Exercise training and endothelial dysfunction in coronary artery disease and chronic heart failure. From molecular biology to clinical benefits

Endothelial dysfunction (ED) has been documented in patients with both coronary artery disease (CAD) and chronic heart failure (CHF)-being responsible for exercise-induced myocardial ischemia in the former and increased afterload in the latter. In the last two decades exercise training has assumed a major role in both cardiovascular disorders. In CAD exercise training has established positive effects on myocardial perfusion. Recently, exercise training has been shown to attenuate paradoxical vasoconstriction in CAD. The improved ED after training explains the improvement of myocardial perfusion in the absence of changes in baseline coronary artery diameter. Since ED has been identified as a predictor of coronary events exercise may contribute to long-term reductions of cardiovascular mortality. In CHF the increased peripheral vascular resistance - especially during exercise - is more important. ED contributes to the peripheral vasoconstriction. Training programs have shown to improve ED in CHF. A long-term study of hemodynamic effects of training in CHF revealed a significant reduction of total peripheral resistance (TPR) that after 6 months with a concomitant increase in stroke volume. In a subgroup analysis a significant correlation between changes in TPR and changes in peripheral ED was observed. Cell culture and animal experiments suggest that shear stress increases the endothelial L-arginine uptake, enhances NO synthase activity and expression, and upregulates the production of extracellular superoxide dismutase, which prevents premature NO breakdown. All these molecular effects converge on a reduction of myocardial ischemic events in CAD and a decrease of afterload in CHF.     

Short- and long-term hemodynamic effects of intra-aortic balloon support in ventricular septal defect complicating acute myocardial infarction

In patients with an infarct-related ventricular septal defect, an intra-aortic balloon pump provides immediate and long-term hemodynamic improvement, resulting in an enhanced effective cardiac output and a reduced left-to-right-shunt and shunt flow ration. In patients who can be stabilized or remain stable, there is no habituation to the effects of the intra-aortic balloon pump; thus, later surgical closure of the ventricular septal defect might be possible in some patients.     

The Confederate medical laboratories

During the Civil War, the scarcity and expense of imported drugs forced the Confederate Army to establish several medical laboratories to manufacture drugs for military use. The laboratories produced medicines from indigenous plants and also made non-plant-based drugs. The Confederate Surgeon General and the Chief Purveyor in Richmond, VA, coordinated activities of most of the laboratories. The laboratories employed talented and resourceful personnel and manufactured a large volume and wide variety of drugs, the most useful of which included ether, chloroform, and opiates. The pharmaceutical quality of the laboratories' output was evidently uneven. Empirical testing in military hospitals helped determine the clinical value of indigenous remedies. The Confederate medical laboratories participated in a coordinated effort to supply the Army with substitutes for drugs whose availability was curtailed or uncertain.     

Determinants of subjective quality of life in post acute patients with schizophrenia

Although Quality of Life (QoL) is of growing interest in schizophrenia research, little is known about putative causal determinants of this multidimensional construct. The present study explored the utility of objective indicators, psychopathological symptoms and psychosocial concepts drawn from empirical findings in community samples and the vulnerability-stress-coping model of schizophrenia for predicting general subjective QoL in post acute patients with schizophrenia. The analyses were based on cross-sectional data from 66 post acute patients with schizophrenia. The relationships between QoL and possible determinants were investigated using correlational analysis, regression analysis and structural equation techniques. As a result no significant relationships between objective indicators and general QoL were found. The strongest significant determinants were depressive symptoms and the psychosocial concepts of negative coping, perceived social support and self-efficacy. The empirical causal modelling results indicated that depression led to a direct negative impact upon QoL, whereas the other determinants had direct negative or positive effects on depression and affected QoL indirectly. One could conclude that to enhance patients' QoL, improvements in depressive symptoms, negative coping style, social support and self-efficacy seem to be most effective.