PubMed Health⌕ Search

Biomedical subjects

H Stepien

Publications and source records attributed to H Stepien.

33 records · Page 2Linked to original sources
PubMed1987

Effects of diazepam on cell proliferation in cerebral cortex, anterior pituitary and thymus of developing rats.

The effect of a single dose (5mg/kg b.w.) of diazepam on the cell proliferation in selected organs of 11-day old female Sprague-Dawley rats has been investigated. The stathmokinetic method (counting of mitoses after colchicine administration) has been used for evaluation of cell replication. The significant fall of the mitotic activity in the parietal cerebral cortex and the anterior pituitary gland was found. On the other hand, the increase of the mitotic activity in thymus was observed. The reported data, taken together with the previous observations from our and other laboratories, suggest the involvement of benzodiazepine receptor in the control of cell proliferation.

Animals↗
PubMed1987

Somatostatin suppression of meningioma cell proliferation in vitro.

Considering the presence of a stereospecific receptor for somatostatin (SST) in human meningioma cells and the possible involvement of this neuropeptide in the growth control of certain meningioma cell lines, the effects of SST on the proliferation of human meningioma cells in vitro was investigated. Tumour tissues for primary cell cultures were obtained surgically from 2 women with histopathological diagnosis of meningothelial meningioma. The incorporation of [3H]-thymidine into meningioma cells DNA was measured as an index of the cells proliferation. It was shown that SST (10(-7)-10(-5) M) significantly inhibited the [3H]-thymidine incorporation. The results have indicated that SST may have an antiproliferative effects on the meningioma tumour cells in vitro.

Adult↗
PubMed1986

Reduced lumbar cerebrospinal fluid corticotropin releasing factor (CRF) levels in amyotrophic lateral sclerosis.

Corticotropin-releasing factor (CRF) is widely distributed within the brain and spinal cord and may have direct extrahypophysiotrophic effects, independent of its pituitary action. The CRF level was measured using, the RIA method in cerebrospinal fluid (CSF) from 5 patients with amyotrophic lateral sclerosis (ALS), and in CSF from 10 patients with discopathy, treated as a controlled group. The median values of CRF level in the patients with ALS was 27.5 pg/ml, and this value was significantly lower than in controls, 53.5 pg/ml (P less than 0.05). These results suggests that CRF may be related in the pathophysiology of ALS.

Aged↗
PubMed1985

Effect of somatostatin on the proliferation of mouse spleen lymphocytes in vitro.

The effect of somatostatin on the spontaneous proliferation of mouse spleen lymphocytes was investigated in vitro. The rate of 3H-thymidine incorporation was used as an index of lymphocyte proliferation. Somatostatin in a concentration of 10(-7) M enhanced the lymphocyte proliferation and abolished the antiproliferative effect of rat hypothalamic extract. Lower concentrations of somatostatin slightly decreased the lymphocyte DNA synthesis.

Animals↗
PubMed1982

Stimulation of lymphocyte proliferation to monitor fractionation of thymus extracts.

Multi-step fractionations by solvent extractions, gel filtrations, ion-exchange chromatography, etc., of bovine thymus extracts were monitored by a standardized assay, in vitro, which led to the described peptides, thymones A, B and C. The assay uses spleen cells from neonatally thymectomized mice as tissue relevant to immunoregulation. Assay of incorporation of [3H]-thymidine into DNA located peaks of activities. Calf thymus outer fraction ("CTO") showed activity, but Fraction 5, synthetic thymosin alpha 1, [G1n1]-FTS, and glutathione, were inactive in this assay.

Animals↗
PubMedDate not supplied

Enhancement of human lymphocyte natural killer activity by somatostatin.

The effect of somatostatin 1-14 (SS) on the natural killer (NK) activity of human peripheral blood lymphocytes was investigated. The NK activity was estimated by means of radioactive chromium (51Cr) assay with the use of human leukemia cells K 562 as targets. The previous exposure of lymphocytes obtained from healthy donors to somatostatin in the concentration of 10(-8) and 10(-6) M resulted in the enhancement of NK activity. The finding provides a further evidence of the immunomodulating somatostatin action.

Adult↗
PubMedDate not supplied

Somatostatin and its analog enhance the formation of human leukocyte migration inhibiting factor: further evidence for immunomodulatory action of somatostatin.

The effect of somatostatin-14 (SST) and somatostatin analog D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH2 (RC-102) on migration inhibition of human leukocytes induced by cardiac antigen or phytohemagglutinin (PHA) was investigated. Both SST and RC-102 augmented the migration inhibition, thus indicating the enhanced formation or action of the leukocyte migration inhibiting factor (LMIF). This finding provides additional evidence for the immunomodulatory action of somatostatin.

Adjuvants, Immunologic↗
PubMedDate not supplied

Hypothalamic-pituitary-thyroid axis and the immune system.

The paper reviews data on bidirectional circuits between the hypothalamic-pituitary-thyroid (HPT) axis and the immune system. The effects of thyroliberin (TRH), thyrotropin (TSH) and of thyroid hormones (thyroxine and triiodothyronine) on the immune system, as well as the effects of mono- and lymphokines on the HPT axis are discussed.

Animals↗
PubMedDate not supplied

Effects of benzodiazepines on thymus cell proliferation.

The effects of three different benzodiazepine receptor ligands viz: diazepam, Ro 5-4864, and Ro 15-1788 on the mitotic activity of rat thymus were investigated. It was found that a single injection of diazepam resulted in a significant increase of the mitotic activity of the thymus cells 36 and 48 hours after drug administration. In contrast, Ro 5-4864 significantly depressed the mitotic activity rate 24 and 36 hours after injection. No significant change after the administration of Ro 15-1788 was found. These findings suggest the involvement of both central and peripheral benzodiazepine receptor in the control of thymus cell proliferation.

Animals↗