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Biomedical subjects

J R Mitchell

Publications and source records attributed to J R Mitchell.

At least 199 records · Page 11Linked to original sources

Echocardiographic comparison of black and white hypertensive subjects.

Echocardiography was used to compare cardiac structure and function in 35 pairs of hypertensive blacks and hypertensive whites matched for age, sex, level and known duration of hypertension, treatment status, and renin level.Echocardiographic abnormalities were common in both groups and included increased ventricular septal thickness and/or left ventricular free-wall thickness in 51 percent of black hypertensives and 69 percent of white hypertensives. Paired analysis indicated no significant difference between black and white hypertensive subjects in any of the echocardiographic parameters including ventricular transverse dimensions (at end diastole and at end systole), left atrial and aortic root dimensions, left ventricular ejection fraction, and mitral valve E-F slope. Thus echocardiographic evaluation of black and white hypertensive subjects, matched for clinical characteristics, suggests a similar prevalence of cardiac abnormalities in the two groups.

Adult↗

Dexamethasone in acute stroke.

Over 13 months 118 patients admitted to hospital with acute stroke were allocated at random to treatment with either dexamethasone or placebo. At one year there was no significant difference in the numbers of survivors or in the quality of life between the two groups. The results suggest that there is no indication for the routine administration of dexamethasone to a heterogeneous group of patients with stroke.

Acute Disease↗

A randomised trial of home-versus-hospital management for patients with suspected myocardial infarction.

Home and hospital management of patients with suspected myocardial infarction were compared in a randomised trial in which a hospital-based team responded to calls from general practitioners. 500 calls were received, and 349 patients (70%) were suspected of having myocardial infarction. Of these, 24% were excluded from the trial on predetermined medical and social grounds; for the remainder (76%) there was no significant difference in the 6-week mortality between the home group (13%) and the hospital group (11%). For the majority of patients to whom a general practitioner is called because of suspected infarction, hospital admission confers no clear advantage.

Adult↗

Self-poisoning: management of patients in Nottingham, 1976.

Analysis of the management of a sample of patients with drug overdoses in Nottingham in 1976 showed that some 10% of the patients who arrived in the casualty department after an overdose were neither admitted nor seen by a psychiatrist. Of the patients who were admitted to medical wards for psychiatric evaluation, 31% were thought to need no further psychiatric action while the default-rate in those who were referred to a psychiatric outpatient clinic was 43%. Both these endpoints showed considerable variations among the 10 psychiatric teams, but of every 100 patients with drug overdose who arrived in the casualty department, 51 left hospital without continuing psychiatric or social action having been taken. As the recommendations of the Hill Committee are not being implemented we suggest that they should be critically re-examined and that the indication for, and value of, psychiatric intervention should be determined.

Adolescent↗

Immune mechanisms in patients with proven vascular disease.

Lymphocyte transformation and serum levels of immunoglobulins and complement were measured in groups of patients with old myocardial infarction, with peripheral vascular disease and in age- and sex-matched controls. There were no significant differences between the groups in phytohaemagglutinin (PHA) induced lymphocyte transformation, in IgA or in serum complement levels. The levels of IgG and IgM were significantly raised in patients with old proven infarcts while the level of IgM was raised in patients with peripheral vascular disease.

Complement System Proteins↗

Drug-induced liver injury.

In the usual course of events, the liver detoxifies hepatocytotoxic intermediates of drug metabolism. But when protective systems are overloaded by normally harmless drugs, the intermediates can cause massive, even fatal, hepatic necrosis.

Acetaminophen↗

Effect of aminoglutethimide on blood pressure and steroid secretion in patients with low renin essential hypertension.

An inhibitor of adrenal steroid biosynthesis, aminoglutethimide, was administered to seven patients with low renin essential hypertension, and the antihypertensive action of the drug was compared with its effects on adrenal steroid production. In all patients aldosterone concentrations in plasma and urine were within normal limits before the study. Mean arterial pressure was reduced from a pretreatment value of 117+/-2 (mean+/-SE) mm Hg to 108+/-3 mm Hg after 4 days of aminoglutethimide therapy and further to 99+/-3 mm Hg when drug administration was stopped (usually 21 days). Body weight was also reduced from 81.6+/-7.2 kg in the control period to 80.6+/-7.0 kg after 4 days of drug treatment and to 80.1+/-6.7 kg at the termination of therapy. Plasma renin activity was not significantly increased after 4 days of treatment but had risen to the normal range by the termination of aminoglutethimide therapy. Mean plasma concentrations of deoxycorticosterone and cortisol were unchanged during aminoglutethimide treatment whereas those of 18-hydroxydeoxycorticosterone, progesterone, 17alpha-hydroxyprogesterone, and 11-deoxycortisol were increased as compared to pretreatment values. In contrast, aminoglutethimide treatment reduced mean plasma aldosterone concentrations to about 30% of control values. Excretion rates of 16beta-hydroxydehydroepiandrosterone, 16-oxo-androstenediol, 17-hydroxycorticosteroids and 17-ketosteroids, and the secretion rate of 16beta-hydroxydehydroepiandrosterone were not significantly altered by aminoglutethimide treatment whereas the excretion rate of aldosterone was reduced from 3.62+/-0.5 (mean+/-SE) in the control period to 0.9+/-0.2 mug/24 h after 4 days and to 1.1+/-0.3 mug/24 h at the termination of aminoglutethimide treatment. The gradual lowering of blood pressure and body weight during aminoglutethimide therapy is consistent with the view that the antihypertensive effect of the drug is mediated through a reduction in the patients' extracellular fluid volume, probably secondary to the persistent decrease in aldosterone production. The observation that chronic administration of aminoglutethimide lowered blood pressure in these patients and elevated their plasma renin activity to the normal range without decreasing production of the adrenal steroids, deoxycorticosterone, 18-hydroxydeoxycorticosterone, and 16beta-hydroxydehydroepiandrosterone, makes it unlikely that these steroids are responsible either for the decreased renin or the elevated blood pressure in patients with low renin essential hypertension.

18-Hydroxydesoxycorticosterone↗