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Biomedical subjects

C Bouchard

Publications and source records attributed to C Bouchard.

At least 361 records · Page 20Linked to original sources
PubMed1995

Changes in plasma electrolytes and muscle substrates during short-term maximal exercise in humans.

This study compared the effects of 3 short-term maximal exercise tests lasting 10, 30, and 90 sec upon blood volume, plasma electrolytes, glucose, glycerol, lactate and skeletal muscle ATP, PC, glycogen, and lactate concentrations. Seven sedentary male subjects were recruited and 5 of them were randomly assigned to each of the 3 protocols. The tests were performed on a modified ergocycle at workloads of 0.9, 0.075, and 0.05 kp.kg-1 body mass, respectively. Muscle biopsies were taken from the vastus lateralis before and immediately after each exercise. Venous blood samples were collected before, immediately after, and during the recovery (5, 20, 60, and 120 min). Plasma volume decreased during the 30- and 90-sec tests and was increased in all tests after 60 min of recovery. Plasma K+ increased during all tests and returned to normal values 5 min postexercise, except after the 90-sec test where it fell below resting values. Plasma Na+ and Cl- were unaffected. Blood lactate increased in all tests, glucose increased after the 90-sec test, and glycerol increased after the 30- and 90-sec tests. All 3 tests brought relatively similar changes in muscle ATP, PC, and glycogen while muscle lactate changes were related to exercise duration. These results suggest that a normal hydration status is important for a subject undergoing short training bouts, and that high-intensity tests of short duration do not require a special nutritional regimen to enhance glycogen reserves.

Adenosine Triphosphate↗
PubMed1995

The lipoprotein lipase HindIII polymorphism modulates plasma triglyceride levels in visceral obesity.

The aim of this study was to investigate the potential interaction between the lipoprotein lipase (LPL) HindIII polymorphism and visceral adipose tissue (AT) accumulation in the modulation of triglyceride levels in visceral obesity. The LPL-HindIII genotype was determined by polymerase chain reaction in 52 min. Twenty-three subjects were heterozygous (+/-) and 28 were homozygous (+/+) for the presence of the restriction site. One subject who was homozygous for the--allele was excluded from analysis. Body mass index (BMI), fasting insulin level, and visceral AT area as measured by computed tomography were positively correlated with triglyceride levels only in subjects homozygous for the + allele. Furthermore, whereas these variables were negatively correlated with plasma HDL2 cholesterol concentrations in the +/+ group, these associations were not found in +/- heterozygotes, with the exception of BMI. To further investigate the interaction of the LPL-HindIII polymorphism with visceral obesity and hyperinsulinemia, the two genotype groups were further subdivided on the basis of BMI (low versus high), fasting insulin level (low versus high), and visceral AT area (low versus high), and their lipoprotein profiles were compared. Elevated levels of abdominal visceral AT were significantly associated with increased triglyceride concentrations in +/+ homozygous men, suggesting that visceral obesity may lead to hypertriglyceridemia in the presence of the +/+ genotype. In the +/- group, variation in the amount of visceral AT was not associated with differences in triglyceride concentration. However, hypertriglyceridemia and an increased cholesterol-to-HDL cholesterol ratio were observed in the hyperinsulinemic state irrespective of LPL-HindIII genotype status.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1995

Developing a health sciences library Gopher: more involved than meets the eye.

The purpose of this paper is to discuss the development of the Health Sciences Library Gopher at St. Louis University (SLU) Health Sciences Center. The authors will outline university criteria from the Office of Computing and Information Services, library selection criteria, bibliographical access, reference and instructional implications, data entry and maintenance, and the role of the library's Internet Committee. All libraries have been awed by the tremendous amount of resources available through the Internet; the challenge is to not be intimidated but to be innovative in designing systems that can present these resources to the library client in the most easily understandable approaches possible. The Internet Committee in the SLU Health Sciences Center Library has designed a framework for the construction of "menus" to lead the client to selected Internet resources. Some of the issues confronted include relating the Internet resources to the library's Collection Development Policy, coordination of Internet resources to other bibliographic sources (Journal Holdings List, Intelligent Catalog), and educating staff and clients to manage a wide range of new resources as well as traditional ones in electronic formats.

