Existence de sels biliaires et de cérébrosides associés à des protéines chezMoniezia expansa

Sans résumé     

Mesure de l'oxydation phosphorylante à l'aide de phosphore radioactif dans la cellule hépatique

Summary We have briefly described an apparatus which permits us to register quantitatively different substances labelled with radioactive isotopes, formerly separated by paper chromatography. We were able to show by the Krebs' method, thus simplified, that the oxidative resynthesis of ATP is diminished in the hepatic homogenates of rats during a beri-beri crisis.     

Etude photophysique de la ptérobiline

Summary The first results of a photophysical study on pterobilin (biliverdin IX , a Lepidopter blue bile pigment) are presented. From the absorption and fluorescence spectra, it is deduced that the low yield of fluorescence indicates a desactivation of the excited singlet state occurring mainly by a non-radiative process. Analyses of the chemical compounds formed after irradiation of pterobilin in methanol show that it is rearranged into a series of new blue pigments among which phorcabilin and sarpedobilin (the two neobiliverdins IX isolated from Lepidopters) have been identified.

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Remerciements. Nous remercions le ProfesseurJ. Bergerard pour son intérêt. Ces recherches ont été réalisées dans le cadre de l'ATP CNRS No. 4699-10.     

Etude de la consommation d'oxygène et de la teneur en acide désoxyribonucléique du foie à divers âges chez le rat

Summary The quantitative study of whole liver DNA and liver nuclei DNA at various ages, and the simultaneous study of oxygen uptake shows the following facts:(1) The rate of oxygen consumption to the fresh weight or to the DNA or to diploid chromosomes group is the same for the adult or the young aged 8 days. The values of oxygen consumption calculated for one cell or for one nucleus (taking notice of the fact that the mean level of liver nuclei DNA varies with the age) at 8 days is only the half of the adult value. Even at two months the value is 20% lower than in the adult.(2) In older animals there is a decrease of oxygen uptake which is more noticeable on a cellular scale than with the classical rate to fresh or dry weight. We affirm the fact that the diminution of the oxygen uptake of each cell is compensated by the increase of the number of cells.     

Sur l'apparition d'organes variés dans l'ectoblaste, à la suite de la centrifugation de la blastula et de la gastrula chez les Amphibiens

Summary The centrifugation of the Amphibia blastula or gastrula produces in the ectoblastic area the appearance of complexes of ecto- and mesoblastic organs. Experiments of explantations and cultivationin vitro and also of grafts on a normal embryo demonstrate that those very abnormal secundary embryos are formed without any intervention of the normal organizer. The ectoblastic cells that undergo this increase of morphogenetic potential are characterized by a great concentration of ribonucleic acid in their cytoplasm (this part of work in collaboration withJ. Brachet). Those secundary embryos vary greatly in their frequence, their nature, and their location, depending on the stage in which the centrifugation was done. It is supposed that the nature of the organs formed is dependent on the degree of potency attained by the ectoblast at the time when the reaction arises that is produced by the cellular trauma.     

Etude de la distribution du calcium dans l'os haversien avec le radioanalyseur à microsonde électronique

Summary The distribution of calcium in the fine-fibred bone tissue of the human adult tibia is measured with the electron probe X-ray microanalyzer. Variations in the calcium concentration may be related to the stratified fine structure of the bone matrix.     

L'action du chlorure de lithium et du sulfocyanure de sodium sur la viscosité de la nucléohistone et des extraits d'embryons d'Amphibiens

Summary (1) LiCl increases the viscosity and decreases the rigidity of nucleohistone; NaSCN has opposite effects.(2) The effects of LiCl and NaSCN on the viscosity of amphibian embryo extracts, as observed byRanzi and his coworkers, seem to be due to the action of these salts on nucleohistone.     

Etude de l'activité adénosinetriphosphatasique et hexokinasique de cristallins de lapins soumis à une irradiation locale par les rayons X

Summary The irradiation of the lens by a simple dose of 1400 r, gives a very important and lasting reduction of its hexokinase activity. Its ATPase activity shows an increase during the first four days and a return to normal again. The variations observed here (that isin vivo) are different from the ones noted after irradiation of these enzymesin vitro.

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

Sur la teneur en composés polyphosphoriques de l'oxychlorure de phosphore hydraté et des esters amides polyphosphoriques de la thiamine

Zusammenfassung Hydratisiertes Phosphoroxychlorid besteht aus zyklischen und langkettigen Polyphosphorsäure-Chloriden, die nicht beständig sind und leicht hydrolysiert werden. Hydratisiertes Phosphoroxychlorid erlaubt die Synthese von langkettigen Thiaminpolyphosphorsäureestern, die mehr als drei Phosphorsäure-Reste je Molekül enthalten.     

