死后眼组织变化与死亡时间推断

眼组织推断死亡时间一直是国内外法医学界的研究热点之一,从肉眼观到镜下观,从细胞水平到分子水平,不断有新的研究成果和报告出现。大量研究资料表明,随着死亡时间的延长,眼角膜、视网膜、玻璃体液及房水等均出现规律性的变化,并与死亡时间高度相关,可用于死亡时间推断。本文对其在法医学领域的研究进展作以综述。     

头面部软组织厚度的观测报告

选用30具成尸,在头面部设34个测量点(中线上14、侧面20),测了各点软组织的厚度;观测了眼在眶中的位置、眼裂的内外径、外耳厚、上下高、前后宽及纵轴斜向前下方的角度、口裂的宽度和上下唇的厚度、外鼻的上下长,鼻底的宽,鼻尖的高和鼻孔的口径等,为面貌复原、整容、头面部软组织损伤后的整形修复提供解剖学资料。     

生物试样中巴比妥类药物固相提取柱上衍生化GC/MS分析

建立生物试样中常见巴比妥类药物的固相提取和柱上衍生化GC／MS分析法。将预制的血或肝分别在pH6．0和pH2.2的条件下过预活化的GDX－403吸附小柱，再用缓冲浪和蒸馏水各4ml顺序洗柱。最后用4ml丙酮／氯仿（1：1）溶剂洗脱样品，离心弃除水相，80℃挥至近干，用50μl乙醇定溶、取净化的样品2～4μl挥至近干，加20μl0．2molTMAH衍生化试剂，直接进样0.5μl，柱上衍生化GC／MS（GC）分析。在试验条件下，当血和肝分别添加2．0μg和5．0μg混合药物，回收率≥80％，相对标准差（RSD）优于±10％，检测限优于5ng（信／噪比≥2）。该法能有效地排除类脂物和组胺的干扰，可用于治疗量级药物分析和婴幼儿中毒案检验。     

Radiocarbon Analysis of Human Remains: A Review of Forensic Applications

Radiocarbon analysis of organic materials, with the comparison of values with those of the post‐1950 modern bomb curve, has proven useful in forensic science to help evaluate the antiquity of evidence. Applications are particularly helpful in the study of human remains, especially with those displaying advanced decomposition of soft tissues. Radiocarbon analysis can reveal if the remains relate to the modern, post‐1950 era and if so, also provide information needed to evaluate the death and birth date. Sample selection and interpretation of results must be guided by knowledge of the formation and remodeling of different human tissues, as well as contextual information and the approximate age at death of the individual represented. Dental enamel does not remodel and thus captures dietary radiocarbon values at the time of juvenile formation. Most other human tissues do remodel but at differing rates and therefore collectively offer key information relative to the estimation of the death date.     

荧光标记STR分型技术检验腐败组织基因型

探讨腐败组织荧光标记STR分型检测技术的应用价值。应用含12个STR基因座及一个性别基因座的2个荧光标记的复合扩增系统,对40例1～6周的腐败肌肉提取的DNA进行扩增,用变性聚丙烯酰胺凝胶电泳,PE377测序仪分析基因型。所检测样本在12个STR基因座均扩增出特异性谱带,并可判定其基因型。荧光标记STR检测技术对腐败组织分型可靠,在实际检案中具有较高的应用价值。     

尸体脏器中几种镇静药物气相色谱/质谱测定的研究

本文应用气相色谱/质谱(GC/MS)技术,研究了尸体脏器中五种巴比妥酸盐、导眠能、苯妥英的定性和定量分析方法。应用SE-54毛细柱找到了良好分离条件。以安眠酮作内标,建立了定量分析程序。应用这个方法,可在1小时内完成定性分析,检测限为5ng;定量分析的准确度和精密度均为±10％。     

