Background Age-related macular degeneration (AMD) is the leading cause of blindness in people over 50 years old,of which 90％ cases are caused by choroidal neovascularization (CNV).Current treatments on AMD have gained great achievements,but there are still some drawbacks.So we need to search for new targets to cure CNV.Objective This study was to construct two combined lentiviral vectors for rat Slit2 gene RNA interference (RNAi) and verify its interfering effects on Slit2 gene in rat retinal pigment epithelial (RPE) cells.Methods Two specific siRNA sequences targeting towards rat Slit2 gene were designed and were annealed to DNA sequences.The DNA sequences and GV248-enhanced green flourescent protein (EGFP) vectors were combined together as recombinant vectors and then were identified.The GV248-EGFP vector,helper 1.0 and helper 2.0 were transfected together into 293T cells and the two combined lentiviral vectors for rat Slit2 RNAi were gained from the cell supernatant after 72 hours of transfection.The titers of the combined lentiviral vectors were measured.The cells were divided into blank control group,Lv-EGFP vector group,Lv-rSlit2-siRNA1 group and Lv-rSlit2-siRNA2 group.The interference efficacy of the combined lentiviral vectors targeting to rat Slit2 gene were identified by real-time fluorescence quantitative PCR and Western blot.The sequence with higher interference efficacy was transfected to rat RPE cells again.The transfected and nontransfected rat RPE cells were treated with 0,100,200 and 400 μmol/L CoCl2 for the preparation of hypoxia models.The expression of vascular endothelial growth factor-A (VEGFA) mRNA in rat RPE cells was finally measured by real-time fluorescence quantitative PCR and the concentration of VEGFA protein in cell supernatant was assayed by ELISA.Results The recombined lentiviral vectors for rat Slit2 gene R NAi were successfully constructed.The titers of the two reconbinant sequences were 5× 108 TU/ml and 3×l08 TU/ml,with the transfected rate ≥70％.The relative expression levels of Slit2 mRNA in the Lv-rSlit2-siRNA1 group and LvrSlit2-siRNA2 group were 0.67±0.09 and 0.23±0.11,respectively,which were lower than 1.03±0.31 and 0.92± 0.07 in the blank control group and Lv-EGFP vector group (all at P＜0.01).The expression levels of Slit2 protein in the Lv-rSlit2-siRNA1 group and Lv-rSlit2-siRNA2 group were 0.62±0.07 and 0.49±0.02,respectively,which were lower than 1.00±0.10 in blank control group and 0.95±0.11 in Lv-EGFP vector group (all at P＜0.01).Significant differences were found in the expression of VEGFA mRNA and protein in RPE cells among different concentrations of CoC12 groups (mRNA:F tration =127.998,P＜0.01;Fgroup =69.663,P＜0.01.Protein:F ion =17.059,P＜ 0.01;Fgroup =91.791,P＜0.01),and the expression of VEGFA mRNA and the concentration of VEGFA protein were evidently lower in the Lv-rSlit2-siRNA2 group than those in the blank control group after being treated by 100,200 and 400 μmol/L CoCl2 (all at P＜0.01).Conclusions Recombined lentiviral vector for rat Slit2 gene RNAi is successfully constructed,which can effectively knockdown rat Slit2 gene and inhibit the expression of VEGFA in rat RPE cells.

Objective To evaluate the safety and therapeutic effect of covered expandable metallic stent placement combined with interventional chemotherapy in treating malignant esophago-tracheal fistulae. Methods A total of 60 patients with esophago-tracheal fistula were enrolled in this study. The patients were randomly divided into control group (n=28) and study group (n=32). Patients of the control group were treated with covered stent implantation only, while patients of the study group were treated with combination use of covered stent implantation and interventional chemotherapy. All the patients were followed up regularly, the short-term and long-term results were determined, and the effect rate, median survival time and complications were statistically analyzed. Results Among the 60 patients, successful obstruction of the fistula was obtained in 58 with a success rate of 96.7%. The median survival time of the 58 patients was 5.8 months. The median survival time of the control group and the study group was 3.6 months and 8.7 months respectively, the difference between the two groups was statistically significant (P<0.05). The one-month, 3-month and 6-month effect rates were 78.1%, 68.8% and 62.5% respectively. The incidence of esophageal stent re-stenosis in the study group was much lower than that in the control group. Conclusion The combination use of covered stent implantation and interventional chemotherapy can effectively improve the median survival time of patients with malignant esophago-tracheal fistula, and reduce the occurrence of stent-related complications. Therefore, covered expandable metallic stent placement combined with interventional chemotherapy is an effective and safe treatment for malignant esophago-tracheal fistulae.

