[Etiopathogenesis of non-insulin-dependent diabetes]. / Etiopathogénie du diabète non insulinodépendant.

Two major mechanisms, peripheral insulin resistance and impaired insulin secretion participate concomitantly but to a variable extent to the pathogenesis of non-insulin-dependent diabetes, whose heterogeneity, suspected for a long time, is now confirmed by the recent discoveries of the molecular biology. Mutations of several genes governing key-steps of the recognition of the glucose signal, insulin secretion or its peripheral effect have been found in some particular cases, but presently not at a large scale among non insulin-dependent diabetic patients. The tendency to worsening of the metabolic disturbances with the time, even under adequate therapy, can be explained by the vicious circle of glucose toxicity, but other mechanisms like amylin, responsible of the deposition of amyloid in the islets, may play a role. So, despite the acquisition of many new knowledges, the pathogenesis of non-insulin-dependent diabetes keeps nowadays a part of its mystery.

[Comparative study of the lipid composition of seminal fluid and ovulatory peritoneal fluid in humans]. / Etude comparative de la composition lipidique du liquide séminal et du liquide péritonéal ovulatoire dans l'espèce humaine.

Sperm capacitation is accompanied by changes in the lipid composition of the sperm membrane. The purpose of this study is to compare the lipid composition of the semen with that of peritoneal fluid. These two media have opposite effects on sperm capacitation. Cholesterol, triglyceride and phospholipids were measured in seminal fluid (15 specimens) obtained by sperm centrifugation immediately after liquefaction and in the peritoneal fluid at ovulation (15 specimens) obtained through transvaginal puncture. The lipid composition of these two media is different from that of serum. Seminal fluid is characterized by a high level of phospholipids, 14.79 +/- 3.67 g/l as against 0.53 +/- 0.12 g/l in peritoneal fluid. The level of cholesterol is identical in the two media. The cholesterol/phospholipid ratio is therefore lower in seminal fluid than in peritoneal fluid (0.022/0.79). Lecithins are raised in peritoneal fluid as are sphingomyelins and the phosphatidylethanolamines, which are the most important phospholipids in seminal fluid. It therefore can be postulated that the cholesterol/phospholipid ratio, which is low in seminal fluid, and its richness in sphingomyelin brings about stabilization of the membrane cover which corresponds to a decapacitated state, whereas the cholesterol/phospholipid ratio, which is higher in peritoneal fluid, makes for greater fluidity, and this corresponds to the state of capacitation. These preliminary results obtained from human material do not in any way contradict those obtained from animal studies.