist only in the aforementioned fields of academia ( authorship , editorial board members , professoriate ) ?
is gender imbalance more prominent in certain countries or specific ' traditionally male ' specialties ?
four international intensive care medicine ( icm ) congresses from three continents were evaluated in terms of female faculty members and speakers .
the organizers were the european society of intensive care medicine ( esicm ) , the department of intensive care medicine of erasme university hospital in brussels , in association with the belgian society of intensive care and emergency medicine ( isicem ) , the society of critical care medicine ( sccm ) and the australian and new zealand intensive care society / australian college and critical care nurses ( anzics / acccn ) . using the scientific programmes of the congresses ,
the proportion of female faculty members was calculated to be 6% in the 32nd isicem and 15% in the 24th esicm meetings that took place in march 2012 and october 2011 , respectively .
the percentage was higher in the united states 41st sccm congress ( 25% ) , whereas in the upcoming 37th anzics / acccn women account for 35% of all invited speakers .
interestingly , when the non - medical participants were excluded ( mainly nurses and pharmacists ) , the medical female representation amounted to a disappointing 10% , 15% and 16% in the esicm , sccm and anzics / acccn meetings , respectively .
the numbers are , at least , disheartening . as advancement in academic medicine is tightly correlated to the external influence of one 's scholarly work and the invitations to present that work publicly , the under - representation of women in the most esteemed intensive care meetings globally poses a significant question : why are women so minimally represented ? surely it can not be the pipeline effect , the notion that an insufficient number of women have been in medicine long enough in order to advance to the top tiers of academia .
women have occupied at least 50% of the medical positions for the past 25 years in several fields , without ever assuming the same proportion of leadership roles as their male colleagues .
equally unsupported is the explanation that women are less committed to their careers because of family and other personal responsibilities .
recent studies have suggested that a balance between work and other activities is as important to men as it is to women , at least among the younger physicians [ 14 - 16 ] , and that there is no significant gender difference in the reported importance of career advancement or in the extent to which work and personal life conflicted .
another proposed explanation , the lack of quality in the work produced by women , has been dismissed by housri and colleagues , who showed an increased frequency with which female authors are cited as well as an increased rate of publication in the journals with higher impact factors .
most likely , the paucity of women speakers in icm congresses is another manifestation of the ' glass ceiling effect ' : that is , the observation that despite increased entry of women into the fields traditionally held by men , their advancement into the most prestigious , highest - paying , and leadership positions is still limited .
several explanations have been proposed : traditional gender roles imposed historically , gender discrimination with many , subtle manifestations , and a lack of same - sex mentors and role models .
the resulting scarcity of women at higher ranks may explain their under - representation in icm meetings , since the candidate pool of potential speakers remains small .
however , another explanation that has been proposed , albeit in a different setting , is that the ' homogeneity and concentration of power may have contributed to certain unintended biases ' .
it is suggestive that out of the 23 scientific advisors and collaborators that contributed to the 32nd isicem meeting , none were female ( interestingly , all managerial and secretarial staff were women ) .
the numbers were marginally better across the atlantic , with 6 out of 38 ( 16% ) members of the planning committee of the 41st sccm congress being female medical doctors .
could the observed gender imbalance be partly due to the small number of women in decision - making posts ?
in conclusion , the scarcity of female speakers and faculty members in icm congresses strongly suggests the existence of a ' glass ceiling ' in the field of critical care .
clearly , these results constitute solely a snapshot of each society 's annual congress and , even if every attempt was made to correctly identify the gender of faculty members , there is always room for error .
it is also possible that the balance would be somewhat different in icm conferences of other , ' traditionally female ' , sub - specialties ( for example , in paediatric icm ) .
however , the exceptionally low female representation in the congresses validates the perception that although women have made remarkable strides in the last decades , a gender gap still remains .
it is present in a specialty that was not , up to now , considered to be gender - biased , and appears to be a global phenomenon . simply acknowledging the problem will bring us a step closer to its resolution .
after all , wasting ' half our genetic pool of intelligence , creativity and experience ' will only hinder the improvement of health care for all , a loss that medicine simply ' ca n't afford ' .
anzics / acccn : australian and new zealand intensive care society / australian college and critical care nurses ; esicm : european society of intensive care medicine ; icm : intensive care medicine ; isicem : belgian society of intensive care and emergency medicine ; sccm : society of critical care medicine .
| during the past 50 years , the participation of women in medicine has increased dramatically . however , this encouraging influx has not been accompanied by equality for male and female faculty in terms of rank attainment , leadership roles and salaries .
there is considerable evidence that women are still under - represented in the higher echelons of academic medicine , either as heads of departments , authors of scientific papers or members of editorial boards .
participation in medical congresses is another important measure of medical achievement ; this manuscript comments on the female representation in four of the largest international meetings in the field of intensive care medicine ( icm ) .
it notes the scarcity of female faculty members and proposes several explanations for this phenomenon .
the notable under - representation of women in the icm congresses suggests the existence of a ' glass ceiling ' in the field of intensive care medicine , a specialty that , up until today , hasn't been considered as traditionally ' male ' . |
it is well - documented in the international literature that elevated levels of cholesterol , triglycerides , and glucose are significant risk factors , among others , for coronary heart disease ( chd ) .
considerable efforts were made in the past to inform people of the critical consequences their lifestyle could have on their metabolic profile . as a result of alterations in the dietary habits in western europe , usa , and canada , in the past 30 years , there has been a decline in cholesterol levels as well as in chd mortality in these countries .
the ingestion of saturated and trans fatty acids and dietary cholesterol and consumption of fruit and vegetables highly influence low - density and high - density lipoprotein cholesterol levels and consequently , the occurrence of chd .
a rational hypothesis is that in rural populations of countries around the mediterranean sea , the incidence of high glucose , cholesterol , and triglyceride levels in the blood should be significantly lower , compared to urban populations , because of the diet pattern similar to the mediterranean model .
the primary purpose of this study was to investigate the mean levels of serum lipids and glucose , compare them within different age and sex groups , in a rural population located in the ormos korthiou municipality in the southern region of andros island , greece [ figure 1 ] .
this study included measurements recorded in the regional surgery unit ( a primary care setting ) of ormos , the capital city of korthi municipality in the southern region of andros .
the examinations were conducted during a screening program for community health promotion supported by the municipal authorities .
individuals that had not measured the levels of glucose and cholesterol for at least 1 year prior to the study were invited through public announcement to participate in the study .
the exclusion criteria were age < 30 years and > 95 years , body mass index between 18.5 and 30 ( normal weight and preobese individuals , according to who classification ) , current diagnosis of coronary disease or diabetes , current use of lipid - and / or glucose - lowering drugs and of course denial of participation .
all individuals presented in the regional surgery unit and did not meet any of the exclusion criteria were included in the study .
after acquiring the complete medical history of each participant , blood samples were obtained between 8.00 a.m. and 10.00 a.m. after an overnight fast .
the physician obtained blood samples from finger pricks made using disposable lancets and determined the plasma concentrations of total cholesterol and glucose with accutrend gct ( roche diagnostics , basel , switzerland ) .
the device used for the measurements did not precisely quantify cholesterol values below 150 mg / dl and above 300 mg / dl . in these cases , the values 150 mg / dl and 300 mg / dl were used for statistical analysis .
two consecutive measurements were taken , and the mean value was used for the study .
data summary ( 242 participants ) for the purposes of the study , participants were arbitrarily divided into the following age groups :
group 1 , comprising individuals who were between 30 and 49 years of agegroup 2 , 50 - 59 yearsgroup 3 , 60 - 69 yearsgroup 4 , 70 - 79 years ; andgroup 5 , 80 - 99 years .
group 1 , comprising individuals who were between 30 and 49 years of age group 4 , 70 - 79 years ; and group 5 , 80 - 99 years .
the completed data forms were analyzed using microsoft excel 2007 for windows ( microsoft corporation , redmond , wa , usa ) and spss version 16.0 for windows ( spss inc . ,
the differences in the mean values in terms of age groups were assessed by the analysis of variance method and bonferroni post hoc test .
the work that was undertaken conforms to the provisions of the declaration of helsinki ( as revised in tokyo 2004 ) .
two hundred and forty - two individuals , 90 men and 152 women ( 37% and 63% respectively ) , were included in the study .
data on the levels of glucose and cholesterol were available for 186 and 170 individuals , respectively .
the mean value of serum glucose level was 125.1 42.4 mg / dl with no significant difference found between men and women ( men 122.38 42.43 and women 126.61 42.59 .
p = 0.645 ) . a statistically positive correlation was established between age and glucose values ( p < 0.01 ) .
the mean value of total serum cholesterol level was 225.2 44.9 mg / dl with a statistically significant difference between men and women ( men 207.03 44.57 , women 236.09 41.89 .
in contrast , no correlation was found between cholesterol values and age ( p = 0.694 ) .
comparison between the different groups did not reveal statistically significant differences even if for the case of glucose , the result was only marginal ( p = 0.051 ) [ figure 2 ] .
about glucose levels , the results emphasized the need for intensive monitoring of glucose levels in people who are unaware of their metabolic status .
most of the participants stated that they had not had their metabolic blood values measured for several years .
the total cholesterol values were quite elevated in all the participants irrespective of age ; moreover , the values were higher in women than in men .
this difference in values could be attributed to the fact that women underwent blood examinations very rarely compared to men , who were more aware of the threat of chd .
the study had a primary focus on the relatively younger population and an observation of special interest is that the total cholesterol concentration values were not very different between the age groups .
the cholesterol level in group 1 ( 30 - 49 years ) was 220 mg / dl while that in group 5 ( 80 - 99 years ) was 208 mg / dl .
younger men and women mentioned that cholesterol value was not an issue of major concern for them , although they admitted that it was widely known that even younger adults are in danger of chd .
the active population of the area is 2547 people ( 2001 census ) and consequently , approximately 10% of the population participated in the study .
the results of the study show an increase in the prevalence of hyperglycemia and hypercholesterolemia in the island population .
the findings of this study corroborate results from previous studies where the importance of screening control was demonstrated and highlight the absolute necessity for the regular investigation of the metabolic profile of populations inhabiting greece . | background : this study conducted as part of a screening program for the promotion of community health in the primary care setting of ormos korthi in andros , greece .
the objective of this study was to identify the levels of glucose and total cholesterol in individuals without major cardiovascular problems in order to identify cases of undetected dyslipidemia and high blood glucose levels , in a rural population located in the southern part of andros island , greece.methods:in total , 242 individuals ( 152 women , mean age 65.1 12.3 and range 33 - 91 years ) were examined for the determination of serum glucose and total cholesterol levels .
participants were arbitrarily divided into 5 age groups and statistical differences between groups investigated.results:the mean serum glucose level was 125.1 42.4 mg / dl and the mean total serum cholesterol level was 225.2 44.9 mg / dl .
statistical differences were not observed between the age groups in either the glucose or cholesterol levels .
difference between men and women was not significant regarding glucose levels while women had significantly elevated levels of total cholesterol ( p < 0.01 ) .
age was significantly correlated with glucose , but statistical analysis did not show significant correlation between age and total cholesterol levels.conclusions:the present study confirms that dyslipidemia and high blood glucose levels are prevalent among the rural populations of greece and therefore informative campaigns and structured screening programs are required to promote preventive health care . |
tuberculosis ( tb ) is of notable public health significance globally with the greatest disease burden documented in sub - saharan africa ( ssa ) .
the world health organization ( who ) estimated about 8.7 million incident cases of tb with about 1.45 million deaths due to tb in 2011 globally .
a minority of patients with tb present with clinically overt symptoms ; hence , the need among clinicians to possess a high index of suspicion for early diagnosis and initiation of appropriate treatment .
adrenal , pituitary , thyroid , pancreatic , calcium , gonadal , and glucose abnormalities have been well - described among tb patients .
this review article will broadly focus on describing the extent and pathogenesis of adrenal insufficiency , diabetes mellitus ( dm ) , disorders of calcium - vitamin d metabolism , thyroid dysfunction , and hypogonadism among african tb patients .
tb involvement of the adrenal glands is well - documented and is one of the commonest causes of adrenal insufficiency in developing countries with high tb prevalence .
evaluation of adrenal function among tb patients is of great significance because cortisol deficiency is associated with unexplained sudden and early mortality .
chronic inflammatory conditions like tb are associated with increased levels of proinflammatory cytokines like tumor necrosis factor-. these cytokines inhibit adrenal cortisol synthesis and adrenal insufficiency ensues .
anti - tb drugs like rifampicin also cause cortisol deficiency by inducing increased hepatic metabolism of cortisol . adrenal insufficiency in the setting of tb can also occur secondary to coexisting adrenal infiltration by human immunodeficiency virus ( hiv ) coinfection and neoplasms like kaposi sarcoma and lymphomas . studies from africa on the degree of adrenal insufficiency among tb
the reason for this disparity is the varying criteria for defining adrenal insufficiency and diagnostic methods used .
odeniyi et al . , in a study among 44 adults with smear positive tb in nigeria documented a prevalence of subclinical adrenal insufficiency of 23% after a low dose 1 adrenocorticotrophin hormone ( acth ) stimulation test .
there was no statistical difference noted between the basal cortisol levels of the tb patients and the 100 healthy controls ( 239.9 nmol / l vs. 229.1 nmol / l , p = 0.661 ) .
this study demonstrates that an acth stimulation test may be a better test to confirm or exclude adrenal insufficiency in tb patients . in another case - control study by mugusi et al .
, on 50 hospitalized patients with chronic pulmonary tb in tanzania , an abnormal adrenal response was noted in 16 ( 32% ) patients .
adrenal insufficiency in this study was defined as a 60-min cortisol response < 21.7 g / dl ( < 600 nmol / l ) and/or an increment < 10.8 g / dl ( < 300 nmol / l ) after an acth stimulation test .
hypotension is a common clinical sign associated with adrenal insufficiency as noted in this study .
patients with an impaired cortisol response were reported to have lower mean supine and erect diastolic blood pressures compared to those with a normal response ( supine : 64 mm hg vs. 74 mm hg , p < 0.01 and erect : 62 mm hg vs. 73 mm hg , p < 0.05 ) . in south africa , varying prevalence of adrenal insufficiency among tb patients has been documented . this could be explained by the differences in races being studied and study definitions of adrenal insufficiency .
ross et al . , in a cross - sectional study to determine the specific etiology of addison 's disease in a large south african cohort found a prevalence of 8% among tb patients , while soule reported a prevalence of probable tb - related addison 's disease to be 34% ( 18%-active tb disease and 16%-old tb disease ) among 50 hospitalized patients . in another case - control study by kaplan et al . , to assess the magnitude of adrenal insufficiency and the effect of hiv coinfection on adrenal function in 21 healthy controls and 18 hiv positive and 22 hiv negative hospitalized tb patients , a very low frequency of hypoadrenalism of 1.6% ( documented in 1 hiv negative tb patient ) was reported .
hiv sero status did not significantly affect the serum cortisol levels after administration of the 1 g acth stimulation test .
post et al . , in another prospective study did not find any evidence of adrenal insufficiency among 50 hospitalized patients with newly diagnosed active pulmonary tb . in this study ,
adrenal insufficiency was defined as a peak cortisol concentration 550 nmol / l after a 250 g stimulation acth test irrespective of the basal cortisol levels .
adrenal insufficiency is invariably accompanied by unspecific clinical features like fatigue , salt craving , myalgia , nausea and vomiting , abdominal pain , postural hypotension , and hyperpigmentation .
hyponatremia , hypoglycaemia , hyperkalemia , unexplained easinophilia and mild prerenal azotaemia are the common biochemical findings .
presence of any of these clinical features among tb patients should prompt evaluation of adrenal function using either measurement of basal early morning serum cortisol levels or an acth stimulation test .
management of adrenal insufficiency involves long - term low dose oral glucocorticoid and mineral corticoid replacement therapy and timely initiation of anti - tb therapy with the standard regimen .
rifampicin , an integral drug in tb treatment , is a known potent inducer of the cytochrome p450 enzymes which may result in enhanced clearance of the endogenous cortisol produced by the adrenal cortex .
however , two prospective studies reported from south africa and malawi , though limited by the relatively small patient numbers , reported no impairment in adrenal function due to rifampicin .
the latter study demonstrated no increase in mortality in tb patients in the early phases of treatment .
recent evidence suggests that diabetic patients have an increased tendency to develop tb due to impaired cell - mediated immunity , renal failure , micronutrient deficiency , and pulmonary microangiopathy .
chronic infections like tb are associated with reactionary hyperglycemia which occurs due to increased production of counter - regulatory stress hormones like epinephrine , glucagon , cortisol , and growth hormone that act synergistically .
the prevalence of dm among tb patients in the published african studies ranges from 2.1% to 16.4% .
this disparity in the prevalence could be explained by the varying diagnostic techniques used in the studies [ 75 g oral glucose tolerance test ( ogtt ) , measurement of fasting and random blood sugar level ] .
the earliest study in africa by marais in south africa among 436 tb patients reported a prevalence of 2.1% . in another cross - sectional study done in tanzania by mugusi et al .
, assessing glucose tolerance using a 75 g ogtt in 506 hospitalized patients with sputum - positive pulmonary tb found an initial prevalence of 6.7% .
oluboyo and erasmus in a study among 54 nigerians with active pulmonary tb found 3 ( 5.6% ) and 20 ( 37% ) patients to have dm and impaired glucose tolerance , respectively , following a 75 g ogtt . in conakry , guinea using fasting capillary blood sugar testing , the prevalence of dm among tb patients was 3.35% .
four ( 31% ) patients had not been diagnosed with dm prior to the study .
dm in this study was significantly associated with an increased age ( p < 0.0001 ) , obesity ( p < 0.005 ) , sedentary lifestyle ( p
< 0.0004 ) , and previous family history of diabetes ( p < 0.04 ) or obesity ( p < 0.04 ) . in another cross - sectional study performed in nigeria to determine the prevalence of dm in 351 tb patients by measuring the fasting blood sugar level , dm as defined by levels 126 mg / dl was noted in 20 patients ( 5.7% ) .
half of these patients were not known diabetic patients prior to initiation of tb treatment .
significantly , diabetic patients with tb coinfection were noted to have a higher mean age than those with only tb disease ( 41.5 13.9 years vs. 34.15 13 years , p = 0.02 ) .
no significant statistical difference was noted between these two groups in relation to duration of cough and sputum positivity . in another study performed in uganda ,
dm in this study was defined as a random blood sugar level 200 mg / dl in the presence of the usual signs and symptoms of dm like polyuria .
of the 22 tb patients diagnosed with dm , only 5 ( 22.7% ) were known diabetics at baseline .
dm in this study on multivariate analysis was significantly associated with a raised mean serum alanine transaminase ( alt ) concentration 80 u / l [ odds ratio ( or ) : 11.42 95% confidence interval ( ci ) : 2.15 - 60.59 , p = 0.004 ] and paradoxically , hiv had a protective effect ( or : 0.17 95% ci : 0.06 - 0.51 , p = 0.002 ) .
this association between raised mean alt concentrations and dm in tb patients has not been described in any african studies . increased serum alt concentrations are a strong predictor of insulin resistance in addition to signifying direct hepatocellular damage either due to hepatotrophic viruses like hepatitis c or hepatosteatosis which have been demonstrated to be associated with dm .
however , in this study , assessment for hepatitis b , c , or hepatosteatosis was not done . the largest african study to date examining the prevalence and clinical predictors of dm in tb patients by faurholt - jepsen et al .
, performed in mwanza , tanzania reported a relatively high prevalence of dm of 16.4% ( n = 197 ) among 1205 patients . in this study , age of 45 - 55 years and high waist circumference , that is , > 90 cm for both sexes ( or : 4.94 , 95%ci : 2.34 - 10.42 , p <
additionally , severe underweight was also associated with dm among male tb patients ( or : 2.52 , 95%ci : 1.34 - 4.74 , p = 0.004 ) .
infections like tb are often associated with reactionary hyperglycemia that may resolve following appropriate treatment hence lowering rates of factual dm . in the study by mugusi et al .
, a documented decrease in the crude diabetes prevalence rate from 6.5% to 4% was noted following a repeat ogtt on 25 patients with an initial diagnosis of dm . in another similar study by oluboyo and erasmus an ogtt after 3 months of anti - tb treatment later found only one patient to be frankly diabetic compared with three at initiation of anti tb therapy .
compelling evidence shows that dm alters the clinical presentation of tb and its outcomes in terms of causing delayed sputum / culture conversion , increased case fatality , and treatment failure . in a large cross - sectional study by faurholt - jepsen et al .
, performed in mwanza , tanzania among 1250 urban tb patients , dm was associated with small changes in tb manifestations .
tb patients with dm comorbidity had a higher neutrophil count ( 0.5 10 cells l , 95% ci : 0.2 - 0.9 , p = 0.001 ) than nondiabetic tb patients .
serum c - reactive protein ( 18.8 mg l , 95% ci : 8.2 - 29.4 , p = 0.001 ) and alpha-1-acid glycoprotein ( 0.2 g l , 95% ci : 0.03 - 0.3 , p = 0.02 ) as acute phase reactants were also similarly higher in patients with diabetes .
self - report of fever as a symptom of tb was also more frequent among diabetics with tb patients compared with those without dm ( or : 2.9 , 95% ci : 1.5 ; 5.7 , p = 0.002 ) .
there was no difference in mycobacterium tb positive culture status and hiv sero positivity between the two groups .
in relation to clinical recovery or treatment outcome in the same study , patients with tb - dm comorbidity experienced a slower improvement in weight and haemoglobin concentrations compared to those with tb alone at 2 and 5 months of follow - up .
faurholt - jepsen et al . , in a prospective cohort study of the same study population also demonstrated that dm is a strong predictor of early mortality during anti tb treatment . in the initial 100 days
, diabetes was associated with a fivefold increased risk of mortality [ relative ratio ( rr ) : 5.09 , 95% ci : 2.36 - 11.02 , p < 0.001 ] among hiv uninfected , and a twofold increase among hiv coinfected patients ( rr : 2.33 95% ci : 1.20 - 4.53 , p = 0.012 ) .
screening of tb patients for dm in africa and other tb endemic regions using either a 75 g ogtt , measurement of glycated hemoglobin , fasting or random blood sugar level , is therefore , of paramount importance ; because dm is associated with adverse clinical outcomes and greatly alters clinical presentation .
screening for dm is also advised before initiation of anti - tb therapy and later in the course of the disease ( preferably 3 months after initiation of therapy ) to exclude reactionary hyperglycaemia that resolves with treatment .
treatment of dm among patients with tb should involve the use of insulin or oral hypoglycaemic agents ( ohas ) in order to achieve the optimal goals of therapy , that is , maintaining an hba1c of < 7% , random blood sugar level < 180 mg / dl or a fbg level < 120 mg / dl .
however , therapeutic doses of most glucose lowering drugs may need to be increased during the initial phases of tb treatment .
this is because rifampicin induces an acute transient hyperglycemia due to its effect of augmenting intestinal absorption of glucose . due to its cytochrome p450 enzyme inducing properties
patients should receive standard anti - tb therapy of 6 or 8 months depending on the regimen used with pyridoxine supplementation .
this is due to increased tissue conversion of 25-hydroxyvitamin d3 ( 25(oh ) d3 ) to 1,25-dihydroxyvitamin d3 ( 1,25(oh ) 2d3 ) or calcitriol .
the frequency of hypercalcemia among tb patients in africa varies among countries mainly due to the differences in the prevalence of coexisting vitamin d deficiency ( vdd ) and extent of calcium intake . to my knowledge ,
dosumu and momoh in a cross - sectional study to determine the prevalence of hypercalcemia among 120 newly diagnosed tb patients in nigeria found a prevalence of 27.5% . however , only 12% of the patients had symptomatic hypercalcemia warranting medical intervention . majority of the african studies have documented no occurrence of hypercalcemia with corrected hypocalcaemia predominating . this high frequency of hypocalcaemia is due to the high prevalence of coexisting vdd among african tb patients .
vdd has been described among african tb patients living in developed countries and in africa .
the prevalence of vdd among tb patients in africa is reported to range from 8.5% to 62.7% .
this discrepancy in the frequency is probably due to the differences in geographical locations of the countries , dietary habits , baseline hiv coinfection , and techniques of vitamin d measurement .
darker skin pigmentation , chronic infections like hiv , malabsorption , lower sunshine exposure , and renal and liver dysfunction have been described as risk factors for vdd .
adequate vitamin d levels in form of calcitriol are associated with increased production of cathelicidin by the immune cells .
this is by enhancing the process of fusion of the phagosome and lysosome in infected macrophages and increasing intra cellular oxidative stress . due to the high prevalence of vdd among tb patients , additional research in form of randomized clinical trials to evaluate the effect of oral vitamin d and calcium replacement therapy on clinical outcomes and prevention of tb in africa
protracted critical illness is often associated with a disruption of the hypothalamic - pituitary - thyroid axis , resulting in reduced stimulation of the thyrotropes and impairment of thyroid hormones release .
case reports of tb of the thyroid gland with subsequent destructive thyroiditis and thyroid dysfunction have also been documented .
sick euthyroid syndrome is the most frequently encountered biochemical abnormality . in a cross - sectional study of 50 hospitalized patients with active tb in south africa ,
the sick euthyroid syndrome in this study was defined as a serum free triiodothyronine ( t3 ) concentration less than 3.3 pmol in the absence of clinical or biochemical features of primary or secondary hypothyroidism .
kaplan et al . , in another cross - sectional study done in south africa reported a prevalence of sick euthyroid syndrome of 42% among 40 patients with active tb .
a reduced thyroid stimulating hormone level was noted to be significantly associated with hiv sero positivity ( 1.57 vs. 3.39 miu / l , p < 0.006 ) in this study .
hiv sero status did not have any significant effect on the free thyroxine ( t4 ) and triiodo thyronine ( t3 ) concentrations .
a case report from somalia documented a unique case of tb of the thyroid gland in an euthyroid young patient presenting as a thyroid mass .
alterations in thyroid gland function among critically ill patients have been highly associated with adverse patient outcomes and increased mortality .
screening and treatment of thyroid dysfunction among suspected tb patients will , therefore , aid in determining and improving the prognosis .
thyroxine replacement therapy in critically ill patients with sick euthyroid syndrome is a very controversial issue and is not advocated .
thyroxine replacement is recommended in all cases of hypothyroidism and selected cases of sub clinical hypothyroidism .
male hypogonadism ( primary and secondary ) is a common endocrinopathy among tb patients especially in the setting of hiv coinfection .
kaplan et al . , reported prevalence of male hypogonadism among tb patients to be 73% and 88% , respectively .
the prevalence of hiv sero positivity in the studies was 4% and 45% , respectively .
the former study demonstrated a significant positive correlation between total serum testosterone levels and free serum t3 concentrations ( p < 0.01 ) and body mass index ( p < 0.01 ) .
male hypogonadism is associated with unspecific clinical features like loss of libido , erectile dysfunction , increased body fat mass , reduced muscle mass and strength , gynecomastia , and reduced bone mineral density .
screening with an early morning serum free testosterone level is recommended in male tb patients suspected to have hypogonadism .
replacement therapy in cases of testosterone deficiency is highly advised to improve sexual performance and reduce the risks of pathological fractures , dyslipidemia , dysglycemia , obesity , and hypertension .
tb involvement of the adrenal glands is well - documented and is one of the commonest causes of adrenal insufficiency in developing countries with high tb prevalence .
evaluation of adrenal function among tb patients is of great significance because cortisol deficiency is associated with unexplained sudden and early mortality .
chronic inflammatory conditions like tb are associated with increased levels of proinflammatory cytokines like tumor necrosis factor-. these cytokines inhibit adrenal cortisol synthesis and adrenal insufficiency ensues .
anti - tb drugs like rifampicin also cause cortisol deficiency by inducing increased hepatic metabolism of cortisol . adrenal insufficiency in the setting of tb can also occur secondary to coexisting adrenal infiltration by human immunodeficiency virus ( hiv ) coinfection and neoplasms like kaposi sarcoma and lymphomas .
studies from africa on the degree of adrenal insufficiency among tb patients have reported varying prevalence ranging from 0% to 40% .
the reason for this disparity is the varying criteria for defining adrenal insufficiency and diagnostic methods used .
odeniyi et al . , in a study among 44 adults with smear positive tb in nigeria documented a prevalence of subclinical adrenal insufficiency of 23% after a low dose 1 adrenocorticotrophin hormone ( acth ) stimulation test .
there was no statistical difference noted between the basal cortisol levels of the tb patients and the 100 healthy controls ( 239.9 nmol / l vs. 229.1 nmol / l , p = 0.661 ) .
this study demonstrates that an acth stimulation test may be a better test to confirm or exclude adrenal insufficiency in tb patients . in another case - control study by mugusi et al .
, on 50 hospitalized patients with chronic pulmonary tb in tanzania , an abnormal adrenal response was noted in 16 ( 32% ) patients
. adrenal insufficiency in this study was defined as a 60-min cortisol response < 21.7 g / dl ( < 600 nmol / l ) and/or an increment < 10.8 g / dl ( < 300
hypotension is a common clinical sign associated with adrenal insufficiency as noted in this study .
patients with an impaired cortisol response were reported to have lower mean supine and erect diastolic blood pressures compared to those with a normal response ( supine : 64 mm hg vs. 74 mm hg , p < 0.01 and erect : 62 mm hg vs. 73 mm hg , p < 0.05 ) . in south africa , varying prevalence of adrenal insufficiency among tb patients has been documented . this could be explained by the differences in races being studied and study definitions of adrenal insufficiency .
ross et al . , in a cross - sectional study to determine the specific etiology of addison 's disease in a large south african cohort found a prevalence of 8% among tb patients , while soule reported a prevalence of probable tb - related addison 's disease to be 34% ( 18%-active tb disease and 16%-old tb disease ) among 50 hospitalized patients . in another case - control study by kaplan et al . , to assess the magnitude of adrenal insufficiency and the effect of hiv coinfection on adrenal function in 21 healthy controls and 18 hiv positive and 22 hiv negative hospitalized tb patients , a very low frequency of hypoadrenalism of 1.6% ( documented in 1 hiv negative tb patient ) was reported .
hiv sero status did not significantly affect the serum cortisol levels after administration of the 1 g acth stimulation test .
post et al . , in another prospective study did not find any evidence of adrenal insufficiency among 50 hospitalized patients with newly diagnosed active pulmonary tb .
in this study , adrenal insufficiency was defined as a peak cortisol concentration 550 nmol / l after a 250 g stimulation acth test irrespective of the basal cortisol levels .
adrenal insufficiency is invariably accompanied by unspecific clinical features like fatigue , salt craving , myalgia , nausea and vomiting , abdominal pain , postural hypotension , and hyperpigmentation .
hyponatremia , hypoglycaemia , hyperkalemia , unexplained easinophilia and mild prerenal azotaemia are the common biochemical findings .
presence of any of these clinical features among tb patients should prompt evaluation of adrenal function using either measurement of basal early morning serum cortisol levels or an acth stimulation test .
management of adrenal insufficiency involves long - term low dose oral glucocorticoid and mineral corticoid replacement therapy and timely initiation of anti - tb therapy with the standard regimen .
rifampicin , an integral drug in tb treatment , is a known potent inducer of the cytochrome p450 enzymes which may result in enhanced clearance of the endogenous cortisol produced by the adrenal cortex .
however , two prospective studies reported from south africa and malawi , though limited by the relatively small patient numbers , reported no impairment in adrenal function due to rifampicin .
the latter study demonstrated no increase in mortality in tb patients in the early phases of treatment .
recent evidence suggests that diabetic patients have an increased tendency to develop tb due to impaired cell - mediated immunity , renal failure , micronutrient deficiency , and pulmonary microangiopathy .
chronic infections like tb are associated with reactionary hyperglycemia which occurs due to increased production of counter - regulatory stress hormones like epinephrine , glucagon , cortisol , and growth hormone that act synergistically .
the prevalence of dm among tb patients in the published african studies ranges from 2.1% to 16.4% .
this disparity in the prevalence could be explained by the varying diagnostic techniques used in the studies [ 75 g oral glucose tolerance test ( ogtt ) , measurement of fasting and random blood sugar level ] .
the earliest study in africa by marais in south africa among 436 tb patients reported a prevalence of 2.1% . in another cross - sectional study done in tanzania by mugusi et al .
, assessing glucose tolerance using a 75 g ogtt in 506 hospitalized patients with sputum - positive pulmonary tb found an initial prevalence of 6.7% .
oluboyo and erasmus in a study among 54 nigerians with active pulmonary tb found 3 ( 5.6% ) and 20 ( 37% ) patients to have dm and impaired glucose tolerance , respectively , following a 75 g ogtt . in conakry , guinea using fasting capillary blood sugar testing , the prevalence of dm among tb patients was 3.35% .
four ( 31% ) patients had not been diagnosed with dm prior to the study .
dm in this study was significantly associated with an increased age ( p < 0.0001 ) , obesity ( p < 0.005 ) , sedentary lifestyle ( p
< 0.0004 ) , and previous family history of diabetes ( p < 0.04 ) or obesity ( p < 0.04 ) . in another cross - sectional study performed in nigeria to determine the prevalence of dm in 351 tb patients by measuring the fasting blood sugar level , dm as defined by levels 126 mg / dl was noted in 20 patients ( 5.7% ) .
half of these patients were not known diabetic patients prior to initiation of tb treatment .
significantly , diabetic patients with tb coinfection were noted to have a higher mean age than those with only tb disease ( 41.5 13.9 years vs. 34.15 13 years , p = 0.02 ) .
no significant statistical difference was noted between these two groups in relation to duration of cough and sputum positivity . in another study performed in uganda ,
dm in this study was defined as a random blood sugar level 200 mg / dl in the presence of the usual signs and symptoms of dm like polyuria .
of the 22 tb patients diagnosed with dm , only 5 ( 22.7% ) were known diabetics at baseline .
dm in this study on multivariate analysis was significantly associated with a raised mean serum alanine transaminase ( alt ) concentration 80 u / l [ odds ratio ( or ) : 11.42 95% confidence interval ( ci ) : 2.15 - 60.59 , p = 0.004 ] and paradoxically , hiv had a protective effect ( or : 0.17 95% ci : 0.06 - 0.51 , p = 0.002 ) .
this association between raised mean alt concentrations and dm in tb patients has not been described in any african studies . increased serum alt concentrations are a strong predictor of insulin resistance in addition to signifying direct hepatocellular damage either due to hepatotrophic viruses like hepatitis c or hepatosteatosis which have been demonstrated to be associated with dm .
however , in this study , assessment for hepatitis b , c , or hepatosteatosis was not done . the largest african study to date examining the prevalence and clinical predictors of dm in tb patients by faurholt - jepsen et al .
, performed in mwanza , tanzania reported a relatively high prevalence of dm of 16.4% ( n = 197 ) among 1205 patients . in this study , age of 45 - 55 years and high waist circumference , that is , > 90 cm for both sexes ( or : 4.94 , 95%ci : 2.34 - 10.42 , p <
additionally , severe underweight was also associated with dm among male tb patients ( or : 2.52 , 95%ci : 1.34 - 4.74 , p = 0.004 ) .
infections like tb are often associated with reactionary hyperglycemia that may resolve following appropriate treatment hence lowering rates of factual dm . in the study by mugusi et al .
, a documented decrease in the crude diabetes prevalence rate from 6.5% to 4% was noted following a repeat ogtt on 25 patients with an initial diagnosis of dm . in another similar study by oluboyo and erasmus an ogtt after 3 months of anti - tb treatment later found only one patient to be frankly diabetic compared with three at initiation of anti tb therapy .
compelling evidence shows that dm alters the clinical presentation of tb and its outcomes in terms of causing delayed sputum / culture conversion , increased case fatality , and treatment failure . in a large cross - sectional study by faurholt - jepsen et al .
, performed in mwanza , tanzania among 1250 urban tb patients , dm was associated with small changes in tb manifestations .
tb patients with dm comorbidity had a higher neutrophil count ( 0.5 10 cells l , 95% ci : 0.2 - 0.9 , p = 0.001 ) than nondiabetic tb patients .
serum c - reactive protein ( 18.8 mg l , 95% ci : 8.2 - 29.4 , p = 0.001 ) and alpha-1-acid glycoprotein ( 0.2 g l , 95% ci : 0.03 - 0.3 , p = 0.02 ) as acute phase reactants were also similarly higher in patients with diabetes .
self - report of fever as a symptom of tb was also more frequent among diabetics with tb patients compared with those without dm ( or : 2.9 , 95% ci : 1.5 ; 5.7 , p = 0.002 ) .
there was no difference in mycobacterium tb positive culture status and hiv sero positivity between the two groups . in relation
to clinical recovery or treatment outcome in the same study , patients with tb - dm comorbidity experienced a slower improvement in weight and haemoglobin concentrations compared to those with tb alone at 2 and 5 months of follow - up .
faurholt - jepsen et al . , in a prospective cohort study of the same study population also demonstrated that dm is a strong predictor of early mortality during anti tb treatment . in the initial 100 days , diabetes was associated with a fivefold increased risk of mortality [ relative ratio ( rr ) : 5.09 , 95% ci : 2.36 - 11.02 , p < 0.001 ] among hiv uninfected , and a twofold increase among hiv coinfected patients ( rr : 2.33 95% ci : 1.20 - 4.53 , p = 0.012 ) .
screening of tb patients for dm in africa and other tb endemic regions using either a 75 g ogtt , measurement of glycated hemoglobin , fasting or random blood sugar level , is therefore , of paramount importance ; because dm is associated with adverse clinical outcomes and greatly alters clinical presentation .
screening for dm is also advised before initiation of anti - tb therapy and later in the course of the disease ( preferably 3 months after initiation of therapy ) to exclude reactionary hyperglycaemia that resolves with treatment .
treatment of dm among patients with tb should involve the use of insulin or oral hypoglycaemic agents ( ohas ) in order to achieve the optimal goals of therapy , that is , maintaining an hba1c of < 7% , random blood sugar level < 180 mg / dl or a fbg level < 120 mg / dl . however
, therapeutic doses of most glucose lowering drugs may need to be increased during the initial phases of tb treatment .
this is because rifampicin induces an acute transient hyperglycemia due to its effect of augmenting intestinal absorption of glucose . due to its cytochrome p450 enzyme inducing properties
patients should receive standard anti - tb therapy of 6 or 8 months depending on the regimen used with pyridoxine supplementation .
this is due to increased tissue conversion of 25-hydroxyvitamin d3 ( 25(oh ) d3 ) to 1,25-dihydroxyvitamin d3 ( 1,25(oh ) 2d3 ) or calcitriol .
the frequency of hypercalcemia among tb patients in africa varies among countries mainly due to the differences in the prevalence of coexisting vitamin d deficiency ( vdd ) and extent of calcium intake . to my knowledge ,
dosumu and momoh in a cross - sectional study to determine the prevalence of hypercalcemia among 120 newly diagnosed tb patients in nigeria found a prevalence of 27.5% .
. majority of the african studies have documented no occurrence of hypercalcemia with corrected hypocalcaemia predominating .
this high frequency of hypocalcaemia is due to the high prevalence of coexisting vdd among african tb patients .
vdd has been described among african tb patients living in developed countries and in africa .
the prevalence of vdd among tb patients in africa is reported to range from 8.5% to 62.7% .
this discrepancy in the frequency is probably due to the differences in geographical locations of the countries , dietary habits , baseline hiv coinfection , and techniques of vitamin d measurement .
darker skin pigmentation , chronic infections like hiv , malabsorption , lower sunshine exposure , and renal and liver dysfunction have been described as risk factors for vdd .
adequate vitamin d levels in form of calcitriol are associated with increased production of cathelicidin by the immune cells .
this is by enhancing the process of fusion of the phagosome and lysosome in infected macrophages and increasing intra cellular oxidative stress . due to the high prevalence of vdd among tb patients , additional research in form of randomized clinical trials to evaluate the effect of oral vitamin d and calcium replacement therapy on clinical outcomes and prevention of tb in africa are justified .
protracted critical illness is often associated with a disruption of the hypothalamic - pituitary - thyroid axis , resulting in reduced stimulation of the thyrotropes and impairment of thyroid hormones release .
case reports of tb of the thyroid gland with subsequent destructive thyroiditis and thyroid dysfunction have also been documented .
sick euthyroid syndrome is the most frequently encountered biochemical abnormality . in a cross - sectional study of 50 hospitalized patients with active tb in south africa , 46 ( 92% ) patients were found to have sick euthyroid syndrome .
the sick euthyroid syndrome in this study was defined as a serum free triiodothyronine ( t3 ) concentration less than 3.3 pmol in the absence of clinical or biochemical features of primary or secondary hypothyroidism .
kaplan et al . , in another cross - sectional study done in south africa reported a prevalence of sick euthyroid syndrome of 42% among 40 patients with active tb .
a reduced thyroid stimulating hormone level was noted to be significantly associated with hiv sero positivity ( 1.57 vs. 3.39 miu / l , p < 0.006 ) in this study .
hiv sero status did not have any significant effect on the free thyroxine ( t4 ) and triiodo thyronine ( t3 ) concentrations .
a case report from somalia documented a unique case of tb of the thyroid gland in an euthyroid young patient presenting as a thyroid mass .
alterations in thyroid gland function among critically ill patients have been highly associated with adverse patient outcomes and increased mortality .
screening and treatment of thyroid dysfunction among suspected tb patients will , therefore , aid in determining and improving the prognosis .
thyroxine replacement therapy in critically ill patients with sick euthyroid syndrome is a very controversial issue and is not advocated .
thyroxine replacement is recommended in all cases of hypothyroidism and selected cases of sub clinical hypothyroidism .
male hypogonadism ( primary and secondary ) is a common endocrinopathy among tb patients especially in the setting of hiv coinfection .
kaplan et al . , reported prevalence of male hypogonadism among tb patients to be 73% and 88% , respectively .
the prevalence of hiv sero positivity in the studies was 4% and 45% , respectively .
the former study demonstrated a significant positive correlation between total serum testosterone levels and free serum t3 concentrations ( p < 0.01 ) and body mass index ( p < 0.01 ) .
male hypogonadism is associated with unspecific clinical features like loss of libido , erectile dysfunction , increased body fat mass , reduced muscle mass and strength , gynecomastia , and reduced bone mineral density . screening with an early morning serum free testosterone level is recommended in male tb patients suspected to have hypogonadism .
replacement therapy in cases of testosterone deficiency is highly advised to improve sexual performance and reduce the risks of pathological fractures , dyslipidemia , dysglycemia , obesity , and hypertension .
awareness about the occurrence of these endocrine disorders among adult patients with tb should be emphasized among clinicians working in the africa and other high tb endemic regions .
there is a compelling need to urgently recognize and efficiently manage these endocrinopathies , because early management is associated with improvement in the quality of life and reduction of mortality . | a broad spectrum of endocrine conditions has been reported among adult patients with tuberculosis in africa . this review aims to describe the magnitude and pathogenesis of the following endocrinopathies among patients with tuberculosis in africa : adrenal insufficiency , diabetes mellitus , disorders of calcium and vitamin d metabolism , thyroid dysfunction and hypogonadism .
pubmed database and google scholar were used to search for the relevant published english language studies and case reports relating to endocrine abnormalities and tuberculosis in africa up to july 2013 .
the search terms used were endocrine dysfunction , endocrine abnormalities , adrenal insufficiency , diabetes mellitus , thyroid dysfunction , hypogonadism , disorders of calcium and vitamin d metabolism , tuberculosis , africa .
reference lists of the identified articles were further used to identify other studies .
adrenal insufficiency , diabetes mellitus and calcium - vitamin d abnormalities were the most prevalent and frequently reported endocrine disorders among adult patients with tuberculosis in africa .
a meticulous endocrine evaluation among tuberculosis patients with suspected endocrine abnormalities should be encouraged in africa and other high tb endemic regions .
treatment of these endocrine disorders has generally been shown to improve quality of life and reduce mortality . |
routine diabetes care remains a family practice activity for which the canadian diabetes association ( cda ) has set standards since 1999 .
previous work in 7 canadian provinces examining the management of t2 dm patients between 1998 and 1999 found family physicians were falling short of best practice guidelines , particularly in screening for microvascular disease , managing hypertension , hyperlipidemia , and prescribing antiplatelet medication . currently , family physicians ' performance levels in their regular patients in ontario are unknown
. this knowledge could help family physicians target certain areas of diabetes care , in service planning for the future .
the goals of this study were to examine a small group of actual family physicians ' management practices in following best practices and achieving targets in actual clinical care following on from the widespread dissemination of best practice documents , in the following areas : glycemic screening , control and management strategies , documentation and counselling for lifestyle habits , prevalence of comorbidities , screening for hypertension , hyperlipidemia , and use of appropriate recommended preventive medications ( see the appendix ) .
this paper describes the results of a detailed chart audit looking at diabetes care in the practices of 18 community - based family physicians in ontario .
we conducted a retrospective chart audit in a total of 18 family doctors ' offices in ontario as part of a study evaluating the effectiveness of a community - based diabetes risk - assessment program ( the results of which are described elsewhere ) .
the practices were predominantly fee - for - service and some primary care group practices with a mixture of fee - for - service and capitation .
practices provided lists of names of all patients who were rostered to each family physician and who were over the age of 40 , for invitation to the diabetes - risk assessments . from these , a number of charts of people with diagnosed diabetes were unintentionally randomly selected .
patients who had a previous diagnosis of diabetes prior to february 2004 were audited and information concerning routine care that they received between february 1st 2004 and february 1st 2000 extracted .
this care would have been received before the diabetes risk - assessment program started and thus would not have been affected by it .
the data extracted was based upon the most recent and relevant best practice guidelines [ 1 , 3 ] . where there were several readings , these were averaged for the whole year and the average reading
was considered in the analysis . where data were not available in the chart it was assumed those actions were not done and therefore missing .
physician demographic data ( gender , years in practice , and certificant status with the college of family physicians of canada ) and practice demographics were collected by a direct questionnaire to each physician .
it was estimated that for a sample size of approximately 100 , under the most conservative assumptions , the 95% confidence intervals could be calculated to the nearest + / 10% .
univariate analysis was performed to look at the proportions of patients who had certain clinical characteristics . to take into account clustering due to the potential similarities of patients attending a particular physician , the intracluster correlations ( iccs ) and
a total of 96 charts were audited , of people who had a diagnosis of diabetes recorded in their charts ( see table 3 for characteristics ) .
the sample consisted of 51% males , 1/3 employed , 38% retired and the mean age was 68 years old ( sd = 12.02 ) .
the mean number of years since diagnosis of diabetes was 8.8 and all patients had visited their family doctor at least once during the 1 year audit period .
patients were unevenly clustered between the family physicians , and numbers of patients with diabetes per physician ranged from one to eleven .
the average a1c reading in this group of patients was 7.07 ; mean a1c was within target ( 7.00 ) in 76% of patients ( icc = 0.02 ) ( table 4 ) .
ninety - six per cent of patients had one a1c reading during the 1-year audit ; 75% had four a1c readings in the year ( icc = 0.006 ) .
most ( 89% ) were on medication ; 42% on oral medication , about half just one oral agent ( 50% ) , a small proportion on insulin only ( 10% ) , and very small proportion on both types of agent ( 1% ) . in more than half of the charts exercise ( 57.3% ) and
diet ( 57.7% ) were mentioned as having been discussed , and a small number ( 15.5% ) had been referred to a dietician .
secondary data analysis shows that 17.8% of patients ( n = 16 , icc = 0 ) had an a1c less than or equal to 0.06% , and 32.2% ( n = 29 , icc = 0 ) had achieved an a1c of less than or equal to 0.07% and 50.0% ( n = 45 , icc = 0 ) had an a1c greater than 0.07% .
optimal control for those at risk of nephropathy ( < 0.065% ) was achieved in 27.5% , optimal control in general was achieved in 23.1% , and suboptimal control was achieved in 49% .
more than half of the patients had hypertension ( 59% ) a quarter had dyslipidemia ( 24% ) , and 15% had diabetes related complications ( table 5 ) .
nearly all patients had documentation of blood pressure readings ( 98% ) and lipid profiles ( 97% ) ( table 6 ) .
the mean bp reading was 134/74 mmhg and 31% ( icc = 0 ) met the target for systolic and 85% ( icc = 0 ) met the target for diastolic bp .
bmi could not be calculated for 40% ( icc = 0.094 ) ( table 7 ) . where bmi was recorded , 27% were obese and 20% were overweight ( icc = 0.132 ) .
one in 10 were current smokers ( 10.2% , icc = 0.433 ) and only 1% consumed alcohol heavily ( icc = 0.150 ) .
this study presents data from medical charts covering 18 different nonacademic practitioners in a small region of ontario . existing canadian - published data
concerned with management and control of diabetes in family practice concentrates on small numbers of practices [ 6 , 7 ] or has looked at recruiting charts of those who have attended the physician for checkups , and have not been randomly selected therefore may not be an accurate representation of the state of diabetes management in canada .
others use different time periods for audit of charts and different criteria for physician and patient recruitment , and focus on different locations [ 8 , 9 ] . in this study in the grimsby region
, family physicians were successfully monitoring a1c levels , and reaching targets in 3/4 of patients .
nearly 2/3 of patients had been counselled about diet in some form , more than 1/2 on exercise and nearly all ( 90% ) were on medication .
over half ( 60% ) had a record of their weight and/or bmi . in a previous and much larger canadian study , harris et al .
collected data from 16 practices , 55 physicians , 549 charts , and 10 charts per physician , located all over canada for one year from february 1st 1998 .
less patients had reached cda targets for a1c ( 40% less , with a1c target reached in 35% ) and fewer had their a1c readings recorded ( 25% less ) ; 25% more patients were on oral medication only ; nearly 20% less of the charts mentioned dietician counselling and nearly 30% less charts mentioned exercise ; 30% less charts had lipid profiles measured and the mean total cholesterol was higher ; there was more hypertension and hyperlipidemia .
these results suggest that the grimsby group of family physicians have been more successful in the care of their patients than those in the harris 's study conducted 7 - 8 years earlier
. this may be indicative of a wider change amongst family physicians and their behaviour in practice . a more recent study in newfoundland , canada ,
in 160 patients from 8 practices , showed that 48% had reached best practice guideline targets for a1c .
more patients were at target for systolic and diastolic bp readings , and the same percentage were documented as having hypertension , but more as having cerebrovascular and coronary artery disease .
it was not possible to compare medication , lifestyle and physician demographics since these were not reported .
when physicians were asked to estimate what proportion of patients were at targets for a1c , this group of practitioners overestimated their results by 20% .
forty percent were at target for systolic bp compared to 31% in grimsby and 42% for diastolic bp compared to 85% .
a large study in nijmegen , netherlands , looked at the progress of diabetes targets between 1993 and 1999 in a network of academic family practices that were informed of their own clinical practice using feedback from audits .
they concluded that over the 7-year period , a1c targets of < 7.0 mmol / l were met by 22% more patients , lipid targets by 20% more patients , and that 11% more met blood pressure targets .
another north american study compared attainment of targets in a cohort of 86 patients over a 4-year period in academic practices , from 1999 to 2003 and concluded that though a1c values improved , actual target attainment overall did not change . in our study ,
76% achieved a1c targets and extrapolating from harris 's data it is possible that an improvement from 35% to 76% was achieved for attainment for a1c targets over a 7 - 8-year period .
improvement of targets may partly be due to change in practice structure and feedback that has and is occurring .
a recent study across north america of 141 clinicians and 822 patients concluded that certain practice - based factors worsened a1c outcomes in patients ; for example patients in academic practices , in multispecialty practices or in solo practitioners ' practices had worse a1c outcomes ; whereas patients in practices having a nurse practitioner or physician assistant had improved a1c outcomes .
they point out that in primary care their sample of patients were complex with advanced disease and complications , and 40.5% achieved a1c levels of < 7
they recommend that diabetes registries , and specific clinical parameters for disease monitoring are required .
other evidence also shows that audit feedback can improve patient outcomes and target attainment [ 12 , 13 ] , and may result in more frequent monitoring of patients .
the audit presented here is an example of such an audit that can be easily set up and disseminated to practitioners or that they can set up themselves in an electronic medical record .
examining attainment of diabetes targets internationally , canadian practitioners ' achievement of 76% of patients at target for a1c compares favourably ; in estonia , a study of 200 patients in primary care showed 50% had achieved their targets a1c levels of < 7 mmol / l ; in singapore where care has been traditionally in endocrinology clinics but is being shifted to primary care , after this shift of care , more than 50% achieved their a1c targets in primary care compared to endocrinology clinics ; in belgium in 120 gp practices 54% achieved their a1c levels of < 7 mmol / l .
it should be mentioned that targets vary in countries , though as far as possible a target of < 7
also , in international situations , certain practice - based factors will be prevalent that can affect clinical care .
however , these global figures provide a crude estimate upon which to compare standards of care . in this data , reported iccs are consistent with the literature [ 18 , 19 ] with higher values for process issues and are thus more likely to reflect a particular practicing - style of a particular family doctor . though the icc values are small , they are positive , and have small confidence intervals , indicating that for certain variables such as mean fpg value ( icc = 0.16 ) , being on medication / insulin for glycemic control ( icc = 0.05 ) , on lipid lowering medication ( icc = 0.02 ) , numbers of readings for blood pressure ( icc = 0.06 ) , and dietician consultation having been sought ( icc = 0.08 ) , the specific physician to which the patient belonged would somewhat influence the patients ' values for these variables .
some icc values were zero or near zero , indicating that the physician a patient belonged to did not exert any influence on that variable .
remuneration methods of each practice could have affected the diabetes care offered in that practice . in capitated models of remuneration
there are incentives for reaching certain targets for patient care , but these do not exist in a fee - for - service model of care .
it was not possible to explore this effect in this data due to the small number of practices .
typical clinical practices of each physician with respect to diabetes care were not collected due to the small number of physicians ( n = 18 ) in the sample , though the area sampled had a mixture of mainly fee - for - service practices and a few groups paid on a capitated model .
limitations of this studythough the results may not be generalisable to practices from different areas , or directly to international figures , they will be comparable to those of similar demographic make - up . in 2001 ,
compared to ontario as a whole , the grimsby area population had less ethnic minorities , was more educated , and had a higher income . although diabetes care seems to be improving it is possible that this improvement is just regional ( not ontario - wide or canada - wide ) and specific to the grimsby area .
though the results may not be generalisable to practices from different areas , or directly to international figures , they will be comparable to those of similar demographic make - up . in 2001 , compared to ontario as a whole , the grimsby area population had less ethnic minorities , was more educated , and had a higher income .
although diabetes care seems to be improving it is possible that this improvement is just regional ( not ontario - wide or canada - wide ) and specific to the grimsby area .
. it may not be feasible to suppose that further improvements can be made to care and realistically , this may be as good as clinical care can get in primary care for diabetes .
comparison with international data seems to imply that there is global improvement in diabetes targets , with some geographical areas improving more than others .
, failure to intensify therapy appropriately and difficulty in keeping up to date with guidelines .
care can be improved by continuous audit and feedback to practitioners . however , despite these challenges , these results from this audit show that although there was room for improvement , diabetes targets were mainly being met according to the best practice guidelines in this sample of family doctors and this population .
. it may not be feasible to suppose that further improvements can be made to care and realistically , this may be as good as clinical care can get in primary care for diabetes .
comparison with international data seems to imply that there is global improvement in diabetes targets , with some geographical areas improving more than others .
failure to intensify therapy appropriately and difficulty in keeping up to date with guidelines .
care can be improved by continuous audit and feedback to practitioners . however , despite these challenges , these results from this audit show that although there was room for improvement , diabetes targets were mainly being met according to the best practice guidelines in this sample of family doctors and this population . | objective . diabetes care is an important part of family practice .
previous work indicates that diabetes management is variable .
this study aimed to examine diabetes care according to best practices in one part of ontario .
design and participants .
a retrospective chart audit of 96 charts from 18 physicians was conducted to examine charts regarding diabetes care during a one - year period . setting .
grimsby , ontario .
main outcome measures .
glycemic screening , control and management strategies , documentation and counselling for lifestyle habits , prevalence of comorbidities , screening for hypertension , hyperlipidemia , and use of appropriate recommended preventive medications in the charts were examined .
results .
mean a1c was within target ( less than or equal to 7.00 ) in 76% of patients ( icc = 0.02 ) , at least 4 readings per annum were taken in 75% of patients ( icc = 0.006 ) .
nearly 2/3 of patients had been counselled about diet , more than 1/2 on exercise , and nearly all ( 90% ) were on medication .
nearly all patients had a documented blood pressure reading and lipid profile .
over half ( 60% ) had a record of their weight and/or bmi . conclusion .
although room for improvement exists , diabetes targets were mainly reached according to recognized best practices , in keeping with international data on attainment of diabetes targets . |
subarachnoid hemorrhage ( sah ) resulting from rupture of intracranial aneurysms is a highly fatal condition with a mortality rate as high as 50% in the 1st month . although vasospasm was the main cause of mortality and morbidity after aneurysm rupture , the conscious-2 trial showed no significant effect of clazosentan , an endothelin receptor antagonist , on preventing vasospasm - related sequelae .
these disappointing results might indicate complex and uncertain pathophysiology of the cerebral vasospasm in patients with sah .
in addition to vasospasm , established predisposing factors for poor clinical outcome after aneurysmal sah include older age , female gender , hypertension , smoking , and larger amount sah on admission computed tomography ( ct ) .
in addition , manifestation of both local and systemic inflammation has been shown to associate with worse clinical outcome .
cyclophilin a ( cypa ) , a specific secreted oxidative stress - induced factor , is ubiquitously distributed and abundantly expressed in vascular smooth muscle cells .
in addition to multiple intracellular functions , such as immunophilins and components of the cell cycle , cypa has extracellular roles in inflammatory diseases such as rheumatoid arthritis and atherosclerosis .
the characteristic pathological features of an aneurysm are intense oxidative stress , inflammation , and apoptosis of smooth muscle cells . in an animal study of abdominal aortic aneurysm ,
satoh et al showed that intracellular and extracellular cypa , derived from vascular smooth muscle cells , plays an important role in the formation of an aneurysm .
furthermore , piechota - polanczyk et al found decreased tissue levels of cypa in simvastatin - treated patients with abdominal aortic aneurysm .
however , to our knowledge , the clinical implication of cypa in ruptured intracranial aneurysmal microenvironment has not been investigated .
the purpose of our study was to investigate the associations between the neurological outcome and cypa levels , measured both at the orifice of ruptured saccular intracranial aneurysm and in the remote peripheral vein .
our hypothesis was that manifestation of high plasma cypa is a prognostic biomarker for worsening clinical course .
the approval from the institutional ethics review board of changhua christian hospital , changhua , taiwan was received for this study , which was performed in compliance with the helsinki declaration .
the patients or next of kin gave written informed consent for participation . from 2011 to 2013 , patients with the diagnosis of ruptured saccular intracranial aneurysms were prospectively recruited and treated with endovascular embolization .
the exclusion criteria included histories of brain tumor , head trauma , ischemic stroke , or hematological disorders .
we documented a battery of confounding risk factors associated with aneurysm rupture , including age , gender , smoking , as well as histories of hypertension and diabetes mellitus .
the clinical severity of sah was evaluated by a neurologist ( csl , 18 years of clinical experience in neurology ) with the glasgow coma scale and modified rankin scale on admission ( day 0 ) and day 30 recorded , respectively .
noncontrast ct and ct angiography of the brain were performed with a dual source ct system ( somatom definition flash , siemens healthcare , forchheim , germany ) with standardized protocols for all patients .
the ct an giography was performed with antecubital injection of nonionic contrast material ( ultravist 370 , bayer - schering healthcare , berlin , germany ) at flow rate of 4 ml / second using a power injector and the following scanning parameters : 132 mas at 100 and 140 kv , rotation time 0.33 seconds , pitch 0.9 , and slice acquisition 64 0.6 mm .
images were reconstructed with a slice thickness of 0.75 mm each 0.5 mm with a 512 512 matrix and individually adapted the field of view ( 130150 mm ) .
the delay between the injection of contrast and the start of the scan was set to 40 seconds .
the source images of ct angiography were then transferred to a stand - alone workstation ( wizard , siemens , forchheim , germany ) and reconstructed with the volume rendering method .
an interventional neuroradiologist ( kwl , 18 years of clinical experience in neurointerventions ) weighed the fisher grade on the noncontrast brain ct images .
a culprit aneurysm was determined based on the sah distribution and aneurysm location found on ct angiograms .
we performed a focused 3-dimensional rotational digital subtraction angiography of every culprit aneurysm identified on the ct images with an axiom artis zee biplane ( siemens medical solution , erlangen , germany ) neuroradiologic angiography system . the standard endovascular procedures and adjunctive therapies
in addition to recording the aneurysmal location , number , size , and morphology , the neuroradiologist gauged the vasospasm grade , on a scale of 0 to 4 . for each patient , blood samples were drawn from a microcatheter at the orifice of the ruptured culprit intracranial aneurysm and in a remote peripheral vein .
we used commercially available enzyme - linked immunosorbent assay kits ( uscn life science , wuhan , china ) to gauge the aneurysmal and venous cypa levels .
we dichotomized the day-0 glasgow coma scale scores at 13 and the day-30 modified rankin scale score at 3 .
the fisher and vasospasm grades of 3 or higher were categorized as high - grade abnormalities . mann
whitney u and fisher exact tests were used to exam the differences between groups for the continuous and categorical variables , respectively .
the pearson chi - squared test was used to assess the difference of dichotomous clinical severities among patients with different locations of the culprit aneurysm .
the correlations between the plasma level of aneurysmal cypa and the confounding factors were evaluated with the spearman rank correlation coefficients .
optimal cutoff values for the plasma cypa levels within 3 days after aneurysm rupture to predict the neurological outcome on day 30 were determined by constructing the receiver operating characteristic curves .
generalized linear models were used to estimate the association between the high cypa levels and dichotomous 30-day outcome after adjusting for potential confounding factors , including age , gender , hypertension , smoking , multiple aneurysms , aneurysm size , vasospasm , and fisher grades .
ibm spss statistics ( version 20 ; ibm corp . , armonk , ny ) and medcalc ( version 14.10.2 ; medcalc software , mariakerke , belgium ) were used for the statistical analyses .
the approval from the institutional ethics review board of changhua christian hospital , changhua , taiwan was received for this study , which was performed in compliance with the helsinki declaration .
the patients or next of kin gave written informed consent for participation . from 2011 to 2013 , patients with the diagnosis of ruptured saccular intracranial aneurysms were prospectively recruited and treated with endovascular embolization .
the exclusion criteria included histories of brain tumor , head trauma , ischemic stroke , or hematological disorders .
we documented a battery of confounding risk factors associated with aneurysm rupture , including age , gender , smoking , as well as histories of hypertension and diabetes mellitus .
the clinical severity of sah was evaluated by a neurologist ( csl , 18 years of clinical experience in neurology ) with the glasgow coma scale and modified rankin scale on admission ( day 0 ) and day 30 recorded , respectively .
noncontrast ct and ct angiography of the brain were performed with a dual source ct system ( somatom definition flash , siemens healthcare , forchheim , germany ) with standardized protocols for all patients .
the ct an giography was performed with antecubital injection of nonionic contrast material ( ultravist 370 , bayer - schering healthcare , berlin , germany ) at flow rate of 4 ml / second using a power injector and the following scanning parameters : 132 mas at 100 and 140 kv , rotation time 0.33 seconds , pitch 0.9 , and slice acquisition 64 0.6 mm .
images were reconstructed with a slice thickness of 0.75 mm each 0.5 mm with a 512 512 matrix and individually adapted the field of view ( 130150 mm ) .
the delay between the injection of contrast and the start of the scan was set to 40 seconds .
the source images of ct angiography were then transferred to a stand - alone workstation ( wizard , siemens , forchheim , germany ) and reconstructed with the volume rendering method .
an interventional neuroradiologist ( kwl , 18 years of clinical experience in neurointerventions ) weighed the fisher grade on the noncontrast brain ct images .
a culprit aneurysm was determined based on the sah distribution and aneurysm location found on ct angiograms .
we performed a focused 3-dimensional rotational digital subtraction angiography of every culprit aneurysm identified on the ct images with an axiom artis zee biplane ( siemens medical solution , erlangen , germany ) neuroradiologic angiography system .
in addition to recording the aneurysmal location , number , size , and morphology , the neuroradiologist gauged the vasospasm grade , on a scale of 0 to 4 . for each patient , blood samples were drawn from a microcatheter at the orifice of the ruptured culprit intracranial aneurysm and in a remote peripheral vein .
we used commercially available enzyme - linked immunosorbent assay kits ( uscn life science , wuhan , china ) to gauge the aneurysmal and venous cypa levels .
we dichotomized the day-0 glasgow coma scale scores at 13 and the day-30 modified rankin scale score at 3 .
the fisher and vasospasm grades of 3 or higher were categorized as high - grade abnormalities . mann
whitney u and fisher exact tests were used to exam the differences between groups for the continuous and categorical variables , respectively .
the pearson chi - squared test was used to assess the difference of dichotomous clinical severities among patients with different locations of the culprit aneurysm .
the correlations between the plasma level of aneurysmal cypa and the confounding factors were evaluated with the spearman rank correlation coefficients .
optimal cutoff values for the plasma cypa levels within 3 days after aneurysm rupture to predict the neurological outcome on day 30 were determined by constructing the receiver operating characteristic curves .
generalized linear models were used to estimate the association between the high cypa levels and dichotomous 30-day outcome after adjusting for potential confounding factors , including age , gender , hypertension , smoking , multiple aneurysms , aneurysm size , vasospasm , and fisher grades .
ibm spss statistics ( version 20 ; ibm corp . , armonk , ny ) and medcalc ( version 14.10.2 ; medcalc software , mariakerke , belgium ) were used for the statistical analyses .
a total of 39 consecutive patients with ruptured saccular intracranial aneurysm underwent endovascular treatments in our neuroangiography suite . excluding 3 patients ( 7.7% ) due to inadequate blood sampling , we included 36 patients with 39 aneurysms found . among the 36 patients , the mean age was 55 years ( range 3282 ) and 52.8% were female .
we secured all the ruptured intracranial aneurysms with platinum detachable coils within 1 day after admission .
the ruptured aneurysms occurred most commonly in the anterior and posterior communicating arteries ( 14 and 13 patients , 53.8% and 50.0% , respectively ) .
the less common locations were middle cerebral artery , internal carotid artery , and vertebral artery ( 4 , 3 , and 2 patients , 11.1% , 8.3% , and 5.5% , respectively ) .
patients with different locations of the ruptured aneurysm did not show significant different dichotomous clinical severities on admission and day 30 ( p = 0.13 and 0.12 , respectively ) .
the ruptured intracranial aneurysms were generally small ( median 5 mm ; range 218 ) .
the median plasma cypa levels were 62.5 ng / ml ( range 26.0147.0 ) and 77.1 ng / ml ( range 15.7182.0 ) at the orifices of the ruptured aneurysms and in the remote peripheral veins , respectively .
the manifestation of higher aneurysmal and venous cypa levels were significantly associated with worse initial clinical severity ( p = 0.004 and 0.03 , respectively ) and 30-day outcome ( p = 0.01 and 0.02 , respectively ) . in the univariate analyses ,
the poor 30-day outcome was also significantly associated with high vasospasm grade and marginally associated with older age .
table 2 demonstrates a strong correlation between the aneurysmal cypa level and the venous counterpart ( = 0.89 ; p <
0.001 ) as well as a moderate correlation between the aneurysmal cypa level and age and high fisher grade ( = 0.39 and 0.41 ; p = 0.02 and 0.01 , respectively ) .
patient characteristics correlations between aneurysmal cyclophilin a ( cypa ) level and other variables receiver operating characteristic analyses showed cutoff values of 69.0 ng / ml ( sensitivity 61.9% ; specificity 86.7% ; p = 0.002 ) and 85.8 ng / ml ( sensitivity 52.4% ; specificity 93.3% ; p = 0.007 ) for the aneurysmal and venous cypa levels , respectively , to predict poor 30-day outcome . in a generalized linear model ,
patients with high levels of aneurysmal cypa were 15.66 times ( 95% confidence interval , 1.48166.24 ; p
= 0.02 ) more likely to have worse 30-day neurological outcome than those with the low levels after adjustment of the age , gender , and other confounding factors ( table 3 ) .
we discovered the association between high plasma levels of cypa measured within 3 days after aneurysm rupture and worse 30-day neurological outcome .
the aneurysmal cypa levels showed a strong correlation with the corresponding venous cypa levels while the venous levels were significantly higher than the aneurysmal counterpart .
the mechanisms involving the aneurysm formation and rupture include chronic inflammation and progressive destruction of the arterial wall , associated with premature senescence of vascular smooth muscle cells , oxidative stress , and increased local production of proinflammatory cytokines . in an animal study , jin et al found that cypa is secreted by vascular smooth muscle cells in response to reactive oxygen species , which feature cardiovascular disease states .
satoh et al demonstrated that the formation of abdominal aortic aneurysm in the angiotensin ii - induced apoe mice model can be completely prevented against a cypa background .
furthermore , cypa was found to associate with susceptibility of structural components of the aortic wall to aortic dissection in a mouse model .
these findings approve the role of cypa in the formation of an abdominal aortic aneurysm .
however , the clinical implication of high cypa level in the microenvironment of intracranial aneurysms has not been investigated in the english literature .
our results were the first to reveal the prognostic role of cypa in patients with ruptured intracranial aneurysm .
in our study , the plasma level of cypa was positively associated with age , a finding consistent with the results in a cohort of patients with diabetes mellitus and in a cohort with coronary artery disease . furthermore
, cypa expression was found significantly higher in elderly rats than in young ones . although not measured with the same laboratory testing kit nor in the same patient age group , the plasma level of cypa ( median 77.1 ng / ml ) in our patients ( mean age 55 years ) with ruptured intracranial aneurysm was apparently higher than the levels in the cohort of coronary artery disease ( 4th quartile cypa 17.550.9 ng / ml ; median age 68 years ) .
in addition , we found that patients with high fisher grades had higher plasma level of cypa than those with low grades .
these findings may suggest an elevation of plasma cypa after sah although our patients were not recruited before rupture of the aneurysm and the baseline cypa levels were not available .
histologically , ruptured intracranial aneurysms manifest significant endothelial damage and inflammatory cell invasion , which may exist before aneurysm rupture .
hence , the accumulation of plasma cypa may be explained by increased excretion from activated inflammatory cells , such as diseased vascular smooth muscle cells , macrophage , and lymphocyte , either in the aneurysmal lumen or in the subarachnoid space . in our results ,
although it is conceivable to measure higher plasma levels of cypa in patients with larger intracranial aneurysms , the association was not evident in our patient group .
the mismatch might be contributed partly by the small aneurysm sizes in our patients and partly by the overwhelming inflammatory reaction in the relative large subarachnoid space . as a result
, the plasma cypa levels might more likely reflect the local and systemic inflammation than the aneurysm size .
this study 's main strength was the simultaneous measurements of the plasma level of cypa at the orifice of the ruptured saccular aneurysm and the venous counterpart to reveal the association between the inflammatory biomarker in the early phase of aneurysm rupture and neurological outcome .
first , the patients in our study were relatively small in number , and the results were from a single medical center .
second , we excluded patients undergoing surgical clipping in order to eliminate a variety of surgical confounding factors .
third , we measured the plasma cypa levels once within 3 days after aneurysm rupture and targeted to find early biomarkers to predict clinical course .
furthermore , we did not routinely assess imaging dynamics of the vasospasm and associated delayed cerebral ischemia .
however , a large series showed that the occurrence of delayed cerebral ischemia does not contribute to worse outcomes . in conclusion
, the early manifestation of focal and systemic inflammation , reflected by plasma cypa levels , is associated with poor neurological outcome in patients with ruptured intracranial aneurysm .
the result delineates a prognostic role for cypa in the ruptured intracranial aneurysm and suggests cypa as a potential target in treating aneurysmal sah . | abstractcyclophilin a ( cypa ) , an oxidative stress - induced factor , was found to play an important role in the aneurysm formation .
our working hypothesis was that the plasma level of cypa in ruptured intracranial aneurysm could predict the neurological outcome.from 2011 to 2013 , a total of 36 patients with ruptured saccular intracranial aneurysm were recruited in our study . before coil embolization , we draw blood samples at the orifice of a culprit aneurysm and in the remote peripheral vein for measurements of the cypa levels .
we utilized the modified rankin scale 30 days after aneurysm rupture as the outcome measure .
generalized linear models were used to estimate the adjusted odds ratios of the poor neurological outcome given the presence of high plasma level of cypa.the aneurysmal and venous cypa levels were significantly associated with the initial clinical severity ( p = 0.004 and 0.03 , respectively ) and 30-day outcome ( p = 0.01 and 0.02 , respectively ) .
the aneurysmal cypa levels modestly correlated with age and high fisher grade ( = 0.39 and 0.41 ; p = 0.02 and 0.01 , respectively ) . the aneurysmal cypa levels strongly correlated with the venous counterpart ( = 0.89 ; p < 0.001 ) .
patients with high levels of aneurysmal cypa were 15.66 times ( 95% ci , 1.48166.24 ; p
= 0.02 ) more likely to have worse neurological outcome than those with the low levels after adjustment of the age , gender , and the documented confounding factors.high plasma level of cypa is a significant prognostic biomarker for poor neurological outcome in patients with ruptured intracranial aneurysm . |
more than 80% occur in the submandibular gland or its duct , probably because of its more viscous saliva , longer duct , and higher mineral content in the saliva , 4 - 10% have been reported in the parotid gland and 1 - 7% in the sublingual gland or minor salivary glands .
the etiological factors of the sialoliths are unknown , but inflammation is the widely accepted causative condition .
hypotheses regarding the pathogenesis suggest that , there is an initial organic nidus which progressively grows by the deposition of inorganic and organic substances or that intracellular microcalculi are excreted in the canal and act as a nidus for further calcification . in some cases , the existence of mucosal plugs acting as a nidus in the ductal system was reported . a possibility of debris , bacteria or substances migrating in the salivary ducts from oral cavity has also been suggested .
bilateral or multiple - gland sialolithiasis occurs in fewer than 3% of cases . in patients with multiple stones
submandibular stones close to the hilum of the gland tend to become large before they become symptomatic .
giant salivary gland stones are those stones measuring over 1.5 cm and have been rarely reported in the medical literature .
giant salivary gland stones measuring over 3 cm are extremely rare , with only scanty reported cases .
although , sialolith may occur at any age from 6 up to 70 years old but , most cases occurs under the age of 40 years .
a 51 year old male patient reported to the department of oral medicine and radiology with complaint of pain and swelling on left side of floor of the mouth .
patient noticed the swelling for past three months , pain aggravated while eating . the tongue was slightly elevated . on clinical examination
a hard mass was palpable on the floor of the mouth on left side with a small ulceration towards midline . through the ulceration a yellowish white stone like material was seen [ figure 1 ] .
on radiographic examination occlusalview revealed radio - opaque mass in relation to mandibular left canine and premolars [ figures 2a and b ] .
the size of the stone was approximately 15 mm and it was fragmented [ figure 3 ] .
the patency of the duct was maintained by inserting a drain and area was sutured .
the patient was followed - up two weeks post operatively to check salivary function of the gland . on review
the left submandibular gland was palpable but clear saliva could be expressed from the duct .
sialolith visible on the left side of floor of the mouth ( a , b ) opg and mandibular anterior occlusa l view showing radio opaque sialolith in the region of mandibular left canine and premolar surgically extracted sialolith a 40 year old male patient reported to the department of oral medicine and radiology with complaint of ulceration on the floor of the mouth left side [ figure 4 ] .
patient also reported with a stone like thing in his hand which exfoliated from the ulcerated area that morning .
patient had history of pain and swelling one year back which relieved on taking analgesics .
the pain again started after 10 days on the left side of floor of the mouth .
this was gradual in onset and increased on taking meal and relieved on taking analgesic . on clinical examination the ulceration was seen on the left side of the floor of the mouth of size approximately 2 cm [ figure 5 ] .
a 51 year old male patient reported to the department of oral medicine and radiology with complaint of pain and swelling on left side of floor of the mouth .
patient noticed the swelling for past three months , pain aggravated while eating . the tongue was slightly elevated . on clinical examination
a hard mass was palpable on the floor of the mouth on left side with a small ulceration towards midline . through the ulceration a yellowish white stone like material was seen [ figure 1 ] .
on radiographic examination occlusalview revealed radio - opaque mass in relation to mandibular left canine and premolars [ figures 2a and b ] .
the size of the stone was approximately 15 mm and it was fragmented [ figure 3 ] .
the patency of the duct was maintained by inserting a drain and area was sutured .
the patient was followed - up two weeks post operatively to check salivary function of the gland . on review
the left submandibular gland was palpable but clear saliva could be expressed from the duct .
sialolith visible on the left side of floor of the mouth ( a , b ) opg and mandibular anterior occlusa l view showing radio opaque sialolith in the region of mandibular left canine and premolar surgically extracted sialolith
a 40 year old male patient reported to the department of oral medicine and radiology with complaint of ulceration on the floor of the mouth left side [ figure 4 ] .
patient also reported with a stone like thing in his hand which exfoliated from the ulcerated area that morning .
patient had history of pain and swelling one year back which relieved on taking analgesics .
the pain again started after 10 days on the left side of floor of the mouth .
this was gradual in onset and increased on taking meal and relieved on taking analgesic . on clinical examination the ulceration was seen on the left side of the floor of the mouth of size approximately 2 cm [ figure 5 ] .
salivary calculi are usually small and measure from 1 mm to less than 1 cm .
giant sialoliths are rare and are defined as the size of 3.5 cm or larger .
large and giant calculi may perforate the floor of the mouth by ulcerating the duct or may result in a skin fistula by causing a suppurative infection .
however , large sialoliths have been frequently reported in the body of salivary glands , they have rarely been described in the salivary ducts , particularly without any complaints from the patients .
some unusual large salivary calculi may be seen without a long history , because of the lesions were generally asymptomatic .
it is believed that a calculus may enlarge at the rate of approximately 1 to 1.5 mm per year .
the key step in diagnosis of sialolithiasis is the elucidation of a thorough history and careful clinical examination .
submandibular gland calculi have been reported to be radio opaque in 80% to 94.7% of cases . in the anterior floor of the mouth
sialoendoscopic system was developed in the 1990 's as an endoscopic technique , which examine the ductal system completely due to the small size of scopes .
, clinical and radiological features of two large sialoliths which were in the size of 1.8 and 2.1 centimeters were presented .
they were located in wharton 's ducts and the patients complained of pain and occasional swellings . in both cases
the treatment of sialolithiasis depends upon the location and size of thesialolith . in case of small sialoliths ,
conservative methods such as proper hydration of the patient , application of moist warm heat and massaging the gland in conjunction with sialogogues may be considered .
sialodochoplasty can be performed to remove the submandibular sialoliths which are located close to the orifice of wharton 's duct . to remove the stones distal to the punctum
, a transverse incision can be made distally on the stone taking care not to injure the lingual nerve . in the management of large sialoliths which are located in the close proximal duct , extracorporeal shock wave lithotripsy can be considered .
endoscopic intracorporeal shock wave lithotripsy is also gaining importance because of less damage to the adjacent tissues during the procedure .
sialadenoscopy , which is a non - invasive technique , can be used to manage large sialolithsas well as ductal obliteration .
co2 laser , because of its advantages of minimal bleeding , less scarring , clear vision and minimal post - operative complications , is gaining its popularity in the treatment of sialolithiasis . | sialoliths are the most common diseases of the salivary glands
. they may occur in any of the salivary gland ducts but are most common in wharton 's duct and the submandibular gland .
this report presents clinical and radio graphical signs of two unusually large sialoliths which exfoliated by itself .
there were painless swellings on the floor of the mouth in both cases .
radiographical examination revealed large irregular radioopaque mass superimposed right canine and premolar areas .
sialoliths were yellow in color and approximately 1.8 cm and 2.1 cm in size . |
the action plan of the world health organization ( who ) for prevention and control of non - communicable diseases ( ncds ) in 2013 - 2020 has aimed a 25% relative reduction in the prevalence of hbp .
in addition to the effects of fetal programming , several factors determine the blood pressure ( bp ) level in childhood , which is associated with the adult bp level through the tracking phenomenon .
hence , the prevention of ncds , namely cardiovascular diseases in adulthood should begin from childhood .
in addition , hbp in childhood may induce target organ damages , such as left ventricular hypertrophy , thickening of the carotid vessel wall , retinal vascular changes , subtle cognitive changes , and even premature development of atherosclerosis .
prevalence of hbp is increasing in the pediatric population in accordance with the childhood obesity epidemic and life - style widespread changes .
alarming data exist on the considerable prevalence of childhood overweight and its metabolic consequences , not only in industrialized countries , but also in developing countries .
the strong relationship of even early stages of hbp ( pre - hypertension [ htn ] , pre htn ) with obesity and environmental factors , as air pollution , noise pollution and passive smoking suggest that its prevalence will be escalating . in the transitional state communities with rapid urbanization ,
most risk factors identified for pediatric hbp are modifiable by life - style change , moreover monitoring of their time - trend is of significant importance .
ncds have a remarkable prevalence among iranian adults , and the risk factors of ncds are quite prevalent in iranian children and adolescents .
high systolic blood pressure ( sbp ) has been recognized responsible for most deaths in all regions of iran .
limited experience exists on evaluating ncds risk factors such as hbp in iranian pediatric population at national level . considering the aforementioned importance of pediatric health status and inspired by who recommendations ,
a national ongoing school based surveillance system for health risk and protective factors named childhood and adolescence surveillance and prevention of adult non - communicable diseases ( caspian ) study was established in iran .
the current study aims to determine the bp mean and percentiles , as well as and the prevalence of hbp in a nationally representative sample of iranian children and adolescents .
we have previously described the methods of the 4 phase in details , and here we present it in brief .
caspian - iv study is a national cross - sectional survey conducted during the year 2011 - 2012 in 30 provinces of iran .
the study population comprised of 19 to 18-year old school students equally from both genders .
a total sample size of 14,880 was determined to cover all study objectives and then was divided proportionally to population size of urban and rural areas and equally in three educational levels ( elementary , intermediate and high school ) .
clusters were the individual schools and it was scheduled to obtain 10 sampling units ( students with their parents ) in each of 48 randomly selected schools for every province .
the students questionnaires were based on the who global school - based student health survey ( gshs ) program by adding some questions .
these scales are comprehensive and can assess many different aspects of students health as demographic data , diet , physical activity , smoking , violence and other risky behaviors , medical history , family characteristics , relation with parents and peers , etc . ,
supervision on the whole project was considered by principal investigators at national and sub - national levels .
anthropometric measures consisting height , weight , hip , waist and wrist circumferences were measured according to the standard protocols .
then , body mass index , waist to hip and waist to height ratios were calculated .
bp was measured by expert health care professionals using standardized and calibrated mercury sphygmomanometers in a sitting position from the right arm . with the zero point of manometer at the level of the student 's hearth ,
appropriate size cuffs were used considering cuff bladders covering 80 - 100% of the arm circumference and approximately two - thirds of the length of the upper arm without overlapping .
after enough rest for the subject to calm down , bp readings were taken twice for each person with 5 min interval .
the readings at the first korotkoff sound were considered as the sbp and at the fifth sound as the diastolic blood pressure ( dbp ) .
pre htn was considered as bp equal or greater than the age- and gender - specific 90 percentile after adjusting for weight and height or bp equal or more than 120/80 mmhg according to the fourth report of the working group ( formerly task force ) on blood pressure control in children , commissioned by the national heart , lung and blood institute of the national institutes of health of america .
when bp was equal or over the age- and gender - specific 95 percentile value , it was considered as htn .
the study was approved by national and discrete regulatory organizations of the ministry of education and institutional ethical and scientific review boards .
clear explanation of the study aims and methods anteceded taking written informed consent from parents and verbal assent from students .
the project was completely free of charge for all participants statistical analysis was performed using survey data analysis methods by the stata software : statacorp .
mean and standard deviations ( sd ) with 95% confidence intervals ( cis ) were calculated . for nominal or categorical variables , frequencies and prevalence rates with the same ci were recorded .
student t - test and chi - square tests were used for comparing that data between relevant groups , where applicable .
we have previously described the methods of the 4 phase in details , and here we present it in brief .
caspian - iv study is a national cross - sectional survey conducted during the year 2011 - 2012 in 30 provinces of iran .
the study population comprised of 19 to 18-year old school students equally from both genders .
a total sample size of 14,880 was determined to cover all study objectives and then was divided proportionally to population size of urban and rural areas and equally in three educational levels ( elementary , intermediate and high school ) .
clusters were the individual schools and it was scheduled to obtain 10 sampling units ( students with their parents ) in each of 48 randomly selected schools for every province .
the students questionnaires were based on the who global school - based student health survey ( gshs ) program by adding some questions .
these scales are comprehensive and can assess many different aspects of students health as demographic data , diet , physical activity , smoking , violence and other risky behaviors , medical history , family characteristics , relation with parents and peers , etc . ,
supervision on the whole project was considered by principal investigators at national and sub - national levels .
anthropometric measures consisting height , weight , hip , waist and wrist circumferences were measured according to the standard protocols . then , body mass index , waist to hip and waist to height ratios were calculated .
bp was measured by expert health care professionals using standardized and calibrated mercury sphygmomanometers in a sitting position from the right arm . with the zero point of manometer at the level of the student 's hearth ,
appropriate size cuffs were used considering cuff bladders covering 80 - 100% of the arm circumference and approximately two - thirds of the length of the upper arm without overlapping .
after enough rest for the subject to calm down , bp readings were taken twice for each person with 5 min interval .
the readings at the first korotkoff sound were considered as the sbp and at the fifth sound as the diastolic blood pressure ( dbp ) .
pre htn was considered as bp equal or greater than the age- and gender - specific 90 percentile after adjusting for weight and height or bp equal or more than 120/80 mmhg according to the fourth report of the working group ( formerly task force ) on blood pressure control in children , commissioned by the national heart , lung and blood institute of the national institutes of health of america .
when bp was equal or over the age- and gender - specific 95 percentile value , it was considered as htn .
the study was approved by national and discrete regulatory organizations of the ministry of education and institutional ethical and scientific review boards .
clear explanation of the study aims and methods anteceded taking written informed consent from parents and verbal assent from students .
the students questionnaires were based on the who global school - based student health survey ( gshs ) program by adding some questions .
these scales are comprehensive and can assess many different aspects of students health as demographic data , diet , physical activity , smoking , violence and other risky behaviors , medical history , family characteristics , relation with parents and peers , etc . ,
supervision on the whole project was considered by principal investigators at national and sub - national levels .
anthropometric measures consisting height , weight , hip , waist and wrist circumferences were measured according to the standard protocols . then , body mass index , waist to hip and waist to height ratios were calculated .
bp was measured by expert health care professionals using standardized and calibrated mercury sphygmomanometers in a sitting position from the right arm . with the zero point of manometer at the level of the student 's hearth ,
appropriate size cuffs were used considering cuff bladders covering 80 - 100% of the arm circumference and approximately two - thirds of the length of the upper arm without overlapping .
after enough rest for the subject to calm down , bp readings were taken twice for each person with 5 min interval .
the readings at the first korotkoff sound were considered as the sbp and at the fifth sound as the diastolic blood pressure ( dbp ) .
pre htn was considered as bp equal or greater than the age- and gender - specific 90 percentile after adjusting for weight and height or bp equal or more than 120/80 mmhg according to the fourth report of the working group ( formerly task force ) on blood pressure control in children , commissioned by the national heart , lung and blood institute of the national institutes of health of america .
when bp was equal or over the age- and gender - specific 95 percentile value , it was considered as htn .
the study was approved by national and discrete regulatory organizations of the ministry of education and institutional ethical and scientific review boards .
clear explanation of the study aims and methods anteceded taking written informed consent from parents and verbal assent from students .
statistical analysis was performed using survey data analysis methods by the stata software : statacorp .
mean and standard deviations ( sd ) with 95% confidence intervals ( cis ) were calculated . for nominal or categorical variables , frequencies and prevalence rates with the same ci were recorded .
student t - test and chi - square tests were used for comparing that data between relevant groups , where applicable . missing data were not included in the analyses .
overall , 13486 out of 14880 invited students with a response rate of 90.6% participated in the study .
participants consisted of 6640 girls ( 49.2% ) and 6846 boys ( 50.8% ) with one of their parents , 75.6% from urban areas .
nearly 46%of them were elementary school , 25.9% intermediate school and 28.1% high school students .
mean ( sd ) age of participants was 11.47 ( 3.36 ) years , without significant difference between boys ( 12.36 [ 3.39 ] years ) and girls ( 12.58 [ 3.32 ] years ) . as you can be seen in table 1 , the mean ( sd ) sbp of all participants was 101.52 ( 13.46 ) mmhg and their mean dbp was 64.88 ( 11.41 ) mmhg .
blood pressure and anthropometric measures of participants : the caspian - iv study overall , the prevalence rate ( 95% ci ) of pre htn was 3.25% ( 2.79 - 3.8 ) for sbp ( in 13367 measures ) , 1.25% ( 0.98 - 1.6 ) for dbp ( in 13349 measures ) and 3.13% ( 2.71 - 3.62 ) for sbp and/or dbp ( in 13350 measures ) .
the corresponding figures for htn were 0.92% ( 0.73 - 1.16 ) , 3.08% ( 2.58 - 3.67 ) and 3.75% ( 3.21 - 4.36 ) , respectively .
these together yield a total rate of 4.17% ( 3.84 - 4.52 ) for elevated sbp , 4.33% ( 3.99 - 4.68 ) for elevated dbp and 6.88% ( 6.45 - 7.32 ) for elevated sbp and/or dbp .
as shown in table 2 , chi - square test showed that the prevalence rates of pre htn and htn were different in terms of gender and were significantly higher in boys than in girls .
prevalence of different categories of blood pressure according to gender : the caspian - iv study the prevalence rates of elevated levels of sbp and sbp and/or dbp were significantly higher in urban than in rural residents too [ table 3 ] .
prevalence of different categories of blood pressure according to the living area : the caspian - iv study
the current nationwide survey revealed a substantially high prevalence rate for hbp among iranian children and adolescents . by considering the additive prevalence of pre htn and htn ,
the prevalence rate of high sbp and/or dbp was 6.88% ; and isolated high sbp and dbp were documented in 4.17% and 4.33% of participants , respectively . in the previous phase of this nationwide study , 5.35% of children and adolescents had bp levels equal or more than the 90 percentile values .
the increased rate in the current phase of this study may be attributable to unhealthy life - style and nutritional patterns and low physical activity levels in the pediatric age group .
other studies about hbp in iranian children and adolescents have been conducted in some cities and no other nationwide study has been performed on pediatric cardio - metabolic risk factors .
a series of nationwide studies conducted among iranian adult population , entitled the survey of risk factors of ncds included individuals with 15 - 65 years of age .
their results are reported in 10 years age groups , e.g. , 15 - 24 year - old group and according to adults definitions , therefore their results are not comparable with the caspian studies . by considering the cut point 95 percentile to define htn , the prevalence of htn would be expected to be around 5% and in fact 1 - 3% following the recommended three separate measurements in children with an initial bp measurement 95 percentile .
for instance , the prevalence of systolic and diastolic hypertension in sousse , tunisia , was reported as 6.4% and 4.5% , respectively .
in germany , the prevalence of hbp was 13% according to national standard curves and 2% according to the definition proposed by the international diabetes federation for metabolic syndrome . in portugal ,
pediatric htn had prevalence of 2 - 5% . in adolescents of texas , united states of america ( usa ) ,
the prevalence rates of htn and pre htn are reported as 3.2% and 15.7% , respectively . in another study in the usa , a remarkable proportion of youths ( 6.9% ) had htn or nearly met its definition .
two other studies in usa reported different prevalence rates , in one of them , 12.7% of youths had pre htn and 5.4% had htn , whereas in another study , these rates were 3.4% and 3.6% , respectively .
these differences between studies can be explained by racial , ethnic and genetic issues , different socio - economic states , environmental circumstances , as well as dietary and physical activity habits of participants . in the current study ,
significant gender difference was documented in the frequency distribution of hbp , with higher prevalence rates of pre htn and htn in boys than in girls .
this finding is consistent with a longitudinal study that showed the risk of developing persistent htn is higher in boys than it is for girls .
however , in the previous survey of the caspian study , the prevalence of hbp was higher in girls than in boys .
another survey did not detect any difference in terms of gender for the prevalence of hbp in the pediatric age group .
the gender differences documented in some studies may be explained by various factors as pubertal status , as well as physical activity and dietary patterns . in the current study ,
elevated sbp and elevated sbp and/or dbp were more prevalent in urban than in rural residents .
some studies in other populations have reported conflicting results in this regard . in a study in india , the prevalence rates of pre htn and htn were 2.9% and 2.8% in urban children and 2.8% and 2% in rural children , without statistically significant difference between them .
likewise , in another region of india , 5.9% of children had htn and 12.3% had pre htn , with comparable rates of elevated bp in urban and rural areas .
contrary to their findings , in ghana , rural children showed lower rates of htn than urban children .
in contrast , in a study in children living in the rural area of alabama , usa , the prevalence rates of pre - htn and htn were 6.7% and 14.9% , respectively , which shows much higher rates than our study .
lower rates of hbp in rural residents is probably due to a better life - style including healthier dietary and physical activity habits and lower mental stress and pollutants levels in rural than in urban areas .
it must be remembered that the definition of hbp in the pediatric population is based on the age- and gender - specific bp percentiles . due to regional differences in the bp percentiles , using various definitions for hbp , different distribution of reference bp data and difficulties in the measurement of bp in children including the necessity of using appropriate cuff size , the findings of different studies may show some variations .
overall , the level and pattern of hbp in children and adolescents which we studied needs attention .
the prevalence rate of hbp including pre - htn and htn is noteworthy in the pediatric population of iran .
it is necessary to use national standards for bp percentiles and design and implement targeted interventions based on research findings for various age groups . | background : the global health burden has faced toward non - communicable diseases ( ncds ) . it is suggested that adulthood blood pressure ( bp ) is tracked from childhood .
this study aims to evaluate the mean bp and the prevalence of prehypertension and hypertension in the iranian pediatric population.methods:in a national survey as the 4th phase of childhood and adolescence surveillance and prevention of adult non - communicable diseases study and through random multistage cluster sampling , a national sample of iranian school students , aged 6 - 18 years , were recruited .
data gathered by means of modified world health organization global school - based student health survey questionnaire , a weight disorders determinants questionnaire and anthropometric and bp measurements .
prehypertension ( htn ) was defined as bp equal or greater than 90th age and sex specific percentile or 120/80 mmhg and htn was defined as bp 95th percentile.results:a total of 13486 students entered the study ( 49.2% girls , 75.6% urban ) .
mean age of participants was 11.47 3.36 years . a total rate of 4.17% ( 3.84 - 4.52 95% ci ) for high systolic bp ( sbp ) , 4.33% ( 3.99 - 4.68 ) for high diastolic bp ( dbp ) and 6.88% ( 6.45 - 7.32 ) for high sbp and/or dbp was depicted.conclusions:the prevalence rate of high bp ( pre - htn together with htn ) is substantially high in this population .
it is needed to study the causative situations and implement relevant interventions . |
melanoma is a malignancy of pigment - producing cells ( melanocytes ) located predominantly in the skin but also found in the eyes , ears , gi tract , leptomeninges , and oral and genital mucous membranes .
the incidence of malignant melanoma appears to be increasing at an alarming rate throughout the world over the past 3040 years and continues to increase in the united states , canada , australia , asia , and europe [ 13 ] .
melanoma accounts for 65% of all deaths from skin cancer , reflecting its lethal nature .
most head andneck melanomas ( 7090% ) occur on the face , with the cheek the most common site .
malignant melanomas of the neck ( 7% ) and scalp ( 3% ) are much less frequent [ 6 , 7 ] .
although malignant melanomas of all cutaneous sites are slightly more common in women , melanomas of the head and neck are twice as common in men [ 7 , 9 ] .
head and neck melanoma also tends to affect a slightly older aged group than melanomas in other sites . head and neck melanoma in children is a very rare and is usually associated with giant congenital nevus .
melanoma that does not originate in the skin is a very rare tumor and is considered as one of the most deadly of all human neoplasms [ 12 , 13 ] .
primary mucosal melanomas represent only 1.73% of all primary melanomas [ 1 , 14 ] . generally , survival from head and neck melanoma
is reported as 17% at 5 years and the 10-year survival rate is 5% . we have reviewed the published reports and text - books , intending to give an overall picture of malignant melanomas of the head and neck .
the sequence of events in which normal melanocytes transform into melanoma cells , referred to as melanoma genesis , is poorly understood .
it likely involves a multistep process of progressive genetic mutations that ( 1 ) alter cell proliferation , differentiation , and death and ( 2 ) impact susceptibility to the carcinogenic effects of ultraviolet radiation .
recent data suggest multiple pathways of melanoma pathogenesis , with melanomas in sun - protected skin ( trunk ) developing in association with a high nevus count and intermittent ultraviolet radiation as opposed to those developing on sun - exposed skin in patients with low nevus counts and chronic sun exposure [ 17 , 18 ] . in a recent meta - analysis ,
gandini et al , found a possible positive correlation between an individual 's number of nevi and the overall risk of melanoma .
other risk factors include fair complexion , excessive childhood sun exposure and blistering childhood sunburns , an increased number of common and dysplastic moles , a family history of melanoma , the presence of a changing mole or evolving lesion on the skin , and , importantly , older age [ 20 , 21 ] .
patients having at least one affected first - degree relative possess a higher likelihood of developing malignant melanoma .
a new or changing mole or blemish is the most common warning sign for melanoma .
variation in color and/or an increase in diameter , height , or asymmetry of borders of a pigmented lesion are noted by more than 80% of patients with melanoma at the time of diagnosis .
symptoms such as bleeding , itching , ulceration , and pain in a pigmented lesion are less common but warrant an evaluation .
the american cancer society developed the abcdes to serve as a simple guideline of early melanoma warning signs .
border irregularity : the edges are ragged , notched , or blurred . color variegation : pigmentation is not uniform and may display shades of tan , brown , or black ; white , reddish , or blue discoloration is of particular concern . diameter : a diameter greater than 6 mm is a characteristic , although some melanomas may have smaller diameters ; any growth in a nevus warrants an evaluation . evolving : changes in the lesion over time
are a characteristic ; this factor is critical for nodular or amelanotic ( nonpigmented ) melanoma , which may not exhibit the classic criteria above .
more recent use of the ugly duckling warning sign , wherein skin examination is focused on recognition of a pigmented or clinically amelanotic lesion that simply looks different from the rest , may assist with detection of lesions that lack the classic abcde criteria ( e.g. , nodular , amelanotic , or desmoplastic melanomas ) .
experienced visual inspection is often the key to distinguishing a melanoma from other common benign pigmented skin lesions , such as lentigo simplex , junctional nevus , compound nevus , intradermal nevus , blue nevus , amalgam tattoo , addison 's disease , and heavy metal poisoning .
superficial spreading melanomas are the most common type . they are typified by an initial radial ( spreading ) growth phase with eventual development of a vertical growth phase .
superficial spreading melanoma is frequently associated with a nevus and often occurs in younger patients .
they tend to start as a slow growing , flat patch in sun - exposed areas ( often the face and neck ) .
they have a proclivity for the dermal - epidermal junction and tend to follow hair follicles .
not all such lesions are acral lentiginous ; however , they have a defined histologic appearance .
desmoplastic melanomas can be seen in association with preexisting melanocytic lesions and can more frequently be amelanotic , making their diagnosis more difficult .
they tend to be characterized by infrequent metastasis with a higher local recurrence rate , as well as more frequent perineural involvement .
mucosal melanomas most frequently present in the nose and/or sinuses , followed by the oral cavity and nasopharynx .
hidden , clinically silent areas , diagnosis often occurs late , requiring more radical treatment and contributing to the poorer prognosis .
the most important aspects of the initial workup for patients with melanoma are a careful history , review of systems , and physical examination .
sentinel lymph node biopsy ( slnb ) is generally indicated for pathologic staging of the regional nodal basin(s ) for primary tumors greater than or equal to 1 mm depth and when certain adverse histologic features ( e.g. , ulceration , high mitotic rate , and lymphovascular invasion ) are present in thinner melanomas .
published data have shown that baseline and surveillance laboratory studies ( e.g. , lactate dehydrogenase [ ldh ] level , liver function tests ) , chest radiography ( cxr ) , and other imaging studies ( e.g. , ct scanning , positron emission tomography [ pet ] scanning , bone scanning , and mri ) are not typically beneficial for stage
i / ii ( cutaneous ) melanoma patients without signs or symptoms of metastasis [ 2628 ] .
screening ct or pet may be considered if the patient has documented nodal metastasis based on results from the slnb , although the yield is low ( 0.53.7% ) in the setting of regional nodal micrometastasis and correlates with increasing tumor thickness , ulceration of the primary tumor , and/or large tumor burden in the sentinel lymph node(s ) .
the criterion standard for melanoma diagnosis is histopathologic examination of clinically suggestive skin or mucosal lesions .
an excisional biopsy ( or deep saucerization technique ) with narrow margins is preferred when possible . in the case of lentigo maligna ,
a broad , paper - thin shave biopsy or multiple smaller biopsies may be the best techniques .
the biopsy report should generally include the following : tumor thickness ( breslow depth ) ; presence of ulceration ; anatomic level of invasion ( clark level ) , no longer necessary as per 2010 ajcc staging ; presence of mitoses , noted as 0 or 1 or more per millimeter squared ; presence of regression ( associated with lower rates of sentinel node positivity and improved disease - free survival ) ; lymphatic / vessel ( lymphovascular ) invasion or vascular involvement ; host response ( tumor - infiltrating lymphocytes ) .
immunohistochemical staining for lineage ( s-100 , homatropine methylbromide 45 [ hmb-45 ] , melan - a / mart-1 ) or proliferation markers ( proliferating cell nuclear antigen , ki67 ) may be helpful in some cases for histologic differentiation from melanoma simulators . malignant cells often nest or cluster in groups in an organoid fashion ; however , single cell can predominate .
the melanoma cells have large nuclei , often with prominent nucleoli and show nuclear pseudoinclusions due to nuclear membrane irregularity .
this finding is interpreted as a more aggressive feature , compared with the findings of round or polygonal cell varieties . in 2009 ,
the american joint committee on cancer ( ajcc ) melanoma task force ( table 2 ) revised the staging system for cutaneous melanomas based upon the results of their multi - institutional study of 17,600 patients [ 32 , 33 ] .
staging adheres to the traditional tumor - node - metastasis ( tnm ) classification system .
this system classifies melanomas on the basis of their local , regional , and distant characteristics , as follows : stage i and ii : localized primary melanoma stage iii : metastasis to single regional lymph node basin ( with or without in - transit metastases ) stage iv : distant metastatic disease .
estimated 5-year overall survival ( os ) in the staging table is based on analysis of worldwide data encompassing nearly 60,000 patients in the 2008 ajcc melanoma staging database .
two popular microstaging systems for melanoma are the clark levels and the breslow thickness classification . in the past
, breslow depth of invasion has been shown to have prognostic significance , as has clark level of invasion . in the new system ,
breslow depth plays a more vital role , while clark level is deemphasized ( relevant only for t1 lesions ) .
other changes include the presence or absence of tumor ulceration , as well as tumor ( t ) thickness limits at 1.0-mm , 2.0-mm , and 4.0-mm depth for defining t stage .
stages i and ii were confined to clinical staging , while stages iii and iv used pathologic information from the nodes to define staging . where the 1997 system used the size of nodal metastases to judge prognosis , new data have shown that the number of metastatic nodes is more relevant .
the new system reflects that relevance by basing the n ( nodal ) stage on number of nodes involved like single or 2 - 3 or 4 metastatic nodes . in - transit metastases , which were grouped with the t staging in the 1997 system ,
are now included with the n staging . in general , in - transit metastases have been recognized to portend a poorer prognosis , which is reflected in the new system .
distant metastases are now grouped into one of three groups : m1a ( including subcutaneous nodules / distant nodes ) , m1b ( confined to lung metastases ) , and m1c ( for all other visceral sites ) .
elevated lactate dehydrogenase ( ldh ) serum level also is associated with poor prognosis , and patients with distant metastases and increased ldh are stage m1c regardless of site of metastasis .
suspicious lesions are defined by the abcd(e ) criteria and the last criterion , which is a relatively recent addition , emphasizing monitoring of benign lesions to evaluate change over time . for suspicious lesions ,
the prognosis and treatment of cutaneous melanoma depend greatly on the thickness of the lesion .
thus , the key to evaluation of suspected lesions focuses on obtaining a full - thickness biopsy .
excisional biopsy is the best choice for small lesions or for large lesions in cosmetically favorable locations .
excisional biopsy should extend down to the subcutaneous fat , with a small ( 2 - 3 mm ) peripheral margin .
punch biopsy can be performed for large lesions or for lesions with a low suspicion of melanoma in a cosmetically unfavorable location .
likewise , techniques that do not permit a full - thickness sample , such as shave or curette biopsy , are discouraged .
furthermore , pigmented lesions should not be definitively treated with laser therapy , electrocautery , or cryotherapy unless biopsy analysis proves them to be noncancerous .
some controversy exists in a number of areas . in terms of excision of the primary site
, thin melanoma margins are generally accepted to be 1 cm . for melanomas greater than 2 mm in thickness ,
however , krown and chapman noted that the ideal margin width for these deeper lesions has not been adequately studied .
more information regarding current excision margin recommendations is reviewed on the subject by lens . in the head and neck regions , adequate margins may not be possible or advisable due to cosmetic or functional concerns .
radiation therapy also has been controversial in the past due to the fact that the radiosensitivity of melanoma was at least considered questionable .
adjuvant radiation therapy for neck disease has been shown to be beneficial for patients with aggressive disease .
there are also data that support radiation treatment alone for regional disease control in head and neck melanoma , although no direct comparison of radiation versus surgical treatment has been studied . for most solid tumors , including cutaneous malignant melanoma ,
the most powerful predictor of survival is the status of the regional lymph nodes . as the understanding of the tumor biology of malignant melanoma continues to evolve , the traditional role for lymphadenectomy in the evaluation of at - risk regional nodes has been challenged .
but according to some studies , using this technique adequate disease removal ( e.g. , clinically negative neck , nonfixed disease , and small nodes ) is possible . radical neck dissections , unless indicated because of disease extent , should be avoided due to unnecessary morbidity . because of the high risk of occult involved nodes , neck dissection should accompany parotidectomy for positive parotid disease
the site of the primary lesion must be considered when neck dissection is planned in order to remove all intervening lymphatic drainage to the suspicious or positive node .
the primary site must also be considered when one plans elective lymph node dissection ( elnd ) for clinically negative necks . for primary lesions involving the parietal or frontal scalp , temple , lateral forehead , lateral cheek , or ear ,
superficial parotidectomy in conjunction with neck dissection is appropriate because the parotid may harbor the primary echelon nodes .
the debate on neck dissection continues as therapeutic nodal dissection has not been definitively shown to have a survival benefit ; it improves locoregional control . adding further complexity to this debate
, data show that recurrence rates in the neck after neck dissection are higher than those in the axillary or inguinal areas .
thus , until recently , a strong argument could be made for the wait - and - see approach to the clinically negative nodal basin because of the morbidity of dissection without evidence of a clear survival benefit .
but recent study has shown that high - dose interferon ( ifn ) alfa-2b can be given as an adjuvant treatment for high - risk melanomas and indicated that elective nodal dissection should not be delayed until disease is clinically detectable . in this study , relapse - free survival and overall survival rates improved in patients treated with ifn alfa-2b versus controls subject .
the widespread use of sentinel lymph node ( sln ) biopsy in the management of head and neck melanoma has been limited by several concerns .
one is that the lymphatic drainage in the head and neck region is complex , with multiple primary channels and the potential for multiple sln sites .
secondarily excision of these nodes can be technically challenging as small distances between sentinel nodes make detection and isolation difficult . furthermore , approximately 2530% of the sentinel nodes is found within the parotid gland , and concern of facial nerve injury has led many surgeons to advocate superficial parotidectomy over sln biopsy . and
lastly , the cooperation of experienced pathologists and nuclear medicine staff are essential to the success of the procedure .
slns were successfully localized in greater than 90% of cases , with the combined use of blue dye mapping and gamma probe lymphoscintigraphy .
describe accurately localizing intraparotid slns in at least 93% of cases [ 46 , 47 ] .
numerous adjuvant therapies have been investigated for the treatment of localized cutaneous melanoma following complete surgical removal .
no survival benefit has been demonstrated for adjuvant chemotherapy , nonspecific ( passive ) immunotherapy , radiation therapy , retinoid therapy , vitamin therapy , or biologic therapy .
adjuvant interferon ( ifn ) , alfa-2b , is the only adjuvant therapy approved by the us food and drug administration for high - risk melanoma ( currently defined as stages iib , iic , and iii ) , which is associated with a 4080% chance of relapse and death .
monoclonal antibodies are also considered as a second - line treatment for unresectable or metastatic melanoma .
the most important prognostic factors for cutaneous melanoma of the head and neck are as follows : increasing clark level of invasion , increasing tumor thickness , site that is scalp , greater than 1 mitosis per high power field , clinical ulceration , component of epitheloid cells , especially with pleomorphism , presence of microscopic satellites , lack of tumor infiltrating lymphocytes , and regional lymph node metastasis .
the incidence of melanoma of the head and neck has been increasing dramatically in the last several decades .
head and neck melanoma is a complex disease especially in its treatment considerations . thus a more aggressive treatment is done when morbidity is not significantly increased . as in any other cancer , best opportunity for cure lies in early and aggressive treatment . | the incidence of malignant melanoma appears to be increasing at an alarming rate throughout the world over the past 3040 years and continues to increase in the united states , canada , australia , asia , and europe .
the behavior of head and neck melanoma is aggressive , and it has an overall poorer prognosis than that of other skin sites .
the authors review the published literature and text books , intending to give an overall picture of malignant melanomas of the head and neck and a special emphasis on treatment considerations with controversies in treatment including biopsy , radiation therapy , sentinel node biopsy , and nodal dissection . |
neonatal hemochromatosis ( nh ) is defined by liver disease associated with siderosis of the extrahepatic tissues 1 .
the most frequent cause of nh is a gestational alloimmune disorder called gestational alloimmune liver disease , which results from the transplacental transfer of maternal immunoglobulin g ( igg ) antibodies 2 .
although about 80% of nh patients can survive without liver transplantation because of exchange transfusions and intravenous ig therapy , some of the patients with more serious disease require transplantation 3 .
nh with rtd has been reported in only five cases , all of which were stillborn or resulted in early neonatal death 58 .
we describe a case of surviving patient who had nh with rtd and underwent peritoneal dialysis and liver transplantation from her father .
a 29-year - old woman was referred to our hospital at 35 weeks gestation in her second pregnancy with atypical genital bleeding .
she had been diagnosed with poor fetal growth and oligohydramnios from 30 weeks of gestation .
a female infant was born by spontaneous vaginal delivery at 35 weeks with a birth weight of 1544 g ( 2.8 standard deviations , sd ) , a birth length of 42 cm ( 1.6 sd ) , and a head circumference of 29 cm ( 1.8 sd ) .
apgar scores were 1 ( 1 min ) and 6 ( 5 min ) .
physical examination revealed calvarial bone hypoplasia with enlarged fontanels and hepatosplenomegaly , but with no other abnormalities .
renal ultrasound showed hyperechogenicity of both kidneys , but the size and morphology were normal .
anuria , skull ossification defects , and renal hyperechogenicity suggested renal tubular dysgenesis . because the anuria persisted longer than 48 h and serum creatinine
had increased to 3.0 mg / dl , peritoneal dialysis was performed on day 3 ( fig.1 ) .
spontaneous urination was first observed on day 6 , and it increased gradually ; therefore , peritoneal dialysis was discontinued on day 10 .
finally , serum creatinine reached normal levels ( 0.5 mg / dl ) on day 30 .
ivig , intravenous immunoglobulin ; d - bil , direct bilirubin ; pt - inr , prothrombin time / international normalized ratio .
hepatic failure was suspected on day 9 because of hepatosplenomegaly , a poor coagulation profile ( pt - inr : 2.07 ) , jaundice ( direct - bilirubin : 9.1 mg / dl ) , thrombocytopenia ( platelets : 7.2 10/mm ) , and hypoglycemia . congenital infections and metabolic disorders were ruled out by blood examinations . on the basis of the clinical course of acute liver failure and the complication of rtd , nh was suspected .
however , she had a normal iron level of 138 g / dl and a ferritin level of 280 ng / ml . moreover
, magnetic resonance imaging of the abdomen did not reveal hepatic and extrahepatic siderosis on day 15 . to obtain a definitive diagnosis ,
a liver biopsy was performed on day 30 , concomitant with the surgical ligation of the ductus arteriosus .
the liver biopsy revealed an increase in stainable iron within the hepatocytes , confirming our diagnosis of nh ( fig.2 ) .
moreover , a marked loss of hepatocytes and cholestasis was detected and the remaining hepatocytes were multinucleated .
( b ) parenchymal fibrosis was extensive in most areas ( azan staining , original magnification 100 ) .
iron staining was predominantly both inside and outside the hepatocytes ( berlin blue staining , original magnification 200 ) .
vitamin e was administered starting at day 16 ( 25 iu / kg / day ) , whereas vitamin k was intravenously administered periodically after birth .
she received continuous infusions of ffp and repeated transfusions of platelets because of her overwhelming liver dysfunction .
her liver function did not improve ; however , she gained weight , reaching 2500 g , which indicated that she was able to accept a liver transplantation from an adult ( fig.1 ) .
a living donor liver transplantation with segment 2 monosubsegment graft ( 130 g ) for her was performed on day 59 .
the liver extracted from patient was replaced by small nodules and overall fibrosis was progressing .
microscopically , the liver showed almost total distortion of the lobular architecture , loss of the hepatocytes , and a diffuse increase in fibrous tissue .
a high degree of iron deposition in hepatocytes was observed , which was definitely findings in neonatal hemochromatosis .
first , the infusion of ffp and peritoneal dialysis were effective in treating persistent hypotension and renal failure in rtd with nh . to the best of our knowledge ,
second , repeated exchange transfusions improved the jaundice and coagulopathy , facilitating the patient s growth for subsequent liver transplantation regardless of her status as a preterm infant .
nh with rtd has only been reported in five cases , all of which were fatal or resulted in early neonatal death because of coagulopathy and liver failure 57 . in the case
reported here , ffp infusion and peritoneal dialysis were effective in maintaining systemic blood pressure and organ perfusion .
this is supported by a recent report on a neonatal case of inherited rtd with an angiotensinogen gene mutation ; this patient survived for more than 18 months with a treatment regimen that comprised ffp infusion and peritoneal dialysis 9,10 . because the diagnosis of rtd was made on the basis of the clinical symptoms and the hyperechogenicity of both kidneys in the present case , a kidney biopsy was required to confirm the diagnosis .
however , the kidney biopsy was difficult to perform because of the presence of severe coagulopathy .
liver failure did not improve regardless of a plurality of times of exchange transfusion and other medications .
moreover , her liver biopsy showed the remaining hepatocytes were multinucleated . on basis of clinical course and biopsy observation , we determined surgical liver transplantation was essential in this case .
most liver transplantations for children in japan are performed using the liver from one of the patient s parents .
our patient was very young , because of which we had to wait until her body weight reached at least 2500 g to accept an adult liver , and we thus treated her jaundice and coagulopathy with exchange transfusions .
fortunately , she developed no serious hemorrhage but instead showed weight gain , indicating growth .
our case report indicates that even a premature infant of nh with rtd can survive with peritoneal dialysis and exchange transfusions .
| key clinical messagewe report the first surviving case of neonatal hemochromatosis with renal tubular dysgenesis .
renal failure was treated with peritoneal dialysis .
although hepatic failure from neonatal hemochromatosis was progressive , repeated exchange transfusions improved jaundice and coagulopathy .
the patient gained weight and received a liver transplantation from her father . |
they occur in approximately 1 in 100,000 or represent 12% of all pancreatic neoplasms . some of the tumors may be part of the multiple endocrine neoplasia type one syndrome ( men-1 ) .
etps are categorized on the basis of their clinical manifestation into functioning and nonfunctioning tumors .
functioning tumors are associated with a clinical syndrome caused by inappropriate secretion of hormones . within this group are insulinomas , glucagonomas , somatostatinomas , gastrinomas , vasoactive intestinal polypeptide producing tumors ( vipomas ) and other less common tumors .
it has also been called verner - morrison syndrome , pancreatic cholera or wdha ( watery diarrhea / hypokalemia / achlorhydria ) syndrome .
this syndrome is characterized by secretory diarrhea which ranges between 0.5 and 15 l/24 h and which is usually the most prominent symptom at presentation .
it results in severe loss of potassium and bicarbonate , which in turn lead to metabolic acidosis and dehydration .
additional features include hypercalcemia with normal parathyroid hormone levels , hyperglycemia , and occasionally flushing of the face and the chest .
the diagnosis of a vipoma is confirmed by measurement of plasma vip , and levels above 60
nonfunctioning etps are not associated with a distinct hormonal syndrome , but may still show elevated hormone levels in the blood or immunoreactivity in tissue sections .
the majority of nonfunctioning etps express and/or secrete pancreatic polypeptide ( pp ) , which can therefore serve as a general tumor marker in etps .
pp was discovered in 1968 , when kimmel and colleagues , while purifying chicken insulin , found a new peptide hormone which they named
first , cases of pure pp - producing tumors , so - called ppomas ; second , mixed etps containing pp cells ; and third , cases of pp cell hyperplasia .
although pp frequently occurs in patients with etps , elevated serum levels of pp were not connected with specific clinical symptoms .
herein , we report only the fifth case of the world literature with a pure ppoma of the pancreatic head causing wdha syndrome .
a 46-year - old woman was admitted to our hospital because of a 2-year history of diarrhea .
one month prior to admission , she had undergone ct imaging of the abdomen , which showed a pancreatic head tumor , 4.2 3.3 cm in size ( fig .
her medical history revealed an appendectomy as a child and a benign cyst of the right breast . on admission , physical examination revealed a thin woman in no acute distress .
determination of peptide hormones in the serum showed greatly increased concentrations of pp with 4,370 pg / ml ( normal up to 80 pg / ml ) .
surprisingly serum levels of vip were normal with 8.5 pmol / l ( norm up to 36 pmol / l ) , the same was found for gastrin with levels of 12 pg / ml ( norm up to 60 pg / ml ) .
abdominal ultrasound showed a hypoechoic tumor in the pancreatic head 4.8 3.6 3.2 cm in size .
her serum pp level after removal of the tumor was 55 pg / ml and was completely suppressed by 1 mg intravenous atropine .
after a follow - up of three years she remained well without any watery diarrhea or any other signs of tumor recurrence .
2b ) in diameter , with a weight of 12 g. microscopically the neoplasm was an endocrine tumor , proven by a strong expression of chromogranin a ( fig . 2c )
it had a well - defined capsule and was made up of small cuboidal to slightly elongated cells with round nuclei and clear to eosinophilic cytoplasm .
the tumor cells were arranged in various patterns , a characteristic feature of islet cell tumors .
results of immunohistochemical staining specific for insulin , glucagons , somatostatin , and gastrin were negative .
2b ) in diameter , with a weight of 12 g. microscopically the neoplasm was an endocrine tumor , proven by a strong expression of chromogranin a ( fig .
it had a well - defined capsule and was made up of small cuboidal to slightly elongated cells with round nuclei and clear to eosinophilic cytoplasm .
the tumor cells were arranged in various patterns , a characteristic feature of islet cell tumors .
results of immunohistochemical staining specific for insulin , glucagons , somatostatin , and gastrin were negative . however , staining for pp was positive in the main tumor mass ( fig .
in mammals , virtually all of the pp - producing cells are located in the pancreas . they have been found within the islets , scattered in the exocrine compartment , and lining the ducts . within the islets
the pp cells are located mainly in the periphery , wedged between the a and b cells .
pp islet cells are relatively abundant in both the murine ventral and dorsal pancreatic buds by day 15.5 of gestation .
subsequently , at day 18.5 of gestation , the total number of pp cells in the murine ventral bud has doubled , whereas the number in the murine dorsal bud has essentially remained unchanged .
this nonhomogenous distribution of pp cells can also be seen in the human neonate . indeed
, pp cells are more numerous in the uncinate process than in the body and tail and rest of the pancreatic head .
infusions of pp in man demonstrate that , at physiological levels , it acts solely on the pancreas and gallbladder by inhibiting the secretion of bile and of pancreatic enzymes and juice .
that is this not always the case as illustrated in this case and table 1 . in 1979
, there was still controversy about how often wdha syndrome , with a causal pancreatic tumor , is mediated by excessive secretion of vip .
although elevated vip serum levels were measured in the majority of patients , there have been reports about so - called pseudo - verner - morrison syndromes with a clinical wdha syndrome in the presence of normal vip serum levels .
were the first to report on a patient with diarrhea due to a pancreatic tumor in whom pp was markedly elevated in the plasma with normal levels of vip in the plasma . in 1980
four years later , strodel et al . published a series of eight patients with pp - producing islet cell tumors .
two patients presented with diarrhea , but in only one of them a pancreatic tumor was found and resected . the last report came from mortenson and bold .
they described a 64-year - old woman who presented with watery diarrhea in the presence of men-1 syndrome . of various potential pancreatic endocrine hormones , only serum levels of pp were elevated .
radiologic imaging failed to identify a pancreatic tumor ; her diarrhea was therefore managed with subcutaneous administration of somatostatin .
three years later she developed gallstone pancreatitis with the subsequent development of a pancreatic pseudocyst . at exploration for drainage of the pseudocyst ,
final pathology documented a pancreatic endocrine tumor with immunohistochemical staining demonstrating the presence of pp . beside these four cases ,
there have been multiple case reports about ppomas , excluded from table 1 because either of lacking wdha syndrome or because no real circumscribed pancreatic tumor could be identified [ 9 , 10 ] .
as shown in table 1 , the normal serum level of vip and the elevated serum level of pp suggest that the symptoms in our patient seem to be derived from the high levels of circulating pp . a correlation between the serum pp concentrations and the wdha syndrome
could be demonstrated by absence of the syndrome after removal of the tumor due to an immediate fall in serum pp .
preoperatively us , ct scan or endoscopic ultrasound are the procedures of choice and are usually effective , because these tumors are relatively large [ 11 , 12 ] . also srs can be performed to differentiate endocrine from nonendocrine pancreatic tumors .
recognition of etps is imperative because of their good resectability and excellent long - term survival compared to that of ductal pancreatic carcinoma [ 13 , 14 ] .
this may require partial pancreatoduodenectomy in large tumors with local signs of malignancy or enucleation like in the present case .
some years ago , jensen described eight different neoplastic disorders that can cause chronic diarrhea .
this list included gastrinomas , vipomas , glucagonomas , somatostatinomas , and calcitonin - producing tumors .
the present case suggests that , although rare , ppomas have to be added to this list . | we report the case of a 46-year - old female patient with wdha ( watery diarrhea / hypokalemia / achlorhydria ) syndrome caused by a pancreatic polypeptide - producing tumor in the head of the pancreas . whereas vip and other pancreatic endocrine hormones were in the normal range , only serum levels of pancreatic polypeptide
were elevated .
imaging studies identified a pancreatic tumor in the head of the gland .
after laparotomy , the tumor of 3 cm in size was enucleated .
final pathology documented a pancreatic endocrine tumor with immunohistochemical staining demonstrating the presence of pancreatic polypeptide .
the patient remained cured after a follow - up of more than three years .
the present case illustrates that , although rare , wdha syndrome may be associated with a pancreatic polypeptide - secreting endocrine tumor of the pancreas . |
as altitude increases , the weight of air decreases , and the atmospheric pressure decreases .
low atmospheric pressure means there is more space between air molecules . as a result ,
the
number of oxygen molecules existing in the same volume of air deceases , so the amount of
oxygen intake decreases in the uplands , even if the same amount of air is respired .
that is ,
an increase in altitude reduces oxygen partial pressure in the pulmonary alveoli as well as
the blood s ability to carry oxygen due to reduced atmospheric pressure , causing hypoxia .
therefore , for an individual to consume the same amount of oxygen in the uplands as is
consumed in the lowlands , the volume of air respired needs to increase1 , 2 .
exposure to low
oxygen due to altitude change acts as a powerful stimulus to induce diverse changes in the
lungs3 . when exposed to upland
environments , the densities of erythrocytes , hemoglobin , capillary vessels , and myoglobin in
the skeletal muscles increase , which may improve the body s ability to transport oxygen4 .
since cardiopulmonary function is improved
and athletic performance is affected as a result of processes adapting to the
characteristics of upland environments1 ,
upland training is widely used as a method to intensively reinforce physiological functions
centering on cardiopulmonary function6 .
since respiration supplies oxygen for the performance of activities of daily living ( adl ) ,
breathing disorders affect the performance of adl6 .
that is , the efficiency of the respiratory function is closely
related to that of the circulatory function , and is important not only for the performance
of athletes , but also for the health of the general population .
upland - related studies have mostly dealt with athletes training1 , 7,8,9,10 , and studies conducted among the general population living in the
uplands are lacking . in korea , where approximately 70% of the country s area is mountainous ,
methods for improving respiratory function utilizing upland environments should be
particularly useful .
accordingly , the authors of this study examined the effects of
alternate living experiences in the uplands and the lowlands on respiratory function and
oxygen saturation in order to provide basic data for improving cardiopulmonary function
exploiting altitude .
the study subjects were 100 female students in the 1st through 4th grades of k university ,
which is located at an altitude of approximately 850 m. the study took place from march 27
to april 10 , 2013 .
the mean age and height of the study subjects , comprising 25 freshmen
( 18.920.57 years , 163.044.25 cm ) , 25 sophomores ( 19.960.54 years , 161.525.45 cm ) , 25
juniors ( 21.040.35 years , 159.844.40 cm ) , and 25 seniors ( 22.120.67 years ,
160.80 4.17 cm ) , were 20.51 years and 161.30 cm , respectively .
the study
subjects were selected from among those who had no history of smoking , and had no
respiratory organ disease , or symptoms that would have affected their lung capacity .
the
study s objectives and procedure were explained to the subjects and individual consent to
participate was obtained from all of them .
the study was approved by the ethical committee
of the kangwon national university hospital institutional review board . in korea , one school
year is divided into two semesters and each semester consists of 15 or 16 weeks . except for
the freshmen , the students who were the subjects of this study took classes at the school
located at an altitude above sea level of approximately 850 m for approximately 30 weeks per
year .
these students spend at least 15 weeks per semester at the school located in the
uplands ; they then go home to the lowlands during vacations .
when this study was conducted ,
freshmen had been attending the school for approximately one month , and the students in the
more senior grades had already experienced living arrangements alternating between the
uplands and the lowlands . in this study , oxygen saturation , heart rate , and cardiopulmonary function were measured at
the same time on the 8 floor of a building ( altitude at least 850 m ) located at
the highest level of k university , and in the student life center located in the lowlands .
oxygen saturation and heart rates ( beats per minute , bpm ) were measured using a heart rate
and arterial blood oxygen saturation measuring instrument ( pulse oximeter , mp110p mek - ics
co. , korea ) .
the pulse oximeter was attached to the subject s middle finger with subjects
and the values were measured in a stable state 68 times during five minutes .
pulse oximetry is a non - invasive method ,
using an instrument that can monitor oxygen saturation easily and quickly , and indicate the
measured values as spo2 . in this study ,
forced vital capacity ( fvc ) , forced
expiration volume of 1 sec ( fev1 ) , peak forced expiratory flow ( pef ) , forced
vital capacity of 1 sec were measured using cardiopulmonary measuring instruments ( microplus
spirometer , uk carefusion co. ) , and the fev1/fvc ratio was calculated .
when a subject arrived at the location where she was to be measured , she was instructed to
rest for approximately five minutes to ensure that she was stabilized .
then , oxygen
saturation and heart rate were measured using the right index finger .
demonstrations and
explanations about the posture required were provided before measuring the cardiopulmonary
functions , which were measured three times .
vital capacity was measured using the method recommended in the chronic
obstructive pulmonary disease treatment guidelines11 by referring to the standardized guidelines11 for the implementation and reading of pulmonary function
tests published by the american thoracic society and the european respiratory society .
when
pulmonary functions were measured , the subject was instructed to look forward , standing in
an upright position .
the subject was instructed to maximally inhale and then exhale as
quickly and strongly as possible for the longest time possible , while holding the nose
firmly and biting the mouthpiece properly . to obtain better measurement results ,
the subject
was encouraged by the researcher saying , more , more , more , hoo~. the subject was
instructed to rest for approximately two seconds after each measurement so as not to record
rebound measurements . when measured values could not be properly obtained , because the
subject coughed or otherwise , the subject was instructed to rest , after which the
measurement was repeated .
the data were analyzed using spss 12.0 for windows by conducting one - way anova to test
respiratory functions and oxygen saturation according to grade .
this study was conducted to examine the effects of living in the uplands and the lowlands
on respiratory functions and oxygen saturation .
oxygen saturation , heart rate , and
respiratory functions of students in different grades at different altitudes were examined .
the freshmen showed statistically significant differences between the uplands and the
lowlands in all items except pef and fev .
heart rates were higher in the uplands , oxygen
saturation was higher in the lowlands , fvc was higher in the lowlands , and
fev1/fvc was higher in the uplands .
significant differences in oxygen saturation
were noted in sophomores and significant differences in oxygen saturation and pef were noted
in juniors . on the other hand , there were no statistically significant differences in any of
the items measured in the uplands and the lowlands among the seniors .
therefore , it can be
said that alternating living experiences in the uplands and the lowlands affects respiratory
functions ( table 1table 1 .
differences in oxygen saturation and pulmonary functions with altitudefreshmensophomoresjuniorsseniorsmsdupland hr82.8812.02 * 81.1611.0480.649.83**79.689.78lowland hr78.0410.23 * 76.8411.8575.927.63**80.1211.31upland saturation97.800.96**97.41.04**98.201.0097.881.05lowland saturation98.440.77**98.320.80**98.321.1897.961.24upland pef293.2074.61321.6067.01345.3559.70**356.7757.35lowland pef283.1084.11307.0462.84326.2762.70**356.1557.56upland fvc2.730.48**2.930.502.700.312.890.26lowland fvc2.980.48**2.980.532.660.392.860.38uplandfev2.590.512.690.422.620.282.750.23lowland fev2.650.462.690.402.570.352.700.30upland ratio92.136.60 * 92.097.6897.013.8295.375.40lowland ratio88.928.51 * 91.178.1596.735.3294.935.60*p < 0.05 , * * p < 0.01 ) . to examine the effects of alternating living experiences in the uplands and
the lowlands on oxygen saturation , heart rate , and respiratory functions , differences in the
values between grades in the uplands and the lowlands were examined separately ( table 2table 2 .
differences in vital capacity according to gradeplaceitemgradenmsduplandoxygen saturation ( % ) 12597.800.96297.401.04398.201.00497.881.05hr ( bpm)12582.8812.02281.1611.04380.649.83479.689.78fev1 ( ml)1252.590.5122.690.4232.620.2842.750.23fvc ( ml)1252.730.4822.930.5032.700.3142.890.26pef ( ml)**125293.1874.602321.6067.003345.3559.704356.7757.40fev1/fvc ( % ) * * 12592.136.60292.097.68397.013.82495.375.40lowlandoxygen saturation ( % ) 12598.440.77298.320.80398.321.18497.961.24hr ( bpm)12578.0410.23276.8411.85375.927.63480.1211.31fev1 ( ml)1252.650.4622.690.3932.570.3542.700.30fvc ( ml)*1252.980.4822.980.5332.660.3942.860.38pef ( ml)**125283.0984.102307.0462.803326.2762.704356.1557.60fev1/fvc ( % ) * * 12588.928.51291.178.15396.735.32494.935.60*p < 0.05 , * * p < 0.01 , hr : heart rate , fev1 : forced expiratory
volume of one sec , fvc : expiratory flow rate obtained by fastest expiration after
maximal inhalation , pef : peak expiratory flow , fev1/fvc : the ratio of
forced expiration volume of 1 sec to forced vital capacity . ) . in the uplands
, there were no significant differences in oxygen saturation
and heart rate between grades .
there were statistically significant differences in pef and
fev1/fvc ( p < 0.05 ) .
pef was shown to be the highest in seniors , followed by
juniors , sophomores , and freshmen , in order of precedence , and fev1/fvc was the
highest among juniors ( 97.013.82 ) and the lowest among sophomores ( 92.097.64 ) . in the
lowlands , there were no significant differences in oxygen saturation and heart rate between
grades .
there were significant differences in fvc , pef , and fev1/fvc between the
grades .
fvc was shown to be the lowest among juniors ( 2.660.39 ) , pef was the
highest among seniors ( 356.1557.60 ) , and fev1/fvc was the highest
among juniors ( 96.735.32 ) and the lowest among freshmen ( 88.928.51 ) ( table 2 ) . * p < 0.05 , * * p < 0.01 * p < 0.05 , * * p < 0.01 , hr : heart rate , fev1 : forced expiratory
volume of one sec , fvc : expiratory flow rate obtained by fastest expiration after
maximal inhalation , pef : peak expiratory flow , fev1/fvc : the ratio of
forced expiration volume of 1 sec to forced vital capacity .
cardiopulmonary functions by grade in the uplands and the lowlands were judged after
dividing the subjects into lower grade students ( freshmen , sophomores ) , who had less
experience of alternating living between the lowlands and the uplands , and upper grade
students ( juniors , seniors ) , who had more experience . in the uplands , the cardiopulmonary
functions of lower grade students and those of upper grade students showed statistically
significant differences ( x = 0.014 ) .
upper grade students showed only normal
spirometry ( ns ) ( 70% ) and mild restriction ( mr ) ( 30% ) , and some lower grade students showed
moderate restriction ( mor ) , mild obstruction ( mo ) , and moderate severe restriction ( mosr ) ,
indicating that they were experiencing cardiopulmonary function disorders ( table 3table 3 .
assessment of on breathing disorders n(%)nsmrmormosrmomoototalupland*a29 ( 58%)10 ( 20%)5 ( 10%)2 ( 4%)4 ( 8%)0 ( 0%)50 ( 100%)b35 ( 70%)15 ( 30%)0 ( 0%)0 ( 0%)0 ( 0%)0 ( 0%)50 ( 100%)lowland**a30 ( 60%)7 ( 14%)0 ( 0%)2 ( 4%)10 ( 20%)1 ( 2%)50 ( 100%)b29 ( 58%)19 ( 38%)1 ( 2%)0 ( 0%)1 ( 2%)0 ( 0%)50 ( 100%)a : freshmen+sophomore , b : juniors+seniors , ns : normal spirometry , mr : mild
restriction , mor : moderate restriction , mosr : moderate severe restriction , mo : mild
obstruction , moo : moderate obstrction ) . in the lowlands ,
the cardiopulmonary functions of lower grade students and
those of upper grade students showed statistically significant differences ( x =
0.005 ) .
ns showed the highest proportion in both lower grade and upper grade students . in
the lowlands ,
lower grade students showed ns , mo , mr , mosr , and moderate obstruction ( moo ) ,
while upper grade students showed ns , mor , mo , and mr ( table 3 ) .
a : freshmen+sophomore , b : juniors+seniors , ns : normal spirometry , mr : mild
restriction , mor : moderate restriction , mosr : moderate severe restriction , mo : mild
obstruction , moo : moderate obstrction
this study was conducted to examine the effects of alternating living experiences of the
uplands and the lowlands on oxygen saturation and respiratory function in order to provide
basic data for improving cardiopulmonary function exploiting altitude . in this study , there were differences in oxygen saturation , heart rate , and most
respiratory function items between the uplands and the lowlands among the freshmen ; however ,
there were no differences in any of the items among the seniors . to take in the same amount
of oxygen taken at sea level at 850 m in the uplands ,
the amount of ventilation would have
to increase two - fold . to compensate for this
therefore , long - term life in the uplands improves the blood s oxygen carrying
capacity2 .
this can explain the
phenomenon that was apparent in the present study in which freshmen who had just began
living in the uplands showed higher oxygen saturation and heart rates , increased fvc , and
decreased fev1/fvc .
seniors who had long - term experience of alternating life
between the uplands and the lowlands did not show differences in any of the items .
therefore , it can be said that alternating living experiences in the uplands and the
lowlands affects pulmonary functions , even without continuous exposure to the upland
environment . when exposed to the upland environment , and the associated low - pressure , low - oxygen
environment , the heart rate increases to at a slightly higher level than in the lowlands due
to the action of the sympathetic nerve and an increased energy metabolic rate
. the heasr
rate it returns almost to the original level , after adapting to the upland environment ,
after approximately one week12 .
therefore , the reason why differences in oxygen saturation and heart rate between the grades
did not appear in both the upland - and lowland - living students was that even the freshmen had
started school at least three weeks earlier , and thus , all of the students had already
adapted to their environment . in the uplands , pef and fev1/fvc
were shown to be
higher among upper grade students , who indicated smooth expiration .
this indicates that
upper grade students had better adaptability to the uplands than lower grade students . in
the lowlands
, fvc was shown to be higher among lower grade students , and pef and
fev1/fvc were shown to be higher among upper grade students , compared to those
from the uplands , indicating that the pulmonary functions of the upper grade students were
better .
therefore , even alternating living between the uplands ( during semesters ) and the
lowlands ( during vacations ) , as opposed to continuous life in the uplands , appears to
improve respiratory function . when an individual returns to the lowlands after training in
the uplands , his / her maximum oxygen intake increases , aerobic enzymes are activated ,
mitochondria count increases , glycogen storage ability improves , capillary vessel density
increases , hemoglobin concentration increases , and heart functions are activated13 .
however , in this study , although there
were differences in respiratory function tests between grades , there were no differences in
oxygen saturation and heart rate , unlike the findings of the study conducted by bartsch and
saltin13 .
the degrees of respiratory functional disorders by grade in the uplands and the lowlands
were judged after dividing the subjects into the lower grade students ( freshmen , sophomores )
who had less experience of alternating living between the lowlands and the uplands , and the
upper grade students ( juniors , seniors ) who had more experience of doing so . in the uplands ,
the upper grade students showed only ns ( 70% ) and mr ( 30% ) , indicating that their breathing
was normal or had slight limitations . on the other hand , some lower grade students showed
moderate breathing restrictions , severe breathing restrictions , and mild breathing
disorders .
in the lowlands , lower grade students showed fewer breathing disorders compared
to the uplands , although some had breathing disorders , and upper grade students showed more
cases of slight restriction .
this was due to
large lung capacity , as living in the uplands did not seem to inhibit breathing .
the maximum
oxygen intake at 1,800 2,300 m corresponds to approximately 8085% of that at sea level and
increases by approximately 25% after a 2- to 3-week adaptation periods .
the fact that
increases in the maximum oxygen intake in the uplands is not shown to be the same as those
at sea level indicates the human body s adaptability to low oxygen environments .
therefore ,
upper grade students having longer experience of exposure to upland environments are thought
to have shown more breathing disorders in the lowlands than in the uplands because their
bodies had adapted to the upland environments .
kim et al.5 reported that cardiopulmonary functions improved after upland
training . in that study ,
upper grade students who had been exposed to upland environments
for a longer time generally showed better respiratory functions , as in our study .
currently , physical strength and the body s abilities based on cardiopulmonary and
respiratory functions are known to be insufficient among students as well as in the general
population . both athletes and the general population could benefit from upland training .
periodic living in the uplands is considered to be an effective method for improving
respiratory function ; however , most people can not move on a regular basis . in this study
, we
were unable to determine the period of upland living required to influence an improvement in
respiratory function ; therefore , further studies are necessary . through such studies ,
researchers may discover methods for improving cardiopulmonary function or breathing
disorders exploiting natural environmental conditions , for athletes as well as for the
general population . | [ purpose ] the purpose of this study is to examine the effects on respiratory function
and oxygen saturation of intermittent life in the uplands at an altitude above sea level
of approximately 850 m. [ subjects and methods ] the study subjects were on 100 female
student subjects attending a university located in the uplands .
the subjects oxygen
saturation , heart rates and respiratory functions were measured at the university , which
has campuses both in the uplands and the lowlands .
[ results ] freshmen showed differences
in oxygen saturation , heart rate , and most respiratory function items between the
different altitudes ; however , seniors did not exhibit any differences .
there were no
differences in oxygen saturation and heart rate between the uplands and the lowlands
either group . in the uplands , peak forced expiratory flow
was shown to be high in the
seniors , who also had better cardiopulmonary function .
[ conclusion ] senior students , who
had been exposed to the upland environment for a longer period of time , generally showed
better respiratory function .
therefore , alternating living between the uplands and the
lowlands can be said to improve an individual s respiratory function . |
duplicated gb is often picked up on ultrasonography , however there are a lot of differentials .
since , 99 m tc hida follows hepatobiliary physiology , any tracer concentration in gb fossa is confirmatory for presence of gb , thus in turn increasing the specificity in picking up anatomical variants as in our case .
a 15 year old boy presented with intermittent pain in right hypochondrium for a week . physical examination revealed no local tenderness .
ultrasonography ( usg ) of the abdomen revealed two cystic formations in the gall bladder ( gb ) fossa with no distinct visualisation of cystic duct .
after fasting for 6 - 8 hours , 5 mci of 99 m tc mebrofenin ( hida ) was injected intravenously and dynamic images were acquired for 1 hour , at a frame rate of 1 minute / second .
images revealed normal hepatocellular tracer extraction with visualization of the hepatic and common bile ducts at 10 minutes .
two foci of tracer uptake were seen in the region of gb fossa [ figure 1a - arrows ] at 15 minutes , which persisted till the end of the study .
anterior static pre fatty meal image showed two intense foci of tracer uptake in gb fossa [ figure 1b - arrow ] .
post fatty meal anterior static image showed reduction in size and counts in both structures in gb fossa [ figure 1c - arrows ] .
detection of two globular structures in gb fossa , which contract after fatty meal , is specific for duplicated gb .
it was further confirmed by drawing regions of interest ( rois ) on gb moieties , on pre and post meal images , which showed reduction in counts by more than 50% . since gb visualization was within normal time range , with preserved contractile function post fatty meal , patient
was kept on medical therapy , low fat diet and antibiotics , and follow up was recommended .
( a ) dynamic hida scan images showing visualisation two separate foci in gb fossa at 15 minutes ( arrows ) and normal intestinal tracer excretion ( thick arrow ) ( b ) pre meal anterior static image showing two separate gb fossa moieties ( arrows ) ( c ) post fatty meal anterior static image showing significant tracer excretion following gb contraction confirming that the moieties are duplicated gb moieties an 8-year - old boy presented with recurrent abdominal pain and occasional vomiting since a few months .
usg of the abdomen showed two pear shaped structures in the gb fossa , seen as two adjacent anechoic structures oriented in the same plane [ figure 2a - arrows ] ; consistent with duplicated gb , with separate cystic ducts .
coronal magnetic resonance imaging ( mri ) showed the duplicated gb [ figure 2b - arrows ] .
after adequate preparation , serial static 99 m tc mebrofenin hepatobiliary study was performed ; images being acquired in anterior , right lateral and right anterior oblique views every 2 - 5 minutes .
static anterior images showed two distinct moieties in gb fossa [ figure 3-arrow and arrowheads ] , confirming the diagnosis on usg and mri , of duplicated gb .
post meal static image [ figure 4b ] was compared with pre meal static image [ figure 4a ] , latter showed significant reduction in gb counts ( arrows ) , suggesting normal contraction of the gb , thus ruling out obstruction .
( a ) ultrasonography showing two anechoic structures in gb fossa ( arrows ) ( b ) duplicated gb seen on coronal mri ( arrows ) serial static hida images in anterior , right lateral and right anterior oblique views confirming the presence of duplicated gb ( arrows and arrowheads ) static anterior view ( a ) pre meal ( b ) post meal , showing tracer excretion following gb contraction
a 15 year old boy presented with intermittent pain in right hypochondrium for a week . physical examination revealed no local tenderness .
ultrasonography ( usg ) of the abdomen revealed two cystic formations in the gall bladder ( gb ) fossa with no distinct visualisation of cystic duct .
after fasting for 6 - 8 hours , 5 mci of 99 m tc mebrofenin ( hida ) was injected intravenously and dynamic images were acquired for 1 hour , at a frame rate of 1 minute / second .
images revealed normal hepatocellular tracer extraction with visualization of the hepatic and common bile ducts at 10 minutes .
two foci of tracer uptake were seen in the region of gb fossa [ figure 1a - arrows ] at 15 minutes , which persisted till the end of the study .
anterior static pre fatty meal image showed two intense foci of tracer uptake in gb fossa [ figure 1b - arrow ] .
post fatty meal anterior static image showed reduction in size and counts in both structures in gb fossa [ figure 1c - arrows ] .
detection of two globular structures in gb fossa , which contract after fatty meal , is specific for duplicated gb .
it was further confirmed by drawing regions of interest ( rois ) on gb moieties , on pre and post meal images , which showed reduction in counts by more than 50% . since gb visualization was within normal time range , with preserved contractile function post fatty meal , patient
was kept on medical therapy , low fat diet and antibiotics , and follow up was recommended .
( a ) dynamic hida scan images showing visualisation two separate foci in gb fossa at 15 minutes ( arrows ) and normal intestinal tracer excretion ( thick arrow ) ( b ) pre meal anterior static image showing two separate gb fossa moieties ( arrows ) ( c ) post fatty meal anterior static image showing significant tracer excretion following gb contraction confirming that the moieties are duplicated gb moieties
an 8-year - old boy presented with recurrent abdominal pain and occasional vomiting since a few months .
usg of the abdomen showed two pear shaped structures in the gb fossa , seen as two adjacent anechoic structures oriented in the same plane [ figure 2a - arrows ] ; consistent with duplicated gb , with separate cystic ducts .
coronal magnetic resonance imaging ( mri ) showed the duplicated gb [ figure 2b - arrows ] . after adequate preparation
, serial static 99 m tc mebrofenin hepatobiliary study was performed ; images being acquired in anterior , right lateral and right anterior oblique views every 2 - 5 minutes .
static anterior images showed two distinct moieties in gb fossa [ figure 3-arrow and arrowheads ] , confirming the diagnosis on usg and mri , of duplicated gb .
post meal static image [ figure 4b ] was compared with pre meal static image [ figure 4a ] , latter showed significant reduction in gb counts ( arrows ) , suggesting normal contraction of the gb , thus ruling out obstruction .
( a ) ultrasonography showing two anechoic structures in gb fossa ( arrows ) ( b ) duplicated gb seen on coronal mri ( arrows ) serial static hida images in anterior , right lateral and right anterior oblique views confirming the presence of duplicated gb ( arrows and arrowheads ) static anterior view ( a ) pre meal ( b ) post meal , showing tracer excretion following gb contraction
duplication of gb is a rare congenital anomaly , occurring in about one per 4,000 births .
differential diagnosis based on sonographic findings include gallbladder diverticula , gb fold , phrygian cap , choledochal cyst , pericholecystic fluid , focal adenomyomatosis , and intraperitoneal fibrous bands , which results in a diagnostic dilemma .
