不同死亡方式大鼠心肌组织中ATP、ADP和AMP含量比较

目的比较不同死亡方式对大鼠心肌组织能量物质变化的影响,为判断不同死亡方式及死亡时间提供依据。方法180只大鼠随机分为三组,以不同方式(失血、窒息、断颈)处死,高效液相色谱法检测死后0、0.5、1、1.5、2、3、4、6、8、12、18和24h大鼠心肌组织中的ATP、ADP、AMP含量。结果三组不同死亡方式大鼠心肌组织的ATP、ADP、AMP的含量在大部分时间点做组间比较有明显差异(P<0.05);每组不同死亡方式的大鼠心肌组织中ATP、AMP的含量随时间的变化有明显的差异(P<0.01),而各组中的ADP在死亡一定时间后无明显差异。结论不同死亡方式的大鼠心肌组织中能量物质死后变化可以用作对死亡方式及某种方式不同死亡时间做出判断的依据。     

DNA含量变化与死亡时间推断的研究进展

在法医学实践中,死亡经历时间的推断具有重要的实践价值,但其准确推断却一直是法医学实践的难题,因而也一直是法医学研究的热点。法医DNA技术是近年来发展起来的在分子水平进行死亡时间推断的新技术、新方法,同传统方法相比,具有很大的优势,本文对该技术提出的背景、发展、优缺点以及发展前景进行综述,着重对DNA含量变化与其相关性的研究进展进行讨论。     

The changes of fourier transform infrared spectrum in rat brain

Estimation of the time since death (postmortem interval [PMI]) is one of the most difficult problems in forensic investigations, and many methods currently are utilized to estimate the PMI. The goal of this study was to investigate the changes of attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra of rat brain from postmortem time 0-144 h. The intensity ratios of major absorbance bands were examined (I(1066)/I(1392), I(1168)/I(1392), I(1234)/I(1454), I(1301)/I(1392), I(1647)/I(2956), I(2921)/I(2850), and I(1647)/I(1539)). The spectra of rat brain displayed prominent changes with increasing PMI. The band at 2871 and 1737 per cm became weak with the time increasing and even disappeared at postmortem 96 and 72 h, respectively. A close linear correlation was shown between the relative absorption intensity and the PMI, and the I(1234) /I(1454) offered a stronger correlation (r = 0.973). Our results indicate that ATR-FTIR spectroscopy may be a useful technique for estimating the PMI.     

核酸及蛋白质在死亡时间推断中的应用

死亡时间(postmortem interval,PMI)推断一直是法医学研究的重点与难点.机体死亡后,组织细胞发生自溶,核酸等大分子物质发生降解,其中DNA含量呈逐渐下降趋势,与PMI具有一定的线性关系,管家基因β-actin、GAPDH mRNA具有一定的稳定性,也可作为内参照进行PMI推测.本文综述了目前DNA、...     

Postmortem Blood Concentrations of R‐ and S‐Enantiomers of Methadone and EDDP in Drug Users: Influence of Co‐Medication and P‐glycoprotein Genotype

Abstract: We investigated toxicological and pharmacogenetic factors that could influence methadone toxicity using postmortem samples. R‐ and S‐methadone were measured in femoral blood from 90 postmortem cases, mainly drug users. The R‐enantiomer concentrations significantly exceeded that of the S‐enantiomers (Wilcoxon’s test, p < 0.001). The samples were divided into four groups according to other drugs detected (methadone only, methadone and strong analgesics, methadone and benzodiazepines, or methadone and other drugs). There was no significant difference in any of the R‐methadone/total methadone ratios among the four groups. The median R/S ratio was 1.38, which tends to be higher than that reported for the plasma of living subjects. In addition, we investigated whether small nucleotide polymorphisms in the MDR1 gene that encode the drug transporter P‐glycoprotein were associated with the concentrations of R‐ and S‐methadone and its metabolite 2‐ethylidene‐1,5‐dimethyl‐3,3‐diphenylpyrrolidine. No significant association was detected.     

大鼠死后肌动蛋白降解与死亡时间的相关性

目的观察大鼠死后不同时间心肌、肝、脾、肺、肾、脑和骨骼肌肌动蛋白（actin）的降解规律,为晚期死亡时间（postmortem interval,PMI）的推断寻找客观指标。方法28只SD大鼠随机分为7组,经机械性窒息致死后．分别置于20℃恒温箱内,于0、24、48、72、96、120和168h后剖取以上器官,应用免疫印迹技术检测各组织内actin的含量,SPSS11．5软件对所得数据进行方差分析。结果大鼠死后上述各器官actin含量均随PMI的延长而逐渐下降,与PMI相关,决定系数（R2）均在0．75以上。但actin在上述各器官内的降解速度有显著差异（P〈O．05）,在脑组织中降解速度最快,其余依次为肺、脾、肝、肾、心肌和骨骼肌。结论尽管大鼠死后心肌、肝、脾、肺、肾、脑和骨骼肌actin的降解规律具有组织差异性,但是actin在上述组织中的含量变化与PMI相关．有助于较晚期PMI的推断。     

