Forensic characteristics and genetic substructure analysis of the Handan Han population, Northern China.

We analysed the forensic characteristics and substructure of the Handan Han population based on 36 Y-STR (short tandem repeat) and Y-SNP (single nucleotide polymorphism) markers. The two most dominant haplogroups in Handan Han, O2a2b1a1a1-F8 (17.95%) and O2a2b1a2a1a (21.51%), and their abundant downstream branches, reflected the strong expansion of the precursor of the Hans in Handan. The present results enrich the forensic database and explore the genetic relationships between Handan Han and other neighbouring and/or linguistically close populations, which suggests that the current concise overview of the Han intricate substructure remains oversimplified.

Haplotype analysis of 36 Y-STR loci in a Chinese Han population from Anhui Province, Eastern China.

We analyzed haplotypes for 36 Y chromosomal STRs (Y-STRs), including 27 Yfiler Plus loci and 9 additional STRs (DYS549, DYS643, DYS508, DYS447, DYS596, DYS444, DYS557, and DYS527a/b) in 2018 unrelated Chinese Han individuals from Anhui Province using DNATyperTM 36Y Kit. Phylogenetic analysis was performed to determine the genetic relationship of the Anhui Han population with other neighboring and/or linguistically close populations.

Population genetic analysis of the Globalfiler STR loci in 3032 individuals from the Altay Han population of Xinjiang in northwest China.

The genetic polymorphisms of 21 autosomal short tandem repeat (STR) loci included in the GlobalFiler™ PCR Amplification Kit were evaluated in 3032 unrelated individuals Altay Han of Xinjiang, northwest China. All of the loci reached the Hardy-Weinberg equilibrium. These loci were examined to determine allele frequencies and forensic statistical parameters. SE33 showed the greatest power of discrimination in Altay Han population, whereas TPOX showed the lowest. The combined discrimination power and probability of excluding paternity of the 21 autosomal STR loci were 0.999999999999999999999999889838 and 0.999999996664704, respectively. Both pairwise genetic distance and phylogenetic methods indicated that the Altay Han had the closest genetic relationship with the Han origin and Hui populations. The present results revealed that the GlobalFiler system had a high level of polymorphism in Altay Han population and hence could be a powerful tool for forensic application and population genetic study.

Evaluation of specific neural marker GAP-43 and TH combined with Masson-trichrome staining for forensic autopsy cases with old myocardial infarction.

It has been a puzzling forensic task to determine the cause of death as a result of old myocardial infarction (OMI) in the absence of recognizable acute myocardial infarction. Recent studies indicated that the heterogeneous cardiac nerve sprouting and sympathetic hyperinnervation at border zones of the infarcted site played important roles in sudden cardiac death (SCD). So, the present study explored the value of growth associated protein-43 (GAP-43) and tyrosine hydroxylase (TH) as objective and specific neural biomarkers combined with Masson-trichrome staining for forensic autopsy cases. Myocardium of left ventricle of 58 medicolegal autopsy cases, 12 OMI cases, 12 acute/OMI cases, and 34 control cases, were immunostained with anti-GAP-43 and anti-TH antibodies. Immunoreactivity of GAP-43 and TH identified nerve fibers and vascular wall in OMI cases and acute/OMI cases. Specifically, TH-positive nerve fibers were abundant at border zones of the infarcted site. There were a few GAP-43 and TH expressions in the control cases. With Masson-trichrome staining, collagen fibers were blue and cardiac muscle fibers were pink in marked contrast with the surrounding tissue, which improved the location of nerve fibers. Thus, these findings suggest that immunohistochemical detection of GAP-43 and TH combined with Masson-trichrome staining can provide the evidence for the medicolegal expertise of SCD due to OMI, and further demonstrate a close relationship between sympathetic hyperinnervation and SCD.

Analysis of 27 Y-chromosomal STR haplotypes in a Han population of Henan province, Central China.

A total of 1225 unrelated Han males from Henan province were analyzed with the prototype Yfiler® Plus kit (Life Technologies, Thermo Fisher Scientific, Waltham, MA, USA). The calculated gene diversity (GD) values ranged from 0.3855 to 0.9673 for the DYS391 and DYS385a/b loci, respectively. The discriminatory capacity (DC) was 86.94 % with 1065 observed haplotypes using 17 Yfiler loci, by the addition of 10 Y-STRs to the Yfiler® Plus system, the DC was increased to 98.94 % while showing 1212 observed haplotypes. Among the new incorporated Y-STRs, DYS576, DYF387S1, DYS518, DYS627, and DYS449 were major contributors to enhancing discrimination. In the analysis of molecular variance, the Henan Han population clustered with Asian origin populations and showed significant differences from other reference populations. In this study, the improvement of adding additional Y-STR markers with the Yfiler® Plus kit provided substantially stronger discriminatory power in the Henan Han population.