Computer Communication Networks↗
PubMed1995

Regional variation in adipose tissue metabolism of severely obese premenopausal women.

Lipolytic and lipoprotein lipase (LPL) activities were studied in isolated human adipocytes obtained from two intraabdominal depots (round ligament and omental) and from the subcutaneous abdominal region of nine severely obese premenopausal women (with body mass indices ranging from 37 to 51 kg/m2), aged 36 +/- 3 yr, undergoing gastrointestinal surgery. Both fat cell weight and LPL activity were significantly greater in round ligament adipose cells than in subcutaneous abdominal or in omental adipocytes (P < 0.05). The antilipolytic effect of insulin and the sensitivity to this hormone were also higher in round ligament adipose cells than in omental adipocytes (P < 0.05). Although epinephrine initiated a similar biphasic profile of response in all cell types, the catecholamine promoted a weaker inhibition of lipolysis in omental adipocytes than in subcutaneous abdominal adipose cells (P < 0.05). In addition, a lack of regional variation was found in the maximal antilipolysis initiated by UK 14304 and the alpha 2-adrenoceptors was higher in both subcutaneous abdominal and round ligament fat cells than in omental adipocytes. Moreover, the maximal lipolytic response to isoproterenol or to agents acting at post-receptor levels was not different among fat depots. Finally, a lower beta-adrenergic lipolytic sensitivity associated with a reduced beta-adrenoceptor density was observed in round ligament as compared to omental adipose cells. These data suggest that in massively obese premenopausal women, omental and round ligament adipose tissues show distinct metabolic properties that may contribute to limit the impact of intraabdominal obesity.

Adipocytes↗
PubMed1995

[Problems caused by anesthesia of patients with severe burns].

The treatment of severe burns requires repeated and various surgical procedures under general anaesthesias. Requirements differ according to the evolution phase of the burnt lesion. Three first post-traumatic days are marked by a major oedema and a large haemodynamic instability. Hypovolemia during 12 to 24 hours is followed by an hyperkinetic phase. The secondary period can last several weeks to several months before the cutaneous recovery is complete. Septic risk is then major and dénutrition constant. Problems raised by surgery differ according to the type of surgery: early excision of deep bums, bath therapy, skin graft, dressing. These procedures are often haemorrhagic and painful. Thermal status is constantly threatened. This type of pathology interferes with the pharmacology of anaesthetic drugs. Hypoprotidemia and change of protein-binding modify drug kinetics. Continuous use of opiates and sedatives is source of tolerance and tachyphylaxis. The number of acetylcholine receptors is increased, contraindicating the use of depolarizing muscle relaxants and often induces a resistance to the nondepolarizing muscle relaxants. The knowledge of these alteration leads to discuss indications of anaesthetics, analgesics and muscle relaxants most frequently used in these patients. During anaesthesia the positioning of the patient takes into account the surgical needs. Hypothermia prevention is mandatory. Peroperative resuscitation is dominated by maintenance of haemodynamic balance, compensation of hydroelectrolytic and blood losses, treatment of septic complications. Should be the same who has in change the patient in the intensive care unit.

Anesthesia, General↗
PubMed1995

The HERITAGE family study. Aims, design, and measurement protocol.

The HERITAGE family study (HEalth, RIsk factors, exercise Training And GEnetics) will document the role of the genotype in the cardiovascular, metabolic, and hormonal responses to aerobic exercise training. A consortium of five universities in the United States and Canada are involved in carrying out the study. A total of 90 Caucasian families and 40 African-American families with both parents and three or more biological adult offspring are being recruited, tested, exercise-trained in the laboratory with the same program for 20 wk, and re-tested. Oxygen uptake, respiratory exchange ratio, blood pressure, heart rate, cardiac output, blood lactate, glucose, and free-fatty acids are measured during exercise, and maximal oxygen uptake is determined before and after training. Plasma lipids, lipoproteins and apoproteins, glucose and insulin response to an intravenous glucose load, plasma sex steroids and glucocorticoids, and body fat and fat distribution are assessed. Dietary and activity habits and other life style components are assessed by questionnaires, prior to, during, and after training. A variety of genetic analyses will be undertaken, including heritability studies and major gene effects, for each phenotype and its response to regular exercise. Cell lines are established, and DNA sequence variation at a variety of molecular markers will be determined for association and linkage studies.

