核酸染色技术辅助推断晚期死亡时间的初步研究

A preliminary study of inferring long PMI with HE staining and Pyronine-methyl green staining combined with image analysis technique

目的探讨HE染色与吡罗红-甲基绿特殊染色结合图像分析技术辅助推断晚期死亡时间的可行性。方法在明确死亡时间的尸体解剖案例中分别取脑、脾脏、肌肉组织作为实验检材,离体放置,以2d为起始时间点,分别以2d、4d、6d、8d、10d、12d为时间点进行取材。将取得的组织块制备石蜡切片经HE染色及吡罗红-甲基绿特殊染色后放置于OLYMPUS BX61自动金相显微镜下利用IPP 5.0显微图像分析软件测量其各个时间点的平均光密度值。测量得到的各个时间点的光密度值用SPSS 13.0软件进行Kruskal-Wallis检验。结果脾脏、肌肉在2d、4d、6d三个时间点上光密度呈现出具有统计学意义的规律性的下降趋势,脑组织在各个时间点内光密度值波动无规律性。脑组织的特殊染色的效果比脾脏、肌肉组织的效果要好。脑组织经特殊染色后其DNA光密度值/(RNA+底色光密度值)在2d、4d、6d时具有统计学意义的规律性的下降趋势。结论死后1周以内的尸体脾脏及胸大肌组织经HE染色与脑组织经吡罗红-甲基绿特殊染色结合图像分析技术可以辅助推断死后经过时间,为晚期死亡时间的推断提供辅助证据。

Objective To explore the feasibility of inferring long PMI with HE staining and Pyronine-methyl green staining combined with image analysis technique. Methods The brain ,spleen and muscle tissues were collected from cases that the PMI had been determined. We extracted samples at 2d, 4d, 6d, 8d, 10d, 12d respectively. The average optical density of supporting tissues paraffin section was measured by using IPP5.0 microscopic image software. Experimental data were analyzed by Kruskal-Wallis test using SPSS13.0 software. Results Spleen and muscle showed a significant degradation on day 2, day 4 and day 6. The optical density of brain tissue showed unregularity fluctuation at all time points. The optical density of DNA/（RNA＋impression）. showed a significant degradation on day 2, day 4 and day 6 by Pyronine-methyl staining of brain tissues. Conclusion HE staining of spleen and muscle combined with pyronine-methyl green special staining of brain and image analysis technique can be used to infer PMI within one week, providing evidence for determination of late PMI.