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Biomedical subjects

A Wacker

Publications and source records attributed to A Wacker.

At least 19 recordsLinked to original sources
PubMed1998

[75 years after Dandy, Fay and Mixter--looking back on the history of neuroendoscopy].

The first neuroendoscopic operation was done in the year 1910 by the urologically practicing doctor Victor Darwin Lespinasse (1878-1946). Lespinasse never published this procedure. He only reported the case in front of a local surgical society. Several years later (1922/23) the first endoscopic operations in the brain were published by three neurological surgeons within one year (Dandy, Fay and Mixter). This 75 year anniversary is the background for the following historical overview.

Endoscopes↗
PubMed1993

[Prognostic indicators of psychogenic diseases in adulthood based on childhood variables].

Using the data of the Mannheim Cohort Projekt (Schepank, 1987, 1990), the authors investigate possible correlations between psychic symptoms in childhood, risk and protective factors with regard to psychogenic disorders in adulthood. For this, the number of symptoms and the "Impairment-Score" as the degree of psychogenic complaints were related to each other by determining Spearmen's rank correlation coefficient. Additionally, the predictive power of these three variables were investigated by means of discriminance analysis. It could be shown, that the severity of psychogenic illness in adulthood increases with the number of childhood symptoms. There was no evidence for the hypothesis of an increasing predictive power for the assembled variables (number of symptoms, risk factors, and protective factors) in comparison with the single variables. The results found are, however, comparable to the data of two prospective longitudinal studies.

Adaptation, Psychological↗
PubMed1980

Enzymatic hypermethylation of DNA in mouse-mouse somatic cell hybrids.

Somatic cell hybrids between mouse L fibroblasts (A9 cells) and Ehrlich ascites tumour cells were constructed by use of poly(ethyleneglycol). The hybrids were selected in hypoxanthine/aminopterin/thymidine medium and morphologically different syncaryons were isolated by a micromanipulation. They were simultaneously analysed for their tumourogeneity, a release of certain proteins into the culture medium, the activity of pyrimidine salvage pathways, and the extent of enzymatic DNA methylation. None of these hybrids gave a rise of tumours if transplanted into DBA/2 mice. Two of the hybrids released a protein immunologically cross-reacting with antibody against C-peptide of human proinsulin. Activities of pyrimidine salvage pathways as measured by incorporation of [14C]deoxycytidine into DNA cytosine and thymine, respectively, are different in the analyzed cells. Enzymatic DNA methylation in somatic cell hybrids was significantly elevated as compared to the parental cell lines.

Animals↗
PubMed1980

Quantitative determination of small amounts of L-penicillamine in D-penicillamine after desulfurization with Raney nickel.

Commercially available D-penicillamine is desulfurized with Raney nickel at room temperature in aqueous solution. L-Valine derived from contaminating L-penicillamine is determined colorimetrically by the amino acid oxidase/peroxidase reaction, using 2,2'-azino-di-[3-ethyl-benz-thiazoline-sulfonate(6)] (ABTS). The procedure assures the quantitation of L-penicillamine contaminating D-penicillamine down to the level of 0.1%.

Drug Contamination↗
PubMed1978

[Antiviral activity of plant components. 1st communication: Flavonoids (author's transl)].

Some drugs effective against influenza contain flavonoids. We therefore examined the antiviral effect of hesperidin, hesperidinmethylchalcon, trihydroxyethylrutin, catechol, quercitrin, rutin and aurantiin against vesicular stromatitis virus (VSV) action on mouse fibroblasts and that of hesperidin against influenza virus in HeLa cells system by means of dye uptake measurements (Finter) and by plaque reduction test, respectively. Preincubation of the cells with the flavonoids 6--8 h before virus addition was inevitable. Protection of cells against virus action persisted for about 24 h and it abruptly disappeared after an addition of hyaluronidase. Maximal inhibition of virus action was achieved with a concentration of 200 microgram/ml flavonoid.

Adsorption↗
PubMed1977

Aminoacylation of rat liver transfer RNA with L-penicillamine. On the specificity of the aminoacylation reaction.

L-]14C]Penicillamine is bound to RNA from rat liver in an in vitro reaction catalyzed by rat liver aminoacyl-tRNA synthetases. Addition of certain naturally occuring amino acids results in a significant decrease of L-penicillamine binding. The most potent inhibitor of this binding is L-valine, followed by L-isoleucine and L-threonine. Amino acids without structural relationship to L-penicillamine in the non-functional part of the molecule, such as L-phenylalanine, are ineffective. Studies on the competition of L-penicillamine and L-isoleucine, respectively, with L-valine demonstrate the high specificity of the aminoacylation reaction. They show that the change of L-penicillamine binding to tRNA Val is considerably lower than that of L-valine.

Amino Acids↗