Amperometric study on lanthanum polytungstates

Zusammenfassung Es wurde die Zusammensetzung von Lanthanwolframat-Niederschlägen untersucht, die sich aus Lanthannitrat- und Natriumwolframat-Lösungen verschiedener Polymerisationsgrade bilden. Die Reaktionen wurden bei verschiedenem pH, in rein wässrigem oder wässrig-alkoholischem Milieu durch amperometrische Titration verfolgt. Im pH-Bereich von 5,5–6,5 bildet sich La₂O₃ · 3WO₃, bei einem pH von 4,2–5,5 La₂O₃ · 7WO₃.

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Acknowledgment: O. P.Sharma is grateful to the Council of Scientific and Industrial Research, New Delhi, for financial assistance and to Principal V. G.Garde for providing research facilities.     

Der Sauerstoffumsatz der Leber von Ratten während der Höhenakklimatisation

Summary The O₂-consumption of liver tissue of male rats of different ages during the first 10 days at an altitude of 3540 m was significantly decreased on the 5th and 7th day. The deviation from the controls at ground level was – 19% in 40-day-old and – 30% in 11-month-old male rats.

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Auslandsstipendiat der Schweizerischen Regierung (1963–64). Für die Überlassung eines Laboratoriums und der Apparate möchte ich Herrn Prof.A. v. Muralt auch an dieser Stelle danken.

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Die Arbeit wurde unterstützt von der Max-Planck-Gesellschaft zur Förderung der Wissenschaften, Deutschland. Ein Teil der Versuchstiere wurde uns freundlicherweise von der Hoffmann-La Roche AG, Basel, durch Herrn Dr.Loosli, Füllinsdorf (BL) zur Verfügung gestellt.     

Bactericidal activity againstPseudomonas aeruginosa is acquired by cultured human monocyte-derived macrophages after uptake of myeloperoxidase

Myeloperoxidase (MPO) is an enzyme located within polymorphonuclear neutrophils capable of producting cytotoxic oxidant species that are particularly active against bacteria with polysaccharide capsules.Pseudomonas aeruginosa (10⁶ bacteria per 1 ml) are killed within 1 h in vitro by a MPO/H₂O₂/Cl^– system (48 mU=132 ng of MPO). The question arose as to whether human macrophages would acquire cytotoxic activity when loaded with this enzyme. Monocytes were therefore isolated from human blood and cultured for up to ten days to induce maturation to macrophages. These cells lost endogenous MPO within five days while H₂O₂ production in response to stimulation by phorbol myristate acetate (10^–6M) decreased to 23% within ten days. On the other hand, their capacity to take up exogenous MPO increased fourfold from day three to day ten. Human macrophages cultured from eight days (when both H₂O₂ production and MPO uptake were sufficient) were therefore used to study the effects of MPO uptake on cytocidal activity againstPseudomonas aeruginosa. After a 1 h MPO loading period, macrophages (5×10⁵ cells per ml) were incubated in the presence of bacteria (0.5 to 2×10⁶ bacteria per ml) for 2 h at 37°C. At a bacteria/macrophage ratio of 1, only 34.8±7.0% of bacteria survived (compared to killing by non-loaded macrophages), while 74.4±9.3% survived at a ratio of 4. From these results, we conclude that loading macrophages with exogenous MPO could enhance their microbicidal activity, suggesting a potentially useful therapeutic application.     

Avilamycin

Summary A strain ofStreptomyces viridochromogenes produced a new crystalline antibiotic, Avilamycin, related to but not identical with Curamycin and Exfoliatin. Avilamycin, C₆₃H₉₄O₃₅Cl₂, gave on solvolytic degradation the following products: dichloroisoeverninic acid, 2-deoxy-d-rhamnose, 2,6-di-O-methylmannose, 4-O-methylfucose,l-lyxose and 3,5-diacetoxy--caprolactone.     

Dissociation-constants of metal-ion-complexes with alkaline phosphatase from pig kidney

Summary Using metal-ion buffers it was possible to remove Zn²⁺, Mg²⁺ and Mn²⁺ ions of pig kidney alkaline phosphatase reversibly. The dissociation constants obtained are K_EMg:4·10^–7 M, K_EMn:4·10^–8 M and K_EZn:8·10^–13 M (22°C, pH:9.6, :0.07).Acknowledgement: The authors thank Dr.H. U. Wolf for helpful suggestions and valuable discussion and MissH. Köth for technical assistance.     

