Search PubMed⌕ Search

Biomedical subjects

C Bouchard

Publications and source records attributed to C Bouchard.

At least 595 records · Page 33Linked to original sources
PubMed1984

Adipose tissue characteristics of ex-obese long-distance runners.

Mean fat cell diameter and lipolytic activities of adipose tissue were determined in five ex-obese runners (EOR) who had experienced a mean weight loss of 39.5 kg during the course of a long-distance running program. At the time of investigation, their mean weekly running distance was 95 km in which no diet manipulation was needed to maintain their body weight. Body fat was estimated to be 14.3 percent of their body weight. Despite the high amount of exercise, subjects were not able to reduce body weight any further. Their values were compared with those obtained in the two following groups (1): six elite long-distance runners (ER) having a lower percent body fat (percent fat = 9.5); (2) five sedentary controls (SC) who were paired for adiposity with EOR (percent fat = 14.4). All subjects were submitted to a biopsy of subcutaneous fat in the suprailiac region, in which mean fat cell diameter was 57.5, 74.5, and 86 microns in EOR, ER and SC respectively. Basal and epinephrine-stimulated lipolysis were similar in EOR and SC, while ER exhibited higher values. These results indicate that exercise-training can produce important weight losses when subjects are capable of tolerating high levels of energy expenditure for extended periods of time. Moreover, the reduced fat cell diameter for a higher adiposity in EOR as compared to ER suggests that resistance to further fat loss may occur when the fat cell size is markedly reduced. No deficit in maximal epinephrine stimulated lipolysis of isolated fat cells was found in EOR in comparison to SC subjects, but they failed to adapt like lean ER subjects.

Adipose Tissue↗
PubMed1984

Adaptive changes to training in adipose tissue lipolysis are genotype dependent.

In order to study the effects of heredity and of physical training on adipose tissue morphology and metabolism, 15 pairs of monozygotic twins (MZ) (six males and nine females), aged from 16 to 24 years, weighing 56.2 +/- 9.1 kg and with 13.9 +/- 8.2 percent body fat, were submitted to a biopsy of adipose tissue in the suprailiac region. In addition, eight pairs of twins (four male and four female) took part in a 20-week ergocycle training program, five days a week, 40 min a day, at 80 percent of their maximal heart rate. Adipocyte diameter (AD) was assessed on collagenase isolated fat cells. Basal (BL), epinephrine submaximal (10(-5) M) (ESML) and epinephrine maximal stimulated lipolysis (10(-4) M) (EML) were determined on isolated fat cells. Intraclass correlation coefficients indicated significant intrapair resemblance before training for all fat morphological and metabolic indicators (0.78 less than or equal to ri less than or equal to 0.93). Training significantly increased VO2 max (pre: 44.7 +/- 7.6 (ml/kg) vs post: 50.8 +/- 5.0; P less than or equal to 0.001). No training effect was found in percent body fat and AD. Training significantly increased BL, ESML, and EML (P less than or equal to 0.01). Moreover, twins of the same MZ pair yielded identical responses in ESML and EML with training. Intraclass coefficients for the magnitude of change in activity over pretraining values reached 0.84 and 0.90 respectively. Apparently a genetically determined response to training could not be found for BL. These results show that training per se has an effect on adipose tissue lipolysis beyond variation in fatness. Furthermore, sensitivity of stimulated lipolysis to training appears to have a genetic basis.

Adipose Tissue↗
PubMed1983

A method to assess energy expenditure in children and adults.

A variety of studies has a need to estimate the amount and pattern of daily energy expenditure. To this end, a 3-day activity record was developed and is described. Every 15-min period over 3 days, including a weekend day, was qualified in terms of energy cost on a 1 to 9 scale corresponding to a range of 1.0 MET to 7.8 METs and higher. A reliability study of 61 subjects indicated a highly reproducible procedure as shown by an intraclass correlation of 0.96 for mean kcal of energy expenditure over 3 days. Repeatability was unchanged whether or not the hours of sleep were included in the record. Samples of 150 children and 150 adults were also drawn to investigate the relationship between energy expenditure, physical working capacity, and body fatness. Results support the hypothesis that mean energy expenditure per kg of body weight is significantly correlated with physical working capacity expressed per kg of body weight (r = 0.31; p less than 0.01). Mean energy expenditure per kg of body weight is negatively related to body fat (-0.08 less than or equal to r less than or equal to -0.13). It is concluded that the 3-day activity record is a procedure suitable to estimate energy expenditure in population studies.

