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Biomedical subjects

T Brun

Publications and source records attributed to T Brun.

32 records · Page 2Linked to original sources
PubMed1993

Glucose regulates acetyl-CoA carboxylase gene expression in a pancreatic beta-cell line (INS-1).

Acetyl-CoA carboxylase (ACC) catalyzes the production of malonyl-CoA which may act as a metabolic coupling factor in nutrient-induced insulin release. We have studied the long term regulation of ACC by nutrients using the cell line INS-1. Glucose, from 5 to 20 mM, elicited a 15-fold increase in ACC mRNA. The effect was detected after 4 h and reached a maximum by 24 h. ACC protein accumulation followed that of ACC mRNA, and glucose did not modify the half-life of the ACC transcript. Glucose caused a dose-dependent rise in the glucose 6-phosphate content of INS-1 cells. 2-Deoxyglucose, which is phosphorylated by glucokinase but is not further metabolized, induced ACC mRNA. The effect of glucose was blocked by the glucokinase inhibitors mannoheptulose and glucosamine and was not mimicked by the 3-O-methyl or 6-deoxy analogues of glucose, which are not phosphorylated. Activation of the Ca2+, cAMP, and C-kinase pathways with high K+, forskolin, and phorbol 12-myristate 13 acetate, respectively, caused insulin release but not ACC mRNA induction. Basal insulin release, at 5 mM glucose, correlated with the ACC protein content of INS-1 cells preincubated for 24 h at various glucose concentrations. In conclusion, glucose is a potent inducer of the ACC gene, and glucose 6-phosphate may mediate its effect. Different signaling systems mediate the action of glucose on insulin release and ACC gene expression. The data strengthen the view that ACC plays a pivotal role in nutrient-induced insulin release.

Acetyl-CoA Carboxylase↗
PubMed1993

Impact of large-dose vitamin A supplementation on childhood diarrhoea, respiratory disease and growth.

One hundred and seventy-two 0.5-3.0-year-old children in a mountainous area of northern Hebei Province of China were randomly assigned to a vitamin A supplementation group (n = 98) or a control group (n = 74) for a 1 year double-blind study. Capsules containing 200,000 IU vitamin A and 40 IU vitamin E were given to the children in the experimental group 3 and 9 months after baseline examination. During the 12 month study period, there was a significant reduction in the incidence of diarrhoea (P < 0.01) and respiratory disease (P < 0.01) in the children of the experimental group compared to the control. Risk of diarrhoea and respiratory disease were respectively 2.5 and 3.4 times higher in the control children. Serum retinol and IgA levels of the treatment group were significantly higher than that of control group (P < 0.01) 7 weeks after first supplementation. There was no significant difference in saliva IgA level between groups. No significant differences in growth were observed. It was concluded that supplementation with large doses of vitamin A decreased the incidence and severity of diarrhoea and respiratory disease in these children, possibly through enhanced activity of the immune system, but had no effect on growth over 1 year.

Anthropometry↗
PubMed1992

The assessment of total energy expenditure of female farmers under field conditions.

The paper reviews methods, and their difficulties, in the measurement of the daily energy expenditure of rural women under field conditions in developing countries. Since all methods need to be validated against a reference method which is usually based on indirect calorimetry, examples of the use of this technique are given. The energy costs of most agricultural and daily tasks of rural women in developing countries have been measured. Large intra- and inter-individual variations in the cost of a single activity occur, so repeated measurements are needed to obtain a valid mean energy cost for a specific activity for a homogeneous group of individuals. Much work remains to be done on the assessment of the duration and the intensity of the physical activity of the rural adolescent and adult female population. Studies indicate that the workload of most rural women in developing countries is excessive and frequently associated with acute poverty.

Agriculture↗
PubMed1990

Questioning riboflavin recommendations on the basis of a survey in China.

Riboflavin status was surveyed in adults aged 35-64 y in 65 counties (two communes per county) in the People's Republic of China by erythrocyte glutathione reductase activity coefficients (EGRACs), by urinary excretion of riboflavin 4 h after the oral administration of 5 mg riboflavin (one commune per county), and by direct measurement of food intake over a 3-d period (one commune per county). EGRAC data were highly correlated between sexes (p less than 0.001) and between neighboring communes within the same county (p less than 0.001) and with riboflavin intake (p less than 0.001). The urinary-riboflavin-load test data were not correlated either with EGRAC or with riboflavin intake. Approximately 90% of the survey subjects were found to be deficient by Western and Chinese reference standards and allowances. Upon reconsideration of the Western experimental data originally used to establish these recommendations, it is suggested that riboflavin allowances are set too high both in China and in Western countries.

