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Biomedical subjects

R E Schoen

Publications and source records attributed to R E Schoen.

11 recordsLinked to original sources
PubMed1991

Pseudo-obstruction associated with colonic ischemia: successful management with colonoscopic decompression.

Colonic pseudo-obstruction has been associated with colonic ischemia in only 7-10% of cases. When both conditions are present, most authors recommend immediate laparotomy because of the additional weakening of the bowel wall induced by the presence of ischemia and the resultant increased risk of perforation. We report on three patients with pseudo-obstruction and right-sided colonic ischemia who were successfully managed with colonoscopic decompression with tube placement. Surgery may not be required in patients with pseudo-obstruction and associated colonic ischemia.

Colon↗
PubMed1990

Is electroconvulsive therapy safe?

Electroconvulsive therapy is controversial and readily arouses the passions of both its supporters and detractors. In this article, Dr Schoen, an internist, discusses various aspects of this 50-year-old technique, including risks, contraindications, and physiologic effects.

Electroconvulsive Therapy↗
PubMed1988

Hormonal and metabolic effects of calcium channel antagonists in man.

Calcium is a component of many metabolic reactions. By blocking calcium transport across cell membranes, calcium channel antagonists can therefore theoretically affect numerous metabolic and hormonal processes. In vitro studies have often documented just such an effect. Because of the expanding use and prevalence of calcium antagonists in clinical practice, a review of their in vivo effects on hormones and metabolism is warranted. The effect on glucoregulatory hormones, calcium regulatory hormones, anterior and posterior pituitary secretion, the renin-angiotensin axis, plasma catecholamines, and plasma lipids and lipoproteins is herein reviewed. The various calcium antagonists, by virtue of their distinct chemical structures, influence metabolism in their own unique manner. Despite the widespread involvement of calcium in hormone action, however, calcium channel antagonists have little dramatic impact on hormone regulation. This is, in part, due to the drug dosage used in clinical practice and to the inherent compensatory mechanisms built into normal endocrine function. The development of agents with greater and more potent metabolic specificity, however, coupled with the ability to target drug action, holds promise for expanded therapeutic application in the future.

Adrenal Cortex Hormones↗
PubMed1976

Skeletal muscle vascular volume changes with increased venous pressure.

Dog gracilis muscles were removed, enclosed in a plethysmograph and perfused at constant inflow pressure or constant inflow. Circulating blood volumes were measured by the constant infusion technique using RBC-51Cr or albumin-131I. Control venous pressure averaged 3 mm Hg and elevations (delta PV) over the range of 5-40 mm Hg were produced. Volume changes were determined during and following delta PV by plethysmography and by changes in total muscle radioactivity. Changes in total (amount of blood in the tissue), active (circulating), and mobilized vascular volumes were calculated. Active vascular volumes and total vascular volumes increased with venous pressure increments up to 25 mm Hg and then plateaued. Active vascular volumes (indicators) increased by amounts significantly greater than the increases in total vascular volume (plethysmography). Volume changes in the constant flow groups were double those in the constant pressure groups. The mobilized active vascular volume (active vascular volume change minus total vascular volume change) consists of a volume of blood contained in vessels unattainable by the indicators during the control period but which were made available to the indicator by the delta PV. Mobilized vascular volume averaged 45% of the active vascular volume change. With venous pressure elevation there was an increase in the RBC-51Cr volume to albumin-131I volume ratio. This suggests a redistribution of red cells with respect to plasma, possibly resulting from reduced plasma skimming.

Animals↗