L'endocrinologie des invertébrés

Sans résumé     

Préparation des sous-unités de la dopamineβ hydroxylase humaine et des anticorps anti-sous-unités

Summary The present study deals with the dissociation of human dopamine hydroxylase (DBH) in subunits with a mol. wt of 79,500, and the preparation of specific antibodies in rabbits. No cross-reactivity was observed between human DBH and antibodies against human DBH subunits.

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Nous remercions Madame M. Le Maout pour son excellente aide technique.

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Ce travail a bénéficié de l'aide de l'INSERM (contrat no 75.4.161.2).     

Cytologie comparée des Muridae. L'origine des Ellobii

Summary (1) The present paper deals with the chromosomial cytology of 11 species and underspecies ofMuridae. (2) The diploïd number being the same (2N=42), there are striking differences between two species ofBandicota, B. indica showing about 20 big metacentric chromosomes which are lackingB. bengalensis. (3)Meriones blackleri is characterized by 72 chromosomes, the species previously described possessing either 44 or 60 elements. (4) The study ofPhenacomys ungava confirms the view that 56 (54) is the primitive number in theMicroti. There is an interesting parallelism between the morphological and the cytological data. (5) A missing link betweenMicroti andEllobii has been found inMicrotus oregoni which possesses 17 chromosomes, its digamety belonging to the typeX-O, X-X. (6) Owing to the fact thatM. oregoni is more fossorial than the otherMicrotus, it is a morphological intermediate betweenMicroti andEllobii. (7) The genusChilotus (Baird) is also fully valid.     

Biosynthèse des hormones stéroïdes

Summary The different pathways of biosynthesis are described, by which steroid hormones are producedin vivo in the gonads, the adrenal cortex and the placenta, orin vitro by corresponding tissue preparations. First of all a short outline of the origin of cholesterol from acetyl coenzyme A through the biological isoprene unit, the pyrophosphate of ³-iso-pentenol, through squalene, lanosterol and zymosterol is given. Partial side-chain degradation of cholesterol, where ACTH plays an important role, leads to pregnenolone and further to progesterone.The latter compounds are the starting material for the other steroid hormones. On the one hand, they are converted in the gonads and adrenals into 17-hydroxy derivatives, in which the side chain is completely removed by enzymes of the said and also of non-endocrine tissues, to form the androgens. Furthermore the adrenals produce their own typical androgens. After hydroxylation of the angular 19-methyl group, androgens are aromatised to estrogens.On the other hand, the adrenal converts progesterone by hydroxylation in 21- and, depending on the case, also in 11- and/or 17-position into the classical adrenocortical hormones. The special feature of an 18-hydroxylation and -dehydrogenation forms part of the biogenesis of aldosterone; a new example is given for the methods used towards its elucidation, consisting in the biosynthetic conversion of progesterone into two virtual intermediates, 18-oxo-progesterone and 21-desoxyaldosterone, which already contain the 18-aldehyde group, characteristic for aldosterone.The regulation of the biogenesis of the different hormones is mentioned and compounds are discussed which block one or other of the biosynthetic steps.

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D'après une conférence faite aux VIes Journées biochimiques latines, Genève (Suisse), 25 mai 1961.

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Publication No. 179Über Steroide. Communication No. 178 voirK. Heusler, P. Wieland etA. Wettstein, Helv. chim. Acta, sous presse.     

Photolyse ultraviolette et photoréactivation des bactéries — Aspects de dépolymérisation et repolymérisation des acides nucléiques bactériens

Summary Electrophoretic analysis of bacterial substance proves the departure, from UV irradiated microbes screened from light for a certain time, of substances which were responsible for increasing the charge density by surface unit during the first moments which follow the irradiation by UV rays. Spectrophotometric analysis of liquids having contained these bacilli proves concommitantly the diffusion of those substances from the bacterial substance to the aqueous phase and reveals their nature. The photoreactivity which is possible during the first moments following the UV irradiation of bacilli, due to the presence of the fragments of depolymerisation of nucleic acid macromolecule in the bacterial substance, becomes impossible after the departure (diffusion) of those fragments to the aqueous phase. These observations seem to show that the phenomenon of photo-reactivity is connected with the repolymerisation of the macromolecule primitively divided of desoxyribonucleic acid.     