99 m tc hida is a bile analogue which gets metabolised by the biliary pathway . following a fatty meal
, there is a physiological gb contraction , resulting in tracer excretion into the common bile duct and subsequently into gut .
thus , nuclear hida scan is a physiological and specific modality to pick up anomalies in the hepatobiliary tree and gb .
also , contraction of both the gb moieties following fatty meal , rules out the presence of choledochal cyst , which is a close differential and confirms presence of duplicated gb . in cases
where duplicated gb is diagnosed on usg , hida scan is done to rule out obstruction , as prevalence of cholelithiasis and obstruction is more in association with duplicated gb . both cases highlight the role of hida scan in detecting duplicated gb .
in addition , in case 1 , where usg findings are equivocal , a dynamic hida study with fatty meal provides diagnostic accuracy ; whereas , in case 2 , where duplicated gb is diagnosed , serial static hida study helps to rule out associated obstruction . | gall bladder ( gb ) duplication is a rare condition often found incidentally ; most of these detected on screening ultrasonography ( usg ) for abdominal colic .
nuclear hepatobiliary scan , popularly known as hepatobiliary iminodiacetic acid ( hida ) scan , with its biliary kinetics , is highly specific for picking up abnormalities related to biliary tract and gb . we report two cases of duplication of gb visualized on hida scan .
first case highlights the role of hida scan in diagnosis of duplicated gb , where usg was equivocal with a number of differentials , whereas in the second case , hida helped to rule out obstruction in this case of duplicated gb identified on usg ; ruling out biliary cause for the abdominal colic . |
amniocentesis is one of the most popular and safe methods of invasive prenatal diagnosis of chromosomal abnormalities .
it is performed in patients with high risk of having a child with birth defects [ 13 ] . in 2007 ,
the pomeranian region was the first to introduce the guidelines in everyday practice in 2008 .
the main purpose of the program was described as the early identification of the risk of fetal abnormalities via biochemical screening , the early diagnosis of fetal malformations with ultrasound examination , and the increase of the availability of prenatal screening in poland .
other aims included the development of a prenatal screening system in poland , the preparation of an algorithm for non - invasive and invasive prenatal diagnosis , and the improvement of prophylaxis in families with a high risk of genetic disorders through molecular diagnosis and genetic counselling . to be included in the prenatal screening program ,
the pregnant woman had to meet at least 1 of criteria listed below : a maternal age of 35 years or more ; a chromosomal abnormality in a previous fetus or child ; a known structural chromosomal abnormality in the pregnant mother or the father of the baby ; a significantly high risk of giving birth to a child with genetic disease conditioned by 1 known gene or with disease with multifactorial conditioning ; a fetal malformation found at the ultrasound examination or a high risk of chromosomal abnormality according to the biochemical screening . before the introduction of the prenatal screening program ,
invasive diagnostic procedures were offered to patients with the aforementioned indications . a very low availability of biochemical and ultrasound screening implied that very few patients referred for amniocentesis , chorionic villus sampling , or fetal blood sampling as a result of an abnormal result in the screening .
the national health insurance agency hoped that a group of patients over 35 years of age with low risk of fetal chromosomal abnormality in the biochemical screening would not ask for an invasive diagnosis and , on the other hand , that a group of young women with a high risk will undergo amniocentesis .
the result of these changes should thus increase the detection of chromosomal abnormalities without increasing the number of invasive procedures .
the aim of the study was to analyze the differences in the indications for amniocentesis in the patients living in urban and rural areas before and after introduction of the prenatal screening program by the polish national health insurance agency in the pomeranian region of poland in 2008 .
indications for all 2578 consecutive amniocenteses performed in the department of obstetrics of the medical university of gdansk between 1996 and 2010 were recorded .
the department was the referral center for the pomeranian region , where the prenatal screening program was first introduced in 2008 .
every woman referred for amniocentesis was first counselled by a geneticist and signed an informed consent .
biparietal diameter , femur length , abdomen circumference , the localization of the fetus and placenta , and amniotic fluid volume were assessed .
amniocentesis was performed using the yale spinal 22 gauge needle under ultrasound guidance . the volume of withdrawn amniotic fluid in ml was equal to the gestational age in weeks , as hanson proposed . in the case of an ineffective first attempt to obtain amniotic fluid
if the second amniocentesis failed and no amniotic fluid was obtained , the patient was scheduled for a repetition of the procedure 1 week later .
after every amniocentesis , the fetal heart rate was confirmed , and bleeding to the amniotic cavity was excluded . in rh - negative women with negative rh antibodies ,
300 g of human anti - rhd immunoglobulin was administered intramuscularly . in all cases indication for amniocentesis , patient age , and the gestational age
if there were 2 indications , the one suggesting a greater risk of chromosomal aberration was chosen ( for example , if the patient was 36 years old , and biochemical screening gave a risk of 1:20 , the biochemical screening was recorded as the first indication for amniocentesis ) . in the first part of the study , 2062 ( 80% ) women living in urban areas ( group a ) were compared to 516 women ( 20% ) living in rural areas ( group b ) . in the second part of the study , patients were divided into 2 groups .
group i consisted of 1704 women who underwent amniocentesis before the introduction of the prenatal screening program ( 1996 to 2007 ) .
the patients referred from 2008 to 2010 ( 874 women ) , after the introduction of the prenatal screening program , constituted group ii .
indications for amniocentesis were compared between group of 1399 urban patients and referred from 19962007 ( group ia ) and 663 women referred after 2007 ( group iia ) .
we also compared 305 rural patients referred before 2008 ( group ib ) and 211 after 2008 ( group iib ) ( tables 1 and 2 ) .
the median age of the patients was 37 years , and ranged from 16 to 50 in group a ( urban ) and the median age of patients was 36 ( ranged from 1548 ) in group b ( rural ) . there were 1851 women ( 71.77% ) older than 34 years .
amniocentesis was performed at between 10 and 20 weeks of gestation ( average 14 weeks ) in group a , and at between 11 and 20 weeks of gestation ( average 15 weeks ) in group b , as calculated according to the last menstrual period , fisher test p=0.727 .
fisher s exact test was used to compare variables when expected differences were small ( < 5% ) and test of independence was used to compare categorical data .
table 3 shows that the majority of women were referred for advanced maternal age ( 35 years or more ) it was the reason of testing in 1417 of the urban women ( 69% ) and in 314 rural patients ( 61% ) ( p<0.001 ) .
the only significance difference between the 2 groups in indication for amniocentesis was chromosomal abnormality of a previous child , which was the indication for amniocentesis for 91 ( 4.4% ) of the urban women compared to 36 ( 7.0% ) of the rural women ( p<0.001 ) .
tables 1 and 2 present changes of indications for amniocentesis in urban and rural women after introducing the prenatal screening program in the pomeranian region in 2008 .
table 1 shows that frequency of performing amniocentesis for advanced maternal age and fetal malformations in a previous pregnancy significantly decreased ( from 73% to 60% and from 2.4 to 0.6 respectively , p=0.004 and p=0.033 , respectively ) .
no other significant differences regarding indications for amniocentesis were found between urban and rural women before and after 2008 .
table 2 shows that in the rural women , frequency of referrals for maternal age ( 66% and 54% , p<0.001 ) significantly decreased .
we observed significant increase of referrals for positive results of biochemical screening ( 12% and 28% , p<0.001 ) , fetal abnormality diagnosed in ultrasound ( 5% and 6% , p<0.001 ) , and chromosomal abnormality in a previous pregnancy ( 6.9% and 7.1% , p=0.009 ) .
prenatal cytogenetic diagnosis has been recognized for more than 40 years as a reliable method for the detection of fetal chromosome abnormalities in patients with high risk of having a child with birth defects .
amniocentesis was developed at the end of the 1960s as a diagnostic tool following the ability to culture amniotic fluid samples and , as a result , the first fetal karyotypes were obtained , making this the safest of the invasive procedures .
the information that the baby does not carry any chromosomal abnormality despite the high risk is essential for the mother .
when the abnormality is confirmed , there is a possibility of termination of pregnancy or time to prepare for having a child with birth defects .
nevertheless , there is a possibility of fetal loss associated with invasive procedures and it should be performed only in patients when the risk of chromosomal abnormality is very high .
initially , advanced maternal age was the main referral reason for amniocentesis , as it was well known that fetal aneuploidies and maternal age are positively correlated .
the combination of maternal age , ultrasound , and biochemical markers used nowadays has changed the paradigm of antenatal screening for down s syndrome world - wide .
women choose to have invasive diagnosis for a variety of reasons , mainly for positive screening , but also because of advanced maternal age , a previously affected child , or presence of ultrasound markers of aneuploidy . on average , between 5% and 10% of pregnant women decide to have invasive tests . nowadays , as a consequence of the introduction of effective screening methods
many women over age 35 or who previously had a child with birth defects choose non - invasive tests and do not insist on invasive procedures if the results were negative .
frequency of referrals due to maternal age and affected child in a previous pregnancy decreased after introduction of the prenatal screening program in poland . in poland ,
probably it is not well accepted in rural areas that older women are at higher risk of giving birth to a child with chromosomal abnormality .
additionally , higher frequency of chromosomal abnormality in a previous pregnancy and fetal malformation diagnosed in ultrasound observed in the group of rural patients suggests that for rural women the indications for amniocentesis have to be stronger than for urban women to decide on invasive testing . in poland ,
all pregnant women should be offered information about screening methods in pregnancy , including a combined assessment of down s syndrome risk in the first trimester based on maternal age , nuchal translucency measurement , serum free human chorionic gonadotropin ( hcg ) , and pregnancy - associated plasma protein a ( papp - a ) , called the double test or papp - a test , by the prenatal care physicians . until 2007 , all
patients could have the test , but at their own expense . in 2008 in the pomeranian region it became free for a group of patients over 35 as a result of introducing the prenatal screening program .
this resulted in higher frequency of referrals for invasive testing because of positive biochemical screening , because screening became available for many women who could not otherwise afford it .
restricting invasive procedures to women at an increased risk has more than halved the proportion of women having an invasive procedure only because of advanced age .
we proved that introducing the prenatal screening program in poland reduced the percentage of women undergoing invasive procedures due to advanced maternal age only .
many of them have a possibility of choosing non - invasive testing and avoid a risk of loosing the pregnancy due to amniocentesis when the screening result is negative .
more and more women do not see advanced maternal age as a risk factor strong enough to insist on invasive testing .
there are considerable difficulties in planning and investing funds by national health systems where combined screening is concerned .
screening does not lead directly to a reduction in number of the chromosomal abnormalities , but only helps in the decision as to whether to perform prenatal diagnosis of the chromosomal abnormality , which is neither curable nor preventable .
the effect of combined screening is to avoid fetal deaths as a result of invasive diagnostic procedures performed on healthy fetuses , and implementation of this program should be supported at the national level .
the results of our analysis of the indication for amniocentesis in urban and rural patients revealed that after the introduction of the prenatal screening program by the national health insurance agency in the pomeranian region of poland , amniocentesis was performed in both groups more often after an abnormal result of biochemical screening ( a significant increase ) .
introducing the prenatal screening program in poland decreased frequency of invasive testing for maternal age or giving birth to a child with malformations in a previous pregnancy . in the rural women ,
advanced maternal age is less frequently accepted as a reason for high - risk of fetal aneuploidy , which is probably a reason for the lower frequency of patients receiving amniocentesis for maternal age , and higher frequency for fetal malformation in ultrasound screening , genetic disease , or fetal malformation in the family history compared to the urban patients .
high risk detected in biochemical screening is still relatively rarely the reason for invasive testing .
it should be emphasized that its popularization in both groups of patients may increase the detection rate .
the prenatal screening program needs to be continued for both public health and financial reasons . | backgroundthe aim of the study was to analyze differences in the indications for amniocentesis in patients living in urban and rural areas before and after introduction of the prenatal screening program by polish national health insurance agency in the pomeranian region in 2008.material/methodsindications for 2578 amniocenteses performed in the department of obstetrics of the medical university of gdansk between 1996 and 2010 were recorded.resultsadvanced maternal age accounted for 69% of women in urban areas and 61% of women in rural areas being referred for amniocentesis ( p<0.001 ) .
there was also a significant difference between locations in chromosomal abnormality in previous pregnancy , accounting for 4% of referrals for amniocentesis in urban areas compared with 7% of referrals in rural areas .
in urban areas , advanced maternal age accounted for 73% of referrals between 19962007 compared with 60% of referrals for amniocentesis between 2008 and 2010 ( p=0.004 ) , and in rural areas it was 66% and 54% , respectively ( p<0.001 ) .
abnormal result of biochemical screening surprisingly accounted for 13% of referrals for amniocenteses between 19962007 in urban areas compared with 28% after 2008 ( p<0.001 ) . in rural areas
this indication accounted for 12% referrals before 2008 and for 28% from 2008 onward ( p<0.001).conclusionsthe results of the study suggest that in both urban and rural areas there was a significant decrease in advanced maternal age as a reason for referral for amniocentesis , but a significant increase in abnormal results of biochemical screening as an indication for amniocentesis after 2008 . |
recently , a growing body of evidence has suggested that a transient increase in insulin resistance is a component of pubertal development .
there is a phenomenon of increasing insulin resistance that begins in early puberty , peaks in the mid of puberty , and resolves by the end of puberty in normal weight children [ 25 ] .
however , data about the insulin resistance pattern during adolescence in obese subjects has been discordant [ 6 , 7 ] . given that insulin resistance is a feature of obesity and hallmarks metabolic syndrome , moreover , puberty is a high risk developmental period for obesity related disease , it is important to understand the modulators of pubertal insulin resistance
. it has been well accepted that adipose tissue is a dynamic endocrine organ releasing a number of adipocyte - specific factors named adipokines , " which are critical for regulating metabolism in both health and disease . of various adipokines , leptin and adiponectin
leptin expression and plasma concentrations have been shown to be proportional to adipose tissue mass in humans and are therefore increased in adiposity [ 8 , 9 ] and reduced after weight reduction in both adults [ 10 , 11 ] and children [ 12 , 13 ] . with the anti - inflammatory , antiapoptotic , and proangiogenic properties ,
adiponectin is one of the most potent adipokines with respect to its insulin - sensitizing activity [ 14 , 15 ] . in the light of growing obesity epidemics in children and adolescents worldwide ,
further studies on adipokines and insulin resistance during puberty are clearly warranted . to our knowledge , despite well - observed gender differences in body composition and adipokines during adolescents [ 35 , 16 ] , few studies have examined gender - specific association of adipokines alternations with puberty insulin resistance . therefore , the aim of our study was to assess the correlation of the dynamics of insulin resistance with leptin and adiponectin , as well as anthropometric measures of body fat during puberty in a large sample of chinese children and adolescents .
subjects were recruited from a cross - sectional population - based survey : the beijing child and adolescent metabolic syndrome ( bcams ) study as described elsewhere .
the cohort contained 3530 children aged 618 years and classified as normal weight ( bmi 85% ) , overweight ( bmi > 85% but 95% ) , and obese groups ( bmi 95% ) according to age- and gender - specific bmi percentiles cutoffs defined by the working group on obesity in china .
however , a total of 3223 children including 1616 boys and 1607 girls who met the following eligibility criteria were included for the current analysis : ( 1 ) subjects without missing data ; ( 2 ) lack of diabetes mellitus and other underlying chronic diseases ; ( 3 ) no current regular medications .
informed consents from participants and/or parents / guardians were obtained before entering into the study .
the bcams study was approved by the ethics committee at capital institute of pediatrics in beijing .
a detailed description of the sample collection and detection procedures has been previously published . in short , subjects were evaluated for body mass index ( bmi ) , bmi z - score by age and gender , waist circumference , fat - mass percentage and ( fat% ) , systolic and diastolic blood pressure ( sbp and dbp ) .
bmi and fat% were used as measures of general adiposity , whereas waist circumference was used as measures of central adiposity .
waist circumference was measured midway between the lowest rib and the superior border of the iliac crest with an inelastic measuring tape at the end of normal expiration to the nearest 0.1 cm .
venous blood samples were collected by direct venipuncture after an overnight ( minimum 12 h ) fast .
the samples were centrifuged , aliquoted , and immediately frozen and stored at 80c for future analysis of lipids and hormones .
serum lipids including triglyceride ( tg ) , total cholesterol ( tc ) , high - density lipoprotein cholesterol ( hdl - c ) , low - density lipoprotein cholesterol ( ldl - c ) ( enzymatic methods ) , and plasma glucose ( glucose oxidize method ) were assayed using the hitachi 7060 c automatic biochemistry analysis system .
serum insulin , adiponectin , and leptin were measured by sandwich enzyme - linked immunosorbent assays ( elisa ) , which were developed and performed centrally in key laboratory of endocrinology in peking union medical college hospital .
the insulin assay had a sensitivity of 0.5 mu / l and an interassay cv of < 9.0% , and no cross - reactivity to proinsulin ( < 0.05% ) .
assay characteristics for the measurement of adiponectin and leptin were as follows : intra - assay cvs of < 5.4% and < 7.4% , respectively ; interassay cvs of < 8.5% and < 9.3% , respectively [ 17 , 20 ] .
pubertal development was assessed by tanner stage of breast development ( girls ) and testicular volume ( boys ) .
this assessment was performed visually by two pediatricians of the same gender as the child .
subjects were divided into gender and tanner stage ( t ) as follows : prepubertal ( t1 ) , early pubertal ( t2 ) , midpubertal ( t3 - 4 ) , and late pubertal ( t5 ) .
bmi was calculated as weight ( kg ) divided by height squared ( m ) .
insulin resistance index was calculated by homeostasis model assessment of insulin resistance ( homa - ir ) as follows : fasting insulin ( mu / l ) fasting glucose ( mmol / l)/22.5 .
unless otherwise stated , all results were displayed as mean standard error ( se ) .
one - way anova was used for comparison of multiple groups ( as indicated ) with post hoc comparison being used to evaluate group differences . for contribution of multiple independent variables on one dependent variable
clinical and metabolic data of the subjects separated according to sex and weight are shown in table 1 . between boys and girls , in normal weight group , differences existed in most parameters except diastolic blood pressure ( dbp ) , hdl - c , and adiponectin . in both overweight and obesity groups , boys and girls had similar age , diastolic blood pressure , and levels of adiponectin and lipids ( tc , tg , hdl - c , ldl - c ) .
moreover , there was no bmi difference between overweight boys and girls , whereas obesity boys had larger bmi value than obesity girls .
boys had greater bmi z - score than girls in each weight group . within either sex , bmi , bmi z - score , waist circumference , fat% , sbp , dbp , and levels of tg , leptin and
homa - ir values increased with adiposity , while hdl - c and adiponectin decreased with adiposity .
children and adolescents were separated according to bmi ( normal weight , over weight , and obesity ) , tanner stage , and gender ( figure 1(a ) ) . in all three weight groups ( normal weight , over weight , and obesity ) ,
bmi increased throughout puberty in both genders , with faster increment occurring in early puberty ( t1t3 ) . from t1 to t4 , boys had higher bmi than girls in all three groups ( p < 0.001 ; figure 1(a ) ) , but at the end of puberty ( t5 ) , the difference in bmi disappeared between boys and girls .
measurement of waist circumference rose steadily across pubertal stage in all groups except a slight falling from t4 to t5 in overweight and obesity boys ( figure 1(b ) ) .
however , unlike bmi , waist circumference was significantly higher in boys than in girls at each t stages regardless of weight .
as shown in figure 1(c ) , in all three groups , fat% increased continuously with puberty progression in girls but exhibited almost no change in boys , thus reached the biggest difference at the end of puberty ( t5 ) between the two genders .
figure 2(a ) showed that in all three weight groups , leptin levels in girls increased steadily with pubertal development .
its levels in boys raised parallel to that in girls in early puberty , then , after peaking at t2 , it decreased till the end of puberty especially in those overweight or obese . differences of leptin levels between two genders were significant at t25 ( p < 0.001 ) in normal weight group , at t35 ( p < 0.001 ) in overweight and obesity groups . before puberty ,
serum adiponectin levels had no significantly difference between girls and boys in all three groups ( figure 2(b ) ) .
the levels , then , declined with pubertal procession for both sexes , with faster decline rate in boys .
consequently , adiponectin levels were lower in boys than that in girls during puberty , and the differences were significant at t2 ( p < 0.01 ) and t3 ( p < 0.05 ) in normal weight , t2 ( p < 0.05 ) and t5 ( p < 0.05 ) in overweight , and t3 ( p < 0.01 ) in obesity group , respectively . as shown in figure 2(c ) , homa - ir indices of boys and girls increased with the onset of puberty , reaching the highest value at t3-t4 ( p < 0.001 ) , almost twice of that at t1 in all three weight groups .
however , the homa - ir indices of boys and girls decreased at t4 - 5 in overweight and obesity groups , while stayed high till the end of puberty in normal weight group . at the end of puberty ( t5 ) ,
indices of homa - ir in overweight and obesity boys were similar to that before puberty . in spite of the falling from t4 to t5 , indices of homa - ir at t5 were still higher than that before puberty in overweight and obesity girls ( p < 0.01 ) .
as a whole group , girls had lower homa - ir indices than boys in early puberty , but not in mid- and later puberty . obviously , homa - ir values of both genders in obesity and overweight groups were higher than that in normal weight group at any t stage ( all p < 0.01 ) .
firstly , multivariate analyses for homa - ir were stratified by sex and bmi ( table 2 ) .
leptin showed a strong and independent predictor of homa - ir , in boys ( p < 0.001 ) and girls ( p
adiponectin was an independent determinant of homa - ir in overweight ( p = 0.023 ) and obesity boys ( p = 0.001 ) and overweight girls ( p = 0.01 ) .
waist circumference was independently associated with homa - ir in obesity children ( boys , p = 0.006 , girls , p < 0.001 ) . replacing waist circumference with fat% or bmi z - score
however , fat% was a contributor to homa - ir only for obese girls ( beta : 0.126 , p = 0.034 ) and bmi z - score only for obese children ( beta : boys , 0.086 , p = 0.027 ; girls , 0.140 , p = 0.003 ) ( data not shown ) .
moreover , tanner staging showed independent contributor to homa - ir in all groups except in obese girls . secondly , to identify which parameters were better indices to predict insulin resistance during puberty , we further separated the subjects by sex and pubertal development ( table 3 ) . in boys , leptin and waist circumference contributed more or less the same to homa - ir ( beta value : 0.253 versus 0.207 ) before puberty .
after the onset of puberty , leptin became a prominent determinant of homa - ir ( beta at t2 : 0.407 , t3 : 0.515 , p < 0.001 , resp . ) , and adiponectin ( p = 0.001 ) emerged as a contributor to homa - ir in midpuberty .
in late puberty , beta value of leptin decreased , and waist circumference and adiponectin were no longer determinants of homa - ir . in girls ,
leptin represented a stronger contributor to homa - ir than waist circumference , while adiponectin was not an independent contributor to homa - ir throughout puberty . when fat% or bmi z - score was inserted as a covariate instead of waist circumference , the relationship between leptin and homa - ir did not change ( data not shown ) . in boys ,
however , in girls , fat% was independently associated with homa - ir before and in late puberty .
bmi z - score showed independent association with homa - ir only before puberty in boys .
to our knowledge , the present cross - sectional analysis is the largest study on the relationship of the pubertal insulin sensitivity with tanner stage , sex , body composition , and adipokines in nonobese and obese children and adolescents to date .
out data demonstrated that in both nonobese and obese children , homa - ir index increased significantly in mid - tanner stage , confirming the presence of insulin resistance in puberty [ 27 ] .
moreover , bmi , waist circumference , fat% , and levels of leptin and adiponectin in serum changed with the progression of puberty , and those changes were of sex differences . in the current study , although bmi and waist circumference in both genders increased progressively with pubertal development , body composition modifications were sexually dimorphic : fat% increased with puberty in girls but not in boys .
this sexual difference suggests that the accumulation of fat in girls may largely explain the accretion of bmi during puberty but in boys the increment in bmi may be mainly attributed to accumulation of fat - free tissue . moreover , gender differences in bmi disappeared at the end of puberty , while differences in waist circumference remained at late puberty , with boys having higher waist circumference than girls . since it has been reported that in children waist circumference is more associated with visceral fat , our results indicate that boys tend to have a more fat distributed prominently in the abdominal area during the pubertal process .
gender itself also influences the change pattern of leptin levels : in our study , leptin levels in girls increased steadily with progression of puberty ; however , in boys , the levels of leptin increased transiently at the beginning of puberty , followed by a decrease till late puberty particularly in those overweight or obese .
consequently , girls had on average twice as much leptin as boys at the end of puberty .
it has been known that leptin circulates at levels directly proportional to body fat ; however , in boys , fat% measured in our study did not decrease like leptin , but was stable during puberty even in those overweight or obesity .
this dissociation might be explained by the method measuring fat mass which is not able to differentiate subcutaneous fat tissue and visceral fat tissue .
bulk of evidence have showed that leptin mrna expression is enhanced in subcutaneous located adipocytes compared to visceral adipocytes [ 24 , 25 ] and that circulating levels of leptin correlate with subcutaneous and total ( not visceral ) adipose tissue .
this is in consistence with our founding in girls that change of bmi , fat% , and leptin was similar , because adipose tissue in girls might develop prominently in the subcutaneous depots .
inversely , in boys , body fat percent measured by more accurate ( method i.e. , dual energy x - ray absorptiometry ) , has been found to be decreased during puberty .
furthermore , as indicated by waist circumference in our study , males , relative to females , tend to partition fat to the visceral spaces ; they would be expected to have lower serum leptin concentrations than females . indeed , our study certificated that leptin levels declined in overweight and obesity boys in puberty .
thus , gender differences in both body composition and body fat distribution during puberty lead to the variations of serum leptin concentrations .
however , due to the limitations of the bia method , we could not investigate the relationship between leptin levels and different fat depots in our subjects .
moreover , gender differences in synthesis , transport , or clearance of the leptin and a potential role of gonadal steroids also contribute to the gender distinction of serum leptin .
it has been reported that circulating concentrations of testosterone significantly negatively correlate with circulating concentrations of leptin normalized to fat mass in males but not in females .
studies in both human and rodents have suggested that the inhibition by circulating androgens is one reason to explain the lower levels of leptin in males .
in addition , the summit of leptin level at the onset of puberty in boys can be interpreted by the permissive action of leptin on trigger of puberty . in our analysis
, in both sexes , there was a significant decrease in adiponectin levels as children transitioned to puberty .
our data were consistent with previous studies which have reported that at the beginning of puberty , adiponectin levels are similar in boys and girls . however , most studies show that adiponectin levels in healthy girls remain almost no change during the pubertal process [ 3336 ] , although woo et al .
have reported a fall in obese girls . on the other hand , in boys , similar to our findings , it has been revealed that adiponectin levels decrease in midpuberty ( between t2 and t3 ) and remain low till the end of puberty . from midpuberty
the falling of adiponectin levels in boys have been most likely due to rising androgen levels .
according to two studies of pubertal children [ 33 , 37 ] , adiponectin levels are inversely correlated with androgen concentrations ( and particularly testosterone in boys ) .
higher testosterone production at increased tanner staging leads to a decrease of sex hormone binding globulin which is positively associated with adiponectin , and moreover , administration of testosterone to hypogonadal males has been shown to suppress adiponectin levels .
otherwise , similar to leptin , human adiponectin gene expression has been found to be lower in visceral compared to subcutaneous fat , and this might be another reason for the decline of adiponectin level in boys .
the decrease of adiponectin in girls observed in our study possibly resulted from the increase in fat mass percent in this period .
briefly , gender difference in adiponectin level during puberty is strongly associated with serum androgen concentrations and sexual dimorphism of changes in body composition and fat distribution .
although pubertal insulin resistance has been observed and studied for many years , the cause of it is uncertain [ 16 , 40 ] . in the present study , we developed multivariate regression analysis to determine which parameter , either adiposity , body composition , or adipokines , was more related to the maturational increases in homa - ir . in the analysis , we stratified our subject by gender , weight , and puberty to specify the associations of the above parameters with homa - ir .
we found that leptin was an independent determinant of the pubertal insulin resistance . and ,
regardless of sex and obesity status , leptin emerged as a stronger contributor to pubertal homa - ir than fat% , waist circumference , or bmi z - score , which were traditional measurements of obesity .
however , it is intriguing when looking at the trends of leptin concentration and homa - ir , which were very different during puberty .
thus it should be noted that although leptin in our study appeared more related to homa - ir , its contribution to puberty insulin resistance might still be limited , because leptin together with all these parameters observed in multivariate analysis could only explain less than half of the total variance of homa - ir ( i.e. , r ranged at 0.330.48 ) . associations between adiponectin and insulin resistance have been controversial between studies .
some studies have reported moderately strong inverse correlations , independently of potential confounders including age , race , sex , total fat , and tanner stage , while others have not shown associations after being adjusted for body weight . in our study , when were the children grouped by sex and puberty , the relationship between falling adiponectin level and homa - ir varied with sex , pubertal development , and other covariates in the models ( different anthropometry measurements : bmi , waist circumference or fat % ) . in the weight - stratified groups , adiponectin presented as an independent indicator of homa - ir in overweight and obesity boys and overweight girls but not in lean subjects .
that particularly central obesity , exerted an effect on the relationship of adiponectin with insulin resistance .
moreover , among traditional adiposity indicators , waist circumference was more related to homa - ir than bmi z - score and fat% during puberty in both genders . in agreement with our results ,
waist circumference has been found to be an independent predictor of insulin resistance in black and white youth .
it has been stated that in children , waist circumference is more associated with visceral fat , whereas bmi is more related to subcutaneous fat .
interestingly , only visceral fat is associated with fasting insulin and tg in obese adolescent girls .
thus , waist circumference , a marker of abdominal obesity , has been recommended as an important component of pediatric metabolic syndrome definition .
however , it also should be noted that the limitations of the bia method employed by our study to measure fat% might be an important reason of bias in considering the contribution of boy composition to homa - ir .
nonetheless , although the traditional simple measurements of adiposity could not be substituted for their contribution to pubertal insulin resistance , the adipose - derived adipokines , especially leptin , rather than those traditional adiposity indicators , like bmi , waist circumference , or fat% , are more sensitive to detect high - risk individuals of metabolic syndrome at an early age .
therefore , monitoring these adipokines as a supplement to anthropometric measurement would be expected to provide important information for assessing metabolic risks as early as in childhood .
the major strength of this study was that we comprehensively evaluated the relative role of anthropometric measurements , biochemical parameters , and adipokines in predicting insulin resistance estimated by homa - ir in puberty in a large representative sample of chinese children . nevertheless , several limitations of our study should be acknowledged .
first , the bia method we used can not distinguish visceral from subcutaneous fat and barely assessed the effect of different adipose deposit on pubertal insulin resistance .
second , the results were limited by the use of homa rather than the gold standard technique , that is , hyperinsulinemic - euglycemic clamp , for its complexity in large pediatric population .
third , cause - and - effect relationships could not be inferred because of the cross - sectional nature of the study design . despite these limitations , our investigation provides some robust cross - sectional data on metabolic and anthropometric characteristics and their association with pubertal insulin resistance of obese and nonobese chinese individuals during pubertal development .
in conclusion , both obese and nonobese children experience a stage of decreased insulin sensitivity during puberty .
bmi , waist circumference , fat% , and adipokines change with the progression of puberty , and these changes are of sex dimorphism .
increase of leptin level is a reliable indicator of the pubertal insulin resistance as estimated by homa - ir , and adiponectin can be envisioned as obesity - associated predictor of insulin resistance in puberty .
therefore , in pubertal children , increase in serum leptin level and decrease in adiponectin level may allow the early identification of at - risk individuals , providing important prognostic information in predicting insulin resistance and metabolic syndrome .
however , longitudinal studies are necessary to evaluate the role of adipokines in the normal process of growth and in the development of obesity - related disease in childhood . | a transient increase in insulin resistance ( ir ) is a component of puberty .
we investigated the impact of body composition and adipokines on ir during puberty in chinese children .
this study included 3223 schoolchildren aged 618 years .
ir was calculated using homeostasis model assessment ( homa - ir ) .
we revealed that body mass index ( bmi ) and waist circumference increased gradually during puberty in both genders , while fat - mass percentage ( fat% ) increased steadily only in girls .
change of leptin showed striking sexual dimorphisms : in girls leptin increased steadily during puberty , whereas in boys , after a transient rise at the beginning of puberty , leptin declined by tanner staging even in those overweight or obese . inversely , adiponectin level decreased significantly during puberty . in both genders ,
homa - ir started to increase at the beginning of puberty , peaked in the middle , and revised at late puberty in overweight / obesity boys while it stayed high till the end of puberty in girls and normal weight boys .
multivariate regression analysis revealed that leptin presented a stronger indicator of homa - ir than anthropometric measures during puberty .
our results demonstrated that gender - specific fat% and leptin changed with pubertal development .
leptin emerged as a stronger predictor of ir than traditional anthropometric indices , suggesting a prominent role in the development of pubertal ir . |
among the acute esophageal injuries , intramural hematoma of the esophagus ( ihe ) is an uncommon clinical entity .
ihe may occur spontaneously1 or secondarily2 to either sudden intraesophageal pressure changes or direct mucosal injury / trauma .
patients usually present with a sudden onset of severe retrosternal pain , dysphagia , or hematemesis .
the diagnosis is made by contrast esophagography , esophageal endoscopy , and computed tomography ( ct).3 conservative management is successful in almost all patients , with spontaneous resolution of the hematoma in approximately 2 to 3 weeks.4 - 6 despite the increasing number of reports on ihe , many physicians are still unfamiliar with this condition .
we report here a case of ihe which occurred after endoscopic pinch biopsy and was recovered following conservative management in a patient who was taking long - term aspirin medication .
a 60-year - old woman visited our gastroenterology clinic in october 2010 for a routine endoscopic examination . at examination , she was hemodynamically stable .
she had a history of hypertension and diabetes mellitus which was controlled with losartan ( 25 mg ) , carvedilol ( 6.25 mg ) , and glimepiride ( 2 mg ) .
she also had a medical history of long - term low - dose aspirin intake , and had undergone nephrectomy and total thyroidectomy for incidentally detected renal cell carcinoma and thyroid carcinoma .
black colored spot densities and mucosal irregularities were noted in the upper portions of the esophagus .
small ulcers were observed in the gastric body of the stomach and the duodenum was unremarkable in appearance .
a biopsy specimen was taken from the upper esophagus with an olympus fb-21k-1 biopsy forceps ( olympus co. , tokyo , japan ) ( fig .
three hours after the biopsy , she experienced worsening chest discomfort , dysphagia , and hematemesis .
she then received emergency esophagogastroduodenoscopy ( egd ) which revealed luminal narrowing with an extensive bulge in the posterior wall of the esophagus .
a soft bluish submucosal lesion had extended from the upper esophagus to beyond the gastroesophageal junction ( fig .
chest ct showed an elongated non - enhancing mass involving the posterior wall of the entire esophagus which extended across the gastroesophageal junction into the fundus and body of the stomach ( fig .
the patient was administered a high - dose acid suppression therapy by continuous intravenous administration of pantoprazole ( 8 mg / hr ) .
follow - up egd performed 12 days later revealed complete resolution of the submucosal hematoma and a longitudinal deep ulcer replacing the previous mucosal tear ( fig . 1d ) .
healing of the esophageal ulcer and complete resolution of the hematoma were confirmed by repeat egd performed 3 months later .
ihe is an uncommon condition within the spectrum of esophageal injuries ranging from mucosal tear ( mallory - weiss syndrome ) to transmural perforation ( boerhaave 's syndrome ) .
ihe is also known as intramural esophageal perforation,7 intramural dissection of the esophagus,8 and esophageal apoplexy.9 cases of ihe have been reported more frequently in middle - aged or elderly females .
elderly patients with intrinsic coagulopathies or who are taking anticoagulant or antiplatelet medication are at higher risk for ihe.10 the three most common presenting symptoms are chest pain , hematemesis , and dysphagia with odynophagia .
other reported symptoms include back pain , epigastric pain , nausea , and vomiting.11 hematemesis may indicate temporary bleeding due to a mucosal tear .
following gradual enlargement of a hematoma , the submucosal layer may become structurally weak and mucosal tear and bleeding may occur at the weakest point.12 hematemesis frequently occurs at the onset of ihe but stops spontaneously . in the present case ,
a longitudinal ulcer revealed by follow - up egd was believed to be caused by healing of the mucosal tear .
submucosal hemorrhage that dissects the submucosal plane and ruptures through the mucosa is one potential mechanism .
the disorder may occur spontaneously,1 or it can be secondary to endoscopic sclerotherapy for esophageal varices,13 esophageal dilatation,14 food impaction,15 improper swallowing of drug pills,16 or coagulopathy.10,17 however , as in our case , endoscopic biopsy is a rarely reported cause of ihe .
diagnosis of ihe is facilitated by gastrograffin - contrast upper gastrointestinal series ( which classically indicates a mucosal " stripe " sign ) , computed tomography imaging , or esophageal endoscopy.1 ct reveals an elongated non - enhancing mass inseparable from the esophagus containing hyperdense areas .
esophageal endoscopy is also useful but is invasive and may actually precipitate or worsen the condition .
the general course is uneventful , even when mucosal lesions are extensive . in most patients ,
complete resolution of their symptoms occurs in 2 to 3 weeks with conservative treatment.4 - 6 our patient was also treated conservatively and showed a complete recovery .
most patients can be treated using intravenous nutrition and analgesics with discontinuation of oral feeding .
h2 blocker or proton pump inhibitor administration is considered for the suppression of gastric acid production and reflux to the esophagus.18 we therefore decided to administer ppi to prevent additional invasive therapy such as endoscopic therapy or surgery .
surgical intervention usually is required only to control bleeding.19 sudhamshu et al.20 reported a case of hematoma happened to be incised for biopsy , which resulted in rapid decompression .
cho et al.12 performed an endoscopic incision of the hematoma , in which case the lesion did not resolve spontaneously .
thus , only rare cases require endoscopic therapy after the failure of conservative treatment , such as in patients with potential airway obstruction , or those with persistent or worsening symptoms.12,20 in many cases , including ours , ihe patients have a medical history of aspirin or anti - coagulant intake .
in contrast , yen et al.,2 lauzon et al.,11 and cho et al.12 reported that patients diagnosed with ihe had no prior history of coagulopathy or anticoagulant or aspirin use .
however , there were no apparent differences in clinical course between the two occasions ( i.e. , taking or not taking anticoagulant medication ) . based on our experience with the present case ,
we believe that even patients with persistent symptoms and mucosal tears from ihe will improve with a conservative approach . in addition , more experience is necessary before a definitive statement can be made . some cases required endoscopic therapy2 or surgery19 for resolution of ihe . in conclusion
, ihe should be considered as a potential complication after endoscopic esophageal biopsy in patients taking long - term aspirin medication . | intramural hematoma of the esophagus ( ihe ) is an uncommon form of esophageal injury , which may be an intermediate of mucosal tear ( mallory - weiss syndrome ) or transmural rupture ( boerhaave 's syndrome ) . to date
, the pathogenesis of ihe has not been well documented .
ihe may occur within the submucosal layer of the esophagus following dissection of the mucosa .
the most commonly presented symptoms are sudden retrosternal pain , dysphagia and hematemesis .
the disorder can occur spontaneously or secondarily to trauma . in this report , we present a case of ihe which occurred after endoscopic biopsy and was recovered following conservative management in a patient who was taking long - term aspirin medication . |
a hepatic lymphangioma is a rare benign neoplasm characterized by cystic dilatation of the lymphatic vessels in the hepatic parenchyma , and usually occurs as part of systemic lymphangiomatosis.1 a solitary hepatic lymphangioma is extremely rare in adult patients.12 the prognosis for hepatic lymphangioma is good and patients have no need for further treatment after surgical resection .
we present here a rare case of a female patient who underwent right hepatectomy for solitary giant hepatic lymphangioma .
a 42-year - old female presented to the emergency department with a complaint of severe abdominal pain of the right upper quadrant for 1 day .
a physical examination revealed a huge , palpable mass occupying the right region of the abdomen .
ultrasonography revealed a hemorrhagic complicated giant cystic mass with septation and multifocal hyperchoic solid components in the right liver ( fig .
1 ) . abdominal computed tomography ( ct ) revealed a giant and relatively well - defined homogenous cystic mass of size 2330 cm , with few septa occupying the segment vii and viii of the liver and extending from the diaphragm to the right iliac crest ( fig .
hematologic results were within normal ranges as follows : a white blood cell count of 6,660/mm ( segmental neutrophil 81.4% ) , hemoglobin level of 13.3 g / dl , hematocrit of 38.9% , platelet count of 384,000/mm , total protein level of 6.1 g / dl , albumin level of 4.2 g / dl , total bilirubin level of 0.71 mg / dl , aspirate aminotransferase level of 32 iu / l , alanine aminotransferase level of 38
serologic tumor markers such as carcinoembryonic antigen ( cea : 1.22 u / ml ) and carbohydrate antigen 19 - 9 ( ca19 - 9 : 0.6 u / ml ) were normal .
, a giant cystic tense mass was found at the right two segments of the liver ( segments vii and viii ) , accompanied with minimal spillage of old bloody fluid through the small tearing of a thinned cystic wall .
we aspirated about 3,500 ml volume of cystic fluid to improve the working space and to manipulate the cyst , by which the cyst was decompressed .
the cystic fluid levels of cea and ca 19 - 9 were 0.54 and 0.6 u / ml , respectively .
gross pathology revealed a mass of around 2330 cm in size with a unilocular cyst and a pinkish white smooth inner surface , which was filled with a coffee - like fluid and sludge ( fig .
4a ) . immunohistochemical staining revealed that these endothelial - lined cells are positive for cd31 , but negative for hepatocytes , ck19 and ck20 ( fig .
she was discharged on postoperative day 10 and has been followed up for 18 months without evidence of recurrence .
lymphangiomas are generally considered to be congenital malformations of the lymphatic system , and they occur mostly in the neck , mediastinum and retroperitoneum ; they are seldom found in the liver.123456 most hepatic lymphangiomas usually have a non - specific clinical presentation such as vague abdominal pain or mass of the affected side.1234 the major complaints were related to the compression of surrounding structures by the large lesion . in our case , the patient suffered from sudden pain in the right abdomen , which is considered to be a localized peritoneal sign of cystic fluid leakage from the tumor . although the typical ultrasonography or computed tomography feature of hepatic lymphangioma is a cystic or multicystic hepatic mass with internal septations , the accurate preoperative diagnosis of hepatic lymphangioma is difficult because the these findings can be confused with other cystic tumors such as bile duct cysts , and biliary cystadenomas and cystadenocarcinomas.78 although we could not perform magnetic resonance imaging in our hospital , it may also help with the diagnosis of lymphangioma , and usually shows a multi - lobulated heterogeneous mass with low signal intensity on t1-weighted images and high signal intensity on t2-weighted images.8 the accurate diagnosis was made by pathological examination .
histologically , lymphangiomas are classified into three subtypes according to the congenital dilated lymphatic channels : capillary ( super - microcystic ) , cavernous ( microcystic ) , or cystic ( macrocystic).56 the histogical findings of the hepatic lymphoma are similar to those of other intra - abdominal lymphangiomas .
hepatic lymphangiomas are characterized by cystic dilatation of the lymphatic vessels in the hepatic parenchyma filled with lymph fluid , and are unilocular or multilocular in appearance.1234 the diagnosis in our case was ultimately found to be the cystic type .
the histological features of cystic lymphangiomas include the following : flat endothelial lining of the cyst rather than cuboidal epithelium ; lymphoid aggregates in the cyst wall ; and smooth muscle in the cyst wall.5 in addition to these histological characteristics , the endothelial lining cells usually react positively with cd31 or factor viii - related antigen , but negatively with cytokeratin on immunohistochemical staining.5 in our case , the immunochemistry with cd31 was used for the detection of endothelial cells of the hepatic lymphangioma and supported its diagnosis .
in contrast to hepatic lymphangiomas , biliary cystadenomas usually demonstrate pathological features such as a cyst with a single lining of cuboidal to columnar epithelium supported by thick fibro - connective tissue and papillary foldings into the cyst .
the standard treatment for hepatic lymphangioma is complete surgical resection since incomplete excision may often lead to a recurrence.4 liver transplantation is also considered in patients with an unresectable giant hepatic lymphangioma or poor hepatic function.9 the prognosis following complete resection is excellent . although the prognosis of a solitary hepatic lymphangioma is favorable after surgical resection , we recommend that the patient should undergo follow - up because of the possibility of recurrence . | a hepatic lymphangioma is a rare benign neoplasm that is usually associated with systemic lymphangiomatosis .
a solitary hepatic lymphangioma is extremely rare .
therefore , we present a rare case of a female patient who underwent right hepatectomy for solitary giant hepatic lymphangioma .
a 42-year - old female presented to the emergency department with complaint of severe abdominal pain of the right upper quadrant . abdominal computed tomography showed an approximately 2330-cm sized , giant , relatively well - defined , homogenous cystic mass with few septa in the right liver ( segments vii and viii ) .
the preoperative diagnosis was a giant hepatic cystadenoma or cystadenocarcinoma .
we performed right hepatectomy .
the permanent histopathological report revealed cystic lymphangioma of the liver .
although the prognosis of solitary hepatic lymphangioma after surgical resection is favorable , recurrence has been reported in literature . |
numerous studies have underscored the significance of the early parenting experiences in the development of depression in adulthood .
negative experiences in childhood may make children more susceptible with respect to psychopathological development during their lifespan ( 1 - 3 ) .
mood disorders in children can be attributed to genetic vulnerability or unhealthy parenting styles ( 4 ) .
beck 's model suggested that the effect of parenting on depression might be at the schematic level of cognition .
they are important beliefs and feelings about oneself and the environment , which the individual admit without any question .
dysfunctional schemas are generally believed to develop early in life and , once activated , negatively distort the categorization and interpretation of information , bringing about depression .
such beliefs are usually outcomes of poor parenting or other traumatic experiences ( 1 , 5 ) . therefore
, poor parenting may contribute to depression in offspring through its effects on children s beliefs about themselves , their future , or ways of interpreting life experiences .
particularly , children reared in a controlling environment , and especially those with no warmth and care may develop ways of thinking that increase their vulnerability to depression in the short term , as well as over the course of development into adulthood .
consequently , it can be hypothesized that unhealthy core beliefs develop the necessary cognitive level to understand the links between poor perceived parental styles in childhood and subsequent depression . in this respect ,
the present study made an attempt to examine the association between recalled parenting styles and the emergence of depression in adulthood and the role of dysfunctional schemas as mediators or moderators . in this regard , there are four types of early life experiences that result in early maladaptive schemas .
the first is frustration of needs , which occurs when the child experiences inadequacy of a good thing .
this experience brings about schemas such as emotional deprivation or abandonment in the early environment .
the schemas , which appeared with this experience , are mistrust or abuse ; defectiveness or shame ; and vulnerability to harm . in the third type ,
the child experiences too much of a good thing . the parents indulge to cater everything for the child .
the schemas emerged from these experience are dependence or incompetence ; and entitlement or grandiosity .
the child selectively identifies with and internalizes the parent s thoughts , feelings , experiences , and behaviors .
an investigation considered the potential role of core beliefs in the relationship between recalled parenting in childhood and major depression in adulthood . in this regard
the depressed group was varied by poorer perceived parenting and 3 unhealthy core beliefs ( defectiveness or shame , self - sacrifice ; and insufficient self - control ) ( 7 ) .
it is also hypothesized that the relationship between parental representation and depression can be mediated by cognitive vulnerability factors ( 8) . to indicate the significant role of toxic early experiences , a study displayed that perceptions of childhood emotional abuse and emotional neglect were associated with later symptoms of anxiety and depression and mediated by schemas of vulnerability to harm , shame , and self sacrifice ( 9 ) .
recently , it was also shown that dysfunctional attitudes and automatic thoughts mediate the effects of the perceived rearing on depression ( 10 ) .
most parents use a variety of styles depending on their culture and social demands , but it is also necessary to look at the role that a culture plays in parenting style . as the schema approach emphasizes , early childhood experiences , innate temperament of the child , and cultural origins influence the development of early maladaptive schemas .
one of the goals of the present study is to compare the parenting styles of respondents in india and iran and distinguish the differences of the targeted communities . regarding cultural influence on parenting style ,
their study indicated no apparent culture - dependent association between parental child - rearing styles and the occurrence of mood disorders ( 12 ) . according to the family systems ' perspective
, mothers and fathers parenting styles are interrelated in a mutually dependent manner , so that , the relationship between mothers and fathers parenting makes an important contribution to children s functioning , perhaps more important than the contributions of each one of them alone ( 13 , 14 ) .
the present study attempted to investigate contributions of maternal and paternal styles to the adulthood depression and the role of early maladaptive schemas as mediators or moderators in this association .
the sample was selected randomly and consisted of 200 females diagnosed with ( mild to moderate ) depression .
a sample of 100 participants was selected from one indian and one iranian metropolitan cities each ; pune and tehran , respectively .
this number was selected , according to the statistical methods and the required larger sample size ( samples above 40 people are listed among large samples ) ( 15 ) .
the age range of the participants was 16 - 60 years ( india 30.26 11.46 years ) and ( iran 31.92 10.08 years ) . because , the homogeneity in the degree of depression experienced by the participants was needed beck depression inventory was used for identifying the participants with mild or moderate depression .
written permission was obtained from the head of the department to carry out the research in different places ( hospitals and clinics ) .
after diagnosis of psychiatrists , the patients were referred to the researcher who established the rapport and explained the details of the research . meanwhile , informed consent was taken , the participant s cooperation was solicited and confidentiality was assured that their responses were to be used only for the research purpose .
beck depression inventory ( bdi ) test was designed by dr aaron t. beck in 1961 .
it consists of 21 questions regarding how the subject has been feeling in the last week and each answer was scored on a scale of 0 to 3 .
the cutoff was used as follows : 014 , minimal depression ; 1520 , mild depression ; 2130 , moderate depression ; and 3163 , severe depression .
bdi - ii had good internal consistency ( = .90 ) and its total score was not significantly correlated with gender , age , or ethnicity ( 16 ) .
also , bdi - ii appears to have strong psychometric support as a screening measure for depression among older adults in the general population ( 17 ) .
the persian version of bdi - ii has high internal consistency ( cronbach = 0.87 ) and acceptable test - retest reliability ( r = 0.74 ) in iran ( 18 ) .
the test retest reliability ( r = 0.82 ) and very good internal consistency ( = 0.96 ) of bdi were reported in india too ( 19 ) .
young schema questionnaire ( ysq - sf ) was developed in 1998 by jeffery young .
participants are asked to choose the highest score from 1 to 6 on the rating scale ( likert scale ) that explain them . for the purpose of achieving the goals of the present study , all scores ( 1 to 6 )
this questionnaire contains 90 items to measure early maladaptive schemas ( emss ) in 18 subscales , including 5 domains as follows : domain i ; emotional deprivation ( ed ) , abandonment ( ab ) , mistrust / abuse ( ma ) , social isolation ( si ) , and defectiveness / shame ( ds ) ( 1 ) ; domain ii ; failure ( fa ) , dependence / incompetence ( di ) , vulnerability to harm ( vh ) , and enmeshment ( em ) ; domain iii ; entitlement ( et ) , and insufficient self - control ( is ) ; domain iv ; subjugation ( sb ) , self - sacrifice ( ss ) , and approval seeking ( as ) ; domain v ; emotional inhibition ( ei ) , unrelenting standard ( us ) , negativity / pessimism ( np ) , and punitiveness ( pn ) . the questionnaire possesses very good internal consistency ( 20 , 21 ) .
a study indicated the cronbach coefficient of 0.94 in iran ( 22 ) . in the present study ,
the young parenting inventory ( ypi ) is a 75-item questionnaire in which respondents rate their mothers and fathers separately on a variety of behaviors that could have contributed to the development of the schemas .
it reflects such childhood environments that are likely to shape the development of specific schemas .
the only exceptions are items 1 through 5 , which assess the origins of emotional deprivation and are scored in reverse .
a research sought to validate the inventory , indicated its cronbach scores > 0.70 with good internal consistency ( 23 ) . a study in iran reported consistency coefficient of 0.69 for the ypi - mother form and 0.80 for the ypi - father form ( 24 ) . in the present research ,
the cronbach was attained for subscales of mother and father in iran ( 0.92 ) and india ( 0.93 ) .
the sample was selected randomly and consisted of 200 females diagnosed with ( mild to moderate ) depression .
a sample of 100 participants was selected from one indian and one iranian metropolitan cities each ; pune and tehran , respectively .
this number was selected , according to the statistical methods and the required larger sample size ( samples above 40 people are listed among large samples ) ( 15 ) .
the age range of the participants was 16 - 60 years ( india 30.26 11.46 years ) and ( iran 31.92 10.08 years ) . because , the homogeneity in the degree of depression experienced by the participants was needed beck depression inventory was used for identifying the participants with mild or moderate depression .
written permission was obtained from the head of the department to carry out the research in different places ( hospitals and clinics ) .
after diagnosis of psychiatrists , the patients were referred to the researcher who established the rapport and explained the details of the research . meanwhile , informed consent was taken , the participant s cooperation was solicited and confidentiality was assured that their responses were to be used only for the research purpose . the collection of data lasted from january 2009 until the end of 2010 .
beck depression inventory ( bdi ) test was designed by dr aaron t. beck in 1961 .
it consists of 21 questions regarding how the subject has been feeling in the last week and each answer was scored on a scale of 0 to 3 .
the cutoff was used as follows : 014 , minimal depression ; 1520 , mild depression ; 2130 , moderate depression ; and 3163 , severe depression .
bdi - ii had good internal consistency ( = .90 ) and its total score was not significantly correlated with gender , age , or ethnicity ( 16 ) .
also , bdi - ii appears to have strong psychometric support as a screening measure for depression among older adults in the general population ( 17 ) .
the persian version of bdi - ii has high internal consistency ( cronbach = 0.87 ) and acceptable test - retest reliability ( r = 0.74 ) in iran ( 18 ) .
the test retest reliability ( r = 0.82 ) and very good internal consistency ( = 0.96 ) of bdi were reported in india too ( 19 ) .
young schema questionnaire ( ysq - sf ) was developed in 1998 by jeffery young .
participants are asked to choose the highest score from 1 to 6 on the rating scale ( likert scale ) that explain them . for the purpose of achieving the goals of the present study , all scores ( 1 to 6 )
this questionnaire contains 90 items to measure early maladaptive schemas ( emss ) in 18 subscales , including 5 domains as follows : domain i ; emotional deprivation ( ed ) , abandonment ( ab ) , mistrust / abuse ( ma ) , social isolation ( si ) , and defectiveness / shame ( ds ) ( 1 ) ; domain ii ; failure ( fa ) , dependence / incompetence ( di ) , vulnerability to harm ( vh ) , and enmeshment ( em ) ; domain iii ; entitlement ( et ) , and insufficient self - control ( is ) ; domain iv ; subjugation ( sb ) , self - sacrifice ( ss ) , and approval seeking ( as ) ; domain v ; emotional inhibition ( ei ) , unrelenting standard ( us ) , negativity / pessimism ( np ) , and punitiveness ( pn ) .
a study indicated the cronbach coefficient of 0.94 in iran ( 22 ) . in the present study ,
the young parenting inventory ( ypi ) is a 75-item questionnaire in which respondents rate their mothers and fathers separately on a variety of behaviors that could have contributed to the development of the schemas .
it reflects such childhood environments that are likely to shape the development of specific schemas .
the only exceptions are items 1 through 5 , which assess the origins of emotional deprivation and are scored in reverse .
a research sought to validate the inventory , indicated its cronbach scores > 0.70 with good internal consistency ( 23 ) . a study in iran reported consistency coefficient of 0.69 for the ypi - mother form and 0.80 for the ypi - father form ( 24 ) . in the present research ,
the cronbach was attained for subscales of mother and father in iran ( 0.92 ) and india ( 0.93 ) .
beck depression inventory ( bdi ) test was designed by dr aaron t. beck in 1961 .
it consists of 21 questions regarding how the subject has been feeling in the last week and each answer was scored on a scale of 0 to 3 .
the cutoff was used as follows : 014 , minimal depression ; 1520 , mild depression ; 2130 , moderate depression ; and 3163 , severe depression .
bdi - ii had good internal consistency ( = .90 ) and its total score was not significantly correlated with gender , age , or ethnicity ( 16 ) .
also , bdi - ii appears to have strong psychometric support as a screening measure for depression among older adults in the general population ( 17 ) .
the persian version of bdi - ii has high internal consistency ( cronbach = 0.87 ) and acceptable test - retest reliability ( r = 0.74 ) in iran ( 18 ) .
the test retest reliability ( r = 0.82 ) and very good internal consistency ( = 0.96 ) of bdi were reported in india too ( 19 ) .
young schema questionnaire ( ysq - sf ) was developed in 1998 by jeffery young .
participants are asked to choose the highest score from 1 to 6 on the rating scale ( likert scale ) that explain them . for the purpose of achieving the goals of the present study , all scores ( 1 to 6 )
this questionnaire contains 90 items to measure early maladaptive schemas ( emss ) in 18 subscales , including 5 domains as follows : domain i ; emotional deprivation ( ed ) , abandonment ( ab ) , mistrust / abuse ( ma ) , social isolation ( si ) , and defectiveness / shame ( ds ) ( 1 ) ; domain ii ; failure ( fa ) , dependence / incompetence ( di ) , vulnerability to harm ( vh ) , and enmeshment ( em ) ; domain iii ; entitlement ( et ) , and insufficient self - control ( is ) ; domain iv ; subjugation ( sb ) , self - sacrifice ( ss ) , and approval seeking ( as ) ; domain v ; emotional inhibition ( ei ) , unrelenting standard ( us ) , negativity / pessimism ( np ) , and punitiveness ( pn ) .
a study indicated the cronbach coefficient of 0.94 in iran ( 22 ) . in the present study ,
the young parenting inventory ( ypi ) is a 75-item questionnaire in which respondents rate their mothers and fathers separately on a variety of behaviors that could have contributed to the development of the schemas .
it reflects such childhood environments that are likely to shape the development of specific schemas .
the only exceptions are items 1 through 5 , which assess the origins of emotional deprivation and are scored in reverse .
a research sought to validate the inventory , indicated its cronbach scores > 0.70 with good internal consistency ( 23 ) .
a study in iran reported consistency coefficient of 0.69 for the ypi - mother form and 0.80 for the ypi - father form ( 24 ) . in the present research ,
the cronbach was attained for subscales of mother and father in iran ( 0.92 ) and india ( 0.93 ) .
descriptive statistics tests and hierarchical multiple regression were executed for the purpose of analyzing data .
firstly , for the aim of making normality of the data , kolmogorov - smirnov test was performed .
table 1 shows the mean and standard deviation of age and education of the targeted populations and the percentage of participant s occupations as well .
the correlation , mean scores , and standard deviations of variables are presented in tables 2 and 3 in iran and india , respectively . of 21 correlations , all were significant at p < 0.01 and p < 0.05 level .
the results demonstrated the highest correlation between subscales of dysfunctional schemas , parenting styles , and bdi scores as follows : father and mother parenting style ( r = 0.542 ) , bdi scores and mistrust /abuse ( ma ) ( r = 0.438 ) , maternal style and entitlement ( et ) ( 0.434 ) , bdi scores and defectiveness / shame ( ds ) ( r = 0.426 ) , maternal style and emotional deprivation ( ed ) ( r = 0.412 ) , maternal style and mistrust /abuse ( ma ) ( r = 0.404 ) all at p < 0.01 level in iran .
the results revealed the highest association between paternal and maternal style ( r = 0.858 ) , father schemas and enmeshment ( em ) ( 0.455 ) , mother schemas and enmeshment ( em ) ( r = 0.447 ) , mother schemas and emotional deprivation ( ed ) ( r = 0.415 ) , father schemas and emotional deprivation ( ed ) ( r = 0.402 ) in india all at p < 0.01 . since there were significant relationships between perceived parenting styles , depression , and early maladaptive schemas , we examined mediation and moderation models of 18 early maladaptive schemas .
the results exhibited that dysfunctional schemas failed to moderate the correlation between parenting style and depression .
however , it indicated that only abandonment ( ab ) and punitiveness ( pn ) mediated the correlation between parenting styles and depression .
table 4 demonstrates the relationships between parenting styles and depression that are mediated by abandonment .
the first step involved examining the relationship between mother style ( predictor variable ) and bdi ( dependent variable ) , beta = 0.254 , sig .
the first criterion for mediation as defined by baron and kenny was met ( 25 ) . in the second step ,
the relationship between the predictor variable ( mother style ) and the mediator variable ( abandonment ) was tested .
the results of this regression analysis showed that mother style significantly predicted ab , beta = 0.205 , sig = 0.043 , f = 4.208 .
the third step required that the relationship between the predictor variables ( mother style , ab ) and the outcome variable ( bdi ) be examined . as expected , both mother style ( beta = 0.196 , sig .
= 0.048 , f = 6.488 ) and ab ( beta = 0.302 , sig .
= 0.003 , f = 12.381 ) significantly predicted bdi . as it is observed , beta would be reduced and was significant when ab was included .
the final step showed that the strength of the association between parenting style and depressive symptoms was significantly reduced when the mediators were added to the mode .
table 5 presents the association between father parenting styles and depression , mediated by abandonment .
the first step , involved examining the relationship between parenting style - father ( the predictor variable ) and bdi ( the depended variable ) ( beta = 0.298 , sig .
the relationship between the predictor variable ( father style ) and the mediator variable ( abandonment ) was tested .
the results indicated that paternal style significantly predicted abandonment ( the mediated variable ) ( beta = 0.247 , sig .
abandonment also significantly predicted depression when controlling for recalled paternal style ( beta = 0.220 , sig .
when abandonment was included in the regression analyses , recalled paternal styles significantly predicted depression ( beta = 0.251 , sig .
= 0.025 , f = 7.381 ) . in the final step , with hierarchical regression , the significance of the decrease in beta coefficients of the predictor variables , the significance of the relationships between the mediating variables , and the predictor and criterion variables were analyzed . consequently
, beta coefficient was reduced in the third step compared to the first step . to test the hypothesis stating that the relationship between father parenting styles and depressive symptoms mediated by punitiveness , multiple regression analyses were conducted , which are demonstrated in table 6 . in order to investigate the mediator role of punitiveness between perceived parenting style ( ypi ) and depressive symptoms ( bdi scores ) ,
a significant regression between the independent variable and the dependent variable was found ( beta = 0.298 , sig .
= 0.008 , f = 7.381 ) . in the second step , a significant relationship between the independent variable and the mediating variable was observed ( beta = 0.310 , sig .
next , the mediating variable significantly relates to the dependent variable when both the independent variable ( beta = 0.225 , sig .
= .046 , f = 4.103 ) and mediating variable ( beta = 0.259 , sig .
finally , the coefficient relating the independent variable to the dependent variable was higher ( in absolute value ) than the coefficient relating the independent variable compared to the dependent variable in the regression model , with both the independent variable and the mediating variable predicting the dependent variable .
this study considered the potential role of core beliefs in the relationship between recalled parenting in childhood and depression in the adulthood . because all maladaptive schemas are mostly traced back to childhood environment , the present study aimed to explore the effect of early maladaptive schemas on the relationship of childhood maltreatment and toxic experiences with depressive symptoms .
we tried first to evaluate the correlation between early maladaptive schemas and negative parenting styles and depression , then to find out the role of core beliefs as mediators or moderators in this relation .
similar to the previous researches , the present study demonstrated that exposure to inadequate parenting is associated with increased risk of depression in adulthood .
these results pointed out the relationship of parenting styles and early maladaptive schemas with depression in both countries .
the outcomes obtained in this part are consistent with beck s and young s theory .
they hypothesized that maladaptive schemas are generally developed early in life and , once activated , negatively distort the cognitive patterns , leading to depression .
such beliefs are usually the consequence of poor parenting or other traumatic experiences ( 1 , 5 ) . the results also showed that perceived parenting style ( father and mother ) was linked with symptoms of depression in both countries , i.e. , apart from cultural influences on parenting styles , any inadequacy in parenting leads to psychological problems in adulthood .
this finding is compatible with an investigation on the relationship between parental bonding and mood disorder in six european countries .
it showed that the relationship between parental child - rearing styles and mood disorders was mostly homogeneous across the six countries ( 12 ) .
the present study exhibited the correlations of subscales of early maladaptive schemas and parenting styles with depressive symptoms .
this finding is consistent to some extent with the result of a study that found the correlation between parenting style and vulnerability to depression in adulthood ( 7 ) .
the results showed that dysfunctional schemas failed to moderate the correlation between parenting style and depression .
it indicated that the mediation role restricted to abandonment had a mediated role in the association of maternal styles with depression in iran .
the schemas of this domain result from early experiences of an unpredictable and explosive family environment .
people possessing schemas of this domain are anticipated not to receive their needs for security , safety , stability , nurturance , and empathy in the family in a predictable way .
it is theorized that abandonment schema usually occurs when the parent has been inconsistent , unstable or unreliable in meeting the child s basic needs .
it involves the sense that parents are unable to continue providing emotional support or practical protection because they are emotionally unstable and abandon the person in favor of someone better ( 26 ) .
the results in india can be explained by considering the father 's authority and prominent role in his family ; he has a prerogative to behave in his own way .
unhealthy paternal style leads to the insecure feeling that the father might unpredictably abandon the family .
hence , these unhealthy schemas originate from the father s parenting style in an indian family . in the iranian family system ,
if a mother is unstable or unreliable in meeting the child s basic needs , abandonment schema might be formed .
the analysis of the data also revealed that punitiveness schema mediated the effects of perceived paternal style on depression scores in india .
according to schema approach , punitiveness schema refers to the belief that people should be harshly punished for making mistakes .
this schema includes difficulty in forgiving mistakes of oneself or others , due to unwillingness to consider extenuating circumstances .
generally , parents contribute to shape this toxic schema by blaming , punishing , or being verbally abusive when their children make mistakes ( 26 ) .
as it was mentioned , in indian families , the father has the critical role .
if the father criticizes and punishes too much or be verbally abusive , these states contribute to form punitiveness schema in children .
furthermore , the results support significant differences between parental styles as a result of family environments and cultural distinctions in iran and india .
it could be concluded that paternal and maternal rearing are each crucial in the mental health of a child .
the result of this part is consistent to some extent with investigations stating that when the child experiences inadequacy of a good thing in the early environment , the frustration of needs occurs and the schemas such as emotional deprivation or abandonment develops ( 6 ) .
a study also indicating cognitive styles mediated the link between the parental representation and depression ( 8 , 10 ) . since the schema approach emphasizes early childhood experiences , innate temperament of the child , and cultural origins influence in the development of early maladaptive schemas . in order to find out the effect of cultural origins , the present study explored the differences between the targeted countries .
the results are compatible with the study indicating culture influences parental practice in child rearing ( 11 ) . in summary
, it can be concluded that poor parenting styles contribute to dysfunctional schemas , which lead to depression in adulthood .
punitiveness and abandonment schemas mediated the correlation between negative paternal style and depression in india . on the other hand , abandonment schema operated as a mediator between maternal style and depression in iran .
hence , the results indicated that mothers and fathers styles have significant contribution to the mental health and function of children in adulthood . moreover , according to the results obtained from two countries , it can be inferred that parenting styles were influenced by cultural sources .
it can be claimed that the present study is a pioneer to find out the role of dysfunctional schemas as mediators and moderates in relationship between recalled parenting style and depression in both countries .
the main limitation of the present research is the sample that was restricted to females only .
thus , the findings can not be generalized across both genders . in future studies , the researcher may attempt to extend the study , which could be undertaken on a different gender group and to compare genders to identify their early maladaptive schemas and further parenting style .
the results of this research offer interesting insights into the relationship between parenting styles and cognitive styles .
the findings suggest that clinical work on adults with symptoms of depression might need to take note of parental style .
in addition , prospective research could focus on delineating the relationship between specific negative parenting styles and specific cognitive styles in individuals with depression .
the main limitation of the present research is the sample that was restricted to females only .
, the researcher may attempt to extend the study , which could be undertaken on a different gender group and to compare genders to identify their early maladaptive schemas and further parenting style .
the results of this research offer interesting insights into the relationship between parenting styles and cognitive styles .
the findings suggest that clinical work on adults with symptoms of depression might need to take note of parental style .
in addition , prospective research could focus on delineating the relationship between specific negative parenting styles and specific cognitive styles in individuals with depression . | background : many studies have reported that inadequate parental styles can contribute to depressive symptoms through dysfunctional cognitive styles.objectives:this study aimed to investigate the association of dysfunctional schemas and parenting style with depression , as well as the role of maladaptive schemas such as moderators and mediators in iran and india.patients and methods::the study sample was selected randomly and consisted of 200 ( age group 16 - 60 y ) depressed females ( mild to moderate ) ; 100 from tehran ( iran ) and another 100 from pune ( india ) .
the type of the research was causal - comparative .
the data collection took place in hospitals and clinics in the targeted cities .
descriptive statistic tests and hierarchical multiple regression were executed ( for the purpose of analyzing data ) by spss 17.results:it was demonstrated that the association between parenting and depression was not moderated by early maladaptive schemas . on the contrary , the results supported meditational models in which parenting styles are associated with the cognitive schemas , and these in turn are related to depressive symptoms .
it was also found that abandonment mediates the impacts of maternal style on depression in iran . on the other hand , abandonment and punitiveness
schemas mediated the relation between paternal style and depression in india.conclusions:these findings suggest that the correlation between childhood experiences and depression in adulthood are mediated by dysfunctional schemas . |
good 's syndrome ( gs ) was first described by dr robert good in 1954 .
good 's syndrome is a rare combination of thymoma and hypogammaglobulinemia , and features with few or absent b lymphocytes , cd4 + t cell lymphopenia , and abnormal ratio of cd4 + : cd8 + t cell .
an increased risk for infections in gs patients has been demonstrated by many case reports and reviews , but most infections are mild and can be managed at the outpatient department .
good 's syndrome patients , when with moderate - to - severe infections , have to be hospitalized , but most of the hospitalized cases were described in a form of case report .
the largest series of reported gs patients who were hospitalized for infections , only included 5 patients .
another study by malphettes included 21 gs cases , but the paper did not state whether these patients were hospitalized for infections .
this study presented a series of 12 gs patients hospitalized for infections in our hospital , and the clinical characteristics of this rare disease were illustrated .
the medical files of patients who were hospitalized at peking union medical college hospital from january 2001 to july 2015 were searched for the discharge diagnosis of good 's syndrome .
the following data were retrieved for analysis : age , sex , clinical symptoms , laboratory findings , sites of infection , treatment , and outcomes .
good 's syndrome is defined as following : ( 1 ) the presence of thymoma , confirmed by chest computed tomography and/or pathology ; and ( 2 ) hypogammaglobulinemia , defined as serum immunoglobulin g ( igg ) < 5 g / l , and/or immunoglobulin a ( iga ) < 0.7 g / l , and/or immunoglobulin m ( igm ) < 0.4
an infection was diagnosed when clinical manifestations indicated infection ( fever , cough , sputum , diarrhea , etc ) and corresponding pathogens were identified .
the infection was also diagnosed if clinical manifestations for infections were unequivocal and the treatment aiming at the infection was effective even no pathogen was isolated .
quantitative data were expressed as mean value standard deviation , and qualitative results were described as percentage .
a total of 14 patients with good 's syndrome were initially identified during this period .
two patients were excluded because of no infection associated with their hospitalization , and 12 patients were eligible for this study .
female patients accounted to three - fourths of 12 patients , and the patient age was ranged from 38 to 70 years ( mean age 56.7 + 10.1 years ) .
clinical characteristics of good 's syndrome patients hospitalized for infections the thymoma was histologically confirmed in all patients and resected in 10 of them .
the histological classification of thymoma was available for 7 patients : 3 with type ab , 3 patients with type a , and 1 patient with type b3 .
b lymphocyte was significantly decreased in all patients , ranging from 0 to 9 cells/l ( 1.5 + 2.6 cells/l ) .
cd4 + t lymphocyte was also decreased ( 350.3 + 150.7 cells/l ) , and the ratio of cd4 + : cd8
+ t lymphocyte was inversed in all patients ( 0.49 + 0.16 ) .
serum igg , iga , and igm concentrations were all decreased , and the mean concentrations were 2.3 + 1.9
respiratory and intestinal tracts were the most common sites of infection , which occurred in 7 and 4 patients , respectively .
encephalitis was diagnosed in 1 patient , and the site of infection in 1 patient was not specified .
clinical symptoms were associated with the sites of infection . in patients with pulmonary infection ,
fever and cough were the most common clinical symptoms ( 7/7 ) , whereas diarrhea occurred in all patients with intestinal tract infection ( 4/4 ) .
pathogens were identified in 10 patients including cytomegalovirus ( cmv ) in 5 patients , p. jirovecii and c. difficile in 2 patients , k. pneumonia in 2 patients , and s. pneumonia and h. influenza in 1 patient .
eleven patients survived the infections , and only 1 died from severe pneumonia caused by p. jirovecii .
to the best of our knowledge , this study presented the largest series of gs patients who were complicated by infections in a single center .
we revealed several interesting findings : ( 1 ) infections were the most frequent cause for hospitalization of gs patients ; ( 2 ) respiratory and intestinal tracts were the most common sites of infection in hospitalized gs patients ; ( 3 ) opportunistic pathogens including cmv and p. jirovecii were commonly detected in hospitalized gs patients with infections .
both our study and the literature showed that gs had a peak incidence of infection in the 5th and 6th decade .
a systemic review demonstrated that 83.3% of gs patients caught infections . in this study ,
the infections were identified in 85.7% of the hospitalized gs patients , suggesting that infection was the most frequent cause for hospitalization of gs patients .
this finding implies that gs should be suspected in a thymoma patient with recurrent infections .
it has been reported that upper and lower respiratory tracts were the most common sites of infection in gs patients .
upper respiratory tract infection and superficial fungal infection were precluded in this study because they generally would not be hospitalized .
however , in gs patients who were regularly followed for a long period of time , as high as 85.7% of patients had at least 1 episode of pneumonia .
a systemic review showed that diarrhea occurred in 31.8% of gs patients , but only 11.4% of patients were infectious . a higher percentage ( 58.3% ) of patients with diarrhea
was detected in this study , and 33.3% of them had infectious diarrhea , demonstrating that the intestinal tract is another frequent site of infection in gs patients .
bacteria , especially encapsulated bacteria including s. pneumonia , h. influenza , k. pneumonia , are the most important pathogens in infected gs patients .
similar pathogens were identified in our study . recurrent bacterial infection in gs patients most likely reflects the igg deficiency , the part of problems with gs .
different from common variable immunodeficiency ( cvid ) , cell - mediated immunodeficiency is a common manifestation in gs patients .
cd4 + t lymphocyte count was decreased in all patients and was < 400 cells/l in 58.3% of patients .
although pathogenic bacterium is the most common pathogen in all gs patients , opportunistic pathogens associated with cell - mediated immunodeficiency including cmv ( 41.7% ) and p. jirovecii ( 16.7% ) , frequently caused opportunistic infections in hospitalized gs patients in this study .
cmv often appeared to cause intestinal infection , and p. jirovecii led to pulmonary infection .
thymoma features with autoimmunity , and 32.7% to > 50% of patients with thymoma exhibited autoimmune manifestations .
pure red cell aplasia ( prca ) was the most common autoimmune complication associated with gs as shown by this cohort .
leukopenia is also a common finding in gs patients , as was detected in 33.3% of patients in this study .
although myasthenia gravis ( mg ) is a common comorbidity of thymoma , it is relatively rare in gs patients . in fact , none of our gs patients exhibited mg symptoms , which was consistent with another gs series .
thymectomy is usually recommended in all patients with thymoma to prevent locally invasive growth and metastasis of tumor cells .
however , the thymectomy is usually ineffective in improving immunodeficiency in gs patients , and it might worsen hypogammaglobulinemia in rare cases .
immunoglobulin replacement has been used to maintain appropriate serum igg concentration to reduce infection . in this study , 83.3% of gs patients
were infected and they received immunoglobulin replacement therapy in addition to antibiotics , resulting in clearance of infections in the majority of patients .
therefore , we recommend immunoglobulin replacement as standard therapy in all hospitalized gs patients with infections .
the only patient who died in this study was an old woman who developed prca .
she was on corticosteroid and immunosuppressant therapy when she caught pulmonary infection with p. jirovecii . in our opinion
, the immunosuppressive drugs contributed more to her death than gs itself . because gs is a rare disease , the value of this study is limited by relatively small number of enrolled patients .
additionally , there are no definite criteria for hospitalization of gs patients , which may have resulted in biased findings by this study .
nonetheless , this study excluded many mild or less important infections , which highlighted important infections in gs patients that should be managed timely and carefully . in conclusion , infections are a common manifestation in gs patients and are the most frequent cause for hospitalization . beside the pathogenic bacteria ,
we recommend a combination of antibiotics with immunoglobulin replacement as standard therapy for hospitalized gs patients with infections . | abstractgood 's syndrome ( gs ) is a rare combination of thymoma and hypogammaglobulinemia , resulting in immunodeficiency .
patients with gs are highly susceptible to bacterial infection , particularly encapsulated bacterial infection in upper and lower respiratory tracts .
good 's syndrome patients with moderate - to- severe infection are often hospitalized .
clinical features of gs patients remain to be characterized.patients with the discharge diagnosis of gs and simultaneous infection from peking union medical college hospital between january 2001 and july 2015 were retrospectively analyzed.among 14 hospitalized gs patients , 12 of them were admitted for severe infections .
mean patient age was 56.7 + 10.1 years .
average concentrations of serum igg , iga , and igm were 2.3 + 1.9
g / l , 0.28 + 0.28
g / l , and 0.06 + 0.07
g / l , respectively .
respiratory and intestinal tracts were the most common sites for infection , which occurred in 7 and 4 patients , respectively .
pathogens identified in 10 patients included cytomegalovirus in 5 patients , pneumocystis jirovecii , clostridium difficile in 2 patients , klebsiella pneumonia in 2 patients , and streptococcus pneumonia and hemophilus influenza in 1 patient .
ten patients were treated with antibiotics and immunoglobulin replacement .
only 1 patient who was on immunosuppressant therapy died from p. jirovecii pneumonia.infection was the most frequent cause for hospitalization of gs patients .
both respiratory and intestinal tracts were the most common sites of infection .
cytomegalovirus and p. jirovecii represented 2 common opportunistic pathogens isolated from hospitalized gs patients with infections . |
an increasing body of research is based on the classification and evaluation of the rate of dna evolution in coding regions . in many cases nucleotide substitutions
are classified according to their impact on the encoded protein and the resulting classification can be used for a variety of analyses .
classification of synonymous ( ks ) and non - synonymous ( ka ) substitutions can be used to detect the presence or absence of selection ( 1 ) and the classification of substitutions according to codon position can be used with sophisticated evolutionary models to better reconstruct phylogenies . in both of these cases
the programs that perform the analysis , such as paml ( 2 ) , require a codon alignment as input .
owing to the degeneracy of the genetic code , where a single amino acid can be encoded by multiple codons , it is often preferable to align protein sequences rather than the underlying coding dna as it increases sensitivity at longer evolutionary distances and prevents the introduction of frame shifts into an alignment .
thus the construction of a protein alignment first and then reverse translating this into a codon - based dna alignment is invariably the optimal solution and provides reliable alignments to perform correct evolutionary analyses . in the ideal case
where the protein and the corresponding dna match perfectly , the conversion from a protein alignment into the corresponding codon alignment can be achieved by replacing each amino acid residue with three nucleotide residues , a procedure which is implemented in several tools , e.g. aa_to_dna_aln in the bioperl toolkit ( 3 ) , revtrans ( 4 ) , transalign ( 5 ) and aa2dna ( ) .
however it often happens that the corresponding dna sequence has mismatches when compared with its theoretical protein sequence , or contains untranslated regions ( utrs ) and polya tails . in such instances ,
moreover the analysis of pseudogenes , which are an interesting subject of molecular evolution studies , requires dealing with frame shifts and inframe stop codons .
these situations , which are rather frequent in large - scale analysis of sequenced genomes , can not be solved by the programs mentioned above and therefore require additional solutions .
here we describe a web server , pal2nal , which converts a protein sequence alignment into the corresponding codon alignment , despite the presence of mismatches between the protein and the dna sequences , utrs and polya tails in the input dna sequences , and frame shifts and inframe stop codons in the input alignment .
another useful feature of this server is that it is possible to obtain codon alignments for specific regions of interest , such as functional domains or particular exons by selecting the positions in the input protein sequence alignment .
the server requires a multiple sequence alignment of proteins and the corresponding dna sequences as input .
the internal action of the program can be divided into three main steps : ( i ) upload the protein sequence alignment and dna sequences , ( ii ) reverse translation , i.e. conversion of the protein sequences into the corresponding dna sequences in the form of regular expression patterns and ( iii ) generation of the codon alignment . in the second step ,
for example , a short peptide sequence , mdp , is reverse - translated into a regular expression pattern of the dna sequence as ( a(ut)g)(ga(utcy))(cc . ) . for frame shifts ,
we adapted the notation used in genewise ( 6 ) : if an insertion or deletion is found in the coding region , it is represented by the number of nucleic acid residues at that site instead of an amino acid code .
for example , m2p indicates that there is 1 nt deletion between methionine and proline . with this notation , it is easy to convert the peptide sequence into a regular expression pattern , in this case ( a(ut)g) .. (cc . ) . after converting into a regular expression pattern
, the input dna sequence is searched with the pattern to obtain the corresponding coding region .
this was achieved by extending 10 amino acid regular expression matches in both directions until the entire coding region of the input dna sequence is covered .
the regions between the extended fragments and those not covered by the extension are taken as mismatches , and reported , if any , in the output . in the third step , the protein sequence alignment is converted into the corresponding codon alignment by replacing each amino acid residue with the corresponding codon sequence .
the pal2nal server takes the following two files as input : ( i ) a multiple sequence alignment of proteins either in the clustal or in the fasta format and ( ii ) the corresponding dna sequences in the fasta format .
an example of the application of pal2nal is shown in figure 1 . in this example , a multiple sequence alignment of human dihydrofolate reductase in the clustal format ( 7 ) ( figure 1a ) and the corresponding dna ( or mrna ) sequences in the fasta format ( figure 1b ) are used as input .
the second sequence of this example is a pseudogene , and it contains two frame shifts and three inframe stop codons .
the program automatically trims all utrs and polya tails , and successfully converts the protein alignment into the codon alignment , despite the presence of a mismatch and two frame shifts ( figure 1c ) . if some positions of the input alignment are marked with # under the alignment ( figure 1a ) , the corresponding regions are also marked in the output codon alignment ( figure 1c ) .
the users can select a codon table : either universal ( default ) or
this option should be selected if the codon alignment is to be further analyzed by codeml to calculate ks and ka since the paml package does not accept codon alignments containing gaps or inframe stop codons .
if the second option ( remove gaps and inframe stop codons ) is selected and the input is a pair of sequences , this option also allows to calculate ks and ka values by the codeml program ( 8) included in the paml package .
the calculation of ks and ka is only performed for sequence pairs because the computationally demanding construction of phylogenetic topologies would be required for alignments with more than two sequences .
if there are mismatched codons between the protein and the dna sequences , the users can either remove or retain such codon sites by this option .
( v ) use only selected positions . with this option , only the codon alignment corresponding to the regions marked by
this option is very useful because it allows the construction of codon alignment for a certain exon or a domain or conserved blocks , for example those identified automatically by gblocks ( 9 ) .
the pal2nal server ( ) is useful for constructing codon multiple alignments , which are required in many molecular evolutionary analyses , such as the calculation of ks and ka values . for a large - scale analysis ,
the distribution version of the pal2nal script , which is written in perl and works in command line , is also available for download .
we successfully applied the distribution version of pal2nal , for example , to the detection of human pseudogenes ( 10 ) and to the annotation of genes in human chromosomes 2 and 4 ( 11 ) .
an example of pal2nal input and output files . ( a ) the first input file : a multiple sequence alignment of human dihydrofolate reductase ( genbank accession no .
bc070280 ) and its pseudogene in the clustal format with the notation used in genewise for frame shifts .
frame shifts and inframe stop codons in the pseudogene are shown in orange . under the alignment ,
( b ) the second input file : the corresponding dna ( or mrna ) sequences in the fasta format . utrs and polya tails are shown in cyan to indicate how these regions are excluded from the resulting output .
the position of the codon that does not correspond with the input protein sequence is shown in red .
the regions of alignment blocks correspond to those specified in the input protein alignment are indicated by
( d ) output with the following option setting : remove mismatches , yes ; use only selected positions , yes ; output format , paml . with this setting , | pal2nal is a web server that constructs a multiple codon alignment from the corresponding aligned protein sequences .
such codon alignments can be used to evaluate the type and rate of nucleotide substitutions in coding dna for a wide range of evolutionary analyses , such as the identification of levels of selective constraint acting on genes , or to perform dna - based phylogenetic studies .
the server takes a protein sequence alignment and the corresponding dna sequences as input .
in contrast to other existing applications , this server is able to construct codon alignments even if the input dna sequence has mismatches with the input protein sequence , or contains untranslated regions and polya tails .
the server can also deal with frame shifts and inframe stop codons in the input models , and is thus suitable for the analysis of pseudogenes .
another distinct feature is that the user can specify a subregion of the input alignment in order to specifically analyze functional domains or exons of interest .
the pal2nal server is available at . |
the soils and roots used in this study were collected from a mine ( 12812'50 '' e , 3704'05 '' n ) located in jecheon , korea . the mine was closed in 1981 after about 20 years of mining molybdenum and other heavy metals .
ten samples of soils and roots were randomly collected within a radius of 20 m from the mine - tail . a natural forest area located at 200 m from the mine - tail
was selected as a control site , and another 10 samples were randomly collected within a radius of 20 m. the collected samples were packed into polyethylene bags and transported to the laboratory .
root samples for molecular analysis were stored at 80 , and the root samples for mycorrhizal root colonization rate and the soils for spore analysis were stored at 4. the heavy metal concentration in the soil samples was analyzed in a soil analysis laboratory ( jeil analysis center , seoul , korea ) .
amf spores were extracted from 10 g of dried soil samples using wet decanting and sucrose density gradient methods .
spores were identified by the morphological characteristics of spore walls , such as number , thickness , color , structure , and surface ornamentations .
dna was extracted from spores , and small subunit ribosomal dna fragments were amplified by nested pcr .
the first pcr was performed using the universal primers ns1 and ns4 , and the product was used as template for the second amplification using amfspecific primers , aml1 and aml2 .
the second pcr product was then sequenced ( solgent co. , daejeon , korea ) .
a sequence - similarity search of the national center for biotechnology information ( ncbi ) database was conducted using the basic local alignment search tool ( blast ) algorithm .
six roots of lespedeza cyrtobotrya were selected from 20 root samples for mycorrhizal colonization and community analysis . to examine the amf colonization rates ,
the plant roots were washed and stained with trypan blue according to the methods described by koske and gemma .
the roots were observed under a microscope ( axio imager ; carl zeiss , jena , germany ) , and root colonization rates were measured by the previously described magnified intersects technique .
dna was extracted from surface - sterilized root samples using the dneasy plant mini kit ( qiagen , venlo , netherlands ) with 30% h2o2 solution .
nested pcr was performed to amplify the small subunit rdna using primers ns1 and ns4 for the first pcr and aml1 and aml2 for the second pcr as previously described for spores .
the pcr product was purified using solgent pcr purification kit and cloned using t - blunt pcr cloning kit following the manufacturer 's instructions .
the nucleotide sequence of 20 clones from each sample was determined using an automated sequencer , and identified through blast and phylogenetic sequence analysis . only the sequences belonging to glomeromycota
were included in the analysis . in order to determine the phylogenetic relationships among operational taxonomic units ( otus ) , representative sequences for each otu were selected and aligned with the closest matches obtained from genbank by blast using the clustalx algorithm in mega5 .
neighbor - joining phylogenetic analysis was conducted in mega5 using a bootstrap analysis with 1,000 replicates .
relative abundances for amf communities in soils and roots were estimated based on the molecular and morphological identification data for each root sample .
univariate analysis of variance ( anova ) was used to evaluate the fixed effect of the sampling site on the percent mycorrhizal root colonization rates and the species diversity of amf communities .
pearson correlation analysis was performed to test the effects of heavy metals on amf communities using the statistical package , spss - win ver .
soil chemical analysis for heavy metals ( as , pb , cd , ni , and zn ) showed that the concentrations of as and zn were significantly higher in the abandoned mines than in the natural forest ( table 1 ) .
pb was not detected in both the soils collected in this study , and cd was detected in the soil at both sites but showed no significant difference between locations .
morphological and molecular analysis of spores in rhizosphere soils showed that 8 species of 7 genera were found in the post - mining area , and 6 species of 5 genera of amf were found in the natural forest area ( table 2 , fig .
relative abundance showed that claroideoglomus etunicatum was the most dominant species in the post - mining area and that rhizophagus irregularis was dominant in the natural forest area ( table 2 ) .
the total spore numbers were higher in the mining area than those in the natural forests .
shannon 's index and species evenness were also higher in the mining area than that in the natural forest but were not statistically significant .
correlation analysis of heavy metal concentration with relative abundance of spores showed that a. longula has a strong positive relationship with the heavy metals as and zn , which were significantly higher in the mining area ( table 3 ) .
the accumulation of heavy metals significantly influenced the amf spore communities in the soil for a long period .
mycorrhizal root colonization rates were significantly higher in the mine area ( 81.33 2.67% ) than in the natural forest area ( 61.67 2.85 ) at p < 0.05 , suggesting that significantly high concentrations of heavy metals affect mycorrhizal symbiosis with host plants at the mining sites .
cloning results for amf - colonizing roots allowed identification of 7 otus in the mine area and 5 otus in the species of the forest area ( table 4 , fig .
relative abundance showed that glo6 was dominant in both the mine and the natural forest areas .
glo2 , glo5 , and glo7 were found only in the mine area , and glo4 was found only in the forest area . in this study ,
more diverse amf sequence types were found in the roots of plants in the mining area with high concentration of heavy metals .
however , some previous studies showed that otu number and root colonization rates were decreased with increasing concentrations of heavy metals .
thus , it is considered that diversity of amf could be increased or decreased according to the intensity of the heavy metals which act as a disturbance .
shannon indices were not significantly different between the two areas ( table 4 ) , and correlation analysis showed no significant relationship between the relative abundances of amf species and heavy metal concentrations .
significantly , higher heavy metal concentrations , especially of zn , might be the reason for the higher colonization rates in the mining area .
it has been reported that high accumulation of zn stressed the host plants and increased amf colonization in their roots .
the reason might be that though some amf species are sensitive to heavy metals , other species are tolerant of high heavy metal concentration in soil .
previous studies show that amf species belonging to claroideoglomus are often tolerant to heavy metals , and the results of this study showed that species of claroideoglomus were significantly more in the mine area .
additionally , a. longula showed a strong positive correlation with as and zn and is consistent with previous results that the frequency of a. longula is higher in higher concentrations of zn .
in addition , a. leptoticha , which was found only in the mining area in this study , was also frequently found in contaminated soil containing zn .
however it have been reported that amf communities in soil contaminated by heavy metals more affected by other chemicals in the soil than heavy metals .
thus , the diversity of amf communities in abandoned mine area should be considered with factors of the soil environments as well as the intensity of the disturbance .
the species mainly found in abandoned mines with a long period of ecological disturbance belonged to glomaceae .
previous studies showed that the glomaceae species were dominant under stress conditions such as ecological disturbances , suggesting that glomaceae species are better adapted to disturbed environments than other species . in this study , amf species , c. etunicatum , r. irregularis , r. intraradices in glomaceae were species having a high relative abundance common to both abandoned and natural forest area .
the result was consistent with previous studies of heavy metal contaminated areas , suggesting that the emergence of these species would be the results of strong selection pressure in the settlement process of plants than the intensity of the disturbance . in conclusion
, this study showed that the anthropogenic disturbance of mining activities affects the amf communities . | in this study , we collected rhizosphere soils and root samples from a post - mining area and a natural forest area in jecheon , korea .
we extracted spores of arbuscular mycorrhizal fungi ( amf ) from rhizospheres , and then examined the sequences of 18s rdna genes of the amf from the collected roots of plants .
we compared the amf communities in the post - mining area and the natural forest area by sequence analysis of the amf spores from soils and of the amf clones from roots .
consequently , we confirmed that the structure of amf communities varied between the post - mining area and the natural forest area and showed significant relationship with heavy metal contents in soils .
these results suggest that heavy metal contamination by mining activity significantly affects the amf community structure . |
hyperinsulinaemic hypoglycaemia ( hh ) occurs because of inappropriate secretion of insulin by the pancreatic beta cells .
the congenital forms of hh ( chi ) occur because of defects in key genes involved in insulin secretion .
the commonest and most severe forms of chi are due to mutations in the abcc8 and kcnj11 genes [ 2 , 3 ] , encoding the sulfonylurea receptor 1 ( sur1 ) and inward rectifier k(+ ) channel kir6.2 ( kir6.2 ) subunits of the atp - sensitive potassium ( katp ) channel , respectively .
the katp channels play a pivotal role in glucose - stimulated insulin secretion and couple glucose metabolism to membrane electrical activity and insulin release in the pancreatic beta cells .
the molecular basis of the chi observed in these patients involves defects in the biogenesis and turnover of katp channels , in the trafficking of channels to the plasma membrane and alterations in the open - state frequency through changes in nucleotide sensitivity [ 58 ] .
dominant abcc8/kcnj11 mutations are less frequently reported and generally cause mild medically responsive hh [ 912 ] or in rare cases , severe unresponsive hh .
two reports suggest that medically responsive hh due to a dominantly inherited abcc8 mutation may progress to diabetes mellitus ( dm ) in later life [ 9 , 12 , 14 ] .
however , this was not supported in a recent case series where only 4 out of 29 adult mutation carriers developed dm .
hence , it is not clear whether dominantly acting mutations in the genes that cause diazoxide - responsive hh in childhood are associated with later development of dm in adulthood . in this study
, we present the phenotype of eight different heterozygous abcc8/kcnj11 mutations in nine families and report the prevalence of dm in the adult mutation carriers .
we show that dominant mutations can cause a variable phenotype ranging from asymptomatic macrosomia to transient / persistent hh as well as progression to dm in later life .
the probands are a subgroup of children referred to the tertiary hyperinsulinism service at great ormond street hospital nhs trust , london , uk .
they include those children with hh who were diazoxide responsive and were identified to be heterozygous for a katp channel mutation .
the diagnosis of hh was based on diagnostic criteria described previously ( i.e. inappropriately elevated insulin concentrations at the time of hypoglycaemia with corresponding low concentrations of plasma -hydroxybutyrate and fatty acids ) .
diazoxide responsiveness was defined as the ability to maintain normoglycaemia without the support of intravenous glucose .
clinical information ( birthweight , age at presentation , treatment details of hh ) was collected from the case notes and the referring clinicians .
family history was specifically explored with regards to symptoms of hypoglycaemia and presence / absence of dm and phenotypic details of individuals affected by hypoglycaemia / dm ( birthweight , age of presentation , treatment details ) was collected .
the study was approved by the regional ethical committee and written consent was obtained from the families .
the single exon of the kcnj11 gene and the 39 exons of abcc8 were amplified by pcr using previously reported primers .
single - strand sequencing was carried out using standard methods and an abi3730 capillary sequencer ( applied biosystems , warrington , uk ) and sequences were compared with the published sequences ( nm_000525 and nm_000352.2 [ which incorporates the alternatively spliced amino acid in exon 17 { l78224 } ] ) using mutation surveyor 3.24 software ( softgenetics , state college , pa , usa ) . following identification of a mono - allelic katp channel mutation in the proband ,
microsatellite analysis ( powerplex 16 system , promega , southampton , uk ) was undertaken to confirm family relationships when a de novo mutation was identified .
genetic analysis was then offered to the siblings of the proband ( parental consent obtained ) and to the siblings and parents of the parent identified as heterozygous for the mutation .
co - segregation studies were then undertaken with the available phenotypic data and results of the genetic analysis .
functional analysis of mutant channels functional analysis of the novel abcc8 mutations ( a1508p , a1537v , l1431f , l1390r and q1459e ) and the kcnj11 mutation ( i284del ) was carried out .
mutations were introduced in hamster sur1 ( also known as abcc8 ) cdna and mouse kir6.2 ( also known as kcnj11 ) cdna using the quik - change site - directed mutagenesis kit ( agilent technologies , stockport , uk ) .
mutant katp channel was reconstituted in human embryonic kidney 293 ( hek293 ) cells by transfection using fugene hd ( roche , burgess hill , uk ) according to the manufacturer s instructions . enhanced green fluorescent protein , 50 ng , was also co - transfected to determine transfection efficiency.following successful transfection , an rb flux assay was used to determine functionality of the reconstituted channels as described previously by muzyamba et al . .
the rb efflux assay is based on the principle that when cells are loaded with rubidium , its distribution between intracellular and extracellular spaces is an indicator of channel activity as rb is similar in size and charge to k and is handled by the channels in a manner similar to k. briefly , 24 h after transfection cells were incubated overnight with minimum essential medium ( mem ) containing rb ( 0.037 mbq / ml ) at optimum conditions ( 5% co2 , 37c ) . the assay medium was then aspirated and the cells were washed twice with 2 ml hepes buffered nacl ( hbs ) ( 10 mmol / l hepes , 10 mmol / l glucose , 130 mmol / l nacl , 7 mmol / l kcl , 2 mmol / l cacl2 and 1 mmol / l mgcl2 , ph 7.4 ) .
the cells were then incubated with 2 ml of hbs medium with or without channel stimulants and/or inhibitors .
the following conditions were used : control cells ( no drugs ) ; cells treated with 100 mol / l diazoxide ; cells treated with 100 mol / l diazoxide plus 10 mol / l glibenclamide ; cells treated with 2.5 mmol / l nacn ( sodium cyanide ) and 20 mmol / l 2-deoxy - d - glucose ; and cells treated with 2.5 mmol / l nacn , 20 mmol / l 2-deoxy - d - glucose and 10 mol / l glibenclamide .
the concentrations of the drugs stated have been shown to be effective on this cell line .
the supernatant fraction was aspirated after 5 min into scintillation vials for counting and the cells were then lysed with 2% triton / hbs solution .
cherenkov radiation in the supernatant fraction and cell lysates was measured and the efflux was calculated as a percentage relative to the total amount of radioactivity incorporated .
significant differences were tested by employing the one - way anova and bonferroni post - test .
significant differences are reported as : * p 0.05 , * * p 0.01 and * * * p 0.001.the level of mutant protein produced in the transfected cells was detected using western blotting .
the antibody anti - sur1 nbd2 was raised in sheep to the peptide epitope etllsqkdsvfasfvradk ( university of dundee , dundee , uk ) and subsequently used as described previously by muzyamba et al . .
an anti - sheep igg secondary antibody ( sigma , poole , uk ) linked to horseradish peroxidase and the ecl detection kit ( ge healthcare , amersham , uk ) were used to detect protein production .
ogtt and bmi the adult mutation carriers were divided into those with a history of dm ( gestational or other , n = 8) and those without ( n = 8) .
a 2 h ogtt was conducted in the relatives of adult mutation carriers who had no history of dm to ensure that undiagnosed impaired glucose tolerance / dm was detected .
patients with ongoing hypoglycaemia ( ii-2 , family a and iii-2 , family f [ fig . 1 ] ) were excluded .
six adults met the criteria but one participant ( ii-1 , family e [ fig . 1 ] )
blood glucose concentrations were measured at 0 and 120 min following an oral load of glucose ( 75 g ) in the remaining five adult mutation carriers .
the bmi of the adult mutation carriers with normal glucose tolerance ( n = 5 ) and with dm ( n = 8) was calculated and the means were compared using the student s t test .
individuals who progressed from hypoglycaemia to diabetes are indicated by symbols that are half - filled and half - hatched vertically .
m / n denotes a heterozygous abcc8/kcnj11 mutation and n / n a normal genotype .
the kcnj11 mutation is indicated by * ; the remaining are abcc8 gene mutations partial pedigrees showing inheritance of the dominant mutations in the ten families .
black symbols denote children / adults with hypoglycaemia . individuals who progressed from hypoglycaemia to diabetes are indicated by symbols that are half - filled and half - hatched vertically .
five of the mutations were novel ( l1390r , l1431f , q1459e , a1508p and a1537v ) and two have been reported previously in patients with dominantly inherited hh ( g1479r and r1539q ) . each mutation was identified in a single family with the exception of g1479r , which was identified in two unrelated families .
all mutations affected residues that are highly conserved across species and occurred within nucleotide - binding domain 2 of sur1 , a previously reported hotspot for dominantly acting mutations .
the remaining proband was heterozygous for an in - frame deletion ( i284del ) in the kcnj11 gene.of the 35 adult family members ( including 18 parents ) and eight siblings screened for the identified mutation , 16 adults and five siblings tested positive .
this included eight parents , of whom seven were affected with hypoglycaemia or dm . in the remaining case ( family c ) although the mutation ( g1479r ) had been inherited from the unaffected father it was shown to co - segregate with hh in the family having been identified in the proband s two affected siblings and paternal cousin . in two families
there was no history of hypoglycaemia or dm ( fig . 1 , family i and j ) .
confirmation of family relationships by microsatellite analysis demonstrated that the l1390r and g1479a mutations had arisen de novo in the proband .
functional analysis of mutant channels the r1539q and g1479r abcc8 mutations have been characterised previously by pinney et al . and
the rb flux assay showed that the channels with the mutant proteins ( sur1 [ a1508p , l1431f , l1390r , q1459e or a1537v ] or kir6.2 [ i284del ] ) were non - functional as evidenced by the lack of rb efflux on exposure to the channel agonist diazoxide or metabolic inhibition ( fig .
production of the mutant sur1 proteins l1431f , l1390r , q1459e and a1537v did not differ from the wild - type sur1 protein on western blot analysis ( fig .
2a g effects of sur1/kir6.2 mutants on katp channel function studied with rb efflux .
the rb efflux was assayed 48 h after transfection in control cells ( horizontal hatching , no drugs ) , cells treated with 100 mol / l diazoxide ( diagonal hatching ) , cells treated with 100 mol / l diazoxide plus 10 mol / l glibenclamide ( vertical hatching ) , cells treated with 2.5 mmol / l nacn and 20 mmol 2-deoxy - d - glucose ( black ) and cells treated with 2.5 mmol / l nacn , 20 mmol / l 2-deoxy - d - glucose and 10 mol / l glibenclamide ( white ) .
( a ) wild type ; ( b ) l143f ( abcc8 ) ; ( c ) a1508p ( abcc8 ) ; ( d ) i284del ( kcnj11 ) ; ( e ) l1390r ( abcc8 ) ; ( f ) q1459e ( abcc8 ) ; ( g ) a1537v ( abcc8 ) .
data represent means sem for three different experiments performed in triplicate ( n = 9 ) ; * * * p < 0.001 .
h western blot analysis of sur1 shows that the production of the mutant sur1 proteins l1431f , l1390r , q1459e and a1537v did not differ from the wt sur1 protein ( 177 kda ) .
wt , wild type a g effects of sur1/kir6.2 mutants on katp channel function studied with rb efflux .
the rb efflux was assayed 48 h after transfection in control cells ( horizontal hatching , no drugs ) , cells treated with 100 mol / l diazoxide ( diagonal hatching ) , cells treated with 100 mol / l diazoxide plus 10 mol / l glibenclamide ( vertical hatching ) , cells treated with 2.5 mmol / l nacn and 20 mmol 2-deoxy - d - glucose ( black ) and cells treated with 2.5 mmol / l nacn , 20 mmol / l 2-deoxy - d - glucose and 10 mol / l glibenclamide ( white ) .
( a ) wild type ; ( b ) l143f ( abcc8 ) ; ( c ) a1508p ( abcc8 ) ; ( d ) i284del ( kcnj11 ) ; ( e ) l1390r ( abcc8 ) ; ( f ) q1459e ( abcc8 ) ; ( g ) a1537v ( abcc8 ) .
data represent means sem for three different experiments performed in triplicate ( n = 9 ) ; * * * p <
h western blot analysis of sur1 shows that the production of the mutant sur1 proteins l1431f , l1390r , q1459e and a1537v did not differ from the wt sur1 protein ( 177 kda ) .
wt , wild type clinical characteristics of children with hh the clinical characteristics of the 14 children with hh ( nine probands and five affected siblings ) are summarised in table 1 .
the median age at presentation was 1 day and median birthweight was + 2.21 sd score ( sds ) .
hypoglycaemia resolved within 1 week in one case but the remaining children ( aged 111 years ) received ongoing diazoxide treatment .
table 1clinical characteristics of the 14 children with hhfamilyindividual / sexmutation / genebirthweight sdsage at presentationdiazoxide responsivelength of treatment with diazoxideaiii-1/femalea1537v ( c.4610c > t)/abcc8 + 4.661 dayyescontinuing at 4 yearsbiii-3/femaleg1479r ( c.4435g > a)/abcc8 + 1.371 dayyescontinuing at 11 yearsciii-1/maleg1479r ( c.4435g > a)/abcc8 + 2.821 dayyescontinuing at 1.4 yearsciii-2/femaleg1479r ( c.4435g > a)/abcc8 + 1.652 daysyescontinuing at 8.5 yearsciii-3/maleg1479r ( c.4435g > a)/abcc8 + 2.232 daysyescontinuing at 5.1 yearsciii-4/femaleg1479r ( c.4435g > a)/abcc8 + 1.932 daysyescontinuing at 1.5 yearsdiii-1/femaleq1459e ( c.4375c > g)/abcc8 + 3.141 dayyescontinuing at 5.8 yearsdiii-2/maleq1459e ( c.4375c > g)/abcc8 + 2.521 dayyescontinuing at 6 weekseiii-1/femalei284del
( c.850_852del)/kcnj11 + 1.481 dayyescontinuing at 1.8 yearsfiv-3/maler1539q ( c.4616g > a)/abcc8 + 2.191 dayyescontinuing at 3.2 yearsfiv-2/maler1539q ( c.4616g > a)/abcc8 + 0.071 daynanagiv-1/malel1431f ( c.4291c > t)/abcc80.981 yearyescontinuing at 2.5 yearshiv-1/malea1508p ( c.4522g > a)/abcc8 + 4.091 dayyescontinuing at 9.2 yearsiii-1/femalel1390r ( c.4619t > g)/abcc8 + 3.221 dayyescontinuing at 11 yearsna , not applicable , as had transient hypoglycaemia that did not require treatment with diazoxide clinical characteristics of the 14 children with hh na , not applicable , as had transient hypoglycaemia that did not require treatment with diazoxide phenotype of the adult mutation carriers the median birthweight of the adult mutation carriers ( n = 16 ; data available for ten individuals ) was high at + 1.39 sds ( ranging from 2.11sds to + 2.45sds , table 2 ) .
interestingly , five of the six adult mutation carriers who were macrosomic at birth developed hypoglycaemia .
two of these had persisting hypoglycaemia at 28 and 39 years of age ( fig . 1 : family a , ii-2 and family f , iii-2 ) , whilst one had a history of transient neonatal hypoglycaemia ( fig . 1 : family e , ii-1 ) ( table 2 ) .
two other adults had a past history of hypoglycaemia that progressed to dm ( family b ii-2 and family h iii-2 ) .
table 2summary of the clinical features of the adult mutation carriersfamilypatient / ethnicitycurrent age ( years)bmi ( kg / m)bw sdshypoglycaemia / past or currentdiabetestreatmentogtt blood glucose ( mmol / l)fasting2 haii-2/white british2821 + 1.42yes , currentnanilnanaaii-3/white british3026.2 + 1.23noyes , gdm at 26 and 29 yearsdietarynanaai-2/white british5721nonona4.05.3bii-2/white british4433 + 1.4yes , pastyes , gdm at 23 years , overt diabetes at 30 yearsinsulin ( metformin tried initially)nanaci-2/white irish7332.2nonona4.94.9cii-2/white irish3231.4 + 0.35nonona4.87.2cii-3/white irish3729.62.11nonona5.44.4dii-2/white british3023noyes , gdm at 21 , 23 and 25 yearsinsulin during pregnanciesnanaeii-1/white british20+2.07yes , pastnot knowni.v .
glucose for neonatal hypoglycaemianot knownnot knownfii-4/white irish7223.7noyes , 47 yearsmetformin+gliclazidenanafiii-2/white irish3921.6 + 2.45yes , currentnanilnanafiii-3/white irish3525.10.39nonona3.77.0fiii-4/white irish4042.20.58noyes , gdm at 36 years , overt diabetes at 39 yearsmetforminnanagiii-5/black african4324.9noyes , 20 yearsinsulinnanahii-2/white british6528.4noyes , 50 yearsinsulinnanahiii-2/white british4031.1 + 1.38yes , pastyes , 38 yearsmetforminnanayes / no in the case of normal ogtt and , if yes , age of diagnosis is shown ; na if current hypoglycaemiaif applicablebw , birthweight ; na , not applicable ; nil , hypoglycaemia not requiring treatment with drugsof the remaining 11 adult mutation carriers , there was a history of diabetes ( gestational or other ) in six further individuals ( family a , ii-3 ; family d , ii-2 ; family g , iii-5 ; family f , ii-4 and iii-4 ; and family h , ii-2 ) .
the remaining five adults ( family a i-2 , family c i-2 , ii-2 , ii-3 and family f iii-3 ) had no history of hypoglycaemia / dm . in total
, 5/16 adult mutation carriers had or had had hypoglycaemia and eight either had gestational diabetes ( gdm ) in multiple pregnancies or were currently diabetic .
the age at diagnosis of dm ranged from 20 to 50 years with a median of 31 years ( see table 2 ) .
none of the 19 adult family members ( aged 2068 years , median 40 years ) who did not carry the abcc8/kcnj11 mutation were known to be affected with diabetes ( fig .
1).according to the who criteria none of the five asymptomatic adult mutation carriers investigated had impaired fasting glucose / impaired glucose tolerance or dm . there was no significant difference in the mean bmi of the adult mutation carriers who developed dm from those who did not ( p = 0.7 ) .
summary of the clinical features of the adult mutation carriers yes / no in the case of normal ogtt and , if yes , age of diagnosis is shown ; na if current hypoglycaemia bw , birthweight ; na , not applicable ; nil , hypoglycaemia not requiring treatment with drugs
this case series reports the phenotype of eight ( six novel ) dominant abcc8/kcnj11 mutations .
we identified 30 individuals ( 14 children and 16 adults ) with heterozygous katp channel mutations from ten families .
nineteen of the 30 ( 63% ) had a past / current history of hypoglycaemia and eight adults ( 50% ) had a history of gestational diabetes in multiple pregnancies or were currently diabetic .
the hyperinsulinaemic phenotype of these mutations was mild and diazoxide responsive , as reported in the literature previously [ 9 , 11 , 12 ] .
of the 14 children , 13 required treatment with diazoxide , whilst the remaining had transient hypoglycaemia that remitted in the neonatal period .
these included a pair of siblings ( family f [ fig . 1 ] ) heterozygous for the r1539q mutation in the abcc8 gene who had hypoglycaemia for different durations .
the older sibling required brief treatment with intravenous glucose after birth while the younger sibling continued to require diazoxide therapy at 3 years of age , demonstrating the variability in the phenotype of hh within the same family . of the 16 adult mutation carriers , two
were recognised to have had hypoglycaemic episodes after the diagnosis of hh in their children .
three others had a previous history of hypoglycaemia ; of these individuals , one had had transient neonatal hypoglycaemia treated with intravenous glucose , while the other two had had more persistent hypoglycaemia that remitted in young adulthood .
the remaining adult mutation carriers ( 11/16 ) had no current / past history of hypoglycaemia .
nevertheless , in utero hyperinsulinism was evident from the higher birthweights of the mutation carriers .
hence , these dominant katp mutations result in a varied phenotype , ranging from asymptomatic macrosomia to persistent hh requiring diazoxide treatment .
in contrast to the paper by huopio et al . , in which all the patients inherited their mutation from their mothers , our probands inherited the mutations from either the maternal or paternal allele , refuting the possibility of a parent - of - origin effect or an imprinting defect .
it has been debated whether dominant katp channel mutations causing hh predispose to the development of dm in adulthood [ 9 , 11 , 14 , 18 ] .
first reported a dominant inactivating abcc8 mutation , e1506k ( e1507k according to reference sequence nm_000352.2 ) , that caused hh progression to hypoinsulinaemic dm during middle age [ 9 , 14 ] . in their study , adults heterozygous for this particular mutation showed reduced insulin secretory capacity and only 1/11 adults had normal glucose tolerance .
in addition , the individuals who developed dm had reduced insulin sensitivity ( 3/4 individuals with dm were overweight ) .
the authors hypothesised that the primary insulin secreting defect may be related to beta cell apoptosis due to raised intracellular calcium concentrations and that the accompanying insulin resistance may be the reason for conversion from impaired glucose tolerance to dm .
another family with this mutation has recently been reported with hh in childhood and later - onset diabetes .
interestingly , insulin deficiency is observed in the beta cell - specific dominant - negative kir6.2 mouse .
described a patient with hh due to a de novo abcc8 mutation who presented with dm at 10.5 years of age .
this child was obese ( bmi 30.2 kg / m ) , supporting the hypothesis that insulin resistance in conjunction with a dominant katp channel mutation can predispose to the development of dm .
however , a recent study that looked at the prevalence of dm in a large number of families with dominant katp channel mutations reported diabetes in just 13.8% of the adult carriers . the prevalence of dm in this cohort was comparable with the estimated prevalence of type 2 dm in adults in the usa , which ranges from 9.6% to 21% .
in contrast we identified two adults who developed dm in adulthood following hypoglycaemia in early life and six adults who were diagnosed with either gdm or overt diabetes before the age of 50 years . excluding the two adults who had symptoms of hypoglycaemia at the time of the study , the prevalence of dm ( gestational or other ) was high , with 8/14 adult mutation carriers being affected in our cohort .
this may even be an underestimate as some individuals who do not have dm may go on to develop it later .
in contrast , none of the 19 adult non - carriers of the abcc8/kcnj11 mutation within these families were known to be diabetic .
the difference in the reported prevalence of diabetes in the adult mutation carriers in our study and that of the us study can be partly explained .
first , there were a high percentage of adults with ongoing hypoglycaemia ( 51% ) in the american study .
surprisingly , these adults were not excluded from the final analysis of the adults affected with dm .
second , adults with gdm were excluded from the final reporting of patients with dm .
the authors argue that the development of gdm in adults with a dominant katp channel mutation may not have the same implication for the eventual development of diabetes as it may reflect impaired glucose - stimulated insulin release due to a direct consequence of defective katp channel activity . however , gdm per se forms an important diagnosis and has implications for the management of the individual during her pregnancy and for the growing fetus .
hence , we believe that the increased risk of gdm merits reporting in this study . however , it is also clear that not all adult mutation carriers develop dm .
we confirmed normal glucose tolerance in five of the adults who had no history of dm . in our cohort , the mean bmis of those with normal glucose tolerance ( n = 5 ) and those with dm ( n = 8) were not significantly different .
nevertheless , the adults who developed overt diabetes following gdm in multiple pregnancies did have higher bmis ( 33 and 42.2 kg / m ) than those adults who did not develop overt diabetes following gdm ( 23 and 26 kg / m )
. however , these data must be interpreted with caution as the number of individuals in each group was small .
in addition , patients with the same g1479r mutation had varied glucose tolerance , suggesting that the development of dm is not mutation specific and other environmental / genetic factors may be involved .
this study confirms that dominant abcc8/kcnj11 mutations can lead to a variable phenotype of neonatal hh , impaired glucose intolerance and diabetes mellitus later in life .
the mechanistic explanation for the neonatal hh involves subtle defects in the function of katp channels .
we carried out rb flux assays to prove the pathogenicity of the novel mutations identified in the study .
the homozygous in vitro model was not stimulated by the katp channel agonist diazoxide , a finding which is consistent with these mutations being disease causing .
western blotting confirmed that the mutant sur1 proteins were produced in the cell ( fig .
katp channels are assembled from mutant and wild - type sur1 and kir6.2 subunits ( channel hetero - octomers are formed with zero to four sur1 and kir6.2 mutant subunits ) .
the eventual katp channel activity is based on the number of mutant subunits present ( in the complex consisting of both mutant and wild - type subunits ) and the extent to which the mutant subunit exerts its adverse effect on channel activity .
the resulting impairment in channel activity is sufficient to activate the downstream voltage - gated calcium channels and thus trigger unregulated insulin secretion .
these patients respond to diazoxide presumably because some wild - type sur1 subunits are present and allow diazoxide activation .
the milder phenotype of dominant mutations reflects the subtle katp channel defect in comparison with recessive mutations , which lead to defects in channel biogenesis , trafficking and assembly .
the mechanism of glucose intolerance and diabetes mellitus in patients with dominant abcc8/kcnj11 mutations is not so clear at present .
exhaustion , increased beta cell apoptosis as a result of raised intracellular calcium concentration and the influence of other genetic or environment factors .
further studies are required to understand how these mutations cause glucose intolerance and diabetes later in life .
dominant mutations in abcc8/kcnj11 cause a varying phenotype ranging from asymptomatic macrosomia to persistent hh in childhood .
this has important implications for follow up of children with dominantly acting abcc8/kcnj11 mutations and the management of the adult carriers . | aims / hypothesisdominantly acting loss - of - function mutations in the abcc8/kcnj11 genes can cause mild medically responsive hyperinsulinaemic hypoglycaemia ( hh ) . as controversy exists over whether these mutations predispose to diabetes in adulthood we investigated the prevalence of diabetes in families with dominantly inherited atp - sensitive potassium ( katp ) channel mutations causing hh in the proband.methodswe studied the phenotype of 30 mutation carriers ( 14 children and 16 adults ) from nine families with dominant abcc8/kcnj11 mutations .
functional consequences of six novel missense mutations were examined by reconstituting the katp channel in human embryonic kidney 293 ( hek293 ) cells and evaluating the effect of drugs and metabolic poisoning on the channels using the 86rb flux assay.resultsthe mutant channels all showed a lack of 86rb efflux on exposure to the channel agonist diazoxide or metabolic inhibition . in the families ,
dominant abcc8/kcnj11 mutations were associated with increased birthweight ( median + 1.56 sd score [ sds ] ) .
fourteen children had hh and five adults were reported with hh or hypoglycaemic episodes ( 63% ) .
progression from hypoglycaemia to diabetes mellitus occurred in two individuals .
eight adults had a history of gestational diabetes in multiple pregnancies or were diabetic ( diagnosed at a median age of 31 years ) . within these families ,
none of the 19 adults who were not carriers of the abcc8/kcnj11 mutation was known to be diabetic.conclusions/interpretationthe phenotype associated with dominant abcc8/kcnj11 mutations ranges from asymptomatic macrosomia to persistent hh in childhood . in adults , it may also be an important cause of dominantly inherited early - onset diabetes mellitus . |
simple bone cyst or unicameral bone cyst ( ubc ) are benign cystic lesions commonly found in femur and humerus . however hand is a very rare site of occurrence .
a 7 year old right hand dominant girl presented to us with chief complaints of pain and swelling in right 4th metacarpal since 2 month .
on imaging , plain radiographs of right hand showed expansile lytic lesion on metaphyseal - diaphyseal region of 4th metacarpal with pathological fracture .
mri showed cystic lesions with internal loculations and fluid - fluid levels ( fig 2 ) .
we performed aspiration which showed serosanguinous fluid with haemorrhagic tinge . with the diagnosis of unicameral bone cyst in mind we performed and closed intramedullary nail with k wire .
however it should be considered as important differential since it warrants simple treatment and extensive procedures should be avoided .
simple bone cyst or unicameral bone cyst ( ubc ) are benign cystic lesions seen commonly in skeletally immature persons .
ubc are also seen in tibia , calcaneus , cuboid , lumbar spine and pelvis .
very few cases of ubc have been described in hand include metacarpals ; phalanx ; hamate and lunate .
treatment described for ubc of hand commonly involves curettage and bone grafting [ 2 , 3 , 4 , 5 , 6 , 7 ] .
we describe ubc of metacarpal in a skeletally immature girl with diagnostic dilemma treated simply with closed k wire insertion .
a 7 year old right hand dominant girl presented to us with chief complaints of pain and swelling in right 4th metacarpal since 2 month .
swelling was of insidious onset and healed gradually progressive . no history of trauma or infection .
, it was a solitary , diffuse and bony hard swelling over 4th metacarpal of right hand which was tender on palpation and no local rise in temperature .
the range of movement at 4th metacarpophalangeal joint was terminally restricted due to pain in all directions .
patient was earlier seen by various orthopaedic surgeons who investigated the lesion and advised excision of cyst with bone grafting
. on imaging , plain radiographs of right hand showed expansile lytic lesion on metaphyseal - diaphyseal region of 4th metacarpal with pathological fracture .
mri showed cystic lesions with internal loculations and fluid - fluid levels ( fig 2 ) .
we repeated the plain radiograph which showed expansile lesion with pathologic fracture on 4th metacarpal ( fig 1 ) . with these investigations available we performed a biopsy which showed serosanguinous fluid with haemorrhagic tinge . with the diagnosis of unicameral bone cyst in mind we performed and closed intramedullary nail with k wire ( fig 3a ) .
the cyst showed signs of healing within a month ( fig 3b ) and k wire was removed .
there is no recurrence at 18 month follow up and range of motion is full at metacarpo - phalangeal joint .
cystic lesion at meta diaphyseal region with pathological fracture t2w coronal section showing fluid fluid levels in cystic lesion of 4th metacarpal a : immediate postoperative radiograph ; 3b : at 1 month follow up cyst showing signs of healing ; 3c : at 2 month follow up the cyst is completely healed
the differential diagnosis of lytic cystic lesion in hand in a skeletally immature patient include unicameral bone cyst , aneurysmal bone cyst , osteoblastoma , giant cell reparative granuloma , enchondroma and intraosseous ganglion cyst .
intraosseous ganglion cyst is a benign lesion commonly seen in carpus and presents as expansile lesion .
giant cell reparative granuloma is reactive benign lesion classically seen in skull and facial bones and also in small tubular bones of hands and feet .
osteoblastoma are benign bone forming lesion commonly found in spine and rarely in hand . on radiograph
osteoblastoma , enchondroma , intraosseous ganglion cyst and giant cell reparative granuloma were excluded in our case based on typical histopathology findings .
aneurysmal bone cyst ( abc ) presents as eccentric expansile lesion with blood filled cavities . on mri
it shows fluid - fluid levels , however this finding is not specific for it .
radiograph may show classic fallen leaf sign representing a piece of bone due to pathologic fracture .
the characteristic fluid - fluid level seen in abc is due to sedimentation of erythrocytes within serosanguinous fluid this finding is observed only in 60% of cortical abc .
the other lesions showing fluid - fluid levels are chondroblastoma , telangiectatic osteosarcoma , fibrous dysplasia , unicameral bone cyst , giant cell tumour , intraosseous ganglion cyst , plasmacytoma and osteomyelitis .
thus in our case the lesion can still be either ubc or abc . to further reach the diagnosis we performed aspiration of the lesion .
thus with all above finding radiograph , mri and aspiration taken together an informed diagnosis of ubc was made in our case of centric expansile lesion with fluid fluid level and serosanguinous aspirate .
treatment options for ubc include observation , curettage and bone grafting , intralesional steroid injection and recently intramedullary nailing .
various theories have been proposed in pathogenesis of ubc like dysplasia within the cyst due to trauma , intraosseous synovial cyst and more recently venous occlusion leading to increased intramedullary pressures .
thus leading to conclusion that re - establishing these vascular channels may lead to healing of cyst .
use of titanium elastic nails to open the connection between the medullary canal and cyst and break the septae within the cyst have been well documented in treatment of long bones ubc .
the cyst showed signs of healing within a month and was completely healed in 3 months with no recurrence till date .
however it should be considered as important differential since it warrants simple treatment and extensive procedures should be avoided .
unicameral bone cyst of metacarpal although rare should be kept in mind while diagnosing cystic lesion since it requires simple treatment . | introduction : simple bone cyst or unicameral bone cyst ( ubc ) are benign cystic lesions commonly found in femur and humerus . however hand is a very rare site of occurrence .
treatment described for ubc of hand commonly involves curettage and bone grafting.case report : a 7 year old right hand dominant girl presented to us with chief complaints of pain and swelling in right 4th metacarpal since 2 month .
on imaging , plain radiographs of right hand showed expansile lytic lesion on metaphyseal - diaphyseal region of 4th metacarpal with pathological fracture .
mri showed cystic lesions with internal loculations and fluid - fluid levels ( fig 2 ) .
there was minimal soft tissue extension .
we performed aspiration which showed serosanguinous fluid with haemorrhagic tinge . with the diagnosis of unicameral bone cyst in mind we performed and closed intramedullary nail with k wire .
the cyst healed up completely within 2 months .
there was no recurrence at 18 month follow up.conclusion:in conclusion simple bone cyst is very rare in metacarpal bone .
however it should be considered as important differential since it warrants simple treatment and extensive procedures should be avoided . |
participants were from the health abc study , an ongoing longitudinal study that investigates changes in body composition as a common pathway by which multiple diseases contribute to disability .
participants ( n = 3,075 ; 48.4% male and 41.6% black , aged 7079 years ) were recruited in 19971998 from pittsburgh , pennsylvania , and memphis , tennessee , using procedures previously described ( 17 ) .
a telephone interview determined eligibility using the following inclusion criteria : no difficulty performing activities of daily living , walking one - quarter of a mile or climbing 10 steps without resting ; no reported need of assistive devices ( e.g. , cane , walker ) ; no active treatment for cancer in the prior 3 years ; no life - threatening illness ; and no plans to leave the area for 3 years .
participants provided informed consent before examinations , and the study was approved by institutional review boards at the university of pittsburgh and the university of tennessee health science center . a national glycohemoglobin standardization program (
ngsp)-certified hba1c assay using modern chromatographic techniques was performed for the first time at the 20002001 follow - up ( year 4 ) , which served as the baseline visit for this analysis . of the 3,075 participants in the health abc study
, we excluded 187 who did not survive to baseline , 634 who had diagnosed diabetes ( based on annual self - report from 1997 to baseline , the use of antihyperglycemic medication from 1997 to 1 year prior to baseline [ medication use was not available at baseline ] , or hba1c 6.5% or fpg 126 mg / dl at our baseline visit ) , and 464 participants who had missing hba1c or fpg values at baseline .
finally , we also excluded participants without adequate follow - up after baseline , including 59 survivors who did not develop diabetes , but were missing at the final examination at year 7 , and 41 participants who did not develop diabetes , died during follow - up , and missed the clinical visit within 1 year of death ( because we could not determine whether they developed diabetes ) .
hba1c was measured using tosoh 2.2 plus ( tosoh bioscience , tokyo , japan ) , a fully automated glycosylated hemoglobin analyzer that uses nonporous ion - exchange high - performance liquid chromatography for separation of hba1c , with any labile glycohemoglobin subfractions chromatographically separated from the shiff base .
the hba1c assay was ngsp certified and standardized to the diabetes control and complications trial ( dcct ) assay method .
fpg was measured after 8 h of fasting using the automated glucose oxidase method ( vitros system ; ortho clinical diagnostics , rochester , ny ) .
the study outcome was a binary variable indicating whether a participant developed diabetes at any time between baseline and subsequent year 7 evaluation .
incident diabetes included new self - report of physician - diagnosed diabetes ( obtained annually ) , the use of oral antihyperglycemic medications or insulin ( available at visits at years 1 , 2 , 4 , 6 , and 7 of follow - up ) , or a single value of hba1c 6.5% collected at years 2 , 6 , and 7 . given that fpg was not repeated when obtained and given the known short - term variability in measures of fpg ( 18 ) , we did not use fpg criteria to define our primary outcome .
participants were classified as high risk for diabetes based upon two separate definitions : 1 ) ifg ( fpg 100125 mg / dl ) or 2 ) elevated hba1c ( 5.76.4% ) .
participants were then categorized into four mutually exclusive groups : 1 ) normal glucose tolerance , based on fpg < 100 mg / dl and hba1c < 5.7% ; 2 ) ifg only , based on fpg 100125 mg / dl but hba1c <
5.7% ; 3 ) elevated hba1c only , based on hba1c 5.76.4% but fpg < 100 mg / dl ; and 4 ) both ifg and elevated hba1c , based on fpg 100125 mg / dl and hba1c 5.76.4% . in addition to age , race , sex , and site ( pittsburgh vs. memphis ) , several known risk factors for diabetes were assessed at baseline , including bmi , systolic blood pressure ( average of two sitting systolic blood pressure measurements ) , and self - reported physical activity ( weekly walking time ) .
smoking status was based on self - report and was available 1 year prior to baseline .
multivariable logistic regression analyses were performed to estimate the odds ratios of incident diabetes ( from baseline to year 7 ) .
the multivariable models were adjusted for age , sex , race , site , systolic blood pressure , bmi , smoking , and weekly walking time ( none , < 150 min / week , or 150 min / week ) . to compare the odds of diabetes associated with each prediabetes category , we compared two models : first
, ifg was compared with normal fpg ( irrespective of hba1c ) , and second , elevated hba1c was compared with normal hba1c ( irrespective of fpg ) .
model fit was assessed with residual analysis and goodness - of - fit statistics . to examine the odds of diabetes associated with the combination of the two tests , fpg and hba1c
, we developed a model with three dummy - coded variables : ifg only , elevated hba1c only , and both ifg and elevated hba1c ( individuals who had neither ifg nor elevated hba1c were the reference group ) , and we calculated odds ratios for these categories .
interaction terms crossing race and sex with the three dummy - coded predictor variables were added to the multivariable logistic regression model to assess race and sex as potential effect modifiers .
odds ratios for the different levels of the effect modifying variable were reported separately for race and sex . to evaluate the utility of obtaining both tests ( hba1c and fpg ) for predicting diabetes
, we compared the fully adjusted model containing ifg with a model that additionally contained elevated hba1c .
the accuracy of each logistic regression model was assessed by examining both discrimination and calibration .
discrimination is the ability of the model to correctly distinguish those who develop the outcome ( diabetes ) from those who do not .
this was calculated with a c statistic , which estimates the area under a receiver operating characteristic curve ( auc ) .
the difference in the auc between the two models was compared with the delong method ( 19 ) . because the c statistic is a rank - based statistic , it is very difficult for a new marker ( in our case , elevated hba1c ) to significantly change the value of auc ( 20 ) .
accordingly , two additional measures were used integrated discrimination improvement ( idi ) and net reclassification improvement ( nri)to provide additional information beyond auc ( 21 ) .
idi measures the incremental increase in the predicted probabilities for the subset experiencing an event ( diabetes ) and the incremental decrease for the subset not experiencing an event .
the absolute idi depends on the event rate observed and therefore may be small if events are rare , whereas relative idi is a percentage .
nri evaluates the net number of individuals reclassified correctly as high versus low risk for diabetes using the model with elevated hba1c compared with the model without elevated hba1c .
this is done by calculating how many individuals who developed diabetes increased in risk category and how many individuals who did not develop diabetes decreased in risk category .
additional analyses were performed with alternate definitions of the outcome : the first analysis was based on diabetes diagnosed by self - report only ( available annually ) ; the second was based on self - report or use of medications only ( i.e. , without the aid of diagnostic tests performed in the course of the study ) ; the third was based on self - report , use of medications , fpg ( 126 mg / dl ) , or hba1c ( 6.5% ) ; and the fourth was based on self - report , use of medications , or fpg ( 126 mg / dl ) . to address the timing of diabetes diagnosis , loss to follow - up , and death
as a competing variable , we additionally analyzed the data using cox proportional hazards regression and a fine and gray subdistribution hazards model ( 22 ) using the primary outcome of diabetes based on self - report , medication use , or hba1c 6.5% . in time - to - event models , we used the date of the clinic visit at which diabetes diagnosis was reported or laboratories were performed , and we censored participants at the time of death or at the last clinic visit when they contributed information about diabetes diagnosis .
an additional sensitivity analysis using the who definition of ifg , i.e. , fpg 110125 mg / dl , was also performed .
when this definition is used , it is specified in the text ; when unspecified , ifg refers to the american diabetes association ( ada ) definition .
all analyses were performed using sas statistical software ( version 9.3 , sas institute , cary , nc ) .
p values < 0.05 for two - sided tests are interpreted to indicate statistical significance .
hba1c was measured using tosoh 2.2 plus ( tosoh bioscience , tokyo , japan ) , a fully automated glycosylated hemoglobin analyzer that uses nonporous ion - exchange high - performance liquid chromatography for separation of hba1c , with any labile glycohemoglobin subfractions chromatographically separated from the shiff base .
the hba1c assay was ngsp certified and standardized to the diabetes control and complications trial ( dcct ) assay method .
fpg was measured after 8 h of fasting using the automated glucose oxidase method ( vitros system ; ortho clinical diagnostics , rochester , ny ) .
the study outcome was a binary variable indicating whether a participant developed diabetes at any time between baseline and subsequent year 7 evaluation .
incident diabetes included new self - report of physician - diagnosed diabetes ( obtained annually ) , the use of oral antihyperglycemic medications or insulin ( available at visits at years 1 , 2 , 4 , 6 , and 7 of follow - up ) , or a single value of hba1c 6.5% collected at years 2 , 6 , and 7 . given that fpg was not repeated when obtained and given the known short - term variability in measures of fpg ( 18 ) , we did not use fpg criteria to define our primary outcome .
participants were classified as high risk for diabetes based upon two separate definitions : 1 ) ifg ( fpg 100125 mg / dl ) or 2 ) elevated hba1c ( 5.76.4% ) .
participants were then categorized into four mutually exclusive groups : 1 ) normal glucose tolerance , based on fpg < 100 mg / dl and hba1c < 5.7% ; 2 ) ifg only , based on fpg 100125 mg / dl but hba1c <
5.7% ; 3 ) elevated hba1c only , based on hba1c 5.76.4% but fpg < 100 mg / dl ; and 4 ) both ifg and elevated hba1c , based on fpg 100125 mg / dl and hba1c 5.76.4% .
in addition to age , race , sex , and site ( pittsburgh vs. memphis ) , several known risk factors for diabetes were assessed at baseline , including bmi , systolic blood pressure ( average of two sitting systolic blood pressure measurements ) , and self - reported physical activity ( weekly walking time ) .
smoking status was based on self - report and was available 1 year prior to baseline .
multivariable logistic regression analyses were performed to estimate the odds ratios of incident diabetes ( from baseline to year 7 ) .
the multivariable models were adjusted for age , sex , race , site , systolic blood pressure , bmi , smoking , and weekly walking time ( none , < 150 min / week , or 150 min / week ) . to compare the odds of diabetes associated with each prediabetes category , we compared two models : first
, ifg was compared with normal fpg ( irrespective of hba1c ) , and second , elevated hba1c was compared with normal hba1c ( irrespective of fpg ) .
model fit was assessed with residual analysis and goodness - of - fit statistics . to examine the odds of diabetes associated with the combination of the two tests , fpg and hba1c
, we developed a model with three dummy - coded variables : ifg only , elevated hba1c only , and both ifg and elevated hba1c ( individuals who had neither ifg nor elevated hba1c were the reference group ) , and we calculated odds ratios for these categories .
interaction terms crossing race and sex with the three dummy - coded predictor variables were added to the multivariable logistic regression model to assess race and sex as potential effect modifiers .
odds ratios for the different levels of the effect modifying variable were reported separately for race and sex . to evaluate the utility of obtaining both tests ( hba1c and fpg ) for predicting diabetes , we compared the fully adjusted model containing ifg with a model that additionally contained elevated hba1c .
the accuracy of each logistic regression model was assessed by examining both discrimination and calibration .
discrimination is the ability of the model to correctly distinguish those who develop the outcome ( diabetes ) from those who do not .
this was calculated with a c statistic , which estimates the area under a receiver operating characteristic curve ( auc ) .
the difference in the auc between the two models was compared with the delong method ( 19 ) .
because the c statistic is a rank - based statistic , it is very difficult for a new marker ( in our case , elevated hba1c ) to significantly change the value of auc ( 20 ) .
accordingly , two additional measures were used integrated discrimination improvement ( idi ) and net reclassification improvement ( nri)to provide additional information beyond auc ( 21 ) .
idi measures the incremental increase in the predicted probabilities for the subset experiencing an event ( diabetes ) and the incremental decrease for the subset not experiencing an event .
the absolute idi depends on the event rate observed and therefore may be small if events are rare , whereas relative idi is a percentage .
nri evaluates the net number of individuals reclassified correctly as high versus low risk for diabetes using the model with elevated hba1c compared with the model without elevated hba1c .
this is done by calculating how many individuals who developed diabetes increased in risk category and how many individuals who did not develop diabetes decreased in risk category .
additional analyses were performed with alternate definitions of the outcome : the first analysis was based on diabetes diagnosed by self - report only ( available annually ) ; the second was based on self - report or use of medications only ( i.e. , without the aid of diagnostic tests performed in the course of the study ) ; the third was based on self - report , use of medications , fpg ( 126 mg / dl ) , or hba1c ( 6.5% ) ; and the fourth was based on self - report , use of medications , or fpg ( 126 mg / dl ) . to address the timing of diabetes diagnosis , loss to follow - up , and death
as a competing variable , we additionally analyzed the data using cox proportional hazards regression and a fine and gray subdistribution hazards model ( 22 ) using the primary outcome of diabetes based on self - report , medication use , or hba1c 6.5% . in time - to - event models
, we used the date of the clinic visit at which diabetes diagnosis was reported or laboratories were performed , and we censored participants at the time of death or at the last clinic visit when they contributed information about diabetes diagnosis . an additional sensitivity analysis using the who definition of ifg , i.e. , fpg 110125 mg / dl , was also performed .
when this definition is used , it is specified in the text ; when unspecified , ifg refers to the american diabetes association ( ada ) definition .
all analyses were performed using sas statistical software ( version 9.3 , sas institute , cary , nc ) .
p values < 0.05 for two - sided tests are interpreted to indicate statistical significance .
additional analyses were performed with alternate definitions of the outcome : the first analysis was based on diabetes diagnosed by self - report only ( available annually ) ; the second was based on self - report or use of medications only ( i.e. , without the aid of diagnostic tests performed in the course of the study ) ; the third was based on self - report , use of medications , fpg ( 126 mg / dl ) , or hba1c ( 6.5% ) ; and the fourth was based on self - report , use of medications , or fpg ( 126 mg / dl ) . to address the timing of diabetes diagnosis , loss to follow - up , and death as a competing variable
, we additionally analyzed the data using cox proportional hazards regression and a fine and gray subdistribution hazards model ( 22 ) using the primary outcome of diabetes based on self - report , medication use , or hba1c 6.5% . in time - to - event models
, we used the date of the clinic visit at which diabetes diagnosis was reported or laboratories were performed , and we censored participants at the time of death or at the last clinic visit when they contributed information about diabetes diagnosis .
an additional sensitivity analysis using the who definition of ifg , i.e. , fpg 110125 mg / dl , was also performed .
when this definition is used , it is specified in the text ; when unspecified , ifg refers to the american diabetes association ( ada ) definition .
all analyses were performed using sas statistical software ( version 9.3 , sas institute , cary , nc ) .
p values < 0.05 for two - sided tests are interpreted to indicate statistical significance .
among the 1,690 participants during the baseline visit , the mean ( sd ) fpg was 92.8 mg / dl ( 9.5 ) , and the median was 92.0 mg / dl ( interquartile range 8698 ) .
respective values for hba1c were 5.3% ( 0.4 ) and 5.3% ( 5.15.6 ) . the baseline characteristics of study participants are presented in table 1 .
there were 779 ( 46.1% ) men and 1,152 ( 68.2% ) white participants in the present analysis .
of the study participants , 358 ( 21.2% ) were identified as having ifg at baseline , 376 ( 22.2% ) as having elevated hba1c , and 1,125 ( 66.6% ) as having normal glucose tolerance ( i.e. , neither elevated fpg nor elevated hba1c ) . among participants with dysglycemia , 189 ( 33.5% )
had ifg only , 207 ( 36.6% ) had elevated hba1c only , and 169 ( 29.9% ) had both abnormalities .
baseline ( 20002001 visit ) characteristics of the 1,690 participants from baseline to year 7 , 183 ( 10.8% ) participants developed diabetes based upon self - report , medication use , or hba1c 6.5% . among the 183 participants with incident diabetes , 102 ( 55.7% ) were white and 83 ( 45.4% ) were men ( table 2 ) .
characteristics of participants who did and did not develop diabetes during follow - up among individuals with ifg ( irrespective of hba1c ) and elevated hba1c ( irrespective of fpg ) at baseline , 28.2 and 33.2% developed diabetes , respectively . in fully adjusted logistic regression models , the odds ratios for diabetes were 6.2 ( 95% ci 4.48.8 ) and 11.3 ( 7.816.4 ) in those with ifg and elevated hba1c , respectively .
the c indices ( for the two fully adjusted models with ifg and elevated hba1c ) were 0.76 ( 95% ci 0.720.79 ) and 0.81 ( 0.770.84 ) , respectively .
when categorized into four mutually exclusive groups , diabetes developed in 3.4% of those with normal fpg and hba1c , 10.6% of those with ifg only , 21.3% of those with elevated hba1c only , and 47.9% of those with both ifg and elevated hba1c ( p value for comparison across categories < 0.001 ) .
in fully adjusted models , the odds ratios for diabetes were 3.5 ( 95% ci 1.96.3 ) in those with ifg only , 8.0 ( 4.813.2 ) in those with elevated hba1c only , and 26.2 ( 16.342.1 ) in those with both ifg and elevated hba1c .
the spearman correlation coefficient between elevated hba1c and ifg was 0.31 ( p < 0.001 ) , allowing both variables to be included in the same model .
only participants with nonmissing values for all covariates were included in this analysis , resulting in a sample of 1,623 , with 172 participants who developed diabetes during follow - up .
the auc for the fully adjusted model with ifg was 0.76 , and the auc for the model additionally containing elevated hba1c was 0.83 ( auc difference 0.07 , p value for auc difference < 0.001 ) .
the idi for evaluation of the added predictive ability of the model with elevated hba1c was 0.10 ( 95% ci 0.080.12 ) with the relative idi of 101.5% ( p value < 0.001 ) .
the nri analysis with a prespecified risk category ( < 20 vs. 20% predicted risk for diabetes ) resulted in 13.0% net reclassification improvement ( 95% ci 4.421.7% , p = 0.004 ) ( table 3 ) .
net reclassification of 11.0% occurred in those with diabetes and 2.0% in those without diabetes .
the hosmer - lemeshow test showed p values that were not significant for both models , suggesting that the model fit was acceptable .
reclassification of predicted risk for diabetes after addition of hba1c to the model diabetes developed in 83 ( 10.7% ) of the men and 100 ( 11.0% ) of the women ( p = 0.83 ) and 102 ( 8.9% ) of white and 81 ( 15.1% ) of black participants ( p < 0.001 ) .
the p values for interaction terms for sex and each of the three dummy - coded variables ( ifg only , elevated hba1c only , and both ) were 0.084 , 0.016 , and 0.002 , respectively . fully adjusted odds ratios for the development of diabetes in men were 8.6 ( 95% ci 3.421.9 ) , 24.2 ( 9.561.8 ) , and 51.1 ( 21.2123.2 ) for ifg only , elevated hba1c only , and both ifg and elevated hba1c ; in women , the corresponding odds ratios were 1.5 ( 0.54.6 ) , 4.6 ( 2.48.7 ) , and 20.4 ( 10.938.0 ) , respectively .
the interaction terms for race and each of the three dummy - coded variables were not statistically significant . fully adjusted odds ratios for the development of diabetes in white participants were 3.2 ( 95% ci 1.56.6 ) , 10.2 ( 5.020.8 ) , and 34.9 ( 19.163.8 ) for ifg only , elevated hba1c only , and both ifg and elevated hba1c ; in black participants , the corresponding odds ratios were 4.6 ( 1.613.3 ) , 5.8 ( 2.911.7 ) , and 14.9 ( 6.832.6 ) , respectively . when we used diabetes definition based solely on 1 ) self - report ; 2 ) self - report or use of diabetes medications only ; 3 ) self - report , use of diabetes medications , fpg 126 mg / dl , or hba1c 6.5% ; or 4 ) self - report , use of medications , or fpg 126 mg / dl , 95 , 107 , 199 , and 141 individuals were identified as having incident diabetes , respectively .
logistic regression analyses using these definitions yielded qualitatively similar results to those of the primary analysis ; however , ifg was a stronger predictor in models that used fpg - based outcomes .
results based on these definitions are shown in the supplementary data , with detailed results presented for the outcome based on self - report , use of medications , fpg , or hba1c .
cox proportional hazards regression based on the primary outcome ( self - report , use of medications , or hba1c
6.5% ) showed the following fully adjusted hazard ratios ( hrs ) : 3.4 ( 95% ci 1.96.0 ) , 7.6 ( 4.812.0 ) , and 21.2 ( 14.032.3 ) for ifg only , elevated hba1c only , and both ifg and elevated hba1c , respectively .
fine and gray analysis to account for competing risk of death yielded essentially the same hrs ( supplementary data ) .
when we used the who definition of ifg ( fpg 110 to < 126 mg / dl ) , diabetes developed in 48% of those with the who definition of ifg ( 48 of 100 ) .
however , of 183 participants who developed diabetes , 135 did not have ifg according to who . the odds ratio for diabetes in the fully adjusted model was 11.4 ( 95% ci 7.118.4 ) in those with a who ifg ( c index 0.72 [ 0.680.77 ] ) . when both who ifg and elevated hba1c were considered together ,
diabetes developed in 3.6% ( 46 of 1,279 ) of those with both normal tests , 34.3% ( 12 of 35 ) of those with who - defined ifg only , 28.6% ( 89 of 311 ) of those with elevated hba1c only , and 55.4% ( 36 of 65 ) of those with both abnormal tests .
from baseline to year 7 , 183 ( 10.8% ) participants developed diabetes based upon self - report , medication use , or hba1c 6.5% . among the 183 participants with incident diabetes , 102 ( 55.7% ) were white and 83 ( 45.4% ) were men ( table 2 ) .
characteristics of participants who did and did not develop diabetes during follow - up among individuals with ifg ( irrespective of hba1c ) and elevated hba1c ( irrespective of fpg ) at baseline , 28.2 and 33.2% developed diabetes , respectively . in fully adjusted logistic regression models , the odds ratios for diabetes were 6.2 ( 95% ci 4.48.8 ) and 11.3 ( 7.816.4 ) in those with ifg and elevated hba1c , respectively .
the c indices ( for the two fully adjusted models with ifg and elevated hba1c ) were 0.76 ( 95% ci 0.720.79 ) and 0.81 ( 0.770.84 ) , respectively .
when categorized into four mutually exclusive groups , diabetes developed in 3.4% of those with normal fpg and hba1c , 10.6% of those with ifg only , 21.3% of those with elevated hba1c only , and 47.9% of those with both ifg and elevated hba1c ( p value for comparison across categories < 0.001 ) .
in fully adjusted models , the odds ratios for diabetes were 3.5 ( 95% ci 1.96.3 ) in those with ifg only , 8.0 ( 4.813.2 ) in those with elevated hba1c only , and 26.2 ( 16.342.1 ) in those with both ifg and elevated hba1c .
the spearman correlation coefficient between elevated hba1c and ifg was 0.31 ( p < 0.001 ) , allowing both variables to be included in the same model . only participants with nonmissing values for all covariates were included in this analysis , resulting in a sample of 1,623 , with 172 participants who developed diabetes during follow - up .
the auc for the fully adjusted model with ifg was 0.76 , and the auc for the model additionally containing elevated hba1c was 0.83 ( auc difference 0.07 , p value for auc difference < 0.001 ) .
the idi for evaluation of the added predictive ability of the model with elevated hba1c was 0.10 ( 95% ci 0.080.12 ) with the relative idi of 101.5% ( p value < 0.001 ) .
the nri analysis with a prespecified risk category ( < 20 vs. 20% predicted risk for diabetes ) resulted in 13.0% net reclassification improvement ( 95% ci 4.421.7% , p = 0.004 ) ( table 3 ) .
net reclassification of 11.0% occurred in those with diabetes and 2.0% in those without diabetes .
the hosmer - lemeshow test showed p values that were not significant for both models , suggesting that the model fit was acceptable .
diabetes developed in 83 ( 10.7% ) of the men and 100 ( 11.0% ) of the women ( p = 0.83 ) and 102 ( 8.9% ) of white and 81 ( 15.1% ) of black participants ( p < 0.001 ) .
the p values for interaction terms for sex and each of the three dummy - coded variables ( ifg only , elevated hba1c only , and both ) were 0.084 , 0.016 , and 0.002 , respectively . fully adjusted odds ratios for the development of diabetes in men were 8.6 ( 95% ci 3.421.9 ) , 24.2 ( 9.561.8 ) , and 51.1 ( 21.2123.2 ) for ifg only , elevated hba1c only , and both ifg and elevated hba1c ; in women , the corresponding odds ratios were 1.5 ( 0.54.6 ) , 4.6 ( 2.48.7 ) , and 20.4 ( 10.938.0 ) , respectively .
the interaction terms for race and each of the three dummy - coded variables were not statistically significant . fully adjusted odds ratios for the development of diabetes in white participants were 3.2 ( 95% ci 1.56.6 ) , 10.2 ( 5.020.8 ) , and 34.9 ( 19.163.8 ) for ifg only , elevated hba1c only , and both ifg and elevated hba1c ; in black participants , the corresponding odds ratios were 4.6 ( 1.613.3 ) , 5.8 ( 2.911.7 ) , and 14.9 ( 6.832.6 ) , respectively .
when we used diabetes definition based solely on 1 ) self - report ; 2 ) self - report or use of diabetes medications only ; 3 ) self - report , use of diabetes medications , fpg 126 mg / dl , or hba1c 6.5% ; or 4 ) self - report , use of medications , or fpg 126 mg / dl , 95 , 107 , 199 , and 141 individuals were identified as having incident diabetes , respectively .
logistic regression analyses using these definitions yielded qualitatively similar results to those of the primary analysis ; however , ifg was a stronger predictor in models that used fpg - based outcomes .
results based on these definitions are shown in the supplementary data , with detailed results presented for the outcome based on self - report , use of medications , fpg , or hba1c .
cox proportional hazards regression based on the primary outcome ( self - report , use of medications , or hba1c
6.5% ) showed the following fully adjusted hazard ratios ( hrs ) : 3.4 ( 95% ci 1.96.0 ) , 7.6 ( 4.812.0 ) , and 21.2 ( 14.032.3 ) for ifg only , elevated hba1c only , and both ifg and elevated hba1c , respectively .
fine and gray analysis to account for competing risk of death yielded essentially the same hrs ( supplementary data ) .
when we used the who definition of ifg ( fpg 110 to < 126 mg / dl ) , diabetes developed in 48% of those with the who definition of ifg ( 48 of 100 ) .
however , of 183 participants who developed diabetes , 135 did not have ifg according to who .
the odds ratio for diabetes in the fully adjusted model was 11.4 ( 95% ci 7.118.4 ) in those with a who ifg ( c index 0.72 [ 0.680.77 ] ) . when both who ifg and elevated hba1c were considered together ,
diabetes developed in 3.6% ( 46 of 1,279 ) of those with both normal tests , 34.3% ( 12 of 35 ) of those with who - defined ifg only , 28.6% ( 89 of 311 ) of those with elevated hba1c only , and 55.4% ( 36 of 65 ) of those with both abnormal tests .
we found that ifg and elevated hba1c increase the likelihood of developing diabetes over 7 years by approximately 6- and 11-fold , respectively , compared with normal glycemic parameters .
however , when fpg and hba1c results are considered together , the odds for diabetes in individuals with both abnormalities were substantially higher ( ~26-fold ) .
indeed , the ability to predict whether an older individual will develop diabetes was improved when the results of fpg and hba1c were considered together .
several studies predominantly conducted in the middle - aged populations suggest that hba1c is strongly predictive of future diabetes ( 710 ) . a recent systematic review involving a total of 44,203 individuals ( mean age 53.4 years ) showed that the 5-year incidence of diabetes ranged between 25 and 50% for baseline hba1c 6% and between 9 and 25% for baseline hba1c 5.56% across 16 studies ( 7 ) .
in addition , a recent examination of the value of hba1c in the atherosclerosis risk in communities study ( mean age 56.7 years ) supports its strong association with subsequent diabetes , cardiovascular events , and mortality ( 23 ) .
one japanese longitudinal study evaluated the value of hba1c in predicting diabetes and compared this directly with fpg ( 24 ) . among 6,241 adults without diabetes ( mean age 49.9 years ) and
after a mean follow - up of 4.7 years , the adjusted risk for incident diabetes was increased similarly 6-fold for those with ifg alone and for those with elevated hba1c alone , but the risk was substantially higher ( nearly 32-fold ) for those identified by both ifg and elevated hba1c compared with normoglycemic individuals . however , these data are based on analysis of an ethnically homogeneous , predominantly male ( 75% ) , and younger cohort , which raises questions with regard to generalizability to older u.s .- based populations .
few data on the actual incidence of new - onset diabetes in elderly individuals exist in the prior literature . in our study of older adults ,
10.8% of participants developed diabetes over 7 years ( roughly approximating an annual incidence of 1.5% per year ) , which is similar to the annual incidence of diabetes among persons 65 years old in the u.s .
the effect of elevated hba1c and ifg on the odds of diabetes was comparable in our study with the effect observed in younger populations , although elevated hba1c appeared to be a stronger predictor in our study .
proportions of health abc participants who developed diabetes over 7 years were 10.6 , 21.3 , 47.9 , and 3.4% in those with ifg alone , elevated hba1c alone , both ifg and elevated hba1c , and normal parameters at baseline , respectively ( compared with the incidence of diabetes over 5 years of 8.5 , 7.3 , 37.6 , and 1.1% , respectively , in the japanese study ) ( mean age of 49.9 years ) .
the ada guidelines recommend the use of either test , hba1c or fpg , to identify individuals at risk for diabetes ( 1 ) .
another option is to measure both tests , either simultaneously or in sequence , but this strategy is more costly ( 26 ) .
several investigators have specifically evaluated whether obtaining two tests is better than either one alone in predominantly younger populations . in studies conducted in japan and china , the ability to predict diabetes with both fpg and hba1c was significantly better than with either one alone ( 2729 ) . in a u.s .
study , the incidence of diabetes was substantially increased in those with elevated fpg and hba1c compared with those with only one elevated test , but more detailed analyses of combined testing were not performed ( 8) . in the health abc study , over 7 years , diabetes developed in roughly one of four participants with ifg and one of three participants with elevated hba1c when only one of these tests was considered . when both tests were considered together ,
the probability of diabetes was only 12 in 10 for participants with one elevated value ( hba1c or fpg ) and close to 1 in 2 for those with both elevated values .
interestingly , when the who definition of ifg was applied ( fpg 110 to < 126 mg / dl ) , participants with this type of ifg had a similar 1 in 2 probability of developing diabetes over time . in our study , we also compared several measures of discrimination and calibration for models with and without elevated hba1c.the auc , which reflects the ability to distinguish participants who develop diabetes from those who do not , improved significantly when elevated hba1c was added to the model already containing ifg and several diabetes risk factors , although the absolute change was small ( auc difference 0.07 , p < 0.001 ) .
most new markers or risk do not result in a large absolute change in auc , and some have questioned the utility of relying on auc differences alone to establish the importance of new predictors ( 20 ) .
the relative value of idi in our study indicates that the difference in predicted probabilities between events ( diabetes ) and nonevents ( no diabetes ) increased by 101.5% between the model without hba1c and the model with hba1c , resulting in a significantly greater discriminatory capacity .
perhaps the most intuitive and clinically relevant measure of model performance for diabetes prediction is the nri . using this method ,
we a priori selected two categories of risk that were clinically meaningful , indicating a predicted risk of diabetes of 20% during the follow - up period of our study .
thirteen percent of the participants were correctly reclassified for diabetes risk when hba1c was added to the model , which is a statistically significant difference ( p = 0.004 ) .
these data suggest that dual screening may improve identification of older participants with the highest odds of developing diabetes when the current definitions of prediabetes endorsed by the ada are used .
one could also argue for a stepwise approach , in which fpg is obtained first .
if fpg is elevated by the who criterion ( 110 to < 126 mg / dl ) , then the risk of diabetes is substantial ( 48% over 7 years according to our study ) , and further testing may not be necessary . if , on the other hand , fpg is normal by the ada criterion ( < 100 mg / dl ) , diabetes risk is quite low at 6% over the next 7 years and , again , additional tests may not be required .
when fpg is mildly elevated ( i.e. , 100110 mg / dl ) , measuring hba1c may indeed help inform the patient and their care provider of subsequent diabetes risk .
although we did not evaluate the cost - effectiveness of dual testing strategies , our data do provide insight into interpretation of results of both hba1c and fpg which are actually often available together in clinical practice .
it is worth noting that many prior studies on prediction of diabetes included only caucasian subjects ( 9,10 ) or were confined to a single asian group ( 24 ) .
it is now well recognized that the use of hba1c may differ depending on race , with consistently higher hba1c values obtained in black patients ( 3,16 ) .
these differences may reflect higher underlying glucose levels ( 30 ) or differences in the duration of hemoglobin exposure to glucose ( 31 ) . in our biracial study ,
the interaction between race , baseline glycemic status , and development of diabetes was not significant , suggesting that the overall results of our study can be applied to the black participant subgroup .
we did find a significant interaction by sex : the odds ratio for diabetes associated with elevated hba1c or ifg was lower among women compared with men .
prior studies have not reported sex differences in prediction of diabetes based upon glycemic measures ( 8,32 ) , and our results will need to be confirmed in future studies .
data on fpg and hba1c were not available at each annual follow - up , and therefore , logistic regression analyses were performed .
odds ratio can overestimate the risk ratio when the outcome of interest is common ( > 10% ) ( indeed , the 26.2-fold higher odds of diabetes in those with both elevated hba1c and ifg corresponds to a 14.1-fold higher risk ratio using the method of zhang and yu ) .
our sensitivity analyses , which accounted for time - to - event , yielded qualitatively similar results .
we defined the diagnosis of diabetes based on hba1c values , self - report , or medication use and did not apply a single fpg as a criterion .
however , the results did not differ substantially when fpg was also considered in the outcome definition in a secondary analysis ; however , in that analysis , ifg and elevated hba1c each increased the likelihood of diabetes similarly .
finally , we evaluated the impact of elevated hba1c and fpg on diabetes diagnosis but not on other outcomes that are important to patients .
effective interventions are available for adults diagnosed with prediabetes to reduce the risk of subsequent diabetes ( based on glycemic measures ) ( 34 ) , but it is worth noting that there are no clear data on improvements in clinical outcomes , such as cardiovascular disease or microvascular complications .
future studies will need to evaluate whether screening for diabetes in this age - group with both fpg and hba1c leads to better health outcomes and whether this is cost - effective . in summary , we found that ifg and elevated hba1c are associated with increased odds for subsequent diabetes in older adults .
older adults with both ifg and elevated hba1c are at very high risk for diabetes , whereas those with two normal tests are unlikely to develop the disease over the next 7 years .
future studies of new - onset diabetes in older adults are needed to better understand the natural history of this condition and to document the effect of diabetes screening on clinical outcomes in the elderly . | objectiveto determine which measures impaired fasting glucose ( ifg ) , elevated hba1c , or both
best predict incident diabetes in older adults.research design and methodsfrom the health , aging , and body composition study , we selected individuals without diabetes , and we defined ifg ( 100125 mg / dl ) and elevated hba1c ( 5.76.4% ) per american diabetes association guidelines .
incident diabetes was based on self - report , use of antihyperglycemic medicines , or hba1c
6.5% during 7 years of follow - up .
logistic regression analyses were adjusted for age , sex , race , site , bmi , smoking , blood pressure , and physical activity .
discrimination and calibration were assessed for models with ifg and with both ifg and elevated hba1c.resultsamong 1,690 adults ( mean age 76.5 , 46% men , 32% black ) , 183 ( 10.8% ) developed diabetes over 7 years .
adjusted odds ratios of diabetes were 6.2 ( 95% ci 4.48.8 ) in those with ifg ( versus those with fasting plasma glucose [ fpg ] < 100 mg / dl ) and 11.3 ( 7.816.4 ) in those with elevated hba1c ( versus those with hba1c
< 5.7% ) .
when fpg and hba1c were considered together , odds ratios were 3.5 ( 1.96.3 ) in those with ifg only , 8.0 ( 4.813.2 ) in those with elevated hba1c only , and 26.2 ( 16.342.1 ) in those with both ifg and elevated hba1c ( versus those with normal fpg and hba1c ) .
addition of elevated hba1c to the model with ifg resulted in improved discrimination and calibration.conclusionsolder adults with both ifg and elevated hba1c have a substantially increased odds of developing diabetes over 7 years .
combined screening with fpg and hba1c may identify older adults at very high risk for diabetes . |
urothelial carcinoma of the upper urinary tract ( renal pelvis and ureter ; uut - uc ) is an infrequent genitourinary malignancy accounting for 5 % of urothelial cancers and less than 10 % of renal tumours .
analysis of epidemiological and survival patterns of uut - uc over the past 30 years in a review of a large , population - based database in the usa has shown that the incidence of uut - uc has slowly risen , and that increasing patient age , male gender , afro - american race , bilateral uut - uc and regional / distant disease are all associated with poorer survival . for the primary diagnosis and staging of uut - uc , radiographic imaging by intravenous and retrograde pyelography and ct scanning , ureteroscopic visualization and biopsy of the tumour , and urine cytology are usually performed . although f - fdg is the radiopharmaceutical most frequently used in pet , fdg is not a useful tracer for the detection of primary tumours of the urinary tract because of its renal excretion
. therefore , the utility of fdg pet in the detection of urinary tract tumours is limited to distant metastases [ 3 , 4 ] .
it has been reported that fdg pet / ct is superior to conventional evaluations in detecting occult metastases in patients with invasive bladder cancer [ 5 , 6 ] . however , another study has shown no advantage of fdg pet / ct over ct alone for lymph node staging in invasive bladder cancer . a number of studies have demonstrated that pet / ct with c - choline ( choline pet / ct ) is useful in the detection of lymph node metastases of prostate cancer [ 815 ] and also the detection of primary prostate cancer with certain limitations [ 1620 ] .
however , to the best of our knowledge , there have been no studies on the efficacy of choline pet / ct in the initial diagnosis and local staging of uut - uc .
the purpose of this pilot study was to prospectively evaluate the impact of choline pet / ct in localizing the primary tumour and staging of uut - uc . in this study ,
the effects of the choline pet / ct findings on the clinical management of uut - uc and the outcomes in patients with uut - uc were also evaluated .
all procedures followed the clinical guidelines of our hospital and were approved by the institutional review board .
a complete description of the study was given to all participating patients and a consent form was signed by the patients .
we enrolled 16 consecutive patients with a clinical suspicion of uut - uc ( 9 men , 7 women ; age range 51 83 years , mean sd 69 10.8 years ) who were referred to the department of urology of our hospital between march 2008 and january 2011 .
all patients were examined using choline pet / ct 3 65 days ( mean 19.2 days ) before surgery .
two patients were inoperable and one patient needed no surgery ; all remaining patients underwent laparoscopic nephroureterectomy together with partial cystectomy ( lnux ) . in the patients who were diagnosed with lymph node metastases , lymphadenectomy was performed .
in addition , after choline pet / ct some of the patients received neoadjuvant chemotherapy with gemcitabine and cisplatin [ 22 , 23 ] and chemotherapy with methotrexate , vinblastine , doxorubicin and cisplatin , with gemcitabine and carboplatin , and with gemcitabine .
pet and ct imaging was performed using a combined pet / ct system ( biograph sensation 16 ; siemens medical solutions , forchheim , germany , and hoffman estates , il ) .
the system combines a full - ring pet scanner equipped with lutetium orthosilicate crystal detectors and a 16-slice high - resolution spiral ct scanner .
all patients were examined after fasting for 6 h. choline pet / ct was performed 10 and 20 min after intravenous injection of 3.7 mbq / kg of c - choline . in the pet / ct scanner ,
their arms were down and their hands were clasped on the abdomen throughout the scanning procedure rather than elevated above the head .
first , a topogram was acquired to define the imaging range for both ct and pet .
the range was typically chosen to extend from the scull base to the mid - thigh level .
a single nonenhanced continuous spiral multislice ct scan was performed ( 120 kvp tube voltage , 100 mas effective tube current , 16 1.5-mm detector configuration , gantry rotation time 420 ms , 30-mm table feed per rotation ) .
attenuation was measured during the first half of helical rotation , and the effective tube current was automatically modulated for the second half ( care dose ; siemens medical solutions , hoffman estates , il ) .
data were acquired for 1 min per bed position following the ct scan . in all patients scanning
the mean radiation doses used in this study were 1.1 msv in choline pet and 7.05 msv in ct .
ct images with a matrix size of 512 512 and a slice thickness of 3 mm with a 1.5-mm increment were generated using filtered back - projection .
pet images with a matrix size of 128 128 were reconstructed using a 3-d numerical reconstruction algorithm ( e.soft ; siemens medical solutions ) .
ct - derived attenuation maps were used for pet attenuation correction . for visual and quantitative analysis
, images were displayed on a clinical image analysis workstation that allowed interactive exploration of ct , pet and fused pet / ct image data .
the loci where choline uptake was visibly higher than the activity of adjacent areas were tentatively considered uptake - positive . for each uptake - positive locus
the intensity of uptake was further analysed semiquantitatively . for this purpose the coronal slice that contained the maximum uptake
was selected and the maximum standardized uptake value ( suvmax ) with regard to body weight was determined . in this study , it was demonstrated that , when suvmax was lower than 2.2 , the contour and extent of the uptake area were vague .
the size of tumours ( long diameter short diameter height ) was measured on ct images .
histopathological examinations were performed in 14 of the 16 study patients . in 13 patients specimens
were obtained from tissue resected during lnux and in 1 patient from tissue obtained at autopsy .
kaplan - meier analysis was used to compare the survival of the patients with uut - uc in relation to the presence and location of metastases .
the analyses were performed with the log - rank test using spss v. 20 ( ibm , armonk , ny ) .
the suvmax at 10 and 20 min after injection were compared using the paired t - test .
all procedures followed the clinical guidelines of our hospital and were approved by the institutional review board .
a complete description of the study was given to all participating patients and a consent form was signed by the patients .
we enrolled 16 consecutive patients with a clinical suspicion of uut - uc ( 9 men , 7 women ; age range 51 83 years , mean sd 69 10.8 years ) who were referred to the department of urology of our hospital between march 2008 and january 2011 .
all patients were examined using choline pet / ct 3 65 days ( mean 19.2 days ) before surgery .
two patients were inoperable and one patient needed no surgery ; all remaining patients underwent laparoscopic nephroureterectomy together with partial cystectomy ( lnux ) . in the patients who were diagnosed with lymph node metastases , lymphadenectomy was performed .
in addition , after choline pet / ct some of the patients received neoadjuvant chemotherapy with gemcitabine and cisplatin [ 22 , 23 ] and chemotherapy with methotrexate , vinblastine , doxorubicin and cisplatin , with gemcitabine and carboplatin , and with gemcitabine .
pet and ct imaging was performed using a combined pet / ct system ( biograph sensation 16 ; siemens medical solutions , forchheim , germany , and hoffman estates , il ) .
the system combines a full - ring pet scanner equipped with lutetium orthosilicate crystal detectors and a 16-slice high - resolution spiral ct scanner .
all patients were examined after fasting for 6 h. choline pet / ct was performed 10 and 20 min after intravenous injection of 3.7 mbq / kg of c - choline . in the pet / ct scanner ,
their arms were down and their hands were clasped on the abdomen throughout the scanning procedure rather than elevated above the head .
first , a topogram was acquired to define the imaging range for both ct and pet .
the range was typically chosen to extend from the scull base to the mid - thigh level .
a single nonenhanced continuous spiral multislice ct scan was performed ( 120 kvp tube voltage , 100 mas effective tube current , 16 1.5-mm detector configuration , gantry rotation time 420 ms , 30-mm table feed per rotation ) .
attenuation was measured during the first half of helical rotation , and the effective tube current was automatically modulated for the second half ( care dose ; siemens medical solutions , hoffman estates , il ) .
data were acquired for 1 min per bed position following the ct scan . in all patients scanning
the mean radiation doses used in this study were 1.1 msv in choline pet and 7.05 msv in ct .
ct images with a matrix size of 512 512 and a slice thickness of 3 mm with a 1.5-mm increment were generated using filtered back - projection .
pet images with a matrix size of 128 128 were reconstructed using a 3-d numerical reconstruction algorithm ( e.soft ; siemens medical solutions ) .
for visual and quantitative analysis , images were displayed on a clinical image analysis workstation that allowed interactive exploration of ct , pet and fused pet / ct image data .
the loci where choline uptake was visibly higher than the activity of adjacent areas were tentatively considered uptake - positive . for each uptake - positive locus
the intensity of uptake was further analysed semiquantitatively . for this purpose the coronal slice that contained
the maximum uptake was selected and the maximum standardized uptake value ( suvmax ) with regard to body weight was determined . in this study , it was demonstrated that , when suvmax was lower than 2.2 , the contour and extent of the uptake area were vague .
the size of tumours ( long diameter short diameter height ) was measured on ct images .
histopathological examinations were performed in 14 of the 16 study patients . in 13 patients specimens were obtained from tissue resected during lnux and in 1 patient from tissue obtained at autopsy .
kaplan - meier analysis was used to compare the survival of the patients with uut - uc in relation to the presence and location of metastases .
the analyses were performed with the log - rank test using spss v. 20 ( ibm , armonk , ny ) .
the suvmax at 10 and 20 min after injection were compared using the paired t - test .
the profiles of the 16 study patients , and the choline uptake determined as suvmax and the sizes estimated on ct images of the primary tumours are shown in table 1 .
the clinical findings , treatment , and outcomes in the patients , and histopathological findings of the primary tumours are shown in table 2.table 1patient profiles and c - choline uptake and sizes of primary tumours estimated on pet / ct imagespatient no.age ( years)sexprimary tumoursidelocation
c - choline uptake ( suvmax)size ( mm )
10 min20 min161mrightrenal pelvis2.483.7929 25 20267frightrenal pelvis5.524.3637 26 20350fleftureter2.802.9410 9 12473frightureter < 2.2 < 2.2indeterminable
556mrightureter < 2.2 < 2.215 15 15
681mrightrenal pelvis3.833.4319 25 12783mrightrenal pelvis2.742.8310 9 12881mleftrenal pelvis2.313.228 8 15969fleftrenal pelvis4.063.9723 20 121075mrightureter2.492.1810 9 81164frightureter6.096.2811 10 81253mrightrenal pelvis7.858.0846 45 401356frightureter3.252.6412 11 121481mleftureter3.973.7910 10 101567frightureter < 2.2 < 2.214 14 501681mrightureter6.593.8025 17 25
long diameter short diameter height
nonmalignancytable 2clinical findings , treatment , and outcomes in patients and histopathological findings of tumourspatient no.tnm classification
treatmentinterval from pet / ct to lnux ( days)histopathological findingsoutcomedays after lnux
1iii ( t3n0m0)lnux33uc , g2 > g3 pt3 , ly0 , v0 , n0ned1,5302iv ( t4n2m1)inoperable uc , g3 , pt4died from cancer25 ( after pet / ct ) 3i ( t1n0m0)lnux45malignant lymphomaned1,5604lnux10no malignancyned6995ned60a ( t1an0m0)lnux14uc , g1 , pta , ly0 , n0 , v0died from cancer7257i ( t1n0m0)lnux7uc , g2 , pt1 , ly0 , n0 , v0ned1,4518i ( t1n0m0)lnux13uc , g2 , pt1 , ly0 , n0 , v0ned1,4269ii ( t2n0m0)lnux42uc , g2 = g3 , pt2 , ly0 , v0 , n0ned1,40210i ( t1n0m0)lnux45uc , g2 > g3 , pt1 , ly0 , v0 , n0ned1,39911iv ( t2n1m0)nac + lnux + mvac4uc , g2 - 3 , pt2 , ly+ , v+ , n+ned1,41412iv ( t4n0m1)lnux + mvac65uc > scc , g3 , pt4died from cancer18013lnux3igg4-related diseasened74314iv ( t3n1m0)lnux + ( g + cbdca)3uc , g3 , pt3 , inf , ew0 , ly0 , n0died from cancer60015
iv ( t4n0m0)lnux + nac61uc , g3 , pt4 , inf , ly2 , v1,n0alive with cancer59216iv ( t3n2m1)inoperable , galive with cancer510 ( after pet / ct )
lnux laparoscopic nephroureterectomy and partial cystectomy ; nac neoadjuvant chemotherapy with gemcitabine and cisplatin ( two cycles ) before or after lnux ; ned no evidence of disease chemotherapy : mvac methotrexate , vinblastine , doxorubicin , and cisplatin ( three cycles ) after lnux ; g + cboca gemcitabine and carboplatin ( three cycles ) after lnux ; g gemcitabine ( three cycles )
according to sobin et al .
interval ( days ) between lnux and 14 july or 10 september 2012 .
if patient died , interval between lnux and death . in patients who underwent no lnux , interval between pet / ct and 14 july or 10
september 2012 or deathmetastases in the sacral lymph nodes and 4th lumber spine were found 380 days after lnux
metastases in the sacral lymph nodes and 4th lumber spine were found 380 days after lnux patient profiles and c - choline uptake and sizes of primary tumours estimated on pet / ct images
long diameter short diameter height clinical findings , treatment , and outcomes in patients and histopathological findings of tumours
lnux laparoscopic nephroureterectomy and partial cystectomy ; nac neoadjuvant chemotherapy with gemcitabine and cisplatin ( two cycles ) before or after lnux ; ned no evidence of disease chemotherapy : mvac methotrexate , vinblastine , doxorubicin , and cisplatin ( three cycles ) after lnux ; g + cboca gemcitabine and carboplatin ( three cycles ) after lnux ; g gemcitabine ( three cycles )
according to sobin et al
.
interval ( days ) between lnux and 14 july or 10 september 2012 .
if patient died , interval between lnux and death . in patients who underwent no lnux , interval between pet / ct and 14 july or 10
september 2012 or deathmetastases in the sacral lymph nodes and 4th lumber spine were found 380 days after lnux
metastases in the sacral lymph nodes and 4th lumber spine were found 380 days after lnux of the 16 study patients , 13 were choline uptake - positive and the other 3 were uptake - negative in the urothelial lesions ( table 1 ) .
in the three choline uptake - negative patients , the suvmax values were < 2.2 at both 10 and 20 min .
except for two inoperable patients and one patient who needed no surgery , all patients underwent lnux .
the specimens obtained by lnux or autopsy ( patient 2 ) were examined histopathologically , which confirmed that of the 13 choline uptake - positive patients , 11 patients ( patients 1 , 2 , 6 12 , 14 , and 16 ) had uut - uc , 1 ( patient 3 ) had malignant lymphoma , and 1 ( patient 13 ) had igg4-related disease ( table 2 ) .
of the three uptake - negative patients , two ( patients 4 and 5 ) had no malignancies and 1 ( patient 15 ) had uut - uc ( table 2 ) . of the 2 patients with no malignancies , one ( patient 4 ) underwent lnux , and the lesion
. the other patient ( patient 5 ) did not undergo lnux , but no malignancy was diagnosed based on his local and clinical findings . the uptake - negative patient with uut - uc ( patient 15 ) underwent lnux and the lesion was confirmed histopathologically to be uut - uc . of the 12 patients with uut - uc , 7 had renal pelvis carcinoma and 5 had ureteral carcinoma ( table 1 ) . in 6 of the 11 choline uptake - positive patients with uut - uc ,
the suvmax at 10 min was higher than at 20 min , and in 5 of these patients the suvmax at 20 min was higher than at 10 min .
there was no statistically significant difference between the suvmax values of the urothelial lesions at 10 min and those at 20 min .
the other 12 patients with uut - uc showed choline suvmax ranging from 2.48 to 7.85 ( mean sd 4.15 1.73 ) at 10 min and from 2.83 to 8.08 ( 3.95 1.54 ) at 20 min , and a patient with malignant lymphoma in the left ureter ( patient 3 ) also showed choline uptake ( suvmax 2.80 at 10 min and 2.94 at 20 min ; tables 1 and 2 ) .
there was incidentally a patient with igg4-related disease [ 25 , 26 ] who had a tumorous lesion in the right ureter ( patient 13 ) , and the lesion showed weak but definite choline uptake ( suvmax 3.25 at 10 min and 2.64 at 20 min ; tables 1 and 2 ) .
the sensitivity of choline pet / ct in the detection of uut - uc was 92 % ( 11 of 12 patients ) .
the nonmalignant tumorous ureteral lesion associated with igg4-related disease with positive uptake was considered false - positive as judged only on the basis of malignancy or nonmalignancy , whereas the other two nonmalignant ureteral lesions in patients 4 and 5 were uptake - negative . in 5 of the 12 patients with uut - uc ( patients 2 , 11 , 12 , 14 and 16 ) choline pet / ct also showed definite choline uptake in the sites corresponding to metastases , patients 11 and 14 had metastases only in the regional lymph nodes , and patients 2 , 12 and 16 also had distant metastases ( table 3 ) .
these metastatic lesions were detected first by choline pet / ct performed in this study .
choline uptake in the metastatic lesions was determined as suvmax and the size of the lesions was estimated on ct images ( table 3 ) .
the suvmax values in the metastatic lesions were as high as in the primary tumours , ranging from 2.55 to 10.39 ( 5.75 1.85 ) at 10 min and from 2.28 to 11.80 ( 5.45 2.10 ) at 20 min . in 10 of 15
choline uptake - positive metastatic lesions , the suvmax values at 10 min were higher than those at 20 min , in 4 the suvmax values at 20 min were higher than those at 10 min , and in 1 the suvmax values at 10 and 20 min were equal .
the suvmax values at 10 min were significantly higher than those at 20 min ( p < 0.05 ) .
the size of the largest metastatic tumours ( 41 33 40 mm , left aortic lymph nodes in patient 16 ) approximated that of the primary tumour ( 46 45 40 mm , right renal pelvis in patient 12 ) .
in one inoperable patient ( patient 2 ) , metastases were found in the skull , sixth thoracic spine , pelvis , left lung , and the right lower paratracheal and subaortic lymph nodes ; in another inoperable patient ( patient 16 ) , metastases were found in the left supraclavicular lymph nodes and the left anterior mediastinal lymph nodes as well as in the regional lymph nodes including the left aortic and common iliac lymph nodes ( table 3 ) .
the metastatic tumours in the regional and distant lymph nodes were surgically resected ( patients 11 , 12 and 14 ) except in two inoperable patients ( patients 2 and 16 ) .
table 3properties of metastatic lesionspatient no.locationsuvmaxsize ( mm )
10 min20 min2right lower paratracheal ln5.094.5728 21 14subaortic ln5.394.4117 12 10thoracic spine ( vi)5.104.7117 15 12right iliac bone9.297.6035 33 20left lung2.552.2821 17 16skull5.074.4016 13 1611right internal iliac ln4.925.2211 10 912right renal hilar ln4.683.5721 10 12thoracic spine ( vi)6.456.0119 16 14thoracic spine ( xii)7.367.5536 30 26 right iliac bone10.3911.8028 25 1614left sacral ln4.735.1510 10 1016left aortic ln5.075.4641 33 40left common iliac ln5.855.8530 17 35left supraclavicular ln5.914.7320 10 10left anterior mediastinal
ln4.163.8210 10 10
ln lymph node
long diameter short diameter height properties of metastatic lesions
long diameter short diameter height the outcome in all 16 study patients was checked on 14 july or 10 september 2012 ( 592
the outcomes in patients with distant metastases , with metastases only in the regional lymph nodes , and without metastases are compared in table 4 and fig .
