Biomedical subjects
Publications and source records attributed to U Wenzel.
The relative surface tension xi = (Pi/Mv)4 can be used in structure-activity studies as additional parameter. Here, Pi = parachor, Mv = molar volume (Tables 1 and 2) of the substituents. Some examples demonstrate the application.
The present investigation into the pharmacokinetic behaviour of the propolis constituent pinocembrin which produces a relatively good antimicrobial effect in vitro, points to possible causes of its therapeutical failure when mice infected with Candida albicans were used as a model. The biological half-life periods for the phases of invasion and elimination were 26 and 268 min, respectively. The biological availability was 25%. Almost 15% of pinocembrin are excreted unchanged in faeces and urine. Even in case of oral application of doses of up to 500 mg/kg, the serum pinocembrin concentrations did not equal the MIC (minimal inhibitor concentration) values required in vitro. A considerable first-pass effect and accelerated processes of elimination are discussed as possible causes. It appears from the present findings that pinocembrin may be utilizable only for the external treatment of stomatomycoses.
IQ measurements were performed in 33 patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (110.6 +/- 13.9), in 29 unaffected siblings (113.8 +/- 11.3) and in 48 parents (104.4 +/- 9.4). The results were significantly higher than normal in the patients and siblings, but not in the parents. They were also significantly higher in the patients and siblings as compared to the parents. It is concluded that neither pre- or postnatal androgen exposure nor a genetic linkage can be made responsible for the increased IQ in congenital adrenal hyperplasia, but that more likely methodological factors (such as outdated standards) account for the higher values in patients and siblings.
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The Kleine-Levin syndrome (periodic hypersomnia and megaphagia in adolescence) was considered till 1962 to be a disorder limited to the male adolescents. Since 1924, however, a few female cases have been reported about. These, being approximately 20 patients, are registered by their essential symptoms together with 2 additional cases observed by the author. Moreover, prospective catamneses, covering periods of more than 12 years, were described for the first time. Probably, the Kleine-Levin-syndrome is the product of disturbed functions involving structures of hypothalamus and the reticular system. The syndrome seems to belong to the same groups of periodical diseases as migraine: in particular it exhibits similar relations to the genital cycle. Therapeutical success was attained by administration of amphetamines. In course of time, the episodes become spontaneously rarer and mostly cease.
Yellow and white mutants of the strains Nocardia pellegrino SN 5108 R have been isolated. Regarding their morphological and physiological properties, the mutants are identical with the wild type bacteria with the exception of their pigmentation and lipid composition. However, the pigment composition (number, Rf-values and spectra of the pigment components) of the yellow mutant is identical with that of the wild type; as a consequence, the modified pigmentation of the yellow mutant cannot be explained by an altered pigment synthesis. The wild type cells and the mutant SN 5108 G contain three main pigment components designated as I, II and III. Components II and III posses a marked indicator character and show a bathochromic shift in solutions of pH 12 or higher. Components II and III contain functional groups which are able to react with acetic acid yielding acetylated products; after acetylating, no bathochromic shift in alkali occurs. Intact cells of the wild type retain their orange-red pigmentation in buffer solution with a pH-value of 12 or higher. Cells of the yellow mutant, however, change the yellow color immediately after the alkali treatment to orange-red; this new color is identical with that of the wild type and can be changed to yellow by placing the cells into 1 N HCl. Regarding these facts it seems to be very probable that the functional groups of the pigment components II and III are differently bound in the wild type and mutant cells. In the mutant, they are accessible to OH- ions yielding a bathochromic shift while in the wild type cells, OH- ions are unable to provoke this shift. It seems to be also probable that different lipids in the two strains are responsible for the binding of the pigments. So far known, this is the first observation about the occurence of pigment mutants with an altered pigment binding site in the cells.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.