Abbau von Quarz mit Brenzkatechin

Summary Fine divided HF-etched quartz was dissolved in a 0.2M solution of pyrocatechol at pH 9.6. Between 17 and 40 °C the dissolution rate (v _s ) follows the equation: logv _s =0.0295 T-20.87 At 25 °Cv _s amounts to 0.8 · 10^–12 g cm^–2 sec^–1. With several phenols the dissolution rate of quartz decreases in the order: pyrocatechol > pyrogallol > 2, 3-dihydroxynaphthalene.     

Verbesserte Methode zur Gewinnung und Verarbeitung von freien Zellen aus kleinsten Volumina von Körperflüssigkeiten mittels Membranfiltration

Summary A cell collector for concentrating small numbers of exfoliated cells on membrane filters from minute volumes (0.05–3 ml) of body fluids and culture media is described. The apparatus incorporates a membrane pump, delivering a vacuum of 10–100 mm Hg. Filtration units (funnels and filter holders) with filtrating areas of 3, 5 and 8 mm diameter are used depending on the volume and the cell content of the fluid to be investigated. A rapid staining procedure based on the classical May-Grünwald-Giemsa technique for light microscopic observations and a modified technique for processing the cell-coated filters for electron microscopy are presented in some detail.

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Mit Unterstützung durch den Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

Beeinflussung der ATPase aminspeichernder Granula von Nebennierenmark und Milznerven durch Thallium

Summary ATPases of the amine storing granules from bovine adrenal medulla and splenic nerves are inhibited by Tl⁺⁺⁺ 3×10^–5 and 5×10^–6 M, respectively. Tl⁺ up to 10^–3 M is ineffective. By T1⁺⁺⁺ in concentrations of 10^–4 M or more, proteins are precipitated, so that the enzyme inhibiton by these concentrations is unspecific. If T1⁺ is oxidized to Tl⁺⁺⁺ in the organism, the inhibition of granular ATPase may be responsible for the alterations of the catecholamine metabolism observed in thallium intoxication.     

Wood quality of eightEucalyptus species in Zambia

Résumé La densité du bois et la longueur de la fibre ont été l'objet de recherches dans 8 espèces d'Eucalyptus de Zambie. Les espèces diffèrent considérablement par leur densité (0.487–0.614 g/cm³), mais non par la longueur de leurs fibres (0.84–0.93 mm).     

The effect of temperature on the respiratory function of coelacanth blood

Zusammenfassung Die Sauerstoffdissoziationskurve vomLatimeria-Blut zeigt eine grössere Affinität zu Sauerstoff bei 15°C (P₅₀=2–3 mm) als bei 28°C (P₅₀=18.0 mm). Diese Unterschiede und die geringe Sauerstoffkapazität sind für eine Diskussion über das Überleben des Fisches beim Aufsteigen aus grosser Tiefe an die Gewässeroberfläche massgebend.     

Influence of cyclic nucleotides on protein synthesis in vascular smooth muscle

Summary The incorporation of leucice-¹⁴C into protein in bovine mesenteric arteries was augmented by cyclic GMP (10^–3 M) and decreased by cyclic AMP (10^–3 M). There was no effect of 5 AMP (10^–3 M). The phosphodiesterase inhibiting drugs theophylline (10^–3 M) and papaverine (5×10^–5 g/ml) both decreased the leucine-¹⁴C incorporation.We are indebted to Mrs.Lena Burlin for hear assistance. Finacial support has been provided by the Swedish State Medical Research Council (No. 04X-101X-4498).     

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.     

Zum Reaktionsmechanismus von Oxydasen

Summary The reactivity of copper(I)-complexes towards molecular oxygen in relation to some copper containing enzymes has been studied. The oxydation of simple amine-complexes proceeds at a rate of about 10³–10⁴ Mol^–1 Lt Min^–1. Replacing the amine by amides and peptides has a strong retarding effect. A copper(I)-cysteine complex exhibits the interesting property of adding O₂ reversibly.     

Zur Wirkung von Colchiceinamiden an Zellenin vitro undin vivo

Summary Colchiceine-N-mono-methylamide is 3–4 times as active as colchicine as shown by its effect on the mouse-ascites-tumor (Ehrlich) and on fibroblastsin vitro.     

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.     

Die Wirkung von Theophyllin auf den cellulären Ca-Stoffwechsel des Warmblüterherzens

Summary In isolated, electrically driven, left guineapig atria, theophylline (5×10^–4 g/ml) increased the rate of⁴⁵Ca uptake and release without affecting the total myocardial Ca content and the amount of exchangeable cellular Ca. In sheep and calf heart preparations, theophylline (10^–4–10^–3 g/ml) increased Ca inward current during excitation (as examined indirectly by Ca dependent changes of membrane potential in TTX-containing solutions) as well as tension development. It is concluded that the positive inotropic effect of theophylline in mammalian hearts is due to an increase in Ca influx during the excitation process.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Zum Nachweis von Aminen im 10−10-Mol-Maßstab. Trennung von 1-Dimethylamino-naphthalin-5-sulfonsäure-amiden auf Dünnschichtchromatogrammen

Summary For the sensitive determination of amines their 1-dimethyl-amino-naphthalene-5-sulphonyl derivatives were separated in two-dimensional thin-layer chromatograms. 10^–10–10^–11 mole per amine can be detected, when the fluorescence of the DANSyl-compounds is excited by the 365 mµ Hg line.     

