The influence of site of collection on postmortem morphine concentrations in heroin overdose victims

When assaying for postmortem morphine concentration, significant site sampling variability exists between central and peripheral sampling sites and even within sampling regions of the body. To study the variation, 76 suspected heroin overdoses were identified. Each had femoral artery (FA) and vein (FV), left and right ventricle and pooled heart blood samples obtained at autopsy. Forty-four tested positive for morphine. Morphine concentrations were determined by gas chromatography/mass spectrometry, with sampling site differences reported as log-transformed ratios and compared by signed rank test.The mean FA to FV ratio for total morphine was 1.2 (range 0-4.5). The ratio for left heart to right heart total morphine was 1.1 (range 0.4-3.2). Left ventricular to FV total morphine ratio was 2.0 (range 0.6-6.9). In these opioid overdose deaths, FA and FV morphine concentrations are usually similar, although up to 4.5-fold differences were noted. Centrally obtained morphine concentrations are on average twice as high compared with peripheral morphine concentrations. Left and right ventricular morphine concentrations were usually similar, although up to 3.2-fold differences were noted (left side higher).     

早期心肌梗死死后诊断的法医病理学研究进展

心源性猝死在成人猝死的死因中占首位,心肌梗死是冠心病猝死的主要机制之一,由于早期心肌梗死发生突然,且可在短时间内死亡,肉眼和镜下都缺乏典型的形态学改变,一直都是法医实践中研究的热点,本文回顾多年来心肌梗死的研究成果在法医学中的应用及局限,展望新的临床指标在法医工作中的可行性,期望提高死后心肌梗死诊断的准确率。     

积温法则进行死亡时间推断

应用昆虫发育历期和积温法则推测死亡时间是法医学重要技术。本文对蝇蛆和蛹应用倒计积温的方法进行死亡时间推断,获得与实际死亡时间一致的结果。     

我国法医昆虫学的研究进展

法医昆虫学是应用昆虫学知识解决有关法律问题的法医学分支学科。在推断死亡时间等方面具有明显优势。本文在阐述法医昆虫学定义和研究内容基础上,综述尸体上的昆虫生态群落演替现象、昆虫发育形态学、DNA分析技术的应用、法医昆虫毒理学等法医昆虫学问题在我国的研究进展。     

死后离体人肝组织的激光共聚焦显微拉曼光谱分析

目的观察和探讨人死后肝组织细胞激光共聚焦显微拉曼光谱的变化规律及其与死亡时间的关系。方法离体肝组织于死后48～72h内每隔4h提取样品,采用激光共聚焦显微拉曼光谱技术进行检测。观察800cm-1～3 200cm-1范围内检测样本特征峰的变化,指认其对应的化学基团,选择强度比值I1094/I2923作为响应值,并进行统计学计算。结果在48～72h内,随时间的延长,肝组织细胞主要散射峰峰位无明显变化,而其峰强度有明显差异;与核酸有关的峰（1 094cm-1）强度随时间推移有明显下降;与脂类有关的峰（1 454cm-1、2 923cm-1）强度变化不明显;各相对峰强（I1094/I2923）随死亡时间的推移而减小,并得到回归方程（r=0.914）。结论人死后肝组织细胞DNA降解随死亡时间延长呈下降趋势,I1094/I2923值与PMI呈负线性关系。激光共聚焦显微拉曼光谱技术有望成为推断死亡时间的检测方法。     

The Impact of Gender,Age and Tissues in vitro on Estimating Postmortem Interval by FTIR Spectroscopy

To investigate the influence of such individual factors as gender,age and tissues in vitro to the postmortem interval(PMI) by the Fourier transform infrared(FTIR) spectrometer in animal experiments.SD rats were classified into male and female groups,different age groups(21-day,42-day and 63-day group),and tissues in vitro and in vivo groups.The rats were sacrificed by cervical dislocation,whose bodies were kept in a controlled environmental chamber set at(20±2) ℃ and 50% humidity.The liver,kidney,spleen,myocardium,brain,lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem.With the change of PMI,no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points.All the experimental groups showed no significant changes when compared with the controls.The gender,age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.     

