【作者】 陈瑶清；

【导师】 文继舫； 蔡继峰；

【作者基本信息】 中南大学 ， 病理与病理生理学， 2008， 硕士

【摘要】 背景:死亡时间（Postmortem Interval PMI）是法医学尸体检验要求解决的重要问题之一,对进一步确定案件性质和阐明作案过程有重要的价值。当前推断死亡时间的方法主要包括:（1）根据尸体现象推断死亡时间。（2）根据胃肠内容物消化程度推断死亡时间。（3）利用昆虫学知识推断死亡时间。（4）根据DNA降解程度推断死亡时间。（5）根据酶化学和组织学变化推断死亡时间等等。由于人眼玻璃体本身具有受到眼眶的保护及相对隔绝的解剖特点,尸体腐败和外界污染等因素对其影响小。玻璃体液容易获取,检测方法简便、相对可靠,尤其是死后玻璃体液中很多物质的化学变化较血液与脑脊液内的要缓慢得多,且相对稳定,变化规律性较强。根据文献报道,目前大多数对眼玻璃体液的研究还停留在动物实验阶段。由于人和动物的种属差异性,很多的研究结果在法医实践中价值不大。本研究用死后人的玻璃体液,通过先进的仪器和有效的方法,检测到死后玻璃体液更多的指标,发现更多与死亡时间密切相关的成分。目的:用玻璃体液化学成分规律变化推断死亡时间,对多指标进行分析,建立各自的回归方程以及多元回归方程,并计算出相应的死亡时间的预测区间,综合分析,减少误差,使玻璃体液能更广泛地应用于法医实践,尽可能更加准确地推测死亡时间。方法:1.用日本产HITACHI.7060全自动生化分析仪对玻璃体液化学成分（钠、氯、尿素、肌酐、钾、钙、镁、无机磷）进行测定。2.人体死后不同时间玻璃体液化学成分测定的样本:死亡时间在0.3～148小时以内尸体的双眼玻璃体液。3.用SPSS13.0统计软件,将所得数据进行正态性检验后再进行单元及多元回归分析。结果:1.玻璃体液中钠、氯、尿素、肌酐、钾、钙、镁、无机磷与死亡时间均有一定的相关性。2.钾离子浓度与死亡时间线性关系明显,方程为PMI=0.702+0.186K⁺（r=0.512;R²=0.262,校正R²=0.259）,PMI的95%预测区间为:（PMI-1.96×3.60,PMI+1.96×3.60）。玻璃体液中无机磷浓度与死亡时间的相关性大,随死亡时间缓慢地升高,方程为PMI=1.617+0.681P（r=0.544;R²=0.296,校正R²=0.293）,PMI的95%预测区间为:（PMI—1.96×0.85,PMI+1.96×0.85）。3.钾离子（K⁺）、钠离子（Na⁺）、磷（P）、镁离子(Mg²⁺)与死亡时间的多元回归方程为:PMI=5.292+0.142K⁺-0.022Na⁺+0.670P-1.007Mg²⁺（r=0.633;R²=0.4000,校正R²=0.388）,PMI的预测区间为:（PMI-1.96×1.31.PMI+1.96×1.31）。结论:1、玻璃体液中的钠、氯离子与死亡时间呈负相关;尿素氮、肌酐、钾离子、钙离子、镁离子、无机磷与死亡时间呈正相关;其中无机磷和钾离子浓度与死亡时间线性关系最明显。2、结合磷、镁离子、钾离子和钠离子一起建立多元回归方程,可以加强方程的拟合度,更好的反应出玻璃体液随死亡时间变化的关系。3、本研究未发现左、右眼玻璃体液各化学成分有差异。更多还原

【Abstract】 Background:The estimation of postmortem interval （PMI） is one of the important issues to be solved for the examination of dead body in the medical jurisprudence. PMI is great value to determine the nature of the case and to clarify the process of crime in the forensic medicine.There are many ways to estimate the PMI.The ways refer to multidisciplinary fields. The current methods of estimating the PMI mainly include postmortem phenomena, contents of in intestines and stomach, DNA degradation, enzyme chemistry and histology, entomology.Human vitreous humor is under the protection of the orbital and isolated from the outside.The Corruption、contamination and other factors exercise influence over human vitreous.The humor vitreous can be acquired easily and be detected simply.The results of the test is relatively reliable.The postmortem change of chemical components of human vitreous varies more slowly than of blood and cerebrospinal fluid. It is more stable and more irregular. According to reports in the literature, most of experimental research still remains at the stage of trials on animals. As the human and animal species diversity, many of the findings are of little value in the forensic practice. We can detect more chemical components of human vitreous which are undiscovered and are closely related to PMI by advanced equipment and effective ways. Objective:To estimate the PMI with multi-index and set up their separate regression equation and calculate the prediction intervals of PMI is to analyze comprehensively and try to decrease the error. Thus we could make human vitreous humor be widely used in forensic medicine practices and estimate the PMI correctly.Methods:1. HITACHI.7060 auto-biochemistry instrument made in Japanese was used to analyze all the collected samples.2. The checking sampling of human vitreous humor in different time after death: the vitreous humor was taken from the death from 0.3 to 109 hours.3. Statistical analysis was performed using the SPSS program package （SPSS, version 13.0）. The collected data were test by Gaussian distribution （Q-Q plots） first, then analyzed the linear correlation between the PMI and one of the chemical compositions in vitreous humor separately and all together.Results:1. The relationship between the contents of these chemical components （includes the sodium, chlorine, urea, creatinine, potassium, calcium, magnesium, phosphorus） and PMI is certain.2. The content of potassium appeares best linear relation with PMI. The equation of PMI is PMI=0.702+0.186K⁺（r=0.512; R²=0.262, regulate R²=0.259）. The prediction interval of PMI is （PMI - 1.96×3.60, PMI+1.96×3.60）. The content of phosphorus ascends with the time since death and has remarkable relevance to PMI. The equation of PMI is PMI=1.617 + 0.681P （r =0.544; R²=0.296, regulate R²=0.293）. The prediction interval of PMI is （PMI-1.96x0.85, PMI+1.96×0.85）.3. The gradual regression equation of PMI is PMI=5.292+0.142K⁺-0.022Na⁺+0.670P-1.007Mg²⁺ （r=0.633; R²=0.4000, regulate R²=0.388）. The prediction interval of PMI is （PMI-1.96×1.31, PMI+1.96×1.31）.Conclusions:1. The concentration of sodium and chloridion are inversely related to PMI.The concentration of urea, creatinine, potassium, calcium, magnesium, phosphorus are on the contrary. There is a significantly linear relation between the concentration of phosphorus and potassium and PMI.2. The gradual regression equation was obtained for the concentration phosphorus of, calcium, potassium and sodium.It can improve the fit of the equation, reflects the linear relation between the chemical components of human vitreous humor and PMI. We can estimate PMI more accurately.3. The chemical components of human vitreous have no differences between left and right eyes in this study.更多还原