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M Oertel

Publications and source records attributed to M Oertel.

24 records · Page 2Linked to original sources
PubMed1993

Selenium-dependent regulation of type I 5'-deiodinase expression.

Selenite concentration regulates activity and expression of the p27 substrate-binding subunit of type I 5'deiodinase (5'-D) and of a protein labeled with bromoacetylthyroxin (BrAcT4), or p30, with yet unknown function in a porcine-kidney epithelial cell line (LLC-PK1) cultured in serum-free medium. p27 is metabolically labeled by 75-selenite and affinity labeled by BrAc[125I]T4. Compared with glutathione peroxidase, expression of the p27 5'D subunit (5'-DI) is observed at 10-fold-lower concentrations of selenium in the growth medium, suggesting an intracellular hierarchy of selenite utilization. Selenium deficiency retards cell growth and prevents 5'-DI expression and may thus impair thyroid hormone action in vivo.

Affinity Labels↗
PubMed1992

Selenium supply regulates thyroid function, thyroid hormone synthesis and metabolism by altering the expression of the selenoenzymes Type I 5'-deiodinase and glutathione peroxidase.

Selenium supply appears to be insufficient in several regions of Europe as indicated by analysis of plasma and tissue selenium content and measurements of selenium dependent glutathione peroxidases (GPx). Selenium deficiency alters both thyroid hormone synthesis and tissue specific activation by 5'deiodinase isoenzymes. Human and rat Type I 5'deiodinase have been identified as selenoprotein containing selenocysteine in its active site. Regulation of selenium dependent expression of Type I 5'deiodinase occurs at the transcriptional and posttranscriptional level and a cellular hierarchy of selenite incorporation was found for Type I 5'deiodinase over GPx in LLC-PK1 kidney cells. The role of other newly discovered selenoproteins for thyroid hormone synthesis, activation, and action has to be investigated.

Animals↗
PubMed1992

The nude rat is established as a model for endocrine studies: regulation of thyroid function and xenotransplantation of a thyroid tumor cell line.

The thyroid physiology of athymic nude rats, rnu/rnu, is characterized and established here as an animal model to study transplanted thyroid tumors. Male rats were catheterized 5 days before experiments were started. The mean thyroid-stimulating-hormone (TSH) plasma concentrations were 2.9 +/- 0.6 ng/ml during infusion of 0.25 ml/h of 0.9% NaCl (n = 12). T3 plasma concentrations were 2.6 +/- 0.4 ng/ml. T4 plasma levels were 22.0 +/- 5.6 micrograms/dl. A bolus of 0.1 mg thyrotropin-releasing hormone (TRH) significantly increased TSH plasma concentrations (P less than or equal to 0.001; from 2.9 +/- 0.6 to 7.8 +/- 1.1 ng/ml, n = 12). No pulsatile TSH secretion was observed in a 2-hour period with blood samples taken every 10 minutes (n = 12) and hourly sampling disclosed no circadian variation of TSH during a 24-hour period (n = 4). Successful xenografting was possible in 12 of 15 cases using a follicular thyroid carcinoma cell line (FTC 133). Measurement of human thyroglobulin (hTg) by a hTg IRMA revealed high levels in rats with functional FTC tumors, whereas no hTg was detected in untransplanted rats or animals with nonfunctional transplants.

Animals↗
PubMed1991

[Concepts, experiences and problems in the gradual reintegration into the work process. Results of an inventory taking].

Within the scope of an exploratory inventory check on measures of gradual reintegration into the work process, basic information has been collected for the first time. The programmes up to now implemented by rehabilitating agencies are presented with regard to their structural principles and various financing schemes. A critical assessment of introduction, implementation and success of these measures and their determinants is given, as well as proposed improvements and demands made by experts and the patients concerned.

Adult↗