Objective To evaluate the prognostic value of RAS association domain family 1A gene (RASSF1A) methylation in patients after hepatocellular carcinoma (HCC) hepatectomy.Methods A total of 260 patients with HCC who underwent hepatectomy were enrolled.HCC tissues and tumor adjacent tissues which were 2 cm away from the tumor edge of the patients were obtained.The clinicopathological data of patients were collected.The methylation of RASSF1A in HCC tissues and corresponding tumor adjacent tissues was determined by methylation specific polymerase chain reaction (PCR).The correlation between the expression rate of RASSF1A methylation and clinicopathological characteristics was analyzed by chi-square test.Log-rank test was performed to analyze the relation between RASSF1A methylation and overall survival rate.Univariate and multivariate Cox statistical techniques were used to identify the influence factors in the prognosis of HCC.Results Among 260 HCC tissues and corresponding tumor adjacent tissues,RASSF1A promoter hypermethylation was detected in 214 HCC tissues (82.3 ％) and 101 corresponding tumor adjacent tissues (38.8％),and the difference was statistically significant (x2 =102.824,P ＜ 0.01).There was no correlation between RASSF1A methylation and age,gender,liver cirrhosis,α-fetoprotein level,maximum diameter of tumor,Barcelona Clinic Liver Cancer (BCLC) stage,hepatitis B virus (HBV) infection,smoking and alcohol drinking (all P＞0.05).The 5-year overall survival rate of patients with negative RASSF1A methylation was 93％,while that of patients with positive RASSF1A methylation was 51 ％,and the difference in overall survival rate between the two groups was statistically significant (x2 =26.556,P ＜ 0.01).Univariate and multivariate Cox regression analysis indicated that liver cirrhosis,BCLC stage and RASSF1A methylation were the main influence factors in the death of patients with HCC after surgery (Wald=16.767,8.791,16.286; all P＜0.01).Conclusion RASSF1A methylation is not only one of the predictive factors of survival rate in patients with HCC after hepatectomy,but also an independent prognostic factor of HCC.

Objective To explore the application of PBL teaching method and brainstorming method in the training of medical students' medical record writing ability,in order to strengthen the cultivation of medical students' medical record writing ability.Methods 122 medical undergraduate interns of Grade 2010 majoring in clinical medicine in our hospital were taken as the research object,of which 60 were in the experimental group,62 were in the control group.PBL teaching combined with brainstorming method was used in the experimental group,while the control group used the traditional teaching method of teaching.After the end of the training course,data were analyzed using SPSS 19.0 software,count data and measurement data were analyzed using chi square test and t test to carry out the significant test between the two groups of data,the training effect was compared between the two groups.Results The results of questionnaire in the experimental group were significantly higher than those in the control group,and the difference was statistically significant,The experimental group theory test scores were higher than the control group[(84.28 ± 6.65) vs.(74.52 ± 6.75)],and the difference was statistically significant;The experimental group outstanding achievement ratio was higher than the control group,and the difference was statistically significant;The proportion of operation and non operative medical records in the experimental group were higher than that in the control group (P=0.005,P=0.004).Conclusion Combined application of PBL teaching method and brainstorming method plays a positive role in superposition and complementation.It gives full play to and mobilizes the students' enthusiasm and initiative,and the training effect is obviously superior to the traditional teaching method,therefore it is worth popularization and application in the training of students' medical record writing ability.

Purpose: Neoadjuvant chemotherapy is strongly recommended for advanced gastric cancer due to good local control and a high rate of R0 dissection with this strategy. Minimally invasive techniques such as laparoscopy-assisted or total laparoscopic approaches is becoming more and more acceptable in the treatment for gastric cancer. However, the safety and efficiency of total laparoscopic D2 gastrectomy (TLG) for advanced gastric cancer after neoadjuvant chemotherapy have not been well evaluated. Methods: A retrospective study in a single center from 2014 to 2016 was conducted. A total of 65 locally advanced gastric cancers were treated by laparoscopy-assisted gastrectomy (LAG) or TLG. Parameters which include operation time, blood loss, complications, hospital stay, 3-year overall survival, and 3-year disease-free survival were used for comparison. Results: The time of operation in the TLG group was shorter than in the LAG group (P = 0.013), blood loss was less (P = 0.002) and time to first flatus was shorter (P = 0.039) in the TLG group than that in the LLG group. Intraoperative and postoperative complications were comparable in both groups. No significant difference was found in 3-year overall and disease-free survival. Conclusion For patients with locally advanced gastric cancer after neoadjuvant chemotherapy, laparoscopic D2 gastrectomy can be considered as a safe and efficient alternative. A further multicenter prospective randomized controlled study is needed to elucidate the applicability of this technique for advanced gastric cancer.

