Alterations of the skeletal muscle contractile apparatus in necrosis induced by myotoxic snake venom phospholipases A: a mini-review.

Skeletal muscle necrosis is a common clinical manifestation of snakebite envenoming. The predominant myotoxic components in snake venoms are catalytically-active phospholipases A (PLA) and PLA homologs devoid of enzymatic activity, which have been used as models to investigate various aspects of muscle degeneration. This review addresses the changes in the contractile apparatus of skeletal muscle induced by these toxins.

Skeletal muscle fiber hypercontraction induced by Bothrops asper myotoxic phospholipases A ex vivo does not involve a direct action on the contractile apparatus.

Myonecrosis is a frequent clinical manifestation of envenomings by Viperidae snakes, mainly caused by the toxic actions of secreted phospholipase A (sPLA) enzymes and sPLA-like homologs on skeletal muscle fibers. A hallmark of the necrotic process induced by these myotoxins is the rapid appearance of hypercontracted muscle fibers, attributed to the massive influx of Ca resulting from cell membrane damage. However, the possibility of myotoxins having, in addition, a direct effect on the contractile machinery of skeletal muscle fibers when internalized has not been investigated.

The process for recognizing of foreign medical degrees in Costa Rica: a statistical survey for the past 15 years.

This article presents the most important developments in the recognition process of foreign medical degrees in Costa Rica over the past fifteen years. Most applicants received their medical degrees in Cuba, Venezuela, Nicaragua and Mexico. By far the most numerous group completed their studies in Cuba, followed by graduates from Venezuelan and Nicaraguan universities, the number of which has increased in the last five years.

Cytotoxicity of snake venom Lys49 PLA2-like myotoxin on rat cardiomyocytes ex vivo does not involve a direct action on the contractile apparatus.

Viperid snake venoms contain a unique family of cytotoxic proteins, the Lys49 PLA homologs, which are devoid of enzymatic activity but disrupt the integrity of cell membranes. They are known to induce skeletal muscle damage and are therefore named 'myotoxins'. Single intact and skinned (devoid of membranes and cytoplasm but with intact sarcomeric proteins) rat cardiomyocytes were used to analyze the cytotoxic action of a myotoxin, from the venom of Bothrops asper.

Chemotherapy triggers cachexia by deregulating synergetic function of histone-modifying enzymes.

Background: Chemotherapy is the first line of treatment for cancer patients. However, the side effects cause severe muscle atrophy or chemotherapy-induced cachexia. Previously, the NF-κB/MuRF1-dependent pathway was shown to induce chemotherapy-induced cachexia.