肌原纤维小片化指数与人体死亡时间的相关性

摘要

目的 研究死后人体骨骼肌肌原纤维小片化指数(myofibril fragmentation index,MFI)与死亡时间的关系.方法 采用双缩脲法测定室温下死后不同时间人体右肱二头肌和右股四头肌的全蛋白浓度,紫外分光光度计测定540 nm处的吸光度,得到骨骼肌MFI值.以死亡时间为自变量(x),MFI值为因变量(y),进行回归分析.结果 在死后早期,人体骨骼肌MFI值随着时间延长逐步增高,之后趋于平缓,以12 h内最为显著.死后0～12 h,右肱二头肌回归方程为y=32.660+3.227 x(r=0.9879),右股四头肌回归方程为y=32.380+3.495 x(r=0.9839).结论 MFI与死亡时间相关性强,结合法医实践经验,对于死后早期(尤其12 h内)死亡时间推断具有良好的应用前景.%Objective To study the relationship between myofibril fragmentation index (MFI) of human skeletal muscle and postmortem interval (PMI). Methods The protein concentrations of human right bi-ceps brachii muscle and right quadriceps femoris muscle were obtained at different PMI, and detected at room temperature by biuret method. The MFI of skeletal muscle at 540 nm was measured by ultraviolet spectrophotometer. Regression analysis was performed with time of death as independent variable (x) and MFI as dependent variable (y). Results In early PMI, the MFI of human skeletal muscle increased obviously according to the prolongation of PMI, and peaking by 12 h and then tended to steady. Within 12 h after death, the regression equations of right biceps brachii muscle and right quadriceps femoris muscle were y=32.660+3.227 x(r=0.9879) and y=32.380+3.495 x(r=0.9839), respectively. Conclusion There's high correlation between MFI and PMI. Combining with forensic practice, MFI can be used for the estimation of early PMI (especially in 12 h).