Biomedical subjects
Publications and source records attributed to P Stoffel.
Successful total removal of a renal cell carcinoma extending through the tricuspid valve into the right ventricle is reported. The rarity of this case prompted a review of the literature in which only right atrium involvement in this type of tumor was found.
Desipramine (DMI) is an important antidepressant drug and a lysosomotropic substance. In cultured fibroblasts it interferes with lysosomal functions, e.g. phospholipid degradation. Chronic exposure of cells with DMI induces storage of phospholipids. Subcellular fractionations of cultured human fibroblasts that had been exposed to a short pulse of 3H-DMI showed accumulation of DMI in two acidic compartments, one of high density represented the lysosomes and one of much lower density may contain pinosomes. In chronically exposed cells DMI accumulated in the subcellular fractions of lower density only. DMI induced an important shift of lysosomal enzymes from vesicles of high density to the ones of lower density. Phospholipids were accumulating in those vesicles of lower density as well as in the fractions that contained plasma membranes. DMI also accumulated in one part of the Golgi vesicles of acute and chronically exposed cells. In the latter phospholipids and arylsulfatase A activity were also accumulating. DMI possibly interferes with membrane recycling. This eventually could induce changes in phospholipid content and composition in the plasma membrane which may have important implications for membrane functions.
In 25 patients, 21 of whom had coronary heart disease, left ventricular high-fidelity pressure measurements, M-mode-echocardiograms, phono- and electrocardiograms were carried out before and 20 min after peroral administration of 50 mg isosorbide-5-mononitrate. Left ventricular relaxation was assessed by the isovolumic relaxation time, left ventricular max negative dP/dt, the time constant, T, of left ventricular pressure decay during the isovolumic relaxation period, and peak fall of meridional wall stress (max negative dS/dt). Following isosorbide-5-mononitrate the heart rate was not altered; left ventricular systolic pressure, however, decreased from 129 to 117 mmHg (P less than 0.001) as did the end-diastolic pressure from 15 to 8 mmHg (P less than 0.001). The left ventricular end-diastolic diameter decreased from 53 to 50 mm (P less than 0.001) and left ventricular peak stress from 182 to 142 X 10(3) dynes/cm2 (P less than 0.001). Max dP/dt and left ventricular systolic shortening remained essentially unchanged, indicating that contractility during the isovolumic-contraction phase as well as during ejection was not influenced. Max negative dP/dt, max negative dS/dt, and the isovolumic relaxation time also remained unchanged. T, however, decreased from 54 to 45 ms (P less than 0.001). We conclude that peroral administration of isosorbide-5-mononitrate is followed by a decrease in pre- and afterload, but also by an increase in the speed of left ventricular relaxation as evidenced by the diminished T. Since T has been reported as being load-independent, its decrease either reflects a genuine effect of isosorbide-5-mononitrate on left ventricular relaxation or results from a diminution of residual ischemia.