Jawahar Mehta

Neutrophils as potential participants in acute myocardial ischemia: relevance to reperfusion.

An interaction among leukocytes, platelets and endothelial cells is important in atherogenesis and in maintenance of blood flow and vascular tone. These complex cell-cell interactions are mediated by release of such metabolic substances as arachidonic acid metabolites, growth factors, oxygen free radicals and endothelium-derived relaxing factor. These substances participate in the regulation of blood flow in health and disease, and perturbation in the delicate equilibrium among various cellular elements may lead to evolution and propagation of myocardial ischemia. During reperfusion of ischemic myocardium, neutrophils together with platelets cause capillary plugging in the coronary microcirculation and exert detrimental effects on endothelial function resulting in the no reflow phenomenon, ventricular arrythmias, loss of coronary vascular reserve and, perhaps, extension of cellular injury. This review addresses the mechanisms of cell-cell interactions with special reference to myocardial ischemia and the potential for development of improved therapy to protect and preserve ischemic myocardium.

Impaired canine coronary vasodilator response to acetylcholine and bradykinin after occlusion-reperfusion.

Previous studies indicate impairment of coronary arterial ring relaxation in response to acetykholine (ACh) following coronary reperfusion, mediated via loss of endothetium-derived relaxing factor (EDRF). To examine if coronary vasodilator reserve is reduced following coronary ocdusfon-reperfusion in intact animnk, 16 open-chest mongrel dogs were subjected to 1 hour of total left circumflex (Cx) coronary artery occlusion followed by reperfusion for 1 hour. Prior to Cx occlusion, coronary blood flow increased and vascular resistance decreased (both p±O.Ol) in response to ACh and bradykinin (BK). Following reperfusion, Increase in Cx coronary flow in response to both vasodilators was significantly (p±O.Ol) impaired. Myocardial histology showed extensive neutrophil infiltration and capillary plugging by neutrophils in the Cx compared with the left anterior descending coronary artery-supplied myocardium. Myocardial myetoperoxidase activity was also increased in the Cx compared with the left anterior descending region (p±0.02). Pretreatment of four dogs with indomethadn partially reduced the vasodilator response to BK but not to ACh. However, indomethadn did not affect reperfusion-induced attenuation of BK or AChs coronary vasodilator effects. To determine if calcium blocker verapamil would modify reperfusion-induced impairment in coronary vasodilator reserve, six dogs were treated with verapamil. Although verapamil enhanced coronary vasodilator effects of ACh and BK, it did not modify reperfusion-induced attenuation of coronary vasodilator reserve. Myocardial neutrophil accumulation and myeloperoxidase activity was also similar in control, indomethacin, and verapamil-treated dogs. These observations suggest that coronary reperfusion impairs coronary vasodilator reserve in intact dogs. This impairment is not modified by prostaglandin inhibition or by calcium blockade. Besides loss of EDRF, capillary plugging by neutrophils may contribute to the altered coronary flow reserve observed in the immediate post-reperfusfon period. Furthermore, indomethacin or verapamil are not effective in modifying the reperfusion-related impairment of coronary vasodilator reserve.

The effect of myocardial infarction on sexual functioning

The purpose of this study was to evaluate the long-term effects of myocardial infarction on the marital and sexual functioning of 100 married male VA patients. Data were collected from questionnaires sent to subjects six months following discharge from the hospital. The study shows that a large number (30 percent) of the patients still had not resumed sexual intercourse six months after their discharge. The data also indicate that sexual activity generally reduced in frequency and that this decrease was related to a variety of concerns. It is also shown that high frequencies of sexual dysfunctioning occurred, specifically erectile difficulties (60 percent), premature ejaculation (37 percent) and retarded ejaculation (54 percent). The need for active sexual counseling as part of a comprehensive rehabilitation program is discussed.

Mixed tocopherols are better than alpha-tocopherol as anti-oxidantsas good as statins

Curr Res Cardiol Vol 3 No 4 Winter 2016 128 Central Arkansas Veterans Healthcare System and the University of Arkansas for Medical Sciences, Little Rock, AR, USA, 2Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, China, 3Myeloma Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA