ESTIMATION OF POSTMORTEM INTERVAL BY POSTMORTEM BIOCHEMICAL CHANGES

死亡时间的估计是法医学研究的重要内容之一。20例已知PMI病例法医尸检时取脑、肺、心、肝、肾5个尸检器官组织，尸检时间间隔为1 ~ 120小时（平均25.81小时），测定血管内皮生长因子（VEGF）表达的时间过程。人肝癌源性Hep 3B细胞系作为对照。VEGF水平随PMI增加呈线性增加，肺（r=0.95，肾（r=0.89））和肝脏（r=0.88） PMI增加至15小时。VEGF水平在PMI 24 h后下降，随后保持稳定。在脑组织中，VEGF水平在PMI 24小时后开始升高，并在PMI 40小时内随PMI线性升高（r=0.94），然后开始下降。在心脏中，PMI与VEGF水平无明显相关性。在某些情况下，如婴儿死亡和窒息死亡，出现了一些差异。总之，在法医和病理生理学中，测量缺氧诱导的各种身体器官中的VEGF水平似乎是估计24小时内PMI的有用方法。该方法在临床和基础医学中也可能适用于缺血性疾病。

Estimation of the post-mortem interval (PMI) is one of the most important tasks in forensic medicine. Five autopsy organ tissues such as brain, lungs, heart, liver and kidneys were taken at the time of forensic autopsy from 20 known PMI cases with a range of postmortem intervals ranging from 1 to 120 hrs (the mean was 25.81 hrs) and the time-course of vascular endothelial growth factor (VEGF) expression was measured. The human hepatoma-derived Hep 3B cell line was used as a control.The levels of VEGF increased linearly with the PMI up to 20 hrs in lung (r=0.95 and in kidney (r=0.89), and up to 15 hrs PMI in liver (r=0.88). The VEGF levels fell after 24 hrs PMI, and then remained stable. In brain, the levels of VEGF started to increase after 24 hrs PMI and increased linearly with PMI up to 40 hrs in brain (r=0.94) and then begin to fall. In heart, there was no clear correlation between the PMI and VEGF level. Some variations occurred in selected cases, such as the infant and asphyxial deaths.In conclusion, measurement of hypoxia-inducible levels of VEGF in various body organs appears to be a useful method of estimating the PMI up to 24 hrs in forensic medicine and pathophysiology. This method is alsoprobably applicable in ischaemia in clinical and basic medicine.