分子标志物microRNA在法医学中的研究进展

微小核糖核酸(microRNA,miRNA)是一类长度为18～24个核苷酸的内源性非编码小分子RNA,其表达具有高保守性、时序性和组织特异性。miRNA不易被RNA酶降解,对温度、酸碱度等环境因素的变化有较强的抵抗性,在腐败组织中也能检测出来。因此,miRNA在法医学体液来源鉴定、死亡原因推断等方面具有广阔的应用前景。本文就miRNA作为在体液鉴定、死亡时间推断以及死亡原因分析等法医学实践中的应用进行简要综述。     

MicroRNA在心血管疾病方面的研究现状及应用前景

MicroRNA(miRNA或mi R)是一类21~25nt大小的高度保守的内源性单链非编码RNA,在生物体内广泛存在。近年来,在临床研究中与心血管疾病相关的mi RNA不断得以证实,但其在法医学鉴定方面的研究尚未有报道。本文就mi RNA的研究进展及其在心血管疾病中的应用,以及在心源性猝死法医学鉴定中的应用前景进行综述。     

mRNA和microRNA在机械性窒息死推断中的研究进展

机械性窒息死的推断是法医学鉴定的难点之一。利用实时荧光定量PCR（fluorogenic quantitative RT-PCR,RT-qPCR）技术检测RNA表达水平变化规律,并据之推测机械性窒息死亡的原因,近年来已成为研究热点。本文对mRNA和microRNA（miRNA或miR）在机械性窒息死推断的研究文献进行复习综述,并重点探讨miRNA在该类死因推断中的应用,以期为机械性窒息死推断提供新的思路。     

法医物证学miRNA分析的研究进展

在种属和体液鉴定及降解检材等特殊案件的分析时,转录水平的miRNA所具有的生物属性及表达特点,使其能够发挥基因组DNA所不具备的价值。本文通过概述法医物证学miRNA研究的现状,对法医miRNA分析的研究策略和法医物证学应用前景进行了综述,以期为法医miRNA分析的应用研究提供借鉴。     

miRNA451用于法医学血液鉴别的可行性研究

目的探讨miRNA451是否可以用于法医学血液类物证的鉴别。方法以法医学常见血液类(外周血和月经血)及非血液类(精液、唾液、阴道分泌液)体液样本为研究对象,提取总RNA,以RT-qPCR方法检测miRNA451的表达,利用SPSS 22.0进行统计分析。结果 miRNA451在外周血及月经血中均具有高表达的特点,且表达量显著高于在唾液、精液及阴道分泌液等非血液类物证中的表达量(6组P均0.05);放置一年的血斑中miRNA451表达量与新鲜血液无显著差异。结论 miRNA451在血液类体液样本中的表达水平显著高于非血液类体液样本,且稳定性良好,可作为法医学血液类体液样本鉴别的良好分子标记物。     

基于microRNA表达谱初步构建PLS-DA体液识别模型

针对外周血、唾液、精液、月经血、阴道分泌物这五种法医学常见的体液样本，采用二代测序（NGS）平台检测获得microRNA(miRNA)表达谱，使用偏最小二乘判别分析（PLS-DA）建立基于这五种体液的识别模型，并探讨PLS-DA在法医体液溯源中的应用价值。经优化小分子RNA文库制备过程，采用Ion Torrent S5 XL测序系统对前述法医学五种体液样本（每种10例）进行小RNA测序，以PLS-DA构建体液识别模型，评估不同数量miRNA标记组合下预测的准确性。本研究获得法医学常见五种体液样本的miRNA表达谱，外周血与月经血中表达量前10名的miRNAs有6个重叠；唾液和阴道分泌物中表达量前10名的miRNAs有4个重叠。基于全数据集、107个和11个miRNAs构建的体液来源识别模型的准确率分别为0.95、0.94、0.89。本研究通过NGS测序分析获得了五种体液样本的miRNA组（miRNome），利用PLS-DA初步构建了体液识别模型，对于应用miRNome进行体液识别的相关研究具有参考价值。     

