Comptes rendus des seances de l'Academie des sciences. Serie III, Sciences de la vie最新文献

Effects of two halogenated acetamides (chloroacetamide-iodoacetamide) and of three chlorinated volatile solvents on the ethane-pentane test, as an index of in vivo lipid peroxidation have been studied. Chloroacetamide stimulates alcanes production. Iodoacetamide acts only on pentane exhalation. The three chlorinated solvents seem to induce moderate lipoperoxidation, and the apparent increase of hydrocarbons might also result from decreased metabolism.

Parathyroid glands from patients in chronic haemodialysis and with secondary hyperparathyroidism have been studied by electron probe X ray microanalysis and analytical ion microscopy. Aluminium associated with phosphorus has been detected in phagolysosomes of parathyroid cells (chief cells and oxyphil cells).

The existence of UDP-galactose:galactosyltransferase activities at the external surface of cultured neurons from chick embryo hemispheres, was demonstrated. [14C]-galactose was transferred upon cellular substrates present on the neuronal surface and upon exogenous substrates (ovomucoïd) bound to Sepharose beads. The activity of ectogalactosyltransferase was not due to a leakage of intracellular enzymes into the incubation medium nor to an intracellular enzymatic activity utilizing [14C]-galactose obtained from the hydrolysis of UDP-[14C]-galactose. Kinetics of these ectogalactosyltransferases were analysed. The results support the hypothesis of a communication and/or interaction among the nerve cell surfaces via glycoconjugates or their biosynthetic enzymes.

Somatocrinin (hp-GRF-44), a growth hormone releasing factor, stimulates acute pituitary response in a 11 years and 4 months old boy, with growth hormone deficiency. The capability of the anterior pituitary to secrete growth hormone in response to an IV injection of somatocrinin (120 micrograms 4 micrograms/kg) was documented, therefore proving the hypothalamic origin of the deficit which had been suspected because of association of diabetes insipidus and hyperprolactinemia.

The common marine Mussel Mytilus edulis, present in an uranium containing sea water at trace level, is shown to concentrate the radionuclide which is detected, with high values, in the digestive gland lysosomes and in the kidney spherocrystals. Within both of these target organelles, uranium is always associated with high phosphorus contents, with which low iron, sulfur, zinc and copper contents may be found. Thus, soluble uranium which was absorbed is then concentrated in the form of an insoluble phosphate in the storage organelles.

Estradiol 17 beta concentration and cytoplasmic estradiol binding sites were determined in the magnum of immature and developing female Quail. In the immature magnum, estradiol concentration per gram of tissue was 26 times higher than in the plasma. Early sexual development was correlated with an increase in plasma and magnum concentrations of estradiol and of cytoplasmic binding sites in the magnum. However, the ratio of binding sites concentration to that of intra-tissue of estradiol, and the intracellular distribution of estradiol (cytoplasm versus nucleus) were similar in immature and developing Quail. The results indicate that the presence of estradiol and of binding sites in the target cells of the magnum are not sufficient to induce cell proliferation.

The analysis of acoustic signals, in the loud calls of the subadult male, with Gibbons (H. concolor gabriellae) shows several progressive modifications between the calls of the juvenile and those of the adult male. All the characteristics of antiphonal duos are not integrated at the same rate within the call of the adult male.

238U+ was detected in Mytilus edulis collected from the Pas-de-Calais and the Baie de Seine. Storage organs were mantle, digestive gland, intestine epithelium and gonad where the highest values occurred. Uranium uptake happened via gill and digestive tractus, and excretion via kidney. Hemocytes played an important part in uptake, storage and excretion of the metal. M. edulis which was shown to concentrate the radionuclide from the marine environment where the metal exists at trace level, is then proposed as an uranium pollution indicator organism.