Die Wirkung von Demecolceinamiden an Zellenin vitro

Summary A series of demecolceinamids was examinedin vitro on chicken fibroblasts, leucocytes, and different bacteria. It was found that with increasing length of the side chain on ring C the antimitotic activity is decreasing while the antibacterial effect is increasing.     

Antirachitische UV-Aktivierung von Hundehautin vitro undin vivo

Summary The antirachitic activation of dog skin by ultraviolet radiation is very small; this indicates a low content of provitamin D in this kind of skin. In contrast with other species and their body regions there is in the dog no parallelism between antirachitic activation and number and function state of sebaceous glands.     

Zur Wirkung von Strahlenschutzstoffen an Thymuszellen

Summary Lymphocytes of the thymus can be protected against early pycnotic degeneration by several SH-compounds. Protective and non-protective SH-compounds induce the same reaction in the non-irradiated mouse, weight loss caused by cell migration, stimulation of the reticulum. A direct relationship between the activity of the reticulum and the radioresistance of lymphocytes was not found.     

Zur bakteriziden Wirkung von komprimiertem Sauerstoff

Summary In this article the writer suggests an explanation for the germicide effect of compressed oxygen. The production of poisonous products of metabolism can be ignored, because the bacterial development is normal after removal of the pressure. Lack of nutritive material through inhibition of metabolism and permanent damage to the enzymes is also not a satisfactory explanation. The possibility is discussed that oxygen as an acceptor of electrones creates an ionisation of important parts of the cell and resulting in the death of the bacteria. The effect seems to be similar but weaker than that of H₂O₂.     

Zur Frage der Wirkung von DTPA auf Säugerchromosomen in vitro

Summary The influence of DTPA on the chromosome aberration rate of Chinese hamster cells in culture was studied. No increase of the aberration rate was observed after treatment with 10^–2 and 10^–3 M concentrations.     

Differenzierung der Wirkung von Desinfizienzienin vitro

Summary In testing the effects of various disinfectants onStaphylococcus aureus andBact. coli in respiration experiments two greatly differing types of action were found whose variations are described by two characteristic respiration curves.Some disinfectants act onStaphylococcus according to one type of action and onBact. coli according to the other.Various disinfectants act on the same bacteria partly according to one type of action and partly according to the other.     

Differenzierung der Wirkung von Desinfizienzienin vitro

Ohne Zusammenfassung     

Zur Wirkung von Zn++ auf die Nukleinsäurebiosynthese von Aszites-Tumorzellen

Summary Ascites tumour cells have been employed to study the reactivity of Zn⁺⁺ on nucleic acid biosynthesis. 10^–4 M Zn⁺⁺ caused a selective inhibition of DNA synthesis of intact cells. The rate of RNA- and protein-biosynthesis, however, remained unchanged. The activity of DNA polymerase as well as DNA dependent RNA polymerase was strongly affected by Zn⁺⁺ in vitro.     

Zur leukotaktischen Wirkung von Aminosäuren in Liquor cerebrospinalis

Summary Intercisternal injections of-aminobutyric acid,l-asparagin,l-glutamine,l-leucine andl-norleucine exert a strong leukotactic action and in dogs result after a short time in a maximum cell increase of 76,000/3 cells.     

Zur Wirkung von Oxytocin auf einen autorhythmischen glatten Gefässmuskel

Summary The influence of oxytocine on the spontaneously contractile portal vein of the rat has been investigated. This octapeptide decreases the active tension and abolished it completely at a concentration of 5×10^–7g/ml. The effect is not caused by an adrenergic mechanism but by a direct action on the smooth muscle cell.     

Zur Wirkung von Narkotin auf den Hustenreflex und auf die Bronchialmuskulatur

Summary In experiments on cats cough reflexes were elicited by mechanical stimuli applied to the mucosa of the tracheobronchial tree. Narcotine was found to diminish or to depress the cough reflex in doses of 0.1–1.0 mg/kg and was thus about as effective as codeine. On the bronchial muscles narcotine produced no effect or a bronchodilatation whereas codeine produced a bronchoconstrictor effect. As an isochinoline derivative narcotine should not be liable to cause addiction.     

Disputanda Differenzierung der Wirkung von Desinfizienzienin vitro,von W. Schuler

Ohne Zusammenfassung     

Zur Frage einer antagonistischen Wirkung von Herzglykosiden und Nebennierensteroiden am Kationentransport der Erythrocytenmembran

Summary Previous experiments indicating antagonistic effects of cardiac glycosides and corticosteroids on ion transport in red cells and published independently from our own laboratories¹ and byBernstein ² could not be repeated under a variety of experimental conditions.     

