Objective To compare the short-term efficacy between da Vinci robotic and laparoscopic radical gastrectomy for gastric cancer.Methods Database including PubMed,EMBASE,the Cochrane Library,Medline,the China National Knowledge Infrastructure (CNKI),Wanfang Database,VIP and China Biomedicine were searched with the key words of gastric cancer,gastrectomy,da Vinci surgical system,laparoscopic,laparoscopy,胃癌,胃切除术,达芬奇机器人手术系统and腹腔镜.Literatures published between May 2002 and March 2014 were retrieved.Related controlled trials containing the clinical efficacy of da Vinci robotic and laparoscopic radical gastrectomy for gastric cancer were enrolled in the study,and then the literatures were screened and the data were extracted by 2 independent reviewers.The quality of the literatures was assessed,and the data were analyzed using the RevMan 5.2 software.Patients receiving da Vinci robotic surgery and laparoscopic surgery were allocated into the robotic group and laparoscopy group,respectively.The count data were analyzed using the relative risk (RR) and 95％ confidence interval (95％ CI),and the measurement data were analyzed using weighted mean difference (WMD) and 95％ CI.The heterogeneity of the data was analyzed using the I2 test.Results Eleven literatures including 3 698 cases were enrolled in the study.There were 953 patients in the robotic group and 2 745 patients in the laparoscopic group.There were significant differences in the operation time,volume of intraoperative blood loss,time of postoperative flatus,time of first oral intake and duration of postoperative hospital stay between the 2 groups (WMD =51.23,-36.96,-0.24,-0.26,-1.11,95％ CI:28.01-74.46,-61.28--12.65,-0.42--0.06,-0.39--0.14,-1.92--0.29,P ＜ 0.05).There was no significant difference in the number of lymph nodes resected,the distance to proximal and distal resection margin and overall incidence of postoperative complications (WMD =1.63,0.21,0.06,RR =1.11,95％ CI:-0.49-3.76,-0.65-1.06,-0.13-0.25,0.90-1.37,P ＞ 0.05).Conclusion Da Vinci robotic radical gastrectomy for gastric cancer is safe and feasible,with the advantages of minimal invasion and rapid postoperative recovery.

Objective To investigate the anti tumor effects of cytotoxic T lymphocytes induced by tumor antigen specific dendritic cells. Methods Soluble tumor antigen was prepared by four freeze thaw cycles of gastric tumor cell line SCG7901. Anti gastric tumor vaccine was acquired by co incubation of tumor antigen and mouse bone marrow derived dendritic cells and cultured with granulocyte/macrophage colony stimulating factor and interleukin 4. Antigen specific cytotoxic T lymphocytes were induced by this tumor vaccine from the spleen and were applied to tumor bearing nude mice. Results Tumor growth was significantly inhibited and the apoptosis of tumor cells was promoted extensively. Conclusions Antigen specific dendritic cell tumor vaccine may play an important role in future immunotherapy of gastric cancer.

Objective To investigate the expression of Ezrin in gastric cancer tissues and its clinical significance.Methods Gastric cancer tissues and adjacent normal gastric tissues from 60 patients with gastric cancer were collected from June 2008 to May 2009 at the Southwest Hospital.The mRNA and protein expressions of Ezrin were detected by using the reverse transcription polymerase chain reaction and western blot.The relationship between Ezrin and the gender and age of patients,and tumor differentiation,pathological staging,depth of invasion and lymph node metastasis was analyzed.All data were analyzed using the t test,chi-square test and Spearman rank correlation.Results The Ezrin mRNA expression level was increased in 33 (55％) cases of adjacent normal gastric tissues and 21 (35％) cases of gastric cancer tissues; the Ezrin protein expression level was increased in 45 (75％) cases of adjacent normal gastric tissues and 22 (37％) cases of gastric cancer tissues.The mRNA and protein expressions of Ezrin in the normal adjacent gastric tissues were 1.30 ± 0.04 and 3.57 ± 0.45,respectively,which were significantly higher than 0.53 ± 0.36 and 0.96 ± 0.18 in the gastric cancer tissues ( t =5.309,22.617,P ＜ 0.05 ).The mRNA expression of Ezrin was positively correlated with the protein expression of Ezrin (r =0.602,P ＜ 0.05 ).The mRNA and protein expressions of Ezrin were related to the pathological stages,depth of invasion and state of lymph node metastasis (x2 =6.41,6.49,4.62; 5.40,8.87,4.12,P ＜ 0.05),but not to the gender,age and tumor differentiation (x2 =0.50,0.07,1.07 ; 0.01,1.16,1.96,P ＞ 0.05).Conclusion The mRNA and protein expressions of Ezrin are significantly decreased in the gastric cancer tissue,which might be responsible for genesis,development and metastasis of gastric cancer.