Activities of Daily Living↗
PubMed1983

Familial resemblance in catecholamine changes to cold stress and maximal exercise.

Parents and children from 38 families were submitted to a cold-stress and maximal treadmill test. The number of subjects varied depending on the measurements. Plasma epinephrine and norepinephrine, blood pressure and heart rate were measured before, during and after a cold hand immersion test (in a water bath at 5 degrees C for 2 min), as well as before and after maximal exercise (modified Balke). Scores were adjusted for the effects of age and sex through multiple-regression procedures (age + sex + age X sex + age2 + age3), yielding residuals which were submitted to analysis. Characteristic variations during cold stress were observed. Maximal exercise yielded a mean aerobic power of 43 ml/kg min-1 (SD = 10), a mean maximal heart rate of 192 (SD = 10) and a mean maximal blood lactate of 65 mg/100 ml (SD = 23). Family resemblances in cold stress and maximal exercise adaptive reactions were investigated by comparison of between-family over within-family means of squares. In response to the cold stress, there were indications of family lines in induced changes for systolic blood pressure, epinephrine, and total catecholamines at 1 min after the test (p less than or equal to 0.05). Furthermore, parent-child correlations were significant and reached 0.38 for epinephrine, 0.28 for norepinephrine, and 0.34 for total catecholamines. Familial concentrations could not be detected before or 8 min after the cold stress. There are no indications of family resemblance in plasma catecholamine concentrations following exposure to maximal-exercise stress. It is concluded that genetic variation is probably contributing only moderately to catecholamine changes under cold stress and very little under exercise stress.

Adolescent↗
PubMed1983

[Psychosocial intervention and violence towards children : a critical reflection on Québec practice.].

The importance of socio-economic and structural factors in the explanation of child abuse, is often underestimated by practitioners. As a consequence, the inter-ventive models generally adopted are based essentially on the consideration of personal factors (alcoholism, parental immaturity, childhood experience of abuse, etc.). In the light of the numerous scientific studies which demonstrate the multidimensional character of the relevant factors, a reconceptualization of this problem, and of which action strategies to privilege, is imperative. The ecological model seems appropriate to the understanding of the reciprocal interaction between the individual and the significant environments. These environments (micro-meso-exo-macrosystem) may directly or indirectly influence the family in difficulty. The suggested types of intervention would prevent the enrichment on the heightening of the personal and community resources of collectivities; they invite practitioners to analyze constantly, and to modify, when necessary, the meso/ exo/and maxosystemic elements of environments; they are grounded in the opening of boundaries and in the integration of the different services offered to these families : informal, semi-formal and formal services. It appears to be essential that an epistemological rupture occur in the paradigm that guides our practice, so as to develop a more global comprehension of this problem area, and to intervene locally at the level of the collectivities in whom ultimately resides the right to define their needs and to identify the necessary means of response. Within this framework intervention would be dynamic (proactive) and not reactive, specific to each community and integrated with the efforts already being made (or remaining to be developped) by community members. Thus the practitioner might also develop a feeling of belonging to the neighbourhood which would protect him from exhaustion and from a growing sense of powerless-ness, apathy and futility brought on principally by the daily observation of future.

English Abstract↗
PubMed1983

Tests of anaerobic alactacid and lactacid capacities: description and reliability.

