Molecular Genetic Analysis of One Sudden Unexplained Death in the Young by Whole Exome Sequencing / 法医学杂志

OBJECTIVE@#To find the mutation of disease-causing genes of sudden unexplained death syndrome (SUDS) in the young by whole exome sequencing in one case.@*METHODS@#One SUDS case was found no obvious fatal pathological changes after conventional autopsy and pathological examination. The whole exome sequencing was performed with the Ion Torrent PGM™ System with hg19 as reference sequence for sequencing data. The functions of mutations were analyzed by PhyloP, PolyPhen2 and SIFT. A three-step bioinformatics filtering procedure was carried out to identify possible significative single nucleotide variation (SNV), which was missense mutation with allele frequency < 1% of myocardial cell.@*RESULTS@#Four rare suspicious pathogenic SNV were identified. Combined with the analysis of conventional autopsy and pathological examination, the mutation MYOM2 (8_2054058_G/A) was assessed as high-risk deleterious mutation by PolyPhen2 and SIFT, respectively.@*CONCLUSION@#Based on the second generation sequencing technology, analysis of whole exome sequencing can be a new method for the death cause investigation of SUDS. The gene MYOM2 is a new candidate SUDS pathogenic gene for mechanism research.

Estimation of postmortem interval by detecting thickness of cornea using ultrasonic method / 法医学杂志

OBJECTIVE@#To explore the postmortem changes of cornea thickness measured by ultrasonic pachymetry.@*METHODS@#Eleven rabbits were randomly divided into two groups: one group with intact corneal epithelium and another group without intact corneal epithelium. In the later group, the corneal epithelium of the rabbit was scraped using mechanical elimination method. The corneal thickness was monitored continuously by ultrasonic pachymetry at several postmortem interval points in rabbits of the two groups. The changes of corneal thickness and postmortem interval were explored by relative regression analysis.@*RESULTS@#The thickness of the cornea showed a strong non-linear correlation with the postmortem interval in the group with intact corneal epithelium. The group with intact corneal epithelium showed the correlation coefficient 0.922 and the group without intact corneal epithelium showed the correlation coefficient 0.822, respectively.@*CONCLUSION@#The corneal thickness measured by ultrasonic pachymetry shows a potential value for estimating early postmortem interval. The intact corneal epithelium is a crucial factor for the measurement of cornea thickness by ultrasonic pachymetry.

A population genetic study of 22 autosomal loci of single nucleotide polymorphisms / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate polymorphisms and forensic efficiency of 22 non-binary single nucleotide polymorphism (SNP) loci.</p><p><b>METHODS</b>One hundred ethnic Han Chinese individuals were recruited from Dongguan, Guangdong. The 22 loci were genotyped with matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS).</p><p><b>RESULTS</b>Nine loci were found with a single allele, 4 loci were found to be biallelic, whilst 9 loci were found to have 3 alleles. For 13 polymorphic loci, the combined discrimination power and power of exclusion were 0.999 98 and 0.9330, respectively. For the 9 non-biallelic loci, the combined discrimination power and power of exclusion were 0.9998 and 0.8956, respectively. For motherless cases, the combined power of exclusion was 0.6405 for 13 polymorphic SNPs and 0.6405 for 9 non-binary SNPs.</p><p><b>CONCLUSION</b>Non-binary loci have a greater discrimination power and exclusion power per SNP.</p>

Pericytes are correlated with the permeability of rat corneal neovascular vessels induced by alkali burn / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Corneal neovascular leakage can lead to edema and secondary scarring. Previous studies have shown that pericytes play a key role in maturation of angiogenesis. The present studies investigate the relationship between vascular permeability and pericyte coverage of endothelial cells in rat corneal neovascular induced by alkali burns.</p><p><b>METHODS</b>Corneal neovascular vessels induced by alkali burns was performed in Sprague-Dawley rats. Corneas were excised on 1, 2, 3, 5, 7 and 10 days after cauterization. The vascular permeability rate was measured by the Evans blue method. The microvessel pericyte coverage index (MPI) was applied to quantify the pericyte coverage through double immunofluorescent staining of frozen sections of corneas with CD31 as the endothelial and alpha-smooth muscle actin (alpha-SMA) as the pericyte markers. The correlation between permeability rate and MPI was analyzed. Pericyte coverage was confirmed ultrastructually using transmission electron microscopy.</p><p><b>RESULTS</b>The vascular permeability rate was (1.14 +/- 0.17), (0.24 +/- 0.08), (0.29 +/- 0.16), (0.14 +/- 0.10), (0.09 +/- 0.06) and (0.05 +/- 0.04) microg x ml(-1) x mm(-2) respectively on 1, 2, 3, 5, 7 and 10 days after cauterization. The MPI was 0, 16.07%, 11.95%, 43.84%, 73.97% and 86.21% respectively at the above mentioned time points. The correlation coefficient between MPI and the permeability rate was -0.943 (P = 0.005).</p><p><b>CONCLUSIONS</b>Pericyte recruitment was significantly correlated with the permeability of corneal neovascularization induced by alkali burns in rats. Therapeutic strategies aiming at anti-leakage should be most effective if they promote pericytes proliferation in the course of corneal neovascularization.</p>