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Biomedical subjects

M Witt

Publications and source records attributed to M Witt.

At least 109 records · Page 6Linked to original sources
PubMed1987

Comparison of acute toxicities of deoxynivalenol (vomitoxin) and 15-acetyldeoxynivalenol in the B6C3F1 mouse.

The acute toxic effects of deoxynivalenol (DON) and 15-acetyldeoxynivalenol (15-ADON) were compared in the B6C3F1 female mouse after oral and intraperitoneal exposure. Using the abbreviated procedure of Lorke (Archs Toxicol. 1983, 54, 275), LD50 values for DON were estimated to be 78 mg/kg (oral) and 49 mg/kg (ip) whereas the LD50 values for 15-ADON were 34 mg/kg (oral) and 113 mg/kg (ip). Acute doses of these toxins resulted in extensive necrosis of the gastro-intestinal tract, bone marrow and lymphoid tissues, and focal lesions in kidney and cardiac tissue. The minimum doses required for these histopathological effects were consistent with LD50 estimations. The results indicate that 15-ADON was more or less toxic than DON depending on the route of administration. Risk assessments for DON should therefore consider the potential for 15-ADON occurrence and toxicity in food and feed.

Animals↗
PubMed1987

HLA expression on human germinal cells.

Ejaculated human seminal plasma cells obtained from 46 healthy men and 48 infertile patients were tested for expression of HLA class I and II antigens by complement-mediated cytotoxicity, cell-binding radioimmunoassay (CB-RIA), and an ELISA involving monoclonal antibodies (mAbs). In a group of healthy men tested for HLA expression on human spermatozoa, 4 of 46 were positive for class I and II HLA antigens. However, the results were negative in a second examination of the same donors, possibly on account of alterations with time in the expression of various subpopulations of cells which are antigen positive or antigen negative. In a group of infertile patients, we found positive expression of HLA class I and II antigens in 7 of 48 men. The samples contained immature and mature sperm but no contaminating leucocytes or epithelial cells.

Antibodies, Monoclonal↗
PubMed1987

Galactose and fucose binding sites in anterior pituitary cells of the rat. Detection by means of biotinylated lectins.

The oligosaccharide chains of adenohypophyseal glycoprotein hormones fulfill important functions concerning their stability and biological activity. Galactose, histochemically detectable by the Peanut lectin (PNA), could be found after removal of sialic acid in cells situated mainly in the medioanterior region of the pituitary. The Ulex europaeus I lectin (UEA I) reacted with fucose containing sites predominantly in the Golgi-apparatus of nearly all cells. After incubation with neuraminidase, however, fucose may be detected also in the cytoplasm of cells of the medioanterior region. The biological significances of the results is discussed.

Animals↗
PubMed1985

Influence of pyrazolones on hepatic glutathione in rats.

Aminophenazone, phenazone, propyphenazone, and paracetamol given to female Wistar rats in a dose of 3 mmol/kg decrease the GSH content in the liver by 24, 18, 58, and 24 per cent, respectively. After the repeated administration (5 days) only aminophenazone depletes the hepatic GSH. The pretreatment with phenobarbital or cobaltous chloride has an influence only on the effect of propyphenazone. Hepatotoxins cause more extensive hepatotoxic alterations than the drugs investigated, however, their influence on the hepatic GSH level is negligible. Therefore it can be concluded that a temporary GSH depletion is not always linked with a hepatotoxic effect.

1-Propanol↗
PubMed1983

Some aspects of structure of murine H-2d antigens.

The apparent molecular weight of proteins precipitated by normal rabbit serum from lysates of lymph node cells ranged from 10 000 to 150 000. Mono-specific anti-H-2d serum precipitated molecules composed of heavy and light chains with Mr of 47 000 and 12 000, respectively. Tunicamycin treatment caused a decrease of the molecular weight of heavy chain by 4 000 and a change of pI from 5.2 - 5.9 to 5.4 - 5.8. Non-glycosylated heavy chain exhibited Mr of 43 000. The oligosaccharide side chains were resistant to digestion by endo-beta-N-acetylglucosaminidase H. The Mr and pI of beta 2-microglobulin were not altered by treatment with tunicamycin and endo-beta-N-acetylglucosaminidase H. Tunicamycin caused a 50% decrease of overall synthesis of cellular proteins.

Acetylglucosaminidase↗
PubMed1982

Partial purification, characterization and cell-free translation of mRNAs coding for H-2d antigens.

Microsomal RNA from SL2 cells was fractionated on oligo(dT)cellulose into three fractions: I was very similar to the non-fractionated RNA, II contained 28S and 18S rRNA, III [poly(A)RNA] of 4 - 50S, constituted 1.0-2.1% of the total RNA pool and was still contaminated with rRNAs. The last fraction was synthesized at the highest rate. Anti-H-2d serum precipitated cell-free translation products of 17S (heavy chain) and 10S (beta 2-microglobulin) mRNA fractions obtained by centrifugation on 10-30% linear sucrose gradient. beta 2-Microglobulin synthesis was 5-fold higher as compared with the heavy chain synthesis. Anti-H-2d serum precipitated translation products with Mr of 47 000-48 000 (H-2Dd and H-2Kd heavy chains) and 12 000 (beta 2-microglobulin). With liver mRNA, the patterns of translation products were identical, but beta 2-microglobulin synthesis was lower by a half than heavy chain synthesis. H-2d heavy chain messenger constituted 0.3-0.4% of the enriched fraction and was purified 15-20--fold.

Animals↗
PubMed1971

Hirsutes.

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17-Ketosteroids↗