Axon guidance molecules,slit glycoprotein (Slit) and Roundabout receptors (Robo) were firstly identified in the central neural system of Drosophila melanogaster.The Slit-Robo signal plays a crucial role in axon guidance,inflammation,tumor metastasis and angiogenesis,of which the role of Slit2-Robo pathway in angiogenesis has drawn a greater attention and still remains conflicting.Herein,we provide a review on the role of Slit2-Robo pathway in ocular angiogenesis and vascularization of other organs and systems.We hope this review will be the basis of further study on the mechanism of Slit2-Robo signaling on angiogenesis and provide new target for the therapy on ocular vascular disease

Objective:To explore the diagnosis, treatment and prevention of biliary hemorrhage after percutaneous transhepatic choledochoscopic lithotomy(PTCSL).Methods:Retrospective summary and analysis were made on 48 cases of PTCSL completed by the hepatobiliary surgery department of Hunan Provincial People′s Hospital (the First Affiliated Hospital of Hunan Normal University) from January 2016 to December 2020.Results:Biliary hemorrhage occurred in 3 cases after operation, of which 1 case was considered to have a small amount of biliary mucosa bleeding, and the bleeding was stopped after blood transfusion, hemostatic agents and appropriate fluid rehydration. In the other case, a small amount of blood oozing around the T-tube sinus canal was accompanied by a small amount of bloody fluid in the T-tube, which was considered to cause arterioles or venules accompanied by bile duct bleeding during sinus expansion during operation, and the bleeding stopped after compression. Another patient underwent a short time drainage of hemorrhagic fluid ≥100 ml in T tube 15 days after operation, and was prepared for interventional therapy while receiving blood transfusion products and conservative treatment. Celiac arteriography was performed, and pseudoaneurysm was found in the right anterior lobe of the liver. Embolization was performed later and the patient discharged 10 days after embolization.Conclusions:Biliary hemorrhage is one of the more common complications after PTCSL. Increasing the understanding of this complication provides a guarantee for the safety of surgery and has clinical significance for patients with accelerated postoperative recovery.

Objective:To analysis the application value of rigid ureteroscope combined with holmium laser in diagnosis and treatment of complicated hepatolithiasis guided by three-dimensional visualization technology.Methods:50 patients with complex hepatolithiasis treated in Hunan People′s Hospital from October 2016 to March 2019 were selected as the study subjects. They were divided into observation group and control group by simple random method. 20 cases underwent rigid ureteroscope combined with holmium laser under the guidance of three-dimensional visualization technology were taken as observation group, 30 cases underwent rigid ureteroscope combined with holmium laser by traditional imaging diagnosis were taken as control group. The differences between the two groups in operation time, intraoperative bleeding volume, stone residual rate, postoperative hospital stay and postoperative complications were statistically analyzed.Results:The residual rate of calculi in observation group was 10% (2/20), while it was 40% (12/30) in control group; the amount of bleeding during operation in the observation group was (170.9±18.0)ml, and it was (371.6±37.0)ml in the control group; the operation time of observation group was (179.0±14.3)minutes, and it was (340.2±24.3)minutes in the control group; the postoperative hospital stay of observation group was (8.3±1.5)days, and it was (10.1±1.8)days in the control group; postoperative biliary hemorrhage occurred in 1 cases of the observation group, biliary tract leakage occurred in 2 cases, postoperative biliary hemorrhage occurred in 3 cases of the control group, biliary tract leakage occurred in 4 cases.Conclusions:Rigid ureteroscope combined with holmium laser guided by three-dimensional visualization technology can further improve the clinical efficacy in the diagnosis and treatment of complex hepatolithiasis. which is worthy of clinical application.

【Objective】 To investigate the unqualified rate of anti-HIV detection of blood screening laboratories in Beijing-Tianjin-Hebei region, and explore the differences in anti-HIV detection ability and influencing factors in each laboratory. 【Methods】 Through filling questionnaires via e-mail, the anti-HIV ELISA unqualified rate and confirmed (WB) positive results (data) from January to December 2018 from 15 blood screening laboratories in Beijing-Tianjin-Hebei region were collected. Our laboratory was responsible for data collection and confirmation, and statistics software SPSS22.0 was used for analysis. 【Results】 1) There was a statistically significant difference among the unqualified rate of anti-HIV ELISA(6.77‱~35.71‱) and confirmed positive rate(0.60‱~3.56‱) in 15 blood screening laboratories in Beijing-Tianjin-Hebei region (P<0.05); 2) There were significant differencse among the ELISA unqualified rate and the confirmed positive rate of 8 reagents for anti-HIV detection(P<0.01), and the sensitivity of the 4th generation detection reagent and the imported reagent was higher than that of the 3rd generation reagent and the domestic reagent. The anti-HIV ELISA unqualified rate of R5 was the highest (19.08‱). 3)There were significant differences in the anti-HIV ELISA unqualified rate of R1, R2, R3, R5 and R7 reagents among different blood station laboratories(P<0.05), and there were no significant differences in the anti-HIV ELISA unqualified rate of R4, R6 and R8 reagents among different blood station laboratories(P>0.05). 4)The unqualified rate of anti-HIV ELISA of laboratories using different regents showed significant differences(P<0.05), except H, J, M. The unqualified rate of imported reagent was significantly higher than that of domestic reagents of laboratories using imported and domestic reagents combinations(P<0.05), except O. 62.5% (5/8) laboratories using domestic 3^rd and 4^th generation reagent combination showed significant differences in the unqualified rates among different reagents(P<0.05); 5) The positive rate of single-reagent(62.02%~95.45%)in 15 blood screening laboratories showed significant difference(P<0.001), and A was the lowest (62.02%). 【Conclusion】 The anti-HIV detection ability among 15 blood screening laboratories in Beijing-Tianjin-Hebei region is quite different. The application of different reagents is the main factor for the difference, and other factors such as personnel, instruments and test strategies also has a great impact on the detection of anti-HIV. It is still necessary to promote the process of homogenization of blood testing quality among blood screening laboratories in Beijing-Tianjin-Hebei region.