In spite of the fact that rectal stromal tumor accounts for only 4.2％ of the gastrointestinal stromal tumor,its surgical treatment is still very difficult and challenging due to the special anatomical position of rectum,its complicated anatomical relationship with adjacent organs,and whether the anus be preserved.Local resection of rectal stromal tumor is feasible and reasonable owing to its biological characteristics.However,there are many approaches and methods for local resection and no consensus has been reached.The clinical data of 18 patients with rectal stromal tumor who were treated by local resection via transposterior approach at the Peking Union Hospital from March 2003 to September 2012 were retrospectively analyzed.The surgery not only applies with the oncology treatment principle,but also preserves anus and limits the surgical injury to a large extent.Therefore,it is one of the most ideal surgical methods for the treatment of rectal stromal tumor.

Objective To evaluate transsphincteric operation (Mason operation) for rectal tumors.Methods Retrospective study was used to analyze the experience of Mason operation for 150 patients with mid and lower rectal tumors between Aug 1990 to Dee 2008. Results There were villous adenoma in 75 cases,early rectal cancer in 48 and advanced rectal cancer in 9,submucosal carcinoid nodule in 23.Of the 126 rectal tumor patients,120 underwent partial rectectomy,6 underwent segmental rectectomy.Seventeen out of the 21 rectovaginal fistula or rectourethral fistula cases underwent successful one-stage repair.Six patients(4%)developed wound infection.Five patients(3.3%)were complicated with recto-cutaneous fistula.Two patients(4.3%) suffered from local recurrence in 46 followed up early staged rectal carcinoma with a five-year survival rate of 84.5%(39/46).On discharge from hospital no patient suffered from incontinence.Conclusion Mason operation is satisfactory with good exposure and simple access to the rectum,which Was suitable for those lesions that could be locally resected on mid and lower rectum.

Objective To evaluate transanal endoscopic microsurgery (TEM) for the resection of rectal neoplasms. Methods In order to analyze the therapeutic effect of TEM in the management of rectal tumors, clinical data of 110 patients with rectal neoplasms treated by TEM between April 2006 and August 2009 were summarized and analyzed retrospectively. Result The mean diameter of rectal lesions was 1.7±0.8 (range, 0.5 ～5.5)cm. The average distance of lesions from the anal verge was 7.4 ±2.6(range, 4 ～20) cm. 40 lesions were located at the anterior wall of the rectum, 29 on the posterior wall,22 on the left wall and 19 on the right. Surgical procedures included the transmural excision (98 cases) and the submucosal excision with partial muscular layer excision (12 cases). The average operating time was 73.5 ±31.1 (range, 25 ～180) min. The mean operative blood loss was 10.8 ±7.8 (range, 3 ～60) ml.The postoperative pathological examination identified 41 rectal adenomas、 35 rectal adenocarcinomas or carcinomatous changes of adenomas (21 Tis, 6 T1, and 8 T2 cases), 14 rectal carcinoids, 1 stromal tumor、1 leiomyoma and 18 cases of inflammatory polyps or others. Surgical margins of all specimens were negative.Postoperative complications included 2 cases of anal hemorrhage, one case of pulmonary infection and one urinary infection with a postoperative morbidity of 3.6%. The average postoperative stay was 3.4 ± 1.3( range, 2 ～ 8 ) d. With a mean follow-up period of 12. 5 (3 ～ 40) months, no tumor recurrence or metastasis was found. Conclusions TEM shows advantages of decreased blood loss, good therapeutic effect, and fast recovery of the patients, which can be adopted as the choice of therapy for small and well confined rectal neoplasms.

ObjectiveTo evaluate the reasonableness of total mesorectal excision (TME) in the management of rectal cancer. Methods The carcinoembryonic antigen (CEA) level of surgically removed distal mesorectum (3?cm below the tumor),tumor tissue and normal mesocolon was detected by microparticle enzyme immunoassay in 26 rectal cancer patients. Results The CEA level in normal mesocolon was (1.6?1.0)?ng/g, and (62.5?85.2)?ng/g in distal mesorectum(P1?000?ng/g).ConclusionsIn patients with rectal cancer, much higher CEA level in distal mesorectum than in normal mesocolon might indicate distal mesorectal dissemination. It is necessary to routinely perform TME in the surgical management of middle and lower rectal cancer.

