Objective　Exploring how to check the proportional hazards assumption of the Cox model,and the solutions to non-proportional hazards between the covariates and the hazard function.Methods　With a example data set of Ⅲc stage ovarian serous cystadenocarcina,illustrating how to use graphical methods to check the proportional hazards assumption of the Cox model.Results　the predictor of post-surgery administering medicine times violated the proportional hazards assumption of the Cox model.Conclusion　when using the Cox model to analyze the predictors of survival time,checking whether the predictors violate the proportional hazards assumption of the Cox model or not should be paid attention to.

Objective To analyze the association of the single nucleotide polymorphism (SNP) of Toll-like receptor 7 (TLR7) and Toll-like receptor 9 (TLR9) with chronic hepatitis C virus (HCV)infection.Methods A total of 150 patients with chronic hepatitis C (CHC) admitted to Renmin Hospital of Wuhan University from January 2011 to May 2012 and 168 healthy controls were enrolled in the study.The genotypes of TLR7 IVS2-151 (rs179009) were detected by Sanger sequencing,and the genotypes of TLR9 T-1486C (rs187084) were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).SPSS 15.0 was used for statistical analysis,and goodness-of-fit test for HardyWeinberg equilibrium was also performed.Results The frequency of TLR7 IVS2-151G was higher in malepatients with CHC than that in male controls (41.4％ vs.21.6％,x2 =7.250,P =0.007,OR =0.389,95％ CI:0.194-0.781) ; however the female CHC patients had a higher frequency of TLR7 IVS2-151A than the female controls (76.9％ vs.63.1％,x2 =7.202,P =0.007,OR =1.942,95％ CI:1.192-3.164).No significant difference in the distribution of TLR9 T-1486C (rs187084) gene SNP was observed betweenCHC and control groups (P ＞0.05).Conclusion TLR7 IVS2-151 (rs179009) is correlated with HCV infection,which may be involved in the pathogenesis of CHC.

Objective To investigate expression of slug and E-cadherin in pancreatic cancer tissues and determine the inhibitory effects of anti-Slug, an anti-sense plasmid, on the invasion of pancreatic cancer cell lines in vitro. Methods Slug and E-cadherin protein and mRNA was analyzed by IHP and RT-PCR in 36 cases of pancreatic cancer. Then anti-Slug plasmid was transfected into herin and Slug expression. The inhibitory effects of anti-sense Slug were also detected by Transwell motility assay and Matrigel invasion assay. Results The expression of Slug and mRNA in metastatic pancreatic cancer tissue was higher than that in non-metastatic tissue. E-cadherin and mRNA was lower in metastasis tissues(P＜0.05). The inverse relationships were further observed by transient transfection of anti-Slug into SW1990H4 cells. The downregulated expression of Slug and re-expression of E-cadherin were found. The Slug mRNA levels were 0.985±0.016,0.973±0.014, 0. 554±0. 011 after 0, 48 h of transfection of anti-sense Slug, and that of E-cadherin were 0.120±0.001, 0.360±0.002, 0. 727±0. 006, respectively. The diference was significant between different time points (P＜0.05). The Slug mRNA levels were 0. 206±0.017, 0.968±0.015, and that of E-cadherin were 0. 18±0.002,0.727±0.006 after stable transfection of anti-sense Slug, and control plasmid, respectively. The diference was significant (P＜0.05). The motility activity(393±28, 352±24, 96 ±13 )and the invasion activity (223 ± 69, 202 ± 64, 65 ±19) of1 antisense Slug transfectant cells were significantly decreased as compared with those of control cells (P＜0.05). Conclusions Higher expression of slug and lower expression of E-cadherin is related to the invasion and metastasis in pancreatic cancer. A reverse corelation of E-cadherin and Slug expression exists in pancreatic cancer. Slug is possibly a potential target for cancer gene therapy blocking invasion and metastasis in human pancreatic cancer.

