组织细胞DNA含量变化与死亡时间的相关性研究

目的研究人死后各器官组织细胞DNA降解变化规律,探讨其在推断死亡时间方面的应用价值,为推断死亡时间提供科学依据。方法已知死亡时间人尸体的心、肝、脾、肾,按死后6,12,24和48h四个时间段取材,制成石蜡切片,经Feulgen染色并图像分析;同时将各器官组织按不同时间段取材,制成单细胞悬液,应用流式细胞仪检测DNA含量。结果(1)人体各器官组织细胞经FCM检测,脾细胞核DNA随死亡时间延长呈现较好的下降梯度,而心、肝、肾,则由于自溶较快,死后6h细胞核DNA含量已很低,其变化情况与死亡时间的相关性不佳;(2)各器官组织细胞核DNA染色强度指数均随死亡时间的延长而下降。结论(1)机体死亡后,各器官组织细胞核DNA含量随死亡时间延长逐渐减少,具有一定的变化规律,其中以脾细胞核DNA含量的变化趋势与死亡时间最具相关性,肝、肾次之,而心最差;(2)方法学分析,图像分析技术(IAT)与流式细胞术(FCM)两种检测方法在研究组织细胞DNA含量变化方面,各有利弊,可互补不足。

The research of relationship between DNA degradation and postmortem interval

Objective To investigate the relationship between the DNA degradation in cells and postmortem interval. Methods Tissue pieces of the heart, liver, spleen and kidney of one corpse (male, 54 years old, died of mechanical injury, PMI of 6h) were obtained in 6, 12, 24, 48 h after death, fixed in Carnoy fluid, and then paraffin sections were prepared, stained with Feulgen and analyzed by Image analysis technology (IAT). Meanwhile the single-cell suspension of tissues of the man was prepared and inspected by FCM after PI stained. Results The amount of DNA of in heart, liver and kidney of human had a repid degraded in first 6 hours after death, that in the spleen showed a better relationship between DNA degradation and PMI. The results was verified by FCM and IAT. Conclusion The degradation of DNA of and human tissues shows a well relationship with PMI, especially in spleen. It is useful in estimation of PMI.