Modifications de l'excitabilité des centres vasopresseurs hypothalamiques par des injections locales de catécholamines

Summary The blood pressure is not disturbed by a local injection of norepinephrine into the hypothalamus, but the excitability of vasopressor centres is affected. Often, the excitability of these centres is decreased; sometimes, it is increased, and, more rarely, it is first potentiated and then inhibited. Epinephrine has the same action, but dopamine is less potent; isoprenaline produces both facilitation and inhibition of these centres, but the facilitating effect is more frequent than with norepinephrine.     

Principes généraux de la magnétochimie,ses applications à l'étude des structures

Summary This article presents the general principles of magnetochemistry, its methods and the results to which it leads. Firstly, the definitions of magnetic units of isotropic substances are defined. Then the main apparatus for measuring magnetic susceptibilities is indicated.The notion of a magneto-chemical system is developed and its use in the study of molecular structure is shown. Finally, the author shows how magnetochemistry has been used to study the electronic delocalisation in aromatic molecules, and the concomitance existing between this delocalization and the biological properties of certain substances, such as their mitotic and carcinogenic activities.     

Animalisation de l'œuf de l'oursinParacentrotus lividus par des substances polysulfoniques

Summary The effects of two compounds with sulfonic acid groups, chlorazol sky blue and Germanin (Bayer 205), are being studied on the developing egg of the sea urchin,Paracentrotus lividus. The chlorazol sky blue (1/5000) is a very effective animalizing agent. In dilute solutions (1/25000 and 1/100000), it induces the development of radial larvae. The lithium chloride counteracts the animalizing effects of chlorazol sky blue. The Germanin has an animalizing effect only at high concentrations. The penetration of these agents appears essential for the animalization. The reaction of the sulfonic acid groups with the basic groups of the intracellular proteins appears to be concerned with the animalizing effect. The results of these experiments are discussed in relation to the animalizing effects of various sulfonated dyes and zinc ions.     

Mesure de l'oxydation phosphorylante à l'aide de phosphore radioactif dans la cellule hépatique

Summary We have briefly described an apparatus which permits us to register quantitatively different substances labelled with radioactive isotopes, formerly separated by paper chromatography. We were able to show by the Krebs' method, thus simplified, that the oxidative resynthesis of ATP is diminished in the hepatic homogenates of rats during a beri-beri crisis.     

Recherches sur la fraction Y des protéines de muscles de Lapin

Summary The proteinic material corresponding toDubuisson's electrophoretic gradient has been prepared by a new method. This fraction migrates as a single peak in the U-tube, but is heterogeneous in the ultra-centrifugation.     

Observation et étude quantitative de corpuscules d'aspect virusal dans des cultures de sarcome de Rous

Zusammenfassung In vitro gezüchtete Zellen des Rous'schen Sarkoms wurden der Wirkung von Röntgenstrahlen und radioaktivem Alkohol (CH₃C¹⁴H₂OH) ausgesetzt und darauf elektronenoptisch untersucht. In einem geringen Prozentsatz der untersuchten Kulturen (9,5%) konnten virusartige Partikelchen von 60 bis 90 mµ Durchmesser intra- oder extrazellulär dargestellt werden, die mit den vonClaude, Porter undPickels gefundenen identisch sind und wahrscheinlich dem Rousschen Virus zugeordnet werden können. Es wurden Kolonien von solchen Gebilden intrazytoplasmatisch in Form von Einschlusskörperchen beobachtet. Auch unbestrahlte Kontrollen von Sarkomzellen wiesen Viruskörperchen auf, wenn auch bisher in geringerem Prozentsatz.Es ist vorderhand noch unsicher, ob der Bestrahlung eine primäre Rolle in der Darstellbarkeit dieser Viren zukommt.     

Age des halos pléochroïques de la granodiorite de Lausitz

Summary By a quantitative study of pleochroic haloes in biotite, the haloe age of the Lausitz granodiorite, in comparison with the granite age of the Elba Isle, was estimated to 280±150 M.Y. The granodiorite is either caledonian or hercynian.

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Attachée à l'Institut Interuniversitaire des Sciences Nucléaires.     