BACKGROUND: Measuring result of the lower limb alignment is often influenced by various factors, such as femoral bowing angle (FBA) in different positions.OBJECTIVE: To measure the FBA and femoral valgus correction angle (VCA) in different positions after CT reconstruction of lower limb model, and simulating X-ray examination, and to explore the rule of FBA affecting lower limb alignment.METHODS: Twenty patients undergoing CT angiography of lower extremity artery were enrolled, three-dimensional reconstruction of low limb was established on Mimics13.0 software based on CT data, and the FBA in standard posture was determined. All patients were divided into groups A (FBA > 2°), B (2° > FBA > 0°), C (0° > FBA > -2°) and D (FBA <-2°) (n=5 per group). Then each model was revolved through the vertical axis from 20° of internal rotation to 20° of external rotation by 2° for one motion, and 21 three-dimensional images were transformed into two-dimensional images to obtain the X-ray images of low limb. FBA and VCA in different positions were measured.RESULTS AND CONCLUSION: (1) The outcome measurements showed that FBA tended to be decreased in internal rotation and increased in external rotation. (2) VCA tended to be increased in external rotation and decreased in internal rotation. (3) FBA was positively correlated with VCA in the different positions (P < 0.01). (4) These results suggest that FBA can be altered with rotation and even expose influence on VCA. The bigger FBA is, the more influence on the lower limb alignment. Therefore, it is advisable to conduct the full length X-ray of lower limb in a standard posture, especially for the patients with larger FBA.

OBJECTIVETo evaluate the relationship between osteopontin gene genetic polymorphisms and susceptibility of nasopharyngeal carcinoma in Guangxi Zhuang people.

METHODSWith a hospital based case-control study, osteopontin gene polymorphisms were compared between patients with nasopharyngeal carcinoma and healthy outpatients as a controls in Zhuang population in Guangxi. The single nucleotide polymorphisms at rs1126772 and rs9138 sites of the osteopontin gene were determined by polymerase chain reaction-single base extension technique (PCR-SBE) and DNA sequencing technology. The comparison between genotype and allele frequency distribution differences in case and control group was accomplished by a χ(2) test. The frequencies of haplotypes in osteopontin gene in different groups were analyzed.

RESULTSThere were no differences between the patients and controls in the genotype or allele frequencies of osteopontin gene rs1126772 site (

GA/GGOR = 0.94, 95%CI 0.37-2.37, χ(2) = 0.182, P = 0.891; AA/GG:OR = 0.86, 95%CI 0.35-2.12, χ(2) = 0.834, P = 0.773) or rs9138 site (

CA/CCOR = 1.42, 95%CI 0.88-2.29, χ(2) = 2.023, P = 0.155; AA/CC:OR = 1.77, 95%CI 0.78-4.01, χ(2) = 1.901, P = 0.168). The frequency of GA haplotype in the patients was significantly higher than that in the controls (P = 0.003), and the GA haplotype was associated with a significantly increased risk of nasopharyngeal carcinoma (OR = 4.84, 95%CI 1.59-14.71).

CONCLUSIONThe haplotype GA of osteopontin gene rs1126772 and rs9138 sites increases the risk of nasopharyngeal carcinoma in Guangxi Zhuang people.

Carcinoma ; Case-Control Studies ; China ; Disease Susceptibility ; Gene Frequency ; Genetic Predisposition to Disease ; epidemiology ; Genotype ; Haplotypes ; Humans ; Nasopharyngeal Neoplasms ; epidemiology ; genetics ; Osteopontin ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Single Nucleotide