1 . an inoperable patient ( patient 2 ) died from cancer 25 days after choline pet / ct and another inoperable patient ( patient 16 ) was alive with cancer 510 days after choline pet / ct . of the other two patients with metastases only in the regional lymph nodes , one ( patient 14 ) died from cancer 600 days after lnux , and one ( patient 11 ) had no evidence of disease 1,414 days after lnux .
of seven patients with uut - uc without metastases , five ( patients 1 , 7 , 8 , 9 and 10 ) had no evidence of disease 1,399
1,530 days after lnux , one ( patient 6 ) died from another cause 725 days after lnux , and one ( patient 15 ) was alive with cancer 592 days after lnux , although in this patient metastases in the sacral lymph nodes and fourth lumbar spine were found 380 days after surgery ( the footnote relating to patient 15 in table 2 ) .
patients with malignant lymphoma ( patient 3 ) or with igg4-related disease ( patient 13 ) had no evidence of disease 1,560 and 743 days after lnux.table 4outcomes in patients with distant metastases , with metastases only in regional lymph nodes , and without metastasespatient groupno . of patientssurgical treatmentoutcomedied from canceralive with cancerno evidence of disease
with distant metastases2 ( patients 2 , 16)no surgery1
1
1 ( patient 12)lnux + lymphadenectomy1
with metastases only in regional lymph nodes2 ( patients 11 , 14)lnux + lymphadenectomy1
1without metastases6 ( patients 1 , 7 , 8 , 9 , 10 , 15 )
1
5
lnux laparoscopic nephroureterectomy and partial cystectomy
seven patients had no metastases , but one died from another cause and was excluded
died from cancer 25 days after pet / ct
died from cancer 180 days after lnux
died from cancer 600 days after lnux
judged 510 days after pet / ct
see the footnote relating to patient 15 in table 2
judged 743 1,530 days after lnuxfig .
1kaplan - meier survival curves showing survival in patients with distant metastases ( three patients ) , with metastases only in the regional lymph nodes ( two patients ) , and without metastases ( six patients ) .
see the footnotes to tables 2 and 4
outcomes in patients with distant metastases , with metastases only in regional lymph nodes , and without metastases
lnux laparoscopic nephroureterectomy and partial cystectomy
seven patients had no metastases , but one died from another cause and was excluded
died from cancer 25 days after pet / ct
died from cancer 180 days after lnux
died from cancer 600 days after lnux
judged 510 days after pet / ct
see the footnote relating to patient 15 in table 2
judged 743 1,530 days after lnux kaplan - meier survival curves showing survival in patients with distant metastases ( three patients ) , with metastases only in the regional lymph nodes ( two patients ) , and without metastases ( six patients ) .
see the footnotes to tables 2 and 4
pet / ct images of the primary and metastatic tumours and the photographs of the primary tumours after resection in patients 1 , 12 and 11 are shown in figs . 2 , 3 and 4.fig .
a , b choline pet / ct images of the primary tumour at 10 min ( a ) and 20 min ( b ) after injection .
choline uptake at 10 min is positive but weak ( suvmax 2.48 ) compared with that at 20 min ( suvmax 3.79 ) .
a choline pet / ct images of the primary tumour at 10 min after injection ( suvmax 7.85 ) .
c , d choline pet / ct images of the metastatic lesions at the 12th thoracic spine ( suvmax 7.36 , c ) and the right iliac bone ( suvmax 10.39 , d ) at 10 min after injection .
e maximum intensity projection image . the metastatic lesions in the sixth thoracic spine and the right iliac bone are seen ( arrows)fig .
a choline pet / ct images of the primary tumour at 10 min after injection ( suvmax 6.09 ) .
c choline pet / ct images of the metastatic lesions at the right internal iliac lymph nodes at 10 min after injection ( suvmax 4.92 ) .
a catheter is inserted into the right ureter ( a , d ) urothelial carcinoma of the left renal pelvis in patient 1 .
a , b choline pet / ct images of the primary tumour at 10 min ( a ) and 20 min ( b ) after injection .
choline uptake at 10 min is positive but weak ( suvmax 2.48 ) compared with that at 20 min ( suvmax 3.79 ) .
circles tumour sites urothelial carcinoma of the right renal pelvis in patient 12 . a choline pet / ct images of the primary tumour at 10 min after injection ( suvmax 7.85 ) .
c , d choline pet / ct images of the metastatic lesions at the 12th thoracic spine ( suvmax 7.36 , c ) and the right iliac bone ( suvmax 10.39 , d ) at 10 min after injection .
e maximum intensity projection image . the metastatic lesions in the sixth thoracic spine and the right iliac bone are seen ( arrows ) urothelial carcinoma of the right ureter in patient 11 . a choline pet / ct images of the primary tumour at 10 min after injection ( suvmax 6.09 ) .
c choline pet / ct images of the metastatic lesions at the right internal iliac lymph nodes at 10 min after injection ( suvmax 4.92 ) .
c - choline is a small molecule that after intravenous injection is very quickly integrated into the cell membrane as phosphatidylcholine .
it is a marker of membrane metabolism , and is subject to very late urinary excretion , so that the renal pelvis and ureter are free of urinary radioactivity at the time of image acquisition .
nevertheless , there have been no studies so far on the efficacy of choline pet / ct in the detection of the primary tumour and metastases of uut - uc ; this was the principal motive for performing this study .
of the 16 study patients with suspicion of uut - uc examined in the present study , in 12 uut - uc was confirmed . of the other four , one had malignant lymphoma , one had igg4-related disease , and two had benign diseases .
of the 12 patients with uut - tc , 11 ( 92 % ) were choline uptake - positive and the other 1 was false - negative on choline pet / ct .
the patient with malignant lymphoma and the patient with igg4-related disease were uptake - positive , and the two patients with nonmalignant diseases were uptake - negative .
malignant cells have elevated levels of choline and upregulation of choline kinase activity [ 2730 ] .
studies have been conducted to evaluate the ability and usefulness of choline pet / ct in detecting cancer within the prostate and in differentiating cancer from normal tissue and/or benign disease [ 1619 ] . in summary , these studies indicate that the use of choline pet / ct for initial diagnosis and local staging of prostate cancer can not be recommended as a first - line screening method in men at high risk of prostate cancer . in contrast , there have been a number of studies demonstrating that choline pet / ct is useful in detecting and staging lymph node metastases of prostate cancer [ 815 ] . in another study evaluating the ability of choline pet to detect bladder cancer before cystectomy , normal bladder showed little uptake , and primary bladder cancer was visualized in 10 of 18 patients with residual invasive disease in the cystectomy specimen .
of the 12 patients with uut - uc examined in the present study , choline pet / ct revealed distant metastases in three , metastases only in the regional lymph nodes in two , and no metastases in seven . both distant metastatic lesions and
regional lymph node metastases showed definite choline uptake and similar suvmax to the values in the primary tumours of uut - uc . according to the diagnostic findings on choline pet / ct , one of three patients with distant metastases and two patients with metastases only in the regional lymph nodes underwent lnux and lymphadenectomy , and seven patients without metastases underwent lnux . as shown in table 4 and fig . 1 ,
the outcome in patients with uut - uc corresponded to the patient classification based on the presence or absence of metastases and locoregional or distant metastases .
these results suggest that choline pet / ct is useful in staging as well as in the primary diagnosis of uut - uc .
choline uptakes determined as suvmax at 10 min were significantly higher than those at 20 min in metastatic tumours of uut - uc ( p < 0.05 ) , whereas these was no statistically significant difference between the suvmax values at 10 min and those at 20 min in the primary tumours of uut - uc .
although the reason for the difference between the primary and metastatic tumours of uut - uc is not yet known , the finding suggests that choline uptake takes place earlier in metastatic tumours than in primary tumours of uut - uc .
the results indicate that choline uptake should be determined at both 10 and 20 min after injection for the detection of the primary and metastatic tumours of uut - uc .
because the number of patients assessed in this pilot study was rather small , confirmation of this conclusion must await further follow - up studies with greater numbers of patients .
besides uut - uc , the tumours developed in the ureter of a patient with malignant lymphoma and a patient with igg4-related disease were choline uptake - positive .
igg4-related disease , which is characterized by elevated serum igg4 concentrations and tumefaction or tissue infiltration with igg4-positive plasma cells , is an under - recognized condition about which knowledge is now growing rapidly [ 25 , 26 ] .
the present study demonstrated that inflammatory pseudotumour developed in the ureter of a patient with igg4-related disease and the tumour showed definite choline uptake .
to our knowledge there have been no prior reports of definite choline uptake in tumorous lesions associated with igg4-related disease .
the results of the present study showed that choline pet / ct is useful in detecting the primary tumours and metastases of uut - uc and potentially in providing valuable prognostic information .
besides uut - uc , the ureteral tumours associated with malignant lymphoma and igg4-related disease showed definite choline uptake .
follow - up studies with greater numbers of patients are needed to make the conclusions more reliable .
the results of the present study showed that choline pet / ct is useful in detecting the primary tumours and metastases of uut - uc and potentially in providing valuable prognostic information .
besides uut - uc , the ureteral tumours associated with malignant lymphoma and igg4-related disease showed definite choline uptake .
follow - up studies with greater numbers of patients are needed to make the conclusions more reliable .
| purposewe conducted a pilot study to prospectively evaluate the efficacy of pet / ct with 11c - choline ( choline pet / ct ) for primary diagnosis and staging of urothelial carcinoma of the upper urinary tract ( uut - uc).methodsenrolled in this study were 16 patients ( 9 men , 7 women ; age range 51 83 years , mean sd 69 10.8 years ) with suspected uut - uc . the patients were examined by choline pet / ct , and 13 underwent laparoscopic nephroureterectomy and partial cystectomy .
lymphadenectomy and chemotherapy were also performed as necessary in some of the patients .
of the 16 patients , 12 were confirmed to have uut - uc ( 7 renal pelvis carcinoma and 5 ureteral carcinoma ) , 1 had malignant lymphoma ( ureter ) , 1 had igg4-related disease ( ureter ) , and 2 had other benign diseases ( ureter).resultsof the 16 study patients , 13 showed definite choline uptake in urothelial lesions , and of these , 11 had uut - uc , 1 had malignant lymphoma , and 1 had igg4-related disease .
three patients without choline uptake comprised one with uut - uc and two with benign diseases .
of the 12 patients with uut - uc , 3 had distant metastases , 2 had metastases only in the regional lymph nodes , and 7 had no metastases .
distant metastases and metastases in the regional lymph nodes showed definite choline uptake .
the outcome in patients with uut - uc , which was evaluated 592
1,530 days after surgery , corresponded to the patient classification based on the presence or absence of metastases and locoregional or distant metastases .
choline uptake determined as suvmax 10 min after administration was significantly higher than at 20 min in metastatic tumours of uut - uc ( p < 0.05 ) , whereas there was no statistically significant difference between the suvmax values at 10 and those at 20 min in primary tumours of uut-uc.conclusionthis study suggests that choline pet / ct is a promising tool for the primary diagnosis and staging of uut - uc . |
heparan sulfate ( glucosamine ) 3-o - sulfotransferase 4 hypoxia - inducible factor 1 subunit lung endothelial cells platelet - derived growth factor receptor telomeric repeat - binding factor 2 tumor endothelial cell vascular endothelial growth factor wilms tumor suppressor 1
inhibition of tumor angiogenesis is widely accepted as a valuable therapeutic option for cancer treatment and a large number of cancer patients benefit from treatment with inhibitors of the angiogenic vascular endothelial growth factor ( vegf ) . however
, different tumor types show unique features in their vasculature depending on tissue specificity and the expression pattern of pro- and anti - angiogenic molecules and their cognate receptors .
thus , it is not surprising that , in addition to positive antitumor effects , increased invasion and metastasis have also been noted in divergent experimental models targeting vegf .
these observations support the notion that other proangiogenic factors play a role in sustained tumor angiogenesis and progression .
we previously found that the wilms tumor suppressor wt1 is highly expressed in vessels of human tumors but not in healthy adjacent tissues , and is required for angiogenesis .
furthermore , wt1 is implicated in vessel formation during development and in pathophysiological conditions such as myocardial ischemia as a transcriptional target of hypoxia - inducible factor 1 ( hif1a ) .
wt1 encodes a zinc - finger transcription factor with crucial functions in development and was originally identified as a tumor suppressor based on its mutational inactivation in wilms tumor .
however , because of its overexpression in a variety of human cancers , it is now considered a potential oncogene . like wt1 ,
expression of the telomeric repeat - binding factor 2 ( trf2 , also known as terf2 ) , which plays a central role in telomere capping , is frequently increased in human tumors .
consistent with a potent oncogenic role of a high level of trf2 , its downregulation in cancer cells reduces tumorigenicity whereas its overexpression favors oncogenesis .
we showed that the high level of trf2 found in cancer cells positively regulates the expression of hs3st4 encoding heparan sulfate ( glucosamine ) 3-o - sulphotransferase 4 , which is involved in the recruitment of nk - cells , thus revealing that trf2 upregulation can have oncogenic properties through cell non - autonomous mechanisms . in our recent work
1 ) . we found that trf2 was highly expressed in the tumor vasculature of different human cancer types , but not in the vessels of healthy tissues . using ex vivo approaches , we demonstrated that tumor - derived endothelial cells ( tecs ) expressed higher levels of trf2 than endothelial cells from healthy lung tissues ( lecs ) and exhibited a higher angiogenic potential .
we further showed that upregulation of trf2 in the tumor endothelium is the result of its transcriptional activation by wt1 . in agreement with an important angiogenic role of trf2 overexpression in tecs , depletion of trf2 in these cells led to loss of their angiogenic properties , and overexpression of trf2 in lecs conferred on them the high angiogenic potential of tecs .
overall , these findings suggest that trf2 might play a role in vascular development and in cases of ischemia , as has been shown for wt1
.
figure 1.telomeric repeat - binding factor 2 ( trf2 ) regulates angiogenesis by acting as a transcription factor independent of its function in telomere protection .
furthermore , trf2 expression is upregulated in tumor - derived endothelial cells , most likely because trf2 is a transcriptional target of the wilms tumor suppressor 1 ( wt1 ) , which is highly expressed in the tumor vasculature . in tumor
endothelial cells , trf2 binds and transactivates the platelet - derived growth factor receptor ( pdgfr ) promoter , which stimulates angiogenesis .
overall , by activating tumor angiogenesis and cancer cell proliferation , trf2 emerges as a valuable multi - hit target for cancer therapy .
telomeric repeat - binding factor 2 ( trf2 ) regulates angiogenesis by acting as a transcription factor independent of its function in telomere protection .
, trf2 expression is upregulated in tumor - derived endothelial cells , most likely because trf2 is a transcriptional target of the wilms tumor suppressor 1 ( wt1 ) , which is highly expressed in the tumor vasculature . in tumor
endothelial cells , trf2 binds and transactivates the platelet - derived growth factor receptor ( pdgfr ) promoter , which stimulates angiogenesis .
overall , by activating tumor angiogenesis and cancer cell proliferation , trf2 emerges as a valuable multi - hit target for cancer therapy .
next , we investigated how a high trf2 level boosted the angiogenic properties of tecs .
first , we did not observe telomere uncapping and initiation of the dna damage response ( ddr ) upon modulation of trf2 levels , indicating that the angiogenic function of trf2 in endothelial cells is uncoupled from its role in telomere capping .
second , by screening for angiogenic targets of trf2 , we found that trf2 increases the expression of platelet - derived growth factor receptor ( pdgfrb ) .
autocrine growth stimulation of tumor endothelial cells through pdgfrb that is evoked by interaction with cancer cells has been postulated , underlining the diversity of proangiogenic mechanisms in tumor angiogenesis and the resulting difficulties in establishing adequate antiangiogenic therapies for cancer treatment .
third , using different approaches we demonstrated that trf2 is a direct transcriptional activator of pdgfrb that is capable of binding and activating the pdgfrb promoter .
overexpression of pdgfrb could rescue the inhibition of endothelial cell proliferation caused by depletion of trf2 , but only partially rescued the effects on the migratory potential of these cells .
this indicates that trf2 might also activate factors other than pdgfrb that are implicated in endothelial cell migration . the fact that telomere factors such as trf2 bind extra - telomeric sites to regulate transcription is not unprecedented ( reviewed in ) .
our finding that trf2 binds and activates the pdgfrb promoter should facilitate dissection of the mechanism by which trf2 acts as a transcriptional regulator and consequently will have strong implications for basic and biomedical research .
taken together , these findings reveal a novel mechanism by which trf2 transcriptionally controls tumor angiogenesis independent of its role in telomere protection .
they further suggest that pathways controlling replicative potential ( telomere ) and those controlling energy supply ( angiogenesis ) co - evolved for a better control of tissue homeostasis and renewal .
they also point to trf2 as a novel multi - hit target in cancer therapy , as it is implicated in both the proliferation of cancer cells through cell autonomous and non - autonomous mechanisms and in the angiogenic properties of tecs .
thus , compared to classic antiangiogenic therapies , the identification of molecules that target trf2 might be a major advance for cancer treatment through hitting 2 birds with one stone .
the study was supported by the ligue nationale contre le cancer ( equipe lablise , eg ) , the institut national du cancer ( inca ) program telochrom , the anr ( national research agency ) programs innatelo and the investments for the future labex signalife ( reference anr-11-labx-002801 ) , the fondation arc ( association pour la recherche sur le cancer ) , and fondation de france ( kdw ) .
m el ma is supported by a fellowship from the ligue nationale contre le cancer and the fondation arc pour la recherche sur le cancer . | we recently showed that telomeric repeat - binding factor 2 ( trf2 ) regulates gene expression to promote angiogenesis .
we found that trf2 is highly expressed in tumor vessels and transcriptionally activates platelet - derived growth factor receptor to promote endothelial cell angiogenic properties independently of its function in telomere protection .
this work identifies trf2 as a promising dual target for cancer therapy . |
secondary hyperparathyroidism ( shpt ) is a major complication of chronic kidney disease ( ckd ) , resulting from disturbances in the regulation of parathyroid hormone ( pth ) , calcium , phosphorus , and vitamin d. although hyperphosphatemia appears to be particularly important in the development of shpt , the complication often occurs early in stage 3 of kidney failure , before the development of hyperphosphatemia .
several factors , including pth and vitamin d , play a criticalrole in this system .
fibroblast growth factor23 ( fgf23 ) , a recently identified phosphatonin , is also implicated .
although , a significant role of fgf23 inphosphate homeostasis in physiological conditions is described in many studies with the kidney functioning normally , few studies are available on end - stage renal disease .
one of the most commonly cited morbidity associated with end - stage kidney disease is renal osteodystrophy , secondary to the alterations in mineral metabolism . to understand the interrelatedseries of events leading to that , it is first necessary tostudy the mineral metabolism and its physiological process .
the present study aims to evaluate the relation between serum fgf23 , phosphorus , and pth in end - stage renal disease patients with shpt on regular hemodialysis .
all patients who had shpt and were on regular hemodialysis in nephrology unit in suez canal university hospital , from january to july 2010 , were included in the study ( case group , comprising 46 patients ) .
twenty healthy adults ( with normal kidney function ) matched for age and gender were considered as the control group .
serum phosphorus , calcium , ferritin , albumin , hemoglobin level , blood urea , and creatinine were assessed by standard protocols at the department of clinical pathology in suez canal university hospital .
intact fgf23 concentrations were measured using human fgf-23 ( c - term ) elisa kit according to manufacturer 's ( immutopics , inc .
serum samples were collected from each individual at a single time point and kept at 70c until analysis . before the commencement of the study
, informed consent was obtained from all individuals selected for the study . the aim and the value of the work
there was no chance of any harm being inflicted on them ; on the contrary , all would have the benefits of follow - up and the results of the study .
the study was approved by the ethics committee of the faculty of medicine , suez canal university .
the student t test , correlation coefficient , and chi - square tests were used to evaluate the results .
chi - square test was used for qualitative variables , while independent t test was used for quantitative variables .
before the commencement of the study , informed consent was obtained from all individuals selected for the study . the aim and the value of the work
there was no chance of any harm being inflicted on them ; on the contrary , all would have the benefits of follow - up and the results of the study .
the study was approved by the ethics committee of the faculty of medicine , suez canal university .
the student t test , correlation coefficient , and chi - square tests were used to evaluate the results .
chi - square test was used for qualitative variables , while independent t test was used for quantitative variables .
all the patients ( 46 patients ) of the case group were on hemodialysis for an average duration of 4.9 years .
the age of the patients ranged from 20 to 52 years ( 34.7 + 11.8 ) years .
forty - one ( 89.8% ) patients were on regular vitamin d and calcium supplements .
the control group consisted of 20 healthy adults with normal kidney function ; their mean age was 30.37.9 years .
table 2 shows that fgf23 has a significant positive correlation with serum phosphorus , urea , creatinine , ferritin , hemoglobin , and pth levels ( p < 0.01 ) .
table 3 shows that pth has a significant positive correlation with serum phosphorus level ( p < 0.01 ) .
the scatter plots show positive correlation between fgf23 and serum phosphorus levels ( r= + 0.9 ; p <
0.001 ) and between fgf23 and serum pth levels ( r= + 0.6 ; p < 0.01 ) [ figure 1 and figure 2 ] . laboratory characteristics of the studied patients in comparison to control correlation between fgf-23 and various parameters correlation between parathyroid hormone level and other parameters correlation between fgf-23 and serum phosphorus level correlation between fgf-23 and parathyroid hormone
shpt is an insidious disease that develops early in the course of ckd and increases in severity as the glomerular filtration rate deteriorates .
it is not yet proven if there is any direct relationbetweenpth and fgf23 . in our study ,
levels of both pth and serum phosphorus in the case group , were significantly higher in comparison with those in the control group .
as the number of functioning nephrons decreases , the failing kidneys are unable to excrete phosphorus and there is a progressive increase in serum phosphorus levels .
the ongoing inability to excrete phosphorus leads to continual over - stimulation of the parathyroid glands , tissue hyperplasia , and over - secretion of pth .
the development of shpt in our patients was most likely a sequela of this series of classic events .
hemoglobin levels were significantly low in the case group and negatively correlated with both pth and fgf23 levels , which indicates that shpt may have a partial role in the development of anemia in patients with ckd .
high pth levels may contribute to anemia by directly inhibiting the production of red blood cells and increasing their fragility .
shpt can also cause marrow fibrosis , further decreasing the production of red blood cells .
it is worth noting , that a recent prospective study has shown that fgf23 mediates the development of hypophosphatemia after i.v iron poly - maltose administration . in our study ,
most of the patients received parenteral iron , and further correlation was observed between ferritin and fgf23 blood levels , which warrants further studies to evaluate the mechanism whereby parenteral iron therapy influences fgf23 metabolism and to identify additional systemic factors regulating fgf23 production , in order to enhance our understanding of phosphate homeostasis . in addition , the possible role of fgf23 in the development of anemia is explicable .
the degree of fgf23 elevation , seen in the current data , correlates positively with thedegree of hyperphosphatemia . in experimental studies , phosphate loading in mice increasesfgf23 levels .
previous studies on dietary phosphate as a regulator of fgf23 showed conflicting results.[1417 ] small sample size , and differences in magnitude or duration of altered phosphate intake may explain the contradictory results .
although fgf23 inhibits phosphate re - absorption in the proximaltubule , leading to hypophosphatemia , phosphate levels were significantly high in our case group in spite of the concomitant 4-fold increases in fgf23 levels .
the possible explanation is that the kidney , which is the principal target of fgf23,is no longer responsive to fgf23 in ckd .
another explanation is that , in early stage of ckd , serum fgf23 is elevated to maintain normal serum phosphate levels by promoting urinary phosphate excretion ; but in patients at the advanced stage , overt phosphate loading may overcome such compensation for decreased glomerular filtration rate ( gfr ) despite markedly elevated fgf23 levels .
on the other hand , the precise mechanism and site of definitely increased fgf23 levels havenot been evaluated in the present study .
it is possible thatboth increased production and decreased metabolism or clearanceof fgf23 contributes to elevated levels of fgf23 in ckd .
althoughno studies have yet documented increased production of fgf23,the correlation of fgf23 levels with increasing blood urea and creatinine in our study and therapid decrease in fgf23 levels in some patients after renaltransplantation in other studies , suggest that fgf23 is cleared by the kidney .
previous in vivo studies have shown a stimulatory effect of 1,25(oh)2vit d3 on circulating fgf23 levels in rodents and in humans.[2022 ] it is an interesting point as most of our studied patients received high doses of active vitamin d , which may be implicated in the pathophysiology of the observed rises in fgf23 . however , the function ofhigh fgf23 levels in the control of phosphate levels in ckd is still unexplained , and more studies are necessary .
however , there is growing evidence that pth may stimulate fgf23 expression and secretion by bone tissue . in the setting of primary hyperparathyroidism , elevated fgf23 concentrations
have been observed by several groups.[2325 ] on the other hand , in the study by hiroyuki et al .
, no difference in serum fgf23 levels was found between healthy controls and primary hyperparathyroidism patients with normal renal function ; also , there were no significant relations detected between serum fgf23 levels and the levels of pth .
as several agents influence the release of pth and fgf23 , the presence of altered calcium or magnesium levels , subsequent to administration of variable supplements to the patients , confounds the interpretation and conflicts of any association between fgf23 and circulating levels of pth .
a strongpositive correlation between elevated fgf23 levels and the severity ofhyperparathyroidism in ckd group ( case group ) was observed in our study . although the mechanism of this finding is unclear , it is possible that chronic phosphate retention as reflected by elevated fgf23 levels may have contributed to further stimulation of pth secretion , progression of parathyroid hyperplasia , and parathyroid cell proliferation .
another possibility is that high levels of fgf23 at baseline may be a consequence of prolonged active vitamin d administration for severe hyperparathyroidismin our patients , as mentioned above .
therefore , fgf23 might indirectly contribute to the development of shpt associated with renal insufficiency .
furtherstudies are required to document the effects of fgf23 on pth production and secretion and on parathyroid cellproliferation and to assess the role of fgf23 estimation in predicting the future development of refractory shptin ckd .
the precise role of extremely elevated fgf23 in the control of hyperphosphatemia ; and their direct effect on parathyroid function and development of anemia in ckd patients on hemodialysis still remain unclear .
their positive correlation with pth may suggest that fgf23 is a central factor in the early pathogenesis of shpt.using fgf23 as a biomarker for assessing phosphate retention or as a predictor of morbidity and future development of refractory shpt in ckd needs more studies . | introduction : secondary hyperparathyroidism ( shpt ) is an insidious disease that develops early in the course of chronic kidney disease ( ckd ) and increases in severity as the glomerular filtration rate deteriorates .
recent studies have identified fibroblast growth factor-23 ( fgf23 ) as a new protein with phosphaturic activity .
it is mainly secreted by osteoblasts and is now considered the most important factor for regulation of phosphorus homeostasis .
it is not yet proven if there is any direct relation between parathyroid hormone ( pth ) and fgf23 .
the present study aims to evaluate the relation between serum fgf23 , phosphorus , and pth in end - stage renal disease in patients with shpt on regular hemodialysis.materials and methods : forty - six consecutive ckd adult patients ( case group ) and 20 healthy adults ( control group ) were included in the study .
all patients had shpt and were on regular hemodialysis .
both groups were subjected to full medical history , clinical examination and biochemical studies .
serum phosphorus , calcium , ferritin , hemoglobin level , blood urea , creatinine , pth , and fgf23 were analyzed.results:levels of fgf23 were significantly higher in the case group in comparison with those in the control group , viz .
, 4-fold , and positively correlated with pth .
phosphorus levels in the case group were significantly high in spite of the increasing levels of fgf23 . both pth and fgf23
were positively correlated with phosphorus and negatively with hemoglobin levels.conclusion:shpt and fgf23 may have a partial role in the development of anemia in patients with ckd .
fgf23 could be a central factor in the pathogenesis of shpt .
its role in controlling hyperphosphatemia in ckd is vague . |
dermatophytes are responsible for a variety of clinical manifestations in man , trichophyton rubrum being the commonest isolate worldwide .
they are assuming greater significance both in developed and developing countries due to illnesses like diabetes , hiv infection and the use of immunosuppressive drugs .
overall ringworm infections account for 10% of the total cases who attend the skin outpatient department .
the indian subcontinent has a varied topography and the hot and humid climate which is more conducive to the acquisition of fungal infections .
the nature of dermatophytosis may change with the passage of time , living conditions and evolution of preventive measures and hygienic conditions in society .
the study was conducted in the department of microbiology and dermatovenerology at igmc shimla over a period of one year from may 2008 to april 2009 . the study group comprised of hundred clinically suspected cases of dermatophytosis . a detailed clinical history including age , sex , duration and the clinical presentation were recorded . as per the involvement of the anatomical site they were grouped into various clinical types .
direct microscopy using 10% potassium hydroxide ( koh ) for skin scrapings and epilated hairs and 40% koh for nail specimens was done .
the koh wet mounts were screened under low power ( 10 ) and then at high power ( 40 ) for visualization of the fungal hyphae .
septate hyphae with or without branching and a diameter of 2 - 4 m , or hyphae with arthroconidia were taken as a criterion to label the slide as koh positive .
the second part of the sample was inoculated on two sets of sabourauds dextrose agar containing chloramphenicol ( 0.05 mg / ml ) and cyclohexamide ( 0.1 - 0.4 mg / ml ) and incubated at 25 and 37c .
the cultures were examined twice a week and if no growth was obtained till 4 weeks they were declared negative .
the culture isolates were further identified by studying the colony morphology and microscopic examination of the lactophenol cotton blue mounts .
further special tests like hair perforation , urease production and slide culture were performed wherever necessary according to standard techniques .
peak incidence of dermatophytosis was seen in the third decade of life ( 28% ) .
out of 100 cases 77 ( 77% ) presented with a single site involvement while 23 ( 23% ) had affliction of two or more anatomical sites .
tinea corporis was the commonest clinical presentation ( 27.7% ) followed by tinea cruris ( 22% ) .
association of tinea corporis with other clinical types was present in 12 out of 23 ( 52.17% ) cases .
combination of tinea unguium with tinea pedis and tinea mannum was seen in 11 ( 47.8% ) and 4 ( 17.3% ) out of 23 cases respectively . on koh wet mount examination 80 out of 100 ( 80% )
out of these only 57 samples was culture positive . there were 11 koh negative samples that yielded growth on culture .
overall , 68% samples were culture positive , taking into consideration both koh positive and negative specimens [ table 1 ] .
correlation between clinical type , koh and culture culture positivity was highest in tinea corporis ( 80.95% ) and lowest in cases of tinea barbae ( 33.33% ) as depicted in table 2 .
trichophyton was the most common genus in 66 out of 68 ( 97.05% ) culture isolates .
trichophyton rubrum was the commonest species ( 66.17% ) followed by trichophyton mentagrophytes ( 19.11% ) , trichophyton violaceum ( 7.35% ) , trichophyton verrucosum ( 2.94% ) .
there was one isolate each of trichopyton tonsurans ( 1.47% ) and microporum gypseum respectively [ table 3 ] .
maximum number of cases were seen in the age group of 21 - 30 years ( 28% ) , followed by 31 - 40 years ( 24% ) and males were affected more than females .
it can be attributed to the fact that the males may be more prone because of prolonged vigorous outdoor activity and increased perspiration which creates an environment for the development of tinea infection . in the present study tinea corporis
this pattern of clinical preponderance has been observed in other studies . on the contrary reports from manipal and aurangabad
perhaps these areas are hot and humid as compared to our region which has a temperate climate which accounts for the difference .
some reports quote similar rates however others have reported a larger proportion of cases with this clinical type .
this could be attributed to the difference in the personal hygiene and habits of the people .
wet mount examination positivity rates ranging from 23.8% to as high as 91.2% have been reported . in our study
selection criteria of cases and skill involved in sampling techniques perhaps accounts for the difference .
thus all koh negative samples should be cultured . in a study conducted in ludhiana 13.2% of koh negative samples exhibited growth on culture which coincides with our observations .
non visualization of hyphae on direct microscopy could possibly be due to a severe inflammatory reaction which obscures them .
a variability in culture isolation ranging from 44.6% to70.7% has been found in the indian sub - continent . in
this anthropophillic species has become well adapted to the human skin as climatic and crowded living conditions enhance its prevalence .
trichophyton violaceum was isolated from cases of tinea capitis in children in the prepubertal age group .
however in a study conducted in hyderabad higher isolation rates upto 14.68% have been observed . this could be attributed to the predominant muslim population who wear caps and thus are more prone to the acquisition of superficial fungal infections .
one isolate each of trichophyton verrucosum and microsporum gypseum were obtained from cases of tinea facei .
both these species were isolated from children with a rural background so a probable transmission of infection could have occurred from above sources .
isolation of microsporum gypseum from one case is of special interest in the present study as this genus is generally less commonly encountered in india .
one isolate each of trichophyton violaceum and trichopyton tonsurans were recovered from nail specimens on culture .
the present study has given us a clear insight regarding the mycological pattern of dermatophytosis in this region .
the overall findings suggest that the study is comparable to those from different parts of india . | introduction : dermatophytosis is defined as the fungal infection of the skin , hair and nails by a group of keratinophillic fungi known as dermatophytes.aims and objectives : this study is an attempt to find out various species of dermatophytes in clinically suspected cases of dermatophytosis.materials and methods : one hundred samples were subjected to direct microscopy by potassium hydroxide wet mount ( koh ) and isolation on culture with sabourauds dextrose agar.results:out of these 80 ( 80% ) samples were koh positive while 20 ( 20% ) were koh negative .
overall culture positivity rate was 68% .
dermatophytosis was more common in males , the m : f ratio was 4:1.conclusion : total seven species were isolated on culture .
trichophyton rubrum ( 66.17% ) was the commonest isolate followed by trichophyton mentagrophytes ( 19.11% ) , trichophyton violaceum ( 7.35% ) , trichophyton tonsurans ( 2.94% ) and one isolate each of epidermophyton floccosum and microsporum gypseum ( 1.47% ) . |
upper tract transitional cell carcinoma ( tcc ) , i.e. , tcc of the renal pelvis and ureter accounts for only 5% of all urothelial tumors and 10% of all renal tumor cases .
stage of the tumor is the single most important prognosticator for the outcome of this disease . in west , spectrum of the diseases skewed to lower stage , so that the most of the cases are detected at an early stage which is often amenable to endoscopic treatment .
there is paucity of data on indian patients regarding the clinical presentation and various pathological characteristics .
herein , we present our data and the outcome of treatment of upper tract tcc .
data of 40 consecutive patients who were diagnosed for upper tract tcc between january 2000 and january 2010 were collected from medical case records , pathology data base , and hospital information system .
the age , sex , symptoms , ptnm staging , tumor size , location of the tumor with respect to the pelvis and ureter , necrosis , lymphovascular invasion , duration of follow up , details of the bladder , local and systemic recurrences were analyzed .
preoperative diagnosis was based on contrast - enhanced computerized tomography ( cect ) of the whole abdomen and urine cytology ( 3 samples ) .
retrograde pyelogram was done in three patients but none of the patients had ureteroscopy with biopsy .
of 40 patients , 34 had nephroureterectomy with bladder cuff excision and two patients imperatively had lower ureteric excision along with bladder cuff as they were having diabetic nephropathy .
four patients had systemic metastasis at the time of presentation , who were managed with either neoadjuvant chemo ( 2 ) or symptomatic treatment due to presence of widespread metastasis and poor performance status of the patients ( 2 ) .
those patients who received four cycles of neoadjuvant chemotherapy showed progression of the disease and were eventually treated symptomatically .
cystoscopy was done on every patient as part of protocol to see for concomitant bladder tumor .
then , laparoscopic nephroureterectomy along with bladder cuff excision was done in 27 cases through four ports in diamond configuration [ figure 1 ] . after mobilizing the colon and clipping and cutting hilar vessels
then , modified gibson incision was given and the specimen removed along with 2 cm bladder cuff [ figure 2 ] .
open surgery was done through two separate , i.e. , sub - costal and gibson incision . port sites and gibson incision hypovascular tumor in left pelvicalyceal system with nephroureterectomy specimen lymph node dissection was started since august 2007 and before that , no routine lymphadenectomy was being done .
the limit of lymph node dissection was up to the common iliac group for upper ureteric and pelvic tcc and up to the external iliac group for lower ureteric tcc .
cross tab and logistic regression analysis was done on the effect of various clinicopathological characteristics on the outcome which was defined as patients developing recurrence or dying due to upper tract tcc .
kaplan meir survival analysis was done to derive cancer - specific survival and recurrence - free survival .
mean duration ( range ) of follow up was 36.6 ( 12 to 100 ) months .
demographic characteristics none of the patients had tumor in the bladder or contralateral kidney at the time of presentation .
of eight bladder recurrences , six were found on routine check cystoscopy without any symptoms .
majority of them had ta low - grade tumors and two had high - grade lamina invasive tcc .
one of the two patients died as he had associated metastasis and the other one had orthotopic neobladder and is doing well .
one patient was treated with cisplatinum and gemcitabine chemotherapy ( six cycles ) with complete response [ figure 3 ] and the other patient died .
pathological characteristics recurrence after surgery local recurrence which responded to chemotherapy of 16 patients who had recurrences , 11 died due to tcc and five are surviving following the bladder recurrence .
the 5-year cancer - specific survival was 26 5.1% ( 20.5 - 39.3% ) [ figure 4 ] and recurrence - free survival was 36.33% [ figure 5 ] .
cancer specific kaplan meir survival plot of the total patients recurrence free kaplan meir survival plot of the total patients on logistic regression analysis of the demographic and pathological characteristics on outcome , only necrosis ( p value 0.032 and odds ratio 6.600 ) had statistically significant impact on outcome .
t stage , grade of the lesion and lymph node dissection did not have significant impact on outcome as most of our patient presented very late with higher stages and grades .
in the recent literature , due to improved imaging and rigorous search for the cause for microscopic hematuria , majority of upper tract tcc have been described to present as low t stage .
the incidence of ta to t1 tumors vary from 44 to 60% in these studies .
there are no data available on indian patients on upper tract tcc . as microscopic hematurias
is neither looked for and nor evaluated extensively , it is not surprising that our patients present very late in the course of the disease .
as the stage is considered the most important prognostic factor , early detection would improve the survival in this disease .
most of our patients were detected with symptoms and only four patients ( 11.1% ) presented in ta to t1 stage .
similarly , though the grade of the disease has bearing on the survival , there are studies for and against grade as poor prognostic marker for recurrence .
upper tract tcc is a malignancy of the seventh decade with male to female ratio of 3 : 1.[57 ] in our study , the mean age at the time of presentation was 62.7 years and majority of our patients were males with the male to female ratio of 7 : 1 .
male preponderance was also seen in bladder cancer in our previously published data . whether this could be explained by the smoking habit in males or environmental factors
bladder recurrence has been described in the range of 18 to 37% . in one study of 60 patients of upper tract tcc
, none of the clinical or pathological parameters were having statistically significant impact on intravesical recurrence . in our study
, all patients with bladder recurrence presented within 18 months and most of them had low stage and low grade .
this is in contradiction to the concept of field change described with tcc as despite having high stage and grade of tcc in the upper tract , none had concomitant bladder tumor at the time of presentation . secondly , most of them had recurrence of low grade and stage .
bladder recurrence did not present with any symptoms , which underscores the importance of regular check cystoscopy .
this pattern and incidence of bladder recurrence ( 22% ) is similar to the pattern described in the western studies .
another important observation from this study was that all of the recurrences after initial surgical treatment , bladder recurrence was the least likely to cause death .
the need and the extent of lymph node dissection has been standardized recently.[1315 ] in one of the largest experiences on 830 patients , the lymph nodes identified in the biopsy specimen was only 13.2% and the median yield was only 1 .
lymph node dissection was started since 2007 and it was done in 38.8% of cases .
the laparoscopic nephrectomy positivity rate of 35.7% in our study is much higher than the reported incidence of 4 to 9.9% in the literature .
this could be explained by the late presentation in the course of the disease . due to the small sample size
five - year recurrence - free and cancer - specific survivals in our study were 36.33% and 26 5.1% ( 20.5 - 39.3% ) , respectively , which is much lower than the reported survival in western literature in current series . in the study by margulis et al .
, data on 1 363 patients treated with radical nephroureterectomy at 12 academic centers were collected and the 5-year recurrence free survival and cancer specific survival was ~69% and 73% , respectively . in another series on 100 patients ,
the poor result in indian patients may be due to late presentation as most of our patients had higher stage of the disease , which is the single most important predictor for the survival . though the cytology and ureteroscopy form the integral part of initial investigations , all our patients were diagnosed on cect .
surprisingly , the yield of cytology despite having a high stage and grade was very low ( 10% ) . possible explanation could be that most of our patients presented with gross hematuria indicating necrosis and slough at the higher stage of the disease and patients had dead cells in urine instead of living cancer cells .
ureteroscopy would help in very early stage of the disease in patients who get evaluated for microscopic hematuria ; therefore , it did not form the mainstay of diagnosis as most of our patients were diagnosed on cect .
lymphovascular invasion and necrosis are other poor prognosticators and are associated with higher t stage and grade of the disease.[1619 ] though lymphovascular invasion was reported in only one case , it possibly explains the reporting bias ( under - reporting ) in our series but necrosis was almost a universal finding , which was found in 30 ( 83.3% ) .
this study has limitation of sample size . since indian patients are presenting late and having high stage at the time of presentation , importance of proper evaluation of patients presenting with microscopic hematuria
should be stressed which will help in detecting upper tract tcc at an early stage .
indian patients with upper tract tcc present late and are having high stage at the time of diagnosis .
five - year cancer - specific and recurrence - free survival is very low in comparison with the western literature .
importance of proper evaluation of patients presenting with microscopic hematuria should be stressed , which will help in detecting upper tract tcc at an early stage , and also in paving the way for preserving nephron by adopting to less - invasive approaches . | introduction : disease spectrum of upper tract transitional cell carcinoma ( tcc ) in indian patients is not known . herein , we present data on clinical presentation , pathological characteristics , and the outcome of treatment of upper tract tcc.materials and methods : clinicopathological data of patients who were diagnosed for upper tract tcc between january 2000 and january 2010 were collected from the hospital information system and case records .
preoperative diagnosis was based on contrast - enhanced computerized tomography of the whole abdomen and urine cytology .
cross tab and logistic regression analysis was done on the effect of various clinicopathological characteristics on the outcome and cancer - specific and recurrence survival were derived.results:there were total 40 patients , 35 ( 87.5% ) of them were male .
the mean age was 62.7 7.9 years .
the most common symptom was gross hematuria present in 30 ( 75% ) .
mean tumor size was 2.8 1.2 cm .
median duration of follow up was 36 ( 12 to 100 ) months .
laparoscopic nephroureterectomy was done in 27 patients along with bladder cuff excision and seven patients underwent open surgery .
thirty two ( 88.8% ) patients had invasive t stage and high - grade lesions were seen in 24 ( 66.6% ) .
lymphovascular invasion was found only in one case and necrosis in 30 ( 83.3% ) .
necrosis was found to be the poor prognostic factor .
five - year recurrence - free and cancer - specific survivals were 36.33% and 26% , respectively.conclusion:patients with upper tract tcc present very late with a high - stage disease and a very low 5-year cancer - specific and recurrence - free survivals . |
male infertility is generally characterized by dysfunctions in processes of adhesion , penetration , and fusion of sperm with oocyte . during spermatogenesis
, the haploid round spermatids undergo an elongation phase , cytoplasmic droplet rejection , and eventually differentiate into mature spermatozoa .
the formation of mature spermatozoa is a unique process involving a series of meiotic and mitotic changes in the cytoplasmic architecture , replacement of somatic cell - like histones with transition proteins , and the addition of protamines leading to a highly packaged chromatin .
the sperm chromatin is normally a highly organized , compact structure consisting of dna and heterogeneous nucleoproteins .
this condensed and insoluble nature protects the genetic integrity and facilitates the transport of the paternal genome through female reproductive tract .
several studies have demonstrated that failure of fertilization can be attributed to the defects which lie in chromatin decondensation in infertile cases.[57 ] during spermiogenesis , the structure of chromatin is permanently modified .
the first step of this process takes place in haploid round spermatids and includes replacement of somatic histones by transition proteins 1 and 2 ( tnp1 and tnp2 ) . in the phase of elongated spermatids , tnp1 and tnp2
are replaced by protamines . after binding of protamines to nuclear sperm chromatin , the process of gene transcription is completely inactivated .
, an attempt was made to compare the in vitro sperm nuclear chromatin decondensation between fertile and infertile males .
a total of 65 infertile males who referred to the mediwave ivf and fertility hospital ( mysore , india ) for further evaluation and treatment were recruited as subjects for this study . on the other hand ,
institutional ethical clearance was taken from university ethical clearance committee and written informed consent letters were obtained from all participants before entering the study .
the semen samples were collected from the infertile subjects as well as the control group through masturbation after 3 - 5 days of ejaculatory abstinence .
the samples were collected in a sterile plastic container in a room especially provided for this purpose by following the world health organization ( who ) guidelines .
the collected semen samples were allowed to liquefy at 37c for 30 minutes and were analyzed within 1 hour after collection . physical examination such as liquefaction time , color , odor , and ph
basic microscopic examination was carried out to record the count , vitality , density , morphology , and motility of the sperm according to the who guidelines .
semen samples were diluted with ethylenediaminetetraacetic acid ( edta ) and sodium dodecyl sulfate ( sds ) mixture and incubated with equal volume of glutaraldehyde / borate buffer at 37c for 60 minutes .
then , 10 microliters of the incubated mixture were placed on a clean glass slide and 200 spermatozoa were examined under a microscope using a 40x objective .
the obtained values were recorded and subjected to statistical analyses using the statistical software called prism3.0 .
the mean values of the groups were analyzed by analysis of variance ( anova ) .
the semen samples were collected from the infertile subjects as well as the control group through masturbation after 3 - 5 days of ejaculatory abstinence .
the samples were collected in a sterile plastic container in a room especially provided for this purpose by following the world health organization ( who ) guidelines .
the collected semen samples were allowed to liquefy at 37c for 30 minutes and were analyzed within 1 hour after collection . physical examination such as liquefaction time , color , odor , and ph
basic microscopic examination was carried out to record the count , vitality , density , morphology , and motility of the sperm according to the who guidelines .
semen samples were diluted with ethylenediaminetetraacetic acid ( edta ) and sodium dodecyl sulfate ( sds ) mixture and incubated with equal volume of glutaraldehyde / borate buffer at 37c for 60 minutes .
then , 10 microliters of the incubated mixture were placed on a clean glass slide and 200 spermatozoa were examined under a microscope using a 40x objective .
the obtained values were recorded and subjected to statistical analyses using the statistical software called prism3.0 .
the mean values of the groups were analyzed by analysis of variance ( anova ) .
table 1 shows the spermiogram which includes sperm count , viability , motility , and semen fluid volume .
the asthenospermic condition revealed decreased semen volume ( 1.2 0.4 ) compared to the controls .
in fact , oat and oligospermic conditions were accompanied with less sperm viability which was followed by asthenospermia and teratozoospermia .
decreased motility was recorded in asthenospermic ( 25.4 7 ) and oligoasthenoteratozoospermic ( 17 3 ) conditions . figure 1 depicts the response of sperms to ncd test in different infertile conditions .
decreased level of ncd was observed in oat condition , oligospermia , and idiopathic conditions whereas asthenospermic cases presented nearer values to the control groups . statistical analysis ( anova )
recorded evident significant variation ( p < 0.05 ) between different infertility conditions and the control group for ncd test .
the response of spermatozoa for ncd test in different infertile conditions and the control group in figure 2 .
spermiogram details of different infertile conditions response of spermatozoa in different infertile conditions for nuclear chromatin decondensation test ( one - way analysis of variance : p < 0.05 ; f = 10.42 ; r2 = 0.38 ) o : oligosepermia , t : teratozoospermia , a : asthenospermia , i : idiopathic , oat : oligoasthenoteratozoospermia , c : controle sperm nuclear chromatin decondensation ( ncd ) response in different infertile subgroups ( white arrows indicate negative response and black arrows indicate positive response . )
plate a : ncd response in teratozoospermic cases plate b : ncd response in oligospermic cases plate c : ncd response in asthenospermic cases plate d : ncd response in oligoasthenoteratozoospermic cases plate e : ncd response in the control group
successful fertilization and formation of pronucleus depends on the sperm ncd ability in the oocyte .
the failure of sperm decondensation in the oocyte due to sperm abnormalities is unrecognizable by conventional semen analysis .
this study demonstrated reduced sperm chromatin decondensation in different infertile subgroups compared to the control group .
cho et al . established that a subset of infertile men ( 5 - 15% ) possessed complete protamine deficiency . by genetic analysis
, they confirmed that it was due to a mutation of protamine gene cluster . environmental stress , gene mutations , and chromosomal abnormalities can disturb the highly refined biochemical events that occur during spermatogenesis , and this can ultimately lead to an abnormal chromatin structure . in our study ,
oligospermia and oat condition accompanied with very less chromatin decondensation which indicates abnormal protamine package and susceptibility to dna damage . since
such protamines are small , i.e. only half of the size of the core histones which are extremely basic , around 55 - 70% of the amino acids among them are arginine . furthermore , the sperm protamines also contain numerous cysteine residues , which are used to generate disulfide cross - links between adjacent protamine molecules during chromatin condensation .
the 4 levels of organization for packaging in the spermatozoa are ( i ) chromosomal anchoring , which refers to the attachment of the dna to the nuclear annulus ; ( ii ) formation of dna loop domains as the dna attaches to the newly added nuclear matrix ; ( iii ) replacement of histones by protamines , which condenses the dna into compact ; and ( iv ) chromosomal positioning .
dna stability of sperm also depends on the amount and ratio of disulfide bonds ( s - s ) , non - covalent bonds between zinc and sulfhydryl groups ( sh = zn = sh ) , and free thiol group which reflects the epididymal maturation and more or less normal function of male genital glands . moreover , the ability of ncd depends on the sh = zn = sh bonds . in this study ,
although we expected negative response of teratozoospermic condition to ncd due to abnormal shaped sperm heads , our results were positive which indicates that dna damages were not evident in the teratozoospermic subjects assessed in this study .
other infertile conditions in our study subjects showed poor or no response in ncd test which could be due to low levels of protamines .
low levels of protamine ( pn1 , pn2 ) may lead to accumulation of dna damages in sperm , morphological abnormalities , initiation of apoptotic pathway , inactivation of mitochondria , and decreased sperm motility .
several studies have suggested that poor chromatin packaging and/or damaged dna may contribute to failure of sperm decondensation after intracytoplasmic sperm injection ( icsi ) and thus failure of fertilization .
hence , ncd of spermatozoa and subsequent male pronucleus formation are essential for fertilization and normal embryonic development .
the knowledge of sperm ncd is important in the field of assisted reproductive technique ( art ) . this study helped in examining the levels of fertilization capacity and nuclear stability of the spermatozoa in different subgroups of infertile population | background : infertility is a condition associated with multiple etiologies .
sperm nuclear chromatin decondensation is one of the important events that occur during fertilization .
abnormal spermatogenesis leads to improper protamine package and chromatin condensation .
the aim of the study was to analyze and understand the levels of fertilization capacity and nuclear stability of the spermatozoa in different infertile subgroups.material and methods : a total of 65 infertile males and 24 fertile males were employed in the study .
infertile subjects were classified into different groups according to the world health organization ( who ) protocol . in this study , in vitro nuclear chromatin decondensation status was assessed in different subgroups of infertile males .
the obtained data was then statistically analyzed.results:decreased sperm chromatin decondensation was observed in different infertile subgroups compared to the control group ( p < 0.05 ) .
spermatozoa with swollen head indicated a positive response and unswollen head indicated a negative response.conclusion:this study asserts that abnormal nuclear decondensation is a potential factor that diminishes the fertilizing capacity of the sperms among different subgroups of infertile males . |
it is estimated that the planet is host to 8 to 10 million species of plants and animals with approximately 1.5 million currently documented in the catalogue of life .
yet much of our current knowledge of biochemical , molecular genetic , and cellular processes relies on studies of fewer than a dozen model organisms .
it is a safe bet that a majority of the findings and data from the institutes mentioned earlier are derived from work on these organisms ( humans included ) . without question ,
the sharp focus on a handful of model organisms has paid off and , in large measure , has led many observers to proclaim this to be the century of the life sciences .
the downside , of course , is that we know very little about the biology of the vast majority of organisms with which we share the planet .
grocery stores . these can be grown inexpensively and in abundance , handle the rigors of transport , have a long shelf life , and often taste very good . however , spend a few hours in bangkok and it becomes clear there is a bounty of insanely delicious fruits and vegetables that never make it into the food bins of chain grocery stores .
for example , there are more than 100 varieties of mangoes , each with a distinctive taste and texture . yet our grocery stores , for sound economic reasons , only stock one or two varieties .
it should be pointed out that grocery stores are beginning to respond to these yearnings , and their shelves now include exotics such as rambutan and lychee .
it is clear that molecular and cellular biologists are experiencing similar yearnings , wanting to taste the scientific delights of non model organisms .
bob goldstein , a well - established caenorhabditis elegans investigator at the university of north carolina chapel hill , has invited tardigrades ( water bears ) into his lab ( gabriel et al . , 2007 ) . like drosophila and c. elegans , tardigrades are multicellular organisms that molt , undergo complex development , and have a complex nervous system .
tardigrades have fascinated biologists for centuries , because they are indestructible : they survive years of dehydration , high pressure , freezing , and even the punishing environment of outer space .
the goldstein lab is applying its c. elegans chops toward understanding the development and biology of these creatures .
similarly , the marshall lab at the university of california san francisco has begun studying stentor , a single - celled organism with a length of 1 mm ( slabodnick and marshall , 2014 ) .
this boeing 747 of the cellular world has a complex body plan , sophisticated behavior , and a memory . it can be sliced and diced , with the fragments behaving like the chopped brooms in the sorcerer 's apprentice : each piece regenerates to become a new intact cell .
marshall 's group is studying stentor to understand the mechanisms regulating cell and organ size . in my lab , we have focused on the order hymenoptera ( ants , wasps , and bees ) to understand the mysteries of virgin birth ( ferree et al . , 2006 ) .
females in this order are capable of parthenogenesis , and when one cracks open their oocytes , the images are so bizarre one might as well be looking at the cell biology of an organism from mars .
each oocyte nucleus buds off hundreds of satellite nuclei that contain core centrosome components rather than chromosomes . on egg laying , these blossom into hundreds of functional centrosomes , each with its own microtubule - organizing center ( mtoc ) .
these are only a few of the countless examples of organisms with fascinating biology that have been largely overlooked by the molecular and cell biologists . with the advent of rna interference ( rnai ) ; clustered , regularly interspaced short palindromic repeats ( crispr ) tools ; advanced imaging technologies ; and a battery of fluorescent reagents , the timing is perfect for labs to adopt new non model organisms .
unfortunately , it is very difficult for a lab to obtain the funding required to launch into the molecular or cell biology of a new organism . a new institute for the study of non
model organisms would help fill this void . instead of yet another artist 's rendition of the double helix
, the institute 's lobby would be filled with terraria , cages , and ponds stocked with exotic creatures , the centerpiece being a large aquarium containing hundreds of elysia chlorotica , a stunning green sea slug that feeds on algae and absorbs chloroplasts into its cells , with the chloroplasts remaining functional and the slug becoming photosynthetic .
the institute would include a full - time staff of investigators and would host visiting researchers .
in addition to state - of - the - art core microscopy , mass spectrometry , and sequencing facilities , there would be a team of experts to help with cultivation and propagation of the unusual organisms being studied .
an entire wing of the institute would be devoted to organisms and ideas that once enjoyed popularity but have fallen out of favor ( e.g. , sciara coprophia , a fungal gnat harboring disposable chromosomes ) .
this wing would include a beautiful library and a team of scholars to read classic texts and manuscripts by the likes of thomas morgan , ernst haeckel , e. b. wilson , and theodor boveri .
once a month , these scholars would host a seminar in which they would present highlights of the texts to the institute
. a second wing , sponsored by carolina biological supply , would be devoted to the study of the wonderful organisms sold to high school biology classes : euglena , centipedes , tarantulas , sow bugs , and many others .
for example , there are a number of unisexual hybrid fish species ( lampert and schartl , 2008 ) . during meiosis
, the hybrid eliminates all the chromosomes derived from one of the parental species ( that is , if a and b refer to the chromosomes from each parental species , a / b hybrids produce only a gametes and mate with b males to produce only a / b progeny ) .
one can imagine that there would be interesting unexpected molecular and cellular processes underlying this unusual form of reproduction .
this has resulted in an extensive parts list and given rise to the emerging fields of systems and synthetic biology , as well as the promise of bioengineers crafting designer organisms . however , even though many of these organisms were sequenced more than a decade ago , we still know little about the placement and function of a large fraction of these parts .
imagine having a parts list for a motorcycle in which half of the pieces just have an identification number assigned to them with no description or picture to hint at their function or how they fit into the whole .
engineers relying on this list would be forced to build new motorcycles based only the well - characterized parts , a vehicle i certainly would not want to ride down the freeway . writing a decade after the sequencing of the human genome , edwards and colleagues stated , yet more than 75% of the protein research still focuses on 10% of proteins that were known before the genome was mapped
they also found that , in spite of the fact that the human genome contains approximately 500 kinases , 65% of the papers published in 2009 focused on the same 50 kinases studied in the 1990s .
i imagine other investigators have shared our experience , in which genome - wide genetic screens yield lists peppered with uncharacterized genes .
some of these will have hints of a domain ( leucine zipper , pdz , sh3 , etc . ) , and , like a child peering through the torn wrapping of a birthday present , we vainly try to guess at their function .
while there are many reasons for our collective reluctance to pursue these orphaned genetic elements , lack of funding probably ranks at the top of the list . thus there is a great need for an institute devoted entirely to the study of uncharacterized genes .
swat - like teams of investigators at the institute would be tasked with rapidly characterizing these genes .
a battery of reagents , including antibodies , green fluorescent protein constructs , mutants , rnai and crispr constructs , and purified proteins , would be developed for this work .
once every year , the results of their efforts would be published in plos neglected genes . in the entrance hall of this well - funded institute would be a rube goldberg exhibit , the kind you see at airports , consisting of ramps , tubes , levels , pulleys , paddles , and springs that transport ping - pong balls .
once a year , on april 14th ( the declared date of completion of sequencing the human genome ) , all 365 researchers would gather around the exhibit for the selection ceremony .
these balls would have the gene identification numbers of 365 randomly selected , uncharacterized genes .
the researchers task is clear : they have a year to characterize their assigned genes .
spend any amount of time at the bench and strange unanticipated results crop up : non - mendelian outcomes in a crossing scheme , an unexpected band on a gel , or an unusual fluorescent image .
perhaps the most famous example is morgan 's discovery of the white - eyed fruit fly .
his capture and breeding of this oddity led to proof of the chromosome theory of inheritance , the discovery of sex linkage , and the founding of a new field of science : genetics . all too often , however , our response to a surprising result is to mention it to a colleague over lunch or at a meeting , but , unfortunately , the pressures of productivity and funding demand we ignore them and move on . for example , while i was teaching an undergraduate genetics lab , my students made an interesting chance discovery .
the class was using a drosophila line in which a cell cycle kinase was inappropriately expressed in the fly eye , producing a dominant abnormal rough - eye phenotype .
if this line was outcrossed to drosophila directly taken from the wild , the phenotype was suppressed , yet no suppression occurred when it was crossed to wild - type lab strains of drosophila .
somehow , genomes of drosophila from nature but not from the lab were able to shut down ( or compensate ) for the misexpressed kinase .
i have often thought about following this up but have yet to put flies to pad .
an informal survey of my colleagues revealed that each of them had encountered multiple examples of interesting puzzling observations that have been left by the wayside .
launching an institute for the advancement of odd results would provide a means to follow up on interesting serendipitous findings .
researchers could send very brief descriptions of their findings to the institute . a selection committee composed of biomedical scientists , psychics , and clairvoyants
the researcher who submitted the project would serve as an advisor , while the institute would supply two years worth of resources , personnel , and reagents to carry out the initial studies .
the entrance to this institute would be a visual celebration of the odd and unusual .
the grand opening would include collections of barbed wire , human hair , and ufo debris . clearly , my list of imagined institutes is incomplete , and others might have different priorities .
colleagues have suggested establishing institutes for unorthodox collaborations , frugal science , and experimental conferences , as well as the think - tank for theoretical genetic screens . where would these institutes be located ?
marco polo describes its citizens as self - confident and prudent , because any change in andria involves some novelty ( change ) in the stars and every innovation in the city influences the sky 's pattern , before taking any decision , they calculate the risks and advantages for themselves and for the city and for all worlds . | in his classic novel invisible cities , italo calvino describes a series of fantastic imagined cities that fulfill core human needs that remain unmet in ordinary cities . in light of the recent founding of a number of high - profile biomedical institutes ,
calvino 's descriptions encourage us to consider the unmet needs of the biomedical community and imagine unorthodox institutes designed to fulfill these needs . |
metabolic syndrome ( mes ) is defined as a cluster of atherosclerotic risk factors , including abdominal obesity , elevated serum triglycerides , decreased hdl cholesterol , elevated blood pressure , and elevated serum plasma glucose [ 13 ] .
insulin resistance is a central feature in the pathogenesis of mes in addition to an unhealthy diet and physical inactivity promoting overweight and genetic factors [ 1 , 57 ] . as obesity increases worldwide ,
this leads to an increased incidence and an earlier onset of mes [ 3 , 8 , 9 ] .
( gdm ) , a disorder in glucose and insulin metabolism , is one of the most common complications in pregnancy .
depending on the population and the diagnostic criteria used , the prevalence is roughly 1%14% of pregnancies [ 10 , 11 ] ; and the occurrence is increasing worldwide [ 12 , 13 ] .
the most important risk factors for gdm are prepregnancy overweight , high maternal age and a family history of type 2 diabetes .
women with a history of gdm are at increased risk of developing type 2 diabetes and also mes after delivery [ 1517 ] . among canadian women with a history of gdm , the prevalence of mes was 20% at as early as three months postpartum . according to studies from the usa and denmark , approximately 30%40% of women with a history of gdm
the aim of this study was to determine the prevalence of mes and its components at one year postpartum among finnish women who in early pregnancy were at increased risk of developing gdm .
the study is a part of a cluster - randomized controlled trial , nelli ( counseling and lifestyle during pregnancy , isrctn33885819 ) .
the primary aim of the trial was to prevent gdm among pregnant women who were assessed in early pregnancy to have an increased risk of gdm .
the study was conducted in primary health care maternity clinics in western finland in 20072009 .
the intervention included structured individual counselling on weight gain , diet , and physical activity by public health nurses during five routine visits to maternity clinics .
the women in the control clinics received the usual maternal care , including some lifestyle advice .
pregnant women were recruited by nurses at their first visit ( 812 weeks ' gestation ) in maternity clinics .
women were eligible if they had at least one of the following gdm risk factors : age 40 years , prepregnancy body mass index ( bmi ) 25 kg / m , gdm or any sign of glucose intolerance , a macrosomic baby ( 4500 g ) in any previous pregnancy , or diabetes in first- or second - degree relatives .
the main exclusion criteria were age < 18 years , a gdm diagnosis at 812 weeks ' gestation , twin pregnancy , physical restrictions that precluded exercise , or a clinical history of chronic disease .
a diagnosis of gdm was based on a two - hour 75-gram oral glucose tolerance test ( ogtt ) whose results met at least one of the following criteria : a fasting plasma glucose of 5.3
six hundred forty pregnant women participated in baseline assessment at 812 weeks ' gestation ( figure 1 ) .
of them , 442 ( 69% ) were eligible for the randomized clinical trial ( rct ; intensified counselling or usual care ) , while 198 ( 31% ) were excluded , most of them ( n = 174 , 88% ) due to a gdm diagnosis at 812 weeks ' gestation . at postpartum
the intensified counselling , the usual care , and the early gdm ( originally excluded from the rct ) groups were merged for present analysis .
height was measured at the first maternity care visit , and weight was measured at each maternity care visit and one year postpartum .
waist circumference was measured ( the average of three measurements ) at one year postpartum .
blood pressure was measured in duplicate at each maternity care visit and one year postpartum . because 15% of the weight data from the first visit were missing , self - reported prepregnancy weight was used as the baseline weight .
blood specimens were taken for glucose , cholesterol , hdl cholesterol , and triglyceride analysis after a 12-hour fast , and a two - hour ogtt was performed at 812 and 2628 weeks ' gestation and one year postpartum .
all blood analysis was performed at the ukk institute . for glucose and lipid analysis ,
venous blood was drawn into citric acid / fluoride and edta tubes . during the ogtt
, blood samples were taken between 60 and 120 min after the participants had drunk 75 g glucose in 330 ml water ( glucodyn , ultimed , finland ) .
plasma glucose concentrations were measured fresh within 24 hours after the ogtt , but plasma samples for lipid analysis were stored frozen at 80c until analysed .
glucose , total cholesterol , hdl cholesterol , and triglyceride concentrations were determined in enzymatic assays using a roche cobas mira plus analyser .
mes was diagnosed according to the international diabetes federation ( idf ) and the national cholesterol education program adult treatment panel ( ncep atp - iii ) criteria . at one year postpartum , oral glucose tolerance was evaluated according to the american diabetes association ( ada ) and the world health organization ( who ) criteria .
the primary outcome of this study was the prevalence of mes and its components at one year postpartum .
the background characteristics and descriptive information on components of metabolic syndrome are reported here as means and standard deviations ( sds ) or frequencies and proportions .
a multivariate logistic regression model was used to obtain odds ratios ( ors ) and their 95% confidence intervals ( 95% cis ) to study associations between metabolic syndrome and its explanatory variables .
explanatory variables included were age ( continuous ) , group ( intensified counselling , usual care , and early gdm ) ; and five gdm risk factors ( as used in entrance criteria to the study , that is , bmi 25 kg / m , age 40 years , gdm or any sign of glucose intolerance in any previous pregnancy , a macrosomic baby [ 4500 g ] in any previous pregnancy , and diabetes in first- or second - degree relatives ) .
the results were considered to be statistically significant if p < 0.05 . all analysis was performed with spss software ( version 20.0 ) .
before pregnancy , self - reported weight was 74.2 kg ( range 50.0120.0 kg ) , which was 0.9 kg less than the weight measured at the first maternal clinical visit at 812 weeks ' gestation ( 75.1 kg , n = 127 ) .
the mean prepregnancy bmi was 26.7 kg / m ( range 18.139.5 kg / m ) . at followup measurement ; one year after delivery , the mean weight increase was 1.4 kg ( range from 16.1 to 18.0 kg ) compared with prepregnancy weight .
table 1 shows that one year after delivery , the mean age of the women was 33.1 years ( range 2049 years ) and the mean number of deliveries was 2.0 ( range 18 ) .
the most common inclusion criteria for the study were prepregnancy overweight ( 66% ) and diabetes in relatives ( 53% ) .
twenty - one percent ( n = 30 ) smoked frequently or occasionally before pregnancy .
the prevalence of mes and its components one year after delivery in all women and in the intensified counselling , usual care , and abnormal ogtt groups is presented in table 2 .
three out of four women exceeded the waist circumference limit of 80 cm , and about half reached the limit of 88 cm . compared to the intensified counselling group
, there tended to be more abdominally obese ( waist circumference 88 cm ) women in the early gdm and usual care group . more than one - fourth of all and half of the women with early gdm had elevated fasting plasma glucose ( 5.6
one - fifth of all and one - fourth of women with early gdm also had elevated blood pressure .
on the other hand , almost one - third ( 31% ) according to ncep criteria and one - sixth ( 16% ) according to idf criteria did not meet the criteria for any mes components .
most women ( 52% according to idf and 63% according to ncep ) had one or two mes components , while 8% ( according to both idf and ncep ) had four or five components . according to idf criteria , the prevalence of mes among the participants was 18% ( n = 27 ) and according to ncep criteria 16% ( n = 24 ) . in ogtt , at followup , 8 women ( 5% ) had impaired glucose tolerance according to both who and ada criteria .
seven had mes according to both idf and ncep criteria . in multivariate logistic regression analysis ,
the risk of mes in the group with early gdm tended to be higher compared to the intensified counselling group ( or3.4 , 95% ci 1.011.3 , p = 0.051 ) ( table 3 ) . when analysed by trial inclusion criteria ( gdm risk factors at baseline ) , prepregnancy overweight ( bmi > 25
kg / m ) was a strong predictor for developing mes ( or 3.0 , 95% ci 1.09.2 , p = 0.053 ) .
measurements of mes components at one year postpartum were available for 24% of the women who participated in the baseline measurements and for 32% of those who participated in the followup . compared with the participants for whom the data for mes diagnosis at followup were not available ( n = 466 ) , participants with data for mes ( n = 150 ) were more likely to belong to the usual care group ( 55% versus 45% , p = 0.032 ) and were less likely to be frequent smokers before pregnancy ( 10% versus 22% , p = 0.013 ) .
there were also some more women with gdm diagnosed at 2628 weeks ' gestation ( abnormal ogtt ) among women with mes data available at one year postpartum than among those without mes data ( 18% versus 10% , p = 0.064 ) , but there were no differences in the occurrence of gdm at 812 weeks ' gestation ( 20% versus 24% had early gdm , p = 0.393 ) .
neither were there differences between these two groups in any other background characteristic ( weight or bmi , age , parity , or education ) or laboratory analysis other than ogtt at 2628 weeks ' gestation .
at one year postpartum , mes was diagnosed in nearly one - fifth of the women who had an increased risk of gestational diabetes at the beginning of their pregnancy . especially ; prepregnancy overweight was associated with a higher risk of developing mes . in a prospective finnish population study among nonpregnant women aged 3033 ,
the prevalence of mes was 7%14% according to the idf definition and 4%11% according to the ncep definition .
the prevalence of mes was more common in our study due to our risk - group approach . according to other studies , the prevalence of mes among parous women aged
3040 is no more than 10% depending on country , criteria , and time after delivery [ 18 , 19 , 27 ] .
our study is one of the first followup studies on the prevalence of mes after delivery among young women with risk factors for gdm . according to earlier studies , a history of gdm
is strongly associated with a higher prevalence of mes [ 16 , 20 , 27 ] .
the present study suggests that the risk is high , also among women with risk factors for gdm in early pregnancy , but does not necessarily lead to gdm .
gdm and mes share some risk factors , such as overweight and a genetic tendency towards impaired glucose metabolism .
still , the development of mes after glucose disorders during pregnancy has not been given as much attention as the increased risk of type 2 diabetes after gdm .
in any case , the cardiometabolic risk factors in women at increased risk of gdm should also be followed after delivery . in 2007 ,
the prevalence of obesity among women aged 2534 years in finland was 11.1% ; in our subjects , one year after delivery , it was 2.5 times higher at 27% .
abdominal obesity is one of the most important independent factors in development of metabolic syndrome .
although overweight among young adults is on the rise worldwide , there are few studies of the prevalence of mes among young adults .
the nelli study is one of the largest randomized controlled trials about preventing the development of gestational diabetes .
the nelli trial showed that the lifestyle counselling was effective in controlling the proportion of large - for - gestational - age newborns and improving the women 's diet and had a minor effect on gestational weight gain and decrease in physical activity [ 21 , 3133 ] . since participation in followup measurements at one year postpartum was low ( 24% of the original cohort ) and the total number of participants was modest , the results must be interpreted carefully .
there were more women from the usual care group and fewer frequent smokers before pregnancy .
participants in followup also were more likely to have been diagnosed with gdm in midpregnancy ( 2628 weeks ) as compared with the women who did not participate in mes testing at followup .
women with small children may have found it difficult to find time to come in for testing , especially as it included the two - hour ogtt .
some subjects who showed up for followup testing may have been more health conscious , which is advocated by the fact that there was a smaller proportion of smokers among them . some may have been concerned about ill health due to their gdm diagnosis during pregnancy .
nevertheless , some women with a gdm diagnosis were already being monitored by the healthcare system , and they may have refused to participate in our testing for that reason .
another reason for refusal was a new pregnancy , but the number of these women was unclear .
this study was limited to finnish women , and the results can only be extrapolated to caucasian populations .
one limitation of this study is that , at the followup , the subjects were not queried about hormonal contraception or medications for hypertension or dyslipidemia , which influence the components of mes .
however , when medications were queried in the baseline , none of the women reported taking any cardiovascular medication .
we used self - reported weight before pregnancy , which is not as reliable a measurement as using a scale . when self - reported weight was compared to the available weight measurement at the first maternity clinical visit , the mean difference was less than 1 kg , which could easily be explained by a minimal early pregnancy weight gain .
our study suggests that mes at one year postpartum seems to occur more often among women who in early pregnancy had an increased risk of gdm .
this study suggests that especially women with an increased risk of gdm should be followed up on for cardiometabolic risk factors after delivery .
weight management or reduction before pregnancy and prevention of excessive weight gain during pregnancy are important for the prevention of gdm and of mes .
overweight and obesity among pregnant women may increase , as the average maternal age is rising along with the obesity epidemic , and this represents an even greater challenge in following up on and managing risk factors for chronic diseases .
there is a need for larger population studies on the prevalence of mes among young women , especially among those who are at an elevated risk of gdm . | background . women with a history of gestational diabetes mellitus ( gdm ) are at increased risk for metabolic syndrome ( mes ) after delivery .
we studied the prevalence of mes at one year postpartum among finnish women who in early pregnancy were at increased risk of developing gdm .
methods .
this follow - up study is a part of a gdm prevention trial . at one year postpartum
, 150 women ( mean age 33.1 years , bmi 27.2 kg / m2 ) were evaluated for mes .
results .
the prevalence of mes was 18% according tothe international diabetes federation ( idf ) criteria and 16% according tonational cholestrol education program ( ncep ) criteria .
of mes components , 74% of participants had an increased waist circumference ( 80 cm ) .
twenty - seven percent had elevated fasting plasma glucose ( 5.6
mmol / l ) , and 29% had reduced hdl cholesterol ( 1.3
mmol / l ) .
the odds ratio for the occurrence of mes at one year postpartum was 3.0 ( 95% ci 1.09.2 ) in those who were overweight before pregnancy compared to normal weight women .
conclusions .
nearly one - fifth of the women with an increased risk of gdm in early pregnancy fulfilled the criteria of mes at one year postpartum .
the most important factor associated with mes was prepregnancy overweight .
weight management before and during pregnancy is important for preventing mes after delivery . |
the website of ijp was searched for publications year and issue wise for contributing authors from pharmacy institutions during 20102015 .
based on the geographical addresses , the publications were categorized as national and international and were further categorized to state wise if national , and country wise if international .
the number / frequency of publications by these pharmacy institutes was counted issue wise and its percentage to total publications issue wise and year wise was calculated .
articles were categorized as editorial , educational forum , research article and review article , letter to the editor , drug watch , short communication , and book review .
research articles were further classified whether preclinical ( animal studies ) or clinical ( human ) .
preclinical research was further categorized based on the investigational product whether a plant product / extract or chemical / synthetic product .
a total of 1034 articles were published in ijp from 2010 to 2015 . of these ,
189 ( 18% ) articles were published by pharmacy institutes [ table 1 ] of which 90% ( n = 170 ) were contributed from pharmacy institutes within india while 10% ( n = 19 ) publications were from countries such as china ( 4 ) , usa ( 3 ) , turkey and iraq ( 2 ) , iran , sri lanka , egypt , tanzania , indonesia , australia , malaysia , france ( 1 ) , respectively . within india ,
the top 5 contributing states included karnataka ( 43 ) , maharashtra ( 25 ) , gujarat ( 21 ) , madhya pradesh ( 18 ) , and tamil nadu ( 13 ) .
year - wise publications in indian journal of pharmacology from pharmacy institutes articles were categorized as editorial , educational forum , research article and review article , letter to the editor , drug watch , short communication , and book review .
a good percent of research manuscripts were published from pharmacy institutes [ table 2 ] .
of 189 articles published from pharmacy institutes , 141 ( 74.60% ) articles were research manuscripts as compared to 46% from institutes other than pharmacy ; mostly medical and other biomedical institutes .
contributions in drug watch ( 16.5% vs. 1.6% ) , and case reports were comparatively less from pharmacy institutes .
distribution of articles published in indian journal of pharmacology research publications from pharmacy institutes were further classified into preclinical and clinical studies .
preclinical studies were further categorized based on the type of investigational product whether of plant extract or synthetic / drug product [ table 3 ] .
most of the publications from pharmacy institutes were researched on animals ( 92% ) while only 8% were clinical studies .
most of the preclinical studies ( 64% ) researched screening of plant extracts for their pharmacological actions as compared to drug studies ( 36% ) . categorizing research publications in indian journal of pharmacology
the preclinical studies screened the plant extracts for various activities such as immunosuppressive properties , antidiabetic activity hepatoprotective effects , for inflammatory bowel disease , antiurolithiatic and antioxidant activity , against neurotoxicity , cardiotoxicity , obesity , anti - inflammatory and antiulcer activity , in acute renal failure , antidiarrheal , antinociceptive / analgesic activity , antihyperlipidemic , antidepressant / anxiolytic , etc .
articles were categorized as editorial , educational forum , research article and review article , letter to the editor , drug watch , short communication , and book review .
a good percent of research manuscripts were published from pharmacy institutes [ table 2 ] .
of 189 articles published from pharmacy institutes , 141 ( 74.60% ) articles were research manuscripts as compared to 46% from institutes other than pharmacy ; mostly medical and other biomedical institutes .
contributions in drug watch ( 16.5% vs. 1.6% ) , and case reports were comparatively less from pharmacy institutes .
preclinical studies were further categorized based on the type of investigational product whether of plant extract or synthetic / drug product [ table 3 ] .
most of the publications from pharmacy institutes were researched on animals ( 92% ) while only 8% were clinical studies .
most of the preclinical studies ( 64% ) researched screening of plant extracts for their pharmacological actions as compared to drug studies ( 36% ) . categorizing research publications in indian journal of pharmacology the preclinical studies screened the plant extracts for various activities such as immunosuppressive properties , antidiabetic activity hepatoprotective effects , for inflammatory bowel disease , antiurolithiatic and antioxidant activity , against neurotoxicity , cardiotoxicity , obesity , anti - inflammatory and antiulcer activity , in acute renal failure , antidiarrheal , antinociceptive / analgesic activity , antihyperlipidemic , antidepressant / anxiolytic , etc .
scientific writing and publication mark the endpoint of research that has been performed , completed , peer - reviewed and accepted and complements teaching and training , clinical service and patient care . since 1969 ijp ( issn 02537613 ) is an official publication of the indian pharmacological society , a peer - reviewed open access biomedical specialty periodical from india .
ijp s website was searched for publications by contributing authors from pharmacy institutes from 2010 to 2015 .
a total of 1034 manuscripts were published in ijp in 6 years with an average of 172 publications per year .
a total of 189 ( 18% ) were from pharmacy institutes both from and outside india with an average of 31 publications per year .
in india as per aicte , there are 445 institutes offering pharmacy education to 24,672 students and as per mci , there are 462 institutes offering medical education to 63,535 students pharmacy institutes offering masters in pharmacology approximate to 239 while 257 medical institutes offer 789 seats in md pharmacology and dm clinical pharmacology . although number of pharmacy institutes have grown with time , the temporal trends in terms of the number of publications by pharmacy institutes has not increased .
most of the manuscripts were contributed from pharmacy institutes located in the indian states such as karnataka , maharashtra , madhya pradesh , gujarat , and tamil nadu which also house more number of pharmacy institutes .
although ijp charges no publication fees , international contributors stood to 10% only , possibly influenced by number of factors such as scope of research , marketing strategy of publication house , citations , indexing , and impact factor of the journal . although publication volumes are comparatively low from pharmacy institutes , number of research manuscripts from pharmacy institutes was higher ( 75% vs. 46% ) as compared to other biomedical institutes .
the reasons may range from noble to base reasons including but not limited to postgraduate pharmacy curriculum , policies laid by regulators of pharmacy education , multi and interdisciplinary integration and collaboration , the pharmaceutical industry of the country , expanded role offered by pharmacists in healthcare , rich indigenous medical system , government policies supporting public - private partnerships and at the bottom of the list necessary evil for job or promotion .
however , 64% of these research manuscripts studied in vitro , in vivo screening of phytochemical constituents of indigenous plant extracts or formulations for its pharmacological activity .
the reason for this trend seems that phytochemical research is both cost and time effective .
medicinal plants are resources of new drugs and pharmacological properties of an herbal formulation depend on phytochemical constituents present therein .
however , in the present context , most of the plant research is limited to screening activity . very few of these researched plant activity undergoes characterization and standardization of well - defined active constituents to undergo reliable clinical trials . taking
otherwise this trend may also translate not only as a cost and time effective mode of research but publication as well .
molecular and cellular pharmacology studies still need to the forefront of research by pharmacy institutes since 92% research by pharmacy institutes is preclinical as per present data .
pharmacy institutes with well - established animal house facilities can serve as research hubs in the drug development process .
regulatory drugs and cosmetics act , schedule y preclinical studies can be integrated to pharmacy curricula . in the present study ,
with multi and interdisciplinary collaborations in the pharmacy profession , areas like clinical pharmacy can manipulate an accurate make use of medicines on before , during and after the prescription is written .
thus , today s pharmacist will evolve to conduct research in pharmacovigilance , prescription patterns , antibiotic use and misuse , drug adherence , drug interaction , nuclear medicine , and specialized areas of treatment .
this study has not made a comparative analysis between publications made by medical , pharmacy , and other biomedical institutes which could focus their relative contributory role .
furthermore , publications from 2010 to 2015 by pharmacy institutes only have been incorporated . in conclusion , publication in ijp complements teaching and training , research and clinical service offered by biomedical community .
temporal trends in pharmacology publications in ijp by pharmacy institutes infers that research by pharmacy institutes needs to be more science oriented with well - defined objectives leading to molecular and cellular pharmacology . with the increased responsibility and scope of pharmacy profession in health care , contributions in clinical studies
this study has not made a comparative analysis between publications made by medical , pharmacy , and other biomedical institutes which could focus their relative contributory role .
furthermore , publications from 2010 to 2015 by pharmacy institutes only have been incorporated . in conclusion ,
publication in ijp complements teaching and training , research and clinical service offered by biomedical community .
temporal trends in pharmacology publications in ijp by pharmacy institutes infers that research by pharmacy institutes needs to be more science oriented with well - defined objectives leading to molecular and cellular pharmacology . with the increased responsibility and scope of pharmacy profession in health care , contributions in clinical studies
| objective : publications in indian journal of pharmacology ( ijp ) are the face of contemporary pharmacology practices followed in health - care profession - a knowledge - based profession .
it depicts trends in terms of quantity ( proportions ) , quality , type ( preclinical / clinical ) , thrust areas , etc .
, of pharmacology followed by biomedical community professions both nationally and internationally .
this article aims to establish temporal trends in pharmacology research by pharmacy institutes in light of its publications to ijp from 2010 to 2015.methodology:the website of ijp was searched for publications year and issue wise for contributing authors from pharmacy institutions and analyzed for types of publications , their source and the categories of research documented in these publications.results:a total of 1034 articles were published , of which 189 ( 18% ) articles were published by pharmacy institutes , of which 90% ( n = 170 ) were contributed from pharmacy institutes within india whereas 10% ( n = 19 ) from international pharmacy institutes .
75% of these were research publication , the majority of which ( 65% ) were related to preclinical screening of phytochemical constituents from plants.conclusion:with multi and interdisciplinary collaborations in pharmacy profession the trend needs to improve toward molecular and cellular pharmacology and clinical studies . |
it has been argued that the degree of asymmetry in bilateral features is one of the fundamental factors underlying human attractiveness .
one such study was done by goel et al . to detect the asymmetries and their correlation with malocclusions in karnataka population .
they concluded that there was decrease in magnitude of the asymmetry as higher regions of craniofacial skeleton was approached .
studies conducted by profitt and severt assessing facial asymmetries in orthodontic patients clinically found a prevalence ranging from 12% to 37% in north carolina , united states , 23% in belgium , and 21% in hong kong .
performed a similar study to evaluate the size and shape - related craniofacial skeletal asymmetries , and concluded wider left side of the face and a shorter vertical dimension on the right side .
kowner in a classic experiment on the perception of attractiveness based on symmetry conducted in japan concluded that limited asymmetry may be simply more aesthetic , regardless of its function .
fong et al . in a study conducted in taiwan concluded that 68% of the study population showed chin deviation to the left side and ( 32% ) to the right side . in another study ,
anistoroaei et al . concluded that facial asymmetry was present in 4.7% of patients ; they also concluded that a significant correlation was evidenced between facial asymmetry and type of malocclusions , age , and type of dentition . while most of the studies have concluded that no quantitative differences in different types of measurements of face exists in relation to face , some studies , such as the one conducted by ercan et al .
, concluded that the number of significantly asymmetric linear distances between the two halves of the face was greater in females than that in males .
cheng in his review concluded the symmetry of the face is highly influenced by soft tissue landmarks .
the purpose of the present study was to evaluate the prevalence of skeletal facial asymmetry using frontal cephalograms and frontal photographs among the adults of tirupati , andhra pradesh , hitherto assessing the correlation of skeletal facial asymmetry and soft tissue facial asymmetry as well as to assess the gender differences in the prevalence of facial asymmetry .
a total of 100 residents ( 50 males and 50 females ) of tirupati , andhra pradesh in the age group of 1825 years were selected for the study through randomized sampling [ tables 1 and 2 ] . before commencement of the study ,
sample size and mean age group of the sample mean age group of the study groups the inclusion criteria were clinically acceptable facial symmetry , presence of full complement of teeth , no history of pathology / trauma / surgical intervention or orthodontic treatment , and no congenital abnormalities in the maxillofacial region .
the sample size was calculated using the following formula : e = z/2/n facial photographs were taken with a canon power shot a 650 is camera and by the same photographer .
participants were made to stand and assume natural head position , so that their frankfurt horizontal ( fh ) planes will be parallel to the floor .
the analysis for assessment of transverse frontal facial asymmetry was done by using frontal asymmetry analysis suggested by grummons [ figure 1 ] . for subjective evaluation ,
frontal photographs were assessed by using composite photographs . list of land marks used in this study this is a vertical reference line . according to grummons , mid sagittal reference ( msr ) closely follows visual plane formed by subnasale and the midpoint between the eyes and eyebrows , and hence msr was selected as the key reference line [ figures 2 and 3 ] .
( a ) line from midpoint of z plane through ans , ( b ) line from midpoint of z plane through fr - fr line four planes were drawn to show the degree of parallelism and symmetry of the facial structures .
three planes connected the medial aspects of the zygomatic frontal sutures ( zz ) , the centers of the zygomatic arches ( za ) , and the medial aspects of the jugal processes ( j ) .
another plane was drawn at menton parallel to the z plane [ figure 4 ] .
two triangles ( right and left ) were formed by joining the ag , me , and co points on both sides , representing the mandibular morphology .
the linear measurements for all the three sides of the triangles were recorded along with the measurements of the angles formed by joining co , go , and me points on both sides [ figure 5 ] .
mandibular morphology the vertical offset as well as the linear distance was measured from msr to co , nc , j , ag , go , and me were measured .
the linear distance to msr from the land marks co , nc , j , ag , go , u ,
l , and me was calculated for paired structures , the distance away from the midline was determined for both landmarks , and the difference between the distances was calculated . for unpaired points , the horizontal distance to the midline will be determined [ figure 6 ] .
frontal photographs of the participants were taken and each photograph is divided into left and right sides and left half of the face and its mirror image are joined together and similarly right half of the face and its mirror image were joined to form two facial composites , i.e. , l - l ( left composite ) and r - r ( right composite ) .
facedness of the sample or population refers to the side with highest total prevalence [ figure 7 ] .
according to grummons , mid sagittal reference ( msr ) closely follows visual plane formed by subnasale and the midpoint between the eyes and eyebrows , and hence msr was selected as the key reference line [ figures 2 and 3 ] .
( a ) line from midpoint of z plane through ans , ( b ) line from midpoint of z plane through fr - fr line
four planes were drawn to show the degree of parallelism and symmetry of the facial structures .
three planes connected the medial aspects of the zygomatic frontal sutures ( zz ) , the centers of the zygomatic arches ( za ) , and the medial aspects of the jugal processes ( j ) . another plane was drawn at menton parallel to the z plane [ figure 4 ] .
two triangles ( right and left ) were formed by joining the ag , me , and co points on both sides , representing the mandibular morphology .
the linear measurements for all the three sides of the triangles were recorded along with the measurements of the angles formed by joining co , go , and me points on both sides [ figure 5 ] .
the vertical offset as well as the linear distance was measured from msr to co , nc , j , ag , go , and me were measured .
the linear distance to msr from the land marks co , nc , j , ag , go , u , l , and me was calculated for paired structures , the distance away from the midline was determined for both landmarks , and the difference between the distances was calculated . for unpaired points , the horizontal distance to the midline will be determined [ figure 6 ] .
frontal photographs of the participants were taken and each photograph is divided into left and right sides and left half of the face and its mirror image are joined together and similarly right half of the face and its mirror image were joined to form two facial composites , i.e. , l - l ( left composite ) and r - r ( right composite )
. facedness of the sample or population refers to the side with highest total prevalence [ figure 7 ] .
the data were statistically collected and tabulated in microsoft excel . the data was stastically analyzed using the statistical package for the social sciences ( spss ) version 16.0 program statistical analysis package software .
independent t - test was used to find the differences between different measurements and the significance in the measurements of the right and left side dimensions , if any .
the data was checked for the normal distribution using t - statistics and then the correlation coefficients between the various parameters were calculated using pearson 's correlation to determine which would produce a higher value .
table 3 shows the bilateral facial widths observed at z , co , za , j , nc , ag , go distances , as total widths , right side , and left side . table 4 shows total bilateral facial widths observed at z , co , za , j , nc , ag , and go for males .
table 5 shows total bilateral facial widths observed at z , co , za , j , nc , ag , and go for females .
bilateral facial widths observed at z , co , za , j , nc , ag , and go distance as total width , right side , and left side bilateral facial widths observed at z. co , za , j , nc , ag , and go for males bilateral facial widths observed at z. co , za , j , nc , ag , and go for females the results showed statistically significant difference between the mean z , co , za , j , nc , ag , and go values of males and females ( p < 0.01 ) .
the difference between the right and left sides were statistically insignificant ( p > 0.01 ) .
the test revealed that only co distance was statistically significant ( p < 0.01 ) .
the means and standard deviation of vertical distances from the right and left z , co , za , j , nc , ag , and go to the msr on both groups are shown in table 6 .
vertical offset of z. co , za , j , nc , ag , and go tables 68 shows bilateral widths of co - go , go - me , co - me , and gonial angle to assess the mandibular morphology ( p < 0.05 ) .
there was statistically significant difference between the mean co - me value and gonial angle of the right and left sides .
total bilateral widths and gonial angle to assess the mandibular morphology bilateral widths and gonial angle to assess the mandibular morphology in males table 9 shows the bilateral widths and gonial angle to assess the mandibular morphology in females .
the results were statstiscally significant for the coronoid and menton distance and the coronoid gonion and menton distance .
bilateral widths and gonial angle to assess the mandibular morphology in females table 10 shows mandibular offset at menton .
menton deviated to the left side in 55% ( 2.6 1.4 mm ) and deviated to right in 3% ( 1.6 0.28 mm ) . in 58% males
deviation was towards left ( 2.4 1.02 ) and towards right 4% ( 1.7 0.3 mm ) .
mean angles formed by z , za , j , me , and occlusal planes with msr shows that there was no statistically significant canting .
parallelism of facial structures tables 12 and 13 show the sidedness of the face by subjective evaluation of composite photographs of 100 participants . out of a total of 100 participants
, it was observed that 81 were right faced ( r - r ) and 19 were left faced .
thirty - nine males were observed to be right faced ( r - r ) and 11 were observed to be left faced ( l - l ) . whereas in females ,
42 were observed as right faced ( r - r ) and 8 were observed to be left faced ( l - l ) .
therefore , in males and females , facedness is towards the right , and female faces were more right faced than males ( p > 0.01 ) .
table 3 shows the bilateral facial widths observed at z , co , za , j , nc , ag , go distances , as total widths , right side , and left side . table 4 shows total bilateral facial widths observed at z , co , za , j , nc , ag , and go for males .
table 5 shows total bilateral facial widths observed at z , co , za , j , nc , ag , and go for females .
bilateral facial widths observed at z , co , za , j , nc , ag , and go distance as total width , right side , and left side bilateral facial widths observed at z. co , za , j , nc , ag , and go for males bilateral facial widths observed at z. co , za , j , nc , ag , and go for females the results showed statistically significant difference between the mean z , co , za , j , nc , ag , and go values of males and females ( p < 0.01 ) .
the difference between the right and left sides were statistically insignificant ( p > 0.01 ) .
the test revealed that only co distance was statistically significant ( p < 0.01 ) .
the means and standard deviation of vertical distances from the right and left z , co , za , j , nc , ag , and go to the msr on both groups are shown in table 6 .
vertical offset of z. co , za , j , nc , ag , and go tables 68 shows bilateral widths of co - go , go - me , co - me , and gonial angle to assess the mandibular morphology ( p < 0.05 ) .
there was statistically significant difference between the mean co - me value and gonial angle of the right and left sides .
total bilateral widths and gonial angle to assess the mandibular morphology bilateral widths and gonial angle to assess the mandibular morphology in males table 9 shows the bilateral widths and gonial angle to assess the mandibular morphology in females .
the results were statstiscally significant for the coronoid and menton distance and the coronoid gonion and menton distance .
bilateral widths and gonial angle to assess the mandibular morphology in females table 10 shows mandibular offset at menton .
menton deviated to the left side in 55% ( 2.6 1.4 mm ) and deviated to right in 3% ( 1.6 0.28 mm ) . in 58% males
deviation was towards left ( 2.4 1.02 ) and towards right 4% ( 1.7 0.3 mm ) .
mean angles formed by z , za , j , me , and occlusal planes with msr shows that there was no statistically significant canting .
parallelism of facial structures tables 12 and 13 show the sidedness of the face by subjective evaluation of composite photographs of 100 participants . out of a total of 100 participants
, it was observed that 81 were right faced ( r - r ) and 19 were left faced .
thirty - nine males were observed to be right faced ( r - r ) and 11 were observed to be left faced ( l - l ) .
whereas in females , 42 were observed as right faced ( r - r ) and 8 were observed to be left faced ( l - l ) .
therefore , in males and females , facedness is towards the right , and female faces were more right faced than males ( p > 0.01 ) .
this has been verified and stressed upon by many researchers dating back from shah and joshi and peck et al .
a posteronterior cephalometric radiographic study of 100 participants with pleasing symmetrical faces and normal occlusions was conducted with the objective of evaluating the extent of facial asymmetry .
frontal photographs were obtained and studied for subjective evaluation of facial asymmetry seen in the selected tirupati population . the frontal analysis suggested by grummons
was used to assess the patients for the transverse ( skeletal ) facial asymmetries as it provides clinically relevant information regarding specific locations and amounts of facial asymmetry and measures mandibular morphology , which can be seen to play a major role in asymmetries .
the results of the present study [ table 1 ] showed that the bilateral total widths of z , co , nc , ag , and co on the right side was greater than those on the left side , however , the difference was statistically insignificant except for co. only the co distance was statistically significant ( p < 0.01 ) .
this shows that asymmetry was present more in the condylar region and towards right side .
the difference between the right and left side mean absolute asymmetry for z , nc , abd j distances are less than those for co , ag , and go .
none of the studies on facial asymmetry measured vertical offsets . in the present study , vertical offsets of z. co , za , j , nc , ag , and go were also measured and no statistical difference between males and females ( p > 0.01 ) . for the assessment of the mandibular morphology , co - ag , co - me , and ag - me and gonial angle were statistically analyzed [ table 2 ] .
the possible cause of asymmetry in gonial angle are asymmetry functional patterns such as unilateral chewing patterns , muscular atrophies , etc .
it shows that gonial angle is the only region where the right side is larger than the left side .
mandibular length ( co - me ) and gonial angle ( co - go , me ) showed statistically significant difference between the right and left sides , with right side being larger in total as well as in males and females .
this is in accordance with a similar study conducted by shah and joshi and azevedo et al .
chin deviations in our study showed a left sidedness , which is in agreement with findings of severt and profit .
the high incidence of chin deviation may be due to the asymmetries of mandibular length , which also showed high incidence .
the possible reason given by woo is the increased size of the right hemisphere of brain .
the mean values obtained for the angles formed by the various planes used in this analysis were more or less parallel to each other .
these findings are in agreement with ricketts and grummons . in our study on composite photographic analysis ,
mild asymmetry was observed both in males and females with males having wider faces than females .
me - co length showed statistically significant right sidedness in total ( p < 0.01 ) ; males ( p < 0.05 ) , females ( p < 0.05 ) .
the findings in our study are in concordance with many studies , however , left side laterality was observed in few studies .
seventy - eight percent of males and 88% females were observed as right faced ( r - r ) on composite photographic analysis .
the findings in our study are in concordance with those carried out by farkas and cheung , and ferrario virgilio et al .
generally , skeletal deviation must be greater than 4 mm to render the asymmetry visible in an individual 's face .
therefore , other authors consider an asymmetrical face as having bone deviations equal to or greater than 2 mm .
this might be the major drawback of the study because the present study utilized photographs also for determining the depth of facial asymmetries .
other main limitations of the study are the errors in identifying the anatomical landmarks in posteroanterior cephalograms due to superimposition of many craniofacial structures . a three - dimensional topographic study or cone - beam computed tomography ( cbct )
complete cbct software to identify different landmarks three dimensionally could also be helpful in marking the facial asymmetries .
other advanced means such as the use of stereophotogrammetry , ( three - dimensional photography ) or quantifying facial soft tissue asymmetry by a three - dimensional imaging - based method , or use of the weibull distribution - based comparison of a person 's asymmetry with respect to a large sample of symmetrical faces would be more accurate .
composite photographs of hundred participants revealed that facedness is towards right , however , this laterality was not statistically significant . both posteroanterior cephalograms and composite photographs showed right - sided laterality .
in the evaluation for an orthodontic treatment , asymmetry of the face should be considered and may only be noticed with a morphometric analysis .
the present data may be of use for future clinical studies , but studies with larger sample at different geographical locations are warranted . a classification for asymmetry based on the data collected for the asian group would be useful for future research on this subject .
the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s )
has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal .
the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .
the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s )
has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal .
the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .
| aims and objective : the human face is the most prominent aspect in human social interactions , and therefore , it seems reasonable opting for orthodontic treatment is to overcome psychosocial difficulties relating to facial and dental appearance and enhance the quality of life in doing so.materials and methods : posteroanterior cephalograms and frontal photographs of 100 participants ( 50 males and 50 females ) were analyzed to evaluate skeletal asymmetry by the analysis suggested by grummons .
soft tissue facial asymmetry was analyzed by composite photographic analysis .
the data were statistically analyzed using the statistical package for the social sciences version 16.0 software .
independent t - test was used to find the differences between different measurements.results:all participants showed mild asymmetry and right - sided laterality .
the difference between the right and left sides were statistically insignificant ( p > 0.01 ) .
the test revealed that only co distance was statistically significant ( p < 0.01 ) , and all the other values are not statistically significant.conclusion:composite photographs of hundred participants revealed that facedness is towards the right , however , this laterality was not statistically significant . both posteroanterior cephalograms and composite photographs showed right - sided laterality .
gender difference in both skeletal and soft tissue asymmetry is not statistically significant . |
regarding increased rates of premature and low birth weight newborns as well as associated
factors with high risk pregnancies , the number of infants who require admission to neonatal
intensive - care units ( nicu ) is growing .
along with the increasing complexity of technology and the development of the nicu wards ,
the survival of these newborns have improved .
currently , the number of neonatal intensive
care units in hospitals has met a rise ; however , more complex diseases and preterm infants
requiring critical care are also increasing . a major share of the responsibility for such
care practices is related to the nurses working in the nicus.these changes have raised the need for skilled nurses with
specialty regarding the infants more than ever .
nursing in intensive care units is dynamic , and nurses have to meet complex and changing
needs of critically ill patients . since competence is considered as a substantial part of
mitigating the risks and damages to the patient , it is of great importance in the intensive
care units . the complexity of competence dimensions have made it difficult to provide a single
definition of competence . in most studies ,
the benner definition ( 1982 )
is referred to explain the concept of competence , which defines
competence as the ability to perform a task to obtain optimum and favorable results in
changing conditions in the real world .
the definition of competence can also be very
simple , consisting of professional standards that the nurses use as an activation
directory .
professional competence in general activities of nurses includes a set
of knowledge , abilities and skills . in some definitions , in addition to knowledge , abilities
and skills , the concepts such as performance ,
memarian et al . , showed that the most important noviceal factor affecting the process of
obtaining competence include work experience , effective communication , interest to the
profession , responsibility , accountability and personal factors such as knowledge and
skills , respecting ethical and professional principles and respect to self and others . among
external factors ,
environmental factors including efficient education system and providing
technology , and professional factors including effective management , control , monitoring and
having work permission can be mentioned .
community and government support , marital status and participation at in - service training
programs are also the factors that affect the competence . during the competence acquisition process , with the development of practical skills and
gaining insight based on work experience and effective ethical practices by the nurses , the
problem solving skills and interacting with patients among the nurses will be
improved .
one of the major challenges in assessing clinical competence of nurses is using tools with
appropriate validity and reliability .
challenges in assessing and measuring nursing competence are due to a variety of nursing
roles , which are resulting from the complexity of nursing activities and human interactions
that measurement of each , even alone , is a difficult task .
problems regarding reliability
and validity of assessment tools are seen when the tools used in assessing the clinical
experience have a good validity , while the reliability of these devices is not considered ;
as a result , the presence of several variables in clinical environments may affect the
results . in the recent years , nursing education in iran has focused on theoretical education that
could lead to the gap between knowledge and practice in nursing . while in the developed countries since 1994 , competence - based
education and evaluation is a main priority .
currently our information about clinical competence of nurses in the neonatal intensive
care units and applying the nursing skills by them is scarce .
because of this lack of information ; we decided to investigate
the clinical competence of nurses working in the neonatal intensive care units affiliated to
tehran university of medical sciences .
this was a cross - sectional study , in which a total of 132 nurses working in neonatal
intensive care units in the hospitals affiliated to tehran university of medical sciences
were selected by census method during july 2012 to march 2013 . among them , 117 nurses were
completed and returned the questionnaire .
the inclusion criteria were having at least six months of experience in nicu and nurses
interest for participating in research . as our methodology was descriptive
there were no
exclusion criteria , unless the participant asked to withdraw from the research .
the first part of the questionnaire
was the researcher - made part that assessed the nurse s demographic characteristics included
age , marital status , job experience , educational status , specialized training programs ,
employment status , hours per month work and interest in the nursing profession .
the second
part was the " competency inventory for registered nurses questionnaire ( cirn ) .
this
questionnaire was used for the first time by ming liu et al . , in 2007 in china .
the questionnaire has 59 items in 7 aspects
which assess the clinical competence of nurses .
the dimensions and items include critical
thinking and tendency to do research ( 10 items ) , clinical care ( 10 items ) , leadership ( 10
items ) , moral and legal activities ( 8 items ) , professional development ( 8 items ) ,
interpersonal relationships ( 6 items ) and training and mentoring ( 7 items ) . to measure the
competence level , a five - point likert scale ( 1 : never , 2 : rarely , 3 : sometimes , 4 : most of
the times and 5 : always ) was used for scoring each items .
according to the total score of
the questionnaire , the nurses competency was measured as poor : < 225 , moderate : 225 - 273 ,
and good : > 273 , respectively . to ensure the translation accuracy , an expert in english language familiar with the nursing literature
was asked to
review the tool by back - translation method. the face and content validity of the research
tools evaluated by ten expert faculty members of tehran university of medical sciences .
the
questionnaire made available to 10 nurses working in the neonatal intensive care units of
the hospitals affiliated to tehran university of medical sciences after undergoing validity
processes .
one month later , the questionnaires refilled by the same subjects and the
reliability of the tool evaluated using test - retest method ( correlation coefficient : 0.78 ) .
also , the cronbach 's alpha method was used in order to determine the correlations between
competence aspects ( correlation coefficient : 0.89 ) .
the questionnaires were completed by nurses as a self - assessment method and by head nurses
as a supervisor.the spss software version 13 was used for data analysis .
descriptive
statistics methods including the frequency , mean ( sd ) and inferential statistics methods
including pearson correlation coefficients were used for analysis .
the relationships between
the categories of clinical competence and other factors such as demographic factors were
assessed by the pearson correlation coefficient , t - test and chi - square test . in this
study a written permission was obtained from ming liu for using the tool cirn .
after obtaining the license from the medical ethics committee of tehran university of
medical sciences ( the ethical code number : 92/d/130/839 ) , by referring to the research
environments and assuring the subject and authorities regarding anonymousness and
confidentiality of information and explaining the objectives of the study , the required data
were collected .
also we have observed all different aspects of ethical codes including
voluntary participation , confidentiality , informed consent and autonomy .
of the 132 questionnaires , 117 ( 89% ) questionnaires were completed and returned to the
researcher .
the mean job experience of
subjects was 8.39 ( 5.7 ) years work that 4.79 ( 3.67 ) years work were in the neonatal
intensive care unit .
the educational level of the nurses was as follows : bachelor of
nursing : 92.4% , and master of sciences ( msc ) in nursing : 7.6% .
the nurses who had undergone
no specialized training programs regarding infants nursing accounted for 35% , while 42.7%
had participated in workshops related to nursing care of the infants , such as breastfeeding
and newborn resuscitation , and 22.3% had passed the infants nursing courses . the employment status of the participants was as following : novice nurses ( 12% ) ;
short - time contracts ( 1 year ) ( 6.8% ) ; long - term contracts ( 2 - 5 year ) ( 54.7% ) and formally
employed ( 26.5% ) .
the mean hours work per month among the nurses was as 72.88 ( 34.28 ) hours
( table 1 ) . among demographic variables , three
variables of marital status , employment status and interest in the nursing profession had
a direct statistically significant correlation with the degree of clinical competence of
individuals ,
so that the mean competency score of married and single participants was 239.01
and 228.17 respectively ( p - value = 0.007 ) .
the mean competency score of nurses with
short - time contracts was 219.62 while nurses with long - term contracts had the mean
competency score equal to 240.52 ( p - value = 0.03 ) . also based on our findings ,
the mean competency score for the nurses who had low level of
interest in the nursing profession was 238.52 , however , the mean competency score for nurses
who had high level of interest in the nursing profession was 246.91 ( p - value = 0.03 ) ( table 1 ) .
t - test and fisher 's exact test , direct statistically
significant relationship the pearson correlation coefficient was used to evaluate the relationship among the
dimensions of clinical competence of the nurses .
hence , all of the seven dimensions of
clinical competence were tested in a two - by - two pattern after categorization into 3 levels :
weak / poor : < 225 , moderate : 225 - 273 and good : > 273 using t - test and chi - square test .
the test results showed that there was a direct statistically significant relationship among
all aspects of clinical competence , which means with increased competence in one aspect , the
rates of competence in other dimensions will also increase ( p - value < 0.001 ) . in our
research
most of the participants ( 92.3% ) had good critical thinking and research attitude ,
moderate clinical care ( 65.8% ) , moderate leadership ( 73.5 ) , good interpersonal
relationships ( 85.5% ) , moderate legal and ethical practice ( 75.2% ) , moderate professional
development ( 69.2 ) , and moderate teaching
in this study , more than half of the nurses ( 65.8% ) had a moderate competence . in
mertojaet al . ,
, studies , most of the nurses reported their competence as good ,
which is not consistent with the results of the present study . in a study by ying et al .
, to investigate the relationship between clinical competencies
and organizational atmosphere , most of the nurses assessed their competence as highly
competent , which is not consistent with the results of the present study .
the reason for
high levels of care provided in the studied hospital may be due to its educational nature
and position , since in such environments , the nurses are constantly learning and used to
teach the nursing students . in another study , bahraini et al .
, evaluated the nurses ' clinical competence working in
hospitals affiliated to shiraz and bushehr universities of medical sciences .
the nurses in their self - assessment had reported their competence at good level , which is
not consistent with the results of the present study . in this comparison ,
the nurses in
hospitals affiliated to shiraz university of medical sciences had a better competence level ,
which bahraini et al . , considered due to factors such as better educational facilities , more
in - service training programs , and organizing of educational processes . given that the
study conducted in the neonatal intensive care units and teaching hospitals affiliated with
the university , the nurses in these wards have many opportunities for experiential learning
in the real environments .
however , perhaps one of the issues may affect the nurses ' competence would be not
conforming the nursing standards such as the number of shifts required and further working
hours per month that could cause fatigue and exhaustion in nurses and leaving them no
opportunity to study and doing research .
one of the standards in the nicu , which is not
followed , is the nurse to patient ratio .
this ratio in some level of nicu is 1 to 1 , and in
some other is two nurses per one baby based on the patient 's condition . in our research environment ,
the ratio is most
of the 3 patients per one nurse . at such times
, the nurse probably would not have enough
time to perform the care tasks appropriately , and obviously not enough time to study and
update information , and thus , he / she will estimate his / her competence lower than the real
rates .
one of the most important issues in nursing is to employ nurses based on standards
developed by the ministry of health .
the curriculum and terms document of subspecialty
pediatrics and perinatal medicine approved by the iran ministry of health and medical
education states that " the care of patients in the nicu must be provided under the
supervision of and by specially trained and experienced nurses in neonatal intensive care .
the nurses working in nicu must have at least five years of experience of working in one of
the child or infants wards such as infants ' medical and surgical wards or operating room .
it
is referred that employing the graduates in master 's degree of nursing in the nicus and the
nurses with bachelor 's degrees that have at least five years of experience in the mentioned
units is permitted .
however , we found
that all nurses working in the neonatal intensive care units do not meet the ministry of
health standards . due to the shortage of skilled human resources ,
the hospitals have
employed the nurses with little working experience . as reported , in some cases
, the nurses
had not passed the courses required to work in the nicus .
a study conducted in scotland refers to the same challenge that the nurses working in
infants units are graduated nurses in nursing courses for adults or children .
although such nurses receive some training courses before working formally in nicus , but
they have not yet achieved the full competence in this regard .
they also need supervising in
performing nursing activities , and it refers that there is a need to pass the nicu - required
complementary nursing courses to provide nursing care with good quality in such units . in
addition , standardized training courses according to the required competencies are
needed . also ,
according to specialty in the neonatal intensive care units and given the standards
for hiring nurses in nicus , the need for specialist nurses is issued .
however , only 7.6% of nurses in the study population have passed the master of nursing ,
despite the existing standard that defines the nurses working in the neonatal intensive
units should have at least 5 years ' experience of working with infants or children s
associated wards . among the nurses working in neonatal icus
as noted above , one reason to employing the novice students in nicus is the
workforce shortage . in the present study ,
there was statistically significant relationship between marital
status , employment status , number of hours per month work , interested in a neonatal
intensive care units and the level of clinical competence .
as shown , interest in the
profession is also considered as factors affecting the competence ; hence it is better to provide the conditions in such a way that
people can choose their academic field based on their interest , and thus , select the nursing
profession and serve in hospital wards .
given the extension and complexity
of competence , the number of evaluation items is very high and this can affect the given
responses .
however , to reduce the restrictions of the self - assessment method , supervisor
assessment method was also used simultaneously .
to improve and enhance the clinical competence of nurses in performing their professional
tasks and roles in a safe way and with good quality , some effective variables on the
competence of individuals , including : interest in the nursing profession , employment status ,
passing neonatal intensive theoretical and practical training courses and the amount of
overtime working hours should be considered .
employing interested and competent nurses and
considering the standards required in the nicu can increase the quality of care in these
wards .
this project was sponsored by the school of nursing and midwifery , tehran university of
medical sciences .
also , all the nursing managers , supervisors , and nurses in the studied
hospitals were cooperated in the implementation of project that we would mind to appreciate
them one by one .
| introduction : clinical competence of nurses working in the
neonatal intensive care units together with advancements in medical science and technology
increased the survival rate of newborns that need specialized care . to ensure the quality
of care and provide
the safety of patients , evaluating the clinical competence of nurses
seems necessary .
this study aimed to evaluate the clinical competence of nurses in the
neonatal intensive care units .
methods : in this cross - sectional study , 117 nurses working
in the neonatal intensive care units of the hospitals affiliated to tehran university of
medical sciences were selected by census method .
the research tool was development of
competency inventory for registered nurses questionnaire which completed by
self - assessment .
the mean clinical competence scores of participants categorized into 3
levels : weak : < 225 , moderate : 225 - 273 and good : > 273 . data were analyzed by spss
version 13 using the pearson correlation coefficient , t - test and chi - square test .
results : the highest levels of competence were related to
critical thinking and research attitude and interpersonal relationships , and the lowest
level was related to training and mentoring .
there was a direct statistically significant
relationship between marital status , employment status , level of interest in working in
the neonatal intensive - care units and the clinical competence of nurses .
conclusion : since the clinical competence of nurses in the
neonatal intensive care units is vital , some variables such as interest in the nursing
profession , employment status , the neonatal intensive theoretical and practical training
courses and the amount of overtime working hours should be taken into consideration . |
the motor vehicle accidents are one of the major reasons for cervical spine injuries ( especially upper cervical spine ) in 0 - 9 age group , whereas sports injuries are one of the major reasons for cervical spine injuries ( especially lower cervical spine ) over the age of 10 .
some factors such as larger head , underdeveloped neck musculature , partially ossified wedge - shaped vertebral bodies and more angled facet horizontally , ligamentous elasticity make the upper cervical more sensitive to spine injuries under the age of 10 . from the age of 10 ,
the younger age group ( aged 0 - 10 years ) is more prone to upper cervical spine facet dislocations .
however , ufds in the lower cervical spine are found to be less common in this age group in the literature .
this article presents a 9-year - old boy who suffered from locked ufd without neurological deficits .
the head of the boy had been entrapped and squeezed by the automatic sliding garage door and he had tried to pull back his head forcefully [ figure 1 ] . after the injury , he had been brought to local hospital for the neck pain .
after the clinical and radiologic examination , c6 - 7 ufd was diagnosed and tried to treat with cervical collar .
because of the unresolved neck pain and limited motion of the neck , the patient admitted to our center after three months of injury
. there was no focal neurologic deficit and injury of the other systems on physical examination .
the locked facet dislocation between the c6 - 7 level and anterolisthesis of c6 and loss of cervical lordosis were seen on x - ray .
there was left locked ufd without associated fracture on three - dimensional computerized tomography ( 3d - ct ) , and no disc and spinal cord ( sc ) damage on magnetic resonance imaging ( mri ) was seen [ figure 2 ] . due to the delayed dislocation ,
after partial laminectomy , ligamentum flavum excision and left facet joint reduction with the help of lamina spreader was performed ; fixation was obtained by c5-c7 posterior instrumentation . in the same stage ,
c6 - 7 discectomy , cage implantation and c6 - 7 anterior plating was performed via anterior subaxial approach [ figure 3 ] .
three months after the surgery , there was no pain with motion and fusion was seen in the first third month control [ figure 4 ] .
( a ) injury mechanism : distraction and rotation ( b ) left unilateral facet dislocation of c6 - 7 ( a ) the facet dislocation between c6 and c7 and anterolysthesis of c6 and loss of cervical lordosis were seen on lateral cervical x - ray . ( b ) left unilateral facet dislocation was observed on ct ; ( c ) there was no associated sc damage on mri postoperative ( a ) anteroposterior ( b ) lateral x - ray interbody fusion on a ) coronal and b ) sagittal ct imges c ) facet fusion on sagittal ct image
ufd is more common in adults than in children and occurs as a result of flexion - rotation forces leading to partial or complete damage to interspinous , posterior longitudinal ligament , capsule and disc in the cervical spine .
the motor vehicle accidents and sports injuries are common reasons of the cervical spine injuries .
after the head of the boy had been entrapped and squeezed by the sliding door , he tried to pull it back forcefully . pulling out the head suddenly and forcefully toward back may have created flexion and rotation movements on the cervical spine . in the presence of neck pain and restricted motion ,
the clearing process always requires a complete clinical evaluation , and occasionally warrants adjunctive imaging . if there is any suspicion , diagnosis should be confirmed by ct and mri in addition to direct x - rays . while the surgical treatment is the first preferred method by most surgeons in adult patients , closed reduction is performed in children in the absence of neurologic deficit because of the growing and healing potential of the children .
a case with similar injuries without neurologic deficit and treated with closed reduction under general anesthesia was published by prada et al . due to the delayed case , no closed reduction attempt was tried .
fibrotic tissue occurring after the injury can damage to sc and make a mechanical barrier for reduction in delayed cases without neurologic deficit .
chen et al . reported an article about a 22-month - old child with ufd and neurological deficit and without disc damage on mri .
after failed closed reduction , posterior reduction and fixation had been performed , and good results were reported .
presented a case of 10-month - old infant with neurologically intact c6 - 7 ufd . although failed closed reduction they applied conservative treatment with custom - made orthotics . at the 2-month follow - up normal cervical alignment and at the end of the 18-month follow - up ,
posterior approach was chosen first in order to achieve direct reduction and to increase the stability anterior approach was performed in the same session .
it is thought that to obtain rigid fixation in this delayed case would prevent the instability and redislocation . during the follow - up , no complication was observed .
but in patients who underwent cervical fusion , malalignment and adjacent segment degeneration may occur .
mcgrory et al . presented that after surgical fixation of fractures and dislocations of the cervical spine , osteoarthritic changes occurred in the adjacent segments as a long - term complication .
however , surgical fixation is required for the case of recurrent instability , failed closed reduction , irresponsible to conservative treatment and delayed diagnosis .
unilateral cervical locked facet is a rare injury in pediatric population especially under 10 of age . because of its rarity
also these injuries can be seen as a result of rare injury mechanism and a detailed radiologic examination should be carried out not to overlook an accompanying pathology .
surgical treatment should be preferred in the presences of locked and delayed ufd cases especially .
the long term results of surgical intervention should be strictly followed for adjacent segment degeneration . | most of the cervical spine injuries in the pediatric population are typically seen in the upper cervical region .
unilateral cervical facet dislocation ( ufd ) in subaxial region is a rare injury in pediatric population . in this paper ,
a rare case of delayed locked ufd in a 9-year - old boy with rare injury mechanism treated surgically is reported .
clinical and radiological findings were described .
the patient with c6 - 7 ufd without neurologic deficit was underwent open reduction and internal fixation via anterior and posterior combined approaches .
significant improvement of pain and free motion in cervical spine was obtained .
there was no complication during the follow up .
only three case reports presented about the lower cervical spine injury with ufd under the age of 10 were found in the literature . |
however , limitations and complications from using autografts include a limited quantity and chronic donor site pain [ 1 , 2 ] .
this has led to the need for an ideal bone graft substitute . an ideal substitute must have enhanced capabilities to reduce or eliminate the need for an autograft altogether and are necessary to provide support , fill voids , and enhance biologic repair of defects .
the need for tissue - engineered constructs is increasing and advances in the field have led to the use of scaffolds , cells , and factors to regenerate organs and tissues .
the integration of the biological , physical , and engineering sciences will create the new constructs that regenerate and restore the functional state of damaged tissues . using tissue engineered constructs such as biobased scaffolds as bone graft substitutes
tissue - engineered constructs , specifically biopolymers , can promote successful bone healing when originating from natural proteins found in the body .
ovalbumin ( oa ) is being used in this study because it is a biopolymer found in chicken egg whites , has a molecular mass of 45 kda , and is comprised of 386 amino acids with 10% of the amino acid sequence conserved when compared to human serum albumin .
oa is comprised mainly of -helix and -sheet , but when introduced to an alkaline environment ( ph > 7 ) , it transforms to a predominantly -sheet structure .
it can be used to create biocompatible scaffolds that aid in osteoblast adhesion and mineralization into 3d structures .
ovalbumin is more readily available and cheaper ( $ 40/kg , sigma aldrich ) than using synthetic or other natural biopolymers .
ovalbumin contains nineteen lysines per oa molecule which are necessary for chemical crosslinking with a common agent , glutaraldehyde ( ga ) .
glutaraldehyde crosslinking is governed by reactions with -amino groups of lysines ( figure 1 ) .
the ga crosslinking process has been shown to alter cellular response due to its cytotoxicity and may alter osteoblastic responses through modification of the scaffolds .
however , it has been previously reported that using ga as a crosslinker for other biopolymer scaffolds such as collagen , alginate , and keratin has not affected biocompatibility [ 1113 ] .
therefore , small concentrations of ga will be used to prevent cytotoxicity , and oa scaffolds may also be created using this method . both a material and biological perspectives are needed to fully understand interactions in the body to make biomaterial scaffolds successful . from a material perspective , the extent of how surface properties and material characteristics affect cell behavior must be determined .
it is also important to know the parameters that govern positive cell response to a biomaterial and what in vitro models reproduce these parameters in order to conduct successful research . using these results as a guideline
biobased polymers need to be researched for further tissue engineering advances , specifically their use in bone regeneration .
this study aims to create a biobased oa scaffold and investigate the effects of adhesion , growth , and differentiation of preosteoblast cells on these structures .
to create an oa solution , 5.0 g oa from chicken egg white , grade ii ( sigma aldrich ) and 0.01 g dithiothreitol ( sigma aldrich ) minimum 99% titration were dissolved in 30 ml borate buffer ( ph 9.5 ) and 50 ml deionized ( di ) water .
the solution was stirred overnight at room temperature and dialyzed using snake skin dialysis tubing in water at room temperature for three days .
scaffolds were fabricated using sodium chloride salt porogen , oa solution , and ga ( sigma - aldrich , grade i , 25% in h2o ) crosslinker .
one gram sieved salt with particle sizes 90150 m was measured into wells of a 12-well plate .
two and a half milliliters dialyzed oa solution was pipetted over the salt of each well plate .
ten percent ga to oa solution by volume was pipetted into the wells to introduce crosslinking .
each well was stirred to ensure equal distribution and placed on a shaker overnight to allow for crosslinking . once cross - linked
, the scaffolds were removed from the well plates and placed in 150 ml of 100 mm glycine ( sigma aldrich ) solution at 35c to terminate ga crosslinking .
after one hour the scaffolds were taken out of the glycine solution and placed in a beaker of di water to commence the salt leaching process .
the beakers were placed on a shaker and the scaffolds remained in di water for three days and water changed twice a day during the process .
the next day they were placed in a lypholizer at 80c and 10 torr overnight to remove excess water .
a trinitrobenzenesulfunic acid ( tnbsa ) assay as described by hermanson was performed to measure the number of -amino groups in the scaffolds to determine percent crosslinking .
scaffolds with 10% ga to oa solution by volume crosslinking as well as oa powder ( as previously discussed ) as a control were used in the study .
briefly , 11 mg dry scaffold was placed in a 50 ml screw cap tube with 1 ml of 4% nahco3 and 1 ml 0.5% tnbsa .
the vial was placed in a water bath with a stirring bar at 320 rpm at 40c for four hours .
three milliliters of 6 m hcl was added to the vial to hydrolyze the reaction and then the vial was placed in the autoclave for one hour at 120c and 1517 psi to hydrolyze and dissolve the protein .
after autoclaving , the solution was diluted with 20 ml di water and read on a uv - vis spectrophotometer at 350 nm .
the surface and cross - sectional area scaffold morphologies were viewed using the fesem ( leo / zeiss 1550 , munich , germany ) .
samples were sprayed with 15 m thick conductive gold - palladium coating under vacuum in an argon atmosphere .
average pore size was determined by viewing fesem images in a q analysis program and measuring the diameter of 25 different pores .
scaffolds were mechanically tested by compression using an instron 5869 with a 100 kn load cell .
compression tests were carried out on samples with approximately twenty millimeter diameters and approximately seven millimeter heights at a crosshead speed of 2 mm / minute .
scaffolds were submerged in phosphate buffered saline ( pbs ) solution for two days , completely wetting the samples to allow for wet compression testing .
differential scanning calorimetry ( dsc ) thermal measurements were performed on wet scaffolds and a noncross - linked oa film as the control with a netzsch 889 analyzer from 30c to 350c at a heating rate of 10c / minute under a helium atmosphere .
scaffolds were placed in 48-well plates containing mc3t3-e1 preosteoblasts suspended in 0.5 ml medium ( 10,000 cells / scaffold ) for 4 hours and 96 hours .
mc3t3-e1 cells were cultured in expansion medium containing -minimum essential medium ( mem ) plus 10% fetal bovine serum ( fbs ) and 1% antibiotic / antiomycotic .
cell staining consisted of fixing the cells for 5 minutes using 0.5% by volume triton x-100 , 4% by volume formaldehyde and 1 mmol / l cacl2 , 2 mmol / l mgcl2 in phosphate buffered saline at ph 7.4 .
the scaffolds were then rinsed and postfixed for 20 minutes in the same fixative as before without triton x-100 .
cells were stained in the dark for 1 hour with 2 m sulforhodamine 101 phalloidin ( texas red ) and 6 m 4,6-diamidino-2-phenylindole ( dapi ) in pbs containing 1 mm caand 2 mm mg after 5 minutes of air drying , the scaffolds were mounted on glass slides with vectashield containing dapi .
cells were seeded and cultured for 3 , 7 , 14 , and 21 days on scaffolds .
three scaffolds and cross - linked films were tested per time period with an empty well as a control .
mc3t3-e1 preosteoblast cells were cultured on ethylene oxide sterilized 5.5 mm diameter scaffolds as well as cross - linked films . a 48-well plate with 0.5 ml expansion medium ( per well ) supplemented with ascorbic acid ( 50 mg / ml ) and -glycerol phosphate ( 10 mmol / l ) to enhance osteoblast differentiation was used .
if differentiation occurred , scaffolds were kept for alp level analysis using a reagent assay .
ocn levels were measured for each time interval using an enzyme - linked immunosorbant assay ( elisa ) kit ( biotechnologies , inc . ) according to the manufacturer 's directions .
all experiments were performed with three scaffolds and cross - linked films unless otherwise specified .
statistical significance was determined by single factor analysis of variance ( anova ) with p < .05 .
the percent crosslinking was calculated by using the average moles of lysine at 350 nm for the oa powder control and 10% ga to oa solution by volume scaffolds .
sem analysis of the scaffolds allowed for morphology and size of pores to be evaluated .
a porous structure was viewed for both surface and cross - sectional area ( csa ) of the scaffolds and average pore size was determined .
average pore size for the surface was 147.84 40.36 m and 111.79 30.71 m for the csa .
the average ultimate stress and elastic moduli for the scaffolds were 6.8 3.6 kpa .
the glass transition temperature ( tg ) of the scaffolds and oa powder control were found . the control had a tg of 240 35c and the scaffold , 320.1 1.4c .
cells were stained with dapi and texas red to look at cell morphology on the scaffolds .
nuclei were stained blue due to the dapi binding to the dna while texas red binds to the f - actin of cells staining it red .
because of the scaffolds autofluoresce , it was impossible to see the stained cell body to determine morphology along the scaffold pores .
however , cell numbers for both the 4-hour and 96-hour time intervals could be determined by counting the stained nuclei . at four hours
the average number of cells on the scaffolds was 60.8 18.9 cells per image and at 96 hours the average number of cells was 153 4.8 cells per image , a twofold increase .
differential studies compared scaffold ocn levels at 3- , 7- , 14- , and 21-day time intervals to standard solutions .
oa powder as a control ( as previously mentioned ) and 10% by volume ga to oa solution cross - linked films were also compared to a standard curve found from the average standard absorbances calculated .
scaffolds at 21 days showed a significant increase in ocn levels when compared to the control and cross - linked film ( figure 3 ) .
a significant alp increase was seen in the control well at 7 , 14 , and 21 days when compared to the control well at 3 days .
alp levels for cross - linked films at 14 and 21 days showed a significant increase compared to cross - linked films at the 3- and 7-day time intervals .
scaffolds showed a significant increase at 14 days when compared to scaffolds at 3 and 7 days and a downregulation of alp production was seen at 21 days ( figure 4 ) .
although ga is a common crosslinking agent , the mechanism and chemistry involved in the crosslinking reaction is not yet fully understood .
it has been shown that varying ga concentration has an effect on crosslinking . at low concentrations of ga ,
it is more probable for ga to crosslink with lysines in oa molecules because the amount of lysines is equal to or greater than the amount ga molecules present . at higher concentrations of ga , it is more probable for ga to react with itself because the amount of ga molecules is larger than the amount of lysines present to crosslink .
therefore , there is a limit to how much ga is able to crosslink with lysine molecules .
this explains why only 35% crosslinking was observed in the scaffolds and confirms that an excess of ga was used .
the average pore size of the scaffolds in this study corresponds with those reported in the literature [ 2022 ] that have been shown as optimal pore size for cell adhesion , proliferation , and differentiation .
the wet compressive mechanical properties of the scaffolds fell below the actual compressive strength of bone .
compact bone is known to have a compressive strength of 150250 mpa due to variability in bone density [ 24 , 25 ] .
although the ideal mechanical strength of biomaterial scaffolds has not yet been determined , previously researched scaffold compressive strengths have fallen within a 245 mpa range [ 2628 ] .
the compressive modulus for bone has been measured to be 520 gpa while biomaterial scaffolds vary from 60 mpa15 gpa .
although oa scaffolds are lower in compressive strength and modulus than other biobased scaffolds as well as natural compact bone , it is not fully understood to what extent scaffolds must mimic natural bone mechanical properties .
they have , however , demonstrated to be a promising substrate for cell growth and bone regeneration as shown by the cellular studies and sponge - like characteristics of the scaffolds .
only glass transition temperatures were observed in the control and scaffold ; therefore , it can be concluded that the scaffolds were amorphous .
the glass transition temperature of the control was determined to be 240c ; so an increase in tg to 320c for the scaffolds confirms crosslinking occurred . using confocal images , cell numbers for the scaffolds at 4 hours and 96 hours were determined and a significant increase between the 4-hour- and 96-hour - cultured scaffolds was seen .
because of this significant increase , it was determined that the preosteoblast cells responded positively to the scaffold and surrounding environment and reached a proliferative state .
alkaline phosphatase studies showed a significant increase in cross - linked films at 14 and 21 days in comparison to cross - linked films at 3 and 7 days .
for the scaffolds , a significant increase in alp was seen at 14 days ; however a decrease in alp production was seen at 21 days .
osteocalcin differentiation studies showed an increase in ocn levels in scaffolds cultured for 3 , 7 , and 14 days when compared to the control well and cross - linked films ; however no significant difference was found .
there was a significant increase in ocn levels in the scaffolds cultured for 21 days when compared to the cross - linked film and control well at the same time interval .
it has been shown that at two weeks in vitro , alp is increased and then downregulated when mineralization begins .
this corresponds with the scaffold ocn data showing a significant increase of ocn at 21 days indicating the beginning of mineralization .
the significant increase in ocn levels at 21 days and the downregulation of alp after the two - week time period indicate that differentiation occurred .
after scaffold fabrication , morphology and pore size were determined and all scaffolds had a csa and surface porous structure comparative to porous scaffolds used in previously reported literature .
glutaraldahyde was used as the crosslinker to create the 3d porous structure and material characterization was conducted on the scaffolds .
a tnbsa assay was conducted to determine percent crosslinking of the scaffolds , and it was determined that ga crosslinking reaction did occur .
however , 100% crosslinking was not reached due to ga intermolecularly crosslinking with itself , not allowing for chemical interaction with all lysines present in oa molecules .
also , an average glass transition temperature , compressive strength , and compressive modulus were found for the scaffolds .
although the average compressive strength and modulus is lower than bone , the needed compressive strength for scaffolds is not known and therefore the scaffolds can not be ruled out as a possible substrate for cell growth and differentiation .
in fact it was shown through cell studies that despite low compressive strength and modulus , mc3t3-e1 preosteoblast cells did increase in number and therefore a proliferative state of the cells was reached .
differentiation studies showed a significant increase in ocn levels at 21 days for scaffolds . a significant increase in alp at 14 days
was seen for the scaffolds as well as a decrease at 21 days corresponding with the increase in ocn at 21 days .
these results signify the beginning of mineralization and support the idea that differentiation did occur .
overall oa scaffolds have shown to be a promising 3d material construct to induce the proliferation and differentiation of mc3t3-e1 preosteoblast cells for bone tissue regeneration . | cell differentiation on glutaraldehyde cross - linked ovalbumin scaffolds was the main focus of this research .
salt leaching and freeze drying were used to create a three - dimensional porous structure .
average pore size was 147.84 40.36 m and 111.79 30.71 m for surface and cross sectional area , respectively .
wet compressive strength and elastic modulus were 6.8 3.6 kpa .
average glass transition temperature was 320.1 1.4c .
scaffolds were sterilized with ethylene oxide prior to seeding mc3t3-e1 cells .
cells were stained with dapi and texas red to determine morphology and proliferation .
average cell numbers increased between 4-hour- and 96-hour - cultured scaffolds .
alkaline phosphatase and osteocalcin levels were measured at 3 , 7 , 14 , and 21 days .
differentiation studies showed an increase in osteocalcin at 21 days and alkaline phosphatase levels at 14 days , both indicating differentiation occurred .
this work demonstrated the use of ovalbumin scaffolds for a bone tissue engineering application . |
the hypothalamus is often times a target for newer potential obesity treatments due to its crucial role in food intake and metabolism .
it is also established that food intake modulation is confounded by numerous players within the hypothalamus , allowing for the research and development of a diverse array of obesity management drug leads that have completely different underlying mechanisms .
the melanocortin system is established amongst these systems ; however , the cannabinoid system , among others , also has an established role .
speculation of a connection between the cannabinoid system and melanocortin system regarding food intake has existed due to their presence in nearby regions of the hypothalamus . moreover ,
suboptimal doses of sr 141716 ( rimonabant ) together with suboptimal doses of -melanocyte - stimulating hormone ( -msh ) are known to behave synergistically in order to reduce food intake .
attempts to develop a safe drug to treat obesity via blocking the cb1 receptor have proven to be elusive and controversial , as drugs such as rimonabant have had to struggle for approval due to numerous reported and suspected side effects , particularly depression .
the role of the melanocortin system in food intake is well - established and prevention of the rapid inactivation of -msh may prove to be a better alternative pathway for potential obesity treatments .
recent studies suggest that prolylcarboxypeptidase ( prcp ) involved in regulating blood pressure and inflammation is an appetite stimulant and , by consequence , prcp inhibitors may prove to be a viable lead to treat obesity .
there have been numerous excellent reviews on melanocortin receptors.16 however , this article only reports the most current information about how the two tectonic physiological processes , namely the proteolytic enzymes of renin - angiotensin system ( ras ) and proopiomelanocortin ( pomc)-derived neuropeptide regulatory processes in the central nervous system might be shifting toward each other .
recent findings suggest that prcp ( a ras enzyme ) regulates -msh ( a pomc - derived neuropeptide ) levels , a theme addressed by the present review .
while this article briefly introduces both prcp- and -msh - mediated processes , it also outlines how brain prcp may play a key role in controlling food intake and weight gain .
the prcp - catalyzed reaction was initially found to be part of the pathway for angiotensin ii ( ang ii ) metabolism in renal tissues , where prcp appeared to control the total amount of ang ii .
odya and others demonstrated that prcp metabolizes ang ii to angiotensin 17 ( ang 17 ) ( figure 1).7 the activation of ang 17 receptor mas ( a g - protein - coupled protein ) by ang 17 results in the generation of nitric oxide ( no ) and prostaglandins.8 thus , ang 17 counteracts ang ii function , providing evidence that prcp regulates the negative effects of ang ii such as high blood pressure and heart failure.9 in addition , the activation of the ang 17 receptor mas may also lead to diminished cell proliferation through down - regulation of the phosphorylation and activation of erk1 and erk2 in the erk1/erk2 map kinase signaling pathway.10,11 in theory , the prcp inhibitors to target the production of pro - inflammatory prostaglandins and promote proliferation through the ang 17 receptor mas - dependent pathway represent a novel approach to suppress unwanted inflammation - causing prostaglandins .
later , it was shown that prcp is one of several enzymes that convert ang ii to a unique bioactive molecule . in vitro studies showed that angiotensin - converting enzyme 2 ( ace2 ) is an exopeptidase that converts ang ii to ang 17 at a much faster rate than prcp.12 these data suggest that ang ii is a poor substrate for prcp .
clinical studies have provided reliable evidence that ace2 is an essential regulator of angiotensin i ( ang i ) , ang ii , and angiotensin - induced cardiac hypertrophy.13 recent studies clearly show increased myocardial levels of ang ii and a significant decrease in ang 17 in ace2-deficient hearts , suggesting that the role of prcp in metabolizing ang ii may be insignificant.9 taken together , these observations suggest that prcp is a redundant catalyst contributing to alternate pathways for ang ii metabolism . while the well - established cardiovascular and renal actions of ang ii are attributed to the angiotensin type 1 receptor ( at1r ) , much less is known about angiotensin iii and its cardiovascular effects . for more than 30 years , it was known that prcp metabolizes ang iii to ang 27 ( figure 1).7 soon after , studies demonstrated that ang iii is a pressor agent whose response , like that of ang ii , is mediated by at1 receptors.14,15 apparently , ang iii has multiple effects on renal function in the diseased kidney and can enhance renal disease through the overproduction of aldosterone , leading to arterial hypertension and/or atrial fibrillation.16 aldosterone maintains blood volume , pressure , and electrolyte balance .
its production is known to be regulated by renin , an enzyme produced in the kidneys .
renin increases in response to low blood pressure , decreased blood flow to the kidneys , or sodium deficiency .
studies indicate that ang iii also activates the secretion of aldosterone.15 recently , we have demonstrated that recombinant prcp ( rpcrp ) metabolizes ang iii to ang 27 , removing phenylalanine ( phe).8 it is tempting to speculate that prcp might funnel the generation of angiotensin 34 ( ang 34 ) through ang 27 ( figure 1 ) .
if the over - secretion of aldosterone by ang iii is viewed as a trigger of arterial hypertension , then inactivation of ang iii by prcp might lead to a decrease in blood pressure .
further studies are required to determine whether prcp is critically important for regulating ang iii - induced hypertension and preserving renal structure and function .
this is an important area of research to pursue given the increasing prevalence of cardiovascular disease and stroke in the older population .
the possible actions of another substrate of prcp , plasma prekallikrein ( pk , fletcher factor ) , have recently begun to receive much attention .
when the complex of high molecular weight kininogen ( hk ) and pk binds to endothelial membrane , pk is rapidly converted to kallikrein by prcp.17 the formed kallikrein then cleaves hk to liberate bradykinin ( bk ) , which leads to no and prostaglandin - i2 formation , as well as subsequent vasodilation , by activating constitutive bradykinin b2 and inducible bradykinin b1 receptors.18,19 the prcp - dependent pk activation pathway might be considered an additional mechanism to preserve the availability of no and prostacyclin as vasodilatory agents in vascular smooth muscle .
we proposed that chronic prcp inhibition might elevate blood pressure . in accordance , we have found that prcp mice have mild hypertension , suggesting a causative relationship between prcp levels and signs of hypertension.20 local skeletal muscle ischemia and acidosis are shown to increase the generation of bk and prostaglandins , the two circulating products of the prcp - induced cell activation ( figure 1).21 the increased acidotic response during exercise and inflammatory mediators such as bk and prostacyclin have been shown to cause abnormal exercise - related symptoms and autonomic responses in congestive heart failure syndrome.22 nonetheless , the long - term elevated concentrations of no and prostacyclin through prcp - dependent pathways may be detrimental and eventually responsible for cardiovascular diseases such as congestive heart disease .
since bk and prostaglandins exacerbate the genesis of the symptoms of exercise intolerance in heart failure,23 the inhibitors of prcp might be effective in ameliorating the exercise - limiting symptoms .
clinical studies demonstrate that prcp is involved in the pathogenesis of inflammatory conditions such as rheumatoid arthritis and infection.24 melanocortin peptides have numerous effects on the host such as the modulation of fever , inflammation and appetite.25 recently , we showed that prcp metabolizes alpha - melanocyte - stimulating hormone 113 ( -msh113 ) to alpha - melanocyte - stimulating hormone 112 ( -msh112),26 ( figure 1 ) .
