Etude immuno-électrophorétique de l'uromucoïde

Summary Concentrated normal urines were investigated by an immuno-electrophoretic technique using specific antiserum directed against uromucoid (=Tamm andHorsfall's urinary mucoprotein).A single precipitation line was observed, which, however, presented two distinct maxima. The faster antigen appeared to be situated between albumin and ₁-globulin, while the slower antigen seemed to be ana ₂-globulin. Both antigens were immunologically identical with uromucoid, although the latter had been eliminated by salt precipitation from the urines used in this experiment.The above findings can best be explained by assuming the occurrence of a polymer series of uromucoid, of which the lower members would be soluble in 0.58M NaCl, while the higher terms would representTamm andHorsfall's mucoproteinsensu stricto. It is suggested that cylindroids and nubecula represent visible forms of uromucoid.     

Action des enzymes sur la gonadotropine urinaire de ménopause

Summary The action of various proteolytic and glucidolytic enzymes on the biological potency of Human Menopausal Gonadotropin was studied. Trypsin, chymotrypsin, papaïn and glucosidase attack the gonadotropin only after 6 h of digestion. Carboxypeptidase and RDE produce a rapid inactivation.     

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.     

L'acide borique,inhibiteur de la copulation gamétique chezAllomyces

Summary Addition of a tiny crystal of boric acid to a drop of buffered water containing male and female gametes ofEuallomyces javanicus completely inhibits copulation in this water mold.Pure gametophytic growth can thus be secured by addition of 1/15,000 boric acid to the starch-yeast extract medium.

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Communication annoncée mais non présentée au VIII^e Congrès international de Botanique, Paris 1954.     

Analyses immunoélectrophorétiques des fractions protéiques du sérum humain séparées par électrophorèse en gel d'amidon

Summary Human plasma components, separated by starch gel electrophoresis, are eluted and concentrated by lyophilisation. Immuno-electrophoretic analysis shows that certain of these fractions are immunologically heterogenous. The authors point out that this immunological criterium should be used before employing an eluted fraction, even if it appears electrophoretically homogenous.      

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.     

Analyse expérimentale de la différenciation embryonnaire chez les échinodermes

Sans résumé     

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.     

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).     

Dosage de la streptomycine par la méthode des dilutions appliquée àKlebsiella pneumoniœ No 41 en milieu synthétique de Monod

Zusammenfassung Klebsiella pneumoniae Nr. 41 wird in einem leicht alkalischen, synthetischen Medium mit Zusatz von Saccharose und einem Indikator (z. B. Kresolrot) wachsen gelassen. Durch Spaltung des Zuckers wird die Reaktion nach der sauren Seite verschoben. Das bei einer bestimmten Streptomycin-Konzentration eben noch stattfindende Wachstum derKlebsiella kann nach etwa 2 Stunden am Umschlag des Indikators erkannt werden.     

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.     

La spécificité de la réaction de Feulgen pour la détection de l'acide thymonucléique

Summary A number of experiments all led to the conclusion that the Feulgen reaction is a valuable test for thein situ localization of thymonucleic acid: there is thus no serious reason to doubt that this acid is a constituent of chromatin and chromosomes.     

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.     

Importance des modifications de la glycémie dans la régulation de la vitesse d'absorption de solutions de glucose de différentes concentrations chez l'animal intact

Summary In intact guinea-pigs fed with glucose solutions of different concentrations, the main limiting factor of absorption is not the gastric emptying but the hyperglycaemia.     

Sur l'origine d'asymétries particulières dans les diagrammes électrophorétiques de solutions de grande viscosité

Summary When electrophoretic studies are made on protein solutions of high viscosity, the beam of light used in the « Schieren » scanning method is partially reflected by the very sharp boundaries which leads to very asymmetric pictures taken by theTiselius-Longsworth method.     

Cinétique de l'inhibition de l'oxydation cuprique de l'acide ascorbique par certains complexants

Summary The authors studied the kinetics of the inhibition of the copper-catalysed oxydation of ascorbic acid by versene and some proteins. The versene-inhibition attains slowly the theoretical value, when added after the Cu⁺⁺ to ascorbic acid. Proteins inhibit non-competitively and completely, when added to the vitamine either after or before the copper. This result may be interpreted as indicating an interaction between protein and the complex (AH-Cu⁺⁺).

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Note N^o 2 sur l'oxydation cuprique de l'acide ascorbique. Note N^o 1, voir réf.³.     

Microméthode potentiométrique pour la détermination de la cholinestérase

Sans résumé     

Microméthode potentiométrique pour la détermination de la cholinestérase

Summary A simple very sensitive and usefull method is described for the potentiometric micro-determination of the cholinesterase of blood serum, globules and tissues, using an ordinary potentiometer and an antimonium electrode. This method makes it possible to determine the cholinesterase in solutions of acetylcholine down to 3 mg %.