DNA分析技术在法医学中的应用及进展

DNA分析技术在许多研究和应用领域发挥重要的作用，尤其在法医学领域具有重要意义。本文对DNA指纹技术、STR、mtDNA测序、SNP等主要DNA分析技术的应用和发展，以及建立DNA数据库的必要性和应用价值进行了系统的阐述。     

全基因组扩增技术最新进展及其法医学应用现状

微量模板DNA的检测,是很多领域迫切需要解决的一个难题。因为其DNA量不足,用现有的技术手段常无法检测成功。全基因组扩增技术可对非常微量的DNA进行均衡的扩增而获得大量的DNA,故被认为是目前解决这一难题的一种基本方法,已被广泛用于法医学、单细胞遗传病的诊断及疾病基因的分析等领域研究,并取得了良好的效果。本文对这一技术的最新研究进展及其在法医学方面的应用现状做一综述。     

2型糖尿病患者mtDNA变异筛查研究

目的探讨线粒体基因突变与2型糖尿病的关系。方法随机筛查222例散发2型糖尿病患者和191名正常对照，以聚合酶链反应、限制性内切酶片段长度多态性及T-A克隆测序和变性高效液相色谱分析技术验证等方法检测线粒体基因突变。结果糖尿病组线粒体基因（3153—3551nt）突变总的发生率（24．32％）明显高于正常组（7．33％）（P〈0．05）；发现3个尚未见报道的新突变位点：A3209T、T3253G和A3467C，而C3497T则在糖尿病中是首次报道；起病年龄、体重指数、空腹血糖、糖化血红蛋白、高密度脂蛋白和糖尿病肾病等指标是线粒体基因突变的相关因素（P〈0．05）。结论温州地区糖尿病患者存在多种线粒体基因点突变，其在糖尿病的发生发展中起重要作用。     

DNA甲基化的功能特点及法医学应用的研究进展

DNA甲基化（DNA methylation）是表观遗传修饰的核心组成部分,在人类发育、衰老、疾病以及肿瘤发生等过程中发挥重要的生物学功能。作为经典遗传标记的有效补充,DNA甲基化具有遗传信息丰富、稳定性高、特异性强且可遗传等特点,可广泛应用于法医学诸多领域研究和实践中,如亲权鉴定、个体识别、年龄推断、同卵双生子鉴别、组织体液斑分析、不明原因猝死分析、职业暴露或环境污染损伤的鉴定和分析案件发生时间等。本文就DNA甲基化的生物学功能、特点及其在法医学中的应用进行综述,旨在为DNA甲基化研究成果在法医学中的应用提供新的思路。     

应用mAPLP方法对湖南地区苗族人群进行mtDNA多态性研究

摘要：目的 应用多重扩增产物片段长度多态性分析方法（multiplex-amplified product-length polymorphism，mAPLP）建立线粒体DNA编码区单核苷酸多态（single nucleotide polymorphism, SNP）快速、准确、有效的分型方法. 方法 根据线粒体DNA SNP 位点（11969A 、10398A、 10400T、12811C、4580A 、14979C）设计两条不同的正向或反向引物（使PCR扩增片段长度不同）和一条共用的反向或正向引物，运用多重PCR方法扩增，扩增产物经8%聚丙烯酰胺凝胶电泳分析. 结果 SNP基因座为片段大小不同的单一谱带，在湖南地区40名无血缘关系苗族个体中，6个SNP基因座的分布频率分别为 0.025/0.975、0.2/0.8、0.2/0.8、0.25/0.75、1.00/0、1.00/0、0.025/0.975.共检出7种单倍型，单倍型分布频率为0.025、0.05、0.125、0.175、0.025、0.05、0.55. 结论 此方法是一种简单、快速、准确、有效的SNP 分型方法，对建立mtDNA编码区SNP数据库，研究人类群体遗传学，进行法医学个体识别等具有很大的应用价值.     

