Analysis of Diglycolic Acid after Mass Poisoning by Diethylene Glycol.

In December 2019, unusual cases of acute renal failure with neurological changes were observed in the State of Minas Gerais, Brazil. Criminal investigations indicated cases of intoxication after consumption of beers contaminated with diethylene glycol (DEG). The elimination of DEG by the body is fast, but its metabolite, diglycolic acid (DA), may persist for a long time. To assess the level of intoxicated victims who consumed the contaminated beers, qualitative and quantitative methods were developed to determine DA in biological matrices by gas chromatography coupled to a mass spectrometer (GC-MS) and gas chromatography coupled to a mass spectrometer with triple-quadrupole mass filter (GC-MS-MS), respectively. The validated qualitative method presents good selectivity and limit of detection of 1 µg/mL (whole blood, urine, vitreous humor and cerebrospinal fluid) and 5 µg/g (liver and kidney), respectively. A quantitative method for whole blood presented satisfactory performance to determine DA. Twelve victims presented positive results for DA in whole blood, with concentrations ranging from 2 to 108 µg/mL. The toxicology laboratory of the Institute of Forensic Medicine of Minas Gerais was the first governmental agency to identify DA in whole blood, vitreous humor, cerebrospinal fluid, kidney and urine in victims affected by this contaminant. The results of this study legally supported the prohibition of the continued consumption of the beer and avoided further intoxications. Our results showed, for real cases of human intoxication, that DA can still be detected in alternative matrices, even when non-detectable in blood, demonstrating the importance of collecting different kinds of samples for a proper investigation.

The role of angiotensin-(1-7) receptor Mas in spermatogenesis in mice and rats.

Evidence regarding the components of the renin-angiotensin (Ang) system suggests that this system plays an important role in male reproduction. However, there are few data available in the literature on the effects of Ang-(1-7) on the male reproductive system. The present study investigated the effects of the genetic deletion and chronic blockage of Ang-(1-7) receptor Mas on spermatogenesis and male fertility. The localization of Mas in mouse and rat testes was determined by binding assays and immunofluorescence, whereas the testis structure and spermatogenic process were morphologically and stereologically analysed by light microscopy. Ang-(1-7) binding and immunofluorescence revealed the presence of Mas in the testes of mice and rats. Although the total numbers of Sertoli and Leydig cells per testis and Leydig cell size were similar in both wild-type and Mas-deficient mice, Mas(-/-) animals exhibited a significant reduction in testis weight and a greater volume of apoptotic cells, giant cells and vacuoles in the seminiferous epithelium. In both mice and rats, an increased number of apoptotic cells were found during meiosis. Due to disturbed spermatogenesis, daily sperm production was markedly reduced in Mas(-/-) mice. Moreover, chronic infusion of A-779 [an Ang-(1-7) antagonist] in rats significantly increased the total number of apoptotic cells and primary spermatocytes in particular stages of spermatogenesis. Taken together, these findings strongly suggest that Ang-(1-7) receptor Mas plays an important role in the regulation of spermatogenesis.