检测肺锶含量鉴定溺死的进一步研究

探索检测肺锶含量鉴定溺死的法医学意义，及水中浸泡时间因素对肺锶含量的影响和本方法的实际应用价值，用ICP检测溺死及死后入水浸泡时间较久的不同时间组（48～96小时）的家兔肺锶含量。结果表明：溺死组肺锶含量显著高于死后入水组（P＜0．01），死后水中浸泡时间（4天）对肺锶含量无明显影响，3例实际检案检测结果证实，本研究具有良好的应用前景。     

测定血锶含量鉴定溺死的法医学意义

为评价血锶含量测定对诊断鉴定溺死的实用价值,作者用家兔进行实验,分别测定溺死与死后入水家兔左心血中锶含量。结果证实:1.死后较短时间内血锶含量测定确可鉴定溺死;2、死后24小时内仅可帮助鉴定溺死。实验表明水中浸泡时间因素对血锶含量确有显著影响。两例实际检案的应用观察,较实验性研究为佳,值得进一步研究。     

血清氟含量测定在溺死诊断上的意义

<正> 考虑到广东的水含氟量高,本文测定了溺死兔的血清氟含量,并与缢死后入水浸泡兔的血清氟含量进行对比。水中氟含量大约比正常人和动物血清氟高15倍。溺死后兔血清氟含量明显高于溺死前。相反,在对照的死后浸泡兔的血清氟含量稍低于死前。人与兔的血清氟含量相近。这提示,血清氟含量测定对高氟区的溺死诊断是有价值的。     

硅藻定量检验和种属鉴定的实验研究

本实验用家兔18只,分为溺死组、死后(抛尸)入水组及对照组,每组各6只。采用消化—光镜法作肺、肝、肾硅藻计数(定量)及种属鉴定检验,同时作水样检验及空白对照。结果:(一)进一步证实生前硅藻可经空气源性进入肺脏并存积于大循环内脏(肝、肾)的概念;(二)提示水中尸体肺脏如有大量硅藻检出,仅此即可作为诊断溺死的可靠依据;空气源性吸入及检验过程中的污染并不影响该检验结果对鉴定溺死的判断。种属分析溺死组肺与水样的主要硅藻种属相符,而肝、肾中硅藻计数及种属分析均无诊断意义。     

血清氟含量测定在溺死诊断上的意义

考虑到广东的水含氟量高,本文测定了溺死兔的血清氟含量,并与缢死后入水浸泡兔的血清氟含量进行对比。水中氟含量大约比正常人和动物血清氟高15倍。溺死后兔血清氟含量明显高于溺死前。相反,在对照的死后浸泡兔的血清氟含量稍低于死前。人与兔的血清氟含量相近。这提示,血清氟含量测定对高氟区的溺死诊断是有价值的。     

PCR-DGGE法检测浮游生物16S rDNA在溺死鉴定中的应用

目的建立并评估PCR-DGGE法检测浮游生物对溺死鉴定的应用价值。方法大白兔30只随机分为3组:溺死组(n=12),死后抛尸组(n=12)和对照组(n=6);溺死组和死后抛尸组又分为2个亚组:东湖水域组(n=6)和墨水湖水域组(n=6)。死后提取心血和肺、肝、肾、脑等组织,匀浆后,采用Percoll密度梯度离心法分离浮游生物并提取其DNA,PCR扩增浮游生物特异的16S rDNA片段后分别用琼脂糖凝胶电泳及DGGE检测分析。2个溺死案例检材同法检验。结果溺死组各组织器官中浮游生物检测多呈阳性:肺(100%)、肝(83%)、肾(75%)、心血(83%)、脑(42%);死后抛尸组仅2例肺组织(16.7%)检出阳性;对照组全部阴性。溺尸肺组织DGGE分型图谱与相应溺死点水样分型图谱相似,而与非溺死点水样分型结果差异显著。2实际案例均呈阳性。结论本方法不仅有助于定性诊断溺死,而且通过比较产物的多样性可以推断溺死地点,在法医学溺死鉴定中具有较大实用价值。     

溺死尸体器官硅藻检出率季节性差异

目的 研究溺水死亡者肺、肝、肾、骨髓等器官淡水硅藻检出率可能存在的季节性差异,为法医学解决水中尸体死因鉴定提供技术帮助与科学证据.方法 收集2009～2011年1、4、7、10月沈阳市浑河中溺死尸体每月(组)各5例;45只家兔分相应月份生前、死后入水组及对照组,分别于当月发现水中尸体后第2天入水,取人及兔肺、肝、肾、股骨骨髓及现场水样备检,应用酶消化法检测各组器官中硅藻数量、种属并与现场水样比对.结果 各组溺死尸体肺中均检出多量硅藻且种属与现场水样一致,春、秋及冬季溺死尸体肝、肾中仅可检出少量体积较小的小环藻等中心纲硅藻,夏季肝、肾及骨髓中均未检出硅藻;各组溺死家兔肺中均检出少量小环藻等中心纲硅藻,肝、肾及骨髓中未检出硅藻.结论 硅藻种群的季节性变化及不同种群硅藻体积的差异可能造成肝、肾等大循环器官中硅藻检出率的季节性差异;仅肺中检出硅藻,肝、肾中硅藻检验结果阴性并不能排除溺死可能.     

