改良醋酸铵盐析法提取福尔马林固定石蜡包埋组织DNA

目的采用改良醋酸铵盐析法提取福尔马林固定石蜡包埋组织DNA,并评价其应用价值。方法取死后24h内人体肾组织用10%中性福尔马林溶液固定7d,石蜡包埋。采用酚/氯仿法、Chelex-100法及改良醋酸铵盐析法提取DNA。经用紫外分光光度计法、AGE及PCR-PAGE检测比较不同方法提取DNA的质量。结果改良醋酸铵盐析法、酚/氯仿法、Chelex-100法OD260/OD280比值分别为1.962±0.195、2.110±0.470、1.018±0.124,两两比较均有显著性差异(P<0.05);3种方法提取DNA含量(μg)分别为0.515±0.447、0.328±0.345、5.346±1.994;AGE电泳图谱可印证上述结果;PCR-PAGE检测显示改良醋酸铵盐析法提取DNA的谱带清晰度好于其它两种方法。结论改良醋酸铵盐析法更适合微量福尔马林固定石蜡包埋组织样本DNA的提取。     

福尔马林固定组织SNP与STR检测的比较

目的检测经长期福尔马林固定的组织降解情况,并比较组织中SNP与STR的检出率。方法本文对24例经福尔马林固定、-20℃保存5年的组织样本,采用Quantifiler?Trio DNA定量试剂盒检测样本DNA的降解系数及浓度,运用55-SNPs SNa Pshot复合分型体系和Power Plex?21试剂盒分别进行SNP与STR检测。结果大部分样本降解系数在1~8,发生不同程度的降解。与未降解样本相比,SNP分型完全一致,检出率为100%;其中8例样本STR分型存在33个等位基因丢失,降解系数均大于2.6,且75.8%的等位基因片段长度大于300bp。当样本检测出16个STR基因座时,似然率与54个SNP相当。当样本检出大于17个STR时,似然率大于54个SNP。STR基因座片段长度与等位基因检出率之间呈负相关。除2例样本降解系数较小却发生等位基因丢失外,其余样本降解系数与等位基因检出率之间呈负相关。结论经福尔马林长期固定的组织DNA易降解,检测SNP明显优于STR,但需要更多的SNP以提高个体识别能力。     

DNA甲基化在组织/体液来源鉴定中的研究进展

对可疑生物样本的组织/体液进行来源鉴别是重建犯罪现场、推断犯罪性质等侦查活动中极为重要的一环。对表观遗传学理论的研究证明运用基因组中存在的组织特异性DNA甲基化差异位点(t DMRs)可以对组织/体液进行来源鉴别。本文旨在通过对近年来DNA甲基化在法医学领域用于鉴定人体组织/体液来源方面的研究成果进行阐述,试图用所得到的信息来分析DNA甲基化作为一种组织/体液鉴定遗传学标记的可能性、优劣点及其应用价值和发展前景,以期能为法医工作者的相关研究及实践提供参考。     

Feasibility of Contactless 3D Optical Measurement for the Analysis of Bone and Soft Tissue Lesions: New Technologies and Perspectives in Forensic Sciences

Abstract:  In forensic pathology and anthropology, a correct analysis of lesions on soft tissues and bones is of the utmost importance, in order to verify the cause and manner of death. Photographs, videos, and photogrammetry may be an optimal manner of immortalizing a lesion, both on cadavers and skeletal remains; however, none of these can supply a detailed three-dimensional (3D) modeling of the lesion. Up to now, only the use of casts has given us the possibility of studying deep lesions such as saw marks with an accurate and complete 3D reconstruction of bone structure. The present study aims at verifying the applicability of 3D optical contactless measurement for the accurate recording of soft tissue and bone lesions, in order to develop a unique and precise method of registering and analyzing lesions, both in forensic pathology and anthropology. Three cases were analyzed: the first, a car accident with blunt force skin injuries; the second, a murder with blunt force injury to the head applied with a metal rod; the third, a series of sharp force knife and saw lesions on bone. Results confirm that 3D optical digitizing technology is a crucial tool in the immortalization of wound morphology in the medico-legal context even on "difficult" substrates such as cut marks and saw marks on bone.     

