Aortic Dissection and Sudden Unexpected Deaths: A Retrospective Study of 31 Forensic Autopsy Cases.

Acute aortic dissection (AAD) is the most common cause of sudden unexpected death related to aortic diseases. A retrospective study of 31 sudden unexpected deaths caused by AAD was conducted at Xi'an Jiaotong University Forensic Center from 2001 to 2012. We summarized the forensic characteristics of AAD and assessed the clinically diagnostic accuracy of AAD. The characteristics of sudden unexpected death due to AAD were male predominant (male: female=6.7:1), relatively young with the mean age of 44, and predominance of type A dissection (77.4%). Cardiac tamponade was the most frequent cause of sudden death (87.1%). Of the 31 cases, 26 (83.9%) patients were not recognized clinically and were misdiagnosed with acute myocardial infarction, coronary artery disease, cholecystitis, acute gastroenteritis, renal/urinary lithiasis, or acute pancreatitis. In summary, AAD can be difficult to recognize, diagnosis is therefore sometimes delayed or missed. The medicolegal death investigation can help physicians have a better understanding of AAD.

Genetic diversity and haplotype structure of 24 Y-chromosomal STR in Chinese Hui ethnic group and its genetic relationships with other populations.

In the present study, 24 Y-chromosomal short tandem repeat (Y-STR) loci were analyzed in 115 unrelated Hui male individuals from Haiyuan county or Tongxin county, Ningxia Hui Autonomous Region, China, to evaluate the forensic application of the 24 STR loci and to analyze interpopulation differentiations by making comparisons between the Hui group data and previously published data of other 13 populations. A total of 115 different haplotypes were observed on these 24 Y-STR loci. The gene diversities ranged from 0.4049 (DYS437) to 0.9729 (DYS385a, b). The overall haplotype diversity was 1 at AGCU 24 Y-STR loci level, while the values were reduced to 0.999237, 0.996949, and 0.996644 at the Y-filer 17 loci, 11 Y-STR loci of extended haplotype and 9 Y-STR loci of minimal haplotype levels, respectively; whereas, haplotype diversity for additional 7 loci (not included in Y-filer 17 loci) was 0.995271. The pairwise FST , multidimensional scaling plot and neighbor-joining tree indicated the Hui group had the closest genetic relationship with Sala in the paternal lineage in the present study. In summary, the results in our study indicated the 24 Y-STRs had a high level of polymorphism in Hui group and hence could be a powerful tool for forensic application and population genetic study.

Polymorphic distribution and forensic effectiveness study of eight miniSTR in Chinese Uyghur ethnic group.

We obtained the allelic frequencies and forensic efficiency data for eight mini short tandem repeat loci including Penta E, D12S391, D6S1043, D2S1338, D19S433, CSF1PO, Penta D and D19S253 loci from a sample of 128 unrelated Uyghur individuals from China. The amplification products of the eight STR loci are <240 bp in size. A total of 94 alleles were observed and the corresponding allelic frequencies ranged from 0.0039 to 0.3438 in the present study. Observed genotype distributions for each locus do not show deviations from Hardy-Weinberg equilibrium expectations. The combined power of discrimination, combined power of exclusion and combined matching probability of the eight STR loci equaled to 0.999999999963373, 0.9997770 and 3.6627 × 10(-11), respectively. Because of the small fragment length of PCR products and the high degree of polymorphisms, the eight STR loci are highly beneficial for the forensic analysis of degraded DNA samples which are commonly observed in forensic cases. The STR data of the Uyghur group were compared with the previously published population STR data of other groups from different ethnic or areas, and significant differences were observed among these groups at some loci.

Allelic polymorphic investigation of 21 autosomal short tandem repeat loci in a Chinese Bai ethnic group.

Population genetic data of 21 autosomal short tandem repeats (STRs) were obtained in a sample of 106 unrelated healthy individuals of Bai ethnic minority born in the Dali Bai Autonomous Prefecture in Yunnan Province. We observed 138 alleles with corresponding allelic frequencies ranging from 0.005 to 0.575. The genotypic frequency distributions at those STR loci were consistent with Hardy-Weinberg equilibrium (Bonferroni's correction was used for Hardy-Weinberg equilibrium tests). The combined probability of exclusion, power of discrimination, probability of matching value for all 21 STR loci were 0.9999975729, 0.999999999999999999872 and 1.28×10(-19), respectively. The population data in this study showed significant differences from the previously published population data of Tibetan and Salar groups in some loci.

