Modeling Methods and Influencing Factors for Age Estimation Based on DNA Methylation / 法医学杂志

Age estimation based on tissues or body fluids is an important task in forensic science. The changes of DNA methylation status with age have certain rules, which can be used to estimate the age of the individuals. Therefore, it is of great significance to discover specific DNA methylation sites and develop new age estimation models. At present, statistical models for age estimation have been developed based on the rule that DNA methylation status changes with age. The commonly used models include multiple linear regression model, multiple quantile regression model, support vector machine model, artificial neural network model, random forest model, etc. In addition, there are many factors that affect the level of DNA methylation, such as the tissue specificity of methylation. This paper reviews these modeling methods and influencing factors for age estimation based on DNA methylation, with a view to provide reference for the establishment of age estimation models.

Research Progress on Computer-Aided Skeleton-Based Individual Identification in Forensic Radiology / 法医学杂志

Individual identification based on imaging data of the skeleton of a corpse is a key technique for forensic identification. To reduce the influence of artificial factors, computer-aided semi-automatic or automatic individual identification has become one of the research directions of skeleton-based individual identification in forensic radiology. Therefore, this paper reviews and summarizes literatures related to estimation of anthropological information such as, age and sex by computer-aided forensic radiology bone characteristics and individual identification based on bone imaging characteristics, in order to provide reference on skeleton-based individual identification in forensic radiology.

Forensic Application of Plant Evidence / 法医学杂志

With the increasingly obvious role of plant evidence in case detection, forensic botany, which provides clues and evidence in crime scene investigation by using botanical research method has attracted growing attention. The common experimental techniques used in forensic botany are morphological examination, physical and chemical examination, molecular genetic examination, and so on. This paper briefly expounds the advantages and disadvantages of different test methods, summarizes the problems that need to be paid attention to in the application of forensic botany by arranging the related literatures and cases of forensic botanical research, in order to provide reference for scene investigation of cases.

Relationship between RNA degradation and postmortem interval in mice / 法医学杂志

OBJECTIVE@#To investigate the degradation changes of beta-actin mRNA and 18S rRNA in different time points and temperature after death, and to explore the relationship between the changes and postmortem interval (PMI) in the brain of mice.@*METHODS@#Twenty-four health adult C57BL/6 mice were randomly divided into two groups (12 each group). They were sacrificed by cervical dislocation and placed in chamber with two different temperature (4 degrees C and 37 degrees C, humidity was 80%). The mice brains were sampled at 6 different time points(immediately, 0.5h, 2h, 6h, 24h, 48h), and total brain RNA were extracted. Ct value of each sample was obtained using RT-PCR and real-time PCR technology, and beta-actin mRNA and 18S rRNA content ratio was calculated. The correlation between the content ratio and PMI was expressed using statistical regression analysis.@*RESULTS@#At 37 degrees C, RNA degradation rate was faster than 4 degrees C, which showed that there was correlation between temperature and RNA degradation. Comparing with the stability of beta-actin mRNA, 18S rRNA was more stable.@*CONCLUSION@#The study on degradation of beta-actin mRNA and 18S rRNA in mice brain using real time PCR technology could provide a new theoretical basis for estimation of PMI and would be supplementary to the traditional methods.

Induction of hypoxia-inducible factor-1alpha in two kinds of rats asphyxiation death models / 法医学杂志

OBJECTIVE@#To investigate the expression of hypoxia-inducible factor 1-alpha (HIF1-alpha) in the heart, lung, liver and kidney in rats died of two typical models of asphyxia.@*METHODS@#Two asphyxia models were made and tissue samples of the dead rats were collected from different groups at various postmortem duration. The expression and the changes of HIF1-alpha in various tissues were examined by immunohistochemistry and image analysis techniques. Results Significant expression of HIF1-alpha was observed in the myocardial fibers, kidney cells, liver cells and lung cells in both asphyxia models, but not in the control group. The expression of HIF1-alpha in various tissues in the rat died of nitrogen gas breathing was found in the nuclei at 0 hour and the expression level decreased gradually thereafter. The HIF1-alpha expression level and duration in various tissues of the rat died of hanging were higher and longer than that of the former group, with a peak of the expression level observed 6 hours after death, and then started to decline in all tissues except the heart where the expression still showed an increase 24 hours after death. The control groups showed a steady expression in the cytoplasm but not in the nuclei.@*CONCLUSION@#HIF1-alpha appears to be a valuable biomarker in the diagnosis of asphyxia within 24 hours after death.

Therapeutic effect of a new recombinant immunotoxin mMIP-1alpha-DT390 on experimental autoimmune encephalomyelitis / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the therapeutic effect of a new recombinant immunotoxin mMIP-1alpha-DT390 on experimental autoimmune encephalomyelitis (EAE).</p><p><b>METHODS</b>EAE was induced in the low-sensitive strain C57BL/6 mice with intraperitoneal injection of myelin basic protein (MBP) to simulate the human disease multiple sclerosis, followed by intramuscular injection of cationic liposome carrying the plasmid DNA SRalpha-mMIP-1alpha-DT390 in the leg muscle to elicit resistance to EAE development. The mice were then examined daily for clinical signs of EAE by an observer blind to the treatment protocol. For immunohistochemistry the mice were anesthetized and perfused with sterile PBS and paraformaldehyde, and the cerebrum, cerebellum, medulla and spinal cord were removed for preparation of serial sections. The mononuclear cells (MNCs) from the EAE mouse spleens were prepared for three-color flow cytometry analysis of the surface markers with appropriate antibodies following the BD Pharmingen cytokine staining protocol.</p><p><b>RESULTS</b>EAE model was successfully established by active MBP immunization in C57BL/6 mice. Administration of the immunotoxin mMIP-1alpha-DT390 significantly delayed the disease onset and lowered the mean clinical score for EAE as compared with the control mice. Immunohistochemistry demonstrated much less CCR5(+) infiltrating cells in the central nervous system in mMIP-1alpha-DT390-treated mice than in the control. The treatment also eliminated reactive T cells in the periphery blood without affecting the number of B cells.</p><p><b>CONCLUSION</b>The immunotoxin mMIP-1alpha-DT390 can attenuate the disease activity of EAE in mice, suggesting its potential use in the treatment of other autoimmune disorders.</p>

