"The big sleep: Elucidating the sequence of events in the first hours of death to determine the postmortem interval".

Recent developments on postmortem interval estimation (PMI) take an advantage of the autolysis process, pointing out to the analysis of the expression of apoptosis and autophagy genes towards this purpose. Oxidative stress plays a role in this signaling as a regulatory mechanism and/or as a consequence of cell death. Additionally, melatonin has been implicated on apoptosis and autophagy signaling, making melatonin a suitable target for PMI determination. The aim of this study was to investigate the early PMI through the analysis of the expression of autophagy genes as well as oxidative stress and melatonin receptor. Our results demonstrated a rapidly increased on the expression of autophagy genes according to the expected sequence of events, then a marked decrease in this expression, matched with the switch to the apoptosis signaling. These results revealed potential candidates to analyze the PMI in the first hours of death, helping to estimate the time-since-death.

Urine melatonin and citrate excretion during the elite swimmers' training season.

The objectives of the study were to evaluate the influence of a whole training season on 6-sulfatoxymelatonin (αMT6s) and citrate excretion in 12 elite swimmers. Urine samples were obtained (before bedtime and after waking up) at the beginning of the season, basic training, macrocycle I, tapering and macrocycle II stages. For αMT6s, at basic training, mainly with aerobic training, the evening concentrations were significantly lower (P < 0.01; P < 0.05) than at the beginning, tapering and macrocycle II stages. At macrocycle II stage, with the maximal training workload, the total sum (evening plus morning) was significantly higher (P < 0.05) than at the beginning, basic training and macrocycle I stages. The ratio (morning/evening) that represents the capacity to produce melatonin at night depending on the evening values at the basic training stage and the nocturnal increment at the macrocycle II stage were significantly higher (P < 0.01) than at all other stages. Citrate morning values at basic training and tapering stages were significantly lower (P < 0.01) than in the evening indicating that a metabolic recuperation took place. The total sum significantly decreased (P < 0.05) as the aerobic training progressed from the beginning to macrocycle I. The basic training ratio (morning/evening) was significantly lower compared to the beginning and macrocycle II stages, and the nocturnal increment was significantly higher (P < 0.05) compared to the beginning. Melatonin and citrate represent complementary markers that could be used to evaluate the assimilation of the training workload by noninvasive methods.