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Biomedical subjects

R Savard

Publications and source records attributed to R Savard.

At least 37 records · Page 2Linked to original sources
PubMed1985

Lack of relationship between changes in adiposity and plasma lipids following endurance training.

In order to study the effect of alterations in fat morphology and metabolism induced by exercise-training on plasma lipids, 13 healthy young men were subjected to a 20-week aerobic training program on bicycle. Training significantly increased maximal aerobic power (VO2 max) (P less than 0.001) and decreased per cent body fat (P less than 0.001). A significant reduction of mean adipocyte diameter and an increase in isolated fat cell epinephrine-stimulated lipolysis were also observed following training. However, with the exception of total cholesterol, no changes were noted in plasma lipids. Neither before nor after training were triglycerides and high density lipoprotein cholesterol (HDL-C) correlated with VO2 max, fat cell diameter and adipocyte-stimulated lipolysis. The present study demonstrates that an important fat loss (mean loss of fat = 3 kg) and a significant gain in VO2 max induced by endurance training do not necessarily produce an increase in HDL-C levels in normal male subjects. Moreover, changes in VO2 max, body fatness and in fat cell epinephrine-stimulated lipolysis produced by endurance training are not related to modifications in plasma lipids in healthy men.

Adipose Tissue↗
PubMed1985

Resting metabolic rate in monozygotic and dizygotic twins.

In order to study the influence of heredity on resting metabolic rate (RMR), 20 monozygotic and 19 dizygotic male twins pairs aged 20.6 (SD 2.9) and 21.4 (SD 3.1) years, gave their consent to participate in the experiment. Fat free weight (FFW) was estimated from underwater weighing. RMR was measured by indirect calorimetry using an open circuit system. RMR was expressed as kJ X min-1, kJ/m2 X h-1, kJ/kg X h-1 and kJ/kgFFW X h-1. Significant intraclass coefficients were observed in MZ twins for the different expressions of RMR. The values ranged from r = 0.45 (P less than 0.05) to r = 0.81 (P less than 0.01). However, DZ twins demonstrated lower intraclass coefficients for RMR, with a range from r = 0.21 to r = 0.44. Significant (P less than 0.05) DZ resemblance was revealed only when RMR was expressed as kJ X min-1 and kJ/kg X h-1. Results of the present study suggest that variations in RMR may have a genetic component. Implications for human energy balance and body fat are discussed.

Adipose Tissue↗
PubMed1985

Adipose tissue lipid accumulation pathways in marathon runners.

Eighteen male marathon runners (mean marathon performance: 2 h 36 min, SD = 7.0 min; VO2 max = 64.1 +/- 15.1 ml/kg . min-1) were submitted to a needle biopsy in the suprailiac region and to various measurements of body fatness: percent body fat (% fat), seven skinfold thicknesses, and mean fat cell diameter. Basal and insulin-stimulated glucose conversion into triglycerides were measured in collagenase-isolated fat cells, while heparin-releasable lipoprotein lipase activity (LPLa) was determined in intact adipose tissue. All body fatness indicators were significantly smaller in marathon runners in comparison to a sedentary control group (P less than 0.001). Fat cell basal and insulin-stimulated glucose conversion into triglycerides as well as LPLa were significantly higher for the runners group (P less than 0.01), differences being particularly important when comparisons were performed between subjects paired for mean fat cell diameter. Pearson interclass correlations between body fatness and fat cell glucose incorporation into triglycerides were low and positive for the sedentary group (0.04 less than or equal to r less than or equal to 0.41), while they were negative for the marathon runners groups (-0.28 less than or equal to r less than or equal to -0.40) with the exception of % fat. Moreover, correlations between LPLa and indicators of body fatness were positive in the sedentary group (0.47 less than or equal to r less than or equal to 0.79), while they were negative in the marathon runners group (-0.03 less than or equal to r less than or equal to -0.63).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1985

Endurance training and glucose conversion into triglycerides in human fat cells.

