Search results for "molecular biology"
showing 10 items of 13669 documents
Kathepsinaktivit�t in Placenten verschiedener Altersstufen
1954
In Placenten verschiedener Altersstufen wurde nach der Methode vonAnson die Kathepsinaktivitat bestimmt. Dabei zeigte sich, das gegenuber der Fruhgraviditat die Aktivitat am Ende der Schwangerschaft deutlich erniedrigt ist. Bemerkenswert ist die Gruppe der echten Schwangerschaftsubertragungen, die die niedrigsten Werte aufwiesen. Die Differenzen zwischen den einzelnen Gruppen sind statistisch signifikant. Die Bedeutung der Fermentaktivitat fur das Wachstum wird diskutiert.
Differential response of neuronal cells to a fusion protein of ciliary neurotrophic factor/soluble CNTF-receptor and leukemia inhibitory factor
2002
Ciliary neurotrophic factor (CNTF) displays neurotrophic activities on motor neurons and neural cell populations both in vivo and in vitro. On target cells lacking intrinsic expression of specific receptor alpha subunits cytokines of the IL-6 family only act in the presence of their specific agonistic soluble receptors. Here, we report the construction and expression of a CNTF/soluble CNTF-receptor (sCNTF-R) fusion protein (Hyper-CNTF) with enhanced biological activity on cells expressing gp130 and leukemia inhibitory factor receptor (LIF-R), but not membrane-bound CNTF-R. At the cDNA level, the C-terminus of the extracellular domain of human CNTF-R (amino acids 1-346) was linked via a sing…
Intestinal conversion of linoleic acid to arachidonic acid in the rat
1993
Abstract The arachidonic acid (C20:4, n-6) appearing in intestinal lymph during linoleic acid (C18:2, n-6) absorption may originate from enterocyte synthesis or from the liver either after secretion in biliary phospholipids at the same time dietary linoleic acid absorption occurs or via plasma. The radioactivity measured in the total bile collected during the 6 hours of linoleic acid absorption is too small to explain hepatic origin of the C20:4 detected by high performance liquid chromatography analysis of labeled fatty acids recovered in the lymph, in the intestinal mucosa, and the intestinal wall at the peak of linoleic acid intestinal absorption. This study confirms the probability that…
Mutagenit�tspr�fung bestrahlter Lebensmittel mit dem ?dominant lethal test?
1973
An insgesamt 716 Ratten und 750 Mausen wurde eine mogliche mutagene Wirkung einer bestrahlten Nahrung gepruft. Fertilitat, Tragezeitdauer, Wurfgrose, Aufzuchtleistung und Geschlechtsverhaltnis zeigten in 5 aufeinanderfolgenden Rattengenerationen keine Storungen in der Reproduktionsfahigkeit an. Es konnte kein Anstieg der Misbildungsrate bei den Rattenfeten beobachtet werden. Auch die Fruchtbarkeit der mannlichen und der weiblichen Tiere der Mausegeneration war ungestort. Durch den “dominant lethal test” an Ratten und Mausen konnte keine embryotoxische oder mutagene Wirkung der bestrahlten Nahrung festgestellt werden, die sich in mit den verwendeten statistischen Methoden erfasbaren Untersch…
Bioactivation of the Fungal Phytotoxin 2,5-Anhydro-D-glucitol by Glycolytic Enzymesisan Essential Component of itsMechanism of Action
2002
An isolate of Fusarium solani, NRRL 18883, produces the natural phytotoxin 2,5-anhydro-ᴅ-glucitol (AhG). This fungal metabolite inhibited the growth of roots (I50 of 1.6 mᴍ), butit did nothave any in vitro inhibitory activity. The mechanism of action of AhG requires enzymatic phosphorylation by plant glycolytic kinases to yield AhG-1,6-bisphosphate (AhG-1,6- bisP), an inhibitor of Fru-1,6-bisP aldolase. AhG-1,6-bisP had an I50 value of 570 μᴍ on aldolase activity, and it competed with Fru-1,6-bisP for the catalytic site on the enzyme, with a Ki value of 103 μᴍ. The hydroxyl group on the anomeric carbon of Fru-1,6-bisP is required for the formation of an essential covalent bond to ζ amino fu…
Kutane und systemische Veränderungen mit Ähnlichkeiten zum Omenn‐Syndrom bei heterozygoter Mutation im RAG2‐Gen
2021
Interferon-alpha stimulates production of interleukin-10 in activated CD4+ T cells and monocytes
1996
In the present study, we investigated the effect of interferon-alpha (IFN-alpha) on the expression of interleukin-10 (IL-10) mRNA and protein synthesis in human monocytes and CD4+ T cells. In mononuclear cells, IFN-alpha induced expression of IL-10 mRNA and further enhanced lipopolysaccharide (LPS)-stimulated IL-10 expression. In purified monocytes, a strong expression of IL-10 mRNA induced by LPS was not further enhanced by IFN-alpha. In highly purified CD4+ T cells, IFN- alpha upregulated IL-10 mRNA upon activation with phytohemagglutinin and phorbol myristate acetate. In purified monocytes, an effect of IFN- alpha on IL-10 protein synthesis was dependent on costimulation with LPS. Maxima…
Dielektrische Verluste bei polaren Molek�len mit mehreren inneren Rotationsachsen
1953
Fur ellipsoidformige Molekule, bei denen der Dipol sich durch Rotation um mehrere innermolekulare Achsen im Felde orientieren kann, wird die Relaxationszeitverteilung berechnet. Diese aus diskreten Einzelwerten bestehende Verteilung stellt eine erste Naherung dar, die mit mittleren Beweglichkeiten der polaren Gruppen und des gesamten Molekuls rechnet. Eine Anwendung auf Messungen an Kettenmolekulen in verdunnter Losung am langwelligen Ende des Gebiets der Dipolabsorption zeigt, das man auf diese Weise Aussagen uber die mittlere Beweglichkeit polarer Gruppen auch bei komplizierteren Molekeln gewinnen kann.
Permian-Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution
2014
The Permian and Triassic were key time intervals in the history of life on Earth. Both periods are marked by a series of biotic crises including the most catastrophic of such events, the end-Permian mass extinction, which eventually led to a major turnover from typical Palaeozoic faunas and floras to those that are emblematic for the Mesozoic and Cenozoic. Here we review patterns in Permian-Triassic bony fishes, a group whose evolutionary dynamics are understudied. Based on data from primary literature, we analyse changes in their taxonomic diversity and body size (as a proxy for trophic position) and explore their response to Permian-Triassic events. Diversity and body size are investigate…