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Biomedical subjects

S G Sheps

Publications and source records attributed to S G Sheps.

At least 109 records · Page 6Linked to original sources

Renovascular hypertension. Relationship of surgical curability to renin-angiotensin activity.

Fifteen patients whose renovascular hypertension was cured or improved by renal artery reconstructive surgery or nephrectomy (or both) underwent studies of their renin-angiotensin systems preoperatively. These studies included measurements of peripheral venous renin activity in the erect position without diuretic preparation, blood pressure response to blockade of endogenous angiotensin II with a saralasin infusion in the acutely sodium-depleted state, and levels of renal venous renin activity, also after sodium depletion. In 13 of these 15 patients who had benefitted from surgical intervention for relief of renovascular hypertension, at least one index of renin dependency was positive. Two patients had negative results in all of the tests. On the basis of these findings, we concluded that cure or improvement of renovascular hypertension is possible even though these three parameters of renin-angiotensin overactivity are negative.

Angiotensins↗

Prazosin-new hypertensive agent. A double-blind crossover study in the treatment of hypertension.

Prazosin hydrochloride, a new antihypertensive agent, is said to be of mild-to-moderate potency when used as a sole agent in mild-to-moderate hypertension and when used in conjunction with other agents in severe hypertension. In our study of 14 patients comparing hydrochlorothiazide with prazosin, the antigypertensive effect of prazosin was less than that of hydrochlorothiazide. The greatest application of prazosin may be in conjunction with thiazide diuretics and beta-adrenergic blocking agents as the second or third drug.

Adrenergic beta-Antagonists↗

Management of the patient with renovascular hypertension.

Renal artery stenosis, either fibromuscular or atheromatous, is probably the most common cause of secondary hypertension in man. Both of these diseases are active, ongoing processes that may be ameliorated but not cured by medical or surgical treatment. The clinical history and examination of the patient with hypertension may help differentiate renovascular hypertension from essential hypertension. The presence of a systolic-diastolic or continuous bruit is often an indicator of severe renal artery stenosis. Systemic hypertension is the physiologic consequence of significant renal artery stenosis. Knowledge of the basic concepts of the renin-angiotensin-aldosterone system, as has evolved from experimental models of renovascular hypertension, forms the basis for understanding the process of evaluation and treatment of such patients. The treatment of choice for the patient with severe hypertension and a functionally significant renovascular lesion is surgical--both in terms of successful treatment of hypertension and improved long-term prognosis. Diligent periodic reevaluation of these patients as well as those with less severe hypertension who are receiving medical treatment enables the physician to select the proper management that offers optimal control of patient blood pressure and avoids target-organ damage to the kidneys, central nervous system, or cardiovascular system.

Humans↗

Single-voided urine metanephrine assays in screening for pheochromocytoma.

To facilitate the screening for pheochromocytoma, we have validated the use of single-voided, spot urine specimens for the determination of total metanephrines. Metanephrine excretion was found to be quite constant throughout the day and night in ten patients with essential hypertension and seven patients with pheochromocytoma. The levels in single-voided specimens were closely correlated to those in 24-hour specimens in 100 hypertensive subjects. The mean +/- 2 SD metanephrine excretion in single-voided urine specimens from 500 hypertensive subjects was 0.351 +/- 0.356 mug/mg of creatinine.

Adolescent↗

Adrenal medullary disease in multiple endocrine neoplasia, type 2: pheochromocytoma and its precursors.

Multiple endocrine neoplasia, type 2 (MEN-type 2), designates the syndrome of medullary thyroid carcinoma, pheochromocytoma, and occasional parathyroid hyperplasia. The thyroid carcinoma, which is usually bilateral and multicentric, is preceded by multifocal C-cell hyperplasia. The adrenal gland manifests pheochromocytoma, which is frequently bilateral and multicentric, and may be malignant. To test the hypothesis that diffuse adrenal medullary hyperplasia is a precursor of pheochromocytoma in this syndrome, we studied the adrenal glands of 19 patients who had MEN-type 2. The findings in the adrenal medulla in these 19 patients were: synchronous bilateral pheochromocytoma in 9 (metastatic in 3); asynchronous bilateral pheochromocytoma in 1 (metastatic); unilateral pheochromocytoma with contralateral diffuse and nodular hyperplasia in 2; unilateral pheochromocytoma with contralateral diffuse hyperplasia in 2; unilateral pheochromocytoma in 1; bilateral nodular hyperplasia in 1; bilateral diffuse hyperplasia in 1; and no abnormality in 2. This spectrum of adrenal medullary pathology suggests that diffuse and nodular medullary hyperplasia are precursors of pheochromocytoma in MEN-type 2.

Adrenal Gland Neoplasms↗

Use of an elastic garment in the treatment of orthostatic hypotension.

The most common cause of orthostatic hypotension is poor postural adjustment. The most severe form of orthostatic hypotension is of unknown etiology; the primary disorder is a degeneration of the peripheral autonomic nervous system, resulting in a decrease in production of catecholamine. Physiologically, there is a failure of arteriolar and venous vasoconstriction and a lack of cardiac response, both in rate and in contractility to sympathetic stimulation. Total and central cardiopulmonary blood volumes are contracted. The application of hydrostatic counterpressure by the use of an elasticized garment is helpful in the management of orthostatic hypotension, especially when used with sodium-retaining steroids to increase intravascular volume.