星形胶质细胞在脑外伤后的反应

本文对星形胶质细胞在脑外伤后的反应进行综述，包括对星形胶质细胞结构和功能的新认识，脑外伤后星形胶质细胞反应的研究模型、检测技术及其在脑外伤后星形胶质细胞发生形态学及代谢方面的变化。强调了星形胶质细胞在脑外伤后形态、蛋白表达和细胞因子表达变化的时间规律性，并对其在脑外伤后法医学鉴定中应用的意义做出展望。     

骨折愈合评估方法的研究进展及其法医学意义

在法医学鉴定中经常需要对骨折形成时间进行鉴定,因此,研究和探讨骨折形成时间的评定方法有着重要的临床及法医学意义.本文综述了超声测量、脉冲测定、数字影像学技术和骨密度检测技术等在评估骨折愈合程度中的应用及其价值.认为综合利用多种评定手段,能为骨折形成时间的法医学鉴定提供科学依据.     

过敏性休克死亡豚鼠器官中IgE的表达及其法医学意义

目的寻找法医学鉴定过敏性休克死亡的病理形态学诊断指标。方法利用组织芯片技术采用免疫组化SP法检测豚鼠过敏性休克死亡后0,6,12,24h等4个时间点的心、肝、肺、肾、脾、胃、肠、气管及扁桃体组织中的IgE的表达。结果实验组肺及气管组织IgE呈阳性表达,脾组织IgE呈弱阳性表达,以死亡即刻表达最强,且随死亡时间的延长而减弱,各时间点的显色信号强度存在显著性差异(P<0.05);实验组其它器官及对照组9个器官均无表达。结论应用免疫组化方法检测IgE在肺、气管、脾组织中的表达,可作为法医学鉴定过敏性休克死亡的病理形态学诊断指标;肺及气管组织IgE阳性强度随时间的延长而减弱,提示法医学鉴定过敏性休克死亡应尽早尸检。     

脑外伤后的星形胶质细胞反应

本文对脑外伤后星形胶质细胞反应进行综述，包括星形胶质细胞结构和功能的新认识，脑外伤后星形胶质细胞反应的研究模型、检测技术，及其在脑外伤后一系列形态学及代谢变化。强调了脑外伤后星形胶质细胞数目、形态和细胞因子表达变化的时间规律性，并对其在脑外伤法医学鉴定中的意义做出展望。     

Identification of Saliva Using MicroRNA Biomarkers for Forensic Purpose

In the forensic science community, microRNA (miRNA) profiling has started to be explored as an alternative tool for body fluid identification. Several origins of body fluid can be distinguished by measuring differential expression patterns of particular miRNAs. However, most of reported saliva miRNAs are nonoverlapping and debatable. The aim of this study was to develop a strategy of identifying saliva using miRNA biomarkers for forensic purpose. Eight miRNA candidates were selected to examine expression abundance in forensically relevant body fluids using hydrolysis probes quantitative real‐time PCR (TaqMan qPCR). Results revealed that none of them was truly saliva specific, and only miR‐200c‐3p, miR‐203a, and miR‐205‐5p were higher or more moderate expression in saliva. A stepwise strategy that combines each of three miRNAs with different body fluid‐specific miRNAs was developed, and three miRNA combinations could effectively differentiate saliva from other body fluids.     