ObjectiveTo investigate the relationship between surgical manipulation and hematogenous spreading micrometastasis in patients with colorectal carcinoma.MethodsNested RT-PCR was used to detect the expression of cytokeratin 20 (CK20) mRNA in the peripheral blood of 37 colorectal cancer patients without distal metastasis (experimental group) undergoing radical resection which were subdivided into group A (tumor drainage veins were first ligated) and group B (without precedent ligation of the veins).Results CK20 mRNA was positive by nested RT-PCR in the peripheral blood in 9 out of 10 colorectal cancer patients with known distant metastasis,while it was negative in all 10 volunteers and all 10 patients with benign colorectal lesions. CK20 mRNA was detected in 14 of 37 (37 8%) cases in the peripheral blood sampled preoperatively, while the positive ratio rose to 59 5% (22/37) during surgical procedures (? 2=4 900, P0 05). ConclusionCK20 mRNA by nested RT-PCR was highly sensitive and specific for the determination of circulating micrometastasis in colorectal cancer patients. Surgical manipulation significantly increased the incidence of hematogenous spreading micrometastasis, which can′t be prevented by precedent ligation of the refluent veins of the tumor during operation.

AIM:To detect and compare the longitudinal mitral annulus diastolic velocity and time interval changes by pulsed Doppler tissue imaging(DTI)in patients with angina pectoris(AP)and myocardial infarction(MI),and to explore the value of mitral annulus diastolic velocities and time intervals for evaluation of global left ventricular diastolic dysfunction.METHODS:Fifty patients with established coronary artery disease were divided into AP group(16 cases)and MI group(34 cases).Sixteen age-matched healthy individuals served as the control group.The septum,lateral,anterior and inferior walls of the mitral annulus were displayed,and selected for DTI spectrum sampling.Peak early and late diastolic velocities and their ratio,time to the onset and peak of the early diastolic wave,and regional isovolumic relaxation time were measured,and the average values of the four mitral annular sites were calculated and presented as Em,Am,Em/Am,QEm,TEm and IVRTm,respectively.RESULTS:Compared with the control group,Em and Em/Am were significantly lower in both the AP and the MI groups(P＜0.01).Em was even lower in the MI group than that in the AP group(P＜0.01).QEm,TEm and IVRTm were significantly longer in the AP and the MI groups than those in control group(P＜0.01 or P＜0.05).IVRTm was even longer in the MI group than that in AP group(P＜0.01).IVRTm had significantly negative correlation with Em(r=-0.64,P＜0.01).CONCLUSION:Em,Em/Am,QEm,TEm and IVRTm as measured by pulsed DTI may be promising indexes for quantitative assessment of global left ventricular diastolic dysfunction in patients with coronary artery disease.Em and IVRTm may indicate the severity of ischemic myocardial damage.

AIM: To investigate killing effect of herpes simplex virus thymidine kinase/ganciclovior system(HSV-TK/GCV) on osteosarcoma cell and its mechanisms.METHODS: Recombinant retroviral vector (DORHyTK) containing hygromycin phosphotransferase-thymidine kinase fusion gene(HyTK) was constructed and introduced into human osteosarcoma cell line OS732 with DOTAP. DNA and total RNA extracted from HyTK expressing cells (OS732TK) were tested by PCR and RNA dot blot analysis. A chemosensitivity of OS732TK cells to GCV and “bystander effect” were measured by means of MTT colorimetric assay. Hoeschst 332258 staining and flow cytometric analysis were performed for mechanism of HSV-TK/GCV system gene therapy. RESULTS: DORHyTK was constructed successfully; the HyTK gene existed and expressed in OS732TK cells; All OS732TK cells were killed after 5 days of exposure to 5 mg/L GCV. The “bystander effect” was observed in both a high population and a low population, but the former was stronger than the latter. Hoeschst 332258 staining revealed the characteristic hallmarks of apoptosis, however necrosis also existed. Flow cytometric analysis of DNA content showed a G0-G1 phase blockade. CONCLUSION: HSV-TK/GCV gene therapy system showed its strong killing effects on osteosarcoma cells OS732; The phenomenon of “bystander effect” was also very apparent. GCV exposure induced both necrotic and apoptotic death in HSV-TK expressing cells, and perturbed the cell cycle. HSV-TK/GCV gene therapy system may provide a new therapeutic approach for treatment of osteosarcoma.