-msh113 is a potent anti - inflammatory agent.27 in addition to the specificity of cleavage , the cellular release of pro - inflammatory mediators seemed to be critical to prcp actions . in theory
, agents that increase production and effects of -msh113 could be used to counteract the effects of pro - inflammatory mediators such as bradykinin and cytokines ( figure 1 ) .
obesity is known to cause inflammation and insulin resistance in the vasculature and non - vascular tissues involved in glucose metabolism.28 evidence suggests that hyperglycemia may contribute to defective no - dependent vasodilation in diabetes.29 the inducible no synthase ( inos ) expression is elevated in adipose tissue of obese people compared to those of lean people30 and is a mediator of inflammation and a key enzyme in insulin resistance.31 the colocalization of -msh113 receptors ( mc4r ) with inos has been reported , suggesting a role for -msh113 in obese people.32 the inactivation of -msh113 by prcp provides a positive feedback loop for postprandial enhancement of food intake and inflammation by inhibiting -msh113 function , as shown in figure 2.26 since prcp regulates the anorectic action of -msh113 , this study highlights the presence of a newly recognized interaction between inflammation , obesity , and the expression and activity of prcp ( figure 2).26 in view of the above studies , we consider that prcp may be a key player in the obesity - associated metabolic complications , inflammatory response , and the host defense mechanism .
the following sections emphasize pertinent findings , which best describe the theoretical perspective on the components of the central melanocortin system and stress the importance of prcp influence in the melanogenic signaling pathway .
pro - opiomelanocortin ( pomc ) , a prohormone with molecular weight of 31 kda , is ubiquitously expressed in various tissues of mammals.33,34 pomc expression in the central nervous system , however , is limited to the arcuate nucleus of the hypothalamus ( arc ) , nucleus tractus solitarius of the caudal medulla ( nts ) , and corticotrophs and melanotrophs of the anterior pituitary ( figure 2).35 the 1200 base pair pomc transcript encodes for the 267 amino acid prohormone with an n - terminal signal peptide of 26 residues.36 as this precursor peptide passes through the golgi stacks , it is targeted , via a specific signal peptide , into regulated secretory granules.37 pomc undergoes extensive posttranslational modification within these secretory granules mediated by a family of serine proteases , the prohormone convertases ( pcs ) , as illustrated in figure 3 .
pomc is cleaved by prohormone convertase 1 ( pc1 ) to produce 22 kda pro - acth and -lipoprotein hormone ( -lph ) ( figure 3).38 pro - acth is further cleaved by pc1 to produce the n - terminus of pomc - joining peptide and 4.5 kda acth .
prohormone convertase 2 ( pc2 ) cleaves acth to acth 117 and corticotropin - like intermediate lobe peptide ( clip ) and -lph to -lipoprotein hormone ( -lph ) and
the synthesis of -msh from pomc involves several specific enzymes in addition to pc1 and pc2 .
first , carboxypeptidase e cleaves the c - terminal basic amino acid residues of acth 117 .
the peptide is then amidated by peptidyl -amidating monooxygenase ( pam ) to produce desacetyl -msh ( des--msh ) .
finally , des--msh is acetylated by n - acetyltransferase ( nat ) to produce acetylated -msh ( act--msh ) , as illustrated in figure 2 .
act--msh is more potent than des--msh in activating melanocortin receptor signaling and in reducing food intake , effects that are likely due to rapid degradation of des--msh .
guo et al have shown that total hypothalamic -msh levels are decreased in leptin - deficient ob / ob mice and increased in leptin - treated ob / ob and c57bl/6j mice .
leptin specifically enhances hypothalamic levels of act--msh without significantly affecting the amounts of des--msh , possibly by activating nat in the pomc neurons.39 the melanocortin receptors are g - protein - coupled receptors with characteristic seven transmembrane domains .
mc5r.4043 the melanocortin receptors are gs - coupled and signal via the adenylate cyclase - camp - protein kinase a second messenger pathway . however , depending on the cell type and the melanocortin receptor expression , signal transduction pathways other than camp may be activated which include inositol triphosphate - diacyl glycerol - protein kinase c ( ip3-dag - pkc ) pathway , extracellular ca influx , map kinase pathway , and the jak / stat pathway.4448 mc1r , mc3r , mc4r and mc5r show 40%60% amino acid homology .
the natural msh peptides have a conserved sequence , his - phe - arg - trp , which plays an important role in the binding of these peptides to specific melanocortin receptors.49 mc1r was the first melanocortin receptor to be cloned and was isolated from human melanoma cell line.40 - , - and -msh and acth are the known agonists whereas agouti is the known antagonist of the mc1r .
mc1r is expressed in human and mouse melanoma cells , human melanocytes , skin glands , and hair follicles.40,5053 -msh , agouti , and mc1r , therefore , play an important role in regulating skin pigmentation and hair color .
the presence of mc1r in the testes and the pituitary has been demonstrated by chhajlani et al.54 mc1r expression in the central nervous system is limited to neurons of the periaqueductal grey in both rat and human brain.55 however , mc1r is widely expressed in cells involved in inflammation such as endothelial cells , neutrophils , monocytes , macrophages , fibroblasts and astrocytes.25,5659 -msh has been shown to inhibit inflammation via mc1r - mediated decrease in the production of inflammatory cytokines such as il-1 , il-6 , and tumor necrosis factor - alpha ( tnf ) , as well as suppression of nf-b.6062 mc2r is encoded by a single gene localized to chromosome 18p11.2.53 acth is the only known agonist of the mc2r.63 using in situ hybridization , xia et al showed that mc2r is highly expressed in the adrenal cortex with the highest expression in the zona fasciculata and zona glomerulosa and relatively low expression in the zona reticularis.64 these findings are consistent with the role of mc2r in mediating the effect of acth on the synthesis and release of corticosteroids .
besides the adrenal cortex , mc2r is expressed in murine adipocytes , which explains the lipolytic effect of acth.59 however , human adipocytes do not express mc2r and there is no evidence to suggest that human adipose tissue is responsive to the lipolytic effect of acth.54 these species differences in the expression of mc2r may be important when studying the role of melanocortins in obesity .
mc2r expression has also been demonstrated in the skin along with three cytochrome enzymes involved in steroid hormone synthesis.65 kapas et al have shown that acth produced in the skin by keratinocytes stimulates dna synthesis and induces cell proliferation via mc2r.66 mc2r , therefore , appears to play an important role in cutaneous pathophysiology .
mc3r is encoded by a single gene localized to the q13.2q13.3 region of chromosome 20.67 since this locus is associated with type 2 noninsulin - dependent diabetes mellitus ( niddm ) , mc3r could represent a candidate gene for niddm.68 mc3r is unique in that it binds to - , - and -msh with similar affinities . using northern blot hybridization and polymerase chain reaction , gantz et al first showed that mc3r is expressed in brain , placental , and gut tissues but not in melanoma cells or in adrenal glands.69 mc3r expression in the brain is highest in the hypothalamus especially in the arcuate nucleus , ventromedial nucleus , preoptic nucleus , lateral hypothalamic area , and posterior hypothalamic area.43 agouti - related protein ( agrp ) , which is normally expressed in the hypothalamus , is a potent antagonist of both mc3r and mc4r.70 however , pomc and agrp neurons in the arcuate nucleus of hypothalamus selectively express mc3r , and not mc4r , suggesting that mc3r might function as a presynaptic autoreceptor regulating the release of melanocortins.71,72 physiological support for this hypothesis was provided by cowley et al,73 who demonstrated that the selective mc3r agonist , d - trp--msh inhibited firing of gfp - labeled pomc neurons in the pvn . also , marks et al showed that peripheral administration of the mc3r agonist stimulates feeding via mc3r - mediated inhibition of the arc pomc neurons.74 an association between mc3r and human obesity has been identified by linkage studies .
several sequence variants have been found in the mc3r coding region and in 5 flanking sequences.75 mc3r variants are associated with subtle changes in weight , leptin levels , and insulin - glucose ratios , but none of these explain human morbid obesity.76 a novel heterozygous mutation i183n in mc3r was identified in two obese patients of the same family.77 functional characterization of i183n showed that this mutation completely abolished the activity of the mutated receptor to stimulate intracellular camp production , suggesting that i183n might play an important role in obesity.78 similarly , tao et al showed that a novel mutation i335s in mc3r results in complete loss of ligand binding and signaling suggesting that this mutation might contribute to obesity.79 however , a recent study evaluating the functional consequences of all mutations found in mc3r and mc4r in severely obese north american adults concluded that mc4r , but not mc3r mutations are associated with severe obesity in this population.80 thus , the significance of mc3r mutations in human obesity is still not conclusively established to date .
mc4r was first cloned by gantz et al in 1993.42 mc4r is a 332 amino acid protein encoded by a single gene , localized to chromosome 18q21.3 . using northern blot analysis and in situ hybridization , mc4r
mc4r expression was notably absent in the adrenal cortex , melanocytes , and placenta.42 mc4r is widely distributed in the central nervous system , especially in the cortex , hippocampus , amygdala , septum , corpus striatum , nucleus accumbens , hypothalamus , nucleus tractus solitarius , visual and motor nuclei of the brainstem , and the dorsal horn of the spinal cord.81 -msh , -msh , and acth are the known agonists and agrp is the known antagonist of the mc4r ( figure 2).70 since mc4r is highly expressed in the hypothalamus and has a strong affinity for -msh it is believed to be a strong candidate for energy balance , appetite control , and body weight regulation .
mc4r knockout mice have been shown to develop a maturity onset obesity syndrome characterized by hyperphagia , hyperglycemia and hyperinsulinemia.82 since this syndrome is similar to the agouti obesity syndrome seen in avy/ mice and agrp - transgenic mice that overexpress agouti and agrp respectively , it is speculated that the primary mechanism by which agouti and agrp produce obesity is chronic antagonism of mc4r.83 cachexia , a chronic wasting syndrome characterized by loss of body weight and muscle mass , is commonly associated with diseases such as cancer and aids .
mc4r mice and mice treated with agrp are resistant to lipopolysaccharide- or tumor - induced cachexia , further supporting the role of mc4r in energy balance and body weight regulation.84 mc5r is a 325 amino acid protein encoded by a single gene located on chromosome 18p11.2.85 mc5r has been shown to bind to all melanocortins except -msh.86 mc5r is the most widely expressed melanocortin receptor .
mc5r mrna is expressed in the adrenal gland , adipose tissue , kidney , leukocytes , lung , lymph node , mammary gland , ovary , pituitary , testis , and uterus.54 mc5r is highly expressed in exocrine glands such as lacrimal , preputial , harderian and sebaceous glands.87 mc5r - deficient mice have a severe defect in water repulsion and thermoregulation due to decreased production of sebaceous lipids .
studies in humans have shown that mc5r immunoreactivity is detectable in the epithelium and appendages , including the sebaceous , eccrine , and apocrine glands . however ,
analysis of mc5r variations in patients with acne , hidradenitis suppurativa , and sebaceous gland dysfunction have failed to suggest a causative role of mc5r in these conditions.88 low levels of mc5r mrna have also been reported in the central nervous system,89 however , the physiological function of mc5r in the brain remains unclear .
linkage analysis in the quebec family study90 revealed a significant association of mc5r polymorphisms with body mass index , fat mass , and resting metabolic rate , thus providing some evidence for the possible role of mc5r in energy balance and body weight regulation .
the pomc neurons , which produce -msh , also express another anorectic peptide cocaine - amphetamine - related transcript ( cart ) .
cell bodies of the pomc / cart neurons are found throughout the rostrocaudal extent of the arcuate nucleus , as well as the periarcuate area of the hypothalamus . within the hypothalamus ,
these neurons project to the periventricular nucleus , paraventricular nucleus ( pvh ) , and the perifornical region.91,92 the pomc / cart neurons also project to the brainstem to innervate the rostral nts , lateral reticular nucleus , ventrolateral medulla , nucleus ambiguous , and the spinal cord , as reviewed elsewhere.93 another critical component of the central melanocortin system within the arc is the neurons expressing neuropeptide y ( npy ) and the potent mc3r / mc4r antagonist agrp ( figure 2 ) .
the npy / agrp neurons have the same distribution as the pomc / cart neurons within the hypothalamus , with the densest fibers innervating the pvh , dorsomedial hypothalamus ( dmh ) , posterior hypothalamus , and septal regions around the anterior commissure.94 the npy / agrp neurons form synapses with the pomc / cart neurons within the arc , thus producing a neuronal network that is responsive to the modulatory effects of several appetite and body weight regulating hormones such as leptin , ghrelin , insulin , and peptide yy ( pyy).73,9598 leptin acts via hypothalamic receptors ( ob - r ) to decrease feeding and increase thermogenesis , resulting in a decrease in body weight . pomc / cart and npy / agrp neurons in the arc are the principal sites of leptin receptor expression and the source of potent neuropeptide hormones , -msh and npy , which exert opposing effects on feeding and metabolism as shown in figure 2 .
subpopulations of npy / agrp neurons that also express gamma - aminobutyric acid ( gaba ) send inhibitory collaterals to the pomc / cart neurons .
gaba inhibits the pomc / cart neurons and blocks the anorexic effect of -msh ( figure 2).99 using electrophysiological techniques , cowley et al showed that leptin stimulates the pomc / cart neurons via two mechanisms : 1 ) depolarization through a nonspecific cation channel and 2 ) hyperpolarization of npy / agrp neurons , leading to a reduction in the release of gaba that , in turn , causes disinhibition of the pomc / cart neurons ( figure 2).73 ghrelin , the endogenous ligand for growth hormone secretagogue receptor ( ghs - r ) , is a potent stimulant of growth hormone release and plays an important role in appetite control and body weight regulation . circulating ghrelin levels
are markedly increased with fasting and before meals and decrease following meals.100,101 plasma ghrelin levels are also influenced by long - term energy balance and are increased in anorexia and decreased in obesity.102,103 within the arc , gsh - r is expressed on the npy / agrp neurons which are thought to mediate the orexigenic effects of ghrelin .
central and peripheral administration of ghrelin induces c - fos in these neurons and increases hypothalamic npy and agrp mrna expression , thus antagonizing the anorexic effects of leptin.95,98,104 also , electrophysiological studies have shown that ghrelin directly activates the orexigenic npy / agrp neurons while coordinately inhibiting the anorexogenic pomc / cart neurons via increased gaba release on them ( figure 2).105 stimulation of food intake by ghrelin is blocked by administration of npy antagonist and is reduced in npy mice.95
lastly , mc3r and mc4r knockout mice show reduced sensitivity to ghrelin as evidenced by decreased ghrelin - induced food intake and growth hormone secretion , thus suggesting an important role of mc3r and mc4r in mediating the orexigenic effects of ghrelin.106 npy is a potent hypothalamic orexigenic peptide , probably the most powerful stimulant of appetite known .
nyp mrna expression in the hypothalamus is significantly increased during lactation and fasting.107 central administration of npy causes robust increase in food intake and body weight in rats.108,109 chronic intracerebroventricular administration of npy to normal rats produces hyperphagia , hyperinsulinemia , and liver and adipose tissue lipogenesis , thus mimicking the hormonal and metabolic changes of obesity.110 recent evidence suggests that ectopic overexpression of npy in other areas of the hypothalamus such as pvh , lateral hypothalamus , and dmh also increases food intake and body weight and that npy knockdown in the dmh ameliorates the hyperphagia , obesity , and diabetes of otsuka long - evans tokushima fatty ( oletf ) rats.111,112 thus , npy in the hypothalamus plays an important role in modulating food intake and body weight ( figure 2 ) .
npy exerts its orexigenic effects probably by inhibiting the arc pomc / cart neurons via its y2 receptor.113 npy is metabolized by several peptidases in the plasma .
recent evidence suggests that npy(136 ) is metabolized into three major fragments : npy(336 ) , npy(335 ) , and npy(235 ) , upon incubation with human serum.114 specific inhibitors of dipeptidyl peptidase 4 , plasma kallikrein , and aminopeptidase p prevent the production of npy(336 ) , npy(335 ) , and npy(236 ) , respectively .
plasma kallikrein metabolizes npy(336 ) to npy(335 ) . since npy(335 ) is unable to bind to npy y1 , y2 , and y5 receptors , npy(335 ) may represent the major metabolic end product of the y2/y5 agonist , npy(336 ) .
a recent study identified two splice variants of prcp ; the second isoform was named prcp2 ( ncbi : nm_199418 ) . unlike prcp , prcp2 has a longer transcript and a unique amino - terminal region .
although its full - length sequence is known , there is no evidence suggesting whether prcp2 mrna encodes a functional protein.24 the prcp gene is speculated to be a candidate gene for essential hypertension.115 mutational analysis of the human prcp has led to a better understanding of prcp - catalyzed reactions .
certain putative mutant forms of human prcp apparently predispose the polymorphic carriers to cardiovascular diseases including hypertension and the risk of preeclampsia.116 the e112d polymorphism in the prcp gene leads to increased antihypertensive effect of benazepril treatment in hypertensive patients.117 we have also demonstrated that prcp mice have mild hypertension.20 our recent studies demonstrated that the prcp - null ( prcp ) mice ate less and had even less fat than the mice with partial loss of the enzyme.26 these observations suggest that prcp is a genetic marker for weight regulation and putative prcp single nucleotide polymorphism ( snp ) variants are associated with mild hypertension .
continued identification of prcp mutations , full - characterization of prcp knockout mice , and studies with knock - in mice with prcp / prcp mutations will provide evidence that prcp is a disease - causing gene for both obesity and hypertension .
meanwhile , we propose that the use of prcp inhibitors should be strongly indicated by a diagnosis of obesity in patients with no systolic or diastolic deterioration .
the prcp - catalyzed reaction was initially found to be part of the pathway for angiotensin ii ( ang ii ) metabolism in renal tissues , where prcp appeared to control the total amount of ang ii .
odya and others demonstrated that prcp metabolizes ang ii to angiotensin 17 ( ang 17 ) ( figure 1).7 the activation of ang 17 receptor mas ( a g - protein - coupled protein ) by ang 17 results in the generation of nitric oxide ( no ) and prostaglandins.8 thus , ang 17 counteracts ang ii function , providing evidence that prcp regulates the negative effects of ang ii such as high blood pressure and heart failure.9 in addition , the activation of the ang 17 receptor mas may also lead to diminished cell proliferation through down - regulation of the phosphorylation and activation of erk1 and erk2 in the erk1/erk2 map kinase signaling pathway.10,11 in theory , the prcp inhibitors to target the production of pro - inflammatory prostaglandins and promote proliferation through the ang 17 receptor mas - dependent pathway represent a novel approach to suppress unwanted inflammation - causing prostaglandins .
later , it was shown that prcp is one of several enzymes that convert ang ii to a unique bioactive molecule . in vitro studies showed that angiotensin - converting enzyme 2 ( ace2 ) is an exopeptidase that converts ang ii to ang 17 at a much faster rate than prcp.12 these data suggest that ang ii is a poor substrate for prcp .
clinical studies have provided reliable evidence that ace2 is an essential regulator of angiotensin i ( ang i ) , ang ii , and angiotensin - induced cardiac hypertrophy.13 recent studies clearly show increased myocardial levels of ang ii and a significant decrease in ang 17 in ace2-deficient hearts , suggesting that the role of prcp in metabolizing ang ii may be insignificant.9 taken together , these observations suggest that prcp is a redundant catalyst contributing to alternate pathways for ang ii metabolism . while the well - established cardiovascular and renal actions of ang ii are attributed to the angiotensin type 1 receptor ( at1r ) , much less is known about angiotensin iii and its cardiovascular effects . for more than 30 years
, it was known that prcp metabolizes ang iii to ang 27 ( figure 1).7 soon after , studies demonstrated that ang iii is a pressor agent whose response , like that of ang ii , is mediated by at1 receptors.14,15 apparently , ang iii has multiple effects on renal function in the diseased kidney and can enhance renal disease through the overproduction of aldosterone , leading to arterial hypertension and/or atrial fibrillation.16 aldosterone maintains blood volume , pressure , and electrolyte balance .
its production is known to be regulated by renin , an enzyme produced in the kidneys .
renin increases in response to low blood pressure , decreased blood flow to the kidneys , or sodium deficiency . the elevation of renin results in an increase in synthesis and secretion of aldosterone .
studies indicate that ang iii also activates the secretion of aldosterone.15 recently , we have demonstrated that recombinant prcp ( rpcrp ) metabolizes ang iii to ang 27 , removing phenylalanine ( phe).8 it is tempting to speculate that prcp might funnel the generation of angiotensin 34 ( ang 34 ) through ang 27 ( figure 1 ) .
if the over - secretion of aldosterone by ang iii is viewed as a trigger of arterial hypertension , then inactivation of ang iii by prcp might lead to a decrease in blood pressure .
further studies are required to determine whether prcp is critically important for regulating ang iii - induced hypertension and preserving renal structure and function .
this is an important area of research to pursue given the increasing prevalence of cardiovascular disease and stroke in the older population .
the possible actions of another substrate of prcp , plasma prekallikrein ( pk , fletcher factor ) , have recently begun to receive much attention .
when the complex of high molecular weight kininogen ( hk ) and pk binds to endothelial membrane , pk is rapidly converted to kallikrein by prcp.17 the formed kallikrein then cleaves hk to liberate bradykinin ( bk ) , which leads to no and prostaglandin - i2 formation , as well as subsequent vasodilation , by activating constitutive bradykinin b2 and inducible bradykinin b1 receptors.18,19 the prcp - dependent pk activation pathway might be considered an additional mechanism to preserve the availability of no and prostacyclin as vasodilatory agents in vascular smooth muscle .
, we have found that prcp mice have mild hypertension , suggesting a causative relationship between prcp levels and signs of hypertension.20 local skeletal muscle ischemia and acidosis are shown to increase the generation of bk and prostaglandins , the two circulating products of the prcp - induced cell activation ( figure 1).21 the increased acidotic response during exercise and inflammatory mediators such as bk and prostacyclin have been shown to cause abnormal exercise - related symptoms and autonomic responses in congestive heart failure syndrome.22 nonetheless , the long - term elevated concentrations of no and prostacyclin through prcp - dependent pathways may be detrimental and eventually responsible for cardiovascular diseases such as congestive heart disease .
since bk and prostaglandins exacerbate the genesis of the symptoms of exercise intolerance in heart failure,23 the inhibitors of prcp might be effective in ameliorating the exercise - limiting symptoms .
clinical studies demonstrate that prcp is involved in the pathogenesis of inflammatory conditions such as rheumatoid arthritis and infection.24 melanocortin peptides have numerous effects on the host such as the modulation of fever , inflammation and appetite.25 recently , we showed that prcp metabolizes alpha - melanocyte - stimulating hormone 113 ( -msh113 ) to alpha - melanocyte - stimulating hormone 112 ( -msh112),26 ( figure 1 ) .
-msh113 is a potent anti - inflammatory agent.27 in addition to the specificity of cleavage , the cellular release of pro - inflammatory mediators seemed to be critical to prcp actions . in theory
, agents that increase production and effects of -msh113 could be used to counteract the effects of pro - inflammatory mediators such as bradykinin and cytokines ( figure 1 ) .
obesity is known to cause inflammation and insulin resistance in the vasculature and non - vascular tissues involved in glucose metabolism.28 evidence suggests that hyperglycemia may contribute to defective no - dependent vasodilation in diabetes.29 the inducible no synthase ( inos ) expression is elevated in adipose tissue of obese people compared to those of lean people30 and is a mediator of inflammation and a key enzyme in insulin resistance.31 the colocalization of -msh113 receptors ( mc4r ) with inos has been reported , suggesting a role for -msh113 in obese people.32 the inactivation of -msh113 by prcp provides a positive feedback loop for postprandial enhancement of food intake and inflammation by inhibiting -msh113 function , as shown in figure 2.26 since prcp regulates the anorectic action of -msh113 , this study highlights the presence of a newly recognized interaction between inflammation , obesity , and the expression and activity of prcp ( figure 2).26 in view of the above studies , we consider that prcp may be a key player in the obesity - associated metabolic complications , inflammatory response , and the host defense mechanism .
the following sections emphasize pertinent findings , which best describe the theoretical perspective on the components of the central melanocortin system and stress the importance of prcp influence in the melanogenic signaling pathway .
pro - opiomelanocortin ( pomc ) , a prohormone with molecular weight of 31 kda , is ubiquitously expressed in various tissues of mammals.33,34 pomc expression in the central nervous system , however , is limited to the arcuate nucleus of the hypothalamus ( arc ) , nucleus tractus solitarius of the caudal medulla ( nts ) , and corticotrophs and melanotrophs of the anterior pituitary ( figure 2).35 the 1200 base pair pomc transcript encodes for the 267 amino acid prohormone with an n - terminal signal peptide of 26 residues.36 as this precursor peptide passes through the golgi stacks , it is targeted , via a specific signal peptide , into regulated secretory granules.37 pomc undergoes extensive posttranslational modification within these secretory granules mediated by a family of serine proteases , the prohormone convertases ( pcs ) , as illustrated in figure 3 .
pomc is cleaved by prohormone convertase 1 ( pc1 ) to produce 22 kda pro - acth and -lipoprotein hormone ( -lph ) ( figure 3).38 pro - acth is further cleaved by pc1 to produce the n - terminus of pomc - joining peptide and 4.5 kda acth .
prohormone convertase 2 ( pc2 ) cleaves acth to acth 117 and corticotropin - like intermediate lobe peptide ( clip ) and -lph to -lipoprotein hormone ( -lph ) and
the synthesis of -msh from pomc involves several specific enzymes in addition to pc1 and pc2 .
first , carboxypeptidase e cleaves the c - terminal basic amino acid residues of acth 117 .
the peptide is then amidated by peptidyl -amidating monooxygenase ( pam ) to produce desacetyl -msh ( des--msh ) .
finally , des--msh is acetylated by n - acetyltransferase ( nat ) to produce acetylated -msh ( act--msh ) , as illustrated in figure 2 .
act--msh is more potent than des--msh in activating melanocortin receptor signaling and in reducing food intake , effects that are likely due to rapid degradation of des--msh .
guo et al have shown that total hypothalamic -msh levels are decreased in leptin - deficient ob / ob mice and increased in leptin - treated ob / ob and c57bl/6j mice .
leptin specifically enhances hypothalamic levels of act--msh without significantly affecting the amounts of des--msh , possibly by activating nat in the pomc neurons.39 the melanocortin receptors are g - protein - coupled receptors with characteristic seven transmembrane domains .
mc5r.4043 the melanocortin receptors are gs - coupled and signal via the adenylate cyclase - camp - protein kinase a second messenger pathway .
however , depending on the cell type and the melanocortin receptor expression , signal transduction pathways other than camp may be activated which include inositol triphosphate - diacyl glycerol - protein kinase c ( ip3-dag - pkc ) pathway , extracellular ca influx , map kinase pathway , and the jak / stat pathway.4448 mc1r , mc3r , mc4r and mc5r show 40%60% amino acid homology .
the natural msh peptides have a conserved sequence , his - phe - arg - trp , which plays an important role in the binding of these peptides to specific melanocortin receptors.49 mc1r was the first melanocortin receptor to be cloned and was isolated from human melanoma cell line.40 - , - and -msh and acth are the known agonists whereas agouti is the known antagonist of the mc1r .
mc1r is expressed in human and mouse melanoma cells , human melanocytes , skin glands , and hair follicles.40,5053 -msh , agouti , and mc1r , therefore , play an important role in regulating skin pigmentation and hair color .
the presence of mc1r in the testes and the pituitary has been demonstrated by chhajlani et al.54 mc1r expression in the central nervous system is limited to neurons of the periaqueductal grey in both rat and human brain.55 however , mc1r is widely expressed in cells involved in inflammation such as endothelial cells , neutrophils , monocytes , macrophages , fibroblasts and astrocytes.25,5659 -msh has been shown to inhibit inflammation via mc1r - mediated decrease in the production of inflammatory cytokines such as il-1 , il-6 , and tumor necrosis factor - alpha ( tnf ) , as well as suppression of nf-b.6062 mc2r is encoded by a single gene localized to chromosome 18p11.2.53 acth is the only known agonist of the mc2r.63 using in situ hybridization , xia et al showed that mc2r is highly expressed in the adrenal cortex with the highest expression in the zona fasciculata and zona glomerulosa and relatively low expression in the zona reticularis.64 these findings are consistent with the role of mc2r in mediating the effect of acth on the synthesis and release of corticosteroids . besides the adrenal cortex , mc2r is expressed in murine adipocytes , which explains the lipolytic effect of acth.59 however , human adipocytes do not express mc2r and there is no evidence to suggest that human adipose tissue is responsive to the lipolytic effect of acth.54 these species differences in the expression of mc2r may be important when studying the role of melanocortins in obesity .
mc2r expression has also been demonstrated in the skin along with three cytochrome enzymes involved in steroid hormone synthesis.65 kapas et al have shown that acth produced in the skin by keratinocytes stimulates dna synthesis and induces cell proliferation via mc2r.66 mc2r , therefore , appears to play an important role in cutaneous pathophysiology .
mc3r is encoded by a single gene localized to the q13.2q13.3 region of chromosome 20.67 since this locus is associated with type 2 noninsulin - dependent diabetes mellitus ( niddm ) , mc3r could represent a candidate gene for niddm.68 mc3r is unique in that it binds to - , - and -msh with similar affinities . using northern blot hybridization and polymerase chain reaction , gantz et al first showed that mc3r is expressed in brain , placental , and gut tissues but not in melanoma cells or in adrenal glands.69 mc3r expression in the brain is highest in the hypothalamus especially in the arcuate nucleus , ventromedial nucleus , preoptic nucleus , lateral hypothalamic area , and posterior hypothalamic area.43 agouti - related protein ( agrp ) , which is normally expressed in the hypothalamus , is a potent antagonist of both mc3r and mc4r.70 however , pomc and agrp neurons in the arcuate nucleus of hypothalamus selectively express mc3r , and not mc4r , suggesting that mc3r might function as a presynaptic autoreceptor regulating the release of melanocortins.71,72 physiological support for this hypothesis was provided by cowley et al,73 who demonstrated that the selective mc3r agonist , d - trp--msh inhibited firing of gfp - labeled pomc neurons in the pvn . also , marks et al showed that peripheral administration of the mc3r agonist stimulates feeding via mc3r - mediated inhibition of the arc pomc neurons.74 an association between mc3r and human obesity has been identified by linkage studies .
several sequence variants have been found in the mc3r coding region and in 5 flanking sequences.75 mc3r variants are associated with subtle changes in weight , leptin levels , and insulin - glucose ratios , but none of these explain human morbid obesity.76 a novel heterozygous mutation i183n in mc3r was identified in two obese patients of the same family.77 functional characterization of i183n showed that this mutation completely abolished the activity of the mutated receptor to stimulate intracellular camp production , suggesting that i183n might play an important role in obesity.78 similarly , tao et al showed that a novel mutation i335s in mc3r results in complete loss of ligand binding and signaling suggesting that this mutation might contribute to obesity.79 however , a recent study evaluating the functional consequences of all mutations found in mc3r and mc4r in severely obese north american adults concluded that mc4r , but not mc3r mutations are associated with severe obesity in this population.80 thus , the significance of mc3r mutations in human obesity is still not conclusively established to date .
mc4r was first cloned by gantz et al in 1993.42 mc4r is a 332 amino acid protein encoded by a single gene , localized to chromosome 18q21.3 . using northern blot analysis and in situ hybridization ,
mc4r expression was notably absent in the adrenal cortex , melanocytes , and placenta.42 mc4r is widely distributed in the central nervous system , especially in the cortex , hippocampus , amygdala , septum , corpus striatum , nucleus accumbens , hypothalamus , nucleus tractus solitarius , visual and motor nuclei of the brainstem , and the dorsal horn of the spinal cord.81 -msh , -msh , and acth are the known agonists and agrp is the known antagonist of the mc4r ( figure 2).70 since mc4r is highly expressed in the hypothalamus and has a strong affinity for -msh it is believed to be a strong candidate for energy balance , appetite control , and body weight regulation .
mc4r knockout mice have been shown to develop a maturity onset obesity syndrome characterized by hyperphagia , hyperglycemia and hyperinsulinemia.82 since this syndrome is similar to the agouti obesity syndrome seen in avy/ mice and agrp - transgenic mice that overexpress agouti and agrp respectively , it is speculated that the primary mechanism by which agouti and agrp produce obesity is chronic antagonism of mc4r.83 cachexia , a chronic wasting syndrome characterized by loss of body weight and muscle mass , is commonly associated with diseases such as cancer and aids .
mc4r mice and mice treated with agrp are resistant to lipopolysaccharide- or tumor - induced cachexia , further supporting the role of mc4r in energy balance and body weight regulation.84 mc5r is a 325 amino acid protein encoded by a single gene located on chromosome 18p11.2.85 mc5r has been shown to bind to all melanocortins except -msh.86 mc5r is the most widely expressed melanocortin receptor .
mc5r mrna is expressed in the adrenal gland , adipose tissue , kidney , leukocytes , lung , lymph node , mammary gland , ovary , pituitary , testis , and uterus.54 mc5r is highly expressed in exocrine glands such as lacrimal , preputial , harderian and sebaceous glands.87 mc5r - deficient mice have a severe defect in water repulsion and thermoregulation due to decreased production of sebaceous lipids .
studies in humans have shown that mc5r immunoreactivity is detectable in the epithelium and appendages , including the sebaceous , eccrine , and apocrine glands .
however , analysis of mc5r variations in patients with acne , hidradenitis suppurativa , and sebaceous gland dysfunction have failed to suggest a causative role of mc5r in these conditions.88 low levels of mc5r mrna have also been reported in the central nervous system,89 however , the physiological function of mc5r in the brain remains unclear .
linkage analysis in the quebec family study90 revealed a significant association of mc5r polymorphisms with body mass index , fat mass , and resting metabolic rate , thus providing some evidence for the possible role of mc5r in energy balance and body weight regulation .
the pomc neurons , which produce -msh , also express another anorectic peptide cocaine - amphetamine - related transcript ( cart ) .
cell bodies of the pomc / cart neurons are found throughout the rostrocaudal extent of the arcuate nucleus , as well as the periarcuate area of the hypothalamus . within the hypothalamus ,
these neurons project to the periventricular nucleus , paraventricular nucleus ( pvh ) , and the perifornical region.91,92 the pomc / cart neurons also project to the brainstem to innervate the rostral nts , lateral reticular nucleus , ventrolateral medulla , nucleus ambiguous , and the spinal cord , as reviewed elsewhere.93 another critical component of the central melanocortin system within the arc is the neurons expressing neuropeptide y ( npy ) and the potent mc3r / mc4r antagonist agrp ( figure 2 ) .
the npy / agrp neurons have the same distribution as the pomc / cart neurons within the hypothalamus , with the densest fibers innervating the pvh , dorsomedial hypothalamus ( dmh ) , posterior hypothalamus , and septal regions around the anterior commissure.94 the npy / agrp neurons form synapses with the pomc / cart neurons within the arc , thus producing a neuronal network that is responsive to the modulatory effects of several appetite and body weight regulating hormones such as leptin , ghrelin , insulin , and peptide yy ( pyy).73,9598 leptin acts via hypothalamic receptors ( ob - r ) to decrease feeding and increase thermogenesis , resulting in a decrease in body weight .
pomc / cart and npy / agrp neurons in the arc are the principal sites of leptin receptor expression and the source of potent neuropeptide hormones , -msh and npy , which exert opposing effects on feeding and metabolism as shown in figure 2 .
subpopulations of npy / agrp neurons that also express gamma - aminobutyric acid ( gaba ) send inhibitory collaterals to the pomc / cart neurons .
gaba inhibits the pomc / cart neurons and blocks the anorexic effect of -msh ( figure 2).99 using electrophysiological techniques , cowley et al showed that leptin stimulates the pomc / cart neurons via two mechanisms : 1 ) depolarization through a nonspecific cation channel and 2 ) hyperpolarization of npy / agrp neurons , leading to a reduction in the release of gaba that , in turn , causes disinhibition of the pomc / cart neurons ( figure 2).73 ghrelin , the endogenous ligand for growth hormone secretagogue receptor ( ghs - r ) , is a potent stimulant of growth hormone release and plays an important role in appetite control and body weight regulation .
circulating ghrelin levels are markedly increased with fasting and before meals and decrease following meals.100,101 plasma ghrelin levels are also influenced by long - term energy balance and are increased in anorexia and decreased in obesity.102,103 within the arc , gsh - r is expressed on the npy / agrp neurons which are thought to mediate the orexigenic effects of ghrelin .
central and peripheral administration of ghrelin induces c - fos in these neurons and increases hypothalamic npy and agrp mrna expression , thus antagonizing the anorexic effects of leptin.95,98,104 also , electrophysiological studies have shown that ghrelin directly activates the orexigenic npy / agrp neurons while coordinately inhibiting the anorexogenic pomc / cart neurons via increased gaba release on them ( figure 2).105 stimulation of food intake by ghrelin is blocked by administration of npy antagonist and is reduced in npy mice.95
lastly , mc3r and mc4r knockout mice show reduced sensitivity to ghrelin as evidenced by decreased ghrelin - induced food intake and growth hormone secretion , thus suggesting an important role of mc3r and mc4r in mediating the orexigenic effects of ghrelin.106 npy is a potent hypothalamic orexigenic peptide , probably the most powerful stimulant of appetite known .
nyp mrna expression in the hypothalamus is significantly increased during lactation and fasting.107 central administration of npy causes robust increase in food intake and body weight in rats.108,109 chronic intracerebroventricular administration of npy to normal rats produces hyperphagia , hyperinsulinemia , and liver and adipose tissue lipogenesis , thus mimicking the hormonal and metabolic changes of obesity.110 recent evidence suggests that ectopic overexpression of npy in other areas of the hypothalamus such as pvh , lateral hypothalamus , and dmh also increases food intake and body weight and that npy knockdown in the dmh ameliorates the hyperphagia , obesity , and diabetes of otsuka long - evans tokushima fatty ( oletf ) rats.111,112 thus , npy in the hypothalamus plays an important role in modulating food intake and body weight ( figure 2 ) .
npy exerts its orexigenic effects probably by inhibiting the arc pomc / cart neurons via its y2 receptor.113 npy is metabolized by several peptidases in the plasma .
recent evidence suggests that npy(136 ) is metabolized into three major fragments : npy(336 ) , npy(335 ) , and npy(235 ) , upon incubation with human serum.114 specific inhibitors of dipeptidyl peptidase 4 , plasma kallikrein , and aminopeptidase p prevent the production of npy(336 ) , npy(335 ) , and npy(236 ) , respectively .
plasma kallikrein metabolizes npy(336 ) to npy(335 ) . since npy(335 ) is unable to bind to npy y1 , y2 , and y5 receptors , npy(335 ) may represent the major metabolic end product of the y2/y5 agonist , npy(336 ) .
a recent study identified two splice variants of prcp ; the second isoform was named prcp2 ( ncbi : nm_199418 ) . unlike prcp , prcp2 has a longer transcript and a unique amino - terminal region .
although its full - length sequence is known , there is no evidence suggesting whether prcp2 mrna encodes a functional protein.24 the prcp gene is speculated to be a candidate gene for essential hypertension.115 mutational analysis of the human prcp has led to a better understanding of prcp - catalyzed reactions .
certain putative mutant forms of human prcp apparently predispose the polymorphic carriers to cardiovascular diseases including hypertension and the risk of preeclampsia.116 the e112d polymorphism in the prcp gene leads to increased antihypertensive effect of benazepril treatment in hypertensive patients.117 we have also demonstrated that prcp mice have mild hypertension.20 our recent studies demonstrated that the prcp - null ( prcp ) mice ate less and had even less fat than the mice with partial loss of the enzyme.26 these observations suggest that prcp is a genetic marker for weight regulation and putative prcp single nucleotide polymorphism ( snp ) variants are associated with mild hypertension .
continued identification of prcp mutations , full - characterization of prcp knockout mice , and studies with knock - in mice with prcp / prcp mutations will provide evidence that prcp is a disease - causing gene for both obesity and hypertension .
meanwhile , we propose that the use of prcp inhibitors should be strongly indicated by a diagnosis of obesity in patients with no systolic or diastolic deterioration .
pro - opiomelanocortin ( pomc ) , a prohormone with molecular weight of 31 kda , is ubiquitously expressed in various tissues of mammals.33,34 pomc expression in the central nervous system , however , is limited to the arcuate nucleus of the hypothalamus ( arc ) , nucleus tractus solitarius of the caudal medulla ( nts ) , and corticotrophs and melanotrophs of the anterior pituitary ( figure 2).35 the 1200 base pair pomc transcript encodes for the 267 amino acid prohormone with an n - terminal signal peptide of 26 residues.36 as this precursor peptide passes through the golgi stacks , it is targeted , via a specific signal peptide , into regulated secretory granules.37 pomc undergoes extensive posttranslational modification within these secretory granules mediated by a family of serine proteases , the prohormone convertases ( pcs ) , as illustrated in figure 3 .
pomc is cleaved by prohormone convertase 1 ( pc1 ) to produce 22 kda pro - acth and -lipoprotein hormone ( -lph ) ( figure 3).38 pro - acth is further cleaved by pc1 to produce the n - terminus of pomc - joining peptide and 4.5 kda acth .
prohormone convertase 2 ( pc2 ) cleaves acth to acth 117 and corticotropin - like intermediate lobe peptide ( clip ) and -lph to -lipoprotein hormone ( -lph ) and
the synthesis of -msh from pomc involves several specific enzymes in addition to pc1 and pc2 .
first , carboxypeptidase e cleaves the c - terminal basic amino acid residues of acth 117 . the peptide is then amidated by peptidyl -amidating monooxygenase ( pam ) to produce desacetyl -msh ( des--msh ) .
finally , des--msh is acetylated by n - acetyltransferase ( nat ) to produce acetylated -msh ( act--msh ) , as illustrated in figure 2 .
act--msh is more potent than des--msh in activating melanocortin receptor signaling and in reducing food intake , effects that are likely due to rapid degradation of des--msh .
guo et al have shown that total hypothalamic -msh levels are decreased in leptin - deficient ob / ob mice and increased in leptin - treated ob / ob and c57bl/6j mice .
leptin specifically enhances hypothalamic levels of act--msh without significantly affecting the amounts of des--msh , possibly by activating nat in the pomc neurons.39
the melanocortin receptors are g - protein - coupled receptors with characteristic seven transmembrane domains .
mc5r.4043 the melanocortin receptors are gs - coupled and signal via the adenylate cyclase - camp - protein kinase a second messenger pathway . however , depending on the cell type and the melanocortin receptor expression , signal transduction pathways other than camp may be activated which include inositol triphosphate - diacyl glycerol - protein kinase c ( ip3-dag - pkc ) pathway , extracellular ca influx , map kinase pathway , and the jak / stat pathway.4448 mc1r , mc3r , mc4r and mc5r show 40%60% amino acid homology .
the natural msh peptides have a conserved sequence , his - phe - arg - trp , which plays an important role in the binding of these peptides to specific melanocortin receptors.49 mc1r was the first melanocortin receptor to be cloned and was isolated from human melanoma cell line.40 - , - and -msh and acth are the known agonists whereas agouti is the known antagonist of the mc1r .
mc1r is expressed in human and mouse melanoma cells , human melanocytes , skin glands , and hair follicles.40,5053 -msh , agouti , and mc1r , therefore , play an important role in regulating skin pigmentation and hair color .
the presence of mc1r in the testes and the pituitary has been demonstrated by chhajlani et al.54 mc1r expression in the central nervous system is limited to neurons of the periaqueductal grey in both rat and human brain.55 however , mc1r is widely expressed in cells involved in inflammation such as endothelial cells , neutrophils , monocytes , macrophages , fibroblasts and astrocytes.25,5659 -msh has been shown to inhibit inflammation via mc1r - mediated decrease in the production of inflammatory cytokines such as il-1 , il-6 , and tumor necrosis factor - alpha ( tnf ) , as well as suppression of nf-b.6062 mc2r is encoded by a single gene localized to chromosome 18p11.2.53 acth is the only known agonist of the mc2r.63 using in situ hybridization , xia et al showed that mc2r is highly expressed in the adrenal cortex with the highest expression in the zona fasciculata and zona glomerulosa and relatively low expression in the zona reticularis.64 these findings are consistent with the role of mc2r in mediating the effect of acth on the synthesis and release of corticosteroids .
besides the adrenal cortex , mc2r is expressed in murine adipocytes , which explains the lipolytic effect of acth.59 however , human adipocytes do not express mc2r and there is no evidence to suggest that human adipose tissue is responsive to the lipolytic effect of acth.54 these species differences in the expression of mc2r may be important when studying the role of melanocortins in obesity .
mc2r expression has also been demonstrated in the skin along with three cytochrome enzymes involved in steroid hormone synthesis.65 kapas et al have shown that acth produced in the skin by keratinocytes stimulates dna synthesis and induces cell proliferation via mc2r.66 mc2r , therefore , appears to play an important role in cutaneous pathophysiology .
mc3r is encoded by a single gene localized to the q13.2q13.3 region of chromosome 20.67 since this locus is associated with type 2 noninsulin - dependent diabetes mellitus ( niddm ) , mc3r could represent a candidate gene for niddm.68 mc3r is unique in that it binds to - , - and -msh with similar affinities . using northern blot hybridization and polymerase chain reaction , gantz et al first showed that mc3r is expressed in brain , placental , and gut tissues but not in melanoma cells or in adrenal glands.69 mc3r expression in the brain is highest in the hypothalamus especially in the arcuate nucleus , ventromedial nucleus , preoptic nucleus , lateral hypothalamic area , and posterior hypothalamic area.43 agouti - related protein ( agrp ) , which is normally expressed in the hypothalamus , is a potent antagonist of both mc3r and mc4r.70 however , pomc and agrp neurons in the arcuate nucleus of hypothalamus selectively express mc3r , and not mc4r , suggesting that mc3r might function as a presynaptic autoreceptor regulating the release of melanocortins.71,72 physiological support for this hypothesis was provided by cowley et al,73 who demonstrated that the selective mc3r agonist , d - trp--msh inhibited firing of gfp - labeled pomc neurons in the pvn .
also , marks et al showed that peripheral administration of the mc3r agonist stimulates feeding via mc3r - mediated inhibition of the arc pomc neurons.74 an association between mc3r and human obesity has been identified by linkage studies .
several sequence variants have been found in the mc3r coding region and in 5 flanking sequences.75 mc3r variants are associated with subtle changes in weight , leptin levels , and insulin - glucose ratios , but none of these explain human morbid obesity.76 a novel heterozygous mutation i183n in mc3r was identified in two obese patients of the same family.77 functional characterization of i183n showed that this mutation completely abolished the activity of the mutated receptor to stimulate intracellular camp production , suggesting that i183n might play an important role in obesity.78 similarly , tao et al showed that a novel mutation i335s in mc3r results in complete loss of ligand binding and signaling suggesting that this mutation might contribute to obesity.79 however , a recent study evaluating the functional consequences of all mutations found in mc3r and mc4r in severely obese north american adults concluded that mc4r , but not mc3r mutations are associated with severe obesity in this population.80 thus , the significance of mc3r mutations in human obesity is still not conclusively established to date .
mc4r was first cloned by gantz et al in 1993.42 mc4r is a 332 amino acid protein encoded by a single gene , localized to chromosome 18q21.3 . using northern blot analysis and in situ hybridization , mc4r was originally found to be expressed primarily in the brain .
mc4r expression was notably absent in the adrenal cortex , melanocytes , and placenta.42 mc4r is widely distributed in the central nervous system , especially in the cortex , hippocampus , amygdala , septum , corpus striatum , nucleus accumbens , hypothalamus , nucleus tractus solitarius , visual and motor nuclei of the brainstem , and the dorsal horn of the spinal cord.81 -msh , -msh , and acth are the known agonists and agrp is the known antagonist of the mc4r ( figure 2).70 since mc4r is highly expressed in the hypothalamus and has a strong affinity for -msh it is believed to be a strong candidate for energy balance , appetite control , and body weight regulation .
mc4r knockout mice have been shown to develop a maturity onset obesity syndrome characterized by hyperphagia , hyperglycemia and hyperinsulinemia.82 since this syndrome is similar to the agouti obesity syndrome seen in avy/ mice and agrp - transgenic mice that overexpress agouti and agrp respectively , it is speculated that the primary mechanism by which agouti and agrp produce obesity is chronic antagonism of mc4r.83 cachexia , a chronic wasting syndrome characterized by loss of body weight and muscle mass , is commonly associated with diseases such as cancer and aids .
mc4r mice and mice treated with agrp are resistant to lipopolysaccharide- or tumor - induced cachexia , further supporting the role of mc4r in energy balance and body weight regulation.84 mc5r is a 325 amino acid protein encoded by a single gene located on chromosome 18p11.2.85 mc5r has been shown to bind to all melanocortins except -msh.86 mc5r is the most widely expressed melanocortin receptor .
mc5r mrna is expressed in the adrenal gland , adipose tissue , kidney , leukocytes , lung , lymph node , mammary gland , ovary , pituitary , testis , and uterus.54 mc5r is highly expressed in exocrine glands such as lacrimal , preputial , harderian and sebaceous glands.87 mc5r - deficient mice have a severe defect in water repulsion and thermoregulation due to decreased production of sebaceous lipids .
studies in humans have shown that mc5r immunoreactivity is detectable in the epithelium and appendages , including the sebaceous , eccrine , and apocrine glands . however ,
analysis of mc5r variations in patients with acne , hidradenitis suppurativa , and sebaceous gland dysfunction have failed to suggest a causative role of mc5r in these conditions.88 low levels of mc5r mrna have also been reported in the central nervous system,89 however , the physiological function of mc5r in the brain remains unclear .
linkage analysis in the quebec family study90 revealed a significant association of mc5r polymorphisms with body mass index , fat mass , and resting metabolic rate , thus providing some evidence for the possible role of mc5r in energy balance and body weight regulation .
the pomc neurons , which produce -msh , also express another anorectic peptide cocaine - amphetamine - related transcript ( cart ) .
cell bodies of the pomc / cart neurons are found throughout the rostrocaudal extent of the arcuate nucleus , as well as the periarcuate area of the hypothalamus . within the hypothalamus ,
these neurons project to the periventricular nucleus , paraventricular nucleus ( pvh ) , and the perifornical region.91,92 the pomc / cart neurons also project to the brainstem to innervate the rostral nts , lateral reticular nucleus , ventrolateral medulla , nucleus ambiguous , and the spinal cord , as reviewed elsewhere.93 another critical component of the central melanocortin system within the arc is the neurons expressing neuropeptide y ( npy ) and the potent mc3r / mc4r antagonist agrp ( figure 2 ) .
the npy / agrp neurons have the same distribution as the pomc / cart neurons within the hypothalamus , with the densest fibers innervating the pvh , dorsomedial hypothalamus ( dmh ) , posterior hypothalamus , and septal regions around the anterior commissure.94 the npy / agrp neurons form synapses with the pomc / cart neurons within the arc , thus producing a neuronal network that is responsive to the modulatory effects of several appetite and body weight regulating hormones such as leptin , ghrelin , insulin , and peptide yy ( pyy).73,9598 leptin acts via hypothalamic receptors ( ob - r ) to decrease feeding and increase thermogenesis , resulting in a decrease in body weight . pomc / cart and npy / agrp neurons in the arc are the principal sites of leptin receptor expression and the source of potent neuropeptide hormones , -msh and npy , which exert opposing effects on feeding and metabolism as shown in figure 2 .
subpopulations of npy / agrp neurons that also express gamma - aminobutyric acid ( gaba ) send inhibitory collaterals to the pomc / cart neurons .
gaba inhibits the pomc / cart neurons and blocks the anorexic effect of -msh ( figure 2).99 using electrophysiological techniques , cowley et al showed that leptin stimulates the pomc / cart neurons via two mechanisms : 1 ) depolarization through a nonspecific cation channel and 2 ) hyperpolarization of npy / agrp neurons , leading to a reduction in the release of gaba that , in turn , causes disinhibition of the pomc / cart neurons ( figure 2).73 ghrelin , the endogenous ligand for growth hormone secretagogue receptor ( ghs - r ) , is a potent stimulant of growth hormone release and plays an important role in appetite control and body weight regulation . circulating ghrelin levels
are markedly increased with fasting and before meals and decrease following meals.100,101 plasma ghrelin levels are also influenced by long - term energy balance and are increased in anorexia and decreased in obesity.102,103 within the arc , gsh - r is expressed on the npy / agrp neurons which are thought to mediate the orexigenic effects of ghrelin .
central and peripheral administration of ghrelin induces c - fos in these neurons and increases hypothalamic npy and agrp mrna expression , thus antagonizing the anorexic effects of leptin.95,98,104 also , electrophysiological studies have shown that ghrelin directly activates the orexigenic npy / agrp neurons while coordinately inhibiting the anorexogenic pomc / cart neurons via increased gaba release on them ( figure 2).105 stimulation of food intake by ghrelin is blocked by administration of npy antagonist and is reduced in npy mice.95
lastly , mc3r and mc4r knockout mice show reduced sensitivity to ghrelin as evidenced by decreased ghrelin - induced food intake and growth hormone secretion , thus suggesting an important role of mc3r and mc4r in mediating the orexigenic effects of ghrelin.106 npy is a potent hypothalamic orexigenic peptide , probably the most powerful stimulant of appetite known .
nyp mrna expression in the hypothalamus is significantly increased during lactation and fasting.107 central administration of npy causes robust increase in food intake and body weight in rats.108,109 chronic intracerebroventricular administration of npy to normal rats produces hyperphagia , hyperinsulinemia , and liver and adipose tissue lipogenesis , thus mimicking the hormonal and metabolic changes of obesity.110 recent evidence suggests that ectopic overexpression of npy in other areas of the hypothalamus such as pvh , lateral hypothalamus , and dmh also increases food intake and body weight and that npy knockdown in the dmh ameliorates the hyperphagia , obesity , and diabetes of otsuka long - evans tokushima fatty ( oletf ) rats.111,112 thus , npy in the hypothalamus plays an important role in modulating food intake and body weight ( figure 2 ) .
npy exerts its orexigenic effects probably by inhibiting the arc pomc / cart neurons via its y2 receptor.113 npy is metabolized by several peptidases in the plasma .
recent evidence suggests that npy(136 ) is metabolized into three major fragments : npy(336 ) , npy(335 ) , and npy(235 ) , upon incubation with human serum.114 specific inhibitors of dipeptidyl peptidase 4 , plasma kallikrein , and aminopeptidase p prevent the production of npy(336 ) , npy(335 ) , and npy(236 ) , respectively .
plasma kallikrein metabolizes npy(336 ) to npy(335 ) . since npy(335 ) is unable to bind to npy y1 , y2 , and y5 receptors , npy(335 ) may represent the major metabolic end product of the y2/y5 agonist , npy(336 ) .
a recent study identified two splice variants of prcp ; the second isoform was named prcp2 ( ncbi : nm_199418 ) . unlike prcp , prcp2 has a longer transcript and a unique amino - terminal region .
although its full - length sequence is known , there is no evidence suggesting whether prcp2 mrna encodes a functional protein.24 the prcp gene is speculated to be a candidate gene for essential hypertension.115 mutational analysis of the human prcp has led to a better understanding of prcp - catalyzed reactions .
certain putative mutant forms of human prcp apparently predispose the polymorphic carriers to cardiovascular diseases including hypertension and the risk of preeclampsia.116 the e112d polymorphism in the prcp gene leads to increased antihypertensive effect of benazepril treatment in hypertensive patients.117 we have also demonstrated that prcp mice have mild hypertension.20 our recent studies demonstrated that the prcp - null ( prcp ) mice ate less and had even less fat than the mice with partial loss of the enzyme.26 these observations suggest that prcp is a genetic marker for weight regulation and putative prcp single nucleotide polymorphism ( snp ) variants are associated with mild hypertension .
continued identification of prcp mutations , full - characterization of prcp knockout mice , and studies with knock - in mice with prcp / prcp mutations will provide evidence that prcp is a disease - causing gene for both obesity and hypertension .
meanwhile , we propose that the use of prcp inhibitors should be strongly indicated by a diagnosis of obesity in patients with no systolic or diastolic deterioration .
obesity is an emerging worldwide public health hazard and is associated with significant morbidity and mortality . although the physiological determinants of normal / abnormal eating behavior have been investigated , the underlying causes and mechanisms of dysregulation of food intake in obesity , type 2 diabetes , and metabolic syndrome are not well understood .
the long - lasting challenge for clinicians and scientists in basic research to unfold the major cause of the dysregulation of the food intake is becoming close to the last battle .
clinical studies indicate that the molecular and cellular mechanisms by which leptin and alpha - melanocyte stimulation hormone ( -msh ) modulate each other s activity result in the regulation of food intake and energy expenditure.118 these studies suggest that -msh is intimately involved in the regulatory mechanism of obesity , energy expenditure , and body weight .
recently , prolylcarboxypeptidase ( prcp ) was found to be responsible for the control of food intake and energy expenditure at a central level .
the molecular mechanisms underlying the suppression of food intake in prcp - deficient mice or by the inhibitor of prcp clearly provide physiological evidence that prcp is an inactivator of -msh.26 thus , prcp is emerging as a new identity involved in the control of food intake and energy metabolism . since -msh can activate both melanocortin 4 receptors ( mc4r ) and melanocortin 1 receptors ( mc1r ) in a decreasing order , the catalysis of -msh113 to -msh112 by prcp would lead to the suppression of both mc4r and mc1r activation as shown in figure 4 . although there are various contributing factors for obesity , the recent research findings indicate that prcp is involved in the development of weight gain and obesity .
an increase in prcp expression or activity may result in obesity due to an imbalance between energy intake and energy expenditure .
although regulation of -msh113-mediated mc4r activation described above is demonstrably important , the importance of the role of prcp on the signaling mechanisms of mc1r in anti - inflammatory response remains an enigma ( figure 4).119 additional studies are needed to determine whether or not prcp regulates -msh113-mediated mc1r activation .
the cellular role of prcp is beginning to be unraveled both at the molecular and physiological levels .
the upregulation of human prcp expression during inflammation has been described.24 on other hand , the prcp knockout mice study demonstrates that prcp is an appetite stimulant .
therefore , the pleiotropic effects of prcp include increased no and prostaglandin bioavailability , decreased vasoconstriction , and increased appetite . in summary , knowledge of the role of prcp in mouse appetite regulation
thus , research on prcp--msh interactions may be important to the further understanding of human obesity .
in addition , the identification of prcp as an inactivator of -msh should provide an attractive therapeutic target in the fight against obesity .
however , due to its pleiotropic effects , the prcp inhibitors must be scrutinized carefully to optimize their use in the treatment and prevention of obesity and obesity - related diseases . | recently , we serendipitously discovered that mice with the deficiency of the enzyme prolylcarboxypeptidase ( prcp ) have elevated -melanocyte - stimulating hormone ( -msh ) levels which lead to decreased food intake and weight loss .
this suggests that prcp is an endogenous inactivator of -msh and an appetite stimulant .
since a modest weight loss can have the most profound influence on reducing cardiovascular risk factors , the inhibitors of prcp would be emerging as a possible alternative for pharmacotherapy in high - risk patients with obesity and obesity - related disorders .
the discovery of a new biological activity of prcp in the prcp - deficient mice and studies of -msh function indicate the importance and complexity of the hypothalamic pro - opiomelanocortin ( pomc ) system in altering food intake . identifying a role for prcp in regulating -msh in the brain may be a critical step in enhancing our understanding of how the brain controls food intake and body weight . in light of recent findings , the potential role of prcp in regulating fuel homeostasis
is critically evaluated .
further studies of the role of prcp in obesity are much needed . |
diabetes mellitus is recognized as a group of heterogeneous disorders , with common elements of hyperglycemia and glucose intolerance due to insulin deficiency , impaired effectiveness of insulin action , or both .
the prevalence of type 2 diabetes increases with age , is increasing worldwide , and its economic impact currently accounts for a significant portion of health care expenditure.1 injection of long - acting insulin is a common therapeutic approach for patients with type 2 diabetes that is poorly controlled with multiple oral regimens.2 unfortunately , although insulin use as the mainstay of treatment for diabetes has resulted in favorable treatment outcomes , poor adherence / compliance continues to be a problem because of fear of insulin or fear of injection , and this can be associated with poor glycemic control , clinical complications , psychological comorbidity , poor general well being and health status , and increased mortality risk in patients with diabetes.3 last but not least , use of insulin is very often considered to be the point of no return in medical intervention for diabetes .
these observations suggest a need for implementation of new therapeutic strategies to delay the need for insulin as far as possible .
berberine , an isoquinoline alkaloid of the protoberberine type and found in an array of plants , has been used in indian and chinese medicine for many decades .
it is present in hydrastis canadensis ( goldenseal ) , coptis chinensis ( coptis or goldenthread ) , berberis aquifolium ( the oregon grape ) , berberis vulgaris ( barberry ) , and berberis aristata ( tree turmeric ) .
berberine and extracts of berberine have demonstrated significant antimicrobial activity against a variety of organisms , including bacteria , viruses , fungi , protozoans , helminths , and chlamydia .
the predominant clinical uses of berberine , at least in the recent past , have included bacterial diarrhea and intestinal parasite infections.4 more recently , clinical research on berberine has revealed novel pharmacological properties and multiple therapeutic applications , mainly concerning hypercholesterolemia and diabetes.5 with regard to the lipid profile , berberine upregulates low - density lipoprotein receptor expression independent of sterol regulatory element - binding proteins , but dependent on extracellular signal - regulated kinases and c - jun n - terminal kinase activation , leading to reductions in total cholesterol and low - density lipoprotein cholesterol of about 30% and 25% , respectively .
this upmodulation occurs via a post - transcriptional mechanism that stabilizes mrna and enables berberine to act as a cholesterol - lowering drug via a mechanism of action different from that of the statins.6 in addition to its cholesterol - lowering properties , berberine reduces triglycerides by about 35% .
these effects on the lipid profile have been observed in both animals and humans.6,7 berberine also has an important additive effect in the presence of statins.8 this is likely due to the ability of berberine to downmodulate proprotein convertase subtilisin / kexin type 9 , a protein which reduces the cholesterol - lowering properties of statins.9 this effect of berberine could be relevant when treating patients with suboptimal control of hypercholesterolemia despite receiving high doses of statins . due to this additive effect , it is quite common to find nutritional supplements containing berberine10 along with a natural source of lovastatin ( ie , monascus purpureus).11 however , these products do not take into consideration the poor standardization of the raw materials12 and the risk to consumers due to the possible presence of mycotoxic contaminants like citrinin.13 berberine has also been shown to be effective in the treatment of diabetes , in which it significantly decreases glycosylated hemoglobin ( hba1c ) , fasting blood glucose , and postprandial blood glucose . in this respect , berberine has an effect similar to that of metformin,14 even if it likely acts via a mechanism different from that of metformin.15 berberine regulates glucose metabolism via multiple mechanisms of action .
it enhances glucose uptake by upmodulation of glucose transporter type 4 , activates 5-amp - activated protein kinase as a consequence of inhibition of mitochondrial function , suppresses adipogenesis by inhibition of peroxisome proliferator - activated receptor gamma and c - enhancer - binding protein alpha function , and decreases intestinal glucose absorption by inhibition of alpha - glucosidase .
16 however , despite these functions , berberine has poor oral bioavailability.17 in humans , this appears to be due to a p - glycoprotein - mediated gut extrusion process18 and substantial excretion in bile.19 p - glycoprotein seems to decrease the amount of berberine able to cross enterocytes by about 90%,20 suggesting that inhibition of p - glycoprotein could potentially improve its oral poor bioavailability . among the potential p - glycoprotein inhibitors , silymarin from silybum marianum could be a good candidate due to its very poor oral bioavailability and its good safety profile.21 therefore , we investigated the activity of a combination of berberine and silymarin when added to oral hypoglycemic regimens for patients with suboptimal glycemic control .
our aim was to evaluate the impact of this approach on body mass index , hyperglycemia , hypercholesterolemia , triglyceride levels , and liver enzymes in patients with type 2 diabetes .
the study was performed in routine clinical practice in accordance with international guidelines and in line with the principles outlined in the declaration of helsinki , so approval from the local ethics board was not required .
this study was carried out in a single center in italy where it is not mandatory to obtain ethical approval when performing experiments involving nutraceutical products .
twenty - two of the 26 patients completed the study , with four dropouts as a result of gastrointestinal discomfort and/or other side effects .
the main inclusion criteria were stable ( for at least 6 months ) but suboptimal glycemic control ( hba1c 7.5%9.5% ) , body mass index > 22 kg / m , age 2575 years , and a negative pregnancy test for female patients .
all patients had suboptimal glycemic control despite use of the following drugs , unchanged at least in the last 3 months : metformin ( n = 20 ) , incretins ( n = 4 ) , sulfonylureas ( n = 14 ) , glitazones ( n = 3 ) , and insulin ( n = 5 ) .
as regards the lipid profile , 12 patients were receiving statins , 1 was receiving a fibrate whereas 5 , previously under treatment with statins , had interrupted the therapy due to unwanted effects , mainly myalgia .
exclusion criteria were moderate to severe liver dysfunction ( serum alanine aminotransferase > 120 iu / l and aspartate aminotransferase > 80
iu / l ) , abnormal renal function ( serum creatinine > 115 mol / l ) , severe heart failure ( new york heart association class iii or greater ) , history of acute diabetic complications , including diabetic ketoacidosis or hyperosmolar hyperglycemic nonketotic coma , psychiatric disease , severe infection , pregnancy or planning for pregnancy , and fasting plasma glucose 200 mg / dl .
all patients received addon nutraceutical therapy , ie , berberol ( pharmextracta , pontenure , italy ) , an oral tablet containing 588 mg of b. aristata extract titered as 85% berberine and 105 mg of s. marianum extract titered as > 60% flavonolignans .
the product , in agreement with the italian legislation ( law number 169/2004 ) had been notified to the minister of health in 2010 ( e10 40753y ) and registered as a food supplement , with both its actives ( standardized extracts of b. aristata and s. marianum ) belonging to the list of botanicals approved as nutraceuticals and its excipients all being food grade .
the patients took two tablets per day on an empty stomach in the late evening for the 90-day duration of the study .
berberol was manufactured by siit ( trezzano s / n , milan , italy ) .
the two actives , ie , b. aristata extract and s. marianum extract , were provided , respectively , by siit and indena , both located in milano , italy .
the statistical analysis was performed using spss 12.0 for windows ( spss inc , chicago , il ) .
statistical differences between baseline and different time points were analyzed using the nonparametric paired t - test .
the statistical analysis was performed using spss 12.0 for windows ( spss inc , chicago , il ) .
statistical differences between baseline and different time points were analyzed using the nonparametric paired t - test .
berberol containing extracts of b. aristata and s. marianum extract , dosed at two tablets daily for 90 days , was demonstrated to be a valid addon treatment option for patients with type 2 diabetes and suboptimal glycemic control . as shown in table 2
, a significant reduction was observed in hba1c , basal insulin , total cholesterol , low - density lipoprotein cholesterol , triglycerides , homa - r ( homeostatic model assessment for insulin resistance , calculated as glucose insulin/405 , where glucose is expressed as mg / dl and insulin as u / ml ) , and alanine transaminase .
there were no significant changes in high - density lipoprotein cholesterol , fasting glucose , body mass index , weight , or waist circumference .
four of the 26 patients diagnosed with type 2 diabetes and suboptimal glycemic control who enrolled in this study dropped out , leaving data for the 22 patients who completed the study .
we investigated the clinical effects of oral treatment using a nutraceutical combination of b. aristata extract ( containing 85% berberine ) and s. marianum extract .
the latter ingredient is included with the aim of enhancing the oral bioavailability of berberine , mostly by reducing p - glycoprotein activity in the gut . to be eligible for entry into this study , patients had to have had suboptimal glycemic control ( hba1c 7.5%9.5% ) unchanged for at least 3 months despite at least 6 months of treatment with a multidrug regimen . according to the international guidelines , hba1c values in this range are linked with an increased risk of developing microvascular and macrovascular complications , and all possible medical effort should be made to reduce hba1c below 7%.22 use of injectable insulin should be delayed as long as possible using oral insulin - saving drug cocktails . the basis for using such cocktails , precisely established on the basis of the metabolic features of a patient , have to be considered carefully , not only because of the very poor patient compliance with insulin injections , but also because delaying insulin therapy should spare endogenous insulin and avoid pancreatic exhaustion.23 in patients with suboptimal glycemic control , we observed an hba1c reduction of about 0.85% after 3 months of treatment with berberol , which was maintained after 6 months of treatment ( data not shown ) .
such a percentage reduction is comparable with that normally obtained in patients treated with acarbose , dipeptidyl peptidase-4 inhibitors ( sitagliptin , vildagliptin , saxagliptin ) , or glitazones , used alone or adjunctive to metformin , to achieve optimal glycemic control .
we did not modify any drug or treatment protocol established before starting treatment with berberol in any of the 22 patients who completed the study . at the same time , no modifications in terms of food intake or lifestyle were suggested or adopted before or during the trial , and this is reflected by the minimal changes in body weight and waist circumference .
a possible mechanism of action of berberol could be its ability to increase insulin sensitivity , as shown by the reduction in homa - r .
another possible mechanism of action could be linked to the acarbose - like action observed by some clinicians.24 this hypothesis should explain some of the gastrointestinal side effects observed , and could explain why four patients dropped out of the trial .
we observed a relevant reduction in total cholesterol , low - density lipoprotein cholesterol , and triglycerides in our patients , all of whom had a cholesterol value within normal range or were on treatment with statins .
this result , already observed by many clinicians , is likely due to the hypocholesterolemic activity of berberine and to an additive effect of berberine when combined with statin therapy .
similar observations have been made in animals and in humans , and berberine has been shown to reduce liver necrosis both in nonalcoholic steatosis and in steatosis due to hepatitis c infection.25 however , these observations need to be confirmed by studies specifically designed to demonstrate a protective effect of berberine on the liver .
berberol is a nutraceutical combination of highly standardized herbal extracts of b. aristata and s. marianum titered , respectively , as 85% berberine and > 60% flavanolignans .
berberol seems to have positive effects in patients with type 2 diabetes and suboptimal glycemic control when given orally in addition to a conventional regimen ( ie , metformin , dipeptidyl peptidase-4 inhibitors , glitazones , acarbose or insulin , alone or as multidrug therapy ) .
berberol seems to improve the cholesterol - lowering properties of statins , and has a positive effect on liver enzymes .
treatment seems to be safe and tolerated at the doses tested , with minimal unwanted effects , which resolve on cessation of treatment without any further consequences .
the results of our pilot study performed in 26 patients need confirmation by larger trials and with better definition of the diabetic patients enrolled . allowing for these limitations ,
berberol can still be considered as a potential oral nutraceutical suitable for use in addition to conventional therapy for type 2 diabetes , with the aim of ameliorating suboptimal glycemic control as a strategy for postponing the use of injectable insulin . | backgroundsuboptimal glycemic control is a common situation in diabetes , regardless of the wide range of drugs available to reach glycemic targets .
basic research in diabetes is endeavoring to identify new actives working as insulin savers , use of which could delay the introduction of injectable insulin or reduce the insulin dose needed . commonly available as a nutraceutical , berberine is a potential candidate.methods and resultsbecause its low oral bioavailability can be overcome by p - glycoprotein inhibitors like herbal polyphenols , we have tested the nutraceutical combination of berberis aristata extract and silybum marianum extract ( berberol ) in type 2 diabetes in terms of its additive effect when combined with a conventional oral regimen for patients with suboptimal glycemic control .
after 90 days of treatment , the nutraceutical association had a positive effect on glycemic and lipid parameters , significantly reducing glycosylated hemoglobin , basal insulin , homeostatic model assessment of insulin resistance , total and low - density lipoprotein cholesterol , and triglycerides .
a relevant effect was also observed in terms of liver function by measuring aspartate transaminase and alanine transaminase . the product had a good safety profile , with distinctive gastrointestinal side effects likely due to its acarbose - like
action.conclusionalthough further studies should be carried out to confirm our data , berberol could be considered a good candidate as an adjunctive treatment option in diabetes , especially in patients with suboptimal glycemic control . |
cochlear implant ( ci ) surgery has become a widespread procedure with clearly increasing numbers around the world to treat deaf and profoundly hearing impaired patients of different age .
histological studies of human cochleae have evidenced different levels of intracochlear trauma induced by the insertion of different ci electrode arrays [ 13 ] .
these reports led to the development of specific insertion techniques and tools for perimodiolar electrodes to minimize the insertion trauma as found earlier with this kind of electrodes [ 1 , 6 ] . over time
, the technology of histological workup of inserted cochleae was refined so that it became possible to investigate cochlear structures with the positioned array in place . before this technological advancement , investigations of cochlear structures were limited insofar that the inserted electrodes had to be removed before workup of the cochlear tissues [ 810 ] .
thus , it was unclear if observed changes were due to the insertion or the pull - out of the electrode array .
the development of those specific insertion techniques showed a limited insertion trauma , but the basilar membrane and the osseous lamina spiralis are at limited risk [ 4 , 11 , 12 ] .
it is therefore of particular interest for surgeons to identify risk factors and structures if an electrode pull - out becomes necessary for several clinical reasons , for example , an exchange of the implant ( due to failure ) , an intraoperative pull - out of an already inserted electrode in order to replace it by a back - up device , and so forth .
the aim of the present study was to investigate possible , intracochlear changes after insertion and extraction of a perimodiolar electrode with state - of the - art traumatic insertion technique and refined electrodes .
the temporal bones were freshly harvested and subsequently worked up . at first , a conventional mastoidectomy with a posterior tympanotomy was performed . the ci electrodes ( see below ) were inserted with the aos technique after removal of the promontory lip , preparation of the round window membrane , and opening and inferior enlargement of the round window .
subsequently , the array was carefully pulled out ( see also below ) . the stapes were removed , and the labyrinth was perfused with formalin ( 4% ) .
then the temporal bones were divided into two groups for further histological analysis . in 5 fresh tbs
5 separate tbs were decalcified by edta , fixed by paraffine , thin - sliced ( 4 ym ) , and stained by haematoxylin - eosin ( he ) . in a separated number of 9 tbs , the bony roof of the scala vestibuli was removed so that a full overview of the basilar membrane was posssible .
after insertion of the electrodes , the pull - out movement of the electrode was digitally frame - captured and analysed via an attached video system .
all tb experiments were done with nucleus advance electrodes ( cochlear corporation , sydney , australia ) .
the histological analysis of the cochlear microstructures revealed no major changes in all 5 tbs , particularly not at or around the modiolar wall ( figures 1 and 2 ) . in one tbs ,
the basilar membrane was elevated up at the basal part of the scala tympani ( figure 2 ) . however , neither a disruption of the basilar membrane was found , nor was a breakup of the osseous lamina spiralis .
if this finding should be classified due to the so - called intracochlear trauma scale by eshraghi et al . , one grade 1 trauma was found ( table 1 ) .
the histological microanalysis revealed no microtraumatization of any intracochlear structure in any of the 5 tbs in series b ( figure 3 ) ( see also table 2 ) .
the analysis of the pull - out procedure showed in 1 out of 9 tbs that the electrode tip was tilted upwards by a 90 turning of the tip ( figures 4 and 5 ) .
when the pull - out was manually controlled by microinstrumentation ( forceps ) and a gentle movement towards the modiolus , the tip tilting could be prevented .
the impact of cochlear implantation on the fine structure of the inner ear has been a subject of research for some years .
the electrode - tissue interface should be investigated on one hand to modify electrode arrays [ 13 , 6 ] and on the other to improve the surgical approach ( i.e. , the site and extension of the cochleostomy ) [ 14 , 15 ] .
this detailed microstructural analysis with the electrode in place was not yet possible in the 80s so that no clear distinction between intracochlear changes due to electrode insertion or extraction could be made .
the recent perimodiolar arrays had not yet been the subject of studies since straight arrays dominated the market .
our present study suggests that the modern , perimodiolar electrodes only cause minor trauma to the cochlear microstructure .
apart from a lifted basilar membrane , no serious damage was found even when applying two different techniques as done in series a and b. the modiolus , which is very closely related to the electrode , remained unaffected .
the results of our study also confirm the findings of [ 4 , 11 , 12 ] of a limited trauma with the difference that in our study the electrode was additionally removed .
this means that the present electrode arrays can be safely inserted , but even safely removed and/or replaced if required .
some additional features , for example , fluid exchange in between labyrinthine compartments , indirect suction forces have to be considered as well .
a complete pull - out of the electrode might become necessary to improve its position , in case of device failure and/or replacement . since the modiolar region with its neurons plays a central role in carrying the electrical stimulus to the other regions of the auditory pathway , its proven integrity after a complete electrode pull - out lets us suggest that a limited pullback of a ci electrode array to better approximate the electrode to its neural interface bears no serious risks to the cochlear microstructures [ 13 , 17 ] .
the audiological results after a device replacement support this suggestion [ 18 , 19 ] .
the only minor change after electrode extraction was found at the basilar membrane as related to an upward tilting of the electrode tip .
the video analysis revealed the tip turning during the extraction of the array ( figures 4 and 5 ) but as outlined above , a gentle and guided pull - out of the electrode ( e.g. , with forceps ) can prevent a lifting - up of the basilar membrane by a tilted electrode tip .
while pulling out the cochlear implant electrode , this procedure should be manually guided to prevent damage to the basilar membrane . | the exchange of an cochlear implant or the re - positioning of an electrode have become more frequently required than a decade ago .
the consequences of such procedures at a microstructural level within the cochlea are not known .
it was the aim of the present study to further investigate the effects of an ci electrode pull - out .
therefore 10 freshly harvested temporal bones ( tb ) were histologically evaluated after a cochlear implant electrode pull - out of a perimodiolar electrode . in additional
9 tb the intrascalar movements of the ci electrode while being pulled - out were digitally analysed by video- capturing .
histologically , a disruption of the modiolar wall or the spiral osseous lamina were not observed . in one tb , a basilar membrane lifting up was found , but it could not be undoubtedly attributed to the pull - out of the electrode . when analyzing the temporal sequence of the electrode movement during the pull - out , the electrode turned in one case so that the tip elevates the basilar membrane .
the pull- out of perimodiolarly placed ci electrodes does not damage the modiolar wall at a microstructural level and should be guided ( e.g. , forceps ) to prevent a 90 o turning of the electrode tip into the direction of the basilar membrane . |
cerebral palsy ( cp ) is the most common cause of upper motor neuron lesions in children , causing spasticity and muscle tendon contractures , leading to bony deformation , weakness , and loss of selective motor control .
kerr graham classified sagittal gait patterns in spastic diplegia by providing a management algorithm based on these patterns [ 1 , 2 ] .
crouch gait is a major sagittal plane deviation defined as a combination of excessive ankle dorsiflexion and knee and hip flexion throughout the stance phase .
this gait pattern is commonly found in children afflicted with severe cp diplegia or quadriplegia .
several hypothesized causes for crouch gait include bony malformations causing lever arm dysfunction [ 4 , 5 ] , tight hip flexors [ 69 ] , and weak muscle support [ 5 , 1013 ] . one of the most common causes of crouch gait is the overlengthening of the gastrocsoleus , producing significant weakness of the gastrocsoleus extensor mechanism of the lower limbs .
crouch gait can also be a natural history of the disability [ 1 , 3 ] .
multilevel orthopedic surgery has been performed to correct severe crouch gait [ 14 , 15 ] .
strengthening the extensor moment , particularly the gluteus maximus , may help improve both hip and knee extension .
orthotics , such as ground reaction ankle foot orthotics ( grafos ) , are used to enhance knee extension ability .
this type of orthotic frequently leads to discomfort , painful areas , and functional disability . for the grafos to be effective
functional electrical stimulation ( fes ) , a well - known intervention , has been used for many years to facilitate muscle groups during walking .
the aim of the system is to facilitate the proper muscle group at the proper timing . so
fes has been mainly used to control dorsiflexors muscles and prevent drop foot at the swing phase [ 18 , 19 ] .
peroneal fes is widely used due to its feasibility , simplicity , and synchronization with gait .
the aim of the present report was to evaluate the short- and long - term effects of muscle stimulation in preventing crouch gait and achieving ankle plantar flexion and knee and hip extension at the stance phase by applying fes to the quadriceps muscles .
immediate and long - term effects were assessed on a subject diagnosed with cp diplegia with a crouch gait pattern .
we present an 18-year - old boy diagnosed with cp diplegia ( gross motor function classification system ( gmfcs ) level ii ] , without cognitive impairment .
he was considered independent according to the activities of daily living . when walking outdoors , he wore grafos bilaterally for 9 years with two quadripods .
his main complaints were weakness , difficulty in prolonged walking and standing , ascending and descending stairs , and dependency on the orthotics .
clinical examination exhibited bilateral hip flexion contracture ( thomas test 25 ) , bilateral limited knee extension of 5 , bilateral extension lag of 30 , and severe hyperpronated midfoot break , leading to excessive external foot progression .
manual muscle testing revealed severe weakness : bilateral weak hip extensors ( 2/5 ) , knee extensors ( 4/5 ) , gastrocsoleus ( 2/5 ) .
valencia , ca , usa ) , which delivers electrical stimulations to the common peroneal nerve , hamstrings , and quadriceps muscles ( fig . 1 ) . for this case study
as described in detail by hausdorff and ring , this system has three main components that communicate via radio frequency signals : ( 1 ) a remote unit giving the patient control over the system ; ( 2 ) an integrated stimulation unit with electrodes placed around the thigh ( the electrodes of the thigh cuff two oval cloth electrodes , proximal : 130 75 mm ; distal : 120 63 mm positioned over the quadriceps to extend the knee ) ; and ( 3 ) a force - sensitive gait sensor placed beneath the foot to detect heel strike and toe off .
computed algorithms analyze the gait sensor s data and information is then transmitted to the stimulation unit to induce knee extension at the appropriate time and exact duration .
necessary adjustments may be performed by a clinician using a handheld computer ( pda ) to set the stimulation intensity , pulse frequency , and gait parameters .
the thigh stimulation ( quadriceps ) can begin and end at any segment in the gait cycle , as defined by the clinician .fig .
raanana , israel ) , generating electrical stimulations to the quadriceps muscles the ness l300 plus neuroprosthesis system ( ness ltd . , raanana , israel ) ,
generating electrical stimulations to the quadriceps muscles a three - dimensional gait analysis was performed using an eight - camera system ( vicon mx giganet motion analysis system , oxford metrics , uk ) at 100 hz and a capturing volume of 3.5 m3.5 m2.5 m. retro - reflective markers were applied on anatomical landmarks to capture gait performance according to the biomechanical model plug - in - gait developed by vicon ( based on the work of murali kadaba and helen hayes hospital ) [ 23 , 24 ] . the initial evaluation ( t1 ) at the gait laboratory included a three - dimensional evaluation of walking at a self - selected normal speed on a 12-m walkway barefoot and wearing his own grafos .
two months after this initial evaluation ( t2 ) , he was fitted with an fes device placed on the quadriceps . during the fitting process , the stimulation parameters and timing of stimulation were set .
quadriceps stimulation was configured to start immediately after heel strike to the pre - swing phase .
a symmetrical waveform was used with a phase duration of 300 s , pulse rate 40 hz , and intensity 40 ma . after adjusting the fes device , the subject practiced walking for 20 min prior to initiating the data capturing . after completing the fitting procedure ,
the subject used the system for training sessions at home on a treadmill . every day , the subject walked 25 min and then trained for 20 min sitting .
after 2 months , he walked with the fes device daily for 30 min and climbed two flights of stairs .
after 6 months of conditioning ( t3 ) , he was evaluated at the gait laboratory . at t2 ,
he was evaluated while performing with and without the fes device ( shod only ) . at t3 ,
his gait was assessed in all four conditions : barefoot , grafos , and with and without the fes device ( shod only ) . our goal was to compare the different conditions and any carryover effect on the maximum knee and hip extension and ankle plantar flexion throughout the stance phase and at midstance .
in addition to his walking evaluation , his ability to ascend and descend stairs was evaluated at t2 and t3 .
we present an 18-year - old boy diagnosed with cp diplegia ( gross motor function classification system ( gmfcs ) level ii ] , without cognitive impairment .
he was considered independent according to the activities of daily living . when walking outdoors , he wore grafos bilaterally for 9 years with two quadripods .
his main complaints were weakness , difficulty in prolonged walking and standing , ascending and descending stairs , and dependency on the orthotics .
clinical examination exhibited bilateral hip flexion contracture ( thomas test 25 ) , bilateral limited knee extension of 5 , bilateral extension lag of 30 , and severe hyperpronated midfoot break , leading to excessive external foot progression .
manual muscle testing revealed severe weakness : bilateral weak hip extensors ( 2/5 ) , knee extensors ( 4/5 ) , gastrocsoleus ( 2/5 ) .
we used the ness l300 plus neuroprosthesis system ( bioness inc . , valencia , ca , usa ) , which delivers electrical stimulations to the common peroneal nerve , hamstrings , and quadriceps muscles ( fig . 1 ) .
for this case study , we used the ness system for electrical stimulation of the quadriceps muscle .
as described in detail by hausdorff and ring , this system has three main components that communicate via radio frequency signals : ( 1 ) a remote unit giving the patient control over the system ; ( 2 ) an integrated stimulation unit with electrodes placed around the thigh ( the electrodes of the thigh cuff two oval cloth electrodes , proximal : 130 75 mm ; distal : 120 63 mm positioned over the quadriceps to extend the knee ) ; and ( 3 ) a force - sensitive gait sensor placed beneath the foot to detect heel strike and toe off .
computed algorithms analyze the gait sensor s data and information is then transmitted to the stimulation unit to induce knee extension at the appropriate time and exact duration .
necessary adjustments may be performed by a clinician using a handheld computer ( pda ) to set the stimulation intensity , pulse frequency , and gait parameters .
the thigh stimulation ( quadriceps ) can begin and end at any segment in the gait cycle , as defined by the clinician .fig .
raanana , israel ) , generating electrical stimulations to the quadriceps muscles the ness l300 plus neuroprosthesis system ( ness ltd . ,
a three - dimensional gait analysis was performed using an eight - camera system ( vicon mx giganet motion analysis system , oxford metrics , uk ) at 100 hz and a capturing volume of 3.5 m3.5 m2.5 m. retro - reflective markers were applied on anatomical landmarks to capture gait performance according to the biomechanical model plug - in - gait developed by vicon ( based on the work of murali kadaba and helen hayes hospital ) [ 23 , 24 ] .
the initial evaluation ( t1 ) at the gait laboratory included a three - dimensional evaluation of walking at a self - selected normal speed on a 12-m walkway barefoot and wearing his own grafos .
two months after this initial evaluation ( t2 ) , he was fitted with an fes device placed on the quadriceps . during the fitting process , the stimulation parameters and timing of stimulation were set .
quadriceps stimulation was configured to start immediately after heel strike to the pre - swing phase .
a symmetrical waveform was used with a phase duration of 300 s , pulse rate 40 hz , and intensity 40 ma . after adjusting the fes device , the subject practiced walking for 20 min prior to initiating the data capturing .
after completing the fitting procedure , the subject used the system for training sessions at home on a treadmill .
every day , the subject walked 25 min and then trained for 20 min sitting .
after 2 months , he walked with the fes device daily for 30 min and climbed two flights of stairs .
after 6 months of conditioning ( t3 ) , he was evaluated at the gait laboratory . at t2 ,
he was evaluated while performing with and without the fes device ( shod only ) . at t3 ,
his gait was assessed in all four conditions : barefoot , grafos , and with and without the fes device ( shod only ) .
our goal was to compare the different conditions and any carryover effect on the maximum knee and hip extension and ankle plantar flexion throughout the stance phase and at midstance .
in addition to his walking evaluation , his ability to ascend and descend stairs was evaluated at t2 and t3 .
tables 1 , 2 , and 3 summarize the kinematic results compared to typically developed ( td ) subjects data recorded at the gait laboratory .
2.table 1sagittal plane kinematic measures of the knee at t1 [ mean standard deviation ( sd ) ] compared to typically developed ( td ) subjects ( mean sd)t1tdbarefootgrafoleftrightleftrightmaximal knee extension at midstance ( )36.35 ( 1.29)32.08 ( 1.98)39.64 ( 2.40)34.01 ( 1.78)8.95 ( 1.89)maximal knee extension at the stance phase ( )33.01 ( 0.08)30.74 ( 0.98)36.24 ( 1.83)32.15 ( 1.55)8.86 ( 2.15)table 2sagittal plane kinematic measures of the ankle and knee at t2 compared to td subjects ( mean sd)t2tdshodfesleftrightleftrightmaximal dorsiflexion at midstance ( )21.50 ( 0.95)16.18 ( 0.37)19.17 ( 1.95)15.60 ( 0.72)17.61 ( 1.22)maximal dorsiflexion at the stance phase ( )31.44 ( 0.29)24.43 ( 1.11)28.80 ( 0.55)21.74 ( 0.933)19.19 ( 1.83)maximal knee extension at midstance ( )39.16 ( 0.96)37.36 ( 1.33)33.23 ( 0.35)36.26 ( 0.85)8.95 ( 1.89)maximal knee extension at the stance phase ( )38.63 ( 1.09)37.23 ( 1.22)32.36 ( 0.67)34.44 ( 0.16)8.86 ( 2.15)table 3sagittal plane kinematic measures of the ankle and knee at t3 compared to td subjects ( mean sd)t3tdgrafoshodfesleftrightleftrightleftrightmaximal dorsiflexion at midstance ( )18.55 ( 1.55)15.53 ( 1.54)14.05 ( 1.59)16.25 ( 1.19)11.18 ( 0.84)15.78 ( 0.29)17.61 ( 1.22)maximal dorsiflexion at the stance phase ( )25.55 ( 0.38)21.37 ( 0.71)31.44 ( 1.58)30.75 ( 0.55)30.32 ( 1.20)30.44 ( 0.25)19.19 ( 1.83)maximal knee extension at midstance ( )38.03 ( 1.12)34.99 ( 0.67)34.99 ( 0.86)35.22 ( 1.44)33.42 ( 1.58)33.45 ( 1.50)8.95 ( 1.89)maximal knee extension at the stance phase ( )36.69 ( 1.38)34.26 ( 0.45)33.71 ( 0.64)34.29 ( 1.47)32.65 ( 1.09)31.04 ( 0.75)8.86 ( 2.15)fig .
2sagittal plane movements of the left and right knee at t3 compared to typically developed ( td ) subjects data ( gray line ) .
dotted line shod , dashed line ground reaction ankle foot orthotic ( grafo ) , solid line functional electrical stimulation ( fes ) sagittal plane kinematic measures of the knee at t1 [ mean standard deviation ( sd ) ] compared to typically developed ( td ) subjects ( mean sd ) sagittal plane kinematic measures of the ankle and knee at t2 compared to td subjects ( mean sd ) sagittal plane kinematic measures of the ankle and knee at t3 compared to td subjects ( mean sd ) sagittal plane movements of the left and right knee at t3 compared to typically developed ( td ) subjects data ( gray line ) .
dotted line shod , dashed line ground reaction ankle foot orthotic ( grafo ) , solid line functional electrical stimulation ( fes ) at t1 , the subject demonstrated a severe crouch gait pattern , with 36.35 left knee flexion at midstance and 32.08 on the right . walking with grafos at t1 did not improve knee kinematics .
a decrease in knee extension was demonstrated at midstance and in maximum knee extension at the stance phase .
knee flexion increased by 3.29 on the left and 1.93 on the right at midstance , while maximum knee extension at the stance phase deteriorated by 3.23 on the left and 1.41 on the right .
similar results were observed at t3 . at t2 , walking with the fes device showed an increase in the patient s ankle plantar flexion and knee extension at midstance ( left ankle 2.33 , right ankle 0.58 , left knee 5.93 , right knee 1.1 ) and increased knee maximal extension , and ankle plantar flexion at the stance phase ( left ankle 2.64 , right ankle 2.69 , left knee 6.27 , right knee 2.79 ) .
the left knee was more extended at midstance with shoes only when compared to grafos at t3 ( 38.03 and 34.99 , respectively ) .
however , maximal ankle dorsiflexion increased with shoes only at the stance phase ( by 5.89 on the left and 9.38 on the right ) , demonstrating that the grafos maximal effect occurs at terminal stance .
walking with the fes device at t3 revealed improvement in knee extension ability at midstance and maximal knee extension at the stance phase bilaterally compared to shoes only and grafos conditions ( maximum knee extension at stance , left and right ) : fes 32.65 , 31.04 , shod only 33.71 , 34.29 , and grafos 36.69 , 34.26. similar results were found at t2 ; however , there was no effect on hip kinematics .
spatiotemporal parameters at t3 revealed an increase in walking speed with the fes device and grafos compared to walking barefoot ( left : 0.73 , 0.67 , and 0.57 m / s , respectively ; right : 0.74 , 0.67 , and 0.55 m / s , respectively ) .
when walking with the fes device , the highest speed was attained due to an increase in step length and cadence . when comparing the patient s walking speed with fes in t3 versus t2 , a higher walking speed , cadence , and bigger step length occurred at t3.table 4spatiotemporal parameters measures at t3 compared to td subjects ( mean sd)grafo 3ness off 3ness on 3tdrightleftrightleftrightleftwalking speed ( m / s)0.67 ( 0.03)0.67 ( 0.05)0.59 ( 0.03)0.61 ( 0.03)0.74 ( 0.02)0.73 ( 0.02)1.39step length ( m)0.52 ( 0.02)0.52 ( 0.03)0.52 ( 0.03)0.5 ( 0.01)0.55 ( 0.03)0.56 ( 0.00)0.74cadence ( steps / min)76.2 ( 2.24)76.2 ( 3.16)69.79 ( 1.47)72.29 ( 0.44)77.77 ( 1.47)78.36 ( 3.46)111 spatiotemporal parameters measures at t3 compared to td subjects ( mean sd ) at t2 , the patient was able to ascend and descend stairs with a step - to pattern , whereas he was able to ascend and descend the stairs with a step - through pattern immediately after adjusting the fes .
in addition , at t3 , he was able to step through stairs in all conditions .
at t1 , the subject demonstrated a severe crouch gait pattern , with 36.35 left knee flexion at midstance and 32.08 on the right . walking with grafos at t1
knee flexion increased by 3.29 on the left and 1.93 on the right at midstance , while maximum knee extension at the stance phase deteriorated by 3.23 on the left and 1.41 on the right .
at t2 , walking with the fes device showed an increase in the patient s ankle plantar flexion and knee extension at midstance ( left ankle 2.33 , right ankle 0.58 , left knee 5.93 , right knee 1.1 ) and increased knee maximal extension , and ankle plantar flexion at the stance phase ( left ankle 2.64 , right ankle 2.69 , left knee 6.27 , right knee 2.79 ) .
the left knee was more extended at midstance with shoes only when compared to grafos at t3 ( 38.03 and 34.99 , respectively ) .
no change was found on the right . however , maximal ankle dorsiflexion increased with shoes only at the stance phase ( by 5.89 on the left and 9.38 on the right ) , demonstrating that the grafos maximal effect occurs at terminal stance .
walking with the fes device at t3 revealed improvement in knee extension ability at midstance and maximal knee extension at the stance phase bilaterally compared to shoes only and grafos conditions ( maximum knee extension at stance , left and right ) : fes 32.65 , 31.04 , shod only 33.71 , 34.29 , and grafos 36.69 , 34.26. similar results were found at t2 ; however , there was no effect on hip kinematics .
spatiotemporal parameters at t3 revealed an increase in walking speed with the fes device and grafos compared to walking barefoot ( left : 0.73 , 0.67 , and 0.57 m / s , respectively ; right : 0.74 , 0.67 , and 0.55 m / s , respectively ) .
when walking with the fes device , the highest speed was attained due to an increase in step length and cadence . when comparing the patient s walking speed with fes in t3 versus t2 , a higher walking speed , cadence , and bigger step length occurred at t3.table 4spatiotemporal parameters measures at t3 compared to td subjects ( mean sd)grafo 3ness off 3ness on 3tdrightleftrightleftrightleftwalking speed ( m / s)0.67 ( 0.03)0.67 ( 0.05)0.59 ( 0.03)0.61 ( 0.03)0.74 ( 0.02)0.73 ( 0.02)1.39step length ( m)0.52 ( 0.02)0.52 ( 0.03)0.52 ( 0.03)0.5 ( 0.01)0.55 ( 0.03)0.56 ( 0.00)0.74cadence ( steps / min)76.2 ( 2.24)76.2 ( 3.16)69.79 ( 1.47)72.29 ( 0.44)77.77 ( 1.47)78.36 ( 3.46)111 spatiotemporal parameters measures at t3 compared to td subjects ( mean sd )
at t2 , the patient was able to ascend and descend stairs with a step - to pattern , whereas he was able to ascend and descend the stairs with a step - through pattern immediately after adjusting the fes .
this effect was also seen at t3 . in addition , at t3 , he was able to step through stairs in all conditions .
to the best of our knowledge , this is the first report evaluating the short- and long - term effects of an fes device on the quadriceps , compared to grafo , aimed to decrease the severity of crouch gait in a cp subject and assist in achieving lower limb extension .
it is the first step to use rapidly developing technology to improve gait and functional ability in cp children by fes .
our patient s gait was a typical crouch gait with excessive hip and knee flexion and dorsiflexion throughout the stance phase .
he has been wearing grafos for 9 years ( for most of the day ) , together with two quadripods .
however , with grafos , he still complained of muscle fatigue when standing for prolonged periods of time and walking .
the subject preferred grafos over barefoot and shoes only , in spite of the fact that his kinematic results did not reveal significant improvement in his lower limb extension .
it was surprising to find that his knee kinematics still revealed a crouch gait pattern when comparing grafos and shoes only conditions .
it appears that the orthotics in this case prevented lower limb flexion rather than facilitated extension .
the subject wore standard sports shoes with a higher heel than the forefoot , which might have caused forward tilting of the tibia , leading to flexion at all levels .
the grafos also supported him and , with proprioceptive feedback , facilitated leaning forward against the orthotics rather than knee extension .
these results concur with previous studies , where knee flexion was not reduced as a result of solid ankle foot orthosis ( afo ) or grafos at the stance phase .
hayek et al . reported no change in ankle dorsiflexion and knee flexion angle at single limb support in children with diplegic cp using solid and articulated afos .
abel et al . reported no significant change in knee position at stance as a result of fixed afos in the cp diplegia group with equinus or pes planovalgus deformities .
rethlefsen et al . also reported no change in knee position during stance in subjects with spastic diplegia walking with fixed or articulated afos .
the limited influence of orthotics on our subject with crouch gait can be explained by his severe external foot progression .
excessive external foot progression causes lever arm dysfunction , thus decreasing the efficiency of the orthotics .
however , they did not evaluate the long - term effects after daily use and training with an fes device nor did they compare the results to walking with shoes only or grafo . comparing all shod conditions from a kinematic point of view favored fes by improving the patient s ability to extend the knees at the stance phase .
the stimulation mainly affected the knee joint and with a small effect on the ankle .
the subject favored fes over grafos due to achieving a more extended support on the lower limb without excessive orthotic support . in addition
, fes gave him the feeling of actively strengthening and extending the knee as opposed to the passive effect of the orthotics .
however , the effect of attaining stronger muscles as described by the subject should be further evaluated .
in addition , the most impressive effect was that fes provided much more support , increased the amount of time the patient was able to walk or stand , and achieved a more upright position .
the positive effect can be attributed to the trend seen in fig . 2 , which shows his ability to achieve a more extended knee position throughout the stance phase .
some difficulty with the use of the fes device was reported due to the discomfort caused by sitting while the device was connected to his thigh .
it should be emphasized that fes will assist in achieving knee extension by supporting the muscle force against restraints preventing knee extension .
tendon or joint contractures , such as knee or hip joint flexion contracture , as is common in crouch gait .
our patient had a knee flexion contracture of 5 and tight hip flexors ( thomas test 15 ) . in cases of severe contractures ,
the fes effect might be limited . walking speed increased at t3 , indicating that the patient acclimated to the fes device over time .
the effect of the stimulation on the patient s functional ability to ascend and descend stairs was immediate , with no need for reeducation . at t2 , he was able to ascend and descend stairs , step through versus step to ( which had been his strategy for years ) , immediately after adjusting to the fes device , which was achieved by receiving more support from the stance limb and its extension , rather than leaning on the device .
however , the kinematics were not captured in the stairs condition . a carryover effect with stairs occurred at t3 .
it seems that the effect is not only due to stronger quadriceps but also due to a motor learning effect .
this report suggests that functional electrical stimulation ( fes ) of the quadriceps muscles may have an important effect on achieving knee extension at stance and decreasing crouch gait , depending on an adequate passive range of motion of the hip , knee extension , and plantar flexion .
patient satisfaction was high due to improved functional ability and the feeling of active strengthening .
the positive effect observed demonstrates the potential of fes as a means of achieving improved gait kinematics and functional ability in a patient with crouch gait . | backgroundcrouch gait is a major sagittal plane deviation in children diagnosed with cerebral palsy ( cp ) .
it is defined as a combination of excessive ankle dorsiflexion and knee and hip flexion throughout the stance phase . to the best of our knowledge ,
functional electrical stimulation ( fes ) has not been used to decrease the severity of crouch gait in cp subjects and assist in achieving lower limb extension.purposeto evaluate the short- and long - term effects of fes to the quadriceps muscles in preventing crouch gait and achieving ankle plantar flexion , knee and hip extension at the stance phase.methodsan 18-year - old boy diagnosed with cp diplegia [ gross motor function classification system ( gmfcs ) level ii ] was evaluated .
the ness l300 plus neuroprosthesis system provided electrical stimulation of the quadriceps muscle .
a three - dimensional gait analysis was performed using an eight - camera system measuring gait kinematics and spatiotemporal parameters while the subject walked shod only , with ground reaction ankle foot orthotics ( grafos ) and using an fes device.resultswalking with the fes device showed an increase in the patient s knee extension at midstance and increased knee maximal extension at the stance phase . in addition , the patient was able to ascend and descend stairs with a step - through pattern immediately after adjusting the fes device.conclusionsthis report suggests that fes to the quadriceps muscles may affect knee extension at stance and decrease crouch gait , depending on the adequate passive range of motion of the hip , knee extension , and plantar flexion .
further studies are needed in order to validate these results . |
polyprenylated acylphloroglucinol
( ppap ) natural products including
nemorosone , clusianone , and hyperforin are structurally complex molecules
having promising chemotherapeutic properties ( figure 1 ) .
ppaps
are highly regarded for their biological activities which include anticancer , antiviral , and
antibacterial properties .
bottlenecks
toward their applications in disease treatment are stability issues , synthetic challenges , and promiscuous biological activity .
thus , medicinal chemistry and biological evaluation of novel analogs
within the ppap family are of high interest but have been underdeveloped . with these challenges in mind , we sought to develop a route that
was both chemically efficient and applicable to diversity - oriented
synthesis ( dos ) .
representative ppap natural
products . as expertly penned by mulzer in
a recent review ,
there are numerous tactics
to render a given synthesis
efficient including biosynthetic considerations . by considering a
biosynthetic hypothesis for a natural product , often innate reactivity
can be exploited , ideally resulting in an efficient synthetic strategy .
in the case of ppaps ,
the molecules are presumed to be derived from
three building blocks : a desoxyhumulone substrate such as 1 and two additional prenyl cation equivalents which react distinctly
to assemble the bicyclo[3.3.1]nonane core via ( a ) dearomative prenylation
and ( b ) alkene - intercepted prenylation ( scheme 1 ) .
union of the prenyl fragments with
the phloroglucinol at either the 2- and 4-positions or the 4- and
6-positions yields nemorosone ( arbitrary absolute configuration shown )
or clusianone , respectively . generally speaking , this isomeric difference
is referred to as type a and type b
throughout this family .
ppap through union of the phloroglucinol core to a geranyl fragment
( dearomatization ) and a prenyl cation ( cascade bicyclo[3.3.1]nonane
assembly ) .
although the biosynthesis is efficient and complexity generating ,
it has yet to be realized in a laboratory setting .
we hypothesized that
pd - catalyzed dearomative conjunctive allylic
annulation ( dcaa ) of desoxyhumulones 1 and 2-methylene-1,3-propanediol
derivative 2 would serve as an efficient biosynthesis - inspired ,
diversity - oriented strategy to access a plethora of ppap analogs 3 possessing many of the essential structural features for
bioactivity ( scheme 2 ) .
such an approach to ppap core structures would take advantage of
biosynthetic , innate reactivity ( phloroglucinol dearomatization ,
allylic alkylation ) and utilize the predictably reactive reagent 2 which has been utilized extensively in conjunctive bond - forming
processes .
herein , we report our initial
discoveries enabling the rapid construction of diverse ppap analogs
for biological evaluation through this modular and step - economic sequence .
in order to realize a diversity - oriented approach
to ppap - type
structures , it was necessary to establish a modular , scalable , and
robust route to allyl - desoxyhumulone scaffolds 1 . the
synthesis of allyl desoxyhumulone 1a , a common intermediate
en route to the natural products plukenetione a , 7-epi - nemorosone , and ( )-clusianone ( scheme 3a ) , has been achieved
by direct c - allylation of 2-acylphloroglucinol 4a with
allyl bromide in low yield due to overalkylation or by selective o - allylation then claisen rearrangement
requiring temperatures exceeding 200 c ( scheme 3b ) .
generally speaking , allylated phenols 5 can be accessed
through high - temperature ( > 200 c ) or lewis acid promoted
-allyl
phenyl ether claisen rearrangements ( scheme 4 ) . due to the sensitivity of acylphloroglucinols
and desoxyhumulones , we wondered if a relatively low - temperature and
neutral formal allyl phenyl ether claisen rearrangement could be achieved
via pd(0)-catalysis .
as shown in scheme 5 ,
we envisioned access to desoxyhumulones via pd - catalyzed decarboxylative
allylation ( dca ) which should controllably
generate diallyl phenyl ether7a in accord with the site - specificity of the dca process .
claisen
rearrangement under mild conditions via allyl phenyl ether ionization and concomitant c - allylation to provide product 1a ( scheme 5 ) .
percent
conversion as determined
by h nmr analysis . to examine the possibility for a mild pd - catalyzed double decarboxylative
allylation / claisen rearrangement sequence yielding desoxyhumulones 1 , we prepared the requisite starting material 6a in > 95% yield from 2-benzoylphloroglucinol 4a and
allyl
chloroformate .
excitingly , we found that
a highly efficient reaction of 6a to the desired product 1a occurred using 1 mol % pd(pph3)4 in
cyclohexane ( cyh ) at 75 c for 2h ( table 1 , entry 1 ) .
of note , reaction for 5 min under the same conditions
resulted in complete conversion to the o - allylated byproduct 7a confirming its intermediacy en route to product 1a .
regarding other solvents , ch2cl2 and thf
yielded only o - allylated products ( table 1 ,
entries 3 and 4 ) , whereas toluene was also found to be a competent
solvent for desoxyhumulone scaffold synthesis ( table 1 , entry 5 ) . to confirm that pd(pph3)4 is involved in
the mild allyl aryl ether claisen rearrangement , we prepared 7a via dca of 6a and resubjected it to the reaction
conditions sans the palladium catalyst .
upon addition of the palladium catalyst under the optimized
conditions ( cyclohexane , 75 c ) , conversion to 1a commences ( scheme 6 ) . regarding the scope of allyl - desoxyhumulone
synthesis via double
dca / formal claisen rearrangement
, phloroglucinols with a variety of
2-acyl groups were found to be compatible coupling partners ( scheme 7a ) .
for example , desoxyhumulones 1a1d having 2-benzoyl- , acetyl- , isobutyryl- ,
and isovaleroyl groups were prepared .
internal allylic substitution
proceeded as desired to afford products 1e and 1f ; however , terminally substituted allylic coupling partners
( e.g. , cinnamyl and prenyl ) afforded complex mixtures .
excitingly , the reaction could be extended to
related aromatic starting materials such as resorcinol 1 g and orcinols 1h1j .
importantly ,
a variety of large - scale ( gram multigram scale ) reactions were
performed for each of the compatible scaffolds identified ( phloroglucinols 1a / d , resorcinol 1 g , and orcinol 1h ) .
all multigram scale reactions were successful with reduced catalyst
loading ( 0.25 mol % pd(pph3)4 ) at an increased
concentration ( 0.5 m in cyclohexane ) . to broaden substrate scope and
further enhance the diversity of ppap analogs for our investigation ,
we also removed the o - methyl group on 1a , 1b , and 1d with bbr3 to access
the unprotected variants 1k1 m ( scheme 7b ) .
in addition to the synthesis
of desoxyhumulones 1a1 m via dca / formal
claisen rearrangement , we
also investigated the synthesis of related scaffolds ( scheme 8) .
interestingly , we found that the mono - allyl phenyl carbonate 8a only underwent dca to provide
allyl phenyl ether 8b under the optimized conditions
and did not undergo formal allyl phenyl ether -claisen rearrangement
regardless of the reaction duration ( scheme 8a ) .
in addition , the double dca / claisen rearrangement was extended
to the chrysin - derived flavone scaffold 9a under slightly
modified conditions ( scheme 8b ) . from the commercially
available flavone chrysin
, we prepared 6,8-diallylchrysin1n without silica gel chromatography
in 99% yield over the two - step sequence via intermediate 9a .
with a variety of desoxyhumulone scaffolds 1a1j in hand , many of which were prepared
in multigram quantities ,
we next turned to the development of the key dearomative conjunctive
allylic annulation ( dcaa ) to provide a diversified set of ppap analogs .
using the model coupling reaction between 1a and 2
, we began our quest for the optimal pd catalyst , solvent ,
and reaction conditions ( table 2 ) .
mono - methyl allyl desoxyhumulone 1a was chosen
as an initial scaffold as it was thought , based on our previous studies , that the methyl ether would direct the annulation
to the 2- and 4-positions of the substrate ( type a
we ultimately identified two standard conditions
( a and b , table 2 , entries 1 and 2 ) that were
utilized throughout
our studies to construct ppap analogs .
standard conditions a ( pd(pph3)4 , cyclohexane ) were found to be highly solvent
dependent as related conditions in dce , toluene , and thf did not produce
the desired product ( table 2 , entries 35 ) .
standard conditions b ( pd / binap ) appeared to be more tolerant to solvent
choice , though reaction times were found to be significantly longer
in lower boiling solvents such as cyclohexane and thf ( table 2 , entries 6 and 7 ) .
standard conditions
a. standard conditions b. 2 mol %
pd2dba3 , 4 mol % rac - binap ,
premixed in reaction solvent
for 10 min , . determined
by h nmrof
the crude reaction mixture .
interestingly , using either the methylated ( 1a1f , scheme 7a ) or the nonmethylated
( 1k1 m , scheme 7b ) desoxyhumulone scaffolds , either type a or
type
b ppap structures could be selectively prepared ( schemes 9 and 10 , respectively ) .
o - methyldesoxyhumulones 1a1f reacted under standard conditions a ( table 2 , entry 1 ) to yield type a ppap analogs 3a3f in excellent yields ( scheme 9a ) .
the reaction tolerated both allyl ( 3a3d ) and -methylallyl ( 3e and 3f ) substitution at c4 and c6 .
type
b annulation adducts 3k3 m under modified conditions via regioselective cyclization at the
more nucleophilic c4 and c6 positions ( scheme 10a ) .
we discovered that increased reaction
times , lower temperatures , and larger catalyst ( pd2dba3/binap ) loadings were required for successful cyclization
to the type b core as low yields were obtained using
standard conditions a or b. as one possible explanation , the nucleophilic
phenolate moiety at c5 may bind to binary palladium(0 ) more effectively
than binap resulting in loss of catalytic activity .
pleasingly , our general purification procedure developed
for dearomatized phloroglucinols and ppap derivatives allowed access to bicyclo[3.3.1]nonanes 3k3 m along with their potassium salts in high yields without the use of silica gel chromatography ( scheme 10a ) .
moreover , using the
grubbs second - generation catalyst , we could
also conveniently access prenylated analogs of both
type a
and b ppaps 3 as shown for prenylated variants 3ca ( scheme 9b ) and 3ma ( scheme 10b ) in excellent yields . all products 3 led to selective prenylation of the monosubstituted allyl
groups leaving the exo - methylene intact .
removal of the methyl enol ether could be accomplished
in good yield revealing the vinylogous acid functionality commonly
found in ppap natural products ( scheme 9b ) .
we opted to store the vinylogous acid 3ca as its dicyclohexyl
ammonium salt , and the type b
scaffolds 3k3 m were stored as potassium salts due to their enhanced stability and shelf life .
we also found that alkyl substitution at c4 and c6
was important
for success of the dcaa reaction ( scheme 11 ) .
while the standard allyl - desoxyhumulone 1a underwent
clean reaction under the optimized conditions to afford 3a , neither the proteo-(4a ) or the chlorinated ( 10a ) variants reacted with conjunctive reagent 2 under standard conditions a or b , likely due to a combination of
steric and electronic influences . from the successful studies on allyl - desoxyhumulones 1a1f ( scheme 9 ) and 1k1 m ( scheme 10 )
, we reasoned that other scaffolds bearing at least a resorcinol
oxygenation pattern , an acyl group , and alkyl substituents at c4 and
c6 should also undergo the desired dcaa process .
we proceeded to test
our hypothesis by further broadening our investigation to construct
a diverse set of resorcinol- and orcinol - derived ppap analogs via
dcaa ( scheme 12 ) .
excitingly , we discovered
that resorcinol derivative 1 g and orcinol derivatives 1h1j yielded
ppap
analogs 3g3j lacking a vinylogous
acid moiety ( scheme 12 , eqs 1 and 2 ) .
moreover ,
the structure of dcaa product 3h was unequivocally determined
by x - ray crystallography ( figure 2 ) .
pyranone heterocycle 3n ( scheme 12 , eq 3 ) , likely resulting from
enhanced nucleophilicity of the unprotected phenol moiety positioned para to the acyl group in 1n ( cf .
dcaa adduct 3n is structurally
similar to the anticancer ppap natural products oblongifolins f and
g. next , starting from allylated methyl
atratate ( 11a ) , available in 1-step from methyl atratate ,
an inexpensive flavoring molecule ( $0.25/g ) , dcaa yielded two - separable products having type
a
the mixture likely
arises from the intermediate anion reacting through either major-
or minor - contributing resonance structures , which can be reasoned
by the fact that keto - stabilized allyl anions prefer to react at the
most - stabilized position .
finally , lupulone
derivative 12a yielded a ppap analog bearing gem - diallyl substitution ( scheme 12 , eq 5 ) .
x - ray crystal structure of analog 3h . in conclusion , we have achieved a biosynthesis - inspired ,
diversity - oriented
synthesis approach to both type a and b ppap analogs .
through the use of two consecutive pd - catalyzed reactions , double
dca / claisen rearrangement and a dcaa , we can rapidly prepare ppap
molecules for biological evaluation .
the reaction is applicable to
a number of electron - rich aromatic substrates bearing a resorcinol
or phloroglucinol substitution pattern .
further studies including
construction of highly diverse ppap - inspired chemical libraries for
biological studies and development of asymmetric dcaa are currently
in progress and will be reported in due course . | polyprenylated
acylphloroglucinols ( ppaps ) are structurally complex
natural products with promising biological activities .
herein , we
present a biosynthesis - inspired , diversity - oriented synthesis approach
for rapid construction of ppap analogs via double decarboxylative
allylation ( dca ) of acylphloroglucinol scaffolds to access allyl - desoxyhumulones
followed by dearomative conjunctive allylic alkylation ( dcaa ) . |
the most important role of vascular endothelium is the control of vascular tone by producing contracting and relaxing agents.1 nitric oxide is one of these factors which are released after the stimulation of endothelial cells by shear stress and some hormones like acetylcholine and cerotonin.2 risk factors such as oxidative stress35 and hypercholesterolemia6 alter the physiological processes of the endothelium system and thereby damage the endothelium .
endothelial dysfunction is associated with the diminished activity of endothelium - dependent hyperpolarizing factor and the decreased production of nitric oxide .
therefore , it leads to clinical consequences that include an increased inflammation , vasoconstriction , and development of atherosclerotic lesions.7 , 8 some in vivo studies have shown endothelial dysfunction in the arteries without angiographically detectable lesions in hypercholesterolemic patients.9 , 10 since impaired endothelium - dependent relaxation in the arteries is the most sensitive marker for the early diagnosis of atherosclerosis , a non - invasive , reproducible , and accurate method is required for the measurement of the endothelial function .
non - invasive evaluation of the endothelial function is an accurate method , which involves measuring acetylcholine - mediated dilation ( amd ) of the vascular lumen . in experimental conditions ,
the evaluation of nitric oxide production is the most useful method for the estimation of the endothelial function .
non - invasive testing involves calculating the changes induced by acetylcholine administration in the diameter of vessels with an ultrasound device.11 most researchers have used manual tracing for the measurement of the arterial diameter in ultrasound images.12 , 13 the manual tracing method is not only based on subjective operator assessment but also time - consuming .
use of such methods increases the reproducibility of the results and also reduces the duration of image processing.14 , 15 in this study , endothelium - dependent dilation produced by acetylcholine as well as nitroglycerine - induced endothelium - independent dilation was evaluated on the abdominal aorta of normal and atherosclerotic rabbits , using a b - mode ultrasound device . in our previous study,16
we presented a new automatic analyzing method for the detection of instantaneous changes in the arterial wall of rabbits abdominal aorta in sequential images of b - mode ultrasound .
we showed that this automatic method is accurate and highly reproducible and also the processing time can be efficiently reduced .
dynamic programming algorithm has the highest accuracy and maximum gradient algorithm has the lowest computation complexity for ultrasound image processing .
therefore , we combined the two algorithms for the automated measurement of instantaneous changes in the arterial diameter . in the present study
, we utilized a new computerized analysis method for the measurement of amd and nitroglycerine - mediated dilation ( nmd ) in sequential ultrasound images on the abdominal aorta during acetylcholine or nitroglycerine infusion in normal and atherosclerotic rabbits and compared the results obtained from the ultrasonic studies with those of histological evaluations .
a total of 12 healthy male new zealand white rabbits , weighing 2.53.0 kg , were purchased from pasteur institute of iran ( tehran , iran ) .
the rabbits were involved in this study after two weeks of adaptation in housing facilities .
all the animals were handled in accordance with the guidelines of universities federation for animal welfare ( ufaw).17 the animal experiments and protocols were evaluated and approved by the animal and ethics review committee of the tarbiat modares university ( tehran , iran ) .
the animals were individually housed in metal cages in air - conditioned room ( 221c ) .
the rabbits were randomly divided into a control group ( a ) , in which the rabbits consumed a standard chow diet ( n=6 ) , and a damaged group ( b ) , in which the rabbits were fed with standard rabbit chow supplemented with 2% cholesterol for four weeks ( n=6 ) .
ultrasound examination of the endothelial function of the rabbits aorta was performed once at the commencement of the study and once at four weeks after the start of high cholesterol diet for the hypercholesterolemic and the normal rabbits . in order to reduce the movement and gas artifact of the rabbits intestines
the rabbits were anesthetized with 50 mg / kg ketamine and 5 mg / kg xylasine ( alfasan co. , the netherlands ) by intramuscular injection .
heart rate and blood pressure were recorded via a monometer on the animal forearm , using a non - invasive blood pressure measurement device ( pet map graphic , ramsey med .
all the animals underwent ultrasonography ( ge med systems , voluson 730 pro , kretztechnik gmbh and co. ohg , austria ) with a nine - mhz linear array transducer ( 612 mhz ) .
the ultrasound probe was placed at the abdominal aorta , 1.5 cm below the renal artery ( figure 1a ) .
a longitudinal axis view of the abdominal aortic artery was obtained from the healthy and atherosclerotic groups ( figure 1b ) .
the transducer was placed with the least possible pressure and allowed the expansion of the abdominal aortic artery in all directions .
ultrasonic examination of the abdominal aortic artery was performed after at least thirty minutes of rest in the supine position and when the heart rate and blood pressure had reached a steady state .
a data acquisition system was used for monitoring and grabbing the changes in the arterial wall at a rate of forty - six frames per second .
sequential images of b - mode ultrasound were acquired at baseline and drug infusions ( acetylcholine and nitroglycerine ) .
the animals received acetylcholine drug at a rate of 0.5 g / kg / min for 15 seconds .
blood pressure was returned to baseline for at least five minutes after the end of drug infusion .
then , nitroglycerine infusion was started at a rate of 5 g / kg / min for 15 seconds . 10
during the acetylcholine and nitroglycerine infusions , ultrasound images were recorded . in off - line analysis ,
instantaneous changes in the arterial diameter at baseline and during acetylcholine or nitroglycerine infusion were obtained , and the endothelial function in the normal and atherosclerotic rabbits was estimated .
all the images were exported to matlab for image processing in matlab software version 7.0.1 ( mat software co. , mathworks , usa ) .
pixel size in digitized b - mode ultrasound image was 0.06 0.06 mm . for off - line analysis , a computerized analyzing method , which was presented in our previous study,16
was employed for detecting the instantaneous changes in the far and near walls in conjunction with the lumen diameter of the artery in sequential b - mode ultrasound images .
briefly , this method is based on the maximum gradient algorithm , and some characteristics of the dynamic programming algorithm were added for our applications . in this method , cost function and reference points were based on the maximum gradient and dynamic programming algorithm , respectively .
application of the algorithm to all of the images generated a sequence of artery diameters throughout three cardiac cycles . in order to evaluate endothelial function ,
amd was calculated as the ratio of the abdominal aorta diameter after acetylcholine infusion to the baseline diameter ( expressed as percent change ) .
amd and nmd were calculated as follows :
1)amd%=dmaxachdmeanbasedmeanbase100
2)nmd%=dmaxngdmeanbasedmeanbase100 where dmax - ach is the maximum systolic diameter after acetylcholine infusion , dmax - ng is the maximum systolic diameter after nitroglycerin infusion , and dmean - base is the mean diameter of the rabbits abdominal aorta over three cardiac cycles at baseline .
blood samples were taken via cardiac puncture after six weeks , and total cholesterol , triglycerides , low - density lipoprotein cholesterol ( ldl ) , and high - density lipoprotein cholesterol ( hdl ) levels were measured with a commercially available spectrophotometric assay kits to compare between the two groups . in order to confirm the ultrasonic results ,
consequently , after the end of the experiment procedures , all the animals were sacrificed with a lethal dose of intravenous pentobarbital sodium for histopathological analysis .
the abdominal aortic artery was quickly removed from the sacrificed rabbits and washed with phosphate - buffered saline .
the segments ( approximately 0.5 cm in length ) of the abdominal aorta were then excised and cut into three equal - sized pieces .
some specimens were opened longitudinally and mounted flat with the intimal side facing up on the slide .
the arteries were fixed in 10% buffered formalin and embedded in paraffin . to characterize the general architecture of the lesions ,
four-m thick cross - sections were cut and mounted on glass slides ( twelve sections in a lamella ) , and thereafter aortic rings were stained with hematoxylin and eosin for light microscopy ( olympus , bx51 , tokyo , japan , magnification 200 ) . digital image acquisition using digital image processing software ( image tools microsoft ,
the intima - media thicknesses of the abdominal aorta in the normal and atherosclerotic rabbits were measured .
comparisons of the data obtained from the normal and atherosclerotic groups were performed using the independent sample t - test and 95% confidence interval ( ci ) .
all the statistical analyses were performed using the spss software package ( spss v. 11.5 , inc .
reproducibility of each experiment was reported as coefficient of the variance percent ( cv ) .
the automated algorithm was run for measuring the instantaneous changes in the far and near walls and also the lumen diameters of the abdominal aorta in the normal and atherosclerotic rabbits at baseline and during acetylcholine or nitroglycerine infusion .
examples of the instantaneous changes in the arterial diameter at baseline and during acetylcholine or nitroglycerine infusion in the normal and atherosclerotic rabbits are shown in figures 2 ( a f ) .
the demographic measurements of the rabbits are depicted in table 1 as mean sd . the rabbits had a normal cardiac function and were comparable in terms of weight , heart rate , systolic and diastolic blood pressures , mean blood pressure , and pulse pressure .
there were no difference in systolic and diastolic blood pressures , mean blood pressure , pulse pressure , heart rate , and weight between the normal and the cholesterol - fed rabbits ( p value > 0.05 ) .
total cholesterol , triglycerides , ldl , and hdl levels were remarkably increased in the serum of the four - week cholesterol - fed rabbits .
significant differences in total cholesterol , triglycerides , ldl , and hdl levels were seen between the normal and the four - week cholesterol - fed rabbits ( table 2 ) .
there were no visible intimal lesions in the aortas of the control group in the microscopic studies .
internal and external elastic laminae could be identified ; and as expected , no smooth muscle cells were observed in the intima .
intimal thickening with fatty deposition was observed in all the hematoxylin - eosin stained specimens of the aortas of the four - week cholesterol - fed rabbits ( figure 3b ) . after four weeks
, elastic laminae could not be identified and macrophage and lipid accumulation within the disorganized elastic laminae caused an increase in intimal thickness .
the intima - media thickness was 0.21 0.02 mm , which became comparable with the control values . in the atherosclerotic group ,
the intima - media thickness was significantly higher than that of the normal artery ( p value<0.05 ) . in the normal arteries , the media consisted of multiple layers of circularly oriented smooth muscle cells .
instantaneous changes in the abdominal aorta diameter at baseline and during acetylcholine or nitroglycerine infusion were obtained , using sequential b - mode images .
peak systolic , end diastolic , and mean diameters of the abdominal aortic artery at baseline and during acetylcholine or nitroglycerine infusion are presented in table 3 .
no significant differences were shown for these parameters between the normal and the four - week cholesterol - fed rabbits .
no differences in the mean abdominal aorta diameter were observed at rest status and during acetylcholine ( ach ) or nitroglycerine ( ng ) infusion for the normal artery .
significant vasodilation effects were detected after acetylcholine administration in the control group and the four - week cholesterol - fed group ( p value<0.05 ) .
amd was 18.491.62 and 10.201.77 percent in the normal group and the four - week cholesterol - fed group , respectively ( figure 4 ) .
nmd was 15.542.35 percent and 14.641.54 percent in the control group and the four - week cholesterol - fed group , respectively ( figure 4 ) .
there was no significant vasodilation effect after the infusion of nitroglycerin in the control group and the four - week cholesterol - fed group ( p value>0.05 ) .
vascular endothelium - dependent vasodilation is impaired by hypercholesterolemia both in human18 , 19 and animal models.20 experimental and epidemiological data have demonstrated that a high cholesterol diet is highly related to the development of hypercholesterolemia.2123 loss of endothelium - derived relaxing factor is the earliest alteration to endothelium after the start of a high cholesterol diet .
endothelial dysfunction , which is measured by amd or flow - mediated vasodilation , is the most important early event in atherosclerosis.24 , 25 several studies have demonstrated that the endothelial dysfunction of peripheral arteries is a useful predictor for coronary artery disease and other cardiovascular risk factors.2628 therefore , a non - invasive , safe , accurate , and reproducible method is required for evaluating the endothelial function .
it seems feasible that amd could be drawn upon as an index of the endothelial function under physiologically - induced shear stress .
whether or not this method can detect changes in the endothelial function , however , has not been examined .
non - invasive measurement of flow - mediated vasodilation using b - mode ultrasound has been applied in human cardiovascular research.2934 moreover , methodological research must be focused on establishing extraction protocols of images to measure the endothelial function .
thus , in this study , amd and nmd of the abdominal aorta in normal and atherosclerotic rabbits were estimated and compared using sequential ultrasound images as the automated method .
the instantaneous changes in the lumen diameter under chemical stimulus could be useful for evaluating the endothelium function . in animal studies ,
the classical method of ex vivo organ bath has been widely used for evaluating endothelial function .
be that as it may , the results obtained from ex vivo studies could not be directly applied to in vivo studies .
some stimulations such as shear stress have a useful effect on the release of endothelium - dependent vasodilation in arteries in vivo .
in addition , it has been noted that in ex vivo studies , arteries are preconstricted before the evaluation of relaxation caused by several vasodilators.10 invasive assessment of the arterial endothelial function by intravascular ultrasound is widely used .
intravascular ultrasound has been employed in human as well as in animal models and yields an accurate assessment of the arterial function and morphology;35 it has , nonetheless , been restricted to invasive applications .
we used non - invasive b - mode ultrasound for evaluating the endothelial function in normal and atherosclerotic rabbits .
the automatic analyzing method was drawn upon for off - line analysis of sequential b - mode ultrasound images .
our previous study16 showed that this method can automatically detect instantaneous changes in the arterial wall without any manual correction .
our method , however , has some limitations due to the difficulty in obtaining artifact - free , high - quality ultrasound images of both far and near vessel walls .
moreover , movement of the probe and respiratory movement during image acquisition may cause artifacts , which should be excluded from analysis . in this study ,
significant endothelial dysfunction was seen in the rabbits given a high cholesterol diet for four weeks .
jayakody et al.36 showed that the amd of aortic rings in rabbits fed a 2% cholesterol - rich diet was significantly impaired as early as four weeks after the start of a high cholesterol diet .
also furchgot et al.37 demonstrated that the amd of the isolated aortic rings in rabbits depended on the endothelial function .
many studies have reported that amd is impaired in atherosclerotic arteries with histological lesions in cholesterol - fed animal model or coronary arteries in human in vitro.38,39 our study showed intima thickening in aortas in the four - week cholesterol - fed rabbits , whereas no microscopic visible intimal lesions were detected in the normal rabbits .
some animal studies have suggested that high plasma cholesterol alone might decrease endothelium - dependent vasodilation.40,41 in contrast , another research group demonstrated that hypercholesterolemia alone did not impair the endothelial function in the aorta of cholesterol - fed rabbits .
lesions.10 our data showed endothelial dysfunction in the arteries with histological changes in the intima in the cholesterol - fed rabbits .
in this study , we used a computerized analyzing method for evaluating endothelium - dependent and independent relaxation in sequential ultrasound images of hypercholesterolemic rabbits .
our method offers the option of evaluating the endothelial function repeatedly and accurately and enables us to investigate functional and structural alterations during the progression of atherosclerosis .
we can apply these results for human arteries and thus evaluate arterial walls during the progression of atherosclerosis , especially in initial symptoms . | background : in this study , we used a new computerized analytical method for the measurement of the endothelial function in sequential ultrasound images and compared it with histological studies , using the abdominal aorta in normal and atherosclerotic rabbits.methods:six rabbits received a standard rabbit chow as the normal group and the other 6 rabbits were fed a high cholesterol diet for four weeks as the atherosclerotic group .
b - mode images of the abdominal aorta with 46 frames per second were saved over three cardiac cycles at baseline and during acetylcholine or nitroglycerin drug infusion in the normal and atherosclerotic rabbits . in order to evaluate endothelial - dependent relaxation , acetylcholine - mediated dilation ( amd )
was measured during the infusion of acetylcholine at a rate of 0.5 g / kg / min and endothelial - independent relaxation was evaluated by measuring nitroglycerine - mediated dilation ( nmd ) during the infusion of nitroglycerin at a rate of 5 g / kg / min .
in addition , the ultrasonic evaluation was confirmed by histopathological evaluation of the abdominal aorta.results:significant differences in amd were detected between the normal and the four - week cholesterol - fed rabbits ( p value<0.05 ) , whereas there were no significant differences in nmd between the two groups ( p value>0.05 ) .
no microscopic intimal lesions were seen in the normal rabbits , but intimal thickening was observed in the histological studies in the four - week cholesterol - fed rabbits . additionally , the total cholesterol , triglycerides , low - density lipoprotein cholesterol , and high - density lipoprotein cholesterol levels were remarkably increased in the sera of the four - week cholesterol - fed rabbits(p value<0.05).conclusion : a new automatic method can help accurately evaluate the endothelial function in normal and hypercholesterolemic rabbits . |
non - melanoma skin cancer ( nmsc ) is the most commonly diagnosed type of cancer .
over 2 million patients are treated for these cancers each year in the usa alone , resulting in nearly $ 1.5 billion total direct costs annually .
unlike many other types of cancer , the rates of nmsc continue to rise , indicating the need to increase research and identify new , more effective therapies .
nmscs are primarily caused by chronic exposure to ultraviolet ( uv ) light from the sun , although chemical exposure , chronic wounds , and viral infection can be risk factors as well [ 1 , 4 ] .
there are two main types of nmsc : basal cell carcinoma ( bcc ) and squamous cell carcinoma ( scc ) .
and although these tumors are rarely metastatic , patients have a high risk of developing additional tumors within 5 years of diagnosis .
sccs make up roughly 16% of all skin cancers and are typically more aggressive than bccs , posing a higher risk for metastasis and leading to approximately 2,500 deaths annually .
the risk of developing skin cancer is very high in the general population , as one in five people will develop skin cancer in their lifetimes ; however , certain populations such as transplant patients are at an even greater risk [ 7 , 8 ] .
angiogenesis , the growth and expansion of the vasculature , is an important process in the growth and metastasis of many cancers , including nmsc .
vascular endothelial growth factor ( vegf ) is a potent pro - angiogenic factor and several studies have established a critical role for vegf in skin cancer .
vegf transgenic and conditional knockout mice subjected to skin carcinogenesis protocols , such as the well - established two - stage chemical carcinogenesis model [ 11 , 12 ] , have demonstrated that vegf promotes skin carcinogenesis through the induction of angiogenesis [ 13 , 14 ] .
additionally , several recent studies have now uncovered direct effects of vegf on keratinocytes and skin tumor cells .
these studies have suggested that in addition to enhancing angiogenesis , vegf may promote skin carcinogenesis by altering the survival , proliferation , or stemness of keratinocytes and tumor cells in an autocrine manner [ 1518 ] .
furthermore , immune cells such as macrophages can respond to directly vegf [ 19 , 20 ] and recent studies indicate that vegf recruits macrophages to skin tumors
. this review will highlight our current knowledge of the angiogenic and newly discovered non - angiogenic activities of vegf that contribute to non - melanoma skin cancer , which are summarized in figure 1 .
angiogenesis is a key process in the growth and spread of many cancers , including skin cancer .
typically , angiogenesis is required for tumors to grow beyond 1 - 2 mm in size and offers a route for tumor cells to disseminate to secondary sites . because of this
, tumor angiogenesis has been an attractive and promising therapeutic target . to induce angiogenesis , tumor cells and cells within the tumor microenvironment
must alter the balance of pro- and anti - angiogenic factors , favoring an angiogenic switch .
when pro - angiogenic signals outweigh anti - angiogenic signals , it allows for capillary sprouting through the proliferation and migration of endothelial cells . eventually , the newly formed vessels supply the tumor with oxygen and nutrients required for continued growth .
many pro - angiogenic factors have been identified and characterized , including basic fibroblast growth factor ( bfgf ) , interleukin-8 ( il-8 ) , platelet - derived growth factor ( pdgf ) , placental growth factor ( plgf ) , transforming growth factor- ( tgf- ) , and vascular endothelial growth factor ( vegf ) .
vegf - a ( referred to as vegf throughout this article ) is a 45 kda heterodimeric heparin - binding protein belonging to the family of vascular endothelial growth factors .
at least 5 splice variants of vegf have been identified in humans , including vegf121 , vegf145 , vegf165 , vegf189 , and vegf206 [ 25 , 26 ] .
vegf binds to three known receptors : vegf receptor-1 ( vegfr-1 ) , vegf receptor-2 ( vegfr-2 ) , and neuropilin-1 ( nrp-1 ) [ 2729 ] .
vegfr-1 and vegfr-2 are tyrosine kinase receptors characterized by a seven immunoglobulin - like extracellular domain , a single transmembrane region , and an intracellular tyrosine kinase domain .
nrp-1 is a single pass transmembrane protein that binds semaphorins as well as some isoforms of vegf .
nrp-1 functions as a coreceptor for the vegfrs , enhancing their activity ; however , nrp-1 may be able to signal independently of vegfrs in response to vegf , particularly in tumor cells .
vegf is well characterized as a potent inducer of angiogenesis and functions as a survival factor and mitogen for endothelial cells [ 34 , 35 ] . in general , vegf is expressed at low levels by epidermal keratinocytes and is upregulated during many pathological processes such as wound healing , psoriasis , and skin carcinogenesis [ 3638 ] .
vegf production by keratinocytes can be induced by many stimuli including hypoxia , transforming growth factor- , keratinocyte growth factor , uv radiation , and the tumor promoter 12-o - tetradecanoylphorbol-13 acetate ( tpa ) , while vegf production is inhibited by the transcription factor fra-1 [ 3946 ] .
strong evidence has demonstrated that vegf plays an important role in skin carcinogenesis . in human skin , vegf is expressed at low levels in normal epidermis , with more differentiated epidermal cell layers generally expressing more vegf than less differentiated epidermal cells [ 4749 ] .
several studies have confirmed that vegf levels are elevated in tumor cells compared to normal epidermal cells using immunohistochemistry and in situ hybridization techniques [ 4749 ] .
tumor cells of human bccs tend to show weak vegf expression [ 47 , 48 , 50 ] with positive tumor cells predominantly localized to the invading margin .
in contrast , sccs , which are typically more aggressive than bccs , display more intense and widespread staining , with higher expression in tumor cells localized near infiltrating inflammatory cells [ 47 , 50 ] . furthermore
vessel density is also high in sccs , especially in late - stage sccs , compared to normal skin , actinic keratoses , bccs , or early - stage sccs [ 48 , 49 ] . in mice , acute exposure to tumor promoters such as tpa or uv light causes upregulation of vegf and induction of angiogenesis in the skin [ 38 , 5153 ] .
vegf expression patterns in murine models of skin carcinogenesis mimic what is observed in human tumors .
a functional role for vegf in skin tumor angiogenesis has been demonstrated through the use of transgenic and conditional knockout mice .
both k6-vegf and k14-vegf transgenic mice which overexpress vegf in epidermal keratinocytes show elevated blood vessel density in the skin and in skin tumors compared to controls [ 13 , 14 , 54 ] .
vegf transgenic mice are also more susceptible to two - step chemical carcinogenesis [ 13 , 14 ] .
in addition to containing a larger number of blood and lymphatic vessels both within and surrounding skin tumors , k14-vegf mice develop chemically - induced tumors more rapidly and also have a dramatically higher incidence of metastasis than controls .
conversely , conditional k14-vegf knockout mice have reduced blood vessel density in tumors and are much more resistant to chemical carcinogenesis
in addition to inducing papillomas and sccs , uv exposure increases vegf levels and neovascularization in the skin [ 52 , 53 , 56 ] .
inhibition of vegf in the skin with compounds such as epigallocatechin-3-gallate ( ecgc ) and myricetin leads to a decrease in angiogenesis and a reduction in the number of uv - induced skin tumors [ 5658 ] .
evidence from orthotopic skin tumor models has also shown a link between vegf , angiogenesis , and tumor development [ 59 , 60 ] .
scc-13 cells transfected with vegf form invasive , highly vascularized tumors when injected subcutaneously or intradermally into nude mice .
similarly , tumors arising from a malignant hacat cell line , which produce large amounts of vegf , initiate angiogenesis more quickly and to a larger degree than hacat cell lines which form benign tumors .
furthermore , treatment with vegfr-2 blocking antibodies reduces endothelial cell proliferation and vessel density in tumors derived from the malignant cell lines to levels comparable to benign cell lines .
in addition , vegfr-2 antibody treatments reduce tumor growth and invasiveness , suggesting that vegf promotes tumor growth by inducing angiogenesis . taken together ,
the evidence from human tumors and animal models demonstrate that vegf is critical for the development , growth , and spread of skin tumors , and these findings have been largely attributed to the promotion of angiogenesis by vegf .
although dermal cells such as macrophages , fibroblasts , and other cell types are known to produce vegf , epidermal keratinocytes are believed to be the principle source of vegf in the skin [ 36 , 45 , 55 , 61 ] .
in addition to stimulating angiogenesis through its actions on endothelial cells , recent evidence has demonstrated that vegf can have direct effects on keratinocytes .
several groups have now identified vegf receptors on keratinocytes , suggesting the possibility of autocrine vegf signaling . currently , there is some disparity in the exact receptor profiles that have been described .
some studies have identified vegfr-1 , vegfr-2 , and nrp-1 on keratinocytes [ 18 , 62 ] ; however , others do not detect vegfr-2 [ 1517 ] .
our lab has shown that vegf induces the proliferation of cultured primary human keratinocytes through vegfr-1 and this finding has been confirmed by others in murine keratinocytes .
additionally , vegfr-1 is expressed in mouse and human skin tumor cells and in squamous cell carcinoma cell lines , suggesting that vegf could affect tumor cells directly .
autocrine functions for vegf in keratinocytes and skin tumor cells have also been suggested by recent functional studies performed in vivo [ 16 , 17 ] .
lichtenberger et al . utilized various conditional knockout mice to uncover a direct role of vegf in skin carcinogenesis using the k5-sos model , in which the ras activator son of sevenless is constitutively activated in the epidermis . in this model ,
k5-sos mice develop skin tumors spontaneously and tumors can be induced rapidly by wounding the skin [ 17 , 64 ] .
keratinocytes were shown to overexpress vegf in the k5-sos model , and k5-specific deletion of vegf reduced tumor development in these mice .
loss of keratinocyte vegf also lead to a decrease in vessel density and a decrease in tumor cell proliferation , and vegf was able to enhance keratinocyte proliferation in vitro . because vegfr-1 expression was detected in murine and human skin cells , epidermal vegfr-1 was deleted in k5-sos mice . a reduction in papilloma development and tumor cell proliferation
was observed in conditional vegfr-1 knockout mice compared to controls , while blood vessel density was unaffected .
together , these studies establish a direct role for vegf in skin carcinogenesis , wherein vegf stimulates tumor cell proliferation through vegfr-1 .
interestingly , an autocrine loop between vegf and nrp-1 has also been discovered . using the two - stage chemical skin carcinogenesis model , beck et al .
cd34 tumor cells were shown to express higher levels of vegf than cd34 tumor cells or normal keratinocytes .
epidermal overexpression of vegf increased the pool of cd34 cscs , while inhibition of vegfr-2 activity with dc101 or conditional deletion of vegf in the epidermis reduced the csc pool and diminished csc proliferation , in addition to reducing the number of established tumors .
conditional deletion of nrp-1 completely blocked tumor formation in the chemical carcinogenesis model compared to control mice which all developed papillomas .
in addition , when conditional nrp-1 knockout mice were crossed with vegf transgenic mice , vegf was unable to promote tumor growth , even though efficient tumor angiogenesis was still observed .
overall , the results suggest that epithelial cell - derived vegf regulates cscs in an autocrine manner . in addition to affecting epithelial cell proliferation and stemness , a recent study suggested that vegf may also directly affect keratinocyte survival in vitro.zhu et al .
showed that exposure to uv light , the primary causative agent of nmsc , increased the expression of vegfr-1 , vegfr-2 , and nrp-1 in primary normal human keratinocytes in vitro and in human epidermis in vivo .
interestingly , vegf was able to protect keratinocytes from apoptosis following exposure to moderate ( 300 j / m ) but not high ( 700 j / m ) doses of uv .
activation of vegfr-2 , but not vegfr-1 , was responsible for the observed increase in keratinocyte survival .
although these results will need to be confirmed in vivo , they suggest that vegf could function as a survival factor for keratinocytes following uv exposure .
in addition to endothelial cells , some immune cells also express vegf receptors , supporting the idea that vegf can have paracrine effects that are not related to its pro - angiogenic activity .
for example , monocytes and macrophages express vegfr-1 and vegf has been shown to be a chemoattractant for these cells [ 19 , 20 ] .
tumor - associated macrophages , particularly m2 macrophages , are believed to promote tumor growth and invasion and well as angiogenesis [ 65 , 66 ] .
recently , linde et al . used an orthotopic tumor model in which control or vegf - transfected hacat cells were injected subcutaneously into mice .
vegf - driven hacat tumors were larger , more vascular , more invasive , and had higher numbers of infiltrating m2 macrophages compared to control tumors .
depletion of macrophages reversed the effects of vegf overexpression , indicating that vegf was influencing tumor development by affecting macrophages . in this model , vegf stimulated the recruitment of macrophages to the tumors but was not sufficient to polarize them .
these studies indicate that in addition to promoting angiogenesis , vegf can influence skin carcinogenesis by recruiting immune cells .
strong evidence has established a critical role for vegf in the development of non - melanoma skin cancers .
vegf is produced by the skin in response to tumor - promoting agents such as tpa and uv light , and skin tumors are known to express elevated levels of vegf . in mouse studies , vegf increases angiogenesis and tumor growth , while the loss of vegf inhibits skin carcinogenesis . to date , these findings have been primarily attributed to the potent pro - angiogenic effects of vegf .
however , the presence of vegf receptors on non - endothelial cell types , such as keratinocytes and macrophages , has expanded our view of the potential functions of vegf .
indeed , new evidence suggests that vegf can impact skin carcinogenesis by directly affecting keratinocytes , tumor cells , and immune cells .
while there is no doubt that vegf plays an important role in skin carcinogenesis , more work is required to characterize the various mechanisms by which vegf contributes to this process and to understand the relative importance of each of these pathways .
further studies will have to be carried out to determine whether these newly described alternative functions of vegf can be targeted to treat nmsc . | vascular endothelial growth factor ( vegf ) is known to play a critical role in the development of non - melanoma skin cancers .
vegf is a potent pro - angiogenic factor and it is elevated in mouse and human skin tumors . the use of transgenic and knockout mice has shown that vegf is essential for tumor development in multiple models of skin carcinogenesis and , until recently , the mechanism of action has been primarily attributed to the induction of angiogenesis . however , additional roles for vegf have now been discovered .
keratinocytes can respond directly to vegf , which could influence skin carcinogenesis by altering proliferation , survival , and stemness . in vivo studies
have shown that loss of epidermal vegfr-1 or neuropillin-1 inhibits carcinogenesis , indicating that vegf can directly affect tumor cells .
additionally , vegf has been shown to promote tumor growth by recruiting macrophages to skin tumors , which likely occurs through vegfr-1 .
overall , these new studies show that vegf carries out functions beyond its well - established effects on angiogenesis and highlight the need to consider these alternative activities when developing new treatments for non - melanoma skin cancer . |
this retrospective study included 964 eyes from 500 subjects including 128 healthy normal eyes and 836 eyes with primary open angle glaucoma had various stages of visual field defects ( 572 early , 164 moderate and 100 severe ) .
both eyes of each patient were included in the study if they satisfied the entry criteria as follows : each eye had a best corrected visual acuity of 20/25 or better , a spherical equivalent refractive error between -5 and + 5 diopters , clear ocular media with no clinically significant cataract , a normal open angle , and no previous intraocular surgical history . the diagnosis of glaucoma was based on the presence of typical glaucomatous optic disc damage , as judged by stereoscopic examination by a glaucoma specialist ( y. j. hong ) , and the presence of glaucomatous visual field loss as measured by sap .
the patients had no significant ocular diseases other than glaucoma and no other diseases affecting visual fields .
the normal controls had no visual field changes on sap , intraocular pressure below 21 mmhg , no optic nerve head or retinal nerve fiber layer changes suggestive of glaucoma , no other ocular disease or surgical history , no diabetes , and no family history of glaucoma .
all subjects were examined using sap ( carl zeiss meditec inc , dublin , ca ) with a 30 - 2 swedish interactive threshold algorithm ( sita ) standard strategy .
the minimal visual field abnormality was determined by sap and was defined as significant when : ( 1 ) the glaucoma heimifield test was " outside normal limits " in 2 consecutive fields ; ( 2 ) 3 or more adjacent points were present in an expected location of the central 24-degree field that depressed below the 5% level on the pattern deviation plot ( pdp ) , one of which must have been below the 1% level in 2 consecutive fields ; or ( 3 ) pattern standard deviation ( psd ) was significant below the 5% level in 2 consecutive tests.10 visual field defects were divided into 3 stages : early , moderate , and severe.11 the early stage of a glaucomatous visual field defect was defined as having : ( 1 ) a mean deviation ( md ) of no worse than -6db , ( 2 ) fewer than 25% of the points depressed below the 5% level and fewer than 15% of points depressed below the 1% level on pdp , and ( 3 ) no point within the central 5-degree field with a sensitivity of less than 15db .
a moderate stage of visual field defect was defined as having : ( 1 ) md of worse than -6 db but no worse than -12db , ( 2 ) fewer than 50% of the points depressed below the 5% level and fewer than 25% of points depressed below the 1% level on pdp , ( 3 ) no point within the central 5-degree field with a sensitivity of less than or equal to 0 db , and ( 4 ) only 1 hemifield containing a point with sensitivity less than 15db within 5 degrees of fixation .
criteria for severe defects in glaucoma were defined as : ( 1 ) md worse than -12 db , ( 2 ) more than 50% of the points depressed below the 5% level and more than 25% of points depressed below the 1% level on pdp , ( 3 ) any point within the central 5-degree field with a sensitivity of less than or equal to 0 db , and ( 4 ) both hemifields containing a point(s ) with sensitivity less than 15 db within 5 degrees of fixation .
the rnfl photographs were recorded with blue reflectance ( " red - free " ) images using the hra1 .
two of authors ( s. hong & s. j. ha ) interpreted the rnfl photos using the two scoring systems ( table 1 ) under the masking of the diagnosis . for darkness scores , the contrast and brightness of rnfl photos were adjusted to distinguish sharply the retinal blood vessels from the background using heidelberg eye explorer program ( heidelberg engineering , dossenheim , germany ) . on location scores
a reference plane was set across the horizontal raphe dividing the papillomacular bundle into two vertical halves .
rnfl in the 15 degrees above and below this reference plane was termed the ' temporal ' sector .
rnfl in the 75 degrees from the end of the ' temporal ' sector to the vertical line dividing the optic nerve head into two halves was termed as ' supero- , and infero- temporal ' sectors for the respective vertical positions .
the remaining 180 degrees of nasal rnfl was designated as the ' nasal ' sector . in cases with a large or multiple rnfl defect over several sectors ,
if the two scores did not agree with each other , the other two glaucoma specialists ( y. j. hong & g. j. seong ) were asked to interpret it .
table 1 showed the scoring methods to assess the rnfl photo.9 the rnfl defect score i was a summation of each score , and the rnfl defect score ii was the product of each score - rnfl defect , darkness , width , and location .
the rnfl defect score i could range from 0 to 11 , and the rnfl defect score ii could range from 0 to 54 .
the interval between the sap and rnfl photography was less than 1 month . to assess correlations between rnfl photographs using hra1 and sap , we compared two rnfl defect scores ( rnfl defect score i and ii ) and visual field indices ( md and psd ) of sap .
statistical comparisons between groups were conducted using an independent 2-tailed student t - test , and p - values less than 0.05 were considered statistically significant . statistical analysis for linear regression
was performed using the medcalc for windows program , version 7.6.0.0 ( medcalc software , mariakerke , belgium ) . statistical analyses other than linear regression were carried out using the program spss for windows , version 11.5 ( spss inc , chicago , il ) .
this retrospective study included 964 eyes from 500 subjects including 128 healthy normal eyes and 836 eyes with primary open angle glaucoma had various stages of visual field defects ( 572 early , 164 moderate and 100 severe ) .
both eyes of each patient were included in the study if they satisfied the entry criteria as follows : each eye had a best corrected visual acuity of 20/25 or better , a spherical equivalent refractive error between -5 and + 5 diopters , clear ocular media with no clinically significant cataract , a normal open angle , and no previous intraocular surgical history . the diagnosis of glaucoma was based on the presence of typical glaucomatous optic disc damage , as judged by stereoscopic examination by a glaucoma specialist ( y. j. hong ) , and the presence of glaucomatous visual field loss as measured by sap .
the patients had no significant ocular diseases other than glaucoma and no other diseases affecting visual fields .
the normal controls had no visual field changes on sap , intraocular pressure below 21 mmhg , no optic nerve head or retinal nerve fiber layer changes suggestive of glaucoma , no other ocular disease or surgical history , no diabetes , and no family history of glaucoma .
all subjects were examined using sap ( carl zeiss meditec inc , dublin , ca ) with a 30 - 2 swedish interactive threshold algorithm ( sita ) standard strategy .
the minimal visual field abnormality was determined by sap and was defined as significant when : ( 1 ) the glaucoma heimifield test was " outside normal limits " in 2 consecutive fields ; ( 2 ) 3 or more adjacent points were present in an expected location of the central 24-degree field that depressed below the 5% level on the pattern deviation plot ( pdp ) , one of which must have been below the 1% level in 2 consecutive fields ; or ( 3 ) pattern standard deviation ( psd ) was significant below the 5% level in 2 consecutive tests.10 visual field defects were divided into 3 stages : early , moderate , and severe.11 the early stage of a glaucomatous visual field defect was defined as having : ( 1 ) a mean deviation ( md ) of no worse than -6db , ( 2 ) fewer than 25% of the points depressed below the 5% level and fewer than 15% of points depressed below the 1% level on pdp , and ( 3 ) no point within the central 5-degree field with a sensitivity of less than 15db .
a moderate stage of visual field defect was defined as having : ( 1 ) md of worse than -6 db but no worse than -12db , ( 2 ) fewer than 50% of the points depressed below the 5% level and fewer than 25% of points depressed below the 1% level on pdp , ( 3 ) no point within the central 5-degree field with a sensitivity of less than or equal to 0 db , and ( 4 ) only 1 hemifield containing a point with sensitivity less than 15db within 5 degrees of fixation .
criteria for severe defects in glaucoma were defined as : ( 1 ) md worse than -12 db , ( 2 ) more than 50% of the points depressed below the 5% level and more than 25% of points depressed below the 1% level on pdp , ( 3 ) any point within the central 5-degree field with a sensitivity of less than or equal to 0 db , and ( 4 ) both hemifields containing a point(s ) with sensitivity less than 15 db within 5 degrees of fixation .
the rnfl photographs were recorded with blue reflectance ( " red - free " ) images using the hra1 .
two of authors ( s. hong & s. j. ha ) interpreted the rnfl photos using the two scoring systems ( table 1 ) under the masking of the diagnosis . for darkness scores ,
the contrast and brightness of rnfl photos were adjusted to distinguish sharply the retinal blood vessels from the background using heidelberg eye explorer program ( heidelberg engineering , dossenheim , germany ) . on location scores
a reference plane was set across the horizontal raphe dividing the papillomacular bundle into two vertical halves .
rnfl in the 15 degrees above and below this reference plane was termed the ' temporal ' sector .
rnfl in the 75 degrees from the end of the ' temporal ' sector to the vertical line dividing the optic nerve head into two halves was termed as ' supero- , and infero- temporal ' sectors for the respective vertical positions .
the remaining 180 degrees of nasal rnfl was designated as the ' nasal ' sector . in cases with a large or multiple rnfl defect over several sectors ,
if the two scores did not agree with each other , the other two glaucoma specialists ( y. j. hong & g. j. seong ) were asked to interpret it .
table 1 showed the scoring methods to assess the rnfl photo.9 the rnfl defect score i was a summation of each score , and the rnfl defect score ii was the product of each score - rnfl defect , darkness , width , and location .
the rnfl defect score i could range from 0 to 11 , and the rnfl defect score ii could range from 0 to 54 .
to assess correlations between rnfl photographs using hra1 and sap , we compared two rnfl defect scores ( rnfl defect score i and ii ) and visual field indices ( md and psd ) of sap .
statistical comparisons between groups were conducted using an independent 2-tailed student t - test , and p - values less than 0.05 were considered statistically significant . statistical analysis for linear regression
was performed using the medcalc for windows program , version 7.6.0.0 ( medcalc software , mariakerke , belgium ) .
statistical analyses other than linear regression were carried out using the program spss for windows , version 11.5 ( spss inc , chicago , il ) .
nine hundred sixty - four eyes from 500 subjects including 128 healthy normal eyes and 836 eyes with primary open angle glaucoma were evaluated . in the glaucoma group ,
572 eyes showed early visual field defects on sap , 164 showed moderate defects , and 100 showed severe defects .
demographic data and visual field indices for sap of subjects are shown in table 2 , and the scoring systems for rnfl photographs using hra1 are shown in table 3 .
