DNA methylation is an important epigenetic system. It plays many crucial roles in the gene regulation. With the development of the high-throughput detection techniques, the bioinformatics study has been an active hot topic in the research of DNA methylation. The major achievements and progress on the prediction of DNA methylation status, the mechanism that the majority of CpG islands are resistant to DNA methylation, the relationship between DNA methylation and other epigenetics, as well as the association between aberrant DNA methylation and the tumorigenesis were reviewed in this article.

Objective To observe the changes of coagulase activity and the DNA expression of coagulase of S.aureus during inducing vancomycin-resistant S.aureus in vitro.Methods Coagulase activity and DNA expression of coagulase of S.aureus were detected.Results The coagulase activity in 6 strains and the expression of coagulase DNA in 1 strain reduced.Conclusion Decreased coagulase activity and DNA expression are probably linked to vancomycin resistance of S.aureus.

Objective To induce vancomycin-resistantant S.aureus in vitro and to observe the changes of coagulase gene sequences of S.aureus and its relationship with vancomycin resistance.Methods DNA sequences of the coagulase were examined by polymerase chain reaction-sigle strand conformation polymorphism(PCR-SSCP) method and were identified by sequencing.Results The altered DNA sequence of coagulase in 1 strain of S.aureus was found.Conclusion The variation of DNA sequences of coagulase gene is probably linked to vancomycin-resistance in S.aureus.

Objective To evaluate serum Slit2 protein level in patients with chronic severe hepatitis B,and the re-lation with extent of liver damage and prognosis of patients.Methods In February-July 2014,patients with chronic hepatitis B(chronic hepatitis group)and chronic severe hepatitis B(chronic severe hepatitis group)in an infectious department were observed,healthy volunteers were as control group,and patients in chronic severe hepatitis group were subdivided into recovery subgroup and non-recovery subgroup based on whether patients had recovered.Serum Slit2 protein,prothrombin activity (PTA),total bilirubin (TBIL),and alanine transaminase (ALT)levels were detected and compared.Results A total of 157 patients (chronic hepatitis group,n =93;chronic severe hepatitis group,n=64)and 10 healthy volunteers were included in the study .Slit2 protein levels were significantly different among three groups(F =5.596,P =0.004),serum Slit2 protein levels in chronic hepatitis group and chronic severe hepatitis group were (4.90±1 .07)ng/mL and (3.09±1 .00)ng/mL respectively,both were higher than (2.10± 0.60)ng/mL in healthy control group (both P <0.05);serum Slit2 protein level in chronic severe hepatitis group was significantly lower than chronic hepatitis group (P <0.05).Serum Slit2 protein level in non-recovery subgroup of chronic severe hepatitis group was significantly lower than recovery subgroup ([1 .88±0.67]ng/mL vs [2.96± 1 .32]ng/mL,t=2.319,P =0.032).Serum Slit2 protein level in patients with chronic hepatitis B was positively correlated with PTA level(r=0.33,P <0.05),but negatively correlated with serum TBIL level (r =-0.46,P <0.05)and ALT level (r=-0.32,P <0.05).Conclusion Serum Slit2 protein level is an important index which can re-flect the prognosis of patients with chronic severe hepatitis,low serum Slit2 level suggests the poor clinical prognosis.

Objective This study was designed to analyze the proteome differences between cancer tissue and surrounding-cancer tissue using Two-Dimensional Gel Electrophoresis (2-DE) in patients with HBV relative HCC.Methods Immobile phase pH gradients (IPGs) for isoelectric focusing of proteins were used as the first dimension,and SDS-polyacrglamide gel electrophoresis(PAGE) as the second dimension. The gels were stained by silver, scanned by ImageScanner, analyzed with ImageMast software.Results Average spots expressed in cancer tissue,cirrhosis tissue and chronic hepatitis tissue were significantly different(P

Objective:To investigate the role of FASL and TRAIL in the AICD (activation induced cell death) of PBLs in patients with chronic hepatitis B.Methods:The PBLs of 20 nonnal control,24 patients with chronic hepatitis B and 24 patients with chronic severe hepatitis B were isolated and cultured with or without phytohemagglutinin( 10 pig/ml) for 48 hours in vitro. After incubation,the cells were harvested by centrifugation and the expression of FASL.,TRAIL in PBLs was assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) and im-munohistochemical staining (SABC Method) .Results-.The expression of FASL mRNANTRAIL mRNA was undetectable in the resting PBLs of three investigated groups, but it was obviously increased after PHA stimulation in vitro. In comparison with the group of normal controls, the expression of FASL mRNA,TRAIL mRNA in PBLs was significantly higher in the group of patients with chronic hepatitis B( P

