Sulfamidés et acides nucléiques

Summary The ribonucleic and thymonucleic acids are antisulphamide forEremothecium Ashbyii and for aSaccharomyces. This effect is due partly to purines, first of all to adenine, but not to any pyrimidines. ForSaccharomyces, the action of adenine is 1/10 of that of PAB acid. The suggestion is made that the bacteriostatic effect of the sulphamide is connected with the nucleic acids of the cytoplasma and the nucleus. Those are studied cytologically with help of the ribonuclease-method ofBrachet. Strong differences appear between the normal cells and the intoxicated ones.     

Etude cytochimique des acides nucléiques dans le cycle germinal de l'Ascaris megalocephala

Ohne Zusammenfassung     

Sur le rôle possible des deux acides nucléiques dans la cellule vivante

Summary According to the writer's theory a great number of different desoxyribonucleic and ribonucleic acids exist in each cell: desoxyribonucleic acids in the nucleus (genes) and ribonucleic acids in the cytoplasm (microsomes). Through catalytic actions the macromolecular desoxyribonucleic acids govern the building of macromolecular ribonucleic acids, and, in turn, these control the production of cytoplasmic enzymes. In truth, the enzymic equipment results simultaneously from the effect of ribonucleic acids (catalytic action) and from the effect of substrates (mass action). This hypothesis explains cellular differentiation (multicellular organism) through constitutional variations of cytoplasmic ribonucleic acids. The writer's fundamental arguments come from the study of bacterial biology, especially from the study of mutations directed by principles of desoxyribonucleic nature.     

La libération des deux acides nucléiques au cours de l'autolyse des bactéries et sa signification

Summary The existence of a process of directed mutation for aBacterium coli through the action of the desoxyribonucleic acid released by anotherBacterium coli during its autolysis raises the question of the behavior of the two sorts of nucleic acids during the autolytic desintegration of the bacterial cell. Working with several germs, we have seen that autolysis releases a nucleoproteidic fraction containing from 20 to 30 per cent of nucleic acid. The desoxyribonucleic acid represents 50 to 70 per cent of the total nucleic acid; this value is very much higher than that of the initial germs, which contain but 20 to 30 per cent. The signification of the easy mobilization of the desoxyribonucleic acid by autolysis is discussed, according to the observations made in usingRobinow's method of nuclear staining.     

Action d'un hépatome ascitique du rat sur les acides nucléiques du pancréas et du rein

Summary Animals having an ascites hepatoma show an increase in the incorporation of P³² into ribonucleic acid and desoxyribonucleic acid of the pancreas, whereas no change is seen in the kidneys. The variations noted in the pancreas may be compared with those observed previously in the liver and the adrenals. It can therefore be presumed that a substance which stimulates biosynthesis or disrupts the normal metabolic balance is produced by the ascites cells.

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Travail effectué avec l'aide matérielle de l'Institut National d'Hygiène.     

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.     

Action d'une dose unique de rayons X,administrée en irradiation totale ou locale,sur les acides nucléiques de la moelle osseuse chez le rat blanc

Summary The biochemical effects on bone marrow of a same dose of X rays (700 r) induced by a total body irradiation or a local irradiation are compared. The ribonucleic acid and the desoxyribonucleic acid of bone marrow show a fall during days 2 to 14 after irradiation, followed by complete recovery on day 21. A significant difference is noted during this period between animals exposed to a total or local irradiation system. The changes consecutive to X rays induced by a total irradiation are prominenter and remain longer than in local irradiation. The direct effect of X rays is probably associated with secondary injury of physiological connexions or other substances affected in total body irradiation.

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

L'effet de la basse température sur l'incorporation de précurseurs des acides nucléiques et des protéines dans les cellules du méristème radiculaire deVicia faba

Summary The uptake of labelled RNA and protein precursors inVicia faba root meristems into nuclei at 4°C is less depressed than in the cytoplasm. Reversion of the normal pattern of incorporation would seem to indicate an inhibition of the RNA transfer from nucleus to cytoplasm.     

Structure moléculaire et activité tuberculostatique dans le groupe des dérivés de la thiourée

Summary A large number of N,N-diarylthioureas and N-aryl-N-pyridylthioureas have been tested forin vitro tuberculostatic activity, and several of them have been found highly active. A series of 1-acyl-4-arylthiosemicarbazides have likewise been investigated, and most of them found to be active at a concentration of 10^–4; this is considered the basic activity corresponding to the molecular grouping -CO-NH-NH-CS-NH-.     

Effets comparés de laβ-propiolactone et du formol sur les propriétés inductrices de l'organisateur chez les amphibiens

Summary -propiolactone-treated dorsal lips ofAmbystoma mexicanum are grafted in the blastocele of young gastrulas. The inducing ability of dorsal lips is not altered. These results are compared with the effects of formaldehyde which suppress the inducing ability. An interpretation of these facts is proposed. The cross-linking reactions which occur between formaldehyde and proteins may be important for the suppressing of the inductive ability by this agent.     

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.     

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.     

Colorants acides et détermination embryonnaire chez les Echinodermes

Summary The effects of three dyes with carboxyl groups are been studied on the developing eggs of the sea urchin,Paracentrotus lividus. Uranin and rose Bengal are both some derivative of the xanthene. Chrome violet CG is a carboxyl derivative of pararosolic acid. In dilute solutions these three dyes induce the development of radial larvae. At higher concentration, uranin and rose Bengal are very effective animalizing agents. Rose Bengal is more active than uranin. Rose Bengal differs from uranin by the fixation of halogens on the molecule of dye which increase the acidity of the carboxyl group. It appears that animalizing activity runs parallel with acidity. The results of these experiments are discussed in relation to the animalizing effects of various acid sulfonated dyes. The possible significance of the combinations between acid dyes and basic components of the cells in the animalization is considered.     

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).     

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.     

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.     

La phosphatase des os et le mécanisme général de l'ossification

Summary A general survey of the actual knowledges on the bone phosphatase is given. The enzyme plays an important rôle in the calcification of bone and teeth, this process being unable to proceed at a physiological speed without the participation of a phosphatase. The biological function of the enzyme is thus to accelerate and not to promote the calcification.The knowledge of the mechanism of phosphatase activity in the skeletal organs and of the chemical composition of the bone salt cannot lead to a full understanding of the physiology of ossification. A prominent function in this field is devoted to the proteins of the ground substance of bone and to their evolution. The study of the protein matrix of bone is now the most important subject of work for the biochemistry of ossification.

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Conférence faite le 28 mai 1946 au Hallerianum de l'Université de Berne.