Relationship between CO II gene of mtDNA of Lucilia sericata and latitude interval / 法医学杂志

OBJECTIVE@#To deduce the region that the geographical species of Lucilia sericata come from and determine the scene of crime (SOC) based on the gene analysis of mtDNA CO II.@*METHODS@#A 635 bp region for CO II of 4 Lucilia sericata (belong to 2 geographical species) were collected and sequenced, compared with the data of GenBank. A neighbour-joining tree with the Tamura and Nei model was constructed by MEGA2.1 package. The number of inherit intervals of inner-species were analyzes by Kimura's two-parameter model and used for construction the relationships between hereditary and latitude interval by SPSS10.5 soft.@*RESULTS@#It showed that they had the relationships between inherit and latitude interval for the 8 geographical species of Lucilia sericata for CO II.@*CONCLUSION@#This method can be the evidence deducing the region that the geographical species of Lucilia sericata come from and further to determine the scene of crime (SOC).

A minisequencing technique for genotyping 12 Y-SNP and its genetic polymorphisms / 法医学杂志

OBJECTIVE@#The aim of the present study was to establish a rapid and robust assay used to simultaneously genotype SNPs by the single nucleotide primer extension (minisequencing) with the SNaPshot Kit and obtain the population genetic data in Chinese population in Sichuan. The analysis of single nucleotide polymorphisms (SNPs) is a promising application in forensic casework.@*METHODS@#12 Y-SNPs, which were SRY2627, SRY1532, M13, M20, SRY8299, Tat, M69, M9, 92R7, M17, M19 and M112, were multiple amplificated and the PCR products were pooled, Purified, and then used as templates for the minisequencing reaction with the commol/Lercially available SNaPshot Kit. Then the products of minisequencing reaction were detected by capillary elcetrophoresis.@*RESULTS@#78 genomic DNA individual samples from Sichuan, China and 5 semen stain samples from sexal criminal scene were analyzed and two haplotypes could be identified.@*CONCLUSION@#A rapid method has been established to analyze the 12 Y-SNPs by multiplex PCR and minisequencing. It can be applied in forensic casework successfully.

Effect of caspase 9 related signaling molecules on the apoptosis of human vascular endothelial cell induced by homocysteine / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To understand the role of mitochondria associated signaling pathway in the apoptosis of human vascular endothelial cell induced by homocysteine (Hcy).</p><p><b>METHODS</b>The mRNA and protein expression levels of the up-stream signaling molecules of caspase 3, Bcl 2, caspase 9, and cytosolic cytochrome-c, were investigated. The in vitro cultured human umbilical vein endothelial cells with homocysteine at different concentrations were incubated for 24 h. The expressions of Bcl 2 and caspase 9 at mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction(RT-PCR) and Western blot. Cytochrome-c in cytoplasm was also detected by Western blot.</p><p><b>RESULTS</b>The expression levels of three signaling molecules were all down-regulated by homocysteine at both mRNA and protein levels in a dose-dependent manner.</p><p><b>CONCLUSION</b>Homocysteine could affect the formation of apoptosome through repressing the expression of Bcl 2 gene and release of cytochrome-c from mitochondria. Decreasing of apoptosome could disturb the activation of caspase 9. The results also indicate that the mitochondria pathway is not the major signaling pathway involved in Hcy-induced apoptosis.</p>

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>

Surgical techniques for the ureterointestinal anastomosis in continent urinary diversion / 中华外科杂志

<p><b>OBJECTIVE</b>To compare the complications of direct and antirefluxing techniques of ureterointestinal anastomosis in continent urinary diversion.</p><p><b>METHODS</b>Sixty-three patients underwent continent urinary diversion. Twenty-four patients were treated by the direct ureteroenteric anastomosis and the others treated by the antirefluxing technique. The follow up studies included following-up the information of ureteric stricture, ureteric reflux, renal function and acute urinary infection. It was assessed for 3 months to 6 years with a mean follow up of 26 months after operation.</p><p><b>RESULTS</b>Of 78 ureters reimplanted using antirefluxing technique. A total of 12 ureters had anastomotic stricture formation postoperatively. Only one of 48 ureters reimplanted using direct anastomoses had anastomotic stricture. The difference between the direct and antirefluxing technique groups was remarkable (chi2 = 4.375, P < 0.05). Furthermore, there was no significant difference between the direct and antirefluxing technique groups in regard to ureteric reflux, renal function and acute urinary infection.</p><p><b>CONCLUSIONS</b>Antirefluxing anastomoses resulted in obviously higher rate of ureterointestinal anastomotic stricture in comparison with the direct anastomosis. The direct ureteroenteric anastomosis may be the suitable choice for patients undergoing continent urinary diversion.</p>

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.