Population data of 30 insertion-deletion markers in four Chinese populations.

In this study, we assessed 30 insertion-deletion polymorphisms (Indels) (Investigator DIPplex® kit) in four Chinese populations (n = 952) and evaluated their usefulness in forensic genetic applications. After the Bonferroni correction at a 95 % significance level (p = 0.0017), there were no deviations from the Hardy-Weinberg equilibrium observed except for the HLD114 locus in the Tibetan ethnic group studied. A high level of discrimination power was observed for the DIPplex® kit in four sample populations (CDP > 0.9999) and the combined random match probabilities (CMP) were in the range of 1.4766 × 10(-11) to 5.2742 × 10(-13). Four Indels have been selected for further analyses as possible ancestry informative single nucleotide polymorphisms. The study support that the Investigator DIPplex® kit provides a powerful supplement to standard short tandem repeat-based kits for individual identification and kinship analysis in the Chinese population.

[Genetic polymorphisms of 30 InDel loci in Chinese ethnic population residing in Tibet].

OBJECTIVE: To analyze the genetic data of 30 insertion and deletion polymorphisms (InDel) loci included in an InvestigatorR DIPplex diagnostic kit, and to evaluate the forensic application in ethnic Tibetan population from China. METHODS: By detecting 226 unrelated individuals with the Investigator(R) DIPplex kit, allelic frequencies and population genetics parameters of the 30 InDels were statistically analyzed and compared with available data derived from other populations from various regions. RESULTS: After the Bonferroni correction at a 95% significance level (P=0.0017), no significant departures from the Hardy-Weinberg equilibrium were observed except for the HLD114 locus. Linkage disequilibrium test showed no significant allelic association between all 30 loci after the Bonferroni's correction. The average heterozygosity (Ho) of all loci was 0.4125, the mean discrimination power (DP) was 0.5618, the mean polymorphism information content (PIC) was 0.3280, and the combined discrimination power (TDP) was 0.999999999990. The combined power of exclusion of all loci was 0.987 849 91 in trio cases and 0.94977125 in duo cases. Genetic distance between Tibetan and Han from Beijing was minimum (0.0068) in the 5 populations, while genetic distance between Tibetan and Uygur was maximal (0.0215). CONCLUSION: Multiplex detection has revealed that these 30 InDel loci have a moderate distribution of genetic polymorphism among ethnic Tibetan group residing in Tibet, China.

Time-dependent appearances of myofibroblasts during the repair of contused skeletal muscle in rat and its application for wound age determination.

OBJECTIVE: To research the relation between the time-dependent appearances of myotibroblasts during the repair of contused skeletal muscle in rat and wound age determination. METHODS: A total of 35 SD male rats were divided into the control and six injured groups according to wound age as follows: 12 h, 1 d, 5 d, 7 d, 10 d and 14 d after injury. The appearances of myofibroblasts were detected by HE staining, immunohistochemistry and confocal laser scanning microscopy. Masson's trichrome staining was utilized to examine collagen accumulation in the contused areas. RESULTS: Immunohistochemical staining showed that α-SMA+ myofibroblasts were initially observed at 5 d post-injury. The average ratio of myofibroblasts was highest at 14 d post-injury, with all samples, ratios more than 50%. In the other five groups, the average of α-SMA positive ratios were less than 50%. The collagen stained areas in the contused zones, concomitant with myofibroblast appearance, were increasingly augmented along with advances of posttraumatic interval. CONCLUSION: The immunohistochemical detection of myofibroblasts can be applied to wound age determination. The myofibroblasts might be involved in collagen deposition during the repair of contused skeletal muscle in rat.

Forensic discrimination of three common brands of kitchen knives in China by ICP-AES and infrared absorption.

A block of an injury instrument will be left in wounds sometimes, and the suspect instrument can be discriminated by comparison with the block that was left through elemental analysis. In this study, three brands (Shibazi, Zhangxiaoquan, Qiaoxifu) of kitchen knives with forged, chop, and slice application series were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Infrared Absorption to investigate the type, number of elements and the reference range used for comparing. The results show that when regarding one or more element as the discriminative threshold, together with 5% relative standard deviation (RSD) as the reference range, all the samples could be distinguished among different series. Furthermore, within the same series, the discriminative capability could reach up to 88.57% for all samples. In addition, elements with high content, such as Cr, Mn, and C, were useful to discriminate among different series, and trace elements, such as Ni, Si, and Cu, were useful within the same series. However, in practice, it is necessary to evaluate the accuracy of the method by Standard Reference Material (SRM) before an examination is performed.