浮游生物16S rDNA检测在大鼠溺死鉴定中的价值

目的建立浮游生物16S rDNA PCR检脸法应用于溺死的鉴定。方法将15只SD大鼠随机分为溺死组、死后抛尸组和正常对照组,死后分别取脑、肝、肾和肺等脏器,提取DNA.用特异性引物扩增浮游生物16S rDNA第三和第四可变区特异片段。结果溺死组5例,肺全部检出(100%)浮游生物16S rDNA;肝、肾分别检出4例(80%);脑检出3例(75%)。死后抛尸组仅1例在肺中检出浮游生物(20%)。正常对照组均未检出。苗论浮游生物16S rDNA PCR检验法可用于溺死的鉴定。     

Micro-XRF法检测肺内抗酸性硅质颗粒及其在溺死诊断中的应用

目的利用微束X射线荧光光谱（microbeam X-ray fluorescence,Micro-XRF）分析技术检测肺内抗酸性硅质颗粒,并探讨其在法医学溺死诊断中的应用价值。方法将32只大白兔随机分为溺死组（n=12）、死后入水组（n=10）和对照组（n=10）,分别提取现场水样和各组肺组织。采用Micro-XRF法测定现场水样和肺组织中抗酸性硅质颗粒的面积含量。结果现场水样中抗酸性硅质颗粒面积含量为4.4mm^2/mL;溺死组、死后入水组、对照组肺组织中抗酸性硅质颗粒面积含量分别为（25.30&#177;10.95）mm^2/g、（1.68&#177;0.63）mm^2/g、（1.65&#177;0.85）mm^2/g;溺死组肺组织中抗酸性硅质颗粒面积含量较死后入水组、对照组差异有统计学意义。结论肺内抗酸性硅质颗粒面积含量可作为一种溺死诊断的指标,Micro-XRF测定法灵敏度高、分析速度快,在法医学溺死诊断中具有潜在的应用价值。     

肺组织硅藻定量分析在实验动物溺死诊断中的应用

目的探讨肺组织硅藻检验在法医学溺死诊断中的应用价值。方法将实验动物随机分为溺死组、死后入水组和陆地死亡组,采用微波消解-真空抽滤-扫描电镜联用的硅藻检验方法对肺组织和溺液硅藻进行定量分析,记录肺组织与溺液硅藻含量的比值(ratio of content of diatoms in lung tissue and drowning fluid,C_L/C_D)。结果溺死组实验兔的C_L/C_D值(5.82±3.50)高于死后入水组(0.47±0.35);溺死组实验猪肺叶不同部位的C_L/C_D值均高于死后入水组;在海水、咸淡水交界、河道淡水及湖泊淡水中,溺死组实验猪的C_L/C_D值均高于死后入水组(P0.05)。动物实验中,C_L/C_D值1.6的案例均来自溺死组。结论 C_L/C_D值是溺死诊断中有较好应用前景的指标。     

溺死大鼠肺组织AQP-1、AQP-4的表达

目的观测生前溺死与死后抛入河水中大鼠肺组织水通道蛋白-1(aquaporin-1,AQP-1)、AQP-4的表达变化。方法将30只健康雄性Wistar大鼠随机分为河水溺死组、抛尸入水组及脱颈致死组。HE染色观察各组大鼠肺组织形态学变化,实时荧光定量PCR法检测各组大鼠肺组织AQP-1、AQP-4 m RNA的表达,免疫组织化学、Western印迹法检测其蛋白表达。结果免疫组织化学法和Western印迹法检测河水溺死组AQP-1蛋白的表达高于抛尸入水组和脱颈致死组(P0.05)。免疫组织化学法显示河水溺死组AQP-4蛋白的表达高于抛尸入水组和脱颈致死组(P0.05),而Western印迹法未检测出三者的差别(P0.05)。河水溺死组大鼠肺组织的AQP-1、AQP-4 m RNA表达高于抛尸入水组(P0.05)。结论河水溺死组的大鼠在急性肺损伤时肺组织AQP-1、AQP-4 mRNA及蛋白表达增高可能对生前溺死与死后抛尸的鉴别有一定意义。     

