Forensic Identification of Diving Deaths. / 潜水死亡的法医学鉴定.

Investigation of the cause of death during diving is one of the contents of forensic pathology. In this article, relevant foreign literature is reviewed to summarize the techniques and methods used in the identification of diving deaths, such as accident reconstruction, diving monitoring data, postmortem CT examination and gas analysis (location and quantity) in the body of the corpse, in order to provide a reference for forensic identification of such cases.

Expression profiling of microRNAs in hippocampus of rats following traumatic brain injury.

The changes of microRNA expression in rat hippocampus after traumatic brain injury (TBI) were explored. Adult SD rats received a single controlled cortical impact injury, and the ipsilateral hippocampus was harvested for the subsequent microarray assay at three time points after TBI: 1st day, 3rd day and 5th day, respectively. We characterized the microRNA expression profile in rat hippocampus using the microRNA microarray analysis, and further verified microarray results of miR-142-3p and miR-221 using quantitative real-time PCR. Totally 205 microRNAs were identified and up-/down-regulated more than 1.5 times. There were significant changes in 17 microRNAs at all three time points post-TBI. The quantitative real-time PCR results of miR-142-3p and miR-221 indicated good consistency with the results of the microarray method. MicroRNAs altered at different time points post-TBI. MiR-142-3p and miR-221 may be used as potentially biological markers for TBI assessment in forensic practice.

Roles of 3,4-methylenedioxymethamphetamine (MDMA)-induced alteration of connexin43 and intracellular Ca(2+) oscillation in its cardiotoxicity.

UNLABELLED: Although it is well known that 3,4-methylenedioxymethamphetamine (MDMA) can cause various cardiovascular abnormalities and even sudden death from cardiac arrhythmia, whether it has any effect on myocardial gap junctions, which might be one of the targets mediating MDMA-induced cardiotoxicity, remains unclear. OBJECTIVE: To test the hypothesis that MDMA may affect the myocardial gap junction protein connexin43 (Cx43) and induce cardiac dysrhythmia. METHOD: (1) In vivo study: adult rats were treated with a single dose MDMA administration (20mg/kg, i.p.). Electrocardiogram detection and immunohistochemical analysis were performed to evaluate cardiac function and expression of Cx43, respectively; (2) in vitro study: cultured ventricular myocytes of neonatal rats were treated with MDMA (10, 100, 1000µmol/L) for 1h. Western blotting and real-time quantitative polymerase chain reaction (RT-qPCR) were performed to investigate the total Cx43 mRNA expression. Immunofluorescent analysis was used to evaluate the amount of junctional Cx43. The phosphorylation status of Cx43 at site Ser368 and intracellular Ca(2+) oscillation were also studied. RESULTS: Obvious changes in electrocardiographic patterns were found in rats following MDMA administration. They were characterized by prolonged QRS duration associated with increased amplitude of QRS complex. The heart rates in treated rats were significantly decreased compared to the rats in the control group. The immunohistochemical findings revealed a significant decrease in Cx43 expression. The in vitro study also showed a marked decline in total Cx43 protein associated with reduction of Cx43 mRNA, whereas the phosphorylated Cx43 at Ser368 was increased. Decrease of junctional Cx43 was found correlated with reduction in N-cadherin induced by high concentration of MDMA. Additionally, confocal microscopy findings revealed alteration of intracellular calcium oscillation patterns characterized by high frequency and increasing influx Ca(2+). CONCLUSIONS: MDMA reduces expression of cardiac gap junction protein Cx43. The increase of phosphorylation status of Cx43 at Ser368 induced by MDMA is attributed, at least in part, to the Ca(2+)-dependent regulation of protein kinase C (PKC) activity. Our findings provide first evidence of MDMA-mediated changes in those cardiac gap junctions that may underlie MDMA-induced cardiac arrhythmia.

[Distribution of diatoms in central city of Beijing].

OBJECTIVE: To explore the quantity and distribution of diatoms in main rivers and lakes in Xicheng, Dongcheng, Chaoyang, Haidian, Fengtai and Shijingshan Districts of the city of Beijing. METHODS: Water samples were examined through the method of disorganizing, which were collected from 16 rivers and lakes in the central city of Beijing in September and October 2011. Diatom species and proportions of water samples were analyzed using DotSlide microscope station. RESULTS: A total of 10 species of diatoms were detected. Cyclotella, Synedra and Melosira etc. were found to be the dominant species via quantitative analysis. Significant differences were observed for diatom species and proportions among the different rivers and lakes. Melosira was found to be the dominant species in the Chang River; Synedra, in the Zhuan River, the Kunyu River and the Taoranting Park; Cyclotella, in the East Moat River, the Ba River, the Liangshui River and the Yongding River; and Navicula, in the Liangma River; Nitzschia, in the diversion canal of the Yongding River. CONCLUSION: The features of distribution of diatoms in the central city of Beijing are outlined. The morphological and relative constituent ratio database of diatoms are established in central city of Beijing.