, 3 show the correlation between rnfl defect scores and visual field indices of sap .
correlations between the rnfl defect score ii and md of sap were the strongest ( y = 9.515 - 1.772 x , r = -0.675 , p<0.001 ) ( fig .
correlations between the rnfl defect score i and psd of sap were the worst ( y=5.841 + 0.380 x , r=0.481 , p<0.001 ) ( fig .
since the rnfl defect score ii and md of sap showed the strongest correlation , correlations between these variables for various stages of visual field defect on sap were evaluated , as shown in table 5 .
the r value of early , moderate , severe , and control groups was -0.404 , -0.129 , 0.034 and -0.313 , respectively .
the strongest correlation between rnfl defect score ii and md of sap was in the early stage visual field loss group ( y=3.980 - 4.125 x , p<0.001 ) .
the second strongest correlation was in the control group ( y=2.849 - 2.386 x , p<0.001 ) .
additionally , linear regression analysis for rnfl defect score ii and md of sap in early glaucoma and control groups showed good correlation ( y=4.604 - 6.620 x , r=-0.524 , p<0.001 ) ( fig .
though rnfl photography is an important part of the examination of glaucoma patients , it is a subjective and qualitative method .
some researchers have tried to develop a grading system for rnfl photography,6 - 8 but interpretation of rnfl photos has remained very difficult . in the present study , we recorded rnfl photographs with blue reflectance ( " red - free " ) images using hra1 .
rnfl loss was assessed using a new scoring system ( table 1).9 on location scores , score " 1 " represents inferotemporal or superotemporal area , " 2 " represents nasal area , and " 3 " represents temporal area ( fig .
since the inferotemporal and superotemporal sectors are the early affected sectors and nasal sector is the late affected sector in glaucoma,12 - 15 we gave additional points to the nasal area .
the rnfl defect score i was a summation of each score , and the rnfl defect score ii was the product of each score - rnfl defect , darkness , width , and location .
the rnfl defect score i could range from 0 to 11 , and the rnfl defect score ii could range from 0 to 54 .
5 . the two new rnfl defect scoring systems strongly correlated with visual field indices of sap . among various combinations , the rnfl defect score ii and the md of sap showed the strongest correlation ( r = -0.675 , p<0.001 ) ( fig .
additionally , these measurements correlated more strongly in the group with normal and early visual field loss compared to the moderate and severe visual field loss groups ( r=-0.313 , p<0.001 ) ( fig .
this suggests that rnfl photography may be more meaningful in early stage glaucoma patients , and rnfl defect score ii can be used to interpret rnfl photography using hra1 for early glaucoma patients . in this study
, we included the glaucoma patients who had a typical glaucomatous optic disc damage and a glaucomatous visual field defect . additionally , the normal control participants had no optic nerve head or retinal nerve fiber layer changes and no visual field defect .
these inclusion criteria may be biased particularly in the early glaucoma patients . in conclusion , we have presented a method for the semi - quantitative interpretation of rnfl photos through the use of a new scoring system for rnfl photography .
this method provides good reliability and may extend the evaluation rnfl photography to non - specialists . | purposeto evaluate retinal nerve fiber layer ( rnfl ) defect by a new scoring system for rnfl photography using the heidelberg retina angiograph 1 ( hra1).methodsthis retrospective study included 128 healthy eyes and 836 primary open - angle glaucoma eyes .
the rnfl photography using hra1 was interpreted using a new scoring system , and correlated with visual field indices of standard automated perimetry ( sap ) . using the presence of rnfl defect , darkness , width , and location , we established the new scoring system of rnfl photos.resultsthe mean rnfl defect score i in the early , moderate , severe , and control groups were 7.3 , 9.2 , 10.4 , and 3.6 , respectively .
the mean rnfl defect score ii in the early , moderate , severe , and control groups were 14.5 , 28.5 , 43.4 , and 3.4 , respectively .
correlations between the rnfl defect score ii and the mean deviation of sap was the strongest of the various combinations ( r=-0.675 , p<.001).conclusionsusing a new scoring system , we propose a method for semi - quantitative interpretation of rnfl photographs .
this scoring system may be helpful to distinguish between normal and glaucomatous eyes , and the score is associated with the severity of visual field loss . |
b cells are central components of adaptive immunity , responding to pathogens by proliferation , differentiation and production of antibodies .
b cells also function in presentation of antigen to t cells and secretion of regulatory cytokines and chemokines . like t cells ,
they express highly variable and clonally restricted antigen - binding receptors , the specificity of which is determined by immunoglobulin variable region gene rearrangement .
the development and function of the b cell is primarily affected by signaling via their b cell antigen receptor ( bcr ) .
an important and controversial topic in the b cell field is the initiation of bcr signaling . in most cases ,
cell - surface receptors signal via ligand - induced subunit oligomerization , conformational changes , or a combination of these .
these receptor / ligand interactions have conformational limitations , likely preserving specificity through a process of coevolution . in contrast , bcr ligands are incredibly diverse and it is imperative to accommodate and discriminate a much broader range of ligand affinity and presentation than other receptors . put another way , b cell effector function including secretion of antibody critical to immunity relies on the ability of the repertoire of bcrs to respond to every possible epitope , in diverse physical contexts , derived from an array of pathogens that are limited only by evolution . as the immune response continues , the pathogen may attempt to evade by modifying antigens , and b cells must keep up with these minor modifications , while also increasing the receptor affinity of the responding b cells .
this diversity of ligand / receptor affinity , orientation , and presentation makes it difficult to resolve a clear mechanism of bcr signal initiation .
thus , many groups have proposed alternative mechanisms of signal initiation and amplification to complement , or dispute , the long established model that simple aggregation of receptors is sufficient to initiate signaling .
here we discuss recent progress and points of contention related to bcr initiation and function .
the bcr is composed of membrane - bound immunoglobulin ( mig ) non - covalently associated with a disulfide - linked heterodimer of cd79a ( ig ) and cd79b ( ig ) [ 1 - 4 ] ( see figure 1 ) .
following ligation of the mig , signals are transduced across the plasma membrane , leading to phosphorylation of the immunoreceptor tyrosine - based activation motif ( itam ) contained in the cytoplasmic tails of the cd79a and b [ 1,2,57 ] .
the kinase primarily responsible for this phosphorylation is thought to be a src - family kinase ( sfk ) : particularly , lyn , which is the predominant sfk expressed in b cells .
phosphorylation of itams leads to sfk binding by src - homology 2 ( sh2 ) domains and the upregulation of kinase activity .
this binding results in the activation and phosphorylation of syk . upon ligation of the bcr ( 1 ) , itams become phosphorylated via activity of sfks ( such as lyn ) and syk .
the signalosome is associated with cd79a non - itam phosphotyrosine residues via binding of the adaptor protein blnk ( not illustrated ) .
activated btk phosphorylates plc2 , which in turn cleaves the phosphoinositide pi(4,5)p2 , releasing ip3 into the cytosol and forming dag ( 3 ) .
the decrease in endoplasmic reticulum [ ca ] activates stim1 , which binds orai in the plasma membrane , forming the crac channel and allowing for the influx of extracellular ca ions ( 4 ) .
rasgrp and protein kinase c ( pkc ) are activated by binding dag , and feed into the mek / map kinase ( 5 ) and nfb activation pathways , respectively .
cd19 plays an important role in amplifying the bcr signal via processive activation of lyn , and activation of pi3k ( 6 ) . along with the recruitment of ph domain - containing signalosome components , the accumulation of pi(3,4,5)p3 drives activation of akt ( 7 ) .
lower panel b cell deactivation : lyn phosphorylates immunoreceptor tyrosine - based inhibition motifs ( itims ) in cd22 and fcriib .
the protein phosphatase shp1 has many substrates , including cd79 , syk , grb2 , and vav , as well as others not shown .
ship1 hydrolyzes the phosphate at position 5 of pi(3,4,5)p3 , while pten removes that at position 3 .
this decrease in pi(3,4,5)p3 concentration results in the disassociation of many ph domain - containing molecules , inhibiting signalosome assembly and downstream signaling . illustrated structures not to scale , references in text .
once syk is activated , the bcr signal is propagated via a group of proteins associated with the adaptor protein b - cell linker ( blnk , slp-65 ) , which has been referred to as a signalosome .
phospho - blnk serves as a scaffold for the assembly of the other components , including bruton s tyrosine kinase ( btk ) , vav 1 , and phospholipase c - gamma 2 ( plc2 ) .
btk , vav 1 , and plc2 contain pleckstrin - homology ( ph ) domains that bind lipid phosphoinositides .
these phosphoinositides are enriched in the inner leaflet of the plasma membrane and are important for the propagation of multiple signaling pathways .
phosphatidylinositol 3,4,5-triphosphate ( pi(3,4,5)p3 ) is the product of the phosphorylation of pi(4,5)p2 at position three by phosphoinositide-3-kinase ( pi3k ) .
pi(3,4,5)p3 is a critical second messenger in bcr signaling and is the specific target of lipid phosphatases that regulate signaling . following their recruitment by blnk , btk phosphorylates plc2 , which in turn cleaves the phosphoinositide pi(4,5)p2 , generating ip3 and dag .
ip3 binds the ip3 receptor ( ip3r ) in the membrane of the endoplasmic reticulum , resulting in the release of the intracellular stores of ca ions .
this reduction in calcium stores activates calcium - release - activated channels , which allow the influx of extracellular calcium ions .
dag binds to ras guanyl nucleotide - releasing protein ( rasgrp ) as well as the classical members of the protein kinase c family , such as pkc in b cells promoting their activity [ 19 - 21 ] .
distal from these events , bcr signaling becomes quite branched , activating multiple kinase cascades ( e.g. erk / map kinases ) and guanine nucleotide exchange factors ( e.g. ras / raf ) .
the consequences of these signals include the translocation of transcription factors ( e.g. nfb , ap-1 , and nfat ) ; the net result of these processes drives activation of the b cell , antigen presentation , cytokine production , cell proliferation and differentiation .
these activating signals are necessary to initiate responses against antigens with pathogenic potential . regulating these responses , as well as silencing autoreactive b cells , are multiple receptors and coupled pathways mediated by phosphatases .
key regulators of proximal bcr signaling include the sh2 domain - containing phosphatase 1 ( shp1 ) , a protein tyrosine phosphatase , as well as sh2 domain - containing inositol 5-phosphatase 1 ( ship1 ) and phosphatase and tensin homolog ( pten ) , lipid phosphatases .
multiple studies have shown that disruption of negative regulatory circuitry can result in subversion of tolerance mechanisms and autoimmunity [ 22 - 25 ] . together ,
bcr signaling and its regulation represent complex and dynamic fields of study . for the sake of brevity
, we will focus this review on a few of the major recent advances in the contentious area of bcr signal initiation .
the definitive requirements for bcr engagement , minimally sufficient to initiate signaling , remain controversial .
additionally , these requirements may differ depending on the physical context of the antigenic epitope .
b cells can recognize an antigen in soluble and immobilized forms , such as adsorbed onto or embedded in the plasma membrane of another cell , bacterium or virus . in the case of free soluble antigen , crosslinking of two or more bcrs
seems to satisfy the minimal requirements for induction of a detectable downstream signal , whereas monovalent soluble ligands do not .
in contrast , monovalent membrane - bound antigens can reportedly induce conformational alterations in the bcr that initiate association with neighboring bcr , and this can lead to signaling . both of these signal initiation models coalesce in the idea that two or more bcrs become closely associated following ligand binding , allowing for transactivation via sfk and syk .
still others propose that it is not aggregation but rather disassociation of preformed oligomeric bcr complexes that releases the receptors from an inhibited state and triggers signaling [ 29 - 33 ] .
reth and colleagues propose a disassociation activation model in which resting b cells have preaggregated bcr that are inhibited via methyl - transferase activity and syk serine kinase activity .
this model proposes that following ligand binding , bcrs move from closed-monomeric or oligomeric states to an open
the proponents of this model argue that the flexibility of the hinge in mig and variability of antigen binding would result in inefficient activation via traditional crosslinking due to steric requirements for signaling , describing this incongruity of antigen / bcr as an unsolved problem of clonal selection .
however , there are two key problems with this argument : firstly , no orientational requirements have been described for the induction of bcr signaling , thus they may not exist , and secondly , the hypothesis fails to account for the diversity of the bcr repertoire .
the first counterpoint is that flexible mig , and non - covalently associated cd79in the round
as evidence against steric restriction of the bcr signal consider signaling by intact monoclonal antibodies ; it was demonstrated decades ago that monoclonal antibodies recognizing spatially distinct igm epitopes can induce signaling .
if there existed a strict orientational requirement for bcr signal , some or most of these antibodies should be incapable of replicating this orientation and inducing signaling .
the second argument of clonal selection and repertoire is simple : the clonal selection theory predicts that the clones capable of responding to an antigen do respond .
thus , clonal selection is a tautology that is self - evident as responding b cells express a bcr capable of signaling regardless of the mechanism of antigen engagement employed .
other arguments against initiation via aggregation include observations that bcrs exist in preformed oligomers , as shown by native gel electrophoresis .
it is likely that bcrs are clustered near each other in highly ordered areas of the plasma membrane , which would explain their apparent association in low - detergent conditions .
however , if they were truly oligomers , this interaction should persist in more harsh detergents , such as the observed association of cd79 with mig .
additionally , frster resonance energy transfer ( fret ) experiments failed to show evidence for oligomerization prior to stimulation .
perhaps bcrs are simply in organized , quiescent clusters poised to signal upon encountering a aggregating ligand . in any case , pre - organization of receptors is not a priori indicative of inhibition , as shown by the pre - ligand - binding assembly domains of tumor necrosis factor receptors .
along with the pre - organization of bcrs , there exists evidence that syk can be activated by a single dual - phosphorylated itam [ 37 - 39 ] . to this end
, we completely agree . however , this argument is downstream of signal initiation , as either the itam must first be phosphorylated , or sfks and syk must be activated , subsequently phosphorylating itams .
thus , we discover a catch-22 in which at least one itam must first be dually phosphorylated before syk can be activated . as sfks
are the likely candidate for this activity , we think the aggregation model allows for the most efficient recruitment of a nearby sfk to drive this activation .
together , most researchers in the field of antigen receptor signaling are in agreement that bcr crosslinking is sufficient to induce signaling , and is the model that best fits current evidence .
responses induced by different physiochemical forms of antigen may vary in their requirement for proximal signaling effectors .
recent work by mukherjee et al . suggested that monovalent antigen induction of bcr signaling is dependent on sfks , whereas sfks play a less critical role in responses to multivalent antigens .
this is in keeping with previous findings using sfk knockout models , suggesting that the syk tyrosine kinase may be sufficient to initiate signaling in response to multivalent antigens , mediating phosphorylation of receptor itams .
the authors employed in silico modeling to predict the differential roles of syk and sfks in responses to multivalent antigens that induce clustering or to homogenous , monovalent antigens .
these models predict that syk is critical for bcr signaling via positive feed - forward functions and is able to compensate for sfk deficiency when the stimulating antigen is sufficiently avid .
the model s predictions were interrogated by in vitro experiments measuring responses in the presence of syk and sfk pharmacologic inhibitors .
the results of these experiments support the model , though interpretations are compromised somewhat by use of the md4 system : md4 b cells are capable of signaling in response to soluble monovalent hen egg lysozyme ( hel ) in the absence of inhibitors .
this appears to be a unique property of hel , as others have demonstrated that monovalent soluble antigens are incapable of inducing signaling .
indeed , with the exception of hel , previous studies demonstrate that monovalent antigen - induced signaling depends on antigen adsorption to lipid membranes .
an explanation of the ability of monovalent hel to induce signaling probably lies in the highly charged nature of hel , and , likely , rapid spontaneous multimerization , or adsorption on cell surface carbohydrates .
decades of studies indicate that truly monovalent soluble antigens ( e.g. monovalent fab fragments of anti - bcr antibodies ) do not induce detectable signaling .
nonetheless , the findings of mukherjee et al . support the concept that responses to paucivalent antigens are more dependent on sfks than responses to high avidity antigens , confirming the authors general predictions .
cd19 , a b cell - restricted membrane glycoprotein , functions both as an accessory in bcr signaling and , when associated with cd21 , as a bcr co - receptor for complement c3dg fragments .
the requirement for cd19 in this response may be related mechanistically to the apparent requirement for sfk in bcr signaling induced by low - avidity antigens .
it seems likely that the forward - feeding mechanism of cd19 as both a substrate and processive activator of sfks may provide amplification of sfk activity critical to sustain cell activation when bcr stimulation is suboptimal .
thus , experimental approaches towards understanding minimal thresholds of bcr stimulation should consider requirements for sfks and cd19 , due to their complementarity .
interestingly , mattila et al . recently demonstrated that spontaneous bcr signaling as a result of cytoskeletal disruption is dependent on cd19 and cd81 .
the authors use superresolution microscopy ( dstorm ) to demonstrate the existence of bcr in preformed
nanoclusters that associate with syk upon antigen stimulation , and higher level clustering of bcr induced by anti - ig antibodies . despite decades of knowledge that the cytoskeleton affects bcr signaling , the advent of advanced imaging techniques has allowed for a more refined understanding of these mechanisms
. the cytoskeleton acts both in organizing and immobilizing bcrs in the resting cell , as well as amplifying signaling by allowing for b cell spreading and synapse formation .
further , cd19 and cd81 are shown to be dispensable for the initiation of signaling in response to soluble , multivalent antigens .
these latter results seem inconsistent with previous reports that suggested a critical role for cd19 in the activation of ph domain - containing signaling intermediaries .
however , this discrepancy may be explained by the redundant action of b - cell adaptor for phosphoinositide-3-kinase ( bcap ) in activation of pi3k , allowing for the propagation of the bcr signal in the absence of cd19 .
thus , cd19 may be critical for signaling in response to low - avidity antigens because it enhances sfk and pi3k activation , though in response to high - avidity antigens , it may be redundant with the activity of syk and bcap .
as well as having differing antigen avidity requirements for the initiation of signaling , syk and sfks play different roles in signal propagation .
syk appears completely positive , both in its forward - feeding amplification of itam and auto - phosphorylation , as well as activation of downstream components .
by contrast , the sfk lyn activates both positive and negative regulators of bcr signaling , such as cd22 , fcriib , shp1 and ship1 .
recent studies suggest that by toggling between mono- and dual - phosphorylated states , itams drive syk - mediated activation versus lyn - mediated inhibitory signaling .
indeed , in chronically antigen - stimulated anergic b cells , cd79a is monophosphorylated , driving chronic activation of inhibitory ship1 signaling .
ship1 and shp1 have recently been shown to play an additional role in b cells , modulating bcr signaling in the germinal center where b cells engage in the somatic mutation of their bcr , and those with resultant increased affinity for antigen are selected for survival and class switching .
these phosphatases are upregulated in germinal center b cells and oppose positive bcr signaling at differing levels throughout the cycle of these highly proliferative cells . as a net result of this signal dampening ,
the delicacy of the balance of positive and negative signaling is also demonstrated by the effects of altering lyn levels , as both under and over - expression results in autoimmune phenotypes .
other sfks expressed by b cells , e.g. fyn , have been demonstrated to have only activating signaling qualities , while blk is localized on endoplasmic reticulum structures where it appears to regulate ip3 receptor function .
these observations illustrate an important role for lyn in tolerance , while fyn and syk are more important as signaling intermediaries in cell activation . underscoring the importance of regulating signals transduced by the bcr
many of these self - specific cells are probably silenced by virtue of ignorance because their autoantigens are monovalent or in low abundance and therefore do not induce signaling .
the first , by zikherman , parameswaran & weiss , shows that in specific - pathogen - free mice , a significant proportion of mature nave b cells show evidence of ongoing bcr signaling .
signaling was reported in these studies by gfp expression in b cells from transgenic mice expressing gfp under control of the nur77 promoter , a transcript driven by early antigen - receptor signaling events .
interestingly , they found that transitional-3 cells , a compartment previously shown to contain anergic cells , were highly enriched for gfp+ cells .
additionally , they found that some gfp+ b cells were present in virtually every compartment , characterized by decreased surface igm .
these findings suggest that a significant proportion of peripheral b cells are stimulated by autoantigens but are spared from activation by regulatory mechanisms .
a second study involved analysis of the autoantigen - specific b cells in the normal repertoire of animals expressing an ectopic autoantigen ( soluble ovalbumin ) as well as the natural autoantigen glucose-6-phosphate isomerase ( gpi ) .
the authors demonstrate that in the case of these soluble , presumably monovalent , self antigens , the autoreactive cells appear to be ignorant of antigen in their environment .
this is not completely unexpected , and echoes the previously discussed studies : namely , soluble , monovalent antigens fail to trigger bcr signaling .
interestingly , they did find b cell intrinsic tolerance , similar to anergy , when the autoantigen ovalbumin was membrane - bound , and therefore sufficient to induce a bcr signal .
to summarize , bcr signaling is initiated via ligation of mig under conditions that induce phosphorylation of the itams in cd79 .
this results in the activation of syk , sfks , and other signaling intermediaries ( i.e. blnk , btk , vav1 , plc2 ) .
these are recruited via association with bcr or ph - domains binding to pi(3,4,5)p3 . while sfks play roles throughout the process , they appear to be especially necessary in the initiation of signaling by low - avidity antigens .
the glycoprotein cd19 is dually important in its amplification of activation of the sfk lyn , and in activation of pi3k .
it is our opinion that this role for cd19 in the amplification of lyn and activation of pi3k is most critical in examples of low - avidity reactions , whereas , in the case of high - avidity stimuli , syk and bcap exhibit compensatory capabilities .
there exist multiple negative regulators of bcr signaling , critical for b cell - intrinsic tolerance .
however , recent studies have shown that many potentially autoreactive cells appear functionally nave , and those that have encountered sufficient antigen to signal can be found in all b cell compartments , and are characterized by lower surface igm expression .
it is likely that these cells are maintained in the periphery with decreased levels of bcr stimulation and do not become activated due to the
conditional dominance of inhibitory signaling ( i.e. in the steady - state the b cell is not activated by autoantigen ) . though this anergy may seem to flirt with autoimmunity
, one could imagine that this is necessary to avoid extensive exploitation of molecular mimicry by pathogens .
further , an increase from normal physiological levels of certain self - antigens is associated with some tumors and other pathophysiologies .
thus , the maintenance of these autoreactive b cells , poised to react to homeostatic disruption , may be important for tumor surveillance and pathogen defense .
we hope we have conveyed the evolving status of principles that govern b cell antigen receptor signal initiation and its outcome .
these factors include antigen valency , affinity , concentration , physical context , and chronicity of stimulation ; additionally , intrinsic properties of the responding cell , including the relative levels of receptors and signaling intermediaries that function to propagate and regulate signal transmission .
finally , given the complexity of the universe of antigens , the net effect of these factors must be to both respond to pathogenic stimuli and limit these responses , while preventing responses to autoantigens .
| b lymphocytes and their differentiated daughters are charged with responding to the myriad pathogens in our environment and production of protective antibodies .
a sample of the protective antibody produced by each clone is utilized as a component of the cell s antigen receptor ( bcr ) .
transmembrane signals generated upon antigen binding to this receptor provide the primary directive for the cell s subsequent response . in this report
, we discuss recent progress and current controversy regarding b cell receptor signal initiation , transduction and regulation . |
triathlon is a challenging individual sport that involves the disciplines of cycling ,
swimming , and running ; these disciplines are combined in a continuous manner through two
transitions1 .
the ability to sustain
high metabolic power for long periods is very important for athletes competing in
triathlons .
several field - based studies have shown that physiological and morphological
functional characteristics change negatively with age2 , 3 .
it is very important that
triathletes have suitable anthropometric and physiological characteristics to advance
performance in the three disciplines involved .
some studies have found that anthropometric
characteristics are associated with better performance , especially during the swimming and
running components of triathlon competitions4 .
the triathletes anthropometry was found to account for 47% of the
variance in triathlon performance landers5 .
it is also well known that endurance runners have low levels of body
mass and that it is related to improved running performance6 , 7 .
thus , success in a
competitive sport is determined not by anthropometric characteristics alone , but by a
combination of other characteristics such as physiological variables .
a high maximal oxygen uptake ( vo2max ) is a physiological characteristic that
plays an important role in the performance of triathletes in competitions .
however ,
vo2max has not been shown to be a good predictor of triathlon performance in
elite triathletes8 .
in fact , the
vo2max plateau duration has more correlation to triathlon performance than the
vo2max value9 .
other
important physiological characteristics , such as anaerobic power and capacity , which are
required during to perform sprints , overtake , break away , or follow with the group , are very
important for the performance of triathletes , particularly at the end of the triathlon
competitions10 .
heart rate recordings
have been used to assess maximal heart rate , minimum heart rate , and training intensity
among sportsmen , particularly in endurance sports11 .
heart rate variability ( hrv ) , which is analyzed from the heart
rate recordings , provides information about the training load and psychophysiological status
in endurance sports such as triathlons and cycling .
a reduction in the high frequency
component and an increase in the low frequency component of the power spectrum of hrv have
been shown to relate with fatigue and training load12 , and it has been demonstrated that continued exposure to prolonged
periods of intense cycling exercise ( about 3-week ) can cause a marked reduction in hrv
indices in cyclists .
thus , anthropometric characteristics may not be the only determinants of competitive
athletic performance ; a combination of other physiological characteristics such as maximal
oxygen uptake and anaerobic power and capacity may also play significant roles .
the
objective of the study was to compare of body composition , heart rate variability , aerobic
and anaerobic performance between competitive cyclists and triathletes .
after a 2-weeks pre - season training period for the participants in the aerobic and
anaerobic performance tests , the anthropometric , body composition , and heart rate
variability measurements were performed at a temperature - controlled performance laboratory
in a public university .
six cyclists ( age 32.33.0 yrs ; height 175.55.5 cm ; body mass
75.47.4 kg ; training experience 9.74.8 yrs ) and eight triathletes ( age 36.25.6 yrs ;
height 181.64.1 cm ; body mass 74.33.8 kg ; training experience 10.62.9 yrs ) ( 14 males
athletes in total ) who had participated for more than three years in regional and national
competitions were recruited for the study .
all the athletes were notified of the research
procedures , requirements , benefits , and risks before obtaining informed consent .
the study was approved by the
research ethics committee of the local university and was conducted in a manner consistent
with the institutional ethical requirements for human experimentation in accordance with the
declaration of helsinki .
standardized testing procedures were followed as defined in the
american college of sports medicine guidelines ( acsm)13 .
all measurements were performed by the same researchers after
overnight fasting , at a similar time of the day - in order to have similar chronobiological
characteristics14 .
the temperature
( 2022 c ) and relative air humidity ( < 60% ) of the room were consistent throughout all
the steps of the study .
the subjects were asked not to exercise exhaustively on the day
prior to assessment .
the height and weight were measured for each volunteer while they were wearing light
clothing and no shoes and socks .
weight was measured to the nearest 0.1 kg using calibrated
scales ( seca , germany ) , while the height was measured to the nearest 0.1 cm using a
calibrated stadiometer ( holtain ltd , england ) . a gulick anthropometric tape ( holtain ) with
an accuracy of 1 mm was used to measure the circumferences of the waist , hip , abdominal ,
thighs , and calves . to estimate the body fat percentage , a seven site skinfold thickness
technique was used with a scientific skinfold caliper ( holtain , uk ) to the nearest 0.1 mm .
the anatomical sites used were : the chest , abdominal , thigh , triceps , suprailium ,
subscapular , and iliac crest .
body density was estimated using the equation that has been
validated for males aged 18 to 61 years15 .
the body density estimate was in turn used to estimate the body fat
percentage using the siri equation : [ % body fat = ( 495 / body density ) 450 ] .
fat mass was
calculated by the transformation of the percent body fat values [ fat mass = ( body mass
% body fat)/100 ] .
lean body mass was determined by the fractionation of body mass into two
components : lean body mass = body mass fat mass ) .
body mass and body fat percentage were
measured using bioelectrical impedance analysis ( tbf 401 a , tanita , tokyo , japan ) .
two
measurements were taken for each of these variables , and then the average values were used
to perform the statistical analysis .
all of the athletes completed an incremental treadmill
test on a motorized treadmill ( cosmed , italy ) according to the procedures suggested by
rossato et al.11 . during the test
, the
expired gases were analyzed using a breath - by - breath automated gas - analysis system ( oxycon
mobile ; viasys healthcare , hoechberg , germany ) and heart rate was monitored continuously
throughout the test with a polar s610 heart rate monitor ( polar , finland ) .
mean hr and vo2 values measured during the test were used as maximum values
( hrmax and vo2max ) .
heart rate variability ( hrv ) was measured using
the omegawave sport technology system ( omegawave technologies , llc , portland , or , usa ) as
described in the manufacturer s reference manual and standardized guidelines for the
measurement of hrv .
hrv was tested , the athletes voided their bladders and lay in a supine
position for 15 minutes in silence with the lights dimmed ; the actual hrv recording took
67 min . before any strenuous activity16 .
after hrv test , the wingate anaerobic test ( want ) was conducted using a mechanically braked
cycle ergometer ( 834 e , monark , vansbro , sweden ) according to the procedures suggested by
inbar et al.17 . during the test ,
the
athletes were verbally encouraged to give the maximum effort possible . at the end of the
test
, the peak power and mean power were calculated automatically by the want test computer
program .
a fatigue index ( fi ) was calculated using the following equation17 : fi = [ ( peak power output - minimum power
output ) / peak power output ] 100 .
the data are reported as means and standard deviations .
before using the parametric tests , the assumption of normality
differences in the all tests performance variables between the cyclists
and the triathletes were tested by the nonparametric wilcoxon signed rank tests for
independent samples .
effect sizes ( ) values of < 0.20 , 0.200.60 , 0.601.2 ,
1.22.0 , 2.04.0 were considered to represent small , moderate , large , very large and
extremely large differences , respectively18 .
all statistical analyses were performed with the spss version
16.0 , and the level of statistical significance was set at p<0.05 .
table 1table 1.anthropometric characteristics and body composition of the cyclists and
triathletesskinfold thicknesstriathletes ( n=8)cyclists ( n=6)chest ( mm)10.14.310.33.6abdominal ( mm)17.92.719.23.2thigh ( mm)12.73.614.92.3triceps ( mm)9.91.912.63.7supraspinal ( mm)11.83.912 . 84.4subscapular ( mm)12.84.812.94.3iliac crest ( mm)7.91.99.72.6sum 7sf ( mm)83.223.292.524.1body fat ( % ) 17.73.219.33.2fat mass ( kg)13.22.814.63.2lean body mass ( kg)61.12.760.83.7 shows the anthropometric characteristics and body composition of the cyclists
and triathletes . there were no significant differences between the anthropometric
characteristics and body composition of the cyclists and triathletes .
however , cyclists had
a higher body fat percentage ( 17.719.3% , p=0.44 , =0.23 moderate effect ) and
fat mass ( 13.214.6 kg , p=0.44 , =0.22 moderate effect ) compared to the
triathletes . in addition , lean body mass was higher in the triathletes ; however , no
significant difference was found ( 61.160.8 kg , p=0.89 , = 0.03 small
effect ) .
table 2table 2.aerobic performance of cyclists and triathletesincremental treadmill testtriathletes ( n=8)cyclists ( n=6)vo2max ( ml.kg.min)58.55.757.75.8hrmax ( b.min)187.18.1193.56.7hrresting ( b.min)59.67.360.79.5maximum power ( w)527.564.8516.662.1maximum power ( w.kg)7.10.96.80.8 shows the aerobic performance of the cyclists and triathletes studied . there
were no significant differences in the aerobic performances responses of the cyclists and
triathletes .
however , triathletes demonstrated higher vo2max
( 58.557.7 ml.kg.min , p=0.85 , =0.07 small effect )
and maximum power ( 7.16.8 w.kg , p=0.21 , =0.14 small effect )
compared to the cyclists . in addition , hrmax was higher in the cyclists , but no
significant difference was found ( 187.1193.5 b.min , p=0.09 , =0.39
moderate effect ) .
table 3table 3.anaerobic performance of cyclists and triathleteswanttriathletes ( n=8)cyclists ( n=6)peak power ( w)796.474.6933.3189.5peak power ( w.kg)10.71.312.42.3average power ( w)586.945.8702.5139.3average power ( w.kg)7.90.89.31.7minimum power ( w)377.529.0471.790.9*minimum power ( w.kg)5.10.46.31.2*fatigue index ( % ) 52.44.149.32.2 * p
the cyclists
group showed statistically significant differences in minimum power ( 377.5471.7 w , p=0.02 ,
=0.57 moderate effect ) and relative minimum power ( 5.16.3 w.kg ,
p=0.02 , =0.55 moderate effect ) compared to the triathletes .
table 4table 4.heart rate variability responses of cyclists and triathleteshrvtriathletes ( n=8)cyclists ( n=6)sdnn ( ms)50.216.857.220.9rmssd ( ms)35.718.842.224.2tp ( ms)1066.0860.7804.7756.4lf ( ms)643.4545.5537.0411.1hf ( ms)279.1314.8456.2420.6lf / hf4.33.72.43.0lfnu72.115.158.719.1hfnu27.915.141.219.1vlf ( ms)161.9202.2131.570.1sdnn : standard deviation of rr interval ; rmssd : root mean square of successive
differences in rr intervals ; tp : total power ; lf : low frequency ; hf : high frequency
components ; nu : normalized units ; vlf : very low frequency components shows the heart rate variability responses of the cyclists and triathletes
studied .
there were no significant differences in any heart rate variability responses
between cyclists and triathletes .
sdnn : standard deviation of rr interval ; rmssd : root mean square of successive
differences in rr intervals ; tp : total power ; lf : low frequency ; hf : high frequency
components ; nu : normalized units ; vlf : very low frequency components
the aim of this study was to compare the body composition , heart rate variability , aerobic
and anaerobic performances between competitive cyclists and triathletes .
the study revealed
no significant differences in the seven sites skinfold thicknesses , body fat percentage , fat
mass , and lean body mass between cyclists and triathletes .
moro et al.19 also found no differences in seven sites skinfold
thicknesses in cyclists and triathletes , except for medial calf skinfold thickness . in
addition ,
laursen et al.20 observed no
significant differences in body mass or the sum of five skinfolds between cyclists and
triathletes .
furthermore , rst et al.4
found no differences in anthropometric characteristics and body composition between
triathletes and cyclists .
in contrast , millet et al.21 , found significant differences in height and body mass between
competitive cyclists and triathletes .
brunkhorst and kielstein7 , found that cyclists who were males had a higher bmi and larger
thighs and were taller when compared to the male triathletes .
in addition , landers et
al.5 reported a strong and positive
correlation between height and mass in elite triathletes who were males .
these reported
findings are similar to the results of the present study and indicate that anthropometric
characteristics are similar in competitive cyclists and triathletes .
previous researches
have shown that the physical characteristics of athletes may play a role in determining
performance .
the participant s anthropometry was found to account for 47% of the variance in
triathlon performances5 , and low levels of
adiposity positively influenced swimming and running performance during triathlons4 , 22 .
other performance and anthropometric characteristics studies have revealed that endurance
runners have low levels of body mass and reduced skinfold thickness , which are related to
improved running performance6 .
given these
findings , successful performance may not be determined only by physiological
characteristics , but it may also be affected by a combination of anthropometric and
physiological characteristics .
knechtle et al.22 suggested that the anthropometry of triathletes is associated with
training volume .
the seven sites skinfold thickness , body fat percentage , and fat mass were
lower in triathletes than in cyclists ( table 1 ) .
these finding can be explained by the nature of triathlon training , because running training
and overall training volume cause a reduction in the skinfold thickness of the lower
limbs .
the present study also showed that triathletes had higher relative vo2max values
compared to cyclists .
similarly , triathletes generally possess high vo2max values
in studies , compared with cyclists in studies19 .
we believe this might be because triathletes divide their training
time into three disciplines ( swimming , cycling , and running ) and their training volume and
overall training time are higher than that of cyclists . generally , vo2max values
are reported as relative because of extra body mass affects running performance negatively .
for example , costill et al.23 reported a
relationship between both absolute and relative vo2max and running performance ,
and a stronger relationship was found for relative compared to absolute vo2max
( r=0.83 and 0.59 respectively ) .
the specificity of each discipline can influence the aerobic
performance ; cyclists achieve a higher performance than triathletes in cycling tests ,
whereas the opposite is observed in running tests24 .
numerous studies have demonstrated that vo2max and
wpeak value measured by treadmill are higher for triathletes compared to cycle
ergometer25 .
the present study also
showed that triathletes had higher maximum power measured with treadmill compared to the
cyclists maximum power measured by cycle ergometer . in similar with our result , mujika and
padilla26 showed that wpeak value of
4403.3 w was reported for 14 elite cyclists , compared to a wpeak of 439 w for 24
professional cyclists .
we believe that this difference might be because of the specific
features of the individual sports , their requirements , and the different measurement
tools .
the wingate anaerobic test ( want ) is the gold standard for evaluating anaerobic
capacity17 .
there were no significant
differences in absolute and relative peak and average power and fatigue index obtained on
the want between the cyclists and triathletes , except for minimum power . in a similar study
showed that triathletes and cyclists had lower peak power and mean power than we found in
our results .
furthermore , higher values of peak power and average power have been reported
for cyclists , although similar statistical results to the present study have been obtained
in the literature19 .
according to the
sport - specific requirements , anaerobic power and capacity are more important for cyclists
than triathletes .
a cycling race is characterized by power maintained for prolonged periods
of time and high peak power for short periods of time for sprints8 .
in contrast , triathletes perform fewer sprints during the
cycling race than cyclists , since a higher demand on the anaerobic energy system during
cycling may accelerate the process of muscle fatigue , and reduce the performance of the
triathletes during running .
however , it is believed that anaerobic fitness is important for
the performance of triathletes , since the intervals in short - distance triathlon races permit
the athletes to perform sprints when they overtake , break away , or follow with the group and
when they pick up speed again1 . in
addition , a previous study demonstrated a relationship between running speed and heart rate
from low to submaximal speeds27 .
one limitation of the present study is the fact that we monitored hrv for 7 min .
prolonged
recordings ( 24-hour ) for hrv is a better assessment to reflect training load and to collect
psychophysiological information for this study . in conclusion ,
the anthropometric
characteristics , aerobic and anaerobic profile , and heart rate variability were similar in
triathletes and cyclists .
triathletes demonstrated higher vo2max , power outputs
and fatigue indexes , suggesting that the specificity of their training caused different
anthropometric , psychophysiological , and physiological adaptations in triathlon and cycling .
these parameters could provide further information about the anthropometric and
psychophysiological profile of cyclists and triathletes . | [ purpose ] the aim of this study was to compare the body composition , heart
rate variability , and aerobic and anaerobic performance between competitive cyclists and
triathletes . [ subjects ] six cyclists and eight triathletes with experience in competitions
voluntarily participated in this study .
[ methods ] the subjects body composition was
measured with an anthropometric tape and skinfold caliper .
maximal oxygen consumption and
maximum heart rate were determined using the incremental treadmill test .
heart rate
variability was measured by 7 min electrocardiographic recording .
the wingate test was
conducted to determine anaerobic physical performance .
[ results ] there were significant
differences in minimum power and relative minimum power between the triathletes and
cyclists .
anthropometric characteristics and heart rate variability responses were similar
among the triathletes and cyclists .
however , triathletes had higher maximal oxygen
consumption and lower resting heart rates .
this study demonstrated that athletes in both
sports have similar body composition and aerobic performance characteristics . |
assessment measures currently used by clinicians to aid in determining if a person is safe are typically validated for outcomes that do not include safety .
safety , or the ability to live without unintentional harm or injury , is clinically important in geriatric rehabilitation because of the risk of self - neglect or disorientation , whether or not a person has been diagnosed with frailty or dementia .
concerns arise about unintentional falls , harm from medication errors , or failure to take care of daily needs .
research into safety outcomes is urgently needed to provide information to determine when older adults are at risk of declining health due to self - neglect .
little is known about the ability of assessment tools to predict safety as an outcome .
measures for use with people with dementia have been validated by examining their scores in relation to outcomes such as daily living skills [ 25 ] , discharge status [ 6 , 7 ] , community functioning , or likelihood of independent living [ 3 , 5 ] .
these data , although important for establishing the validity of a tool for measuring real - life outcomes , lack a direct link with predicting safety .
it is important to establish a reliable and valid outcome measure that addresses safety in the community for older adults .
incidents of harm were defined as unintentional events that through self - neglect or disorientation ( i.e. , with no intent of self - harm ) lead to : physical injury to self ( including exacerbation of chronic illness ) or other ; and/or damage or loss of property .
the intent was to capture outcomes for which persons with cognitive deficits would be more susceptible than persons with intact cognition . in their study , the number of incidents was assessed by administering a telephone questionnaire to the caregiver .
types of incidents were recorded and classified into the following categories : failure to eat and drink ; failure to report a medical condition ; failure to use prescribed assistive devices ; failure to maintain personal hygiene ; failure to take medication properly ; failure to recognize a familiar environment ; failure to turn off electrical appliances ; failure to judge fraudulent activities .
results of the study demonstrated that the mini mental status exam and three neuropsychological tests of recognition memory , executive function , and conceptualization predicted harm in a sample of cognitively impaired people who lived alone .
the accuracy of caregiver report may be challenged , and data demonstrating its accuracy would allow more definitive conclusions regarding the predictive validity of measures for this outcome . the method of measurement using a telephone interview of a knowledgeable caregiver is a feasible administration method for measuring the outcome
first , the use of a telephone interview , compared to in - person home visits , requires less time from the study participants , is less burdensome for busy caregivers , and is more cost effective for the research team .
telephone information about incidents is likely to be similar to in - person home visit information because in both cases the research team must rely on reporting of incidents that have occurred in the recent past .
second , proxy reporting has the advantage of minimizing reporting bias on the part of the older adult , especially if cognitive impairment is suspected . in a population of patients on a geriatric rehabilitation unit such as in this study , some persons may have diagnosis of dementia , whereas others may have physical deficits only , or suspicion of cognitive deficits .
persons with confirmed or possible dementia are likely to have difficulty recalling recent events , may lack insight into abilities , or may have fear of reporting injury .
proxy reporting may minimize reporting bias also by facilitating the person with dementia , who may be suspicious or lack the ability to understand study information , to have comfort with the research study .
a caregiver may be more likely to understand explanations about confidentiality and lack of negative consequences in reporting incidents .
cooperation with the research team by a trusted caregiver may be less likely to prompt suspicion on the part of the person with dementia .
lastly , the use of proxy reporting by a caregiver is supported by literature reviews of patient - proxy reliability , especially when the report is related to observable constructs .
patient - proxy agreement is the highest for measures that examine observable behaviours such as eating and dressing or level of functioning .
less observable outcomes such as quality of life or satisfaction showed lower levels of agreement [ 12 , 13 ] .
the objectives of the study were two folds : first , to determine the test - retest reliability of measuring the outcome incidents of harm by caregiver interviews and second , to determine the validity of measuring the outcome
incidents of harm compared to ( i ) physician reports on medical charts and ( ii ) caregiver daily logs .
the incident of harm caregiver questionnaire was designed based on the definition of incidents of harm from tierney et al .
participants were recruited as part of a broader prospective study , the purpose of which was to examine the predictive validity of predischarge measures to predict postdischarge incidents of harm for six months after discharge .
consent was obtained for the research team to access medical records , for the caregiver to be contacted for a telephone interview once per month for six months after the patient was discharged , and for the family physician to be contacted if there was any change in health status .
patient and caregiver pairs were eligible for the study if the patient was over age 65 , undergoing assessment for possible dementia ( diagnosis of dementia was not required ) , and the caregiver was identified by the patient and caregiver as the most knowledgeable person about the patient .
a diagnosis of dementia was not required in order to broaden the sample , as a portion of inpatients , although suspected of having cognitive deficits and queries about their ability to manage at home , have not been given a formal dementia diagnosis .
exclusion criteria were delirium or a query from the health care team of elder abuse ( to avoid possible reporting bias from an abuser ) .
for this study , the data collection described was completed after patients were discharged from hospital during the six month followup period .
a research assistant , who was blind to medical record information , contacted the caregivers by telephone and administered the incident of harm caregiver questionnaire once each month for six - months ( see the appendix for questionnaire ) .
the questionnaire asked the caregiver to identify whether any incident of harm had occurred ( yes / no ) and whether it was due to self - neglect or disorientation ( yes / no , see figure 1 for study procedures ) .
if an incident was reported , the caregiver was requested to identify from a list the most likely reason for the occurrence ( type of incident ) , or if the caregiver reported being unable to provide a reason or type , the response was recorded as unknown .
if no incident of harm was noted , the interviewer asked so is everything going ok ? to gain information about overall functional status and give further opportunity to ask about possible incidents of harm . for
test - retest reliability , caregivers were contacted up to five days after one monthly interview and readministered the questionnaire .
the interviewer attempted to contact the caregiver for test - retest administration after the third monthly interview , but if contact was not made within five days , the test - retest administration occurred in a later month .
the number and types of incidents of harm were compared between the two interviews . for validity , medical record information was reviewed to give a comparison between caregiver and physician report for any incident that required medical intervention .
if information about an incident requiring medical attention was not available on the electronic chart , the family physician was contacted by fax to complete a one - page questionnaire ( adapted with permission from dr .
caregivers were also requested to keep a daily log of number and types of incidents for either the first or second month after discharge .
these were returned by post to the researcher . if the caregiver failed to return the daily log , the researcher phoned to request that it be completed for the current month .
test - retest reliability for incident occurrence ( yes / no ) was calculated using kappa , and for type of incident ( failure to complete adl , etc . ) using proportion agreement .
data were collected on the total number of incidents of harm reported by caregivers and the total number of these requiring medical interventions . only the incidents that required medical intervention were verifiable by checking medical information .
the validity of caregiver reported incidents of harm was tested against physician reports and caregiver daily logs using kappa for incident occurrence ( yes / no ) and proportion agreement for type of incident .
the sample of patients ( n = 47 ) was composed of 55% females with a mean age of 83.3 years including 14 participants over the age of 85 ( see table 1 for patient characteristics ) .
a total of 45 caregivers and patients contributed data to the study and two caregiver participants dropped out by declining to answer or return followup calls .
of the 45 caregiver participants , 39 completed 6 months of followup , 2 died , 2 caregivers dropped out while consenting for their information to remain in the study , and 2 became ineligible due to admission of the older adult to long - term care facilities .
responses were grouped into categories according to the method of tierney for all incidents ( n = 35 ) .
the highest proportion of incident was of the type failure to use mobility devices correctly
( n = 11 , 31.4% ) , followed by failure to use medication correctly ( n = 7 , 20.0% ) , failure to perform adl
( n = 6 , 17.1% ) , and unknown type ( n = 5 , 14.3% ) .
test - retest reliability was obtained from 38 caregivers , in the fifth month on average ( sd = 1.1 ) , with minimum of two and maximum of five days between test and retest ( mean= 3.1 , sd = 1.1 ) .
the test - retest reliability was high for the occurrence of an incident of harm each month ( yes / no , kappa = 1.0 ) and the type of incident ( percent agreement = 100% , table 2 ) .
caregiver reports were validated by checking medical charts or by contacting the family physician regarding any incident that required a medical visit .
there were a total of 16 incidents of harm reported by the caregiver that required a medical visit .
for a small number of incidents ( n = 3 ) , information was not available on the hospital chart and verification was obtained by contacting the family physician .
a response was received for two of these three incidents and the third incident was noted as a missing data point because of non - response .
there was no disagreement with medical charts ( kappa = 1.0 ) ( n = 15 ) for the occurrence of an incident of harm ( yes / no ) ( table 2 ) .
the type of incident was compared between the caregiver report and notes found on the medical chart ( n = 15 ) ( table 3 ) .
any information regarding the possible reason for the medical visit was obtained by reading the entire chart , including physician and other health care team members .
the medical chart did not report the type of incident ( unknown ) in the majority of cases ( n = 9/15 , 60.0% ) .
an example is that the person was seen for an exacerbation of copd symptoms , and the medical chart did not indicate the type of incident ( e.g. , failure to take medication correctly ) .
for those incidents for which a type was reported ( n = 6 ) , there was agreement in 3/6 cases ( 50% ) . for those that require medical attention , the most frequent type of incident reported by the caregivers was failure to take medication correctly ( n = 8/15 ) , and in the majority of these cases ( n = 6/8 , 75% ) , the medical chart did not report a type of incident .
the validity of the telephone interview method was also examined by asking caregiver participants to track incidents for one month using a daily log .
20/36 respondents needed more than one reminder to complete the log , or additional mailing of a new copy , having lost the first copy .
there was no disagreement between the diary and phone calls about whether the incident occurred ( kappa = 1.0 , p < 0.001 ) and the types of incidents ( percent agreement = 100% ) .
first , the test - retest reliability of the caregiver report by telephone was very high .
it was apparent that events of harm that were reported were events that were not easily forgotten in a few days . nor did recall of the type of event change .
this indicates that the caregiver report was valid as a measurement of incident of harm outcome using proxy report . in the cases where there was disagreement between the caregiver and the medical chart , the information from the caregiver was more specific about the potential type of incident compared to the medical chart .
although proxy reporters may not have been present for all incidents , such as falls or medication errors , the high agreement with medical chart data demonstrates a lack of bias in caregiver reporting when incidents were serious enough to require medical care .
this indicates that any incident noted by the caregiver was reported to the research team .
the incident of harm outcome can be viewed as a more objective and observable outcome than , for example , satisfaction , depression , or optimism which have been noted to be less objective and , therefore , more difficult for proxies to rate accurately .
the validity of proxy report for the incidents of harm outcome concurs with the literature reporting good patient - proxy agreement with observable behaviours .
strong agreement between the telephone interview and daily log further validates the data collection method .
it indicates that the method of reporting incidents of harm did not affect whether or not an incident was reported .
although the telephone interview did not specifically ask about the number of incidents , the data from the daily logs showed that some caregivers had noted more than one incident in a month .
the telephone interview asked for recall of the entire month , suggesting that it may not have been collecting the same level of detailed data as the diary .
future studies may benefit from modifying the telephone questionnaire to gather data on not only whether an incident occurred in the past month , but also how many occurred .
however , the high agreement between daily log and telephone interview for reporting whether an incident occurred validates the telephone interview as an appropriate method for collection of data regarding the occurrence of incidents of harm .
furthermore , the return rate , despite multiple reminders and effort on the part of the researchers , indicated that the daily log was more burdensome for the caregivers , thus making the telephone interview the preferred method of data collection .
the data from this study indicate that the measurement of incidents of harm through telephone interviews can provide a valid estimate of whether or not an incident occurred according to caregivers and medical staff for this sample .
it can be used to validate tools for outcomes related directly to safety in the home environment . the outcome
outcome that has been noted to be of urgent need in geriatrics and clinical assessment .
the outcome incidents of harm has value for validation of health care measurement tools used in a broad range of populations and health care settings .
the ability to predict community safety is important for clinical assessment with populations such as people with mental illness and acquired brain injury , and the incidents of harm
the outcome is particularly pertinent in the older adult population for which decisions about independent living and the need for community services often depend on the determination of safety .
future research is needed to examine whether rehabilitation interventions influence this outcome and the characteristics of patients ( e.g. , age , sex , comorbidities , cognitive status ) and caregivers ( e.g. , live - in or not live - in ) who are at greater risk for harm outcome .
caregivers assume a burden by caregiving , which adds to the stress from various other roles including work and parenting .
caregivers may , therefore , have reported incidents of harm based on their perceived tolerance for risk to the individual .
those who were more anxious about risk may have reported more incidents , those less anxious may have reported an incident but may have stated its consequences were minor and no significant injury occurred .
thus , recall and reporting bias may have either raised or lowered the number of incidents reported .
however , when reports by the caregivers were checked against medical charts , the agreement was high , indicating minimal reporting bias for incidents requiring medical intervention .
reliability data were based upon reports from telephone interviews of the caregiver , and , therefore , are limited because both sources of data come from the same person .
validity data , although checked against medical records , were also validated using daily logs from the same person , through a different reporting method .
further research is needed to examine whether reliability was influenced by the number of times the measure was administered ( i.e. , month one versus month 6 ) , and characteristics of the caregiver .
proxy report may have lowered the number of incidents reported because proxies may not have been aware of all incidents . however , as previously described , proxy report may have minimized the likelihood of reporting bias on the part of the older adult .
the medical chart also may have been influenced by recall and reporting bias such that the medical team may have suspected that the medical visit had been precipitated by disorientation or self - neglect but may not have noted any suspicions on the chart .
the telephone interview method for measurement of incidents of harm demonstrated good test - retest reliability and validity in this sample .
the measurement of incidents of harm by telephone interview with a proxy caregiver showed high agreement with daily logs , while having higher return rates than daily logs .
a conservative conclusion is that the data from this outcome measurement can be used as a valid estimate of the true occurrence of incidents of harm .
more broadly , these data can be used to support the further use of this method of measurement of incidents of harm in research , especially because the outcome incidents of harm reflects how a person is managing in the community , for which there is an urgent need .
followup interview checklist : harm outcome
name of patient participant :
outcome : incidents of harm :
can you tell me if any of the following have occurred with your(e.g . , parent , spouse ) in the past month ?
(a)any injury to self or another person ( including exacerbation of a chronic illness ) , property loss , or property damage(b)occurrence of the incident due to self - neglect or behaviours related to disorientation ( unintentional )
any injury to self or another person ( including exacerbation of a chronic illness ) , property loss , or property damage occurrence of the incident due to self - neglect or behaviours related to disorientation ( unintentional ) in your opinion , what might have been the most important reason for the occurrence ? ( type of incident ) not completing adl ( eating , hygiene , dressing ) not using medications correctly : not using mobility devices correctly : not using kitchen or electrical devices correctly : not detecting fraud : not reporting a medical condition : not recognizing a familiar environment : note whether medical attention was sought and from where ( e.g. , hospital , family physician ) if no incident of harm is reported , ask so , is everything going ok ? | objectives . defining and validating
a measure of safety contributes to further validation of clinical measures . the objective was to define and examine the psychometric properties of the outcome
incidents of harm . methods .
the incident of harm caregiver questionnaire was administered to caregivers of older adults discharged from hospital by telephone .
caregivers completed daily logs for one month and medical charts were examined .
results .
test - retest reliability ( n = 38 ) was high for the occurrence of an incident of harm ( yes / no ; kappa = 1.0 ) and the type of incident ( agreement = 100% ) .
validation against daily logs found no disagreement regarding occurrence or types of incidents .
validation with medical charts found no disagreement regarding incident occurrence and disagreement in half regarding incident type .
discussion .
the data support the incident of harm caregiver questionnaire as a reliable and valid estimation of incidents for this sample and are important to researchers as a method to measure safety when validating clinical measures . |
since mccully1 first reported the relationship between homocysteine and atherosclerosis , hyperhomocysteinemia ( hhcy ) has come to be recognized as an independent risk factor for atherosclerotic vascular disease.2 further , some studies have demonstrated that hhcy might be involved in the pathophysiology of many neuropsychiatric disorders , including brain atrophy , epilepsy , and alzheimer s disease.35 here we report a patient diagnosed with spinal cord demyelination who presented with hhcy and a homozygous mutation of the gene encoding methylenetetrahydrofolate reductase ( mthfr ) c.677c > t .
a 53-year - old man was admitted to our hospital with a 7-day history of numbness below thoracic level ( t)10 .
cervical and thoracic spinal magnetic resonance imaging ( mri ) demonstrated that the spinal cord was swollen at cervical level ( c)7t3 , which was considered to represent inflammatory lesions ( figure 1a ) .
we treated him with a 7-day course of intravenous prednisone 10 mg / day , and however , this was ineffective . to further distinguish it from the subacute combined degeneration of the cord , we tested his serum homocysteine , vitamin b12 , and folate , which revealed normal serum vitamin b12 ( 268.00 pg / ml ; normal range 211.00911.00 pg / ml ) , elevated serum homocysteine ( 44.49 mol / l ; normal range 515 mol / l ) , and decreased serum folate ( 2.70 ng / ml ; normal range 3.117.5 ng / ml ) . using a previously described method,6 we detected genetic polymorphisms rs1801133 ( c.677c > t ) and rs1801131 ( c.1298a > c ) on the mthfr gene , which encodes the methylenetetrahydrofolate reductase , a key enzyme in homocysteine metabolism .
the results showed that the patient carried the tt genotype of the mthfr c.677c > t gene variant and no mutation was found in rs1801131 of the mthfr gene ( figure 2 ) . in light of these findings ,
the patient was treated with intramuscular cobalamin injections ( 500 g / day ) , vitamin b6 orally ( 30 mg / day ) , and folate orally ( 5 mg / day ) .
he was discharged on oral cobalamin 500 g / day and oral vitamin b6 30 mg / day .
a subsequent spinal mri performed 3 months after symptom onset showed near resolution of the original lesion ( figure 1b ) .
mol / l , normal range 515 mol / l ; vitamin b12 544.10 pg / ml , normal range 211.00911.00 pg / ml ; folate 12.20 ng / ml , normal range 3.117.5 ng / ml ) .
here we describe a patient with spinal cord demyelination whose symptoms , initial laboratory findings , and imaging results suggested acute myelitis , and in whom prednisone was ineffective .
he had neither anemia nor abnormal serum vitamin b12 , and there were no other clinical or laboratory signs ( red blood cell count , mean corpuscular volume , hematocrystallin , and albumin values were normal ) of malabsorption .
a spinal mri then showed that the lesion was not confined to the dorsal and lateral spinal cord .
further , considering the acute onset and atypical clinical presentation , it seemed inappropriate to make a diagnosis of spinal cord demyelination , at least of a typical type .
further examination revealed that , except for the elevated plasma homocysteine and folate deficiency , the patient was homozygous for the gene encoding mthfr c.677c > t .
based on these findings , we treated the patient with b vitamins , and his symptoms gradually improved . as an important enzyme in folate and homocysteine metabolism , mthfr c.677c > t polymorphisms have been associated with hhcy.7 many studies have demonstrated that high levels of homocysteine can increase the risk of vascular disease,2,8 but reports of spinal cord demyelination and hhcy are rare .
our case suggests that people with mutation of the mthfr gene combined with hhcy and folate deficiency might be highly susceptible to demyelination .
first , mthfr mutation - induced disturbances in methylation process can result in a lower methylation rate of myelin basic protein , which plays an important role in the tight compaction of myelin sheath through association with acidic lipids on the cytosolic side of the membrane bilayer , and the decreased methylation of it could cause conformational change and splitting of the myelin sheet.9 jaiser and winston10 have proposed that methylation of myelin protein is limited by disorders of the methylation cycle , which also contribute to both copper deficiency myelopathy and spinal cord demyelination .
second , hhcy is proatherogenic and prothrombotic , so increases the risk of ischemic disease , and might indirectly promote demyelination .
further potential mechanisms for demyelinating neuropathy may relate to hhcy , which can promote neuronal hypersensitivity to excitotoxicity and apoptosis.5,11 successful treatment with vitamin b supports such speculation .
the mutation was found by chance in our patient and we still do not know how it occurred .
in addition to heredity , internal and external environmental factors , such as infection and radiation during growth and development , may also contribute to this mutation .
however , the possibility that the mthfr c.677c > t genotype , especially in the presence of folate deficiency , could promote hhcy and affect the spinal cord can not be ignored.12,13 in summary , it is important to pay attention to plasma homocysteine , vitamin b12 , and folate levels in the patient with spinal cord demyelination or other myeleterosis .
if these are abnormal , treatment with b vitamins should be started promptly , particularly in those who also have mthfr gene mutation . | hyperhomocysteinemia ( hhcy ) has been recognized as an independent risk factor for atherosclerotic vascular disease . here
we report a patient who suffered from spinal cord demyelination combined with hhcy .
the patient was admitted to our hospital with a diagnosis of acute myelitis . however , hormone therapy was ineffective .
further investigations revealed that he had hhcy and a homozygous mutation of the gene encoding methylenetetrahydrofolate reductase ( mthfr ) c.677c > t , which is a key enzyme involved in homocysteine metabolism . in view of these findings
, we treated the patient with b vitamins and his symptoms gradually improved .
spinal magnetic resonance imaging performed 3 months after onset showed near recovery of the lesion . to our knowledge ,
similar reports are rare . |
a total of 109 i. ricinus specimens were collected in northern and central italy ( figure 1 ) , identified by using standard taxonomic keys , and stored at 20c .
specifically , 89 ticks ( 70 adults and 19 nymphs ) were collected by dragging vegetation in different parts of trentino province in april
october 1997 and 1999 , and 10 ticks ( 7 adults and 3 nymphs ) by dragging in feltre ( veneto region ) in march 2000 .
ten more ticks ( 7 adults and 3 nymphs ) were collected from a patient at the ospedale di careggi in firenze in may 1997 .
the man had been bitten in parco nazionale delle foreste casentinesi ( toscana region ; see figure 1 ) a number of hours earlier but did not display any illness .
mif tests with r. conorii antigens were performed on his arrival at the hospital and again 4 weeks later ; results were negative in each instance .
tick samples were placed in 50 l of 10 mm trishcl ( ph 8.0 ) , heated at 90c for 10 min , crushed with a sterile plastic homogenizer , and treated with 10 g of proteinase k at 50c for 3 h. polymerase chain reaction ( pcr ) of a 341-bp portion of glta was performed by using the primers rp cs.877p and rp cs.1258n under conditions previously described ( 10 ) . these primers were chosen for an initial screening because they are known to amplify all rickettsiae ( 11 ) .
dots represent places where ticks were not found to have rickettsiae ; different shapes represent the places where irita1 ( terlago , denno , verv ) , irita2 ( molina di ledro , drena ) and irita3 ( drena ) were detected . in feltre
( 2 ; veneto region ) only irita1 was detected , while in parco nazionale delle foreste casentinesi ( 3 ; toscana region ) only irita2 was detected .
one hundred nine pcrs were performed , and nine positives ( two adult females , three adult males , and four nymphs ) were found .
an initial estimate of the overall prevalence in italian i. ricinus is thus 8.25% . to better establish intrageneric relationships ,
the nine positive samples were subjected to further pcr analysis with the primer pairs rr 17.61p / rr 17.492n and rr 190.70p / rr 190.602n ( 10 ) , which amplified 394-bp and 488-bp portions of 17kda and ompa , respectively .
pcr bands for all three genes were then sequenced directly by using abi prism sequencer ( perkin - elmer , foster city , ca ) . to compare the sequences obtained during this study with those of other rickettsiae ,
sequences present in genbank were selected by means of blast as well as on the basis of previous reports ( 1,12 ) .
sequences were converted to their putative amino acid sequences and aligned by using the program clustal x ( ftp://ftp-igbmc.u-strasbg.fr/pub/clustalx/ ) .
based on these alignments , nucleotide alignments were performed manually , and phylogenetic relationships were inferred by maximum likelihood ( ml ) .
the appropriate model of sequence evolution was determined by modeltest 3.06 ( http://zoology.byu.edu/crandall_lab/modeltest.htm ) , and trees were produced using the program treepuzzle 5.0 ( www.tree-puzzle.de ) , which provides branch lengths as well as quartet puzzling support values at each node with > 50% support .
comparisons of the sequences identified with those from closely related sfg rickettsia spp . are shown in the table ; figure 2 shows the results of phylogenetic analysis .
glta - based results ( figure 2a ) show that all strains detected are sfg rickettsiae . for 17kda ( figure 2b ) ,
no identical sequences for irita2 and irita3 were present in genbank , and they clustered with r. cooleyi ( isolated from i. scapularis in texas ) .
ompa was the most variable of the three genes analyzed ( figure 2c ) and could only be amplified from irita2 and irita3 .
consistent with the results from glta , ompa from irita2 was 100% identical to irr / munich ; however , two substitutions were found between these two sequences and that of irs4 .
notably , for ompa , the cluster to which irita2 and irita3 belong also contains a strain detected in spain ( 14 ) .
this finding suggests that these bacteria may be widespread in europe . on the basis of ompa ( and 17kda ) sequences ,
the clade containing irita2 and irita3 was closest to a clade containing r.
cooleyi and an endosymbiont ( 10 ) , both hosted by i. scapularis .
all previous attempts to amplify ompa from r. helvetica by using various primers have failed , which suggests that the gene is either absent or too variable to work with primers designed from other sfg bacteria ( 12 ) .
taken together , the results from the three genes indicate that the clade containing irita2 and irita3 represents a lineage divergent from the seven described previously ( 1 ) .
the number of ticks examined from trento , feltre , and toscana were 89 , 10 , and 10 respectively .
phylogenetic analyses of rickettsiae based on glta ( a ) , 17 kda ( b ) and ompa ( c ) . based on analyses in modeltest 3.06 , the models of substitution chosen for analysis in treepuzzle 5.0 were trn+g for glta and 17kda , and hky+g for ompa .
genbank accession numbers for each sequence , including those found in this study ( irita1 - 3 ) , are shown adjacent to each strain .
our results represent the first demonstration of rickettsiae in italian i. ricinus and the first use of molecular - sequence based methods to identify rickettsiae in italy .
one bacterium , r. helvetica , occurs in several parts of europe and has been implicated as a human pathogen .
the other two strains have only recently been discovered in i.
ricinus from slovakia and germany .
whether they are pathogenic is not known , but since other rickettsiae of previously unknown pathogenicity have subsequently been shown to be associated with disease ( r. helvetica and r. slovaca ) , these new strains warrant attention . several studies on rickettsioses in italy have been published in the last two decades , and they all report r. conorii as the causative agent . as msf is the only known rickettsiosis in italy , diagnostic tests use r. conorii as the only antigen for serologic assays ( 16,17 ) .
however , since sfg rickettsiae cause cross - reactions , confusion about the source of the illness may occur .
although antibiotic therapy is generally effective for all sfg - related diseases , a better understanding of how different rickettsiae cause different symptoms will only come with their correct identification . during 19961999 in the regions we sampled , 23 rickettsioses ( assumed to be msf ) were reported from veneto , 42 from toscana , and 3 from trentino province ( italian ministry of health , unpub . data ) .
while many were likely to be msf cases , the possibility exists that some were caused by other sfg ( perhaps r. helvetica ) .
unlike most studies , one serosurvey in northeastern italy ( 18 ) used the complement - fixation test , which is less prone to cross - reactions ( 19 ) ; none of the sera tested was found positive for antibodies to rickettsiae .
this finding may be explained by the use of r. conorii , r. rickettsii , r. typhi , and r. akari as the only antigens .
serosurveys such as these could therefore benefit from the use of antigens from the bacteria identified in our study .
i. ricinus is one of the most abundant tick species in italy , having a very low host specificity and a record of attaching to large numbers of humans ( 8) .
the results reported here add sfg rickettsiae to the list of potentially dangerous pathogens that italian i. ricinus carry . | ixodes ricinus from italy were examined for the first time to detect whether rickettsiae were present . using molecular methods
, we detected three different spotted fever group rickettsiae , including rickettsia helvetica .
our results raise the possibility that bacteria other than r. conorii are involved in rickettsial diseases in italy . |
er stress due to an accumulation of unfolded or misfolded proteins activates the unfolded protein response ( upr ) signaling pathway in eukaryotic cells and has been shown to be involved in c. albicans morphogenesis .
upr signaling activates a variety of downstream transcripts , including the bzip transcription factor hac1 that impacts c. albicans hyphal growth in response to er stress .
tunicamycin ( tm ) and dithiothreitol ( dtt ) induce the upr by inhibiting n - linked glycosylation of secreted proteins and preventing disulfide bond formation , respectively .
we found that c. albicans and c. dubliniensis calcineurin mutants are hypersensitive to tunicamycin and dtt compared with the wild - type ( fig . 2 ) .
furthermore , the role of crz1 in er stress is different in c. albicans compared with c. dubliniensis ( fig . 2 ) .
while c. dubliniensis crz1/crz1 , crz2/crz2 , and crz1/crz1 crz2/crz2 double mutants grew similarly to wild - type in the presence of tm , the c. albicans crz1/crz1 mutant exhibited attenuated growth that was intermediate between wild - type and calcineurin mutants ( figs . 1
and
2 ) , indicating a divergent function of crz1 in er stress responses in both candida species .
interestingly , we found that the c. dubliniensis wild - type strainis hypersensitive to the er stress inducer dtt compared with the c. albicans wild - type strain ( fig .
2 ) , indicating that the tolerance to protein misfolding has been reduced in c. dubliniensis compared with c. albicans .
calcineurin functions are conserved whereas crz1 has different roles during er stress in c. albicans and c. dubliniensis . c. dubliniensis and c. albicans calcineurin mutants were hypersensitive to the er stress inducers tunicamycin ( tm ) and dithiothreitol ( dtt )
. the c. albicans crz1/crz1 mutants , but not c. dubliniensis crz1/crz1 mutants , exhibit tm sensitivity intermediate between wild - type and calcineurin mutants .
cells were grown overnight in ypd medium at 24c , washed twice in dh2o , 5-fold serially diluted , and spotted onto ypd medium containing tm ( 1 g / ml ) or dtt ( 45 mm ) .
another crucial factor for hyphal growth and virulence of c. albicans is the ability to respond to environmental ph changes .
both calcineurin and crz1 have been demonstrated to play a role in c. albicans tolerance to changes in environmental ph through the rim101/pacc ph - sensing pathway .
previoius studies have shown that rim101 acts in parallel with calcineurin and crz1 to allow for adaption to alkaline ph in c. albicans .
furthermore , crz1 , crz2 , and calcineurin are needed for adaptation to acidic ph in c. albicans .
c. dubliniensis forms true hyphae less efficiently than c. albicans in response to ph shifts in vitro . here , we show that c. dubliniensis cna1/cna1 and cnb1/cnb1 mutants are hypersensitive to acidic and alkaline phs compared with wild - type ( fig .
3 ) , whereas c. albicans calcineurin mutants did not show attenuated growth at acidic ph . this result differs from previous studies where calcineurin was shown to be required for growth at acidic ph and may be attributable to the use of different ph buffering systems or experimental procedures . taken together
, we conclude that in c. dubliniensis calcineurin plays a greater role in acidic ph homeostasis compared with its role in c. albicans ( figs . 1
and
3 ) .
interestingly , while c. dubliniensis and c. albicans crz1/crz1 mutants grew similarly to wild - type at acidic ph , they exhibited attenuated growth that was intermediate between wild - type and calcineurin mutants at alkaline ph .
however , c. dubliniensis crz2/crz2 mutants did not have growth defects in acidic or alkaline ph ( fig . 3 ) .
these results suggest that alkaline ph homeostasis is controlled by the crz1-dependent calcineurin pathway in c. dubliniensis and c. albicans , whereas acidic ph homeostasis is governed by a crz1-independent calcineurin pathway in c. dubliniensis .
calcineurin is essential for growth at alkaline conditions ( ph = 9 ) in c. dubliniensis and c. albicans . while c. dubliniensis calcineurin mutants had attenuated growth at acidic ph , the c. albicans calcineurin mutants did not .
cells were grown overnight in ypd medium at 24c , washed twice in dh2o , 5-fold serially diluted , and spotted onto ypd medium containing 150 mm hepes buffered at ph 2 or 7 . for ph 9 medium , ypd was buffered with 150 mm ph 14 hepes ( 85 ml of ypd plus 15 ml of 1 m hepes at ph 14 ) .
the phs of solid media were confirmed with ph indicator strips ( sigma - aldrich , z134147 ) .
to determine if the calcineurin inhibitor fk506 exhibits synergism with caspofungin against the echinocandin - resistant strain dpl278 , we performed disk diffusion and checkerboard assays following the procedures described by the clinical and laboratory standards institute ( clsi ) protocol m27-a3 .
the dpl278 strain is resistant to caspofungin but susceptible to azoles ( fig . 4
and
table 1 ) .
we further found that the resistance to caspofungin of the dpl278 strain was reversed by supplementation with fk506 ( fig .
meanwhile , we demonstrated that fk506 exhibits synergism with caspofungin , fluconazole , or posaconazole against c. dubliniensis wild - type and echinocandin - resistant strain [ fractional inhibitory concentrations ( fic ) < 0.5 , table 1 ] , suggesting that these drug combinations have therapeutic potential for c. dubliniensis infections . figure 4 .
calcineurin inhibitor exhibits synergism with caspofungin against wild - type and echinocandin - resistant c. dubliniensis strain .
disk diffusion assays were used to determine echinocandin and azole susceptibility of a wild - type ( cd36 ) and an echinocandin - resistant strain ( dpl278 ) .
cells were grown overnight at 30c , and cells at a density of 0.1 od600 ( in 100 l ) were spread on the surface of ypd medium in the absence or presence of fk506 ( 1 g / ml ) .
the disk ( 6 mm ) containing 5 l of caspofungin ( cas , 5 g ) , posaconazole ( psc , 1 g ) , or fluconazole ( flc , 10 g ) was placed on the surface of the plates , and incubated at 30c for 48 h. one wild - type c. dubliniensis strain ( cd36 ) and one echinocandin - resistant strain ( dpl278 ) were grown overnight with shaking at 30c and washed twice in dh2o .
the od600 was taken of the cultures with a spectrophotometer and diluted to 0.01 od600/ml in rpmi-1640 medium ( sigma r6504 , 8.4 g in 1 l dh2o buffered to ph = 7 with sodium hydroxide pellets ) .
minimum inhibitory concentrations ( mic ) of each drug alone and fractional inhibitory concentrations of the drugs in combination were determined using the broth microdilution method according to the clinical and laboratory standards institute ( clsi ) protocol m27-a3 .
final concentrations of fluconazole ( flc ) and caspofungin ( cas ) ranged from 16 to 0.0312 g / ml . fk506 concentrations ranged from 4.0 to 0.063 g / ml while posaconazole ( psc ) concentrations ranged from 2.0 to 0.0039 g / ml . fic index = ( miccombined drug 1/micalone drug 1 ) + ( miccombined drug 2/micalone drug 2 ) fic 0.5 ( synergy ) , > 0.5 but < 1.0 ( additive ) , > 1.0 but 2.0 ( no interaction ) , > 2.0 ( antagonism ) . | candida dubliniensis , an emerging fungal pathogen , is the closest known species to the established pathogenic species candida albicans .
despite the fact that these two species share > 80% genome sequence identity , they exhibit distinct properties such as less hyphal growth , reduced pathogenicity and increased sensitivity to sodium stress and elevated temperatures in c. dubliniensis compared with c. albicans .
it is , however , largely unknown whether signaling pathways are conserved in the two candida species .
calcineurin signaling is known to be required for hyphal growth in cryptococcus neoformans and aspergillus fumigatus but remains elusive in c. albicans .
our recent study showed that calcineurin plays a clearly demonstrable role in controlling hyphal growth , drug tolerance and virulence in c. dubliniensis . here , we extend our studies and show that calcineurin is conserved in controlling endoplasmic reticulum stress but distinct in governing ph homeostasis . furthermore , we demonstrate that azole or echinocandin drugs in combination with the calcineurin inhibitor fk506 exhibit a synergistic effect against c. dubliniensis wild - type and echinocandin - resistant strains .
the involvement of calcineurin in a variety of fungal virulence attributes and as a target for fungicidal synergism with azoles and echinocandins highlights the potential of combination therapy with calcineurin inhibitors for treating candida infections . |
squamous cell carcinomas of the head and neck region are a unique challenge to the radiation oncologist because of the close relationship of various structures in the region that are responsible for maintaining the aero - digestive functions of the body along with the inherently complex topography .
brachytherapy can be delivered in several situations and in combination with other forms of therapy . in the majority of areas like the tongue , buccal mucosa and oropharynx
external radiation of 40 - 50 gy is delivered over a period of 4 - 5 weeks followed by brachytherapy .
this approach allows sterilization of microscopic cells in tissues surrounding the tumor and also reduces the tumor size in order to limit the implanted volume .
the high chance of occult contralateral and ipsilateral neck node metastatsis also makes this technique a sensible procedure .
however , the pretreatment volume should be clearly recorded as this volume is always implanted , regardless of the size of the tumor at the time of brachytherapy .
ldr brachytherapy still represents a well proven option as an exclusive modality treatment for early stage of head and neck tumors .
evidence points that for early and superficial lesions of the tongue or floor of the mouth , brachytherapy may provide a better cure rate with lesser toxicity as compared to ebrt alone or ebrt with brachytherapy .
local control rates can be as high as 80 - 90% , with minimal late toxicity . using brachytherapy as the sole modality can almost double the local control rates for smaller lesions of the oral tongue .
when ldr brachytherapy is used alone , doses of 66 - 70 gy are delivered to the primary tumor ( gtv ) with a safety margin which includes the potential area of microscopic spread ( ctv ) .
the margins chosen vary according to location , type of tumor and personal experience , but usually margins of 1 - 1.5 cm are chosen with care to avoid the mandible as far as possible .
radiotherapy and surgery allows 80% of local control rate in t1 - 2 tumors with limited neck node involvement [ 1 , 2 ] .
this method is generally used for small lesions of the tongue or oropharynx where the risk of occult nodal metastasis may be as high as 30% .
exclusive brachytherapy offers comparable results to surgery in terms of local control and survival in small tumors without cosmetic and functional side effects that are often carried out by surgery ( table 1 ) . in 1987 , the gec ( groupe europeen de curietherapie ) estro , summarized treatment results of more than 2 000 cases from different european countries and demonstrated that for t1 - 2 lesions of mobile tongue , exclusive brachytherapy offers better local control rates than the integration of brachytherapy and ebrt [ 9 , 10 ] . the possible reason could be the shortening of the total treatment time with the use of exclusive brachytherapy amplifying the biological response in the process . with this method
in addition , it eliminates errors due to setup inaccuracies to a significant extent and thus can minimize the irradiated volume by reducing the planning target volume ( ptv ) .
acute radiation reaction is sharply localized and usually occurs after treatment completion , therefore the treatment interruptions due to acute reactions are uncommon and radiation morbidity is limited . in this way , better cosmetic results can be obtained due to reduced volume of tissue exposed to high dose of radiation .
results of exclusive ldr brachytherapy for the tongue and floor of mouth carcinoma the gec - estro data have been confirmed by several authors from leading institutions .
a group from paris published a retrospective analysis on 160 patients who underwent radical ldr brachytherapy for a t1 - 2 floor of the mouth cancer . at 5 years after treatment 89% of the patients were disease - free .
the rates of local tumor failure were 10% of all patients , 7% of t1 tumors , and 12% of t2 .
the 5-year actuarial survival rate for all patients was 76% , 88% for t1 , and 74% for t2 .
the group from nancy analyzed a group of 207 patients with a cancer of the floor of the mouth treated with exclusive irradiation .
external beam irradiation to the tumor bed and the node areas and complementary ldr brachytherapy to the primary tumor was applied in 105 cases and an exclusive ldr brachytherapy to the tumor with or without neck dissection of the node areas was delivered to the remaining 102 cases . in the first part of the study brachytherapy was performed according to the hairpin technique and later with the plastic tubes following the parisian system .
the local control rates at 5 years were 97% and 72% , respectively , for t1 - 2 tumors , while the 5-year specific survival rates were 88% and 47% , respectively .
authors concluded that patients treated by exclusive brachytherapy for t1 - 2 n0 tumors had better 5-year results ( 92% local control ; 76% specific survival ) than those treated by combined therapy ( 63% local control ; 35% specific survival ) .
exclusive brachytherapy has been demonstrated to be effective and safe also in locations in which the treatment is technically more difficult to perform . in a series of 44 patients treated with exclusive interstitial brachytherapy for a t1 or t2 squamous carcinoma of the velotonsillar area ,
5-year overall and progression - free survival rates of 76% and 68% were obtained respectively .
it has been proven by many authors that brachytherapy may also provide a useful method for the treatment of patients with recurrent , persistent , or the second of primary head and neck malignant tumors in a previously irradiated region .
that can be considered as useful tool in addition to ebrt , surgery and chemotherapy in locally advanced t3 - 4 tumors .
another aspect that has been intensely investigated was the optimal dose , dose rate , and other technical parameters in order to maximize the tumor response without raising the number of treatments complication . according to the gec recommendations , in an exclusive ldr brachytherapy treatment for t1 - 2 tumors , a total dose of not more than 70 gy with a dose rate of 0,45 to 0.6 gy per hour
a dose rate of 0.42 gy per hour or less should be used to deliver total doses of 50 to 60 gy . with the progress of hdr treatments ,
a very interesting issue came into view about how the experience of ldr brachytherapy can be used for calculation of biological equivalent and safe dose in terms of normal tissue tolerance .
japanese authors compared exclusive ldr and hdr brachytherapy for t1 - 2 tumors of the mobile tongue . in a group of 59 patients , they discovered that the 5-year local control rate was not different between the two groups ( 77% vs. 76% , respectively ) . with the higher incidence of acute adverse effects in the hdr group ,
they have analyzed retrospectively a group of 47 patients with head and neck cancers treated with brt alone ( 24 patients ) or brt and ebrt ( 23 patients ) delivered with an effective dose rate of 0.5 to 0.7 gy per hour .
these data support some opinions that ldr brachytherapy for head and neck tumors can be effectively and safely replaced by hdr or pdr treatments .
it is rarely indicated except in situation where gross residual or recurrence is documented and there are some contraindications for ebrt .
the most regular clinical situation takes place after resection of a recurrent tumor in a previously irradiated area .
ldr brachytherapy doses of 50 to 60 gy have for several decades been used for the treatment of patients with recurrent head - and - neck cancer , with 30 - 70% salvage rate and 30 - 40% complication rates . for hdr brachytherapy
the most frequently recommended doses range from 3 - 4.5 gy per fraction in 8 - 18 fractions .
according to commonly accepted rules , before implantation of the catheters , the oral cavity should be kept dry with adequate preanesthesia medication , including scopolamine and suction .
the borders of the tumor should be marked with a marker such as castellani s paint , gentian violet , or with a surgical marker .
the patient s lips should be retracted and the tongue should be pulled or depressed . then the implantation can be performed .
it is important to keep in mind that the anterolateral needles of an implant of the oral cavity should be kept away from the mucosa covering the bone in the upper and lower gum , as well as from the periosteum , teeth and bone . in order to avoid hot spots around each needle
it is recommended to maintain the distance with the use of a regular fluoride carrier that is thickened on the inside by one to four layers ( 2 - 8 mm ) . in another series ,
103 patients with t1 or t2 tongue carcinoma were treated by a single - plane implantation of ir pins .
sixty of them were treated by brt alone , and the rest of patients with external irradiation and/or chemotherapy . from this group 48 and 55 patients
the use of a spacer reduced about 50% of the absorbed dose at the lingual side surface of the lower gingival to that with the absence of a spacer .
mandibular osteonecrosis occurred in 2.1% and 40.0% , with and without a spacer , respectively ( p = 0.0004 ) .
due to simplicity and flexibility of this procedure , most of the modern day interstitial implants are inserted with the use of plastic catheters which are introduced under the guidance of hollow needles .
lesions beneath the tongue , or in the floor of the mouth , should be implanted through the dorsum of the tongue in case of using the standard needles .
the anterolateral needles pass the tongue and are reinserted into the floor of the mouth . the implants should be extended beyond the visible or palpable tumor by at least 1 cm in all directions . if the technique of interstitial implants with nylon tubing is used for lesions of the oral tongue or floor of the mouth , a submental or submaxillary approach is preferred .
the exit points of the guides in the oral cavity are verified with the index finger of the other hand .
the major nylon tubing is threaded through the metallic guides and looped around the dorsum of the tongue and then it exits through a parallel metallic guide . in the next step
the nylon thread is secured by a crimp with a metallic button at one end .
the procedure continues with other loops , leaving the other end open for insertion of the radioactive sources . in order to facilitate removal
it is suggested to put a silk thread through the loop of each nylon tube inside the oral cavity .
the position of the sources is then verified on an x - ray films using radiopaque inactive dummy sources and finally the appropriate ir wires or seeds in nylon tubing are inserted .
implantation with rigid needles of the posterolateral border of the tongue via the oral cavity requires pulling the tongue forward in order to start the implantation at the base of the tongue .
the first needle is inserted pointing inferiorly posterior at about 45 degrees ; a lesser angle is used for successive needles .
eventually , the tongue returns to its normal position and the implant needles takes a vertical position .
an inactive gutter guides were placed into the tongue , and under fluoroscopic control it was verified whether the gutter guides were parallel .
the iridium hairpins were afterloaded into the guides , which were removed at that time .
a suture was used to secure each hairpin to the tongue . in order to decrease the irradiation given to the mandible it is recommended to suture a cotton roll between the tongue and the mandible . this way the tongue is displaced medially .
the risk of mandibular necrosis in patients with oral cancer treated with ldr brachytherapy is about 10% .
no serious incidence of this complication was observed where tumor site ( mobile tongue vs. floor of mouth ) , dental status , or total physical dose was considered .
an essential correlation between the incidence of bone necrosis and two main parameters was found , with dose rate ( p < 0.02 ) and reference volume ( p < 0.05 ) .
a threshold value may be suggested for both dose rates ( 0.5 gy per hour ) and reference volume ( 25 000 mm ) .
interstitial application of catheters in the region of the base of the tongue is a difficult method that requires good medical training and adequate surgical skills . due to tissue oedema and high risk of airway obstruction
, it is highly recommended to perform an elective temporary tracheostomy before the main procedure .
implantation of the base of the tongue and the posterolateral border of the oral tongue is best to accomplish with the help of long metallic or teflon catheters with guides inserted through the submaxillary / subdigastric region .
this can be done with the index finger of the other hand in the oropharynx to verify the position of the guide at the exit point of the tongue base .
the nylon thread is inserted through the tubing into the oropharynx , looped around , and brought out through the opposite guide .
the metallic guides are withdrawn from the submental region and the nylon tubes are secured externally with metallic buttons as described earlier . occasionally , it is not achievable to open the oral cavity adequately . in this case
it is suggested to perform a submandibular implant with metallic guides and afterloading of ir .
after implant localization x - ray films with dummy sources are taken . then the ir wire or seeds in nylon threads are inserted into the nylon tubing or metallic guides .
the implantation technique of the ir hairpin or plastic tube have been elaborated and ameliorated by pierquin et al . and mazeron et al . .
depending on the extent of the lesion the iridium hairpin procedure is used with one gutter guide placed in the soft palate in the transverse plane and additional gutter guides placed vertically into the anterior tonsillar pillars .
iridium hairpins are afterloaded into the gutter guides , which are removed as described earlier .
if the uvula is absorbed by the tumor , it should be amputated before implantation .
in my opinion low dose rate brachytherapy is still considered radiobiologically superior to the other forms of brachytherapy .
the reason lies in the differential repair kinetics of the tumor and the normal cells .
the repair half life for normal tissues ( t1/2 = 1.5 hrs ) is lesser than that for tumors , so continuous application of low dose radiation allows healing of the radiation induced subleathal damage during the course of the radiation itself . this way
ldr brachytherapy is still considered potentially less toxic then hdr brachytherapy , when it is essential to reach the limits of the normal tissue toxicity for maximizing tumor control of for example definitive treatment of small lip and tongue cancers using brachytherapy as a single way of treatment . on the other hand ,
hdr brachytherapy allows significant flexibility in planning the procedure and as an afterloading technique it moderates radiation protection .
the higher dose rate permits immediate treatment , it reduces patient discomfort and allows opd based treatment which unlike ldr brachytherapy often takes several days .
the high dose rate however , negates the biological advantage of ldr brachytherapy and therefore the treatment needs to be administered in several fractions . this way the overall treatment time is longer for the majority of head and neck cancer patients .
the total dose has to be corrected and lowered in order to avoid excessive late toxicity .
the exact magnitude of this correction remains an area of controversy with various authors recommending values between 45 - 55% of ldr doses .
another field of discussion is the dose per fraction and it has been observed that doses higher than 4.5 gy per fraction in the head and neck region often lead to unacceptable rates of tissue necrosis . in case of using hdr brachytherapy after ebrt , the hdr doses need to be suitably corrected and the doses delivery usually vary from 40 - 50 gy in 3 - 4 gy per fraction , administered twice daily with a suitable interfraction interval of 6 hours or more [ 2528 ] . selected results of combined ebrt and hdr boost are presented in table 2 . selected results of exclusive hdr brachytherapy in oral cavity carcinomas are presented in table 3 .
results of hdr brachytherapy boost after ebrt results of exclusive hdr brachytherapy in tongue carcinoma some superficial tumors of the head - and - neck region ( buccal mucosa , hard palate , oral cavity ) can be treated with brachytherapy using molds .
the recommended total dose ( prescribed at 0.5 cm depth ) in ldr brachytherapy is about 60 gy .
brachytherapy in a dose of 15 to 30 gy can also be applied as a boost of 45 to 50 gy ebrt .
complications of brachytherapy depends of a significant extent on the irradiated volume and the dose inhomogenity .
transient soft tissue necrosis can be expected in 15 - 20% patients which usually resolves spontaneously .
if the area of necrotic bone is up to 1 cm it is usually very promising to obtain healing with conservative treatment .
in contrast to ebrt the risk of neural and salivary gland toxicity is very low . | in poland , the classical ldr brachytherapy for head and neck carcinomas with ir-192 wires or hairpins has completely disappeared some time ago after 30 years of successful clinical use .
can this technique be fully and safely replaced by hdr or pdr application ?
this option seems attractive because of new possibilities of 3d reconstruction and computer real - time treatment planning and optimization .
however , in my opinion , long time is needed to get a clinical and scientific experience that has been accumulated for decades with the use of ldr technique . |
infection with hepatitis b virus ( hbv ) remains a frequent etiology of cirrhosis and hepatocellular carcinoma with estimated 360 million individuals with chronic infection worldwide .
although vaccination will ultimately reduce the disease burden due to hbv , antiviral therapy can favorably alter its natural history .
goals of therapy include suppression of hbv replication to delay progression of liver disease reducing the risk of hepatic decompensation and hepatocellular carcinoma as well as infectivity to other individuals .
although standard interferon alpha was licensed for the treatment of chronic hbv infection over two decades ago more widespread therapy became feasible with the advent of well - tolerated oral antiviral nucleoside and nucleotide agents .
however , shortly after the introduction of the first nucleoside analogue , lamivudine , treatment induced mutations in the viral genome were identified .
subsequently adefovir , a nucleotide analogue , efficacious in presence of lamivudine induced mutations was licensed , but its use was also associated with emergence of genomic antiviral resistance .
antiviral resistance has also been identified with more recently introduced nucleoside analogue , telbivudine , and entecavir but to date no clinically significant mutations have been recognized with tenofovir , a nucleotide analogue .
society guidelines and treatment algorithms endorse close monitoring of subjects treated with oral antiviral therapies for development of viral mutants [ 35 ] .
a resistance mutation is an amino acid change that decreases sensitivity to an antiviral drug .
mutations can be divided into primary and secondary mutations , the former an amino acid substitution that results in decreased susceptibility to an antiviral agent , whereas the latter is compensatory amino acid substitution(s ) restoring the functional defect in the hbv polymerase activity associated with primary drug resistance ; hence , secondary mutations restore replicative fitness to hbv .
the primary resistance mutations are rtm204v / i within the ymdd motif for lamivudine , rtn236 t , and/or rta181t / v for adefovir .
telbivudine has a high degree of cross - resistance with lamivudine , with its primary resistance mutation m204i and secondary mutations l80i
entecavir has two distinct patterns of resistance that both include the ymdd mutation associated with lamivudine resistance , rti169 t + rtl180 m + rtm204v + rtm250v and rtl180 m + rtt184 g + rts202i + rtm204v ; however , other resistance patterns have been reported .
hbv replication includes an inherently error prone reverse transcriptase , as it does not have a 3-5 proofreading exonuclease activity . on average approximately 10 virions
are produced daily , with estimated 8 10 mutations / base pair / year .
hbv and therefore do not persist in circulating blood in the absence of an agent inducing resistance . although drug resistant mutants are selected by antiviral therapy , a number of reports have described their identification in apparently treatment nave subjects with lamivudine resistance mutations , specifically the m204i / v ranging from 0.8 to 27% [ 7 , 9 , 10 , 13 , 15 , 17 , 18 , 21 , 22 ] .
implications of hbv resistance mutants in treatment nave patients include concerns about the inappropriate use of agents with similar resistance patterns .
generally reports of detection of antiviral resistant mutants in treatment nave patients have been in sera collected after the introduction of the oral antiviral agents ; further , several reports do not specify the timeframe from which sera was collected hence making interpretation of this relationship more difficult .
the aim of our study was to determine whether resistant mutations were present before the era of antiviral hbv therapy .
we used deidentified residual blood sera collected from july 1986 to july 1992 at the university of miami .
all of the patients had chronic hbv infection ( detectable hbsag positive for at least 6 months ) with a detectable viral load ( at least 10 pg / ml ) , hbeag seropositivity , and absence of hiv coinfection ( negative anti - hiv by enzyme immunoassay ) .
serological markers of hbv were analyzed using commercially available enzyme immunoassay kits ( abbott laboratories , abbott park , il and roche ) .
hbv dna assay was performed with the abbott liquid hybridization hbv dna quantitative assay ( genostics , abbott , chicago , il ) .
genotyping was done with the inno - lipa hbv genotype kit ( innogenetics , belgium ) .
amplification of hbv dna was completed with the roche high pure viral nucleic acid kit ( roche diagnostics , indianapolis , in ) and the mutation analysis was accomplished with the inno - lipa hbv dr v2/v3 ( innogenetics , belgium ) . the inno - lipa hbv dr v2/3 reverse hybridization assay can detect single nucleotide mismatches associated with lamivudine , adefovir , and entecavir resistance comprising 5% or more of the viral population .
descriptive statistics were processed using the sas 9.2 program package ( sas institute , inc . , cary , nc ) .
of the 50 patients whose sera were included 86% were male , average age was 40 12 years , 86% were genotype a , 6% were genotype f , 3.5% were genotype d , and 3.5% were genotype c with a mean hbv dna of 126 pg / ml ( table 1 ) .
no detectable mutations were present in 47 of the 50 samples with inno - lipa hbv dr 2/3 testing .
three of the 50 samples had indeterminate results for certain codons ( 180/181 , 236 , and 250 ) ; these three samples were submitted to innogenetics laboratories in belgium where direct pcr sequencing confirmed that there were no mutations within these codons .
our results suggest that prior to the introduction of oral antiviral agents hbv resistant mutants were absent in treatment nave patients .
detection of hbv resistant mutants in treatment nave patients in other reports has a number of possible explanations .
alternatively patients may have had unrecognized exposure to antiviral agents , for instance , contained in herbal preparations .
a number of other groups have reported the presence of resistant hbv mutants in treatment nave patients . to determine whether these reports were pertinent
the following criteria were applied : ( 1 ) treatment nave hepatitis b treatment , ( 2 ) absence of hiv coinfection , ( 3 ) hepatitis b dna polymerase mutation testing performed ( any method ) , ( 4 ) the time period of blood sera collection specified , and ( 5 ) including 10 or more subjects .
we identified 18 reports , including abstracts , for further analysis ( table 2 ) .
only one of the eighteen papers examined sera in the before 1995 era , matsuda et al . .
an additional paper performed a phylogenetic cluster analysis on hbv sequences before 1995 from the national center biotechnology institute database .
matsuda et al . evaluated 50 japanese patients ' sera , the majority obtained pre-1995 .
twenty ( 40% ) were asymptomatic carriers , and sera were assessed by pcr ( both by enzyme - linked minisequence assay and by restriction fragment length polymorphism ) .
a second group of 10 ( 20% ) individuals had their sera examined prior to lamivudine therapy and were assessed for surface antigen loss .
all screening sera were collected from 1976 to 1992 and sequenced by pcr for ymdd mutation and found to be negative .
lastly , there was a third group of 20 individuals who were treated with lamivudine ; however , prior to initiating lamivudine therapy , the ymdd motif was assessed among treatment subjects , and sera had been collected from 1994 to 2000 .
no treatment induced mutations were detected in this group . in another report chinese investigators sought to determine if widespread oral antiviral use had increased resistance to therapy and whether drug resistant strains had been transmitted by patients .
direct pcr sequencing was performed from 328 treatment nave patients , predominantly genotype c and hbeag positive .
approximately 4% of patients had lamivudine associated viral resistance mutations , less than 1% had adefovir ( 0.6% ) , and entecavir ( 0.3% ) related viral mutants .
phylogenetics were performed to assess the genetic distance between hbv reverse transcriptase sequences in sera collected between 2005 and 2006 and controls submitted to the national center for biotechnology information ( genbank ) before 1995 .
phylogenetic analysis is a method used to assess genetic evolutionary changes over a period of time .
the cohort compared to the genetic bank was found to be similar ( genetic distance of 0.02 ) , allowing the authors to conclude that the advent of nucleos(t)ide therapy did not accelerate evolutionary change .
kobayashi et al . reported the presence of viral mutants in eighteen treatment nave chronic hbv patients .
13 ( 72% ) of whom had the ymdd wild type , while 5 ( 28% ) had mutants .
other reports , with the exception of matsuda et al . , ( table 2 ) had samples from 1995 onwards , all with variable results and frequencies of viral mutants .
first , the sample size is relatively small . from our literature search , of the eighteen selected papers ( table 2 )
, 75% had sample sizes larger than 50 , with the average size including approximately 170 patients .
second , we had three of the fifty samples that had indeterminate results on the inno - lipa dr2/3 testing .
these samples were confirmed to not have resistance mutations ; however , at the expense of a relatively less sensitive test , direct pcr sequencing .
third , reverse hybridization assay , such as inno - lipa is known to be extremely sensitive ( able to detect viral resistance constituting 5% or more of the total viral population ) ; however , the test does not detect novel mutations and may not be as sensitive as ultradeep pyrosequencing ( udps ) [ 10 , 27 ] .
finally as the samples were deidentified limited demographic information could be obtained about the subjects , such as ethnicity . in regard to ethnicity , however , as the majority of subjects had genotype a , one could infer that they were of north american - european descent .
in conclusion , our results support the hypothesis that hbv drug resistance mutations did not antedate introduction of oral antiviral agents and that the detection of drug resistance in an apparently treatment nave subject suggests either unrecognized prior antiviral therapy or infection by an inoculum from a treatment experienced patient . | introduction .
the aim of this study was to assess whether hepatitis b virus drug resistant mutations antedated the widespread use of nucleos(t)ide analogues in treatment nave patients .
a number of reports have suggested that drug resistant mutants can be detected in apparently treatment nave patients . study .
fifty deidentified serum samples collected from 1986 to 1992 from patients with replicative chronic hbv infection at the university of miami were genotyped and tested for resistance mutations using a line probe assay innolipa hbv dr v2/v3 .
serum hbv dna was measured .
all patients had documented chronic hbv infection with a detectable viral load , hbeag seropositivity , and absence of hiv infection .
results . of the 50 individuals included , 86% were male , mean age was 40 12 years , and mostly genotype a. the mean hbv dna was 126 pg / ml ( range 6.4 to 557.0 ) .
no mutations were identified .
conclusions .
the absence of drug induced mutations in these sera collected several years prior to the introduction of oral antiviral therapy suggests that these mutations do not occur in treatment nave populations .
detection of drug resistance in an apparently treatment nave subject suggests either unrecognized prior antiviral therapy or infection by an inoculum from a treatment experienced patient . |
approximately 55 000 new cases are diagnosed with non - hodgkin 's lymphomas ( nhls ) in the united states . despite current therapeutic strategies including chemotherapy , transplantation , and passive immunotherapy with monoclonal antibodies ,
the recent years have witnessed the development of a variety of promising immunotherapies for treating patients with b - cell nhls .
vaccine strategies targeting nhls have largely focused on using the idiotype ( i d ) of the tumor immunoglobulin ( ig ) individually expressed on the surface of malignant b cells as tumor - specific antigen ( ag ) .
after decades of work , some clear evidence of clinical efficacy in phase i / ii trials using i d protein vaccines has accumulated , despite results from phase iii trials seem disappointing [ 2 , 3 ] .
furthermore , streamlined production of these patient - specific vaccines is required for eventual clinical application .
several strategies are being developed to improve these results and include optimization of antigen delivery and presentation as well as enhancement of antitumor t cell function .
dna vaccines have emerged as a novel lymphoma vaccine formulation for antigen - specific immunotherapy .
such a method is an attractive and effective approach for active therapeutic vaccination since it does not require the production and isolation of a purified protein for each patient , a process that is expensive , laborious , and time - consuming .
the protein is endogenously produced and secreted , which may result in more efficient antigen presentation in both classes i and ii major histocompatibility complex ( mhc ) pathways resulting in enhanced anti - id immune responses .
in addition to their safety , stability , ease of production , dna vaccines are highly flexible , allowing coexpression of several types of antigens and immunological proteins .
furthermore , the performance of dna vaccines may be improved by in vivo electroporation ( ep ) as a safe and efficient method of in vivo delivery resulting in greatly enhanced dna uptake , protein expression levels , and degree of local inflammation .
dna vaccination has been applied to therapy of experimental murine lymphomas ( for reviews , see hurvitz and timmerman and neelapu et al . ) .
dna vaccines that express either the tumor - derived i d or the tumor variable ( v ) regions in a single - chain fv conformation ( scfv ) have been constructed . however , due to the weak immunogenicity in most cases , their effectiveness depend on carrier proteins or adjuvant proteins linked to the i d structures [ 914 ] .
idiotypic antigenic determinants lying mainly within the complementary - determining regions ( cdrs ) 3 have been considered a hot spot of particular interest for construction of subunit vaccines [ 1518 ] .
vaccines including only this minimal antigenic domain were proved to induce antibody response [ 19 , 20 ] .
we demonstrated that dna immunization of outbred mice with different patient - derived vhcdr3 peptides elicited antibodies able to recognize native antigens on individual patient 's tumor cells .
recently , our group has shown the tumor protective effects recruited by cdr3-based dna vaccines in a poorly immunogenic , highly aggressive murine b - cell lymphoma model . a dna vaccine containing a vhcdr3 epitope of the 38c13 b - cell lymphoma , administered in combination with the vlcdr3-encoding plasmid , provided tumor protection and long - term tumor - free survival in 60% of syngeneic mice . in the current study to enhance the potency of this vaccination platform
, we used the dna fusion vaccine design encoding tumor ags linked to pathogen - derived sequences , aimed to provide cd4 t cell help .
engagement of cd4 t helper ( th ) cells has been shown to play a major role in linking and coordinating innate and adaptive immune responses [ 4 , 23 ] .
many attempts to incorporate exogenous helper antigens into dna vaccine design to break tolerance to self ( tumor ) antigens and to improve efficacy by helper t cells have been described [ 2428 ] .
fusion protein of tetanus toxin fragment c ( ttfrc ) first domain to human cea - derived peptide provided activating signals required for dna vaccines against weak ags . based on such finding
, we generated a dna vaccine consisting of a fusion between a sequence belonging to ttfrc and the vhcdr3109116 epitope already described .
here we present data on the antitumor efficacy of the cdr3-based dna fusion vaccine delivered by intramuscular electroporation in a b - cell lymphoma model .
38c13 , a carcinogen - induced b - cell lymphoma in the c3h / hen murine strain , expresses an igm/ surface antigen , is mhc ii , and was cultured in rpmi 1640 , 10% heat - inactivated fbs , 2 mm l - glutamine , 100 u / ml penicillin , 100 u / ml streptomycin , and 50 m -mercaptoethanol .
tetanus toxin ( tt ) fragment - encoding dna was amplified by pcr from chromosomal dna of recombinant streptococcus gordonii strain gp1253 ( kindly provided by dr .
the primers ( forward 5-ccg ctc gag tca aca cca att cca ttt tc-3 and reverse 5'-ccc aag ctt tgt cca tcc ttc atc tgt-3 ) , containing the restriction sites xhoi and hindiii ( in bold ) , respectively , were designed to amplify the sequence coding for amino acids 8561313 of tetanus toxin gene ( genbank accession no .
the tt fragment spans from aa 856 to aa 1313 ( h - chain ) and included 9 amino acids of fragment b ( aa 856864 ) .
the amplified fragment was inserted in the cloning vector puc19 , and the resulting recombinant plasmid was named puc - tt856 - 1313 .
sequencing of the cloned tt fragment revealed three - point mutations ( already present in the tt - expressing recombinant s. gordonii strain ) , which lead to three amino acids substitutions in the protein sequence : n919d , n998d , and m1240v .
the plasmid puc - tt856 - 1313 was used as template for the amplification of the partial tt fragment sequence ( tt933 - 1126 ) .
the fusion vaccines ptt933 - 1126-vhcdr3 and ptt933 - 1126-vlcdr3 were assembled by pcr amplification using the tt933 forward primer ( 5-cta gct agc gcc acc atg gtt ata gtg cat aaa-3 , nhei site underlined ) in combination with either the tt1126vhcdr3 reverse primer ( 5-atagtttagcggccgcttaaatgtagtcaaagtacccttcgtatgtatcatatcgtaaag-3 , noti site underlined ) or the tt1126 vlcdr3 reverse primer ( 5-atagtttagcggccgcttatccaaacgtgtacagattatcatactgtagacatgtatcatatcgtaaag-3 , noti site underlined ) .
the vh cdr3 sequence specifies the 8-mer h-2k anchor modified yegyfdyi109 - 116 epitope of the murine b - cell lymphoma 38c13 i d , while the vl sequence expressed the 11-mer peptide starting with the cysteine88 ( i.e. , cys104 in the imgt unique numbering ) and encompassing the cdr3 and the conserved phenylalanine and glycine residues of framework ( fr)4 . the reverse primer overlapped the tt933 - 1126 carboxyl region and contained an overhang encoding the 38c13 i d peptides , fusing it to tt933 - 1126 c terminus .
a dna fragment encoding the tt933 - 1126 sequence alone was also obtained by means of the tt933 forward primer together with tt1126 reverse primer ( 5-atagtttagcggccgcttatgtatcatatcgtaaag-3 , noti site underlined ) .
the tt933 forward primer also encoded the kozak consensus sequence and an atg start codon .
the expression plasmid prc110-nts - il-2 was used as recipient for cloning of the recombinant fragments under the rsv promoter .
the resulting pcr products were ligated into prc110-nts - il-2 as nhei - noti fragments .
all constructs were sequenced , and plasmid dna was purified for vaccination using a qiafilter giga kit endotoxin - free ( qiagen s.p.a . ,
male c3h / hen ( h-2k ) mice , 8- to 9-week old , were obtained from charles river italia s.p.a .
( calco , italy ) and maintained in the animal facility at the sacro cuore catholic university of rome , italy .
all animal experiments , including anaesthetic procedures , were conducted in accordance with protocols approved by the italian ministry of health . for protective experiments , on day 0 anesthetized mice ( ketamine - domitor mixture ; pttvhcdr3 group , n = 7 ; ptt group , n = 6 ) were vaccinated with a total of 50 g dna plasmid in 150 mm phosphate saline buffer into two sites of posterior muscle legs and received booster injection 3 weeks later .
both vaccinations were followed by electroporation with btx ecm 830 pulse generator ( harvard apparatus , ma , usa ) at 175 v / cm , 10 ms square - wave pulses , 1 hz . muscles were pretreated with bovine hyaluronidase as reported elsewhere .
n = 6 ) received a mock vaccination by injection with phosphate saline buffer .
serum samples were collected by tail bleeding 3 weeks after priming and 2 weeks after boosting injections .
all groups were challenged 2 weeks after the booster vaccination by intraperitoneal injection of 2 10 38c13 tumor cells . in the therapeutic setting , on day 0 c3h /
hen mice were challenged i.p . with a lethal dose of 38c13 ( 2 10 ) tumor cells .
dna electrotransfer was performed 4 days after challenge and repeated 11 days later , with a total of 80 g dna plasmids pttvhcdr3/pttvlcdr3 or with 50 g of ptt ( 6 mice / experimental group ) .
animals were checked for visible abdominal tumors and tumor development was monitored daily by abdominal palpation .
the native peptides nh2-dpnyydgsyegyfdywaqgttl - cooh ( igm 38c13vh 101122 ) and nh2-mhtavyycakgaqgaslgkayffdcwgqgtqvtvss - cooh ( vh cdr3-pa ; ) were synthesized by primm ( primm s.r.l . , italy ) and dissolved in the suggested buffer prior to use .
elisa plates were coated with 50 g / ml of vh 101122 peptide or vh cdr3-pa as irrelevant peptide and incubated o.n . at 4c .
mice sera , diluted 1 : 100 in pbs 1x/0,1% bsa/0,05% tween 20 , were added and incubated for 2 hours at r.t .
reactive antibodies were detected with sheep antimouse igg hrp - conjugated ( 1 : 5000 diluted , amersham biosciences , italy ) .
mice ( 3 animals / experimental group ) were culled 1 week after booster dna injection and spleens were removed .
spleens were perfused with 10 ml rpmi 1640 culture medium , cell suspension were passed through 100 m nylon cell strainer ( bd falcon , bd biosciences europe , belgium ) to remove large cells aggregates , and then centrifuged at 1,000 rpm for 10 minutes .
cells were resuspended in 1 ml medium , counted , centrifuged a second time and then resuspended in 90% fbs/10%dmso and cryopreserved until assessment . to assess priming of cd8 t cells , splenocytes harvested from groups of immunized mice
were processed for detection on intracellular ifn-. cells ( 2 10/well ) were incubated for 5 hours at 37c in 24-well plates in 2 ml complete medium supplemented with 2 mm sodium pyruvate , 1% nonessential amino acids ( 1% of 100x stock ) .
splenocytes were stimulated with 100 g / ml vh 101122 in the presence of 1 l / ml cell culture of golgi plug ( bd biosciences europe , belgium ) .
following incubation , stimulated cells were washed twice and fc receptors were blocked by incubation with rat antimouse cd16/cd32 ( fc block ; bd biosciences pharmingen , ca , usa ) for 30 minutes .
cells were stained with alexa fluor 488 antimouse ifn- ( clone xmg1.2 ) for intracellular labelling and analyzed by facscalibur using cell quest pro software ( bd , ca , usa ) .
data collection was gated on live spleen lymphocytes by forward and side angle scatter , utilised to exclude dead cells , debris , nonlymphoid cell , and cell aggregates .
values indicated in the facs plots refer to double positive cells ( cd8 ifn- ) as percentage of total lymphocytes population .
typically , less then 0.08% positive cells were detected beyond the statistical marker in the above negative controls .
data from elisa assay were analysed by unpaired , two - tailed t - test .
survival analyses were performed using the kaplan - meier method and the log - rank test .
tumor - bearing animal proportions and intracellular cytokine staining proportions were compared by x analysis ( medcalc software , mariakerke , belgium ) .
in this study a dna fusion vaccine containing pathogen - derived sequence as an immunoenhancer element was generated .
the h-2k mhc class i binding motif - guided epitope prediction ( syfpeithi database , http://www.syfpeithi.de ) was applied to a tt fragment that spans from aa 856 to aa 1313 ( genbank acc .
an amino acids region was selected ( ttfrc933 - 1126 ) which overlaps some of cd4 t - cell epitopes ( the tt947 - 967 epitope , the tt1084 - 1099 epitope , tt1058 - 1077 epitope ) present on the microbial toxin sequence [ 3335 ] .
furthermore , this ttfrc portion should lack of potentially competing epitopes as regards vhcdr3109 - 116 epitope , avoiding phenomenon of immunodominance . to construct the dna vaccine , the amplified fragment tt933 - 1126vhcdr3109 - 116
this fragment was cloned into prc110-nts backbone vector , and the recombinant plasmid designed as pttvhcdr3 , as reported in figure 1(a ) .
likewise , the recombinant plasmid pttvlcdr3 was obtained by cloning the amplified fragment tt933 - 1126vlcdr388 - 98 in the same backbone vector .
a plasmid encoding the tt933 - 1126 sequence alone in the same backbone vector was also obtained and named ptt .
plasmid dna vaccination was performed using the rsv promoter driving tt933 - 1126vhcdr3109 - 116 expression plasmid ( pttvhcdr3 ) , while ptt was used as control vaccine .
experimental design of protective and immunological studies is showed in figures 1(b ) and 1(c ) , respectively .
the levels of antibody response specific to dna fusion vaccine were evaluated in mice following intramuscular immunization .
humoral immune response elicited after pttvhcdr3 or ptt immunizations was assayed by elisa for vh peptide ( d101l122 ) reactive antibodies .
individual blood samples were collected from mice ( pttvhcdr3 group , n = 7 ; control groups , n = 6 ) 3 weeks after dna priming and 2 weeks after boosting injections . the response profile for each vaccine group has been depicted in figure 2 .
elisa test failed to detect antibody titers when performed with mice sera collected after priming as well as analyses of individual sera within the pttvhcdr3 group revealed no noticeable differences compared to unimmunized and ptt control groups ( figure 2(a ) ) .
two weeks after boosting , mice immunized with pttvhcdr3 dna vaccine showed sera positive for antibodies directed against the vh peptide ( d101l122 ) ( figure 2(b ) ) . compared with ptt control vaccine and unimmunized groups , the pttvhcdr3 vaccine group antibody level was statistically significant ( p = .0045 and p = .0014 , resp . ) .
the lack of antibody response after priming suggests that boosting is critical for antibody induction .
reactivity of mouse sera against a cdr3 irrelevant peptide ( vh cdr3-pa ) generated no significant response ( table 1 ) . to investigate whether our vaccination strategy could induce positive cd8 t cell responses to vhcdr3 epitope , c3h / hen mice ( n = 3 ) were vaccinated with the same dna dose and regimen .
splenic lymphocytes were harvested 1 week after booster injection and processed for their ability to induce vh peptide ( d101l122 ) positive ifn--producing t cells responses .
flow cytometry analyses in figure 2 showed the percentage of cd8 t cells producing ifn-. splenocytes isolated from pttvhcdr3 vaccinated mice generated a significantly higher frequency of ifn--positive cd8 t cell precursors compared to mice vaccinated with the ptt control vaccine ( p < .0001 ) .
a graphical representation of the number of vh peptide(d101l122)-positive cd8 t cells is depicted in figures 2(c ) and 2(d ) .
thus , our data suggest that vaccination with pttvhcdr3 induces priming of cd8 t lymphocytes .
to address the protective tumor immunity of pttvhcdr3 dna vaccine , we performed prophylactic vaccination experiments .
the details of the immunization protocol and the tumor challenge are described in figure 1(b ) .
the immunization regimen was previously developed for another cdr3-based vaccine formulation and proved to be efficacious .
two weeks after the last dna electrotransfer , animals ( pttvhcdr3 group , n = 7 ; control groups , n = 6 ) were challenged intraperitoneally ( i.p . ) with a lethal dose of 38c13 tumor b - cells .
lymphoma was monitored for each mouse and the protective efficacy of fusion vaccine was evaluated in terms of survival of mice over the next 120 days .
immunization with the pttvhcdr3 dna significantly impacted tumor growth and ensured long - term tumor - free survival of about 85% of treated mice ( p = .0027 ) ( figures 3(a ) and 3(b ) ) .
cohorts vaccinated with the ptt control vaccine or phosphate buffer showed poor lymphoma resistance , with all mice showing median survival time of 19 days .
the potent prophylactic antitumor effect prompted us to assess the therapeutic vaccination against established 38c13 tumor .
therefore , based on our previous data and recent findings ( manuscript in preparation ) , we evaluated the combined effect of vhcdr3 and vlcdr3 peptides fused to tt933 - 1126 frc portion in a therapeutic setting .
four days after challenging c3h / hen mice ( 6 mice / experimental group ) with a tumorigenic dose of 38c13 cells , dna electrotransfer with pttvhcdr3/pttvlcdr3 or with ptt was performed and repeated 11 days later . even though the timing of tumor onset was similar for the plasmids injected mice and the control mice , at days 1822 postchallenge all untreated and ptt control mice succumbed .
dna vaccination with pttvhcdr3/pttvlcdr3 resulted in a trend toward a prolongation of life span through day 35 posttumor challenge , although the delay in death rate was not statically significant ( table 2 ) .
we have previously developed a dna - based vaccine containing the 8-mer h-2k anchor modified yegyfdyi109 - 116 epitope of vhcdr3 sequence of the murine 38c13 b - cell lymphoma .
the vhcdr3 epitope has been shown to be protective in combination with the vlcdr3 peptide in a murine tumor protection experiment . in the current study
, we aim to gain insights into the enhancement of the effectiveness of the vhcdr3-based dna vaccine in terms of specific immune responses and tumor protection in mice .
induction of potent immune responses against self - tumor antigens is not an easy task .
fusion of the antigen with foreign universal th epitopes ( such as tetanus toxoid epitopes ) has been shown to brake the tolerance to self - antigen and render a weak tumor antigen more immunogenic .
engagement of cd4th cells has been shown to play a major role in linking and coordinating innate and adaptive immune responses [ 4 , 23 ] .
thus , a dna fusion vaccine was generated following fusion of a sequence derived from ttfrc to the vhcdr3109 - 116 epitope to help immune responses against the tumor antigen .
vaccine efficacy was assayed in a highly aggressive and weakly immunogenic murine model of b - cell lymphoma .
we demonstrated that the fusion dna vaccine pttvhcdr3 was able to induce detectable levels of antibodies against the peptide encompassing the vhcdr3 sequence .
humoral immune response could not be achieved by first plasmid electrotransfer suggesting that boosting is critical for antibody induction for this antigen system .
furthermore , plasmid - driven ttvhcdr3 immunization resulted in the induction of significantly higher frequency of ifn--producing cd8 t cell precursors as compared to control group .
prophylactic vaccination with pttvhcdr3 dna vaccine through the intramuscular route in combination with electroporation strongly affected the onset of highly aggressive 38c13 b - cell lymphoma .
inhibition of lymphoma growth led to significant and long - lasting protection from tumor in syngeneic mice with about 85% surviving , compared to nave animals or those given the ptt control vaccine .
this study demonstrates that fusion of exogenous protein to tumor - specific epitope converted an ineffective vaccine , namely , pvh , into one with considerable activity . the potent prophylactic antitumor effect prompted us to assess the tumor immunity in a therapeutic setting , which is more clinically relevant .
preliminary data obtained by using this dna platform strategy provide proof of principle for the treatment of already established tumor in our model .
further enhancement of the potency of cdr3-based dna vaccines is necessary in a therapeutic scenario ; experiments testing new combinations of other crucial cytokines are under evaluation .
attempts to identify the mechanism of id - induced antitumor immunity to malignant b - cells have yielded variable results . despite results from early clinical trials with i d vaccines suggest that both humoral and cellular immune responses may be independently associated with tumor regression and improved progression - free survival [ 3842 ] , the relative importance of the antibody and cell mediated immune response is still uncertain .
experiments are currently ongoing to explore the relative role of cellular versus humoral immunity for vaccine efficacy in our system .
the functional insertion of microbial sequence within the dna vaccine was aimed to stimulate cd4 t cell help that is critical for inducing and maintaining an effective ctl response [ 23 , 43 ] .
deeper analyses are needed to explore the role , if any , of vhcdr3 peptide - specific cd8 t cells precursors in the generation of immune responses via cd4 t cell - mediated mechanisms .
the involvement of cd4 t helper lymphocytes at the effector phase of anti - tumor responses is coherent with th cell - dependent dcs licensing
required for optimal vaccine efficacy , in the absence of mhc class ii molecules expression by tumor cells [ 28 , 45 ] .
licensed dcs presenting peptides from both ttfrc portion and tumor antigen can be able to activate the large repertoire of anti - ttfrc cd4 t cells .
lastly , employing electrotransfer for the delivery of a dna vaccine should improve the availability of the antigen , since ep increases and prolongs protein expression level and also results in recruitments of infiltrating inflammatory cells to the administration site .
this study demonstrates that fusion of exogenous protein to tumor - specific epitope converted an ineffective vaccine into one with considerable activity .
immune responses recruited by cdr3-based dna fusion vaccine involve anti - id antibody production and suggest the possible contribution of cd8 t lymphocytes .
a vaccination protocol consisting of a naked dna priming and boosting is attractive by virtue of ease and less time - consuming production .
furthermore , safety is also achieved since adverse immune response can be avoided ( i.e. , immunity generated against some viral vectors ) .
the cdr3-based dna fusion vaccines strategy may prove to be a highly useful approach against b - cell lymphoma .
optimal integration of active immunization approaches into standard therapies suggests dna vaccination as an effective treatment to eradicate minimal residual diseases during clinical remission following standard chemotherapy in lymphoma patients . | therapeutic vaccination against idiotype is a promising strategy for immunotherapy of b - cell malignancies .
we have previously shown that cdr3-based dna immunization can induce immune response against lymphoma and explored this strategy to provide protection in a murine b - cell lymphoma model .
here we performed vaccination employing as immunogen a naked dna fusion product .
the dna vaccine was generated following fusion of a sequence derived from tetanus toxin fragment c to the vhcdr3109116 epitope .
induction of tumor - specific immunity as well as ability to inhibit growth of the aggressive 38c13 lymphoma and to prolong survival of vaccinated mice has been tested .
we determined that dna fusion vaccine induced immune response , elicited a strong protective antitumor immunity , and ensured almost complete long - term tumor - free survival of vaccinated mice .
our results show that cdr3-based dna fusion vaccines hold promise for vaccination against lymphoma . |
glaucoma is a chronic , progressive , optic neuropathy requiring the long - term use of antiglaucoma eye drops .
these medications containing preservatives may induce ocular damage , such as squamous metaplasia , subconjunctival fibrosis , and a decrease in goblet cells .
a correlation has been found between preservatives and dry eye , in two drugs with 39% dry eye and three drugs with 43% dry eye [ 2 , 3 ] .
additionally , it was reported that the inflammatory reaction of tear modification might be influenced by antiglaucoma medications .
however , the long - term use of antiglaucoma eye drops with preservatives is inevitable , since preservative - free antiglaucoma eye drops are not provided in many developing countries .
therefore , it is of utmost importance to compare the effects of various antiglaucoma therapies with preservatives , which likely stimulate inflammation , on the ocular surface .
human leucocyte antigen expression , a marker of inflammation , was confirmed to be slightly higher in the patients treated with preservative - free timolol than in the control .
moreover , preserved latanoprost causes an increase in human leucocyte antigen expression , when compared with preservatives alone .
the conjunctiva contributes to the tear mucous layer and regulates the immune system of the ocular surface .
the long - term use of antiglaucoma eye drops has a negative influence on conjunctival structures , including the goblet cells , epithelial cells , dendritic cells , and the subepithelial collagen fibers .
ex vivo studies have demonstrated that topical antiglaucoma eye drops induce structural aberrations of the conjunctiva , including a decline in goblet cells , and an increase in inflammatory cells , squamous metaplasia , and subconjunctival fibrosis [ 7 , 8 ] . in recent years , the application of laser scanning confocal microscopy ( lscm ) has provided a promising method to study the structures of the ocular surface in glaucoma [ 912 ] .
recent studies have demonstrated that , compared with patients using preservative - free eye drops , aberrations were found in the corneal structures and tear function in the patients using preserved medications [ 13 , 14 ] .
previous studies have utilized the technique of capturing images of the conjunctival structures [ 15 , 16 ] , while others have confirmed the coherence of the goblet cell density ( gcd ) in different pathological statuses between the lscm and impression cytology methods [ 17 , 18 ] .
mastropasqua and colleagues demonstrated that the density of goblet cells was significantly higher in glaucomatous patients treated with preservative - free medication than in those treated with preservative containing medications using the methods of both lscm and impression cytology .
however , there is a deficit in the literature comparing the effects of different kinds of antiglaucoma eye drops with preservatives on conjunctiva in vivo , with regard to the epithelium , the inflammatory cells , and the collagen fibers .
monitoring conjunctival structure may be much more valuable in evaluating the side effects of antiglaucoma medications and providing reliable evidence for the administration of antiglaucoma therapy , especially in developing countries where preservative - free antiglaucoma eye drops are not provided .
this study aimed to evaluate conjunctival structures , including the epithelial cell density ( ecd ) , gcd , dendritic cell density ( dcd ) , and subepithelial collagen fiber diameter ( sfd ) , using lscm , and to assess the tear function using schirmer 's i test ( st ) and the lachrymal film break - up time ( but ) in subjects exhibiting the long - term use of topical antiglaucoma therapy . furthermore , there has been much interest in comparing the differences in the conjunctival structure and tear function with various topical antiglaucoma medications .
this cross - sectional observational study was conducted on 80 patients diagnosed with primary open - angle glaucoma ( poag ) and 20 healthy age - matched volunteers .
the subjects were divided into 5 groups based on the antiglaucoma eye drops that they used as follows .
group 1 ( normal group ) included 20 eyes of 20 healthy volunteers ( average age : 64.1 years , ranging from 29 to 81 years ; male / female : 12/8 ) in accordance with the following criteria : no history of ocular trauma or surgery , no current or long - term ocular eye drop use , no allergic mucosal pathology , no contact lens use , and the absence of ocular or systemic diseases that may have affected the conjunctiva .
group 2 ( beta - blocker group ) included 20 eyes of 20 patients ( age : 60.0 years , ranging from 30 to 76 years ; male / female : 12/8 ) accepting treatment with carteolol hydrochloride 2% ( mikelan ; otsuka , tokushima , japan ) twice daily .
group 3 ( alpha adrenergic agonist group ) included 18 eyes of 18 patients ( age : 62.6 years , ranging from 38 to 79 years ; male / female : 11/7 ) accepting treatment with brimonidine tartrate 0.2% ( alphagan ; allergan , california , usa ) twice daily .
group 4 ( prostaglandin group ) included 21 eyes of 21 patients ( age : 61.2 years , ranging from 32 to 80 years ; male / female : 14/7 ) using travoprost 0.004% ( travoprost ; alcon , texas , usa ) once daily .
group 5 ( combination therapy group ) included 21 eyes of 21 patients ( age : 63.5 years , ranging from 23 to 87 years ; male / female : 13/8 ) accepting treatment with two or three antiglaucoma eye drops , including a beta - blocker , alpha adrenergic agonist , and prostaglandin analogue .
groups 2 through 5 met the following inclusion criteria : the diagnosis of poag treated with the indicated topical antiglaucoma medications for at least 6 months , without changes .
the diseases of the patients were all well controlled with medical therapy , and glaucoma was defined according to the criteria set forth by the international society for geographical and epidemiological ophthalmology .
the exclusion criteria included ocular or systemic diseases that may have affected the conjunctiva , current use of contact lenses , and a history of ocular surgery or trauma .
this study was approved by the ethics committee of the eye , ear , nose , and throat hospital of fudan university and in accordance with the tenets of the declaration of helsinki .
the participants in this study accepted comprehensive ophthalmic examinations , including a biomicroscopic examination , evaluation of ocular surface disease index questionnaire ( osdiq ) , st , but , and lscm examinations .
all of the patients were given the osdiq to complete , where the 12 items were graded on a scale of 4 to 0 ( 4 , all of the time ; 3 , most of the time ; 2 , half of the time ; 1 , some of the time ; and 0 , none of the time ) , and the total osdiq score was calculated on a scale of 0 to 100 .
after the osdiq was completed , a detailed ophthalmological examination was performed in all of the patients .
the tear film stability was measured using the but with fluorescein and recorded as the mean value of three successive measurements .
additionally , the tear production was determined using the st without topical anesthesia and expressed as the wet length of the strip for a 5 min measurement .
the interval was at least 15 minutes , and all of the examinations were completed in one day by the same investigator .
the heidelberg retina tomograph / rostock cornea module ( heidelberg engineering gmbh , dossenheim , germany ) was applied in this study . a 60x water - immersion objective lens and a 670 nm diode laser as a light source
the scanning area was 400 mm 400 mm , with lateral and vertical resolutions of 1 mm each .
before examination , the eye was topically anesthetized using 0.4% oxybuprocaine hydrochloride ( benoxil ; santen pharmaceutical , japan ) .
the patients were asked to position their heads in the headrest and gaze steadily at the fixation tool .
the images of the nasal bulbar conjunctivae were taken 5 mm away from the limbus and recorded at one point along the z - axis as a single scan .
the ecd was studied to investigate the morphology and number of the conjunctival epithelia , and the gcd was studied to investigate the morphology and number of goblet cells .
the dcd was studied to investigate the morphology and number of dendritic cells , while the sfd was studied to investigate the morphology and diameter of the subepithelial collagen fibers .
three images ( without motion blur or compression lines ) were selected to calculate the cellular densities of the basal epithelial cells of the conjunctiva ( 1525 m deep ) , goblet cells ( 525 m deep ) , and dendritic cells ( 525 m deep ) using the cell count software ( heidelberg engineering gmbh ) in the manual mode .
we selected a square for the region of interest ( roi ) , and the rois of the gcd and dcd were the largest ( maximum roi : 0.1589 mm ) .
the roi of the ecd was not smaller than one - fourth of the largest roi .
furthermore , the sfd ( 25130 m deep ) analysis method was described in a previous study .
the data were expressed as the density sd ( cells / mm ) , and all of the images were analyzed by the same investigator .
the ivcm operator and the analyzer in this study were two different individuals who were masked with regard to the patients ' history and treatment .
the statistical analyses were performed using spss 16.0 ( spss , chicago , illinois , usa ) .
the basic descriptive statistics were reported as the means and standard deviations , while the one - way analysis of variance ( anova ) was used to compare the means of five independent groups , using the post hoc bonferroni test .
the demographic profile of the subjects in this study is shown in table 1 , and the mean age and period of treatment were statistically similar between the evaluated groups ( p > 0.05 ) .
there were statistically significant differences found among the control group and the antiglaucoma medication groups in the values of osdiq , st , and but ( p < 0.05 ) , and the clinical data ( osdiq , st , and but ) for the evaluated groups is reported in table 2 .
the bonferroni tests showed that no significant difference was found in the values of the osdiq , st , and but between the antiglaucoma groups ( p > 0.05 ) .
a statistically significant difference was found in the gcd among the five evaluated groups ( f = 19.464 and p = 0.000 ) , and the bonferroni tests showed significant differences in the gcd between the evaluated groups ( p < 0.05 ) , with the exception of group 2 and group 3 , group 2 and group 5 , and group 3 and group 5 . this data suggested that the gcd showed a significant reduction in all antiglaucoma therapy groups with respect to the control .
moreover , the prostaglandin group revealed a statistically significant difference when compared with the other glaucoma groups , whereas there was no pronounced difference between the other antiglaucoma therapy groups .
there was a statistically significant difference in the dcd among the five evaluated groups ( f = 11.295 and p = 0.000 ) , and the bonferroni tests showed that significant differences were found in the dcd between the evaluated groups , except group 2 and group 3 , group 2 and group 4 , and group 3 and group 4 ( p < 0.05 ) .
this data suggests that the dcd of the subjects in the glaucomatous therapy groups was significantly higher than that in the control .
furthermore , the monotherapy group showed a statistically significant difference from the combination therapy group .
the sfd revealed a statistically significant increase among the five evaluated groups ( f = 6.721 and p = 0.000 ) , and the bonferroni tests showed that there were significant differences in the sfd between the evaluated groups ( p < 0.05 ) , with the exception of group 1 and group 4 , group 2 and group 3 , group 2 and group 5 , and group 3 and group 5 .
this data suggests that the sfd showed a significant increase in all antiglaucoma medication groups with regard to the control group , except for the prostaglandin group .
moreover , a significant decline was found between the prostaglandin group and the other antiglaucoma medication groups , whereas there was no pronounced difference between the other antiglaucoma medication groups .
no statistically pronounced difference was observed in the ecd between the antiglaucoma medication groups and the control group ( p > 0.05 ) . the confocal microscopy data ( ecd , gcd , dcd , and sfd ) for the glaucoma and control groups is reported in table 3 , and the confocal microscopy images are given in figure 1 .
the majority of patients with primary glaucoma must receive medical treatment for most of their lifetimes .
chronic side effects have been drawing more and more attention , among which ocular surface disorders are relatively common .
the current study has confirmed the significant changes in the conjunctival structures and tear function with regard to the effects of various antiglaucoma medications .
interestingly , less pronounced changes were found in the prostaglandin group than in the other antiglaucoma medication groups . as the primary source of ocular mucin ,
the goblet cells are extremely vulnerable to toxic substances and inflammatory reactions . in the current study ,
the goblet cells were confirmed to be significantly decreased in all of the antiglaucoma medication groups , with respect to the control .
previously , a similar conclusion was drawn in the histopathology following the long - term effects of antiglaucoma eye drops containing preservatives [ 8 , 21 ] .
moreover , the mucin expression was found to be reduced due to exposure to the preservative on the human ocular surface .
interestingly , the reduction in the gcd was less pronounced for the prostaglandin group , when compared with the other two monotherapy groups in the current study .
reached a similar conclusion using the impression cytology method , while mastropasqua et al . reported a significant increase in the gcd of glaucomatous patients treated with preservative - free tafluprost , using lscm and impression cytology
one possible explanation is that the antioxidant properties of the prostaglandins counteract the prooxidative properties of the preservative .
as the strongest antigen presenting cells , dendritic cells express lymphocyte costimulatory molecules and secrete cytokines to initiate immune responses . in the current study ,
the dendritic cells in the conjunctiva after long - term antiglaucoma therapy were significantly increased , when compared to the control group .
, who reported that conjunctival inflammation was documented by the activation and the increase of the dendritic cells .
reported that the human leucocyte antigen is overexpressed in the dendritic cells of the patients with antiglaucoma medications , when compared with the controls [ 5 , 24 ] .
the dcd of the patients who received multiple therapies was observed to be significantly higher than in those who were on monotherapy in the current study , which was consistent with a previous study in immunohistology .
surprisingly , there was no significant difference revealed in the dcd between the monotherapy groups using lscm .
in one previous study , the preserved prostaglandins were consistently related to less toxic side effects than the bak counterpart in a conjunctival cell line [ 25 , 26 ] .
however , the dendritic cells served as the strongest antigen presenting cells actively participating in local immunoreactions and might not be useful in evaluating the degree of the inflammatory reaction but may be valuable as an early inflammatory marker in the conjunctiva in vivo .
subepithelial fibrosis has been demonstrated to develop in patients after the long - term use of antiglaucoma eye drops , likely caused by the increase in the fibroblasts in the subepithelial substantia propria [ 5 , 8 ] . in the current study
, the sfd was measured using lscm to evaluate the degree of subepithelial fibrosis resulting from different antiglaucoma medications .
interestingly , the mean sfds in the antiglaucoma medication groups showed a significant increase when compared with the control , with the exception of the prostaglandin group .
similarly , nuzzi et al . confirmed a significantly high fibroblast density in patients treated with long - term antiglaucoma medications .
furthermore , terai et al . found that conjunctival specimens receiving latanoprost manifested less inflammatory cell density and stromal collagen density than those receiving timolol , presumably related to the mechanism of the upregulation of mmp-1 and mmp-3 .
prostaglandins might counteract the effects of the preservatives on subepithelial fibrosis and may be beneficial to glaucoma surgery .
although we correlated quite a bit of information among the groups , including age , gender , and treatment duration , the patients also differed in the lifestyle and initial condition of the ocular surface , which have great influences on evaluating the effects of antiglaucoma medications .
another limitation of this study was that no preservative - free therapy group was designed , because preservative - free antiglaucoma eye drops were not available in china .
this made it difficult to determine the different effects on the conjunctiva between the active compounds and the preservatives of the antiglaucoma medications .
finally , the ivcm method , which was used to determine the gcd , was difficult , with regard to capturing the images and discriminating the goblet cells .
therefore , only one location of the bulbar conjunctiva was selected to observe the gcd , which could pose a significant bias , while the nasal conjunctiva hosted the drugs for a prolonged time period , which might show poor microscopic features . in further studies ,
several locations should be examined and an average taken in order to minimize the bias . in conclusion , our study confirmed the significant differences in the conjunctival structures based on the effects of various antiglaucoma therapies .
less pronounced changes were found in the prostaglandin - treated eyes than in the other kinds of antiglaucoma therapies .
the gcd , dcd , and sfd might , therefore , become valuable markers to evaluate the side effects of antiglaucoma therapy on the conjunctiva in vivo .
future studies should enroll patients with newly diagnosed glaucoma without any antiglaucoma therapy , design a preservative - free antiglaucoma medication group , and take advantage of both confocal microscopy and impression cytology to evaluate the changes in the conjunctiva . | purpose .
the study was aimed at comparing the long - term effects of different antiglaucoma eye drops on conjunctival structures using laser scanning confocal microscopy .
methods .
eighty patients diagnosed with primary open - angle glaucoma and twenty healthy volunteers were included in this study .
the participants were divided into 5 groups according to the different medications .
the lachrymal film break - up time , schirmer 's i test , and ocular surface disease index questionnaire were performed in all subjects .
the confocal microscopy was used to observe the basal epithelial cell density ( ecd ) , goblet cell density ( gcd ) , dendritic cell density ( dcd ) , and subepithelial collagen fiber diameter ( sfd ) .
results .
statistically significant differences were found among the control group and the antiglaucoma therapy groups in the values of three clinical data ( p < 0.05 ) .
the gcd , dcd , and sfd showed significant differences in all glaucoma groups when compared to the control ( p < 0.001 ) .
moreover , the prostaglandin group differed from the other antiglaucoma therapy groups in the gcd and sfd ( p < 0.05 ) . conclusions .
our study confirmed the significant differences in the conjunctival structures based on the effects of antiglaucoma medications .
less pronounced changes were found in the patients treated with prostaglandin analogue than in the other kinds of antiglaucoma therapies . |
currently , 1,457 residential care facilities across south korea provide rehabilitation
counseling , treatment , and training to disabled individuals as they prepare to reenter
society ( disability act , section 48 ) .
the number of individuals enrolled in these long - term
care facilities is estimated to be 80,8461 . those with a developmental disability , for whom the impairment is not
apparent or is delayed , such as individuals with intellectual disability and autism spectrum
disorder ( development disability act , section 2 ) ,
have steadily increased in number over the
years to reach a total of 418,543 in 20141 .
many developmentally disabled individuals reside in long - term care
facilities to achieve independence through treatment and rehabilitation . in addressing these figures ,
the ministry of health and welfare2 has made a tremendous effort to provide quality services
under the stated vision of from destination to the residence of choice .
its major policy
goals include a shift to small - scale care facilities , establishment of quality standards ,
and promotion of both suppliers and users right to choose . reflecting these changes
, many
care facilities are developing and implementing various programs designed to incorporate
individual resident needs and desires with the aim of improving their quality of life .
these
programs and services are offered through local communities and facilities in various
formats3 .
unfortunately , services related to residents recreational activities are scarce , and due
to an insufficient supply of professional staff and funding , as well as information on
disabled individuals as it pertains to these programs , advancing these programs in a
systematic manner has been challenging .
more specifically , it is difficult for disabled
individuals to participate in everyday sports and fitness activities , because of the
insufficient number of fitness facilities available to them , and the limited options in
terms of the type of fitness activities they can engage in .
consequently , without someone s
active encouragement and support , a mere attempt at participation can be challenging for
intellectually disabled individuals . due to these issues
, many individuals with an
intellectual disability residing in long - term care facilities tend to spend countless hours
without being able to engage in physical activity , despite the relative abundance of time at
their disposal4 , 5 .
this results in an increased risk of obesity as well as other
health problems among these individuals . compromised health status can lead to a secondary
dysfunction .
obesity , in particular , can lead to other highly prevalent chronic conditions
such as diabetes and hypertension , which have become a serious threat to those residing in
long - term care facilities6 .
previously conducted korean studies on obesity and individuals with intellectual disability
analysed individuals residing in occupational rehabilitation facilities , a long - term care
facility , and welfare facilities and employed in an occupational rehabilitation facility
.
however , research on the health of intellectually disabled individuals residing in care
facilities is lacking7 .
this study investigated the effects of a walking exercise program on the obesity rate among
intellectually disabled individuals residing in a residential care facility .
the ultimate
aim of this study was to confirm the critical importance of active obesity management
through a fitness program that promotes regular physical activity and to provide the basic
data required for effective obesity management of the disabled residing in residential care
facilities .
the study subjects were 9 individuals with intellectual disability residing in a
residential care facility located in chungju city , chungcheongbukdo province .
the
participants were deemed overweight or obese based on an inbody assessment conducted prior
to the intervention .
none of the participants was receiving antipsychotics , and none had
visual , auditory , neurological or orthopedic impairments that impeded normal walking .
a
thorough explanation of the study purpose was provided , after which consent was obtained
from each participating individual .
the study period lasted 16 weeks , from august 1 to november 30 , 2014 .
an occupational
therapist assessed each participant s body weight , body composition ( body mass index [ bmi ] ,
body fat , and abdominal fat ) , basic fitness ( muscle strength and flexibility ) , and waist
circumference .
the walking exercise used in this study is one of the most widely known cardiovascular
exercises .
it is the easiest
and the most familiar form of exercise , both physically and mentally .
most people enjoy
walking as a type of exercise regardless of age , fitness level , or technique , and it is
associated with very little risk of injury .
it is therefore well - suited for individuals with
intellectual disability8 . for these reasons ,
each session
included approximately 10 minutes of warm - up and cool - down , during which participants
focused on range of motion and active stretching .
the main portion of the walking exercise
program , which consisted of 3 walking sessions per week , was designed following the world
health organization ( who ) physical activity guidelines for adults between the ages of 1864
years9 . in order to reap greater health
benefits from the exercise program ,
a minimum of 300 minutes per week/ 100 minutes per
session was ensured with the help of 2 rehabilitation specialists .
additionally , they are at an increased risk of malnutrition due to food - drug interaction ,
metabolic dysfunction , and other developmental dysfunctions
. these individuals also tend to
exhibit unhealthy eating habits such as fussy eating , preference for high - calorie food ,
binge eating , and obsessing over food , all of which predispose them to increased body weight
due to excess fat accumulation .
this study used an inbody 230 ( biospace , korea ) , a body composition measurement device , to
assess the changes in the participants body weights according to the dietary intake during
participation in social rehabilitation programs , dining - out , outdoor activities , and camps ,
as well as to track the effects of the walking exercise program .
measurements were taken in
the morning and post - exercise , on the same day of each month . because body weight
measurement can vary significantly depending on the time of day and the amount of food
intake , the participants body weight were measured on an empty stomach to ensure accuracy
and minimize deviation .
inbody 230 ( biospace , korea ) was used to track the changes in participants body
compositions during participation in the walking exercise program .
bmi , body fat , and
abdominal fat , which are used to assess obesity , were measured and recorded .
participants were instructed to remove any personal adornments such as wristwatches and
similar items .
sufficient information on the measurement method and correct body posture
required for accurate measurement as well as visual cues were provided .
participants were instructed to take off
their socks followed by cleansing of the palms and soles with wet wipes , after which they
were assisted in standing correctly on the spot marked on the device for accurate
measurement .
participants were instructed to hold the device handles with both hands , with their arms
slightly parted for measurement of body weight , which was followed by impedance analysis of
each body segment .
a total of 10 measurements were taken for the impedance analysis , which
consisted of measurements at 2 different frequencies ( 20 khz and 100 khz ) of 5 different
body segments ( right arm , left arm , torso , right leg , left leg ) .
the 4-electrode 8-point
impedance method and a direct segmental multi - frequency bioimpedance method ( dsm - bia ) were
used .
baseline fitness refers to the physical ability required by an individual for a normal
daily life .
it can be distinguished into health fitness and sports fitness . in consideration
of the 2014 fitness assessment and evaluation guidelines issued by the ministry of health
and welfare s community integration health promotion project ,
this study measured
participants muscle strength and flexibility ( components of health fitness ) prior to
starting the exercise program . in order to examine the changes ,
sit - up counts and trunk flexibility were measured after providing a
thorough explanation and visual cues to the participants .
sit - ups , used traditionally as a method for measuring strength , are easily administered , as
they require only a mat and a timer10 . in
this study , participants were instructed to lie supine on the mat with knees bent and
fingertips behind their ears ; they were asked to raise the upper body until their elbows
touched the knees and then roll back down to the starting position .
the flexibility test used in this study , which required the participants to bend their
torso at the hips , is a widely known and standardized test .
participants were instructed to
remove their shoes and stand on the device with the backs of both heels touching the stand .
they were instructed to gently press the knees and bend the torso . at the point where
participants could hold the position for at least 2 seconds
the test was performed twice for each participant , and the better
result of the two was accepted .
waist circumference is closely associated with diabetes , cardiovascular diseases , and risk
of hypertension .
this study followed the body weight management guidelines recommended by the type 2
diabetes clinical research center designated by the ministry of health and welfare .
additionally , to track the changes before and after the exercise program , measurements were
taken once a month .
measurements were taken after providing a thorough explanation of the
procedure as well as visual cues to the participants .
participants were instructed to stand
with their feet approximately 2530 cm apart , and measurements were taken with a tape
measure between the lowest ribs and hip bone ridge .
descriptive statistics
were used for the participants general characteristics . to compare changes in body weight ,
baseline fitness ( strength and flexibility ) , the waist circumference , a non - parametric test
( the friedman test ) was used . for the analysis of the changes in bmi , body fat , and
abdominal fat , a non - parametric test ( the wilcoxon signed rank test )
a descriptive statistical analysis was conducted to analyze the general characteristics of
the 9 study participants who were residing in a residential care facility .
their average age
was 42.33 years and their average height was 160.69 cm . concerning disability ratings , 6
participants had a level 1 disability , 1 participant had a level 2 disability , and 2
participants had a level 3 disability ( table
1table 1.general characteristicsnumber ( n)age ( yrs)length ( cm)disability rating1st grade ( n)2nd grade ( n)3rd grade ( n ) 942.310.5160.79.8612 ) .
wilcoxon s signed - rank test , a non - parametric testing method , was used to compare changes
in the participants body composition before and after the exercise program .
the results of
the analysis show that average bmi decreased from 26.8 pre - exercise to 25.9 post - exercise ;
average body fat decreased from 35.4% pre - exercise to 31.0% post - exercise ; and average
abdominal fat decreased from 1.0% pre - exercise to 0.9% post - exercise .
the analysis results
for all 3 indexes indicate that the changes were statistically significant , suggesting that
the walking exercise program had a positive effect on the participants body composition
( table 2table 2.body composition analysis ( n=9)itempre - treatpost - treatmeansdmeansdbmi * * 26.8 3.6 25.9 3.4 body fat ( % ) * * 35.4 7.8 31.0 8.7 abdominal obesity ( % ) * * 0.98 0.05 0.93 0.05 * * p < 0.01 ) . the friedman test , a non - parametric test , was used to analyze the monthly changes in
participants as they participated in the walking exercise program .
the results of the
analysis indicate that the participants average body weight steadily decreased over 4
months , from 69.6 kg to 67.3 kg .
statistical verification yielded =35.289 and a
99.9% confidence level , indicating that the decrease was statistically significant ( table 3table 3.comparison of participants physical characteristics before and after the
exercise regimen ( n=9)base1 month2 months3 months4 monthsmeansdmeansdmeansdmeansdmeansdweight ( kg ) * * * 69.6 11.0 69.3 11.0 68.510.9 67.9 10.7 67.3 10.6 strength ( kg ) * * * 16.34.919.76.021.35.622.66.024.87.5flexibility ( cm ) * * * 3.339.633.229.762.118.920.948.841.178.11waist size ( cm ) * * * 37.34.536.64.536.24.635.84.635.14.2 * * * p < 0.001 ) . therefore ,
the friedman test was also used to examine the changes in the monthly baseline fitness
levels ( strength and flexibility ) during participation in the walking exercise program .
the
results of the analysis show that the average strength steadily increased from 16.3 to 24.8
over 4 months .
statistical verification yielded =30.341 and a 99.9% confidence
level , indicating that the increase in strength was statistically significant ( table 3 ) .
the average flexibility , which was 3.3 cm pre - exercise , also steadily increased over the 4
months to 1.2 cm .
statistical verification yielded =29.3972 and a 99.9%
confidence level , indicating that the increase was statistically significant ( table 3 ) .
therefore , the exercise regimen
had a positive effect on the participants average strength and flexibility .
the friedman test was also used to analyze the monthly changes in the average waist
circumferences of the participants during participation in the walking exercise program .
the
results of the analysis show that the participants average waist circumference steadily
decreased over 4 months , from 37.3 cm pre - exercise to 35.1 cm post - exercise .
statistical
verification yielded =34.583 and a 99.9% confidence level , indicating that the
decrease was statistically significant ( table
3 ) .
therefore , the exercise program had a positive effect on the participants waist
circumference .
obesity is a serious health problem that reduces life expectancy and threatens the quality
of life of individuals with disability12 ,
and threatens their health , as it is often a precursor to highly prevalent chronic
conditions such as diabetes and hypertension .
although the cause of obesity among disabled
individuals is unclear , changes in body composition due to inactivity and muscle atrophy as
well as physiological changes are implicated13 .
the most relevant studies have reported higher obesity prevalence
among individuals with disability than among healthy individuals , and an even higher
prevalence rate of morbid obesity14,15,16 .
for individuals residing in a long - term care facility , in particular , a low level of
physical activity and limited living sphere can easily lead to obesity .
increased abdominal fat , among the various criteria used to evaluate obesity , is known to
result in decreased balance as it negatively affects flexibility while shifting the
musculoskeletal structure17 .
obesity
tends to cause arching of the affected individual s back , and increased stress on the
muscles surrounding the spine can result in back pain18 .
subsequent postural instability can also lead to low back pain and
diminished flexibility , and the resulting limited range of motion can lead to secondary
inactivity and obesity19 .
the main goal
of obesity management is to decrease the size of the fat tissues while minimizing the
effects on fat free mass ( ffm ) .
cardiovascular exercise is known to be the very effective at
decreasing the amount of accumulated fat by utilizing fat as fuel to produce energy .
walking
exercise , like many other cardio exercises , improves cardio - respiratory endurance and
increases secretion of growth hormones ( epinephrine and nor - epinephrine ) , which are known to
promote loss of accumulated fat .
furthermore , increased hormone secretion promotes protein
synthesis , which has a positive effect on muscle growth and increased ffm . walking exercise
is actively promoted for fat loss , as it is a very effective low - impact exercise that
carries a low risk of injury .
therefore , this study implemented a walking exercise program
for overweight individuals with intellectual disability residing in a residential care
facility .
the program followed the who physical activity guidelines for adults9 and was designed to incorporate 3 exercise
sessions per week for 16 weeks , during which the participants body weight , body composition
( body fat and abdominal fat ) , baseline fitness level ( strength and flexibility ) , and waist
circumference were continually monitored .
the most important component of obesity management is continuous weight management , which
requires a great deal of effort .
overweight individuals with disability residing in
residential care facilities must make it a daily habit to exercise for weight management
using life redesigning programs . in this study ,
the participants body weight steadily
dropped over the 16 weeks of the obesity management program from an average of 69.6 kg to
67.3 kg , a 2.3 kg decrease .
previous studies have reported that increased physical activity
leads to increased calorie burn and activation of enzymes that extract energy from fat
cells , which results in an active supply of energy , fat loss , and decreased body weight .
additionally , the participants average bmi decreased by 0.9 , from 26.8 to 25.9 ; average
body fat decreased by 4.4% , from 35.4 to 31.0 ; and the average abdominal fat decreased by
0.1% , from 1.0 to 0.9 .
the average waist circumference decreased from 37.3 cm to 35.1 cm , a
2.2 cm decrease .
these results are attributable to energy expenditure during walking and
consequent decrease in body weight and fat .
according to a study20 , walking utilizes
90% of all muscles ( including lower and upper extremity muscles ) , strengthens the muscles
and increases the stability of the upper segment of the spine .
the results of this study
support these findings as well , as evidenced by the fact that the participants average
muscle strength increased by 8.5 more sit - ups , from 16.3 to 24.8 .
average flexibility also
increased from 3.3 to 1.2 , which is a 4.5 cm increase .
walking exercise appears to be an effective exercise , and an active walking program had
positive effect on the level of obesity , and significantly reduced body weight , body fat and
waist circumference21 .
also , walking
exercise contributed to reductions in body weight and body fat by increasing muscle tissue ,
maintaining muscular strength and increasing flexibility22 .
these reports support our present findings , which suggest that
walking serves as an effective exercise for overweight and obese individuals with
intellectual disability .
as this study involved only 9 obese
individuals with intellectual disability residing in a single residential care facility , the
findings can not be generalized .
additionally , the participants dietary intake including
meals and snacks served at the facility , as well as other dietary intake occurring while
participating in various activities , was not controlled . for these reasons , verifying the
pure effects of the exercise program was difficult .
it would be beneficial for future
studies to address controlling of the various factors that may influence the study
results .
this study investigated the effects of a 16-week walking exercise program in overweight and
obese individuals with intellectual disability residing in a residential care facility .
it
was found that the participants body weight , body composition ( bmi , body fat , and abdominal
fat ) , and waist circumference decreased significantly , while baseline fitness ( muscle
strength and flexibility ) improved significantly . obesity management is critically important
for individuals with intellectual disability residing in residential care facilities .
accordingly , walking
exercise programs should be offered to obese individuals with intellectual disability
residing in residential care facilities . | the purpose of this study was to confirm the critical importance of active obesity
management through a fitness program , and to provide foundational data required for
effective obesity management of disabled persons residing in residential carse facilities .
[ subjects and methods ] the study period lasted 16 weeks , from august 1 to november 30 ,
2014 .
the study participants comprised 9 individuals and they participated in a walking
exercise program .
an occupational therapist assessed each participant s body weight , body
composition ( body mass index [ bmi ] , body fat , and abdominal fat ) , basic fitness ( muscle
strength and flexibility ) , and waist circumference .
collected data were encoded by items
and analyzed with spss ver.18.0 . [ results ]
it was found that the body weight , body
composition ( bmi , body fat , and abdominal fat ) , and waist circumference decreased
significantly , while baseline fitness ( muscle strength and flexibility ) improved
significantly .
