猪眼玻璃体液钾离子、次黄嘌呤浓度变化与PMI推断

目的 研究猪眼玻璃体液成分变化及其与死亡时间(postmortem interval,PMI)的关系.方法放血处死家猪后取带眼睑的眼球96只,随机分为24组,在避光、温度(15±2)℃、湿度(50±5)%条件下分别放置2～96h,采集玻璃体液,运用全自动生化检测仪、超高效液相色谱检测K+、Na+、Cl-及次黄嘌呤(hy...     

DNA定量技术在死亡时间推断中的研究进展

死亡时间推断是法医病理学研究的热点及难点之一.随着分子生物学技术的发展,DNA的定量已广泛应用于死亡时间推断的研究.本文主要对机体死后不同组织和器官中DNA含量随时间的降解情况,以及单细胞凝胶电泳、Feulgen染色图像分析技术、流式细胞仪等近年来新的DNA定量技术应用于死亡时间推断研究中的进展进行了综述.     

大鼠死后脑、心肌和肾组织β-actin mRNA的降解与早期死亡时间的关系

目的 研究SD大鼠脑、心肌和肾组织细胞内β-actin mRNA的降解与早期死亡时间的关系,为早期死亡时间的推断寻找新的指标.方法 大鼠处死后置于20℃的环境中,分别于死后不同时间点提取脑、心肌、肾的总RNA,采用实时荧光定量RT-PCR方法检测总RNA中β-actin mRNA的水平(Ct值),分析死后经过时间与Ct...     

Variation in Developmental Time for Geographically Distinct Populations of the Common Green Bottle Fly,Lucilia sericata (Meigen)*

Abstract: Time between death and discovery of remains, or postmortem interval (PMI), can be assessed using blow fly maggot age. Forensic entomologists rely on published, often nonlocal, species‐specific developmental tables to determine maggot age. In a series of common garden experiments, we investigated the developmental rate variation between populations of Lucilia sericata collected from Sacramento, CA, San Diego, CA, and Easton, MA at 16°C, 26°C, and 36°C. For the 16°C trial the time measurement started at egg hatch, while for the higher temperatures the experiment began at oviposition; the wandering stage signified the endpoint for all experiments. The distribution of developmental times differed significantly (ANOVA, p < 0.001) between the three populations within each temperature treatment. We discovered that regional variation of developmental times within a blow fly species exists. This study demonstrates the importance of assembling local population‐specific developmental tables when estimating larval age to determine PMI.     

Growth of Chrysomya megacephala (Fabricius) Maggots in a Morgue Cooler*

Abstract: In estimating the postmortem interval (PMI) using maggots obtained during autopsy, the forensic entomologist makes decisions regarding the effects of low‐temperature storage of the body on the insects. In this case report, a corpse was found in an abandoned house in the residential area of Bukit Mertajam, Penang, Malaysia. The maggots were found to be alive inside the mouth of the deceased although the corpse had been in the morgue cooler for 12 days. The maggots were reared and identified as Chrysomya megacephala (Fabricius). The emerged adult flies were kept as a stock colony, and the duration of development under the indoor fluctuating temperature regime was studied. The total duration of developmental process of this species was 9.5 ± 0.5 days, and the PMI estimated was 3.2 ± 0.6 days. This case report demonstrates the survival of Ch. megacephala maggots for 12 days and their growth inside the morgue cooler.     

Human Electrical Muscular Incapacitation and Effects on QTc Interval

Human Electrical Muscular Incapacitation (HEMI) is used to subdue combative individuals. Changes in cardiac electrical activity have been proposed as the cause of death in a small fraction of these individuals. The current study sought to determine whether changes in QTc interval occur after HEMI exposure. Twenty‐four participants had EKG readings before a 5‐second HEMI exposure and within 30 min after exposure. All subject EKGs were read by a data‐blinded cardiac electrophysiologist who calculated a QT corrected (QTc) interval. QTc interval was calculated using Bazett method. QTc prolongation was defined as >430 ms and a threshold of 30 ms for identifying QTc lengthening. Five participants experienced QTc prolongation and six had QTc lengthening. One participant developed QTc prolongation exceeding 500 ms, which carries a risk of developing multifocal ventricular tachycardia. These results suggest that HEMI exposure may cause EKG changes with a risk of ventricular tachycardia.     

Bioelectrical Impedance as a Technique for Estimating Postmortem Interval,,

Estimation of postmortem interval (PMI) is a critical component of death investigation. A cadaver can be hypothesized to be a resistor–capacitor (RC) circuit the impedance (Z) of which changes in a quantifiable manner as the cadaver decomposes. This hypothesis was tested using bioelectrical impedance analysis (BIA) equipment to apply a current with a fixed amplitude at a single frequency to four cadavers over time and measuring two components of Z, resistance (R) and reactance (X_c). Quadratic regression analysis between Z and accumulated degree days (ADD) showed a statistically significant parabolic relationship. The parabolic relationship poses an initial challenge to the use of the method, and additional research is needed to address this issue. However, the results of the reported research support the hypothesis that Z measured using BIA has a relationship to PMI.     

家兔眼玻璃体液21例元素含量PMI关系的研究

目的寻找一种精确推定PMI的方法。方法应用电感耦合等离子体质谱(ICP-MS),系统研究了家兔死后96h内眼玻璃体液21种元素含量与PMI的相关性。结果眼玻璃体液Co、Mo、Cd、Sb、I、Pb、Bi、Li共8种元素与PMI无关。K、Mg、Fe、P、Na、Al、Ca、Ti、Ni、Cu、Zn、Sr、Ba共13种元素含量与PMI有关。结论眼玻璃体液K、Mg、Fe、P、Na、Al、Ca、Ti、Ni、Cu、Zn、Sr、Ba共13种元素与PMI有关。为研究人尸体眼玻璃体液元素与PMI的关系奠定了选择指标的基础。