Objective To investigate the influence of HCV core protein on cell apoptosis, cell cycles and cell telomerase activities of HepG2 cells. Methods A eukaryotic expression plasmid containing HCV C gene was constructed by DNA recombinant technique and the recombinant plasmid was transfected into HepG2. Thereafter, HepG2 cells transfected with recombinant eukaryotic expression plasmid were obtained. The HCV C mRNA and protein in HepG2 cells transfected with recombinant plasmid were verified by RT PCR and indirect immunofluorescence assay. The HepG2 cells were studied as follows: (1) The cell proliferation ratio of three groups cells(HepG2 cells transfected with the recombinant plasmid, HepG2 cells transfected with blank plasmid and HepG2 cells without transfection) was evaluated by MTT assay; the cell cycles were also examined by FACS. (2) The apoptotic ratio of three groups cells were examined by FACS. (3) The cell telomerase activities of all three group cells were examined by TRAP ELISA assay. Results (1) The cell proliferation ratio in the group of HepG2 cells transfected with recombinant plasmid was higher than that of the group of HepG2 cells transfected with blank plasmid or the group of HepG2 cells without transfection; The proportion of phase S in the group of HepG2 transfected with the recombinant plasmid was significantly higher than that of the group of HepG2 without transfection. (2) The apoptotic ratio in the group of HepG2 cells transfected with recombinant plasmid was significantly lower than that of the group of HepG2 cells transfected with blank plasmid or the group of HepG2 cells without transfection. (3) There were no significant differences among the three group cell telomerase activities. Conclusions (1) HCV C protein had the potential role in inhibiting cell apoptosis. (2)HCV C protein could induce HepG2 cells from phase G 0/1 to phase S, and might promote cell proliferation, inhibit cell apoptosis. (3) HCV C protein had no influence on cell telomerase activities of HepG2 cells, thus HCV C protein regulated cell cycle, promoted cell proliferation and inhibited cell apoptosis not by enhancing cell telomerase activities.

OBJECTIVE To investigate the drug resistance and the prevalence of inducible clindamycin resistance in clinical isolates of Staphylococcus aureus and evaluate the clinical value of cefoxitin disk diffusion method and oxacillin disk diffusion for detection of meticillin-resistant S.aureus(MRSA).METHODS Bacteria identification and susceptibility test were performed by VITEK-2 system and K-B disk method.The PBP2a was detected by latex agglutination and MRSA was identified by cefoxitin disk diffusion method and oxacillin disk diffusion.The inducible resistance of erythromycin to clindamycin was checked by D-test according to the standards of CLSI(NCCLS).The statistical analysis was performed by WHONET 5.4 and SPSS 13.0 software.RESULTS Resistant rate to penicillin and ampicillin was 98.9% and 100.0%,respectively.Vancomycin-resistant(VRE) or intermediate strains were not found.Of the 93 S.aureus isolates,MRSA and meticillin-sensitive S.aureus(MSSA) were 58(62.4%) and 35(37.6%),respectively.The resistant rate of MRSA to 11 antibiotics was higher than MSSA.The sensitivity and specificity of cefoxitin disk diffusion method were 98.3% and 97.1%,respectively,those of oxacillin disk diffusion were 75.9% and 94.3%.Of the 9 isolates resitant to erythromycin but susceptible to clindamycin,5(55.6%) showed inducible resistance to clindamycin.CONCLUSIONS Resistance of S.aureus is quite serious.Cefoxitin disc diffusion method is a simple and reliable method for the detection of MRSA.The inducible resistance of erythromycin to clindamycin in S aureus should be checked by D-test in clinical microbiology laboratory routinely.

Objective To investigate the expression of oncogenes and tumor suppressor genes in hepatitis B virus (HBV) related hepatocellular carcinoma (HCC). Methods mRNA was extracted from cancerous and paracancerous tissues of 22 patients with HBV related HCC and synthesized into cDNA. The cDNA labeled with 33p dATP was hybridized for cDNA microarray each consisting of 3170 genes or expressed sequence tags (EST). The differential expression genes were searched in gene data base and verified using RT PCR. Results The differential expression of 1369 genes or EST was identified including 121 genes or EST altered 2 times or more in cancerous tissues compared with paracancerous tissues. Compared with paracancerous tissues, 88 showed overexpression and 33 genes were down regulated. The positive expression of transmembrane 4 superfamily member 1 (TM4SF1) in cancerous tissues was 86.4 % and could not be detected in paracancerous tissues (P

Objective To evaluate the clinical value of epicardial echocardiographic examination in cardiac valve surgery.Methods Epicardial echocardiography were performed in 46 patients undergoing valvular plasty or valvular replacement surgery to estimate the function of valve and left ventricle and residual shunt during cardiac surgery.Results Twelve cases of 46(26.1％)showed abnormality during cardiac surgery.Two cases of 15 patients performed valvuloplasty were changed to valvular replacement because of remarkable regurgitation of native valves.There was 1 case of periprosthetic leakage,3 cases of left atrial appendage thrombus,1 case of patent foramen ovale and 5 cases of low ejection of left ventricle in all 31 cases of valvular replacement.Conclusions Epicardial echocardiograpyc examination is an effective examination in cardiac valve surgery with clearly image,simplicity operation and promptness.