Purpose　To observe the killing effect of HSV-TK/GCV system on osteosarcoma cells. Methods　The eukaryotic exprssoin vector (tgCMV-HyTK) containing HSV-TK gene was transduced into human osteosarcoma cell lines SAOS-2 by DOTAP. Total RNA extracted from HSV-TK expressing cells (SAOS-2TK) were tested by RNA dot blot analysis. A chemosensitivity of SAOS-2TK cells to GCV and “bystander effect” were measured by means of MTT colrimetric assay. Results　HSV-TK gene was expressed in SAOS-2TK cells. SAOS-2TK cells were susceptible to the cytotoxicity of GCV. A meaningful “bystander effect” was demonstrated. Conclusion　HSV-TK/GCV system may kill selectively the human osteosarcoma cell line SAOS-2.

AIM To establish anti-osteosarcoma antibody producing hybridoma cell lines and to study the characterization of the monoclonal antibodies. Methods BALB/c mice were immunized with human osteosarcoma cells OS-9607 and the immunized spleen cells were fused with SP2/0 cells to raise hybridoma. The propert of antibody and it's cytotoxic effect were studied respectively with immunohistochemistry methods using OS-9607 and normal hepatocytes、 Western Blot methods and MTT method. Results A hybridoma cell line named 3D9 was established and it secreted high quality mAbs steadily. 3D9 cell had all the characteristics of hybridoma. The mAb's corresponding antigens was specifically and highly expressed in human osteosarcoma. With enzyme-labeled immunohistochemical staining on formaldehyde -fixed sections from human osteosarcoma,it was found that 83％ of the specimens expressed the corresponding antigen. Most of them were expressed on the nuclear of cells, no positive expression was observed in kinds of normal tissues. Western Blot showed 3D9's corresponding molecule weight is Mr54 000. MTT assay proved that the cytotoxicitis of effective groups were higher than control groups. Conclusion A high quality hybridoma is cultured and the mAb secreted by it has osteosarcoma specificity and obvious cytotoxic effect. It may be a new biochemical mark of osteosarcoma, and it's clinical prospect of immunotherapy will be wide.

AIM: To investigate killing effect of herpes simplex virus thymidine kinase/ganciclovior system(HSV-TK/GCV) on osteosarcoma cell and its mechanisms.METHODS: Recombinant retroviral vector (DORHyTK) containing hygromycin phosphotransferase-thymidine kinase fusion gene(HyTK) was constructed and introduced into human osteosarcoma cell line OS732 with DOTAP. DNA and total RNA extracted from HyTK expressing cells (OS732TK) were tested by PCR and RNA dot blot analysis. A chemosensitivity of OS732TK cells to GCV and "bystander effect" were measured by means of MTT colorimetric assay. Hoeschst 332258 staining and flow cytometric analysis were performed for mechanism of HSV-TK/GCV system gene therapy. RESULTS: DORHyTK was constructed successfully; the HyTK gene existed and expressed in OS732TK cells; All OS732TK cells were killed after 5 days of exposure to 5 mg/L GCV. The "bystander effect" was observed in both a high population and a low population, but the former was stronger than the latter. Hoeschst 332258 staining revealed the characteristic hallmarks of apoptosis, however necrosis also existed. Flow cytometric analysis of DNA content showed a G 0-G 1 phase blockade. CONCLUSION: HSV-TK/GCV gene therapy system showed its strong killing effects on osteosarcoma cells OS732; The phenomenon of "bystander effect" was also very apparent. GCV exposure induced both necrotic and apoptotic death in HSV-TK expressing cells, and perturbed the cell cycle. HSV-TK/GCV gene therapy system may provide a new therapeutic approach for treatment of osteosarcoma.