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Biomedical subjects

P Lefebvre

Publications and source records attributed to P Lefebvre.

At least 199 records · Page 11Linked to original sources
PubMed1986

[Not Available].

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Academies and Institutes↗
PubMed1986

Enhancement of O6-methylguanine-DNA-methyltransferase activity induced by various treatments in mammalian cells.

The O6-methylguanine-DNA-methyltransferase (methyltransferase) activity was determined in a rat hepatoma cell line after treatment with ultraviolet or gamma-irradiation, heat treatment, or incubation with cis-diamminedichloroplatinum(II),2-methyl-9-hydroxyellipticinium, or bleomycin. The assay measured the removal of O6-methylguanine from 3H-alkylated DNA by cellular extracts. The results show that 48 h after the various treatments, the methyltransferase activity is increased by 2- to 5-fold. This increase is due to de novo specific protein synthesis. It is not related to a modification of the cell cycle parameters, as a similar enhancement is observed in plateau-phase cells treated with ionizing radiations or cis-dichlorodiammineplatinum(II). The increase of the methyltransferase activity measured using an alkylated substrate represents an actual increase of the active molecules in the cells, as the mutation frequency is much lower in cells treated with N-methyl-N'-nitro-N-nitrosoguanidine 48 h after an irradiation (3 Gy) than in nonirradiated cells. This induction of the methyltransferase was not observed in Chinese hamster ovary cells after gamma-irradiation, and therefore it does not seem to occur in cells which have a low constitutive level of O6-methylguanine repair.

Animals↗
PubMed1986

[Amelioration of glucose tolerance and correction of reactive hypoglycemias induced by intravenous calcium infusion cannot be explained by modifications in blood glucagon levels].

Glucagon is not involved in intravenous calcium-induced improvement in glucose tolerance nor in correction of reactive hypoglycemia. Recent investigations have shown that intravenous (IV) calcium infusion improved blood glucose values in patients with moderately impaired glucose tolerance, and suppressed hypoglycemia in patients with isolated reactive hypoglycemia. The aim of this study was to investigate the possibility that these changes were secondary to calcium induced alterations in glucagon (IRG) secretion. Four groups of subjects were studied: group 1: normal controls (n = 7); group 2: patients with isolated hypoglycemia (n = 9); group 3: patients with impaired glucose tolerance without reactive hypoglycemia (n = 9) and group 4: patients with impaired glucose tolerance and reactive hypoglycemia (n = 10). All patients were submitted in randomized order to two 5 hour oral glucose tolerance tests (OGTT, 75 g glucose), during a simultaneous infusion, either of saline or of calcium (calcium gluconate 36.3 mEq/5 h.), starting 30 minutes before the OGTT. In none of the groups did calcium infusion influence basal plasma IRG. In group 1 and 3, oral glucose significantly suppressed IRG, and during IV calcium infusion this suppression disappeared. In group 2, glucose ingestion resulted in a paradoxical increase in IRG both during saline and during calcium infusion. In group 4, oral glucose induced a significant drop in plasma IRG and a rebound rise during hypoglycemia, results which were unaffected by IV calcium infusion. These data suggest that glucagon is not involved in the alterations of blood glucose profiles during OGTT observed during intravenous calcium infusion.

Adult↗
PubMed1986

[Human anisakiasis: 5 cases in northern France].

We report 5 cases of human anisakiasis revealed respectively by an acute intestinal obstruction due to multiple small bowel stenosis, an acute inflammatory ileitis simulating appendicitis, ulcer type epigastralgia, purulent peritonitis and a latent small bowel tumor. Diagnosis was established in 4 cases on microscopic analysis of bowel specimens (eosinophilic granulomas and/or parasitic fragments) and in 1 case at gastroscopy. Serodiagnosis was positive in 2 of 4 cases and the consumption undercooked fishes was found in 4. In small samples we estimated the infestation (1 to 50 parasites) by anisakis larvae of 3 fish species: 80 p. 100 for herrings, 63 p. 100 for mackerels and 100 p. 100 for whitings. This work emphasizes the role of anisakiasis as a source of digestive symptoms and intestinal eosinophilic granuloma.

Adult↗
PubMed1985

[Not Available].

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Global Health↗
PubMed1984

Metabolic availability of glucose ingested 3 h before prolonged exercise in humans.

The aim of the present study was to investigate the extent to which an oral load of glucose ingested 3 h before a 4-h exercise bout of moderate intensity represents an energy source readily available during that exercise. Therefore, five healthy male volunteers drank 100 g of naturally labeled [13C]glucose dissolved in 400 ml of water, rested for 3 h, and then exercised on a treadmill for the next 4 h at about 45% of their individual maximum O2 consumption. Total glucose oxidation was derived from nonprotein respiratory quotient and exogenous glucose oxidation evaluated by the 13C methodology as previously described. Total carbohydrate oxidation averaged 285 +/- 17 g during the 7 h of the test, the global amount of carbohydrate oxidized during the exercising period was 253.1 +/- 16.9 g/4 h. Exogenous glucose oxidation averaged 11.3 +/- 0.7 g during the 3-h period of rest and increased markedly after the beginning of exercise, reaching 18.9 +/- 2.2 g/30 min during the first 30 min of exercise; the total amount of exogenous glucose oxidized during the 4 h of exercise was 67.5 +/- 9.4 g. Throughout the whole period of exercise, blood glucose concentrations remained between 3.5 and 4.0 mmol/l. Exercise induced a major fall in plasma insulin levels that reached undetectable values after 3 and 4 h, whereas plasma glucagon levels tended to rise, but their level never significantly exceeded the basal values; plasma free fatty acids and glycerol increased markedly during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Epidemiology of drug abuse in the French army].

French medical service has carried on an epidemiological study of toxicological conducts for the last ten years. But, in 1982, the number of registered cases has undergone a deflation of 19 p. 100 compared en 1981. Without to jump to conclusions, then, general statistics note an aggravation of these toxicological conducts, such an acknowledgment is hopeful. It would be a sign of nearest decline of endemic toxicomania in our state.

France↗
PubMed1983

[Not Available].

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Equipment and Supplies↗
PubMed1983

[Not Available].

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France↗