Effet inhibiteur de la tétrabénazine sur l'influence corticosurrénalienne de la réserpine

Summary Reserpine provokes an intense and long-lasting (more than 20 h) stimulation of the adrenocortical activity of the rat. Tetrabenazin (50 mg/kg) also produces an adrenocortical stimulation which is, however, of a much shorter duration. The injection of tetrabenazin 1 h before the injection of reserpine (5 mg/kg) prevents the prolonged stimulating effect of reserpine on the adrenal cortex. This effect can be compared with the blocking effect of tetrabenazin, a short-acting central depressant with monoamine-liberator properties, against the prolonged central sedative influence of reserpine.     

Influence de laβ-mercaptoéthylamine sur la réponse de l'intestin grêle du rat à une irradiation rœntgénienne localisée

Summary Intra-peritoneal injections of 15 mg of B-mercaptoethylamine in rats, with an average weight of 200 g, protect the small intestine against a local irradiation of 500 r on the antero-upper portion of the abdomen.This protection is proved mainly, as compared with the control, by a smaller decrease of cells still in mitosis after 12 and 24 hours and of the migrant cells in resting stage, by a greater precocity and higher quantitative value of the post-radiation normal and subnormal mitotic processes, and by variations in the mitotic formula (namely, in protected animals, a relatively high increase in the amount of metaphases).These experiments seem to prove a certain local and immediate action of the radio-protector, whose effects are not solely limited to the preparation of the generating system of the intestine for the later complete repair of the digestive epithelium.

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(Travail du Centre anticancéreux de l'Université de Liège et du Centre national belge pour l'étude de la croissance normale et pathologique).     

Recherches sur le mécanisme de la rétraction du caillot et de la métamorphose visqueuse des plaquettes

Summary The concept, that viscous metamorphosis of platelets and clot retraction is initiated by thrombin and a dialyzable factor was confirmed. Under certain circumstances glucose acts as dialyzable factor. Clot retraction seems to depend upon the catabolism of glucose.     

Conséquences de la thymectomie sur la formule leucocytaire chez le cobaye

Summary In infantile guinea pigs, thymectomy determined a decrease of the leucocyte count in the circulating blood, resulting essentially from the decreased number of lymphocytes.Eosinophiles increased noticeably in the same animals.Thus the consequences of thymectomy were proved to be exactly opposite to those of administration of thymus extract as described in a previous publication.     

Sur le rôle de la sélection sexuellen dans l'évolution

Zusammenfassung Von Darwins Theorie der geschlechtlichen Zuchtwahl ausgehend werden einige Resultate experimenteller Forschung dargestellt, die auf neue Aspekte dieser Frage hinweisen. Es wird der qualitative Unterschied zwischen interspezifischer und intraspezifischer geschlechtlicher Zuchtwahl aufgezeigt. Die erstere hindert den Genaustausch zwischen den Arten, die letztere dagegen führt zu einem optimalen Genaustausch innerhalb einer Art. Es werden die Rolle der Weibchen und Männchen, der selektive Wert des Wildtypus verglichen mit Mutanten und die genetische Basis der Aktivität der Männchen diskutiert.     

Activitéin vivo de dérivés de la thiourée contre le virus de l'influenza

Summary A large number of sulphur-containing compounds bearing the thiourea group -NH-CS-NH-, including substituted thiocarbanilides, 1-acyl-4-arylthiosemicar-bazides, 1-(arylaminothioformyl)-thiosemicarbazides, 4-aryl-1-(arylaminothioformyl)- thiosemicarbazides, and other related substances have been tested for potential antiviral activity. Several of these compounds have been found chemotherapeutically active against influenza virus.

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Communication présentée au Congrès international de Chimie pure et appliquée de Zürich (Juillet 1955).     

Considérations cliniques sur le rôle des hémines

Sans résuméConférence principale, présentée à la Société suisse de biologie médicale lors de la 127^e Assemblée générale de la Société helvétique des sciences naturelles à Genève, le 31 août 1947.     

Action de l'orientation et de la qualité de la lumière sur le développement des protonémas de Bryales

Summary The radiations coming from Blanc Brillant de Luxe' fluorescent stimulate the growth and ramification of protonema ofCeratodon purpureus (Hedw.) Brid. This stimulation is caused by red light (660 nm). Multidirectional lightening is more favorable than unidirectional exposition.     

