Validation studies of the ParaDNA® Intelligence System with artificial evidence items

Short tandem repeat (STR) profiling is one of the mostly used systems for forensic applications. In certain circumstances, STR profiling is time-consuming and costly, which potentially leads to delays in criminal investigations. LGC (Laboratory of the Government Chemist, UK) Forensics has developed a robust STR profiling platform called the ParaDNA^® Intelligence Test System which can provide early tactical intelligence and aid investigators in making informed decisions on sample prioritization for detection. Here, we validated the ParaDNA intelligence test for its application in forensic cases using a range of mock evidence items following guidelines set by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Specifically, we tested the sensitivity and accuracy of the ParaDNA intelligence test, as well as the success rates for detecting mock samples and for use in case scenarios. Our findings demonstrate that the ParaDNA intelligence test generates useful DNA profiles, especially for samples such as blood, saliva, and semen that contain ample DNA, indicating the benefits of including ParaDNA as a prior step in forensic STR profiling pipelines.     

加减薯蓣丸治疗轻中度肾精亏虚证老年期痴呆的磁共振波谱研究

目的 采用氢质子磁共振波谱（1H magnetic resonance spectroscopy,1H MRS）检查结合神经心理学量表的方法,评价加减薯蓣丸对老年期痴呆患者的治疗效果。方法 收集2015年12月至2017年4月湖北省中医院脑病科及老年病科的血管性痴呆（vascular dementia,VD）及阿尔茨海默病（Alzheimers disease,AD）肾精亏虚证患者各20例,另选认知功能正常者20例作为对照组。入选老年期痴呆患者在内科治疗的基础上予以加减薯蓣丸治疗。对老年期痴呆患者治疗前后及对照组受试者进行简易精神状态评价量表（mini mental state examination,MMSE）、日常生活能力量表（activities of daily living,ADL）、痴呆证候分型量表（syndromes differentiation scale for dementia,SDSD）评估及1H MRS检查。结果 加减薯蓣丸显著升高VD及AD患者降低的MMSE评分（P＜0.05）,降低其升高的SDSD评分（P＜0.05）,但对ADL评分的改善作用无统计学意义（P＞0.05）。1H MRS检查表明,加减薯蓣丸显著升高VD和AD患者双侧额叶下降的N 乙酰天门冬氨酸（N aspart acetyl,NAA）/肌酸（creatine,Cr）水平（P＜0.05）,而降低双侧额叶升高的胆碱复合物（choline,Cho）/Cr作用无统计学意义（P＞0.05）。加减薯蓣丸对VD患者和AD患者MMSE、SDSD、ADL评分和双侧额叶NAA/Cr、Cho/Cr的作用差异无统计学意义（P＞0.05）。结论 加减薯蓣丸改善轻中度老年期痴呆患者认知功能的机制可能与促进损伤的神经细胞修复有关。     

口蹄疫病毒O型和A型交互反应性单克隆抗体的筛选与鉴定

不同血清型口蹄疫病毒(FMDV)之间不能产生交叉免疫保护,但是血清学的交叉反应确实存在。本研究旨在建立一种筛选型间交互反应性抗体的方法,以期为解析FMDV血清型间保守的抗原结构奠定基础。本方法主要依据单个B细胞抗体技术,首先采用两种不同的荧光染料FluoProbes 647H和Pacific Blue分别标记O型与A型FMDV 146S灭活抗原,然后利用流式细胞分选技术,从免疫牛外周血单个核细胞(PBMCs)中分选出结合两种抗原的特异性B细胞,通过单个B细胞抗体基因测定,获得Ig G抗体重链与轻链可变区编码序列,并将可变区基因插入含有牛IgG抗体恒定区的pcDNA3.4载体中,构建IgG抗体的重链与轻链表达质粒。将重链与轻链表达质粒共转染中国仓鼠卵巢悬浮细胞(CHO-S)进行完整抗体表达。结果显示,通过该方法获得了5株FMDV特异性单克隆抗体,其中4株(H64、R82、I16、R29)经间接免疫荧光(IFA)检测都可特异性识别O和A型FMDV;ELISA结果显示,H64、R82、I16与O、A型抗原均具有较好的亲合力;Western-blot结果显示,I16可特异性结合O、A型FMDV结构蛋白VP2中的线性表位,说明在衣壳蛋白VP2上存在血清型间保守的抗原表位,通过本研究进一步加深了对FMDV抗原结构的认识。     

DNA Recovery From Tape-Lifting Kits: Methodology and Practice

In the case of suspicious deaths, the technique of 1:1 taping is often used in Belgium. It consists of affixing a large number of adhesive tapes to the body of the victim. It is conventionally aimed at obtaining microtraces (e.g., fibers, hair) and is usually not used for DNA analysis. However, in some cases, DNA analysis of certain areas of interest identified on the 1:1 taping material can offer a last resort solution. The four-step method that is described in this article involves the selection of areas of interest on the body (Step 1), the selection of the corresponding tapes (Step 2), the decontamination of the tapes (Step 3), the selection of areas of interest on the tapes, for DNA sampling (Step 4). The method is illustrated by its successful application in four murder cases. In each case, DNA profiles of good quality could be identified, including profiles of persons different from the victim.     

