Sequence polymorphisms of the mitochondrial DNA control region in 100 Chengdu Hans in China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the genetic polymorphisms of the mitochondrial DNA (mtDNA) control region in Chengdu Han population.</p><p><b>METHODS</b>Sequence polymorphisms of the mtDNA control region, hypervariable regions I and II from 100 unrelated Chinese Hans were determined by PCR and direct sequencing.</p><p><b>RESULTS</b>Sequences of 404 nucleotides for hypervariable region I and 379 nucleotides for region II were obtained. Ninety-two and fifty variable sites were revealed in region I and region II respectively as compared to the reference sequence, and a total of 97 different genetic patterns from both the regions I and II were determined. The probability of identity was estimated at 1.84% for region I, 1.94% for region II, and 1.18% for both the regions.</p><p><b>CONCLUSION</b>These results suggest that sequence polymorphism of mtDNA control region would be very useful in forensic practice as a marker for individual identification.</p>

The expression of bFGF and its receptor FGFR1 in rat after fluid-percussive brain injury / 法医学杂志

OBJECTIVE@#Study on the pattern of changes of bFGF and FGFR1 immunoreactivity occurred in the experimental brain injury model for the purpose of providing the scientific basis for molecular pathological diagnosis, forensic identification, clinical treatment as well as further ascertaining the molecular mechanism of brain injury.@*METHODS@#Male SD rats were divided into normal control, sham operation control and injury groups. The rats of injury groups were subjected to moderate lateral fluid percussion brain injury (0.2 mPa). The injury groups were then subdivided into 30 min, 1, 3, 6, 12 h, 1, 3, 7 d groups according to the time elapsed after injury. The SP immunohistochemistry method was used to examine the expression of both bFGF and FGFR1 factors in rat brain.@*RESULTS@#In the brain of normal control and sham operation control groups, the low expression levels of bFGF and FGFR1 were observed. The increase of bFGF and FGFR1 immunoreactivity could be observed 6 h after injury in cortex and brain stem, reached to the peak at 1 d and remained at the high level up to 3 d, then partly declined at 7 d. In hippocampus, however, the increase occur as early as 3 h after injury, reached to the peak at 1 d and then decreased progressively, and returned to basal level at 7 d.@*CONCLUSION@#The results suggested that brain injury induced the gene expressions of bFGF and FGFR1. The bFGF may contribute to maintenance of nerve cell survival and the repair of damaged neural tissues after CNS injury and the patterns of their level change were quite regular and can be used for timing of injury in forensic medicine aspect.

A population study of three Y-STR loci by multiplexing in Han population in Chengdu, China / 法医学杂志

OBJECTIVE@#To establish a better method determining three Y-STR loci.@*METHODS@#A multiplex of Y-STRs and amplify simultaneously three Y-STRs loci.@*RESULTS@#Establish successfully a multiplexing system of three Y-STR loci (DYS390, DYS391 and DYS393) followed by a population genetic study of Han population in Chengdu, China.@*CONCLUSION@#The diversity of haplotype is 0.8965, the value of discrimination and the chance of exclusion chance is 0.8965 with the standard error 0.0081. This established system is one of the good tools in personnel identification and genetic study.

DNA-based technique and species identification / 法医学杂志

The species identification plays a key role in forensic analysis. Generally, three methods have been applied for this purpose, they are morphologic-based, serologic-based and DNA-based techniques. This review mainly discussed the DNA-based technique and evaluate it's value in species identification of forensic science.

Genetic polymorphism of the STR DXS9898 locus in Han population / 法医学杂志

OBJECTIVE@#Studying the genetic polymorphism of X-STR locus DXS9898 in Han population.@*METHODS@#296 unrelated Chinese individuals (199 females and 97 males) living in Chengdu were investigated using PCR and PAG electrophoresis followed by silver staining.@*RESULTS@#6 alleles were observed and the range of fragment size was 189-214 bp. The genotype distribution of DXS9898 locus was in accordance with Hardy-Weinberg equilibrium. Family survey confirmed Mendelian inheritance of alleles. The observed heterozygosity in females was 0.5930, the discriminating power (Dp) were 0.5667 and 0.9420 for males and females respectively. The power of exclusion were 0.5862 and 0.4392 for trio and duo respectively.@*CONCLUSION@#The results demonstrated that the locus is highly polymorphic and can be used in forensic identification and parentage testing.

A study of genetic polymorphism of the STR locus D2S441 in Chinese Han population in Chengdu / 法医学杂志

Using PCR and PAG, followed by silver staining, the tetrameric STR D2S441 locus was studied in 260 unrelated Chinese individuals living in Chengdu. 9 alleles and 26 genotypes were observed. The range of fragment size was 131 bp to 155 bp. The genotype distribution of D2S441 locus in Han population was in accordance with Hardy-Weinberg equilibrium. Family survey confirmed Mendelian inheritance of alleles. The discriminating power (Dp), observed heterozygosity (H), polymorphism information content (PIC) and power of exclusion (PE) were 0.9084, 0.7885, 0.7390 and 0.5778 respectively. The results demonstrated that this locus was highly polymorphic and could be used for forensic identification and paternity testing.

Recent progress of study on single nucleotide polymorphisms / 法医学杂志

Single nucleotide polymorphisms (SNPs) is a new genetic marker system following RFLP and microsatellite polymorphism. It has been shown to have the characteristics of high-density, inheritance stability and facilitation in analysis automation. SNPs can be detected by electrophoresis, endonuclease-cleavage, PCR and sequencing, and can be used extensively in gene mapping, disease-correlativity analysis, population genetics and drug research.

A study on pathological changes of closed diffuse brain injury in rats with H.E., esterification-silver stain and albumin immunohistochemical stain / 法医学杂志

OBJECTIVE@#To observed the pathological changes of closed diffuse brain injury in the rats died immediately and 15 min to 5 days after the injury.@*METHODS@#H.E. staind and esterification-silver stain were applied to investigate the closed diffuse brain injury.@*RESULTS@#In rats died immediately after the concussive injury, a number of shrunken neurons(type I change), distended neurons(type II change) and wave-like nerve fibers were identified in the brain tissue, especially in brain-stem. At 2 h and 8 h after injury, brain edema and axonal swelling appeared clearly in the cortex and white matter, especially in brain-stem. At post-traumatic 8 h and 24 h, the axonal retraction balls began to appear. The amount of neurons undergoing type I and II changes and constraction balls increased along with the survivor time. After 4 days and 5 days, brain edema alleviated, but the retraction balls and axonal swelling still existed. With Esterifica-tion silver stain, the above changes of neurons and nerve fibers were more obvious. With ABC stain, the distribution of albumin(Al) was extended from the perio-vascular area to diffuse distribution. Al positive staining were more obvious in injuried neurons and nerve fibers.@*CONCLUSION@#The distribution of the concussive damage in the brain are coup, contra-coup and centripental.