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。     

非溺死尸体肺脏硅藻最大值在溺死鉴定中的应用初探

探讨非溺死尸体肺脏硅藻最大值（即空气吸入与检验污染之和的最大值）在溺死鉴定中的应用价值。用硝化-光镜法检测贵阳地区40例非溺死尸体肺脏硅藻含量的最大值，同时作了8例溺死尸体肺脏硅藻检验。非溺死组肺脏硅藻最大值2个／5g；溺死组有7例为56～463个／5g，1例是2个／5g。表明（1）水中尸体肺脏硅藻检验值大于最大值（2个／5g），可考虑为溺死；显著大于最大值（本文溺死组7例56～463个／5g）则可鉴定为溺死；（2）等于或小于最大值，提示干性溺死或抛尸入水，可结合尸检发现及案情鉴别。     

Postmortem chest computed tomography for the diagnosis of drowning:a feasibility study

It may be difficult to distinguish the cause of death in drowning cases without specific findings. The aim of this study was to explore the forensic value of thoracic postmortem computed tomography (PMCT) using routine images and three-dimensional (3D) image reconstructions. The imaging data of PMCT examinations of six drowning cadavers, aged 21–54 years, were analyzed. Twelve victims of sudden death from coronary artery disease (CAD) were chosen as a control group. After 3D bilateral lung images were reconstructed using image processing software, an interactive medical image control system was used to measure and analyze parameters including lung volume, lung volume ratio, mean CT value of the whole lung, and lung CT value distribution curves. Lung volume and lung volume ratio were used to assess the shape changes of the lung. Lung CT value distribution curves showed the corresponding number of pixels of the different CT values in the lung image. Lung volume was not significantly larger in drowning cases (mean 2 958 cm³) than in controls (mean 2 342 cm³). Lung volume ratio values in the drowning group (mean 0.3156) were greater than those in the control group (mean 0.2763); (P = 0.02). There was no significant difference between the drowning and control group in the mean CT value of the whole lung. There were differences between lung CT value distribution curves in drowning victims and controls, with drowning victims showing a single peak and CAD cases showing a bimodal distribution. Thoracic PMCT is helpful for the forensic medical diagnosis of drowning. Lung volume ratio and lung CT value distribution are potential indicators to distinguish between drowning and CAD.     

The usefulness of lung surfactant phospholipids (LSPs) in the diagnosis of drowning

The authors have studied the usefulness of some lung surfactant phospholipids (LSPs) isolated from lung tissues as markers of drowning. Two different groups of rabbits were sacrificed by drowning in fresh and salt water, and their phospholipid compositions were compared with those of a non-drowned control series. For the phospholipids studied in lung lavages (phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl glycerol) the proportions differed between the control group and the drowned group, and between the fresh-water and salt-water drowned animals. According to these results, the lipids we have analyzed can be employed as markers in forensic autopsies, where it is necessary to differentiate between death by drowning and postmortem immersion and between fresh-water and salt-water drowning. In lung tissue, only phosphatidyl choline and phosphatidyl inositol showed significative differences. These results also confirm that LSPs are strongly affected in drowning.     

Study of the diagnostic value of iron in fresh water drowning

The aim of our study was to test the diagnostic value of iron (Fe) in fresh water drowning by investigating the postmortem levels of hemodilution in drowning cases compared to control cases. Twenty-six typical fresh water drowning cases were selected from 128 immersion cases autopsied in our Department of Forensic Pathology between 1998 and 2004. The exclusion criteria were a long postmortem interval and other causes of death than drowning. For all selected cases, the diagnosis of drowning was based on the presence of autopsy findings and positive diatom test. A control population of 12 cases was also selected. For each drowning and control case, iron blood levels were measured in the left ventricle (LV) and right ventricle (RV) of the heart. The mean difference of iron concentration (RVFe-LVFe) between the drowning group and the control group was statistically compared. Furthermore, iron measurements were performed in 19 drowning cases showing advanced putrefaction. The mean difference of iron concentration was significantly higher in the drowning cases compared with controls (P<0.001). All drowning cases showed hemodilution. No overlap was found in the RVFe-LVFe levels between the two groups. Resuscitation attempts seemed to have no effect on the results. In cases of drowning showing advanced putrefaction, the iron test was not reliable because biochemical iron measurement was often prevented by no sufficient blood in the heart or postmortem clots. In conclusion, according to our results, iron seems to be a good biochemical marker in fresh water drowning with a short postmortem interval.