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Biomedical subjects

D C Evered

Publications and source records attributed to D C Evered.

At least 37 records · Page 2Linked to original sources
PubMed1977

Hypothyroidism following partial thyroidectomy for thyrotoxicosis and its relationship to thyroid remnant size.

One hundred and twenty-two patients were reviewed 1-7 years after partial thyroidectomy for thyrotoxicosis by two surgeons who had left thyroid remnants of different size. There was no significant difference in the prevalence of hypothyroidism or in the serum levels of thyroxine, tri-iodothyronine or thyroid-stimulating hormone between the two groups of patients. The overall prevalence of hypothyroidism was 16 per cent.

Adult↗
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↗
PubMed1977

A long-term follow up of patients with autoimmune thyroid disease.

A survey in a general practice in the North-East of England in 1963 detected thyroglobulin antibodies in 16.2% of women and 4.3% of men. High titres of antibodies were found in 4.6% of women and 1.6% of men. Forty six subjects with thyroglobulin antibodies (from an original total of fifty-two) were studied in 1972 and forty of these were studied further in 1975. These subjects were compared with a group of age- and sex-matched controls from the original survey. Three of the subjects had developed overt hypothyroidism by 1975 and a raised serum thyroid-stimulating hormone (TSH) concentration was found more frequently in euthyroid subjects peviously found to be antibody positive. There was a striking difference in the antibody studies in that only 26% of the previously antibody positive subjects had thyroglobulin antibodies in 1972 and 30% in 1975. A raised serum TSH concentration was found to correlate with cytoplasmic a-tibodies and particularly with the combination of cytoplasmic and thyroglobulin antibodies.

Adult↗
PubMed1977

Radioimmunoassay of free thyroid hormone concentrations in the investigation of thyroid disease.

Direct radioimmunoassay of free triiodothyronine (fT3) and free thyroxine (fT4) in serum dialysate has been performed in fifty-two normals, twenty-one hyperthyroid, and twenty-one hypothyroid patients. In health, there is an almost equimolar concentration of fT3 and fT4. In hyperthyroidism, the free thyroid hormone concentrations were clearly discriminated from the normals. In a proportion of the symptomatic hypothyroids studied, the free hormone values fell within the normal range, challenging the concept that free thyroid hormone concentrations are the sole determinants of thyroid status. In the population studied, there were statistically significant correlations between fT3 and fT4, as well as the free hormones with their respective total hormone levels. It is concluded that fT3 and fT4 estimated are unlikely to play a major role in the routine investigation of thyroid disease.

Adult↗
PubMed1977

Thyroid-stimulating immunoglobulins in ophthalmic Graves' disease.

Thyroid-stimulating immunoglobulins (TSI) have been detected by receptor assay in the sera of 43% of patients with ophthalmic Graves' disease. Comparison of the receptor assay studies with thyroid function tests indicated that in several patients the antibodies detected by receptor assay were biologically inactive. In other patients, thyroid function appeared to be under TSI control with hyperthyroidism prevented by autoimmune destruction of the thyroid.

Adult↗
PubMed1977

Role of TSH in the changes in thyroidal metabolism of [35S]methimazole in phenobarbital and thyroxine-treated rats.

The effect of phenobarbital (PB) and/or thyroxine on the thyroidal accumulation and oxidation of [35S]methimazole (MMI) and serum TSH levels was studied in rats. PB treatment increased the accumulation of MMI and the serum TSH levels, but concurrent administration of T4 reversed these effects. It was concluded that increased TSH secretion in PB-treated animals was likely to be the major mechanism involved in the increased MMI accumulation. PB also increased the intrathyroidal oxidation of MMI to sulphate. However, in contrast to the PB effect on accumulation, concurrent T4 administration only partially reversed the effect on oxidation. The results suggested that the increased oxidation of MMI in PB-treated animals was due to a direct effect of PB or possibly a combination of this direct effect and the indirect TSH effect. Possible mechanisms postulated for a direct effect were thyroidal microsomal enzyme induction and/or changes in thyroidal protein binding of MMI.

Animals↗
PubMed1977

Inhibition of thyrotrophin-releasing hormone responsiveness by physiological concentrations of thyroid hormones in the cultured rat pituitary gland.

Diced quarter anterior pituitaries from mature females Wistar rats were cultured in synthetic medium with or without added serum. Using each culture as its own control, the thyrotrophin-releasing hormone (TRH) dose-thyrotrophin (TSH) response characteristics of both media were similar; significant TSH secretion being stimulated at TRH doses around 1-5 X 10(-9) mol/l. During days 1-3 of culture, basal TSH secretion fell significantly but TRH responsiveness was unchanged. Neither tri-iodothyronine (T3) nor thyroxine (T4) influenced basal TSH secretion. In both culture media inhibition of TRH responsiveness was demonstrated with concentrations of T3 and T4 within the ranges 1-5 X 10(-12) to 1-5 X 10(-9) mol/l for T3 and 6-5 X 10(-10) to 6-5 X 10(-7) mol/l for T4. Equivalent inhibition was accompanied by similar T3 concentrations whether T3 or T4 supplements were used, suggesting that T4 itself has no feedback action. The similar concentrations of T3 required to inhibit TRH responsiveness in media either with or without serum suggest that the pituitary is responsive not only to free but also to total thyroid hormone concentrations, since serum-free medium contains no thyroid hormone-binding protein.

Animals↗
PubMed1976

Assessment of thyroid hormone assays.

Four techniques for estimating serum T4 and three for estimating serum T3 have been investigated and found to be satisfactory in routine use. Normal ranges for each techniques have been established. Estimation of serum T3 by the commerical kits tested appears to have a high discriminant value in the diagnosis of hyperthyroidism, although the diagnostic definition used inevitably enhances the apparent sensitivity of these techniques. Estimation of serum T4 will identify the majority of patients with symptomatic hypothyroidism. The low sensitivity of T3 in the diagnosis of thyroid failure is confirmed.

Binding, Competitive↗
PubMed1976

The empty sella syndrome.

The empty sella syndrome (ESS) presents a varied clinical and radiographic picture. It may remain asymptomatic or may stimulate an intrasellar growth thereby causing diagnostic and therapeutic problems. An air encephalogram (AEG) is required for diagnosis. The purpose of this paper is to review the clinical and radiological features of the ESS and to discuss the pathogenetic mechanisms involved.

Humans↗
PubMed1976

Actions of growth hormone-release inhibiting hormone (somatostatin) on the renin aldosterone system.

Administration of growth hormone-release inhibiting hormone (GH-RIH, somatostatin), as a 90 minute infusion (10 mug/min), to 3 healthy young men under conditons of active renin secretion acheived by pretreatment with furosemide (80 mg daily for 5 days), caused a mean 30% fall in plasma renin activity, which returned to basal levels immediately after stopping the GH-RIH infusion. Plasma aldosterone levels were not affected during the course of this experiment.

Adult↗