Über Struktur und Aktivität der den H2O2-Zerfall katalysierenden Cu2+-Komplexe. — VI. Differenzierung von nativer RNS und nativer DNS bzw. denaturierter DNS auf Grund der katalytischen Eigenschaften

Summary The catalysis of H₂O₂ decomposition by Cu²⁺-complexes of RNA and DNA has been investigated. It is shown that both complexes decompose H₂O₂, but only the Cu²⁺-RNA-system shows peroxidative activity too, e.g. only in this case the nucleotide bases are degraded. Thermal denaturation of DNA also leads to a Cu²⁺-complex with peroxidative activity, the latter being dependent on the degree of denaturation.

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V. Mitteilung:S. Petri, H. Sigel undH. Erlenmeyer, Helv. chim. Acta49, 1778 (1966).

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12. Mitteilung überMetallionen und H ₂ O ₂; 11. Mitteilung:H. Ch. Curtius, P. Anders, R. Zell, H. Sigel undH. Erlenmeyer, Helv. chim. Acta49, 2256 (1966).     

Rauwolfia alkaloids,XVI. Deserpidine,a new alkaloid fromRauwolfia canescens

Zusammenfassung AusRauwolfia canescens wurde Deserpidin, C₃₂H₃₈O₈N₂, isoliert und eine Konstitutionsformel für dieses neue Alkaloid vorgeschlagen.

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Communication XV,C. F. Huebner et al., J.A.C.S. (in press).

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From lecture given at Columbia University, New York, January 12th, 1955.     

Interaction du 2,4-dichlorophénol et de l'eau oxygénée dans la destruction enzymatique de l'acideβ-indolylacétique

Summary DCP increases IAA destruction by bothLens andPhaseolus root breis. H₂O₂ inhibits catabolism byLens extracts but activates it whenPhaseolus is used, mainly when roots are cultivated in the dark and contain inhibitors of IAA destruction. DCP 1·10^–3 M and H₂O₂ 1·10^–4 or 1·10^–3 volume forLens and DCP 1·10^–4 M and H₂O₂ 1·10^–3 volume forPhaseolus nullify auxin catabolism.     

Obtention d'un dérivé du sclaréol à partir de l'ambréine

Summary One of the products of the chromic acid oxidation of the animal triterpene ambreine (V) has been identified with the lactone C₁₆H₂₆O₂ (III) whichRuzicka and coll. had isolated by oxidation of the plant diterpene sclareol (II). This identification confirms recent findings of the authors and ofRuzicka, Dürst andJeger and shows that the hydroxyle of ambreine (V) is at the same place as the hydroxyle of sclareol which is attached to the perhydronaphtalene ring.

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4^me communication sur les constituants de l'ambre gris     

The effect of hog gastrin on gastric secretion in chronic gastric fistula rats

Résumé L'action de la gastrine de porc a été étudiée chez des rats mâles munis de fistules gastriques. La gastrine était injectée par voie s.c. à des doses de 1–2 ml: 1 ml équivalant à l'activité de 10 g de muqueuse de porc. Le volume de suc gastrique, le volume de suc gastrique par 100 g, l'acidité totale et le débit d'acide accusèrent une pointe dans la première h, alors que la concentration en acide atteignit son maximum vers la troisième h. Le débit de la pepsine diminua entre la troisième et la cinquième h et augmenta légèrement entre la cinquième et la sixième h.

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This research was supported in part by grants from the National Science Foundation (No. GB 6105) and from the AMA ERF, to J. H. T. — Dr.Robitscher of Ayerst Laboratories kindly supplied the ICI-50123.     

Zur Kenntnis des Muscarins

Summary The alkaloid muscarin was isolated from fly agaric. The analyses of crystallized salts (chloride, tetra-chloroaurate,Reinecke's salt) led to C₉H₂₀O₂N⁺ as the simplest formula. The presence of aldehyde and tri-methyl-ammonium groups, which had been assumed hitherto, could not be proved. The quaternary nature of the nitrogen atom was shown. Pharmacological tests on frog heart, rabbit gut and cats show the purely peripheral parasympathomimetic effect of the smallest doses.     

The physiological importance of the interaction of oxygenation between the heme groups of hemoglobin

Zusammenfassung Eine theoretische Betrachtung der Gleichungen vonKlotz bestätigt folgendes: a) die O₂-Aufnahme von Hämoglobin ist nicht nur durch statistische Faktoren bedingt; b) die Bindung der ersten O₂-Moleküle erleichtert die Bindung weiterer Moleküle. Das steht in Übereinstimmung mit der Annahme vonPauling. Die physiologische Bedeutung dieses Phänomens wird graphisch dargestellt. Es wird eine Hypothese vorgeschlagen, die das Auftreten von hyperbolischen Dissoziationskurven unter bestimmten Bedingungen zu erklären vermag.     