Leber遗传性视神经病三种组织间mtDNA基因型差异…

采用ＰＣＲ技术对我国两个Ｌｅｂｅｒ遗传性视神经病家系成员外周血，头发和口腔粘膜３种组织线粒体ＤＮＡ进行扩增，限制性酶切分析，以探计组织间ｍｔＤＮＡ基因型是否存在差异，结果发现一例患者ｍｔＤＮＡ基因型杂合，并且３种组织间突变型ｍｔＤＮＡ所占比例不同，证明线粒体ＤＮＡ组织间存在差异性。     

Leber遗传性视神经病三种组织间mtDNA基因型差异性的研究

采用ＰＣＲ技术对我国两个Ｌｅｂｅｒ遗传性视神经病（ＬＨＯＮ）家系成员外周血、头发和口腔粘膜３种组织线粒体ＤＮＡ进行扩增，限制性酶切分析、以探讨组织间ｍｔＤＮＡ基因型是否存在差异。结果发现一例患者ｍｔＤＮＡ基因型杂合，并且３种组织间突变型ｍｔＤＮＡ所占比例不同，证明线粒体ＤＮＡ组织间存在差异性。     

法医物证学中DNA数据库在法医学及其社会实践中的运用

近年来,法医物证学中DNA数据库的发展非常迅速,在其社会实践（包括公安机关等）中的运用也越来越多,本文初步分析统计了其中的部分运用情况（主要是在公安机关中的运用）,并总结如下,希望对以后法医物证学中DNA数据库的建设、发展及运用有所帮助。     

一个母系遗传非综合征耳聋大家系及mtDNA12SrRNA基因突变研究

目的　对一个非综合征母系遗传耳聋大家系的分子遗传学进行探讨。方法　采用聚合酶链反应（ Ｐ Ｃ Ｒ） ,扩增ｍｔ Ｄ Ｎ Ａ 与非综合征耳聋相关位点ｎｔ１５５５ 和ｎｔ７４４５ 的区域,通过 Ｐ Ｃ Ｒ Ｓ Ｓ Ｃ Ｐ, Ｐ Ｃ Ｒ Ｒ Ｆ Ｌ Ｐ, Ｐ Ｃ Ｒ 产物克隆序列测定等技术对该家系进行了系统研究。结果　发现该家系中全部患者和４ 个母系亲属有ｍｔ Ｄ Ｎ Ａ Ａ１５５５ Ｇ 突变,而家系中正常配偶和对照组（１００ 名正常个体） 的ｍｔ Ｄ Ｎ Ａ１５５５ 位点均无突变;该家系ｍｔ Ｄ Ｎ Ａ７４４５ 位点无突变产生。结论　提示ｍｔ Ｄ Ｎ Ａ Ａ１５５５ Ｇ 位点突变可能是导致该家系患者致聋的主要因素之一。     

中国人LHON患者mtDNA继发突变的筛查

目的分析中国人Leber遗传性视神经病变(Leber's hereditary optic neuropathy,LHON)线粒体DNA 4个继发突变位点与LHON发病的关系.方法分别用突变特异性引物聚合酶链反应,异源双链-单链构象多态性,限制性片段长度多态性和DNA测序方法,对137例LHON患者、60例不明原因球后视神经炎进行mtDNA3394C、9438A、13708A、4216C 4个继发位点的检测,并以100例正常人作对照.结果在4例LHON患者(包括3例11778突变、1例3460突变)、2例不明原因球后视神经炎患者及1例正常人中发现存在13708位点突变(G→A),引起ND5蛋白第458位中度保守丙氨酸变成苏氨酸(A458T).经χ2检验,无统计学意义.在1例正常人中检测到3394位点T→C突变,造成ND1蛋白第30位高度保守酪氨酸变成组氨酸(Y30H).137例LHON患者及60例不明原因球后视神经炎患者均未发现此位点突变.在137例LHON患者、60例不明原因球后视神经炎患者及100例正常人中未检测到9438及4216位点突变.结论我们的研究结果与日本、韩国研究结果相似,初步排除了在中国人kber遗传性视神经病变患者中13708A、3394C、9438A、4216C四种突变协同原发突变发病的可能性.     

