Logistic Regression Analysis of the Mechanism of Blunt Brain Injury Inference Based on CT Images / 法医学杂志

OBJECTIVES@#To study the correlation between CT imaging features of acceleration and deceleration brain injury and injury degree.@*METHODS@#A total of 299 cases with acceleration and deceleration brain injury were collected and divided into acceleration brain injury group and deceleration brain injury group according to the injury mechanism. Subarachnoid hemorrhage (SAH) and Glasgow coma scale (GCS), combined with skull fracture, epidural hematoma (EDH), subdural hematoma (SDH) and brain contusion on the same and opposite sides of the stress point were selected as the screening indexes. χ2 test was used for primary screening, and binary logistic regression analysis was used for secondary screening. The indexes with the strongest correlation in acceleration and deceleration injury mechanism were selected.@*RESULTS@#χ2 test showed that skull fracture and EDH on the same side of the stress point; EDH, SDH and brain contusion on the opposite of the stress point; SAH, GCS were correlated with acceleration and deceleration injury (P<0.05). According to binary logistic regression analysis, the odds ratio (OR) of EDH on the same side of the stress point was 2.697, the OR of brain contusion on the opposite of the stress point was 0.043 and the OR of GCS was 0.238, suggesting there was statistically significant (P<0.05).@*CONCLUSIONS@#EDH on the same side of the stress point, brain contusion on the opposite of the stress point and GCS can be used as key indicators to distinguish acceleration and deceleration injury mechanism. In addition, skull fracture on the same side of the stress point, EDH and SDH on the opposite of the stress point and SAH were relatively weak indicators in distinguishing acceleration and deceleration injury mechanism.

A study on paternity testing with 96 autosomal SNPs / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of applying autosomal single nucleotide polymorphisms (SNPs) on parentage testing.</p><p><b>METHODS</b>All SNP genotyping results of HapMap (r27) were downloaded from the website. With self-made computer programs, SNPs were extracted when their minor allele frequency (MAF) were ≥ 0.30 among all of the 11 HapMap populations. Ninety-six SNPs were chosen and integrated into the Illumina Goldengate bead arrays on the condition that no linkage disequilibrium was found between them. Three father-child-mother trios (9 samples in total) were tested with the arrays. Cumulative paternity index (CPI) was then calculated and compared with genotyping results using 15 short tandem repeats (STRs)(Identifiler(TM)).</p><p><b>RESULTS</b>Family 1 was found to have nine SNPs or seven STRs that did not conform to the Mendelian laws, Family 2 had 13 such SNPs or seven STRs, and Family 3 only had one such SNP but no STR. For Family 3, when all of the 96 SNPs were used in combine, the CPI was 1207, which had contrasted with the CPI by the 15 STRs, i.e., 355 869.</p><p><b>CONCLUSION</b>When applied to paternity testing, the paternity exclusion (PE) value for a SNP is usually less than 1/3 of that of a STR. The proportion of SNPs not comforming to the Mendelian laws for the tested SNPs may not be as high as that of inconsistent STRs over all tested STRs. Because of the low mutation rate of a SNP, the CPI will be greatly reduced even if one SNP did not conform to the Mendelian laws. Therefore, highly accurate testing methods are required to reduce artificial errors when applying SNPs for paternity testing.</p>

Mutation analysis of pathogenic genes in a Henan family affected with congenital stationary night blindness / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect genetic mutations associated with autosomal dominant congenital stationary night blindness (ADCSNB) in a family from Henan province.</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood samples of 14 family members. Based on 3 genes reported previously, PCR primers were designed and corresponding exons containing the mutation sites were amplified with PCR. PCR products were purified and directly sequenced.</p><p><b>RESULTS</b>A c.281C>T heterozygous missense mutation was detected in RHO gene in all of the patients. This mutation can cause a change of the protein structure (p.Thr94Ile). The same mutation was not detected in normal individuals from the family and 50 normal controls.</p><p><b>CONCLUSION</b>A c.281C>T mutation in RHO gene is responsible for the onset of ADCSNB in this Chinese family and results in symptoms of night blindness.</p>

How to draw a conclusion in motherless parentage testing using short tandem repeats as genetic makers / 法医学杂志

OBJECTIVE@#To calculate the exclusion power of STR loci in motherless parentage testing and to discuss how to draw a conclusion if there are inconsistent loci.@*METHODS@#Based on the law of inheritance and allele frequency, the powers of exclusion of STR loci in motherless parentage testing (PE(M)) were calculated. Based on the mean PE(M) and mutation rate of 13 CODIS loci. The probabilities of inconsistence under paternity and non-paternity were calculated respectively according to binomial theorem.@*RESULTS@#The PE(M) of locus having co-dominate alleles could be calculated as: PE(M) = (i = 1)sigma (n) p i 2(1-p (i))2+ (i < j)sigma (n) 2p (i)p (j)(1-p (i)-p (j))2. According to the formula, the average PE(M) of 13 CODIS was 0.411. Based on the mean PE(M) and mutation rate, the likelihood ratio of true father to random man (paternity index) was got using binomial theorem.@*CONCLUSION@#The conclusion in motherless parentage testing could be drawn based on the likelihood ratio (paternity index) derived from mean PE(M) and mutation ratio.

A PCR-RFLP analysis to HLA-B gene among Chinese northern Han populations / 法医学杂志

OBJECTIVE@#To set up the method for analyzing HLA-B gene polymorphism with PCR-RFLP, and to gain population data among northern Chinese Hans of HLA-B's restricted fragments after NlaIII digestion, and to achieve application in forensic medicine practice.@*METHODS@#Sample DNA was extracted by the phenol/chloroform extraction method, 943 bp-long fragments containing HLA-B exon 2 and 3 were got by PCR. The endonuclease NlaIII was applied to cut the PCR products into polymorphic fragments shorter than 943bp, then PAGE and silver staining were used to detect the digestion results, finally the digestion sites were assured by DNA sequencing.@*RESULTS@#Along 943bp-long PCR products, 14 length-different fragments, 20 kinds of fragment combinations were got and 6 cutting site were observed after NlaIII digestion.@*CONCLUSION@#HLA-B gene was highly polymorphic among Chinese northern Hans. Even with only one endonuclease, 14 restricted fragments were got and the PIC was great. Such a HLA-B PCR-RFLP analysis will have values in forensic medicine applications.