Über die Aktivität der Tyrosinase in Tabaksamen

Summary Water or buffered extracts from tobacco seeds (Mont Calme brun) showed both cresolase and catecholase activity of tyrosinase, which was inhibited by 10^–2 M thiourea. No difference of activity could be observed in extracts from old and fresh seeds. Unexpectedly, chlorogenic acid is not oxidized by this tyrosinase.     

Über die tuberkulostatische Wirksamkeit einiger Derivate der para-Aminosalizylsäure

Résumé Nous avons effectué la synthèse d'une série de combinaisons du PAS qui pour la plupart sont nouvelles et dont nous avons évalué le pouvoir bactériostatique. Nous avons pu ainsi mettre en évidence l'activité accrue de quelques combinaisons du PAS avec des dérivés de l'acide chaulmoogrique et montrer que celles ayant un radical cyclopentényl étaient parmi les plus actives.     

Über die Basizität der Knochenmineralien

Summary Interpretations regarding the structure of the bone mineral, based on quantitative data as to the basicity of calcium phosphate, have been complemented by X-ray and electron microscopic investigations. The chemical nature of the bone material is thereby thought to be substituted apatite.

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Ergänzende Bemerkungen zur Arbeit vonJ. Raaflaub, Exper.17, 443 (1961).     

Über die Wasserdurchlässigkeit von Hydrogelen

Summary The permeability of different jellies is measured under various conditions. This property may be of value for the structural analysis of these systems.     

Über die Basizität der Knochenmineralien

Summary The inorganic salts of bone tissue are, owing mainly to their contents of tertiary phosphate, strongly basic. A quantitative evaluation of these base equivalents can be performed through simple titration with acid after solution of the bone salts in a chelating agent (e.g. citrate). Referring to an endpoint of pH 7.40, one finds that per mMol Calcium 0.82 mEq base is set free. With regard to acid-base metabolism, the results indicate that bone phosphate, whichin vivo can be mobilised through osteoclastic resorption, forms a remarkably big base reserve in the animal organism.

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Die vorliegende Arbeit wurde mit der Unterstützung des Schweiz. Nationalfonds zur Förderung der wissenschaftlichen Forschung durchgeführt.     

Über das Glukuronsäurekonjugat eines Cardenolidgenins (3-Epi-digitoxigenin)

Summary After incubation of digitoxigenin with slices from livers of man, rabbit or dog, a total of 5 chloroform-insoluble, highly polar metabolites has been isolated by extraction with ether-ethanol. Two of the products were the sulfuric acid esters of digitoxigenin or 3-epi-digitoxigenin, as demonstrated earlier, and two further ones could not be identified. The fifth metabolite appeared to be identical with 3-epi-digitoxigenin glucuronide.     

Über die Molekulargrösse des Hämovanadins

Summary The red-brown haemovanadin which is contained in the haemolysate (Henze Solution) of blood cells of the ascidiaPhallusia mamillata Cuvier is a chromoproteid with trivalent vanadium as the central atom and sulphuric acid bound coordinatively. It is found to have a molecular weight of 24,400±1,900 according to the estimation of the diffusion coefficient (D_5°=6.87±0.2 · 10^–7 cm² · s^–1 at pH 2.5–2.8).

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Dem Entdecker des Hämovanadins zum 80. Geburtstag gewidmet.     

Über den Chemismus von Zustandsänderungen des Aktomyosins

Summary (1) By means of a simple method the conditions were investigated for contraction and relaxation of actomyosin (AM) under the influence of potassium, magnesium, and calcium ions, of adenosintriphosphate (ATP) or muscle-adenylic-acid and phosphocreatin.(2) Raising the calcium chloride concentration to 0.2 m and raising thep_H from 6.9 to 7.3 hinders the contraction of actomyosin by ATP; in uncontracted AM-gel, ATP leads to a relaxation under these conditions.(3) Relaxation of the contracted gel can be brought about by dissolving in potassium chloride and precipitating by dilution: calcium furthers this relaxation; afterward ATP leads again to a contraction.(4) Remainders of ATP from the first contraction lead in this stage again to a partially contracted gel; phosphocreatin reinforces this effect.(5) Certain SH-groups and amino groups, but not carboxyl groups, are involved in the production of the contraction.(6) SH- and amino groups are also necessary for the ATP-ase effect. The relation of actomyosin-ATP-ase to contraction, of myosin-ATP-ase to relaxation is pointed out.     

