Biomedical subjects

B Bosman

Publications and source records attributed to B Bosman.

4 recordsLinked to original sources

PubMed1997

Increased plasma malondialdehyde associated with cerebellar structural defects.

BACKGROUND: Malondialdehyde (MDA) in plasma is regarded as an indicator for increased lipid peroxidation. METHOD: Measurements of MDA concentrations in plasma were compared among healthy children (n = 31), patients with neurological disorders or epileptic syndromes (n = 15), and children with pontocerebellar structural defects (n = 31), where the cause or genetic defect remained unknown. RESULTS: In healthy children the median MDA value was 5.86 nmol/ml (mean (SD) value: 6.25 (1.97), range: 3.76-11.19). For the group with various neurological disorders or epilepsy, the values were similar with the median value at 5.66 nmol/ml (range 0.22-10.86). Compared with healthy controls and the neurological/ epileptic group, the 31 children with pontocerebellar structural defects had significantly increased MDA values with a median value at 11.29 nmol/ml (mean (SD) value: 11.62 (3.27), range 3.65-19.22). IMPLICATION: These findings of increased plasma MDA in the majority of children with pontocerebellar structural defects of unknown origin raised the question whether increased lipid peroxidation leads to prenatal and postnatal pontocerebellar maldevelopment or degeneration.

Adolescent↗

PubMed1994

Testing of lipoxygenase inhibitors, cyclooxygenase inhibitors, drugs with immunomodulating properties and some reference antipsoriatic drugs in the modified mouse tail test, an animal model of psoriasis.

Topical administration of lipoxygenase and cyclooxygenase inhibitors, antipsoriatic drugs and some immunomodulating drugs on adult mouse tail scales showed variable induction of of orthokeratosis. Dithranol and retinoic acid showed ED50 concentrations of 0.5% and 0.23%, respectively. The lipoxygenase inhibitors catechol and octyl gallate showed ED50 of 2.5 and 13.4%. 10% lonapalene showed 20% activity, curcumin, linoleic acid, primrose oil and AA673 10-15% activity, methyl and ethyl gallate 5% activity, nordihydroguaiaretic acid, diethylcarbamazine, ebselen, esculetin, quercetin, AA861, gallic acid, dodecyl gallate and 15-hydroxyeicosatetraenoic acid no activity. The cyclooxygenase inhibitors indomethacin, acetylsalicylic acid and bufexamac were inactive, benoxaprofen showed 14% activity. The immunomodulating drugs fluorouracil and triamcinolone showed > 10% activity, cyclosporin A and thalidomide no activity. Fumaric acid showed 5% activity. The results show that this model could be proposed for screening antipsoriatic drugs.

Animals↗

PubMed1992

A quantitative method for measuring antipsoriatic activity of drugs by the mouse tail test.

Topical treatment of the mouse tail with antipsoriatic drugs enhances orthokeratotic cell differentiation in the epidermal scales. We developed a new evaluation system for this test which allows quantification of drug efficacy. Drugs were applied topically, once daily, 5 times a week, for 2 weeks. Two hours after the last treatment the animals were sacrificed, longitudinal sections of the tail skin were made and prepared for histological examination (hematoxylin-eosin staining). As indicator of orthokeratosis (OK), the length of the granular layer per scale was measured microscopically with a semiautomatic image evaluation unit and related to the total scale length (= % OK per scale). Drug activity was defined by the increase in the total length of orthokeratotic regions, 100% activity corresponds to a granular layer extending over the whole scale length. In this model dithranol and retinoic acid dose-dependently increased orthokeratosis up to 75 and 79%, respectively. Beech tar, in a concentration of 5% induced a 19% increase in orthokeratosis. Morphometric quantification by image analysis of the conversion of parakeratotic into orthokeratotic regions in mouse tail scales induced by topical drug treatment seems to be a suitable and reliable procedure to investigate new drugs from which antipsoriatic activity may be expected.

Animals↗

PubMed1987

Control of glycolysis by glyceraldehyde-3-phosphate dehydrogenase in Streptococcus cremoris and Streptococcus lactis.

The decreased response of the energy metabolism of lactose-starved Streptococcus cremoris upon readdition of lactose is caused by a decrease of the glycolytic activity (B. Poolman, E. J. Smid, and W. N. Konings, J. Bacteriol. 169:1460-1468, 1987). The decrease in glycolysis is accompanied by a decrease in the activities of glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate mutase. The steady-state levels of pathway intermediates upon refeeding with lactose after various periods of starvation indicate that the decreased glycolysis is primarily due to diminished glyceraldehyde-3-phosphate dehydrogenase activity. Furthermore, quantification of the control strength exerted by glyceraldehyde-3-phosphate dehydrogenase on the overall activity of the glycolytic pathway shows that this enzyme can be significantly rate limiting in nongrowing cells.

Energy Metabolism↗