Comptes rendus hebdomadaires des seances de l'Academie des sciences. Serie D: Sciences naturelles最新文献

The fluorescent products formed from biogenic amines treated with formaldehyde according to the method of Falck and Owman have been studied in the brain of Crepidula fornicata. The microspectrophotometric analysis of cellular indolamines shows excitation emission maxima at 385--525 nm (serotonine) and catecholamine at 410--475 nm upon HCl treatment catecholamine products show a shift of the excitation peak from 410 to 370 nm (dopamine).

The germination rate of spores of C. difficile which is usually lower than 10(-5) is raised to about 5.10(-3) in presence of lysozyme. All spores are initiated by lysozyme when previously treated by sodium thioglycolate. These spores are indeed lysozyme-dependent for germination.

Analysis at 20 genetic loci by starch gel electrophoresis of a population from Greece shows that contrary to most accepted views, the outdoor Eastern Mediterranean Short-tailed Mouse (i) does not belong to the same species as the House Mouse (Mus musculus), (ii) is not less distant from the Eastern European semi-species of House Mouse (biochemical group 2) than from the Western and Mediterranean European semi-species (group 1), and (iii) is not more closely related to the outdoor Western Mediterranean Short-tailed Mouse Mus spretus (group 3), than to M. musculus. It represents a new biochemical group (group 4) and deserves a species rank (Mus spicilegus).

Application of specific radioimmunoassays to various extracts of the locust showed that nervous tissues and specially the optic lobes contain enkephaline-like material. However these immunoreactive substances present an apparent higher molecular weight (700--1 000 dalton) than those of the controls, as tested by chromatography on Sephadex G 25.

Biological effects of microwaves on experimental trypanosomiase in the Mouse depends on the state of development of the animal. In fact such stimulation needs a mature immune system. Nevertheless, the increasing of the molecular immune response is only one of the aspects of protection mechanisms stimulated by such microwaves.

With the potassium ferricyanide method, the localization of the sites of 3 beta-hydroxysteroid dehydrogenase activity has been investigated in the glandular tissue cells, previously fixed, of the Pleurodeles testis. An abundant copper ferrocyanide precipitate, the final reaction product, is observed in the vicinity of the external faces of the membranes of the smooth endoplasmic reticulum, or in contact with them. A very weak reaction occurs in mitochondrial cristae.

The brain structures specifically involved in harmaline-induced tremor have been identified in the Rat by using the 14C-2-deoxyglucose marking Method. The results obtained in an animal treated with tremogenic doses of harmaline, but immobilized with Faxedil, have been compared with those of another animal, not treated, but submitted to the same experimental procedure. The most specifically marked structure was the inferior olive. Secondarily marked structures were the posterior part of the lateral reticular formation, the caudato-putamen area and the prefrontal and frontal cortex.

Frequencygrams are graphs giving indirect information on the contraction of intrafusal muscle fibres. Frequencygrams of Cat spindle primary endings (flexor hallucis longus, soleus and peroneus brevis muscles) were recorded during repetitive stimulation of dynamic gamma axons exerting type II effects. The features of these frequencygrams (periodic increments whose frequency is equal to that of the stimulation and "driving") show that they can be ascribed to a relatively strong and fast intrafusal contraction. Two interpretations are considered.

On the 20th day of fetal life the cell proliferation is higher in the zona glomerulosa. The fate of marked cells in each cell compartment shows centripetal migration. Their displacement, from the 20th day of pregnancy up to five days post-partum, while at that time the adrenal growth is slowered down, suggests a real migration.

Immunoreactive neurons and fibers were localized in the Rat brain by immunocytochemistry using an anti-ACTH 17-39 antiserum. Neither adrenalectomy nor water deprivation affected intensity of distribution of reaction of labelled neurons whereas colchicine increased labelling of hypothalamic perikarya. These results support the neuronal origin of cerebral ACTH.