The distribution of genetic diversity of KIR genes in the Chinese Mongolian population.

Killer cell immunoglobulin-like receptors (KIRs) are expressed on natural killer cells and as such regulate their response against infection and malignancy. KIR genes are variable in gene content and type, which results in different KIR haplotypes, and can be used to discriminate individuals and populations from different regions or ethnic groups. In the present study, we represent the first report on the KIR gene frequency and content diversities of 14 KIR genes (KIR2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) and 2 pseudogenes (KIR3DP1 and 2DP1) in the Chinese Mongolian population. The 16 detected KIR genes were all observed. All the individuals were typed positive for the four framework genes KIR3DL3, 3DL2, 2DL4 and the pseudogene KIR3DP1, as well as for the pseudogene KIR2DP1. The observed carrier gene frequencies (OF) of the other KIR genes ranged from 16% at the KIR2DL2 locus to 93% at the KIR3DL1 locus. Over all, 48 different gene profiles were found in the study population and the most commonly observed KIR gene profile with a frequency of 14% consisted of KIR2DL4, 3DL2, 3DL3, 2DP1, 3DP1, 2DL1, 2DL3 and 3DL1 which belongs to the AA genotype. Principal component analysis (PCA) and the dendrogram illustrated the genetic distances between our study population and previously published populations from other ethnic groups or regions. The results of the present study show that the KIR gene family is highly polymorphic and can be a valuable tool for enriching the Chinese ethnical gene information resources, for anthropological studies, as well as for KIR gene related disease research.

Diversity distributions of killer cell immunoglobulin-like receptor genes and their ligands in the Chinese Shaanxi Han population.

In the present study, 17 killer cell immunoglobulin-like receptors (KIR) genes and KIR ligands (human leukocyte antigen [HLA] -A and -B) were detected by using a polymerase chain reaction-sequence-specific primer (PCR-SSP) method in 104 unrelated healthy Han individuals living in Shaanxi province, China. The observed carrier frequencies of the 12 KIR genes ranged from 0.14 to 0.96. KIR2DL4, 3DL2, 3DL3, 2DP1 and 3DP1 were found to be present in every individual. A total of 51 different KIR gene profiles were identified, in which 11 gene profiles exclusively belonged to the study population. Neighbor-joining phylogenetic tree between the studing population and its neighboring ethnic groups was constructed using the observed carrier frequencies of 13 KIR loci. The phylogenetic tree shows that the Shaanxi Han population, Han populations in different regions, Yi, Japanese, and Koreans were in the same cluster. KIR/HLA relationships show that KIR3DS1(-)/3DL1(+)/Bw4(+) was the most common association in the population. In conclusion, the present study findings reveal the high polymorphism of KIRs in the Shaanxi Han population, demonstrate the KIR/HLA association in the study population, and enrich the KIR and HLA gene resources. The obtained KIR data will further the understanding of genetic relationships among populations in different geographic areas, and assist in answering questions regarding KIR/HLA relationships.

Genetic polymorphism analysis of 15 STR loci in Chinese Hui ethnic group residing in Qinghai province of China.

In the present study, we investigated the diversity distributions of allelic frequencies of 15 short tandem repeats (STRs) loci in a sample of Chinese Hui ethnic group in the Ningxia Hui Autonomous Region. The allelic frequencies of the 15 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA) were obtained from 2975 unrelated healthy Hui individuals. The STR genotyping data of all the samples were generated by DNA extraction, multiple amplification, GeneScan and genotype analysis. The genetic distances among different populations were calculated by using Nei's method and a phylogenetic tree was constructed based on the allelic frequencies of the same 15 STR loci using the neighbor-joining method. A total of 185 alleles were observed in the Hui population, with the corresponding allelic frequencies ranging from 0.0002 to 0.5322. Chi-Square tests showed that all STR loci were in Hardy-Weinberg equilibrium. The forensic statistical parameters of all the loci showed high values. The population data in this study were compared with the previously published population data from other ethnics or areas. The Hui population showed significant differences from the Minnan Han, Uigur, Ewenki, Yi, Tibetan, Maonan and Malay ethnic minority groups in some loci, and from the South Morocco population and the Moroccan population in all the loci. Our results are valuable for human individual identification and paternity testing in the Chinese Hui population and are expected to enrich the genetic information resources of Chinese populations.