Blood Pressure↗

Cardiovascular complications of pheochromocytoma crisis.

Two patients with hypertensive crises due to pheochromocytoma presented with unusual features suggestive of cardiovascular disorders other than pheochromocytoma. These features included transient cortical blindness and other neurologic deficits, electrocardiographic changes indicative of transmural infarction and peripheral arterial spasm. In both patients the diagnosis of pheochromocytoma was made later; removal of the tumor was followed by ready reversal of the clinical and biochemical abnormalities. Management of such cases includes suspicion of the diagnosis in the presence of atypical features, early initiation of therapy with alpha and beta adrenergic blocking agents and a definitive surgical procedure before peripheral vascular changes become irreversible. When an apparent myocardial infarction occurs, the diagnosis of coronary artery disease cannot always be excluded, but rapid stabilization of the clinical and electrocardiographic changes after adrenergic blockade would favor the diagnosis of a catecholamine-induced myocarditis. The coexistence of coronary artery disease and uncontrollable arrhythmias presents an increased risk but, if pheochromocytoma is suspected, surgery may be necessary despite the increased risk.

Adrenal Gland Neoplasms↗

Excretory urographic localization of adrenal cortical tumors and pheochromocytomas.

An excretory urographic evaluation of 124 surgically proved adrenal tumors comprising 65 pheochromocytomas, 36 cortical adenomas and 23 cortical carcinomas is reported. The addition of linear tomography improved the diagnostic accuracy over conventional excretory urography. All types of tomographic examinations demonstrated at least 70% of adrenal tumors. Excretory urographic procedures are relatively safe, simple and economical and should be used as the initial step in attempting to localize clinically suspected and chemically diagnosed adrenal tumors.

Adenoma↗

Parathyroid function in patients with pheochromocytoma.

Serum calcium, serum immunoreactive parathyroid hormone (PTH), and plasma immunoreactive calcitonin were measured in 12 patients with catecholamine-secreting tumors. Only two patients had high serum calcium and immunoreactive PTH concentrations (one also had high basal immunoreactive calcitonin); in both, the hypercalcemia persisted after removal of their pheochromocytomas but was corrected by removal of hyperplastic parathyroid glands and medullary thyroid carcinomas. Of the 10 patients with normal serum calcium and immunoreactive PTH concentrations, 2 had high immunoreactive calcitonin concentrations and medullary thyroid carcinomas alone were found. Our results suggest that [1] hypercalcemia occurs infrequently in patients with pheochromocytoma, [2] chronic circulating catecholamine excess does not cause increased immunoreactive PTH or immunoreactive calcitonin secretion in patients with pheochromocytoma, and [3] the parathyroid disease in patients with pheochromocytoma is a genetically determined component of multiple endocrine neoplasia.

Adolescent↗

Daily and alternate-day corticosteroid regimens in treatment of giant cell arteritis: comparison in a prospective study.

Alternate-day corticosteroid therapy was compared with two daily corticosteroid regimens for the treatment of giant cell arteritis. In a prospective study 60 patients with this disease were randomly assigned to three treatment groups: group A, 15 mg of prednisone every 8 hours; group B, 45 mg of prednisone every morning; and group C, 90 mgof prednisone every other morning. After 1 month of treatment, the arteritis seemed to be completely suppressed in 18 patients in group A and 16 in group B but in only 6 in group C. In the 14 other patients in group C, the continuing symptoms were cyclic and developed during the day steroids were not given. By changing to a daily regimen, the arteritis was controlled in most patients in group C. Adverse reactions to prednisone were noted frequently in groups A and B but rarely in group C.

Aged↗

Large artery involvement in giant cell (temporal) arteritis.

Of 248 patients with giant cell arteritis, 34 had evidence that the disease affected the aorta or its major branches. Symptoms suggestive of large artery involvement were intermittent claudication of an extremity, paresthesias, and Raynaud's phenomenon. Physical findings included absent or decreased large artery pulses and bruits over large arteries. Four patients presented with decreased upper extremity pulses as the initial manifestation of their arteritis. Nine other patients under treatment for temporal arteritis or polymyalgia rheumatica first developed evidence of large artery involvement as corticosteroid therapy was tapered or discontinued. Angiography, performed in 10 patients, was helpful in indicating arteritis rather than atherosclerosis as the cause of large artery disease. Three patients died with aortic rupture, and, at autopsy, widespread giant cell arteritis was found. However, when corticosteroids were given in adequate doses, the response was favorable in most patients; intermittent claudication decreased and the pulses improved.

Adrenal Cortex Hormones↗

Hypertension.

Hypertension, a health problem of epidemic proportions, has not been controlled successfully. Screening efforts are increasing the detection of cases, and current emphasis on treatment rather than detailed evaluation is increasing the incidence of control of hypertension. Patient compliance is crucial, however, because all of the currently available treatments require daily taking of pills by patients who commonly do not understand their disease or the need for treatment. Efforts at increased public education and improved doctor-patient relationships are important if the epidemic is to be overcome. This paper reviews diagnosis, evaluation, treatment, public education, and patient compliance.

Antihypertensive Agents↗