Liu Lijiang, Shu Xiji, Ren Liang, Zhou Hongyan, Li Yan, Liu Wei, Zhu Cheng, Liu Liang
Faculty of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
J Huazhong Univ Sci Technolog Med Sci. 2007 Aug;27(4):362-6. doi: 10.1007/s11596-007-0404-7.
This study evaluated the correlation between DNA degradation of the splenic lymphocytes and the early time of death, examined the early time of death by computerized image analysis technique (CIAT) and identified the best parameter that quantitatively reflects the DNA degradation. The spleen tissues from 34 SD rats were collected, subjected to cell smearing every 2 h within the first 36 h after death, stained by Feulgen-Van's staining, three indices reflecting DNA content in splenic lymphocytes, including integral optical density (IOD), average optical density (AOD), average gray scale (AG) were measured by the image analysis. Our results showed that IOD and AOD decreased and AG increased over time within the first 36 h. A stepwise linear regression analysis showed that only AG was fitted. A correlation between the postmortem interval (PMI) and AG was identified and the corresponding regression equation was obtained. Our study suggests that CIAT is a useful and promising tool for the estimation of early PMI with good objectivity and reproducibility, and AG is a more effective and better quantitative indicator for the estimation of PMI within the first 36 h after death in rats.
本研究评估了脾脏淋巴细胞DNA降解与死亡早期时间之间的相关性，采用计算机图像分析技术（CIAT）检测死亡早期时间，并确定了定量反映DNA降解的最佳参数。收集34只SD大鼠的脾脏组织，在死后的前36小时内每2小时进行一次细胞涂片，采用福尔根-范氏染色法染色，通过图像分析测量反映脾脏淋巴细胞DNA含量的三个指标，包括积分光密度（IOD）、平均光密度（AOD）、平均灰度（AG）。我们的结果显示，在最初36小时内，IOD和AOD随时间下降，AG随时间上升。逐步线性回归分析表明，只有AG拟合良好。确定了死后间隔时间（PMI）与AG之间的相关性，并获得了相应的回归方程。我们的研究表明，CIAT是一种用于估计早期PMI的有用且有前景的工具具有良好的客观性和可重复性，AG是大鼠死后36小时内估计PMI的更有效、更好的定量指标。
