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Biomedical subjects

I Köhler

Publications and source records attributed to I Köhler.

30 records · Page 2Linked to original sources
PubMed1983

Methyl 17 beta-carboxyester derivatives of natural and synthetic glucocorticoids: correlation between receptor binding and inhibition of in vitro phytohaemagglutinin-induced lymphocyte blastogenesis.

Several methyl 17 beta-carboxyester derivatives of natural and fluorinated glucocorticoids were synthesized in order to compare their potency to compete for [3H]dexamethasone binding sites in human spleen tumour cytosols (as a source of large quantities of white blood cells) with their potency to inhibit phytohaemagglutinin-induced blastogenesis of normal human peripheral lymphocytes. The 17 beta-carboxylic acids neither show binding activity nor inhibition of blastogenesis. Methylation partially restores the binding capacity and the intensity of this effect depends on the kind of ring substitutions. The sequence of binding potency is identical compared to that of parent steroids and was found to be in the following order: desoxymethasone greater than dexamethasone greater than corticosterone greater than cortisol greater than progesterone greater than 17-hydroxyprogesterone. The phytohaemagglutinin-induced stimulation of [3H]thymidine incorporation resembles the order of binding potency. The methyl 17 beta-carboxyester derivatives of progesterone, 17-hydroxyprogesterone and betamethasone are inactive. The N-benzyl 17 beta-carboxamide analogs of dexamethasone and betamethasone behave like their corresponding carboxyesters, suggesting an important influence of the side chain conformation of 17 beta-carboxyl derivatives on glucocorticoid receptor binding.

Binding, Competitive↗
PubMed1982

Synthesis of a new disulfide affinity adsorbent for purification of human uterine progesterone receptor.

For purification of the human uterine progesterone receptor, an affinity adsorbent was synthesized in which the specific ligand (16 alpha-ethyl-3-oxo-19nor-androst-4-ene 17 beta-carboxylic acid) was bound to derivatized celulose using a disulfide-group-containing spacer. The purified receptor protein, isolated by reductive cleavage of the disulfide bond, bound the synthetic gestagen R5020 with high affinity (Kd 12.2 nmol/l). The affinity gel was highly efficient. A 24000-fold purification of progesterone receptor with a recovery of 40% could be achieved in a single step within 6 h. By means of dodecyl sulphate/polyacrylamide gel electrophoresis two main polypeptides with molecular weights of about 43000 and 108000 could be demonstrated.

Adsorption↗
PubMed1975

[Effects of Turisynchron and Suisynchron on the thyroid gland in rats during simultaneous administration of TSH].

Thyrotrophin was injected i/p at 2 I.U. daily simultaneously with oral administration of Turisynchron at 100 mg/kg or Suisynchron at 125 mg/kg daily for five days to Wistar rats. The uptake of radio-iodine by the thyroid was reduced, and there were slight changes in thyroid structure. Suisynchron produced a milder inhibition of thyroid regulatory mechanisms than Turisynchron.

Animals↗
PubMedDate not supplied

Constitutional chromosome anomalies in patients with cerebral gigantism (Sotos syndrome).

Two boys are presented with the clinical features of cerebral gigantism and chromosomal variants which have not been described so far in this syndrome. In the first boy a de novo pericentric inversion of chromosome Y was found, the karyotypes of all other investigated family members were normal. The patient had an obstructive hypertrophic cardiomyopathy and atrial septal defect type II. The second boy had inherited pericentric inversion of the heterochromatic region of chromosome 9 from his mother. This chromosome 9 variant was also found in his sister who had a similar phenotype but without gigantism. Endocrine evaluation demonstrated normal results in both boys. The intellectual achievement in both cases was average.

Abnormalities, Multiple↗