OBJECTIVE: To study the effect of hydroquinone on the protein expression on human lymphoblastoid cell TK6,and to explore the molecular mechanism of hydroquinone-induced cellular response. METHODS: The TK6 cells were treated with 20. 0 μmol/L of hydroquinone for 24. 0 hours. Total protein was extracted by protein lysis buffer and quantified. The proteins were separated by two-dimensional gel electroporthressis. After image analysis,the difference in electrophoresis was selected for enzymatic hydrolysis. The mass spectrometry identification was performed using matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry. The TK6 cells were treated with hydroquinone at a concentration of 0. 0,5. 0,10. 0 and 20. 0 μmol/L for 24. 0 hours,and total protein was extracted. The expression of heat shock protein 70( HSP70) and ubiquitin-binding enzyme 2( UBE2N) of which were identified by mass spectrometry were assayed by western blot. RESULTS: A total of 48 differential expression protein spots were detected after hydroquinone treatment,and the mass spectrometry identified 30 differentially expressed proteins with up-or down-regulation. These proteins were related to oxidative stress,mitochondrial energy metabolism,cytoskeleton,cell cycle,DNA damage repair,and so on. The relative expression levels of HSP70 and UBE2 N in TK6 cells of 5. 0,10. 0,20. 0 μmol/L hydroquinone group were higher than those of 0. 0 μmol/L hydroquinone group( P < 0. 05),which was consistent with the mass spectrometry results. CONCLUSION: Hydroquinone can induce cytotoxicity in TK6 cells through oxidative stress,which induces the change of mitochondrial energy metabolism and DNA damage repair.

OBJECTIVETo investigate the DNA methylation changes induced by hydroquinone (HQ) in human bronchial epithelial cells and to explore the role of poly (ADP-ribose) polymerase-l (PARP-l) in this process.

METHODSHuman bronchial epithelial 16HBE cells and PARP-l-deficient 16HBE cells (16HBE-shPARP-l cells) were exposed to HQ (10, 20, 40, 60, and 80 µmol/L) for 48h, while control cells were treated with an equal volume of PBS solution. The changes in genomic DNA methylation were investigated by high-performance capillary electrophoresis, and the expression levels of PARP-l and DNA methyltransferase 1 (DNMT1) were measured.

RESULTSThe percentages of methylated DNA of overall genome (mCpG%) in 16HBE and 16HBE-shPARP-l cells were 4.89%±0.07% and 9.53%±0.51%, respectively; after treatment with 5-aza-2'-deoxycytidine for 72 h, mCpG% decreased to 3.07±0.12% and 6.34%±0.3%, respectively. The one-way analysis of variance revealed significant differences in mCpG% between the cells exposed to different concentrations of HQ in both 16HBE and 16HBE-shPARP-l groups (F = 61.25, P < 0.01; F = 60.36, P < 0.01). For 16HBE cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-1 were 145.0%, 159.0%, 169.0%, 215.0%, and 236.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); for 16HBE-shPARP-l cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-l were 170.0%, 223.0%, 264.0%, 327.0%, and 320.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all). When the dose of HQ reached 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in 16HBE group were 114.0%, 126.0%, 136.0%, and 162.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); when the dose of HQ reached 10, 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in the 16HBE-shPARP-l group were 141.0%, 165.2%, 186.9%, 202.1%, and 217.3%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all).

CONCLUSIONHQ can induce hypomethylation in 16HBE cells, and PARP-1 can regulate DNA methylation in 16HBE cells by influencing the expression and activity of DNMT1.

Cells, Cultured ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; DNA Damage ; DNA Methylation ; Epithelial Cells ; metabolism ; Humans ; Hydroquinones ; toxicity ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerases ; metabolism