Oxidative Stress and Inflammation in Heart Disease: Do Antioxidants Have a Role in Treatment and/or Prevention?

Inflammation triggered by oxidative stress is the cause of much, perhaps even most, chronic human disease including human aging. The oxidative stress originates mainly in mitochondria from reactive oxygen and reactive nitrogen species (ROS/RNS) and can be identified in most of the key steps in the pathophysiology of atherosclerosis and the consequential clinical manifestations of cardiovascular disease. In addition to the formation of atherosclerosis, it involves lipid metabolism, plaque rupture, thrombosis, myocardial injury, apoptosis, fibrosis and failure. The recognition of the critical importance of oxidative stress has led to the enthusiastic use of antioxidants in the treatment and prevention of heart disease, but the results of prospective, randomized clinical trials have been overall disappointing. Can this contradiction be explained and what are its implications for the discovery/development of future antioxidant therapeutics

Issues in contemporary cardiac rehabilitation: A historical perspective

AbstractCardiac rehabilitation consists of exercise, psychosocial support and education and is prescribed most often for patients with coronary heart disease. Its purpose is to facilitate readaptation to normal life through the achievement of maximal functional capability and to reduce heart disease risk factors. It began historically with progressive ambulation after myocardial infarction and by 1980 became a standardized inpatient therapy performed according to a stepped procedure. Predischarge exercise testing was added and has become a meaningful contribution to the concept of risk stratification after an acute coronary event. Rehabilitation has subsequently become part of the outpatient environment and is delivered by multiple models. Meta-analyses have shown that rehabilitation reduces overall and cardiovascular deaths by about 20% and sudden death by about 37% during the year after an acute myocardial infarction. The significance of this, however, must now be modulated by the dynamic role of aggressive coronary intervention. Selection for such intervention has become an important adjunctive aspect of rehabilitation. Newer findings suggest that those stratified at low risk will benefit most by the modification of coronary risk factors, and that patients previously thought to be poor candidates for rehabilitation (such as those with significant left ventricular dysfunction and low work capacity) may experience substantial relative functional benefit. Beyond risk stratification, important contemporary issues include surveillance of patients after angioplasty, the effectiveness of rehabilitation in the attenuation or reversal of both native and vein graft atherosclerosis and consideration of such currently emphasized end points as quality of life and economic evaluation

Sex Determination in Chelydra

T HE SEX OF AN INDIVIDUAL is a fundamental trait, determining (in animals) whether sperm or eggs are transmitted to form the next generation and thus the pattern of genetic contribution. At the same time, a panoply of behavioral, physiological, and morphological traits intrinsically linked to gonadal sex shape the specific phenotypes of individuals and hence the dynamics of populations. Furthermore, mechanisms of sex determination greatly influence the primary sex ratio and potentially the population sex ratio and effective population size, which are important ecological and evolutionary parameters. Indeed, Fisher (1930) demonstrated that under most circumstances 1:1 primary sex ratios are expected and sexdetermining mechanisms that produce such balanced sex ratios should be favored by selection (see also Bull 1983)

Phylogenetics: Which was first, TSD or GSD?

The basic challenge of evolutionary biology is to explain variation or the lack thereof, be it phenotypic, genetic, phy· logenetic, spatial, temporal, and so on. To illustrate, one gross generalization is that phenotypic traits we think of as being very important to organisms tend to be highly conserved (e.g .. binocular vision in vertebrates). probably because the genomic and developmental underpinnings are essentially fiXed. Thus, one striking feature about sex-determining mechanisms (SDMs), a fundamental aspect of sexual or· ganisms, is the enormous variety (Bull1983)