Zur Polymorphie eines Chromosoms innerhalb von Populationen des LaufkäfersCarabus auronitens Fabr

Summary C. auronitens has 26 autosomes (2n), from which one pair — calledA-chromosomes — is relatively long.A-chromosomes consist of an euchromatic and a heterochromatic arm. In 63% of the individuals, theA-chromosomes are intraindividually anisomorph with regard to the length of their heterochromatic arm. According to its length, this arm shows 0–3 secondary constrictions. Hence there are at least 4 different forms of theA-chromosome.     

Variations de l'activité des auxines-oxydases dans les racines duLens

Summary 2, 4-dichlorophenol (DCP), 2, 4-dinitrophenol (DNP) and 2, 4-dinitro-o-cresol (DNC) applied at a concentration of 1.10^–7 to 1.10^–3 M, produce a dramatic increase in IAA-oxidase activity in young cells ofLens root. IAA destruction by breis from root tissues was inhibited by Mn⁺⁺ ion at low concentrations of DCP (1·10^– to 1.10^–7 M), but was enhanced by Mn⁺⁺ ion at higher (1.10^–5 to 1.10^–3 M) DCP levels.

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Ce travail a pu être entreprise grâce à l'appui duFonds national suisse pour la Recherche scientifique.     

Zur Methodik der Artefaktausschaltung bei Anwendung von Diazoniumsalzen in der Histochemie (Phosphatasen,Esterasen usw.)

Summary A post-incubation with 1% sulfanilic acid solution in 10% CH₃COOH (approx. 2–10 min) or 5–10% potash alum or 0.5 mol AlCl₃ in 0, 1n HCl-after the histochemical reaction with diazonium salt-prevents N₂ formation. This gas originates from decomposition of tissue adsorbed diazonium salt which occurs after mounting in glycerin jelly. The inhibition of diazo-group disintegration depends, in the case of sulfanilic acid, on the formation of a diazoamino compound or double salt production with aluminium ions in the case of AlCl₃.     

Die anorganischen Bestandteile des Honigtaues vonMegoura viciae Buckt

Summary In the honeydew ofMegoura viciae Buckt., sucking on the sieve tube sap ofVicia faba, the following cations are present in measurable quantities: potassium (13.0–14.1 mg/ml), sodium (0.04–0.051 mg/ml), magnesium (1.8–2.3 mg/ml) and calcium (0.07–0.09 mg/ml). There are only traces of copper, iron, manganese, zinc, cobalt and molybdenum. Amongst the anions, phosphate was found at 1.9–2.5 and chloride at 0.02–0.05 mg/ml, whereas nitrate and sulphate could not be detected.     

Drug interactions in intestinal absorption of3H-digitoxin in rats

Summary The absorption of³H-digitoxin from perfused rat small intestine was inhibited by probenecid (1.0×10^–2 M), ethacrynic acid (0.5×10^–3 M), and mersalyl (8.0×10^–3 M) indicating that digitoxin absorption is at least partly an active process.     

Kinetik der hepatischen Farbstoffaufnahme von Indocyaningrün. Einfluss von Bilirubin und Natriumglykocholat

Summary Kinetics of hepatic uptake of indocyanine green, a dye which is used for evaluation of liver function, were studied in the rat. The results indicate that the relationship between ICG-dose and initial hepatic dye uptake obeys Michaelis-Menten kinetics suggesting an interaction of the dye with a carrier or fixed site in the liver cell. Thus it was possible to calculate maximum ICG-uptake (v _max ) and the Michaelis constant (K _m ) of this transport system from several submaximal values.v _max was 7.65 (6-06-9.65)²² mg per 100 g liver/min and K _m 0.56 (0.31–0.81)²². Under the influence of substances which inhibit the elimination of dyes by the liver the parametersv _max and K _m showed changes which allowed characterization of the type of inhibition. While sodium glycocholate had no influence on maximum hepatic ICG-uptake and the Michaelis constant bilirubin caused a significant increase of K _m to 1.29 (0.68–1.90)²² without significantly changingv _max . These data suggest that bilirubin interferes with hepatic uptake of indocyanine green by competitive inhibition and that uptake of bile acids is dependent on a different mechanism.     

Die Wirkung von Na3[Ca-DTPA] auf den Glykogengehalt von Niere und Leber der Ratte

Summary DTPA, a derivative of EDTA, in doses of 1, 2, 4, and 8 mmoles kg^–1/d ^–1 causes a histochemically detectable increase of glycogen in the kidneys and a decrease of glycogen in the liver of rats. Furthermore, a severe damage of the intestinal mucosa has been demonstrated; its possible relevance for the pathogenesis of the other findings is discussed.