Detection of microRNAs in DNA Extractions for Forensic Biological Source Identification

Molecular‐based approaches for biological source identification are of great interest in the forensic community because of a lack of sensitivity and specificity in current methods. MicroRNAs (miRNAs) have been considered due to their robust nature and tissue specificity; however, analysis requires a separate RNA extraction, requiring an additional step in the forensic analysis workflow. The purpose of this study was to evaluate miRNA detection in blood, semen, and saliva using DNA extraction methods commonly utilized for forensic casework. RT‐qPCR analysis revealed that the tested miRNAs were consistently detectable across most tested DNA extraction methods, but detection was significantly reduced compared to RNA extracts in some biological fluids. DNase treatment was not necessary to achieve miRNA‐specific results. A previously developed miRNA panel for forensic body fluid identification was evaluated using DNA extracts, and largely demonstrated concordance with results from samples deriving from RNA extracts of semen, blood, and saliva.     

microRNA Detection in Blood,Urine, Semen,and Saliva Stains After Compromising Treatments

Evaluation of microRNA (miRNA) expression as a potential method for forensic body fluid identification has been the subject of investigation over the past several years. Because of their size and encapsulation within proteins and lipids, miRNAs are inherently less susceptible to degradation than other RNAs. In this work, blood, urine, semen, and saliva were exposed to environmental and chemical conditions mimicking sample compromise at the crime scene. For many treated samples, including 100% of blood samples, miRNAs remained detectable, comparable to the untreated control. Sample degradation varied by body fluid and treatment, with blood remarkably resistant, while semen and saliva are more susceptible to environmental insult. Body fluid identification using relative miRNA expression of blood and semen of the exposed samples was 100% and 94%, respectively. Given the overall robust results herein, the case is strengthened for the use of miRNAs as a molecular method for body fluid identification.     

Binary logistic regression models enable miRNA profiling to provide accurate identification of forensically relevant body fluids and tissues

Numerous studies have demonstrated the ability to identify the body fluid of origin of forensic biological stains using messenger (mRNA) profiling. However, the size of the amplification product used in these assays (100–400 bases) may not be ideal for use with environmentally degraded samples. MiRNA profiling represents a potential alternative to mRNA profiling, since the small size of the miRNAs (∼22 bases) might still permit their detection in degraded stains. Previously, we reported the first study involving the forensic use of microRNA (miRNA) profiling, which required screening of 452 candidates. Since our initial screening, hundreds of novel miRNAs have been identified. We have therefore evaluated additional miRNA candidates to further improve the sensitivity and specificity of the body fluid assays. Consequently we have expanded our body fluid identification panel to include 18 miRNAs (comprising 5 original and 13 novel miRNAs). This panel permits the identification of all forensically relevant body fluids and, uniquely, includes miRNAs for the identification of skin.Using normalized miRNA expression data, we constructed body fluid specific binary logistic regression models to permit an accurate identification of the body fluid of interest. Using the developed models, we have obtained 100% accuracy in predicting the body fluid of interest.     

法医毒物鉴定结果科学表述模式的思考

法医毒物鉴定报告是毒物鉴定结果的表述模式。通过对国内外毒物鉴定报告形式和内涵的比较分析,认为我国现行按照《司法鉴定程序通则》规定出具的通用型的毒物鉴定报告尚不够专业、严谨、科学、充分,由于毒物鉴定报告的简约性和模糊性,证据的可靠性、科学性尚存在质疑,毒物分析结果的有效、充分利用尚不能实现。据此,提出毒物鉴定结果表述模式的建议。     

司法鉴定领域分类和能力范围表述的国内外比较研究

对司法鉴定领域开展科学、有效的分类,进行统一规范的能力范围表述,有助于建立完整的司法鉴定标准化体系,能为司法鉴定机构合理规划组织结构、准确定位发展方向提供指引,也能为司法鉴定行业管理部门的规范化管理提供帮助。对该领域分类和能力表述开展国内外比较分析,是实现上述目标的基础性研究。目前我国在司法鉴定领域的分类方法尚未统一,与国外法庭科学认可分类方法相比,尚有部分项目未纳入分类范围之内;国内能力范围表述在目的、方式、详细程度上与国外相比亦有不同。本文对国内外行业管理组织和国际权威认可机构司法鉴定领域分类及能力范围表述进行了比较分析,研究解析其内容及差异,并提出了制定司法鉴定领域分类国家标准、扩展司法鉴定领域分类内容、适时调整司法鉴定能力范围表述内容等建议。