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Biomedical subjects

P Lefebvre

Publications and source records attributed to P Lefebvre.

At least 235 records · Page 13Linked to original sources
PubMed1979

[Associated myasthenia and disseminated lupus erythematosus. A report on two cases and complete review of the published literature (author's transl)].

Two patients aged 47 and 48 years respectively were found to have associated immunity disorders: myasthenia and DLE in the first case, and erythroblastic anemia, myasthenia, a lupus syndrome, and a thymoma in the second case. The association of myasthenia and DLE has been reported 39 times in the published literature (20 times only if stricter biological criteria are applied). The association does not increase the severity of the patient's condition and a thymoma is not present more frequently. Studies on the major histocompatibility complex and lymphocyte levels are still insufficient in this context: the haplotype was HLA A1 B8 in three cases out of seven. The physiopathological data available cannot confirm the possibility of a common pathogenesis in which the thymus and lymphocytes could play a determining role.

Antibodies↗
PubMed1978

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↗
PubMed1977

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↗
PubMed1976

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↗
PubMed1976

Vitamin B 12 and folic acid serum levels in diabetics under various therapeutic regimens.

The aim of the present study was to reconsider the problem of the haematological consequences of biguanide treatment by evaluating serum vitamin B 12 and folic acid levels as well as classical haematological parameters in 30 diabetics treated by metformin. For purpose of comparison, similar evaluations were done in diabetics treated with insulin (27 patients) or sulfonylureas (13 patients). Results indicated that mean serum levels of vitamin B 12 were significantly lower in patients receiving metformin than in both other groups. In the metformin-treated group, five patients had serum levels of vitamin B 12 below 270 pg/ml and five had borderline values. No difference was found in the mean serum folic acid levels between the three groups. Similarly, there were no differences in the red blood cell counts, volumes or haemoglogin concentrations nor in the mean values of serum iron and lacticodeshydrogenase levels between the three groups. Since the haematologic and neurologic complications of vitamin B 12 deficiency may only appear after the deficiency had existed for 10-15 years, the lack of haematological alteration may be explained by the fact that the vitamin B 12 deficiency was not present for a sufficient period of time. We conclude that it may be wise to monitor the haematological values as well as vitamin B 12 levels at regular intervals in diabetic patients treated with metformin so that B 12 hypovitaminosis and its complications can be prevented.

Diabetes Mellitus↗
PubMed1976

Hormones and non-specific humoral factors in the interferences between sodium, glucose and phosphate handling by dog kidney.

Some relationships between renal handling of sodium, glucose and phosphate have been investigated comparatively in dog kidneys studied "in situ", transplanted to the neck vessels of a perfusor animal, or perfused by a pump-oxygenator machine. The results can be summarized as follows: a) The values of tm of glucose per ml of glomerular filtration rate are not significantly different in the presence or in the absence of a perfusor animal, thus ruling out an hormonal modulation. b) An identical curvilinear regression relation between tmG and fractional excretion of sodium is found in the three types of experiments; the response to saline loading is identical; therefore an hormonal control of extrarenal origin is excluded. The differences in the decrease of tm glucose at high or low values of sodium excretion seem best explained by a coupling between glucose transport and one component of sodium transport which should be comparatively less influenced when the impairment of proximal reabsorption is high. c) A competition between glucose and phosphate excretion is observed in the isolated kidney; therefore it depends also at least for some part on intrarenal mechanisms. d) Insulin decreases phosphate clearance by direct renal action, probably by enhancing the tubular reabsorption of this ion as well as of sodium.

Animals↗
PubMed1975

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↗
PubMed1975

[Von Eulenburg's congenital paramyotonia and aptitude for military service. Cases taken from a family with 25 cases since 1789].

The authors present four cases of von Eulenberg's paramyotonia. From the family history it was possible to follow the condition through seven generations since 1780; it confirms the autosomal dominant nature of genetic transmission, with almost complete penetrance. From the clinical standpoint, the condition observed is particularly pure, occurring exclusively in the cold. At no time were paralyses or adynamia independent of the myotonic phenomena and of temperature variations observed. The laboratory investigations carried out, ionic and enzyme, showed no abnormalities. Electromyographic study showed the presence of numerous true myotonic out-bursts, variable in shape and in amplitude, independant of the myotonic phenomenon, and present in the absence of exposure to cold. The effects of the condition on aptitude for military service are examined and in this respects the author recalls that the history of myotonia is intimately bound up with medico-military problems.

Adult↗
PubMed1975

[Acute facial mucormycosis in a diabetic subject. Successful treatment with Amphotericin B].

A 29 year old male, admitted with diabetic keto-acidosis, was found to have rhinocerebral phycomycosis (mucormycosis) involving the left eye and the left hard palate with perforation into the maxillary antrum. Despite late diagnosis, full recovery was obtained following intravenous Amphotericin B (total dose : 3.015 gm in 4 months) and extensive surgery (debridement and unilateral eye enucleation). The circumstances of onset of the disease and its clinical characteristics are discussed; the main features of its management are analyzed.

Adult↗