To study the influence of endurance training on glucose conversion into fat cell triglycerides, 24 (13 women, 11 men) inactive subjects (25.0 +/- 3.8 yr of age) took part in a 20-wk ergocycle training program 4 days and increasing to 5 days/wk, 40-45 min/day, starting at 60% and increasing to 85% of the heart rate reserve. Several body fatness indicators were measured before and after the training program: seven skinfold thicknesses, percent fat, and mean fat cell weight. Fat cell basal and maximal insulin-stimulated glucose conversion into triglycerides were also determined using [14C]glucose. Body fatness indicators decreased significantly after training only in male subjects (P less than 0.05). Basal and maximal insulin-stimulated glucose conversion into triglycerides increased significantly with training (P less than 0.05): pretest values (nanomoles glucose per hour per 10(6) cells) being 24.9 +/- 2.1 and 28.7 +/- 2.5, while post-test values were 30.1 +/- 3.2 and 33.0 +/- 3.4 for basal and insulin-stimulated values, respectively. However, this lipogenic increase was only observed in male subjects (P less than 0.01). Changes in body fatness indicators induced by training were negatively correlated with changes induced in fat cell glucose conversion into triglycerides (-0.24 less than or equal to r less than or equal to -0.45). These results demonstrate that endurance training increases fat cell glucose conversion into triglycerides and suggest that adipose tissue metabolism is part of the adaptive response to training. Moreover, it appears that adipose tissue response to aerobic training is more efficient in males than in females.

Adipose Tissue↗
PubMed1985

Effects of aerobic training on fat distribution in male subjects.

To investigate the effects of aerobic training on adipose tissue morphology and fat distribution, several indicators of body fatness (percent body fat, seven subcutaneous skinfolds, fat cell weight) were assessed in 13 sedentary male subjects (SS) submitted to a 20-wk aerobic training program and in 20 male long-distance runners (LDR). The LDR subjects had a mean +/- SD VO2max of 65.9 +/- 6.5 ml . min-1 . kg-1 and averaged 120 km . wk-1. Training increased the VO2max values of the SS group significantly (pre: 41.9 +/- 7.0 vs post: 53.4 +/- 6.4 ml . kg-1 . min-1; P less than 0.001) and decreased significantly percent body fat (P less than 0.01), sum of skinfolds (P less than 0.01), and fat cell weight (P less than 0.05). Trunk skinfolds were more altered by training than extremity skinfolds, with reductions of 22 and 12.5%, respectively. Significant correlations were found between fat cell weight and percent body fat in SS before and after training (r = 0.75; P less than 0.01), while no significant relationship was noted in the LDR group. Moreover, using the sum of skinfolds divided by percent fat or by fat mass to reflect the proportion of subcutaneous fat to total fat, the LDR subjects exhibited less subcutaneous fat than the SS group (P less than 0.01) and training did not alter these ratios in the SS group. These results suggest that 20 wk of aerobic training can alter body fatness in men but that the induced fat loss does not seem to deplete preferentially subcutaneous fat.

Adipose Tissue↗
PubMed1984

Cortisol hypersecretion and cognitive impairment in depression.

We attempted to investigate the relationship between hypothalamic-pituitary-adrenal axis activity and cognitive function by measuring mean urinary free cortisol (MUFC) excretion and performance on the Halstead Category Test in depressed patients and normal controls. We observed a significant relationship between category test errors and MUFC in the depressed patients, but not in the controls. While an even more robust correlation was observed between age and category test errors in the patients, it appeared that age and depression interacted to produce severe cognitive impairment. Depression-related cortisol hypersecretion or its underlying determinants may contribute to depression-related cognitive dysfunction.

Adult↗
PubMed1984

Effects of exercise-training and detraining on fat cell lipolysis in men and women.

