Der Einfluß von Aneurin und Cholin auf die Spaltung von Tributyrin durch Serum und Erythrocyten

Ohne Zusammenfassung     

Einfluß antianaphylaktisch wirkender Stoffe auf die Antikörperproduktion

Summary To produce antisera of high antibody concentration animals after sensitization with protein have been reinjected with lethal doses of the antigen, protected against the shock-effect by substances with antihistamin properties (as example Antistin). The antibody concentration was considerably higher in these animals as in the other non-protected group reinjected with the highest tolerated antigen dosage.     

Der Einfluß der Nebenniere auf die Kreislaufwirkung des Adrenalins

Summary Traces of nor-adrenaline restore the vascular action of adrenaline altered in epinephrectomized dogs to the reaction of the normal animal. Therefore it is claimed that the adrenals discharge one or several substances into the blood stream, which are necessary for the usual peripheral vascular action of adrenaline. Further investigations are in progress.     

Über den Einfluss desd,l-Methioninsulfoximins auf den Eiweißstoffwechsel bei Erbsen

Summary The influence of thed,l-Methioninesulphoximine on the nitrogen metabolism of germinating seeds has been studied on peas. It has been shown thatd,l-Methioninesulphoximine, even at low concentrations, inhibited the germination of seeds and produced a decrease of growth of the roots. The inhibited germinating seeds contained less non-protein-nitrogen and less asparagine than the control plants. On the basis of the experimental results,d,l-Methioninesulphoximine could be considered as an inhibitor of proteolysis.     

Der Einfluß von Desoxycorticosteron auf die Azetylcholinwirkung am isolierten Froschherz

Summary The action of desoxycorticosteronglucoside was tested on the isolated frog-heart. In concentrations of 10^–6 to 10^–4 a small negative inotropic effect is prevailing. Acting together with acetylcholine, the substance diminishes or abolishes the negative inotropic and chronotropic action of acetylcholine. Eserin has no influence and the inhibition is also observed with cholinchloride and the carbaminoyl ester of choline. This inhibitory action bears a close resemblance to the inhibitory action of thiamin. In both cases a complex mechanism seems to be involved.     

Der Einfluß der Temperatur des Auges auf die spektrale Empfindlichkeitskurve

Summary The influence of the temperature of the eye on the spectral distribution of its sensitivity was studied. The leading idea was that the small long-wave light quanta could only decompose a molecule of the photochemical substances if this molecule had already a sufficient thermal energy. One must therefore expect the sensitivity for long wavelengths to be higher at high temperatures; moreover this influence of temperature is most pronounced for the longest wavelengths. In the measurements the sensitivity for the wavelengths of 660 mµ and 730 mµ were comparedwith each other. In the accompanying figure the slit width of the apparatus at 660 mµ is shown as a function of temperature. The experimental points are close to the lines which were predicted by the theory.     

Über die Beeinträchtigung der Wirkung von Spindelgiften in der Zellkultur durch menschliches Serum sowie durch Seren verschiedener Tierspezies

Summary Chick embryo fibroblasts, cultivatedin vitro, require higher concentrations of podophyllotoxin derivatives for complete mitotic arrest when the medium contains human adult or cord serum than when it contains horse, bovine, guinea pig, rat, mouse, or cock serum. This difference is due to a higher binding capacity of human serum for these compounds. No such difference was found with a colchicine and a peltatin derivative.     

Über die Bindungsart der amidierten Reste derβ-Aminodicarbonsäuren in Eiweißstoffen

Summary Gliadin and chymotrypsinogen, respectively, were treated with alkaline sodium hypochlorite solution equivalent to the carbonamide groups present, and then hydrolysed by acid. The proteins treated with dilute alkaline solution have been assayed in control experiments for their content of N-terminal amino acids. The degradation products identified by paper chromatography seem to indicate that in chymotrypsinogen the amido groups of the amino dicarboxylic acids represent asparaginyl (Ia) and glutaminyl (Ib) residues. In gliadin, besides these residues, the presence of isoglutaminyl residues (IVb) also seems to be probable.     