Le développement des ovaires des ouvrières des abeilles et l'ectohormone des reines

Zusammenfassung Die vorliegende Arbeit soll die Begriffe der «Fruchtbarkeitssubstanz» und des «hemmenden Ektohormons» näher bestimmen. Nach unserer Ansicht können aktivierende und hemmende Faktoren einander entgegengesetzte Wirkungen haben. Das Vorhandensein einer Fruchtbarkeitssubstanz bzw. eines trophischen Faktors geht aus unseren Versuchen ebenso wie aus denjenigenMüssbichlers hervor; dies steht aber nicht im Gegensatz zur Wirkung des hemmenden Faktors, der aus dem Tegument der Königin gewonnen werden kann. Auf Filterpapier dargeboten lösen diese Tegumentextrakte ein charakteristisches Verhalten der Arbeitsbienen aus (Antennenbewegungen, Strecken des Rüssels). Die Reizung der Antennen, die mit der oralen Aufnahme des Ektohormons verbunden ist, scheint für die Hemmung der Ovarialentwicklung bei Arbeitsbienen notwendig zu sein.     

Le contenu astronomique des Sphériques de Ménélaos

Les Sphériques ont été écrites par Ménélaos sous la forme dun traité dapparence purement mathématique. Cependant, la matière qui y est développée dans les deuxième et troisième livres est étroitement liée à des problèmes rencontrés en astronomie: calcul des coordonnées équatoriales du Soleil, établissement de tables dascensions, étude du mouvement du Soleil dans la sphère oblique, levers simultanés. Ce lien, qui demeure implicite dans le texte, a été mis en évidence par deux mathématiciens et astronomes arabo-musulmans, qui ont exposé la signification astronomique de certains théorèmes des Sphériques. Nous présenterons, commenterons et complèterons cette explicitation en classant les théorèmes concernés en trois groupes: sens de variation de certaines grandeurs sur la sphère, propositions de trigonométrie sphérique et applications, sens de variation de rapports entre certaines grandeurs sur la sphère. The Spherics were written by Menelaos in the form of a purely mathematical treatise. However, the material developed in the second and third book is closely linked to problems met in astronomy: computation of equatorial coordinates of the Sun, setting up of rising-time tables, study of the motion of the Sun in the sphaera obliqua, simultaneous risings. This link, which remains implicit in the text, was clearly displayed by two arabo-islamic mathematicians and astronomers, who expounded the astronomical meaning of some theorems of the Spherics. We describe, comment and complement their explanations, by classifying the implications of the theorems in three groups: direction of variation of some quantities on the sphere, spherical trigonometry and applications, direction of variation of ratios of some quantities on the sphere.Presenté par M. Folkerts(Manuscrit reçu le 23 octobre 2002) Publié en ligne le 5 février 2004An erratum to this article can be found at     

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.     

Limitation de l'emploi des cóupes tissulaires pour l'étude des phénomènes métaboliques

Summary The use of tissues slices for metabolic studies gives results valuable only from the qualitative view-point. The histochemistry of liver slices reveals indeed that there is a disappearance of the basophilia of the inner layers of cells and, consequently, autoradiographic preparations of slices incubated with tagged glycine show that the incorporation of the amino-acid is limited to the outer layers of cells.     

Sur l'inhibition sélective des acétylcholinestérasesin vivo chez le chien

Summary 3318 CT [bis(piperidinométhylcoumaranyl-5) cetone diméthiodide] a compound recently synthesized byA. Funke andK. von Däniken, is shown to be a potent and selective inhibitor, bothin vitro andin vivo, of the blood acetyl-cholinesterase (AcChE) of the dog. It produces acetylcholinomimetic symptoms in the animal and sensitizes different responses to acetylcholine and to stimulation of cholinergic nerves without inhibiting the blood non-specific cholinesterase (XChE). However, the action of 3318 CT appears to be limited, both in nature and in intensity, when compared to that of prostigmine, although the latter substance is a less potent inhibitor of AcChEin vitro than is 3318 CT. This difference is probably related to many factors, one of which may be the fact that prostigmine inhibits not only AcChE but also XChE; and it is not yet ascertained that XChE plays no role at all in the limitation of the effect of the stimulations of cholinergic nerves.     

