Platelet norepinephrine and epinephrine concentration in patients with pheochromocytoma.

Platelet and plasma catecholamine concentrations were determined in 17 patients with surgically proven pheochromocytoma (mean age 42.3 years); in 31 patients with borderline hypertension (mean age 35.3 years) and in 9 healthy controls (mean age 39.3 years). Both platelet norepinephrine and epinephrine were significantly increased in patients with pheochromocytoma when compared with hypertensive and control groups (P less than .001). No correlation between platelet and plasma catecholamines was detected in all studied groups. The diagnostic accuracy of platelet catecholamine in pheochromocytoma is limited since increased platelet norepinephrine was found in 35.5% and increased platelet epinephrine was found in 19.4% of patients with essential hypertension.

Effect of insulin immune complexes on human blood monocyte and endothelial cell procoagulant activity.

Insulin antibodies and immune complexes (ICs) are present in most patients with diabetes after initiation of conventional insulin therapy. We studied the ability of bovine insulin, porcine insulin, and human insulin ICs to stimulate the procoagulant activity (PCA) of human blood monocytes (HBMs) and human umbilical vein endothelium (HUVE) in vitro. Polyclonal insulin antibodies from patients with insulin antibody-mediated resistance were isolated by immunoabsorption. PCA expressed by isolated adherent HBMs or cultured HUVE was quantified by radioimmunoassay of fibrinopeptide A with a 1:80 dilution of human plasma. Beef, pork, and human insulin, in quantities determined from titration curves, were added to fixed amounts of antibody to obtain equivalent amounts of ICs. For four different antibodies, the ratios of PCA (expressed by HBMs exposed to ICs or to antibodies alone and normalized for cell numbers) to activity expressed by tissue culture medium were as follows: beef insulin ICs, 2.55 +/- 0.41; por insulin ICs, 1.47 +/- 0.16; human insulin ICs, 1.28 +/- 0.19; and antibody, 1.28 +/- 0.32. The differences between beef and pork insulin ICs and antibody controls were significant. For a fifth antibody, a dose response between beef insulin ICs and PCA expression was demonstrated. For a sixth antibody, HBMs could express PCA when stimulated with antibody of a relatively low binding capacity (0.35 ng bovine insulin per microgram of antibody) only in the presence of lymphocytes. Conditioned medium from these cells significantly stimulated endothelial cell procoagulant activity. These observations raise the possibility that insulin ICs, that is, beef insulin ICs, may generate increased PCA and thereby contribute to the vascular complications of diabetes mellitus.(ABSTRACT TRUNCATED AT 250 WORDS)

Right atrial mobile thrombi: two-dimensional echocardiographic diagnosis and clinical outcome.

Four patients with pulmonary embolism and right atrial mobile thrombi (RAMT) are described. One patient died during intravenous heparin treatment because of a "saddle" pulmonary artery embolus, another died from surgical complications after successful embolectomy. One of the two survivors was treated with intravenous streptokinase and the other with intravenous heparin. Echocardiographically detected RAMT seems a reliable sign of impending massive pulmonary embolism. Pulmonary angiography is unnecessary and may be dangerous. Surgical removal of RAMT, fibrinolytic treatment or intravenous heparin introduced promptly may be lifesaving.