检测浮游生物叶绿素相关基因诊断溺死的实验研究

目的评估浮游生物叶绿素相关基因检测用于溺死诊断的价值。方法将18只大白兔随机分为溺死组（n=10）、死后抛尸组（n=6）和对照组（n=2）,各组分别取心血及肺、肝、肾、脑组织,分离浮游生物并提取其DNA,用PCR技术检测叶绿素相关基因EG（EG1和EG2）及SK（SK1和SK2）。同时用硝酸消化法检验肺和肝组织中的硅藻。结果溺死组心血及肺、肝、肾、脑组织中EG1分别检出9、10、9、7和8例阳性,EG2分别检出8、10、7、5和7例阳性;死后抛尸组仅在心血和肺组织中各检出1例EG1阳性;对照组各组织均未检出EG1和EG2。SK1、SK2除在溺死组心血、肺和肾有少数检出外（≤2例）,在其他组未检出扩增产物。硝酸消化法从溺死组肺、肝组织中分别有9例及3例检出硅藻,死后抛尸组仅在1例肺组织中检出。结论浮游生物叶绿素相关基因EG用于溺死诊断的阳性检出率要高于硝酸消化法,在溺死诊断中具有较高的应用价值。

A study on detecting chlorophyll-related genes of plankton in the diagnosis of death by drowning

Objective To evaluate the value of detecting chlorophyll related genes of plankton in the diagnosis of drowning. MethodsEighteen rabbits were divided randomly into three groups: death by drowning (n=10), postmortem submersion (n=6) and control (n=2). The heart blood, lung, liver, kidney and brain tissues were taken from every rabbit. After isolated plankton from tissues with percoll and extracted their DNA, the chlorophyll-related genes, including EG (EG1 and EG2) and SK (SK1 and SK2), were detected using PCR technique. Meanwhile, diatom test was also performed from lung and liver tissues by nitric acid digestion method. ResultsFor the drowning group, the specific amplification products for EG1 were detected from 9 samples in heart blood, 10 samples in lung, 9 samples in liver, 7 samples in kidney and 8 samples in brain. The products for EG2 were detected from 8 samples, 10 samples, 7 samples, 5 samples and 7 samples accordingly. There were a small number of positives in heart blood, lung and kidney with SK1 and SK2 (≤2). For the postmortem submersion group, only one case was positive from heart blood and lung tissue respectively for EG1. No amplified product was detected for EG1 and EG2 in various tissues in control group, and also no product was detected for SK1and SK2 in other groups. In addition, diatoms were detected from 9 lung and 3 liver tissues in drowning group with the nitric acid digestion, and only one sample of lung was positive in the postmortem submersion group. ConclusionThe detection rate of the chlorophyll-related gene EG with PCR method was higher than that of diatom with nitric acid digestion method in drowning victims, and it can be used as a potentially useful tool for diagnosing drowning.