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Biomedical subjects

J Winkler

Publications and source records attributed to J Winkler.

At least 163 records · Page 9Linked to original sources
PubMed1983

Carp preproinsulin cDNA sequence and evolution of insulin genes.

The nucleic acid sequence of the preproinsulin cDNA of carp (Cyprinus carpio), cloned in the PstI-site of pBR322 (1), has been determined. The sequenced insert of 439 bp includes the complete coding information for carp preproinsulin (108 amino acids), 10 nucleotides of the 5'-and 105 nucleotides of the 3'-nontranslated regions. The nucleotide sequence confirms the previously established amino acid sequence of carp insulin (2) and determines those of the signal (21 aa 1) and C-peptide (35 aa 1). The observed shortness of the signal peptide of carp preproinsulin and the N-terminal addition of 2 amino acids to the carp insulin B-chain suggest that the cleavage site of the signal peptidase has moved. Calculations based on the comparison of known preproinsulin cDNA sequences showed that the evolutionary distance between fresh water and salt water teleostians is not smaller than between man and chicken.

Amino Acid Sequence↗
PubMed1983

Lung strips from guinea pigs as test system for lipoxygenase inhibitors. Inhibition of arachidonic acid-induced contractions by 3-t-butyl-4-hydroxyanisole and nordihydroguaiaretic acid.

Lung strips and tracheal spirals from guinea pigs and rats were compared as test systems for lipoxygenase inhibitors. The contraction of the smooth muscle was induced by addition of arachidonic acid. Lung strips of guinea pigs proved to be the most suitable in vitro model. Under basal conditions half-maximal contraction was produced by 13 microM arachidonic acid (AA) which was strongly inhibited by 50 microM nordihydroguaiaretic acid (NDGA) or 100 microM 3-t-butyl-4-hydroxyanisole (BHA). NDGA and BHA caused a shift of response towards higher concentrations of AA. BHA also produced pronounced dilatations of both basal tonus and carbachol-induced contractions of the preparations from the respiratory tract. It is concluded that the actions of NDGA and BHA on the airway preparations are due to inhibition of the lipoxygenase reaction and, therefore, of leukotriene synthesis. The assumption of the lipoxygenase inhibition is supported by their action on purified lipoxygenase from rabbit reticulocytes which was inhibited by 50% by 0.5 microM NDGA and 160 microM BHA. In contrast, the antioxidant 2,6-di-t-butyl-4-hydroxytoluene (BHT) did not inhibit at all at 1 mM. To the knowledge of the authors this is the first evidence so far reported for the bronchodilating action of BHA.

Animals↗
PubMed1980

Glycosylation of influenza virus proteins in the presence of fluoroglucose occurs via a different pathway.

In the presence of fluoroglucose, an inhibitor of formation of mannosylphosphoryl and glucosylphosphoryl-dolichol, lipid-dependent glycosylation of influenza virus glycoproteins is strongly, but not completely inhibited. The oligosaccharides that were transferred to protein in the presence of fluoroglucose came directly dolichol-linked intermediates. However, they were smaller than the normal high-mannose oligosaccharides and, furthermore, resistant towards digestion with endo-beta-N-acetylglucosaminidase H. By excluding mannosylphosphoryl-dolichol, similar dolichyl-pyrophosphate-liked intermediates were synthesized in vitro by membranes from fluoroglucose-treated cells and they were shown to glycosylate protein.

Dolichols↗
PubMed1979

[Germinating capacity of Clostridium butyricum Jena H 8 in transplantation tumors (author's transl)].

Following parenteral application of spores of Clostridium butyricum their intratumoral germination and oncolysis were demonstrated on a variety of mouse transplantation tumors. The germination and propagation of the clostridia was restricted exclusively to the tumor tissue, they could not be demonstrated bacterioscopically in parallelly run normal tissue specimens. The observed differences of germination and lysis rate are due, in part, to tumor host and transplantate-specific properties.

Animals↗
PubMed1977

The antiarrhythmic effect of prostaglandin E2 on catecholamine-induced arrhythmias.

The antiarrhythmic effect of PGE2 as compared with the adrenergic beta-receptor blocking substance propranolol and the unspecific antiarrhythmic agent ajmaline was examanined on catecholamine-induced arrhythmias of the guinea-pig after preliminary sensibilisation by means of chloroform. Prophylactic administration of the tested substances resulted in a decrease in severity of arrhythmia by 91% after propranolol, by 37% after PGE2 and by 34% after ajmaline. Onset and duration of the arrhythmia were affected only to a negligible degree. The possible mode of action is still under discussion.

Ajmaline↗