Transport of oxygen through membranes containing haemoglobin solutions

Zusammenfassung Die Scholanderschen Befunde über den Sauerstofftransport durch Hämoglobinlösungen werden auf der Basis der irreversiblen Thermodynamik behandelt.     

Nicotinamide administration alters the activities of hepatic microsomal mixed function oxidases

Summary Systemic action of nicotinamide significantly alters the activities of hepatic drug metabolizing enzymes. Male rats injected with nicotinamide have reduced levels of cytochrome P450, demethylases and aniline hydroxylase. The changes appear to be sex-dependent since in the case of female rats activities of p-nitroanisole-o-demethylase and aniline hydroxylase are enhanced whereas cytochrome P450 content remains unaltered.Authors gratefully acknowledge the encouragement given by Professor A.S. Paintal during the course of this investigation. One of us (J.K.B.) is grateful to the Council of Scientific and Industrial Research, New Delhi, for the award of a research fellowship.     

Notch1 functions as a tumor suppressor in mouse skin

Notch proteins are important in binary cell-fate decisions and inhibiting differentiation in many developmental systems, and aberrant Notch signaling is associated with tumorigenesis. The role of Notch signaling in mammalian skin is less well characterized and is mainly based on in vitro studies, which suggest that Notch signaling induces differentiation in mammalian skin. Conventional gene targeting is not applicable to establishing the role of Notch receptors or ligands in the skin because Notch1-/- embryos die during gestation. Therefore, we used a tissue-specific inducible gene-targeting approach to study the physiological role of the Notch1 receptor in the mouse epidermis and the corneal epithelium of adult mice. Unexpectedly, ablation of Notch1 results in epidermal and corneal hyperplasia followed by the development of skin tumors and facilitated chemical-induced skin carcinogenesis. Notch1 deficiency in skin and in primary keratinocytes results in increased and sustained expression of Gli2, causing the development of basal-cell carcinoma-like tumors. Furthermore, Notch1 inactivation in the epidermis results in derepressed beta-catenin signaling in cells that should normally undergo differentiation. Enhanced beta-catenin signaling can be reversed by re-introduction of a dominant active form of the Notch1 receptor. This leads to a reduction in the signaling-competent pool of beta-catenin, indicating that Notch1 can inhibit beta-catenin-mediated signaling. Our results indicate that Notch1 functions as a tumor-suppressor gene in mammalian skin.     

Isolation and characterization of hemagglutinins from the sponge Dysidea herbacea

The sponge Dysidea herbacea (Keller) was found to possess hemagglutinins. The major component, DHA-I, is a protein with a mol. wt of 26,000, which dissociates into subunits of equal size (14,000). It contains large amounts of glutamic acid and aspartic acid residues, but no half-cystine, methionine or histidine residues. DHA-I reacted with rabbit and human AB0 erythrocytes. D-galactose and lactose were effective inhibitors of DHA-I. The sponge also contained a minor component(s) which reacted preferentially with rabbit erythrocytes but not with human AB0 erythrocytes.     

Derivate des 6,11-Dihydrodibenz(b,e)thiepins,eine neue Gruppe von psychotropen Substanzen

Summary Reactions of phthalide and 6-chlorophthalide with sodium salts of thiophenols gaveo-(phenylmercaptomethyl)benzoic acids (III), which were cyclized by the action of polyphosphoric acid to 6, 11-dihydrodibenz(b,e)-thiepin-11-ones (1). These ketones were treated with 3-di-methylaminopropylmagnesium chloride and other basic Grignard reagents and the products (IV) dehydrated to a series of 11-(aminoalkylidene)-6,11-dihydrodibenz(b,e)-thiepins (V), the hydrochlorides of which show psychotropic activity.

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6. Mitt. Synthetische Ataractica, 5. Mitt. siehe eskoslov. farm.11, im Druck (1962).     

Polymethylcyclohexylamine — neue,hypotensiv wirksame substanzen

Summary A series of cyclohexylamine derivatives methylated both on nitrogen atom and in position 1, 2 and 6 of the cyclohexane ring have been prepared. Some of them showed considerable hypotensive and ganglioplegic activity. The most interesting compound is N,N,1,2,2-pentamethylcyclohexylamine (‘penhexamine’) whose activity compares favourably with mecamylamine or dimecamine.

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9. MitteilungGanglioplegica, 8. Mitteilung siehe Českoslov. farm:8 (1959), im Druck.     

Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in human Ascaris lumbricoides.

The phospholipid level in the human parasitic nematode Ascaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.