Distribution of human SNPs and its effect on high-throughput genotyping

Utilizing the results of extensive single nucleotide polymorphism (SNP) studies in humans, stimulated by the International HapMap Project, we present evidence that SNPs are not randomly spaced across the genome, but are somewhat clustered. This observation has important consequences for assay design, since hidden variants in primer sites can affect the accuracy of data. Indeed, using data from the calibration exercises of the HapMap Project, we found instances in which primer site mutations caused allele dropout and other genotyping failures. Given the dynamic nature of SNP discovery, it was inevitable that SNPs would be identified in the primer sites of many assays used for HapMap genotyping. We found that assays with such primer site mutations were correlated with elevated rates of genotype failure and allele dropout. This suggests that taking nearby SNPs into account is important for optimal genotyping assay design.     

眼皮肤白化病Ⅳ型基因MATP的SNPs与皮肤颜色

皮肤颜色差异是人类生物学中最易见、区分不同人群的差异之一,这种差异来自自然的选择,有几个候选基因可以解释其中差异,其中眼皮肤白化病Ⅳ型基因MATP就是其中之一。眼皮肤白化病Ⅳ型基因MATP至今已发现有11种单核苷酸多态性（SNPs）,这些SNPs中有些与皮肤颜色有显著相关,如p.Phe374Leu。     

人工智能在医学的应用研究进展

人工智能技术的快速发展,得益于大数据、数据库、算法、算力的巨大进步,医学研究是人工智能的重要应用方向。人工智能与医学的融合发展,提高了医疗技术水平与医疗服务效率,为医生与医疗设备有效赋能,更好地服务于患者。特别在此次新冠肺炎疫情中取得的巨大成效,足见人工智能在医疗领域中发挥巨大作用,因此吸引了许多研究者不断深入探索。本文对近年来人工智能在医学方面应用的相关文献进行梳理,基于人工智能技术与医学研究的发展背景,重点论述人工智能在药物研发、辅助诊疗、语音识别和语义理解、健康管理、医院管理等领域的应用进展,分析人工智能在医疗领域应用存在的挑战,最后讨论人工智能在医疗领域的发展趋势。 【关键词】人工智能;医学应用;技术挑战;综述     

防御素的研究进展和应用前景

近年来,在植物、昆虫、两栖类、鸟类和哺乳动物体内发现了一组具有抵抗外界微生物侵害的小分子多肽,称为防御素（defensins）。自1984年从人中性粒细胞分离出HNP123以来,已有数十种防御素陆续被发现或报道。防御素具有十分广泛的抗菌谱,对细菌、真菌、病毒等多种微生物都具有杀伤作用,尤其是哺乳动物防御素,除了对细菌、真菌、被膜病毒具有杀伤作用外,还能杀伤支原体、衣原体、螺旋体以及一些恶性肿瘤细胞。由于防御素具有众多的生物活性,因此对于它们的研究目前也越来越受到人们的广泛关注。现本文就防御素的结构与类型、生物活性、应用及基因工程制备做一综述。     

Identification of susceptible genes for complex chronic diseases based on disease risk functional SNPs and interaction networks

Complex chronic diseases are caused by the effects of genetic and environmental factors. Single nucleotide polymorphisms (SNPs), one common type of genetic variations, played vital roles in diseases. We hypothesized that disease risk functional SNPs in coding regions and protein interaction network modules were more likely to contribute to the identification of disease susceptible genes for complex chronic diseases. This could help to further reveal the pathogenesis of complex chronic diseases. Disease risk SNPs were first recognized from public SNP data for coronary heart disease (CHD), hypertension (HT) and type 2 diabetes (T2D). SNPs in coding regions that were classified into nonsense and missense by integrating several SNP functional annotation databases were treated as functional SNPs. Then, regions significantly associated with each disease were screened using random permutations for disease risk functional SNPs. Corresponding to these regions, 155, 169 and 173 potential disease susceptible genes were identified for CHD, HT and T2D, respectively. A disease-related gene product interaction network in environmental context was constructed for interacting gene products of both disease genes and potential disease susceptible genes for these diseases. After functional enrichment analysis for disease associated modules, 5 CHD susceptible genes, 7 HT susceptible genes and 3 T2D susceptible genes were finally identified, some of which had pleiotropic effects. Most of these genes were verified to be related to these diseases in literature. This was similar for disease genes identified from another method proposed by Lee et al. from a different aspect. This research could provide novel perspectives for diagnosis and treatment of complex chronic diseases and susceptible genes identification for other diseases.     

