Potassium uptake by cold-resistant mouse L cells stored at low temperature

Adaptation of a cultured mouse L cell population to 4 degrees C increased the survival of the cells and induced the uptake of potassium from the medium at this temperature.     

Potassium uptake by cold-resistant mouse L cells stored at low temperature

Summary Adaptation of a cultured mouse L cell population to 4°C increased the survival of the cells and induced the uptake of potassium from the medium at this temperature.     

Iso-cannabispiran,a new spiro compound isolated from Panamenian variant ofCannabis sativa L.

Summary An acidic fraction of Panamenian variant ofCannabis sativa L., afforded upon repeated chromatography a new non-cannabinoid phenol {5-hydroxy-7-methoxy spiro-(cyclohexane-1, 1-indan)-4-one}Ia, named iso-cannabispiran.Acknowledgment. Supported in part by NIDA contract No. 271-78-3527 and by the Research Institute of Pharmaceutical Sciences.     

Dopa-decarboxylase and monoamine oxidase activities in a transplantable islet cell tumour of the golden hamster

Zusammenfassung In einem transplantierbaren Inselzelltumor des Goldhamsters, der neben 5-Hydroxytryptamin, Dopa und Dopamin eine bisher unidentifizierte, vermutlich monoaminähnliche Substanz enthält, wurde eine hohe Dopadecarboxylase- und Monoaminooxydaseaktivität gefunden. Nach Dopa-decarboxylasehemmung wurde eine starke Anhäufung von Dopa im Tumorgewebe beobachtet; dieser Befund weist auf eine schnelle Monoaminsynthese und einen schnellen Monoaminumsatz im Tumorgewebe hin.

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This work was supported by grants from the Swedish Cancer Society (67–111) and was carried out within a research organization sponsored by the Swedish Medical Research Council (Projects No. B69-14X-56-05C and B69-14X-712-04C).     

Isolation and morphological studies of a variant ofCeratodon purpureus

Summary Morphological variants from protonema ofCeratodon purpureus (Hedw.) were obtained using nitrosoguanidine (NTG). In one of the variants, reduced growth was accompagnied by hyperbranching and inhibition of caulogenesis. The deposition of branches in this strain can be studied by enzymatic analysis.     

Sulfatase activities towards the regulation of cell metabolism and signaling in mammals

In higher vertebrates, sulfatases belong to a conserved family of enzymes that are involved in the regulation of cell metabolism and in developmental cell signaling. They cleave the sulfate from sulfate esters contained in hormones, proteins, and complex macromolecules. A highly conserved cysteine in their active site is post-translationally converted into formylglycine by the formylglycine-generating enzyme encoded by SUMF1 (sulfatase modifying factor 1). This post-translational modification activates all sulfatases. Sulfatases are extensively glycosylated proteins and some of them follow trafficking pathways through cells, being secreted and taken up by distant cells. Many proteoglycans, glycoproteins, and glycolipids contain sulfated carbohydrates, which are sulfatase substrates. Indeed, sulfatases operate as decoding factors for a large amount of biological information contained in the structures of the sulfated sugar chains that are covalently linked to proteins and lipids. Modifications to these sulfate groups have pivotal roles in modulating specific signaling pathways and cell metabolism in mammals.     

The production of leucylphenylalanine anhydride by a variant ofStreptomyces noursei

Résumé A partir de cultures deStreptomyces noursei, variante No. 5286, on a isolé la 3-benzyl-6-isobutyl-2, 5-dioxopipérazine, en plus des quatre dioxopipérazines disubstituées dont la présence a été signalée précédemment; on n'a pas obtenu de preuve de l'existence d'un dérivé 3-benzylidène-6-isobutyl-ou 3-benzyl-6-isobutylidènecorrespondant à la 3-benzyl-6-benzylidène-2,5-dioxopipérazine déjà connue.     

Transaminase and transferase activities in the pancreatic islet tissue of the teleostCottus quadricornis L.

Zusammenfassung Im isolierten Inselgewebe aus dem Pankreas des TeleostiersCottus quadricornis L. werden verhältnismässig hohe Aktivitäten von Glutaminoxalessigsäure-Transaminase (GOT), Glutaminpyruvatsäure-Transaminase (GPT) und Ornithin-Carbamyl-Transferase (OCT) gefunden)     

Nuclear envelope changes related to cell activation inHelianthus tuberosus L.

Summary The ultrastructure of nuclei from dormant and activatedHelianthus tuberosus tuber cells has been investigated with particular reference to nuclear pore frequency and nuclear envelope invaginations, and the results discussed in relation to observations made on other cell types.     

Hexosaminidase and alkaline phosphatase activities in articular chondrocytes and relationship to cell culture conditions

Hexosaminidase and alkaline phosphatase activities in rabbit articular chondrocytes have been studied under different cell culture conditions. Chondrocytes were cultured in monolayer primary culture, monolayer subcultured to the fifth passage (in vitro aging) and cultured within a collagen gel; enzymatically released cartilage cells were used as control. Under these conditions, the two enzymes behave quite differently in relationship to alteration of the chondrocyte phenotype in culture. Increased lysosomal hexosaminidase activity could be considered to be a marker of the dedifferentiated phenotype in monolayer subculture; membrane alkaline phosphatase activity could be used as a marker of non-proliferating cells.     

The influence of partial synchronization of cell growth on the inhibition of L1210 cell viability by mouse thymus DNA

Résumé Nous avons trouvé que le cycle de la vie de la cellule L1210 règle les effets inhibitoires du DNA du thymus de la souris sur la viabilité cellulaire. Les cellules obtenues à la phase G₂ des cultures partiellement synchronisées étaient inhibitées presque 2 fois plus que les cellules obtenues des cultures asynchroniques. Le DNA n'avait guère d'effet toxique sur les cellules obtenues aux phases S et M. Les fluctuations dans la viabilité cellulaire n'étaient pas causées par des changements proportionnels dans l'absorption du DNA.

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This work was supported in part by grant No. GW-733 of the NSF and by grant No. CA-08763 of the USPHS.     

Enzyme histochemical reaction of mouse ova

Zusammenfassung Nachweis, dass in den Eiern im Mäuseeileiter grosse Quantitäten von ATPase, Cytochromaoxidase, Glukose-6-phosphat-dehydrogenase, Mitochondrialdehydrogenasen, saure und alkalische Phosphatasen lokalisiert sind. In den Eiern im Eierstock hingegen wurden ebenfalls ATPase, Phosphatase und Lactat-dehydrogenase festgestellt, obwohl von den Mitochondrialenzymen nur geringe Mengen gefunden wurden.     

The biological activities of arginine-vasotocin obtained by a new synthesis

Zusammenfassung Eine neue Synthese von Arginin-Vasotocin (= Arg⁸-Oxytocin = Ile³-Arginin-Vasopressin) wird beschrieben. Das reine synthetische Peptid erwies sich in verschiedenen biologischen Testen wirksamer als nach früheren Literaturangaben zu erwarten war.