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.     

Etude de la glucose-6-phosphatase dans la membrane chorioallantoïdienne traitée par des microsomes du foie

Summary In order to test the possibility for microsomes to multiply like viruses, microsomes of chick liver were inoculated on chorioallantoïc membranes. The glucose-6-phosphatase activity, an enzyme located in the liver microsomes, was determined in the treated membranes. The activity decreased during the first 24 h after inoculation. It reached, after 48 h, from two to six times the value attained after 24 h.A suspension of heated granules, or of heatedTétrahymèna géléii, though producing the same lesions of the membrane, did not increase the phosphatase activity of the microsome fraction after 48 h.The present results are compatible with the idea that liver microsomes multiply by autoduplication.     

Essais de solubilisation et de détoxification de la Tyrothricine

Summary As Tyrothricin —Dubos's discovery of the antibiotic agent extracted from cultures ofB. brevis — does not give true aqueous solutions and retains, in the colloïdal state of the usually employed solutions, toxic properties for polymorphonuclear blood cells, we have attempted to effect the solubilization and detoxification of this compound. Treatment with formalin in given proportions results in making it water-soluble. The action of the formalin-treated compound on blood cells suspended in Ringer's solution seems to show a loss of toxicity. Subcutaneous and intramuscular injections in mice do not give visible general toxic effects, and the experiments incite to further investigations in this direction.     

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.     

L'état actuel de la théorie des particules élémentaires et des quanta

Sans résumé     

Avantages et inconvénients de la fixation par perfusion du tissu nerveux à la lumière d'une donnée de cytochimie

Summary It has been extensively demonstrated that perfusion is the best fixation procedure for providing good morphological evidence ofstructures, especially in the case of nervous tissue. But it might be questioned if it should also be preferred whencytochemical data have to be obtained or compared.As a preliminary attempt to answer this question, lipoproteic inclusions in nerve cells of vegetative ganglia of adult cat have been considered. These occur in about 25% of cells after immersion in fixative, whereas if perfusion is used, a relation appears between the amount of saline perfused before the fixative fluid and the percentage of cells containing inclusions: this falls to 10% after 300 ml saline, to 1% after 800 ml. In conclusion, though structural artefacts have been avoided and fixation appears excellent, perfusion is significantly responsible for a definite cytochemical alteration.     

Injection à des souris nouveau-nées de cellules hématopoiétïques homologues de donneurs adultes ou embryonnaires. Fréquence de la greffe érythroblastique et de la «Runt Disease»

Summary The endoveinous injection to newborn mice of homologous hemafopoietic cells either adult or embryonnic, may result in a lasting and functional graft.The former statement can be demonstrated by use of starch gel electrophoresis which shows the specific hemoglobin of the donors.In both uses this graft can induce a runt disease.     

Hydrolyse enzymatique de la propionylcholine,de l'acétylthiocholine et de la butyrylthiocholine par le rectus de grenouille

Summary The enzymatic hydrolysis of propionylcholine (PrCh), acetylthiocholine (AcThCh), and butyrylthiocholine (BuThCh), by extracts of the muscle rectus abdominis, was determined. Inhibition of this hydrolysis by D.F.P. and 3318 CT [bis(pipéridinométhylcoumaranyl- 5)cétone diméthiodide] — utilized over a range of concentrations covering both specific and non-specific concentrations—showed that PrCh is hydrolyzed by an acetylcholinesterase (70%) and an Xcholinesterase (30%), AcThCh by the AcChE (70%), the XChE (15%) and a thioesterase (15%) and BuThCh by the XChE (70%) and a thioesterase (30%).     

Disparition de la 5-hydroxytryptamine dans les granulations des glandes de la peau deDiscoglossus pictus et deRana temporaria après injection de réserpine

Summary 30 min after an intraperitoneal injection of reserpine (5 or 10 mg/kg) in the frog (Rana temporaria) and in the toad (Discoglossus pictus), a substance which has the properties of 5-hydroxytryptamine (argentaffine reaction, azoreaction, indoreaction and fluorescence in U.V. after formaldehyde) disappears from the skin glands; the histochemical reactions are more positive again 1 1/2 to 2 h after the injection of reserpine.     

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).