Pelvocalyceal thickening in HIV-associated nephropathy.

Background: Previously reported causes of renal pelvocalyceal thickening (PCT) include infection, acute tubular necrosis and obstruction. This study was performed to evaluate the significance of PCT noted sonographically in patients with hyperechoic native kidneys.

Methods: We evaluated sonograms of 178 consecutive patients with hyperechoic native (excluding small and hydronephrotic) kidneys for the presence of PCT, and reviewed medical charts of patients with this finding.

Cytosolic Ca profile of resting and thrombin-stimulated platelets from black women with NIDDM.

In this study, human platelets were used as a cellular model for exploring cytosolic free Ca (Cai) regulation in non-insulin-dependent diabetes mellitus (NIDDM). Cai levels were monitored in resting and thrombin-stimulated platelets from obese females with NIDDM; obese, nondiabetic women, and nonobese, nondiabetic women. All subjects were black.

Blood pressure inversely correlates with thrombin-evoked calcium rise in platelets.

Earlier investigations showed a positive correlation between basal cytosolic free calcium in human platelets and blood pressure; however, recent studies have failed to show this relation. We undertook the present work to examine which platelet cytosolic calcium parameters (namely, cytosolic calcium in resting or stimulated states in calcium-containing and calcium-free media) present the least variability and best correlation with blood pressure. We studied 17 healthy white men on three different occasions separated by 1- and 4-week intervals.

Differences in platelet calcium regulation between African Americans and Caucasians: implications for the predisposition of African Americans to essential hypertension.

Objective: To study differences in cytosolic free calcium regulation between African Americans and Caucasians, using platelets as a model for studying cellular physiology.

Design: Platelet calcium regulation in apparently healthy African American and Caucasian males was examined.

Methods: Using fura-2, calcium influx and cytosolic calcium extrusion were monitored after treatment with thapsigargin, an inhibitor of the Ca-ATPase in the dense tubular membrane system.

Thapsigargin-evoked changes in human platelet Ca2+, Na+, pH and membrane potential.

1. In this work we explored the effect of thapsigarin on the intracellular Ca2+, pH, Na+ and membrane potential in human platelets. These parameters were monitored using the fluorescent probes fura-2, 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein, sodium-binding benzofuran isophthalate, and 3,3'-dipropylthiadicarbocyanine iodide.