Whole Plastome Sequences of Two Drug-Type Cannabis: Insights Into the Use of Plastid in Forensic Analyses

DNA is one of the fastest growing tools in forensic sciences, increasing reliability in forensic reports and judgments. The use of DNA has increased in different areas of the forensic sciences, such as investigation of plant species, where plastid DNA has been used to elucidate and generate evidence in cases of traceability of genetically modified and controlled plants. Even with several advances and the practice of using DNA in forensic investigations, there are just few studies related to the identification of genetic tools for the characterization of drug and nondrug-types of Cannabis. Herein, the whole plastomes of two drug-type Cannabis are presented and have their structures compared with other Cannabis plastomes deposited in the GenBank, focusing in the forensic use of plastome sequences. The plastomes of Cannabis sativa “Brazuka” and of the hybrid Cannabis AK Royal Automatic presented general structure that does not differs from the reported for other C. sativa cultivars. A phylogenomic analyses grouped C. sativa “Brazuka” with the nondrug C. sativa cultivars, while the hybrid Cannabis AK Royal Automatic placed isolated, basal to this group. This suggests that the analysis of plastomes is useful toward genetic identification of hybrids in relation to C. sativa.     

祖孙双单亲比对的匹配概率研究

目的推导祖孙双单亲比对的匹配概率(PMGDS)公式,并以随机模拟法进行验证。方法首先,根据定义推导PMGDS的数学公式,依据此公式在19个基因座上计算PMGDS的数值。其次,以随机模拟法设计实验,在19个基因座上计算PMGDS的模拟值。最后,以模拟值对比公式值的方式,对公式进行实验验证。结果研究获得了PMGDS的数学公式,经模拟实验验证显示出良好的符合。结论祖孙双单亲比对的错判概率较低,具有很好的应用价值。     

新冠肺炎疫情期间公安法医应当加强尸体甄别和个体防护

因鉴定体制特点,公安法医除参与尸体有关的现场勘查工作外,还需进行尸体检验工作。在此过程中,可能面对很多风险,受伤和中毒等事件时有发生。然而,国内公安法医对新冠肺炎等传染病流行期间死亡的尸体如何甄别进行尸体检验鉴定,对现场勘查及尸体检验工作的防护只有少量规定,且内容不够详尽。本文对法医在现场勘查中遇到的尸体及尸体检验中实验室建设、职业现状、风险评估及防范措施等进行了论述。最后,建议出台相关的制度规定等具体约束规范措施,以保障公安法医现场勘查及尸体检验工作的顺利进行,以解除基层鉴定机构和鉴定人的后顾之忧。     

冠状病毒感染性疾病尸体检验相关病原学检测回顾与展望

冠状病毒曾经给世界带来两次严重的人类间大流行,包括严重急性呼吸综合征(severe acute re?spiratory syndrome,SARS)和中东呼吸综合征(Middle East respiratory syndrome,MERS),2019年岁末新型冠状病毒肺炎(coronavirus disease 2...     

冠心病猝死的病理学研究——附128例尸检分析

本文报道128例冠心病猝死的法医病理学研究结果。其中冠脉病变4级63例,3级26例,2级29例。3级以上病变者斑块分布多较广泛。各支病变中以左前降支最常见。并发新鲜血栓形成者18例,斑块内出血17例,急性心肌梗死仅2例。36例冠脉斑块有炎性细胞浸润。56例见心肌间质纤维化或小灶疤痕形成。指出虽然我国冠心病发病率较低,但仍是猝死最常见的原因,尤以中壮年男性多见;多数病例无明显诱因而于睡眠中猝死。对冠心病猝死发生的特点、冠脉和心肌病变及病理诊断等进行了分析讨论。     

血友病人单纯外伤性蛛网膜下腔出血的法医学鉴定1例

外伤性蛛网膜下腔出血(Traumatic Subarachnoid Haemorrhage,简称TSAH)在法医病理实践和临床法医鉴定中并不少见,但有关血友病人在头面部轻微外伤后出现单纯性TSAH的相关报道较少,在临床法医鉴定中有一起损伤和疾病同时存在的特殊案例,在该案例鉴定中有一些体会值得借鉴。