Nobuyuki Tsuda

P-selectin and platelet-derived microparticles associated with monocyte activation markers in patients with pulmonary embolism.

Platelet activation markers (platelet-derived microparticles and P-selectin on activated platelets), chemokines (monocyte chemotactic peptide and regulated on activation normally T-cell expressed and secreted), and soluble markers (sP-selectin, sE-selectin, sVCAM-1, and sCD14) were measured and compared in patients with pulmonary embolism (PE). These substances are thought to participate in the pathogenesis of PE. Levels of all of the platelet activation markers, chemokines, and soluble markers were higher in the patients with PE than in normal controls. Levels of platelet activation markers were also significantly increased postoperatively after total knee arthroplasty. Anti-platelet therapy significantly inhibited the elevation of platelet activation markers after total knee arthroplasty. These findings suggest that antiplatelet therapy may be useful for PE-related interaction of platelets, leukocytes, and endothelial cells.

Age-related changes in aortic elasticity determined by gated radionuclide angiography in patients with systemic hypertension or healed myocardial infarcts and in normal subjects

We estimated the aortic volume elasticity (Ve), an index of aortic stiffness, using gated radionuclide angiography, and investigated age-related changes in aortic elasticity in 22 normal control subjects, 30 hypertensive patients and 36 patients with old myocardial infarction. Ve elasticity was calculated noninvasively as a ratio of the pressure change (dP) and the percent volume change (dV/Vo) determined by radionuclide angiography [Ve = dP/(dV/Vo)]. dV/Vo was calculated from the maximal and minimal counts in the aortic arch [dV/Vo = (maximum - minimum)/minimum]. Ve increased significantly with age in normal control subjects (r = 0.62, p less than 0.001), hypertensive patients (r = 0.60, p less than 0.001) and patients with old infarcts (r = 0.59, p less than 0.001). The age-related increase in Ve was significantly greater in hypertensive patients, and that for patients with old myocardial infarcts tended to be greater than in control subjects. Thus, hypertension accelerates the decrease in aortic elasticity with aging. The greater decrease in aortic elasticity resulted in a significant age-related increase in pulse pressure in patients with hypertension and old myocardial infarction.

Significance of αIIbβ3 in Subacute Stent ThrombosisAfter Percutaneous Coronary Intervention

Soluble P-selectin and whole blood aggregation (WBA) were measured after percutaneous coronary intervention in patients who then received antiplatelet therapy. One had subacute thrombosis on day 7. This patient’s WBA exhibited time-dependent enhancement. In addition, the accentuation of WBA on day 3 was observed when anti-αIIbβ3 antibody was added. The remaining 22 patients were divided according to WBA results on day 3 with anti-αIIbβ3 antibody added (A group, WBA enhanced; B group, WBA did not enhance). WBA on day 3 was similar in the two groups. The ratio of WBA with and without anti-αIIbβ3 antibody was higher in group A than in group B. A significant time-dependent increase of soluble P-selectin was observed in the A group. These results suggest that enhancement of WBA with anti-αIIbβ3 antibody after percutaneous coronary intervention predicts subacute thrombosis.