Objective To investigate the associations of single nucleotide polymorphism of ( SNP ) of rs77418916 and rs8108402 in miR-181 with the risk of systemic lupus erythematosus ( SLE) in the Chinese population of Guangxi. Methods The lymphocyte sub-sets were analyzed by flow cytometry. The SNPs of miR-181 gene were detected by single nucleotide primer extension assay with SNaP-shot and DNA sequencing method. The relative expressions of miR-181a and miR-181c in mononuclear cells were detected by real time RT-quantitative PCR. Results The polymorphism of rs8108402 locus contained CC, CT and TT genotypes. The frequencies of CT and TT genotypes as well as the dominant and recessive model were different significantly between SLE group and control group ( CT vs CC:OR=1.50, 95％CI:1.03 to 2.19, P=0.033; TT vs CC: OR=2.65, 95％CI: 1.18 to 5.98, P=0.019; CC/CT vs TT: OR=2.23, 95％CI:1.01 to 4.93, P=0.048;TT/CT vs CC:OR=1.61, 95％CI:1.12 to 2.31, P=0.010) . The polymorphism of rs77418916 locus contain AA, AT and TT genotypes, but no association between rs77418916 polymorphism and susceptibility of SLE was found. The rel-ative expressions of miR-181a and miR-181c genes in SLE group were down-regulated compared with control group ( Z=-3. 22, P<0.01 and Z=-3.24, P<0.01, respectively) , and the patients carrying rs8108402 CT and TT genotype showed lower level of miR-181c compared with the patients carrying CC genotype (Z=-2.51, P<0.05). The absolute numbers of CD3+, CD4+, CD8+ and NK cells were decreased significantly in SLE group compared with that of control group ( P<0.01) . Conclusion The polymorphism of miR-181c rs8108402 may associate with the susceptibility of Chinese SLE patients in Guangxi region. The risk of SLE may increase in the individ-uals caring CT or TT genotype by decreasing the expression of miR-181c gene.

Objective To investigate the effect of exosomes secreted from human lung adenocarcinoma A549 cells under hypoxic or normoxic conditions on the radiosensitivity and invasiveness of normoxia cells.Methods A549 cells were cultured in hypoxic (1％ O2) and normoxic (21％ O2) conditions,respectively.The exosomes (N-EXO and H-EXO) secreted from normoxic or hypoxic A549 cells were collected by ultracentrifugation and its number was measured using a NanoSight detector.The appearance and size distribution of exosomes were observed by a scanning electron microscopy.The exosomal marker protein CD63 was measured by Western blot.The proliferation of cells exposed to X-rays under hypoxic or normoxic conditions were detected by CCK8 assay.The cell uptake situation of exosomes labeled with PKH67 was observed by a fluorescence microscopy.Cell migration and invasiveness were detected by a cell scratch test and transwell assay.The expression of matrix metalloproteinase 2 (MMP2) and MMP9 was detected by ELISA.Cellular radioresistance effect of exosomes was evaluated by a colony formation assay.Results The NanoSight measurement showed the number of exosomes in cell culture medium was increased after hypoxia treatment.The H-EXO and N-EXO showed typical ring cake shape.The size distribution of H-EXO was mainly between 30 nm and 200 nm,smaller than that of N-EXO (50-220 nm).Western blot assay showed that CD63 was expressed in both H-EXO and N-EXO.At 4 and 6 days after 2 Gy X-rays irradiation,cell proliferation rate of hypoxia A549 cells was significantly higher than that of normoxia cells.The green fluorescent marker of exosomes,PKH67,was distributed inside of the cell.Cell scratch test showed that the width of H-EXO group was much smaller than that of N-EXO group at 12,24 and 48 hours after exosomes treatment (t =2.96,6.76,3.35,P ＜ 0.05).Transwell assay showed that the number of transmembrane cells in the H-EXO group was more than that in the N-EXO group and the control group (t =4.84,7.88,P ＜ 0.O1).The expression levels of MMP2 (t =4.70,3.21,P＜0.05) and MMP9 (t =5.61,3.76,P＜0.05) in the supernatant of H-EXO group were significantly higher than those in the control and N-EXO groups.Cell survival assay showed that the D0 values of control,N-EXO and H-EXO group were 2.614,2.552 and 4.50 respectively,indicating that H-EXO could enhance radioresistance of A549 cells significantly.Conclusions This study finds that the number of exosomes released from A549 cells was increased under hypoxic condition but its size becomes smaller than that under normoxia.Hypoxic exosomes can promote the migration of normoxia cells andenhance cell radioresistance as well.

Myxococcus xanthus is a Gram-negative soil bacterium capable of performing sophisticated cellular behaviors and growing one of the most intricate bacterial single-species biofilms in nature. During the process of biofilm formation, social behaviors of M. xanthus cells dominate key steps of the biofilm establishment, e.g., cellular motility on solid surface, predatory behavior by the grouped cells, kin recognition in the community, fruiting body development, myxospore differentiation, and programmed cell death. This review introduces the recent research progress about the M. xanthus biofilms.