[Correlation between percentages of PMN, MNC, FBC and wound age after skeletal muscle injury in rats].

OBJECTIVE: To study the percentages of polymorphonuclear leukocytes (PMN), mononuclear cells (MNC) and fibroblastic cells (FBC) in different post-traumatic intervals after skeletal muscle mechanical injury in rats. METHODS: The rat model of skeletal muscle mechanical injury was established. The rats were divided into injured groups (6 h, 12 h, 1 d, 3 d, 7 d, 10 d and 14 d after injury) and control group. The percentages of PMN, MNC and FBC in different post-traumatic intervals after skeletal muscle mechanical injury were assessed with HE staining and image analysis. RESULTS: At post-injury 6-12h, the percentages of PMN and MNC infiltration appeared in injured sites and that of PMN reached peak. At 1 d, the percentage of MNC infiltration appeared and reached peak, while that of PMN decreased. At 3-7 d, the percentage of FBC gradually increased, while that of PMN and MNC decreased. At 10-14d, the percentage of FBC reached peak. CONCLUSION: The percentages of PMN, MNC and FBC in injured zones showed time-dependent changes, which might be used as reference index for determination of age of skeletal muscle injury.

[Genetic polymorphism and forensic application of 30 InDel loci of Han population in Beijing].

To study the genetic diversities of 30 insertion-deletion (InDel) polymorphisms loci of Han population in Beijing, and to evaluate their forensic application, 210 unrelated healthy individuals of Han population in Beijing were investigated to determine the distributions of allele frequencies by using Investigator DIP system. The PCR products were detected with ABI 3130 XL Genetic Analyzer. Forensic parameters were calculated with relevant statistical analysis software. As a result, after the Bonferroni correction at a 95% significance level, there were no significant departures from Hardy-Weinberg equilibrium or significant linkage disequilibrium between the loci. The power of discrimination (DP) varies between 0.2690 (HLD118) and 0.6330 (HLD45), and the combined discrimination power (TDP) for the 30 InDel loci is 0.999999999985. The combined power of exclusion was 0.98771049 in trio cases (CPE(trio)) and 0.94579456 in duo cases (CPE(duo)). The parentage testing of 32 cases revealed no mutations happened to 30 InDel loci. Multiplex detection of the 30 InDel loci revealed a highly polymorphic genetic distribution in Beijing Han population, which represents a complementary tool in human identification studies, especially in challenging DNA cases.

[Polymorphism of 17 Y-STR loci in She ethnic population in Fujian and genetic relationship with 11 populations].

To investigate the genetic polymorphisms of 17 Y-chromosomal short tandem repeats(Y-STR) loci in She ethnic population from Fujian province, and to evaluate their forensic application values and genetic relationship with other 11 populations, 152 unrelated male individuals of She ethnic population in Fujian were used to determine the distribution of allele frequencies and haplotypes by using Y-filerTM System. Cluster analysis and phylogenic trees were applied to show the genetic distance among the populations. As a result, 50 haplotypes were found in DYS385a/b loci, and 3～11 alleles were found in the rest 15 Y-STR loci. The GD value was from 0.4037(DYS391) to 0. 9725(DYS385a/b). This study has also revealed "off-ladder" alleles at several Y-loci, namely DYS448, DYS393, DYS458 and DYS635, and several occurrences of duplications at the DYS385a/b, DYS19 and DYS390 loci. One hundred and forty-four haplotypes were found in 17 Y-STR loci, of which 138 were unique, 5 were found in 2 individuals, 1 was found in 4 individuals, and the observed haplotypes diversity value was 0.9990. Comparing with 11 populations, the genetic distance between She ethnic and Han population in Zhejiang was the smallest (0.0042), while it was the largest between She ethnic and Tibet ethnic population (0.2380). Cluster analysis and phylogenetic tree both demonstrated that genetic distance between She ethnic and several south Han populations is closer than between She ethnic and non-Han populations. Multiplex detection of the 17 Y-STR loci revealed a highly polymorphic genetic distribution, which would be very powerful for establishing a Y-STR database, for population genetics and forensic practice.

Analysis of sensitivity and specificity: precise recognition of neutrophils during regeneration of contused skeletal muscle in rats.

