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In a previous study of 543 patients we developed, using echocardiographic left ventricular mass as the reference standard, two new sets of criteria that improve the electrocardiographic diagnosis of left ventricular hypertrophy (LVH).

We reviewed the medical records and autopsy reports of 50 patients with systemic lupus erythematosus to determine the clinical and neuropathological features of this disease. Neuropsychiatric disturbances were found in the majority (74%) of the patients, occurring as psychiatric illness only (5 patients), neurological disorders only (15 patients), and both together (17 patients). Central nervous system (CNS) lesions were present in half the patients; embolic brain infarcts (10 patients) and CNS infections (8 patients) were the most common. Cardiac sources of emboli were Libman-Sacks endocarditis (5 patients), chronic valvulitis (2 patients), and left side of heart mural thrombus (2 patients). There was no evidence of active CNS vasculitis. Clinical features of thrombotic thrombocytopenic purpura (TTP) developed during the terminal illness in 14 patients, 7 of whom also had pathological evidence of TTP. Correlation between neuropsychiatric disorders and brain lesions could be made in approximately half the patients. This study indicates that cardiac emboli from Libman-Sacks endocarditis and TTP are common pathogenetic factors of CNS disease in systemic lupus erythematosus, whereas CNS vasculitis is rare.

We studied the ability of a single oral dose of aspirin to inhibit prostacyclin synthesis by human arterial and venous tissue and to inhibit thromboxane A2 synthesis by platelets in 70 patients who were undergoing aortocoronary bypass. A dose of 40, 80, or 325 mg of aspirin was administered 12 to 16 hours before surgery. The generation of thromboxane in serum--which provides an estimate of platelet thromboxane production--was reduced from the control value by 77, 95, and 99 per cent after single doses of 40, 80, and 325 mg of aspirin, respectively. By contrast, prostacyclin production in aortic tissue that was removed at operation was reduced by only 35, 38, and 75 per cent, respectively, in response to these doses. Production of prostacyclin in saphenous-vein tissue (not tested after 40 mg of aspirin) fell only slightly and not significantly after 80 mg but was reduced by 85 per cent after 325 mg. These findings indicate that a low dose of aspirin (40 to 80 mg) can largely inhibit platelet aggregation and thromboxane synthesis but has much less effect on prostacyclin production in arterial and venous endothelium.

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Old Fischer 344 rats are more susceptible to vascular lesions after arterial endothelial injury than are young animals. Thus, 20-26-mo-old Fischer 344 rats developed greater and more persistent intimal proliferative lesions than did 2-5-mo-old rats after aortic endothelial denudation. 3 d after deendothelialization, intimal thickness was increased two-fold in both old and young animals. However, 14 d after endothelial injury, intimal thickness had increased nearly five times in old animals, but had regressed to normal in young animals. Intimal thickness of young aortic grafts transplanted into young recipients did not differ significantly from adjacent host aorta or autotransplanted aortic segments 6 wk after surgery. In contrast, intimal thickness of old grafts transplanted into young recipients was eight times greater than adjacent young host aorta 6 wk after surgery. The density of cell nuclei in the intima of old grafts was also much greater than that in young grafts. Thus, in two experimental models of vascular injury, old rats have consistently had greater myointimal hyperplasia than young rats. The increased proliferative response of aortic smooth muscle cells after vascular injury of old animals may contribute to the increased prevalence of vascular disease with age.