Über die Kristallstruktur des Azulens

Résumé La structure du réseau spatial de l'azulène cristallisé a été déterminée à l'aide des rayons X. Les valeurs des constantes du réseau sont en général les mêmes que celles trouvées parMisch etvan der Wyk. Au contraire, la statistique des interférences observées montre des différences importantes et conduit au groupe spatial P 2₁/a, à la place de P 2₁ et P 2₁/m indiqué par les auteurs cités.

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Erstmals hergestellt vonPl. A. Plattner undA. St. Pfau, Helv. chim. acta20, 224 (1937).     

Lack of pressor effect of dopamine in the pentobarbital-anesthetized rat

Summary The blood pressure and heart rate responses to intravenous dopamine infusion at 2.5, 5.0 and 10.0 g·min^–1·100 g^–1 were studied in conscious and pentobarbital-anesthetized Sprague — Dawley rats. In the conscious rats, dopamine caused a significant dose-related increase in the mean arterial blood pressure which was abolished in the anesthetized rats. The heart rate increased significantly only at the highest dose infused. The responses to equipressor doses of noradrenaline (40 ng·min^–1·100 g^–1) and phenylephrine (1.0 g·min^–1·100 g^–1) were also suppressed in the anesthetized rats. The results suggest that pentobarbital anesthesia depresses the blood pressure response to dopamine infusion in the rat through a depression of activation of alpha-adrenoceptors.16 June 1986     

On the time course of thyrotropin suppression by high doses of thyroid hormones

Summary Basal and stimulated TSH decreased progressively. Basal TSH was suppressed below the detection limit of 0.4 U/ml after 74 h in 2 of the T₃ and all of the T₄ treated indiduals. At this time, in both groups 3 individuals could be significantly stimulated by TRH (about 5% of the pretreatment stimulation). There was no significant difference in the time course of suppression obtained by T₃ or T₄, though plasma T₃ levels in the T₄ treated group were considerably lower.Supported by the Deutsche ForschungsgemeinschaftThe excellent technical assistance of MissM. Knöpfle, MissU. Neun and Mr.G. Magin is gratefully acknowledged.     

Ferrous complexes in the catalase reaction

Zusammenfassung Vor kurzem wurde vonNicholls derWestheimer-Mechanismus des H₂O₂-Zerfalls durch Katalase mit Argumenten einer unseres Erachtens abwegigen Interpretation der polarographischen Kinetik kritisiert. Die Argumente werden durch Hinweise auf unberücksichtigte Arbeiten widerlegt.     

Synthesis and taste properties of anN-(glucose)-saccharin compound

Résumé La saccharine a été fixée par son azote imidique sur le C₆ du glucose, par l'action de la saccharine sodée sur un dérivé protégé dup-toluénesulfonyl-6-O-d-glucose, et élimination des groupes protecteurs pour former un composé hydrosoluble. La saveur amère peut être attribuée à l'élimination du proton imidique de la saccharine.     

Laktationshemmende Wirkung von N-[d-6-Methyl-8-isoergolin-I-yl]-N′, N′-diäthylharnstoff (VÚFB-6638)

Summary The inhibiting effect of orally administered N-[d-6-methyl-8-isoergolin-I-yl], N, N-diethylurea (VÚFB-6638) on the production of milk was found in rats. The inhibition of lactation was ascertained through the observation of the daily weightgains of the suckled puppies (ED₅₀=0.112 mg/kg/day) and through the observation of the presence of milk in the stomach of these puppies, as seen through their abdomen wall (0.084 mg/kg/day). This inhibition could be abolished with exogenous prolactin, which gives evidence that the drug studied acts via the endocrine system.

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Für die technische Assistenz danken wir FrauM. Kommersová und FrauV. Maitová.     

R M values and biological action of testosterone esters

Zusammenfassung Eigene Befunde zum Zusammenhang zwischenR _M -Werten und biologischer Wirkung von Testosteron-Estern werden mit denjenigen vonBiagi (Experientia27, 918 (1971)) verglichen und diskutiert. Durch Anwendung geeigneter chromatographischer Phasen können allgemeiner gültige und mathematisch ausdrückbare Resultate erhalten werden.