RESUMO
Five decades ago, Franz Halberg conceived the idea of ââa circadian-based therapy for cancer, given the differential tolerance to treatment derived from the intrinsic host rhythms. Nowadays, different experimental models have demonstrated that both the toxicity and efficacy of several anticancer drugs vary by more than 50% as a function of dosing time. Accordingly, it has been shown that chemotherapeutic regimens optimally timed with the circadian cycle have jointly improved patient outcomes both at the preclinical and clinical levels. Along with chemotherapy, radiation therapy is widely used for cancer treatment, but its effectiveness relies mainly on its ability to damage DNA. Notably, the DNA damage response including DNA repair, DNA damage checkpoints, and apoptosis is gated by the circadian clock. Thus, the therapeutic potential of circadian-based radiotherapy against cancer is mainly dependent upon the control that the molecular clock exerts on DNA repair enzymes across the cell cycle. Unfortunately, the time of treatment administration is not usually considered in clinical practice as it varies along the daytime working hours. Currently, only a few studies have evaluated whether the timing of radiotherapy affects the treatment outcome. Several of these studies show that it is possible to reduce the toxicity of the treatment if it is applied at a specific time range, although with some inconsistencies. In this Perspective, we review the main advances in the field of chronoradiotherapy, the possible causes of the inconsistencies observed in the studies so far and provide some recommendations for future trials.
RESUMO
Se presenta la Osteotecnia en peróxido de hidrógeno y ácido acético como una herramienta para la conservacón de material óseo para fines docentes en colegios y universidades o de exhibición en museos o instituciones afines. Esta técnica de conservación de material óseo permite además rescatar piezas y estructuras óseas de difícil adquisición. Es un método rápido y muy baja toxicidad, fácil de aplicar y de un costo relativamente bajo en comparación con otros descritos en la literatura.
An Osteotechnique is presented on hidrogen peroxide and acetic acid as a tool for the conservation of bone material with teaching purposes on high schools and colleges, museum exhibitions or similar institutions. This bone preservation technique allowds to rescue pieces and bone structures that are difficult to adquire. It`s a simple and low toxicity method, easy to apply and with relatively low cost compared to other techniques described on the literature.