The purpose of this paper is 1) to describe maximal anaerobic alactacid (AAC) and lactacid (ALC) capacity test and 2) to determine their reliabilities in men and women. The subjects were submitted to either a 10-s (2 trials) or a 90-s (1 trial) all-out ergocycle test for AAC and ALC respectively. Thirty-four male and 24 female subjects were tested for AAC, while 21 males and 19 females took part in the ALC test. A modified bicycle ergometer allowed the exact measurement of the distance and the work load for the computation of the work performed. load for the computation of the work performed. Each subject was tested and retested within 7 days. In both AAC and ALC, male subjects performed more work than women. AAC was 108 +/- 16 (mean +/- SD) and 90 +/- 14 J/kg for males and females respectively while ALC was 486 +/- 50 and 377 +/- 34 J/kg. Although the work load was designed to be 0.09 kp/kg for the AAC and 0.05 kp/kg for the ALC tests, there were wide variations between subjects with respect to the optimal load (AAC: from 0.05 to 0.11; ALC: from 0.03 to 0.06 kp/kg). Reproducibility was consistently high, with intraclass correlations of 0.98 and 0.99 for AAC (AAC-Max) and ALC respectively, with no difference between the male and female subgroups. It is concluded that these AAC and ALC tests, designed under assumptions of face validity, allow for differences between males and females and are highly repeatable.

Adolescent↗
PubMed1983

Association between serum high-density lipoprotein cholesterol and body composition in adult men.

The relationships between measurements of body composition and fasting serum high-density lipoprotein cholesterol (HDL-C) were assessed in 357 men aged 30 to 59 years. The sum of six skinfolds (triceps, biceps, subscapular, suprailiac, abdominal and medial calf), body density through underwater body weighing, lean body mass (kg), body-fat mass, and percent body fat, all three derived from the Siri equation, were obtained. Effects of age, sex, alcohol consumption, cigarette smoking, socioeconomic status, triglycerides, total cholesterol and current energy expenditure were statistically removed through multiple regression procedures. HDL-C was significantly associated with weight, weight/height, weight/height11, weight/height16, body density, body-fat mass, sum of six skinfolds, but not with height alone or lean body mass. These results suggest that, among the body composition measurements, the adipose component is the major contributor to the low but significant association between HDL-C and weight.

Adult↗
PubMed1983

Morphology and metabolism of human fat cells: a reliability study.

Twenty-three male subjects, 31.7 (mean) +/- 7.4 (s.d.) yr of age, weight 70.7 +/- 9.0 kg and with 13.4 +/- 4.7 percent body fat were submitted twice within a week to biopsies of subcutaneous adipose tissue in the suprailiac region. Two biopsies (sample A and B) were obtained on day 1 and two others (sample C and D) in the contralateral region on day 2. Average fat cell diameter (ACD) was assessed by measuring at least 500 cells per subject. There was no significant difference between day 1 and day 2 for ACD (means 1 = 62.6 +/- 12.2 micron; means 2 = 63.2 +/- 12.3 micron). Intra-class reliability coefficient reached 0.97. ANOVA-RBFD showed no day or sample effects (P greater than 0.05) on ACD. Basal (BL), epinephrine submaximal (10(-5) M) (ESML) and epinephrine maximal (10(-4) M) (EML) stimulated lipolysis have been determined for 18 of these subjects. Intra-class reliabilities were moderately high, reaching 0.71 for BL, 0.83 for ESML and 0.72 for EML, respectively. Controlling the level of activity for 36 h prior to the biopsies resulted, however, in increased coefficients. In this case, intra-class coefficients computed with 11 subjects were 0.99 for BL, 0.88 for ESML and 0.85 for EML. The data demonstrate that ACD and lipolytic capacity can be reliably measured, particularly when activity of subjects is controlled during the 36-h period preceding the biopsies.

Adipose Tissue↗
PubMed1982

Fatness and fat patterning among athletes at the Montreal Olympic Games, 1976.