In this report, we applied the TissueFAXS 200 digital pathological analysis system to rapidly and accurately identify neutrophils during regeneration of contused skeletal muscle, and to provide information for follow-up studies on neutrophils to estimate wound age. Rat injury model was established, and skeletal muscle samples were obtained from the control group and contusion groups at 1, 1.5, 2, 3, 4, and 6 h, as well as at 1, 3, 5, and 15 d post-injury (n = 5 per group). The expression of nuclei and neutrophils was detected by hematoxylin and eosin (HE) staining and immunohistochemical (IHC) staining. A total of 20 injury site areas of 0.25 mm2 (0.5 mm × 0.5 mm) were then randomly selected at all time points. A TissueFAXS 200 digital pathological analysis system was used to identify the positive and negative numbers. Knowledge of five professional medical workers were considered the gold standard to measure the false positive rate (FPR), false negative rate (FNR), sensitivity, specificity, and area under the curve (AUC) of receiver operating characteristic (ROC) curves. As a result, with a staining area of neutrophils from 8 µm2 to 15 µm2, the FPR was 4.28%-12.14%, the FNR was 12.42%-64.08%, the sensitivity was 35.92%-87.58%, the specificity was 87.86%-95.72%, the Youden index was 0.316-0.754, the accuracy was 82.80%-88.30%, and the AUC was 0.771-0.826. The AUC was largest when the cut-off value of the staining area was 12 µm2. Our results show that this software-based method is more accurate than the human eye in evaluating neutrophil infiltration. Based on the sensitivity and specificity, neutrophils can be accurately identified during regeneration of contused skeletal muscle. The TissueFAXS 200 digital pathological analysis system can also be used to optimize conditions for different cell types under various injury conditions to determine the optimal cut-off value of the staining area and provide optimal conditions for further study. Furthermore, it will provide evidence for forensic pathology cases.

[Polymorphism of 17 Y-STR loci in Shanxi Han population and genetic relationship with 13 populations].

To investigate the genetic polymorphisms of 17 Y-chromosomal short tandem repeats (Y-STR) loci in Shanxi Han population and to explore their forensic application values and genetic relationship with neighboring populations, 17 Y-STR in 222 unrelated healthy Shanxi Han individuals were amplified with Y-filerTM System, and the PCR products were detected with 3130 Genetic Aanalyzer. The allele frequencies and haplotype diversity were calculated. Y-STR data of another 13 populations were collected from publications. Cluster analysis and phylogenic trees were applied to show the genetic distance among the populations. As a result, a total of 219 haplotypes were identified, and the observed haplotypes diversity value was 0.9999. The gene diversity values (GD) for each locus ranged from 0.3894 (DYS391) to 0.9755 (DYS385a/b). Comparing with 13 populations, the genetic distance between Shanxi and Jihei Han populations was the smallest (0.0001), while the genetic distance between Shanxi and Taiwan population was the largest (0.0152). The phylogenetic tree was similar to the results of clustering analysis. Multiplex detection of the 17 Y-STR loci revealed a highly polymorphic genetic distribution, which would be very powerful for establishing a Y-STR database, for population genetics and forensic practice.

Forensic characteristics and phylogenetic analysis of the Chinese Han population from Chongqing Municipality, Southwest China.

Chongqing Han is an important southern Han group, but investigations on its paternal genetic structure are still limited. Here, we analyzed the forensic and phylogenetic characteristics of the Chongqing Han population based on 27 Y-STR and predicted Y-SNP markers. Based on AMOVA, haplogroup distribution and network analysis, we explored the genetic relationship between Chongqing Han, other Chinese groups and some southern indigenous groups (speaking Kra-Dai, Austronesian, etc).

Insight into molecular profile changes after skeletal muscle contusion using microarray and bioinformatics analyses.

Muscle trauma frequently occurs in daily life. However, the molecular mechanisms of muscle healing, which partly depend on the extent of the damage, are not well understood. The present study aimed to investigate gene expression profiles following mild and severe muscle contusion, and to provide more information about the molecular mechanisms underlying the repair process. A total of 33 rats were divided randomly into control (n=3), mild contusion (n=15), and severe contusion (n=15) groups; the contusion groups were further divided into five subgroups (1, 3, 24, 48, and 168 h post-injury; n=3 per subgroup). A total of 2844 and 2298 differentially expressed genes (DEGs) were identified using microarray analyses in the mild and severe contusions, respectively. From the analysis of the 1620 coexpressed genes in mildly and severely contused muscle, we discovered that the gene profiles in functional modules and temporal clusters were similar between the mild and severe contusion groups; moreover, the genes showed time-dependent patterns of expression, which allowed us to identify useful markers of wound age. The functional analyses of genes in the functional modules and temporal clusters were performed, and the hub genes in each module-cluster pair were identified. Interestingly, we found that genes down-regulated at 24-48 h were largely associated with metabolic processes, especially of the oxidative phosphorylation (OXPHOS), which has been rarely reported. These results improve our understanding of the molecular mechanisms underlying muscle repair, and provide a basis for further studies of wound age estimation.

