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Biomedical subjects

J C McCabe

Publications and source records attributed to J C McCabe.

17 recordsLinked to original sources
PubMed1982

Dysrhythmias caused by histamine release in guinea pig and human hearts.

Histamine is released into the systemic circulation during anaphylaxis, by drugs and by surgical procedures. Studies in animal models have conclusively demonstrated that released cardiac histamine is a major mediator of arrhythmias that occur during anaphylaxis and following the administration of histamine-releasing drugs. Several lines of evidence suggest a similar arrhythmogenic role for cardiac histamine in humans: (1) The human heart is rich in histamine; (2) cardiac histamine can be readily released from human heart in vitro by therapeutic concentrations of drugs; (3) histamine has potent arrhythmogenic effects on the human heart in vitro. Arrhythmogenic effects of histamine include enhancement of normal automaticity, induction of abnormal automaticity, induction of triggered tachyarrhythmias, depression of atrioventricular conduction, and increase in the vulnerability of the ventricles to fibrillation. A combination of H1 and H2 antihistamines is needed to block the arrhythmogenic effects of histamine. Certain arrhythmogenic effects of histamine (e.g. induction of slow responses and delayed afterdepolarizations) can also be blocked by drugs which inhibit the influx of cations through slow channels. In contrast, the commonly-used drug digitalis potentiates the arrhythmogenic effects of histamine. We propose that histamine release produced by drugs and surgical procedures may be an overlooked factor in fatal cardiac arrhythmias. Experimental studies suggest that selective pharmacological methods can be developed to block the arrhythmogenic effects of histamine.

Animals↗
PubMed1977

Surgical treatment of endocardial cushion defects.

A recent surgical experience with the spectrum of atrioventricular (A-V) canal is reviewed. Twenty-five patients underwent surgery for the partial and complete from of this defect in the 4 years from 1971 through 1974. Sixteen had a partial defect, two a transitional defect and seven complete A-V canal. The characteristic murmurs accompanied by cardiac enlargement, pulmonay overcirculation and left axis deviation in the electrocardiogram were sufficient for diagnosis in most cases. Cardiac catherization was performed in all patients preoperatively and in 11 postoperatively. The operative approach, including a double patch modification of the usual repair for complete canal, is considered. Definitive repair, rather than pulmonary arterial banding, is advocated regardless of the patient's age. The operative mortality rate is low in patients with the ostium primum type of defect but is related to associated intracardiac anomalies in those with the complete form of the defect. Residual mitral insufficiency is a common finding after surgical repair of both partial (75 percent) and complete (100 percent) A-V canal. Although no patient in the series died of florid mitral regurgitation, the long-range effects of this complication may lead to mitral valve replacement.

Adolescent↗
PubMed1977

Drug information centres: new role for pharmacists?

In the last few decades there has been a great increase in the number of new drugs available for general use. In consequence, drug information centres have been developed, particularly in U.S.A., to disseminate information on the uses, toxicity and cost of these drugs. Such centres have been slower to appear in the United Kingdom, with the exception of certain specialised centres, e.g. Poisons Information Bureaux. The present report describes the development of a drug information centre in Glasgow and gives preliminary data on its use during the last year. It is proposed that such centres provide a valuable aid in encouraging rational drug use particularly in hospitals. The centres may be run by a variety of interested personnel but in our view the professional group most likely to fill this role adequately is hospital pharmacists.

Drug Information Services↗