The black soldier-fly, Hermetia illucens (Diptera, Stratiomyidae), used to estimate the postmortem interval in a case in Amapá State, Brazil

The black soldier-fly (Hermetia illucens) is a generalist detritivore which is commonly present in corpses in later stages of decomposition and may be useful in forensic entomology. This paper describes the estimation of the postmortem interval (PMI) based on the life cycle of the black soldier-fly in a case in northern Brazil. A male child was abducted from his home and 42 days later his corpse was found in an advanced stage of decay. Two black soldier-fly larvae were found associated with the body. The larvae emerged as adults after 25-26 days. Considering the development cycle of H. illucens, the date of oviposition was estimated as 24-25 days after abduction. Since H. illucens usually (but not always) colonizes corpses in more advanced stages of decay, this estimate is consistent with the hypothesis that the child was killed immediately after abduction.     

Elevated morphine concentrations determined during infant death investigations: artifacts of withdrawal of care

Abstract:  Three cases are reported of elevated postmortem blood morphine concentrations (189–3036 ng/mL) that were observed during the course of death investigations involving three children ranging in age from 1 week to 2 years, all of whom underwent withdrawal of life support. In all three cases, the presence of opiates in postmortem blood was indicated by immunoassay (ELISA) and quantitative confirmatory analysis of free morphine concentrations in postmortem blood was performed by solid-phase extraction followed by gas chromatography/mass spectrometry (GC/MS) in the selected ion monitoring mode. While the practice of withdrawing life support from terminally ill patients, with the accompanying administration of narcotics/analgesics has been reported in the medical literature, it has not been adequately described in the forensic literature. The implications of this practice on the forensic toxicological interpretation of morphine findings are discussed. To our knowledge, this is the first report of postmortem morphine concentrations arising directly from administration in conjunction with withdrawal of care in pediatric patients.     

Diesel fumes do kill: a case of fatal carbon monoxide poisoning directly attributed to diesel fuel exhaust with a 10-year retrospective case and literature review*

While it is known that diesel fuel combustion engines produce much lower concentrations of carbon monoxide (CO) than gasoline engines, these emissions could certainly generate lethal ambient concentrations given a sufficient amount of time in an enclosed space and under suitable environmental conditions. The authors report a case of CO poisoning which was initially referred for autopsy as a presumed natural death of a truck driver found in the secure cab of a running diesel tractor trailer truck. Completion of the preliminary investigation ascribed death to complications of ischemic heart disease (IHD), pending toxicological analysis that included quantification of CO. When the toxicology results showed lethal blood COHbg, the cause of death was re-certified as CO intoxication secondary to inhalation of (diesel) vehicular exhaust fumes. Because of the unique source of fatal CO intoxication in this case, the contributory IHD and the possible contaminants in the putrefied blood, a 10-year retrospective review was conducted on all nonfire related CO deaths autopsied (n = 94) at the Office of the Chief Medical Examiner in Louisville, KY from 1994 to 2003. For validation of the COHbg detection method used by the Kentucky Office of Forensic Toxicology (KYOFT), blood samples from these cases along with controls were submitted to three laboratories using various analytical methods yielding no statistically significant differences. Lastly, an extensive literature review produced no scientifically reported cases of fatal CO poisoning attributed to diesel fuel exhaust.     

死亡大鼠看家基因mRNA时序性降解的组织差异性研究

目的研究死亡大鼠看家基因mRNA时序性降解的组织差异性,评价其用于死亡时间推断的价值。方法SD大鼠20只分为死后0、1、3、5、7d共5组,脊椎脱臼法处死大鼠,提取大鼠心、肝、脾、肺、肾、脑组织,在相应时间段提取RNA,应用一步法RT-PCR技术检测各组织中看家基因GAPDHmRNA和β-actinmRNA的水平,Vilber凝胶图像分析系统测定扩增产物IOD值,SPSS10．0统计软件对数据进行方差分析。结果GAPDHmRNA、β—actinmRNA扩增产物相对灰度与积分光密度值随死后经过时间的延长而逐渐减小,且与死亡时间显著相关,大鼠脾脏和脑组织GAPDHmRNA和β-actinmRNA在死后5d内可检出,心脏和肾脏在死后3d内可检出,而肝脏和肺脏GAPDHmRNA和β-actin mRNA降解较快,仅在死后1d内可检出。结论脑组织和脾脏中mRNA稳定性较好,适用于PMI特别是晚期PMI的推断。除环境温度外,环境湿度也是死亡时间推断中的重要影响因素。