Injection à des souris nouveau-nées de cellules hématopoiétïques homologues de donneurs adultes ou embryonnaires. Fréquence de la greffe érythroblastique et de la «Runt Disease»

Summary The endoveinous injection to newborn mice of homologous hemafopoietic cells either adult or embryonnic, may result in a lasting and functional graft.The former statement can be demonstrated by use of starch gel electrophoresis which shows the specific hemoglobin of the donors.In both uses this graft can induce a runt disease.     

Correction des erreurs de mesure en microphotométrie

Summary The author deals with the errors occurring in microphotometric measurements and their correction. Even in measurements for comparative purposes, they are inavoidable.     

Etude de l'activité adénosinetriphosphatasique et hexokinasique de cristallins de lapins soumis à une irradiation locale par les rayons X

Summary The irradiation of the lens by a simple dose of 1400 r, gives a very important and lasting reduction of its hexokinase activity. Its ATPase activity shows an increase during the first four days and a return to normal again. The variations observed here (that isin vivo) are different from the ones noted after irradiation of these enzymesin vitro.

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Travail effectué avec le concours matériel de l'Institut National d'Hygiène.     

Age des halos pléochroïques de quelques granites tertiaires de la Toscane

Riassunto Sono stati studiati gli aloni dei graniti delle isole di Montecristo e del Giglio (arcipelago toscano) e del continente (Gavorrano).Tale studio ha permesso di dimostrare che il loro consolidamento è avvenuto in momenti diversi la cui successione ripete quella dei corrugamenti appenninici. Le età di tali graniti, comparate a quella dell'Elba (Monte Capanne), sono nel seguente ordine:Elba = Montecristo > Giglio > Gavorrano.I singoli stadi sono largamente spaziati nel tempo e gli intervalli sono risultati dell'ordine di circa dieci millioni di anni.

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Attachée à l'Institut Interuniversitaire des Sciences Nucléaires.

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Comitato Nazionale per le Ricerche Nucleari.     

Variations de l'activité des auxines-oxydases dans les racines duLens

Summary 2, 4-dichlorophenol (DCP), 2, 4-dinitrophenol (DNP) and 2, 4-dinitro-o-cresol (DNC) applied at a concentration of 1.10^–7 to 1.10^–3 M, produce a dramatic increase in IAA-oxidase activity in young cells ofLens root. IAA destruction by breis from root tissues was inhibited by Mn⁺⁺ ion at low concentrations of DCP (1·10^– to 1.10^–7 M), but was enhanced by Mn⁺⁺ ion at higher (1.10^–5 to 1.10^–3 M) DCP levels.

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Ce travail a pu être entreprise grâce à l'appui duFonds national suisse pour la Recherche scientifique.     

Appareil pour la mesure de la consommation d'oxygène des petits animaux de laboratoire

Summary An apparatus has been described for measuring oxygen consumption in small animals. In this apparatus, the temperature changes are very small, the determinations of oxygen consumption are rapid and frequent, the oxygen tension is normal and the animals are in a good state of quietness.     

Séparation par chromatographie sur papier des 21 sulfates de corticostéroïdes

Summary The 21-sulfates of the six following corticosteroids: desoxycorticosterone (DOC), corticosterone (B), 11-dehydrocorticosterone (A), cortisol (F), cortisone (E), and 17 hydroxy-11-desoxycorticosterone (S), were prepared. Their separation by four different paper chromatographic systems was investigated. A method for detection of the spots is described.     

Application de l'analyse discriminante à l'étude des différences anthropométriques selon les groupes sanguins du système ABO

Summary Anthropological measurements on 193 Swiss recruits have been studied using discriminatory analysis. Out of the 9 characters measured on each individual, 3 were chosen to ascertain whether differences between the ABO blood groups exist. Discriminatory analysis gives a simultaneous evaluation of the differences of the 3 measurements. They are found not to be significant.     

Étude cytochimique des groupes sulfhydriles au cours des modifications de la détermination embryonnaire chez l'œuf de l'oursinParacentrotus lividus

Summary A cytochemical study of the distribution of sulfhydryl groups in animalized and vegetalized embryos of the sea-urchinParacentrotus lividus has been made by use of the Bennett's reagent. The distribution of the sulfhydryl groups appears homogeneous in these embryos. No gradient has been observed in the experimental conditions used.