Über die Wirkung von Elastase auf die Blutgerinnung

Summary Purified elastase prepared by adsorption on synthetic zeolite in proper concentrations causes the coagulation of blood. Elastase was found to have no direct coagulative action on purified fibrinogen. Its coagulating action is due to the fact that it reacts with prothrombin to form thrombin. The reaction between prothrombin and elastase is independent of the presence of either platelets, thromboplastin or Ca-ions.     

Die Wirkung einer Leberschädigung durch Thioacetamid auf die mikrosomale Aromatisierung von Testosteron bei der Ratte

Summary Rat liver microsomes, NADPH-regenerating system, and 1, 2-³H-testosterone have been incubated in vitro. The loss of tritium from the steroid, associated with aromatization of testosterone, was linear with time for 20 min and required NADPH. Pre-treatment of the rats with thioacetamide raised the liberation of tritium from 1, 2-³H-testosterone. The results suggest that liver damage by thioacetamide in rats may give rise to increased aromatization of testosterone.     

Der Einfluß der Temperatur auf die Giftwirkung des DDT bei Honigbienen (Apis mellifica L.)

Summary The action of DDT on honey-bees depends to a high extent on the temperature (see graph). At 36°C (breeding temperature) DDT has a far weaker insecticidal action than at 20°C (laboratory temperature). This shows that the insecticidal properties of DDT diminish with the raise of temperature.This resistance to DDT at higher temperature is most propitious for bee-keeping and also explains the fact why in agricultural practice there has been no corroborated case of poisoning of bees, though in laboratory tests DDT avered itself to be toxic to bees.     

Der Einfluß des elektrischen Ladungszustandes der Trägerfolie auf die elektronenmikroskopische Präparation von Kolloiden

Summary It is shown that the distribution of colloid particles on a thin film suitable for examination in the electron microscope depends on the charge of the particles and the film.     

Über die Einwirkung des Schilddrüsenhormons auf die Ossifikation

Summary Larvae ofSalamandra salamandra quadrivirgata Dürigen and tadpoles ofXenopus laevis Daud, treated with a percutaneous application of thyroxin, show a more intensive calcification of their skeletal system after a precocious metamorphosis. The calcified area of bones is increased; additional centres of calcification can be distinguished in quite a number of other skeletal elements. By thyroxin-soaked agar implants in the hindlimbs ofAmbystoma mexicanum, deposition of calcium salts is furthered in the bones of the leg treated, as well as in the adjacent pelvic girdle, thus demonstrating that the thyroid hormone exerts a direct effect upon calcification. It is supposed that during normal metamorphosis the thyroid gland plays an equal part in the process of calcification in the skeletal system.     

Über die Einwirkung von Chlordioxyd auf Pektinstoffe

Ohne Zusammenfassung     

Effekt der Perjodsäure auf die Erythrocytenmembran

Summary M/2 up to M/500 HJO₄ produces a very peculiar ductility of native erythrocyte membranes, whereas a similar effect is hardly observed on the membranes of trypsin-treated erythrocytes. This observation demonstrates indirectly, probably for the first time, the morphological existence of a loose protein-layer assumed by one of the authors to be present on the surface of erythrocytes.     

In-vitro-Versuche über die Methämoglobinbildung durch Chinonderivate

Summary Heubner states that the oxidation of hæmoglobin to methæmoglobin by quinones should be due to a tension between two oxidation-reduction systems, the quinone-hydroquinone system and the hæmoglobin-methæmoglobin system. The authors tried to prove this statement by using various quinones with different oxidation-reduction potentials. An analysis of the results obtained suggests, however, that the oxidation-reduction potential is not the only factor determining the equilibrium. It seems that some other constitutionally conditioned factors also play an important role in this process.Experiments with non-hæmolyzed erythrocytes show that all quinones tested are able to pass through the cellular membrane of the erythrocytes without undergoing any chemical reaction. Thus, the experiments with hæmolyzed solutions and those with intact erythrocytes gave identical results.     

Über die Hemmung des aktiven Kationentransportes durch Herzglykoside

Summary Inhibition of active cation transport through the red cell membrane by cardiac glycosides is not accompanied by alteration of phosphate metabolism (ATP, ADP, 2,3-diphosphoglyceric acid) in contrast to the action of iodoacetate. This fact suggests that the cardiac glycosides act directly on the membrane transport mechanism.