Adult↗
PubMed1988

Energy expenditure over 24 hours, thermal comfort and fat-free mass in Asian men.

Energy expenditure while sitting or sleeping was measured over 24 h in eight young Asian immigrants to France by a suit calorimeter and also by continuous measurement of respiratory gas exchange. Fat-free mass (FFM) was estimated from skinfold measurements. The energy intake per kilogram FFM of the Asians was similar to a group of well-off North Americans of larger body size but similar body composition who had been the subjects of an earlier study. In both groups thermoneutrality was controlled by adjusting the circulating water temperature of the suit calorimeter according to the subjects' preferences. The hourly energy expenditure/kg FFM was 1.2 kcal during sleep and 1.7 kcal while sitting. The mean energy expenditure/kg FFM during a quiet day was 37 kcal/d or 1.5 kcal/h. Using published equations, the estimated BMR was 1490 kcal (6.2 MJ). This estimated value agrees quite well with the BMRs of these subjects as previously determined. In the metabolic room the daily sedentary energy expenditure averaged 1.15 BMR and the energy intake averaged 1.26 BMR for the study subjects in free-living conditions in an urban environment. This is below the 1.4 X BMR currently recommended as a 'minimum' energy intake for subjects of low activity.

Adult↗
PubMed1987

[Zinc and biotin deficiency during prolonged parenteral nutrition in the infant].

The case of a premature hypotrophic infant who, after 4 months of parenteral nutrition, presented with deficiency in both zinc and biotin is reported. The two deficiencies had similar clinical manifestations: dermatitis, alopecia and susceptibility to infection. The diagnosis was confirmed by zinc blood level measurement on the one hand and by urinary organic acids chromatography on the other. The clinical manifestations can only be prevented by an additional intake of zinc and biotin in doses adjusted to the child's age and to the underlying pathology.

Alopecia↗
PubMed1985

Calorimetric evaluation of the diary-respirometer technique for the field measurement of the 24-hour energy expenditure.

The results of measuring the 24-h energy expenditure by the diary-respirometer technique (factorial method) have been compared to those obtained by direct measurement of heat output and continuous recording of oxygen consumption and carbon dioxide production. Anthropometric and skinfold measurements were used to estimate lean body mass in eight male Asian subjects. They remained for 36 h in a metabolic chamber wearing a calorimeter suit. A ventilated hood and differential gas analysers were used to measure oxygen consumption and carbon dioxide production. While the subjects were sitting inactive, the KM respirometer indicated a mean energy expenditure which was significantly lower than with the calorimeter suit or with the ventilated hood. During exercise on an ergometer at 25 W and 75 W the respirometer gave readings of energy expenditure which were also significantly lower than either the ventilated hood or the calorimeter suit. The daily energy expenditure expressed in MJ for a standard body weight of 60 kg (MJ/60 kg) measured from the calorimeter suit was 9.79 MJ; from the ventilated hood, 9.51 MJ; from the diary-respirometer method, 8.30 MJ. The mean energy intake, measured for 10 consecutive d after the the subjects had left the metabolic room was 7.87 MJ, while during their stay in the metabolic room, their spontaneous intake was 7.74 MJ. The diary-respirometer technique tends to cumulate the errors from an incorrect time and motion recording and the potential lack of representativeness of the measurement of the energy cost of the activities. In the present study, it seems that the discrepancy observed between the results of the different methods can be attributed almost entirely to the underestimation of the energy cost of the activities by the respirometer. Contrary to our expectation the diary-respirometer technique does not seem to overestimate systematically the daily energy expenditure.

Adult↗
PubMed1981

Energy expenditure of male farmers in dry and rainy seasons in Upper-Volta.

1. Thirty Mossi male farmers from Upper-Volta were investigated, twenty-three in the dry season (March-April) and sixteen in the rainy season (July-August), eight of them being studied twice. A 48 h time-and-motion study was carried out and the daily energy expenditure was computed. 2. The mean height was 1.70 m and the mean weight 58.5 kg. The averaged percentage of body fat calculated from skinfold thickness was 10. 3. During the dry season the subjects could be classified as very moderately active with an energy output of 10.0 MJ (2410 kcal)/d. By contrast, with an energy expenditure of 14.4 MJ (3460 kcal)/d, they were considered as exceptionally active in July-August when performing the agricultural work. 4. In this study we measured the intensity of physical work in a society where human labour is still the main tool of production. The determination of seasonal variations in energy expenditure may be useful to assess the nutritional requirements in arid zones of West Africa.

Activities of Daily Living↗