Tyrer-Cuzick模型联合SNPs位点在江西地区乳腺癌诊断中应用研究

目的 探讨Tyrer-Cuzick模型联合SNPs位点在江西地区乳腺癌诊断中的应用价值。方法 选取2016年1月~2017年12月我院收治的乳腺癌患者150例作为A组,选择同期乳腺良性肿瘤患者130例作为B组。采用病史采集回顾性分析,使用Gail及Tyrer-Cuzick模型计算乳腺癌患病风险值,比较两者的风险值的灵敏度、准确度,绘制ROC曲线图,比较曲线下面积。使用PCR测序法统计FGFR2基因rs2981582位点基因分型的数目及频率,采用非条件Logist回归分析结果。结果 Tyrer -Cuzick模型应用于风险评估的敏感度66.00%,特异度86.92%,阳性预测值为85.34%,阴性预测值68.90%; 其ROC曲线下面积0.786大于Gail模型的0.665,差异有统计学意义（P＜0.001）;FGFR2基因rs2981582位点在A组基因型CC、CT、TT的分布频率分别为44.00%、43.33%、12.67%,在B组基因型CC、CT、TT的频率分别为38.46%、38.46%、23.08%。结论 Tyrer-Cuzick模型联合rs2981582位点可用于江西地区乳腺癌筛查和诊断,不失为一种新方法,且TT基因型可能增加江西地区乳腺癌患病风险。     

Spermatozoon search in forensic medicine

The search for sperm is part of the examinations wich may be prescribed, following a request of jucicial services, in case of a suspicion of sexual assault. This article applies to detail how the different phases, pre-analytical, analytical and post-analytical, must be absolutely adhered to so that the biologist, expert or not, in charge of this analysis, can be deliver results (positive or negative) that cannot be challenged.     

蛋白质组学及其在生殖医药学中的应用

With the development of proteomics, the application of proteomics in the research for the medicine of reproduction becomes more and more widely, especially in physiology, pathology, toxicology of reproduction and drug discovery. Significant performance has been achieved for instance, PHGPx is identified in mitochondrial capsule by proteomics approach. 53 proteins involved in the spermatogenesis of rat are identified.The toxicological effect of TCDD on placenta of rat has also been conducted. As a kind of tools of molecular biology, proteomics approach brings into full play.     

Comparison of ENCODE region SNPs between Cebu Filipino and Asian HapMap samples

Patterns of linkage disequilibrium (LD) act as the framework for designing efficient association studies; these patterns are being studied and catalogued by The International HapMap Project. The current study assessed the transferability of tag SNPs chosen from HapMap panels to a cohort of 80 individuals from metro Cebu, Philippines, who participated in the Cebu Longitudinal Health and Nutrition Survey (CLHNS). The analyses focused on 627 single nucleotide polymorphisms (SNPs) in the central 40 kb within each of the 10 HapMap ENCODE regions. The similarity between the genetic variants in Cebu Filipino samples and HapMap panels was examined using allele frequency estimates, measures of pairwise linkage disequilibrium (LD), and haplotype frequency estimates. For these measures, strong correlations were observed between the Cebu Filipino samples and the Asian panels from HapMap, with the strongest correlations observed with the Han Chinese from Beijing (CHB) panel. Tag SNPs selected using the HapMap CHB panel were particularly effective at representing the genetic variation in Cebu Filipino samples. These results suggest that the HapMap data will be an effective resource for future studies in Cebu Filipino samples.