How Reliable are Parenchymal Tissues for the Evaluation of Carbon Monoxide Poisoning? A Pilot Study

Dealing with burnt bodies, the forensic pathologist must first of all answer the question whether the victim was alive at the moment of the fire. This study aims at clarifying whether some human solid tissues may be reliably used for the forensic diagnosis of Co poisoning on burnt bodies providing no collectable blood during the autopsy. From 34 selected cases, both cardiac blood and parenchymal samples were collected to perform CO‐oxymeter, spectrophotometry, and gas chromatography tests: blood CO estimations (blood COHb% and blood[CO]) and parenchymal[CO] values have been compared with special focus on R values. The solid tissues having the best correlations with blood CO amount turned out to be the lung (R 0.84), the liver (R 0.83), the kidney (R 0.79), and the spleen (R 0.92).     

Population data for MiniNC01 in a population sample from North-eastern Italy and their use in neoplastic tissues fixed in formalin and embedded in paraffin

To establish a database for the three MiniNC01 loci D10S1248, D14S1434, D22S1045 in a population sample from North-eastern Italy, 102 unrelated individuals were typed. DNA was amplified in a multiplex reaction with subsequent automatic detection using capillary electrophoresis. The obtained data give a contribution to the definition of Italian population miniSTRs allele frequencies for the three analysed loci. These three MiniSTRs were tested on 21 neoplastic tissues and the obtained genotypes were compared to those obtained from normal tissue. Only 3 cases (14.28%) gave a different genotype suggesting a better performance of these markers than traditional STRs.     

正常人心脏传导系统神经组织的免疫组化研究

作者应用抗Ｓ１００抗体，对１０例正常心脏传导系统的神经进行了免疫组化研究。结果显示：Ｓ１００阳性的神经组织在心脏传导系统内广泛分布，其含量以窦房结最多，房室结次之，希氏束和束支最少。该研究获得了正常人心脏传导系统神经组织分布的概貌，为进一步研究心脏传导系统神经组织病变与猝死的关系打下了基础。     

利用尸体软组织生物力学性状时序性变化推断死亡时间

目的探讨尸体软组织生物力学性状时序性变化规律及其推断死亡时间的可行性。方法将实验大鼠用颈椎脱臼法处死,放置25℃恒温培养箱内即刻、6、12、18、24、30、36、42、48、60、72、96、120、144、168、192h,定时、定位、定向、定形切取大鼠胸部正中皮肤、腹壁肌肉、胸主动脉、结肠和小肠的生物力学试件,用电子万能材料试验机检测各试件的极限载荷、应变、应力生物力学参数。结果除主动脉外,尸体皮肤、肌肉、小肠、结肠的各项软组织生物力学参数均呈明显的死后时序性下降趋势。各参数下降趋势具有显著性差异的＂窗口期＂分别为：极限载荷：死后18h内皮肤、小肠呈下降趋势;24h内肌肉、结肠呈下降趋势;96～168h肌肉呈下降趋势;72～192h结肠呈下降趋势。应变：各组织在24h内均呈下降趋势,其结肠72～192h缓慢下降趋势。应力：皮肤18h内呈下降趋势,肌肉、小肠24h内呈下降趋势,结肠36h内呈下降趋势。结论大鼠尸体软组织各生物力学性状在不同的＂窗口期＂存在时序性变化规律,综合各指标可用于推断相应＂窗口期＂内的死亡时间。     

福尔马林固定石蜡包埋组织3种DNA提取方法比较

目的探讨经福尔马林固定1d石蜡包埋组织(FFPET)提取DNA的简易有效方法。方法比较水浴加热、微波加热和二甲苯脱蜡的效果。组织脱蜡后分别采用Chelex-100+层析柱纯化法、DNA IQTM试剂盒磁珠提取法和Chelex-100+磁珠纯化法提取DNA;实时荧光定量PCR技术定量DNA;荧光标记毛细管电泳技术进行STR分型。结果二甲苯脱蜡的效果好于其他两种加热的脱蜡方法(P<0.05)。Chelex-100+层析柱纯化所获得的DNA量显著高于其他两种方法(P<0.05)。结论二甲苯脱蜡、Chelex-100+层析柱纯化法是一种简单、有效的FFPET处理方法。     

用PCR技术鉴定自溶组织性别

本文用聚合酶链反应（PCR）检测已知男性各种不同程度自溶组织石蜡切片中的男性DNA序列。结果表明：自溶程度较低的组织可以用聚合酶链反应鉴定性别：但自溶程度达到核膜消失和细胞结构消失者，其性别鉴定阳性率明显降低，而且在自溶程度较高时，易出现假阴性结果。