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Biomedical subjects

G Gille

Publications and source records attributed to G Gille.

At least 37 records · Page 2Linked to original sources
PubMed1998

Stability and refractoriness of the high catalase activity in the oxidative-stress-resistant fission yeast Schizosaccharomyces pombe.

Effect of oxygen and metabolic substrates (glucose, ethanol) on the catalase activity of anaerobically grown Schizosaccharomyces pombe cells was assessed and compared with that of Saccharomyces cerevisiae in order to determine the catalase activity regulation in S. pombe. In contrast to S. cerevisiae, the total catalase activity of permeabilized S. pombe anaerobically grown cells is higher than that found in aerobically grown cells, is stable and constant under all circumstances (i.e. it is not induced by oxygen and/or substrates), and only a negligible part (3-5%) of it is contributed by de novo protein synthesis during aeration with or without substrates. The patent catalase activity of intact cells rises 2-fold during 6-h aeration without substrate and 7-8-fold in the presence of glucose or ethanol. The increase is not inhibited by cycloheximide and is thus not due to de novo catalase synthesis, but may reflect enhanced transport of catalase to the cell surface or a permeabilization of the plasma membrane during the aeration.

Aerobiosis↗
PubMed1995

Oxidative stress and living cells.

The review deals with the effects of reactive oxygen species, both radical and nonradical (e.g. hydrogen peroxide), on cells and organisms. The chemical and biochemical aspects include description of individual reactive oxygen species, chemical reactions giving rise to them, their interconversions and interactions with metals (Fe2+, Cu2+, Cu+) and other substances (scavengers, antioxidants). The biological aspects concern the specific features and locations of cellular enzyme systems involved in radical production and/or removal. Major harmful effects of the species on the molecular (protein oxidation, lipid peroxidation, damage to DNA) and cellular level (effect on signal transduction, on cell membrane functions and on gene expression) are surveyed. Methods whereby cells and organisms cope with the onslaught of these reactive species are reviewed as well as implications for plant, animal and human health.

Animals↗
PubMed1995

[The health of girls during puberty].

This report is based on many years of working experience in the field of health promotion and sexual education of girls. The hypothetically assumed relation between the subjective feeling of well-being and pubertal influences is reflected in figures. The results reveal strong irritations regarding bodily, affective and social factors which the girls have to cope with. High acceptance is documented for discussions about health and sexuality with a medical expert. Rubella vaccination is recommended as a starting point for activities of the Public Health Service in preventive work with girls in schools.

Adolescent↗
PubMed1993

Effect of hydrogen peroxide on sugar transport in Schizosaccharomyces pombe. Absence of membrane lipid peroxidation.

Stationary unaerated cells of S. pombe containing endogenous substrates but not energized by any exogenous ones take up 2-deoxy-D-glucose, 6-deoxy-D-glucose, D-xylose and D-arabinose actively over diffusion equilibrium. The active uptake is inhibited by 20-100 mmol/L H2O2 which causes an increase in KT but has no effect on Jmax. This "competitive inhibition" indicates that H2O2 affects directly the sugar binding sites of the transporters. The ATP-binding site of the plasma membrane H(+)-ATPase is also affected by 100 mmol/L H2O2; the KT decreases 7-fold, Jmax about 2.5-fold. These effects are not likely to be mediated by membrane lipid peroxidation which appears to be lacking in S. pombe, and this lack may be one of the reasons for the high resistance of this yeast to H2O2. Because of this S. pombe represents a suitable system for studying direct effects of oxidants on membrane proteins.

Antimycin A↗
PubMed1993

Response of catalase activity and membrane fluidity of aerobically grown Schizosaccharomyces pombe and Saccharomyces cerevisiae to aeration and the presence of substrates.

Intracellular catalase (EC 1.11.1.6) activity of permeabilized aerobically grown cells of Schizosaccharomyces pombe was insensitive to cell aeration and inhibition of protein synthesis, and was only mildly enhanced by the presence of glucose and ethanol via de novo protein synthesis. By contrast, the intracellular catalase activity of Saccharomyces cerevisiae, which, in freshly harvested cells, was two to three times lower than that in Sch. pombe, increased on aeration without substrates or with ethanol and was inhibited on aeration with glucose following cell permeabilization. The enhanced intracellular activity was due to de novo protein synthesis while the inhibitory effect of glucose, absent in Sch. pombe, was caused by one of the major glucose metabolites, succinate. The intact-cell catalase activity of both yeasts increased greatly during aeration. In Sacch. cerevisiae, this increase was again prevented by glucose. In parallel, export of catalase to the cell surface increased in both yeasts. This was especially conspicuous in Sch. pombe aerated in the presence of ethanol, and may represent a protective mechanism against the damaging effects of ethanol. The cell-surface-bound catalase activity was confirmed in isolated plasma membranes of both yeasts. The fluidity of the plasma membrane increased during aeration. This effect was further stimulated by the presence of glucose and to a lesser extent by ethanol. Both yeasts exhibited increased extracellular catalase activity during aeration which could not be caused entirely by cell lysis. In Sch. pombe this activity was strongly enhanced by the presence of ethanol.

Aerobiosis↗