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Biomedical subjects

M Dolivo

Publications and source records attributed to M Dolivo.

71 records · Page 4Linked to original sources
PubMed1966

The effect of deprivation of glucose on the ultrastructure and function of the superior cervical ganglion of the rat in vitro.

The superior cervical sympathetic ganglion of the rat kept in vitro in a bicarbonate-buffered Krebs' solution retains its capacity for synaptic transmission and axonal conduction during more than 36 hr. After glucose withdrawal, synaptic transmission is lost in 2(1/2) hr and this loss is irreversible; on the other hand, axonal conduction can still be measured on the postganglionic nerve for more than 24 hr after glucose deprivation. Electrophysiological measurements as well as electron microscope studies revealed specific changes at the level of the presynaptic terminal processes, while the ganglion cells and the satellite cells remained relatively unaltered. The presynaptic lesion due to lack of glucose can be prevented by keeping the preparation in vitro at 6 degrees C. This strongly suggests that this lesion results from a major disturbance of the metabolism of the presynaptic fibers.

Animals↗
PubMedDate not supplied

Characterization of two subcellular fractions isolated from myelinated axons.

Myelin and a heavy membrane fraction (1.0/1.2 fraction) were isolated from rabbit white matter by a slight modification of the procedure for bovine CNS. The specific activities of acetylcholinesterase and Na+, K+-ATPase were higher in the 1.0/1.2 fraction than in myelin. In contrast, the cerebroside content and 2'3'-cyclic nucleotide 3'-phosphohydrolase activity in the 1.0/1.2 fraction were 4.5 and 3.4 times lower than in myelin. Total lipids accounted for only 30% of the 1.0/1.2 fracton's dry weight; for myelin, they represented 70%. Polacrylamide gel electrophoresis showed the presence of many high molecular weight proteins and glycoproteins in the 1.0/1.2 fraction but myelin components were practically missing. Cytochrome c oxidase and NADPH-cytochrome c reductase activities suggested about 15% contamination in the 1.0/1.2 fraction but less than 5% for myelin. In electron micrographs of the 1.0/1.2 fraction, there were many membraneous profiles that varied in size, some mitochondrial fragments, and only a few lamellar whorls of compact myelin. The results suggest that the 1.0/1.2 fraction is different from other myelin-related fractions and is probably enriched in axolemma.

Animals↗
PubMedDate not supplied

Sexual behavior and smoking: risk factor for urethritis in men.

Two hundred men who had symptoms of urethritis and 207 controls were interviewed. Because 60% of the men were of foreign nationality, the analysis of risk factors for urethritis was undertaken separately for the French and foreign subpopulations. The risk factors for urethritis were different for the French and foreign men. For the French men who had smoked, the risk of infection was 2.9 times greater than that for men who had never smoked (95% confidence interval, 1.2-7.6), after taking type of sexual behavior into account. There is a significant increase in the risk of urethritis when the amount of tobacco consumed daily increases (P less than 0.02). This finding suggests that smoking is an independent risk factor.

Chlamydia trachomatis↗
PubMedDate not supplied

[Present sensitivity of Neisseria gonorrhoeae in the Paris area. Results of a comparative therapeutic trial].

From September 1978 to September 1979, the Authors determined the M. I. C. of 16 antibiotics against 420 Neisseria gonorrhoeae strains collected in Paris area, with standard gel dilution technic. These strains remain susceptible to the greatest proportion of antibiotics tested, except streptomycin. It has been noted, however, that sensibility of a certain percentage of strains, has decreased for penicillins, cyclins, macrolides. Some strains producing beta-lactamase has been identified. Authors compared results given by the gel dilution method to those given by the diffusion or so-called "disc" method. This shows no correlation between radius of inhibition and M. I. G., with no reliable criteria to estimate the area of inhibition. Also, four protocols for therapy were followed: spectinomycin, ampicillin-probenocid, thiamphenicol, minocyclin. The patients were surveyed by physical examination and bacteriological tests. No statistically significant differences could be noted between these four protocols. However, considering the size of the samples, it is not possible to conclude. The authors reassess the necessity to survey the drug-sensitivity of Neisseria gonorrhoeae strains, in each geographical area, following an internationally agreed method. They also conclude to the necessity to compare in vitro sensitivity tests with therapeutic schemes suggested by usual sensitivity to main antibiotics.

Anti-Bacterial Agents↗