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Biomedical subjects

A S Mason

Publications and source records attributed to A S Mason.

16 recordsLinked to original sources

Lipodystrophy with hyperlipidaemia: the role of insulin in very low density lipoprotein over-synthesis.

A patient with partial lipodystrophy is described in whom hypertriglyceridaemia was accompanied by marked hyperinsulinaemia. The hyperlipidaemia was due to increased plasma levels of very low density lipoprotein (VLDL). Kinetic studies, performed after injection of autologous radioiodinated VLDL, indicated that the raised VLDL levels were associated with over-production of this lipoprotein. Administration of diazoxide led to a substantial fall in serum insulin levels, accompanied by reduction in VLDL production and in serum triglyceride concentration. The possible role of insulin in inducing hyperlipidaemia by causing over-production of VLDL is discussed.

Adult

Mineralocorticoid replacement in Addison's disease.

Eight patients with treated Addison's disease were studied whilst receiving different doses of fludrocortisone together with a constant intake of glucocorticoid. Plasma renin activity (PRA), blood pressure, pulse rate and plasma potassium and urea concentrations were measured after 2-week periods on each dose. In two patients, PRA measurements indicated that mineralocorticoid replacement therapy had been inadequate. In four others, PRA remained normal throughout the study, even after fludrocortisone had been discontinued, suggesting that the drug was unnecessary for the maintenance of normal sodium balance in these patients. Asymptomatic fludrocortisone overdosage was indicated by a low plasma potassium concentration, but not by PRA measurements which failed in this study to distinguish between adequate and excessive mineralocorticoid replacement.

Addison Disease

Experience with human growth hormone in Great Britain: the report of the MRC Working Party.

The Working Party on human growth hormone (hGH) has during the past decade developed a system for the evaluation and treatment of patients suffering from hGH lack. Today there are nineteen measurement centres in the United Kingdom at which patients are assessed and where the effects of therapy are monitored. The current supply of hGH, which is prepared from pituitary glands collected by pathologists in the National Health Service, is just enough to meet demand, but research conducted on behalf of the Working Party suggests that hGH deficiency is more common than has been thought and that the prevalence may be as high as one in 10 000. If, as is hoped, patients are diagnosed younger and more patients with partial deficiency are recognized, demand may soon outstrip supply. Work is in progress to define better methods of hGH production and optimal dose regimens, both of which will help to minimize the problem of supply and demand. A few children have anti-hGH antibodies, which block growth as a result of treatment. Improved hGH production techniques may result in a less antigenic product and the resolution of this problem. Many of the Working Party's activities began as research and have evolved into service. Because of this shift in emphasis, and although much research is still to be done, responsibility for provision of treatment with hGH transferred from the Medical Research Council to the Department of Health and Social Security in July 1977.

Adolescent

Long-term treatment of acromegaly with bromocriptine.

Seventy-three patients with active acromegaly were treated for three to 25 months with bromocriptine 10-60 mg/day. Seventy-one patients showed symptomatic and objective clinical improvement. This included reduction in excessive sweating, hand and foot size, and the number of headaches; improved facial appearance; and increased energy and libido. Abnormal visual fields became normal in two patients, one of whom had concomitant radiotherapy. Mean circulating growth hormone levels, obtained by averaging serial samples through the day, fell by more than 7 microng/l or became undetectable in 58 patients (79%) but did not reach normal values: only 15 patients had mean levels on treatment of 5 microng/l or less. Twenty-three patients were diabetic before treatment, and glucose tolerance became normal in 15 and improved in a further five. Provided the drug was started slowly side effects were minor when compared with the considerable clinical benefit obtained.

Acromegaly

Male pseudohermaphroditism due to partial end-organ insensitivity to androgens.

A 46XY individual with incomplete male pseudohermaphroditism was studied. The phenotype was distinctive, with a masculine habitus despite a small phallus, gynaecomastia and diminished virilization. Plasma levels of testosterone, oestrogens, gonadotrophins and sex-hormone binding globulin were elevated. It is proposed that this syndrome is a variant of Type I incomplete male pseudohermaphroditism.

Adult

Patterns of antipsychotic drug use in four Southeastern state hospitals.

The drug prescriptions of patients in the four mental hospitals of a state were obtained as of a specific date and subjected to various analyses. The results disclose a high frequency of antiparkinson drug orders (41.5% of the patients), their relationship to polypharmacy (30% of the antipsychotic drug prescriptions were for two or more to be administered simultaneously), the direct relationship between the antipsychotic dose level and antiparkinson drug and PRN orders and the incidence of multiple dose schedules (75%). Also other prescription practices which have received little or no attention are described and discussed.

Antiparkinson Agents

Bromocriptine treatment of acromegaly.

The effects of oral bromocriptine in acromegaly have been studied. A dose of 5 mg six-hourly suppressed circulating growth hormone (GH) levels in nine out of 11 patients treated for seven to 11 weeks. This was associated with considerable clinical improvement in all patients, with abolition of excessive sweating, reduction in soft-tissue thichening, loosening of rings, decrease in shoe size, improvement in facial features, and loosening of dentures. Metabolic changes included improvement in glucose tolerance and reduction in hydroxyproline excretion. Unlike the actions of growth hormone release inhibiting hormone the suppression of GH was not accompanied by a reduction in insulin or glucagon secretion, though prolactin levels were suppressed. Side effects other than mild constipation were not seen when the full dose regimen was reached by slowly increasing the dose from 2-5 mg once daily. Bromocriptine holds promise as a safe and orally effective medical treatment to augment surgical or radiotherapeutic measures directed at the pituitary tumour. Its efficacy during longterm administration remains to be established.

Acromegaly

Plasma free fatty acid turnover in total lipodystrophy.

Basal free fatty acid (FFA) turnover was found to be elevated or at the upper limit of normal in a patient with total lipodystrophy. The decrease in plasma FFA concentration which occurred after intravenous administration of insulin was shown to be primarily due to a fall in the inflow of FFA into the circulation. These results provide support for the suggestion that adipocytes in total lipodystrophy are able to synthesize triglycercide, but that they are unable to store it because of rapid lipolysis.

Adult