[Pathological characteristics of sudden death caused by coronary thrombosis].

OBJECTIVE: To explore medico-legal characteristics of sudden death caused by coronary heart disease combined with coronary thrombosis. METHODS: Ninety-six cases of sudden death caused by coronary heart disease were collected and divided into two groups: thrombus positive and thrombus negative groups. The time onset, induction and pathological features of coronary artery disease were analyzed. RESULTS: Two groups showed man-dominant population. There were no statistical significant differences in season, circadian rhythm and induction factor. The thrombus positive group (age < 40) showed a higher disease incidence. Heart weight and degree of coronary stenosis were lower in thrombus positive group. However, there was no statistical difference in the number of atherosclerotic coronary arteries (> or = 2), the length of coronary lesions and myocardial infarct. But thrombosis positive group showed lower tendency. CONCLUSION: Two groups are man-dominant population and similar induction factor, lesion position, mechanism of death. But thrombus positive group appeared more in a younger population and the degree of coronary stenosis is milder than thrombus negative group. Forensic pathologists should pay more attention to these characteristics in death investigation.

Killer cell immunoglobulin-like receptor gene diversity in the Tibetan ethnic minority group of China.

The aim of this study was to analyze killer immunoglobulin-like receptor (KIR) gene polymorphisms in the Tibetan ethnic minority of China. To that purpose, we have studied KIR gene frequencies and genotype diversities of 16 KIR genes and three pseudogenes (2DL1, 2DL2, 2DL3, 2DL4, 2DL5A, 2DL5B, 2DS1, 2DS2, 2DS3, 2DS4*001/002, 2DS4*003-007, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1, 2DP1, 3DP1*001/002/004, and 3DP1*003) in a population sample of 102 unrelated healthy individuals of the Tibetan population living in Lhasa city, Tibet Autonomous Region of China. Tibetans mainly live in "the roof of the world," the Qinghai-Tibet Plateau of China and surrounding areas stretching from central Asia in the North and West to Myanmar and mainland China in the East, and India, Nepal, and Bhutan to the south. KIR gene frequencies and statistical parameters of Tibetan ethnic minority were calculated. Fifteen KIR genes were observed in the 102 tested Tibetan individuals with different frequencies. The allelic frequencies of the 15 KIR genes ranged from 0.06 to 0.86. In addition, KIR 2DL1, 2DL4, 3DL2, and 3DL3 were found to be present in every individual. Variable gene content, together with allelic polymorphisms, can result in individualized human KIR genotypes and haplotypes, with the A haplotypes being predominantly observed. The results of tested linkage disequilibrium (LD) among KIR genes demonstrated that KIR genes present a wide range of linkage disequilibrium. Moreover, a comparison of the population data of our study with previously published population data of other ethnic groups or areas was performed. The differences of allelic frequency distribution in KIR2DL2, 2DL3, 2DL5, 3DL1, 2DS1, 2DS2, 2DS3, 3DS1, and 2DP1 were statistically significant among different populations using the statistical method of the standard χ(2) test. In conclusion, the results of the present study can be valuable for enriching the Chinese ethnical gene information resources of the KIR gene pool and for anthological studies, as well as for KIR-related disease research.

Population genetic analysis of 15 autosomal STR loci in the Russian population of northeastern Inner-Mongolia, China.

In the present study, we investigated the genetic polymorphisms of 15 autosomal STR loci in the Russian population of northeastern Inner-Mongolia, China as well as its genetic relationships with other populations. DNA typing for 15 autosomal STR loci was performed on 148 randomly selected healthy individuals from the Russian population living in Eerguna, northeastern Inner-Mongolia. Allelic frequencies of these loci were calculated by direct counting. The genotype data of this Russian population was moreover compared to other populations using neighbor-joining method, as such constructing a phylogenic tree. A total of 143 alleles were found in the Russian population with corresponding allele frequencies in the range from 0.0034 to 0.5372. Among all the 15 loci, D18S51 had the highest polymorphism (PIC = 0.8632), whereas TPOX had the lowest (PIC = 0.5179). In the phylogenic tree, this Russian population has a close relationship with the populations of South Siberia and northeastern Asia. This study may increase our understanding of the genetic background of the Russian population in Eerguna, China as such providing useful information for anthropological research, forensic sciences as well as disease-association studies.