Objective To investigate the effects of different CO2 pneumoperitoneum on cell cycle and cell cycle protein of a gastric cancer cell line. Methods Human gastric cancer cell line MNK-45 were exposed to 0,10,12 and 15 mm Hg CO2 pneumoperitoneum in vitro for 4 hrs. Cell cycle was measured by flowcytometry, the expression of CDK4 ,Cyclin D1、Rb and pRb was studied by Western-blot, and the binding ability of CDK4 and Cyclin D1 was evaluated by immunoprecipitation. Results The cell proliferation index in 15 mm Hg CO2 pneumoperitoneum group dropped significantly (27.4% ± 3. 7%) vs. (36. 4% ±3. 3%) ,P <0. 05, while that in other groups did not change significantly. The protein of CDK4、Cyclin D1and binding ability of Cyclin D1 and CDK4 dropped dramatically in the 15 mm Hg CO2 pneumoperitoneum group (0.71%±0.12%),(0.93% ±0.21%),(0.54%±0.11%),(0.18% ±0.02%) vs. (1.05% ±0.16%),(1.40% ±0.24%),(0.75% ±0.14%),(0.31% ±0.02%), all P<0.05. There were no changes of Rb in protein levels, while the phosphorylated Rb dropped obviously. Conclusion There was no obvious effects of clinical CO2 pneumoperitoneum on gastric cancer cells growth and proliferation.

With the development of instrumentation and surgical techniques,laparoscopic gastrectomy has become a promising surgical option for the treatment of gastric cancer.While laparoscopic gastrectomy is high technique-demanding,which hampered its popularization.Compared with traditional laparoscopes,Da Vinci surgical system has more special features,such as flexible robotic arms and three-dimensional imaging,which facilitates surgical procedures.A 58-year-old male patient with gastric cancer underwent Da Vinci surgical system-assisted radical total gastrectomy at the Southwest Hospital in March 2010.The mean operation time and blood loss were 270 minutes and 60 ml,respectively,and the number of dissected lymph nodes was 21.The short-term clinical effect was perfect without postoperative complications.Da Vinci surgical system-assisted radical total gastrectomy is safe and feasible,and it brings challenges to conventional laparoscopes.

Objective To investigate the relationship between the expression of eonnexin 43 (Cx43) and clinicopathologieal characteristics of gastric cancer, and to study the role of Cx43 in peritoneal metastasis of gastric cancer. Methods Thirty-two patients who had gastric cancer and with peritoneal metastasis had been admitted to Southwest Hospital from January 2000 to December 2008. Gastric cancer tissues, adjacent tissues and metastatic peritoneal tissues were obtained postoperatively, and the expression of Cx43 was detected by immunohistochemistry. The relationship between Cx43 expression and clinicopathological characteristics of gastric cancer was analyzed. All data were analyzed via Spearman rank correlation coefficient, Fisher exact probability and chi-square test. Results The expression of Cx43 was mainly detected in the cell membrane and cytoplasm. The positive expres-sion rates of Cx43 in gastric cancer tissues, adjacent tissues and metastatic peritoneal tissues were 34% (11/32), 100% (32/32) and 94% (30/32), respectively. There were significant differences in the Cx43 expression between gastric cancer tissues and adjacent tissues (X~2=28.350, P < 0.01), and between gastric cancer tissues and metastatic peritoneal tissues (X~2 = 21.989, P < 0.01). The expression of Cx43 did not correlate with age and sex of patients (r = -0.030, - 0.169, P > 0.05), but with tumor differentiation, histological type and lymph node metastasis (r = 0.750, 0.642, - 0.357, P < 0.05). Conclusions There is a decreased expression of Cx43 in gastric cancer tissues and a up-regulated expression of Cx43 in metastatic peritoneal tissues. Cx43 may play a positive role in the peritoneal metastasis.