Adolescent↗
PubMed1995

Body fatness in active individuals reporting low lipid and alcohol intake.

OBJECTIVES: To evaluate body fatness in subjects complying with common public health guidelines for lipid and alcohol intake as well as physical activity participation. SUBJECTS: A sample of 358 male subjects who participated in phase 1 of the Quebec Family Study. DESIGN: The association between adiposity, lipid and alcohol intake and physical activity participation was analyzed in the overall sample. A comparison of body fatness in individuals adhering or not to public health recommendations was also performed. RESULTS: Significant positive correlations were observed between the percentage of dietary energy as lipid and adiposity indicators. Accordingly, subjects classified as low-fat consumers displayed significantly lower levels of fat mass and subcutaneous adiposity compared to high-fat consumers. When subjects reporting low lipid and alcohol intake and regular participation in vigorous physical activities were compared to those exhibiting opposite behaviors, the between-group difference in subcutaneous adiposity was doubled and this was essentially explained by an increase in the difference for truncal subcutaneous adiposity. CONCLUSION: These results indicate that the adherence to a lifestyle characterized by high-fat and alcohol intake as well as sedentariness promotes fat gain, particularly in the trunk area.

Adult↗
PubMed1995

Genetics of obesity: an update on molecular markers.

Attempts to define the genetic basis of obesity in the present century probably began with the study of Davenport. A number of papers were published on the topic based on weight for height data prior to the 1970s. Bray has summarized these studies which quite consistently demonstrated that obese children had frequently obese parents. Following this period, the field of genetic epidemiology began to contribute new methods and research strategies in the efforts to define the genetic basis of quantitative multifactorial phenotypes. For the past 15 years or so, a good number of reports have been published regarding the heritability level and the segregation pattern of body mass for stature, and other indicators of obesity. These studies have been summarized recently. The focus of this report is on animal and human studies providing evidence for a role of specific genes in human variation for indicators of obesity.

Animals↗
PubMed1995

Social class interacts with the association between macronutrient intake and subcutaneous fat.

BACKGROUND: A large amount of evidence shows that adiposity is associated both with macronutrient composition of the habitual diet and socio-economic variables. Since dietary habits may covariate with social status, these two groups of factors may act as mutual confounders when studying their independent impact on adiposity. OBJECTIVE: To investigate the independent relationship between educational level and dietary habits with adiposity. To study interactive effects of educational level on the association between macronutrient intake and adiposity. DESIGN: This cross-sectional study was based on dietary records, interviews and anthropometry of 358 men and 368 women of the Québec Family Study. STATISTICS: Partial correlation analyses were applied to clarify independent correlations of body fatness with educational level, dietary habits and other behavioural factors. ANCOVA was used to detect interactive effects of educational level on macronutrient versus adiposity relationships. RESULTS: Inverse associations between educational level and BMI, percent body fat, truncal skinfolds were found in women but not in men. Both protein and lipid intake correlated or tended to correlate positively with some of the adiposity measures in women. Protein intake correlated positively with truncal skinfolds in men of lower but not higher educational level. CONCLUSIONS: The results emphasize the importance of including demographic variables like social status in surveys dealing with the relationships between adiposity and dietary habits.

Adipose Tissue↗
PubMed1995

Relationship between perceptions of physical activity and health-related fitness.