La question des hétérochromosomes chez les Sauropsidés. Oiseaux

Summary The chromosomes of the fowl were studied with the aid ofMakino's andNishimura's water pretreatment squash technique, modified byMatthey, in embryonic spleen and gonads of both sexes. The number of chromosomes was found to be about 78; the numerical variations are to be ascribed to technical difficulties, caused by the extremely small size of the microchromosomes, rather than to an unchromosomelike behaviour of the latter, as was supposed byNewcomer andBrant. As to the exact number of chromosomes, we consider its determination beyond the possibilities of cytology. The 5^th largest pair of the male, represented by a single element in the female, could be identified as the sex chromosome pair, in accordance with the findings ofYamashina. The digamety might be of theZ-O orZ-W type.     

Adénosine triphosphatase et pyrophosphatase des chloroplastes

Summary ATP hydrolysis and inorganic pyrophosphate hydrolysis in chloroplasts of spinach leaves are characterized by a different pH optimum, a different sensitivity to magnesium ions, top-chloromercuribenzoate and to ageing. It is concluded that ATP and inorganic pyrophosphate are likely hydrolyzed by two different enzymes in chloroplasts.     

Sur l'activité tuberculostatique des N-arylglycinespara-substituées

Summary Several compounds belonging to the group ofpara-substituted N-arylglycines have been found to exhibit pronounced tuberculostatic activityin vitro, but are too toxic for practical application. The relationship between chemical structure and activity is similar to that observed in the group of thiocarbanilides.     

Communications préliminaires sur les chromosomes des Plécoptères

Summary The chromosomal sets of five species ofPerlodidæ (Plecoptera) are given in the present paper. The sexual chromosomes belong to three distinct types:X-O,X ₁-X ₂,X ₁-X ₂-X ₃. The author shows that these three types are likely derived from the most primitive patternX-Y, by translocation and inversion.     

Sur l'interaction de la Protamine avec des protéines sériques

Summary We noticed the formation of a precipitate on adding salmine to dilute aqueous protein solution at pH 6–7. Human and bovine serum albumin, human -globulin, and the perchloro- and sulfosalicylosoluble mucoides do not precipitate in this condition. - and -lipoproteins prepared by floatation and by Sandor's technique gave S-shaped nephelometric titration curves, as did haptoglobin, a mixture of the types Hp II-Hp II and Hp II-Hp I. In sera incubated 24 h at 37°C with protamin, the dextran sulphate test and the cetavlon test show a diminished value for -lipo- and -glucoprotein. Lipoprotein degradation is probably enzymatic in nature.     

Activité staphylostatique de composés du groupe des benzophénarsazines

Summary It is shown that certain compounds belonging to the group of angular benzophenarsazines display a high specific bacteriostatic activity towardsMicrococcus pyogenes var.aureus. This biological property provides a further ground of similarity between these compounds and one of their structural analogues, 3,4–5,6-dibenzocarbazole.     

Les transformations des nucléoides deEscherichia coli déclenchées par les rayons X

Summary In order to obtain further knowledge on the action of radiation on living cells we studied the nuclear transformations ofE. coli after exposure to X-rays. Three different phenomena could be observed; One is producting the polychromosomal form of nucleoids, and is reversible. The second, which is probably a rapid lethal effect, expresses himself by the vesicular form of the nucleoids. The third is only concerned with very high doses. The hypothesis, that the fragmentation of nucleoids may be directly related to induction of lysogenic cells is postulated.     

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.     

La question des hétérochromosomes chez les Sauropsidés. I. Reptiles

Summary In contradiction to some Japanese authors (Oguma, Makino, Nakamura), we are unable to find any difference in the chromosome sets of the male and female ofLacerta vivipara (2N = 36). In a saurian, where the analysis is very easy (Chamaeleon bitaeniatus), there are, without the smallest doubt, 24 chromosomes in both sexes (20M + 4m). The evidence of a female heterogamety in turtles is by no means satisfying.     

L'enregistrement microphotographique des courants d'eau autour d'un cilié

Summary The movement of a liquid medium around a protozoan cell evoked by cilia was registered microphotographically. Bright illuminated particles of emulsion or suspension, photographed in the dark field during a long exposure time, mark a course of the water microstreams.