Action répressive de l'oxygène sur la biosynthèse de la fumarique-réductase d'Aerobacter aerogenes

Summary The cells obtained from anaerobic cultures ofA. aerogenes contain both a hydrogenase and a fumaric reductase, but lack one or several electron transporters necessary for the coupling of the two enzymes. It is possible to measure the fumaric reductase activity of the extracts in the presence of hydrogen, hydrogenase and benzyl viologen, using the Warburg manometric technique. In anaerobic cultures the reductase is an inducible enzyme. In aerobic cultures its formation is strongly repressed by atmospheric oxygen.     

Activation de la phosphatase acide par l'acide β-indolylacétique et ses répercussions sur la phosphorolyse de l'amidon

Summary IAA-induced activation of purified acid phosphatase is reported and shown to determine an acceleration of phosphorolysis of starch.     

Effets de l'actinomycine D sur le développement normal et sur les modifications expérimentales de la morphogénèse de l'oeuf de l'oursinParacentrotus lividus

Summary In the presence of actinomycin D (20–40 µg/ml), the development of the eggs of the sea urchin,Paracentrotus lividus, is slowed from the late morula and stopped at the blastula stage. The development is immediately stopped in the blastula treated with actinomycin D (20–40 µg/ml). The inhibitory effects of actinomycin D are prevented by deoxyribonucleic acid. Actinomycin D does not exert animalizing or vegetalizing effects. However, the enhancing of vegetalizing action of lithium and the weakening of animalizing effects of zinc ions and Evans blue have been observed in the presence of actinomycin D. These observations may reflect some difference in the state of dependence of differentiation of entomesodermic and ectodermic structures towards the nucleus.     

Effets de la réserpine sur le développement d'Oedipoda coerulescens L. (Acridien,Orthoptère)

Summary Inhibitory effects of reserpine on ecdysis and chromatic adaptation inOedipoda appear to be linked with changes observed in both neural and neuro-endocrine regulating systems.     

De la réaction mitotique de l'épiderme de la tétine de cobaye à la suite d'applications répétées de diverses substances

Summary (1) The majority of substances tested produced a weaker mitotic reaction of the epidermis of the guinea pig nipple after 3 applications (24 h intervals) of the same substance than after a single application.(2) This decrease in the ability of the epidermic cells to be divided has to be attributed, it seems, to a habit-forming processus and not to an exhaustion of the cells; indeed after two applications of geraniol, the application of a substance of different nature, Hormoestrol, produced in the nipple epidermis a mitotic flare up as intense as that obtained in the epidermis of a nipple not previously treated.(3) Aldehyde C₉ alone, among the substances tested, does not produce a decrease of epidermic mitoses after three applications but induces cellular alterations.     

Pharmacodynamie de la circulation cérébrale

Sans résuméRelation présentée au XXI^e Congrès International des Sciences Physiologiques, Buenos Aires, 9–15 août 1959.     

Action de la triéthylènemélamie sur les mitoses de segmentation de l'œuf de Pleurodèle

Summary Triethylenemelamine (1/400 to 1/12000) induces pseudo-chiasmas and chromosome-breakage in the egg-segmentation mitoses ofPleurodeles waltlii Michah. The primitive effect is stickiness, breakages appear subsequently, but without an interval of time between: the primary physiological and the secondary genetical effect cannot be separated. There are points of breakability, which explains the symmetry of certain fragments. The action is inverted in the epidermal cells of the larvae, where spindle alterations are prominent. Cytodieresis is never inhibited.     

Observations expérimentales sur l'apnée acapnique chez le Chien

Summary Suppression of the chemo-receptors of the carotid sinus and aorta æreas prolongs the acapnic apnea markedly. Animals deprived of their chemo-receptors may even die in apnea.During hyperventilation, the expiratory position of the thorax increases. During the acapnic apnea the inspiratory position returns progressively to normal. During hyperventilation and acapnic apnea, rhythmic changes occur in the tonus of the respiratory muscles. These changes in tonus occur in normal animals as well as in animals deprived of their chemo-receptors and vagi nerves.In normal dogs, hyperventilation and acapnea do not induce a fall in arterial blood pressure. Arterial hypotension occurs, however, during hyperventilation in dogs deprived of their carotid sinus and aortic innervation. During acapnic apnea, the arterial blood pressure rises in animals deprived of their carotid sinus and aortic nerves. A secondary fall of arterial pressure occurs during prolonged acapnic apnea in these animals.