Ein Beitrag zur Kenntnis von Lanatosid D

Summary A preparative method for the isolation of lanatoside D has been developed, and fundamental pharmacological characteristics of the pure compound have been established.The genuine glycoside has been converted to desacetyllanatoside D.     

Ecological and evolutionary implications of digestive processes: Bird preferences and the sugar constituents of floral nectar and fruit pulp

Plants pollinated and dispersed by different groups of birds offer different kinds of sugars in nectar and fruit pulp. The preferences and physiological traits of avian pollinators and seed dispersers are broadly correlated with the sugar composition of the nectar and fruit that they feed on and appear to have influenced the evolution of the sugar composition of the rewards that plants offer. Hummingbirds prefer sucrose whereas many nectar- and fruit-eating passerines prefer glucose and fructose. Preference for hexoses in passerines seems to be associated with poor sucrose assimilation resulting from two physiological mechanisms: lack of intestinal sucrase activity and fast passage rates. Sucrase activity absence appears to be restricted to a single phylogenetic group (the sturnid-muscicapid lineage). Fast passage rates seem to be characteristic of many small frugivores and to hinder the assimilation of complex nutrients that require hydrolysis before absorption. Hummingbirds have extremely specialized digestive traits that allow them to assimilate sucrose at high rates and with extremely high efficiency. These specialized digestive traits appear not to be present in many nectar-feeding passerines.     

Effect of dipyridamole and adenosine monophosphate on cell proliferation in the hemopoietic tissue of normal and gamma-irradiated mice

Combined treatment with dipyridamole and adenosine monophosphate enhances cell proliferation in the hemopoietic tissue of normal and gamma-irradiated mice. This effect can be explained by the elevation of extracellular adenosine, and the receptor-mediated activation of the cell adenylate cyclase system.     

Pheromone and terpene attraction in the bark beetleIps typographus L.

Zusammenfassung Es wird gezeigt, dassIps typographus L. primär durch Terpene und sekundär durch Pheromon der Männchen zu den Brutstämmen gelockt wird.

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This study was performed while J.A.R. was at the Institute of Entomology, Prague, on the exchange program of the National Academy of Sciences, and the Czechoslovak Academy of Science and was approved for inclusion in the U.S. International Biological Program.     

Polarographic determination of DDT

Zusammenfassung Es wird eine schnelle, hochempfindliche polarographische Bestimmung von DDT beschrieben und das durch Nitrieren von DDT erhältliche Tetranitroderivat zur Polarographie verwendet.     

Die Wirkung der Ultraviolettbehandlung auf die Überlebensverhältnisse röntgenbestrahlter Mäuse

Summary 300 r whole body X-ray irradiation of mice did not decrease the circulating platelet count, if this dose was preceeded by 24 h of ultraviolet-irradiation. More animals survived the X-ray (500, 550, 600 r) injury, if the irradiation occurred after ultraviolet treatment given 24 and 48 h before. The number of days survived is also increased. The ultraviolet light seems to have some protective effect against injury caused by X-ray.     

Cumulation of liver lipids after administration of iron

Zusammenfassung Die vorübergehende Kumulation der Leberlipide nach Verabreichung von zweiwertigem Eisen und Askorbinsäure führte zur Annahme, dass der durch Eisen induzierte peroxidative Abbau der ungesättigten Fettsäuren am anomalen Stoffwechsel teilnimmt.     

Interaction of benznidazole reactive metabolites with nuclear and kinetoplastic DNA,proteins and lipids fromTrypanosoma cruzi

Summary Epimastigotes ofTrypanosoma cruzi (Tulahuen strain Tul 0 stock) biotransform benznidazole (N-benzyl-2-nitro-1-imidazone acetamide) to reactive metabolites that bind covalently to DNA, proteins and lipids of the parasite. These effects might be related to the trypanocidal action of benznidazole, a chemotherapeutic agent against Chagas' disease.     

The effect of age and pinealectomy on the hypertension produced by adrenal regeneration

Zusammenfassung Nach Pinealektomie unterbleibt eine Hypertonie (Skelton), falls einseitige Nephrektomie und Adrenektomie mit Enukleation der übrigen Nebenniere bei jungen Ratten durchgeführt wurde. Wird die experimentelle, Hypertonie verursachende Operation bei adulten Tieren praktiziert, so bleibt Pinealektomie ohne jeden Effekt.