死亡人体组织中rRNA亚基的稳定性及影响因素评价

目的探讨人尸体组织中rRNA亚基表达水平的稳定性及影响因素。方法选取3例成人、3例婴幼儿大脑皮质和脾组织,在尸检即刻、48、72、96、120、144、168、192、216、240h,采用实时荧光定量RT-PCR法检测5s、5.8s、18s、28s rRNA的表达水平。结果两个年龄组两种组织中4种rRNA亚基表达量相比较均显示有差异(P0.05)。同种组织比较:脑组织中两个年龄组最后一个时间点与第一时间点4种rRNA亚基的表达量均有差异(P0.05),其他各时间点与第一时间点无显著性差异(P0.05);脾组织中婴幼儿5s rRNA在最后一个时间点,其余3种rRNA亚基最后两个时间点与第一时间点比较有差异(P0.05);成人5s rRNA最后一个时间点,5.8s rRNA亚基最后两个时间与第一时间点比较差异(P0.05),其余两种亚基各时间点与第一时间点相比较均无差异(P0.05)。结论尸体组织中rRNA亚基表达稳定性好,适于作为晚期死亡时间推断的内参基因使用,但需注意指标、组织和年龄段差异性。     

不同染色组织切片及不同组织固定方法对检测STR基因座的影响

目的探讨不同染色组织切片及不同组织固定方法对DNA检验的影响。方法采用Chelex100法及浓缩纯化方法提取DNA,PCR扩增后310型遗传分析仪检测。结果福尔马林固定4天以内或70%乙醇、无水乙醇分别固定1年及15年的HE染色切片可以检见Amel及9个STR基因座。PTAH等5种特殊染色未能检出相应基因座DNA谱带。结论70%乙醇或无水乙醇固定组织,石腊包埋组织及HE染色切片可以作为DNA?STR检验鉴定的样本材料。     

Developing a new scoring method to evaluate human decomposition in a humid,continental (Dfb) climate in Quebec

The published literature shows a lack of methods to evaluate the patterns and extent of decomposition of human remains and to estimate the post-mortem interval (PMI) in humid, continental (Dfb) climates such as Quebec. The aim of this study was to address this gap in the current knowledge base by providing the first observations from human corpses studied under controlled conditions in Quebec. A 12-month study was conducted at the site for Research in Experimental and Social Thanatology; the first human taphonomy facility in Canada. Six human donors with known time of death were deposited across spring (n = 1), summer (n = 3), and autumn (n = 2) 2021. The lack of suitability of the total body score method to evaluate the extent of decomposition at the facility prompted the development of a new scoring system based on the macromorphoscopic changes observed. The scoring system was applied to the donors to evaluate decomposition throughout seasons. All donors followed comparable decomposition trajectories, regardless of the season of deposition. Eighty-five percent of taphonomic patterns appeared in the first 25 experimental days or 5000 Kelvin accumulated degree days (350 ADD). Extensive desiccation of tissues was observed at a median of 21 experimental days across donors, resulting in a plateau within decomposition with no extensive skeletonization. To the authors' knowledge, this is the first published report of experimentally observed desiccation in such a form in a Dfb climate. This study provides new data on the types of decomposition patterns to expect in forensic investigations in southern Quebec and comparable climates.     

压力循环技术用于人指甲DNA提取及方法学评价

目的将压力循环技术（PCT）用于指甲DNA提取,并对方法学进行评价。方法收集10份人指甲样本,剪碎约为1mm×1mm大小,采用10%漂白粉水,10%SDS,10%漂白粉水,无菌水清洗样本。10份样本各分成两组,1组用压力循环技术处理,另1组不作处理,提取DNA经复合扩增并进行STR分型检测,用于评价压力循环技术的作用。取5份指甲样本用血浸泡,5份用去离子水浸泡,之后采用上述清洗方法各清洗1-3次,收集各次清洗用的无菌水提取DNA,经STR分型检测,用于评价清洗对去除外源性DNA的效果。结果 10份经压力循环技术处理的样本中有7例比相应未经处理样本DNA提取量更高,但两组进行统计学处理,差异不具有统计学意义（P〉0.05）;两组样本中提取DNA含量在0.026 ng以上的样本均得到完整的STR分型,与相应口腔拭子样本对照准确无误。血污染和非血污染样本清洗二次以上,均可避免外源性DNA的污染。结论使用压力循环技术并配合本文清洗方法,可有效提高人指甲DNA的提取效率,并避免外源性生物DNA的干扰,保证DNA分型结果的准确。