OBJECTIVE: To assess perceptions of fitness, intensity and frequency of habitual physical activity as predictors of cardiovascular function, metabolic health and obesity. DESIGN: Cross-sectional correlational, with covariance adjustment of data for age and socio-economic status. SETTING: An urban community of some 250,000 people. PARTICIPANTS: Convenience sample of healthy but relatively sedentary subjects, 172 males and 178 females aged 14-68 years. MEASURES: Self-reports of perceived fitness, habitual activity, intensity and frequency of exercise; standard laboratory tests of cardiovascular function (resting heart rate, PWC 150/kg, systolic and diastolic blood pressure), metabolic health (blood glucose, total cholesterol, HDL-cholesterol, triglycerides and uric acid), obesity (body mass index, skinfolds, hydrostatic body fat, and abdominal circumferences) and socio-economic status (education, job classification and income). RESULTS: In men, the strongest associations of fitness markers were with peer comparisons of fitness and activity. In women, such comparisons also yielded significant positive associations, but the most consistent relationships of fitness were with Godin questionnaire ratings of sweat-inducing and frequent heavy activity. Perceptions of intense activity were associated more with cardiovascular than with metabolic health. Perceptions of frequent activity (peer activity ratings, occupational walking, and the number of activities reported) were associated with control of body fat, and to a lesser extent with cardiovascular function, but were unrelated to markers of metabolic health. CONCLUSION: Perceptions of personal fitness, intensity and frequency of habitual activity are all associated with markers of health-related fitness after allowance for effects of gender, age and socio-economic status. The public should thus be encouraged to pursue activity that they perceive as frequent, intense and improving their fitness.

Adolescent↗
PubMed1995

Familial clustering of multiple measures of adiposity and fat distribution in the Québec Family Study: a trivariate analysis of percent body fat, body mass index, and trunk-to-extremity skinfold ratio.

OBJECTIVE: To assess whether independent or common (pleiotropic) familial factors (i.e., genetic and/or common environment) underlie the observed associations among measures of body mass, body fat, and its distribution. DESIGN: A familial correlation model involves both parents and offspring, and gives rise to three types of familial correlations (spouse, parent-offspring, and sibling). A pattern of significant familial correlations suggests that the trait is determined by familial factors (i.e., genetic and/or environmental heritability). Cross-trait familial correlations are also estimated, both within individuals (intraindividual) and between family members (interindividual). Interindividual cross-trait familial correlations (e.g., trait 1 in parents with trait 2 in offspring) lead to the same type of familial inferences regarding bivariate heritabilities. SUBJECTS AND MEASURES: Measures of total body fat (% body fat-%BF), fat distribution (trunk/extremity skinfold ratio-TER), and body mass index (BMI) were assessed in 1239 individuals from 309 nuclear families participating the Québec Family Study. RESULTS: All three adiposity measures are cross-correlated within individuals. However, interindividual cross-trait correlations, which alone are capable of suggesting common familial determinants, are significant only for BMI with each of %BF and TER (bivariate heritabilities of 10% and 18%, respectively), and not for %BF and TER. CONCLUSION: Although all three adiposity measures are correlated within individuals, there appear to be entirely different underlying genes and/or environmental factors influencing the adiposity phenotypes of total body fat and fat distribution. The BMI, however, apparently shares some familial determinants with both total body fat and fat distribution.

Adolescent↗
PubMed1994

Recombinant soluble Fc gamma receptors: production, purification and biological activities.

Soluble forms of low affinity receptors for the Fc portion of IgG circulate in body fluids and regulate immune functions. We describe the transfection, production and purification techniques which allow the preparation, at a laboratory scale, of milligram amounts of glycosylated recombinant mouse and human soluble Fc gamma receptors. These recombinant products bind IgG and are biologically active on immune responses, like their normal counterparts.

Animals↗
PubMed1994

Risk factors for cervical intraepithelial neoplasia: differences between low- and high-grade lesions.

