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Biomedical subjects

W Beck

Publications and source records attributed to W Beck.

At least 91 records · Page 5Linked to original sources
PubMed1982

The relationship between angiographic findings and risk factors in young men with myocardial infarction.

Coronary angiography was performed and risk factors were evaluated 2-4 months after myocardial infarction in 50 men aged 40 years or less. There was a high incidence of heavy cigarette smoking, obesity and hyperlipidaemia among these young men. Single-vessel disease (greater than or equal to 70% coronary obstruction) was found in 52%, double-vessel disease in 22% and triple-vessel disease in 20%, the right coronary artery being more frequently involved (greater than or equal to 70% obstructed) or totally occluded than the left anterior descending or left circumflex coronary arteries, in that order. One of the 2 patients with a normal coronary arteriogram had left ventricular angiographic evidence of previous infarction. There was no apparent difference in the distribution of coronary artery disease in this group of young men from the reported distribution found in older subjects. Neither was there any significant correlation of any single major coronary risk factor or combination thereof with the extent or severity of coronary artery obstruction.

Adult↗
PubMed1982

Closed mitral valvotomy: actuarial analysis of results in 654 patients over 12 years and analysis of preoperative predictors of long-term survival.

The records of 654 patients with mitral stenosis who underwent closed mitral valvotomy over a 12-year period were submitted to actuarial analysis. This revealed a low (2.97%) operative mortality. At 12 years, the overall cumulative proportion surviving was 78%; 47% of patients survived without reoperation. The usual clinical indicators of suitability for closed valvotomy were successful in predicting improved survival. The surgeon's assessment of the suitability of the valve correlated well with outcome. Valvotomy during pregnancy was associated with a good long-term outlook. The presence of pulmonary hypertension and atrial fibrillation did not alter survival significantly. Sex ane age were not associated with adverse prognosis. We conclude that closed mitral valvotomy still has a place in the management of mobile mitral stenosis, particularly in areas where there is a high incidence of rheumatic heart disease and a large number of young patients have mobile mitral stenosis.

Actuarial Analysis↗
PubMed1982

Endocrinological studies of the hypothalamo-pituitary gonadal axis during danazol treatment in pubertal boys with marked gynecomastia.

The present paper evaluates the variations of the hypothalamo-pituitary gonadal axis during Danazol treatment in pubertal boys with marked gynecomastia (breast size more than 6 cm in diameter). Before treatment a normal sleep-dependent gonadotropin increase was found together with a normal response to LHRH stimulation. Plasma prolactin increased at sleep as well. Plasma testosterone values were normal for pubertal age. During Danazol treatment 200 mg daily for 6 months basal gonadotropin levels, the sleep related hormone increases as well as the response to luteinizing-hormone releasing hormone (LHRH) stimulation were blunted. Concomitantly, testosterone values decreased to values seen in pubertal stage II-III. After 6 months of therapy, 4 of 5 boys treated so far, demonstrated a reduction of the gynecomastia to a maximum of 3 cm in diameter. In 1 boy Danazol treatment was finished after 3 months. Because of increased psychological problems a mastectomy was performed. 6 months after cessation of Danazol treatment a normal sleep dependent gonadotropin rhythm and a normal response to LHRH was found again demonstrating a normalization of the physiologic sleep-related gonadotropin rhythms. Plasma testosterone levels nearly increased to values seen before treatment. From the clinical aspect there were no signs of a recurrence of the marked pubertal gynecomastia in all boys treated with Danazol. These results indicate that Danazol is a specific gonadotropin inhibitor acting at the hypothalamo-pituitary level. No side effects on other hormones or on the development of secondary sex characteristics were noted during and after Danazol treatment.

Adolescent↗
PubMed1982

Effects of polychlorinated biphenyls and environmental biotransformation products on aquatic nitrification.

The effects of polychlorinated biphenyls (PCBs) on nitrification were examined for pure cultures and natural reservoir samples. PCBs at concentrations greater than 10 microgram liter-1 inhibited nitrification, principally ammonium oxidation, in one of two natural reservoir environments. However, this inhibition could not be reproduced in pure high-cell-density cultures or in previously contaminated reservoir waters. A PCB environmental biotransformation product, p-chlorophenylglyoxylic acid, and p-chloromandelic acid had no effect on nitrification.

Biotransformation↗
PubMed1981

Aortic valve replacement in the elderly.

With increasing longevity, increasing numbers of patients in their 8th decade present with symptomatic aortic valvular disease. We have examined the results of aortic valve replacement in 30 patients of 70 years or older who underwent isolated aortic valve replacement at Groote Schuur Hospital between January 1969 and January 1979. Follow-up ranged from 1 year to 10 years, with a mean of 2,5 years. There was 1 operative death. Two patients died within the first 6 months of operative complications. The 1-year survival rate was 90%. All hospital survivors showed marked improvement in cardiac functional status. Actuarial statistics on survival show an 84% survival rate at 3 years. Aortic valve replacement is safe and effective in patients over the age of 70 years.

Aged↗
PubMed1981

Coronary artery spasm and myocardial infarction in the absence of angiographically demonstrable obstructive coronary disease.

