La conservation de la vie par le froid

Summary It has been found that, by addition of a certain amount of glycerol, it is possible to store living animal tissues in the frozen state over very long periods of time. The cooling velocity, the temperature of storage and the rate of thawing are important factors. Under the optimal conditions, experiments done on the heart of the chick embryo have shown that complete recovery of the normal physiological activities can be achieved after freezing in liquid nitrogen.     

La synthèse du DNA dans les cellules germinales de l'ovaire de poulet pendant la dernière semaine de la vie embryonnaire

Summary DNA synthesis in the germ cells of the ovary of the chicken embryo during the last week of incubation is studied in vivo and in vitro by tritium autoradiography.     

Notes et documents sur la vie et l'œuvre de René Baire

Sans résumé Présenté par A. P. Youschkevitch     

Influence du sexe,de la carcinogénèse et de la vie en milieu exempt de germe sur la concentration tissulaire en une β-glycoprotéine

Summary We show by quantitative radial diffusion in agarose that a -glycoprotein of tumoral origin present in the lungs, spleen, bone marrow and tumors is present in variable concentrations according to the sex, environment and cycle of experimental tumor development.

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Travail subventionné par l'Institut du Cancer du Canada.     

Étude comparée de la multiplication des cellules germinales à la fin de la première semaine de la vie embryonnaire chez trois espèces de Gallinacés (Gallus domesticus,Meleagris gallopavo,Coturnix coturnix japonica)

Summary Counts were made of the numbers of germ cells in quail embryos aged 4–7 days' incubation. The rate of growth in the population of gonocytes was compared to these of chick and turkey embryos during the same period. The increase is exponential in the three species and the rates are more similar between quail and turkey than between each of them and the chick.     

Action de la capsicine sur la multiplication et la virulence de l'Agrobacterium tumefaciens

Summary It was established that the treatment of liquid cultures ofAgrobacterium tumefaciens with capsicine (in doses of 0.0025–0.01) in the course of 6 h, causes a more abundant and quicker multiplication of the micro-organism and an increase of its virulence, as measured by the method ofBernaerts andDe Ley.     

Ultrastructure de la thyroïde humaine

Summary The ultrastructural changes of the thyroid were studied in Basedow disease and nodular goitre. We observed the important and different changes concerning the ultrastructural pattern of microvillis, secretory droplets, endoplasmatic reticulum and mitochondria. This study throws some light upon human thyroid histophysiology.     

Etude comparée de la composition en oses et en amino-acides de la transferrine et de la lactotransferrine humaines

Summary A comparative study of human lactotransferrin and transferrin has been made with respect to sugar and amino acid composition. The authors conclude that there are significant differences between both types of glycoproteids, which confirm the specificity of lactotransferrin previously demonstrated by physico-chemical and immunological analysis.

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Ce travail a été réalisé grace à une subvention de la Délégation Générale à la Recherche Scientifique et Technique (Contrat 61-FR-170) à laquelle nous adressons nos plus vifs remerciements.

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Avec la collaboration technique de MM.F. Decamps etG. Decroix.

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Avec la collaboration technique de MadameM. P. Louchez et de MesdemoisellesR. Carpentier etM. T. Picque.     

Action de la synthèse protéique sur le transfert de la N-acetylglucosamine dans la muqueuse intestinale de rat

Summary The present report is concerned with an N-acetylglucosaminyltransferase which catalyzes the transfer of N-acetylglucosamine from UDP-N-acetyl-glucosamine to nascent protein chains. This enzyme is localized in a rough microsomes fraction prepared according to the method ofDallner ³.     

Trajectoires et Impasses de la Solution de Schwarzschild

Sans résumé Présenté par J. D. North     

Solubilisation de la monoamineoxydase des mitochondries de foie de rat

Summary The monoamineoxidase of the mitochondria of rat liver may be dissolved up to 50% of the initial activity by treatment with a tensioactive agent followed by ultracentrifugation. The best experimental conditions are obtained with 0.2% of sodium laurylsulphate (pH 7) during 1 h at + 2°C.     

Effets de la 2-mercaptopropionyl-glycine sur la différenciation de l'œuf d'oursin

Summary 2-Mercaptopropionyl-glycine (Thiola) exerted a strong animalizing action on the development of the sea urchin,Paracentrotus lividus. The action of Thiola on the synthesis of superficial and cortical cellular structures newly synthesized during the segmentation is suggested. These changes may alter the circulation of morphogenetic substances between blastomeres.     

Elévation du taux de la corticostérone plasmatique au cours de la surrénalite expérimentale de la souris

Summary Localized lesions of surrenalites may be produced in mice, by one injection of surrenalian heterologous tissue in complete Freund's adjuvant. The titer of plasmatic corticosteron does not decrease but on the contrary increases. These findings may be interpreted as the consequence of the appearance of anti-surrenalian hormone antibodies or of a serous factor stimulating the corticosteron secretion analogous to LATS, seen in Basedow's disease.     

Une combinaison chimique de la fertilisine

Summary The fertilizin of sea-urchins combines with-lipoproteins of mammals sera in the presence of calcium ions. It is suggested that a combination of this type occursin vivo during the sperm-fertilizin interaction.     

Étude de l'activité in vitro de la glycogène phosphorylase de la Carpe (Cyprinus carpio L.)

Summary In this paper we give some values of glycogen phosphorylase activity of heart, red muscle and white muscle from the Carp. We show that in vitro optimum temperature is 25°C for the fish, and not 30°C as in Mammalians. We also made measurements with rat and tench liver, but it has been impossible, under the same experimental conditions, to observe normal release of inorganic phosphorus from G-1-P with carp liver.     

Action du rayonnement X sur la croissance de la plantule d'orge

Summary We have reproduced inHordeum the phenomenon described bySchwartz: absence of proportionality at certain dosages, between the dose of roentgen rays and the biological effect when one irradiates dry seeds and measures the growth of the coleoptile. Cytological analysis shows an enlargement of the epidermic cells of the coleoptiles up to 500.000 r and a decrease of the number of mitosis up to 200.000 r dose at which the mitotic inhibition is nearly complete.The phenomenon described bySchwartz disappears progressively if one waits 3 to 20 days between irradiation and sowing.     

Etude de l'influence de la tension d'O2, de CO2et de l'anaérobiose sur la morphologie et le nombre des colonies de pneumocoque

Summary Cultivation ofStreptococcus pneumoniae is markedly favored by strict anaerobiosis if compared with relative anaerobiosis.

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Remerciements. Je remercie vivement Mme A.M. Schmidt de son assistance technique attentive et de sa collaboration à la rédaction du manuscrit.