Histamine et métaux cancérigènes

Summary In the case of mineral carcinogenic substances, the relation already established for organic carcinogenic substances with histamine is apparent. Silver, nickel, cobalt, chronium, and berryllium form well-characterized complexes with histamine.     

Relation entre la complexion de l'histamine par les carbures cancérigènes et l'effet solvant

Summary A relationship is observed between the action of certain solvents on cancerogenesis and the affinity of histamine for cancerproducing substances. Tw-type solvents, which increase the tumoral incidence brought about by a chemical substance, intensify the reaction of histamine with this substance; while PEG-type solvents, which retard tumorogenesis, inhibit the reaction.     

Biologie et thermodynamique des phénomènes irréversibles

Summary The thermodynamic study of systems in which stationary (non equilibrium) states were possible, led one of us (I. P.) to a number of general conclusions. In the present paper these conclusions are summarized and briefly discussed from a biological standpoint. It appears that the evolution of such systems is towards states with the least production of entropy (per mass unit) compatible with the conditions imposed. In the case of living matter this corresponds approximately to states of minimum metabolism. During this evolution the entropy contained in the system may decrease whilst the heterogenity increases. But this increase in heterogenity can only take place when there is a decrease in the entropy production, that is an evolution of the metabolism. We are thus led to suggest a physicochemical interpretation of Lamarchism. Finally we call attention to the fact that the moderation principle ofLe Chatelier-Braun is not limited to equilibrium states.     

Inhibition de la cancérogenèse spontanée chez les souris R III et AkR par des implants de tissus cancéreux modifiés

Summary (1) After a 24-h passage in a rabbit, fragments of spontaneous isologous mammary carcinoma were implanted under the skin of young R III females. This procedure was found to prevent the appearance of spontaneous mammary tumours in a high percentage of these animals. The subsequent appearance of carcinoma was to be observed in only 23% of treated animals as compared with 51% in controls.(2) After a 24-h passage in a rabbit, fragments of leukotic isologous tissue, implanted subcutaneously in young AkR females, reduced subsequent spontaneous leukomogenesis from 85 to 38%.     

Sur des œstrogènes dérivés du triphényléthylène

Summary A series of derivatives of triphenylethylene have been tested and some of them found to possess interesting oestrogenic properties; the relations between chemical constitution and oestrogenic activity have been discussed.     

Étude électrophorétique concernant les protéines et les acides nucléiques tissulaires a propos de l'inhibition de la cancérogenèse

Summary Cancerous or leukotic tissue fragments modified by a 24 h subcutaneous implantation in the rabbit, become capable of favouring the inhibition of cancerogenesis.This paper is concerned with the study of proteins and nucleic acids of the so-treated implants.     

Sulfamidés et flavinogenèse chezEremothecium Ashbyii

Summary Different sulphanilamides show an inhibiting action onEremothecium Ashbyii. This effect is marked by a diminution in the formation of flavine, visible already before the decrease of the weight of the culture. Peptones possess a very high anti-sulphanilamide power.     

Sur l'influence de l'aneurine sur la formation des nodosités bactériennes nitrogènes

Summary In certain cases, the production of bacterial nodules on legumes can be influenced by aneurin. The preliminary trials should be continued in order to establish the most favourable conditions of aneurin action.     

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.     

Ibn al-haytham et le théorème de Wilson

Sans résumé Présenté par A.-A. P. Youschkevitsch     

Différence d'activité oestrogène entre l'α-bromotriphényléthylène et un de ses analogues pentadeutérié

Summary The oestrogenic activity of -bromo-,-diphenyl--pentadeuteriophenylethylene is compared with that of the non-deuterated analogue, and found to be significantly lower. No sizeable difference was found between the two compounds as regards their preoestrus-inducing activity.     

Sur les variations stressogènes quantitatives de la sérotonine dans le cerveau

Zusammenfassung Das zerebrale Serotonin unterliegt im Verlaufe eines emotionellen Stress bedeutenden quantitativen Veränderungen. Bei Wildhasen, welche 14 Tage lang Schreckzeichen ausgesetzt waren, vermehrte sich die Menge des Serotonins und erreichte ihr Maximum am 7. Tag. Nachher sinkt die Menge unter den Normalwert, um am Ende der zweiten Woche wieder anzusteigen, wobei sie unter dem Normalwert bleibt.     

Activité inhibitrice de certains α,β,β-triaryléthylènes vis-à-vis des sécrétions anté-hypophysaires

Summary An investigation has been made of the inhibitory effects on the secretions of the anterior pituitary of four ,,-triarylethylenes with weak oestrogenic activity. These substances have been found to vary in the degree to which they inhibit each of the secretions investigated.     

Sur la caractérisation de dérivés guanidiques d'origine biologique par électrophorèse et chromatographie sur papier (chromatoélectrophorèse)

Summary Paper chromatography has been used in conjonction with electrophoresis in a perpendicular direction (chromatoelectrophoresis), in order to characterize various guanidoderivatives of biological interest and also citrulline. The isolation of definite spots can be obtained with a satisfactory selectivity by this procedure, at a higher speed than by bidimensional chromatography; and the use of a few coloured reactions (ninhydrine,Sakaguchi, diacetyle--naphtol andp-dimethylaminobenzaldehyde) on the same electrochromatogram has been successfully practised in this field.     

3ème Journée Suisse de Microscopie Électronique et 9ème Séance annuelle du Comité Suisse d'Optique

Sans résuméInstitut de Physique de l'Université de Genève, le 29 juin 1956.     

Paléontologie et expérimentation

Summary Since the morphogenesis of teeth is ruled by organizers (inductors) the change of position of one of them could have brought about an evolution of the denture such as is found in theCreodontia and Carnivores. Modern techniques of organ cultivation will perhaps solve some other paleontological problems (reappearance of teeth whose germs miscarry, modification of the size of the canines, which would permit us to suppose a certain reversibility).     

Le rôle de l'hétérosis dans la compétition entreebony et son allèle normal

Summary Whereas in homozygous state the geneebony noticeably diminishes the sexual activity of the males, it can on the contrary increase it in heterozygous state; but this heterotic effect depends in a large measure on the direction of the crossing, and also on the genic and cytoplasmic context. It depends moreover on the temperature.The role of this activity in the populations whereebony is made to compete with its normal allel is discussed briefly.     

Détection cytochimique de l'acide ribonucléique dans les chromosphères pré- et post-méiotiques des sporanges de résistance d'Allomyces

Summary Premeiotic chromospheres in the immature resistant sporangia (RS) ofAllomyces lose their basophily after treatment with trichloracetic acid, perchloric acid or ribonuclease. Postmeiotic chromospheres in the mature RS, becoming the nuclear caps of the ‘reduced’ zoospores, do not stain with toluidine blue or pyronine after ribonuclease digestion. It is concluded that, as gametic and zoosporic nuclear caps, pre- and postmeiotic chromospheres are transitory cytoplasmic organites rich in RNA.