大鼠脑细胞DNA含量与死亡时间关系的图像分析

Study on the relationship between the postmortem interval and the changes of DNA content in the rat's brain cells by the computerized image analysis

应用计算机图像分析技术 ,测定 15只大鼠死后 48h内不同时间点大鼠脑细胞核DNA含量的面积(Area)、等效直径 (Mean Dia ,MD)、异形指数 (Indexofdensity ,ID)、平均光度 (Averageopticaldensity ,AOD)、积分光度 (Integralopticaldensity ,IOD)、密度变化数 (L Den Coe ,LDC)和平均灰度 (Averagegray ,AG)等七项参数的变化值。结果证明 ,在大鼠死亡后 2 8h内 ,其脑细胞核DNA降解速率与PMI具有一定相关性。将每个参数的测量值进行多项式运算 ,获得了更能体现DNA降解趋势的二项式回归方程。其结果表明 ,应用计算机图像分析技术 ,测量机体死后DNA含量变化 ,将会成为推断PMI精确、客观的新方法。

Estimation the postmortem interval(PMI)is an important subject in forensic medicine practice.Recent research has found that the DNA molecular would degrade immediately following death,and the quantity of DNA in nuclear would be decreasing along with the elapse of the time since death.Seven parameter of cell nuclear,including the area and integral optical density,were chosen and the changes of DNA content in the brain cells of 15 rats were determined at every one hour during 48 horus after death by the auto TV imange analyses system.The results showed that the degradation rate of DNA in nuclear has a certainty relationship with early PMI in rats and indicated that the determination of the quantity of DNA in nuclear is the major method to estimate the PMI.