Zur Diskussion über die Homogenität des Erdinnern

Summary According to considerations put forwards byW. Kuhn andA. Rittmann some years ago, it follows that the chemical composition of the interior of the earth must be rather homogeneous; the well-known discontinuity which occurs at 2900 km with respect to the propagation of longitudinal and transverse waves should not be due to a discontinuity of the material composition (not to an iron core). It is due to a continous decrease of the viscosity and thereby of the relaxation time; transverse waves of a period of e.g. 30 seconds will no more be propagated in a material whose relaxation time for tangential stress is below 30 seconds, while the longitudinal waves will suffer a decrease of the velocity at the same time.A criticism put forward byA. Eucken consists in the argument that a material in which the time of relaxation for tangential stress becomes equal to the period of the vibration will exhibit a considerable absorption coefficient for longitudinal waves too. It is now shown that the distance on which the period of vibration and the relaxation time are approximately equal is small compared with the wave length of the seismic waves in question, from which it follows that the resulting absorption of the longitudinal waves too will only be small.A further consideration shows that a mixture of 99 atomic % hydrogen and 1 atomic % of iron is most probably supercritical at a temperature of 5000° abs.A survey of the solubilities in question shows further that the hydrogen present in a mixture of 90% hydrogen and 10% iron should on the strength of the absorption coefficient be completely absorbed by the iron at 5000° abs. and at a total pressure of 2.10⁶ atmospheres.The main argument why the assumption of an iron core inside the earth must be dismissed remains the fact that the present state must be the result of an asymptotic processus which at least in its final phase has occurred under conditions similar to the present conditions of temperature, pressure and viscosity; these latter conditions are far from permitting the processus of sedimentation etc. which would be required.     

Über die Ursache des gegensätzlichen geotropischen Verhaltens von Sproß und Wurzel

Ohne Zusammenfassung     

Über die Atmungsenzyme des Seeigeleies

Riassunto Le attività citocroma ossidasica, succino-deidrogenasica, DPNH e TPNH cit. c riduttasica sono state studiate in omogenati e frazioni mitocondriali e microsomiali di uova vergini e fecondate diParacentrotus lividus. I mitocondri contengono tutta l'attività citocromossidasica e succinodeidrogenasica, mentre i microsomi solo una metà della attività DPNH cit. c riduttasica totale. Spettri differenziali hanno rivelato la presenza, nei microsomi, di un citocromo avente una banda a 428–430 mµ.     

Über die Abhängigkeit der photodynamischen Wirkung von der Intensität der UV.-Bestrahlung

Summary (1) The relation between photodynamic effect and intensity of ultra-violet radiation was investigated by means of the lethal-curve of yeast cells treated with benzpyrene as photosensibilizer.(2) If the dosis of radiation ist kept constant, the resulting photodynamic effect decreases rapidly with diminishing intensity.

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Teilergebnisse der Dissertation.     

Über die Bedeutung der Nierentätigkeit für die Blutdruckwirkungen eines dehydrierten Ergotderivats,Dihydroergocornin

Summary The present report analyses the blood-pressure action of dihydroergocornine (DHO) in anæsthetized animals without artificial hypertension. Experiments are carried out on intact and nephrectomized animals in cats in which the renal arteries are temporarily clamped, in cats with section of the thoracic spinal cord, and in dogs with grafted kidney. Evidence is presented that the changes in blood-pressure following dihydroergocornine in the intact animal are the result of at least two interacting mechanisms. The one (leading to a depressor effect) is only apparent if certain nervous mechanisms are intact, while the second (leading to a pressor effect) depends on renal function. It is probable that these effects on the circulatory system are produced by different active principles. Experiments in dogs with grafted kidney show that the secondary blood-pressure effect following dihydroergocornine is caused predominantly, to say the least, by means of a humoral mechanism of renal origin.

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Über Chemie und Pharmakologie von Dihydroergocornin siehe: 1aA. Stoll undA. Hofmann, Helv. chim. acta26, 2070 (1943). 1bE. Rothlin, Helv. physiol. acta2, C 48 (1944). 1cE. Rothlin, Bull. acad. Suisse Sci. méd.2, 249 (1947).     

Über die Identität der Ionenpumpen-ATPase in der Zellmembran des Herzmuskels mit einem Digitalis-Rezeptorenzym

Ohne Zusammenfassung     

Über die Wirkung von Mischungen eines antigenhaltigen Plasmas mit einem antikörperhaltigen Serum auf die Entwicklung des Fremdkörpergranuloms

Summary It has been shown that local application of a mixture of precipitating antiserum with homologous plasma or serum promotes markedly the growth of granuloma tissue in the rat.     

Über die 1-Peptidasen des Tuberkelbazillus

Ohne Zusammenfassung