Genetic variation of 17 autosomal STR loci in the Lahu population from Yunnan and phylogenetic structure exploration among 28 populations

This study evaluated the genetic variation of 17 autosomal short tandem repeat (STR) loci included in the PowerPlex® 18D Kit. Samples of 562 unrelated healthy Lahu individuals living in Yunnan Province in southwestern China were investigated. The data were analyzed to provide information on allele frequencies and other statistical parameters relevant to the forensic population. Of the 17 loci, 16 reached the Hardy–Weinberg equilibrium after Bonferroni correction. A total of 176 alleles were identified in 17 STR loci, and allele frequencies ranged from 0.000 890 to 0.578 292. The combined discrimination power (CPD) and probability of excluding paternity (CPE) of the 17 STR loci were 0.999 999 999 999 999 999 489 and 0.999 998 301 753 122. The genetic relationships among 28 populations were also estimated.     

周围剂量当量仪的研制

周围剂量当量仪研制是根据国际辐射单位和测量委员会（ＩＣＲＵ）３９号报告推荐的周围剂量当量而设计的一种数字化智能型辐射防护仪。方法采用能量补偿对探测器进行能响校正。结果补偿结果使得探测器在４７～２３０ｋｅＶ与ＩＳＯ推荐的Ｈ＊（１０）／Ｋａ值误差在５％以内。本文重点描述了周围剂量当量仪探测器部分的工艺结构和剂量学性能以及电子学测量部分的主要功能。结论通过实际应用我们初步获得的结论是由于该仪器可直接测量周围剂量当量，稳定性好且具有自动取平均值特点，它可做为实验室校准用测量仪器，又由于该仪器体积小，电池供电，读数面板又有背光功能，它也可以做为现场仪器用于辐射防护实践的现场测量     

Study of autosomal STR loci with IBS method in full sibling identification

Objective: We investigated the application of 51 autosomal short tandem repeat (STR) loci with the identity by state (IBS) method and a discriminant function algorithm in full-sib identification. Methods: A total of 342 pairs of full sibs (FSs) and 3900 pairs of unrelated individuals (UIs) were genotyped for 51 STR loci. Groups were formed in accordance with discrimination power (DP) values and the number of loci, and IBS scores of FSs and UIs were analyzed and compared. The discriminant functions of FS-UI were determined by using the Fisher discriminant with SPSS software. Results: All IBS in FSs and UIs groups showed normal distributions and there were significant differences between FS-UI. Receiver operating characteristic curves revealed that the detection efficiency of full-sib identification was affected by both the locus polymorphism and the number of loci detected. Comparing the rate of false positive and false negative of discriminant function between groups, a higher average DP value and larger number of loci detected were associated with a lower rate of miscarriage of justice and were more helpful for full-sib identification. Conclusion: STRs with higher DP values should be selected when additional autosomal markers are required for FS identification. Discriminant analysis with the IBS method is highly applicable for the FS-UI test.     

Tri-allelic patterns of STRs and partially homologous non-sister chromatid crossover observed in a parentage test

A maternity testing case is reported, in which the child showed tri-allelic patterns in two short tandem repeat (STR) loci. The genotypes of Penta D of the mother and the child were 9,13 and 9,10,13, respectively. Those of D21S11 were 32.2,35 and 29,35, respectively, but intensity ratio of alleles 29 and 35 of the child was 1:2. These results suggested the copy number variations (CNVs) or trisomy of chromosome 21. By further examination using STR-based chromosome aneuploidy detection kit, three alleles were detected in D21S1411, LFG21 and Penta D, and 2 alleles with intensity ratio of 1:2 were observed in D21S2502, D21S1435, D21S11 and D21S1246. Karyotype and whole-genome SNP array analyses showed that the child had a free trisomy 21. In addition, partially homologous non-sister chromatid crossover occurred at the region 19181770-39499178 on the long arm of chromosome 21.     