[ conclusion ] obesity management is critically important for intellectually
disabled persons residing in residential care facilities .
active care through continuous
program implementation is needed .
accordingly , walking exercise programs should be offered
to obese intellectually disabled persons residing in residential care facilities . |
it is generally recommended to perform surgical treatment in lumbar disc herniation ( ldh ) for patients who suffer from cauda equina syndrome or intractable radicular pain , with or without neurological sensory / motor deficit21 ) .
however , in numerous non - fatal cases , conservative treatment such as a nerve block could be effective92024 ) . in patients with ldh ,
a nerve block is generally performed before considering surgery for radicular pain as well3101320 ) .
recent randomized clinical trials show some evidence that the nerve block is cost - effective in the majority of cases compared to other operative interventions2223 ) .
furthermore , potential complications associated with surgery such as revision , cerebrospinal fluid leakage , hematoma , and infection make spine physicians and patients prefer conservative treatments17141725 ) .
in contrast , many spine surgeons claim that early surgery should be considered an appropriate approach for those patients who have lower thresholds for pain , those who demonstrate lower compliance with multiple nerve blocks for several months , and those who are more likely to fail with long - term pain control .
they argue that early surgery in carefully selected patients with radicular pain can achieve more rapid pain relief than prolonged non - operative treatment14172028 ) .
in addition , there is some evidence that time loss due to delayed surgery following the failure of conservative treatment can lead to unwanted results , such as development of the neuropathic pain , which can be refractory to usual or conventional treatments .
there are numerous studies comparing the clinical results between surgery and nerve blocks , but hardly any studies have suggested decision algorithm and none of them analyzed radiographic data as predicting factors20222329 ) . selecting appropriate treatment modalities for ldh requires thorough considerations of all aspects in order to make balanced decisions which are based on cost - effectiveness as well as possible side effects and complications .
thus , establishing radiological criteria as the prognostic factor for success of treatment between surgery and nerve blocks would be helpful in choosing an optimal treatment option .
authors in this paper have performed a quantitative analysis of radiological factors to determine the correlation of multiple factors with successful outcomes .
a retrospective review was performed to 64 adult patients who were treated with surgery or nerve blocks for single level ldh at our institution from january 2012 to december 2014 , and they were followed up for at least a year .
all of the patients were considered to be surgical candidates by two spine surgeons with more than 15 years of experience , and all of them had initially been recommended for surgery .
the surgery group ( sg ) included 34 patients , and the nerve blocks group ( ng ) included 30 patients who initially refused the surgery .
the inclusion criteria of this study were as follows : patients with 1 ) unilateral or bilateral intractable radicular leg pain and back pain with or without sensory / motor deficit after conservative treatment ; 2 ) l45 level ldh confirmed by magnetic resonance imaging ( mri ) , and 3 ) organized medical records including both clinical and mri data ( pre- and post - treatment ) .
in contrast , the following patients were excluded : 1 ) those with cauda equina syndrome ; 2 ) those with progressive motor deficit ; 3 ) those with previous histories of lumbar surgery ; 4 ) those with histories of psychological disorder ; and 5 ) those with radiological evidence of other pathologies correlated with symptoms such as spinal stenosis .
the clinical outcomes were investigated in the medical records of patients using a visual analogue scale ( vas ) score for leg pain and back pain .
motor deficit was graded according to the medical research council ( mrc ) scale8 ) .
these clinical factors were evaluated pre - procedurally and were repeated at 1 month , 6 months , and 12 months in the outpatient clinic .
a successful outcome was defined as excellent or good based on the macnab classification18 ) .
the data of the patients ' baseline demographic characteristics , comorbidities , and clinical factors are summarized in table 1 .
the disc herniation length , disc herniation area , canal cross - section length , canal cross - section area , canal length - occupying ratio , and canal area - occupying ratio were measured with imagej software , version 1.49 ( nih , bethesda , md , usa ) , obtained from an axial plane scan at the foraminal level pre - procedurally ( fig .
carlisle et al.4 ) published predictive values of the need for surgical intervention by mri analysis , and we used this model for radiological analysis .
canal area boundary tracing was performed from neural arch posteriorly , 4 mm from the anterior surface of the superior facet on both sides anteriorly .
the 4-mm antero - posterior ( ap ) distance in the foramen was estimated as sufficient to allow for normal nerve root function .
the measured interpedicular distance was used as the canal width on the foraminal axial image of the same vertebra .
we performed a transforaminal epidural steroid injection ( tfesi ) to relieve radicular pain with or without a nerve block of medial branch of posterior ramus ( so called medial branch block : mbb ) to relieve additional low back pain .
in particular , the tfesi solution consisted of 1% lidocaine , dexamethasone ( 10 mg ) , and hyaluronidase ( 1500 iu ) as an adjunct .
a 23-gauge spinal needle was introduced to the target point , which was a so - called " safe triangle , " i.e. , above the nerve root and below the pedicle until bony contact was encountered . after verifying the correct needle positioning under ap fluoroscopic control ,
contrast solution was injected to confirm that the material was passing the selected nerve root and was not administered intravascularly .
then , 3 ml of mixed solution was injected into each targeted point . following the procedure ,
the needle was withdrawn , the site was sealed with a sterile dressing , and the patients were monitored for 30 minutes for any untoward side effects .
each patient was evaluated 1 , 6 , and 12 months after the second nerve block . for patients with associated low back pain ,
it was done in usual fashion with injection of additional 2 ml of mixed solution ( without hyaluronidase ) to each site . under general anesthesia ,
the patient was placed prone on the operating table , and the thorax was supported on a wilson frame ( mdt corp . , torrance , ca , usa ) .
a tubular retractor was inserted over the interlaminar area with the blade of the retractor medially . following partial laminectomy under the microscope ,
after identifying the disc material compressing the nerve root and dural sac , the disc fragment was then removed .
we removed disc material from the disc space when the disc was poorly hydrated . in well - hydrated discs ,
the non - herniated disc was preserved because it was beneficial for the preservation of the vitality of the motion segment in well - hydrated discs2 ) .
a nerve hook was used to explore the remnant disc material and to check for foraminal clearance .
patients were discharged on the 1-week postoperative day , and the clinical outcome measurements were performed 1 month after surgery . the mann - whitney u test was used for an analysis of the differences between the clinical and radiological factors of the sg and ng .
a receiver operating characteristic ( roc ) curve was obtained to determine the optimal cutoff values of radiological factors by plotting every possible cutoff value 's sensitivity on the y axis against 1-specificity on the x axis26 ) .
sensitivity was defined as the proportion of patients who were correctly classified in the successful outcome group , whereas specificity was defined as the proportion of patients who were correctly classified in the non - successful outcome group .
the area under the roc curve ( auc ) , which reflects the overall performance of diagnostic accuracy , was also analyzed with medcalc software , version 16.4 ( medcalc software , mariakerke , belgium ) .
general guidelines have been suggested for interpreting the auc : 0.50.7 represents no to low discriminatory power ; 0.70.9 represents moderate discriminatory power ; and > 0.9 represents high discriminatory power111227 ) . with these cutoff values of radiological factors
, multivariate logistic regression analysis was performed using the multiple clinical and radiological factors as independent variables and the successful outcome of the procedure as the dependent variable .
statistical calculations were performed using spss software , version 23.0 ( ibm corporation , armonk , ny , usa ) .
a retrospective review was performed to 64 adult patients who were treated with surgery or nerve blocks for single level ldh at our institution from january 2012 to december 2014 , and they were followed up for at least a year .
all of the patients were considered to be surgical candidates by two spine surgeons with more than 15 years of experience , and all of them had initially been recommended for surgery .
the surgery group ( sg ) included 34 patients , and the nerve blocks group ( ng ) included 30 patients who initially refused the surgery .
the inclusion criteria of this study were as follows : patients with 1 ) unilateral or bilateral intractable radicular leg pain and back pain with or without sensory / motor deficit after conservative treatment ; 2 ) l45 level ldh confirmed by magnetic resonance imaging ( mri ) , and 3 ) organized medical records including both clinical and mri data ( pre- and post - treatment ) .
in contrast , the following patients were excluded : 1 ) those with cauda equina syndrome ; 2 ) those with progressive motor deficit ; 3 ) those with previous histories of lumbar surgery ; 4 ) those with histories of psychological disorder ; and 5 ) those with radiological evidence of other pathologies correlated with symptoms such as spinal stenosis .
the clinical outcomes were investigated in the medical records of patients using a visual analogue scale ( vas ) score for leg pain and back pain .
motor deficit was graded according to the medical research council ( mrc ) scale8 ) .
these clinical factors were evaluated pre - procedurally and were repeated at 1 month , 6 months , and 12 months in the outpatient clinic .
a successful outcome was defined as excellent or good based on the macnab classification18 ) .
the data of the patients ' baseline demographic characteristics , comorbidities , and clinical factors are summarized in table 1 .
the disc herniation length , disc herniation area , canal cross - section length , canal cross - section area , canal length - occupying ratio , and canal area - occupying ratio were measured with imagej software , version 1.49 ( nih , bethesda , md , usa ) , obtained from an axial plane scan at the foraminal level pre - procedurally ( fig .
carlisle et al.4 ) published predictive values of the need for surgical intervention by mri analysis , and we used this model for radiological analysis .
canal area boundary tracing was performed from neural arch posteriorly , 4 mm from the anterior surface of the superior facet on both sides anteriorly .
the 4-mm antero - posterior ( ap ) distance in the foramen was estimated as sufficient to allow for normal nerve root function .
the measured interpedicular distance was used as the canal width on the foraminal axial image of the same vertebra .
we performed a transforaminal epidural steroid injection ( tfesi ) to relieve radicular pain with or without a nerve block of medial branch of posterior ramus ( so called medial branch block : mbb ) to relieve additional low back pain .
in particular , the tfesi solution consisted of 1% lidocaine , dexamethasone ( 10 mg ) , and hyaluronidase ( 1500 iu ) as an adjunct .
a 23-gauge spinal needle was introduced to the target point , which was a so - called " safe triangle , " i.e. , above the nerve root and below the pedicle until bony contact was encountered . after verifying the correct needle positioning under ap fluoroscopic control ,
contrast solution was injected to confirm that the material was passing the selected nerve root and was not administered intravascularly .
then , 3 ml of mixed solution was injected into each targeted point . following the procedure ,
the needle was withdrawn , the site was sealed with a sterile dressing , and the patients were monitored for 30 minutes for any untoward side effects .
each patient was evaluated 1 , 6 , and 12 months after the second nerve block . for patients with associated low back pain ,
it was done in usual fashion with injection of additional 2 ml of mixed solution ( without hyaluronidase ) to each site .
under general anesthesia , the patient was placed prone on the operating table , and the thorax was supported on a wilson frame ( mdt corp . , torrance , ca , usa ) .
a tubular retractor was inserted over the interlaminar area with the blade of the retractor medially . following partial laminectomy under the microscope ,
the ligamentum flavum was detached from the lamina and removed . after identifying the disc material compressing the nerve root and dural sac ,
we removed disc material from the disc space when the disc was poorly hydrated . in well - hydrated discs ,
the non - herniated disc was preserved because it was beneficial for the preservation of the vitality of the motion segment in well - hydrated discs2 ) .
a nerve hook was used to explore the remnant disc material and to check for foraminal clearance . after meticulous hemostasis , saline irrigation was performed .
patients were discharged on the 1-week postoperative day , and the clinical outcome measurements were performed 1 month after surgery .
the mann - whitney u test was used for an analysis of the differences between the clinical and radiological factors of the sg and ng .
a receiver operating characteristic ( roc ) curve was obtained to determine the optimal cutoff values of radiological factors by plotting every possible cutoff value 's sensitivity on the y axis against 1-specificity on the x axis26 ) .
sensitivity was defined as the proportion of patients who were correctly classified in the successful outcome group , whereas specificity was defined as the proportion of patients who were correctly classified in the non - successful outcome group .
the area under the roc curve ( auc ) , which reflects the overall performance of diagnostic accuracy , was also analyzed with medcalc software , version 16.4 ( medcalc software , mariakerke , belgium ) .
general guidelines have been suggested for interpreting the auc : 0.50.7 represents no to low discriminatory power ; 0.70.9 represents moderate discriminatory power ; and > 0.9 represents high discriminatory power111227 ) . with these cutoff values of radiological factors
, multivariate logistic regression analysis was performed using the multiple clinical and radiological factors as independent variables and the successful outcome of the procedure as the dependent variable .
statistical calculations were performed using spss software , version 23.0 ( ibm corporation , armonk , ny , usa ) .
there were no significant differences between the sg and ng in any of the clinical characteristics , including age , sex , comorbidities , duration and neurologic symptoms ( table 1 ) .
there were no severe complications , including nerve root injuries , infections , or bleeding events , in both groups .
vas leg at 1 month ( sg : 1.500.68 , ng : 2.180.83 , p<0.01 ) , 6 months ( sg : 0.930.64 , ng : 1.711.00 , p<0.01 ) and 12 months ( sg : 0.670.66 , ng : 1.240.74 , p<0.01 ) showed significant differences between two groups ( fig .
however , vas back at 6 months ( sg : 0.530.63 , ng : 0.880.81 , p=0.08 ) and 12 months ( sg : 0.370.49 ,
mrc grade was also improved ; however no significant differences were identified between the two groups at 1 month ( sg : 4.570.97 , ng : 4.790.41 , p=0.65 ) and 6 months ( sg : 4.670.84 , ng
mrc grade at 12 months was significantly higher in the ng than in the sg ( sg : 4.670.84 , ng : 4.970.17 , p=0.03 ) .
changes in radiological factors before and 12 months after the procedure were calculated ( table 3 ) .
the disc herniation length and canal length - occupying ratio were significantly decreased in the sg compare to the ng after 12 months from baseline ( p=0.01 ) .
changes in the disc herniation area and in the canal area - occupying ratio were also larger in the sg than in the ng ; however , the results were not statistically significant .
the roc curve for successful leg pain relief at 12 months showed an auc ( 95% ci ) for the disc herniation length of the sg of 0.66 ( 0.460.82 ) and that of the ng of 0.64 ( 0.460.80 ) ( fig .
3 ) . the cutoff values ( sensitivity , specificity ) to distinguish between success and failure with the disc herniation length at 12 months were 6.31 mm ( 0.82 , 0.54 ) for the sg and 6.23 mm ( 0.68 , 0.58 ) for the ng . clinical outcomes was evaluated according to the macnab classification . in the sg ,
the 22 patients ( 94% ) at 1 month , 29 patients ( 97% ) at 6 months and 29 patients ( 97% ) at 12 months experienced excellent or good leg pain relief ( fig .
the 23 patients ( 68% ) at 1 month , 30 patients ( 88% ) at 6 months and 32 patients ( 94% ) at 12 months experienced excellent or good leg pain relief ( fig .
, the 25 patients ( 83% ) at 1 month , 26 patients ( 87% ) at 6 months and 27 patients ( 90% ) at 12 months responded that they have experienced excellent or good back pain relief ( fig .
, the 24 patients ( 70% ) at 1 month , 29 patients ( 85% ) at 6 months and 32 patients ( 94% ) at 12 months responded that they have experienced excellent or good back pain relief ( fig .
the odds ratio ( or ) of the clinical and radiological factors for the successful outcomes of procedures were analyzed by multivariate logistic regression analysis .
the disc herniation length [ or 2.35 ; confidence interval ( ci ) 1.213.98 ] was a predictor for successful outcomes in the sg at 12 months , and the results in the ng revealed 2 independent predictors : disc herniation length ( or 0.05 ; ci 0.0030.89 ) and baseline vas leg ( or 12.63 ; ci 1.6497.45 ) .
no significant radiological predictors were found of successful back pain relief in the two groups .
however , high baseline vas back predicted successful outcomes in the ng at 12 months ( or 11.13 ; ci 1.9463.80 ) .
there were no significant differences between the sg and ng in any of the clinical characteristics , including age , sex , comorbidities , duration and neurologic symptoms ( table 1 ) .
there were no severe complications , including nerve root injuries , infections , or bleeding events , in both groups .
vas leg at 1 month ( sg : 1.500.68 , ng : 2.180.83 , p<0.01 ) , 6 months ( sg : 0.930.64 , ng : 1.711.00 , p<0.01 ) and 12 months ( sg : 0.670.66 , ng : 1.240.74 , p<0.01 ) showed significant differences between two groups ( fig
vas back at 1 month ( sg : 0.670.71 , ng : 1.291.12 , p=0.02 ) also showed significant differences between two groups ( fig .
however , vas back at 6 months ( sg : 0.530.63 , ng : 0.880.81 , p=0.08 ) and 12 months ( sg : 0.370.49 ,
mrc grade was also improved ; however no significant differences were identified between the two groups at 1 month ( sg : 4.570.97 , ng : 4.790.41 , p=0.65 ) and 6 months ( sg : 4.670.84 , ng
mrc grade at 12 months was significantly higher in the ng than in the sg ( sg : 4.670.84 , ng : 4.970.17 , p=0.03 ) .
changes in radiological factors before and 12 months after the procedure were calculated ( table 3 ) .
the disc herniation length and canal length - occupying ratio were significantly decreased in the sg compare to the ng after 12 months from baseline ( p=0.01 ) .
changes in the disc herniation area and in the canal area - occupying ratio were also larger in the sg than in the ng ; however , the results were not statistically significant .
the roc curve for successful leg pain relief at 12 months showed an auc ( 95% ci ) for the disc herniation length of the sg of 0.66 ( 0.460.82 ) and that of the ng of 0.64 ( 0.460.80 ) ( fig .
3 ) . the cutoff values ( sensitivity , specificity ) to distinguish between success and failure with the disc herniation length at 12 months were 6.31 mm ( 0.82 , 0.54 ) for the sg and 6.23 mm ( 0.68 , 0.58 ) for the ng .
the 22 patients ( 94% ) at 1 month , 29 patients ( 97% ) at 6 months and 29 patients ( 97% ) at 12 months experienced excellent or good leg pain relief ( fig .
the 23 patients ( 68% ) at 1 month , 30 patients ( 88% ) at 6 months and 32 patients ( 94% ) at 12 months experienced excellent or good leg pain relief ( fig .
, the 25 patients ( 83% ) at 1 month , 26 patients ( 87% ) at 6 months and 27 patients ( 90% ) at 12 months responded that they have experienced excellent or good back pain relief ( fig .
, the 24 patients ( 70% ) at 1 month , 29 patients ( 85% ) at 6 months and 32 patients ( 94% ) at 12 months responded that they have experienced excellent or good back pain relief ( fig .
4d ) . the odds ratio ( or ) of the clinical and radiological factors for the successful outcomes of procedures were analyzed by multivariate logistic regression analysis .
the disc herniation length [ or 2.35 ; confidence interval ( ci ) 1.213.98 ] was a predictor for successful outcomes in the sg at 12 months , and the results in the ng revealed 2 independent predictors : disc herniation length ( or 0.05 ; ci 0.0030.89 ) and baseline vas leg ( or 12.63 ; ci 1.6497.45 ) .
no significant radiological predictors were found of successful back pain relief in the two groups . however , high baseline vas back predicted successful outcomes in the ng at 12 months ( or 11.13 ; ci 1.9463.80 ) .
we found that leg and back pain improvement was better in the sg during the follow - up period initially ; however , the differences in the vas leg between the two groups decreased from 6 months to 12 months , and vas back at 12 months showed no significant difference .
based on these results , it is possible to assume that these differences could be further reduced over a longer - term follow - up period , although recurrence of disc herniation with the return of pain is also possible .
surgery showed significant reductions in the disc herniation length and in the canal length - occupying ratio at 12 months after the procedure .
however , nerve blocks also showed a decreasing tendency in radiological factors subsequent to the procedure .
matsubara et al.19 ) reported that more degenerated discs and larger initial herniation had larger sizes of herniated fragments , which decreased in 32 patients treated conservatively with ldh . in this study
, there is no evidence of nerve block effect for natural regression of disc herniation neither in positive nor negative ways . in studies evaluating the efficacy of surgery versus conservative treatment for ldh , radiological predictors have been suggested561630 ) .
carlisle et al.4 ) also showed a trend for patients treated with surgery toward having larger disc herniation area , corresponding to a larger percentage canal compromise than the conservatively treated group .
however , the nerve block was not included in conservatively treated group on the above - mentioned studies .
therefore , authors have performed a comparative analysis between surgery and nerve blocks focusing on the radiological data which was not proposed elsewhere . from our study results ,
the patients with disc herniation length of l45 larger than 6.31 mm could be considered as candidates for surgical treatment , whereas those with disc herniation length less than 6.23 mm could be treated with nerve blocks .
the radiological factors as cutoff values at 12 months had close to moderate discriminatory power . while the study is still promising , it has limitations as well .
it was performed retrospectively and the number of patients involved in this study was relatively small especially in the elderly population .
thus , further investigations with a greater number of patients will be needed for the general application of suggested cutoff values .
a regression of the disc herniation could be important in correlation with improvement of symptoms and this could be also examined as a predictor .
single level ldh , which does not represent the entire level of ldh , was selected for the study , although l45 was the most common prolapsed level15 ) .
in addition , the patients sample were not randomly selected and rather patients chose the preferred treatment modality . despite these limitations , to the best to our knowledge , this is the first report to demonstrate the radiological criteria for the ldh treatment options between surgery and nerve block .
disc herniation length was a good predictor for clinical outcome and could be considered as radiological criteria for choosing optimal treatment options for ldh . | objectiveto assess the clinical and radiological factors as predictors for successful outcomes in lumbar disc herniation ( ldh ) treatment.methodstwo groups of patients with single level ldh ( l45 ) requiring treatment were retrospectively studied .
the surgery group ( sg ) included 34 patients , and 30 patients who initially refused the surgery were included in the nerve blocks group ( ng ) .
a visual analogue scale ( vas ) for leg and back pain and motor deficit were initially evaluated before procedures , and repeated at 1 , 6 , and 12 months . radiological factors including the disc herniation length , disc herniation area , canal length - occupying ratio , and canal area - occupying ratio were measured and compared .
predicting factors of successful outcomes were determined with multivariate logistic regression analysis after the optimal cut off values were established with a receiver operating characteristic curve.resultsthere was no significant demographic difference between two groups . a multivariate logistic regression analysis with radiological and clinical ( 12 months follow - up ) data revealed that the high disc herniation length with cutoff value 6.31 mm [ odds ratio ( or ) 2.35 ; confidence interval ( ci ) 1.213.98 ] was a predictor of successful outcomes of leg pain relief in the sg . the low disc herniation length with cutoff value 6.23 mm ( or 0.05 ; ci 0.0030.89 ) and high baseline vas leg ( or 12.63 ; ci 1.6497.45 ) were identified as predictors of successful outcomes of leg pain relief in the ng.conclusionthe patients with the disc herniation length larger than 6.31 mm showed successful outcomes with surgery whereas the patients with the disc herniation length less than 6.23 mm showed successful outcomes with nerve block .
these results could be considered as a radiological criteria in choosing optimal treatment options for ldh . |
chylopericardium is a rare clinical entity that is characterized by the presence of chyle in the pericardial cavity .
its association with lymphangiomas , cystic hygromas , thoracic and cardiac surgery , trauma , radiation and malignancy is well reported [ 2 , 3 ] .
however , primary chylopericardium , in which there is absence of known precipitating factors , is rarely encountered in clinical practice .
the severity of clinical manifestations of chylopericardium is varied and may range from the complete absence of symptoms to cardiac tamponade , and thus a high index of suspicion is required for the prompt recognition of the underlying diagnosis and management of its sequalae . in this report , we present a case of chylopericardium in a 23-year - old woman , presenting with acute shortness of breath in the background of extensive neck vein and superior vena cava ( svc ) thrombosis , of unknown aetiology .
she had been admitted into hospital 2 weeks earlier due to a community acquired pneumonia with parapneumonic collection , which required drainage and intravenous antibiotics .
her initial recovery was uneventful and thus the patient was discharged home a few days later . on this admission ,
a large cardiac shadow was seen on the chest radiogram , and pericardial effusion confirmed on computed tomography ( ct ) of the thorax .
the scan also demonstrated diffuse lymphadenopathy as well as extensive and multifocal thrombosis of the internal jugular veins bilaterally , the brachiocephalic vein and of the svc , managed with therapeutic dose of subcutaneous tinzaparin .
further diagnostic screening for rheumatological , auto - immune and infectious causes was unremarkable , whilst lymph node biopsies were negative for malignancy .
aspiration of the pericardial collection was suggestive of the presence of chyle , a suspicion that was confirmed on biochemical analysis of the aspirate .
cytology and cultures of the aspirate were negative for malignant and infectious causes , respectively ( fig .
figure 1:pre - operative chest radiograph and axial view of a ct thorax , demonstrating a large pericardial collection .
pre - operative chest radiograph and axial view of a ct thorax , demonstrating a large pericardial collection .
after pericardiocentesis , the patient had recurrence and was thus taken to theatre , underwent an anterior left mini - thoracotomy , through which a pericardial window was fashioned , 600 ml of chyle were collected and an 18 fr drain was placed in the pleural cavity .
her postoperative course was uneventful , drain removed on day 3 , and she was discharged home as the collection and her symptoms had resolved .
she remains symptom and collection free at 1 year postoperatively , with no evidence of recurrence on follow - up chest radiographs .
the association of chylopericardium with trauma , previous thoracic or cardiac surgery , congenital lymphangiomas , radiation and malignancy is well recognized [ 25 ] . however , primary chylopericardium is a clinical entity that is more rarely encountered and only diagnosed if all known precipitants have been excluded [ 68 ] .
its pathophysiology remains controversial , and is thought to be related to either elevated pressure in the thoracic duct , or to abnormal communications between the thoracic duct and the lymphatics of the pericardium [ 3 , 6 ] .
clinical manifestations are varied as it is the age spectrum of patients affected , with reports of chylopericardium in neonates through to older adult .
the imaging modalities that can be used to ascertain the underlying cause , with varying specificity and sensitivity , include lymphangioscintigraphy , lymphangiography , monitoring of chest radioactivity after oral intake of i - triolein and observation of the distribution of sudan iii dye in the pericardial cavity after ingestion [ 2 , 3 ] .
however , the diagnosis still relies on the cytology , chemistry and microbiology of pericardial aspirate , obtained via pericardiocentesis . the management of this condition though controversial has two main therapeutic aims .
this can be achieved via pericardiocentesis or surgically with the formation of a pericardial window / partial pericardiectomy , which can be combined with ligation of the thoracic duct and by conventional open methods or via video - assisted thoracoscopic surgery ( vats ) .
the second aim is the avoidance of metabolic , nutritional and immunological compromise , resulting from the loss of chyle , via a diet rich in medium chain triglycerides or , if necessary total parenteral nutrition [ 2 , 9 , 10 ] . in this instance
as pericardiocentesis is associated with a high incidence of recurrence , we opted for the pericardial window , combined with dietetic input to address the patient 's nutritional requirements .
the patient having been informed of her options , opted for the option of conventional surgery in preference to vats , a method that can also be safely used for the same purpose [ 24 ] .
the patient remains symptom - free a year postoperatively , and has been put on a surveillance programme with frequent follow - up . in conclusion , chylopericardium is a clinical entity that is not frequently encountered in the daily clinical practice and requires a high index of suspicion .
its management needs to address both the prevention of cardiac tamponade and the correction of nutritional and metabolic compromise that can ensue . | chylopericardium is a recognized complication of thoracic trauma , surgery or malignancy .
idiopathic or primary presentations , however , are rarely encountered in clinical practice .
the severity of its presentation varies from the complete absence of symptoms to cardiac tamponade .
we present the case of a 23-year - old woman with chylopericardium and extensive neck vein thrombosis that was managed surgically with a pericardial window . |
quackery is rampant among many parts of india.many types of skin diseases and eruption can occur due to practices employed by quacks .
many types of skin diseases and eruption can occur due to practices employed by quacks .
various religious beliefs , socio - cultural and religious practices , and quackery to treat varied medical problems often result in a host of secondary dermatoses . with increasing civilization and migration of population ,
herein , we describe a case of quackery aimed to improve abdominal discomfort , however , leading to peculiar skin eruption thereafter .
a 44-year - old immunocompetent married male was referred for an opinion on multiple strange appearing blisters on the abdominal wall since 3 days . on examination ,
multiple flaccid to tense bullae of size ranging from 1 to 3 cm over erythematous base arranged in a circumferential pattern with a well - defined erythematous margin were present on periumbilical area [ figure 1 ]
multiple hemorrhagic blisters on abdominal skin in a periumbilical area with circumferential distribution on further enquiry , the patient gave the history of abdominal pain and loss of appetite since last 7 days for which he was investigated on the surgical side and was diagnosed to have a small bowel obstruction .
an operative procedure of resection and anastomosis was planned by the surgical team . however , the patient refused to get operated and returned home and visited a traditional healer accompanied by his wife .
the healer gave the patient some unknown pills to consume , which made him to lose his consciousness .
the traditional healer then placed five burning lamps made of wheat dough over his abdomen in the umbilical region and then placed a utensil upside down over his abdomen covering those lamps .
when the patient regained his consciousness , there was a temporary cessation of abdominal cramps , but the patient noticed multiple painful blisters over his abdomen in the later part of the day .
we made a diagnosis of thermal burns resulting from burning lamps and managed the blisters symptomatically via draining and sterile dressings .
we counseled the patient about graveness of his abdominal complaint and made him to get operated for obstructive pathology .
quack is a fraudulent or ignorant pretender to medical skill or a person who pretends , professionally or publicly , to have skill , knowledge or qualifications , he or she does not possess . in our case , the traditional healer placed the burning lamps around the umbilicus with a belief that disease ( evil forces ) may exit the body via natural body orifice ( umbilicus ) [ figures 2 and 3 ] .
lamps made of wheat flour dough arranged circumferentially over periumbilical area ( the procedure was demonstrated on a ward attendant after due permission ) burning lamps and utensil used in the procedure ( not placed on actual patient due to ethical reasons ) branding as a preventive or therapeutic measure for many diseases is widely practiced in many rural parts of india .
practitioners of branding believe that the offending agent can get out of the brand site relieving the body of disease .
. the practice may continue even in later part of life , as the local traditional healer administers the brand mark on different body parts based on the anatomical localization of disease pathology .
tip of a hot metal rod , heated nails , wires , incense sticks , and hot bangles are the commonly used objects to brand the child .
the forehead , face , chest wall , and abdomen are the usual sites of branding .
the pediatric patient usually belongs to a poor illiterate rural family where branding is a continuing tradition prevalent through many generations .
neem ( azadirachta indica ) is one of the most ancient known traditional ayurvedic medicinal plants and is considered to have numerous medicinal properties .
various parts of neem tree are used to treat various dermatological conditions ( leprosy control , syphilitic sores and indolent ulcer , itching , skin ulcers , and eczematous dermatoses ) . however
, a large dose of neem can cause adverse effects including rashes , itching , and swelling and , in more severe cases labored breathing .
neem is considered to be unsafe in pregnancy when taken orally , as it can cause miscarriage .
semecarpus anacardium ( biba ) , also known as marking nut , commonly used by washerman , is well - known for its value in ayurvedic and siddha system of medicine .
it is believed to be helpful in treating illnesses related to the heart , blood pressure , respiration , cancer , and neurological disorders .
however , it has been widely used by quacks for the treatment of rheumatic arthritis , nervous disorders to decrease pain , which often leads to irritation , painful blisters , and irritant contact dermatitis . in developing countries ,
neonatal tetanus and cord infections continue to be an important cause of neonatal morbidity and mortality .
infants with neonatal tetanus often have a concomitant cord infection , which points to a common cause ( unclean delivery and cord care practices ) .
a wide variety of traditional practices and beliefs are associated with cord care . instead of cord
clamp , unqualified midwives use blades of grass , bark fibers , reeds , or fine roots are used to tie the cord , which are often laden with clostridium tetani spores and increase the risk of neonatal tetanus .
cord cutting / crushing is usually done with a variety of unsterile sharp instruments ( scissors , knives , broken glass , stones , sickles , or used razor blades ) . in most cultures ,
some kind of substance is applied to the umbilical stump to prevent bleeding from the stump , to promote separation of the stump , and to keep spirits away .
cow , chicken or rat dung ; ash , oil , butter , spice pastes , herbs , mud , and ghee are the substances applied , associated with high risk of tetanus as they can be contaminated with bacteria and spores .
this can help them avoid unnecessary investigations in case of dermatoses due to quackery and arrive at prompt diagnosis .
practice of quackery can result in unusual dermatological eruptionsa thorough history and a replay of events can provide useful clue in diagnosis .
practice of quackery can result in unusual dermatological eruptions a thorough history and a replay of events can provide useful clue in diagnosis .
practice of quackery can result in unusual dermatological eruptionsa thorough history and a replay of events can provide useful clue in diagnosis .
practice of quackery can result in unusual dermatological eruptions a thorough history and a replay of events can provide useful clue in diagnosis .
practice of quackery can result in unusual dermatological eruptionsa thorough history and a replay of events can provide useful clue in diagnosis .
practice of quackery can result in unusual dermatological eruptions a thorough history and a replay of events can provide useful clue in diagnosis . | a wide prevalence of socio - religious , cultural , and tribal practices in india often leads to a multitude of skin conditions , which can misled the dermatologists in arriving at a diagnosis . with increasing globalization and migration , the practice of indigenous customs and traditions are crossing boundaries , making it imperative for the dermatologists to be acquainted with the cutaneous side effects of these practices . here
, we report a unique case of thermal burn in a circumferential pattern over the umbilical region , a result of the placement of burning lamp over umbilicus to alleviate abdominal discomfort . |
in prosthodontic practice , limited mouth opening in patients is a common occurrence . prosthetic rehabilitation of patient with restricted mouth opening due to any causative factors , presents difficulties at all stages , right from the preliminary impressions to the insertion of prosthesis . a maximal oral opening smaller than the size of a complete denture can make prosthetic treatment challenging .
limited oral opening itself is not a disease but manifest as a consequence of certain conditions namely surgical treatments of orofacial carcinoma , cleft lip , trauma , burns , plummer vinson syndrome , scleroderma , trismus , rheumatism , temporomandibular joint dysfunction syndrome , oral submucous fibrosis , and any damage to masticatory muscles .
a 71-year - old male patient reported to the department of prosthodontics , rama dental college and hospital kanpur ( up ) , india , with the chief complaint of missing teeth and wanted replacement of the missing teeth by means of fabrication of complete denture . on examination , it was found that patient had oral submucous fibrosis with heavy vertical fibrous bands and homogenous leukoplakia on both sides of buccal mucosa which lead to reduced mouth opening of 2.5 cm .
patient was also diagnosed with bilateral angular cheilitis which often bleed on opening mouth wide .
treatment plan included sectional maxillary and mandibular final impression procedures , followed by fabricating maxillary hinged and mandibular sectional and hinged complete denture .
primary impression for maxillary arch was taken using smallest size edentulous stock tray with impression compound ( y dents ; mdm corp . ) , and after proper disinfection ( 1:213 iodophore ) , primary cast was poured in type ii dental plaster ( dentico ; neelkanth mine chem.).two autopolymerizing acrylic resin special trays ( trevelon ; dentsply india pvt . ltd . )
both trays were trimmed one side short of maxillary tuberosity.border molding was done with each tray using low fusing compound ( dpi ; pinnacle , india ) and the final impression was made with light body polyvinyl siloxane addition silicon impression material ( examix nds ; gc company).one sectional impression tray was poured with dental stone ( denstone , grade iii ) . over that cast second sectional impression tray was assembled and the remaining part of the cast was poured.similarly , mandibular primary impression was taken using smallest size stock tray and after disinfection , primary cast was poured .
a conventional special tray was fabricated over the primary cast and that was later sectioned from the midline into two halves .
one hole was drilled in the center of the tray handle and a brass dowel pin was passed through it , from one end to the other end of the hole .
similarly , two holes were drilled over the premolar region on both sides of the tray and the two brass dowel pins were placed vertically in those holes and were connected by acrylic plate which was detachable.border molding and final impression were made individually with the each half of the tray and the tray was joined extra - orally with the help of dowel pin and acrylic plate .
the master cast was poured with dental stone.after obtaining maxillary and mandibular master casts , denture bases were fabricated and then were sectioned from the midline .
after sectioning , the two ends of the denture bases were rejoined from the midline using press buttons ( snap fasteners ; needles ind ) .
wax rims ( link , modeling wax , mdm corp . ) were prepared over the denture bases .
the wax rim was not prepared in the mandibular anterior region because of the presence of the press buttons over the anterior segment of the ridge .
jaw relation was recorded.then the teeth arrangement was done [ figure 1 ] ( lactodent ; pyrax enterprises ) .
patient was called for try-in.after try - in , the press buttons were removed from the maxillary denture base and the gap between the two parts of the denture base was closed by incorporating wax between them and the processing of denture was done in a conventional manner .
similarly , the press buttons were also removed from the anterior segment of the mandibular denture base and the anterior teeth were arranged .
an index was made for the anterior teeth with the help of putty addition polyvinyl siloxane impression material ( exaflex , gc company ) .
the anterior teeth were then removed and placed back in putty index , rest of the denture was processed with heat cure acrylic resin ( trevlon , dentsply ) , without anterior teeth in a conventional manner so that the hinge assembly can be placed later in the anterior teeth region.after processing , the dentures were retrieved , finished , and polished and then again sectioned from the midline with the help of thin disk bur.an orthodontic mandibular molar tube with 1-mm stainless steel wire was used to form a hinge assembly for the maxillary and mandibular sectional dentures so that the dentures can collapse at the midline.for maxillary denture , two mandibular molar tubes ( orthotechno wire and co. ) were used with 1-mm stainless steel wire which was passing through the slot of the tube .
the maxillary denture was placed back over the cast and these assemblies were incorporated between the two sections of the denture in the center of the palatal surface using self - cure acrylic resin and the rest of the gap created during sectioning of the maxillary denture was also filled with self - cure acrylic resin .
proper care was taken to avoid the entrapment of acrylic material inside the hinge , which can block the hinge movement of the dentures.for mandibular denture , one orthodontic mandibular molar tube with 1-mm stainless steel wire was used to form a hinge assembly so that the denture can collapse at the midline .
this assembly was incorporated between the two sections of the denture using self - cure acrylic resin.the mandibular hinge denture was placed back over the master cast and the index of the mandibular denture was made with irreversible hydrocollo i d ( alginate , zelgan 2002 , dentsply ) and the cast was poured with dental stone.over that cast , mandibular anterior teeth were arranged back in their correct position with the help of previously made putty index .
two clasps were adapted over the adjacent teeth to retain the acrylic removable partial denture [ figure 2 ] .
wax - up was done and the acrylic removable partial denture was processed in a conventional acrylization manner.maxillary hinged denture and the mandibular sectional ( separate anterior removable segment ) and hinged denture [ figure 3 ] were placed in patient 's mouth.patient was educated about the insertion and removal of dentures .
instructions were given to maintain the denture.patient was recalled for the follow - up visits to check for the maintenance and patient 's adaptability with the dentures .
first follow - up was done after 24 h of denture insertion followed by 1 week to check for the comfort and any tissue reaction .
initially , patient felt difficulty while placing and removal of the dentures from the oral cavity but with time patient got used to it .
figure 1(a ) maxillary and ( b ) mandibular sectional denture bases with occlusion rims and teeth arrangement
figure 2(a ) maxillary denture sectioned from the midline incorporating two hinge assemblies in the palatal region of the maxillary denture ; ( b ) mandibular acrylized denture with hinge assembly in anterior region . the index of the denture made and the cast obtained , anterior teeth arranged back in position with putty index to make anterior removable partial denture
figure 3(a ) collapsed maxillary hinged and ( b ) mandibular sectional and hinged complete denture with anterior removable partial denture
primary impression for maxillary arch was taken using smallest size edentulous stock tray with impression compound ( y dents ; mdm corp . ) , and after proper disinfection ( 1:213 iodophore ) , primary cast was poured in type ii dental plaster ( dentico ; neelkanth mine chem . ) . two autopolymerizing acrylic resin special trays ( trevelon ; dentsply india pvt . ltd . )
border molding was done with each tray using low fusing compound ( dpi ; pinnacle , india ) and the final impression was made with light body polyvinyl siloxane addition silicon impression material ( examix nds ; gc company ) .
one sectional impression tray was poured with dental stone ( denstone , grade iii ) . over that cast second sectional impression tray
similarly , mandibular primary impression was taken using smallest size stock tray and after disinfection , primary cast was poured .
a conventional special tray was fabricated over the primary cast and that was later sectioned from the midline into two halves .
one hole was drilled in the center of the tray handle and a brass dowel pin was passed through it , from one end to the other end of the hole .
similarly , two holes were drilled over the premolar region on both sides of the tray and the two brass dowel pins were placed vertically in those holes and were connected by acrylic plate which was detachable .
border molding and final impression were made individually with the each half of the tray and the tray was joined extra - orally with the help of dowel pin and acrylic plate .
after sectioning , the two ends of the denture bases were rejoined from the midline using press buttons ( snap fasteners ; needles ind ) .
wax rims ( link , modeling wax , mdm corp . ) were prepared over the denture bases .
the wax rim was not prepared in the mandibular anterior region because of the presence of the press buttons over the anterior segment of the ridge .
then the teeth arrangement was done [ figure 1 ] ( lactodent ; pyrax enterprises ) .
after try - in , the press buttons were removed from the maxillary denture base and the gap between the two parts of the denture base was closed by incorporating wax between them and the processing of denture was done in a conventional manner .
similarly , the press buttons were also removed from the anterior segment of the mandibular denture base and the anterior teeth were arranged .
an index was made for the anterior teeth with the help of putty addition polyvinyl siloxane impression material ( exaflex , gc company ) .
the anterior teeth were then removed and placed back in putty index , rest of the denture was processed with heat cure acrylic resin ( trevlon , dentsply ) , without anterior teeth in a conventional manner so that the hinge assembly can be placed later in the anterior teeth region . after processing ,
the dentures were retrieved , finished , and polished and then again sectioned from the midline with the help of thin disk bur .
an orthodontic mandibular molar tube with 1-mm stainless steel wire was used to form a hinge assembly for the maxillary and mandibular sectional dentures so that the dentures can collapse at the midline .
for maxillary denture , two mandibular molar tubes ( orthotechno wire and co. ) were used with 1-mm stainless steel wire which was passing through the slot of the tube .
the maxillary denture was placed back over the cast and these assemblies were incorporated between the two sections of the denture in the center of the palatal surface using self - cure acrylic resin and the rest of the gap created during sectioning of the maxillary denture was also filled with self - cure acrylic resin .
proper care was taken to avoid the entrapment of acrylic material inside the hinge , which can block the hinge movement of the dentures .
for mandibular denture , one orthodontic mandibular molar tube with 1-mm stainless steel wire was used to form a hinge assembly so that the denture can collapse at the midline .
this assembly was incorporated between the two sections of the denture using self - cure acrylic resin .
the mandibular hinge denture was placed back over the master cast and the index of the mandibular denture was made with irreversible hydrocollo i d ( alginate , zelgan 2002 , dentsply ) and the cast was poured with dental stone . over that cast , mandibular anterior teeth were arranged back in their correct position with the help of previously made putty index .
two clasps were adapted over the adjacent teeth to retain the acrylic removable partial denture [ figure 2 ] .
wax - up was done and the acrylic removable partial denture was processed in a conventional acrylization manner .
maxillary hinged denture and the mandibular sectional ( separate anterior removable segment ) and hinged denture [ figure 3 ] were placed in patient 's mouth .
patient was recalled for the follow - up visits to check for the maintenance and patient 's adaptability with the dentures .
first follow - up was done after 24 h of denture insertion followed by 1 week to check for the comfort and any tissue reaction .
initially , patient felt difficulty while placing and removal of the dentures from the oral cavity but with time patient got used to it .
( a ) maxillary and ( b ) mandibular sectional denture bases with occlusion rims and teeth arrangement ( a ) maxillary denture sectioned from the midline incorporating two hinge assemblies in the palatal region of the maxillary denture ; ( b ) mandibular acrylized denture with hinge assembly in anterior region . the index of the denture made and the cast obtained , anterior teeth arranged back in position with putty index to make anterior removable partial denture ( a ) collapsed maxillary hinged and ( b ) mandibular sectional and hinged complete denture with anterior removable partial denture
several techniques have been described in the literature for the fabrication of sectional and hinged tray / complete dentures , utilizing various mechanisms for connecting each of the components .
pubmed database for the last two decades was reviewed using key words : microstomia , hinged and sectional dentures and different techniques for patients with microstomia are found to be documented [ table 1 ] .
different techniques and denture modifications for microstomia other management techniques described in the literature for patients with restricted mouth opening are surgery , use of dynamic opening devices , and modification of denture design . in cases where microstomia is not manageable by surgeries or dynamic opening devices , modified impression procedure and prosthesis design facilitate prosthetic rehabilitation .
the denture aids for a better function , health , esthetics , and overall well - being of the patient and thus a rewarding service can be provided by the prosthodontist .
the reduction in maximal oral opening ( microstomia ) less than the normal ( 35 - 40 mm ) hinders conventional prosthetic treatment of edentulous patients .
it is often difficult to apply conventional clinical procedures to construct dentures for patients who demonstrate limited mouth opening .
however , with careful treatment planning and prudent designing , the use of either sectional impression techniques and/or sectional dentures , many of the apparent clinical difficulties can be overcome . here ,
the sectional impression procedures and the prosthesis designs are described which aid in fabrication of prosthesis for a patient with the limited mouth opening which aids for a better function , health , esthetics , and overall well - being of the patient .
simplified sectional tray design and ease of fabrication are the major advantages of this technique .
this technique can be accomplished in any dental laboratory , without using complicated machinery or attachment devices for sectioning or assembling the trays / prosthesis together .
the press buttons and mandibular molar bands are easily available and are easy to maintain .
this technique shares disadvantages common to all sectional tray / prosthesis designs , such as additional time , labor , and materials .
however , to determine the long - term success of this technique , periodic recall , maintenance , and further improvements in design are needed . | restricted mouth opening is a definite prosthodontic hindrance to carry out treatment successfully .
restricted mouth opening can be due to many reasons such as microstomia , oral submucous fibrosis , some genetic disorder , and as a result of some surgical treatment . in the past ,
various techniques for prosthetic rehabilitation of limited oral opening have been tried such as surgeries , use of dynamic opening devices , magnetic devices , and modification of denture design . here
we present ; a simplified technique and simple design for fabrication of maxillary hinged and mandibular hinged and sectional complete denture for a patient with restricted mouth opening due to oral submucous fibrosis . |
breast cancer has been one of the most common cancers among women in the united states .
the estimates for 2012 are 226,870 new cases of breast cancer and 39,510 deaths due to breast cancer in women in the united states .
in addition to the incidence and death in women , 2190 new cases of breast cancer incidence and 410 deaths are expected in men in 2012 .
the current treatment modalities have severe adverse effects including endometrial cancer , cardiotoxicity , leukemia , blood clots , nausea , and vomiting , .
the idea of cancer chemoprevention has received more attention since the promotion stage of breast cancer generally is a lengthy process that could be reversible .
previous studies with auraptene showed its chemopreventive effects in rodent models of many cancers including colon [ 47 ] , esophagus , tongue , liver [ 10 , 11 ] , and skin .
these studies in human breast carcinoma cell lines , mda - mb-231 , and mcf-7 indicated the anti - proliferative effects of citrus auraptene . subsequently an in vivo study demonstrated that dietary auraptene ( 500 ppm in the diet ) decreased mammary carcinoma incidence and delayed median time to tumor in n - methylnitrosourea ( mnu ) treated rats .
hplc analysis of the mammary tissues from auraptene treated rats detected auraptene in the low m concentrations at both 200 and 500 ppm dose .
they include inhibition of polyamine synthesis [ 9 , 13 ] , induction of detoxifying enzymes [ 14 , 15 ] , induction of apoptosis [ 3 , 16 ] , inhibition of metalloproteinase [ 17 , 18 ] , and inhibition of cholesterol esterification to name a few .
recently , medina and colleagues reported that auraptene modulated genes under the transcriptional control of estrogen . in our in vivo study , further analysis of the mammary tissues from rats showed that cyclin d1 protein was significantly reduced in auraptene 500 ppm treated animals .
the d - type cyclins control the g1 to s transition during the cell cycle along with e - type cyclins . in up to 50% of primary breast cancers the overexpression of cyclin d1 mrna and protein has been observed .
cyclin d1 overexpression is predominantly found in estrogen receptor positive breast cancer , which is a major subtype of human breast cancer . since cyclin
d1 protein expression was reduced in mammary tissues of auraptene treated rats , we explored the effect of auraptene on cell cycle in human breast carcinoma cell line mcf-7 , which is positive for the estrogen receptor .
the results shed more light on the inhibitory effects of auraptene on cell cycle machinery .
the cells were grown in sterile humidified chamber maintained at 37c and 5% co2 : 95% air .
briefly , 1 10 cells were plated in eight 10 cm dishes , with duplicate dishes in each group .
there were four groups : control ( dmso ) , igf-1 only , igf-1 + auraptene , and auraptene only .
the cells were serum starved on the next day of plating . after 22 h of serum starvation ,
the igf-1 + auraptene and auraptene only groups were pretreated with 10 m of auraptene in dmso ( 0.1% v / v ) .
the control and igf-1 only groups received vehicle . at 24 h of serum starvation ,
the igf-1 only and igf-1 + auraptene groups received 10 ng / ml of igf-1 .
after 8 h and 24 h of igf-1 treatment , the cells were harvested and centrifuged and the supernatant was removed .
the cells were counted and then fixed with ice cold 70% ethanol and kept at 4 overnight .
the next day , the cells were centrifuged , the ethanol was removed and the cells were washed twice with ice cold pbs . then , to each tube 500 l of the propidium iodide solution mix was added ( propidium iodide solution mix was prepared by adding 10 l of triton - x 100 ( 10% stock ) , 200 l of 10 mg / ml rnase solution , and 400 l of 0.5 mg / ml propidium iodide solution to 10 ml pbs ) and incubated for 30 minutes at room temperature , followed by cell cycle analysis using flow cytometry .
the flow cytometry was conducted using a bd lsrii ( bd biosciences ) in the research core facility at the lsuhsc - shreveport .
the instrument has a coherent sapphire laser for 488 nm excitation , a jds uniphase hene laser for 633 nm excitation , as well as a coherent vioflame for 450 nm excitation .
the data were analyzed with facs diva ( bd biosciences ) and modfit lt software ( verify software house ) .
a qrt - pcr array was done to analyze changes in gene expression of cell cycle related genes by auraptene . for this experiment , 1
10 cells were plated in eight 6 cm dishes , with duplicate dishes in each group .
there were four groups : control , igf-1 only , igf-1 + auraptene , and auraptene only . the cells were serum starved on the next day of plating . at 22 h of serum starvation ,
the igf-1 + auraptene and auraptene only groups were pretreated with 10 m of auraptene in dmso ( 0.1% , v / v ) .
the control and igf-1 only groups received vehicle . at 24 h of serum starvation ,
the igf-1 only and igf-1 + auraptene groups received 10 ng / ml of igf-1 .
after 8 h and 24 h of igf-1 treatment , the cells were processed for rna isolation as per the manufacturer 's instructions ( qiagen , rneasy minikit ) .
the isolated rna was treated with dnase to remove any genomic contamination as per the manufacturer 's suggested protocol ( promega ) .
after confirming the quality of rna , 1 g of rna was converted to cdna as per the directions from the manufacturer ( quanta biosciences ) .
the 1 : 10 dilution of cdna was used for amplification with perfecta sybr green fast mix for iq ( quanta biosciences ) in the pcr array ( human cell cycle tox and cancer 96 stellarray qpcr array , lonza ) .
the results from all experiments were analyzed using the global pattern recognition software from bar harbor biotechnology , available on lonza 's website ( http://array.lonza.com/stellarrays/ ) .
the experiment was repeated 3 times at 8 h and also at 24 h after igf treatment .
the analysis of cell cycle data was done by one - way anova followed by tukey / kramer post hoc test , p < 0.01 .
the results from qrt - pcr array studies were analyzed with the global pattern recognition software available on lonza 's website ( http://array.lonza.com/stellarrays/ ) , p < 0.05 .
after 8 h of igf-1 treatment , the harvested cells were run by flow cytometer to analyze the percentage of cells in the different phases of cell cycle ( figure 1 and table 1 ) .
most of the cells of the control group were in the g1 phase ( 92% ) , and there were no significant differences in the percentages of cells in the g1 phase among the treatment groups .
igf-1 did not produce any significant increase in the percentage of cells in s phase of the cell cycle at 8 h and no significant reduction in s phase was found in the auraptene treated cells .
the percentage of cells in g2 in the control and the treatment groups also were almost the same .
the effects of auraptene on cell cycle in the absence of igf-1 was no different than the control group at 8 h. also , there were no apparent differences in the ratio of g2/g1 .
after 24 h of igf-1 treatment , the harvested cells were run by flow cytometer to analyze the percentage of cells in the various phases of cell cycle .
igf-1 treatment resulted in a significantly decreased percentage of cells in the g1 phase compared to all the other groups from 87% in the control to 46% in the igf-1 treated group ( figure 2 and table 2 ) .
there was a corresponding increase in the percentage of cells in s phase in the igf-1 treated group ( from 10% in the control group to 57% in the igf-1 treated group ) .
auraptene pretreatment significantly reduced the percentage of cells in s phase in the igf-1 treated cells and appeared to restore the cells back to control levels of g1 .
the effects of auraptene on cell cycle in the absence of igf-1 were no different than the control group at 24 h. also , there were no apparent differences in the ratio of g2/g1 . in table 3 ,
the significant changes in the gene transcript level with auraptene pretreatment in igf-1 treated cells when compared to the igf-1 alone treated cells at 8 h time point are shown .
there were significant changes in 9 genes , with 6 downregulated and 3 upregulated ones .
the downregulated genes were e2f1 ( e2f transcription factor 1 ) , cdc45l ( cell division cycle 45 homolog ) , e2f2 ( e2f transcription factor 2 ) , mcm3 ( minichromosome maintenance complex component 3 ) , mcm6 ( minichromosome maintenance complex component 6 ) , and uhrf1 ( ubiquitin - like with phd and ring finger domains 1 ) .
the upregulated genes include cdkn2b ( cyclin - dependent kinase inhibitor 2b ) , ddit3 ( dna - damage - inducible transcript 3 ) , and jun ( jun oncogene ) .
the igf-1 alone treatment resulted in the increased transcription of only 2 genes , mcm6 and orc1l ( origin recognition complex , subunit 1-like ) , which are key regulators of cell replication complex . in table 4 ,
the significant changes in the gene transcript level with auraptene pretreatment in igf-1 treated cells when compared to the igf-1 alone treated cells at 24 h time point are shown .
the downregulated genes were cdc45l ( cell division cycle 45 homolog ) , cdc2 ( cyclin - dependent kinase 1 ) , ccna2 ( cyclin a2 ) , kif20b ( kinesin family member 20b ) , chek1 ( chk1 checkpoint homolog ) , cdkn2c ( cyclin - dependent kinase inhibitor 2c ) , chek2 ( chk2 checkpoint homolog ) , e2f1 ( e2f transcription factor 1 ) , uhrf1 ( ubiquitin - like with phd and ring finger domains 1 ) , and ccnb2 ( cyclin b2 ) .
the upregulated genes were ddit3 ( dna - damage - inducible transcript 3 ) , cdkn2b ( cyclin - dependent kinase inhibitor 2b ) , gadd45a ( growth arrest and dna - damage - inducible , alpha ) , and dusp1 ( dual specificity phosphatase 1 ) .
e2f1 , cdc45l , uhrf1 , ddit3 , and cdkn2b were modulated at both 8 h and 24 h.
here , the effects of auraptene on cell cycle and genes involved in the mammalian cell cycle have been described .
this study was conducted after finding the inhibitory effect of auraptene on cyclin d1 protein expression in mcf-7 cells and rat mammary tumors .
we previously showed that in mcf-7 cells 10 m auraptene reduced the cyclin d1 protein expression by about 40% after treating with igf-1 .
in the subsequent animal study , auraptene at 500 ppm dose in the diet significantly delayed the time to tumor compared to the mnu only group .
the rat mammary tumors from auraptene 500 ppm group showed significant reduction in cyclin d1 protein expression .
since cyclin d1 is a key protein that regulates g1/s transition in cell cycle , we hypothesized that auraptene will inhibit the progression of cell cycle .
to our knowledge this is the first study to show a detailing of the effect of auraptene on igf-1 induced stimulation of the cell cycle in a breast cancer cell line .
auraptene significantly reduced the percentage of cells in the s phase at the 24 h time point .
this effect was not observed at the 8 h time point , even though auraptene reduced cyclin d1 expression after 8 h in mcf-7 cells .
this might be due to the fact that inhibition of cyclin d1 is an earlier event , which later resulted in slowing down the progression of cell cycle .
the mitogenic activity of igf-1 was not seen at 8 h , since there was no significant increase in the percentage of cells in the s phase compared to the control cells . at 24 h , a significant increase in the percentage of cells in the s phase was observed .
correspondingly , there was a significant reduction in the percentage of cells in the g1 phase of igf-1 only group .
igf-1 was used to stimulate the serum starved mcf-7 cells because igf-1 has been shown to be in high concentration in rats treated with mnu , which is the same carcinogen we used in our rat study with auraptene .
obese women , who are at higher risk to get breast cancer postmenopausally , also have higher igf-1 blood levels .
it might be interesting to see the effect of auraptene in presence of other mitogens . in the current study , after auraptene pretreatment , we saw a time dependent change in the transcriptional machinery associated with cell cycle along with the inhibition of s phase . at 8 h time point , significant changes
were observed in 9 genes and at 24 h in 14 genes . among these genes ,
therefore , from the fact that these genes are still transcriptionally reduced , it is concluded that the effect of auraptene on cell cycle could persist for at least 24 h. this could be the effect of parent compound or its active metabolites .
the major metabolites of auraptene are umbelliferone and 7-ethoxycoumarin which also have been shown to possess chemopreventive effects .
the cyclin d1 gene was also one of the cell cycle genes whose changes were analyzed along with the other mentioned genes .
we found that there was no significant change in the mrna level of cyclin d1 in the cells treated with igf-1 and auraptene ( data not shown ) .
previous studies have shown that auraptene changed the protein levels of cox-2 , inos , and pro - mmp-7 without changing their transcript levels [ 18 , 26 ] . in the human colorectal adenocarcinoma cell line ht-29 ,
auraptene disrupted the translation of prommp-7 protein synthesis by decreasing phosphorylation levels of 4e binding protein ( 4ebp)1 and eukaryotic translation initiation factor ( eif)4b .
these data along with our results point to the fact that auraptene might be acting on the translational machinery of the cells .
many genes that were modulated by auraptene have been shown to be relevant in many cancers .
most of the prostate and breast - cancer cell lines studied had reduced copy number of cdkn2b gene , whereas in this study we found it upregulated with time after auraptene pretreatment .
cdkn2b , an inhibitor of cyclin d1 induced cell cycle progression from g1 phase to s phase , could contribute to the auraptene induced inhibition of cell cycle at g1 phase .
cdkn2b was found to be increased by auraptene to almost similar extent at both 8 h and 24 h whereas the s phase inhibition was evident at 24 h. this might be because regulation of cdkn2b might be an earlier event that leads to further inhibition of cell cycle machinery at a later time point .
the e2f freed from prb by the cyclin d - cdk complex upregulates the transcription of genes involved in dna - replication
the e2f genes are deregulated in many cancers by various mechanisms like overexpression of cyclin d1 , loss of prb , and expression of human papillomavirus ( hpv ) oncoprotein e7 , to name a few .
cdc45 protein has been shown to be overexpressed in various human cancer cell lines , including mcf-7 .
uhrf1 has been shown to be upregulated in cancer of breast , prostate , pancreas , and so forth [ 3133 ] .
thus at the earlier time point in this study , the downregulation of cyclin d1 could have resulted in the reduced transcription of e2fs and their downstream targets like uhrf1 and mcm complexes resulting in the initiation of cell cycle arrest .
jun or c - jun is a component of the composite transcription factor activating protein-1 ( ap-1 ) and promotes cell proliferation [ 34 , 35 ] .
c - jun is overexpressed in many human cancers and contributes to the invasiveness of human breast cancer cells . in this study
, we found jun upregulated at 8 h time point only and not at 24 h time point that corresponds with the inhibition of s phase at 24 h by auraptene . at
the later time point auraptene pretreatment resulted in greater change in the gene expression of cdc45l , e2f1 , uhrf1 , ddit3 , and cdk2nb .
the other genes modulated by auraptene also have been shown to be deregulated in many cancers .
the dusp1 transcript was dramatically decreased in colorectal cancer compared to normal cells [ 37 , 38 ] .
li and colleagues showed that dusp1 ( mkp1 ) is a transcriptional target of p53 that inhibits mapk pathway activation of cell cycle progression . in
estrogen dependent breast cancer cells , estrogen was shown to increase the expression of cyclin b2 protein and promote cell proliferation .
chek1 overexpression has been seen in human colorectal cancer correlated with advanced tumor and poor prognosis .
cdkn2c is the gene that codes for the cyclin dependent kinase 4 inhibitor c or p18 .
therefore the increased expression of cdkn2c might also be playing an important role in auraptene induced inhibition of cell cycle at g1 phase .
however these 2 genes , having similar functions , are modulated differently by auraptene at 8 h and 24 h. kif20b is a member of the kinesin-6 family .
the kif4a gene was observed to be highly transactivated . in the majority of glioma cell lines ,
kif20b was found to be highly expressed in a majority of human invasive bladder cancers .
thus the overall gene changes brought about by auraptene pretreatment inhibited the progression of cell cycle at the g1 phase in mcf-7 cells .
a few of the above - mentioned genes have been identified as targets of anticancer therapy .
flavopiridol , a cdk1 and cdk2 inhibitor , is being clinically tested against gastric cancer , leukemia , and head and neck cancer .
another cdk1 modulator currently in clinical trials is ucn-01 . in a cell cycle gene array experiment in mcf-10f cells with etodolac , a cox-2 inhibitor
, ccna2 was one of the prominently altered genes . in pc-3 prostate cancer cells , luteolin reduced the transcription of ccna2 along with that of other cell cycle genes and inhibited the proliferation of those cells .
since auraptene modulated these genes , further analysis of its potential as a dietary chemopreventive agent needs to be carried out .
here we investigated the role of auraptene on cell cycle progression of human breast carcinoma cell line , mcf-7 , and we showed the inhibitory effect of auraptene on cell cycle in mcf-7 .
auraptene significantly reduced the percentage of cells undergoing s phase after 24 h of igf-1 treatment .
there were several genes involved in cell cycle that were significantly modulated with auraptene pretreatment .
more genes were modulated at 24 h time point and correspondingly auraptene pretreatment showed inhibition of the cell cycle progression .
overall , auraptene pretreatment produced significant increase in the mrna level of genes known to be upregulated prior to cell cycle arrest and apoptosis .
there was a significant decrease in the mrna level of genes that promote g1/s transition and dna replication .
further studies on the effect of auraptene on cell cycle progression and protein translational machinery in different breast cancer cell lines will provide us with more information about its chemopreventive properties .
however , the results obtained with auraptene in mcf-7 cells throw more light on cell cycle inhibition as one of its chemopreventive mechanisms .
since breast cancer is a multifactorial disease , a combination of drugs should be tried for chemoprevention studies and auraptene could be one of the candidates . | auraptene is being investigated for its chemopreventive effects in many models of cancer including skin , colon , prostate , and breast .
many mechanisms of action including anti - inflammatory , antiproliferative , and antiapoptotic effects are being suggested for the chemopreventive properties of auraptene .
we have previously shown in the n - methylnitrosourea induced mammary carcinogenesis model that dietary auraptene ( 500 ppm ) significantly delayed tumor latency . the delay in time to tumor corresponded with a significant reduction in cyclin d1 protein expression in the tumors .
since cyclin d1 is a major regulator of cell cycle , we further studied the effects of auraptene on cell cycle and the genes related to cell cycle in mcf-7 cells . here
we show that auraptene significantly inhibited igf-1 stimulated s phase of cell cycle in mcf-7 cells and significantly changed the transcription of many genes involved in cell cycle . |
ischemic stroke is the third leading cause of death and the first leading cause of disability in adults around the globe .
stroke is accompanied by a robust inflammatory response , glutamate mediated excitotoxicity , release of reactive oxygen species and the initiation of apoptosis(1 ) .
malignant middle cerebral artery infarction is the most common cause of death during the first week after an ischemic stroke ( 2 ) .
it is defined as a brain infarction affecting most or all of the mca territory , accompanied within days by a massive brain edema causing increased intracranial pressure ( icp ) , clinical deterioration and transtentorial herniation .
the therapeutic window of acute ischemic stroke for thrombolysis drug usage is short and has side effects including higher risk of intracranial hemorrhage ( ich ) ( 3 ) . because of this and other complications ,
use of thrombolysis drug like recombinant tissue plasminogen activator ( rt - pa ) is limited . some experimental research and clinical works
have reported the neuroprotective effect of mild hypothermia ( mh ) and moderate hypothermia ( 4 - 6 ) .
stabilization of the blood brain barrier , down regulation of cerebral metabolism , decrease of excitatory transmitter release and decrease generation of free radicals are of some neuroprotective mechanisms of hypothermia ( 7 , 8) .
several excellent articles have reviewed the protective effects of hypothermia as function of onset time , duration , and depth of hypothermia , as well as its underlying protective mechanisms ( 9 - 11 ) .
this procedure is induced by different methods including : surface - cooling blankets and adhesive pads , the use of an endovascular cooling system and sometimes cold intravenous fluids .
prolonged systemic hypothermia however has some side effects including myocardial arrhythmia , dehydration and blood hypercoagulability ( 12 ) .
there are some experimental and clinical studies indicate that decompressive craniectomy ( dc ) significantly reduced mortality and improved clinical outcomes ( 13 - 16 ) . as an alternative therapy , surgical decompression techniques ( large hemicraniectomy with durotomy ) have been proposed to relieve the high intracranial pressure ( 17 - 19 ) . on the other hand ,
combined general hypothermia and dc yield significant additional benefit including infarct size and neurological scores compared with singular effect of them ( 20 ) .
the combination of mh and minocycline had a small but not significantly additional effect over the single treatments after focal cerebral ischemia in the rat ( 21 ) .
although it has been shown that selective brain hypothermia was neuroprotective in experimental stroke ( 22 ) but , to our knowledge , there are no data available indicating therapeutic effect of direct local cerebral hypothermia with craniectomy in acute ischemic stroke .
therefore , we investigated whether a combination of dc with the local hypothermia , may provide more neuroprotection during the permanent mcao ( middle cerebral artery occlusion ) model of stroke in rats .
male wistar rats were anesthetized with halothane 1% to 1.2% under spontaneous respiration in an air - oxygen mixture .
rectal temperature was maintained between 37c and 37.5c with a thermostat - controlled heating pad .
the right femoral artery was cannulated and physiological parameters including rectal temperature , mean blood pressure , ph , po2 , and pco2 , were monitored .
forty eight male wistar rats ( weighing 220 to 300 g ) were allocated to 4 treatment groups of 12 animals each ( 8 for infarct volume and neurological outcomes and 4 for evans blue ) as following : control , decompressive craniectomy ( dc ) , local hypothermia ( lh ) , hypothermia combined with craniectomy ( hc ) .
focal cerebral ischemia was induced using a modified intraluminal suture method as described previously ( 23 ) . in brief , the bifurcation of right common carotid artery was exposed through a midline incision .
the internal carotid artery and external carotid artery were distally dissected , free from the surrounding tissues under an operating microscope .
after ligation of the external and common carotid arteries , a 30 silicon rubber - coated monofilament was gently inserted through the common carotid artery into the internal carotid artery to 18 - 20 mm beyond the carotid bifurcation at the base of the middle cerebral artery .
then , the distal end of monofilament was tied up and the wound was closed using the surgical suture . the cerebral blood flow ( cbf ) in parietal cortex
the filament was advanced until laser doppler flowmetry indicated adequate mca occlusion by a sharp decrease in ipsilateral blood flow .
the rat was considered as a successful occlusion when its cbf reduced at least to 30% of initial flow .
was made and the parietal and temporal bone was exposed entirely . then the scalp was kept cold for 15 min by pouring 4c normal saline ( two drops per second ) over it .
contralateral temporalis muscle temperature has been reported to approximate closely to the intraparenchymal brain temperature ( 24 ) .
dc was performed in animals by creating a bone flap ( 10 5 mm ) in the temporal and parietal bone with the use of a dental drill .
additional bone was removed under microscopic control with the use of microscissors ( 14 , 20 ) .
no cortical resection of infracted brain was attempted . at the end of the procedure ,
the temporalis muscle and skin flap were adapted and sutured in place . at 48 hr after stroke
, rats were decapitated ; brains removed and cut in to 2 mm coronal sections using a rat brain matrix .
infarct volume was quantified in sections stained with 2% 2,3,5-triphenyltetrazolium chloride using image j analyzer ( nih image , version 1.61 ) ( 25 ) .
the total volume of each hemisphere and infarction was determined by integration of distance of the 6 sections .
infarctions were adjusted to the size of contralateral hemisphere by applying the following formula : infarct volume = ( volume of left hemisphere- ( volume of right hemisphere - measured infarct volume))/volume of left hemisphere ( 26 ) . for these analyses ,
rats were trained on the adhesive removal test of sensorimotor function ( 27 ) , daily for 3 days before stroke .
animals were then tested before surgery and
at 24 and 48 hr post - stroke .
time taken to touch and remove each stimulus from the limb was recorded during 3 trials and averaged .
neurological deficits were recorded at 24 and 48 hr after stroke and determined with a modified 6-point scoring system of bederson and coworkers ( 28 ) as follows : 0 , no observable deficit ; 1 , forelimb flexion ; 2 , forelimb flexion plus decreased resistance to lateral push ; 3 , unidirectional circling ; 4 , unidirectional circling plus decreased level of consciousness ; and 5 , death .
endurance in the wire - hanging test was measured on a horizontal steel wire ( 1 mm ) stretched horizontally 50 cm above a foam pad . for the pole test
, the rat was placed head upward on the top of a vertical wooden rough - surfaced pole ( diameter 1 cm , height 50 cm ) .
each rat was habituated on the day before testing then allowed to descend 5 times on a single session .
the total time needed to turn completely head downward ( time - to - turn ) and the time until the animal reached the floor with its 4 paws ( time - to - come - down ) was recorded .
bbb permeability was determined using evans blue dye ) eb ) extravasation technique , as described earlier ( 30 , 31 ) .
briefly , a catheter was placed into the jugular vein through which 4 ml / kg of eb solution ( 2% evans blue in normal saline , sigma , germany ) was infused into the animal during 5 min period . then , the animal was allowed to completely recover for at least 30 min . after killing the animal with an overdose of sodium thiopental and opening the chest , a catheter was placed into the left ventricle to infuse 300 ml of warm normal saline ( 37c ) for 15 min in order to washout the remains of eb from general circulation . following decapitation , the brain was gently excised
, its cerebellum and olfactory bulb were separated , and the rest was divided into the right and left hemispheres with a brain matrix . each hemisphere was carefully weighed and absorption was measured by a spectrophotometer ( uv7500 , spectro lab , england ) at 620 nm .
physiological parameters and behavioral tests were compared by two - way anova and individual differences determined by tukey s test .
infarct volume and bbb permeability were compared by one - way anova followed by tukey s test . a value of p < 0.05 was considered to be significant .
male wistar rats were anesthetized with halothane 1% to 1.2% under spontaneous respiration in an air - oxygen mixture .
rectal temperature was maintained between 37c and 37.5c with a thermostat - controlled heating pad .
the right femoral artery was cannulated and physiological parameters including rectal temperature , mean blood pressure , ph , po2 , and pco2 , were monitored .
forty eight male wistar rats ( weighing 220 to 300 g ) were allocated to 4 treatment groups of 12 animals each ( 8 for infarct volume and neurological outcomes and 4 for evans blue ) as following : control , decompressive craniectomy ( dc ) , local hypothermia ( lh ) , hypothermia combined with craniectomy ( hc ) .
focal cerebral ischemia was induced using a modified intraluminal suture method as described previously ( 23 ) . in brief , the bifurcation of right common carotid artery was exposed through a midline incision .
the internal carotid artery and external carotid artery were distally dissected , free from the surrounding tissues under an operating microscope .
after ligation of the external and common carotid arteries , a 30 silicon rubber - coated monofilament was gently inserted through the common carotid artery into the internal carotid artery to 18 - 20 mm beyond the carotid bifurcation at the base of the middle cerebral artery .
then , the distal end of monofilament was tied up and the wound was closed using the surgical suture . the cerebral blood flow ( cbf ) in parietal cortex
the filament was advanced until laser doppler flowmetry indicated adequate mca occlusion by a sharp decrease in ipsilateral blood flow .
the rat was considered as a successful occlusion when its cbf reduced at least to 30% of initial flow .
was made and the parietal and temporal bone was exposed entirely . then the scalp was kept cold for 15 min by pouring 4c normal saline ( two drops per second ) over it .
contralateral temporalis muscle temperature has been reported to approximate closely to the intraparenchymal brain temperature ( 24 ) .
dc was performed in animals by creating a bone flap ( 10 5 mm ) in the temporal and parietal bone with the use of a dental drill .
additional bone was removed under microscopic control with the use of microscissors ( 14 , 20 ) .
no cortical resection of infracted brain was attempted . at the end of the procedure ,
at 48 hr after stroke , rats were decapitated ; brains removed and cut in to 2 mm coronal sections using a rat brain matrix .
infarct volume was quantified in sections stained with 2% 2,3,5-triphenyltetrazolium chloride using image j analyzer ( nih image , version 1.61 ) ( 25 ) .
the total volume of each hemisphere and infarction was determined by integration of distance of the 6 sections .
infarctions were adjusted to the size of contralateral hemisphere by applying the following formula : infarct volume = ( volume of left hemisphere- ( volume of right hemisphere - measured infarct volume))/volume of left hemisphere ( 26 ) . for these analyses ,
rats were trained on the adhesive removal test of sensorimotor function ( 27 ) , daily for 3 days before stroke .
animals were then tested before surgery and
at 24 and 48 hr post - stroke .
time taken to touch and remove each stimulus from the limb was recorded during 3 trials and averaged .
neurological deficits were recorded at 24 and 48 hr after stroke and determined with a modified 6-point scoring system of bederson and coworkers ( 28 ) as follows : 0 , no observable deficit ; 1 , forelimb flexion ; 2 , forelimb flexion plus decreased resistance to lateral push ; 3 , unidirectional circling ; 4 , unidirectional circling plus decreased level of consciousness ; and 5 , death .
endurance in the wire - hanging test was measured on a horizontal steel wire ( 1 mm ) stretched horizontally 50 cm above a foam pad . for the pole test
, the rat was placed head upward on the top of a vertical wooden rough - surfaced pole ( diameter 1 cm , height 50 cm ) .
each rat was habituated on the day before testing then allowed to descend 5 times on a single session .
the total time needed to turn completely head downward ( time - to - turn ) and the time until the animal reached the floor with its 4 paws ( time - to - come - down ) was recorded .
bbb permeability was determined using evans blue dye ) eb ) extravasation technique , as described earlier ( 30 , 31 ) .
briefly , a catheter was placed into the jugular vein through which 4 ml / kg of eb solution ( 2% evans blue in normal saline , sigma , germany ) was infused into the animal during 5 min period .
after killing the animal with an overdose of sodium thiopental and opening the chest , a catheter was placed into the left ventricle to infuse 300 ml of warm normal saline ( 37c ) for 15 min in order to washout the remains of eb from general circulation . following decapitation ,
the brain was gently excised , its cerebellum and olfactory bulb were separated , and the rest was divided into the right and left hemispheres with a brain matrix . each hemisphere was carefully weighed and absorption was measured by a spectrophotometer ( uv7500 , spectro lab , england ) at 620 nm .
physiological parameters and behavioral tests were compared by two - way anova and individual differences determined by tukey s test .
infarct volume and bbb permeability were compared by one - way anova followed by tukey s test . a value of p < 0.05 was considered to be significant .
there were no statistically significant differences between groups for intra operative physiological indices ( table 1 ) .
infarct volume in control group was 307.34 18.09 mm and the difference between control and hypothermia ( 82.05 12.86 mm ) , craniectomy ( 137.88 30.38 mm ) and hc ( 27.40 17.61 mm ) groups were statistically significant ( p < 0.001 ; figure 1 ) .
combination therapy with lh and dc were more neuroprotective than dc alone ( p<0.01 ; figure 1 ) .
data of hanging test showed that only hc significantly increased endurance time at 24 or 48 hr after ischemia ( p<0.01 ) , but neither lh nor dc showed any significant difference ( figure 2 ) . while compared to the control group , sticky tape test ( p<0.05 at 24 hr ; p<0.001 at 48 hr ; figure 3 ) showed better behavioral performance only in hc , bederson test showed improved behavioral functions of both lh ( p<0.05 at 24 hr and p<0.01 at 48 hr ) and hc animals ( p<0.01 ) .
neurological deficits were also decreased in lh ( p<0.05 ) or hc ( p<0.05 at 24 hr ; p<0.01 at 48 hr ) groups compared to the dc group at the same times ( figure 4 ) .
absorption values in control , dc , lh and hc were 0.42 0.11 , 0.11 0.01 , 0.10 0.02 and 0.05 0.01 , respectively . compared to the control group , dc ( p<0.05 ) lh and hc ( p<0.01 ) significantly decreased absorption ( figure 5 ) .
although mean absorption were more decreased in combination therapy , there were no significant differences between it and the other groups .
contralateral temporal muscle temperatures were measured by a temporal probe . as expected , there was no significant difference in brain temperature between the control and dc groups . in both lh ( p<0.01 ) and hc ( p<0.001 ) groups ,
brain temperature decreased compared to the control group . compared to the dc group , lh and
infarct volume in control group was 307.34 18.09 mm and the difference between control and hypothermia ( 82.05 12.86 mm ) , craniectomy ( 137.88 30.38 mm ) and hc ( 27.40 17.61 mm ) groups were statistically significant ( p < 0.001 ; figure 1 ) .
combination therapy with lh and dc were more neuroprotective than dc alone ( p<0.01 ; figure 1 ) .
data of hanging test showed that only hc significantly increased endurance time at 24 or 48 hr after ischemia ( p<0.01 ) , but neither lh nor dc showed any significant difference ( figure 2 ) . while compared to the control group , sticky tape test ( p<0.05 at 24 hr ; p<0.001 at 48 hr ; figure 3 ) showed better behavioral performance only in hc , bederson test showed improved behavioral functions of both lh ( p<0.05 at 24 hr and p<0.01 at 48 hr ) and hc animals ( p<0.01 ) .
neurological deficits were also decreased in lh ( p<0.05 ) or hc ( p<0.05 at 24 hr ; p<0.01 at 48 hr ) groups compared to the dc group at the same times ( figure 4 ) .
absorption values in control , dc , lh and hc were 0.42 0.11 , 0.11 0.01 , 0.10 0.02 and 0.05 0.01 , respectively . compared to the control group , dc ( p<0.05 ) lh and hc ( p<0.01 ) significantly decreased absorption ( figure 5 ) . although mean absorption were more decreased in combination therapy , there were no significant differences between it and the other groups .
contralateral temporal muscle temperatures were measured by a temporal probe . as expected , there was no significant difference in brain temperature between the control and dc groups . in both lh ( p<0.01 ) and hc ( p<0.001 ) groups ,
brain temperature decreased compared to the control group . compared to the dc group , lh and
to the best of our knowledge , there are no available data for the effect of directly local brain hypothermia through craniectomy on stroke in rodents .
thus , the novelty of the current study is that we investigated delayed effect of direct brain hypothermia , by opening the scalp , on permanent focal cerebral ischemia in rat .
we observed that both late decompressive craniectomy and local hypothermia decrease infarct volume but combination of them has more neuroprotective effects .
some studies showed that early decompressive craniectomy could significantly decrease infarct volume and mortality rates ( 24 , 32 ) , that were parallel with our study .
many investigators have reported that general hypothermia decreases infarct volume in different models of stroke in rat ( 4 , 8) . on the other hand ,
neuroprotective effect of focal brain hypothermia through scalp has been reported ( 33 ) and mentioned it as a effectual , simple , cost - effective and safe hypothermia method in rats . since neurological evaluations have more clinical importance in stroke patients , we used batteries of neurological tests in the current study .
quantitive neurological evaluations including sticky tape or hanging - wire tests showed that only combination of both craniectomy and local hypothermia improved behavioral functions .
on the other hand , bederson s neurological deficits test showed that local hypothermia alone or its combination with craniectomy is neuroprotective .
only a few studies have examined the influence of hypothermia on delayed reperfusion after ischemic injury . in parallel with our findings , it has been suggested that general hypothermia also improved neurological performances in temporary middle cerebral artery occlusion ( 5 ) .
more interestingly , when applied up to 6 hr after ischemia insult , general hypothermia has decreased neurological deficits after stroke ( 34 ) .
furthermore , we observed that both craniectomy and local hypothermia prevent bbb disruption and although combination of them was more effective , this difference was not significant .
it has been recently reported that combination of general hypothermia and minocycline may also prevent bbb disruption through matrix metalloproteinase ( mmp ) inhibition in focal cerebral ischemia ( 21 ) .
different neuroprotective mechanisms for hypothermia have been postulated including : stabilization of the blood brain barrier , down regulation of cerebral metabolism , elimination of excitatory transmitter release and reduction of free radical generation ( 7 , 8 , 35 ) .
it has been suggested that the attenuation of oxidative dna damage and dna damage triggered pro - death signaling events can be an important mechanism for neuroprotective effect of mild hypothermia in cerebral ischemia ( 36 ) .
protection of basal lamina , reduction in infarct volume and hemorrhage , and reduction in proteolytic enzymes are some of other neuroprotective mechanisms of hypothermia ( 37 ) .
reduction of neuronal inflammation was also mentioned as a main contributor in neuroprotective effects of post - ischemic mild hypothermia ( 38 ) . despite of these advantages of general hypothermia ,
some adverse effects have been limited its using such as myocardial arrhythmia , hypotension , blood hypercoagulability , and hemodynamic instability ( 12 , 39 ) .
a comparison between different methods of hypothermia including intracarotid cold saline infusion , ice cap , and systemic cooling was investigated showing that the former was more effective than other methods ( 40 ) .
hence , these findings suggest that methods like intracarotid cold saline infusion and our current method of directly exposed brain cooling are strategies that not only reveal more neuroprotective effects of hypothermia but also prevent the side effects of general hypothermia . combinations of hypothermia with other methods have been evaluated in some studies .
one study reported that combination therapy of hypothermia with mgso4 reduced infarct volumes at 2 hr and 4 hr after permanent mcao but there was no therapeutic effect at 6 hr or in hypothermia and mgso4 groups singularly ( 41 ) .
another study showed that combination of citicoline with hypothermia suppressed apoptotic processes that are more effective than using each of them lonely ( 42 ) .
jieyong et al showed that the combination between craniectomy and mild hypothermia reduce the infarction size ( 43 ) .
doerfler et al ( 2001 ) showed that combination of decompressive craniectomy at 4 hr after mcao with mild hypothermia have diminished the infarct volume and improved neurological outcomes ( 20 ) .
we increased the therapeutic window of cerebral ischemia to 6 hr by directly local cerebral hypothermia through combination of craniectomy and using of cold saline .
in contrast with the above , we used direct local cerebral hypothermia for 15 min in our experiment .
the brain temperature was decreased to 31.5c in local hypothermia group and 28.5c in combination therapy group , while body temperature was maintained at normal range by warm pad ( 36.5 - 37c ) .
this temperature is lesser than the mild hypothermia which used in most studies ( 33c ) ( 20 , 39 ) .
therefore , we decreased the complication of general hypothermia whereas we increased the depth of hypothermia .
the end point of our study was 48 hr because the animals were become sick and they loosed weight .
our findings reveal that although late decompressive craniectomy and local hypothermia decrease infarct volume , delayed directly brain hypothermia , by opening the scalp , is more neuroprotective in stroke therapy .
further studies are needed to evaluate the best starting time of hypothermia , durations as well as its exact neuroprotective mechanisms . | objective(s ) : hypothermia and decompressive craniectomy ( dc ) have been shown to be neuroprotective .
this study was designed to evaluate neuroprotective effects of delayed singular or combination of dc and local hypothermia on stroke .
materials and methods : cerebral ischemia was induced in 48 wistar rats assigned to 4 groups : control , decompressive craniectomy ( dc ) , local hypothermia ( lh ) , combination of hypothermia and craniectomy ( hc ) .
infarct size and bbb disruption were measured 48 hr after ischemia insult .
neurological deficits were assessed at 24 and 48 hr after stroke by using sticky tape test , hanging - wire test and bederson s scoring system .
bbb disruption was measured by evans blue dye leakage .
results : although infarct size was significantly reduced in lh , dc and hc groups ( p<0.001 ) , combination therapy was more neuroprotective compared to craniectomy alone ( p<0.01 ) .
bbb disruption was significantly reduced in dc ( p < 0.05 ) and lh and hc ( p < 0.01).while sticky tape test ( p<0.05 at 24 hr ; p<0.001 at 48 hr ) and hanging - wire test ( p<0.05 ) showed better behavioral performance only in hc , bederson test showed improved behavioral functions of both lh ( p<0.05 at 24 hr and p<0.01 at 48 hr ) and hc animals ( p<0.01 ) .
neurological deficits were also decreased in lh ( p<0.05 ) or hc ( p<0.05 at 24 hr ; p<0.01 at 48 hr ) groups compared to the dc group at the same time . conclusion : based on our data , although both delayed local hypothermia and craniectomy are protective after stoke , combination therapy of them is more neuroprotective than given alone . |
the co - existence of an aberration in a different chromosome of a klinefelter 's syndrome is rare . still rare
several cases of double aneuploidy of xxy and trisomy 21 have been published since the first report . but occurrence of xxy aneuploidy and 9 chromosome inversion with co - existing schizophrenia has not been reported so far .
a 38-year - old unmarried male was brought to our psychiatric center , sri ramachandra medical college and research institute , chennai , for the complaints of withdrawn behavior , muttering to self , lacking self - care and having disturbed sleep for 2 years .
he used to wander away from home on and off , but used to return home on his own within 23 days .
but he went missing for about 1.5 years before he was traced in a temple and brought to our facility on 10 november 2008 .
he was born of non - consanguineous parents and the delivery was a full - term normal one .
he was reared only by his mother as his father had left their family 2 years after his birth . on discontinuation from school after his failure in 6 standard , from the age of 17 years he undertook several jobs .
family history revealed that his paternal uncle had mental illness , but the details could not be obtained for want of suitable informant . on mental status examination ,
his general appearance was found to be poor , with ill - kempt hair , unclipped nails , and untidy clothes .
he denied the identity of his mother and sister who had brought him , but called them as his relatives .
delusions of persecution and reference , and second person auditory hallucination were present . the orientation to place , persons , and time , and memory for immediate , recent , and remote events were intact .
his intellectual capacity seemed to be mildly backward as indicated by his verbal and performance [ intelligence quotient ( iq ) of 71 and 56 , respectively ] with full scale iq of 63 on assessment with wechsler 's adult intelligence scale that was administered in regional language .
however , the diagnosis of co - morbid mental retardation was shelved considering the possible decline in his cognitive and social spheres as a result of psychosis .
dsm - iv diagnosis of schizophrenia was established after performing the structured clinical interview using the mini international neuropsychiatric interview schedule for psychotic disorders . on general
examination , absence of hair in the axillary region and on the face and chest was observed .
the dimensions of the testes as measured by the ultrasound were 15 mm in length , 10 mm in breadth and 12 mm antero - posteriorly .
hormonal assay showed his free testosterone as 4.70 pg / ml which was low ( reference range 8.827 pg / ml ) .
additionally , the follicle stimulating hormone ( fsh ) and luteinizing hormone ( lh ) levels were detected to be high ( 41.04 and 28.21 miu / ml , respectively ) ( respective reference ranges 915 and 2.45.9 miu / ml ) .
the chromosome analysis of 50 metaphases with gtg banding showed a numerical and a structural abnormality .
the karyotype was mos 47,xxy , inv(9 ) ( p12 ; q12 ) [ 90% ] / 46,xy[10% ] , inv(9 ) ( p12 ; q12 ) and that of klinefelter 's syndrome ( male mosaic ) [ figures 1 and 2 ] .
a small pericentric inversion of chromosome 9 has been noted to be present in up to 1.98% of all individuals tested by cytogenetic laboratories and is seen mostly in african - americans .
it is said that inv(9)(p11q12 ) has no known deleterious effect on carriers and does not appear to be associated with a risk of miscarriage or unbalanced offspring .
it is , therefore , generally considered as a normal variant . notwithstanding this , it is difficult to rule out at this stage the impact of inv(9 ) on the human behavior .
pericentric region of chrosomome 9 was suggested as one of the regions of interest for linkage analysis based on an examination of 120 patients with schizophrenia of whom 4 ( 3.3% ) were found to have a pericentric inversion of chromosome 9 .
a turkish study noted pericentric inversion and enlargement of the heterochromatin region of chromosome 9(inv(9 ) ; 9qh+ ) in 7 out of their 134 schizophrenics ( 5.2% ) .
more recently , a clonal pericentric inversion on chromosome 9 was detected in 1 male patient from a sample of 62 brazilian schizophrenic patients .
there has been no systematic report on the levels of schizophrenia psychopathology in a large sample of people with klinefelter 's syndrome unselected for psychiatric disorders . in a sample of 32 men with klinefelter 's syndrome ,
higher level of schizotypal traits and higher scores for positive and negative symptoms were noted .
case reports on klinefelter 's syndrome with schizophrenia fulfilling the diagnostic criteria have not so far observed the presence of inv(9 ) in their series . despite the absence of unequivocal evidences for any deleterious effect of inv(9 ) , it is still worthwhile to explore whether it has any role in the etiology of schizophrenia , especially when it occurs along with other genotypic aberrations that are suspected to have relevance to psychiatric disorders including the klinefelter 's syndrome .
these anomalies might increase the risk for schizophrenia in a relatively nonspecific way such as contributing to disruption of normal embryogenesis of the nervous system . | klinefelter 's syndrome is a sex chromosome abnormality with low androgen level .
the varied manifestations of the mental symptoms in some of them , that are inexplicable based on their genotype alone , has fascinated the researchers .
we present here a case of klinefelter 's syndrome having a karyotype of mos 47 , xxy , and also inversion in 9th chromosome , with schizophrenia . despite the view that inv 9 is a normal variant , it is still worthwhile to explore whether it has any role in the etiology of schizophrenia especially when it occurs with other genotypic aberrations that are suspected to have relevance to psychiatric disorders including the klinefelter 's syndrome . |
mandibular osteoradionecrosis ( orn ) is a potentially debilitating complication from ionizing radiotherapy , whose incidence is reported to range between 5% and 15% .
orn is most commonly defined as an exposed , irradiated , nonhealing defect of the mandible with symptoms lasting at least 2 to 3 months , without any evidence of tumor recurrence .
although this complication often arises in the first 6 to 12 months after radiotherapy , reports of late incidence suggest a lifelong risk .
the risk factors for orn include a high radiation dose ( > 60 gy ) , previous dental extraction , radiation to the posterior mandible , infection , a large tumor size , malnutrition , poor oral hygiene , and alcohol and tobacco abuse .
although the condition is most often associated with dental extractions or mucosal trauma , spontaneous cases of orn have been recorded .
the treatment for orn was first designed in the 1950s and comprises a multimodal approach utilizing conservative measures such as antibiotic therapy , debridement , and irrigation in the early stages of the disease , while reserving surgical resection and reconstruction for more advanced or refractory cases .
recently , interest in the management of orn has been rekindled with the introduction of newer reconstructive techniques [ 1 - 5 ] .
the purpose of this presentation is to describe our recent experience with a buccinator myomucosal flap implemented for the reconstruction of a partial mandibular defect caused by orn .
a 55-year - old male patient visited at gyeongsang national university hospital with a complaint of tonsil cancer .
he was experiencing problems with his left molar tooth , and the latter was therefore extracted before the patient underwent the next radiation therapy session ( after sufficient time had elapsed ) .
the tonsil cancer was treated with radiation therapy of 7,200 rad . however , a defect appeared in the region where the left molar tooth had been extracted ( fig .
the defect was diagnosed as a case of orn caused by the radiation therapy , and antibiotic administration and symptomatic therapy were followed for 3 months . however , the defect size gradually increased and the necrosis region grew wider , calling for a different type of treatment . on the basis of our experience with tongue reconstruction using a buccinator flap , we planned the reconstruction of the defect site using a buccinator artery - based buccal flap .
after sufficiently sterilizing the defective area , the necrosis region was ground with a drill and was removed in order to view the fresh tissue . afterwards , an incision slightly larger than the defect site was performed in the buccal mucosa ( fig .
after incising the buccal mucosa and the muscle along the upper and anterior borders , the flap was elevated in an anterior to posterior direction ( fig .
when harvesting the buccinator flap , the buccal fat layer was also harvested so that the defect site in the mandible could be obliterated ( fig .
the neurovascular pedicle ( including the buccal artery , vein , and nerve ) was identified ( fig .
the dissection was continued inferiorly and laterally , and lower and posterior incisions were made so that the flap could be elevated .
the flap was then rotated to fill the defect site with buccal fat , and the harvested buccal mucosa was sutured to the mucosa of the defect site ( fig .
one week after the operation , good settlement of the flap was observed ( fig .
one year later , it was found that the donor site and the recipient site were stably healed ( fig .
the patient was healed without particular discomfort , and the orn did not progress any further .
clinicians will agree that injuries of the mandible caused by radiation remain a challenging problem , and can be more difficult to manage than the original cancer .
the disastrous effects of orn of the mandible , including orocutaneous fistulae , pathologic fractures , associated soft - tissue necrosis , and trismus , are clearly much easier to prevent than to treat .
early theories on orn held that three factors radiation , trauma , and infection contributed to the pathophysiology of this disease process .
marx subsequently promoted his 3-h paradigm , whereby radiation induced tissue injuries by causing vessel thrombosis ( hypovascularity ) , leading to hypoxia and the resultant cell death of the skin / mucosa and underlying bony element ( hypocellularity ) .
this theory supported the potential therapeutic role of hyperbaric oxygen therapy ( hbo ) therapy , which marx incorporated into a standardized treatment protocol ( wilford hall hbo orn protocol ) .
orn is , therefore , a problem of impaired and inadequate tissue turnover and wound healing .
no widely - accepted , evidence - based guidelines for the use of hbo therapy in the prevention and management of orn have been established .
protocols utilizing hbo therapy , which were once considered the standard of care , are no longer recommended for the prevention or treatment of orn .
newer theories describing the pathogenesis of orn have stimulated the evolution of conservative management strategies , including the administration of drugs such as pentoxifylline and tocopherol .
bony replacement with flap reconstruction is appropriate for patients with orn who fail to respond to conservative treatment .
nowadays , the primary reconstruction of mandibular defects which have failed to be resolved by conservative treatment is desirable , and even mandatory . with the advent of microsurgical techniques ,
in fact , a vascularized free fibular flap represents an optimal reconstruction method after a mandibular resection [ 11 - 14 ] .
however , the free flap is difficult and slow to perform , and causes a problem of morbidity of the donor site .
therefore , if the mandibular defect is small , a regional pedicle flap from the same oral cavity may be used as an easier way to reduce the duration of the operation and to remove the problem of morbidity of the donor site .
thus , if the mandibular defect is not large , an adjacent buccinator myomucosal flap supplied by the buccal artery may be more useful .
we recently reported that the tongue may be reconstructed using a buccinator myomucosal flap , and the present case reports an advanced method of reconstruction .
when a buccinator myomucosal flap is used , only a linear scar remains at the donor site , and the bony defect of the mandible is filled with harvested buccal fat , which can prevent the progress of the bony defect .
moreover , since the same oral mucosa is used as tissue replacement , contracture can be prevented .
research on the reconstruction of mandibular defects caused by orn using a buccinator myomucosal flap supplied by the buccal artery has just started .
therefore , there is no confirmation that all orns can be treated with a buccinator myomucosal flap .
however , the present report is significant in that an opportunity was created to consider an alternative treatment method to conservative management and free flap surgery .
our results reveal that a buccinator myomucosal flap can be performed for reconstruction of a partial mandibular defect caused by orn , and that the buccinator myomucosal flap is a reliable method to reconstruct small mandibular defects . | the use of a myomucosal flap from the buccinator muscle is a valuable reconstruction method for intraoral defects . in this paper , we report the clinical advantages of using a buccinator myomucosal flap for the treatment of partial mandibular defects caused by osteoradionecrosis .
we implemented a buccinator myomucosal flap for the reconstruction of a partial mandibular defect in a 55-year - old man with tonsil cancer and partial mandibular defects caused by osteoradionecrosis .
the total operating time was 90 minutes .
twelve months after the reconstruction , the patient remains free of disease .
a buccinator myomucosal flap can be used for the reconstruction of partial mandibular defects caused by osteoradionecrosis .
it is a reliable method for reconstructing small mandibular defects . |
a retrospective study was made of 7,567 patients admitted to a tertiary hospital for chest pain from 2005 to 2014 and underwent cardiac catheterization .
patients were divided into two groups : obese and normal with bmi calculated as 30 kg / m and < 25 , respectively .
we assessed the modifiable and non - modifiable risk factors in obese patients and the degree of cad with coronary angiography as obstructive cad ( left main stenosis of 50% or any stenosis of 70% ) , non - obstructive cad ( 1 stenosis 20% but no stenosis 70% ) , and normal coronaries . for statistical analysis , we used chi - square , odds ratio , and univariate log regression .
the distributions of age , sex , and baseline co - morbidities were compared between the two cohorts .
the implication of modifiable risk factors and non - modifiable risk factors were evaluated in those patients including hypertension , diabetes mellitus , obesity , dyslipidemia , tobacco use , cocaine , family history of premature cad , and gender .
dyslipidemia was defined as low - density lipoprotein cholesterol of 130 mg / dl or greater or total cholesterol > 200 mg / dl .
lastly , diabetes mellitus was defined as having fasting blood glucose levels greater than or equal to 126 mg / dl or having a hemoglobin a1c level greater than or equal to 6.5% .
of the 7,567 patients who underwent cardiac catheterization , 414 ( 5.5% ) had a bmi 30 .
obese patients displayed evidence of cad at the age of 57 versus 63.3 in non - obese patients ( p<0.001 ) .
of the 332 patients with cad and obesity , 55.4% had obstructive cad versus 44.6% with non - obstructive cad . in obese patients with cad , male gender and history of smoking were major risk factors for development of obstructive cad ( p=0.001 and 0.01 , respectively ) while dyslipidemia was a major risk factor for non - obstructive cad ( p=0.01 ) .
additionally , obese patients with more than one risk factor developed obstructive cad compared to non - obstructive cad ( p=0.003 ) .
baseline characters of patients with bmi > 30 and diagnosed with obstructive cad and non - obstructive cad approximately 40% presented with st elevation myocardial infarction ( stemi ) , 30% with non
st - segment elevation myocardial infarction ( nstemi ) , and 30% had stable angina as a primary diagnosis .
of the 332 obese patients with cad , 24% received medical treatment , 58% underwent percutaneous coronary intervention ( pci ) , and 18% obtained coronary artery bypass grafting ( cabg ) . in a gender comparison ,
average age of cad in obese males was 55 years compared to 59 in females ( p<0.001 ) .
approximately 67% of males underwent pci ( or : 2.4 , 95% ci : 1.53.6 , p<0.001 ) and 24% obtained cabg ( or : 3 , 95% ci : 1.65.6 , p<0.001 ) , whereas in obese females 43% received medical therapy ( or : 9 , 95% ci : 517 , p<0.001 ) .
the difference outcomes among male and female groups who had cad and bmp30 kg / m
obesity is associated with more morbidity than smoking , alcoholism , and poverty , and may soon become the leading cause of preventable death in the united states , especially given the increased prevalence of morbid obesity from 1 to 6% ( 4 , 7 ) .
obesity increases the risk for htn , dm , dyslipidemia , obstructive sleep apnea , mets , and cardiovascular diseases ( 59 ) .
mets has been associated with up to threefold increase in coronary heart disease ( chd ) alone and is defined by abdominal obesity , atherogenic dyslipidemia , high blood pressure , insulin resistance , a proinflammatory state , and a prothrombotic state ( 3 , 5 , 810 ) .
given that many of these same risk factors from obesity increases the development of cad , excess body fat appears to be deleterious for patients with a history of coronary disease ( 7 , 11 ) .
excess adiposity has been strongly related to first nstemi occurring at a younger age ( 4 ) , and during autopsy studies , the extent of coronary atherosclerosis has been associated with the extent of obesity ( 10 ) .
studies have shown that obese young men , aged 15 to 34 years , have accelerated coronary atherosclerosis ( 7 ) .
android obesity ( upper body and abdominal obesity ) , which is more typical in men , is associated with dm and chd , than gynoid obesity ( lower body , gluteal , or femoral obesity ) , which tend to be metabolically less active ( 3 , 7 , 8) .
adipose cells are endocrine in nature and have a pivotal role in body metabolism homeostasis .
they can release proinflammatory cytokines ( il-6 , crp , tumor necrosis factor - alpha ) and fat - related hormones ( leptin , adiponectin ) , which actively lead to the atherosclerotic process ( 3 , 4 , 8 , 12 ) .
a number of inflammatory responses including increased clotting factors ( fibrinogen , von willebrand factor , factors vii and viii ) , increase plasminogen activator inhibitor type i , decreases endogenous fibrinolysis and a increases prothrombotic state , can leading to cad ( 8 , 12 ) .
one of the adipokines , leptin , controls food intake and energy metabolism , but may be particularly related with cv disease ( 4 ) .
leptin has been associated with perpetuating inflammation and endothelial dysfunction via cholesterol uptake by macrophages , triggering formation of foam cells resulting in atheromatic lesions ( 3 ) .
chronically elevated leptin levels have also been related to negative cad outcomes and increase in stent restenosis ( 12 ) .
adiponectin , on the other hand , may enhance insulin sensitivity and reduce glucose levels , as seen in animal models , and may play a protective role in atherogenesis ( 8) . there , however , appears to be an obesity paradox , where patients with bmi in the range of 3034 have a protective effect against cardiovascular diseases .
research has shown obesity in this range had lower mortality rate with stemi ( 7 ) and had better to no difference in survival after coronary revascularization and cabg when compared to normal weight individuals ( 3 , 5 , 9 , 12 , 13 ) .
those with severe obesity ( bmi > 35 kg / m ) were at increased cardiovascular mortality risk ( 5 ) .
interestingly , the low bmi group ( bmi < 18 ) had the highest mortality risk , even after adjustment for confounders such as age , sex , and cardiovascular risk factors ( 5 , 9 , 12 ) .
the relationship of obesity to chd mortality appears to be u - shaped ( 2 , 7 ) .
one possible explanation for the lack of expected association between bmi and adverse cardiac outcomes in patients with cad could be due to poor association of bmi to discriminate between body fatness and lean body mass , which are associated with opposite outcomes in cardiovascular disease ( 11 ) .
a person with increased muscle mass or gynoid distribution of fat would have the same bmi as a person with increased fat percentage or android distribution of fat .
therefore , waist to hip ratio ( whr ) or waist circumference ( wc ) has been suggested instead of bmi , which was thought to clear up this paradox , but results are inconclusive thus far ( 7 , 14 ) .
alternatively , part of the obesity paradox could come from a subset of patients who , with the help of diet and exercise , lose weight , improve cardiorespiratory fitness ( crf ) , and alter their prognosis as compared to non - obese individuals , who have less room for improvement ( 7 ) .
finally , obese patients tend to have a more aggressive treatment course as compared to the leaner counterpart .
a study showed obese patients under the age of 65 had higher rate of target vessel revascularization ( 5 , 7 ) .
our study encompasses several limitations , one of which is the small sample size . to further strengthen our findings , a multi - centered study may yield stronger findings
also , this is a univariate log regression analysis , not multivariate . also , we evaluated the patients who presented with chest pain only .
severity of cad in obese patients is depicted on non - modifiable and modifiable risk factors such as the male gender and smoking or greater than one risk factor , respectively .
early lifestyle modification including increasing crf and muscular strength had up to a 35% reduction in all - cause mortality ( 12 , 1416 ) , by reducing arterial pressure , preventing lvh , decreasing insulin resistance , and increasing hdl ( 17 ) .
weight loss also proved to significantly lower the rate of adverse outcomes even after adjustment for age , sex , smoking , dyslipidemia , dm , htn , mi , depression , and obese status ( 16 ) .
therefore , it is prudent for patients with bmi of greater than 30 to increase exercise and lose weight .
education on these principles may provide benefit in striving to aid decreasing incidents of cad and possibly lowering cardiovascular events .
the authors have not received any funding or benefits from industry or elsewhere to conduct this study . | objectivein this study , we evaluated obesity as a single risk factor for coronary artery disease ( cad ) , along with the synergistic effect of obesity and other risk factors.methodsa retrospective study of 7,567 patients admitted to hospital for chest pain from 2005 to 2014 and underwent cardiac catheterization
. patients were divided into two groups : obese and normal with body mass index ( bmi ) calculated as 30 kg / m2 and < 25 , respectively .
we assessed the modifiable and non - modifiable risk factors in obese patients and the degree of cad.resultsof the 7,567 patients who underwent cardiac catheterization , 414 ( 5.5% ) had a bmi 30 .
of 414 obese patients , 332 ( 80% ) had evidence of cad .
obese patients displayed evidence of cad at the age of 57 versus 63.3 in non - obese patients ( p<0.001 ) .
of the 332 patients with cad and obesity , 55.4% had obstructive cad versus 44.6% with non - obstructive cad . in obese patients with cad ,
male gender and history of smoking were major risk factors for development of obstructive cad ( p=0.001 and 0.01 , respectively ) while dyslipidemia was a major risk factor for non - obstructive cad ( p=0.01 ) .
additionally , obese patients with more than one risk factor developed obstructive cad compared to non - obstructive cad ( p=0.003).conclusionhaving a bmi 30 appears to be a risk factor for early development of cad .
severity of cad in obese patients is depicted on non - modifiable and modifiable risk factors such as the male gender and smoking or greater than one risk factor , respectively . |
the study was carried on 12-week old male , wistar albino rats weighing 150 - 200 g. the animals were housed in a group of six animals per cage and maintained at 20 - 30c and 50 - 55% humidity in a natural light and dark cycle , with free access to food and water and kept under standard conditions in an animal house facility approved by the committee for the purpose of control and supervision of experiments on animals .
utmost care was taken to ensure that animals were treated in the most humane and ethically acceptable manner . on the day , of the experiment
the femoral artery on one side was exposed , and a polyethylene catheter was inserted into the artery for recording abp .
potency of the catheter was maintained with a heparinized saline solution ( 5000 iu m / l , v / v ) .
the pressure recording system was calibrated with the help of a mercury manometer before each experiment .
cannulation of the femoral vein of the other limb was performed to facilitate drug injection .
rats were administered with different dilutions ( 9.5% , 19.0% , 28.5% , 38.0% , 47.5% , 57.0% , 66.5% , 76% ) of methanol
systolic bp mean abp , and heart rate were recorded on a power - lab data acquisition system with a computerized analysis program .
statistical analysis of the data were performed using one - way analysis of variance , where p < 0.05 were considered as significant , and was expressed as mean standard error of the mean .
on the day , of the experiment , rats were anaesthetized with the chloroform solution .
the femoral artery on one side was exposed , and a polyethylene catheter was inserted into the artery for recording abp .
potency of the catheter was maintained with a heparinized saline solution ( 5000 iu m / l , v / v ) .
the pressure recording system was calibrated with the help of a mercury manometer before each experiment .
cannulation of the femoral vein of the other limb was performed to facilitate drug injection .
rats were administered with different dilutions ( 9.5% , 19.0% , 28.5% , 38.0% , 47.5% , 57.0% , 66.5% , 76% ) of methanol ( 95% v / v , i.v . ) .
systolic bp mean abp , and heart rate were recorded on a power - lab data acquisition system with a computerized analysis program .
statistical analysis of the data were performed using one - way analysis of variance , where p < 0.05 were considered as significant , and was expressed as mean standard error of the mean .
of all the dilutions of methanol used , there was a statistical significant decrease ( p < 0.05 ) , that is , maximum decrease , of diastolic bp from 124.64 5.39 to 62.30 11.9 mmhg observed at the methanol dilution of 66.50% .
similarly , of all the dilutions of methanol used in our study , there was a statistical significant decrease ( p < 0.05 ) , that is , the maximum decrease , of systolic bp from 165.70 5.57 to 112.11 12.0 mmhg , and mean abp from 160.61 12.45 to 86.14 4.11 mmhg observed at the methanol dilution of 76.0%
. the heart rate increased ( from 250 beat / s to nearly 275 beats / s ) following administration of all the methanol dilution from 19.0% till 76.0% of methanol dilution , however , a statistical significant increase ( p < 0.05 ) of heart rate was observed from 239.70 28.80 to 313.55 16.65 beat / s at the methanol dilution of 9.5% [ figures 1 - 4 ] .
effect of different doses of methanol ( 95% v / v ) on diastolic blood pressure ( mmhg ) effect of different doses of methanol ( 95% v / v ) on systolic blood pressure ( mmhg ) effect of different doses of methanol ( 95% v / v ) on mean arterial blood pressure ( mmhg ) effect of different doses of methanol ( 95% v / v ) on heart rate ( beats / min )
the present study investigated the effect of methanol poisoning in rats administered at a different methanol concentration . in this study in rats
, we observed a decrease in diastolic bp , systolic bp and mean abp albeit at different concentration of methanol . in methanol poisoning , low bp ( hypotension ) and respiratory arrest have been reported .
previously , hemodynamic effects of successive intravenous infusions of 20% methanol in anesthetized , mechanically ventilated dogs have been assessed against any spontaneous changes occurring during saline infusions .
about 130 - 200 mg/100 ml or higher blood methanol concentrations progressively decreased stroke volume and cardiac output , systemic bp and blood flow through femoral and common carotid arteries , while total peripheral resistance increased .
death by cardiac arrest was reported to occur at blood concentrations exceeding 400 mg/100 ml . in our study , we observed an overall decreasing tendency of systolic bp , diastolic bp and mean abp with increasing concentrations of methanol though there were little fluctuations in bp . while , the heart rate remained consistently raised at all methanol dilution administered except the lowest concentration ( 9.5% v / v ) where , surprisingly , a greater increase in heart rate was noted .
hence , this can be regarded as an outlier and ignored for making interpretation in this study .
the increase in heart rate could be attributed to the compensatory mechanism for methanol induced hypotension , a major symptom of methanol poisoning . by
the higher increase in heart rate itself is an independent predictor of cardiovascular , noncardiovascular , and total mortality in some population , leading to death .
it was suggested that methanol poisoning potentially alters hemodynamic parameters , as previously , methanol overdose was reported to show changes in the electrocardiogram ( ecg ) wherein patient developed right bundle branch block in addition to left anterior fascicular block , paroxysmal atrial fibrillation and increased left ventricular end - diastolic and end - systolic dimensions . in another report by hazra et al .
reported that the regression of ecg changes coincided with clinical improvement and suggested that they were caused by methanol poisoning .
cardiac contractility and cardiac output were also reported to be reduced and arterial vasodilation develops , which might contribute to hypotension ventricular arrhythmia is often observed .
acidosis has been a well - documented diagnosis during methanol intoxication , but it is unclear whether it is derived directly from formic acid or due to its secondary effects of inducing lactic acidosis .
independent of the etiology of the acidosis , it has been widely reported that metabolic acidosis can lead to various adverse effects to the cardiovascular system . in one animal study with dogs ,
increased susceptibility of the heart to ventricular fibrillation was found during metabolic acidosis . in another animal study with rats , the authors concluded that acidosis produced a marked decrease in heart rate and an increase in p - r interval with no apparent effect on the duration of the qrs complex .
methanol being a potent toxicant in humans has been reported to occur naturally at a low level in most alcoholic beverages without causing harm .
however , illicit drinks made from industrial methylated spirits [ 5% ( v / v ) methanol : 95% ( v / v ) ethanol ] was reported to cause severe and even fatal illness .
no - adverse - effect level for methanol has been poorly documented and , therefore , from the public health perspective , what should be the maximum concentration of methanol in an alcoholic drink that an adult human could consume without risking toxicity due to its methanol content is not widely known . in 2001 ,
paine and davan reported that if an adult takes 4 25-ml standard measures of a drink containing 40% alcohol by volume over a period of 2 h , the maximum tolerable concentration of methanol in such a drink should be 2% ( v / v ) by volume .
however , they suggested that this value only allowed a safety factor of 4 to cover variation in the volume consumed and for the effects of malnutrition ( i.e. folate deficiency ) , ill health and other personal factors ( i.e. ethnicity ) .
in contrast , according to the current european union general limit , 0.4% ( v / v ) methanol at 40% alcohol was reported to provide a greater margin of safety . in our study , we observed a consistent rise in heart rate starting after administration of 19% methanol dilution in rats indicating that the concentration lower than 19% could correspond to the safety margin of 0.4 - 2% ( v / v ) in clinical settings .
the present study is consistent with previous studies suggesting that methanol ingestion leads to severe hypotension as observed from decrease in diastolic bp , systolic bp , and mean abp .
however , severe increase of heart rate suggests activation of a compensatory mechanism to offset hypotension that eventually leads to death in methanol poisoning .
hence , this study emphasizes the need to monitor all the hemodynamic parameters in accidental methanol poisoning . as
, the present study is just a preliminary research work , and therefore it warrants further study to better manage methanol poisoning in actual clinical scenarios . | introduction : methanol ingestion is an uncommon form of poisoning that can cause severe metabolic disturbances , blindness , permanent neurologic dysfunction and death . while methanol itself may be harmless , it converts , in vivo , to highly toxic formic acid .
methanol intoxication clinically manifests as ocular toxicity .
the present study investigated the cardiovascular effects of methanol.materials and methods : on the day of the experiment , wistar rats were anesthetized with urethane .
the femoral artery on one side was exposed , and a polyethylene catheter was inserted into the artery for recording arterial blood pressure ( abp ) .
the catheter was attached to a pressure transducer ( statham - p23d ) .
systolic blood pressure ( bp ) , mean abp , and heart rate were recorded on a power - lab data acquisition system with a computerized analysis program .
rats were administered with different dilutions ( 9.5% , 19.0% , 28.5% , 38.0% , 47.5% , 57.0% , 66.5% , 76% ) of methanol ( 95% v / v , i.v.).results : of all dilutions of methanol , 66.5% dilution showed maximum decrease of diastolic bp from 124.64 5.39 to 62.30 11.90 mmhg ; 76.0% dilution showed maximum decrease of systolic bp from 165.70 5.57 to 112.11 12.0 mmhg , and mean abp from 160.61 12.45 to 86.14 4.11 mmhg .
the heart rate increased ( from 250 beats / s to near about 275 beats / s ) following administration of methanol dilution from 19.0% till 76.0%.conclusion : the present study is consistent with previous studies suggesting that methanol ingestion leads to severe hypotension as observed from decrease in diastolic bp , systolic bp , and mean abp .
however , severe increase of heart rate suggests activation of a compensatory mechanism to offset hypotension that eventually leads to death in methanol poisoning .
hence , this study emphasizes the need to monitor all the hemodynamic parameters in accidental methanol poisoning . |
type 1 diabetes ( t1d ) is an organ - specific autoimmune disease that is characterized by infiltration of lymphocytes into the pancreatic islets and pancreas - specific autoantibodies in the serum ( 1 ) . a variety of genetically predisposed factors and contributing factors
some evidence has suggested that the susceptible genes to t1d are associated with the amplification of the immune response and the rate of progression of the disease ; the role of these genes appear to be more important during childhood than during adult life ( 2 ) .
the association of hla alleles and the development of t1d has been shown by studies on diverse ethnic groups .
however , a genetic predisposition solely conferred by the hla is not sufficient to explain the mechanism that leads to the development of t1d .
therefore , it has been hypothesized that several genes are involved in the development of t1d ( 3 ) .
the cytotoxic t lymphocyte antigen-4 gene ( ctla4 ) and the gene encoding cd28 have been mapped to chromosome 2q33 .
ctla-4 is a glycoprotein receptor expressed on activated t cells and cd28 is involved in the regulation process of the activation of t cells by antigen - presenting cells and subsequent cellular immunity ( 4 ) .
ctla4 has been considered to be a permissive candidate gene involved in the etiology of autoimmune diseases ; this is because ctla-4 plays a role in the regulation of the activation of t cells and as well as t cell and b cell interactions ( 5 ) . according to prior studies on the association of the development of various autoimmune diseases and the ctla4 gene , the 49 a / g polymorphism in ctla4 exon 1 has been reported to be involved in the development of graves ' disease ( 6 ) , hashimoto thyroiditis ( 7 ) , a portion of addison 's disease and rheumatoid arthritis ( 8) . a significant association of t1d with the ctla4 polymorphisms was reported by nistico et al .
( 9 ) for the first time ; this association has been additionally reported by other studies in a variety of ethnic groups ( 10 , 11 ) .
however , in studies conducted in japan ( 12 ) and other countries ( 13 , 14 ) , the association of the ctla4 polymorphisms with the development of t1d has not been confirmed .
the primary purpose of this study was to investigate whether the ctla4 gene was associated with the development of t1d in korean children and adolescents .
furthermore , we studied whether interactions between the ctla4 gene and susceptible hla class ii alleles had a role in the pathogenesis of t1d .
this study included 176 patients ( 92 females , 84 males ) with t1d , who were diagnosed during childhood and adolescence ( mean age , 7.54.0 yr ) from 1992 to 2002 at diabetes clinic of seoul national university children 's hospital .
the diagnosis of t1d was based on the blood glucose level according to the world health organization diagnostic guidelines , clinical symptoms , absolute insulin - dependency , and pancreas - specific autoantibodies .
we reviewed the clinical characteristics , such as diabetic ketoacidosis at the initial presentation , age of onset , family history of t1d , pubertal status at the onset of diabetes , and presence of concomitant autoimmune thyroid disease to determine whether there was an association between the ctla4 polymorphisms and the clinical characteristics . among the study subjects ,
there were 31 patients ( 17.6% ) with autoimmune thyroid disease that were diagnosed by thyroid function tests , anti - thyroid autoantibodies , and/or tsh receptor stimulating antibodies .
genomic dna was extracted from peripheral mononuclear cells using the wizard dna purification kit ( promega , maison , wi , u.s.a . ) , and quantified by spectrophotometer .
hla - drb1 alleles were analyzed by grouping of drb1 using a dynal reli sso hla - drb1 typing kit ( dynal biotech inc . , lake success , ny , u.s.a . ) and primers described previously ( 15 ) .
each hla - drb1 allele was determined by the single strand conformation polymorphism ( sscp ) method .
hla - dqb1 alleles were analyzed by applying pcr - rflp and pcr - sscp methods as described previously ( 16 ) .
for the analysis of the a / g polymorphism at position 49 in the ctla4 exon 1 , the pcr - rflp method was used as described previously ( 7 ) .
amplified samples were digested with the specific restriction enzyme bbvi ( new england biolabs , beverly , ma , u.s.a . ) at 37 for 2 hr , electrophoresed on a 3% agarose gel for 30 min , stained with ethidium bromide , and evaluated .
a 162 bp band was determined to be the a allele and the 88 bp and 74 bp bands were determined to be the g allele .
the c / t polymorphism at position -318 in the ctla4 promoter was analyzed by pcr - rflp methods using known primers 5'-aaatgaattggactggatggt-3'(forward ) and 5'-ttacgagaaaggaagccgtg-3'(reverse ) as described previously ( 18 ) .
the amplified dna products were treated with the msei restriction enzyme ( new england biolabs ) at 37 for 2 hr . the formation of 132/115 bp fragments was determined to be the t allele and the detection of the complete 247 bp fragment was identified as the c allele .
the comparisons of the hla genotypes of the patients and the controls were performed using the two - tailed fisher 's exact test .
the corrected p value ( pc ) was obtained by multiplying the number of all genotypes included .
the odds ratio ( or ) was calculated by the woolf method , and the 95% confidence interval ( ci ) was applied . for the cases with 0 variables ,
the genotype and allele frequencies of the ctla4 exon 1 polymorphism in t1d patients were not different from those in the control subjects ( table 1 ) . the distribution of the ctla4 exon 1 polymorphsims in patients with t1d and autoimmune thyroid disease ( n=31 ) was not different from that in the control subjects .
there was no relationship of the ctla4 exon 1 polymorphism with the clinical characteristics of the patients , such as presence of ketoacidosis , age of disease onset , gender , pubertal status at initial presentation , and concomitant autoimmune thyroid disease .
we analyzed the distribution of the ctla4 exon 1 polymorphism according to the presence or absence of susceptible hla - drb1 alleles ( drb1 * 0301 , * 0405 and * 09012 ) . in the patients without the hla - drb1 * 0301 allele , the frequency of the a allele was significantly higher than in the control subjects ( 43.6% vs. 31.7% ; p<0.05 ) .
we analyzed the distribution of the ctla4 exon 1 polymorphism in a subgroup of patients that did not have two out of the three susceptible drb1 alleles . according to the analysis of the genotype frequency , the frequency of the a / a genotype in the patients without the drb1 * 0301 and * 09012 alleles was significantly higher compared to the control subjects ( 36.0% vs. 14.4% ; p<0.05 ) ( table 2 ) .
according to the analysis of the allele frequency , the frequency of the a allele in the patients without the drb1 * 0301 and * 0405 alleles was significantly higher than in the control subjects ( 45.5% vs. 31.7% ; p<0.05 ) .
in addition , the frequency of the a allele was significantly higher in the patients without the drb1 * 0301 and * 09012 alleles ( 52.0% vs. 31.7% ; p<0.01 ) , and the patients without the drb1 * 0405 and * 09012 alleles ( 54.2% vs. 31.7% ; p<0.05 ) , compared to the control subjects .
the genotype and allele frequencies of the ctla4 promoter polymorphism were not different in the comparison between the t1d patients and the control subjects ( table 3 ) .
the distribution of the ctla4 promoter polymorphism in patients with both t1d and autoimmune thyroid disease was not different from that in the control subjects .
when the patients were divided into subgroups based on the presence of the susceptible hla - drb1 alleles , the distribution of the ctla4 promoter polymorphism was not different in the patients and the control subjects .
it has been reported that the intracellular transduction signals formed by the complex of t cell receptor molecules and ctla-4 molecules suppress the activation of t cells ( 19 ) .
the ctla-4 molecule encodes the t cell receptor that plays a role in the control of the proliferation of t cells , as well as mediating apoptosis of t cells .
therefore , it has been considered to be a strong candidate molecule involved in the development of t cell - mediated autoimmune disease .
however , the functional relationship of the ctla-4 protein with human disease has not been elucidated to date .
the distribution of the ctla4 exon 1 polymorphism among asians and caucasians shows a clear difference .
the frequency of the g allele of ctla4 exon 1 has been reported to be 68% among koreans ( 20 ) , 57.5% ( 21 ) and 63% ( 22 ) among japanese , and 34.2% ( 10 ) and 36% ( 7 ) among caucasians . on the other hand ,
the frequency of the t allele in the ctla4 promoter region has been reported to be 7 - 14% among asians and caucasians ( 23 ) , without a marked ethnic difference noted to date .
our results showed that the distribution of the ctla4 exon 1 polymorphism and the the ctla4 promoter polymorphism in patients with t1d were not different from those in control subjects .
recent studies on the association of the ctla4 polymorphisms and susceptibility to t1d in various ethnic populations showed inconsistent results . according to the studies that included japanese populations , the distribution of the ctla4 exon 1 polymorphisms in patients with t1d was not different from that in normal individuals ( 21 , 22 ) .
24 ) observed that the frequency of the c / c genotype at position -318 in the ctla4 promoter was significantly lower in patients with t1d compared to controls , and they concluded that this polymorphism was associated with t1d .
meanwhile , a clear association was detected between the ctla4 genotype and the degree of expression of the ctla-4 protein ( 25 ) . according to this study , in individuals with thymidine ( -318 t ) in ctla4 promoter region , after the stimulation of cells , the expression of ctla-4 on the cell surface and the expression of ctla4 mrna in unstimulated cells
( 26 ) reported that a reduction in the level of a soluble isoform of ctla-4 ( sctla-4 ) mrna , associated with the disease - susceptible haplotype of ctla4 , could lead to reduced blocking of cd80/cd86 , causing increased activation through cd28 , or to less stimulation of cd80/cd86 . in order to verify the association of the ctla4 polymorphisms with the pathogenesis of t1d , distinctive difference in the distribution of ctla4 genotypes between patients and controls
the results of recent studies suggest that ctla4 polymorphisms are associated with the clinical characteristics of patients with t1d .
( 22 ) reported a patient group with initial diabetic ketoacidosis and positive for the ica512 antibody had a different distribution of the ctla4 polymorphisms compared to control subjects .
other studies showed that the frequency of the g allele of ctla4 exon 1 was higher in patients with a high titer of gad antibodies and high residual function of -cells compared to the control subjects ( 21 , 27 ) . such results may indicate that ctla4 polymorphisms are involved in the more potent immune response and specific clinical characteristics of patients with t1d .
in addition , takara et al . ( 28 ) reported that the frequency of the g allele of ctla4 exon 1 was significantly higher in patients with both t1d and autoimmune thyroid disease concomitantly , compared to the controls .
however , the results of our study showed no association of ctla4 polymorphisms and the clinical characteristics of patients with t1d .
therefore , further study is needed to clarify the association of ctla4 polymorphisms with specific clinical characteristics of patients with t1d .
we analyzed the relationship between the ctla4 exon 1 polymorphism and hla - drb1 alleles to determine whether their interactions had a role in the pathogenesis of t1d . in the diabetic patients that did not have two out of the three susceptible drb1 alleles , that is drb1 * 0301 , * 0405 and * 09012 ,
the frequency of the a allele of ctla4 exon 1 was significantly higher than that in the control subjects .
this finding suggests that the ctla4 polymorphism was associated with the development of t1d only in the patients that had no specific susceptible hla - drb1 alleles .
there have been several reports regarding the association of ctla4 polymorphisms with hla - drb1 allele in the pathogenesis of t1d .
( 29 ) reported that in diabetic patients with the dr4 haplotype , the frequency of the g allele of ctla4 exon 1 was significantly higher .
( 21 ) reported that in children with t1d that did not have susceptible drb1 * 0405 allele , there was a higher frequency of g allele of ctla4 exon 1 compared to normal children . on the other hand ,
( 30 ) conducted a combined transmission analysis of the ctla4 polymorphisms and hla dqa1-dqb1 and reported that in patients with t1d that had susceptible haplotypes , such as hla dqa1 * 0301-dqb1 * 0302 or dqa1 * 0501-dqb1 * 0201 , the protective 84-bp allele of the ( at)n repeat of ctla4 polymorphism was not protective against the development of t1d .
therefore , when patients do not have susceptible hla class ii alleles , the ctla4 polymorphism appears to play some role in the pathogenesis of t1d .
( 21 ) explained that the sensitivity of t - cell activation to the ctla4 mediated pathway after the initiation of the t - cell receptor and dr molecule - antigen complex may be decreased in the absence of susceptible hla - drb1 alleles .
however , because the distribution of both ctla4 and the hla class ii alleles vary in different ethnic populations , further study of the association of these two genes is needed . in conclusion , the results of this study suggest that hla - drb1 and dqb1 alleles play a primary role in pathogenesis of t1d and that the ctla4 exon 1 polymorphism is a genetic factor that mediates the disease associated susceptibility in patients that do not have specific susceptible hla class ii alleles . | we studied the association of cytotoxic t lymphocyte antigen-4 gene ( ctla4 ) polymorphisms with the development of type 1 diabetes ( t1d ) in korean children and adolescents .
a total of 176 korean subjects ( 92 females and 84 males ) with childhood - onset t1d were studied .
the a / g polymorphism at position 49 in ctla4 exon 1 and the c / t polymorphism at position -318 in the ctla4 promoter were analyzed by pcr - rflp methods .
the genotype and allele frequencies of the ctla4 polymorphisms in the t1d patients were not different from those in the controls .
these polymorphisms were not associated with the clinical characteristics or the development of autoimmune thyroid disease in the t1d patients .
the frequency of the a allele was significantly higher in the patients that did not have two out of the three susceptible hla - drb1 alleles , which were drb1 * 0301 , * 0405 and * 09012 , compared to the controls ( p<0.05 ) .
these results suggest that ctla4 polymorphisms do not directly confer any susceptibility to t1d
. however , a ctla4-mediated susceptibility effect on the development of t1d might be significant in children and adolescents that do not have susceptible hla class ii alleles . |
of fundamental interest
to biology is the extent to which electrostatic
interactions enhance the rate of protein protein association .
an essential baseline for determining the magnitude of these rate
enhancements is the basal
kon , which is the rate constant for association in
the absence of electrostatic interactions . in principle
, the basal kon should be measured in the same solvent environment using the
hydrophobic isosteres that is , hypothetical mutants with molecular
shapes that are identical to those of the wild - type proteins , but
are entirely uncharged . however , due to the difficulty of engineering
hydrophobic isosteres , experimental studies have instead estimated
the basal kon by measuring
the kon for the wild - type
proteins at various salt concentrations and extrapolating to the limit
of infinite salt concentration where electrostatic interactions would
be completely screened .
an alternative
approach is to construct the exact hydrophobic isosteres in
silico by setting all partial charges of the wild - type
proteins to zero and directly computing the basal kon by simulating the association of the
hydrophobic isosteres .
ideally , such simulations would involve the
use of flexible molecular models in order to capture conformational
changes during the association process .
however , since the weak associations
of completely hydrophobic proteins are beyond the milliseconds time
scale , it has only been feasible to directly compute the basal kon using rigid , models with
atomically detailed simulations .
theoretical
estimates of the basal kon have also been made using spherical models with orientational constraints and applications of transition - rate theory to rigid , atomistic models . here ,
for the first time , we directly computed
the basal kon for a protein
we focused on barnase and barstar , which are among the most rapidly
associating proteins by virtue of their complementary electrostatic
surfaces .
our simulations employed flexible ,
pseudoatomic protein models of barnase and barstar that were designed
by frembgen - kesner and elcock to retain
the molecular shapes , electrostatic potentials , and diffusion properties
of the corresponding atomistic models at the experimental ionic strength
( 50 mm ) .
the same authors have demonstrated
that the use of these models with standard brute force
simulations can reproduce the experimental kon values of both the wild - type and mutant
protein pairs .
however , they were unable to carry out such simulations
to obtain a statistically robust estimate of the kon for the hydrophobic isosteres ( i.e. ,
the basal kon ) due to
the large computational cost .
a
critical feature of our study is the application of the weighted
ensemble ( we ) strategy to enhance the
sampling of rare events , e.g. the slow association of completely hydrophobic ,
uncharged proteins .
although the we strategy has been previously applied
to protein binding processes using brownian dynamics ( bd ) simulations , these studies were carried out without the inclusion of his ) between ,
and within , the diffusing proteins . in the absence of explicit solvent ,
it has been demonstrated that the translational and rotational diffusion
coefficients of flexible protein models are drastically underestimated
unless intramolecular his are included in the simulations .
in addition , the neglect of intermolecular his
in previous bd studies of protein binding processes is likely to have contributed to their consistent
overestimation of association rate constants .
importantly , our simulations were validated by computing the kon values for both wild - type
barnase and its r59a mutant , which associates more slowly than wild - type
barnase with barstar , and comparing the
computed values to experiment .
the wild - type
and mutant pairs of barnase and barstar were represented using flexible ,
pseudoatomic models developed by frembgen - kesner and elcock .
briefly , the
generation of these models began with all - atom models of the wild - type
proteins , which were based on the crystal structure of the barnase
barstar
complex ( pdb code : 1brs ) ; the same models were used for both
the unbound and bound states .
approximately one pseudoatom was then
used to represent every three amino acid residues ( 33 pseudoatoms
for the 110 residues of barnase and 27 pseudoatoms for the 89 residues
of barstar ) . for the wild - type proteins and r59a mutant barnase ,
the
effective charge method was used to derive
effective charges for the pseudoatomic models such that the electrostatic
potentials of the corresponding all - atom models were reproduced .
boltzmann
equation under experimental conditions ( ph 8 , 25 c , and ionic
strength of 50 mm ) .
pseudoatoms were then
positioned and sized to replicate the electron density envelope of
the all - atom model . to generate models of the exact hydrophobic isosteres
of barnase and barstar , we started with the pseudoatomic models of
the wild - type proteins and set all effective charges to zero .
the energy function consisted of a single intramolecular term involving
flexible , harmonic bonds between the pseudoatoms and intermolecular
terms for electrostatic and nonelectrostatic interactions . to maintain
the molecular shapes of the proteins , three bonds per pseudoatom
nonelectrostatic
interactions were calculated using a very weak go-type
potential energy function with a shallow well depth ( = 0.1
kcal / mol ) .
thus , native contacts were only slightly rewarded by a
weakly attractive lennard - jones - like potential and nonnative contacts
were penalized by a purely repulsive potential .
the well - depth was kept at a minimal value in order to avoid implicitly
double counting the attractive electrostatic interactions , which are
assumed to be a primary driving force for the formation of the barnase - barstar
complex .
two pseudoatoms were considered
to form a native contact if any non - hydrogen atoms of the residues
in the all - atom model were within 5.5 of each other in the
crystal structure of the native complex , yielding a total of 34 intermolecular
native contacts .
all simulations
were carried out using the we path sampling strategy , as implemented in the westpa software package ( https://westpa.github.io/westpa ) . in this strategy , a large number
of simulations , or trajectory walkers , are started
in parallel from the initial state and iteratively evaluated at fixed
time intervals for resampling in which walkers are either
replicated or combined to maintain a similar number of walkers per
bin along a progress coordinate toward the target state .
rigorous
management of the statistical weights associated with each walker
ensures that no bias is introduced into the dynamics . in this
study ,
the we strategy was applied using steady - state simulations
within the framework of the northrup
this framework involves
the definition of two concentric spherical surfaces with radii b and q that correspond to center - to - center
separation distances for barnase and barstar . the inner sphere , or b surface , represents the initial , unbound state , and the
outer sphere , or q surface , is an absorbing surface
that is positioned at a much larger separation distance ( q b ) to avoid wasting computational effort
sampling the indefinite drifting apart of the proteins .
each we simulation
was started from 24 configurations of the unbound state in which barnase
and barstar were randomly oriented at a center - to - center separation
distance of b. a walker was continued until the pair
of proteins either exceeded a separation distance q or satisfied the criterion for the target state for successful association ,
i.e. reaching a threshold value , qrxn ,
in the fraction of native intermolecular contacts , q , that reproduces the experimental kon for the wild - type proteins .
consistent with previous
brute force simulations , b and q were set to 100 and 500 , respectively .
upon reaching the q surface ,
a walker was recycled
by starting a new walker from the unbound state with the same statistical
weight thereby maintaining a steady state and enforcing a constant
effective protein concentration ( 3.2 m ) . upon reaching a particular qrxn value ,
a walker was effectively recycled
after completing the we simulation by removing the walker and its
replicas prior to calculating the kon . for each barnase - barstar pair ,
five independent we
simulations
were performed with different initial random seeds for bd propagation .
in each simulation , the configurational space of the protein pairs
was divided into 760 bins along a progress coordinate that was intended
to capture the slowest protein motions of the association process .
we used a progress coordinate that consisted of three zones : ( a ) a
far zone involving the distance between barnase and
barstar , ( b ) an intermediate zone involving the rms
deviation of barstar from its bound - state position following alignment
of barnase , and ( c ) a near zone involving the same
rms deviation metric as in part b and the fraction of native contacts
between barnase and barstar .
simulations were evaluated for resampling
at fixed time intervals ( or iterations ) of 2 ns to maintain
24 walkers per bin .
each simulation was carried out for 1000 iterations ,
or a molecular time of 2 s ( defined as n
where n is the number of iterations ) . the dynamics of our we simulations
were propagated using the uiowa - bd software , which is the same bd engine that was used for the brute force simulations
by frembgen - kesner and elcock .
consistent
with these simulations , our we simulations were performed at a constant
temperature of 25 c using a standard bd algorithm with the inclusion
of hydrodynamic interactions ( his ) via calculation of the diffusion
tensor using the equations of rotne and prager and yamakawa ; the same values
were used for the hydrodynamic radii of the pseudoatoms to reproduce
the translational diffusion coefficients of the corresponding all - atom
protein models by the hydrodynamics program hydropro ; and a time step of 0.25 ps was used throughout the simulations . for each barnase - barstar pair ,
the kon value was computed from each of five
independent we simulations using conformations that were sampled every
20 ps once a steady state was achieved ( figure s1 , supporting information ) .
all we simulations were sufficiently long to yield relative percent
uncertainties in the average kon of < 20% ( figure s2 , supporting information ) .
the kon from each we simulation was calculated
using the nam method according to the following equation : where k(b ) and k(q ) are the diffusion rate
constants for achieving separation distances of b and q , respectively , and is the probability
of successful collisions , i.e. that a simulation starting from the
unbound state with a separation distance of b ( 100
) reaches the bound state before drifting apart to a separation
distance of q ( 500 ) .
assuming that the motions
of the binding partners are isotropic , k(b ) and k(q ) are given
by the smoluchowski result ; k(r )
= 4dr , where d is the relative translational
diffusion coefficient of the two proteins ( i.e. , the sum of their
corresponding diffusion coefficients ) .
as done for the brute force
simulations by frembgen - kesner and elcock , we used the estimate from hydropro for d ( 2.672 10 ps ) .
the value was calculated using the following
equation : where fssbound is the steady - state flux
into the bound state and fssqsurf is the steady - state flux
into the q surface . as evident in the above equations ,
the influence of his is considered in our calculation of the probability
of successful collisions ( ) , but only approximately on the
diffusion of the two proteins by using the sum of their diffusion
coefficients ( d ) . for each barnase
barstar
pair , we determined the efficiency of a single we simulation relative
to brute force simulation in computing the kon for each of five independent we simulations ;
these efficiencies were then averaged and uncertainties in the efficiencies
were determined by calculating the 95% confidence intervals .
the efficiency
of each we simulation was calculated using the following equation : where tbf and twe are
the wall - clock times required by brute force simulation and the we
simulation , respectively , to generate the same number of independent
( uncorrelated ) association events using the same computing resource
( i.e. , 256 cpu cores of 2.3 ghz amd interlagos processors ) .
association
events were considered independent if , within the period between the
event and one correlation time before the event , their corresponding
trajectories did not share a common simulation segment .
the correlation
time was determined by monitoring autocorrelation of the flux into
the bound state as a function of the lag time and identifying the
first lag time that results in zero autocorrelation ( within a 95%
confidence interval ; see figure s2 , supporting information ) .
since it was not practical to directly obtain
tbf for all of the barnase - barstar pairs ( i.e. , the hydrophobic
isosteres ) , we estimated tbf in a consistent manner for
each pair using the following equation : where mbf is the number of trajectories in a
brute force simulation
to generate the same number of independent association events observed
in a we simulation given that the brute force trajectories
are terminated when the proteins either associate or reach a separation
distance of q according to the nam method ; 0.02 days / trajectory / core
is the average wall - clock time that would be required to complete
a single brute force trajectory before the proteins reach a separation
distance of q ; and ( as defined above ) is
the probability calculated by we for a single brute force trajectory
to generate a successful association event before dissociating to
a separation distance of q.
our general strategy for computing kon values from our simulations was to first identify
a criterion for successful association that reproduces the experimental kon for wild - type barnase and
barstar .
next , we validated the simulations by using this criterion
to calculate the kon for
r59a mutant barnase and wild - type barstar , which associates 9-fold
more slowly than the wild - type proteins , and comparing the calculated kon to the experimental value .
finally , we used this criterion
to estimate the basal kon , i.e. , the kon for
the hydrophobic isosteres in which all effective charges of the wild - type
proteins are set to zero . following the brute force simulations by
frembgen - kesner and elcock , our criterion
for successful association was to reach a threshold value , qrxn , in the fraction of native intermolecular
contacts ,
q ; dynamics were propagated using the same
bd engine with the inclusion of intramolecular his to achieve realistic
diffusive properties of the individual proteins ; and kon values were calculated according to
the nam method ( see methods ) .
figure 1 shows the computed kon as a function of qrxn for all five independent we simulations
of each barnase barstar pair .
the experimental kon for wild - type barnase and barstar
( 2.86 10 m s ) was reproduced when using qrxn values of 0.27 and 0.56 for simulations with and without
intermolecular his , respectively .
these values differ slightly from
those determined by frembgen - kesner and elcock using brute force simulations
and the same protein models ( 0.32 and 0.47 , respectively ) due to more frequent monitoring of the reaction
criterion ( every 20 ps instead of 100 ps ) ; thus , our we simulations
are less likely to have missed conformations that satisfy the reaction
criterion .
importantly , using the qrxn values that we have identified , the computed kon values for r59a barnase and wild - type barstar
are in excellent agreement with experiment , regardless of whether
or not intermolecular his were included ( figure 2 ; see also table s1 , supporting information ) .
the reproduction of experimental kon values for both wild - type
and mutant pairs of barnase and barstar is consistent with results
from brute force simulations , providing
validation of our we simulation protocol .
relative to the basal kon , our computed kon values for wild - type barnase and barstar
are 53- and 103-fold faster with and without intermolecular his , respectively .
these rate enhancements are solely due to the electrostatic interactions
between the wild - type proteins given the omission of intramolecular
electrostatic interactions in our simulations .
computed kon values
for each barnase - barstar pair from each of five independent we simulations
as a function of the fraction of intermolecular native contacts qrxn .
results from simulations without and with
the inclusion of intermolecular hi are shown in the left and right
panels , respectively .
the vertical gray line in each panel indicates
the qrxn value that reproduces the experimental kon for the wild - type pair for
simulations without and with hi ( 0.56 and 0.27 , respectively ) and
was used for calculating kon values for the mutant pairs in that panel .
comparison of computed and experimentalkon values
on a log
scale . reported values from simulation ( with and without intermolecular
hi ) are averages from five independent we simulations with the error
bars representing 95% confidence intervals .
the pseudoatomic protein
model of barnase ( gray ) and barstar ( cyan ) is shown in the upper right
corner .
the basal kon computed from our simulations
with and without intermolecular
his are ( 2.85 1.30 ) 10 m s and ( 5.79 0.17 ) 10 m s , respectively . at the
effective protein concentration maintained in our simulations ( 3.2
m ) ,
our computed basal kon values are similar to those using less computationally
intensive strategies ; in particular , the use of spherical models with
orientational constraints has provided estimates in the range of 1010 m s and the use of rigid , atomistic models in either the application
of transition - rate theory or direct bd
simulation of protein protein association has yielded estimates of 1 10 m s. the similarity of our
estimates to these previous estimates suggests that flexible models
may not be essential for obtaining realistic estimates of kon values for proteins such
as barnase and barstar that do not undergo significant conformational
changes upon binding ( the c rms deviation between
the crystal structures of the unbound and bound conformations is only 0.5 for both barnase
and barstar )
. however , it has not been possible to directly estimate
the basal kon with uncertainties
of < 100% using standard bd simulations with rigid , atomistic models
since the association events were much slower in the absence of electrostatic
forces . on the other hand , our we simulations
with flexible molecular models
enable significantly more precise calculations
of the kon ( uncertainties
of 2246% ) and could therefore be used for even more complicated
binding processes , including ones that involve large conformational
changes .
notably , our computed kon values are significantly lower than that obtained by experiment
from extrapolation to infinite salt concentration ( 1.4 10 m s ) , suggesting that the favorable electrostatic interactions
between the proteins are not completely eliminated at high salt concentrations .
although the inclusion of intermolecular his has no effect on the
ability of the simulation model to reproduce the effects of mutation
on the kon , for a fixed
value of qrxn , the inclusion of intermolecular
his significantly slows down the rate of association for all three
pairs of the barnase - barstar system ( figures 2 and 3 ) .
surprisingly ,
the extent to which kon decreases is essentially the same for wild - type
and r59a mutant pairs ( e.g. , by 5-fold at qrxn = 0.27 ) .
in contrast , the impact of intermolecular
his in the brute force simulations by frembgen - kesner and elcock was
more pronounced for slower associating mutants of barnase such as
r59a in which the electrostatic interactions with barstar are diminished . on the basis of these results ,
it was predicted
that the impact would be the most pronounced for the hydrophobic isosteres
of barnase and barstar .
however , the enhanced sampling provided by
the we strategy reveals no statistical difference between the impact
of the intermolecular his on the kon for the wild - type and r59a mutant pairs . for the hydrophobic
isosteres , our results are inconclusive . although it was possible
to obtain statistically robust estimates of the basal kon
which was the primary goal
of this work our simulations did not reach the level of precision
in the ratio of the kon values with and without intermolecular his that
would be required to determine the effect of his on the association
kinetics relative to the wild - type pair ( note the large confidence
intervals in figure 3 ) . for future studies of this effect , significantly greater sampling
using a larger number of simulations and/or longer simulations would
be required to achieve a sufficient level of precision in the computed kon values , particularly in
the absence of intermolecular his .
ratio of association rate constants konwith hi / konwithout hi computed from simulations
with and without intermolecular
his as a function of the fraction of intermolecular contacts qrxn .
the shaded regions represent 95% confidence
intervals for averages ( filled circles ) from five independent we simulations .
finally ,
it would not have
been practical to obtain converged estimates of the basal kon without the use of the we
strategy .
in addition , a highly scalable , parallel implementation
of this strategy was essential since it would have otherwise required
> 2 years to carry out the simulations using a serial implementation .
to determine the efficiency of parallelized we vs brute force simulation
in estimating the kon , we compared the wall - clock time that would be required of we vs
brute force simulation ( both using the nam framework ) to generate
the same number of independent ( uncorrelated ) association events using
the same computing resource ( 256 cpu cores of 2.3 ghz amd interlagos
processors ) .
figure 4 shows the efficiencies of we simulations relative to brute force
simulations for each barnase - barstar pair ( see also table s2 , supporting information ) . for the wild - type pair ,
a we simulation was 6-fold more efficient than brute force simulation
with the inclusion of intermolecular hi .
this efficiency increased
to 46-fold for the r59a mutant pair and ultimately 131-fold for the
hydrophobic isosteres .
in the latter case , brute force simulation
using the same flexible protein models would be highly impractical ,
requiring 386 days in wall - clock time to generate the same number
of association events ( > 1000 ) as a single we simulation , which
required
only 3 days .
the greater efficiency of we observed for the slower
processes ( i.e. , increasing with the barrier height ) is consistent
with previous we studies of other rare events .
protein association
process for the first time using flexible models with molecular simulations .
in particular , we computed the basal kon for the barnase - barstar system using highly efficient
we simulations .
our computed basal kon is significantly lower than that obtained by experiment
from extrapolation to infinite salt concentration , suggesting that
the electrostatic interactions are not completely eliminated at high
salt concentrations .
this result underscores the importance of directly
computing the basal kon using the true hydrophobic isosteres of the proteins under regular
salt concentrations a goal that can only be achieved by molecular
simulation .
relative to our basal kon , the electrostatic interactions of the wild - type proteins
enhance the rate of association by > 130-fold . as demonstrated by
frembgen - kesner
and elcock using brute force simulations , the inclusion of intermolecular his significantly decreases the
computed kon values for
both wild - type and mutant pairs .
however , the extensive sampling provided
by our we simulations has revealed that the extent by which the kon is reduced is the same for
both the wild - type and r59a mutant pairs .
for the hydrophobic isosteres ,
the relative extent to which the kon was affected by the intermolecular his was inconclusive due
to insufficient precision in the ratio of the kon with and without intermolecular hi .
finally ,
our results demonstrate that we simulations are orders of magnitude
more efficient than brute force simulation in providing converged
estimates of rate constants for the slow associations of proteins
in the complete absence of electrostatic interactions .
the computation
of such rate constants is otherwise impractical when using flexible
protein models even when these models are coarse - grained .
given
its high efficiency , the simulation strategy used in this study would
be useful for even more complicated systems , including those that
undergo large conformational changes upon binding . | an essential baseline for determining
the extent to which electrostatic
interactions enhance the kinetics of protein protein association
is the basal kon , which is the rate constant for association in the absence
of electrostatic interactions .
however , since such association events
are beyond the milliseconds time scale , it has not been practical
to compute the basal kon by directly simulating the association with flexible models . here ,
we computed the basal kon for barnase and barstar , two of the most rapidly associating proteins ,
using highly efficient , flexible molecular simulations . these simulations
involved ( a ) pseudoatomic protein models that reproduce the molecular
shapes , electrostatic , and diffusion properties of all - atom models ,
and ( b ) application of the weighted ensemble path sampling strategy ,
which enhanced the efficiency of generating association events by
> 130-fold .
we also examined the extent to which the computed basal kon is affected by inclusion
of intermolecular hydrodynamic interactions in the simulations . |
technological progress has made it possible for additive manufacturing technologies to be applied successfully in the medical sciences .
one of these techniques is selective laser melting ( slm ) , which consists of producing irregular shape devices by fusing titanium alloy powder , such as ti6al7nb .
although the surgical procedure of implant placement is of great importance , the clinical outcome stands in osseointegration , which represents the ultimate test in morphological and functional rehabilitation of the patient .
the study of bone implants osseointegration should observe the device in a 3d setting in which it is present in the living tissues , considering that the histological examination , despite its great value , is just a 2d representation of the present situation .
whatever the technology used to obtain the implants , foreign body rejection stands as one of the most difficult obstacles the human body has to overcome .
osseointegration is a process that can be hard to induce , which is why , in this study , hydroxyapatite and sio2-tio2 coatings were applied on the implant surface , to enhance the osseointegration process .
micro - ct analysis has proved itself to be appropriate in the measurement of certain in vivo / in vitro parameters such as mineral bone density and cortical bone thickness . bone mineral density ( bmd ) is defined as the volumetric density of calcium hydroxyapatite ( caha ) in a biological tissue in terms of g / cm . the combined density of a well - defined volume which contains a mixture of both bone and soft tissue , such as a selected volume of medullar trabecular bone in a femur or tibia , is measured as bone mineral density , or bmd .
this parameter relates to the amount of bone within a mixed bone - soft tissue region .
ti6al7nb alloy ( ati allvac , monroe nc , usa ) was used to create the sample implants , by selective laser melting technology ( realizer slm 250 machine , realizer gmbh , borchen , germany ) .
the samples were designed with a cylindrical screw - type shape in order to have a good penetration in the bony structure of the rabbit femur , and perfect primary stability at insertion .
the dimensions and properties of the implants were : 10 mm length and 3.3 mm diameter , with a controlled porosity of 2425% , determined through archimede s method iso 273899 .
the implants were divided into three groups : one group uncoated , the second group with ha coating and the third one with sio2-tio2 coating ( figure 1 ) .
the coating procedure was done by immersing the implants into a hydroxyapatite and sio2-tio2 solution .
after that , they were dried in a special oven at 100c for 30 minutes .
the thermal treatment was performed at 600c for 30 minutes for the implants infiltrated with ha and at 400c for 60 minutes for the implants immersed in sio2-tio2 ( rotaru et al . ) .
eighteen new zealand white rabbit ( oryctolagus cuniculus ) were included in this study , divided into 3 groups of 6 individuals .
all rabbits were of the same age ( six months ) and approximately the same weight , kept in standard conditions of temperature , humidity , day / night cycle and they all had the same access to food and water , ad libitum , throughout the experiment .
the rabbits were anesthetized with a xylazine / ketamine cocktail using a dosage of 8 mg xylazine and 80 mg ketamine per kg of body weight .
the study was approved by the ethical committee of the iuliu haieganu university of medicine and pharmacy , cluj - napoca , romania ( no . 407/03.12.2014 ) . the lateral aspect of the femur was shaved and disinfected with iodine solution .
the femur approach was done through the muscle bodies without tampering with the muscle fibers .
a periosteal scraper was used to fully expose the antero - lateral part of the femur .
two cylindrical orifices were created at the proximal area of each femur , using cylindrical 10 mm long burs with ascending dimension : 1 mm - 2 mm 2.8 mm under continuous cooling with saline solution at 800 rotations / min and a 30 nm torque . in the left femur at the upper proximal area
the ti6al7nb - ha implant was placed and in the inferior orifice the ti6al7nb - sio2-tio2 implant was inserted ( figure 2 ) . in the right
the rabbits were sacrificed at one , three and six months intervals after the implants were placed , by a potassium chloride intravenous injection , after inducing general anesthesia .
micro - ct was performed for each specimen in order to evaluate the position of the implant , the bone apposition between the threads of the implant , and the bmd at the implant site .
the measurements were done using the ct - analyser ctan dedicated soft ( figure 3 ) .
the samples were scanned with a bruker skyscan 1172 microct at 80 kv and 100 ma , using a 1 mm cu+al filter , a rotation step of 0.5 and a resolution of 20 m . before scanning rehydration by overnight storage in 0.9% physiological saline , was performed .
the calibration of the machine was done with 8 mm diameter rods ( calibration phantoms ) .
the samples were wrapped in paper tissue , loaded into a plastic tube , thenmoistened with saline , same as the bmd phantom rods .
the obtained slices were reconstructed using the nrecon software ( bruker , belgium ) and analyzed using ctan ( bruker , belgium ) .
the bone surrounding the implant was assessed by selecting it as the region of interest ( figure 3 ) and measuring the bone mineral density as compared to the scanned phantom rods .
after formalin immersion for 2 days the samples were decalcified in an nitric acid solution for 3 days and then prepared for histological examination .
the histological slices were colored with tricrom masson , which gives two separate colors for mineralized bone and for osteoid , thus an image analysis could be performed .
the histological slices were obtained with a leica microtome cutting system with 4 micrometer thickness , and examined with a leica icc50hd cam microscope .
panoramic image of the slice was used by merging images done at 50 magnification ( cs6 version photomerge ) .
cleaning of the artifacts ( bone marrow , muscle fiber etc . ) was then performed in order to have the best result bone ( blue)/osteoid ( red ) figure 4 . by pixel quantification for each color ,
statistical analysis was performed using the medcalc statistical software version 15.2.1 ( medcalc software bvba , ostend , belgium ) .
after formalin immersion for 2 days the samples were decalcified in an nitric acid solution for 3 days and then prepared for histological examination .
the histological slices were colored with tricrom masson , which gives two separate colors for mineralized bone and for osteoid , thus an image analysis could be performed .
the histological slices were obtained with a leica microtome cutting system with 4 micrometer thickness , and examined with a leica icc50hd cam microscope .
panoramic image of the slice was used by merging images done at 50 magnification ( cs6 version photomerge ) .
was then performed in order to have the best result bone ( blue)/osteoid ( red ) figure 4 . by pixel quantification for each color ,
statistical analysis was performed using the medcalc statistical software version 15.2.1 ( medcalc software bvba , ostend , belgium ) .
the rabbits had no post - operative complications and the tissue specimens required for the intended analysis could be processed at state - of - the - art standards .
micro - ct scan performed before the histological analysis of the specimens , showed no implant displacement or osteolysis around the implant threads .
no inflammatory reaction or fibrous tissue was noticed for the implant site at 1 , 3 and 6 months interval .
table i shows the average bmd for the three implant types , and the average percentage of mineralized bone present at the implant surface , seen at the histology examination . at one month
both analyses done ( bmd and histological examination ) were showing a high degree of bone mineralization at the implant site , same as the results for 6 months . at 3 months period a demineralization process for the ti6al7nb sample
was observed , both when calculating the mineralized bone by histology exam and the bmd by the micro - ct exam , while the values for the coated implants are much higher .
the statistical analysis of the results for the three samples shows that there was a positive correlation between the bmd measurement and the histological results , which is highly statistically significant ( r=0.750 ; p=0.02 ) .
one of the best treatment options in bone defect reconstruction is the use of 3d custom made implants .
selective laser melting of titanium alloys is the best option to obtain an irregular shape implant , which can be biocompatible .
the bone growth for a specific implant depends on the design of the implant , surface structure and coating material .
osseointegration improvement of this type of alloys , and their clinical assessment , represents a challenging task .
usually the degree of osseointegration is proven by the histology exam that shows the bone cells proliferation , direct bone - implant contact and the mineralization degree at the implant surface .
micro - ct images allow us to quantify volumetric bone - implant contact , and bone mineral density ( bmd ) of a specific region that are of help in the osseointegration evaluation .
usually , the titanium alloys and the different coatings used to enhance their osseointegration , were studied for a period of 2 , 4 , 6 and 12 weeks after implantation implantation , but none studied the behavior of the alloys for more that 18 weeks , thus we considerered that a longer period of time ( six months ) , would be more appropriate for integration assessment .
it is a known fact that mineralization and demineralization balance require time to be achieved .
