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Biomedical subjects

M Houde-Nadeau

Publications and source records attributed to M Houde-Nadeau.

3 recordsLinked to original sources

Thermogenic response to food: intra-individual variability and measurement reliability.

The objective of this study was to assess the reliability and variability of the thermogenic response to food (TRF) in healthy adult subjects. Eight healthy adults (4 men, 4 women) participated in three sets of measurements of TRF, evaluated by indirect calorimetry with a ventilated hood system during 6 hours after a standardized meal. The reliability of TRF measurement was estimated using a one-way analysis of variance with repeated measurements. After the 6-hour period of measurement, the within-subject coefficient of variation for TRF was 10.7%, while the between-subject variability was twice as high (24.1%, p < 0.01). The overall reliability estimate of TRF was acceptable (RE > or = 0.80) after a single measurement which lasted at least 6 hours postprandially, while duplicate and triplicate measurements reached a similar degree of reliability in 3 hours. These results suggest that intra-individual variability contributes little to the variability commonly seen in TRF studies, provided that the measurement period is at least 6 hours.

Adult↗

Decreased pituitary growth hormone response to growth hormone-releasing factor in cafeteria-fed rats: dietary and obesity effects.

The in vivo and in vitro growth hormone (GH) responsiveness to growth hormone-releasing factor [rGRF(1-29)NH2] was evaluated in a dietary obese rat model. Sprague-Dawley rats were divided into two groups after weaning. The control group received a semisynthetic defined diet, and the cafeteria-fed group was maintained on a mixed energy-rich palatable diet. After 2 months of diet, the cafeteria-fed rats were divided into two groups, according to their degree of weight gain compared to controls: group I: 0%; group II: 24%. After 5 months of diet, the weight increase was, respectively, in groups I and II, 12 and 41%, as compared to controls. Under pentobarbital anesthesia, rGRF(1-29)NH2 was injected intravenously in two consecutive doses of 0.8 and 4.0 micrograms/kg body weight into the control and cafeteria-fed rats. After 2 months of diet, a significant decrease of basal GH levels and GH peak response to the 4.0 micrograms/kg rGRF dose was observed in both cafeteria-fed rat groups as compared to the control group. After 5 months of diet, basal GH levels decreased in both cafeteria-fed groups. However, a significantly blunted GH response to both doses of rGRF occurred only in group II. After 5 months of diet, perifused anterior pituitary cells of control and cafeteria-fed rats were challenged with increasing concentrations of rGRF (6.25, 25 and 100 pM). The basal GH secretion was similar in all groups but the stimulated GH release in response to 25 and 100 pM GRF, expressed as peak value, was depressed in group II, compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