Objective To investigate the effects of CO_2 pneumoperitoneum on the expression of focal adhesion kinase (FAK) of gastric cancer MKN-45 cells. Methods CO_2 pneumoperitoneum with different pressures was simulated in vitro, and the gastric cancer MKN-45 cells were divided into test and control groups. In the test group, gastric cancer MKN-45 cells were cultured in CO_2 pneumoperitoneum with different pressures [5, 10 or 15 mm Hg (1 mm Hg =0.133 kPa)] for 4 hours. The condition of the cells exposed to CO_2 pneumoperitoneum with a pressure of 15 mm Hg was observed at 0.5, 2 and 4 hours. Gastric cancer MKN-45 cells in control group were cultured at normal atmospheric pressure. The expression of FAK and phosphorylated FAK (FAK Tyr397) of each group was detected by Western blot. Multiple-group analysis was done by one-way ANOVA, and intergroup comparison was done by LSD test. Results In CO_2 pneumoperitoneum with pressures of 5, 10, 15 mm Hg, the expression of FAK was 2.14±0.17, 2.07±0.21 and 2.52±0.26, respectively, and the expression of FAK Tyr397 was 1.82±0.28, 1.93±0.52 and 3.71±0.37, respectively. The expression of FAK and FAK Tyr397 in the control group was 2.43±0.46 and 1.71±0.23, respectively. We found significant differences between the 2 groups (F = 2.171, 26.951, P < 0.01). After gastric cancer MKN-45 cells being treated for 0.5, 2 and 4 hours in CO_2 pneumoperitoneum with a pressure of 15 mm Hg, the expression of FAK Tyr397 was 3.41±0.44, 4.12±0.56 and 5.24±0.41 respectively, which is also significantly different (F =116.119, P < 0.01). The expression of FAK Tyr397 was back to 0.72±0.16 1 hour after the release of CO_2. Conclusions CO_2 pneumoperitoneum with different pressures can not promote the expression of FAK in gastric cancer MKN-45 cells which had been cultured for 4 hours, but can activate FAK through promoting its phosphorylation. The degree of FAK phosphorylation increases with pressure and time, and the activity of FAK decreases to pretreatment level rapidly once pressure is released.

The operation path, lymph node dissection and reconstruction of the alimentary tract are the three most technical difficulties of laparoscopy-assisted gastrectomy. The essential difference between laparoscopy-assisted gastrectomy and open gastrectomy is the operation path. Based on our clinical experience, we investigated reasonable paths for laparoscopyassisted gastrectomy. Patients were placed in a supine position with their legs apart, and the operator stood on the left side of the patient. Five trocars were placed in the abdominal wall in a curved line. The operation was carried out in the order of greater gastric curvature, the lower region of the pylorus and antrum,the upper region of the pancreas, omentum minus, cardia, and arcuate diaphragm. From May 2004 to April 2010, we successfully carried out 761 laparoscopy-assisted gastrectomies with satisfactory outcomes.

Objective To investigate the effects of different CO2 pneumoperitoneum pressures on gastric cancer cells' growth and proliferation in nude mouse model of implanted tumor. Methods Human gastric cancer cell lines MNK-45 were exposed under 0、10、12 and 15 mm Hg CO2 pneumoperitoneum for 4 hrs respectively. 2 × 106 processed cells were inplanted into nude mice subcutaneously. Three weeks later, mice were sacrificed and the weight and bulk of the tumor measured. Then we observed the transplantation tumor by HE stain and Ki-67 stain. Results There was no significant difference in tumor's growing time, bulk and weight between 0, 10, 12 mm Hg CO2 pneumoperitoneum groups (7. 8 d, 7. 2 d, 7. 8 d; 1. 2 cm3, 1. 3 cm3, 1. 3 cm3; 1.5 g, 1. 9 g, 1. 6 g)and the control group (7. 3 d, 1. 2 cm3, 1.4 g) (P > 0. 05 ). The growing time of tumor in 15 mm Hg CO2 pneumoperitoneum (12. 5 d) was obviously longer than the control group ( P < 0.05 ) , the bulk and weight of tumor in 15 mm Hg CO2 pneumoperitoneum (0. 5 cm3, 0. 5 g) group significantly decreased compared with the control group (P <0.05). The positive rate of Ki-67 in 15 mm Hg CO2 pneumoperitoneum (27. 5% ) group was obviously lower than the control group (59.6%) (P<0.01). However, there were no significant differences between 0, 10, 12 mm Hg CO2 pneumoperitoneum groups (61.2%, 60.5%, 63.4%) and the control group (P > 0.05). Conclusion Clinically adopted CO2 pneumoperitoneum pressures have no significant effect on gastric cancer cells growth and proliferation.

Although the surgical procedure and approach of da Vinci robotic surgical system-assisted radical resection of gastric cancer are gradually mature,it is rarely used for the resection of gastric stump cancer because of the complexity and low resection rate.In November of 2012,resection of gastric stump cancer using da Vinci robotic surgical system was performed in the Southwest Hospital.The short-term efficacy was satisfactory after the follow-up for 12 months.Da vinci robotic surgical system has the advantages of clear vision,easy manipulation of abdominal adhesion detaching,flexible operation and stable traction during resection of gastric stump cancer.