This case-control study assesses relations of human papillomavirus (HPV) type 16 infection, sexual history, cigarette smoking, and oral contraceptive use to low- and high-grade cervical intraepithelial neoplasia (CIN). A total of 548 high-grade and 338 low-grade CIN cases and 612 controls were identified among women seen at a colposcopy clinic in Quebec, Quebec, Canada, in 1988-1989. Interviews, colposcopy, cervical scrapings, and colposcopically directed biopsies were performed. One pathologist reviewed all histologic slides. Southern blot techniques were used to assay specimens for HPV 16 DNA. Lifetime number of sexual partners was related to low- and high-grade CIN. Presence of HPV 16 DNA was associated with a 8.7-fold (95% confidence interval 5.1-15.0) elevation in estimated relative risk of high-grade CIN. Relative risk of high-grade CIN increased with amount of HPV 16 DNA (p < 0.0001). Estimated relative risk of high-grade CIN in current cigarette smokers was 2.4 (95% confidence interval 1.8-3.2) compared with never smokers and increased with number of pack-years of exposure (p < 0.0001). Long-term (6 years or more) users of oral contraceptives had an estimated relative risk of high-grade CIN of 1.9 (95% confidence interval 1.1-3.3) compared with those who never used such contraceptives. In contrast, presence of HPV 16 DNA, cigarette smoking, and oral contraceptive use showed little or no relation to low-grade CIN. Risk factors for low- and high-grade CIN may differ substantially.

Adult↗
PubMed1994

Waist circumference and abdominal sagittal diameter: best simple anthropometric indexes of abdominal visceral adipose tissue accumulation and related cardiovascular risk in men and women.

The amount of abdominal visceral adipose tissue measured by computed tomography is a critical correlate of the potentially "atherogenic" metabolic disturbances associated with abdominal obesity. In this study conducted in samples of 81 men and 70 women, data are presented on the anthropometric correlates of abdominal visceral adipose tissue accumulation and related cardiovascular disease risk factors (triglyceride and high-density lipoprotein cholesterol levels, fasting and postglucose insulin and glucose levels). Results indicate that the waist circumference and the abdominal sagittal diameter are better correlates of abdominal visceral adipose tissue accumulation than the commonly used waist-to-hip ratio (WHR). In women, the waist circumference and the abdominal sagittal diameter also appeared more closely related to the metabolic variables than the WHR. When the samples were divided into quintiles of waist circumference, WHR or abdominal sagittal diameter, it was noted that increasing values of waist circumference and abdominal sagittal diameter were more consistently associated with increases in fasting and postglucose insulin levels than increasing values of WHR, especially in women. These findings suggest that the waist circumference or the abdominal sagittal diameter, rather than the WHR, should be used as indexes of abdominal visceral adipose tissue deposition and in the assessment of cardiovascular risk. It is suggested from these data that waist circumference values above approximately 100 cm, or abdominal sagittal diameter values > 25 cm are most likely to be associated with potentially "atherogenic" metabolic disturbances.

Abdomen↗
PubMed1994

An exploratory investigation of genetic linkage with body composition and fatness phenotypes: the Québec Family Study.

In the present investigation, we have attempted to identify regions of the genome in which "obesity genes" potentially reside using robust sib-pair linkage analysis. Data were collected on 1,628 individuals in 301 nuclear families residing in the environs of Québec City during the period 1978-1981. In addition to traditional blood group antigens and enzyme polymorphisms, several phenotypes in the obesity domain that are associated with increased morbidity were assessed, including measures relating to heaviness (i.e., the body mass index), body composition and nutrient partitioning (i.e., % body fat), and regional fat distribution without and with standardization for total fat mass (i.e., the sum of six skinfold thicknesses, and the ratio of the sums of trunk to extremity skinfold thicknesses). Three consistent patterns of potential linkage relationships with obesity phenotypes were revealed in these data, involving the marker loci adenosine deaminase, the Kell blood group antigen, and esterase D, which identify chromosomal regions 20q13, 7q33, and 13q14, respectively. Other potential linkages also were identified in the short arm of chromosome 1, interesting because of the presence of the db and fa loci on homologous regions of chromosome 1 in mouse and rat models of obesity, respectively. Each of the tentative linkage relationships reported here warrant follow-up using alternative methods and require replication in independent studies.

Adenosine Deaminase↗