Identifying biomarkers for evaluating wound extent and age in the contused muscle of rats using microarray analysis: a pilot study.

Wound age estimation is still one of the most important and significant challenges in forensic practice. The extent of wound damage greatly affects the accuracy and reliability of wound age estimation, so it is important to find effective biomarkers to help diagnose wound degree and wound age. In the present study, the gene expression profiles of both mild and severe injuries in 33 rats were assayed at 0, 1, 3, 24, 48, and 168 hours using the Affymetrix microarray system to provide biomarkers for the evaluation of wound age and the extent of the wound. After obtaining thousands of differentially expressed genes, a principal component analysis, the least absolute shrinkage and selection operator, and a time-series analysis were used to select the most predictive prognostic genes. Finally, 15 genes were screened for evaluating the extent of wound damage, and the top 60 genes were also screened for wound age estimation in mild and severe injury. Selected indicators showed good diagnostic performance for identifying the extent of the wound and wound age in a Fisher discriminant analysis. A function analysis showed that the candidate genes were mainly related to cell proliferation and the inflammatory response, primarily IL-17 and the Hematopoietic cell lineage signalling pathway. The results revealed that these genes play an essential role in wound-healing and yield helpful and valuable potential biomarkers for further targeted studies.

Vitality and wound-age estimation in forensic pathology: review and future prospects.

Determining the age of a wound is challenging in forensic pathology, but it can contribute to the reconstruction of crime scenes and lead to arrest of suspects. Forensic scholars have tended to focus on evaluating wound vitality and determining the time elapsed since the wound was sustained. Recent progress in forensic techniques, particularly high-throughput analyses, has enabled evaluation of materials at the cellular and molecular levels, as well as simultaneous assessment of multiple markers. This paper provides an update on wound-age estimation in forensic pathology, summarizes the recent literature, and considers useful additional information provided by each marker. Finally, the future prospects for estimating wound age in forensic practise are discussed with the hope of providing something useful for further study.

The densities of visceral organs and the extent of pathologic changes.

In this study, we designed a new device to measure the density of internal organs and correlated with their pathologic changes. The densities of hearts, livers, lungs and brains from 169 autopsy cases were measured with different extent of pathologic changes by an integrated volume-density meter. All samples were divided into 2 groups: intact and pathologic groups. The extent of pathologic changes was classified into 3 stages: slight edema, intermediate edema, severe edema (or severe fatty degeneration only for livers) according to the histologic features. Results show that there were significant differences between each subgroup and intact group and the density was closely correlated with pathologic changes. Therefore, the external parameter of density might offer some clues to its pathologic changes, such as edema and fatty changes.

[The Y-STR polymorphisms and phylogenetic relationships of two minority populations in Liaoning province].

OBJECTIVE: To investigate the genetic polymorphisms of 11 Y-chromosomal short tandem repeats (Y-STR) loci in 484 male individuals from two minority populations, the Hui and Xibe, of Liaoning province, and to evaluate their forensic application values and genetic relationships with other 15 populations of China. METHODS: Eleven Y-STR loci in all samples were amplified with PowerPlex Y System, and the PCR products were analyzed by 310 Genetic Analyzer. Cluster analysis and neighbor-joining tree were applied to show the genetic distance among the populations. RESULTS: In Hui people, 187 haplotypes were identified, and the overall haplotype diversity value was 0.9990. The gene diversity values (GD) for each locus ranged from 0.4783(DYS437) to 0.9679(DYS385a/b); In Xibe people, 237 haplotypes were identified, and the overall haplotype diversity value was 0.9984. The GD value for each locus ranged from 0.3618(DYS391) to 0.9686(DYS385a/b). Comparing with 15 reference populations, the genetic distance between the Hui and Xibe was the nearest (0.0257), and that between the Hui and Yi was the farthest (0.1046), while the genetic distance between Xibe and Korean was also the farthest (0.0978). The NJ tree was similar to the results of clustering analysis and all the 17 populations were clustered into 3 groups. CONCLUSION: The genetic distribution of the 11 Y-STR loci in Liaoning Hui and Xibe ethnic groups showed favorable polymorphisms, therefore are suitable for forensic identification and paternity testing in the local area. The study of haplotype diversity among different populations is useful in understanding their origins, migrations and their relationships.