Myocardial infarction due to spasm of an "angiographically normal coronary artery" is rare, and its significance as a cause of myocardial infarction in patients without obstructive coronary disease has not been determined. Two patients are described with transmural myocardial infarction, nonobstructive coronary arteries, and suggestive evidence of coronary vasospasm as the cause of infarction. In one patient, angiography was carried out within 7 days of infarction and the documentation of normal coronary arteries argued strongly against a thromboembolic cause for infarction. This patient also had the combination of asthma, hypereosinophilia, and a systemic disease suggesting an immunologic disturbance with increased autoantibody production. A temporal association was noted between the episodes of asthma and those of coronary spasm during exacerbation of the eosinophilia, which raised the speculative issue of "allergic" coronary vasospasm. It is concluded that spasm of a nonobstructed coronary artery may cause transmural myocardial infarction. Further documentation is required in order to place this association in perspective among the other potential cause of infarction in patients with normal coronary artery anatomy.

Adult↗
PubMed1980

Long-term survival after orthotopic and heterotopic cardiac transplantation.

Five long-term survivors of heart transplantation were reinvestigated. Two patients had undergone orthotopic heart transplantation over 11 and 9 years earlier and constitute two of the world's longest-surviving patients after this procedure. Three patients had undergone heterotopic heart transplantation (one left heart bypass alone and two biventricular bypass) four to six years earlier. Four of the five patients had had only one or no documented acute rejection episodes. Three had been given blood transfusions. None had had particularly good tissue matching in relation to the donor on HLA typing. All five patients were leading full and active lives. At review two patients had significant coronary artery disease, one severe, presumably due to chronic immune-complex deposition. Heart transplantation remains a major undertaking, but it can offer the patient many years of good-quality life.

Adult↗
PubMed1980

Ventricular tachycardia with torsade de pointes morphology induced by oral disopyramide.

The oral administration of disopyramide for the maintenance of sinus rhythm after cardioversion from atrial fibrillation resulted in prolongation of the Q-T interval and three episodes of ventricular tachycardia with the torsade de pointes morphology. This morphology is characteristic of the arrhythmias of quinidine 'syncope'. Its appearance with disopyramide is not unexpected in view of the quinidine-like effects of the latter and suggests that it should be prescribed with the same caution as quinidine.

Administration, Oral↗
PubMed1980

The clinical assessment and management of patients with prosthetic cardiac valves: A review of current practice at the Cardiac Clinic, Groote Schuur Hospital.

This review deals with the clinical assessment and management of patients with prosthetic cardiac valves. The types of prosthesis available are considered, with special reference to those which have been used frequently at Groot Schuur Hospital. The common complications encountered are described, as well as the clinical features of normally and abnormally functioning prostheses. The management of anticoagulant medication, pregnancy, infective endocarditis, systemic embolism and haemolysis in these patients is discussed. Particular emphasis is placed on the urgent referral to a cardiac department of patients with posthetic malfunction or conditions in which there is a potential for the development of malfunction.

Animals↗
PubMed1980

Endocrine studies in Blackfan-Diamond anemia: evidence for hypothalamic-pituitary dysfunction under frequent transfusion therapy.

A 13 year old boy with Blackfan-Diamond anemia treated with frequent transfusions was investigated for endocrine abnormalities. Prepubertal plasms LH and FSH values, lack of sleep-related hormone rhythms of the gonadotropins, as well as prepubertal responses of LH and FSH to acute stimulation with LHRH strongly suggests that a hypothalamic-pituitary abnormality is the cause of the hypogonadotropic hypogonadism observed in this patient. As a result of impaired stimulation of the gonads plasm testosterone was prepubertal. A three-to fourfold increase of basal plasma PRL values was found without any signs of a typical sleep-dependent increase. Values obtained ranged between 21 ng/ml and 24 ng/ml (normal range 5-8 ng/ml). A normal response to TRH stimulation was found. These results suggest that hemosiderosis may be responsible for the hyperprolactinemia as a result of hypothalamic-pituitary dysfunction. Furthermore, dysfunction is demonstrated by prepubertal responses of LH and FSH to LHRH stimulation.

Adolescent↗
PubMed1980

Diurnal variations of plasma luteinizing hormone, follicle-stimulating hormone, and prolactin in boys and girls from birth to puberty.

Thirty-eight girls and 44 boys were evaluated for nocturnal variations in plasma LH, FSH, and PRL. The children were subdivided into 4 groups according to their stage of sexual maturation. Blood samples were collected at 1800, 2200, 0200, and 0800 h from an indwelling venous catheter. The last sampling was followed by a simultaneous LHRH/TRH test to assess pituitary hormone reserve at different ages. In neither sex were differences of plasma LH values observed in age groups 1 and 2. In age group 3 (stages 2-3), girls demonstrated increased LH levels during sleep. The response to LHRH in this group was similarily high in girls and in girls and boys in age group 4 (stages 4-5). In the oldest group, a rise of plasma LH values at night occurred in both sexes. In girls, a significant nocturnal increase of plasma FSH values was found in age group 2 (prepubertal). In age group 3 (stages 2-3), boys also developed a nocturnal rhythm, with highest plasma FSH levels during sleep. Together with these increased nocturnal plasma hormone levels, a more pronounced response to LHRH stimulation occurred. Increased plasma PRL levels were found in all children at night without increasing basal values with the onset of puberty.

Adolescent↗