The effects of training and detraining on adipose tissue lipolysis were studied in 19 healthy subjects (7 women and 12 men) who were submitted to a 20-week aerobic training program. Thereafter, subjects refrained from exercise for a period of 50 days. Suprailiac fat biopsies were performed before training, after training, and at the end of the detraining period. Mean fat cell diameter and epinephrine stimulated lipolysis (ESL) were assessed on collagenase isolated fat cells. Body density through underwater weighing and skinfolds at seven different sites were also obtained. Training significantly increased ESL (P less than 0.05) in men but not in women. However, ESL values in men returned to pretraining values after the exercise restriction period. No significant changes in women lipolysis were observed under any conditions. Changes in lipolysis were not correlated with changes in body fatness. However, a significant correlation was observed between the increase in ESL produced by training and the subsequent decrease caused by detraining (r = -0.53; P less than 0.05). The present results suggest that lipolysis in fat cells from the female subjects seems to be insensitive to changes in energy expenditure. Moreover, the present study demonstrates that there are high and low responders in adipocytes ESL to variations in habitual energy expenditure.

Adipose Tissue↗
PubMed1984

The effect of a 20-week endurance training program on adipose-tissue morphology and lipolysis in men and women.

In order to assess the effect of endurance training on adipose-tissue morphology and lipolysis, 22 adult subjects (11 men and 11 women) took part in a 20-week ergocycle training program, four to five days a week, 40 minutes a day, at 80% of their maximal heart rate. Before and after training, they were submitted to an adipose-tissue biopsy in the suprailiac region. Fat cell weight (FCW), and lipolytic activity were determined on isolated fat cells. For the whole sample, training significantly reduced FCW (pre: 0.40 +/- 0.13 (mean +/- SD) versus post: 0.36 +/- 0.13 micrograms; P less than 0.05), percentage of fat (pre: 22.0 +/- 8.3 versus post: 19.7 +/- 8.1%; P less than 0.05), and increased adipocyte epinephrine maximal stimulated lipolysis (ESL) (pre: 1.08 +/- 0.49 versus post: 1.69 +/- 0.67 mumol glycerol/30 min/10(6) cells; P less than 0.001). No changes were observed in fat cell number. In women, however, training induced no changes in the fatness indicators (% fat, sum of skinfolds, FCW). The exercise program significantly lowered the adiposity of men (% fat: P less than 0.001; sum of skinfolds: P less than 0.01; FCW: P less than 0.05). In both sexes, a significant increase in ESL was observed after training. ESL of men, however, responded better than that of women to training (ESL of women: 1.36 +/- 0.67 versus ESL of men: 2.02 +/- 0.50 mumol glycerol/30 min/10(6) cells; P less than 0.05), with increases over pre-training values of 46% and 66% in women and men, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1984

Lipogenesis and lipoprotein lipase in human adipose tissue: reproducibility of measurements and relationships with fat cell size.

Lipogenesis from glucose and lipoprotein lipase activity were investigated in humans. The reliability of measurements was quantified and correlations with fat cell weight were assessed. Twenty-four subjects (7 women, 17 men) were studied twice within a 2-week period, along with 17 additional male subjects who were studied once and used only in the correlation analyses. All subjects were not regularly involved in an exercise-training program and were between 18 and 30 years of age. Following an overnight fast, adipose tissue specimens were obtained by suprailiac biopsy and fat cells were collagenase isolated. Mean fat cell weight was obtained from 400 to 500 cell diameter determinations per subject. Basal and insulin-stimulated fat cell lipogenesis from glucose were determined using D-[U-14C]glucose and were reported in nanomoles of glucose per hour per 10(6) cells. Adipose tissue heparin-releasable lipoprotein lipase activity was also determined and expressed in micromoles of free fatty acids per hour per gram of tissue and per 10(6) cells. Fat cell weight, basal and insulin-stimulated lipogenesis and lipoprotein lipase activity per gram showed high reliability of measurement, interclass and intraclass coefficients being 0.83 and over. Lipoprotein lipase activity per 10(6) cells showed a somewhat lower degree of reliability, interclass and intraclass coefficients being, respectively, 0.69 and 0.81. On the other hand, fat cell weight was positively correlated with lipoprotein lipase activity (r = 0.80), while no significant correlation was observed between basal lipogenesis and fat cell weight. Moreover, basal lipogenesis presented no significant correlation with lipoprotein lipase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1984

Level of physical fitness and adipocyte lipolysis in humans.

