Wound Age Estimation by Neutrophil Migration Distance / 法医学杂志

Objective To explore the application of neutrophil migration distance for wound age estimation of skeletal muscles in rats, and to provide methodological basis for follow-up study in future. Methods The skeletal muscle contusion model was established in rats, and the control group and the 2, 4, 6 h post-traumatic groups were set. The law of response of neutrophils that participated in the inflammation after injury was detected by immunohistochemical staining, and the relationship between neutrophil migration distance and injury time was detected by TissueFAXS PLUS software. Results The skeletal muscle was obviously infiltrated with neutrophils 2-6 h after injury. The positive rate of neutrophil was （28.75±0.94）% at 2 h post-traumatic, and reached the peak （45.50±3.63）% at 4 h post-traumatic, then decreased to （31.92±1.56）% at 6 h post-traumatic. The neutrophil migration distances increased with the progress of inflammation, and reached （124.80±12.32） μm, （229.03±21.45） μm and （335.04±16.75） μm at 2 h, 4 h and 6 h, respectively. Conclusion There is a relationship of neutrophil infiltrated number and migration distance and wound age within the 2-6 h after skeletal muscle injury, which could be used for the inference of skeletal muscle wound age.

Comparison of the Skin and Skeletal Muscle Contusion in Rats Induced by Blunt Force with Different Heights / 法医学杂志

OBJECTIVES@#To explore the differences in the repair process of skin and skeletal muscle after contusion caused by blunt force attack with different heights.@*METHODS@#Three degrees of contusion were performed on SD rats' right hind limbs by a designed free-dropping device falling from 15, 30 and 50 cm heights, which as a main consideration factor for degree of injury. The repair process of skin and skeletal muscle at 6 h, 24 h, 3 d, 7 d and 13 d after contusion were observed using routine histological methods.@*RESULTS@#Hematoma within skin and/or muscle was found in the rats' hind limbs after contusion with three different heights. The repair processes were similar at 24 h after contusion. However, with the increase of height, the display degree was more obvious. At 3 d after contusion, the RBC of the hemorrhagic region would be decomposed and elapsed in 15 cm contusion group, but for 30 cm contusion group, it delayed to 7 d. At 13 d after contusion, the similar result was found in 15 cm and 30 cm contusion groups, in contrast, the 50 cm contusion group was still in the proliferative phase.@*CONCLUSIONS@#With the increase of height, the occurring rate of hematoma within skin and muscle at the same time increases, and the more serious histological appearance after contusion, including inflammation and proliferation, the longer healing process are observed. According to the results of present study and considering forensic application, the contusion model with 50 cm height （2.58 J/cm²） is recommended as the experimental animal model for the future study of wound age estimation on contusion.

Time-dependent appearances of myofibroblasts during the repair of contused skeletal muscle in rat and its application for wound age determination / 法医学杂志

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.

Genetic polymorphism of 30 autosomal InDel loci in Chinese uygur population residing in Xinjiang / 解放军医学杂志

Objective To investigate the genetic data of 30 insertion deletion polymorphism (InDel) loci included in Investigator® DIPplex in Uygur population from Xinjiang, and evaluate its application in forensic medicine. Methods Allele frequencies, population genetics parameters of the 30 InDels were determined in 223 unrelated Uygur individuals with Investigator® DIPplex, and they were statistically analyzed and compared with available data of other populations of different races from different regions. Results After Bonferroni's correction, there were no significant departure from Hardy-Weinberg equilibrium or linkage disequilibrium between the loci. The average heterozygosity (Ho) was 0.468 6, the mean discrimination power (DP) was 0.609 5, and the total probability of discrimination power (TDP) reached 0.999 999 999 995. The cumulative probability of exclusion was 0.995 478 in trio cases (CPEtrio) and 0.972 007 in duo cases (CPEduo). The genetic distance between Uygur and Kazakh was closer than those between Uygur and other populations, such as African American. Conclusion Multiplex detection of the 30 InDel loci revealed a moderately high polymorphic genetic distribution in Chinese Uygur population residing in Xinjiang, demonstrating that the Investigator® DIPplex kit can be used as a supplementary tool for human identity tests, especially in challenging DNA cases.

Correlation between percentages of PMN, MNC, FBC and wound age after skeletal muscle injury in rats / 法医学杂志

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.

Polymorphisms of 11 Y-chromosomal short tandem repeat loci in Chongqing Tujia ethnic group and genetic relationships with 16 populations / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic polymorphisms of 11 Y-chromosomal short tandem repeats (STR) loci in Chongqing Tujia population, and to evaluate their forensic application values and genetic relationships with the other 16 populations of China.</p><p><b>METHODS</b>Eleven Y-STR loci in 215 unrelated Tujia individuals from Chongqing were amplified with PowerPlex Y System, and the PCR products were analyzed by 310 Genetic Analyzer. Cluster analysis and phylogenic trees were applied to show the genetic distance among the populations.</p><p><b>RESULTS</b>A total of 195 haplotypes were identified and the overall haplotypes diversity for the 11 Y-STR loci was 0.9942. The gene diversity values (GD) for each locus ranged from 0.3757 (DYS391) to 0.9170 (DYS385a/b). Comparing with other 16 populations, the genetic distance between Tujia and Tibetan was the nearest (0.02467), that between the Tujia and Korean ethnic groups was the farthest (0.25350).</p><p><b>CONCLUSION</b>The genetic distribution of the 11 Y-STR loci in Chongqing Tujia population showed favorable polymorphisms. They are suitable for forensic identification and paternity testing in the local area. The study of genetic diversity among different populations is useful in understanding their origins, migrations and their relationships.</p>

The Y-STR polymorphisms and phylogenetic relationships of two minority populations in Liaoning province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Twenty Y-STR locus multiplex amplification and genetic polymorphism analysis in Han population in Chaoshan area / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study genetic polymorphisms of 20 Y-chromosomal short tandem repeats (STR) in Chaoshan Han population, and to evaluate their value in forensic science.</p><p><b>METHODS</b>Twenty Y-specific STR loci (DYS434, Y-GATA-A10, Y-GATA-H4, DYS438, DYS439, DYS443, DYS444, DYS446, DYS447, DYS448, DYS456, DYS458, DYS460, DYS520, DYS531, DYS557, DYS622, DYS630, DYS635 and DYS709) were amplified by using three fluorescence-labeled multiplex PCR systems and were analyzed by ABI310 genetic analyzer. One hundred and fifty-eight unrelated male individuals of Han population in Chaoshan area were investigated to determine the distribution of allele frequencies and haplotype.</p><p><b>RESULTS</b>The Y-STR multiplexes developed had followed the published nomenclature and ISFG guidelines for STR analysis. Gene diversity ranged from 0.2506 at DYS434 to 0.8034 at DYS447. A total of 157 different haplotypes were observed, and among these, 156 were unique, while 1 was found for two times. The haplotype diversity value calculated from all 20 loci combined was 0.999998. None of Y-STR allele mutation was observed in the 30 father/ son pairs confirmed by autosomal STR analysis.</p><p><b>CONCLUSION</b>The results indicate that the 20 Y-STR loci are highly polymorphic and fathership genealogy inheritance are stable. The three fluorescence-labeled multiplex amplification systems that we constructed are suitable for forensic individual identification and paternity testing in Chaoshan area.</p>