Die Wirkung von Progesteron und Progesteronmetaboliten auf das Wachstum von embryonalem Knorpel in vitro

Summary Embryonic chick bones were cultured in vitro in the presence of progesterone and of a series of progesterone metabolites. It was found that only 5-pregnane-3,20-dione, 3-hydroxy-5-pregnane-20-one, and ⁴-pregnene-20-ol-3-one influence the growth of bones in vitro in a manner similar to progesterone. All other investigated progesterone metabolites exert either a different or no demonstrable action on bone growth.     

Gonadotrope Wirkung von Spermaextrakten

Summary The action of sperm extracts and acetone precipitate of these extracts upon the growth of ovary and uterus was investigated on infantile mice and rats. It was found that injections of the above-mentioned agents increased the uterine and ovarian weights and caused microscopic changes similar to those caused by FSH. The active principle present in the sperm must be a peptid.     

Zur Austestung von Wachstumsinhibitoren für Tuberkelbazillenin vitro

Summary The addition of serum or Tween 80 to a synthetic culture medium for tubercle bacilli considerably reduces the inhibitory effect of various substances with the exception of streptomycin and promin, whose effect is less weakened, and which retain their tuberculostatic action to a considerable degree. The antagonistic effect of Tween 80 is still recognizable in small dilutions where its diffusion effect can no longer be observed.

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Die Arbeit wurde durch einen Arbeitsbeschaffungskredit des Bundes ermöglicht, für dessen Gewährung wir auch an dieser Stelle danken.     

Zur peripheren sympathikushemmenden Wirkung des Clonidins

Summary The influences of clonidine, tetracaine and procaine on the effects of electrical stimulation of the postganglionic sympathetic cardiac nerves have been compared in the isolated perfused rabbit heart. Much lower concentrations of clonidine than of tetracaine were necessary to antagonize the output of noradrenaline and the rise of frequency and contractility. Procaine even in the highest concentration tested did not inhibit the effects of nerve stimulation. In addition to its known central depression of sympathetic tone, clonidine exerts a specific inhibitory action on postganglionic sympathetic neurons.     

Die Wirkung von Desoxycorticosteron auf den aktiven Kationenaustausch an Rattenblutzellen

Summary Cold-stored blood cells of rats, which were depleted of potassium and had gained an equivalent amount of sodium instead, were incubated with 500 mg% glucose at 37°C in serum. Under these conditions an extrusion of sodium from and a re-entry of potassium into the cells could be observed. Desoxycorticosterone, when added in a concentration of 1 mg per ml, was able to slow down the rate of this exchange to three fifths of the rate of untreated cells. With blood of adrenalectomised rats, the same effect of DOC was observed, although the rate without DOC was somewhat lower than in the blood of normal animals. There was no statistically significant difference between the DOC-effect in blood of normal and adrenalectomised rats.     

Die Wirkung von Spirolactonen und von Herzglykosiden auf den Natrium- und Kaliumtransport an Erythrocyten

Summary Experiments made on human red cells showed that spirolactones (SC 5233 and SC 9420) added to the sample as dry powder (10^–3 g/ml) exert an inhibitory action on the active transport of sodium and potassium across the cell membrane. Spirolactone at its saturation concentration in serum (1.5×10^–5 g/ml), however, was ineffective.The inhibitory action was not affected by aldosterone or hydrocortisone.Experiments involving exposure of red cells to spirolactone and a cardiac glycoside simultaneously led to the conclusion that these substances do not have the same mechanism of action. The inhibition caused by spirolactone added to the inhibition due to a supramaximal concentration of ouabain (5 × 10^–4).

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Diese Arbeit wurde unterstützt durch ein Stipendium der CIBA für naturwissenschaftliche, medizinische und technische Forschung.     

Zur Bestimmung der Elastizitätsgrenze von Bindegewebsstrukturen in vitro

Summary Biological connective tissues are not perfectly elastic. They contain viscous, friction, and elastic elements. Consequently, complex mechanical behaviour can be observed. It is not possible to determine an elastic limit, as in inorganic solids. There are difficulties in measuring a natural state which can serve as a reference for mechanical testing procedures. The method described generates a steady state in the test specimen and allows the determination of a relative elastic limit.