The present experiment was conducted to study the influence of exercise training on adipose tissue lipolytic activity and to identify the amount of training required to induce maximal adaptation in humans. Fifty-one male subjects were divided into three groups according to their training regimen: 1) sedentary subjects (SS) (n = 21); 2) trained subjects (TS) (n = 15) who had exercised during a period of 20 wk, 5 days/wk, 45 min/session; and 3) experienced marathon runners (MR) (n = 15) who ran an average of 120 km/wk for many years. Biopsies of fat were performed in the suprailiac region after an overnight fast. Adipocyte diameter (AD) and epinephrine-stimulated lipolysis ( ESL ) were assessed on collagenase-isolated fat cells. A lower AD was noted in the MR group compared with the two other groups. Basal lipolysis (BL) and ESL were significantly higher in TS and MR than in controls. Moreover, BL values were comparable in the two trained groups, whereas ESL in the TS group was higher than in the MR group. These results indicate that training increases suprailiac fat cell lipolysis, which seems to adapt maximally within about 4 mo.

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

CSF 5HIAA and personal and family history of suicide in affectively ill patients: a negative study.

Personal and family histories of suicidality were gathered in 45 patients who met Research Diagnostic Criteria for major affective disorder (n = 32, bipolar; n = 13, unipolar) and compared to CSF values of 5HIAA obtained by two different assays (n = 20, fluorometric; n = 25, high performance liquid chromatography). In separate analyses of the two assay groups, patients who had made a suicide attempt were not significantly different from those who had not in terms of 5HIAA value or family history of suicidality. Furthermore, in suicide attempters, 5HIAA was unrelated to the severity of the attempt.

Adult↗
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

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

[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↗
PubMed1980

Thought disorder and affective inaccessibility in depression.

In addition to familiar themes of depressive thought content, the authors describe changes in the form of language and thinking in depression which reflect serious disturbances in ego functioning. These disturbances are associated with an inability to express and experience a wide range of affects. The authors suggest that paradoxically, this painful state of affective inaccessibility, rather than an excess of depressive feeling, may be a major component of severe and/or prolonged depression. The evolution of this phase of affective blockade may have important theoretical and clinical treatment implications.

Adult↗
PubMedDate not supplied

Calcitonin gene-related peptide receptor in human placental syncytiotrophoblast brush-border and basal plasma membranes.

Minerals, such as calcium and potassium, are essential for fetal development, but their transplacental transport, and in particular, the effect of hormones on this process has not been extensively studied. Human alpha-calcitonin gene-related peptide (h alpha CGRP), a hormone constituted of 37 amino acids, is obtained by the alternative splicing of the mRNA from the calcitonin gene, and could be implicated in placental ion transport. In order to study the presence of this receptor, brush-border and basal plasma membranes were purified, and membrane binding studies were conducted using [125I]h alpha CGRP. The initiation of binding of [125I]h alpha CGRP to both membranes was rapid and reached maximal value after 10 min of incubation at 37 degrees C. Scratchard analysis revealed single-affinity binding sites for h alpha CGRP with Kd equal to 4412.45 +/- 604.81 pM and 2673.24 +/- 552.51 pM for brush-border and basal plasma membranes, respectively, which were significantly different. Moreover, the maximal number of receptors was significantly different (P < 0.001) in both membranes, with Bmax of 627.94 +/- 31.40 fmol/mg protein for brush-border membranes and 343.70 +/- 43.52 fmol/mg protein in basal-plasma membranes. Competitive displacement of [125I]h alpha CGRP with other ligands showed the following potencies; h alpha CGRP approximately h beta CGRP approximately Cys (acm)2,7 CGRP > CGRP (8-37), but no competition was observed with human and salmon calcitonin. Half-maximal displacement for human alpha- and beta CGRP was reached at approximately 10(-10)M for brush-border and basal-plasma membranes. alpha- and beta CGRP, and their fragment and analogue, stimulated cyclic AMP production in placental homogenate ranging from 143-163 per cent. Thus, our results show the presence of CGRP-specific receptors in both the syncytiotrophoblast membranes of human placenta. The role(s) of this related peptide in placenta remains to be investigated.

Binding, Competitive↗