RESUMEN
Rhabdomyolysis is a condition in which skeletal muscle breakdown causes the release of intracellular components into the bloodstream - defined as elevations in serum creatine kinase levels. The etiology of rhabdomyolysis is varied and may be the result of toxin-mediated mechanisms or metabolic derangements, or they may develop secondary to other conditions such as seizures, trauma and prolonged immobilization. In this case, we present a patient with suspected acute toxin-mediated rhabdomyolysis in the setting of trimethoprim-sulfamethoxazole (TMP-SMX) therapy for urinary tract infection. To our knowledge, this marks the fifth case report of an otherwise healthy patient diagnosed with rhabdomyolysis thought to be secondary to TMP-SMX.
RESUMEN
In vitro cell-based assays are an essential and universally used step in elucidation of biological processes as well as in drug development. However, results obtained depend on the validity of protocols used. This statement certainly pertains to in vitro assays of oxidative stress. The holy grail of in vitro models is reliability and predictability of outcomes that relate to a single variable like addition of hydrogen peroxide or xanthine oxidase. Without such validated outcomes, comparison of results among different laboratories is not possible. Achieving this goal requires a thorough understanding of the complex interplay between the cells, their environment, and the experimental assays. Furthermore, as this knowledge is attained, it must be disseminated and used to update and standardize existing protocols. Here, we confirm and extend the effect of pyruvate and cell density on in vitro oxidative stress assays. Cell viability was assessed using a colorimetric assay measuring the reduction of a tetrazolium salt (XTT) into a colored formazan dye. Extracellular hydrogen peroxide concentrations were measured using the foxp3 assay. We confirmed a previously reported finding that pyruvate, a common ingredient in cell culture media, acts as an extracellular scavenger of reactive oxygen species. We also demonstrated that cell density directly correlates with resistance to oxidative stress in tissue culture. It is theorized that the protective effect due to cell density predominantly relates to intracellular factors such as reduced glutathione and extracellular factors such as catalase.