this can explain why the demineralization process was continuous , for the ti6al7nb sample with a peak at about 3 months , followed by remineralization of the site within the following months , reaching a percentage of mineralized bone for 6 months comparable with the one at 1 month ( 94.67% vs. 93.83% ) .
the remineralization process happened in the absence of any tempering force , the implants having a passive condition inside the femoral bone , without any stress applied directly .
the niobium component of the studied alloy has the potential to stabilize the ti6al7nb samples in time , due to the niobium oxides ( nb2o5 ) that are formed at the surface of the implants .
the mineralization process that occurs after 3 months can happen due to the surface oxide layer , which is less soluble and biocompatible , that forms in time .
the micro - ct data , same as the histology examination , showed the same results in terms of bmd evaluation , proving the demineralization process that happens for the ti6al7nb samples . usually an implant is considered to be osseointegrated when bone develops directly on the implant surface , without any fibrotic tissue grown at the interface .
clinically there is no mobility between the bone and the implant , under regular loading conditions , after an appropriate healing period . in our study
we have not seen any fibrotic tissue at the bone - implant interface , also no inflammation was observed .
micro - ct analysis is useful in understanding the circumstances that lead to a poor bone activity response , such as microcracks , plastic deformations or manufacturing deficiencies that can lead to failure ; in our study none of the above was seen .
it has been clinically validated that titanium and its alloys present a superior biocompatibility and fewer foreign body reactions in comparison to other conventional materials .
the bioinert nature of titanium is its principal quality which consigns itself biocompatibility properties , stating that it does not induce a positive reaction in the tissues , but more likely it conditions the absence of a negative reaction , even in the case of demineralization showed for the ti6al7nb implant , no inflammation or adverse reaction were seen at the histological analysis .
implant surface roughness is also responsible for the proportion of osteoblasts proliferation , demonstrating its growth in the case of silicium dioxide sandblasted implants , that can explain the higher value of mineralized bone for the ti6al7nb - sio2tio2 than for the ti6al7nb implants .
coating the implants with hydroxyapatite enhances their viability in time , and influences positively the cellular and protein adhesion , resulting in improved osseointegration .
similar with our work , alzubaydi showed in his study that the ha coated ti-6al-7nb screws after 18 weeks of the implantation seem to be well - tolerated by the bone since no adverse tissue reaction was evident .
however , there was a faster reaction of bone towards the coated implants compared to the uncoated one . in another study ,
had observed that histologic evaluations of orthopedic implants revealed mineralization of interface bone directly onto the ha - coated implant surface , with no fibrous tissue layer interposed between the bone and ha visible at the light microscopic level . in vitro study done by brie ic on ti6al7nb with ha and
sio2 coatings found that the behavior of osteoblasts depends on the type of implant and culture conditions .
ti - sio2 scaffolds sustain osteoblast adhesion and promote differentiation with increased collagen and non - collagen protein production .
ti - ha implants have a lower ability to induce cell adhesion and proliferation but an increased capacity to induce early mineralization . both types of infiltrates have their advantages and limitations , which can be exploited depending on local conditions of bone lesions that have to be repaired . the early mineralization process
, present at the ti - ha coating could explain our results of high mineralized bone for the ti6al7nb -ha implants .
the use of coated implants is of help whenever local or general condition could temper with the normal osseointegration process .
for a good long - term outcome , the ti6al7nb implant need a period of stabilization of about 6 months , any stress applied in this period of time , especially at 3 months could lead to the onset of complications , even implant displacement .
the ha coating represents the best option for the ti6al7nb alloy , that beside the osteoinductive and osteoconducting property ( rotaru el al . ) can induce early mineralization , that supports implant osseointegration .
the histology examination of titanium based implants needs a long time period ( weeks ) in order to have a result , meanwhile the micro - ct examination can produce reliable results in a matter of hours , thus the micro - ct examination is easier and faster to be performed .
further studies that will involve the loading of the implants or force applied to the implant site for the 6 months period of osseointegration should be taken into consideration . | background and aimbone defect reconstruction in the maxillofacial area comes as a necessity after traumatic , oncological or congenital pathology .
custom made implant manufacturing , such as selective laser melting ( slm ) , is very helpful when bone reconstruction is needed . in the present study we assessed the osseointegration of custom made implants made of ti6al7nb with two different coatings : sio2-tio2 and hydroxyapatite , by comparing the bone mineral density ( bmd ) measured on micro - ct and the histological mineralized bone surrounding the implants.methodscustom made cylindrical type implants were produced by selective laser melting , coated with sio2-tio2 and hydroxyapatite and implanted in the rabbit femur .
the animals ( divided into 3 groups ) were sacrificed at 1 , 3 and 6 months and the implants were removed together with the surrounding bone . bone mineral density and histological examination of the bone - implant surface
was performed for each group.resultsbmd and histological examination of the samples determined the quantity of mineralized bone at the implant site , showing a good percentage of mineralized bone for the coated implants at 1 , 3 and 6 months .
the measurements for the implants without coating showed a significant lower quantity of mineralized bone at 3 months compared with the implants with coating , and a good quantity of mineralized bone at 6 months , showing a process of demineralization followed by remineralization in the last month .
the measurements of bmd showed similar results with the histological examination.conclusionsthe use of micro - ct and the measurement of bmd are a reliable , minimally invasive and a quick method of osseointegration assessment . |
hepatitis c patients have fourfold higher incidence of insulin resistance ( ir ) than non - hcv population , that is , healthy controls or chronic hepatitis b patients .
ir is the major feature of the metabolic syndrome ( diabetes type 2 , obesity , hypertension , and cardiovascular disorders ) .
hcv - associated ir may lead to resistance to antiviral therapy , hepatocarcinogenesis , and extrahepatic complications [ 2 , 3 ] .
experimental and clinical findings indicated that hepatitis c virus per se is diabetogenic [ 4 , 5 ] .
it was suggested that increased production of proinflammatory cytokines , especially tnf - alpha , contributes to the development of ir in hcv patients .
tnf - alpha potentiates interferon - gamma- ( ifng- ) triggered transcriptional induction of indoleamine 2,3-dioxygenase ( ido ) , the rate - limiting enzyme of tryptophan- ( trp- ) kynurenine ( kyn ) metabolism .
upregulated ido expression in the dendritic cells and in the liver and increased serum kyn : trp ratio ( ktr ) were reported for hcv patients .
review of clinical and experimental data suggested that kyn and some of its derivatives affect biosynthesis , release , and activity of insulin . we suggested that upregulated trp - kyn metabolism might be one of the mechanisms of ir in hcv patients . to check this suggestion
, we evaluated serum trp and kyn concentrations and ir and pancreatic beta - cell function in hcv patients .
participants were recruited from hcv patients considered for starting a treatment with pegylated interferon - alpha and ribavirin .
the study was approved by tufts medical center irb , and written consents were obtained for participation in the study .
ido activation results in decrease of trp and increase of kyn and , therefore , in elevation of ktr that is used as a marker of ido activity in clinical studies . however , there are some peculiarities related to the use of ktr as a marker of ido activity in hcv patients
. increased ktr was reported in hcv patients but without data on serum trp and kyn levels . on the other hand , the decreased concentrations of both trp and kyn in serum and macrophages and , consequently , decreased ktr were observed in hcv . in the largest ,
so far , study , concentrations of kyn in 176 patients were significantly higher those than in healthy controls , whereas the levels of trp were comparable in the two groups .
authors suggested that in hcv patients serum kyn level can be used as a marker of ido activity .
serum trp , kyn , and kynurenic acid ( kyna ) concentrations were evaluated by hplc - uv - fluorimetric method .
ir was assessed by homeostatic model assessment index , version 2 ( homa2-ir ) , and pancreatic beta - cell function by homa - beta index , based on fasting glucose and insulin levels , using the computer - based solution of the model provided by the diabetes trials unit , oxford center for diabetes , endocrinology , and metabolism ( http://www.dtu.ox.ac.uk/index.php?maindoc=/homa/history.php ) .
serum glucose was measured using an enzymatic , kinetic reaction on the olympus au400e with olympus glucose reagents ( oscr6121 ) ( olympus america inc . ,
serum insulin is measured using the immulite 1000 insulin kit ( lkin1 ) on the immulite 1000 ( siemens medical solutions diagnostics , los angeles , ca , usa ) .
quantitative data are presented using median ( 50th percentile ) and minimum - maximum range .
nonparametric tests ( wilcoxon and mann - whitney u ) were used to assess correlations for nonnormally distributed data .
there were 42 male and 18 female american caucasian hcv patients , 52.2 7.45 years of age .
forty - eight patients had hcv genotype 1 or 4 , and twelve patients had hcv genotype 2 or 3 .
serum kyn concentrations correlated with scores of homa2-ir and homa - beta ( table 1 ) .
trp ( kyn precursor ) but not kyna ( immediate metabolite of kyn ) [ 17 , 18 ] correlated with homa2-ir and homa - beta .
serum kyna concentrations correlated with kyn but not with trp concentrations ( table 1 ) .
the major findings of the present study are the correlations between serum concentration of kyn and scores of homa2-ir and homa - beta in hcv patients . as far as we are aware , this is the first observation of such a correlation . considering that serum kyn concentrations used an index of ido activity in hcv patients , our data suggested a possible involvement of upregulated of trp - kyn metabolism in the development of ir in hcv patients . we did not find correlation between ir indexes and ktr , a marker of ido activity in clinical studies . as it was indicated earlier
( see section 2 ) , in hcv patients , serum kyn concentrations might be considered as an index of ido activity .
present finding of correlation between serum kyn and trp with both homa-2-ir and homa - beta is in line with the reported induction of ir by surplus dietary trp in pigs and with recent observation of increased serum kyn in diabetes retinopathy patients .
association between elevated kyn and trp concentrations and ir might be a result or a cause of ir .
recent review of clinical and experimental data suggested the involvement of kyn pathway of trp metabolism in the development of ir since kyn and some of its derivatives affect biosynthesis , release , and activity of insulin . diabetogenic effect of kyn and its derivatives , xa , 3-hk , and kyna , ( figure 1 ) may be mediated by inhibition of pro - insulin synthesis in isolated rat pancreatic islets and of insulin release from rat pancreas . however , the effective concentrations ( millimolar ) of kyna were much higher than its concentrations ( micromolar ) in pig 's pancreatic juice .
the most plausible candidate for mediation of diabetogenic effect of upregulated try - kyn metabolism is xa .
increased urine excretion of xa was reported in type 2 diabetes patients in comparison with healthy subjects , while xa induced experimental diabetes in rats .
xa might contribute to the development of diabetes via formation of chelate complexes with insulin ( xa - in ) [ 26 , 27 ] and induction of pathological apoptosis of pancreatic beta cells through caspase-3-dependent mechanism [ 28 , 29 ] .
formation of xa from 3-hk depends on the vitamin b6 since its active metabolite , pyridoxal 5-phosphate ( p5p ) , is a cofactor of kynureninase , the enzyme , catalyzing 3-hk metabolism to nad+ ( figure 1 ) .
evaluation of xa should be included in future studies of the role of trp - kyn metabolism in mechanisms of hcv - associated ir .
mechanisms of ir in hcv might be different from those in non - hcv patients .
thus , we observed in agreement with previous finding that a positive correlation between homa - ir and homa - beta was reported in hcv patients , in comparison with negative correlation between hoam-2ir and homa - beta in non - hcv patients . in the present study ,
a strong positive correlation between hoam-2ir and homa - beta was observed as well ( table 1 ) .
our data of correlation between kyn and ir suggested the involvement of trp - kyn metabolism in the development of ir in hcv patients .
detection and treatment of hcv - associated ir are of importance considering that hcv - associated ir may lead to resistance to antiviral therapy , hepatocarcinogenesis , and extrahepatic manifestations , including an increased risk of cardiovascular disorders .
trp - kyn metabolism might be a new target for prevention and treatment of ir in hcv patients . | chronic hepatitis c virus ( hcv ) infection is associated with 50% incidence of insulin resistance ( ir ) that is fourfold higher than that in non - hcv population .
ir impairs the outcome of antiviral treatment
. the molecular mechanisms of ir in hcv are not entirely clear . experimental and clinical data suggested that hepatitis c virus per se is diabetogenic .
however , presence of hcv alone does not affect ir .
it was proposed that ir is mediated by proinflammatory cytokines , mainly by tnf - alpha .
tnf - alpha potentiates interferon - gamma - induced transcriptional activation of indoleamine 2,3-dioxygenase , the rate - limiting enzyme of tryptophan- ( trp- ) kynurenine ( kyn ) metabolism .
upregulation of trp - kyn metabolism was reported in hcv patients .
kyn and some of its derivatives affect insulin signaling pathways . we hypothesized that upregulation of trp - kyn metabolism might contribute to the development of ir in hcv . to check this suggestion , we evaluated serum concentrations of trp and kyn and homa - ir and homa - beta in 60 chronic hcv patients considered for the treatment with ifn - alpha .
kyn and trp concentrations correlated with homa - ir and homa - beta scores .
our data suggest the involvement of kyn and its metabolites in the development of ir in hcv patients
. trp - kyn metabolism might be a new target for prevention and treatment of ir in hcv patients . |
recently
discovered two - dimensional ( 2d ) materials such as graphene ,
fluorographene , graphene oxide , transition metal dichalcogenides ,
hexagonal boron nitride , and phosphorene all have very high surface / mass
ratios , and many of their potential practical applications rely on
their large surface areas .
consequently , there is a need to better
understand their surface properties and the way in which their surfaces
interact with their surroundings . in particular
, there is great interest
in the adsorption of molecules on 2d materials because of its technological
importance .
small molecule adsorption can be used to tune the electrical
properties of 2d materials and is important
in processes that can be exploited in mass , gas , and electrochemical sensing .
all kinds of sensors require a contact between
an analyte and an active material to generate a readout , so it is
essential to have a good understanding of the strength and nature
of the interactions between adsorbed molecules and the sensing surface .
fluorographene ( i.e. , a fluorographite
monolayer ) , fluorinated graphenes , and fluorographite are all active
in electrochemical sensing and have sensing properties that depend
on their c / f ratio and topology .
as such ,
they could potentially be used to create selective sensors in which
specificity is achieved through the interaction of the analyte with
an active zone consisting of a suitable fluorinated graphene .
in addition
to sensing applications , these materials can be used in gas separation
and storage .
it has been demonstrated that
adsorption to graphene is primarily controlled by london dispersive
forces , but little is known about adsorption
to fluorographene and fluorographite .
the few theoretical studies
that have explored the adsorption of small molecules to fluorographene
have suggested that it may have useful applications in hydrogen storage .
adsorption enthalpies on surfaces are usually studied using
adsorption
calorimetry , temperature - programmed desorption , or equilibrium adsorption
isotherms .
recently , we witnessed a renaissance
of inverse - gas chromatography ( igc ) to study the process of adsorption .
this technique measures retention characteristics of gas probes injected
to a column loaded by analyzed material .
its main advantage is that it provides results that represent averages
over the sample s surface .
in addition , adsorption enthalpies
and entropies , and the dependence of these thermodynamic quantities
on the surface coverage , can be obtained directly from igc data .
it was shown that igc provides
adsorption enthalpies consistent with other experimental techniques . quantum chemistry and solid - state physics
calculations
can be used
to characterize intermolecular interactions and predict their strengths .
however , deciphering the nature and strength of molecule
surface
binding by computational means is frequently rather challenging because
the binding energies are usually low and involve physical phenomena
such as london dispersion forces that are difficult to model reliably ; physisorption forces are significantly weaker
than chemisorption ones . in finite molecular
systems , the electron
electron correlation effects responsible
for these noncovalent interactions can be described using the coupled
cluster method , with single and double electron excitations being
modeled iteratively and triple excitations perturbatively ( ccsd(t ) ) ,
or using the perturbative mller
plesset mp2.5 method
( in which energies are calculated as the arithmetic mean of the mp2
and mp3 energies ) . unfortunately , these
methods are not available for periodic systems , which are frequently
superior to finite models when studying the adsorption of molecules
on surfaces .
consequently , methods based
on density functional theory ( dft ) are widely used in such applications .
classical general gradient approximation dft methods are of semilocal
character and thus can not describe the long - range component of the
london forces , which result from nonlocal electron electron
correlation .
the performance
of individual dft methods is usually benchmarked against ccsd(t ) or
mp2.5 calculations on finite systems ( molecular clusters ) , in order
to identify approaches that accurately describe the system of interest .
both ccsd(t ) as well as mp2.5 methods provide highly accurate interaction
energies for various types of molecular clusters with errors of less
than 2 and 4 relative percent , respectively .
ccsd(t ) can be applied to complexes having up to around 35 heavy
atoms , while mp2.5 can handle systems up to twice the size .
unfortunately ,
however , no reference method of comparable quality is currently available
for use with periodic models , with the exception of the stochastic
quantum monte carlo method , that embody exceeding computational demands . in this work
,
we determined isosteric adsorption enthalpies ( h ) and isosteric adsorption entropies ( s )
for five organic molecules ( acetone , acetonitrile , dichloromethane ,
ethanol , and ethyl acetate ) on fluorographite by igc .
we also performed
extensive calculations on finite models of fluorographene to benchmark
various dft methods against ccsd(t ) and mp2.5 .
the application of
symmetry - adapted perturbation theory ( sapt ) to finite model systems allowed us to decipher the nature of the
molecular interactions occurring on the fluorographene / fluorographite
surfaces .
moreover , dft calculations on periodic models helped us
to clarify the roles of various adsorption sites and surface defects
on adsorption to fluorographene , as well as the influence of molecular
clustering .
we conclude that the enthalpies of adsorption to fluorographene / fluorographite
are slightly lower than those for graphene / graphite , i.e. , small molecules
generally bind more strongly to fluorographene and fluorographite
than to their nonfluorinated counterparts .
using
igc we determined the isosteric adsorption enthalpies of five molecular
probes ( table 1 ) to
fluorographite for coverage values ranging from 2 to 20% of the adsorbate
monolayer .
the isosteric adsorption enthalpies of acetone , acetonitrile ,
and ethanol decreased as the surface coverage increased , with saturation
occurring at a coverage level slightly above 10% ( figure 1 ) .
the isosteric adsorption
enthalpies of ethyl acetate and dichloromethane were rather coverage - independent .
the saturated adsorption enthalpies h h reported in table 1 ranged from 6.9 kcal / mol ( dichloromethane )
to 12.8 kcal / mol ( ethanol ) .
isosteric adsorption
enthalpies h ( top )
and entropies s ( bottom ) for five organic
molecules on fluorographite obtained from inverse gas chromatography
as a function of surface coverage .
the dotted lines are eye - guides . averaged over coverage values greater
than 10% . averaged over
coverage values over
220% .
the temperature
interval tmin - tmax ( in k )
was used for data fitting ( see the supporting information ) .
standard
enthalpies of condensation
hcond ( negative standard enthalpies
of vaporization in kcal / mol ) for tmin and tmax were adopted from the literature .
adsorption
enthalpies ( in kcal / mol )
of the same molecules on graphene hgr . were taken from previous works .
when explaining
coverage dependence of the adsorption enthalpies ,
one should take into account the fact that the real material surface
is really complex containing various structural and chemical features
and defects , e.g. , edges , steps , cavities , pores , vacancies , or adatoms .
such features may represent sites , where the adsorbate preferentially
binds ( the high - energy sites ) .
in addition ,
some adsorbates may tend to form clusters over the surface . as the igc provides averaged adsorption enthalpies
over the surface all these effects are involved .
fortunately , the
complexity of the process can be typically deciphered from the plot
of adsorption enthalpy vs coverage in combination with atomistic simulations .
the decreasing adsorption enthalpies of acetone , acetonitrile , and
ethanol with increasing coverage ( figure 1 ) can be explained by the clustering of these
molecules over the adsorbent surface , because the same behavior was
observed for ethanol adsorption to graphene and was attributed to
ethanol clustering over the graphene surface .
this behavior might occur when the adsorption enthalpy of a single
molecule to the surface is greater than the enthalpy of condensation ;
however , we should note that a tendency of clustering is given by
a delicate balance among adsorption enthalpy , enthalpy , and entropy
of clustering .
the rather constant adsorption
enthalpies of dichloromethane to the surface ( at very low coverage
levels ; see figure s1 in the supporting information ) may indicate that the material used in this work had few high - energy
sites or that the enthalpies of adsorption to structural features
that typically correspond to high energy sites ( e.g. , steps , edges ,
cavities , and defects ) are comparable to those for adsorption to a
fluorographene / fluorographite surface lacking such features . computational
methods ( see below ) were used to determine which of these potential
explanations was most plausible .
we measured the adsorption
enthalpies of the same probe molecules
to graphene powder in a previous investigation . on comparing the adsorption enthalpies for
fluorographene / fluorographite and graphene / graphite
, we found that
the enthalpies of adsorption to fluorographite are generally slightly
lower than those for graphene / graphite ( by 1.2 kcal / mol on average ,
corresponding to 14% of the h for graphene ;
see table 1 ) .
this
indicates that small organic molecules bind more strongly to fluorographite
than to graphite and hence that fluorographene / fluorographite more
readily adsorbs guest molecules from its environment .
we used finite
systems to benchmark the accuracy of selected dft
methods when applied to the systems of interest and used the best - performing
methods in these benchmarking studies to perform further calculations
on periodic - boundary models .
two small models of fluorographene / fluorographite
surfaces were used in the benchmarking calculations .
the smallest
model , perfluorohexamethylcyclohexane ( c12f24 ) , was small enough to permit the use of the ccsd(t ) method , which
provides very accurate interaction energies ei for a wide range of complexes .
however , because of the
small size of this model , it may not constitute an adequate representation
of the theoretically infinite fluorographene / fluorographite surface .
we therefore also considered a larger model , hexatriacontafluorotetracosahydrocoronene
( c24f36 ) , which is more representative and was
also used to obtain geometries and enthalpy corrections ( see methods ) .
because it was computationally unfeasible
to perform ccsd(t ) calculations on this larger system , we instead
performed reference calculations using the mp2.5 method , which is
known to approach the quality of ccsd(t ) for many noncovalent complexes .
the use of mp2.5 in this case was validated
by comparing the energies calculated with this method for the smaller
c12f24 system to those obtained with ccsd(t ) .
both ccsd(t ) and mp2.5 explicitly model the dispersion energy , whereas
most dft methods model it implicitly using some kind of correction .
this is one of the reasons why the performance
of dispersion - corrected dft techniques must be carefully tested .
the ccsd(t ) and mp2.5 interaction energies for the dichloromethane
and ethanol complexes of c12f24 were in reasonably
good agreement ( table 2 ) , although the ccsd(t ) interaction energies are systematically more
attractive ( by 10% on average ) than the mp2.5 energies .
this justified
the use of the less expensive mp2.5 method as a source of reference
data for calculations on the large models .
dft functionals with london
dispersion corrections generally provided reasonably accurate energies
for the smaller complexes ( table 2 , figure 2 , figure s2 ) , but optb86b - vdw and vdw - df
overestimated the interaction energy by over 30% for this model .
however ,
it should be noted that the optb88-vdw functional provided the best
agreement with experimental data in a study on the adsorption of small
molecules to graphene .
this may indicate
that the individual dispersion - corrected dft methods do not provide
a consistent treatment of dispersion interactions for finite size
and periodic systems .
together with the limited amount of available
experimental data on such systems , this complicates the assessment
of theoretical methods for adsorption studies
. models of fluorographene
( top ) and their interaction energies ei with dichloromethane , showing the dependence
of the interaction energy on the size of the model system and the
computational method used ( bottom ) .
table 3 summarizes
the interaction energies calculated for complexes of the larger c24f36 system with the five organic molecules using
mp2.5 and various dft functionals .
the mp2.5 results suggest that
the complexes with the largest and smallest interaction energies are
those of ethyl acetate and dichloromethane , respectively , and all
of the tested functionals replicated this trend .
the optb86b - vdw and
vdw - df functionals again strongly overestimated the absolute interaction
energies ( by more than 56% ) , whereas the b97-d3 functional underestimated
the interaction energies by more than 25% .
other dft functionals provided
interaction energies that agreed reasonably well with the reference
mp2.5 values .
the b3lyp - d3 and pbe - d3 functionals gave the most accurate
interaction energies with respect to mp2.5 ( with deviations below
10% ) ; however , pbe - d2 , pbe - ts+scs , and vdw - df2 functionals performed
also well because the ccsd(t ) energies were more negative than the
mp2.5 values for the smaller model .
we obtained near - identical pbe - d3
interaction energies by two different approaches : using localized
gaussian orbitals ( the tzvpp basis set ) as implemented in turbomole
and using plane waves ( pw ) as implemented in vasp ( see also the methods section ) .
the relative deviation from the
mp2.5 energy , ( ei-ei)/ei , is given in parentheses .
to determine how the interaction
energy ei depends on the model
size , we performed calculations on a larger finite model system -
c54f72 .
we also compared all of the results
obtained using finite size models to results for an infinite ( periodic )
model based on a 5 5 fluorographene supercell .
this comparison
was justified by the fact that the calculated adsorption configurations
on fluorographene were similar to those for the finite models ( figure 3 ) .
interaction energies
for small molecules on all four models of fluorographene ( c12f24 , c24f36 , c54f72 , and periodic c50f50 ; see figure 2 ) could be computed
using dft methods implemented in the vasp package ( see the methods section ) , namely the empirically corrected
density functionals pbe - d2 , pbe - d3 , pbe - ts , and pbe - ts - scs , as well
as the nonlocal correlation functionals vdw - df , vdw - df2 , and optb86b - vdw .
we also performed less expensive wave function - based calculations
using the mp2/aug - cc - pvdz method to compare the interaction energies
computed in this way for the three finite systems ( c12f24 , c24f36 , and c54f72 ) to those obtained by dft .
adsorption geometries of acetone , acetonitrile ,
dichloromethane ,
ethanol , and ethyl acetate ( from the top to the bottom , respectively )
on perfluorinated tetracosahydrocoronene ( left column ) and fluorographene
( right column ) .
structures shown in the left and right columns were
obtained by optimization with the b97d and optb86b - vdw density functionals ,
respectively .
dark gray , green , red , blue , yellow , and white represent
c , f , o , n , cl , and h atoms , respectively .
figures 2 and s2 present the results of the calculations performed
for the adsorption of dichloromethane ( and ethanol ) on all four fluorographene
model systems using various methods . in all cases ,
the calculated
interaction energy decreased as the model size increased , i.e. the
small molecules were most strongly bound on periodic fluorographene .
the ratio of mp2.5/cbs interaction energies of dichloromethane and
ethanol molecules with c24f36 and c12f24 equals to 1.2 and 1.3 , respectively .
the same ratio
of mp2/aug - cc - pvdz for dichloromethane complexes equals to 1.4 , whereas
it becomes 1.2 when we consider c54f72 and c24f36 models .
it should be noted here that mp2.5
and mp2 describe the dispersion energy explicitly , which means that
they model well both pairwise and many - body energy terms ( however , strictly speaking , mp2 does not provide
reliable values for the many - body dispersion term ) .
the ratios of the calculated energies of the dichloromethane and
ethanol complexes of c24f36 and c12f24 obtained with different dft methods were generally
similar to the mp2.5 values ( in the cases of pbe - d2 , pbe - d3 , vdw - df2 ,
and optb86b - vdw ) or the mp2 values ( for pbe - ts , pbe - ts - scs , and vdw - df ) .
moreover , the dft interaction energy ratios for the c54f72 and c24f36 models were similar
to those obtained with mp2 .
the tested dft methods thus predict the
effects of increasing surface size similarly to mp2.5 and mp2 , both
of which correctly model many - body terms .
the interaction energies
calculated for the largest finite model
system , c54f72 , were only slightly ( 0.20.8
kcal / mol ) higher than those for the infinite periodic surface ( figures 2 and s2 ) .
this suggests that calculations on c54f72 provide quite good estimates of interaction
energies for fluorographene .
in addition , the relative ordering of
the interaction energies for the studied small molecules on c54f72 matched that for the periodic system .
the calculated interaction energies obtained for the periodic model
system with different density functionals decreased in the following
order : ei > ei >
ei >
ei , ei > ei , ei ( see the interaction curves
in figure s3 ) .
the interaction energies
provided by the dft - d3 and optb86b - vdw / vdw - df functionals thus corresponded
to the upper and lower limits of the dft energy range , which spanned
approximately 3 kcal / mol on average ( 5 kcal / mol for
ethyl acetate ) .
the dft energies calculated for the finite c24f36 model were less variable ( spanning a range of 2
kcal / mol for all small molecules other than ethyl acetate ; see table 3 ) , and those for the
smallest c12f24 model varied still less , with
a range of 1 kcal / mol ( table 2 ) .
the calculations performed using the dft functionals
with empirical dispersion corrections indicated that dispersion interactions
are the most important component of the interaction energy resulting
from the binding of small molecules to the fluorographene surface .
the pure pbe functional yielded a very shallow potential well for
molecular adsorption to fluorographene ( < 1 kcal / mol , figure s3 ) , but substantially more negative adsorption
energies were obtained using functionals with dispersion corrections .
based on the adsorption energies computed using the many - body d3 dispersion
correction , dispersion accounted for 92% of the total binding energy
( e/e ) in the case of acetone , 64% for acetonitrile ,
69% for dichloromethane , 73% for ethanol , and 83% for ethyl acetate .
this trend was confirmed by more rigorous dft based symmetry adapted
perturbation theory ( dft - sapt ) calculations
on the intermediate finite model c24f36 ( see figure 4 ) .
the dispersion
contribution ( calculated as ei/(ei +
ei + ei ) dominated , accounting for
72% , 70% , 73% , 70% , and 76% of the total attractive interaction energies
for acetone , acetonitrile , dichloromethane , ethanol , and ethyl acetate ,
respectively .
the electrostatic term ( 1923% ) represented the
second largest attractive contribution , followed by the induction
or polarization term ( 49% ) ; see figure 4 .
this trend is similar to that observed
for the interaction of small molecules with a finite model of graphene
( coronene , see table s1 for a comparison ) .
in the graphene case ,
the interactions were similarly dominated by
dispersion ( 6266% ) , with lesser contributions from electrostatics
( 2629% ) and induction ( 812% ) .
the relative contribution of electrostatics to binding in the case
of c24f36 was lower than that for graphene ,
which is somewhat surprising given that c
semi - ionic ) , making the distribution of electron density
across the fluorographene plane rather inhomogeneous . decomposition of the total attractive energy into dispersion , induction ,
and electrostatic contributions calculated by dft - sapt for the small
model system c24f36 .
data for the hexatriacontafluorotetracosahydrocoronene model system
( c24f36 ; see figure 3 ) were used to estimate the different contributions
to the adsorption enthalpies of small molecules on fluorographene ( table 4 ) by applying standard expressions from statistical
mechanics under the ideal gas , rigid rotor , and harmonic oscillator
approximations .
the derived enthalpy / energy differences ( h e ) ranged from 1.2 to
1.5 kcal / mol and were used as corrections to derive adsorption enthalpies
from the adsorption energies calculated for the periodic model .
these
adsorption energies ranged from 7.8 to 13.8 kcal / mol
( optb86b - vdw functional , table 5 ) and dominated the calculated adsorption enthalpies because
the correction terms were equal to at most 19% of the calculated
interaction energies .
e and e0 with and without zpe , respectively , internal
energies u , enthalpies h , gibbs energies g , and entropies s ( in cal / molk ) , and the contributions of the zero - point
energy ( e0 ) , thermal ( et ) , enthalpy ( eh ) , and gibbs energy corrections ( eg ) . the adsorption process c24f36 + x c24f36x
was modeled at 313.15 k and 101.325 kpa using the b97d functional .
the correction
to the adsorption
enthalpy was obtained from calculations on perfluorotetracosahydrocoronene
( table 4 ) .
we investigated the potential contributions of
surface irregularities , defects , and molecular configurations to the
adsorption process by studying the roles of ( i ) multilayers , ( ii )
surface steps and edges , and ( iii ) surface defects ( figure 5 ) .
specifically , we compared
the adsorption of ethanol on monolayer and bilayer fluorographene ,
because studies on graphene had previously shown that adsorption to
multilayer graphene was slightly stronger than that to a graphene
monolayer .
conversely , the energy of adsorption
for small molecules on bilayered fluorographene was 1.4 kcal / mol higher
than that for a fluorographene monolayer ( table s2 , supporting information ) .
the addition of a third layer of
fluorographene changed the adsorption energy by less than 0.1 kcal / mol
relative to that for the bilayer .
adsorption geometries of an ethanol molecule
on multilayer fluorographene
and a fluorographene step / edge ( top ) .
adsorption geometries of an
ethanol molecule on fluorographene with vacancy defects and a stone
all adsorption
energies were obtained with the optb86b - vdw density functional . for
molecular clusters ,
steps are regarded as high - energy
sites in multilayered graphene
and graphite because the energy change upon adsorption to steps is
up to 2.5 times greater than that for adsorption to a stepless surface .
the calculated adsorption energies
on steps were only 1020% lower than those for the stepless
surface ( table 6 ) .
taking into account boltzmann distribution of probes between the high - energy
sites and surface , such differences are
barely experimentally detectable , as demonstrated by the corresponding
igc data ( cf .
in addition , the calculated adsorption
energies for ethanol on fluorographene edge sites were less favorable ( 4.0 and 3.1 kcal / mol ) than those for
the surface ( 8.7 kcal / mol , figure 5 ) .
calculated with the optb86b - vdw
density functional ( results obtained with pbe - d3 in parentheses ) .
we also considered four types
of defect sites : ( i ) f vacancies ,
( ii ) c vacancies , ( iii ) c f vacancies , and ( iv ) stone
wales
( sw ) defects , the latter corresponding to lattice reconstructions
in which four hexagons were transformed into two pentagons and two
heptagons [ an sw(5577 ) defect ] ( figure 5 ) . ethanol bound preferentially to the defect - free
surface : its adsorption energies on the defect sites ( 6.7
to 7.2 kcal / mol ) were less negative than those for the perfect
surface ( 8.7 kcal / mol ) .
the experiments
indicated that clustering played a significant role in the adsorption
of ethanol , acetonitrile , and acetone to fluorographene / fluorographite
( cf .
our calculations revealed the formation
of cyclical planar ethanol clusters lying flat on the fluorographene
surface ( figure 5 ) .
the adsorption energies of ethanol dimers , tetramers , and hexamers
on fluorographene were 10.7 kcal / mol , 11.2 kcal / mol ,
and 13.1 kcal / mol per molecule , respectively , and were lower
than the adsorption energy of single molecules ( 8.7 kcal / mol ) .
this strongly suggests that ethanol forms clusters on fluorographene
surfaces and that the measured adsorption enthalpies corresponded
to the binding of ethanol clusters .
the adsorption energy of a single ethanol molecule on fluorographene
( 8.7 kcal / mol ) was lower than on graphene ( 7.7 kcal / mol ) .
on the other hand , the adsorption energies of ethanol clusters on
fluorographene were higher than on graphene ( 11.2 kcal / mol
on fluorographene compared to 15.6 kcal / mol for ( etoh)4 on graphene ) .
this different
adsorption behavior of molecules and clusters is probably due to competition
between h - bonding in the cyclic ethanol clusters ( as occurs on the
graphene surface ) and possible h - bonding between the oh group of an
isolated ethanol molecule and the f atoms of fluorographene : the calculated
o
hf h - bond was
3.2 for a single ethanol molecule positioned on a fluorographene
surface such that its oh moiety was situated in the middle
of an f - triangle ( figure 5 ) .
the calculations indicate that acetonitrile also
formed clusters on the fluorographene surface : the calculated adsorption
energy for a single acetonitrile molecule ( 7.8 kcal / mol ) was
substantially less negative than those for acetonitrile dimers ( 10.6
kcal / mol per molecule ) or trimers ( 10.9 kcal / mol per molecule ) .
the flat antiparallel adsorption geometries predicted for acetonitrile
clusters on the fluorographene surface ( see figure 6 for an image of the trimer ) were very similar
to those identified for free clusters .
hn hydrogen bonding within the acetonitrile
clusters appeared to be weak given the
calculated d(c
f ) distances
for the putative c hf bonds to the fluorinated
surface ranged between 3.2 and 3.5 ( figure 6 ) .
top ( top ) and side ( bottom ) views of the adsorption
geometries
of acetonitrile ( left ) and acetone ( right ) trimers on fluorographene .
selected weak bonds between molecules in clusters ( top ) and between
molecules and surfaces ( bottom ) are highlighted by red dotted lines .
the clustering of acetone
on fluorographene appeared to be less
favorable than ethanol and acetonitrile because the adsorption energies
of the acetone dimer ( 10.9 kcal / mol ) and trimer ( 11.5
kcal / mol ) were comparable to that for a single acetone molecule ( 10.7
kcal / mol ) .
the planar acetone clusters that were predicted to form
on the fluorographene surface ( figure 6 ) do not adopt the typical cyclical structures of free
acetone clusters .
ho = c hydrogen bonding ( figure 6 , d(o c ) = 3.3 ) observed on the fluorographene has also
been observed in free acetone clusters .
the
difference in behavior of the ethanol , acetonitrile , and acetone
molecules and other two adsorbates ( as indicated by experiment ) motivated
us to perform additional calculations with ethyl acetate .
we performed
periodic calculations and evaluated the overall energy balance for
the creation and adsorption of selected ethanol and ethyl acetate
clusters .
the thermodynamic cycle shown in the scheme 1 explained the different behavior of ethanol
and ethyl acetate on the surface , because the energy of clustering
e of ethanol molecules over the surface is
negative ( 2.5 kcal / mol ) favoring formation of clusters , while
the energy of clustering of ethyl acetate over the surface is close
to zero ( 0.3 kcal / mol ) .
e for the process of
clustering is of order of 1 kcal / mol per molecule ( e.g. , h e corrections for ethanol
clusters up to pentamer ranged between 0.91.4 kcal / mol per
molecule ) ; therefore , enthalpy of clustering
of ethyl acetate dimer from monomers on the surface will be positive ,
i.e. , disfavoring formation of surface clusters .
all energies ( in kcal / mol )
are normalized to one ethanol ( ethyl acetate ) molecule .
the clustering on the fluorographene surface complicates
direct comparisons of the measured adsorption enthalpies for the five
molecular probes ( table 1 ) to those obtained from the calculations ( table 5 ) .
in fact , direct comparisons are only really
justifiable for dichloromethane and ethyl acetate .
we therefore corrected
the adsorption enthalpies calculated for acetate , acetonitrile , and
ethanol to account for the effects of clustering , as discussed in
the preceding section .
we also corrected the calculated h values for adsorption to fluorographene ( table 5 ) using the correction terms
calculated for fluorographite surface adsorption ( table s2 ) to enable meaningful comparison of the experimental
and calculated quantities .
a comparison of the experimental and modified
computational results is presented in figure 7 .
experimental ( table 1 , including error bar ) and calculated adsorption
enthalpies ( h ) . calculated values corresponding
to molecular adsorption
( squares ) were corrected for the effect of clustering ( triangles ) .
the calculated enthalpies are based on energies obtained
with the optb86b - vdw density functional .
all of the dft methods systematically underestimated the
strength
of molecule / cluster binding to the fluorographite surface , i.e. , the
calculated h values were always higher than
the experimental values .
the best accuracy was achieved with the optb86-vdw
functional because its h values were closer
to the experimental results than those obtained with any other method .
for clarity , only results obtained with this functional are shown
in figure 7 .
the inclusion
of corrections for clustering always shifted the calculated adsorption
enthalpies toward the experimental values .
for dichloromethane and
ethyl acetate , dft methods that include dispersion corrections based
on nonlocal correlation functional ( i.e. , optb86b - vdw , vdw - df , and
vdw - df2 ) gave adsorption enthalpies that were closer to experiment
than those that use corrections based on atom - centered empirical functions
( dft - dx methods ) .
it has many possible
causes , ranging from the precise implementations of the empirically
corrected dft methods to the correct inclusion of many - body effects , and warrants further investigation .
the
langmuir adsorption model enabled enumeration of both the adsorption
enthalpies and entropies .
the entropies ranged from 19 cal / molk
for dichloromethane to 36 cal / molk for ethanol .
the overall
trends in the adsorption entropies mirrored those for the adsorption
enthalpies ( figure 1 ) .
it has previously been shown that the adsorption entropy of physisorbed
molecules is surface - independent , being governed by the temperature
and the gas phase entropy of the adsorbate .
this might explain the rather good agreement between the measured
adsorption energies and those calculated for the finite fluorographene
models ( table 1 and table 4 ) , although it is
important to bear the effects of the experimentally observed clustering .
the entropy loss upon adsorption corresponded to around 40% of the
total gas phase entropy on average ( table s3 in the supporting information ) , which is consistent with previously
published data .
a restriction of translational
and rotational degrees of freedom of the adsorbed molecule was responsible
for the entropy loss ( table s3 ) .
it should
be noted that the discussed mirroring of entropies might indicate
that stronger binding leads to larger entropy loss due to larger restriction
of the probe conformational freedom on the surface .
we measured adsorption enthalpies of acetone ,
acetonitrile , dichloromethane ,
ethanol , and ethyl acetate on fluorographite by inverse gas chromatography
at surface coverage levels ranging from 2 ( 0.2 for dichloromethane )
to 20% .
plots of the resulting isosteric adsorption enthalpies revealed
that acetone , acetonitrile , and ethanol cluster on the fluorographite / fluorographene
surface .
the calculated saturated adsorption enthalpies
on fluorographene ranged from 6.9 kcal / mol for dichloromethane
to 12.8 kcal / mol for ethanol and were 12 kcal / mol
lower than those previously determined for graphene .
computational
investigations provided deeper insights into the strength and nature
of adsorbate - fluorographene / fluorographite binding .
finite size models
amenable to study using reference theoretical methods were a bit too
small for reliable estimation of interaction energies but were useful
in evaluating the accuracy of the adsorption energies calculated with
various dft methods because they permitted benchmarking against ccsd(t )
and mp2.5 results . these benchmarking studies showed that dispersion
corrected dft functionals performed well and can be safely used for
relative comparisons of adsorption energies .
the finite size models
also provided information on enthalpy corrections , which were rather
modest , ranging from 1.3 to 1.5 kcal / mol . despite the good performance
of the dispersion - corrected functionals in the benchmarking study ,
nonlocal vdw dft functionals ( particularly optb86b - vdw ) achieved the
best agreement with experimental data when using a periodic model
of fluorographene .
computational investigations using these functionals
revealed that we did not detect binding to high - energy sites in the
igc experiments because binding to these structural features , which
is typically very energetically favorable in layered materials , was
either only slightly ( by 1020% for steps ) more favorable or
less favorable ( in the case of edges ) than binding to the surface .
the adsorption enthalpies were largely controlled by the interaction
energies , which were dominated by london dispersive forces .
the clustering
of ethanol , acetonitrile , and acetone on the fluorographene / fluorographite
surface was explained by a delicate interplay between intracluster
and cluster - surface bonding . finally , we estimated adsorption entropies
for the different adsorbates , which ranged from 19 cal / molk
for dichloromethane to 36 cal / molk for ethanol and corresponded
to a loss of 40% of the gas phase entropy upon adsorption .
these results indicate that calculations on finite size models are
adequate for estimating adsorption entropies on fluorographene surfaces .
all measurements were conducted using
an sms igc - sea 2000 instrument
( surface measurement systems ltd . , uk ) in a silanized column ( 3 mm
diameter and 30 cm long ) filled with a 23.9 mg sample of graphite
fluoride ( sigma aldrich ) . before each measurement ,
the sample
was washed at 80 c using he as the carrier gas at a flow rate
of 10 sccm .
the used graphite
fluoride crystals have a laminar morphology , and their surfaces are
dominated by exposed fluorographene planes with a small proportion
of edges and steps .
measurements were carried out with acetone ( merck ,
lichrosolv , for hplc , 99.8% ) , acetonitrile ( lach : ner , hplc supergradient ,
min .
99.9% ) , dichloromethane ( merck , for lc lichrosolv , 99.9% ) ,
ethanol ( merck , gradient grade for lc lichrosolv , 99.9% ) ,
and ethyl acetate ( lach : ner , hplc , min .
primary chromatograms
were recorded at temperatures from 303 to 363 k using he as the carrier
gas at the flow rate of 10 sccm .
the column temperature was controlled
by the instrument oven with declared stability of 0.1 c .
partial pressures of adsorbates were calculated from the primary chromatograms ,
i.e. , peak maxima , using instrument calibration and cirrus plus software
advanced version 1.2.1.2 ( surface measurement systems ltd . , uk ) .
the
partial pressures of individual adsorbates were measured at the given
targeted surface coverage i as
a function of temperature .
the measurements were repeated for various
target surface coverage i , which
ranged from 2% to 20% of monolayer .
the saturated ( 40 c ) adsorbate
vapors were injected into the column , and the injection time was set
up to reach the targeted surface coverage .
the required injection
time was calculated from the targeted surface coverage , known surface
area ( 236.9 m / g ) of the material , adsorbate vapor tension at 40 c , and adsorbate cross sectional
area using cirrus control software advanced version 1.3.3 ( surface
measurement systems ltd . , uk ) .
the low surface coverage
values considered in the experiments permitted application of the
langmuir adsorption model .
this assumption leads to the equation , which we used directly to fit the isosteric
enthalpy of adsorption hi hi and the entropy of adsorption si si ( figure s3 ) for
each considered target surface coverage i .
the partial pressure of the adsorbate , the standard pressure
of 760 torr , the universal gas constant , and the column temperature
are denoted as p , p , r , and t , respectively . the saturated
adsorption enthalpy h h was obtained as the mean value of n particular enthalpies
obtained by fitting .
the error in the saturated enthalpy , h , was determined as the maximum individual hi value .
the
adsorption energy ,
e , was calculated as the difference between
the energy of the most favorable configuration of the complex ( comprising
one molecule / cluster on fluorographene ) and the sum of the energies
of the optimized isolated species ( fluorographene and the molecule
in vacuum ) .
in contrast , the interaction energy , ei , was calculated on the basis of each separated fragment
in the geometry of the complex .
the enthalpy of adsorption , h , was calculated by adding the zero - point energy ( e0 ) and the thermal ( et ) and enthalpic ( eh ) corrections to the adsorption energy , i.e. , h = e + e0 + et + eh .
the corrections e0 , et , and eh were evaluated for the molecule on a finite
model of fluorographene , fully fluorinated tetracosahydrocoronene
( c24f36 ) , i.e. , h e + ( h e ) . for this purpose ,
geometry optimizations and frequency calculations
were performed , and partition functions and thermochemical data ( at
313.15 k and 101.325 kpa ) were obtained . we used the b97d functional and cc - pvtz basis sets for all elements and
the gaussian09 package for calculations
on c24f36 .
reference wave function - based
calculations of interaction energies ei were performed with a small finite model of fluorographene ,
perfluorohexamethylcyclohexane ( c12f24 ) .
accurate
and computationally demanding ccsd(t)/complete basis set limit ( cbs )
interaction energies were determined using the formulahere , the ccsd(t ) correction term was determined
as the difference between the ccsd(t ) and mp2 interaction energies
with the 6 - 31g**(0.25,0.15 ) basis set .
the basis set 6 - 31g**(0.25,0.15 )
is a modified version of the 6 - 31 g * * basis set in which the exponential
parameters of the polarization functions were altered from their original
values to 0.25 ( c , n , f , o atoms ) and 0.15 ( h atom ) .
the mp2/cbs interaction
energies were determined by summing the hartree fock and mp2
correlation energy components , ei = ei + ei , both of which were extrapolated
from the aug - cc - pvdz ( adz ) and aug - cc - pvtz ( atz ) basis sets .
alternative calculations
were performed using the mp2-f12 method
and the cc - pvdz - f12 basis set to evaluate interaction energies . in
these calculations , the core electrons were frozen , and interaction
energies were corrected for the basis set superposition error ( bsse ) .
the mp2.5/cbs interaction energies obtained
for both the previously
mentioned finite models were calculated using the following extrapolation
equation the mp2.5 correction term was computed as a difference between
the mp3 and mp2 interaction energies with the 6 - 31g**(0.25,0.15 ) basis
set . as an alternative to the cbs limit , explicitly correlated mp2-f12
was used without any extrapolation .
all
reference calculations were performed in turbomole 6.6 under the cuby framework with the exception of the mp2.5 correction terms , which
were calculated in molcas 8.0 sapt
decomposition allows the interaction energy to be partitioned
into physically meaningful components . for this purpose
, we used dft - sapt as implemented by hesselmann et al . in the molpro program package , and we collected sapt components into four terms corresponding
to electrostatics , exchange repulsion , induction , and dispersion : we used the lpbe0ac exchange - correlation
potential for monomer
calculations and the cc - pvtz basis set .
dft calculations on periodic fluorographene and its finite models
were performed using the projector - augmented wave ( paw ) method in
the vienna ab initio simulation package ( vasp , version 5.3.5 ) . empirically corrected density functionals ( pbe - d2 , pbe - d3 , pbe - ts , pbe - ts - scs ) and
nonlocal correlation functionals ( vdw - df , vdw - df2 , optb86b - vdw ) that approximately account for nonlocal dispersion interactions
were employed .
the fluorographene sheet was modeled using a 5
5 supercell ( c50f50molecule )
or 7 7 supercell ( c98f98cluster )
with a chair structure , which has been shown to be the most stable
fluorographene conformer .
input geometrical
parameters for fluorographene were obtained by pbe optimization from
our previous works and were as follows : lattice
constant of a = 2.61 , c c bond length
of 1.58 , c f bond length of 1.38 , and c c c
bond angle of 110.9 deg .
multilayer fluorographene structures were
modeled by fluorographene sheets with aa stacking ; an interlayer lattice constant of c = 6
was used as an input for optimization .
for instance , the bilayer step
of fluorographene consists of two sheets in a 5 10 supercell
with the second sheet reduced to a 5 5 supercell and terminated
by 5 + 5 fluorine atoms ( 150 carbon and 160 fluorine atoms in total ) .
as periodic boundary conditions were applied in all three dimensions ,
a periodicity of at least 20 in the out - of - plane direction
was imposed to minimize ( spurious ) interactions between adjacent layers .
the energy cutoff for the plane - wave ( pw ) expansion was set to 400
ev
, a convergence criterion of 10 ev was used
in the scf cycle , and -point calculations were performed .
the
positions of the atoms were relaxed using the conjugate gradient method
until the forces on each atom were below 1 mev / . for the final
geometries of the 5 5 supercells , we recalculated all total
energies with the 3 3 k - point mesh and an
energy cutoff of 500 ev ( see table s4 for
the convergence test )
. finally , the interaction energies for
the c24f36 complexes were also calculated by
dft using gaussian orbitals .
several
functionals ( b97d , b3lyp , and pbe ) and tzvpp basis sets were used in conjunction with the empirical
d3 dispersion correction ; the hybrid
meta m06 - 2x functional was used with
the cc - pvtz basis set . | understanding
strength and nature of noncovalent binding to surfaces
imposes significant challenge both for computations and experiments .
we explored the adsorption of five small nonpolar organic molecules
( acetone , acetonitrile , dichloromethane , ethanol , ethyl acetate ) to
fluorographene and fluorographite using inverse gas chromatography
and theoretical calculations , providing new insights into the strength
and nature of adsorption of small organic molecules on these surfaces .
the measured adsorption enthalpies on fluorographite range from 7
to 13 kcal / mol and are by 12 kcal / mol lower than those
measured on graphene / graphite , which indicates higher affinity of
organic adsorbates to fluorographene than to graphene .
the dispersion - corrected
functionals performed well , and the nonlocal vdw dft functionals ( particularly
optb86b - vdw ) achieved the best agreement with the experimental data .
computations show that the adsorption enthalpies are controlled by
the interaction energy , which is dominated by london dispersion forces
( 70% ) .
the calculations also show that bonding to structural
features , like edges and steps , as well as defects does not significantly
increase the adsorption enthalpies , which explains a low sensitivity
of measured adsorption enthalpies to coverage .
the adopted langmuir
model for fitting experimental data enabled determination of adsorption
entropies .
the adsorption on the fluorographene / fluorographite surface
resulted in an entropy loss equal to approximately 40% of the gas
phase entropy . |
camptothecin ( scheme 1 ) , 4-ethyl-4-hydroxy-(s)-1-h - pyrano [ 3,4:6,7 ] indolizino [ 1,26 ] quinolino-3,14 ( 4h,12h)-dione , the active compound of camptotheca acuminate , is a well - known antitumor drug for gastric cancer , breast cancer and lung cancer .
its primary cellular target is topoisomerase i , and the antitumor activity is attributed to the inhibition of topoisomerase i . as a topoisomerase i poison , camptothecin can bind both dna and topoisomerase i to form a stable ternary complex [ 6 , 7 ] , which prevents dna synthesis and induces the death of cells .
meanwhile , it has also exhibited some other biological activities , such as anti - hiv and against parasitic trypanosomes and leishmania .
there are two forms of camptothecin ( the carboxylate form and the lactone form ) , which exist with different conditions , however , only the lactone one plays the key role in forming the ternary complex . on the other hand , human serum albumin(hsa ) ,
the most abundant protein in the serum , can bind to some drug molecules at two binding sites known as site i ( subdomain iia ) and site ii ( subdomain iiia ) .
it is reported that in the presence of hsa , camptothecin may interact with the site i of hsa , leading to the conversion of camptothecin from active form to inactive form , which evidently reduces the antitumor activities of camptothecin .
thus , the study of the interaction between camptothecin and hsa is highly important for the clinical application of camptothecin .
it is also crucial for maintaining the activity of camptothecin to find an effective way of inhibiting this interaction . in this work ,
we have used electrochemical method to elucidate the interaction between camptothecin and hsa . by comparing with bovine serum albumin ( bsa ) ,
moreover , the inhibitory influence of sodium salicylate to this specific binding is also discussed .
in order to use electrochemical technique to study the interaction between camptothecin and hsa , we have first studied the electrochemistry of the molecule . up to now , no voltammetric study of this species has been reported , although the behavior of camptothecin at a hanging mercury drop electrode has been presented .
we have found that camptothecin is electroactive at a pg electrode in britton- robinson buffer , with the ph range of 2.0 to 7.0 . as shown in fig .
1 , with 4.010 m camptothecin in a ph 4.0 , 0.1 m britton - robinson buffer solution , a well - defined cathodic peak appears at 0.75 v ( vs. sce ) at the pg electrode . meanwhile , a slight anodic peak is also observed .
however , compared with the cathodic peak , the anodic peak is unstable and disappears after several cycles of scanning .
in contrast , no voltammetric peak can be obtained at the pg electrode in the absence of camptothecin .
so , the cathodic peak should be attributed to the reduction of camptothecin at the pg electrode .
the effect of scan rate on the voltammetric behavior of camptothecin has been examined ( fig .
2 ) . the cathodic peak current is found to increase linearly with the scan rate from 100 mv s to 700 mv s. the linear regression equation is : y = 0.01814 + 0.01377x , r = 0.999 , indicating that the reduction process on the electrode surface is mainly adsorption controlled [ 14 , 15 ] .
the ph value plays an important role in the electrochemical behaviors of camptothecin . although well - defined voltammograms can be obtained in the ph range from 2.0 to 7.0 , with the increase of ph value , the cathodic peak shifts negatively .
the cathodic peak potentials are found to be linearly proportional to the ph value , with a slope ( e/ph ) value of 71 mv ph , which suggests a process involving equivalent protons and electrons ( fig .
the cathodic peak current will also change with the ph value . as is shown in fig .
3b , the peak current is the highest at ph 5.0 , which is the best for detection purpose .
so , for the studies of the interaction between camptothecin and hsa , we have selected a ph 4.0 buffer solution .
since the electrochemical behavior of camptothecin on the electrode surface is adsorptioncontrolled , it is necessary to investigate the influence of accumulation time . as is shown in fig .
4 , the cathodic peak current increases significantly within the first 60 s , and then slowly and nearly unchanged later on .
thus , the first 60 seconds are chosen as the optimum time period of accumulation .
further studies reveal that the cathodic peak current increases with the continuous addition of camptothecin and a linear calibration plot ( y = 0.44833 + 0.19886x , r = 0.999 ) can be obtained in the concentration range of 110 m - 110 m ( fig .
5 ) , which suggests that the voltammetric response of camptothecin at a pg electrode can be used for the concentration measurements .
although there are several analytical techniques including uv - spectrometry , fluorescence , infrared spectroscopy , and hplc [ 1820 ] currently available for determining camptothecin , it is still necessary to develop more methods for improving the accuracies of camptothecin measurement .
the limit of detection ( lod ) of this electrochemical method is estimated to be 210 m , defined as three times the signal - to - noise ratio , which can be satisfactory compared with the previous report of 810 m .
the relative standard deviation ( rsd ) of five successive determinations at the concentration of 410 m is 5.6% .
we have then studied the interaction between camptothecin and hsa with electrochemical technique . as shown in fig .
6 , with the addition of hsa into a 0.1 m britton - robinson buffer containing 410 m camptothecin , the peak current of camptothecin decreases distinctly , and no appearance of new redox peaks and no shift of the peak potential is observed .
one is that hsa interacts with camptothecin to form a non - electrochemical complex , which blocks the electron transfer between camptothecin and electrode .
since the electrochemical behavior of camptothecin is an adsorptive process , the competitive adsorption of hsa may also reduce the adsorption of camptothecin and cause the decrease of the peak current of camptothecin .
we assume that it is the interaction between hsa and camptothecin and the formation of the nonelectrochemical complex that makes the decrease of peak current of camptothecin . in order to confirm the specific interaction between hsa and camptothecin and the formation of the non - electochemical complex , we have employed bsa as a contrast .
if no interaction exists and no complex forms between hsa and camptothecin , the decrease of the peak current of camptothecin caused by hsa and bsa should be almost the same .
therefore , the result has not only revealed the existence of the specific binding between camptothecin and hsa , but also suggested that the competitive adsorption of hsa is not the main reason of the decrease of camptothecin peak current .
however , we have not used this agent as the treatment for cancers , and we believe that the specific interaction between the molecule and hsa is a major barrier to be overcome .
effort should be made to inhibit the binding of camptothecin to hsa and increase the amount of active camptothecin .
it has been known that salicylate can specifically bind the site i of hsa with high affinity , so salicylate sodium has been used in this work as a competitive molecule to bind to hsa , which may inhibit the binding of camptothecin with hsa and increase the level of the active camptothecin . as shown in fig .
8 , compared with hsa alone , the decrease of the camptothecin peak current caused by the mixed solution of hsa and salicylate sodium is much less , which indicates that more free camptothecin molecules exist in the presence of salicylate sodium .
the reason is that the binding of salicylate to hsa may prevent the interaction between camptothecin and hsa . as a result
stock solutions were prepared by dissolving known amounts of camptothecin in 10 ml of dimethyl sulphoxide .
stock solutions were prepared by dissolving known amounts of salicylate sodium in 10 ml of methanol .
hsa ( ~99% , molecular mass 69 kda ) and bsa ( ~99% , molecular mass 66 kda ) , were purchased from sigma and used without further purification .
stock solutions were prepared by dissolving known amounts of hsa / bsa in 10 ml of double - distilled water .
double - distilled water , which was purified with a milli - q purification system ( branstead , boston , ma , u.s.a . ) to a specific resistance of > 18m cm was used in all experiments , and all solutions were stored in the refrigerator at 4 c .
the pyrolytic graphite(pg ) rod was purchased from shanghai carbon co. ( shanghai , p.r . china ) .
the substrate pg electrode was prepared by inserting a pg rod in a glass tube and fixing it with epoxy resin .
electrical contact was made by attaching a copper wire to the rod with the help of wood s alloy ( a fusible bismuth - based alloy ) . for pretreatment ,
its surface was then polished to mirror smoothness with alumina ( particle size of approx .
finally , the electrode was thoroughly washed by ultrasonicating in both double - distilled water and ethanol for approx .
cyclic voltammetry ( cv ) was performed with a parc 263a potentiostat / galvanostat ( eg&g ; princeton , nj , usa ) , using a three - electrode configuration at 25 0.5 c .
the reference electrode was a saturated calomel electrode ( sce ) and the counter electrode was a platinum electrode .
all test solutions were thoroughly deoxygenated by bubbling high - purity nitrogen through the solution for at least 10 min .
a stream of nitrogen was blown gently across the surface of the solution in order to maintain the solution anaerobic throughout all the experiments .
stock solutions were prepared by dissolving known amounts of camptothecin in 10 ml of dimethyl sulphoxide .
stock solutions were prepared by dissolving known amounts of salicylate sodium in 10 ml of methanol .
hsa ( ~99% , molecular mass 69 kda ) and bsa ( ~99% , molecular mass 66 kda ) , were purchased from sigma and used without further purification .
stock solutions were prepared by dissolving known amounts of hsa / bsa in 10 ml of double - distilled water .
double - distilled water , which was purified with a milli - q purification system ( branstead , boston , ma , u.s.a . ) to a specific resistance of > 18m cm was used in all experiments , and all solutions were stored in the refrigerator at 4 c .
the pyrolytic graphite(pg ) rod was purchased from shanghai carbon co. ( shanghai , p.r .
china ) . the substrate pg electrode was prepared by inserting a pg rod in a glass tube and fixing it with epoxy resin .
electrical contact was made by attaching a copper wire to the rod with the help of wood s alloy ( a fusible bismuth - based alloy ) . for pretreatment ,
its surface was then polished to mirror smoothness with alumina ( particle size of approx .
finally , the electrode was thoroughly washed by ultrasonicating in both double - distilled water and ethanol for approx .
cyclic voltammetry ( cv ) was performed with a parc 263a potentiostat / galvanostat ( eg&g ; princeton , nj , usa ) , using a three - electrode configuration at 25 0.5 c .
the reference electrode was a saturated calomel electrode ( sce ) and the counter electrode was a platinum electrode .
all test solutions were thoroughly deoxygenated by bubbling high - purity nitrogen through the solution for at least 10 min .
a stream of nitrogen was blown gently across the surface of the solution in order to maintain the solution anaerobic throughout all the experiments . | camptothecin , an anticancer component from camptotheca acuminate , may interact with human serum albumin ( hsa ) at the subdomain iia ( site i ) , and then convert to its inactive form(carboxylate form ) . in this paper , the detailed electrochemical behaviors of camptothecin at a pyrolytic graphite electrode is presented .
the interaction between camptothecin and hsa is also studied by electrochemical technique . by comparing with bovine serum albumin ( bsa ) , which is highly homologous to hsa
, we prove that camptothecin can specifically bind to hsa .
meanwhile , the inhibitory influence of sodium salicylate to this binding is also discussed . |
as our society has become an aging society , improving the quality of life has become one of
the major interests in it . impaired balance and gait abilities due to aging and diseases
therefore , it is clear that
balance problems can directly affect the quality of our lives .
the physical activities of
the elderly can be improved by diverse exercise programs and activities .
it is important to
perform stretching before exercises to prevent injuries and enhance exercise in a more
efficient way1 .
the common type of
stretching is static stretching , and the effect of stretching may vary with the type
applied , intensity , and time2 , 3 . while stretching has positive effects ( e.g. , increases rom ,
injury prevention , and improvement in the ability to perform exercises)3 , negative effects ( e.g. , temporary decreases in maximum
muscle power and stretch - induced impairment in reaction time and movement time ) can appear
immediately after stretching4,5,6 .
in reality , some
elderly individuals complain of temporary difficulties in balance control immediately after
pss .
however , previous studies have been limited to the acute effects of stretching in terms
of the histological and neurological changes during or after stretching7,8,9,10 .
furthermore , only a few
studies have examined the temporary difficulties in balance and gait of elderly populations
after stretching .
therefore , the purpose of this study was to examine the acute effects of
stretching on balance and gait in the elderly .
twenty - five community - dwelling elderly subjects voluntarily participated in this study
under the following criteria : at least 65 years of age , no experience of falls in a year ,
able to walk at least 10 m independently without a walking aid or another person s help , and
a mini mental state examination - korea ( mmse - k ) score exceeding 24 points .
those who had any
particular disease that could affect their performance such as vision or hearing damage , or
any problems in their nervous systems , vestibular organs , or understanding the contents of
the experiment were excluded .
all included patients understood the purpose of this study and
provided written informed consent prior to participation in the study in accordance with the
ethical standards of the declaration of helsinki ( table
1table 1 .
general characteristics of subjectsgender ( m / f)1/24age ( years)79.1 6.2height ( cm)150.1 6.6weight ( kg)54.1 7.5mmse - k ( point)25.6 1.5*p < 0.05 ( mean sd ) .
mmse - k : mini mental state examination - korea each subject performed pss for 5 minutes on a wedge board with an attached nonslip mat on
its contact surface .
subjects were instructed to maintain an upright posture while keeping
their arms to their sides and looking straight ahead .
the angle of inclination of the wedge
board was adjusted to an angle ( 1525 ) at which the subject did not feel uncomfortable . to
examine the changes in balance and gait following the application of 5 min of pss , sway
lengths during quiet standing for 1 min
were measured and functional reach tests ( frts ) ,
timed up and go tests ( tugs ) , and timed 10-meter walk tests ( 10mwts ) were implemented . to
examine the subjects static balance ability ,
each of the subjects was instructed to stand
on a biorescue ( rm ingenierie , rodez , france ) for 1 min with their feet shoulder width apart
and eyes closed while the sway length of the center of mass was measured . in the frts , the
subject was asked to stand with their bare feet shoulder width and to reach forward with
both arms as far as possible without taking a step or touching the wall .
the distance
between the start and end point was measured . in the tugs , the time required for the
subjects to complete the following task was measured : rising from a chair , walking 3 m ,
turning around , walking back to the chair , and then sitting down on the same chair . in the
10mwts ,
the subject was asked to walk 10 m without any aids , and the time required to walk
the 6 m in the middle was measured ; the first and last 2-m sections were excluded to account
for the accelerating and decelerating phases .
the frts , tugs , and 10mwts were repeated three
times by each subject , and the best records were used .
after stretching , the sway distance of the center of mass during 1 min of quiet standing
without visual information increased significantly ( by 6.55 5.03 cm ; p < 0.05 ) .
however , no statistically significant difference was shown in the frts , tugs , or 10mwts
measured 1 min later ( p > 0.05 ; table
2table 2 .
comparison of balance and gait after 5 min of plantar flexor static
stretchingvariablepre ( mean sd)post ( mean sd)sway length ( cm)38.4 15.144.9 17.1*frt ( cm)20.3 8.518.1 7.3tug ( sec)10.3 1.810.0 1.910mwt ( sec)7.6 2.17.2 1.6 * p < 0.05 ( mean sd ) .
sway length : sway length for 1 minute ; frt , functional
reach test ; tug , timed up and go test ; 10mwt , timed 10-meter walk test ) . *
p < 0.05 ( mean sd ) . sway length : sway length for 1 minute ; frt , functional
reach test ; tug , timed up and go test ; 10mwt , timed 10-meter walk test
pss is frequently used for warming up or cooling down in exercise programs to reduce ankle
stiffness , improve joint mobility , or increase physical activity1 .
this study was conducted to examine the acute effects of
5 min of pss on balance and gait in the elderly after stretching .
the results showed that
despite the temporary increase in postural sway distance immediately after stretching , the
subjects recovered their dynamic balance and gait abilities after a short period of
rest .
the duration of stretching can also affect balance . although stretching for a short time
resulted in improvement of balance by promoting muscle activity11 , stretching for a long time adversely affected
balance6 , 12 .
( 2009 ) stated that whereas 15 seconds of stretching
improved balance , 45 seconds of stretching did not affect balance11 .
( 2006)12 and yuk ( 2012)6 , in which longer pss was used , reported that postural sway
lengths increased after 3 minutes and 15 minutes of static stretching . in this study ,
the
sway lengths during quiet standing for 1 min immediately after the application of 5 minutes
of stretching increased compared with before stretching .
static stretching may alter the mechanical and neurologic characteristics of the calf
muscle13 , 14 .
nakamura et al . reported that the passive torque of the
gastrocnemius and the displacement of the myotendinous junction significantly changed at the
2- , 3- , and 4-min points with 5 min of pss15 .
behm et al . reported that reaction / movement time for regaining
balance increased after 45 seconds of stretching4 .
therefore , the temporary increase in the sway length immediately
after stretching shown in this study is attributed to the mechanical and neurologic changes
caused by stretching . however , in the frts , tugs , and 10mwts implemented to examine the
subjects dynamic balance and gait abilities , the reach distance and gait time did not show
any significant difference compared with before stretching .
similarly , stretching studies conducted with stroke patients did not
show changes in walking speed after pss16 , 17 .
limitations of the present study include not only the small sample size but also the fact
that stretching exercises under diverse conditions were not compared with each other .
although the elderly subjects experienced temporary difficulties in maintaining balance
after 5 min of pss , their dynamic balance and gait were not affected when a recovery time of
approximately 1 min had passed .
the authors of this study recommend that elderly individuals
take a brief rest after pss before walking or activities in exercise programs to prevent
falls and perform exercises safely . | [ purpose ] the purpose of this study was to examine the acute effects of five minutes of
plantar flexor static stretching ( pss ) on the balance and gait of the elderly .
[ subjects
and methods ] twenty - five subjects aged 65 years and above performed 5 min of pss in the
form of wedge board standing .
the sway length of each subject s center of mass was
measured to examine the subject s static balance .
it was measured by one minute of quiet
standing with the eyes closed .
functional reach tests ( frts ) , timed up and go tests
( tugs ) , and 10-meter walk tests ( 10mwts ) were performed to examine dynamic balance and
gait before and after pss . [ results ]
the outcome showed significant increases in sway
distances ( 6.55 5.03 cm ) after stretching .
however , in the frts , tugs , and 10mwts , the
reach distance and time did not show any significant changes .
[ conclusion ] these results
suggest that the elderly subjects temporarily experienced difficulties in maintaining
balance immediately after the pss but that their dynamic balance and gait were not
adversely affected after a short period of time .
therefore , to prevent falls and perform
exercises in a safe way , it is recommended to allow patients to rest after performing
pss . |
most of the cells in multicellular organisms are surrounded by a complex mixture of nonliving materials that make up the extracellular matrix ( ecm ) .
the ecm of vertebrates is composed of complex mixtures of proteins ( collagens , laminins , fibronectin , etc . ) and proteoglycans ( chondroitin sulfate , keratan sulfate , etc . )
ecm plays a significant role in regulating numerous cellular functions , including cell shape , adhesion , migration , proliferation , polarity , differentiation , and apoptosis . in pathological conditions such as cancer ,
increased synthesis of certain ecm components and/or increased breakdown with consequent generation of ecm cleavage products can contribute to cancer growth and progression .
integrins are transmembrane glycoproteins that are composed of a set of noncovalently associated and subunits
. there are at least 18 and 8 subunits capable of forming more than 24 heterodimers that account for the structural and functional diversity of the integrin family [ 46 ] .
integrins consist of a large extracellular domain , a single transmembrane domain , and a cytoplasmic tail .
the extracellular portion of integrins binds to ecm proteins , and the intracellular portion binds to cellular cytoskeletal elements such as actin filaments .
the connection also constitutes a signaling platform through which integrins can relay information for major processes such as transcriptional control , cell death , proliferation , and cell migration [ 8 , 9 ] .
there is a growing body of evidence suggesting that alterations in the adhesion properties of neoplastic cells endow them with an invasive and migratory phenotype .
indeed , changes in the expression and/or function of integrins have been implicated in all steps of tumor progression , including detachment of tumor cells from the primary site , invasion of ecm , intravasation into the blood stream , dissemination through the circulation , extravasation into distant target organs , and formation of the secondary lesions [ 5 , 1013 ] .
although at least 24 integrin heterodimers are known , 51 , 64 , v3 , and v6 integrins have been extensively studied in cancer and their expression is correlated with cancer progression in various tumor types [ 1418 ] .
upregulation of these integrins renders cancer cells more motile , invasive , and resistant to anticancer drugs [ 5 , 18 ] . unlike these integrins , expression levels of some integrins , such as 21 and 11 , decrease in tumor cells , which potentially increase tumor cell dissemination [ 1821 ] .
in addition to changes in expression , changes in the function of these integrins also play a critical role in cancer progression .
the way in which integrins are trafficked by the endosomal pathway is now recognized to influence their function [ 6 , 22 ] .
certain integrin heterodimers are continually internalized from the plasma membrane into endosomal compartments and subsequently recycled back to the cell surface , which indicates that the endocytic and recycling pathways have the potential to exert minute - to - minute control over integrin function .
abundant evidence suggests that integrin trafficking regulates cell adhesion to ecm , establishes and maintains cell polarity , redefines signaling pathways , and controls migration [ 6 , 23 ] .
therefore , transcriptional changes , mutational alterations , and deregulated cellular signaling changing endocytosis and recycling of integrins confer invasive and metastatic properties to tumor cells .
integrin trafficking is regulated by members of the ras - associated binding ( rab ) family of small gtpases , which function as molecular switches regulating vesicular transport in eukaryotic cells [ 24 , 25 ] ( figure 1 ) . through their indirect interactions with coat components , motors , and other proteins ,
the rab gtpases serve as multifaceted organizers of almost all membrane trafficking processes including integrin trafficking [ 25 , 26 ] .
approximately 70 types of rab gtpases have now been identified in humans . among these ,
in addition , rab11 mediates slow integrin recycling through recycling endosomes , whereas rab4 mediates fast integrin recycling directly from early endosomes ( figure 1 ) . the pathophysiological roles of rab gtpases in human malignancies have been less studied compared to members of the ras and rho gtpase families . however ,
more attention has been paid to the roles of rab gtpases in cancer in recent years , and several members of the rab family such as rab11 and rab25 have been shown to be aberrantly expressed in various cancer types [ 25 , 28 , 29 ] . because of the important roles of rab gtpases in integrin trafficking , deregulation of rab gtpases is closely related to cancer development and progression [ 24 , 25 , 29 ] .
there are several major endocytosis mechanisms , including clathrin - mediated endocytosis , caveolae - mediated endocytosis , and clathrin- and caveolin - independent endocytosis [ 3033 ] .
clathrin - mediated endocytosis is mediated by small vesicles that have a morphologically characteristic crystalline coat made up of a complex of proteins associated with the cytosolic protein clathrin .
clathrin - coated vesicles ( ccvs ) are found in virtually all cells and form domains of the plasma membrane termed clathrin - coated pits .
clathrin - coated pits can concentrate large extracellular molecules and receptors responsible for the receptor - mediated endocytosis of ligands , for example , low - density lipoprotein , transferrin , growth factors , and antibodies [ 30 , 33 ] .
in contrast , caveolae - mediated endocytosis is mediated by small flask - shape pits , caveolae , in the membrane .
caveolae are the most common reported non - clathrin - coated plasma membrane buds which exist on the surface of many , but not all cell types .
they consist of the cholesterol - binding protein caveolin ( vip21 ) with a bilayer enriched in cholesterol and glycolipids .
clathrin- and caveolin - independent endocytosis includes macropinocytosis and circular dorsal ruffles [ 9 , 30 , 33 ] .
clathrin - dependent endocytosis and caveolin - dependent endocytosis require dynamin and exhibit small vesicles .
like macropinocytosis , circular dorsal ruffles show highly ruffled structures , but this endocytosis is dependent on dynamin .
integrins are known to be endocytosed by clathrin - mediated endocytosis , caveolae - mediated endocytosis , and clathrin- and caveolin - independent endocytosis ( table 1 ) .
it is probable that a given type of integrin heterodimer follows more than one route to internalization depending on regions within a cell , cell conditions , and cell type [ 6 , 34 ] .
for instance , a subpopulation of integrin 51 is internalized into clathrin - coated structures near focal complexes at the cell front , whereas the bulk of integrin 51 follows a nonclathrin pathway from other parts of the cell surface . deregulation of integrin endocytosis is closely related to cancer development and progression [ 9 , 30 ] .
for example , chromosomal deletion and loss of rab21 , a regulator of endocytic trafficking of integrins , has been found in cancer that leads to the accumulation of multinucleate cells in cancer .
the correlation with multinucleate cells is thought to reflect the requirement of rab21-mediated integrin endocytosis for correct cytokinesis .
once internalized , integrins are predominantly recycled back to the plasma membrane , although a fraction of integrin 51 has been shown to traffic to lysosomes for degradation during migration [ 6 , 37 ] .
following endocytosis , integrins travel to early endosomes from which they can either be returned directly to the plasma membrane in a rab4-dependent manner ( the short loop ) or further trafficked to the perinuclear recycling compartment ( pnrc ) before recycling through rab11-dependent mechanisms ( the long loop ) ( table 1 ) .
however , the function of the rab11 family member rab25 ( or rab11c ) is controversial .
rab25 shows highly restricted expression under normal physiological conditions but is upregulated in invasive cancer cell lines and metastatic tumor cells , and its elevated expression is further linked to the aggressiveness of breast and ovarian cancers .
rab25 is a determinant of tumor progression , and the aggressiveness of epithelial cancers and is strongly associated with decreased survival .
in contrast , recent studies showed that rab25 expression is decreased in human colon cancers and triple - negative ( negative for estrogen receptor ( er ) , progesterone receptor ( pr ) , and her2/neu ) breast cancers , and rab25 functions as a tumor suppressor in these cancers [ 4143 ] .
the key roles of rab gtpases in tumorigenesis and tumor progression are closely related to integrin recycling .
for example , rab25 contributes to tumor progression by directing the localization of integrin - recycling vesicles and thereby enhancing the ability of tumor cells to invade the extracellular matrix .
integrin 51 is a receptor for fibronectin and contributes to cancer cell invasion , metastasis , resistance to anticancer drugs , and decreased survival in patients [ 17 , 45 ] .
integrin 51 is internalized by clathrin - dependent , caveolin - dependent , and clathrin- and caveolin - independent mechanisms . for clathrin - dependent endocytosis
, 51 integrin binds to numb , an endocytic protein that influences clathrin - coated pit assembly .
integrin 51 can also internalize with tetraspanin protein , which interacts with ap-2 , an adaptor for clathrin - mediated endocytosis .
clathrin - dependent internalization of 51 integrin with numb or tetraspanin has a profound effect on cell migration .
in addition , 51 integrin can undergo rab21- and clathrin - independent endocytosis that is required for successful cytokinesis .
in some cell types , integrin 51 localizes to caveolae for caveolin - mediated endocytosis [ 6 , 48 ] .
internalized integrin 51 is transported through rab4-positive early endosomes and arrives at the rab11-positive perinuclear recycling compartment .
akt - mediated glycogen synthase kinase ( gsk)-3 phosphorylation is known to deliver 51 from the rab11 compartment to the plasma membrane .
one of the rab11 effectors , rab11 fip1/rcp , associates with integrin 51 and regulates recycling of this integrin .
rab - coupling protein ( rcp ) provides a scaffold that promotes the physical association and coordinated trafficking of 51 and epidermal growth factor receptor 1 ( egfr1 ) .
recently , it was shown that mutant p53 can promote invasion , loss of directionality of migration , and metastatic behavior by regulating the interaction of 51 integrin to rab - coupling protein , which enhances 51 trafficking and signaling . since rab25 ( rab11c , rab11 family member ) binds to rab11 fip1/rcp , it is hypothesized that interaction between them may control integrin 51 trafficking .
recently , it has been shown that rab25 associates with 51 integrin to enhance migration and invasion of cells in three - dimensional microenvironments and directs 51 integrin recycling to dynamic ruffling protrusions at the leading edge of migrating cells , which promotes invasive migration [ 29 , 44 ] .
in addition to rab11 and rab25 , rab21 is required for carcinoma - associated fibroblasts to promote invasion by cancer cells and facilitates integrin 51 accumulation for force - mediated matrix remodeling at the plasma membrane .
it has also been shown that rab21-dependent recycling of integrin 51 is critical for proper activation of rhoa during cytokinesis .
although most endocytosed integrin 51 is known to recycle back to plasma membrane , a subset of this integrin moves to lysosomes for degradation .
this process is very slow , but it is important for 51-dependent cell motility .
overexpression of 64 integrin was seen in several types of cancers including breast cancer and correlated with tumor invasion , increased tumor size and grade , and a poor prognosis [ 5457 ] .
we showed that integrin 64 integrin recycles back to the plasma membrane via the rab11-positive perinuclear recycling compartment .
hypoxia stimulated carcinoma invasion by promoting rab11 trafficking of integrin 64 , which is dependent on hypoxia - inhibited glycogen synthase kinase ( gsk)-3 signaling .
integrin v3 is expressed in a variety of tumors such as melanoma , prostate cancer , and breast cancer .
integrin v3 is overexpressed in activated endothelial cells during tumor - induced angiogenesis , whereas it is absent on quiescent endothelial cells and normal tissues .
it is known that integrin v3 promotes cancer cell survival , migration , invasion , and metastasis [ 4 , 60 , 61 ] .
integrin v3 is endocytosed via clathrin - dependent , caveolin - dependent , or clathrin- and caveolin - independent mechanisms .
numb is an alternative clathrin adaptor and can interact with 3 integrin , which controls v3 integrin endocytosis and cell migration . in some cell types , integrin v3 is internalized by caveolin - dependent mechanisms . in this case
, mt1-mmp is clustered together with caveolin-1 and v3 integrin at motility - associated structures , resulting in increased proteolytic activity , which is important for cell migration and invasion .
a recent study shows that upon growth factors stimulation , integrin 3 abruptly redistributes to circular dorsal ruffles where it is internalized through macropinocytosis , which plays an important role in growth factor - induced cell migration .
internalized integrin v3 recycles back to the plasma membrane via rab4-dependent mechanisms or the rab11-positive perinuclear recycling compartment .
following treatment with pdgf , integrin v3 was rapidly recycled directly back to the plasma membrane from early endosomes via a rab4-dependent mechanism without the involvement of rab11 .
the pkc - related kinase pkd1 influences cell migration by this fast recycling of integrin v3 .
it is known that pkd1 directly interacts with 3 integrin and this interaction promotes fast recycling of v3 integrin from recycling endosomes to the plasma membrane upon growth factor stimulation .
activation of vegfr1 also enhances a rab4a - dependent pathway that transports v3-integrin from early endosomes to the plasma membrane .
recent studies link pkd and vegf signaling in which vegf - a induces recycling of integrin v3 in a pkd1-dependent manner . because of the involvement of rab4 in the recycling of v3 integrin , inhibition of rab4 effector protein ( rab ip4 ) blocks integrin recycling , leading to inhibition of cell adhesion and cell spreading .
another study suggests that supervillin , an actin and myosin binding protein , regulates rapid 3 integrin recycling through collaboration with rab4 and rab5 .
the short - loop recycling of integrin v3 via rab4 does not directly contribute to migration by moving v3 to the cell front , but by antagonizing 51 recycling , which , in turn , influences the cell 's decision to migrate with persistence or to move randomly .
integrin v3 is also recycled to the plasma membrane in a rab11-dependent manner ( long loop recycling ) in which akt promotes this recycling by phosphorylating and inactivating gsk-3 .
integrin v6 is usually expressed at low or undetectable levels in most healthy adult epithelia but is upregulated in many cancers such as colon cancer .
the expression of integrin v6 inhibits apoptosis and promotes tumor cell invasion and metastasis , which is often associated with a more aggressive disease outcome and a poor prognosis [ 18 , 70 ] .
integrin v6 is internalized by a clathrin - dependent mechanism by interaction with hs1-associated protein x1 ( hax1 ) .
hax1 is found in clathrin - coated vesicles , and the cytodomain of 6 integrin interacts with hax1 and is endocytosed , which increases carcinoma migration and invasion .
integrins are key regulators of cell adhesion , migration , and proliferation . therefore , deregulation of their expression and altered functions play critical roles in cancer progression by enhancing cancer cell invasion , metastasis , and survival .
there are now clear indications that integrin trafficking is important to modulate integrin distribution and function . however , more studies are needed to define the molecular mechanisms of integrin trafficking in tumor progression .
it is known that unligated integrins can positively or negatively regulate tumor cell survival and metastasis , and , therefore , signaling arising from endosomal compartments may be important for tumor cell survival .
for instance , it has been shown that rapid recycling of v3 via the rab4 pathway antagonizes the rab11-mediated 51 recycling , which influences the cell 's decision to migrate with persistence or to move randomly . because of the critical roles of integrins in cancer progression , integrins are potential targets for the development of targeted anticancer therapeutics . understanding the mechanism of integrin trafficking will provide valuable information for the development of new anticancer drugs and clues to increase the efficacy of current anticancer therapeutics . | integrins are major mediators of cancer cell adhesion to extracellular matrix . through this interaction , integrins play critical roles in cell migration , invasion , metastasis , and resistance to apoptosis during tumor progression .
recent studies highlight the importance of integrin trafficking , endocytosis and recycling , for the functions of integrins in cancer cells .
understanding the molecular mechanisms of integrin trafficking is pivotal for understanding tumor progression and for the development of anticancer drugs . |
a 39-year - old woman with renal failure secondary to a congenital kidney malformation had been on renal haemodialysis treatment 3 days every week for the previous 17 years .
she presented to the emergency eye clinic with a sudden onset bilateral reduction of vision occurring soon after waking in the morning .
one day previously she had noticed visual obscurations in her left eye also after waking in the morning , which she described as temporary episodes of blurred vision lasting 2 min . she had attended a session for haemodialysis the day prior to when these visual symptoms started .
were found to be 6/5 in the right eye and 6/9.5 in her left eye .
fundoscopy revealed bilateral swollen discs , more so in the left eye than the right ( figure 1 ) .
visual field testing showed an inferior altitudinal defect in both eyes ( figure 2 ) .
an mri scan of the brain was performed to rule out any space - occupying lesion or visual pathway pathology and was found to be normal .
1.fundus photographs right and left eye showing bilateral optic disc swelling .
fig .
2.humphrey's visual fields of the right and left eyes respectively showing bilateral inferior altitudinal loss .
humphrey 's visual fields of the right and left eyes respectively showing bilateral inferior altitudinal loss .
she had also recently been diagnosed with episodes of hypotension associated with dizziness in the mornings .
two weeks prior , she was found to be anaemic with a haemoglobin of 7.5 mmol / l and subsequently received a blood transfusion of 1 unit .
the patient was managed conservatively and monitored for the first few weeks and her anaemia improved to 9.5 mmol / l . one month following her initial presentation she was admitted to hospital with a post - operative foot infection and was treated with intravenous clindamycin . following this
, her vision appeared to progressively decline and was measured at hand movements in her right eye and counting fingers in the left . on this occasion ,
her usual blood pressure had been measured at 110120/80 and on this occasion had been found to be lower than her norm at 90/60 mmhg .
approximately 6 weeks later , her visual acuity improved in both eyes to 6/9 in both eyes ; however , her visual field defect remained unchanged .
the second case is a 49-year - old male with chronic renal failure for the previous 11 years for which he was receiving thrice weekly haemodialysis .
he had a longstanding history of persistent hypotension which fluctuated 100/70 mmhg , peripheral vascular disease , polyneuropathy , a previous episode of ischaemic bowel disease and had on one occasion suffered a cardiac arrest during a period of dialysis .
the patient 's visual symptoms started 4 days before he was seen in the emergency eye clinic .
he describes these symptoms as seeing blank with a few spots of clear vision which lasted 1 h then progressed to complete visual loss .
two weeks prior to this he had fractured his right femur for which he was managed conservatively .
he had also been found to have extremely low blood pressure by his gp in the few days preceding his loss if vision , measuring as low as 70/50 mmhg . in the eye
he denied any headache , temple tenderness , jaw claudication , weight loss or proximal myalgia .
his c - reactive protein was slightly elevated at 30 mg / l ; however , this could be explained by his recent fracture and chronic renal failure . despite the pallid disc swelling
, a diagnosis of temporal arteritis was thought to be unlikely given his age and the absence of symptoms to support it .
in addition there was no evidence of any intraocular inflammation or co - existent retinal pathology .
crowded appearance which would have been consistent with discs at risk of developing ischaemic optic neuropathy .
this coupled with their swollen appearance and history of hypotension supported the diagnosis of anterior ischaemic optic neuropathy ( aion ) was made , and he was given pulsed iv 1 g methylprednisolone per day for 3 days followed by oral prednisolone 1 mg / kg per day in an attempt to hasten any opportunity for recovery of the disc swelling .
3.fundus photographs of right and left eyes showing bilateral optic disc swelling as well as pallor ( more marked in the right eye than the left ) .
fundus photographs of right and left eyes showing bilateral optic disc swelling as well as pallor ( more marked in the right eye than the left ) .
his vision improved to 6/9.5 in the left eye ; however perception of light remained only in the right eye .
the patient was left with an inferior altitudinal and superonasal visual field defect on confrontational analysis in the left eye .
aion is a commonly occurring acute optic neuropathy in the elderly population , caused by infarction of the short posterior ciliary artery which supplies the optic nerve head with resultant ischaemia , oedema and a compartment syndrome leading to further vascular compromise .
it may be subdivided broadly into two types : arteritic or non - arteritic according to the underlying pathology . whilst arteritic aion is associated with giant cell arteritis , the mechanisms underlying the non - arteritic form are in many ways less well understood .
vasculopathic risk factors have been identified including raised blood pressure , cholesterol , poorly controlled diabetes and smoking .
an anatomically crowded or small optic disc is believed to be at risk or prone to such ischaemic events .
hayreh investigated the correlation between nocturnal dips in arterial blood pressure and predisposition to naaion , postulating that hypotension may be the
this is further supported by the observation that patients with visual loss due to naaion frequently present with symptoms on waking .
the combination of such factors is thought to lead to reduced blood flow in the short posterior ciliary arteries and thus reduced blood supply to the optic nerve head and consequent ischaemia .
aion occurring as a result of haemodialysis - associated hypotension was first reported by groggel in 1986 .
since then , a further 17 other episodes have been reported , mostly in the form of isolated case reports ( table 1 ) [ 517 ] .
table 1.a chronological summary of cases reported of naaion as a result of dialysis - induced hypotensionfirst authorjournalyearnunilateral / bilateralother featuresservillaam journal of kidney diseases19861bilateralfirst reportmichaelsonbr j ophthalmol19891bilateralpatient also had optic disc drusenhaidereye19931unilateralconnollyam j ophthalmol19941unilateralreversal of hypotension resulted in partial visual recoverysabeelnephrol dial transp19981bilateraloccurred during dialysisjacksonam j ophthalmol19991bilateralambulatory blood pressure recorded as low as 91/41 mmhgbasrisaudi journal kid disease20021bilateralno improvement with pulsed intravenous methylprednisolonecuxartnefrologia20051bilateraltayneuroophthalmology200932/3 bilateraltwo given steroids and one improved visionnietoindian j ophthalmol20102bilateral ( one within weeks and one simultaneous)no improvement in vision with oral steroidspratsurv ophthal20111unilateralbartlettbmj case reports20111bilateral within weeksbuthainaoman j ophthal20133bilateral simultaneous a chronological summary of cases reported of naaion as a result of dialysis - induced hypotension although there is yet much to be understood about the underlying mechanisms of naaion and the exact role of blood pressure , the reported cases do share some common features .
firstly , all cases were associated with extremely low blood pressure during the time period of visual loss . in one case ,
studied ambulatory blood pressure in a patient undergoing peritoneal dialysis who suffered bilateral naaion and recorded diastolic readings as low as 41 mmhg .
the paper made the point that although blood pressure readings taken in a clinic setting had been normal , 24 h ambulatory readings showed significant dipping predisposing the patient to risk of naaion .
both of our patients had persistently low blood pressure recordings , which were as low as 70/50 mmhg in case 2 .
one of our patients was also found to be significantly anaemic , a finding also commonly seen in renal failure patients and may be an additional risk factor for naaion [ 6 , 10 , 12 ] .
another common finding in these cases is the bilateral occurrence of the optic nerve insult .
data from the ion decompression trial show that second eye involvement in naaion was seen in only 14.7% of patients over a 5-year follow - up period . out of 20 cases reported ( including ours ) 17 suffered bilateral loss of vision , a highly unusual finding in other forms of naaion in which the visual loss tends to be unilateral . in most cases of these hypotension - induced episodes
generally , naion is not associated with pallid disc swelling but with a hyperaemic disc swelling .
pallid swelling , as in case 2 , is a described but not often remembered feature of dialysis - related naion . in our second patient , we used steroids with a significant improvement .
the rationale for the use of steroids is that they result in faster resolution of disc oedema , reduced compression of optic nerve head capillaries and thus improved perfusion and some recovery of surviving axons .
the benefits of this are disputed and there is no definite evidence that final visual outcome is improved .
there is also no proven role of surgical decompression of the optic nerve as shown by the cochrane database systematic review . in patients undergoing haemodialysis
, the question remains as to whether alternative therapies to raise blood pressure can improve visual outcomes .
connolly reported visual recovery after aggressive attempts to raise blood pressure in three hypotensives with aion , one of which was receiving dialysis . in our experience ,
the visual acuity in case 1 did gradually improve , albeit with some residual visual field defect .
they received blood pressure stabilization therapy with an alpha 1 adrenergic pressor agent ; however , it is difficult to establish if this had a direct causative effect .
finally , as the search for alternative management strategies turns to the option of neuroprotection , it has been shown that intramuscular injections of memantine ( nmda receptor antagonist ) in the rabbit prevented ganglion cell loss in experimentally induced ischaemic optic neuropathy .
the role of neuroprotection however in clinical practice with respect to ischaemic optic neuropathy is yet to be defined .
hypotension is a frequent observation and may provide the final insult required to diminish flow to the optic nerve head resulting in often bilateral simultaneous visual loss .
although there are as yet no universally acknowledged treatment modalities for this condition , physicians must firstly be aware that severe visual loss may be a complication of hypotension in haemodialysis patients .
recognition of early signs in the form of transient visual symptoms , especially on waking or during haemodialysis sessions is of importance and a prompt referral to an ophthalmologist may be advisable .
dipping is important and 24 h ambulatory blood pressure monitoring may be required to identify patients with this tendency .
anaemia is an additional risk factor in ischaemic optic neuropathy and must be monitored and controlled .
| hypotension is a commonly encountered complication in haemodialysis patients and is a significant cause of morbidity and mortality . bilateral visual loss in dialysis induced hypotension remains poorly recognized as a complication by both renal physicians and ophthalmologists .
we report 2 cases of patients on renal dialysis who suffered severe longstanding hypotension with bilateral non - arteritic anterior ischaemic optic neuropathy .
both patients experienced bilateral loss of vision over a short time period .
we feel that physicians must be aware of patients complaining of painless visual loss in this high risk group , as control of blood pressure may be the most important factor in prevention of this visually devastating condition . |
periodontitis is an inflammatory disease that causes pathological alterations in the tooth supporting tissues , leading to loss of periodontal structures and tooth loss gradually in later stages .
thus , periodontal disease points to the need form or effective and efficient management of this condition , in an attempt to restrict its impact on general health and patient quality - of - life . because the major cause for periodontal disease is dental plaque , much of the research should be directed toward a more effective and economic means of plaque control that can prevent further disease progression .
thus , more effective methods of management of shallow periodontal pockets are essential for the prevention of disease progression to the later stages . from the past four decades
, sub - gingival irrigation has been used as a possible and effective adjunct for treatment of periodontal diseases .
sub - gingival delivery of antimicrobial agents was shown to be potent both as in office procedures as well as home oral hygiene regime .
various anti bacterial agents such as chlorhexidine ( chx ) , metronidazole , tetracyclines , and povidone - iodine and herbal products such as propolis and dentol , have been tried in the recent past and were proven to be effective as sub - gingival irrigants in the management of shallow periodontal pockets .
however , research still progresses toward identification of drugs , which are more efficient than those currently used .
curcumin ( cu ) is a diferuloyl methane present in extracts of the plant ( turmeric or rhizome ) .
curcuminoids are responsible for the yellow color of turmeric . they are derived from turmeric by ethanol extraction .
cu longa contains three major curcuminoids ( approximately 77% cu , 17%demethoxycurcumin , and 3% bisdemethoxycurcumin ) .
in 1999 reported that cu down - regulates the expression of cox-2 protein , most likely through the down - regulation of nuclear factor- ( nf- ) activation , which is needed for cox-2 expression .
while the efficacy of oral irrigants on the clinical and microbiological parameters remain inconclusive this study aims at evaluating the efficacy of 1% cu solution and compare it with conventional irrigant i.e. , 0.2% chx , and a positive control ( saline ) as an adjunct to thorough scaling and root planing .
a total of 26 patients ( 12 male and 14 female ) in the age range of 30 - 55 years were selected from the outpatient pool after obtaining ethical clearance from institutional review board .
patients who were diagnosed as having chronic periodontitis and at least three sites with probing pocket depth ( ppd)5 mm in three different quadrants and radiographic evidence ( intraoral periapical radiographs ) of horizontal bone loss were considered as eligible for the study .
exclusion criteria were the presence of overhanging restorations , antibiotics or any form of periodontal treatment in the previous 6 months , smoking habits , history of systemic disease that could influence the course of periodontal disease or would require prophylactic antibiotics prior to dental treatment , allergy to the medicaments used and pregnancy .
three sites in three different quadrants in each subject were randomly assigned to each group using simple repeated fair coin tossing method .
impressions of the upper and lower arches were made and acrylic stents were prepared on each patients cast to fit over the occlusal one - third of the teeth selected for the study .
a groove was cut in the acrylic stent so that the probe could be inserted at a standardized point of entry into the pocket at recall visits . during the first visit ( day 0 ) after obtaining informed consent , all the clinical parameters including plaque index ( silness and loe ) , bleeding on probing , redness ( presence / absence ) and ppd were measured .
the pocket depth was measured using a pressure sensitive probe ( aesculap periodontometer , unc15 , aesculap dental ) .
the microbiological parameter assessed was n - benzoyl - dl - arginine-2-naphthylamide ( bana ) enzymatic test .
after recording the clinical parameters , bana test was used to verify the presence of tannerella forsythia , treponema denticola , porphyromonas gingivalis and certain strains of capnocytophaga species .
these anaerobic microorganisms possess a trypsin like enzyme capable of hydrolyzing the synthetic substrate , bana , resulting in a color reaction .
the subgingival plaque samples were taken from the study sites using a curette after removal of supragingival deposits and transferred to the bana card , which was incubated at 55c for 15 min .
the card was subsequently examined for the presence ( positive ) , absence ( negative ) or mild presence ( weak positive ) of a blue color .
1% cu solution was prepared from 1 mg of cu extract dissolved in 5 ml of ethanol , with the addition of 95 ml of glycerol .
the needle was bent in the center at an angle of 110 , which was then inserted subgingivally and irrigation was done for 20s .
a total of 10 ml of the solution was irrigated in each group and at each time interval .
patients were emphasized on the importance of routine plaque control and maintenance . during the second appointment ( day 7 ) ,
plaque index was recorded to analyze the patient 's oral hygiene before repeating subgingival irrigation .
three patients were eliminated from the study due to their improper oral hygiene maintenance with a plaque index score ranging from 2.0 to 3.0 .
repeated sub gingival irrigation was done at baseline , 7 , 14 , and 21 days .
the clinical parameters assessed include clinical parameters were recorded at baseline , 1 , 3 and 6 month intervals .
intra group comparison was performed by paired t - test and inter group comparison by one way anova followed by post - hoc tukey 's test .
chi - square test was carried out to evaluate bleeding on probing , redness and bana test results .
intra group comparison was performed by paired t - test and inter group comparison by one way anova followed by post - hoc tukey 's test .
chi - square test was carried out to evaluate bleeding on probing , redness and bana test results .
after the thorough sub - gingival irrigation at 4 different time intervals including the baseline , results were evaluated at periods of 1 , 3 and 6 months . in the present study , the mean bleeding scores [ table 1 , graph 1 ] decreased drastically in all the groups . at 1 month interval ,
the test groups ( chx-87% and cu-95.7% ) showed significantly ( p < 0.01 ) better reduction in bleeding scores compared with control group ( positive control-52.2% ) .
cu group showed the best results with 95.7% of reduction in bleeding scores . in the intergroup comparison of the bleeding scores at the end of the study period
however , chx group showed the best results with about 82.6% of reduction in bleeding scores compared to baseline .
clinical results and statistical analysis of bleeding on probing for all sites comparison of % of sites with bleeding on probing between the groups at different time intervals the percentage of sites with redness showed highly significant difference from baseline in all three groups [ table 2 , graph 2 ] .
inter group analysis showed significant change ( p < 0.001 ) in the percentage of sites with redness between the test groups ( chx-95.7% , cu-95.7% ) and the control group ( 65.2% ) at 1month interval .
however , intergroup comparisons within the test groups did not show any significant difference throughout the study period ( p < 0.01 ) .
although not statistically significant percentage of sites with redness in the cu ( 73.9% ) and positive control ( 69.6% ) groups increased drastically as compared with chx group ( 17.4% ) by the end of the study period .
clinical results and statistical analysis of redness for all sites comparison of % of sites with redness between the groups at different time intervals the mean plaque index scores showed a significant reduction in all the 3 groups when compared with the baseline [ table 3 , graph 3 ] .
the chx ( 0.85 + 0.22 , 0.98 + 0.18 , 0.93 + 0.15 at 1 , 3 and 6 months respectively ) and cu ( 0.81 + 0.22 , 0.89 + 0.17 , 0.97 + 0.16 at 1,3 and 6 months respectively ) groups showed equivalent reduction in plaque index scores at anytime interval , where as the positive control group showed higher plaque index scores at all the time intervals compared with the test groups ( 1.10 + 0.20 , 1.14 + 0.20 , 1.17 + 0.14 at 1 , 3 and 6 months respectively ) .
clinical results and statistical analysis of plaque index scores for all the groups comparison of plaque index scores between the groups at different time intervals the ppds [ table 4 , graph 4 ] showed a significant reduction in all three groups .
the highest reduction in the ppd scores occurred in the cu group ( 2.70 + 0.63 ) at 1 month evaluation period when compared to chx ( 3.61 + 0.78 ) and positive control group ( 4.30 + 0.76 ) , with the least reduction occurring in the positive control group . however , the evaluation of the ppd scores at the end of the study period showed similar results in all the 3 groups with an average of 2.35 mm , 1.87 mm and 1.70 mm reduction in the chx , cu and positive control groups respectively .
intergroup comparison of pocket depth scores showed a significant difference between the chx and cu groups at 1 month period with cu showing greater reduction .
however , at 6 month interval though there was also statistically significant difference between the two tests groups , chx group showed greater reduction in pocket depths ( i.e. , chx-2.35 mm , cu-1.9 mm , positive control-1.72 mm reduction ) . clinical results and statistical analysis of probing pocket depth scores for all the groups comparison of probing pocket depth scores between the groups at different time intervals the results of the bana test
[ table 5 ] showed a significant shift in the bana positive sites to negative sites in all three groups by the end of study period . at 1 month interval ,
the cu group showed less number ( 17.4% ) of bana positive sites , when compared to the chx ( 21.7% ) and positive control groups ( 21.7% ) .
similar results were also found at the 6 months interval i.e. , cu group showed less number ( 13.0% ) of bana positive sites when compared to the chx ( 26.1% ) and positive control ( 39.1% ) groups .
this shows that the number of bana positive sites remained stable by the end of study period in both chx and cu groups , whereas there is a slight increase in the positive control group .
the results of the bana test [ table 5 ] showed a significant shift in the bana positive sites to negative sites in all three groups by the end of study period . at 1 month interval ,
the cu group showed less number ( 17.4% ) of bana positive sites , when compared to the chx ( 21.7% ) and positive control groups ( 21.7% ) .
similar results were also found at the 6 months interval i.e. , cu group showed less number ( 13.0% ) of bana positive sites when compared to the chx ( 26.1% ) and positive control ( 39.1% ) groups .
this shows that the number of bana positive sites remained stable by the end of study period in both chx and cu groups , whereas there is a slight increase in the positive control group .
cu has been widely studied throughout literature for its anti - inflammatory , anti - oxidant , antibacterial and wound healing , properties .
however , its application in dentistry has been reported only in the last decade . though few studies have been performed to evaluate the clinical and microbiological efficacy of cucumin irrigation as an adjunct to scaling and root planing , none of the randomized clinical control trials evaluated the long - term treatment outcome over a period of 6 months .
several authors have evaluated the efficacy of antiseptics as an adjunct to improving the clinical outcome and the biocide of the disease in moderate periodontitis patients , but none of them have shown a complete reduction and long term efficacy of the drug .
therefore , this randomized clinical control trial aims at evaluating the efficacy of cu as an adjunct to scaling and root planing and to compare it with the gold standard chx solution over a period of 6 months .
chx irrigation has been used in previous studies and was shown to have good antibacterial properties .
chx in an in vivo study when used with a minimum inhibitory concentration of 250 g / ml showed inhibition of 25 bacterial strains from sub gingival samples .
however , few studies have shown that the substantivity of chx in human root dentin is relatively low and decreases with time .
the results of our study show a significant improvement in all the clinical and microbiological parameters in both test and control groups . this can be explained by the fact that thorough good quality srp has a greater impact on the clinical and microbiological findings irrespective of the adjunctive treatment procedures .
the evaluation of the bleeding on probing , and redness showed that there was no significant difference between chx and cu groups at 1 month interval , and the results were better than the positive control group .
this reduction in the bleeding on probing and redness can be attributed to the anti - inflammatory property of cu via ( a ) reducing the inflammatory edema and vascular engorgement in the connective tissue , ( b ) reduction in vascularization by fibrosis of the connective tissue . however , by the end of study period there was a slight increase in the number of sites with bleeding on probing in the cu group , though not statistically significant .
this shows that the concentration of cu used is not sustained and thus does not have long - term effects .
the mean plaque index scores did not show any significant difference between the chx and cu groups at any time interval .
the chx group showed similar results in plaque index scores as that of studies done by vinholis et al . , and paolantonio et al .
the inter group comparison of ppd scores between the test groups showed better result with cu group ( 3.0 mm reduction ) at 1 month interval .
however , by the end of study period all the 3 groups showed no significant differences , with as lightly greater reduction in pocket depth in the chx group .
the increase in the pocket depth scores in cu group from 1 months to 6 months interval might be due to its reduced substantivity on the root surface over a period of time .
the result of the microbiological study shows that , the cu group has a better reduction in the number of bana positive sites at both 1 month interval and by the end of study period .
these results can be attributed to the anti - inflammatory and antioxidant properties of cu .
this proves that though there is no statistically significant difference when compared with chx group , cu shows good potential as a sub gingival irrigant .
chx showed similar percentage of bana positive sites as that of studies by vinholis et al . in consideration of all the clinical and microbiological parameters cu irrigation group showed good results at the first recall visit i.e.,1 month interval .
thus , to obtain better long standing results a long - term regime ( routine irrigation ) or a change in the concentration of the drug can add to the benefits of the drug . as cu acts by suppression of nf- activation which helps in decreasing the antibiotic resistance , it can be undoubtedly used as a routine professional or home care regime , which improves its antibacterial properties and thus shows better results .
the results of this study show a mild to moderate beneficiary effect of cu irrigation when used as an adjunct to srp .
though cu and chx have equivalent efficacy as sub - gingival irrigants , in consideration of the fewer side effects and better patient acceptance cu can be used as effective alternative for chx irrigation .
however , further studies may be required using varied concentrations of the drug to improve the substantivity of the drug and also to prevent early recolonization of periodontal pathogens . | aim : the aim of this study is to evaluate the efficacy of 1% curcumin ( cu ) solution and compare it with conventional irrigant i.e. , 0.2% chlorhexidine ( chx ) gluconate and a positive control ( saline ) as an adjunct to thorough scaling and root planing.materials and methods : a total of 23 patients with non - adjacent probing pocket depths ( ppds ) 5 mm were randomly assigned to chx , cu and positive control irrigation groups and subjected to randomized single blinded clinical control trial .
the clinical parameters bleeding on probing , redness , plaque index , ppd and microbiological parameter n - benzoyl - dl - arginine-2-naphthylamide ( bana ) test were evaluated at baseline , 1 , 3 and 6 months interval.results:at 1 month evaluation , cu group showed better results compared with the other groups . however , by the end of the study period chx group showed the best results with as light recurrence in the cu group .
the results of bana test showed similar results for both cu and chx group throughout the study period.conclusion:the results of this study show a mild to moderate beneficiary effect of cu irrigation when used as an adjunct to scaling and root planing .
further studies may be required using varied concentrations of the drug to improve the substantivity of the drug and also to prevent early re - colonization of periodontal pathogens . |
a 68-year - old male presented with grade 4 nuclear cataract with visual acuity of 20/200 in the left eye .
he had best corrected visual acuity of 20/200 in the right eye and examination of that eye revealed normal pseudophakia with age - related macular degeneration .
stretch pupilloplasty was done for rigid pupil and intraoperative iris trauma was also recorded . at the end of surgery , hydration of the main incision and side ports was done . on first postoperative follow - up , inferior half corneal edema with descemet 's detachment from inferotemporal side port extending to lower one - third of cornea was noted .
but persistent descemet 's detachment and corneal edema was noted on second and third postoperative day .
1.4% sodium hyaluronate was injected after which he developed an intraocular pressure ( iop ) of 40 mm of hg with persisting descemet 's detachment . on the fourth postoperative day ,
anterior chamber wash to clear viscoelastic was done and 0.2 ml of perfluro - n - octane was injected as a single bubble using a 26-gauge needle introduced through superotemporal peripheral cornea . the patient was given immediate head end elevated position which he was advised to maintain for 2 weeks . from the fifth postoperative day onward , the descemet 's membrane was found attached . initially , the area of descemet 's detachment was seen as faintly thickened [ fig .
1 ] which resolved at 1 week after perfluro - n - octane injection [ fig . 2 ] .
fifteen days after perfluro - n - octane injection , the bubble was aspirated and thorough anterior chamber wash was given .
at no point in follow - up after perfluro - n - octane injection , elevated iop or uveitis was noted . at 6 weeks
the central corneal thickness by ultrasonic pachymetry was 517 m before phacoemulsification , 782 m before intervention with perfluro - n - octane and 520 m after removal of perfluro - n - octane .
specular microscopy was performed at another center at 6 months follow - up with endothelial cell density of 2639 cells / mm in the right eye and 2481 cells / mm in the left eye .
perfluro - n - octane bubble in anterior chamber with the area of descemet 's detachment seen as faint thickening .
the superior extent of the area of descemet 's detachment is highlighted by the arrow heads haziness in the area of descemet 's detachment has cleared by 1 week .
perflurocarbon liquids bubble is seen in anterior chamber one - month follow - up showing clear cornea with no evidence of descemet 's detachment
descemet 's detachment can be instrument induced ( scroll like ) or due to injection of fluid ( attached to stroma all around the detachment ) .
descemet 's membrane detachment can also be classified into planar type with the descemet 's membrane separation of less than 1 mm and non - planar type with a separation of greater than 1 mm .
planar detachments are more likely to resolve spontaneously , and non - planar detachments should be repaired early .
small localized descemet 's detachment usually resolves spontaneously , but large one needs intervention in the form of intracameral air , c3f8 or viscoelastic .
since air or gas floats up , inferior descemet 's detachment extending to periphery of cornea may not get attached as in our case .
perflurocarbon liquids ( pfcls ) were initially developed as blood substitute for their property to transport oxygen and their biologic inertness .
pfcl is used because of high specific gravity and immiscibility with water for complex retinal procedures like giant retinal tear surgery .
few reports about retained pfcl in anterior chamber after vitreo - retinal surgery are available in literature , which suggest inflammatory response and corneal toxicity after prolonged exposure of several months .
toxicity with pfcl occurs due to hydrogen containing compounds , unsaturated carbon bonds and impurities like compounds with nitrogen bonds and hydrogen fluoride containing compounds .
, based on their in vitro study on the effect of perflurodecalin on human retinal pigment epithelium and corneal endothelium , suggest the damage is caused by mechanical effect on cell function by impeding the normal metabolic exchange .
caution against the use of pfcl for short- or long - term retinal tamponade in aphakic eyes considering the anterior segment toxicity of pfcl . but weinberger et al . followed up seven eyes with retained pfcl in anterior chamber for a mean follow - up of 9.4 months and showed that retained pfcl in anterior segment did not cause corneal toxicity or ocular inflammation .
we have observed a patient with retained perfluro - n - octane bubble in anterior chamber following dislocated nucleus removal via anterior chamber for 3 months without inflammation or elevated iop ( not reported ) .
based on the personal experience of that case , we decided to manage this patient with pfcl ( perfluro - n - octane ) .
the difference in endothelial cell density between the two eyes was 158 cells / mm .
in routine cataract surgery , an endothelial cell loss of 210% , and in complicated cataract surgery a loss of 1620% is possible . in the case being reported here , the difference in specular count between the two eyes was less than 10% and this loss can be explained by the descemet 's detachment as well as by the repeated manipulations .
the central corneal thickness almost approximated the pre - operative thickness after removing pfcl though the pfcl bubble was in contact with nearly 50% of central cornea .
hence , we consider that perfluro - n - octane was effective in attaching inferior descemet 's detachment and safe in anterior chamber for a period of 2 weeks in this patient intervened by us .
this is the first case of inferior descemet 's detachment managed by intracameral pfcl to be reported as far as our knowledge is concerned ( pubmed key words used were descemet 's detachment + cataract surgery , repair of descemet 's detachment , descemet 's detachment + perfluro - n - octane , descemet 's detachment + pfcl , intracameral pfcl ) . | we report the case of a 68-year - old male who developed descemet 's membrane detachment after temporal clear corneal phacoemulsification which did not settle with air or viscoelastic injection .
the descemet 's membrane was successfully reattached with restoration of 20/50 vision with the help of perfluro - n - octane liquid . to our knowledge , this is the first such case to be reported . |
depression is a common mental health problem among people with visual impairment ( burmedi , becker , heyl , wahl , &
himmelsbach , 2002 ) .
a study in britain showed that people with visual impairment
had a higher prevalence of depression compared with people with good vision , because people
with visual impairment were more likely to experience problems with functioning , which in
turn lead to depression ( j. r. evans ,
fletcher , & wormald , 2007 ) . in managing depression with psychological therapy , cognitive - behavioral therapy ( cbt ) is
known to be effective in a wide age range of patients around the world , including late
adulthood ( serfaty et al . , 2009 ) .
specifically , short group cbt has been shown to reduce depressive symptoms in depressed
indonesian older adults ( utoyo et al . ,
2013 ) . however , in cases involving older adults with physical disabilities , such as
visual impairment , it was recommended that aspects of the therapy should be modified to suit
the impairment ( c. evans , 2007 ) .
this case report aims to report on the results of modifying a standardized cbt for
depression to suit a severe visual impairment condition suffered by an indonesian older
adult .
a 77-year - old indonesian woman who was a retired kindergarten teacher with retinal
detachment ( 75% blindness ) was diagnosed with major depressive disorder based on
diagnostic and statistical manual of mental disorders ( 4th ed .
, text
rev . ; dsm - iv - tr ; american psychiatric association , 2000 ) criteria .
she had no mental health
treatment history and was currently not in any kind of non - pharmacological intervention ,
either exercise or psychosocial .
her change in personality and habit motivated her husband
to seek professional help for her and contacted a psychologist to examine her at home .
the
patient lived with her husband in a house in depok , west java , indonesia .
her retinal
detachment condition started at 2009 due to a head trauma , complicated with previous
cataract surgery and severe anemia .
since then , her visual condition worsens through time .
at the time of the examination , which was in 2012
according to her ophthalmologist , managing her visual
condition required a surgical procedure that was very risky for her age .
therefore , her ophthalmologist only prescribed her
with vitamins to manage her eye condition . separately , she took medicine for her anemia as
prescribed by her internist .
other than her visual condition and anemia , she did not report
to have other medical or psychiatric condition .
her husband complained that her partial sight condition changed
her into a different person : she lost self - confidence and refrained from going outside .
she ,
however , had a different complaint : she felt frustrated due to her failure in doing daily
activities ( such as cooking and preparing food ) .
this study was a clinical case , approved and conducted under supervision of a senior
clinical psychologist and lecturer from the faculty of psychology , university of indonesia ,
depok , indonesia .
written informed consent from the patient and her husband were obtained in
the first meeting of initial assessment .
the main measurement tools for this study were the depression assessments : indonesian
version of beck depression inventory ( bdi ; suwantara , lubis , & rusli , 2005 ) and indonesian
back - translated geriatric depression scale ( gds ; yesavage et al . , 1983 ) .
there were three measurement
points : baseline , mid - test at 3rd week of the treatment , and posttest at 1 week after the
end of treatment ( 5 weeks from baseline ) .
in addition , mini mental status examination ( mmse ; folstein , folstein , & mchugh , 1975 ) was conducted
as part of the initial assessment to assess for possible cognitive impairment that may
prevent her to follow the therapy .
following depression diagnosis of the patient obtained from the pre - test result , an
evidence - based psychological treatment , cbt , is chosen .
cbt has been shown to be effective
in treating depression for older adults , especially because the aim of cbt is to help the
patient identify , challenge , and alter maladaptive thinking ( scogin , welsh , hanson , stump , & coates ,
2005 ) .
the treatment was based on a treatment manual that has been previously shown to be able to
reduce depressive symptoms ( utoyo et
al . , 2013 ) .
it consists of eight sessions of 120 min each , and two sessions were
given per week ( every 3 to 4 days ) .
the content of the therapy were psychoeducation about
depression and cbt itself , activity scheduling and monitoring , relaxation techniques ,
cognitive restructuring , and problem - solving techniques .
the treatment was modified to suit the patients partial sight condition by recording all
the materials into a cd .
this approach was taken because the patient was known to operate a
cd player regularly to listen to music .
this modification of the treatment manual ( utoyo et al . , 2013 ) was done under
all authors permission . also ,
all necessary adaptation to be used in the present study
setting had been discussed .
other concurrent interventions were allowed , but the patient did
not report engaging in any other interventions . for the written section of the treatment
( homework , in cbt terminology ) , the patient did it with her husband s or the therapist s
assistance twice every week .
the homework included , for example , regular breathing
relaxation and progressive muscle relaxation exercise , daily mood monitoring and activity
planning , as well as cognitive restructuring with her husband s or therapist s
assistance .
although reduced memory function
was found , the condition can still be categorized as a result of normal aging process ,
according to the mmse norms for the patient s age group . due to the absence of significant
cognitive impairment , no contra - indication for using cbt
therefore , the patient
was deemed to be suitable to receive cbt for depression .
the depression level of the patient gradually declined across three measurement points for
the bdi and gds ( figure 1 ) . at
baseline , the patient s depressive symptoms scores were categorized as severe depression
( bdi , 25 ) and moderate depression ( gds , 20 ) using their respective norms .
then , at posttest ,
the patient s bdi score was reduced to mild or moderate depression ( bdi , 14 ) , and her gds
score was reduced to no depression ( gds , 10 ) .
furthermore , at posttest , the patient reported
that she was sleeping normally , no longer felt depressed , regained her self - confidence ,
regained her interest to be active , and regained her appetite .
furthermore , she was also no
longer experiencing ulcer and itchiness ( psychosomatic symptoms ) , which she previously
had .
this case report showed that modification of a conventional evidence - based psychological
treatment to suit the patient s visual impairment condition can reduce depressive symptom .
with this result in mind , it is suggested that modifying a currently available
evidence - based treatment to suit patient s condition , rather than inventing a new one , is a
reasonable approach . in addition , this case report provides an illustration of depressive symptoms on visually
impaired depressed indonesian older adult .
the patient experienced conventional symptoms of
depression commonly found in patients in western cultural context , such as feeling
depressed , having difficulty sleeping , losing appetite , and losing self - confidence ( e.g. ,
rush , carmody , & reimitz ,
2000 ; rush et al . , 1986 ) .
this case report runs counter to the notion that depression is a uniquely western phenomenon
( jadhav , 1996 ) , although there
is a slight difference of symptom presentation in common depressive patients in western
cultural context .
the patient was primarily concerned about her ulcer and sleep difficulty
( psychosomatic symptom ) .
this similar emphasis on somatic symptom is also observed on
chinese depressive patients in china , although , interestingly , such emphasis is not found in
white americans or chinese in the united states ( yen , robins , & lin , 2000 ) .
limitations , however , have to be taken into account in interpreting the findings .
assessments and therapy
furthermore ,
this setting preserves external validity as it mimics everyday psychologist practice in
indonesia to sum up , this case report showed that the patient with visual impairment experienced
functioning problem , which leads to depression .
( 2007 ) , who found
that people with visual impairment have functioning problem and higher depressive symptoms .
therefore
, screening and treating depression in people with visual impairment is important .
in the absence of available appropriate psychological treatment ,
this case report showed
that it is possible to modify current evidence - based treatment to suit the need of the
patient .
this is probably no longer needed , once the planned trial on psychological
treatment for depression on people with visual impairment is successful ( margrain et al . , 2012 ) . | depression is a common mental health problem in older adults , especially among those
suffering from visual impairment . a clinical case of an indonesian older adult with
retinal detachment ( 75% blindness ) suffering from major depressive disorder , based on
diagnostic and statistical manual of mental disorders ( 4th ed .
, text
rev . ; dsm - iv - tr ) criteria , was reported . her principal motivation to seek
help was her depressive symptoms , as well as her husband s discomfort with her change .
a
modified standardized cognitive - behavioral therapy was delivered in eight sessions , and a
clinically significant reduction of depressive symptoms was observed at the middle of the
treatment ( session 5 ) ; symptoms were further reduced at follow - up .
this case report showed
that conventional evidence - based psychological treatment can be modified to handle mental
health problems in people with visual impairments . |
the etiology of endodontic failure is multifaceted , but a significant percentage of failures are related to the lack of knowledge of pulp cavity anatomy and failure to negotiate and obturate the canal in its entirety .
the rate of failures after endodontic treatment as apical percolation because of incompletely obturated or a totally missed out canal .
these missed canals contain tissue , as well as microbiota and irritants , which inevitably contribute to failure of endodontic treatment . from early work by hess and zurcher in 1925 , to the more recent studies demonstrating the complex morphological variations of the root canal system , researchers have shown multiple orifices , fins , deltas , loops , accessory canals , and other variations in most teeth .
( 1969 ) observed that failures related to the mesiobuccal root of maxillary molars jeopardized the success of the endodontic treatment and found that teeth with a fourth canal occurred more frequently than those with three canals .
the incidence of two or three root canals in mandibular anterior teeth has been well documented , where 43% of cases had additional canals and the frequency of mandibular canines with two canals has been reported to be between 19.3% and 31.2% .
maxillary canines are considered to be single - rooted , single - canalled teeth and two root canals in a permanent maxillary canine is a rare condition ; but cases with two roots have been reported in the literature ( barkhordar and nyugen , 1985 ; weisman , 2000 ) and a case of endodontic retreatment of maxillary canine with a single root and two root canals was reported by alapati et al .
. a case report of type ii canal in mandibular canine and a recent case report of similar canal configuration in a maxillary canine have also been reported .
all the previous case reports were based on the radiographic examinations of the teeth , both pre - operatively and post - operatively .
the radiographic image is a 2-dimensional representation of a 3-dimensional object and an ideal method of precise determination of the root canal morphology of a tooth is serial sectioning of the tooth , which is impractical in clinical situations .
therefore , other diagnostic methods like spiral computed tomography ( ct ) , cone - beam ct , peripheral quantitative ct , 3d accuitomo xyz slice view tomography are useful in such conditions , to analyze the root canal morphology .
although bilateral occurrence of bi - rooted canines has been reported in primary dentition , there is lack of literature regarding its pertinence in permanent dentition .
this case report describes the diagnosis of bilateral occurrence of two root canals in a single root of maxillary canines and the endodontic management of the right maxillary canine with the aid of spiral ct .
a 25-year - old , south - indian female patient reported with the chief complaint of intermittent pain in the front right upper jaw region for the past 2 months , which had increased in intensity for the past 3 days .
she also complained of food impaction in the same region for the past 1 year .
the patient 's medical history was non - contributory . on clinical examination , the patient 's oral hygiene was moderate and there was a deep carious lesion in relation to the right maxillary canine , which was tender on percussion [ figure 1 ] .
a pre - operative radiograph [ figure 2 ] was obtained , which revealed encroachment of pulp space by dental caries and there was widening of periodontal ligament space .
on the basis of clinical and radiographic findings , a diagnosis of acute exacerbation of a chronic apical periodontitis was made .
the patient received local anesthesia of 2% lignocaine with 1:80,000 epinephrine ( indoco remedies ltd .
, promoted by warren pharmaceuticals , goa , india ) . a rubber dam was placed , and a conventional endodontic access cavity was prepared in the right maxillary canine .
the pre - operative radiograph showed a thin layer of dentin in the middle - third of the canal , indicating that there were two separate canals in the body of the root .
this followed the vertucci 's type - iii canal configuration ( single canal leaving the access preparation , which divides into two within the body and re - unites to exit as one canal ) .
clinical view of the prepared access cavity portrayed the canals like premolars , where one was placed buccally and the other placed palatally [ figure 3 ] . the access cavity was sealed with a sterile cotton pellet and coltosol ( coltene whaledent , switzerland ) . to confirm the unusual morphology and to search for any additional roots and root canals a spiral ct
clinical view of the right maxillary canine ct scan was done with a multi - detector ct scanner taken at 16 slices / second , as per recommendations given by diederichs et al . to reduce the radiation dosage ( collimation , 1 mm
; pitch , 2 ; tube voltage , 80 kv ; tube current , 40 ma ) and all the protective measures were taken to protect the patient from radiation .
axial images were transmitted to a commercially available dental program ( denta scan , advantage windows ; general electric , buc , france ) to reformat panoramic and cross - sectional images in all three planes .
the ct images confirmed the radiographic findings of vertucci 's type - iii canal configuration [ figures 4 and 5 ] and no additional canals or roots other than the two located canals .
a striking feature was that the same canal configuration was found in the contra - lateral canine , which was absolutely healthy [ figure 4 ] ; and also the mandibular central and lateral incisors , canine and the first premolars showed bifid canal pattern bilaterally .
these findings can help the patient in the future because , at any point if the patient needs to undergo an endodontic procedure , these ct images can serve as an excellent guide to provide a quality endodontic treatment .
sagittal view showing the bifid canal pattern ( a ) right maxillary canine ; ( b ) left maxila canine ; ( c ) right mandibular canine axial view of maxilla ( canal bifurcation is indicated with arrows ) ( a ) coronal third ; ( b ) middle third ; ( c ) apical third at the next visit , the working lengths of each canal were estimated by means of an electronic apex locator ( root zx ; morita , tokyo , japan ) and then confirmed by a radiograph .
the canals were initially instrumented with # 15 nickel - titanium files ( dentsply maillefer , switzerland ) under irrigation with 2.5% sodium hypochlorite ( prime dental products pvt .
coronal flaring was carried out by using gates - glidden drills ( numbers 3 and 2 ; mani .
both the canals were cleaned and prepared by hand nickel - titanium files with the conventional step - back technique .
calcium hydroxide intracanal medicament ( apexcal , ivoclar , vivadent , liechtenstein ) was placed in the root canal and the orifice was sealed with a sterile cotton pellet and coltosol .
one week later , calcium hydroxide was removed and the canals were obturated with zinc oxide eugenol sealer and laterally condensed gutta - percha points .
after completion of root canal treatment , a final radiograph was taken to establish the quality of the obturation [ figure 6 ] .
the tooth was restored with a visible light - cured composite ( ceram - x duo , dentsply india pvt ltd , delhi , india ) to build up the missing tooth structure .
the adjacent lateral incisor , which was non vital , was also root canal treated and restored with light cured composite restoration .
variations in root canal anatomy can pose a considerable challenge to endodontic diagnosis and treatment .
a previously treated tooth with unusual root morphology may serve as an excellent reference to determine if that condition exists in the corresponding contralateral tooth currently being considered for therapy .
the prevalence of maxillary canine with bilateral occurrence of 2 canals is rare and the literature regarding its existence is scarce .
the present case report confirms the presence of two canals bilaterally , with the help of spiral ct [ figures 2 and 3 ] and also the current case had a vertucci 's type - iii canal configuration , which has not been reported in the literature so far .
vertucci 's classification was used for classification of the canal morphology as this is a standardized and a versatile method for categorizing known root canal anatomical variations .
alapati et al.(2006 ) reported a case of endodontic retreatment with vertucci 's type - ii canal configuration and cases have been reported with 2 roots previously but , all these cases were diagnosed and treated with the aid of an intra - oral periapical radiograph .
conventional intra - oral periapical radiograph is an important diagnostic tool in endodontics for assessing the canal configuration when taken with different angulations .
nevertheless , it is not a completely reliable diagnostic tool in analyzing complex root canal systems .
the current report is one such case wherein we suspected a single canal initially , but ended finding two canals . in such doubtful cases ,
this paper highlights the role of spiral ct as a prime analytical tool to ascertain root canal morphology .
the applicability of ct to endodontics was studied by tachibana and matsumoto who suggested that this method allowed the observation of the morphology of the roots and root canals and the appearance of the tooth in every direction . moreover ,
the image could be analyzed , altered , and reconstructed by the computer to produce a rapid protyping model using stereolithiography or 3-d printing of the tooth ; which may serve as a physical guide to the endodontist to identify the presence of additional roots .
one of the major concerns regarding usage of ct in dentistry is radiation dosage . in the present study , guidelines by diederichs et al . were used . with these guidelines ,
the effective radiation dosage was reduced to 0.56 0.06 mgy , which is equivalent to a standard panoramic radiograph ( 0.59 0.04 mgy ) .
the newly developed dental ct , the 3d aaccuitomo xyz slice view tomography ( j. morita mfg co , kyoto , japan ) , which is called 3dx multi - image micro ct ( 3dx ) in japan , is excellent in generating an informative image database at a low irradiation dose .
the radiation dose was found to be as low as 0.006 - 0.012 msv when using this technique , as compared to the effective dose of two periapical radiographs in the molar regions 0.01 - 0.02 msv .
properly designed and prepared access cavities help the clinician to diagnose and negotiate the root canal morphology . in certain conditions
the root canals might be left untreated during the endodontic therapy if the practitioner is unable to detect their presence .
hence the ability to locate all the canals in the root canal system is an important factor in determining the eventual success of a case .
expect the unexpected ; this is the scenario any endodontist can confront , as baffling cases like these do prevail . with the advent of latest technology like surgical operating microscope , magnification loupes , ophthalmic dyes , ultrasonic tips , ct ,
detection of extra canals has become easier and it is the responsibility of the clinician to utilize these tools and deliver a quality endodontic treatment , for ensuring optimal success . | aberrations in the root canal system can pose a considerable challenge to the endodontist during root canal treatment .
these anatomical variations are more commonly seen in maxillary molars and mandibular teeth , but only a few cases have been reported with alteration in the internal canal anatomy of maxillary canine .
the present report describes the diagnosis of bilateral occurrence of two root canals in maxillary canines with single root and the endodontic management of the right maxillary canine with the aid of spiral computed tomography ( ct ) .
the ct images revealed the presence of vertucci 's type - iii canal configuration in the right maxillary canine .
the same canal pattern was found in the contra - lateral canine , which was absolutely healthy ; and also all the mandibular anterior teeth and first premolars showed bifid canal pattern . |
any comprehensive hypothesis concerning the pathogenesis of systemic sclerosis ( ssc , scleroderma ) must account for the varying contributions of vascular damage , extravascular tissue fibrosis , and inflammation . while certain clinical features of ssc are overt expressions of vascular injury ( renal crisis , pulmonary arterial hypertension , and raynaud phenomenon ) , our understanding of other organ involvements is less well understood .
complications from scleroderma do have a negative impact on sexual function and in turn on the overall quality of life . in spite of the 80% female predominance of ssc ,
most of the studies on the effect of ssc on sexual function have involved men [ 29 ] .
male erectile dysfunction ( med ) has been noted in as many as 81% of afflicted persons .
med in ssc can be reasonably attributed to scleroderma vasculopathy although cavernosal fibrosis has been implicated as well .
little is known of the impact of scleroderma on female sexual functioning and on quality of female sex life .
the general difficulties in researching female sexual function might explain some of the lack of interest in this area although there has been a marked change in the past year with the publication of several studies [ 1113 ] .
daily and long - acting pde-5 inhibitors have been proven to be safe and effective for med in males with ssc . to our knowledge ,
no studies have been published on successful pharmacological interventions in female ssc patients with sexual impairment .
med is defined as the consistent inability to attain and maintain an erection sufficient to permit satisfactory sexual performance .
the first report of an association between erectile dysfunction and ssc was as recently as 1981 .
prevalence of med in ssc has been found to range from 12% to 81% [ 9 , 16 ] .
the causes of ed associated with ssc are unclear although a number of factors have been suggested including vascular , fibrotic , and neuropathic / dysautonomic factors [ 10 , 15 , 17 ] . while some studies reported correlations between ed in ssc and testosterone and prolactin levels [ 15 , 17 ] others have not [ 1820 ] .
conclude that there is no support for a hormonal basis for ed in ssc as no consistent abnormalities in serum testosterone , follicle - stimulating hormone , luteinizing hormone , prolactin , estradiol , or thyroid hormones have been found .
several studies have ruled out a neurological basis for ed in ssc [ 17 , 21 ] .
recent studies have found links between ed in ssc and penile blood pressure and penile temperature , leading to a link between ed in ssc and vasculopathy . a strong connection between endothelial function and ed has been reported in the general population , supported by the strong linkage of med with coronary artery disease .
in this construct , endothelial injury and dysfunction result in diminished nitric oxide ( no ) production . during normal penile erection ,
nitric oxide diffuses into the vascular smooth muscle cells in the penile corpus cavernosum stimulating guanylyl cyclase and production of cyclic guanosine monophosphate ( cgmp ) .
this in turn activates cgmp - dependent protein kinase ( pkg ) , phosphorylation of several proteins , lowering of intracellular cell calcium , or sensitivity to calcium leading to muscle relaxation .
this relaxation leads to an increase of blood in the corpus cavernosum leading to penile erection .
an insufficient release of nitric oxide from nerve endings or endothelium can lead to an attenuated production of cgmp .
penile vascular damage in ssc patients was assessed using duplex ultrasonography [ 2 , 23 ] showing that penile thermal abnormalities are present in almost all ssc patients .
penile fibrosis has also been shown to be present in almost all ssc patients .
report severe veno - occlusive dysfunction based on histological analysis confirming severe corporeal fibrosis from a biopsy evaluation of a single ssc ed patient .
they postulate that fibrosis could lead to veno - occlusion leading to a reduction of the trabecular fibroelastic compliance and trabecular smooth muscle tone which depend on neurogenic - and endothelial - dependent vasomotility .
penile fibrosis has also been shown to occur in almost all ssc patients with the presence of thickening of the tunica albuginea and hyperechoic spots inside the corpera carnevosa .
conclude that their results showing fibrosis and thermoregulatory dysfunction in ssc patients with ed support the hypothesis that structural modifications induced by ssc lead to a reduced capability of heat exchange and vascular damage .
pde-5 inhibitors enhance erectile function by blocking degradation of cgmp leading to an increase in intracellular cgmp in the corpus cavernosum and penile vasculature .
the result is an increase in the relaxation of the smooth muscle leading to an increased blood flow and penile erection .
there are three pde-5 inhibitor compounds licensed for treatment of med : sildenafil , vardenafil , and tadalafil .
studies in the general population have shown these to be safe and generally effective depending on the etiology and severity of the erectile dysfunction .
ostojic and damjanov described a small case series with unsatisfactory response to on demand sildenafil ( 2550 mg ) .
an open label randomized cross - over study by aversa et al . compared 20 mg tadalafil on demand versus 20 mg in a fixed alternate day schedule . on the fixed alternate day schedule ,
a significant improvement was reported for the flow - mediated dilatation , peak flow velocities of cavernous arteries , reduced plasma levels of et-1 and vascular cell adhesion molecules ( markers of endothelial function ) , and morning erections .
no such results were found for the on - demand regimen suggesting that a constant plasma level of pde-5i might be important for the treatment of med in ssc .
report the results of a study with a daily 10 mg dose of tadalafil for 12 weeks in 14 ssc patients with varying degrees of ed .
improvements were found in erectile function , vascular measures of cavernous arteries , morning erections , and plasma et-1 levels ( reduced levels ) .
there is an inequality in the number of studies focusing on male versus female sexual dysfunction ( fsd ) in the general population and the same holds true in ssc although the disease primarily affects women .
the complexity and multifactorial nature of female sexual response and female sexual dysfunction adds to the difficulty in research in this area .
fsd can have psychological and social components in addition to medical and physiological components .
fsd is defined as persistent or recurring decrease in sexual desire , persistent or recurring decrease in sexual arousal , dyspareunia , and a difficulty in or inability to achieve orgasm .
it is reported to affect 20%50% of all women and can severely impact quality of life and interpersonal relationships [ 28 , 29 ] . changes associated with ssc can have a negative impact on female sexuality and sexual functioning
. symptoms such as skin tightening around the vaginal introitus , joint contractures , muscle weakness , changes in skin around the breasts and breast muscle , and joint pain have been found to be associated with lower levels of sexual functioning , desire , arousal , lubrication , and satisfaction [ 4 , 6 , 30 ] .
many ssc patients experience significant limitations on exercise capacity with dyspnea , decreased stamina , and coughing that may interfere with certain sexual behaviors [ 4 , 30 ] .
medications used to treat ssc - related symptom are also known to impact sexual desire and sexual functioning .
the number of women with ssc reporting sexual dysfunction is higher than those reported in the general population and also higher than those reported in studies on other chronic conditions [ 1113 ] .
bhadauria et al . reported that more than 50% of women with ssc had significantly fewer orgasms and that they reported a decrease in the intensity of their orgasms compared to fewer than 20% of ra patients . in a study by sampaio - barros et al .
some female ssc patients are sexually inactive because of complications related to their disease .
one study reported that 17% of subjects were sexually inactive because of issues caused by their disease . while there are many studies on the use of pde-5 inhibitors in the treatment of ed there are few studies on their use in the treatment of female sexual arousal problems and their effectiveness is in question .
our understanding of the effects of these drugs on female sexual psychophysiology is limited .
animal models of female sexual response show a similar physiological effect of pde-5 on vaginal and clitoral tissues compared to males with no synthase ( nos ) being active in the vaginal epithelium and pde5 enzyme found in vaginal smooth muscle tissue and clitoral shaft .
pde5 inhibition with sidenafil in female rabbits have been shown to lead to increased smooth muscle relaxation .
chivers and rosen conclude that there is clear evidence for the role of no neurotransmitter mechanisms in mediating blood flow and smooth muscle relaxation in the clitoral shaft , vaginal endothelium , and uterine tissues .
however , pde5 inhibitors are not found to be as efficacious in women with sexual dysfunction as in men with ed [ 32 , 33 ] .
studies focusing on the physiological effects of pde5 on genital vasocongestion consistently report effects on genital sexual response while those using self - reported measures provide mixed results .
this is likely due to problems related to the classification and measurement of fsd in women and difficulties related to finding meaningful endpoints in clinical trials due to the complexity of female sexual response compared to men .
chivers and rosen attribute this lack of efficacy of pde-5 inhibitors in women to gender differences in the concordance between physiological and psychological components of sexual response . while there are few studies on the effectiveness of pde-5 inhibitors for fsd in the general population , no studies were found in ssc patients .
the paper by chivers and rosen regarding the effectiveness of pde-5 inhibitors for fsd did not include any studies on the longer acting drug , tadalafil . as part of a study on the safety , tolerability and effectiveness of tadalafil for raynaud phenomenon ( rp )
, female subjects were asked to attempt sex at least once weekly to evaluate potential effects on quality of female sexual functioning .
this prospective randomized , double - blinded , placebo - controlled , and cross - over study compared oral tadalifil at a fixed 20 mg dose daily for a period of 4 weeks versus placebo in female ssc patients .
tadalafil was found to be well tolerated but no statistically significant differences were found in raynaud condition score , frequency or duration of rp episodes between treatment periods .
the study design can be found in figure 1 . there were a total of 5 visits : a screening visit ( visit 1 ) , three intermediate visits ( visits 24 ) , and an exit visit .
data obtained specifically regarding sexual function included the female sexual function index ( fsfi ) and a sexual activity log including the frequency of sexual activity .
this was obtained at visit 2 ( baseline ) and visits 3 and 5 ( after treatment or no treatment period ) .
the fsfi quantitatively assesses six domains of sexual functioning : desire , subjective arousal , lubrication , orgasm , pain , and satisfaction .
a total of 39 patients met all inclusion criteria , agreed to attempt sexual activity at least once weekly and successfully completed all 5 visits . when comparing change from baseline between drug and placebo on the six domains of the fsfi no statistically significant differences
were found although patients reported greater change when on drug versus when on placebo .
a significant difference was found between drug and placebo in the number of sexual activities with ssc patients reporting more frequent sexual activities when receiving drug than when on placebo ( mean number sexual activity drug = 7.24 with sd = 4.53 and a mean of 6.12 and sd of 3.3 on placebo ) .
this difference was statistically significant ( p = .021 ; 2-tailed ) as was the change from baseline ( 1.49 and sd = 2.55 on drug and x = .36 and sd = 2.16 ; p = .024 2 tailed ) .
the only other statistically significant difference in this study was found in a change from baseline in the sexual desire domain of the fsfi for drug although this was not statistically different from the change in the placebo group .
some of the more recent studies on female sexual functioning in ssc confirm the complexity of studying female sexual function as well as the psychological components of it .
depressive symptoms were found to be associated with impaired sexual functioning and sexual distress in ssc [ 11 , 13 ] . in our own studies of quality of female sexual function , we found stronger correlations with the mental component of the sf-36 than with the physical component score .
one lesson is that health care professionals should not dismiss consideration of sexual care and advice in any patient with systemic sclerosis .
sexual dysfunction is a common problem in both men and women with systemic sclerosis . in males ,
the dominant issue is erectile dysfunction which in turn seems tightly linked to vascular dysfunction .
sexual dysfunction in the female patient is no less prevalent but is considerably more complex .
clitoral engorgement , lubrication , orgasm are but some of the components of quality of sexual life . to our knowledge , only one study with pde5-i has been performed in women with confusing and small effects whereas pde5-i are a mainstay agent in med .
the clinician should be reminded that women with scleroderma remain sexually active overall ( 60% ) in spite of a host of physical and psychological difficulties associated with their disease .
complete care should consider agents for vaginal lubrication , advice about positioning and attention to sexual adverse events of therapies . | sexual dysfunction is common in systemic sclerosis ( ssc ) .
male erectile dysfunction ( med ) has been reported in around 80% of subjects and more than half of female patients fulfill criteria for diagnosis as female sexual arousal disorder ( fsad ) . while some evidence supports a role for cavernosal fibrosis , abundant data suggest that med is yet another clinical feature of ssc related to vasculopathy .
the contribution of vasculopathy to the more complex issues of female sexual dysfunction is less clear .
inhibitors of type v phosphodiesterase are effective in men with med secondary to ssc .
limited study in women suggests inconsistent effects on behavior ( frequency ) but not on measures related to perfusion .
sexual activity is an important component of quality of life and an important domain for the caregiver to address ; it is not clear that it warrants primary consideration as a consistent measure of scleroderma - related vasculopathy . |
advanced surface ablation ( asa ) and photorefractive keratectomy ( prk ) and its variations are currently common procedures to correct some refractive errors safely and effectively.1 postoperative pain management is one of the drawbacks of these procedures , which remains an unresolved issue.2,3 current studies , focused on finding corneal pain pathways and alternatives to control it , confirm the relevance of this topic.4 asa and the subsequent corneal epithelial defect leave numerous highly sensitive nerve terminals exposed .
the stimulation of these terminals results in intense pain and neurogenic inflammation.5 with the aim of controlling these effects , researchers have tried some approaches , which are not fully satisfactory . in this vein , although prk causes less postoperative pain than asa , severe pain is present in practically all patients after prk procedure,6 which may limit its acceptance . despite new intrastromal techniques with femtosecond laser which seemed to have reduced this problem , this technique has not been popularized yet , probably due to the worldwide recession environment.2,3 the mechanism of pain after refractive surgery is multifactorial and its understanding seems crucial for an appropriate management.7 recent papers about pain management in postoperative refractive surgery show that it remains an unsolved issue.8,9 the potential target for pain relief has numerous approaches ; for example , a bandage contact lens ( bcl ) is effective in improving postoperative comfort by preventing lid movements over the abraded cornea and reducing stimulation of the nerve fibers sensitive to mechanical stimulation.10 however , wearing a bcl is not enough to eliminate pain in most patients.11 topical nonsteroidal anti - inflammatory drugs ( nsaids ) help reduce pain following prk but could interfere with the healing process.12 furthermore , the direct application of cold balanced saline solution ( bss ) on the cornea is believed to alleviate the pain caused by exposed nerve endings.12 in previously published studies on the evaluation of pain after refractive surgery , some limitations have been observed .
one of them is the time of follow - up . in order to make a good assessment of postoperative pain in refractive surgery ,
a minimum of 72-hour evaluation time is necessary.11,12 studies evaluating pain over a 24-hour postoperative period are considered insufficient.9 although pain is one of the most important limitations of postoperative refractive surgery , there are other symptoms , generically named discomfort , that have been observed in the majority of patients .
therefore , the purpose of this study is to provide data on the patient - referred ocular sensations in terms of postoperative pain , during and after asa , evaluated over 1 week , using a numerical rating scale ( nrs ) and paying attention to other relevant symptoms such as photophobia , burning , tearing , and foreign body sensation .
single - center survey study based on the structured questionnaire relative to the patients perceived symptoms after asa .
the study complies with the updated declaration of helsinki and the spanish biomedical research regulatory requirements .
patients included in this study had to fulfil the following eligibility criteria : 18 years old , with no ocular disease other than ametropia , with myopia ( 0.75 to 9 d ) or hyperopia ( 0.25 to 5 d ) with or without astigmatism , receiving asa on at least one eye . all patients were operated on by the same surgeon ( mjm ) .
patients , who fulfilled the inclusion criteria , were identified , and contacted via phone by the same interviewer ( ems ) .
the study was explained to each patient , and before starting the interview , verbal consent was requested .
asa included topical application of one drop of 5% lidocaine twice at a 10-minute interval , 20 minutes before entering the operating theater .
ethyl alcohol solution ( 17% ) was placed on the cornea within an 8.5 mm solution cone and left in place for 30 seconds .
then a drop of 0.3% ofloxacin ( exocin , allergan , inc . , irvine , ca , usa ) and a drop of 0.18% sodium hyaluronate ( vismed , thea laboratories , sa , barcelona , spain ) were applied .
a therapeutic contact lens ( acuvue oasis , johnson & johnson , new brunswick , nj , usa ) kept at 4c was placed onto the cornea at the end of the procedure . immediately after surgery
patients were given alprazolam 0.5 mg for the first 2 postoperative nights and all other eye - drops ( ofloxacin qid , dexamethasone tid , and artificial tears qid ) that had to be kept at 4c ( fridge temperature ) .
initially , painkillers were not prescribed unless pain was deemed unbearable . in this case , the patient was given a protocol to use a rescue medication .
an ad hoc questionnaire was created to record the patients perceived symptoms after asa ( figure 1 ) .
the questionnaire consists of five parts or domains : 1 ) cognitive orientation , 2 ) pain perception , 3 ) other symptoms ( foreign body , tearing , photophobia , burning ) , 4 ) pain treatment prescribed , and 5 ) miscellanea .
furthermore , pain intensity was evaluated by means of an nrs , ie , 0- no pain and 10- the worst imaginable pain.14 this study was designed assuming that 95% ( internal data ) of the participants would present pain after asa procedure .
it was calculated that a representative sample for a survey study should include 73 subjects , based on the normal approximation with a range of 2.5% for a two - sided 95% confidence interval ( ci ) .
baseline characteristics were summarized with standard descriptive statistics and a descriptive analysis was carried out .
the prevalence of symptoms after asa procedure was estimated and its 95% ci was calculated .
the spearman s correlation coefficient was used to assess the relation between the subjective feeling of pain and age and amount of ablation , and between discomfort and age and amount of ablation .
data analysis was carried out using spss version 15.0 statistical software ( spss inc . ,
single - center survey study based on the structured questionnaire relative to the patients perceived symptoms after asa .
the study complies with the updated declaration of helsinki and the spanish biomedical research regulatory requirements .
patients included in this study had to fulfil the following eligibility criteria : 18 years old , with no ocular disease other than ametropia , with myopia ( 0.75 to 9 d ) or hyperopia ( 0.25 to 5 d ) with or without astigmatism , receiving asa on at least one eye . all patients were operated on by the same surgeon ( mjm ) .
patients , who fulfilled the inclusion criteria , were identified , and contacted via phone by the same interviewer ( ems ) .
the study was explained to each patient , and before starting the interview , verbal consent was requested .
asa included topical application of one drop of 5% lidocaine twice at a 10-minute interval , 20 minutes before entering the operating theater .
ethyl alcohol solution ( 17% ) was placed on the cornea within an 8.5 mm solution cone and left in place for 30 seconds .
then a drop of 0.3% ofloxacin ( exocin , allergan , inc . , irvine , ca , usa ) and a drop of 0.18% sodium hyaluronate ( vismed , thea laboratories , sa , barcelona , spain ) were applied .
a therapeutic contact lens ( acuvue oasis , johnson & johnson , new brunswick , nj , usa ) kept at 4c was placed onto the cornea at the end of the procedure . immediately after surgery
patients were given alprazolam 0.5 mg for the first 2 postoperative nights and all other eye - drops ( ofloxacin qid , dexamethasone tid , and artificial tears qid ) that had to be kept at 4c ( fridge temperature ) .
initially , painkillers were not prescribed unless pain was deemed unbearable . in this case , the patient was given a protocol to use a rescue medication .
an ad hoc questionnaire was created to record the patients perceived symptoms after asa ( figure 1 ) .
the questionnaire consists of five parts or domains : 1 ) cognitive orientation , 2 ) pain perception , 3 ) other symptoms ( foreign body , tearing , photophobia , burning ) , 4 ) pain treatment prescribed , and 5 ) miscellanea .
furthermore , pain intensity was evaluated by means of an nrs , ie , 0- no pain and 10- the worst imaginable pain.14
this study was designed assuming that 95% ( internal data ) of the participants would present pain after asa procedure .
it was calculated that a representative sample for a survey study should include 73 subjects , based on the normal approximation with a range of 2.5% for a two - sided 95% confidence interval ( ci ) .
baseline characteristics were summarized with standard descriptive statistics and a descriptive analysis was carried out . the prevalence of symptoms after asa procedure was estimated and its 95% ci was calculated .
the spearman s correlation coefficient was used to assess the relation between the subjective feeling of pain and age and amount of ablation , and between discomfort and age and amount of ablation .
data analysis was carried out using spss version 15.0 statistical software ( spss inc . ,
chicago , il , usa ) and statxact-8 ( cytel inc . , cambridge , ma , usa ) .
a total of 73 consecutive patients ( 34 men and 39 women ) were included .
the median ( range ) of age was 33 ( 1964 ) years , and 69 ( 95% ) patients received surgery on both eyes . pain intensity and other symptoms
are shown in table 1 : 51% of the patients reported pain during surgery ; 8% of the patients reported more pain during the first eye surgery , 19% during the second eye surgery , and 73% of the patients presented the same pain in both eyes .
ninety - seven percent of the patients reported pain ( score equal or higher than 2 ) during the postoperative period .
the median ( range ) score of the worst pain intensity was 7 ( 010 ) ( mean [ sd ] : 6.3 [ 2.5 ] ) , and 49 patients ( 67% ) had severe pain ( 6 or higher ) .
it is noteworthy that 38 patients ( 52% ) reported a pain intensity higher than 7 .
the median ( range ) duration of the pain was 3 days ( range : 17 ) .
twenty - nine ( 40% ) patients required analgesic treatment in the postoperative period , out of which eleven patients ( 15% ; 95% ci : 825 ) chose analgesic rescue medication and 18 patients ( 25% ) used another painkiller ( metamizol or ibuprofen ) , which was not included in the protocol . regarding the patients impression about the prescribed treatment for pain , 67 patients ( 92% ; 95% ci : 8397 ) scored it as satisfactory or very satisfactory .
regarding other postoperative symptoms such as photophobia , burning , tearing , and foreign body sensation , results are shown in table 1 .
after pain , the most frequent ( 85% ) and most intense symptom was photophobia with a mean ( sd ) intensity score of 8.0 ( 2.2 ) .
burning sensation was also a very prevalent symptom ( 62% ) with a mean ( sd ) intensity score of 6.8 ( 2.5 ) .
it is relevant to mention that 36 patients ( 80% ) had values higher than 5 for burning sensation .
the mean ( sd ) intensity score for tearing was 7.2 ( 2.5 ) .
a high percentage of patients ( 63% ) scored higher than 7 for tearing intensity .
the less common symptom was foreign body sensation with a mean ( sd ) intensity score of 6.1 ( 2.5 ) ; 67% of patients scored equal or higher than 5 for this symptom .
the survey included a question to identify other complaints , referred to by the patients : inability to open eyes ( 8 [ 11% ] patients ) ; itching or sharp ocular pain ( 5 [ 7% ] patients ) ; swollen eyelids ( 3 [ 4% ] patients ) ; dryness ( 4 [ 5% ] patients ) ; and migraines ( 3 [ 4% ] patients ) .
no relationship was found between feeling of pain and age and amount of ablation , and between discomfort and age and amount of ablation . in this study ,
chilled bss was used during surgery and it was recommended that the patient used cold eye - drops to increase analgesia . a protocol of painkillers was not included as a standard in the postoperative medication.15,16 painkillers were used on demand as a rescue medication by the patients themselves .
the proportion of patients reporting additional need for analgesia was 40% ( 29 patients ) , but only eleven of them used the recommended rescue medication .
the rest of the patients ( 25% ) used painkillers not included in the protocol .
a total of 73 consecutive patients ( 34 men and 39 women ) were included .
the median ( range ) of age was 33 ( 1964 ) years , and 69 ( 95% ) patients received surgery on both eyes .
pain intensity and other symptoms are shown in table 1 : 51% of the patients reported pain during surgery ; 8% of the patients reported more pain during the first eye surgery , 19% during the second eye surgery , and 73% of the patients presented the same pain in both eyes .
ninety - seven percent of the patients reported pain ( score equal or higher than 2 ) during the postoperative period .
the median ( range ) score of the worst pain intensity was 7 ( 010 ) ( mean [ sd ] : 6.3 [ 2.5 ] ) , and 49 patients ( 67% ) had severe pain ( 6 or higher ) .
it is noteworthy that 38 patients ( 52% ) reported a pain intensity higher than 7 .
the median ( range ) duration of the pain was 3 days ( range : 17 ) .
twenty - nine ( 40% ) patients required analgesic treatment in the postoperative period , out of which eleven patients ( 15% ; 95% ci : 825 ) chose analgesic rescue medication and 18 patients ( 25% ) used another painkiller ( metamizol or ibuprofen ) , which was not included in the protocol . regarding the patients impression about the prescribed treatment for pain ,
67 patients ( 92% ; 95% ci : 8397 ) scored it as satisfactory or very satisfactory .
regarding other postoperative symptoms such as photophobia , burning , tearing , and foreign body sensation , results are shown in table 1 .
after pain , the most frequent ( 85% ) and most intense symptom was photophobia with a mean ( sd ) intensity score of 8.0 ( 2.2 ) .
burning sensation was also a very prevalent symptom ( 62% ) with a mean ( sd ) intensity score of 6.8 ( 2.5 ) .
it is relevant to mention that 36 patients ( 80% ) had values higher than 5 for burning sensation .
the mean ( sd ) intensity score for tearing was 7.2 ( 2.5 ) .
a high percentage of patients ( 63% ) scored higher than 7 for tearing intensity .
the less common symptom was foreign body sensation with a mean ( sd ) intensity score of 6.1 ( 2.5 ) ; 67% of patients scored equal or higher than 5 for this symptom .
