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Biomedical subjects

R Hall

Publications and source records attributed to R Hall.

At least 487 records · Page 27Linked to original sources
PubMed1978

Labelling of the thyroid cell surface with 125I.

The surface membrane proteins of cultured porcine thyroid cells have been labelled with 125I by the lactoperoxidase method. Evidence that the labelling was restricted to the cell surface was supported by the high viability of the cells in suspension, the high proportion of labelled material in the particulate fraction after homogenization and electron-microscopic autoradiographic studies. The labelled proteins were analysed by electrophoresis on polyacrylamide gels containing sodium dodecyl sulphate and this indicated the presence of ten major labelled protein bands with approximate molecular weights of 175 000, 155 000, 135 000, 88 000, 80 000, 52 300, 39 000, 30 000, 21 000 and 14 300. Comparison of the electrophoretic patterns obtained with cultured human and porcine thyroid cells suggested that there were species differences in the proportions of lower-molecular-weight proteins.

Animals↗
PubMed1978

Solubilization and partial characterization of human and porcine thyrotrophin receptors.

Thyrotrophin (TSH) receptors have been extracted from human and porcine thyroid membranes by treatment with Triton X-100. 125I-Labelled bovine TSH was used to monitor receptor activity. Analysis by gel filtration and electrophoresis on acrylamide gels containing sodium dodecyl sulphate suggested that Triton extracts of human thyroid membranes contained TSH receptors with a molecular weight in the region of 50 000 closely associated with Triton micelles of approximate molecular weight 300 000. Isoelectric focusing studies indicated that the Triton-solubilized TSH binding activity had an isoelectric point of pH 4--4.5. The soluble TSH receptors were heat-labile, showed optimum TSH binding at pH 7.4 and reduced hormone binding at high ionic strength. The TSH binding characteristics of membrane-bound and solubilized human TSH receptors were similar and both preparations gave curved Scatchard plots. Solublized porcine TSH receptors appeared to have a similar molecular weight to the human receptors and were also closely associated with Triton micelles of approximate molecular weight 300 000. Scatchard analysis of TSH binding to membrane-bound or solubilized porcine TSH receptors gave approximately linear plots with association constants of 2.8 +/- 0.95 (S.E.M.) X 10(9) and 1.7 +/- 0.27 x 10(9) l/mol respectively. Comparison of the binding capacities of the solubilized and membrane-bound porcine receptors indicated that the 0.5% Triton extracts contained 40% of the original TSH binding activity and that this was present at a concentration of 25 ng/ml.

Animals↗
PubMed1977

Urinary pregnanetriol excretion in hirsutism.

Eighteen consecutive hirsute women attending an endocrine clinic have been studied by measurement of the urinary pregnanetriol excretion before and following the concurrent administration of corticotrophin and metyrapone. An abnormal increment in pregnanetriol excretion was observed in 11 of these 18 patients. It is suggested that this is evidence that an adrenal abnormality, probably operative at the 21-hydroxylase level, might be a factor responsible for the hirsutism in these 11 patients. Five adrenalectomized women who were also studied showed no significant increase in urinary pregnanetriol excretion in response to concurrent corticotrophin and metyrapone administration.

Adrenalectomy↗
PubMed1977

Evidence for dopaminergic control of thyrotrophin secretion in man.

After administration of the dopamine-receptor-blocking drug, metoclopramide (10 mg orally), there is significant release of thyrotrophin (T.S.H.) in hypothyroid patients which is not evident in euthyroid subjects. This is not due to spontaneous fluctuation in basal T.S.H. levels, and it indicates inhibitory dopaminergic control of T.S.H. release in man. The lack of significant T.S.H. release in euthyroid subjects may be due to the inhibitory effects of normal circulating levels of T3 and T4 on T.S.H. release. The T.S.H. response in hypothyroidism is significantly correlated with both T3 and T4 levels, suggesting suppression of this inhibitory pathway in increasingly severe hypothyroidism.

Administration, Oral↗
PubMed1977

Value of thyroid-stimulating-antibody determinations in predicting short-term thyrotoxic relapse in Graves' disease.

Thirty consecutive patients with hyperthyroid Graves' disease received a 6-month course of antithyroid drugs. Sixteen patients relapsed within 6 months of the withdrawal of antithyroid therapy. All patients with high levels of thyroid-stimulating antibodies (TSAb) at the time of drug withdrawal relapsed within 2 months of discontinuing the antithyroid treatment while all patients with low or undetectable TSAb activity at the time of drug withdrawal remained in remission. It was not possible to predict the disease course in patients who had intermediate levels of TSAb when antithyroid therapy was stopped.

Adult↗
PubMed1977

Cancer markers in patients receiving chemotherapy for colorectal cancer: a preliminary report.

The combination of CEA, hepatic function marker enzymes, and four acute phase reactant proteins (haptoglobin, alpha 1 antitrypsin, alpha 1 acid glycoprotein, and prealbumin) has been used to monitor patients with colorectal cancer receiving chemotherapy. In 18 patients with advanced lesions who survived at least 3 months treatment the markers predicted progression in 92% of 25 incidents of progression; the mean lead time was 2.8 months. A rising CEA was only present in 28%, but in these patients it gave a mean lead time of 4 months. In the group of 14 patients with minimal residual disease progression to clinically detectable disease has occurred in 9 of them. In these cases the markers predicted progression with a mean lead time of 6 months; in a further six patients the markers have indicated progression, but as yet their disease is not detectable, the mean lead time being at least 8.6 months. CEA and the liver enzyme markers are the most sensitive indicators of progression of the minimal residual disease group.

Alkaline Phosphatase↗
PubMed1977

Effects of nomifensine, an inhibitor of endogenous catecholamine re-uptake, in acromegaly, in hyperprolactinaemia, and against stimulated prolactin release in man.

1. Nomifensine, an inhibitor of endogenous catecholamine re-uptake, did not affect the growth hormone (GH) or prolactin levels in patients with acromegaly or hyperprolactinaemia. It does not, therefore, have any therapeutic role in these conditions at the dosage used in this study. 2. It had no effect on thyrotrophin-releasing hormone (TRH)-induced thyrotrophin (TSH) or prolactin release in males, yet caused marked suppression of monoiodotyrosine (MIT)-induced prolactin release in males but not in females. 3. The significant suppression of MIT-induced prolactin release in males is likely to reflect the dopamine (DA) agonist activity of the drug and its lack of effect in the other situations tested could be dose related. 4. It is proposed that the difference in male and female patterns of prolactin response to MIT after nomifensine, could be due to a "damping" effect of oestrogen on the hypothalamic dopaminergic system.

Acromegaly↗