Exploring the potential for age estimation using facial image sensing technology for postmortem investigation

In this study, we examine the potential for using face imaging sensing technology in place of a human forensic practitioner to estimate the age of cadavers. We used the age estimation software FieldAnalyst for Signage Ver. 6.0 AW32. To validate the usefulness of its age estimation for living subjects, images of 28 subjects were taken at three angles (+30°, 0°, and −30°) with respect to the horizontal plane, with their eyes open and closed. The highest positive correlation between mean the estimated age and the actual age (y = 1.02x − 0.35, and Spearman’s rank correlation coefficient of 0.78, P < 0.001) was obtained when the subjects had their eyes closed and the image was captured at an angle of 0°. The ages of 93% of the subjects were estimated within ±10 years of their actual ages. We then applied this procedure to 61 cadavers with their eyes closed. Facial images were taken at an angle of 0° with respect to the horizontal plane and used to estimate the ages of the cadavers. Although a positive correlation between the actual and mean estimated ages was obtained (y = 1.28x + 0.43, Pearson’s correlation coefficient of 0.69, P < 0.001), the mean estimated ages of only 39.3% of the subjects were within ±10 years of their actual ages. It appears that this technology is not accurate enough to use to determine the age of a cadaver. Therefore, medical inspectors with adequate knowledge and experience are still required for postmortem examination.     

Aging is only significant factor causing CPR-induced injuries and serious injuries

BackgroundCardiopulmonary resuscitation (CPR) sometime cause severe injuries and can affect quality of life, lead to long-term disabilities or death of the patient. The aim of this study is to identify the risk factors causing CPR-induced injuries and those of serious injuries.MethodsThis was a retrospective forensic autopsy study in a single institution. Among 885 forensic autopsies undertaken between 2011 and 2018, those in which the victim had undergone CPR immediately after cardiac arrest were recorded. ‘Serious injuries’ were defined as an Abbreviated Injury Scale (AIS) score ≥ 3. CPR-induced injuries were evaluated by three experienced forensic pathologists. With the background and history of the patient, the circumstances of cardiac arrest and risks of causing CPR-induced injuries were determined by multivariate analyses.ResultsSeventy-five victims comprised the study cohort. CPR-induced injuries were found in 52 victims (69.3%). Rib fracture was the most common (60.0%), followed by sternal fracture (37.3%), heart injury (21.3%) and liver injury (8.0%). Multivariate analysis revealed higher age to be an independent factor causing CPR-induced injuries (odds ratio [OR], 1.07, P < 0.001). Thirty-six victims had 39 serious injuries in the chest or abdomen: fracture of ≥ 3 ribs (35 cases), aortic dissection (two), lung contusion (one) and rupture of the heart (one). Multivariate analysis revealed higher age to be an independent factor causing CPR-induced serious injuries (OR, 1.09; P < 0.001).ConclusionAging was the significant factor causing CPR-induced injuries and serious injuries.     

Next generation sequencing and its applications in forensic genetics

It has been almost a decade since the first next generation sequencing (NGS) technologies emerged and quickly changed the way genetic research is conducted. Today, full genomes are mapped and published almost weekly and with ever increasing speed and decreasing costs. NGS methods and platforms have matured during the last 10 years, and the quality of the sequences has reached a level where NGS is used in clinical diagnostics of humans. Forensic genetic laboratories have also explored NGS technologies and especially in the last year, there has been a small explosion in the number of scientific articles and presentations at conferences with forensic aspects of NGS. These contributions have demonstrated that NGS offers new possibilities for forensic genetic case work. More information may be obtained from unique samples in a single experiment by analyzing combinations of markers (STRs, SNPs, insertion/deletions, mRNA) that cannot be analyzed simultaneously with the standard PCR-CE methods used today. The true variation in core forensic STR loci has been uncovered, and previously unknown STR alleles have been discovered. The detailed sequence information may aid mixture interpretation and will increase the statistical weight of the evidence. In this review, we will give an introduction to NGS and single-molecule sequencing, and we will discuss the possible applications of NGS in forensic genetics.     

电离辐射对小鼠移植性肝癌作用的实验研究

目的研究不同剂量γ射线照射对小鼠移植性肝癌形成的影响。方法γ射线照射后６小时，给予小鼠右肩胛尾侧部皮下接种Ｈ２２肝癌细胞，观察各组小鼠的肿瘤形成及生长情况。另外，观察了γ射线对小鼠足垫迟发性超敏反应（ＤＴＨ）、ＮＫ细胞活性及血清ＳＯＤ含量的影响。结果０．３及０．６Ｇｙγ射线照射后，小鼠肿瘤潜伏期延长，０．１５及０．３Ｇｙ照射后，小鼠ＮＫ细胞活性及ＤＴＨ反应增强，０．１５～１．２Ｇｙ照射后，小鼠血清总ＳＯＤ及Ｍｎ－ＳＯＤ含量均显著升高。结论电离辐射对小鼠移植性肝癌的作用与照射对小鼠免疫功能及ＳＯＤ水平的影响密切相关。