Muscle diseases can constitute a large variety of both acquired and hereditary disorders. Myopathies in systemic disease results from several different disease processes including endocrine, inflammatory, paraneoplastic, infectious, drug- and toxin-induced, critical illness myopathy, metabolic, and myopathies with other systemic disorders. Patients with systemic myopathies often present acutely...

Statins are cholesterol-lowering drugs widely used in the prevention of cardiovascular diseases; however, they are associated with various types of myopathies. Statins inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and thus decrease biosynthesis of low-density lipoprotein cholesterol and may also reduce ubiquinones, essential coenzymes of a mitochondrial electron transport ch...

Zidovudine (AZT) inhibits HIV-1 replication in AIDS. A limiting side effect is AZT-induced toxic myopathy. Molecular changes in a rat model of AZT-induced toxic myopathy in vivo helped define pathogenetic molecular, biochemical, and ultrastructural toxic events in skeletal muscle and supported clinical and in vitro findings. After 35 d of AZT treatment, selective changes in rat striated muscle ...

Human mitochondrial tRNA (hmt-tRNA) mutations are associated with a variety of diseases including mitochondrial myopathies, diabetes, encephalopathies, and deafness. Because the current understanding of the precise molecular mechanisms of these mutations is limited, there is no efficient method to treat their associated mitochondrial diseases. Here, we use a variety of known mutations in hmt-tR...

Mitochondrial dysfunction due to nuclear or mitochondrial DNA alterations contributes to multiple diseases such as metabolic myopathies, neurodegenerative disorders, diabetes and cancer. Nevertheless, to date, only half of the estimated 1,500 mitochondrial proteins has been identified, and the function of most of these proteins remains to be determined. Here, we characterize the function of M19...

Cardiac muscle involvement is not a rare complication in muscle disorders as is most commonlyseen in muscular dystrophies. Hypertrophic and/or dilated cardiomyopathy progresses in parallel with disease progression in most of patients with Duchenne and Becker muscular dystrophies, though cardiac failure mayprecede skeletal muscle symptoms, especially in Becker form. Cardiac muscle involvement is...

Rhabdomyolysis may result from various factors, namely trauma, exercise, medications, infections, endocrine disorders, congenital myopathies, and metabolic diseases. Among the latter, mitochondrial fatty acid b-oxidation (FAO) defects frequently cause recurrent rhabdomyolysis. FAO disorders are recessively inherited and have a combined incidence of 1:9,300, estimated after implementation of new...

We have blocked creatine kinase (CK)-mediated phosphocreatine (PCr) -->/<-- ATP transphosphorylation in skeletal muscle by combining targeted mutations in the genes encoding mitochondrial and cytosolic CK in mice. Contrary to expectation, the PCr level was only marginally affected, but the compound was rendered metabolically inert. Mutant muscles in vivo showed significantly impaired tetanic fo...

Chronic intestinal pseudo-obstruction is an uncommon syndrome characterized by relapsing episodes suggesting intestinal obstruction during which no mechanical causes are identified to account for symptoms. Etiologic factors may be manifold. Among them a number of neurologic conditions, gastrointestinal smooth muscle myopathies, endocrino-metabolic and autoimmune diseases, and the use of selecte...

Inflammatory myopathies are a heterogeneous group of myopathies in which there is biopsy-evident inflammation. In its evaluation it is essential to use neurophysiological techniques that provide information on the nature of the process. This paper reviews the electromigram pattern characteristic of inflammatory myopathies, its diagnostic value, limitations, and some clues on the interpretation ...