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Biomedical subjects

M Beaudoin

Publications and source records attributed to M Beaudoin.

At least 37 records · Page 2Linked to original sources
PubMed1989

Hippocampal damage induced by ischemia and intra-amygdaloid kainate injection: effect on N-methyl-D-aspartate, N-(1-[2-thienyl]cyclohexyl)piperidine and glycine binding sites.

The N-methyl-D-aspartate receptor channel-complex is widely distributed in the hippocampus, particularly in the CA1 region, in the terminal field of CA3 pyramidal axons and in the fascia dentata, in the terminal field of the perforant pathway. In the present study, we have examined, in the rat, the effect of specific lesions of various neuronal populations of the hippocampus on the distribution of several markers of the N-methyl-D-aspartate receptor-channel complex. Anoxic-ischemic treatment produced a destruction of CA1 pyramidal cells (postsynaptic element): this was associated with a 50% loss of N-methyl-D-aspartate, glycine and N-(1-phenylcyclohexyl)piperidine binding sites. In contrast, the destruction of CA3 pyramidal cells and their axons (presynaptic element) by kainate treatment did not induce significant changes in the density of binding sites. The present results therefore strongly support an exclusively postsynaptic localization of the N-methyl-D-aspartate receptor-channel complex in CA1; the possibility of a localization of the remaining binding sites on glial cells or interneurons is discussed. In the molecular layer of the fascia dentata, the anoxic-ischemic treatment produced a partial destruction of the median perforant pathway (presynaptic element) associated with a decrease in the density of N-methyl-D-aspartate, N-(1-[2-thienyl]cyclohexyl)piperidine and glycine binding sites; this suggests that, in contrast to CA1, in the molecular layer of the fascia dentata, N-methyl-D-aspartate receptor-binding sites are located both pre- and postsynaptically.

Amygdala↗
PubMed1983

[Predictive value of preoperative acidity tests in ulcer recurrence after supraselective vagotomy].

The authors have analysed the predictive value of the basal and peak gastric acidity levels, measured preoperatively, in a series of 27 supraselective vagotomies. They recommend care in the choice of this operation for hypersecretors and they propose criteria for the preoperative selection of the candidates. They suggest determination of the preoperative basal gastric acidity level and a cimetidine suppression test to identify patients at high risk for recurrence of the ulcer.

Adult↗
PubMed1981

[Bacteroides fragilis. Maternal-placental and foetal contamination (author's transl)].

In order to study the maternal-placental and foetal contamination, cytologic study and aerobic-anaerobic cultures were performed on 1 000 placentae of infants who were referred to the Intensive Care Unit. Bacteroides were isolated from 30 specimens, and on smears, Gram negative bacteria were found on 11 of these cases. Only in 2 infants Bacteroides were isolated from blood, gastric aspirate and meconium; 20 infants were said to be infected on clinical and biological bases; eight were normal. Bacteroides infection is usually benign; the symptoms are not specific; the diagnosis is often delayed and the treatment uneasy. Nowadays, Carbenicillin, Ticarcilin, Cefoxin or Metronidazole are advised, according to the sensibility of the organism.

Anti-Bacterial Agents↗
PubMed1980

[Clostridium perfringens infection and necrotising enterocolitis].

During a four year period (1974--1977) 21 infants died as a result of severe necrotising enterocolitis (N.E.C.). In 9 cases, Clostridium perfringens was isolated. When this organism is recovered either from the placenta or from the first meconium and or when the signs of the disease appear within a few days of birth, materno-fetal transmission of the infection may be suspected. The infection occurs most frequently in neonates in whom the gastrointestinal tract was already colonized by Clostridium.

Clostridium Infections↗
PubMed1975

Effects of taurodihydrofusidate, a bile salt analogue, on bile formation and biliary lipid secretion in the rhesus monkey.

Bile salts play a major role in bile formation and biliary lipid secretion. Sodium taurodihydrofusidate (TDHF), a derivative of the antibiotic fusidic acid, closely resembles bile salts in terms of structure, micellar characteristics, and capacity ot solubilize otherwise insolbule lipids. We have therefore studied the biliary secretion of this bile salt analogue and its influence on bile formation and biliary lipid secretion in primates. Alert, unanesthetized female rhesus monkeys prepared with a total biliary fistula were allowed to reach a steady bile salt secretion rate before each study. In three animals (group I),[14C]TDHF was infused intravenously. Most of the compound was secreted rapidly in bile chemically unchanged. The biliary secretion of this drug produced a twofold increase in bile flow; however, the bile salt output was markedly reduced during the infusion. In spite of this reduction, the phospholipid output remained essentially unchanged whereas the cholesterol output increased almost twofold. In five other animals (group II), the effect of TDHF on the bile salt secretion was further investigated by an intravenous infusion of [14C]taurocholate followed by a combined infusion of [14C]taurocholate and TDHF. When TDHF was added to the infusate, a reduction in the [14C]taurocholate output and a progressive rise in the plasma [14C]taurocholate concentration were observed in each animal. An analysis of the data in both groups indicates that (a) the most likely explanation to account for the decreased bile salt output is that the bile salt analogue, TDHF, interfered with bile salt secretion into the biliary canaliculi; (b) TDHF induces a greater secretion of biliary water than was observed with bile salts, an effect consistent with a stimulation of the bile salt-independent canalicular flow; (c) at similar 3alpha-hydroxysteroid secretion rates TDHF caused a significant increase in cholesterol secretion compared to that induced by bile salt. This finding suggests that TDHF affects cholesterol metabolism or secretion in a way distinct from bile salts. Thus, the solubilization of biliary lipids in mixed micelles, although essential, is only one of the factors which determine their secretion into bile.

Animals↗