多温度下死后心血pH值随时间变化的三维拟合函数研究

目的 探讨通过测量多温度条件下家兔右心血液pH值进行死亡时间推断的可行性.方法 48只家兔随机分为6组,空气栓塞法处死后于10℃、15℃、20℃、25℃、30℃和35℃的不同死亡时间点采集右心血液;用PB-10型pH仪测量样本pH值;SPSS统计软件进行回归分析;MATLAB软件进行数学分析.结果 各温度组右心血液pH值变化与死亡时间呈高度相关(R2=0.974 ～0.982);获得拟合的曲面方程.结论 利用插值函数拟合pH值与死亡时间的曲面方程可进行温度变化条件下的死亡时间推断.     

Infrared Imaging of the Crime Scene: Possibilities and Pitfalls

All objects radiate infrared energy invisible to the human eye, which can be imaged by infrared cameras, visualizing differences in temperature and/or emissivity of objects. Infrared imaging is an emerging technique for forensic investigators. The rapid, nondestructive, and noncontact features of infrared imaging indicate its suitability for many forensic applications, ranging from the estimation of time of death to the detection of blood stains on dark backgrounds. This paper provides an overview of the principles and instrumentation involved in infrared imaging. Difficulties concerning the image interpretation due to different radiation sources and different emissivity values within a scene are addressed. Finally, reported forensic applications are reviewed and supported by practical illustrations. When introduced in forensic casework, infrared imaging can help investigators to detect, to visualize, and to identify useful evidence nondestructively.     

Effect of Temperature on Six Different Developmental Landmarks within the Pupal Stage of the Forensically Important Blowfly Calliphora vicina (Robineau‐Desvoidy) (Diptera: Calliphoridae)

This study investigates the pupal development times of the blow fly Calliphora vicina, which were studied in the laboratory at six different constant temperatures (15, 20, 23, 25, 28, and 30°C each ± 1°C). Lower thresholds (t_L) for development were estimated from the linear regression of the developmental rates on each temperature. These data have made it possible to calculate the accumulated degree days (ADD) necessary for C. vicina to complete the larval stage and to achieve adult emergence. The minimal duration of development from oviposition to adult emergence was found to be inversely related to temperature. Additionally, six landmarks in pupal development are showed, and for each of the landmarks, the ADD value was calculated for every rearing temperature involved. These data assist in calculating the duration of the pupal stage based on morphological characteristics and would be of great value for future forensic entomological casework.     

3种特殊染色在急性心肌梗死死后诊断中的应用比较

目的对比观察苏木素-碱性复红-苦味酸染色(HBFP染色)、变色酸2R-亮绿染色和Heidenhain染色在急性心肌梗死死后诊断中的应用价值。方法以大鼠急性心肌梗死模型、法医检案急性心肌梗死心脏标本作为研究对象,采用HBFP染色、变色酸2R-亮绿染色和Heidenhain染色进行对比观察。结果①3种特染方法在大鼠心肌缺血15min时均可观察到阳性染色,且阳性染色面积随缺血时间的延长而扩大;②大鼠急性心肌缺血4h心脏标本在-20℃、4℃及室温条件下保存至14d,3种特染方法仍可见阳性着色,但变色酸2R-亮绿染色和HBFP染色随保存时间的延长而出现着色能力下降,阳性区域变小的趋势,Heidenhain染色效果最为稳定;③急性心肌梗死检案标本中,3种特染方法均可显示缺血心肌纤维,发病1h内死亡者Heidenhain染色优于另外两种染色。结论 3种特染均可客观的显示出急性心肌梗死早期病理改变,其中Heidenhain染色更具稳定性和可操作性。