微波消解-扫描电镜联用法在溺死诊断中的应用

目的探讨微波消解-扫描电镜联用法在溺死诊断中的应用价值。方法收集已知死因的尸体标本105例,其中水中尸体85例(生前溺死70例,死后抛尸入水15例),陆地自然死亡尸体20例。水中死亡案例同时收集落水处水样。分别用微波消解-扫描电镜联用法(方法 A)和硝酸破机-光镜联用法(方法 B)对上述尸体的离体肺、肝、肾、骨髓组织及水样进行硅藻定性、定量检测。结果①溺死尸体的肺、肝、肾、骨髓中及落水处水样硅藻检出率:A法分别为100%、94.3%、92.9%、82.9%、100%,硅藻检验阳性率为100%;B法分别为90%、62.9%、51.4%、28.6%、92.9%,硅藻检验阳性率为65.7%。②两种方法检出的硅藻种类与落水处水样中硅藻的种类均一致。③两种方法在死后入水尸体离体的肺中也检出少量硅藻(<3个/2g肺组织),但在死后入水尸体的其它脏器及陆地自然死亡尸体脏器中均未检出硅藻。结论微波消解-扫描电镜联用法较硝酸破机-光镜联用法对尸体离体组织脏器中的硅藻检出率高,方法灵敏,定性准确。

The application of microwave digestion technique and scanning electron microscopy to diatom test in diagnosis of drowning

Objective To evaluate the practical value of microwave digestion technique and scanning electron microscopy(SEM) for diatom test in diagnosis of drowning.Method 105 autopsied cases were divided into three groups: drowning group(70 cases),post-mortem immersion group(15 cases who were thrown into water after death on land) and control group(20 cases died of natural causes on land).Qualitative and quantitative diatom tests were performed with both methods microwave digestion technique with SEM(method A) and nitric acid digestion with light microscopy(method B) in the lung,liver,kidney and bone marrow of them and in the water samples of drowning group.Results The diatom-detectable rates in the drowning group were 100%,94.3%,92.9%,82.9%,and 100% in lung,liver,kidney,bone marrow and water respectively with the method A;and 90%,62.9%,51.4% 28.6%,and 92.9%,with the method B.The positive rates of diatom test were 100% and 65.7% for method A and method B respectively.The types of diatom in organs of drowning group detected by both method A and method B were the same with the samples of water.A few diatoms(<3 /2g) were also found in the lungs in the post-mortem immersion group with the two methods,but no diatom was detected in other organs of the post-mortem immersion group and in all organs of control group died of natural causes on land.Conclusion Comparing with the method of nitric acid digestion with light microscopy,the method of microwave digestion technique with SEM is higher rate of detection,more sensitive and accurate to diatom test.