the survey included a question to identify other complaints , referred to by the patients : inability to open eyes ( 8 [ 11% ] patients ) ; itching or sharp ocular pain ( 5 [ 7% ] patients ) ; swollen eyelids ( 3 [ 4% ] patients ) ; dryness ( 4 [ 5% ] patients ) ; and migraines ( 3 [ 4% ] patients ) .
no relationship was found between feeling of pain and age and amount of ablation , and between discomfort and age and amount of ablation .
in this study , chilled bss was used during surgery and it was recommended that the patient used cold eye - drops to increase analgesia . a protocol of painkillers was not included as a standard in the postoperative medication.15,16 painkillers were used on demand as a rescue medication by the patients themselves .
the proportion of patients reporting additional need for analgesia was 40% ( 29 patients ) , but only eleven of them used the recommended rescue medication .
the rest of the patients ( 25% ) used painkillers not included in the protocol .
asa and prk result in a complex cascade of events that trigger sensory afferent fibers in the cornea , producing various degrees of pain.4 it is admitted that postoperative pain resulting from corneal epithelial debridement remains a significant limitation to the acceptance and usefulness of these procedures.5,17,18 in prk , epithelial debridement is performed;19 thus techniques to preserve the epithelium are used in an attempt to decrease postoperative pain.20 but the effect of removal of epithelial flap versus preservation of the flap on postoperative pain is unclear.4 in a study , epi - lasik versus off - flap epi - lasik were compared , and subjective pain scores were lower at 2 hours follow - up in the off - flap epi - lasik group , but not at 4 , 6 , 8 , 10 or 24-hour intervals.21 in other study , postoperative pain was similar between epi - lasik and off - flap epi - lasik groups.22 our results are in line with previous studies , in that severe pain was present in practically all patients after asa procedure,23 and the time course of pain was as expected.24 pain begins within 1 hour .
its intensity increases until 4 hours after the surgical procedure , peaking at approximately 24 hours postoperation,25 and subsides within 72 hours after surgery , when reepithelialization is complete.24,26 therefore , the results of this study provide evidence that the peak of pain is at 24 hours and median duration of pain is 3 days . in consequence , a complete postoperative pain assessment after asa should be performed for at least this number of hours .
management of acute postoperative pain is a challenge for any surgery and acute ophthalmologic postoperative pain is not an exception . likewise , intraoperative pain is also important .
moreover , data available on the perception of pain during asa procedure and its frequency are scarce.27 our study evaluated intra - operatory pain finding that half the patients notice pain during surgery .
another novelty in the outcome of this study is that 73% of these patients referred to the same pain in both eyes and only 19% reported more pain in the second eye .
there are studies reporting the subjectivity of patients pain after first eye cataract surgery versus second eye,28 but we have not found any regarding asa .
another important result is 25% of patients used painkillers outside the protocol , acting by themselves instead of using the recommended rescue medication .
this lack of compliance was attributed by the patients to the potential side effects related to the prescribed medication .
it is noteworthy that patients who have undergone refractive surgery are generally young and healthy , so they may be considered as healthy volunteers .
besides , they have been previously informed about the transience of the postoperative discomfort and pain . therefore , it is fair to say that the benefit of the operation prevails over other negative features .
that is to say , the emotional aspect tends to minimize the postoperative symptoms.8 our study did not allow for predicting what type of patients might be at increased risk for pain intolerance .
in fact , this could be another area of ocular pain research . to use a questionnaire or other kind of noninvasive test at the time of deciding whether to perform asa , prk or another refractive procedure could help the ophthalmologist in the control of postoperative pain .
consequently , this may help minimize the number of patients with severe postoperative pain and discomfort .
a crucial issue dealing with pain is how to measure it in clinical practice . in our study ,
different types of scales have been developed to evaluate pain , including visual analog scale ( vas ) and various categorical scales using faces , numbers , or verbal categorical descriptors,29 although , none has been specifically developed and validated for ophthalmic pain.17 the majority of previous investigators have used general pain scales to measure pain after ophthalmic procedures.23 the most recommended methods for the assessment of pain intensity are nrs , verbal rating scale ( vrs ) , or vas , because all of them provide sufficient power to describe pain intensity.30 most of the reviewed papers used versions of scales according to current recommendations , primarily nrs-11 , vrs up to seven categories , and vas-100 mm.31 nrs and vrs , which are validated scales , showed a high concordance between them and are equally sensitive in assessing acute pain after surgery.27 in a review , these three scales for the assessment of postoperative pain intensity in adults were evaluated.30 this study concluded with a novel idea .
the most important choice is not the type of scale , but the conditions related to its use , such as a standardized choice of anchor descriptor , methods of administration , and time frame , among others.30 they believed that all of these areas can be improved by an international consensus process following the medicine - based evidence rules , which should include improving and standardizing the use of nrs.30 the validity of the vas and nrs for pain could be extended by using other clinically relevant descriptors of pain such as the proportion of patients reporting need for analgesia.32 in our study where 97% of patients reported pain in the postoperative period , only 40% of patients mentioned that they required analgesics .
another important limitation of refractive surgery is the existence of postoperative discomfort.26 with this respect , a study stood out because the author distinguished between pain and discomfort , explaining that discomfort is a group of symptoms characterized by photophobia , burning , tearing , and foreign body sensation , and all of them were individually evaluated.13 most of the studies only evaluate some of these symptoms , with photophobia being the most frequent.5 in a recent study , 13 most patients reported discomfort with a score of 8 or 9 on a 10-point pain scale , while in our study , photophobia was the only symptom with a score of 8 .
after postoperative pain , photophobia was the prevalent symptom present in 85% of our patients .
these results are in line with other reports.5,24,25 on the other hand , factors such as age and amount of ablation were not associated with pain and discomfort after asa .
similar findings have been reported.13 although , it is worth mentioning that in our study , all age groups are not represented since the patients included are very young . therefore , this study suggests that a new pain management strategy is necessary at least during the 3 days postoperative asa .
similarly , there are other symptoms related to ocular discomfort which should call our attention to lead us toward better postoperative care .
recent studies have reviewed pain management strategies after prk.4,3335 these strategies include the use of cold bss during the procedure,34 and the postoperative placement of extended - wear bcls until reepithelialization occurs.35 topical nsaids are often used to manage pain and discomfort following refractive surgery.4 common ocular adverse events of topical nsaids include transient burning , stinging , and conjunctival hyperemia , and the most serious adverse events are superficial punctate keratitis , corneal infiltrates , epithelial defects , and corneal melts.33 moreover , there is also concern that topical nsaids may lead to delayed epithelial healing .
this was the main reason why these topical drugs were excluded from our asa postoperative clinical protocol .
instead , oral medications approved for neuropathic pain , such as gabapentin and pregabalin , are adjunctive agents that help minimize the use of topical medication.36 despite the fact that oral nsaids are considered excellent analgesics in many acute pain settings , they have not been specifically studied for post - prk pain.37 oral analgesics , such as opiates , may be used for moderate - to - severe pain after prk because opioid receptors present in the cornea respond to them.4 with the advent of new methods of analgesia targeting specific corneal sensory afferent nociceptors , discomfort can be minimized with less impact on corneal healing.4 these concepts might be important to evaluate in future studies looking at optimization of pain management .
there are several limitations to this study , which should be considered before drawing any conclusions .
the study design ( survey study ) , the use of a telephone questionnaire instead of a personal interview , and the type of population analyzed ( from a single geographical site and operated on by a single surgeon in the center of reference ) might underestimate or overestimate the generalization of the results beyond the population and conditions studied .
likewise , since the patients were directly asked about pain , photophobia , burning , tearing , and foreign body sensation , this kind of questioning might overestimate the results .
nevertheless , this type of procedure ( telephone questionnaire ) in a survey study is considered reliable and valid and has been used for evaluating acute events38,39 and chronic pain.40 on the other hand , one of the problems related to telephone surveys is their duration , which could influence the quality of the answer .
this study was done in a 10-minute time period . in spite of these limitations ,
in conclusion , our results suggest that several comorbidities such as pain , photophobia , burning , tearing , and foreign body sensation are prevalent after an asa procedure . among them , postoperative pain should be taken into consideration because of its prevalence and intensity .
these results justify additional research to get a more efficient postoperative analgesic protocol after ophthalmologic surgical procedures . | purposelaser vision correction is one of the most commonly performed elective surgical procedures in ophthalmology . generally , discomfort besides pain ( photophobia , burning sensation , tearing , and foreign body sensation ) after these procedures is not taken into consideration in the clinical practice .
the objective is to provide data on these symptoms and their relevance after advanced surface ablation ( asa).methodssingle - center survey study based on a structured questionnaire relative to the patients perceived symptoms after asa .
inclusion criteria were : 18 years old , no ocular disease , with myopia ( 0.75 to 9 d ) or hyperopia ( 0.25 to 5 d ) with or without astigmatism , receiving asa on at least one eye . all procedures were performed by the same surgeon .
a descriptive analysis was performed.resultsseventy-three consecutive patients ( 34 men and 39 women ) were included in the study .
the median ( range ) of age was 33 ( 1964 ) years .
sixty - nine patients had surgery done on both eyes .
postoperative pain was the most frequent comorbidity ( 97% [ 95% confidence interval { ci } : 90100 ] ) with a median ( range ) of intensity ( verbal numerical rating scale ) score of 7 ( 210 ) .
photophobia : 85% ( 95% ci : 7592 ) ; burning sensation : 62% ( 95% ci : 5073 ) ; tearing : 59% ( 95% ci : 4770 ) ; and foreign body sensation : 48% ( 95% ci : 3660 ) were also prevalent postoperative symptoms .
pain during asa was reported for 44% ( 95% ci : 3256 ) of patients.conclusioncomorbidities such as pain , photophobia , burning sensation , tearing , and foreign body sensation are prevalent after asa procedure .
postoperative pain should be taken into consideration due to its prevalence and intensity .
a new and more efficient postoperative analgesic protocol should be established . |
since 2007 , genome - wide association studies ( gwass ) have emerged as a powerful tool to identify disease - related genes for many common human disorders and other phenotypes .
the national human genome research institute ( nhgri ) and the centers for disease control and prevention ( cdc ) both maintain online resources for tracking published gwass .
data from the cdc huge navigator , an online , curated and searchable knowledge base in human genome epidemiology , show that the number of published gwass grew from only a handful before 2007 to more than 300 as of mid - march 2009 .
gwass are characterized by the need for very large study populations and replication samples because the expected effect sizes are small and the expected number of false positive findings is large .
thus , although the cost of genotyping has decreased rapidly ( and is expected to decrease further ) , gwass remain a costly approach . recently , the national cancer institute announced $ 96 million in grants over 4 years to support post - gwas cancer studies to replicate and understand the biological basis of gene discoveries .
these investments are in addition to the approximately $ 3 billion spent on the human genome project , which was justified to the public largely on the basis of its potential to identify genetic risk factors leading to prevention and treatment of common diseases .
the conventional gwas approach is a hypothesis - free , systematic search of tagging single nucleotide polymorphisms ( snps ) across the genome to identify novel associations with common diseases .
although many such associations have been found and replicated , their effect sizes are modest at best ( odds ratios mostly between 1.0 and 1.5 ) and they generally lack sufficient clinical sensitivity , specificity and predictive value to serve as risk or screening markers . furthermore , in the absence of contextual information - such as potential functional implications at the molecular level , influence on physiologic processes or potential environmental interactions - these associations provide only a starting point for further research .
pharmacogenomics has often been represented as the leading edge in translating human genomic research for clinical practice , creating the basis for personalized medicine .
it examines inter - individual variation in drug effects as a function of genetic variation by integrating epidemiological , genetic , pharmacological and clinical measurements .
results of the 12 pharmacogenomics gwass published so far are summarized in a recent review by crowley et al .
six gwass evaluated the association of genetic variation with drug efficacy , five evaluated adverse effects , and one examined a dose - response relationship ( warfarin ) .
the gwas approach has succeeded in discovering new associations with adverse drug effects , even though the biological mechanisms may be obscure .
an example is the recent identification of a common variant in the sclo1b1 gene that markedly increases the risk of statin - induced myopathy ( odds ratio : 4.7 - 61.1 , p = 4.1 10 ) .
the investigators estimated that 60% of incident myopathy could be attributed to the newly identified variant .
gwass have also found genetic variants associated with individual responses to drugs , including analgesics and chemotherapeutic agents .
gwass have been recognized as an important approach for uncovering polymorphisms accounting for individual differences in drug efficacy and drug safety . a vast reservoir of observational studies and randomized clinical trials ( rcts ) - completed , ongoing or planned - provides a largely untapped resource for pharmacogenomic studies of drug safety and efficacy . in particular ,
rcts allow for precise measurement of drug exposure and consistent ascertainment of phenotype ; randomization produces unbiased treatment assignments and helps balance unmeasured confounding factors .
performing gwass within clinical trials , in which more potentially interacting variables can be identified , measured and controlled , improves efficiency .
khoury and wacholder recently stressed that effects measured in gwass will be correct only when gene - environment interactions are taken into account ; pharmacogenomic studies examine gene - environment interactions by definition .
so far , most such studies have included far fewer participants ( average approximately 200 ) than the very large sample sizes typical of gwass of common diseases .
nevertheless , even small pharmacogenomics gwass have been successful in identifying robust associations because reducing variability in the definition and ascertainment of exposure and outcome increases their power to detect clinically meaningful effects .
the absolute cost of gwass in pharmacogenomics remains as high as in other fields , but in the context of drug rcts and observational studies for side effects , the marginal cost of genotyping is small : as roses recently pointed out , the entire investment in dna sample collection and genotyping up to now is only a small fraction of the currently estimated cost to develop a single drug . at present , investment in gwass ,
pharmacogenomics and clinical trials of drug safety and efficacy are not coordinated . from 2001 to mid - march 2009 ,
huge navigator identified 2,967 articles on pharmacogenomics , of which only 299 ( 10% ) were clinical trials and 12 ( 0.4% ) were gwass ; these 12 articles accounted for just 4% of all gwass ( figure 1 ) . a coordinated approach to gwass in rcts
a first step would be to collect appropriate biological samples from all clinical trial participants and obtain their informed consent for future pharmacogenomic research studies .
overlap of human genome epidemiology ( huge ) , pharmacogenomics ( pgx ) and genome - wide association study ( gwas ) literature , from 2001 to mid - march 2009 .
numbers indicate the results obtained when pubmed and huge navigator publication databases were searched by the following terms : pubmed : " pharmacogenet * or pharmacogenom * " ( pgx ) .
huge navigator ( total publications 40,858 ) : " pharmacogenomics " ( pgxe ) ; " gwas " ( gwas ) .
many drug adverse effects are rare , coming to light only after a drug becomes available for widespread use .
clinical trial participants are a key reference population for subsequent investigation of adverse effects in case - control gwass .
in addition , observational studies built on practice - based settings ( such as the health maintenance organization ( hmo ) research network ) can provide clues to adverse drug effects and differences in effectiveness in ' real ' world settings , outside the restricted conditions of rcts .
so far , only two gwass have been conducted in drug clinical trials ; each of these studies provides relevant insights for future research .
a study of electrocardiographic abnormalities during iloperidone treatment of schizophrenia illustrated the feasibility of performing gwass in a phase iii clinical trial evaluating the efficacy , safety and tolerability of a novel drug .
a report on statin - related myopathy demonstrated the efficiency of performing a nested case - control gwas within a clinical trial . given their efficiency and potential for leading to useful clinical medicine and public health applications , it seems surprising that so few gwass have been done in the field of pharmacogenomics , especially within clinical trials . the incentives for conducting such studies deserve closer evaluation .
the us food and drug administration has encouraged clinical trial sponsors to submit pharmacogenomic data , including gwass , on a voluntary basis .
the national institutes of health has recently established funding priorities and requirements for gwass in government - funded clinical trials . in parallel , the prevailing method of reporting results - typically limited to novel ' gwas hits ' or to one candidate gene at a time - should be revisited .
recently , the investigators in the catie trial of antipsychotic therapy in schizophrenia demonstrated the feasibility of sharing complete pharmacogenomic study data and discussed the utility of this approach for the scientific community .
comprehensive reporting of gwas results in standardized formats will enhance opportunities for evidence synthesis through meta - analysis .
thus , gwass can not only identify novel associations for further study , but can help counter the selective reporting and pursuit of false positive findings that may occur when pharmacogenomic studies are limited to candidate genes .
the past few years have seen a flurry of gwas findings , but few have found their way to clinical application .
pharmacogenomics studies , especially clinical trials , provide a promising setting for the gwas approach , which has already shown success in identifying key genetic determinants of drug efficacy and adverse effects . despite the potential for effective translation of such findings
gwas : genome wide association study ; huge : human genome epidemiology ; nhgri : national human genome research institute ; rct : randomized clinical trial ; snp : single nucleotide polymorphism .
ig , mg , and mjk were involved in drafting the manuscript and have given final approval of the version to be published .
we thank wei yu and mindy clyne for development and curation of the huge navigator knowledge base .
this research was supported in part by the appointment of ig to the research participation program at the centers for disease control and prevention administered by the oak ridge institute for science and education through an interagency agreement between the us department of energy and the cdc .
the findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the cdc . | despite large public investments in genome - wide association studies of common human diseases , so far , few gene discoveries have led to applications for clinical medicine or public health .
genome - wide association studies in the context of clinical trials of drug safety and efficacy may be quicker to yield clinical applications .
certain methodological concerns , such as selection bias and confounding , may be mitigated when genome - wide association studies are conducted within clinical trials , in which randomization of exposure , prospective evaluation of outcome and careful definition of phenotype are incorporated by design . |
how ring e3 ligases mediate e2-to - substrate ubiquitin - like protein ( ubl ) transfer remains unknown .
here we address how the ring e3 rbx1 positions nedd8 s e2 ( ubc12 ) and substrate ( cul1 ) .
we find that existing structures are incompatible with cul1 nedd8ylation and report a new conformation of rbx1 that places ubc12 adjacent to cul1 .
we propose ring domain rotation as a general mechanism for ubl transfer for the largest family of e3s . | |
clinically , primary glaucoma presents two major subtypes : primary open - angle glaucoma ( poag ) and primary angle closure glaucoma ( pacg ) .
the classification relies mainly on the anterior segment anatomy , particularly that of the anterior chamber angle .
pacg is characterized by obstruction of aqueous fluid drainage through the trabecular meshwork from the anterior chamber of the eye .
the anterior chamber depth ( acd ) is a main factor affecting the drainage of aqueous humor .
pacg affects as many as 4.5 million people in china , and it has been reported that asian populations are at higher risk of developing pacg than other ethnic groups .
eyes with pacg usually display characteristic anatomical features such as a shorter corneal diameter , a steeper corneal curvature , a shallower anterior chamber , a thicker and more anteriorly positioned lens , and a shortened eyeball , often accompanied by hyperopic refraction error .
the risk factors for developing pacg include age , family history , and being female .
first - degree relatives were found to have a 6- to 9-fold increased risk of developing pacg .
siblings of chinese patients with pac or pacg have almost a 50% probability of having narrow angles and are more than 7 times more likely to have narrow angles than the general population .
there is also a higher prevalence among inuits and asians compared to caucasians , suggesting a genetic predisposition for the disorder . because the ocular anatomic features are predisposing factors for pacg , genes involved in regulation of axial length and structural remodeling of connective tissues may contribute to development of pacg . some tissue remodeling genes including membrane frizzled - related protein ( mfrp ) [ 7 ,
8 ] , extracellular matrix metalloprotease-9 ( mmp-9 ) [ 911 ] , and methylenetetrahydrofolate reductase ( mthfr ) have been reported to be associated with pacg .
even though heat shock protein 70 ( hsp70 ) does not regulate tissue remolding directly , it regulates the expression of matrix metalloproteases ( mmps ) and is thought to be associated with pacg .
however , the above findings remain controversial and have not been replicated by independent studies .
recently , a genome - wide association study ( gwas ) identified three new susceptibility loci for pacg , including rs11024102 in plekha7 , rs3753841 in col11a1 , and rs1015213 in pcmtd1-st18 .
however , the mechanism of these genes in pacg pathogenesis is unclear , and the biological plausibility is absent .
we hypothesized that plekha7 , col11a1 , and pcmtd1-st18 might contribute to pacg by influencing ocular biometry .
thus , in this study , we attempted to replicate the association between these three loci with primary angle closure ( pac ) instead of pacg to investigate whether the snps of these three genes are associated with ocular biometry .
pac is the earlier stage of pacg and shares the same anatomical features ; however , pac does not present glaucomatous optic neuropathy .
our definition of pac includes asymptomatic individuals with occludable angles who have not had an acute attack as well as those who have had an attack but received prompt treatment and suffered no detectable nerve damage .
the study was a part of the jiangsu eye study and was conducted according to the declaration of helsinki and approved by the ethics committee of the affiliated hospital of nantong university .
each participant was fully informed of the purpose and procedures involved in the study and signed the informed consent form .
all participants were recruited from a population - based prevalence survey on eye diseases using a cluster random sampling strategy in funing county of jiangsu , china . of
the 6032 people screened , 232 people with pac and 306 controls were enrolled in the study .
pac subjects and controls were matched in groups for sex and age and were ethnically homogenous .
there was no difference between the control group and the pac group in gender , age , or systemic disease distribution .
all study participants were residents of funing county of jiangsu , china , aged 50 years and above .
each participant received a thorough ophthalmic examination , included best - corrected visual acuity , anterior segment photography , goldmann applanation tonometry , fundus examination , optic disc photography , visual field , objective refraction , and subjective refraction .
the subjects with a peripheral chamber depth less than one - third of corneal thickness were invited for gonioscopy , a - scan ultrasonography , and ultrasound biomicroscopy ( ubm , sw-3200s , suoer , china ) examinations .
the detailed protocol for gonioscopy and ubm was reported previously by barkana et al . .
three measurements of acd and al were made by a - scan to get mean values , and mean values of binoculus were used for statistical analyses .
pac was defined according to the international society of geographical and epidemiologic ophthalmology ( isgeo ) classification by foster et al . :
( 1 ) either eye has the presence of an occluded angle ( at least 180 degrees of closed angle in which the trabecular meshwork is not visible on gonioscopy or iris apposition to the trabecular meshwork more than 180 degrees on ubm ) ; ( 2 ) at least one of the following features was detected : peripheral anterior synechiae , intraocular pressure > 21 mmhg , excessive pigment deposition on the superior trabecular meshwork , iris whirling , history of symptoms , or intraocular pressure elevated 8 mmhg after ubm examination in dark conditions ; ( 3 ) no signs of secondary angle closure ; ( 4 ) no signs of glaucomatous optic neuropathy and peripheral visual loss ; ( 5 ) no previous ocular surgery or laser therapy .
the criteria for enrollment of the control group were ( 1 ) peripheral chamber depth more than one - third of corneal thickness , ( 2 ) intraocular pressure less than 21 mmhg , ( 3 ) normal optic nerve heads with cup - to - cup ratio less than 0.5 , ( 4 ) normal visual field , ( 5 ) no family history of glaucoma , ( 6 ) no ophthalmic diseases except slight cataract , and ( 7 ) : refractive error less than three diopters .
genomic dna was extracted from the peripheral blood of each individual using the qiagen blood dna mini kit ( qiagen , valencia , ca ) , according to the manufacturer 's instructions and stored at 20c .
the samples were genotyped by taqman aenotyping assay ( applied biosystems , foster city , ca , usa ) using the real - time pcr 7500 system ( applied biosystems , foster city , ca , usa ) .
the assay ids are c_2981015_10 for rs11024102 ( an snp in intron region ) , c_2947954_10 for rs3753841 ( a missense snp ) , and c_7479939_10 for rs1015213 ( a snp in intergenic region ) .
pcr reactions were performed in a total volume of 10 l containing 1 l ( 10 ng ) dna , 5 l taqman universal master mix , 0.20 l taqman snp genotyping assay mix ( 40x ) , and 3.8 l dnase - free , sterile filtered water . amplification was carried out with an initial denaturation at 95c for 5 min , followed by 40 cycles of denaturation at 95c for 30 s and annealing at 60c for 30 s. statistical analysis was performed with spss version 15.0 software .
differences in age and gender between pac subjects and controls were assessed using t - test and chi - square test , respectively .
hardy - weinberg equilibrium was tested using chi - square test . to analyze the association of these three snps with pac and controls , the frequency of genotypes and alleles
logistic regression analysis was performed to calculate the odds ratio ( or ) value , the 95% confidence interval ( 95% ci ) , and to adjust the confounding effects of age and gender . if any positive association was found in the initial analysis , bonferroni correction was performed .
three genetic models were analyzed : the additive model defined as minor allele homozygotes versus heterozygotes versus common allele homozygotes , the dominant model as heterozygotes plus minor allele homozygotes versus common allele homozygotes , and the recessive model as minor allele homozygotes versus common allele homozygotes plus heterozygotes .
the association of these three snps with al , acd , and ds was also assessed under the additive genetic model , dominant model , and recessive model using t - test .
the call rates of all snp genotyping were 100% and the call accuracies were 100% in a randomly selected 10% sample .
all 3 snps conformed to hardy - weinberg equilibrium ( p > 0.05 ) except for pcmtd1-st18 rs1015213 in controls .
none of the three polymorphisms showed differences in the distribution of allele frequencies ( table 3 ) and genotypes ( table 4 ) between the cases and controls .
all three snps were not significantly associated with biometric parameters including acd , al , and ds ( table 5 ) .
this study , to the best of our knowledge , is the first population - based study to investigate the association of rs11024102 , rs3753841 , and rs1015213 with pac and pac relevant biometric parameters such as acd , al , and ds in a han chinese population .
the design of a population - based study can minimize sample selection bias often present in hospital - based case - control study .
we attempted to replicate the association between these three loci with pac instead of pacg to verify the relationship between these snps and anatomic features .
the results show that the variations of plekha7 rs11024102 , col11a1 rs3753841 , and pcmtd1-st18 rs1015213 were not associated with either pac or biometric factors in han chinese population .
plekha7 encodes pleckstrin homology domain - containing protein 7 , which is involved in the maintenance and stability of epithelial and endothelial adherens junctions .
plekha7 is expressed in the cornea , iris , and trabecular meshwork ( tm ) .
increased resistance to drainage of aqueous humor through the pressure - dependent tm is believed to be responsible for poag . however , the pathogenesis of pacg is distinct from that of poag .
eyes with pacg tend to share certain anatomic biometric characteristics and have nothing to do with aqueous humor outflow facility . in our present study
, we did not find any association between rs11024102 and pac , nor did we find any association between rs11024102 and biometric parameters .
type xi collagen is a minor fibril - forming collagen , controlling fibril growth , diameter , and assembly of major collagens .
mutations in col11a1 cause marshall syndrome , stickler syndrome , and stickler - like syndrome ; these disorders are all characterized by midfacial hypoplasia , sensorineural hearing deficit , and nonprogressive axial myopia .
hyperopic and shorter axial length , but not axial myopia , is well - known predisposing factor for pacg . in our present study ,
the distribution of genotypes of rs3753841 was similar in the pac and in the control group , as were the biometric parameters .
pcmtd1 encodes protein - l - isoaspartate o - methyltransferase domain - containing protein 1 that is expressed in the cornea , iris , and tm .
st18 encodes the suppression of tumorigenicity 18 protein , expressed in the cornea and lens , but not in the tm . in our study ,
the minor allele frequency of rs1015213 was low , which is consistent with previous reports [ 14 , 22 ] .
there was no significant difference between the two groups in the genotype frequency or alleles for rs1015213 nor any significant difference between rs1015213 and biometric parameters .
's report that reported the three loci susceptible for pacg by a gwas study with a two - stage strategy .
sample size and ethnic distribution are two main factors that can influence the results of genotype association studies .
vithnan 's study included 1854 pacg cases from an asian population in stage 1 and 1917 pacg cases from 6 sample collections ( two in china , and one each in uk , singapore , india , and saudi arabia ) .
the power analysis based on their data indicated that our study is underpowered ( < 50% ) to detect any association of the 3 tested snps .
however , all subjects included in this study are han chinese and subjects in both groups were age and gender matched .
moreover , the study was community based , thus decreasing the confounding of possible population stratification .
we believe that our sample size is reasonable to detect a biologically meaningful association if it exists .
another possible reason that we did not replicate the vithana 's report might be due to the different definition of the phenotypes , pac in our study and pacg in vithana 's study .
because the number of pacg patients in this community cohort did not meet the basic requirements to conduct an independent association study , we excluded this phenotype .
day et al . conducted a genotype - phenotype analysis of these three snps with the ocular biometry of 988 european people .
they found that the a allele of rs1015213 was nominally associated with acd ( p = 0.046 ) but not associated with al or corneal keratometry .
rs11024102 and rs1015213 were not associated with ocular biometry , which is consistent with our results .
another limitation in our study is that al and acd parameters are only available for the pac group .
it is time consuming and technically demanding to invite all 6032 participants for ubm , gonioscopy , and a - scan examinations . additionally , the development of pacg is complex and likely depends on polygenic inheritance .
it appears that each anatomic characteristic is not determined by a series of independent genes acting with no relation to other components but is instead an additive outcome of the action of a large number of genes .
the sequence variants of plekha7 rs11024102 , col11a1 rs3753841 , and pcmtd1-st18 rs1015213 do not appear to be associated with pac and ocular biometry in our study . because the plekha7 rs11024102 , col11a1 rs3753841 , and pcmtd1-st18 rs1015213 were reported to be associated with pacg
, the lack of association of these snps may be due to a different phenotype being assessed . | genome - wide association study ( gwas ) analysis identified three new susceptibility loci for pacg . in this study , we aimed to investigate whether these three loci in plekha7 , col11a1 , and pcmtd1-st18 are associated with pac and ocular biometric characteristics , such as axial length ( al ) , anterior chamber depth ( acd ) , and diopter of spherical power ( ds ) .
the study was a part of the jiangsu eye study .
the samples were collected from 232 pac subjects and 306 controls from a population - based prevalence survey conducted in funing county of jiangsu , china .
the single nucleotide polymorphisms ( snps ) of rs11024102 in plekha7 , rs3753841 in col11a1 , and rs1015213 in pcmtd1-st18 were genotyped by taqman - mgb probe using the rt - pcr system .
none of the three polymorphisms showed differences in the distribution of genotypes and allele frequencies between the pac group and the control group .
no significant association was determined between the 3 snps and al , acd , or ds of pac subjects .
we concluded that even though plekha7 rs11024102 , col11a1 rs3753841 , and pcmtd1-st18 rs1015213 are associated with pacg , those sequence variations are not associated with pac in a han chinese population .
our results also did not support a significant role for these three snps in ocular biometry such as al , acd , and ds . |
squamous cell carcinoma ( scc ) is amongst the top 3 common skin cancers , ranking behind basal cell carcinoma ( bcc ) and ahead of melanoma .
it is a tumor that is locally invasive and which has the capacity to metastasize .
prognostically , it also occupies an intermediate position between bcc and melanoma , with bcc being locally invasive but typically nonmetastasizing , while melanoma having the well - known capability to metastasize .
however , diagnostic challenges are occasionally encountered and contributed mainly by the myriad of histopathologic mimics of scc and small biopsies that sample only part of the lesion . for the simulators of scc , on the one hand , there are benign squamous lesions that appear to be infiltrative histopathologically . on the other hand , there are other malignant skin tumors that may display squamous differentiation or which elicit squamous proliferation that mimic scc .
misdiagnosis of benign lesions as scc would result in unnecessarily extensive surgery , while delayed diagnosis of scc could lead to local tissue destruction by tumor , sometimes metastatic disease , and even death .
some malignant differential diagnostic entities , for example , melanoma and merkel cell carcinoma ( mcc ) , have worse prognosis or require different surgical strategies and differ in the need for adjuvant treatment [ 3 , 4 ] .
this review will present all the salient benign and malignant differential diagnoses of scc , highlight diagnostic pitfalls , and suggest strategies for clinching the appropriate diagnosis .
inverted follicular keratosis is a lesion that histopathologically shows downgrowths of follicular squamous epithelium and the adjacent epidermis .
it commonly occurs in middle - aged and elderly patients , presenting as a scaly papule , nodule , or plaque .
in contrast to scc , it has circumscribed borders , and significant cellular atypia is not seen ( figures 1 and 2 ) . a pitfall with regard to differential diagnosis of a supposedly benign squamous keratosis
histologically , attention should be turned away from the hyperkeratotic superficial horn to the underlying lesional epithelium , which may be limited in amount in the specimen ( figure 3 ) .
the presence of significant atypia or abnormal maturation would raise the possibility of actinic keratosis or bowen disease or even the superficial aspect of an invasive scc .
pseudoepitheliomatous hyperplasia ( peh ) is a florid proliferation of the epidermis that may occur in the setting of chronic skin ulcers , abscesses , burns , and infections .
peh with neutrophilic microabscesses is typically seen in halogenodermas , infections like chromomycosis and blastomycosis , granuloma inguinale , leishmaniasis , and pemphigus vegetans . while the squamous epithelium of peh can appear infiltrative , resembling well - differentiated scc , careful attention
should show that marked cellular atypia and abnormal mitotic activity are absent ( figures 4 and 5 ) . a careful search for an inciting infective process
should be carried out with examination of deeper levels and use of microbiological special stains . in challenging cases ,
close clinical correlation and followup are required ; rare cases require repeat biopsy for evaluation .
infundibulocystic hyperplasia is a distinctive follicular epithelial proliferative process with formation of dilated canals containing keratotic material . presenting clinically as a nodule or plaque , it features histologically bland lesional squamous cells and a relatively superficial noninfiltrative deep edge ( figure 6 ) . when a short clinical evolution is noted and the lesion has a crateriform architecture , the features relate more to keratoacanthoma ( vide infra ) . when marked cellular atypia or abnormal mitosis
is noted , or if deeply infiltrative tongues are present , the lesion should be regarded as malignant , and an appropriate designation is infundibulocystic scc ( figure 7 ) .
verrucous hyperplasia is another type of epidermal squamous proliferation typified by broad and superficial downgrowths of the epidermis ( figure 8) .
this condition usually occurs in the skin within and around the external genitalia and the oral cavity , in reaction to a variety of chronic irritative etiologies .
this feature can be difficult to assess in superficial or poorly oriented biopsies . nevertheless , verrucous hyperplasia is well known to occur in close proximity , or to precede verrucous carcinoma .
its presence in the context of a clinically worrying lesion should prompt close followup or a deeper and wider biopsy .
eccrine squamous syringometaplasia ( ess ) is a reactive process characterized by squamous metaplasia of eccrine ducts and glands [ 10 , 11 ] .
it commonly occurs in the axillary and groin regions and presents as nodules and plaques .
ees is most well described as an adverse drug reaction , mostly to chemotherapeutic drugs .
while it should not be confused with scc clinically , it could cause some confusion histologically .
the lesion features cytologically bland squamous islands in the dermis that are closely associated with eccrine lumina and conforming to a lobular configuration ( figure 9 ) .
desmoplastic trichoepithelioma presents clinically as an enlarging nodule and shows cords and nests of basaloid cells with horn cyst formation , embedded within a sclerotic dermal stroma ( figures 10 and 11 ) .
the hyperplastic downgrowth of the epidermis and the cords of basaloid tumor cells give a pseudoinfiltrative appearance mimicking the features of scc .
the reassuring absence of significant atypia and the paucity of mitotic activity should be sought for .
the cohesive tumor cells growing as cellular sheets or cord - like manner streaming within a sclerotic dermis can appear concerning .
in unusual clinical contexts , benign lesions of varied nature may mimic scc both clinically and histopathologically .
meningioma has been known to occasionally be located outside the intracranial location to involve the scalp .
histopathologically , the syncytial sheets or whorled arrangement of tumor cells may impart a squamoid appearance ( figure 12 ) . the presence of nuclear pseudoinclusions , psammoma bodies and the absence of significant atypia , in most cases , should allow distinction from scc .
immunohistochemistry is of limited value in distinguishing the entities as both meningioma and scc share expression of ema , and the former is sometimes reactive for cytokeratins as well .
another form of lesional tissue that may sometimes cause diagnostic confusion is decidualized endometrial tissue occurring outside the confines of the female genital tract .
the most common context of this is endometriotic deposits in the skin and soft tissue of the abdominal wall or perineum , where background therapy with progestational agents causes decidualization of the endometrial stromal component ( figure 13 ) .
such decidualized cells are plump and form sheets , complete with well - defined intercellular borders , simulating scc , if not for the notable absence of nuclear atypia .
ka is a well - differentiated squamoproliferative tumor , with a fairly rapidly growing clinical course ( figure 14 ) .
some authorities consider it a variant of scc , while others regard it as a unique entity in view of its typically self - involuting course .
histopathologically , it features a cup - shaped or crateriform architecture , containing a central keratinous plug , bounded by lobules of lesional squamous epithelial cells ( figure 15 ) .
features that favor a lesion as a ka rather than being an scc include a limited pushing deep front , distinct tumour - stromal interface , and lesional squamous cells with abundant cytoplasm centrally .
while there have been numerous studies investigating the differences between ka and scc of the molecules involved in the regulation of cellular proliferation , apoptosis and the cell cycle , the histomorphology , as well as consideration of the clinical tempo of the lesion are still the most practical aspects in routine diagnosis .
an scc can sometimes have a crateriform architecture mimicking a ka ( ka - like scc ) .
in this regard , at least part of the tumor should have marked cytologic atypia , frequent or abnormal mitoses , or infiltrative margins ( figures 7 and 16 ) .
a shave biopsy that samples only the superficial part of a well - differentiated example of such a lesion could potentially lead to an underdiagnosis of an scc ( figure 16 ) . where there is diagnostic doubt about a particular lesion , a complete excision should be recommended .
proliferating tricholemmal tumor ( ptt ) , also known as proliferating pilar tumor or pilar tumor , is a well - circumscribed proliferation of squamous cells [ 18 , 19 ] .
it commonly occurs on the scalp or other parts of the head and neck as a gradually enlarging nodule or tumor ( figure 17 ) .
histopathologically , apart from conventional squamous cells , the tumor shows cellular areas with characteristic clear cytoplasm and abrupt pilar - type keratinization ( figure 18 ) .
there is a spectrum of appearances which may translate to different biologic behaviors . in a study by ye et al .
those with infiltrative borders but no significant atypia , increased mitoses , or necrosis had a local recurrence rate of 15% , while tumors which were infiltrative and which displayed cellular atypia , necrosis , and abnormal mitotic activity had a 50% chance of developing recurrence or metastasis to the regional lymph nodes .
the latter category could be termed as a malignant ptt and viewed as equivalent to conventional scc .
pathological examination of the entire lesion is necessary to assess the borders of the tumor as well as for the possible presence of necrosis and cytologic variation .
bowen disease clinically presents as a plaque in covered as well as uncovered skin areas ( figure 19 ) .
histopathologically , it features full thickness dysplasia , incorporating loss of polarity of the epidermis , nuclear pleomorphism , and mitosis at all levels ( figures 3 and 20 ) . in usual cases ,
all three entities display single and groups of atypical cells within the epidermis . the tumor cells of paget disease generally cluster above an intact basal layer of epidermis and may be demonstrated to contain mucin .
melanoma tumor cells often contain melanin although paget cells have been known to show this feature as well .
immunohistochemistry helps to distinguish the entities : the tumor cells of bowen disease are p63 positive , those of paget 's disease react for p - cea , ber - ep4 , ck7 , and cam5.2 , while melanoma cells are positive for s-100 and melan - a . not uncommonly , bowen disease shows a markedly undulating basal contour and can be associated with subjacent dermal fibroplasia , raising the possibility of whether early invasion has occurred .
the neoplastic epithelium of bowen disease can also colonize eccrine ducts , potentially exaggerating the incorrect impression of invasion ( figure 20 ) .
examination of deeper levels or more blocks of tissue may reveal foci of convincing invasion , characterized by single or small jagged clusters of infiltrating tumor cells within unequivocally desmoplastic dermal stroma .
the typical bcc is characterized by basaloid cellular proliferation with peripheral palisading and tumor - stromal cleft formation .
the infiltrating tumor cells may not uncommonly appear squamoid and raise the possibility of scc .
immunohistochemistry can be helpful as bcc , and not scc , is positive for ber - ep4 and bcl-2 ( figure 21 ) .
the two variants of bcc that have significant squamous components are keratotic bcc ( figure 22 ) and basosquamous carcinoma ( metatypical bcc ) , the latter having a worse prognosis than bcc in general
. a careful assessment of the tumor would usually show areas of more typical bcc .
the other skin cancer in the head and neck that occasionally mimics a poorly differentiated scc is sebaceous carcinoma .
this tumor is disposed of in sheets and lobules of cells with bubbly cytoplasm that indent an atypical nucleus .
( ema + ve , ber - ep4 ve ) , sebaceous carcinoma ( ema + ve , ber - ep4 + ve ) , and bcc ( ema ve , ber - ep4 + ve ) .
more recently , markers that have been found to be more specific for sebaceous carcinoma include adipophilin and androgen receptor , which in turn are usually negative in bcc and scc .
spindle cell melanoma is one of the classic differential diagnoses for pleomorphic spindle cell tumors of the skin .
while cytological features may not enable distinction from a spindle cell scc and atypical fibroxanthoma ( afx ) , the presence of a junctional component helps delineate spindle cell melanoma ( figure 23 ) .
in contrast , careful examination of a spindle cell scc may reveal overlying bowen disease or actinic keratosis . by immunohistochemistry ,
expression of one or more of the cytokeratins helps distinguish the tumor from spindle cell melanoma which would instead express s-100 .
other skin carcinomas that sometimes feature squamous differentiation include merkel cell carcinoma ( mcc ) , porocarcinoma , and sebaceous carcinoma [ 23 , 27 , 28 ] .
this is likely a manifestation of divergent differentiation of the tumor or varied differentiation of tumor stem cells .
careful examination of mcc would usually show up the more typical malignant small round cells of mcc as well as dot - like expression of ck20 and positivity for the neuroendocrine markers synaptophysin , neurofilament protein , and cd56 . as for porocarcinoma
, the neoplastic poroid cells should be discernible with duct lumina formation decorated by ema and p - cea immunohistochemistry .
an scc present in the skin may occasionally represent direct invasion from an underlying malignancy or metastatic deposit .
in such situations , the importance of clinical history and correlation can not be overemphasized .
the tumor tends to show a centre that is based in the dermis or subcutis ( figure 24 ) .
the overlying epidermis tends to show only reactive features or be ulcerated by the growth of the subjacent tumor .
anaplastic large cell lymphoma and lymphomatoid papulosis are cd30-positive lymphoproliferative disorders that have reported cases being associated with epidermal hyperplasia .
while the epidermal hyperplasia is often mild in degree , it can be very florid with features of pseudoinfiltration which mimic scc , raising the possibility of a collision between the carcinoma and lymphoproliferative process ( figure 25 ) .
cellular atypia of the epidermal hyperplasia , while usually absent , has sometimes been reported .
mitoses of the squamous cells , if present , should be seen to be located at the basal layer of the squamous islands and not be abnormal in form .
scc can sometimes coexist with other malignant skin tumors within the same tumor mass , the most likely context being collision tumors .
combinations of scc with melanoma or mcc are most well known [ 30 , 31 ] .
the practical importance is that on finding a prominent scc component , the coexistence of a potentially more aggressive tumor , or a tumor that may require specific adjuvant therapy , should be sought for .
such a concurrence is not surprising as ultraviolet light exposure is a well known and common risk factor .
another plausible etiologic factor that has emerged more recently is that of human polyomaviruses . while the merkel cell polyomavirus has been closely linked to mcc , its detection and role in scc are less consistent and clear [ 3133 ] .
interestingly , the virus has been detected in two cases of combined scc and mcc .
in summary , this review serves to highlight the spectrum of conditions that could mimic scc : benign , preinvasive , and malignant . being aware of the pertinent differential diagnoses provides the setting to minimize the pitfalls in the diagnosis of challenging cases which feature squamous proliferation .
this , coupled with a systematic assessment for the criteria required for an scc diagnosis , helps in the rendering of a correct diagnosis . of the adjunctive studies ,
immunohistochemistry is the most widely used , helping to indicate the histogenesis of the lesional cells of nonsquamous mimics . in difficult cases ,
a detailed and relevant history of cancers of the skin and other organs should be sought for .
the clinical tempo of the lesion , knowledge of the site , size , and other characteristics are all critical pieces of information to the pathologist .
if a lesion is clinically concerning , but the biopsy features are benign or nonspecific , further levels on the block often prove useful .
rarely , a summative assessment of inadequate material or of an atypical lesion that can not exclude malignancy may have to be given with a recommendation for complete excisional biopsy .
as always , this is balanced against the factors of cosmesis and practicability . on the one hand , the final reexcision specimen provides the opportunity for further evaluation of the residual lesion for definite diagnosis . on the other hand
, the repeat excision often represents the definite surgical treatment for the lesion if it indeed turns out to be malignant .
such a pragmatic approach offers the rendering of a safe yet clinically useful diagnosis when diagnostically challenging cases are encountered . | squamous cell carcinoma ( scc ) is a common and important primary cutaneous malignancy . on skin biopsies ,
scc is characterized by significant squamous cell atypia , abnormal keratinization , and invasive features .
diagnostic challenges may occasionally arise , especially in the setting of small punch biopsies or superficial shave biopsies , where only part of the lesion may be assessable by the pathologist .
benign mimics of scc include pseudoepitheliomatous hyperplasia , eccrine squamous syringometaplasia , inverted follicular keratosis , and keratoacanthoma , while malignant mimics of scc include basal cell carcinoma , melanoma , and metastatic carcinoma .
the careful application of time - honored diagnostic criteria , close clinicopathological correlation and a selective request for a further , deeper , or wider biopsy remain the most useful strategies to clinch the correct diagnosis .
this review aims to present the key differential diagnoses of scc , to discuss common diagnostic pitfalls , and to recommend ways to deal with diagnostically challenging cases . |
melioidosis , though endemic in the southeast asian regions , such as thailand , singapore malaysia and australia , was also reported from africa , north and south america , pacific and caribbean islands , middle east and europe . in india , it is more prevalent in the south ; though also reported from other parts .
the disease is underreported due to its protean manifestations and low physician index of suspicion .
many laboratories relying on conventional culture methods confuse it with pseudomonas species due to common phenotypic characteristics .
john et al reported that the disease could be more prevalent than what is available in literature .
we report two who were undiagnosed initially and presented to us within 3 months of each other . both belonged to madhubani district in bihar , raising possibilities that the area could be endemic for the disease .
a 65-year - old male presented with fever , cough with breathlessness for last 2 months , alongwith swelling , redness and pain affecting both ankles for 7 days .
two months earlier , he was treated for clinically suspected typhoid with no resolution of the fever . at the same time
body temperature was 101 f , bp was 90/70 mmhg , respiratory rate 50/min , heart rate 128/minute .
investigations showed a total leukocyte count ( tlc ) of 24,000/mm , the peripheral blood smear revealedtoxic granulations and vacuolations , the liver enzymes wereraised with the values of aspartate aminotransferase ( sgot)- 160 iu / l , alanine aminotransferase ( sgpt)- 82
iu / l , alkaline phosphatase ( alp)- 1120 iu / l , g - glutamyl transferase ( ggt)- 216 iu / l , lactate dehydrogenase ( ldh ) 387 iu / l . , a chest x - ray showed homogenous consolidation on theleft side , an ultrasound showed bilateral pleural effusions and mild ascitis ; high sensitivity c - reactive protein ( hs crp ) level was 233.8 mg / dl , procalcitonin level was 0.5 ng / ml , glycosylated hemoglobin ( hba1c ) level was high at 11.10% , acid - fast stain ( afb ) from sputum carried out for 3 days , malarial antigen , widal test , urine culture were all negative .
he was ventilated and based on a clinical diagnosis of sepsis , started on an empirical therapy with piperacillin / tazobactum and clindamycin .
he continued to be febrile and on day 3 , right ankle was surgically drained and pus collected for culture .
blood culture put up in the fully automated bactec ( beckton and dickinson ) showed positivity on the third day and grew nonfermenting , oxidase - positive flat , dry , wrinkled colonies which were subsequently identified as burkholderia pseudomallei in microscan 96 si ( siemens , frimley , camberley , uk ) .
burkholderia pseudomallei was alsoisolated from his endotracheal secretions and pus . a 58-year - old male presented with fever ( on and off from last 1 to 11/2 years ) , cough , pain and swelling of left knee for last 2 weeks .
he was a known diabetic for last few years . on presentation , his temperature was 100 f , pulse 90/minute ; blood pressure 94/50 mmhg , respiratory rate 38/minute .
left knee was hot and tender ; however , anx - ray of the knee was normal .
oxygen saturation was 80% for which he was started on non - invasive ventilator support .
investigations showed a tlc of 10,900/cubic mm , the liver enzymes were raised with values of sgot- 117 iu / l , sgpt- 175 iu / l , alp- 69 iu / l , ggt 81 iu / l , ldh- 289 iu / l .
hscrp level was 166.7 mg / dl , procalcitonin level was 0.9 ng / ml . hb a1 c level was 10.0% .
sputum for afb ( stain and culture ) , malaria antigen test and widal test were all negative .
blood cultures were sent from two different peripheral sites on the day of admission . on day 3 of admission , he had spikes of fever .
burkholderia pseudomallei was isolated from all these blood samples . both the strains were resistant to ceftazidime ( mic>32 mg / l ) and sensitive to imipenem ( mic
< 2 mg / l ) , co - trimoxazole ( mic < 1/19 mg / l)and tetracycline ( mic < 2 mg / l ) .
antibiotics were escalated to imipenem ( 50 mg / kg / day ) in both cases .
both cases responded well and were discharged on maintenance therapy with co - trimoxazole and doxycycline for 20 weeks .
a 65-year - old male presented with fever , cough with breathlessness for last 2 months , alongwith swelling , redness and pain affecting both ankles for 7 days .
two months earlier , he was treated for clinically suspected typhoid with no resolution of the fever . at the same time
body temperature was 101 f , bp was 90/70 mmhg , respiratory rate 50/min , heart rate 128/minute .
investigations showed a total leukocyte count ( tlc ) of 24,000/mm , the peripheral blood smear revealedtoxic granulations and vacuolations , the liver enzymes wereraised with the values of aspartate aminotransferase ( sgot)- 160 iu / l , alanine aminotransferase ( sgpt)- 82
iu / l , alkaline phosphatase ( alp)- 1120 iu / l , g - glutamyl transferase ( ggt)- 216 iu / l , lactate dehydrogenase ( ldh ) 387 iu / l . , a chest x - ray showed homogenous consolidation on theleft side , an ultrasound showed bilateral pleural effusions and mild ascitis ; high sensitivity c - reactive protein ( hs crp ) level was 233.8 mg / dl , procalcitonin level was 0.5 ng / ml , glycosylated hemoglobin ( hba1c ) level was high at 11.10% , acid - fast stain ( afb ) from sputum carried out for 3 days , malarial antigen , widal test , urine culture were all negative .
he was ventilated and based on a clinical diagnosis of sepsis , started on an empirical therapy with piperacillin / tazobactum and clindamycin .
he continued to be febrile and on day 3 , right ankle was surgically drained and pus collected for culture .
blood culture put up in the fully automated bactec ( beckton and dickinson ) showed positivity on the third day and grew nonfermenting , oxidase - positive flat , dry , wrinkled colonies which were subsequently identified as burkholderia pseudomallei in microscan 96 si ( siemens , frimley , camberley , uk ) .
a 58-year - old male presented with fever ( on and off from last 1 to 11/2 years ) , cough , pain and swelling of left knee for last 2 weeks .
he was a known diabetic for last few years . on presentation , his temperature was 100 f , pulse 90/minute ; blood pressure 94/50 mmhg , respiratory rate 38/minute .
left knee was hot and tender ; however , anx - ray of the knee was normal .
oxygen saturation was 80% for which he was started on non - invasive ventilator support .
investigations showed a tlc of 10,900/cubic mm , the liver enzymes were raised with values of sgot- 117 iu / l , sgpt- 175 iu / l , alp- 69 iu / l , ggt 81 iu / l , ldh- 289 iu / l .
hscrp level was 166.7 mg / dl , procalcitonin level was 0.9 ng / ml . hb a1 c level was 10.0% .
sputum for afb ( stain and culture ) , malaria antigen test and widal test were all negative .
blood cultures were sent from two different peripheral sites on the day of admission . on day 3 of admission , he had spikes of fever .
burkholderia pseudomallei was isolated from all these blood samples . both the strains were resistant to ceftazidime ( mic>32 mg / l ) and sensitive to imipenem ( mic < 2 mg / l ) , co - trimoxazole ( mic < 1/19 mg / l)and tetracycline ( mic < 2 mg / l )
. antibiotics were escalated to imipenem ( 50 mg / kg / day ) in both cases .
both cases responded well and were discharged on maintenance therapy with co - trimoxazole and doxycycline for 20 weeks .
it is an emerging infectionin india with the first case reported in a child from dapoli in maharashtra in 1990 .
it is reported also from kerela , karnataka , east , northeast and the south east .
found fever to be the commonest complaint ( 96% cases ) and diabetes mellitus as a predisposing factor which we found in both our cases .
the second case had a long history of fever attributable to the chronic form of melioidosis .
burkholderia pseudomallei is present as an environmental saprophyte in soil and fresh surface water in endemic regions ; posing a high risk of infection to this group of people .
lack of clinical know - how of this disease and insufficient laboratory expertise usually hamper the diagnosis of the disease .
further epidemiological studies are indicated to determine the geographical prevelance and risk factors of this condition . | melioidosis is endemic in the south asian regions , like thailand , singapore malaysia and australia .
the disease is more pronounced in the southern part of the country .
it is caused by burkholderia pseudomallei which causes systemic involvement , morbidity and mortality associated with the disease is high . due to highly varied clinical presentation , and low general awareness
this infection is largely underdiagnosed and under reported in our country .
most laboratories in the country still rely on conventional culturing methods with their low sensitivity , adding to the under reporting . to enhance physician awareness we describe here two cases who presented to our institute after months of misdiagnosis . |
multislice computed tomography with high spatial resolution plays an important role in the imaging delineation of temporal bone . with the advance of computed tomography ( ct ) technology , a sharp increase in ct scan use has been observed in recent years .
consequently , there is a growing concern regarding the potential risks of radiation exposure , particularly for children , and various methods and strategies based on individual patient attributes and ct technology have been explored to decrease the radiation dose level during the imaging of temporal bone .
recently , a ct scanner employing an integrated circuit ( ic ) detector potentially reducing image noise and improving spatial resolution by means of reduced crosstalk between detector channels was introduced into clinical practice .
unlike the discrete circuit ( dc ) system of conventional ct detector technology , this new type of detector combines the photodiodes and the analog - to - digital converters ( adcs ) on a single board into an ic detector .
this reduces the transmission time of analog signal , thus reducing the power consumption , heat dissipation , and electronic noise . as a result
, the ic detector technology lowers the image noise by means of reduced loss of information during the transfer of analog - to - digital signals compared with dc detector technology .
the ic detector technology is considered to be particularly useful for low - dose ct scans because electronic noise becomes more and more dominant with decrease in the amount of detected photons .
the present study was designed to evaluate the quality of images acquired with low - dose ct equipped with the ic detector through comparative analysis between the ic and conventional dc detectors in respect of the depiction of anatomic landmarks of the temporal bone in pediatric patients .
this retrospective study was approved by our institutional review board with written informed consent waived . from october 2013 to may 2014 , 86 consecutive low - dose ct examinations were performed in patients <3 years of age with clinical signs suspicious for various inner and middle ear abnormalities were selected upon reviewing electronic medical records of our hospital . of them ,
48 patients were scanned on a 128-slice ct scanner equipped with a conventional dc detector ( somatom definition flash ; siemens healthcare , forchheim , germany ) and the other 38 patients were imaged on a similar ct scanner equipped with an ic detector ( stellar ; siemens healthcare , erlangen , germany ) .
exclusion criteria consisted of any evidence of severe abnormalities of temporal bone ( such as middle / inner ear dysplasia or trauma , or infectious conditions leading to destruction of the skull base , or patients with electric devices at the skull base ) affecting anatomic evaluation established by 2 radiologists who did not involve in the further studies . with the criteria ,
16 ( 6 with ic and 10 with conventional dc detector ) patients were excluded because of tympanitis with erosion of auditory ossicles ( n = 10 ) , middle ear dysplasia ( n = 2 ) , and cochlea implants
finally , a total of 140 temporal bone studies of 70 patients were included in the study ; 38 patients including 20 males and 18 females ( mean age , 9 months ; range , 3 months to 3 years ) were scanned on the ct scanner equipped with a conventional dc detector and the other 32 patients including 18 males and 14 females ( mean age , 10 months ; range , 2 months to 3 years ) were imaged on a similar ct scanner equipped with an ic detector .
the scanning parameters were the same for both detectors : slice acquisition was 2 0.6 64 , by means of a z - flying focal spot ; gantry rotation , 0.5 seconds ; tube voltage , 80 kv ; and tube current time product , 150 effective mas .
all images were reconstructed using a sharp kernel ( b60 ) with a field of view of 100 mm and with a slice thickness of 0.6 mm and an increment of 0.4 mm .
the reading sessions were done on a picture archiving and communication system workstation using axial sections and multiplanar reformations generated with the integrated software tools .
two radiologists ( 12 and 10 years of experience in interpreting head and neck imaging , respectively ) who were unaware of the ct scanning parameters reviewed the images independently . in accordance with our clinical routine , reviewers were free to choose the appropriate planes and all images were displayed at a window level of 800 hounsfield units ( hu ) and a window width of 4000 hu . to quantitatively evaluate the image quality , we measured the image noise ( standard deviation [ sd ] of the ct number in hu ) of the brain stem region by placing circular regions of interest of 50 mm . for subjective analysis , 2 reviewers evaluated the image quality with respect to the visibility of 35 anatomic landmarks ( table 1 ) by using 5-point quality rating : 1 , anatomic structures not identifiable because of poor image quality ; 2 , structures identifiable , but no details assessable , resulting in insufficient image quality ; 3 , anatomic structures still fully assessable in all parts and acceptable image quality ; 4 , clear delineation of structure and good image quality ; and 5 , very good delineation of structure and excellent image quality .
values for the 2 observers who evaluated the image quality the statistical analyses were performed with the statistical software of spss ( version 19.0 , spss inc , chicago , il ) for microsoft windows . for the continuous variables , kolmogorov
smirnov test was applied to assess the normality of data distribution , and levene test was used to evaluate the equality of variance .
patients ages of the ic and the dc detector groups were compared using independent t test , and the sex composition using fisher exact test . for the quantitative analysis ,
the image noise was expressed as mean sd and the intergroup difference for each category was tested with the unpaired t test . for the qualitative analysis , the differences for the subjective scores of the images acquired by 2 detector systems were tested with the mann
inter - reader variability for the subjective evaluation of image quality was assessed with the statistics .
the values of 0.4 were considered to indicate positive but poor agreement , while the values of 0.410.75 and > 0.75 indicated good and excellent agreement .
this retrospective study was approved by our institutional review board with written informed consent waived . from october 2013 to may 2014 , 86 consecutive low - dose ct examinations were performed in patients <3 years of age with clinical signs suspicious for various inner and middle ear abnormalities were selected upon reviewing electronic medical records of our hospital . of them ,
48 patients were scanned on a 128-slice ct scanner equipped with a conventional dc detector ( somatom definition flash ; siemens healthcare , forchheim , germany ) and the other 38 patients were imaged on a similar ct scanner equipped with an ic detector ( stellar ; siemens healthcare , erlangen , germany ) .
exclusion criteria consisted of any evidence of severe abnormalities of temporal bone ( such as middle / inner ear dysplasia or trauma , or infectious conditions leading to destruction of the skull base , or patients with electric devices at the skull base ) affecting anatomic evaluation established by 2 radiologists who did not involve in the further studies . with the criteria ,
16 ( 6 with ic and 10 with conventional dc detector ) patients were excluded because of tympanitis with erosion of auditory ossicles ( n = 10 ) , middle ear dysplasia ( n = 2 ) , and cochlea implants
finally , a total of 140 temporal bone studies of 70 patients were included in the study ; 38 patients including 20 males and 18 females ( mean age , 9 months ; range , 3 months to 3 years ) were scanned on the ct scanner equipped with a conventional dc detector and the other 32 patients including 18 males and 14 females ( mean age , 10 months ; range , 2 months to 3 years ) were imaged on a similar ct scanner equipped with an ic detector .
the scanning parameters were the same for both detectors : slice acquisition was 2 0.6 64 , by means of a z - flying focal spot ; gantry rotation , 0.5 seconds ; tube voltage , 80 kv ; and tube current time product , 150 effective mas .
all images were reconstructed using a sharp kernel ( b60 ) with a field of view of 100 mm and with a slice thickness of 0.6 mm and an increment of 0.4 mm .
the reading sessions were done on a picture archiving and communication system workstation using axial sections and multiplanar reformations generated with the integrated software tools .
two radiologists ( 12 and 10 years of experience in interpreting head and neck imaging , respectively ) who were unaware of the ct scanning parameters reviewed the images independently . in accordance with our clinical routine , reviewers were free to choose the appropriate planes and all images were displayed at a window level of 800 hounsfield units ( hu ) and a window width of 4000 hu . to quantitatively evaluate the image quality , we measured the image noise ( standard deviation [ sd ] of the ct number in hu ) of the brain stem region by placing circular regions of interest of 50 mm . for subjective analysis , 2 reviewers evaluated the image quality with respect to the visibility of 35 anatomic landmarks ( table 1 ) by using 5-point quality rating : 1 , anatomic structures not identifiable because of poor image quality ; 2 , structures identifiable , but no details assessable , resulting in insufficient image quality ; 3 , anatomic structures still fully assessable in all parts and acceptable image quality ; 4 , clear delineation of structure and good image quality ; and 5 , very good delineation of structure and excellent image quality .
the statistical analyses were performed with the statistical software of spss ( version 19.0 , spss inc , chicago , il ) for microsoft windows . for the continuous variables , kolmogorov
smirnov test was applied to assess the normality of data distribution , and levene test was used to evaluate the equality of variance .
patients ages of the ic and the dc detector groups were compared using independent t test , and the sex composition using fisher exact test . for the quantitative analysis ,
the image noise was expressed as mean sd and the intergroup difference for each category was tested with the unpaired t test . for the qualitative analysis , the differences for the subjective scores of the images acquired by 2 detector systems were tested with the mann
inter - reader variability for the subjective evaluation of image quality was assessed with the statistics .
the values of 0.4 were considered to indicate positive but poor agreement , while the values of 0.410.75 and > 0.75 indicated good and excellent agreement .
no statistical differences in age and sex composition were found between ic and dc detectors ( p > 0.05 ) . there was a significantly lower image noise in datasets acquired with the ic compared with the dc detector ( p < 0.001 ) .
the mean ( sd ) image noise was 56.6 versus 46.0 hu for the dc versus ic detector .
the overall noise reduction was up to 19% for the images acquired with the ic detector compared with the dc detector .
the values for qualitative assessment revealed a high interobserver agreement for all 35 fine anatomical structures , showing a mean of 0.94 ( range , 0.821.0 ) for images acquired with ic detector and 0.96 ( range , 0.851.0 ) for images acquired with dc detector .
table 1 shows the values for the 2 observers who evaluated the ct images , and table 2 summarizes the mean sd scores of image quality and the p values .
mean scores and p values for qualitative analysis of the image quality between the 2 detector systems with respect to the visibility of temporal bone , the mean subjective scores of images acquired with ic detector were superior to the scores with conventional dc detector for all of the 35 structures .
significant differences were obtained for 30 of the 35 structures in the anatomy depiction between ic and dc detectors ( p < 0.05 ) .
no difference was observed between the ic and conventional dc detectors ( p > 0.05 ) for delineation of the remaining 5 structures including the horizontal semicircular canal , superior semicircular canal , posterior semicircular canal , vestibule , and incus body .
our study demonstrated that use of the ic detector improved the image quality with respect to the depiction of anatomic landmarks of pediatric temporal bone as compared with the use of the conventional dc detector in low - dose ct . in our low - dose ct protocol ,
the mean values of volume ct dose index ( ctdivol , mgy ) and dose length product ( dlp , mgycm ) provided by the ct scanner were 9.8 and 42 , respectively . the ctdivol and dlp of this low - dose protocol were approximately 5 and 4 times lower , respectively , than that of standard - dose protocol ( 120 kv , 200 mas ) . in the acquisition of ct data
, the image noise mainly comes from quantum noise from photon statistics and electronic noise associated with the photon detection system , or ct detectors .
electronic noise usually has a minor effect on the image quality in the case of routine dose ct scanning .
however , the amount of detected photons can decrease to a level at which the signal from the photons is comparable to the electronic noise for low - dose ct scanning . compared with standard detector with adc installed on a separate board , the photodiode and adc in the ic detector are integrated into the same silicon chip that is attached to the backside of scintillating ceramic detector .
the integration of the electronics with the detector element reduces the time during which the signal is in analog form , thereby reducing the amount of electronic noise that is added to the signal .
the temporal bone is ideally suited for low - dose ct because of the high intrinsic contrast of the osseous structures surrounded by air component .
low - dose ct of temporal bone is mainly used for preoperative assessment of the anatomy in the diagnosis of middle and inner ear dysplasia and the selection of cochlear implant candidates for children <3 years old in our hospital based our experience and manufacturer 's recommendation .
a prior study has reported that the normal temporal bone anatomy in young children using 80 kv could be adequately assessed by radiologists but not by otologists with a significant reduction in radiation exposure compared with the previously used high - dose protocol . in that study ,
the image quality was qualitatively assessed only by using a 5-point scale , no quantitative methods were applied . in the present study , we applied both quantitative and qualitative methods to assess the quality of images obtained with the 2 detector systems .
, 86% of the temporal bone landmarks were significantly delineated by the using of ic detector , superior to the conventional detector . in particular , the anatomical structures that are crucial for diagnosis of auditory ossicular dysplasia and inner ear surgery such as the ossicular chain and modulus
were better delineated with the ic detector ( figures 13 ) . in the remaining 14% landmarks ,
the mean score of image quality acquired by ic detector was also higher than that by conventional dc detector although there was no significant difference .
better objective and subjective image quality was achieved with the ic detector , suggesting that further dose - reduction methods may be applied with comparable image quality by the use of ic detector .
oblique axial images reformatted in the stapes main plane obtained with ( a ) conventional ( 16-month - old child ) and ( b ) integrated circuit ( ic ) detectors ( 16-month - old child ) .
critical structures such as the stapes head ( 1 ) , anterior crus of stapes ( 2 ) , oval window ( 3 ) , vestibule ( 4 ) , stapedius muscle ( 5 ) , and posterior crus of stapes ( 6 ) are better delineated with ic detector .
oblique coronal reformatted images in cochlea plane with ( a ) conventional ( 16-month - old child ) and ( b ) integrated circuit ( ic ) detectors ( 16-month - old child ) .
critical structures such as the vestibule ( 1 ) , osseous spiral lamina of cochlea , and cochlear window ( 3 ) are better delineated with ic detector .
axial reformatted images in internal auditory canal plane obtained with ( a ) conventional ( 12-month - old child ) and ( b ) integrated circuit ( ic ) detectors ( 12-month - old child ) .
critical structures such as the vestibule ( 1 ) , labyrinthine segment of facial nerve canal ( 2 ) , internal auditory canal ( 3 ) , and canal of the inferior division of the vestibular nerve ( 4 ) are better delineated with ic detector . the present study aimed to evaluate the image quality with respect to the delineation of temporal bone by 2 different detector technologies .
the main purpose of this study was to gain insight into the potential for further dose reduction in temporal ct .
focused studies with selected participant populations are ongoing in the pathologic conditions of temporal bone .
our preliminary data showed that the image quality acquired with ic detector was superior to that with conventional dc detector , suggesting that this technology is feasible for imaging of different disease categories and enables imaging with comparable quality at even lower radiation dose . | abstractthe purpose of this study was to determine the performance of low - dose computed tomography ( ct ) scanning with integrated circuit ( ic ) detector in defining fine structures of temporal bone in children by comparing with the conventional detector.the study was performed with the approval of our institutional review board and the patients anonymity was maintained .
a total of 86 children <3 years of age underwent imaging of temporal bone with low - dose ct ( 80 kv/150 mas ) equipped with either ic detector or conventional discrete circuit ( dc ) detector .
the image noise was measured for quantitative analysis .
thirty - five structures of temporal bone were further assessed and rated by 2 radiologists for qualitative analysis .
statistics were performed to determine the agreement reached between the 2 radiologists on each image .
mann
whitney u test was used to determine the difference in image quality between the 2 detector systems.objective analysis showed that the image noise was significantly lower ( p < 0.001 ) with the ic detector than with the dc detector .
the values for qualitative assessment of the 35 fine anatomical structures revealed high interobserver agreement .
the delineation for 30 of the 35 landmarks ( 86% ) with the ic detector was superior to that with the conventional dc detector ( p < 0.05 ) although there were no differences in the delineation of the remaining 5 structures ( p > 0.05).the low - dose ct images acquired with the ic detector provide better depiction of fine osseous structures of temporal bone than that with the conventional dc detector . |
on may 2 , 2003 , a 47-year - old - woman , who lived in northwestern slovenia , was admitted to the department of infectious diseases , university medical centre ljubljana , slovenia , with a 7-day history of fever < 40.0c , severe headache , nausea , dry cough , malaise , intense myalgia , and arthralgia .
the last bite occurred 14 days before onset of her illness while she was walking in the woods near her home ; no skin lesions appeared at the site of the bites .
she had not been vaccinated against tbe , nor had she traveled outside slovenia during the last few years .
when she sought treatment , her body temperature was 38.5c , pulse rate was 90 beats / min , and blood pressure was 110/70 mm hg . with the exception of fever , the physical examination did not show any notable abnormality ; rash and meningeal signs were not present .
routine laboratory tests showed leukopenia , thrombocytopenia , abnormal liver function test results , elevated concentration of serum c - reactive protein , and elevated procalcitonin levels ( table 1 ) .
the fever subsided in 3 days ( on day 10 after the onset of her illness ) , and the patient was discharged from the hospital .
her condition improved , but the headache persisted and intensified . on may 13 , she was reexamined in our department , and lumbar puncture was performed .
cerebrospinal fluid examination showed normal protein and glucose concentrations but a mildly elevated number of leukocytes ( 7 x 10/l ) . at subsequent evaluations , the patient reported feeling better . on day 20 after onset , the control laboratory test results , including liver function test results , were within the normal range . several microbiologic procedures , including those for determining infections with a. phagocytophilum , ehrlichia chaffeensis , b. burgdorferi s.l . , and tbe virus , were performed to elucidate the cause of the illness .
giemsa - stained peripheral blood smear examination by light microscopy for the presence of ehrlichial morulae within leukocytes was negative .
serum samples were tested by an indirect immunofluorescence assay for the presence of specific igg antibodies to a. phagocytophilum ( strain usg3 propagated in hl60 promyelocyte cells ) , igm and igg antibodies to e. chaffeensis antigens ( mrl diagnostics , cypress , california , usa ) , and igm and igg antibodies to b. burgdorferi s.l ( whole cells of a local isolate of b. afzelii were used as an antigen ) .
the presence of serum tbe virus igm and igg antibodies was assessed by enzyme - linked immunosorbent assay ( elisa ) ( dade behring marburg gmbh , marburg , germany ) .
the results of serologic tests indicating recent infection with a. phagocytophilum and tbe virus are depicted in table 2 .
primers ehr521 and ehr790 , which amplified the 16s rrna gene of a. phagocytophilum , produced a fragment of the expected size ( 293 bp ) in the acute - phase blood specimen ( figure ) ( 12 ) .
no nucleic acids were amplified with primers specific for e. chaffeensis he1 and he3 ( table 2 ) ( 13 ) .
* pcr , polymerase chain reaction ; elisa , enzyme - linked immunosorbent assay ; ifa , indirect immunofluorescence assay ; ig , immunoglobulin ; neg , negative ; pos , positive ; tbev , tickborne encephalitis virus .
primers ehr521 and ehr790 specific to a. phagocytophilum and primers he1 and he3 specific to e. chaffeensis .
cut - off value for tbev igm is 0.2720.372 and for igg is 7.5 u / ml , according to the manufacturer 's procedure polymerase chain reaction amplification of anaplasma phagocytophilum dna from the patient 's acute - phase blood sample .
amplified dna was separated by electrophoresis through the 2% agarose gel stained with ethidium bromide .
lane 1 , patient sample ( note the presence of the band at 293 bp ) ; lane 2 , negative sample ; lane 3 , negative control ( no - dna template control ) ; lane 4 positive control ( dna extracted from the cultured isolate of a. phagocytophilum ) .
few reports have been published on serologic evidence of coinfection with tbe virus and a. phagocytophilum in europe . the results on groups of persons representing different risk categories for tick exposure in switzerland provided serologic evidence of coinfection with a. phagocytophilum and tbe virus ( 9 ) .
weber et al . , who retrospectively tested serum specimens of patients with lyme borreliosis or tbe for antibodies to a. phagocytophilum , reported similar findings ( 10 ) .
although serologic data suggested coinfection with a. phagocytophilum and tbe virus , no confirmation of acute hge was obtained among the residents of switzerland . in the czech republic , where tbe is endemic , among 67 patients hospitalized for tbe , 6 ( 9% ) were seropositive to a. phagocytophilum ( 11 ) . in slovenia
, the background seroprevalence of hge in children and young adults ( 15% ) was found to be similar to that of lyme borreliosis ( 15% ) and tbe ( 13% ) ( 14 ) .
in addition , a prospective study was performed to establish the etiologic agents of acute febrile illnesses that occurred within 6 weeks after a tick bite in residents of slovenia , by using a combination of microbiologic and clinical criteria .
out of 130 adult patients , 36 ( 28% ) had laboratory evidence of tbe virus infection ( all had clinically confirmed disease ) , whereas 4 of 22 ( 17% ) patients with the evidence of a. phagocytophilum infection , had confirmed hge .
infection by multiple organisms ( > 1 ) was found in 19 ( 15% ) of 130 patients .
four of them had confirmed tbe and also met the study criteria for probable hge but not for confirmed hge ( 7 ) .
the clinical signs and symptoms of hge are unspecific and usually consist of fever , headache , chills , malaise , myalgia , or arthralgia , which often occur after a tick bite .
laboratory analysis shows leukopenia , thrombocytopenia , lymphopenia , elevated activity of hepatic enzymes , and an elevated concentration of c - reactive protein ( 7 ) .
however , leukopenia and thrombocytopenia are common not only in hge patients but also during the initial phase of tbe , in which they were found in 67% and 71% of patients , respectively ( 15 ) . for most patients in whom tbe develops
our patient , however , had a monophasic course of febrile illness , which was observed in 27% of patients with tbe in slovenia ( 16 ) . in our report , the diagnosis of tbe was established by the presence of a febrile illness after a tick bite with headache , mild lymphocytic pleocytosis , and demonstration of serum igm and igg antibodies to tbe virus by elisa , the serologic method of choice with the specificity 99.9% for igm and 99.5% for igg and the sensitivity 99.8% and 96.8% for igm and igg , respectively ( 17 ) .
the presence of tbe igm antibodies 144 days after the onset of illness in our patient ( table 2 ) is not surprising because the igm antibodies as a rule persist for several months after acute infection ( 17 ) .
however , changes in antibody titers as demonstrated in our patient attest for recent infection . the febrile illness associated with leukopenia , thrombocytopenia , an elevated concentration of serum c - reactive protein , and the demonstration of a. phagocytophilum infection by seroconversion as well as a positive pcr result also met the criteria for confirmed hge . to our knowledge ,
the patient reported herein represents the first case of concurrent confirmed tbe and confirmed hge .
some reports suggest that coinfection with more than 1 tickborne pathogen may influence the natural history of each of the corresponding diseases , making the clinical course more severe and the outcome less favorable ( 1 ) . in spite of proven coinfection and fulfillment of criteria for confirmed tbe and hge ( and the absence of treatment with doxycycline , which could have influenced the natural course of hge ) ,
however , the information obtained from a single patient does not allow for a reliable conclusion on the potential influence of tbe virus and a. phagocytophilum coinfection on the clinical features and course of the combined illness . | we report a patient with febrile illness and epidemiologic and clinical findings consistent with human granulocytic ehrlichiosis and tickborne encephalitis , in whom infection with anaplasma phagocytophilum was demonstrated by polymerase chain reaction and seroconversion .
tickborne encephalitis virus infection was established by serum immunoglobulin ( ig ) m and igg antibodies . |
progressive supranuclear palsy ( psp ) is the second most common cause of parkinsonism [ 1 , 2 ] .
common symptoms of psp include parkinsonism with progressive vertical gaze palsy , postural instability with falls , akinesia , and cognitive impairment [ 3 , 4 ] .
further , psp causes neuronal degeneration in the brainstem , including in the substantia nigra , tegmentum , and superior colliculus ; tau pathology that accompanies tuft - shaped astrocytes has also been observed in the superior and middle frontal gyri in psp .
earlier magnetic resonance imaging ( mri ) studies have primarily used regions of interest analyses to examine brain atrophy [ 7 , 8 , 9 , 10 , 11 ] . however , the results of such analyses depend largely on the arbitrary locus and size that examiners select retrospectively . also , this method is time - consuming and only measures relatively large areas , potentially overlooking finer differences .
voxel - based analysis using statistical parametric mapping ( spm ) was developed to examine focal differences in brain anatomy .
this method can eliminate the effects of differences in size , and voxel - by - voxel comparison allows one to perform a prospective statistical analysis of differences in gray matter loss and changes in metabolism .
using voxel - based morphometry ( vbm ) with mri [ 12 , 13 ] and voxel - based positron emission tomography ( pet ) analysis [ 14 , 15 , 16 , 17 , 18 ] of psp cases , reductions in gray matter and metabolic activity have been observed primarily in the frontal lobe and basal midbrain .
however , patients in previous pet and mri studies have differed with regard to the clinical stage of the disease .
thus , a comparison between the metabolic changes and decreases in gray matter in patients is difficult to make . the strength of the present study is a direct comparison of fluorodeoxyglucose ( fdg ) and vbm in the same psp subjects .
based on the success of large multicenter alzheimer disease neuroimaging studies ( e.g. adni and aibl ) , there is increasing interest in neuroimaging measures as secondary or surrogate markers of outcome for therapy trials on neurodegenerative diseases .
the modality that can diagnose psp in its early stages more adequately remains to be identified .
the primary aim of this study was to compare the distribution of glucose hypometabolism and atrophy simultaneously in the same group of patients .
the cognitive disturbances that occur in psp are referred to as subcortical dementia [ 19 , 20 ] .
psp patients demonstrate significant deficits in recall and moderate forgetfulness , despite intact short - term and implicit perceptual memory .
psp is also accompanied by memory loss and more common deficits , including executive dysfunction , decreased working memory , psychomotor slowing , non - fluent aphasia , and , at times , profound behavioral changes that mimic frontotemporal dementia [ 21 , 22 ] . despite the clinical significance of dementia ,
no study has examined the brain structures that are affected during cognitive impairment in patients with psp . in this study
, we selected psp patients with relatively mild cognitive impairment and examined the changes in the associated brain regions .
in this study , we included 16 probable psp patients [ 5 females and 11 males ; age : 64.9 ( 6.4 ) years ; mini - mental state examination ( mmse ) score : 21.0 ( 4.4 ) ] and 20 cognitively normal controls [ 8 females and 12 males ; age : 64.8 ( 6.4 ) years ; mmse score : 29.8 ( 0.6 ) ] .
these patients had been admitted to the infirmary at our institution between april 1996 and march 2002 to undergo an evaluation for dementia and had agreed to be registered in the database ; they were followed up for > 2 years . in order to ensure that the imaging protocols and the types of pet and mri scanners were the same throughout the observation period
the participants informed consents were obtained when they registered in the dementia registry database , but due to the retrospective design of this study informed consent was not required .
all patients were examined by neurologists and psychiatrists and underwent standard neurological and neuropsychological examinations , laboratory tests , electroencephalography , cranial mri , and f - fdg - pet .
the criteria for psp of the national institute of neurological disorders and stroke society were used to select patients for inclusion : a gradually progressive disorder ; onset at 40 years of age ; vertical ( upward and downward gaze ) supranuclear palsy and prominent postural instability with falls in the 1st year of the disease , and no evidence of other diseases that could explain the features above .
our patient group had mild cognitive impairment [ mmse score : 21.0 ( 4.4 ) ] .
all patients fulfilled the criteria for probable psp , and all subjects who were included had been followed up for 3 years after study entry .
the diagnosis of psp was confirmed in all cases at the follow - up evaluation .
the patients characteristics , including extrapyramidal signs , parkinsonism , and cortical symptoms , are shown in table 1 .
all control subjects had mmse scores 28 and exhibited no clinical evidence of cognitive deficits or neurological disease .
we did not detect any abnormal findings with regard to age - related atrophy or changes in white matter , including white matter hyperintensities .
a 1.5-tesla signa horizon mri system was used for this study ( ge medical systems , milwaukee , wisc .
sagittal , coronal , and axial t1-weighted spin echo images ( tr / te / nex : 550/15/2 ; 5 mm thick , 2.5-mm gap ) and axial t2-weighted fast spin echo images ( 3,000/21,105/2 ) were obtained to detect abnormalities .
vbm analyses were conducted using coronal 3d spoiled gradient echo ( spgr ) images [ 23 , 24](14/3/2 , 20 flip angle , 220-mm field of view , 256 256 matrix , 124 1.5 mm contiguous sections ) .
the 3d - spgr images were constructed with a voxel size of 0.86 0.86 1.5 mm .
then , the images were reconstructed into 2.0-mm isotropic voxel images by the spm / vbm methods .
the detailed pet procedure has been described previously . in brief , fdg - pet images were obtained using a headtome iv scanner ( shimadzu , kyoto , japan ) .
the subjects were examined in the resting condition with their eyes closed and ears unplugged . after a transmission scan , a 12-min emission scan was started 60 min after an intravenous injection of 185370 mbq fdg .
the slice number was 14 , and the slice interval was 6.5 mm in the z - motion mode . anatomical normalization and statistical processing of the pet and mr images were performed using spm for windows , version 8 ( spm 8 ; wellcome department of cognitive neurology , london , uk ) .
the calculations and image matrix manipulations were performed using matlab r2009b ( mathworks , natick , mass .
all coronal spgr mri datasets were reconstructed into axial datasets and subsequently converted to analyze format and displayed with the right hemisphere on the right side of the image .
next , we applied dartel ( an algorithm for accurate diffeomorphic image registration ) , implemented as a toolbox in spm 8 , to create a set of group - specific templates . using these templates
finally , the gray matter probability values were smoothed using an 8-mm full - width at half maximum gaussian kernel to match the pet analysis .
the dartel procedure , in addition to the previous spatial normalization methods that were developed by ashburner , improves anatomical precision . for fdg - pet , all individual pet images were co - registered with mri .
the images were transformed into a standard stereotactic anatomical space using the dartel flow that was created in the mri normalization .
further , all pet and mri images were smoothed using an isotropic 8-mm gaussian kernel to increase the signal - to - noise ratio and compensate for differences in gyral anatomy between individuals .
the individual fdg images were adjusted by proportional scaling to a mean value of 5.0 mg 100 ml min .
the metabolic activity , gray matter , and white matter were compared between patients and controls and analyzed by a 2-sample t test .
the correlations between mmse scores and brain structures were then examined with regard to metabolic activity , gray matter , and white matter by voxel - wise regression analysis , considering total intracranial volume , gender , and age as nuisance parameters .
each comparison between patients and controls was analyzed by a statistical design in the 2-sample t test . in this study
, we applied an uncorrected threshold of p < 0.001 on the basis of the results obtained in the previous studies , in which the frontal lobes and the midbrain were found as the regions of hypometabolism [ 15 , 16 , 17 , 18 ] or decreased gray matter [ 12 , 13 ] in patients with psp .
in this study , we included 16 probable psp patients [ 5 females and 11 males ; age : 64.9 ( 6.4 ) years ; mini - mental state examination ( mmse ) score : 21.0 ( 4.4 ) ] and 20 cognitively normal controls [ 8 females and 12 males ; age : 64.8 ( 6.4 ) years ; mmse score : 29.8 ( 0.6 ) ] .
these patients had been admitted to the infirmary at our institution between april 1996 and march 2002 to undergo an evaluation for dementia and had agreed to be registered in the database ; they were followed up for > 2 years . in order to ensure that the imaging protocols and the types of pet and mri scanners were the same throughout the observation period
the participants informed consents were obtained when they registered in the dementia registry database , but due to the retrospective design of this study informed consent was not required .
all patients were examined by neurologists and psychiatrists and underwent standard neurological and neuropsychological examinations , laboratory tests , electroencephalography , cranial mri , and f - fdg - pet .
the criteria for psp of the national institute of neurological disorders and stroke society were used to select patients for inclusion : a gradually progressive disorder ; onset at 40 years of age ; vertical ( upward and downward gaze ) supranuclear palsy and prominent postural instability with falls in the 1st year of the disease , and no evidence of other diseases that could explain the features above .
our patient group had mild cognitive impairment [ mmse score : 21.0 ( 4.4 ) ] .
all patients fulfilled the criteria for probable psp , and all subjects who were included had been followed up for 3 years after study entry .
the diagnosis of psp was confirmed in all cases at the follow - up evaluation .
the patients characteristics , including extrapyramidal signs , parkinsonism , and cortical symptoms , are shown in table 1 .
all control subjects had mmse scores 28 and exhibited no clinical evidence of cognitive deficits or neurological disease .
we did not detect any abnormal findings with regard to age - related atrophy or changes in white matter , including white matter hyperintensities .
a 1.5-tesla signa horizon mri system was used for this study ( ge medical systems , milwaukee , wisc .
sagittal , coronal , and axial t1-weighted spin echo images ( tr / te / nex : 550/15/2 ; 5 mm thick , 2.5-mm gap ) and axial t2-weighted fast spin echo images ( 3,000/21,105/2 ) were obtained to detect abnormalities .
vbm analyses were conducted using coronal 3d spoiled gradient echo ( spgr ) images [ 23 , 24](14/3/2 , 20 flip angle , 220-mm field of view , 256 256 matrix , 124 1.5 mm contiguous sections ) .
the 3d - spgr images were constructed with a voxel size of 0.86 0.86 1.5 mm .
then , the images were reconstructed into 2.0-mm isotropic voxel images by the spm / vbm methods .
the detailed pet procedure has been described previously . in brief , fdg - pet images were obtained using a headtome iv scanner ( shimadzu , kyoto , japan ) .
the subjects were examined in the resting condition with their eyes closed and ears unplugged . after a transmission scan ,
a 12-min emission scan was started 60 min after an intravenous injection of 185370 mbq fdg .
the slice number was 14 , and the slice interval was 6.5 mm in the z - motion mode .
anatomical normalization and statistical processing of the pet and mr images were performed using spm for windows , version 8 ( spm 8 ; wellcome department of cognitive neurology , london , uk ) .
the calculations and image matrix manipulations were performed using matlab r2009b ( mathworks , natick , mass .
all coronal spgr mri datasets were reconstructed into axial datasets and subsequently converted to analyze format and displayed with the right hemisphere on the right side of the image .
next , we applied dartel ( an algorithm for accurate diffeomorphic image registration ) , implemented as a toolbox in spm 8 , to create a set of group - specific templates . using these templates
finally , the gray matter probability values were smoothed using an 8-mm full - width at half maximum gaussian kernel to match the pet analysis .
the dartel procedure , in addition to the previous spatial normalization methods that were developed by ashburner , improves anatomical precision . for fdg - pet , all individual pet images were co - registered with mri .
the images were transformed into a standard stereotactic anatomical space using the dartel flow that was created in the mri normalization .
further , all pet and mri images were smoothed using an isotropic 8-mm gaussian kernel to increase the signal - to - noise ratio and compensate for differences in gyral anatomy between individuals .
the individual fdg images were adjusted by proportional scaling to a mean value of 5.0 mg 100 ml min .
the metabolic activity , gray matter , and white matter were compared between patients and controls and analyzed by a 2-sample t test .
the correlations between mmse scores and brain structures were then examined with regard to metabolic activity , gray matter , and white matter by voxel - wise regression analysis , considering total intracranial volume , gender , and age as nuisance parameters . each comparison between patients and controls
was analyzed by a statistical design in the 2-sample t test . in this study , we applied an uncorrected threshold of p < 0.001 on the basis of the results obtained in the previous studies , in which the frontal lobes and the midbrain were found as the regions of hypometabolism [ 15 , 16 , 17 , 18 ] or decreased gray matter [ 12 , 13 ] in patients with psp .
using fdg - pet , we observed a reduction in metabolic activity in the bilateral frontal lobes and midbrain tegmentum in the psp group compared with normal controls ( p < 0.001 , uncorrected ; fig .
, we compared gray matter volume in the bilateral frontal lobes , anterior cingulate gyrus , right middle temporal gyrus , and right midbrain between patients and normal controls ( p < 0.001 , uncorrected ; fig . 1b ; table 2 ) .
white matter volume decreased significantly in the bilateral thalami , midbrain tegmentum , and right frontal lobes ( p < 0.001 , uncorrected ; fig . 1c ; table 2 ) .
the decrease in white matter in the midbrain was more marked than the reduction in gray matter in the visual analysis .
the extent to which the white matter decreased was less than the decrease in hypometabolism in psp patients .
a positive metabolic and structural correlation with mmse was observed in the left frontal lobe in regression analysis ( p < 0.001 , uncorrected ; fig . 2 ; table 3 ) .
additional reductions in gray matter were noted in the right frontal lobe and bilateral rectal gyri ( fig . 2 ; table 3 ) .
3b ) images of a male patient with psp ( mmse score : 23 ) and a normal female subject ( mmse score : 30 ) of the same age ( 68 years ) .
slight midbrain and bilateral frontal lobe atrophy was observed on visual inspection of the conventional t1-weighted image of the psp patient compared with the healthy control ( fig .
3a ) ; however , the psp patient experienced more severe hypometabolism in the midbrain and bilateral frontal lobes , including the medial and lateral frontal lobes .
4b ) images of a demented male patient with psp ( mmse score : 17 ) and a normal female subject ( mmse score : 30 ) of the same age ( 70 years ) .
abnormalities in the midbrain were not observed on visual inspection of the conventional t1-weighted image and fdg - pet images of the psp patient compared with the healthy control ; however , slight atrophy and more severe hypometabolism were noted in the psp patient in the bilateral frontal lobes ( fig .
using fdg - pet , we observed a reduction in metabolic activity in the bilateral frontal lobes and midbrain tegmentum in the psp group compared with normal controls ( p < 0.001 , uncorrected ; fig .
, we compared gray matter volume in the bilateral frontal lobes , anterior cingulate gyrus , right middle temporal gyrus , and right midbrain between patients and normal controls ( p < 0.001 , uncorrected ; fig . 1b ; table 2 ) .
white matter volume decreased significantly in the bilateral thalami , midbrain tegmentum , and right frontal lobes ( p < 0.001 , uncorrected ; fig . 1c ; table 2 ) .
the decrease in white matter in the midbrain was more marked than the reduction in gray matter in the visual analysis .
the extent to which the white matter decreased was less than the decrease in hypometabolism in psp patients .
a positive metabolic and structural correlation with mmse was observed in the left frontal lobe in regression analysis ( p < 0.001 , uncorrected ; fig . 2 ; table 3 ) .
additional reductions in gray matter were noted in the right frontal lobe and bilateral rectal gyri ( fig . 2 ; table 3 ) .
figure 3 shows mr ( fig . 3a ) and fdg - pet ( fig .
3b ) images of a male patient with psp ( mmse score : 23 ) and a normal female subject ( mmse score : 30 ) of the same age ( 68 years ) .
slight midbrain and bilateral frontal lobe atrophy was observed on visual inspection of the conventional t1-weighted image of the psp patient compared with the healthy control ( fig .
3a ) ; however , the psp patient experienced more severe hypometabolism in the midbrain and bilateral frontal lobes , including the medial and lateral frontal lobes .
4b ) images of a demented male patient with psp ( mmse score : 17 ) and a normal female subject ( mmse score : 30 ) of the same age ( 70 years ) .
abnormalities in the midbrain were not observed on visual inspection of the conventional t1-weighted image and fdg - pet images of the psp patient compared with the healthy control ; however , slight atrophy and more severe hypometabolism were noted in the psp patient in the bilateral frontal lobes ( fig .
this study is the first head - to - head comparison of fdg and vbm in the same group of psp subjects .
the fdg - pet and mri scans showed that relatively similar regions experienced significant reductions in metabolic activity , gray matter , and white matter primarily the frontal lobe and midbrain tegmentum .
first , the visual extents of the regions in which there were significant changes were much greater on fdg - pet than on mri .
further , the correlation between the frontal lobe and mmse scores in psp patients was similar in all evaluations .
compared with atrophy , the cluster volume of gray matter hypometabolism was greater , which implies that fdg - pet is more important in the differential diagnosis of psp .
fdg - pet revealed hypometabolism in the bilateral frontal lobes and midbrain tegmentum , in agreement with previous pet studies [ 14 , 15 , 16 , 17 , 18 ] .
vbm analysis disclosed significant reductions in gray matter in the lateral frontal lobe , including the middle and inferior frontal gyri , midbrain , and middle frontal gyrus .
additional gray matter reductions in the hippocampus and parahippocampal gyrus were noted in another study .
the cluster volume in our study appeared to be smaller than in previous vbm studies .
such misregistrations could be observed in the periventricular area and the deep brain structures , such as the striatal nucleus and brainstem .
the greater reduction in midbrain gray matter ( compared with white matter ) that was observed in one study might be explained by the misregistration of structures .
however , there would be some space to discuss the structural changes in the midbrain . in this study , t1-weighted imaging was used for vbm analysis .
t1-weighted imaging is less sensitive to changes in iron deposits in the brainstem , which complicates the discrimination of mr signals between gray matter and white matter in the brainstem .
another study that used surface rendering without segmenting the gray and white matter observed brainstem atrophy in psp patients ; however , due to limitations in measuring the volumes of regional structures , a new method for measuring brainstem atrophy in psp should be developed our procedure vbm using dartel revealed greater reductions in the white than in the gray matter in the midbrain tegmentum .
further , the cluster volume of gray matter hypometabolism was much higher compared with gray matter atrophy in psp patients .
our results show that atrophy and hypometabolism in the frontal lobe are as important as in the basal midbrain in the diagnosis of psp patients exhibiting cognitive dysfunction .
in fact , as shown in figure 4 , we identified a demented psp patient who only experienced hypometabolism and atrophy in the frontal lobe but not in the basal midbrain .
if we consider psp with regard to dementia , disease progression in the frontal lobe versus the midbrain is not synchronized .
the cognitive changes that occur in psp are referred to as subcortical dementia , which is associated with cognitive impairment , including prominent deficits in recall and moderate forgetfulness , despite intact short - term and implicit perceptual memory .
neuropsychological studies employing the frontal behavioral inventory suggest the presence of frontal lobe dysfunction in psp patients .
moreover , neuropathological studies have demonstrated that the middle frontal gyrus is a representative region in which abnormal glial cells , accompanied by abnormal tau protein , appear , further supporting our data .
the relationship between the unified parkinson 's disease rating scale score and structural changes has to be elucidated in future studies .
our results suggest that in addition to the basal midbrain , the frontal lobe is a part not to be missed in the diagnosis of demented psp patients who do not experience hypometabolism or atrophy in the midbrain .
a limitation of this study is that the diagnosis of psp in our patients was not confirmed by autopsy .
second , we did not compare the diagnostic performance between mri and pet in diagnosing psp .
third , this study used an old type of pet scanner and the slice interval of 6.5 mm may be relatively large to evaluate midbrain metabolism precisely .
further , we compared the pet and mri findings only with raw data and did not perform the atrophy correction .
atrophy may have contributed to the extent of the reduced signal shown in the pet scan . however , the methods for atrophy correction are still in the developing stages , and future studies have to develop an appropriate technique for atrophy correction
. finally , the use of vbm with the dartel algorithm continues to be refined ; advances in its precision and accuracy might pave the way for a more detailed study of psp pathology .
compared with atrophy , the cluster volume of gray matter hypometabolism was greater , which implies that fdg - pet is more important in the differential diagnosis of psp .
fdg - pet revealed hypometabolism in the bilateral frontal lobes and midbrain tegmentum , in agreement with previous pet studies [ 14 , 15 , 16 , 17 , 18 ] .
vbm analysis disclosed significant reductions in gray matter in the lateral frontal lobe , including the middle and inferior frontal gyri , midbrain , and middle frontal gyrus .
additional gray matter reductions in the hippocampus and parahippocampal gyrus were noted in another study .
the cluster volume in our study appeared to be smaller than in previous vbm studies .
such misregistrations could be observed in the periventricular area and the deep brain structures , such as the striatal nucleus and brainstem .
the greater reduction in midbrain gray matter ( compared with white matter ) that was observed in one study might be explained by the misregistration of structures .
however , there would be some space to discuss the structural changes in the midbrain . in this study , t1-weighted imaging was used for vbm analysis .
t1-weighted imaging is less sensitive to changes in iron deposits in the brainstem , which complicates the discrimination of mr signals between gray matter and white matter in the brainstem .
another study that used surface rendering without segmenting the gray and white matter observed brainstem atrophy in psp patients ; however , due to limitations in measuring the volumes of regional structures , a new method for measuring brainstem atrophy in psp should be developed our procedure vbm using dartel revealed greater reductions in the white than in the gray matter in the midbrain tegmentum .
further , the cluster volume of gray matter hypometabolism was much higher compared with gray matter atrophy in psp patients .
our results show that atrophy and hypometabolism in the frontal lobe are as important as in the basal midbrain in the diagnosis of psp patients exhibiting cognitive dysfunction .
in fact , as shown in figure 4 , we identified a demented psp patient who only experienced hypometabolism and atrophy in the frontal lobe but not in the basal midbrain .
if we consider psp with regard to dementia , disease progression in the frontal lobe versus the midbrain is not synchronized .
the cognitive changes that occur in psp are referred to as subcortical dementia , which is associated with cognitive impairment , including prominent deficits in recall and moderate forgetfulness , despite intact short - term and implicit perceptual memory .
neuropsychological studies employing the frontal behavioral inventory suggest the presence of frontal lobe dysfunction in psp patients .
moreover , neuropathological studies have demonstrated that the middle frontal gyrus is a representative region in which abnormal glial cells , accompanied by abnormal tau protein , appear , further supporting our data .
the relationship between the unified parkinson 's disease rating scale score and structural changes has to be elucidated in future studies .
our results suggest that in addition to the basal midbrain , the frontal lobe is a part not to be missed in the diagnosis of demented psp patients who do not experience hypometabolism or atrophy in the midbrain .
a limitation of this study is that the diagnosis of psp in our patients was not confirmed by autopsy .
second , we did not compare the diagnostic performance between mri and pet in diagnosing psp .
third , this study used an old type of pet scanner and the slice interval of 6.5 mm may be relatively large to evaluate midbrain metabolism precisely .
further , we compared the pet and mri findings only with raw data and did not perform the atrophy correction .
atrophy may have contributed to the extent of the reduced signal shown in the pet scan .
however , the methods for atrophy correction are still in the developing stages , and future studies have to develop an appropriate technique for atrophy correction .
finally , the use of vbm with the dartel algorithm continues to be refined ; advances in its precision and accuracy might pave the way for a more detailed study of psp pathology .
this head - to - head study of fdg - pet and mri demonstrates that in psp patients the extent of metabolic changes is greater than that of changes in gray and white matter .
moreover , mmse scores were associated with changes in the frontal lobe in psp patients , which will be beneficial in diagnosing psp patients with cognitive impairment who do not develop hypometabolism or atrophy in the midbrain and will contribute to future neuropathological and neurophysiological studies of psp .
| background / aimsthe aim of this study was to compare differences in morphological and functional changes in brain regions in individual patients with progressive supranuclear palsy ( psp ) and correlate their mini - mental state examination ( mmse ) score with anatomy and function using magnetic resonance imaging ( mri ) and 18f - fluorodeoxyglucose positron emission tomography ( fdg - pet).methodssixteen psp patients and 20 age - matched healthy volunteers underwent fdg - pet and 3-dimensional mri .
gray matter , white matter and metabolic activity were compared between patients and normal controls . in addition , possible correlations between the mmse score and brain function / anatomy were examined.resultsthe psp group had reduced cerebral glucose metabolism , and lower gray and white matter volumes in the frontal lobes and midbrain compared with normal controls . in psp subjects ,
the metabolic changes observed in the pet scans were greater than the loss in gray and white matter observed in the mri scans .
the mmse scores were positively correlated with volume and fdg uptake in the frontal lobe.conclusionfdg-pet is a more effective tool in the diagnosis of psp than mri . atrophy and hypometabolism in the frontal lobe are as important as in the basal midbrain for differentiating psp patients who primarily exhibit cognitive dysfunction from normal controls . |
inguinal hernia is the protrusion of abdominal organs into the inguinal canal through the natural or acquired defect of the abdominal wall .
operation of inguinal hernia represent the most frequent surgical intervention in the domain of general surgery with about twenty million procedures performed a year worldwide .
frequency of inguinal hernia in men is 25% , and in women 2% . in men , indirect inguinal hernias
risk of inguinal hernia increases with age and annual incidence in persons older than 75 years is about 50% . on average
about two thirds of inguinal hernias are indirect and one third is direct ( 1 ) .
application of prosthetic mesh in inguinal hernia repair results in reduced incidence of relapse , and fibrin glue used as mesh fixative , has contributed to comfortable postoperative period with mild controlled pain and rapid return to daily activities .
the method is simple and it can be performed by all surgeons , even by those who have no special interest in hernia surgery .
the aim of this study was to compare two methods of fixation of polypropylene mesh for inguinal hernia repair according to lichtenstein , using fibrin glue fixation and suture fixation .
prospective and retrospective analysis of 60 patients , who underwent inguinal hernia surgery , were performed at the department of surgery , university clinical center in tuzla .
the experimental group consisted of 30 patients who underwent surgery using the modified method by lichtenstein
the control group consisted of 30 patients who underwent surgery using a conventional method by lichtenstein suture polypropylene mesh fixation .
both groups were proportionally represented by patients with unilateral , direct ( m1 , m2 ) and indirect ( l1 , l2 ) , inguinal hernia , age 18 to 80 years with physical status asa 1 and asa . from the study
were excluded : persons with recurrent , bilateral and hernia type l3 and m3 , persons with body mass index above 35kg / m , those with prolonged use of analgetics , steroids , and anticoagulant drugs , persons addicted to alcohol or drugs , persons suffering from cirrhosis of the liver , with immunodeficiency syndrome , and severe damage to physical or mental health that could affect the investigation .
all patients were analyzed according to the following information : age , gender , body mass index ( bmi ) , type , location and size of the hernia , preoperative level of pain ( presurgical pain level ) , surgical techniques , intrasurgical complications , duration of surgery , postsurgical pain level , postsurgical complication ( ecchymosis , hematoma , seroma , wound infection , pain ) , reintervention , postsurgical hospital stay , postsurgical quality of life and postsurgical functional activities .
all patients were classified according to the standard anesthetic protocol asa ( american society of anesthesiologists ) and had surgery under general anesthesia . polypropylene mesh ( prolene , ethicon germany , weight
100g / m2 , 164x96 micron pore size , dimensions 15x8 cm ) , is placed on the back wall of the inguinal canal , and the fixation of the mesh is done with individual slowly resorbable suture ( poliglactin 910vicryl 2.0 ) and fibrin glue ( tissucol kit , baxter , usa ) , ( figure 1 ) .
polypropylene mesh fixation with fibrin glue ( tissucol ) overall postoperative complications and the patient s ability to return to regular activities were followed for 3 months .
postoperative patients examination was made after 7 days , 1 month , and 3 months .
pain level was evaluated by visual analogue scale ( vas ) , graded from 0 - 10 , before surgery , first day after surgery , seventh day after surgery , 1 month and 3 months after surgery . in statistical data analysis methods of descriptive and inferential statistics
data are expressed as the median value and range or the mean standard deviation appropriate .
a p - value less than 0.05 was considered as significant in all of the tests .
the study included 56 male ( 93.3% ) and 4 female ( 6.7% ) patients , evenly distributed in groups .
group a had an average age of 52.3 years and group b of 50.3 years .
preoperative characteristics of patients in 35 ( 58.3% ) patients right - sided hernias were found ( group a-17 , group b-18 ) , and in 25 ( 41.7% ) patients left - sided hernias were found ( group a-13 , group b-12 ) .
intraoperative hernia presentation was : l1 - 19 ( 31.7% ) , l2 - 16 ( 26.6% ) , m1 - 6 ( 10% ) , m2 - 19 ( 31.7% ) .
group a had , l1 - 9 , l2 - 8 , m1 - 3 , m2 - 10 .
group b had , l1 - 10 , l2 -8 , m1 - 3 , m2 - 9 ( table 2 ) .
preoperative and intraoperative characteristics of inguinal hernias study results and statistical analysis of data showed significant differences in the duration of surgery between methods a
the results showed that the duration of surgery by method a was shorter by 5,667 min as compared to method b the intensity of pain evaluated by visual analogue scale ( vas ) was measured on 5 occasions : before surgery , first day after surgery , seventh day after surgery , 1 month and 3 months after surgery .
significantly lower pain level was noted in group a after the first and seventh postoperative day , as well as a month after the surgery .
mean values of vas the first day after surgery was 3.53 vs. 4.70 , seventh day after surgery 2.23 vs. 3.16 , a month after surgery 0.80 vs.1.56 .
these values show significant differences between group a and group b. there was a statistically significant difference in pain intensity between samples first day after surgery ( p = 2.281 e-06 ) .
specifically , calculated t - test value ( -5.256 ) is outside of the range which indicates that the null hypothesis ( 2.00 ) for bidirectional test values of arithmetic means in observed populations can not be accepted .
in addition to the risk of 5% , working hypothesis stating that there is a statistically significant difference in pain intensity between group a and group b seventh day after surgery ( p = 4.7314 e-06 ) is accepted . measured t - test value ( -5.06 )
is outside of the range which indicates that the null hypothesis ( 2.00 ) for bidirectional test values of arithmetic means in observed populations can not be accepted . based on the obtained results
it can be concluded that there is a significant differences in the severity of pain between the two groups seven day after surgery .
in addition , based on the obtained results it can be concluded that there is a statistically significant difference in pain intensity between the groups investigated a month after surgery ( p = 7.0051 e-06 ) .
measured t - test value ( -6.19 ) is outside of the range which indicates that the null hypothesis ( 2.00 ) for bidirectional test values of arithmetic means in observed populations can not be accepted .
there was no statistically significant difference in pain intensity between the two groups three months after surgery ( p = 0.4468 ) .
measured t - test value ( -0.7658 ) is outside of the range which indicates that the null hypothesis ( 2.00 ) for bidirectional test values of arithmetic means in observed populations can not be accepted ( figure 2 ) .
results obtained by comparing the arithmetic mean of the intensity of pain before surgery ( v11 ) , first day after surgery ( v12 ) , seventh day after surgery ( v13 ) , one month after surgery ( v14 ) and 3 months after surgery ( v15 ) .
paresthesia in the area of the surgical wound or scar was significantly lower in group a. peresthesia in the same area was followed for seven days , one month and three months after surgery .
the ratio between group a and b was as follows : the seventh day after surgery 13.3 vs. 26% , one month after surgery 6.6 vs. 20% , 3 months after surgery 3.3 vs. 13.3% ( p = 0.035 ) ( figure 3 ) .
comparative diagram of paresthesia in studied groups during the early postsurgical phase 17 complications were observed , two in group a ( ecchymosis 1 , seroma 1 ) , and 15 in group b ( ecchymosis 6 , seroma 9 ) .
results showed that 28/30 ( 93.3% ) patients from the group a and 15/30 ( 50.0% ) patients from the group b had no complications .
therefore , group a had significantly less postsurgical complications than group b. the results obtained by statistical processing of the total number of complications between the two groups , with a calculated p value = 0.024 , indicates a statistically significant difference in the number of complications ( table 3 ) .
comparative analysis of the total number of complications in studied groups the results confirmed ( with the risk of 0.05 ) a working hypothesis , according to which there is a statistically significant difference in complications ecchymosis ( p = 0.048 ) between the surgery method a and method b. the results also confirmed ( with the risk of 0.05 ) the second working hypothesis , according to which there is a statistically significant difference in the proportion of complications seroma ( p = 0.033 ) between the surgery method a and method b. the results showed that there were no complications such as hematoma and recurrence , and that there is no statistically significant difference in the proportion of these complications between surgery method a and method b ( 4 ) .
successful surgical treatment of inguinal hernia implies a low rate of recurrence , permanent relief of pain and discomfort caused by a hernia , as well as a low incidence of postoperative complications . for last fifteen years
inguinal hernia surgery by lichtenstein is the first and most widely used open tension - free method .
systematic review on the use of fibrin glue in abdominal wall repair showed to be more beneficiary for fixation of polypropylene mesh with fibrin glue than mechanical suture fixation .
the literature analyzed was from : medline , embase , and the cochrane library plus databases .
articles found showed randomized clinical trials , non randomized comparative studies and case series that included minimum of 10 patients . in these studies fibrin glue has proven to be biocompatible with the surrounding tissue . in patients treated with fibrin glue
, there was a lower prevalence of acute and chronic postoperative pain , and hemorrhagic complications ( 5 ) .
our results largely agree with published studies that compared the fixation of the mesh with fibrin glue and suture technique in open inguinal hernia repair by lichtenstein ( 6 ) .
data obtained during our research , showed that the use of fibrin glue for fixation of polypropylene mesh in inguinal hernia repair achieved excellent results , with significantly fewer side effects as compared to the conventional method of suture fixation .
the results confirmed that the seroma type of complications are significantly less present in fibrin glue fixation methods , while the ecchymosis type of complications are insignificant when using suture techniques .
mean surgical time was reduced by 10% in the group where the fixation was performed using fibrin glue .
patients in this group had less local hemorrhagic complications ( hematoma , ecchymosis , seroma ) than the patients from the suture group . in the early postoperative period , patients from the fibrin glue group had lower pain intensity and paresthesia ( numbness ) in the groin .
the differences in the results after 7 days and 1 month proved to be significant , however , after 3 months they were not significant .
paresthesia was more prominent in the suture group even after 3 months , in that way showing a significant difference ( 4 ) . a prospective
, multicenter study was designed to compare fibrin glue with conventional suture tissue fixation in inguinal hernia repair by lichtenstein .
five hundred and twenty patients were analyzed in whom mesh fixation was performed using fibrin glue ( 349 patients ) or suture ( 171 patients ) .
average pain intensity by vas in the preoperative phase was 2.9 , with no significant difference between the groups .
surgery parameters were similar between the treated groups , with the exception of the average duration of the surgery .
the surgery was shorter in patients where fibrin glue was used ( 55.6 vs. 61.2min , p < 0.001 ) .
patients in fibrin group also rarely experienced early local hemorrhagic complications ( hematoma , ecchymosis ) as compared to suture group .
after a one - month assessment , patients from the fibrin group reported significantly less pain , paresthesia , and discomfort , as compared to patients from suture group .
there was a lower incidence of hematoma ( 1.7 vs. 8.2% ) and ecchymosis ( 8.6 vs. 15.2% ) in patients treated with fibrin glue , as compared to patients in the suture group ( both p = 0.001 ) .
the average vas value for pain intensity was significantly lower in the group treated with fibrin glue ( 2.5 vs. 3.2 ; p < 0.001 ) ( 7 ) . one randomized study compared the suture technique , cyanoacrylate glue and fibrin glue as a means of fixation of polypropylene mesh .
morbidity in suture group was 38.98% , in the fibrin glue group was 9.62% , and in cyanoacrylate glue group 10.71% ( suture group vs. fibrin glue , p < 0.001 ; suture group vs. cyanoacrylate glue , p <
the presented results show that the mesh fixation with fibrin glue in open , tension - free repair by lichtenstein is simple , safe and effective .
this method of fixation show distinct advantages over staple fixation , with slight possibility of chronic pain , and complications from the wound recurrence .
mesh fixation with fibrin glue is simple procedure that is related to the reduction of postoperative inguinal pain .
fixation with glue causes less nerve injuries , the pubic periosteum injuries , or injuries to blood vessels than conventional methods that are associated with iatrogenic tissue trauma and neuropathic pain . during polypropylene mesh fixation with fibrin glue minimal retraction
is required . greater retraction , as in suture methods , leads to increased tissue contusion and short - term pain .
therefore , consistent with our results , a small contusion of soft tissues associated with minimal postoperative pain is what makes this method more advanced .
therefore , fibrin glue can be considered as the first option in the fixation of polypropylene mesh in open inguinal hernia repair . | abstractthe aim : of this study was to compare two methods of polypropylene mesh fixation for inguinal hernia repair according to lichtenstein using fibrin glue and suture fixation.material and methods : the study included 60 patients with unilateral inguinal hernia , divided into two groups of 30 patients suture fixation and fibrin glue fixation.all patients were analyzed according to : age , gender , body mass index ( bmi ) , indication for surgery the type , localization and size of the hernia , preoperative level of pain and the type of surgery .
overall postoperative complications and the patient s ability to return to regular activities were followed for 3 months.results and discussion : statistically significant difference in the duration of surgery , pain intensity and complications ( p<0.05 ) were verified between method a , the group of patients whose inguinal hernia was repaired using polypropylene mesh
fibrin glue and method b , where inguinal hernia was repaired with polypropylene mesh using suture fixation .
given the clinical research , this systematic review of existing results on the comparative effectiveness , will help in making important medical decisions about options for surgical treatment of inguinal hernia.conclusions:the results of this study may impact decision making process for recommendations of methods of treatment by professional associations , making appropriate decisions on hospital procurement of materials , as well as coverage of health funds and insurance . |
many different genetic mechanisms of sex determination have been discovered in nature and studied deeply , using molecular - genetic tools ( reviewed in cline and meyer 1996 ; marin and baker 1998 ; zarkower 2001 ; williams and carroll 2009 ; charlesworth and mank 2010 ; gamble and zarkower 2012 ; hughes and rozen 2012 ) . in humans ,
a dominant male - determining gene is present on the y chromosome , whereas in drosophila melanogaster the dose of x chromosomes is the primary determinate of sex , and in c. elegans sex is determined by the ratio of x chromosomes to autosomes .
the outcomes of these pathways are also different : males and females are the result in humans and d. melanogaster vs. males and hermaphrodites in c elegans . in the yeast saccharomyces cerevisiae ( reviewed in ni et al .
2011 ) diploid a/ organisms are derived by the fusion of opposite - sex , a and haploids that are able to switch genetic material from one of two silent mating - type loci ( hmr and hml ) to the active mat locus through gene conversion initiated by the ho endonuclease . in plants that are obligate outcrossers , self - incompatibility ( si ) loci prevent productive self - fertilization , thereby effectively creating many mating types ( reviewed in barrett 2002 ) .
( 2014 ) examined the genetic basis of mating in the yeast zygosaccharomyces sapae , which typically lives in osmotically stressful environments , is often the cause of food spoilage and displays predominantly clonal reproduction .
z. sapae is closely related to other species that reproduce sexually , leaving open questions of whether z. sapae has the genes that normally determine sex and what factors promoted the transition toward asexuality in this lineage .
the z. sapae genome indeed contains genes homologous to those involved in mating - type determination in related yeast species , but it is unusual in containing three different versions of the mating - type locus and two ho endonuclease genes , in addition to one version of the a mating - type locus .
the identification of the a genotype leads the authors to propose that the stressful conditions in which this yeast normally finds itself could promote genome instability , with the sex chromosome perhaps being a hot spot for recombination and mutation .
this genome instability in turn would produce mating - type imbalances that could disfavor or entirely prevent sexual reproduction , thereby contributing to genetic diversity in mating strategy among zygosaccharomyces yeasts .
( 2014 ) investigated the genetic and evolutionary basis of self - incompatibility in the plant tribe biscutelleae ( brassicaceae ) , which has a sporophytic self - incompatibility system ( ssi ) in which the pollen ( male gamete ) phenotype is determined by the diploid genotype of the paternal plant .
the pollen typically expresses cysteine - rich proteins ( scr ) that are thought to interact with a transmembrane receptor ( srk ) produced on the pistil that receives the pollen .
successful fertilization depends on different alleles being present at the s locus of pollen and pistils .
( 2014 ) characterized srk - like ( srkl ) sequences in biscutella neustriaca individuals from eight phenotypic incompatibility groups and discuss the association between srkl sequences and self - incompatibility phenotypes and the similarities and differences between biscutella and the better - studied but distantly related brassicaceae such as brassica and arabidopsis .
sex chromosomes spend different amounts of time in males and females during an organism s evolution , usually experience less recombination than autosomes , and are often subject to dosage compensation .
these differences lead to different selective pressures acting on sex - linked genes compared to the autosomal ones . taken further , as essential genes move from the sex chromosome to autosomes ,
sex chromosomes can be lost and replaced with new ones that evolve from ancestral autosomes .
blackmon and demuth ( 2014 ) used phylogenetic analysis to reveal the tempo of y chromosome turnover in coleoptera .
they analyzed karyotypes of 4724 beetle species that have heterogametic males that are xy , xo , or xy+ .
xy+ are sex chromosome bivalents that display distance pairing ( no synapsis ) and thus do not recombine , allowing the authors to distinguish how differences in sex chromosome pairing and meiotic recombination influence the evolution of the sex chromosomes in two major beetle lineages , adephaga ( which have only xy and xo species ) , and polyphaga ( where over half of all species are xy+ ) . blackmon and demuth ( 2014 ) find that in adephaga , new y chromosomes are evolving at the same rate as they are lost , whereas in polyphaga y chromosomes are twice as readily gained as lost .
the authors propose that different meiotic mechanisms that evolve to ensure sex chromosome segregation affect the tempo of y chromosome gain and loss .
many sex chromosome pairs have a recombining region with largely similar gene content [ pseudoautosomal region ( par ) ] .
kirkpatrick and guerrero ( 2014 ) use par to study sex - antagonistic ( sa ) selection .
sa selection acts on alleles that are beneficial in one sex but detrimental to the other .
sex chromosomes tend to bear more sa alleles than autosomes , presumably due to their sex - specific inheritance and limited recombination .
this study uses coalescent models to show that sa selection , together with limited recombination , should lead to different patterns of neutral genetic variation on the x and y ( or z and w ) chromosomes .
the authors test their model in silene latifolia , a plant with young recombining sex chromosomes , to illustrate their approach .
the process of meiosis ensures that haploid complements of chromosomes segregate to each gamete through the processes of chromosome pairing , synapsis , and recombination . given that sex chromosomes are either not homologous along their entire length ( xy , zw ) or hemizygous ( xo , zo )
, additional mechanisms have evolved to ensure their segregation during meiosis . while homology - dependent mechanisms function in heterogametic organisms , it is not known how meiosis is altered in the hemizygous sex to ensure segregation of the single sex chromosome .
furthermore , male and female gametes are morphologically distinct and undergo meiosis at different times during their developmental trajectories .
2014 examined the mechanisms that ensure segregation of the hemizygous x chromosome in c. elegans males ( xo ) .
they demonstrate that double - strand dna breaks ( dsb ) are important for segregation of the hemizygous x and present evidence that dsbs could mediate sister chromatid synapsis ( pseudosynapsis ) , instead of the typical synapses formed between homologs .
they go further and show that different genes function to provide feedback on autosomal synapsis and dsb repair pathways .
they posit that these fundamental differences in meiotic processes evolved to accommodate hemizygosity of the x chromosome .
zhang et al . ( 2014 ) examined the transcriptomes and proteomes during the differentiation of maize anthers , a model system well suited for this study because of the relative ease of collecting tissues at different developmental stages . in angiosperms ,
the germline arises from somatic flower cells through a switch from mitotic proliferation to meiosis .
2014 ) examined several stages on this developmental trajectory , from initial specification to final germinal and somatic cell differentiation .
they describe transcriptome composition at different stages and show that many genes with meiotic functions are expressed prior to the onset of germ cell differentiation and meiosis .
consistent with recent findings in other systems , they also find a low correlation between transcript abundance and protein abundance , suggesting a major role of post - transcriptional regulation in this developmental process .
the inaugural collection highlights only some areas of sex - specific biology ; there are many remaining questions and discoveries to be made on a broad range of topics .
this growing resource will illuminate the myriad ways in which sex differences influence biological processes . | in this commentary , michelle arbeitman et al . ,
examine the topic of the genetics of sex as explored in this month 's issues of genetics and g3 : genes |genomes |genetics .
these inaugural articles are part of a joint genetics of sex collection ( ongoing ) in the gsa journals . |
cystic fibrosis ( cf ) is an inherited disease resulting in the formation of thick , sticky mucus in the lungs and digestive pathways .
pseudomonas aeruginosa is the most common bacterial isolate that persists in cf lungs by evading host defenses and clearance mechanisms , contributing to declining lung function [ 1 , 2 ] . in order to grow and thrive ,
however , in the case of infection , iron is not freely available in the host and is predominantly found in iron - binding proteins such as transferrin , lactoferrin , and ferritin .
thus , due to the low bioavailability of free iron , bacteria produce iron - chelating small molecules known as siderophores that are secreted in apo - form and imported as ferric complexes [ 1 , 4 ] .
p. aeruginosa produces two siderophores , pyoverdine ( figures 1(a ) , and 1(b ) ) and pyochelin , that are found to be important for biofilm development and bacterial virulence . as a host defense strategy
, mammals have evolved strategies to limit bacterial growth by producing antibacterial iron - depleting innate immune defense proteins , such as neutrophil - gelatinase - associated lipocalin ( ngal ) , that specifically scavenge bacterial ferric and apo - siderophores , therefore preventing bacteria from establishing infection [ 5 , 6 ] .
ngal is a 25 kda protein also known as siderocalin , lipocalin 2 , uterocalin , and 24p3 , that exhibits antibacterial activity .
ngal - deficient mice are more susceptible to bacterial infections and ngal is required for pulmonary host defense against klebsiella pneumoniae .
lipocalins such as ngal share a common tertiary structure , the so - called lipocalin fold , characterized by an eight - strand antiparallel -barrel with a calyx that contains the ligand - binding site .
ngal is expressed and secreted upon stimulation by many cells and also acts as a growth and differentiation factor in various tissues , mainly in the kidney .
one study has shown that ngal levels are highly elevated in cf serum and bronchoalveolar lavage fluid ( balf ) . in spite of the abundance of ngal in serum and balf of cf patients , p. aeruginosa infections persist for many years .
pathogenic bacteria evolved under the pressure of iron limitation to survive and evade host immune systems by producing structurally modified siderophores that do not bind to ngal . pathogenic gram - negative bacteria
harbor the iroa gene cluster that mediates bacterial evasion of ngal [ 12 , 13 ] .
for example , salmonella typhimurium , a gram - negative bacterium , produces a glycosylated enterobactin known as salmochelin [ 11 , 14 ] .
no homologs of the iroa gene cluster were found in the published pseudomonas genomes , although p. aeruginosa produces three types of pyoverdines .
for example , bacillus anthracis , a gram - positive bacterium , produces a siderophore known as petrobactin that does not bind to ngal ; klebsiella pneumonia , a gram - negative bacterium , produces a siderophore known as yersiniabactin that also does not bind to ngal and thereby evades the host 's antibacterial iron - depleting defense .
further , vibrio cholerae produces vibriobactin , a catecholate siderophore that evades ngal recognition by unique iron coordination in the ferric vibriobactin form .
it is not known if pyoverdine , the major siderophore produced by p. aeruginosa , evades this innate defense mechanism and whether this contributes to inability of cf patients to clear this bacterium from their lungs .
therefore , the aim of this work was to determine if pyoverdine binds to the antibacterial protein ngal .
we hypothesized that ngal does not bind pyoverdine , allowing p. aeruginosa to establish infections and persist in cf lungs .
hence , this iron - depleting innate host defense mechanism may be dysfunctional and impaired in cf . in this paper
we employed a fluorescence - based assay to characterize the binding of pyoverdine to human ngal and molecular modeling of ngal pyoverdine complexes to predict possible protein - ligand interactions . here
we report that neither apo- nor ferric pyoverdine bind to ngal , results that are further supported by computational predictions indicating lack of interaction of pyoverdine with ngal at its conventional ligand - binding site .
we conclude that pyoverdine is a stealth siderophore that evades ngal recognition , thereby allowing p. aeruginosa to establish infections .
1757-lc ) produced in a mammalian system rather than a bacterial source was purchased from r&d systems ( minneapolis , mn , usa ) .
highly purified and structurally defined pyoverdines were obtained from sigma - aldrich ( st louis , mo , usa ) in apo - form , that is , aferric pyoverdine ( catalog no .
0926 kb ) , and sterile bovine serum albumin ( bsa , endotoxin free tissue culture grade , cas 9048468 ) were purchased from sigma - aldrich .
human ngal contains two tryptophan residues : w31 located at the base of the hydrophobic calyx and w79 located inside the calyx ( i.e. , the ligand - binding site ) .
therefore , we employed an established tryptophan fluorescence - quenching assay [ 13 , 15 ] to determine the binding of pyoverdine to ngal . since 2,3-dhba is the core functional moiety in pyoverdine that binds iron , the fluorescence assay was first optimized by testing ferric iron and 2,3-dhba complexes diluted in 0.1 m tris , ph 8.0 , as the ligand for potentially quenching intrinsic tryptophan fluorescence in rhngal and in sterile bsa .
enterobactin ( ent ) , the major siderophore from e. coli and other enteric bacteria , was used as a positive control .
the enterobactin stock solution was dissolved in dmso , whereas apo - pyoverdine ( pvd ) and ferric pyoverdine ( pvd - fe ) stocks were dissolved in sterile water ; then , serial dilutions of the siderophores at 100 , 50 , 25 , and 12.5 m were made in an assay buffer ( 50 mm tris , 10 mm cacl2 , 150 mm nacl ph 7.5 ) .
fifty l of each dilution was then transferred into triplicate wells ( f16 black maxisorp plates from nunc ) .
fifty l of rhngal was added into each well at a final concentration of 2 m and incubated for 30 min at room temperature .
recombinant hngal alone was incubated with assay buffer without any siderophore and used to measure intrinsic tryptophan fluorescence .
the plate was then read at excitation and emission wavelengths of 280 and 340 nm , respectively , in the endpoint mode using a microplate reader with fluorescence detection .
results are presented as the percent of tryptophan fluorescence remaining compared to rhngal alone . among
18 published crystal structures of ngal , we selected two human ngal structures solved by strong and coworkers [ 18 , 19 ] to serve as the basis for the molecular modeling study files 1l6 m and 1qqs from the protein data bank ( pdb ) . for simplicity , we refer to the 1l6 m structure as the ngal
trimer and the 1qqs structure as the ngal monomer in this paper .
both structures were solved to 2.4 resolution , the highest resolution solved to date for an ngal structure bound to enterobactin , and in the same space group ( p41212 ) .
the two structures are virtually identical in terms of conformation even though differences were observed in crystal packing in spite of matching space groups .
three monomers were observed in the 1l6 m structure while the 1qqs structure was a homodimer with only one monomer .
moreover , ngal has been found in a 25 kd monomeric and 45 kd dimeric biological forms , as well as a 135 kd heterodimer with mmp9 [ 2123 ] . due to the numerous structural similarities , minor distinctions in crystal packing , and the availability of different quaternary forms of ngal ,
the 1l6 m and 1qqs structures were selected as interesting models for predicting different types of interactions that pyoverdine might be able to make with ngal and for proposing structure - activity relationships .
another important structural feature relevant to this study is the presence and location of tryptophan residues in the ngal structures .
however , coordinates for the ngal monomer ( 1qqs ) contained a w79a where the side chain of w79 was disordered in the structure and modeled as an alanine .
otherwise , all other tryptophans present in the crystal structures were used for molecular modeling .
covalent attachment of the sugars n - acetyl - d - glucosamine and -d - mannose and the lipid decanoic acid to the monomer protein were retained .
polar hydrogens were added to each protein and each set of modified pdb coordinates was converted to pdbqt format using autodock tools .
pdbqt format includes information about partial atomic charges and atom types in addition to the otherwise conventional pdb format .
coordinates for ferric pyoverdine ( pvd - fe ) were extracted from pdb file 2w78 , which describes a complex between iron - bound pvd - atcc13535 and its transporter protein from p. aeruginosa .
the iron atom was excluded from the working ferric pyoverdine file to generate the analogous coordinates for pyoverdine without iron bound ( i.e. , apo - pyoverdine ) .
other heteroatoms present in the 3cmp file including the sodium and sulfate counterions were excluded .
prior to the docking experiment , a grid box was selected in autodock tools to encompass all atoms within either the modified ngal monomer or trimer structure .
the search space for autodock vina was defined to be the dimensions of the 3d grid box .
ngal is an antibacterial innate defense protein that limits bacterial growth by binding to and sequestering siderophores .
we hypothesized that ngal does not bind pyoverdine , allowing p. aeruginosa to persist in cf lungs . to test this hypothesis , we measured the direct binding of pyoverdine ( figure 1 ) to rhngal using the tryptophan fluorescence - quenching method .
human ngal contains two tryptophan residues : w31 , which is located at the base of the hydrophobic calyx , and w79 , located at the ligand - binding site .
if pyoverdine binds to ngal it would be expected to cause the quenching of the intrinsic fluorescence of tryptophan .
the quenching of the intrinsic tryptophan fluorescence of rhngal in a dose - dependent manner was first optimized using iron complexed to 2,3-dihydroxybenzoic acid ( fe - dhba ) ( figure 2(a ) ) .
as expected , increasing concentrations of fe - dhba led to increased quenching , suggesting binding of the siderophore core iron - binding structure to ngal . as another positive control , enterobactin induced a response similar to that of fe - dhba .
ferric enterobactin - ngal complexes showed a fluorescence decrease as the siderophore concentration increased , indicating fluorescence quenching and binding of the ligand to ngal ( figure 2(b ) ) .
in contrast to enterobactin , neither apo - pyoverdine nor ferric pyoverdine reduced the intrinsic tryptophan fluorescence of rhngal significantly ( figure 2(b ) ) .
tryptophan fluorescence was only diminished by less than 10% of the ngal baseline fluorescence even when a high dose of pyoverdine was used , suggesting that pyoverdine does not bind to ngal even when complexed with iron which is known to increase the affinity of siderophore binding to ngal .
thus , ngal does not exert an antibacterial function against p. aeruginosa and , therefore , pyoverdine is a stealth siderophore .
docking of apo - pyoverdine ( figure 1(a ) ) to the ngal trimer predicted nine different docking sites or modes ( figure 3(a ) ) .
1 , 2 , 4 , 5 , 7 , 8 , figure 3 ) clustered at an interface between subunits within the ngal trimer .
3 , 6 , 9 , figure 3 ) were at the periphery of a subunit near the ngal calyx without being fully buried within the hydrophobic binding pocket .
when apo - pyoverdine docked at the periphery of a subunit , the ligand was also near a tryptophan residue . docking modes 6 and 9 for apo - pyoverdine were in proximity to both w31 and w79 as best seen in the 180 rotational view ( figure 3 , right ) . in docking mode 3 ,
all nine of the docking modes for the apo - pyoverdine ligand localized to the outer surface of the ngal monomer ( data not shown ) . in eight of the nine docking modes ,
apo - pyoverdine docked near the opening of the calyx but not within the ligand - binding pocket . as with the apo - pyoverdine structures , autodock vina predicted nine positions in which ferric pyoverdine could dock into the ngal trimer ; however , none of the ferric pyoverdine molecules were predicted to bind near or inside ngal 's ligand binding pocket ( figure 4(a ) ) .
further , autodock vina predicted nine positions in which ferric pyoverdine could dock onto the ngal monomer structure . in each case , however , the position of the docked ligand was at the surface of the protein and not near or inside the calyx ( figure 4(b ) ) .
this computational data strongly suggests that ferric pyoverdine does not bind to ngal , which is consistent with the experimental results .
enterobactin , the major siderophore in e. coli and many other pathogenic enteric bacteria , binds to ngal with very high affinity [ 18 , 28 ] .
the binding and molecular docking of ferric enterobactin to ngal is well established and extensively investigated . in order to validate the docking results obtained for pyoverdine , ferric enterobactin ( figure 1(d ) )
was used as a positive control for computational docking to the ngal trimer ( figure 5 ) and monomer ( data not shown ) .
autodock vina predicted 9 positions in which ferric enterobactin could dock into the trimeric ngal protein crystal structure pdb 1l6 m .
seven different docking modes ( nos . 1 , 2 , 3 , 4 , 5 , 6 , and 9 ) indicate that ferric enterobactin could dock inside the ngal calyx as been reported in the crystal structure of ferric enterobactin - bound ngal . the remaining two docking modes ( nos .
7 and 8) predicted ferric enterobactin docking away from the calyx and between the ngal subunits ( figure 5 ) .
overall , autodock vina accurately simulated the binding of ferric enterobactin to the ngal trimer at the ligand binding site ( i.e. , inside the calyx of ngal ) .
further , ferric pyoverdine was superimposed on ferric enterobactin docked into ngal calyx with a transparent surface presentation .
the results reflect again the inability of ferric pyoverdine to dock into the calyx ( figure 6 ) .
the more negative the value , the tighter the predicted binding . for the apo - pyoverdine interaction with the ngal trimer , predicted binding affinities were very similar for the nine modes , ranging from 6.4 to 6.9 kcal / mol .
predicted binding affinities for apo - pyoverdine with the ngal monomer ( 5.8 to 6.5 kcal / mol ) were slightly lower in range than those for the analogous trimer complex ( table 1 ) .
data for ferric pyoverdine interactions gave slightly tighter predicted binding than that for apo - pyoverdine interactions : predicted binding energies of 8.2 to 9.2 kcal / mol for the trimer and 7.6 to 8.9 kcal / mol for the monomer .
consistent with biological trends , iron - bound siderophores were predicted to have stronger binding interactions with ngal monomer or trimer than their corresponding apo - forms . in all permutations ,
docking mode 1 represented the highest affinity conformation of the ligand interacting with the ngal . in every case ,
docking mode 1 was computed to have a higher binding energy in interaction with the trimer over the monomer , although even this mode for pyoverdine gave low predicted affinity .
in contrast , the tightest predicted binding affinities were computed for the ferric enterobactin interactions with the ngal trimer ( 9.7 to 11.8 kcal / mol ) . while all of the predicted binding affinities are moderate in scale , none of the pyoverdine values are comparable to the range predicted for ferric enterobactin binding with ngal .
p. aeruginosa is an opportunistic pathogen that causes severe infection not only in cf patients but also in critically ill patients in intensive care units where it can cause ventilator - associated infections .
it is a major nosocomial pathogen associated with significant morbidity and mortality ( 4060% ) in immunocompromised patients and in certain hospital units like burn and palliative care .
p. aeruginosa possesses several virulence factors , one of which is pyoverdine , the major siderophore that sequesters iron from the host to facilitate bacterial growth [ 30 , 31 ] .
pyoverdine is a virulence factor required for establishing infection and biofilm formation . in response to infection
, the host secretes ngal that sequesters bacterial siderophores thereby preventing bacteria from establishing infection .
the role of ngal in innate immunity is well established and although ngal - deficient mice develop normally , they are more susceptible to bacterial infections .
ngal is required for pulmonary host defense against klebsiella pneumonaie , indicating that ngal is an important mediator in innate host defense .
however , not all bacterial siderophores are recognized by ngal and some pathogenic bacteria modify their siderophore structure to evade ngal recognition [ 1113 , 16 , 17 ] .
it has been shown that salmochelin , a major siderophore in pathogenic salmonella , is a glucosylated form of enterobactin [ 11 , 12 , 33 ] .
the glycosylation renders the molecule bulky such that it would not fit within the ngal calyx , thus evading innate immune defense .
p. aeruginosa does not contain the iroa gene cluster responsible for the glycosylation of catecholate - based siderophores that do not bind to ngal [ 1 , 3 ] .
compared to other dihydroxybenzoic - acid-(dhba- ) based catecholates that bind to ngal such as enterobactin , pyoverdine is a structurally bulky molecule due to its dihydroxyquinoline chromophore .
we postulated that pyoverdine is a stealth siderophore that does not bind to ngal . here
we show that pyoverdine evades ngal recognition and therefore likely facilitates iron acquisition by p. aeruginosa which supports establishing infection .
, we found that pyoverdine did not bind to ngal , neither in the apo - form nor when complexed with iron .
in contrast , enterobactin bound to ngal causing strong tryptophan quenching . using molecular docking we showed that pyoverdine did not dock into the calyx of ngal while identical approaches indicate that enterobactin docks to ngal with high affinity .
we conclude that pyoverdine is a virulence factor and a stealth siderophore which allows p. aeruginosa to establish infection .
lipocalins act as carrier proteins for a variety of ligands including small - molecule drugs [ 34 , 35 ] .
other members of the lipocalin family have also been shown to act as siderocalins , that is , binding and sequestering bacterial siderophores [ 36 , 37 ] .
tear lipocalin , also called lcn1 , has been shown to sequester enterobactin but not pyoverdine which lends strong support to our results [ 38 , 39 ] . unlike ngal that preferably binds catecholate - based siderophores , tear lipocalin can bind wide range of bacterial and fungal siderophores including catecholate - based and hydroxamate - based siderophores .
in contrast to ngal and tear lipocalin , galline ex - fabp , a lipocalin expressed in chicken serum and egg white , has been reported to sequester both glucosylated enterobactin and pyoverdine .
it is also a sensor for lysophosphatidic acid and is reported to have dual ligand specificities .
the recently published crystal structure of galline ex - fabp explained the dual ligand specificity due its expanded multichambered cavity .
ngal is reported to be a rigid and quite stable lipocalin with a smaller calyx that does not undergo conformational changes upon ligand binding [ 18 , 19 ] which explains why pyoverdine binds to ex - fabp but not to ngal .
similar to ngal , galline ex - fabp was shown to exert strong bacteriostatic activity against e. coli and b. subtilis but not against pseudomonas aeruginosa due to low affinity of interaction between ex - fabp and ferric pyoverdine .
we also performed similar bacterial growth inhibition assay with ngal and p. aeruginosa and found only 10% reduction in bacterial growth ( data not shown ) ; therefore we concluded that ngal is not bacteriostatic for p. aeruginosa .
p. aeruginosa produces another siderophore called pyochelin which is a small chatecholate - based molecule with iron - binding affinity .
recently , strong and coworkers crystallized ngal bound to pyochelin ( pdb 3u03 , deposited at the rcsb protein data bank ) and the crystal structure clearly shows that pyochelin docks inside the calyx of ngal but without binding avidly .
however , pyochelin is not essential for establishing infection since a p. aeruginosa mutant that lacks pyochelin successfully established infection and formed a biofilm .
chronic infections caused by p. aeruginosa as seen in cf are associated with biofilms that protect the bacteria against the host killing mechanisms as well as increase resistance to antibiotics [ 4 , 30 ] . in established biofilms of cf airways
, p. aeruginosa thrives and downregulates pyoverdine since iron is abundant in the airway surface liquid due to chronic inflammation [ 41 , 42 ] .
therefore , pyoverdine is important for establishing infections but not for well - established infections like that in biofilms . in summary
, we show that pyoverdine , the major siderophore in p. aeruginosa , is a stealth siderophore that evades ngal recognition . | pseudomonas aeruginosa is the most common pathogen that persists in the cystic fibrosis lungs .
bacteria such as p. aeruginosa secrete siderophores ( iron - chelating molecules ) and the host limits bacterial growth by producing neutrophil - gelatinase - associated lipocalin ( ngal ) that specifically scavenges bacterial siderophores , therefore preventing bacteria from establishing infection .
p. aeruginosa produces a major siderophore known as pyoverdine , found to be important for bacterial virulence and biofilm development .
we report that pyoverdine did not bind to ngal , as measured by tryptophan fluorescence quenching , while enterobactin bound to ngal effectively causing a strong response .
the experimental data indicate that pyoverdine evades ngal recognition .
we then employed a molecular modeling approach to simulate the binding of pyoverdine to human ngal using ngal 's published crystal structures .
the docking of pyoverdine to ngal predicted nine different docking positions ; however , neither apo- nor ferric forms of pyoverdine docked into the ligand - binding site in the calyx of ngal where siderophores are known to bind .
the molecular modeling results offer structural support that pyoverdine does not bind to ngal , confirming the results obtained in the tryptophan quenching assay .
the data suggest that pyoverdine is a stealth siderophore that evades ngal recognition allowing p. aeruginosa to establish chronic infections in cf lungs . |
adrenocortical carcinoma ( acc ) is a rare malignant tumour of the adrenal cortex with an approximate incidence of 1 to 2 cases per million adults annually [ 1 , 2 ] .
most of these tumours are functional , presenting clinically with cushing 's syndrome and/or signs of virilization .
it is extremely rare for an adrenocortical tumour to present as an adrenal medullary tumour viz . , a pheochromocytoma , thus posing a diagnostic and therapeutic challenge . here ,
we report the case of an acc mimicking a pheochromocytoma clinically , biochemically and radiologically .
a 45-year - old female presented with complaints of vague abdominal pain for 3 years .
she was diagnosed with hypertension and put on anti - hypertensive medication but failed to achieve control with regular use of the prescribed medication . on examination
the pulse rate was 92 bpm , regular , good volume , without delay . blood pressure ( bp ) was 170/100 mmhg , right arm , supine .
a ballotable mass of 5 5 cm was palpated in the right lumbar region , firm , non - tender , non - fluctuant and non - pulsatile .
ultrasound of the abdomen showed a 5 5 cm solid - cystic mass overlying the right kidney .
cect abdomen confirmed the presence of a right suprarenal tumour measuring 6 5 5 cm with solid - cystic components and fluid levels suggestive of intratumoural haemorrhage .
magnetic resonance imaging ( mri ) of abdomen suggested an space occupying lesion in the right adrenal gland with multiple cystic spaces of variable sizes suggestive of pheochromocytoma .
fat planes to the adjacent structures were preserved with no evidence of metastases ( figs 14 ) .
figure 1:cect abdomen showing an inhomogeneously dense right suprarenal mass ( transverse section ) .
figure 2:cect abdomen showing an inhomogeneously dense right suprarenal mass ( coronal section ) .
figure 3:mri abdomen showing a hyperintense right suprarenal mass ( transverse section ) .
figure 4:mri abdomen showing a hyperintense right suprarenal mass ( coronal section ) .
24-h urinary vanillyl mandelic acid ( vma ) was 8.8 mg ( n=1.87 mg/24 h ) .
owing to limited resources and low socio - economic status of the patient , further diagnostic biochemical tests , such as fractionated plasma - free metanephrines , urinary catecholamines and metanephrines , could not be undertaken .
pre - operative control of bp was achieved within 3 weeks with oral phenoxybenzamine 10 mg during the first week , increased to 10 mg 6 h during the second week and 10 mg 4 h during the third week .
volume expansion was achieved with 0.9% normal saline infusion 2 l / day during the immediate pre - operative week . during elective right adrenalectomy ,
the bp shot up to 180/140 mmhg ( pre - operative bp was 140/90 mmhg ) .
no anti - hypertensive agents were prescribed during the hospital stay or on discharge ( figs 5 and 6 ) .
histopathological analysis reported a well - encapsulated cellular lesion composed of sheets , cords and trabeculae of round to oval epithelial cells with abundant eosinophilic cytoplasm and vesicular nuclei showing grade 12 pleomorphism .
foci of bizarre - looking cells with frequent mitotic figures ( 12/10 hpf ) seen .
acc is a rare malignant tumour of the adrenal cortex with an incidence of 1 to 2 cases per million adults annually and bimodal presentation mostly during the fourth to fifth decade of life and the first decade [ 1 , 2 ] .
most of these tumours are functional , and secrete glucocorticoids and androgens excessively , causing clinical cushing 's syndrome and signs of virilization , both of which can be the initial presentation .
the annual incidence is 28 cases per million and presents during the third to fourth decade of life , with 10% cases occurring in children .
the clinical history of pheochromocytoma includes episodic headaches , palpitations and diaphoresis with severe uncontrolled hypertension .
these spells are due to the excess secretion of catecholamines viz . , epinephrine and norepinephrine .
depending on the catecholamine secreted , hypertension is either paroxysmal or persistent , rarely absent .
biochemical diagnosis of acc is done by the standard 24-h urinary cortisol excretion test and the 1 mg - dexamethasone suppression test in the presence of cushing 's syndrome and by serum adrenal androgens in the presence of virilization . whereas , the diagnosis of pheochromocytoma can be supported by the measurement of catecholamine metabolites such as plasma metanephrines , 24-h urinary catecholamines or their metabolites such as vma and metanephrines .
radiologically , a suprarenal mass , with a non - homogenous density on cect scans with fluid levels suggestive of intratumoral haemorrhage goes in favour of pheochromocytoma . intermediate - to - high - intensity lesions on t2 imaging of the mri go in favour of malignant carcinomas , whereas pheochromocytomas are very high - intensity tumours owing to higher water content .
another significant utility of the mri is to evaluate the surrounding fat planes and exclude metastases .
ultrasound has less sensitivity for detecting adrenal incidentalomas and is highly user dependant . in the present case ,
our patient , was in her fifth decade of life , presenting with vague symptoms such as diffuse abdominal pain with a palpable mass , episodic headache , palpitation and vertigo , with uncontrolled hypertension and postural hypotension .
she had raised urinary vma level of 8.8 mg/24 h ( n = 1.87 mg/24 h ) with normal serum and 24-h urinary cortisol levels .
an intra - operative boom in the bp on handling the tumour further confirmed it .
this peculiar behaviour of the adrenocortical tumours is due to the neuroendocrine differentiation , known as pseudo - pheochromocytomas .
such tumours show positivity for markers such as neuron - specific enolase , and synaptophysin and negativity for chromogranin .
testing for calretinin and inhibin further increases the sensitivity and specificity in differentiating an adrenocortical neoplasm from pheochromocytoma . in the literature ,
only 14 cases have been reported so far making these tumours a rare entity , but which can still cause a diagnostic dilemma . to the best of our knowledge , | adrenocortical carcinoma ( acc ) is a malignant tumour arising from the adrenal cortex , whereas pheochromocytoma is a tumour of the adrenal medulla with occasional presence at extra - adrenal sites .
most of the adrenocortical tumours present clinically with cushing 's syndrome and signs of virilization due to over - production of the respective hormones .
it is , however , rare for an adrenocortical tumour to present clinically as a pheochromocytoma .
we report the case of a 45-year - old female presenting with clinical symptoms and signs of pheochromocytoma and investigations that resulted in a diagnostic dilemma .
the histopathological examination confirmed the presence of acc after the tumour was excised .
this phenomenon was due to the presence of neuroendocrine features of acc referred to , as a pseudo - pheochromocytoma with extremely limited data in the literature . |
thyroid dysfunction is coupled to adverse outcomes in both the mother and the fetus and is particularly associated with the cognitive and neurological development of the fetus [ 1 , 2 ] . women are more susceptible to developing thyroid disease later in life if they exhibit thyroid dysfunction or test positive for antibodies during pregnancy .
the early and appropriate detection of thyroid dysfunction and timely interventions that improve maternal - fetal prognosis require reliable gestational specific reference intervals ( ris ) of the thyroid hormones . during pregnancy , hormonal changes and
moreover , many established thyroid ris during pregnancy differ by assay , ethnicity , and region making it difficult to extrapolate values for all women and areas [ 411 ] .
thus , the use of trimester- and assay - specific ris in pregnancy is recommended by clinical guidelines [ 12 , 13 ] .
the aim of this study is the establishment of trimester- and assay - specific ris of thyroid stimulating hormone ( tsh ) and free thyroxin ( ft4 ) for pregnancy in an iodine - sufficient area of henan , china .
a total of 3314 women who consumed iodized salt were initially enrolled from the outpatient and inpatient departments of the third affiliated hospital of zhengzhou university from january 2013 until january 2014 .
the exclusion criteria consisted of a history of thyroid disease or goiter , use of medications that may affect thyroid function , any other chronic diseases , patients positive for thyroid peroxidase and/or thyroglobulin antibodies ( tpoab > 35 iu / ml , tgab > 40 iu / ml , chemiluminescence assay ) , pregnancy - associated complications , or twin pregnancy .
a total of 501 women were excluded due to the exclusion criteria , 36 were excluded as outliers , and the remaining 2777 women were assigned to four groups according to the number of weeks of gestation : t1 = 112 weeks , t2 = 1327 weeks , t3 = 2840 weeks , and nonpregnant women .
the median gestational ages ( range ) at the first , second , and third trimesters were 12.0 ( 4.312.9 ) , 17.6 ( 13.027.9 ) , and 37.6 ( 28.041.9 ) weeks , respectively .
the mean ages ( range ) for women in their first , second , and third trimesters and nonpregnant women were 29.1 4.8 ( 1644 ) , 28.9 4.6 ( 1847 ) , 28.9 5.1 ( 1748 ) , and 29.1 4.7 ( 1943 ) years , respectively , with no significant difference .
this study was approved by the ethics committee at the third affiliated hospital of zhengzhou university .
fasting blood samples were collected from all the subjects in a sitting position in the morning and centrifuged at 4000 rpm for 10 min within 1 hour .
subsequently , the serum tsh , ft4 , tpoab , and tgab levels were assayed using automated chemiluminescence within 2 hours with an immulite 2000 system and siemens kits ( siemens healthcare diagnostics products limited , munich , germany ) according to the manufacturer 's instructions .
the functional sensitivities of serum tsh , ft4 , tpoab , and tgab were 0.004 miu / l , 3.99 pmol / l , 5.0 iu / ml , and 2.2 iu / ml , respectively .
the ris were calculated according to the guidelines of the clinical and laboratory standards institute .
box plots were used to identify the possible outliers , which were excluded when the d / r ratio was greater than 1/3 . for tsh and ft4 analyses ,
the medians and 2.597.5th percentiles were defined for all reference subjects . in comparisons between the study groups , age
was assessed using a one - way anova followed by a bonferroni correction , while the tsh and ft4 levels were assessed using kruskal - wallis one - way anova .
we identified 36 patients as outliers using box plots , and data from these patients were excluded from the analysis .
the tsh ris in the first , second , and third trimesters of pregnancy were 0.073.96 , 0.274.53 , and 0.485.40 miu / l , respectively , while the tsh ri was 0.695.78
the ft4 ris in the first , second , and third trimesters were 9.1618.12 , 8.6716.21 , and 7.8013.90 pmol / l , respectively , but the ri was 8.2416.61
the tsh level exhibited a significantly ( p < 0.001 ) increasing trend from the first to the third trimester and remained lower than the prepregnancy levels .
ft4 level showed a significantly decreasing trend with increasing gestational age ( p < 0.001 ) and was the lowest in the third trimester ( figure 1 ) .
during pregnancy , metabolic demands increase , and hormonal changes result in alterations of the pituitary - thyroid axis . the negative feedback of tsh decreases due to tsh receptor activation by human chorionic gonadotropin ( hcg ) , which shares alpha - subunits and considerable homology with the beta - subunit of tsh . the tsh level peaks at 1012 weeks of gestation , while triiodothyronine ( t3 ) and thyroxine ( t4 ) levels increase up to 50% with an accompanying increase in thyroxin binding globulin ( tbg ) levels .
the clearance of iodine in the kidneys is enhanced during pregnancy [ 12 , 14 ] .
thus , it is inappropriate to assess thyroid function by t3 and t4 . in this case ,
currently , in china , different trimester - specific ranges which were provided by the manufacturers were used .
however , these ranges varied significantly and were higher than 2.5 miu / l , which was recommended by the american thyroid association ( ata ) .
thus , it was suggested that each region or even each laboratory should establish its own trimester - specific ris by china .
establishing trimester - specific reference intervals in each population is essential for accurate assessment of thyroid function .
this study aimed to provide trimester- and assay - specific ris of tsh and ft4 in pregnant women in henan , china , in an iodine - sufficient area .
these population - specific and method - specific reference intervals will be useful for screening china pregnant women for thyroid disease . in our study ,
the lower limits of tsh ris were similar to those of the ata guidelines and other studies .
however , the upper limits of tsh were higher than those observed in caucasian populations and comparable to those in asian populations ( table 2 ) .
this confirmed the results of la'ulu and roberts , who found that asians have increased levels of tsh . in the three studies that used the immulite 2000 assay for indian , korean , and chinese ( our study ) subjects ,
the upper tsh limit was higher than in other studies , which could be a consequence of the combined effects of ethnicity and methodology .
previous studies in china have shown similar ris of tsh , regardless of the assay used [ 4 , 5 , 7 , 8 , 17 ] .
the ris for ft4 in our study were comparable to those of other studies ( table 2 ) with mild differences , possibly resulting from different measurement techniques .
van deventer and soldin [ 18 , 19 ] stated that the optimal method to assess ft4 during pregnancy is liquid chromatography / tandem mass spectrometry ( lc / ms / ms ) because most immunoassays have a significant method - specific bias related to the binding proteins .
however , lc / ms / ms is not available in most clinical laboratories , which suggests that standardizing thyroid function tests should be a major priority [ 20 , 21 ] .
la'ulu and roberts found higher ris in asian populations . in our study , the rates of positive tpoabs and tgabs were 8.20% ( 270/3292 ) and 5.04% ( 166/3292 ) , and the double positive rate was 2.58% ( 85/3292 ) when thyroid disease or goiter was excluded . in the tpoab- and/or tgab - positive individuals , 74.07% ( 260/351 ) were pregnant , and 25.93% ( 91/351 ) were not pregnant .
however , we only enrolled antibody - negative women for ri determination . thus , other factors such as the exclusion criteria , study population characteristics , method of ri estimation , and iodine status could contribute to this discrepancy .
it is essential to establish trimester - specific and assay - specific ris in asian countries to accurately assess thyroid function .
first , thyroid function could not be measured consecutively in each individual , and interindividual variation could exist .
however , the daily consumption of iodized salt has been mandatory in china for many years ; therefore , we assumed that all enrolled participants ingested sufficient amounts of iodine . in conclusion , we established ris for tsh and ft4 in pregnant chinese women
. these ris will be useful for screening for thyroid diseases in pregnant chinese women . | objective .
the guidelines of the american thyroid association ( ata ) recommend an upper limit reference interval ( ri ) of thyroid stimulating hormone ( tsh ) of 2.5
miu / l in the first trimester of pregnancy and 3.0 miu / l in subsequent trimesters , but some reported ranges in china are significantly higher .
our study aimed to establish trimester- and assay - specific ris for thyroid hormones in normal pregnant chinese women . methods . in this cross - sectional study , 2540 women with normal pregnancies ( first trimester , n = 398 ; second trimester , n = 797 ;
third trimester , n = 1345 ) and 237 healthy nonpregnant control subjects were recruited .
serum tsh , free thyroxin ( ft4 ) , thyroid peroxidase antibody ( tpoab ) , and thyroglobulin antibody ( tgab ) levels were determined by automated chemiluminescence with an immulite 2000 system ( siemens , erlangen , germany ) .
after outliers were excluded , the 2.597.5th percentiles were used to define the ris .
results .
the ris of thyroid function in the first , second , and third trimesters of pregnancy and in nonpregnant controls were 0.073.96 , 0.274.53 , 0.485.40 , and 0.695.78 miu /
l for tsh and 9.1618.12 , 8.6716.21 , 7.8013.90 , and 8.2416.61 pmol / l for ft4 , respectively . conclusion .
the trimester- and assay - specific ris of thyroid function during pregnancy differed between trimesters , which suggests that it is advisable to detect and avoid misclassification of thyroid dysfunction during pregnancy for women in henan , china . |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.