Six skinfold measurements for male and female athletes (N=456) at the 1976 Montreal Olympic Games were analyzed to identify principal components of fatness and anatomical distribution of fat, i.e., fat patterning. As in non-athletes, two principal components were evident among the athletes. All skinfolds were correlated positively with the first component, which was termed fatness, while extremity fat measurements were correlated positively and trunk measurements were correlated negatively with the second principal component, which was termed an extremity/trunk ratio component. The two principal components accounted for about 85% of the variance. The first component was related to control variables in order of descending contribution to its variance as follows: sex (21-31%), sport (19%), ethnicity (3%), and age (1-3%). Likewise, the second component (extremity/trunk ratio) was related to the control variables: sex (20-35%), age (4-7%), ethnicity (2%), and sport (2%). Fatness is more influenced by sport and by inference training than is the anatomical distribution or patterning of fat on the extremities relative to the trunk. The latter characteristic may be more dependent on biological or environmental factors unrelated to sport and training.

Adipose Tissue↗
PubMed1982

[Morphology and metabolism of human adipose tissues: relation to sex, body fat and level of training].

In order to study human fat cell morphology and metabolism in both sexes, with different levels of fatness and physical training, 53 subjects (14 women and 39 men), 25.9 +/- 7.6 (mean +/- SD) years of age, weighing 64.8 +/- 10.8 kg and with 14.8 +/- 4.7% body fat were submitted to a biopsy of subcutaneous adipose tissue in the supra-iliac region. Average fat cell diameter (ACD) was assessed by measuring at least 500 cells per subject. Basal (BL), epinephrine sub-maximal (10(-5) M) (ESML) and epinephrine maximal (10(-4) M) (EML) stimulated lipolysis have been determined on collagenase isolated fat cells. Female subjects have larger ACD (83.4 +/- 12.3 micrometer vs. 62.5 +/- 11.9 micrometer) (P less than or equal to 0.001) and lower BL, ESML, and EML than men (P less than or equal to 0.05). After control over age and sex of subjects, there were significant and negative correlations between all fatness indicators (ACD, fat mass in kg, percent body fat, sum of 9 skinfolds) and BL, ESML and EML. A completely randomized factorial ANOVA design revealed a significant effect of fatness level on BL, ESML and EML, but a non-significant trend for the effect of physical training on the same variables. It is concluded that lipolytic activity is more related to body fatness than to the training status. However, training tends to accentuate lipolytic activity as shown by values of BL, ESML and EML found in the lean highly trained subjects of the study.

Adipose Tissue↗
PubMed1981

Isoelectric focusing of red cell phosphoglucomutase (E.C.: 2.7.5.1) at the PGM1 locus in a French-Canadian population.

Phosphoglucomutase1 (PGM1) polymorphism was studied in a French-Canadian population of Québec city, Canada by means of a low voltage (max 500 V) isoelectric focusing (IEF) procedure on vertical polyacrylamide gel slabs. Frequencies of the four common PGM1 genes estimated from the phenotype distribution in 308 unrelated individuals were PGM1(1+), 0.61 (+/- 0.02); PGM1(1-), 0.13 (+/- 0.01); PGM1(2+), 0.18 (+/- 0.02); and PGM1(2-), 0.08 (+/- 0.01). The segregation patterns observed in 154 families, which included 31 different mating types and 353 children, confirmed a Mendelian inheritance of four autosomal genes. The distribution of the PGM1 phenotypes observed or expected in a Hardy-Weinberg equilibrium was compared with that of other populations. A significant (P < 0.001) difference was found between the Québec population and a Black population from Keneba, Gambia, West-Africa.

Alleles↗
PubMed1981

Cortical bone, body size, and skeletal maturity in ice hockey players 10 to 12 years of age.

Cortical bone dimensions of the second metacarpal were analyzed relative to chronological age, skeletal maturity and body size in 280 ice hockey players 10 through 12 years of age. Defencemen had the largest cortical bone dimensions, followed by forwards and goalkeepers respectively. After removing the effects of height, weight, chronological age, and skeletal age by analysis of covariance procedures, boys at the forward position had larger estimated periosteal diameter, cortical thickness, and cortical area, than either defencemen of goalkeepers. Compared to non-athletic boys from Montreal and Philadelphia, the young hockey players had a larger periosteal diameter, cortical thickness, and cortical area for the same stature. The results suggest a possible role for the effects of physical activity on cortical bone deposition.

Age Determination by Skeleton↗