Distributions of HLA-A and -B alleles and haplotypes in the Yi ethnic minority of Yunnan, China: relationship to other populations.

OBJECTIVE: To investigate the distributions of human leukocyte antigen (HLA)-A and -B alleles and HLA-A-B haplotypes in the Yi ethnic minority of the Yunnan Province, situated in southwestern China. METHODS: DNA typing for HLA-A and -B loci was performed using the polymerase chain reaction-sequence-based typing (PCR-SBT) method on 114 randomly selected healthy individuals of the Yi population. The allelic frequencies of HLA-A and -B loci were calculated by direct counting and HLA-A-B haplotypes were estimated using the expectation maximization algorithm. RESULTS: A total of 17 HLA-A and 38 HLA-B alleles were found in the Yi population. The most frequent alleles were A*2402 (32.46%), A*1101 (26.32%), and A*0203 (10.09%) at the HLA-A locus and B*4601 (12.28%), B*1525 (10.09%), B*4001 (8.77%), and B*3802 (7.89%) at the HLA-B locus. The predominant HLA-A-B haplotypes were A*2402-B*1525 (7.86%) and A*0203-B*3802 (5.64%), followed by A*1101-B*4001 (4.69%). Phylogenetic analysis indicates that the Yi population in the Honghe, Yunnan Province of China basically belongs to groups of southeastern Asian origin, but shares some characteristics with northeastern Asian groups. CONCLUSION: The present study may add to the understanding of HLA polymorphism in the Yi ethnic group that was poorly defined previously, and provide useful information for bone marrow transplantation, anthropological research, and forensic sciences as well as for disease-association studies.

[Gene expression profiling in drug addicted brain].

Drug addiction, a chronic brain disease caused by interaction of in vitro drug toxification and in vivo gene susceptibility, has been widely studied but its underlining mechanism is so far been elucidated. A major goal in this field is to identify drug-induced molecular changes and their effects on brain function. By the advance of high throughput technologies in genomics and transcriptomics, the whole gene expression profile in addicted brain could be obtained and proved to be a very powerful tool to unclose the molecular mechanism underlying the addiction biology context. Here, we summarized the progress of serial analysis of gene expression (SAGE) and microarray, as well as their application in drug addiction.

[The changes of Fourier transform infrared spectroscopy in rat's brain].

OBJECTIVE: To apply Fourier transform infrared (FTIR) spectroscopy to study the process of postmortem degradation of the rat brain and to provide a new way for the estimation of postmortem interval (PMI). METHODS: The rats were sacrificed by cervical dislocation and the bodies were kept in a controlled environmental chamber set at (30 +/- 2) degrees C. To measure the content of the chemical groups in postmortem rat brains at the different time points from 0 to 36 h using the FTIR spectrograph. RESULTS: With prolongation of PMI, the peak position of main absorbance bands in the FTIR spectra showed no significant changes, while the peak levels showed dramatic changes: (1) The relative peak intensity of 1080 cm(-1), 1238 cm(-1) (I1080/I1398, I1238/I1398) associated with nucleic acid decreased obviously; (2) The peak intensity ratio at Amide I, II (I1647/I1541) decreased; (3) The peak intensities at 1456 cm(-1) and 1398 cm(-1) showed a decreased and an increased trend, respectively; (4) Compared to the peak intensity of 1647 cm(-1), the peak intensities at 2852 cm(-1), 2871 cm(-1), 2923 cm(-1), and 2958 cm(-1) tended to increase, with only a slightly increased tendency in peak intensity of 2871 cm(-1). CONCLUSION: FTIR spectroscopy may be potentially used as an effective method for estimating the PMI in medicolegal practice using brain tissue sample.

[Expression of synaptophysin in experimental diffuse brain injury].

OBJECT: To investigate the changes in the expression_level of synaptophysin following diffuse brain injury (DBI) in rats and to correlate the changes of the synaptophysin expression_level with the post injury time interval. METHODS: Wister rats were used as a DBI model induced by Marmarou method. The changes of synaptophysin immunoreactivity on coronal sections of the rats sampled at different post-injury time intervals were used as a marker. The densitometry of the synaptophysin immunoreactivity was documented by imaging technique and analyzed by SPSS software. RESULTS: The expression level of synaptophysin in DBI rats showed dynamic changes following DBI as well as during the repairing period. CONCLUSION: The changes of synaptophysin level may be used as a marker for estimation of the post injury time interval in DBI.