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Biomedical subjects

H Why

Publications and source records attributed to H Why.

13 recordsLinked to original sources

Metabolic consequences of alcohol dependency.

Alcohol dependency leads to a variety of biochemical adaptations and morphological changes which may be considered as either adaptive or destructive. This ranges from the utilization of ethanol as a metabolic fuel, to overt tissue and cellular damage, and may lead to increases in morbidity and mortality. Virtually every organ system is affected by either acute and chronic ethanol exposure and numerous metabolic pathways are altered. As a consequence of these wide ranging effects, it is extremely difficult to cover every aspect of alcohol toxicity in a single review. Instead, attention is focussed on selected areas, such as nutrition and protein metabolism in the liver and bone (and to a lesser extent, skeletal muscle and the gastrointestinal tract). The aim is to illustrate the numerous ways in which alcohol affects the body.

Alcohol-Related Disorders↗

Protein synthesis in the heart in vivo, its measurement and patho-physiological alterations.

Changes in cardiac protein composition occur in a variety of patho-physiological situations and are usually accompanied by modifications in protein synthesis. Although adjustments in protein synthesis during starvation may be adaptive, the alterations in protein synthesis seen in response to ethanol ingestion may be pathological and an important step in the genesis of alcoholic heart muscle disease. The alterations in heart muscle in hypertension are initially adaptive but in the long term they are deleterious, and involve both transcription and translation. While adequate methods exist for quantifying the amount of mRNA for contractile and non-contractile proteins, such studies of gene-expression provide no dynamic information on the rate at which tissue proteins are lost or accrued. This can only be determined by measuring the rate of protein turnover, i.e. either protein synthesis or protein breakdown. Techniques for directly determining the rates of protein breakdown are limited or involve surgical procedures. Methods for measuring the rate of protein synthesis are described, and are illustrated by their application to the investigation of starvation and ethanol toxicity. In particular, attention is focused on the fact that reliable rates of protein synthesis are obtained only if the specific radioactivity of the precursor at the site of protein synthesis (aminoacyl-tRNA) is assessed.

Animals↗

The deleterious effects of alcohol on the heart: involvement of protein turnover.

Ethanol ingestion can induce a variety of metabolic changes in the heart, and recent studies have even suggested that moderate ethanol intake confers cardio-protective effects in reducing mortality due to coronary artery disease. However, in this review we explore the consequences of excessive ethanol intake or alcohol misuse. We investigate the epidemiology of alcohol misuse, and thereafter present evidence supporting the existence of a specific alcoholic heart muscle disease (AHMD). The prevalence of AHMD is described and the contributing mechanisms are discussed. These include the involvement of free radicals, defects in intermediary metabolism and the formation of acetaldehyde adducts. Special attention has been paid to ethanol-induced changes in protein turnover. Our studies show that ethanol impairs the protein synthetic pathways, affecting the contractile proteins per se, as well as the subcellular organelles as exemplified by the mitochondria. Acetaldehyde appears to be a particularly potent toxin. The experiments described in this review emphasize the need for investigative studies in intact models. The mechanisms inherent in the pathogenesis of AHMD may be applicable to other heart muscle disorders.

Alcohol Drinking↗

Heart failure.

Explore the source record for details and available documents.

Aged↗

Enteroviruses and myocarditis.

Myocarditis causes distinctive histological changes of the myocardium and is most commonly caused by enterovirus infection. Enterovirus RNA has been detected in tissue samples obtained from patients with myocarditis by endomyocardial biopsy. Similar findings in dilated cardiomyopathy support the hypothesis that it results from myocarditis in some cases and that enterovirus infection plays a pathogenetic role in the disease process.

Cardiomyopathy, Dilated↗