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Biomedical subjects

F Mosora

Publications and source records attributed to F Mosora.

At least 37 records · Page 2Linked to original sources

Oxidation of an exogenous glucose load using naturally labelled 13C-glucose. Effect of butylbiguanide therapy in obese mildly diabetic subjects.

The effect of a 14 day-administration of butylbiguanide was investigated in a group of 10 obese patients with mild-to-moderate glucose intolerance. Glucose tolerance was significantly improved, while fasting blood glucose and plasma levels of free fatty acids, insulin and glucagon remained unchanged. The estimation of the amount of the oral glucose load oxidized into CO2 was performed by means of a recently described procedure using "naturally labelled 13C-glucose" as tracer. The curves depicting the oxidation of the exogenous glucose load were similar in shape and magnitude before and after administration of the biguanide; in the latter case, however, slightly higher rates of oxidation of exogenous glucose were recorded during the 2nd, 3rd and 4th hours of the test. These data do not provide evidence that the biguanide-induced improvement in glucose tolerance in patients with mild-to-moderate glucose intolerance is associated with any inhibiting or delaying effect of this type of drug on intestinal absorption (and subsequent oxidation) of the exogenous glucose load. On the contrary, a slight, but statistically significant, increase in the oxidation of exogenous glucose has been observed after butylbiguanide.

Adult↗

Effect of glucose ingestion on energy substrate utilization during prolonged muscular exercise.

The distribution of substrates utilized during prolonged exercise was investigated in normal human volunteers with an without ingestion of 100 g exogenous glucose. The energy provided by protein oxidation was derived from urinary nitrogen excretion and the total energy provided by carbohydrates and lipids was calculated from respiratory quotient (RQ) determinations. The contribution of exogenous glucose to the energy supply was determined by an original procedure using "naturally labeled 13C-glucose" as metabolic tracer. Protein oxidation provided between 1 and 2% of the total energy requirement; this amount was not affected by glucose ingestion. In the absence of exogenous glucose ingestion, carbohydrate were progressively replaced by lipids as source of energy. Exogenous glucose contributed markedly to total carbohydrate oxidation and decreased the percentage of energy derived from lipids. In addition, ingestion of exogenous glucose resulted in a significant economy of endogenous carbohydrates and permitted to prolong the duration of exercise.

Adult↗

Quantitative evaluation of the oxidation of an exogenous glucose load using naturally labeled 13C-glucose.

Maize glucose was used as a natural tracer for studies of metabolism. It is richer in 13C than common vegetables and foods derived from these, and the C02 formed from it is consequently richer in 13C than the CO2 expired by man fed on a diet of common vegetables. The quantitative results, obtained by measurement of delta 13C of the expired CO2 and of VCO2 during the oxidation of an exogenous glucose load (about 100 g) in eight normal subjects over 7 hr, have shown a consumption of 28.64 +/- 1.44 g of glucose (mean +/- SEM), which represents about 30% of the load given. A comparison is made with the results obtained from other methods and the originality and usefulness of this new quantitative procedure is outlined.

Adult↗

[Effect of antioxidant substances on the level of free organic radicals naturally present in the rat diaphragm].

Using the electron spin resonance method, the effect of antioxydants on the number of natural organic free radicals is studied in the case of the diaphragm of the Rat. The effect observed shows an important decrease in the free radical concentration, which may, in the case of ascorbic acid and BHT, lead to their complete disappearance. These results are discussed in the light of the hypothesis according to which antioxydants play a role in the lengthening of the life span because of their fundamental character of inhibitors of free radicals.

Animals↗

Naturally labeled 13C-glucose. Metabolic studies in human diabetes and obesity.

The 13C/12C ratio in most commercial preparations of glucose used in clinical investigation is much higher than that of expired air. Variations in expired air 13C, after glucose load, are indicative of the catabolism of this exogenous glucose. The changes in the 13C/12C ratio of CO2 in expired air after oral administration of glucose were determined by mass spectrometry. Results in eleven healthy volunteers and seven obese subjects with normal oral glucose tolerance tests (OGTT) are reported. In all cases, the administration of glucose resulted in a marked rise in the 13C/12C ration of expired CO2, reaching its maximum at the fourth hour and then declining progressively. In seven obese patients with chemical diabetes and in five insulin-dependent diabetics, the 13C/12C ratio of expired CO2 during OGTT was significantly reduced, in comparison with the results obtained from the control groups. This study demonstrates the potential of this procedure using "naturally labeled" 13C glucose for the metabolic studies in man as anticipated from previous studies of Duchesne and his coworkers.

Adolescent↗

Glucose naturally labeled with carbon-13: use for metabolic studies in man.

The ratio of carbon-13 to carbon-12 is much higher in most commerical preparations of glucose used for oral glucose tolerance tests than it is in carbon dioxide in expired air. This recent discovery provided a novel and potentially significant means of studying glucose metabolism. The changes in the ratio of carbon-13 to carbon-12 in carbon dioxide expired after oral glucose administration were determined by mass spectrometry. In six healthy male volunteers, the administration of glucose resulted in a marked, reproducible rise in the isotopic ratio in expired carbon dioxide; the ratio reached its maximum at 4 hours and then declined progressively.

Adult↗