Abstract:Left bundle branch pacing engages in the electrical activation through left bundle branch area and produces ventricular electrical synchronization. This pacing has been considered as an attractive mode to achieve normal physiological pace markers. For patients with the site of block in infra-Hisian or distal His bundle，left bundle branch pacing can bypass the block region. As a new technology，left bundle branch pacing is still in the stage of clinical exploration. The definition，criteria，efficacy and safety of left bundle branch pacing need further investigation and validation in large randomized clinical trials.

Abstract:His bundle is a continuation of the atrioventricular node and begins to divide into left and right bundle branches at the top of the interventricular septal muscle. The trunk of His bundle penetrates the central fibrous body and extends to the left bundle branch，which runs below the junction of the noncoronary sinus and the right coronary sinus. Left bundle branches distribute under the endocardium. The right bundle branch is relatively slender and runs on the moderator band. In clinical practice，His-Purkinje system pacing（HPSP）has achieved good results in patients with atrial fibrillation associated with heart failure and heart failure associated with left bundle branch block. HPSP could also maintain ventricular synchrony in ventricular pacing dependent patients. This paper provides a review the anatomy and the application of HPSP.

Abstract:Conventional right ventricular apical pacing is deleterious to heart function and as a result，mortality increases. His bundle pacing utilizes the special conduction system of the heart and activates the double ventricular chamber simultaneously that models physiological pacing model efficiently. Different clinical studies have demonstrated that the feasibility，safety and effectiveness of applying His bundle pacing. Left bundle branch area pacing is a novel method proposed in the further exploration of physiological pacing，with the merits of overcoming the shortcomings of His bundle pacing，such as low success rate，low sensitivity and high threshold. This article provides a comprehensive review over the most up-to-date research progress of clinical application using His bundle pacing and Left bundle branch area pacing.

Abstract:Objective：This study aims to explore the feasibility and safety of his bundle pacing（HBP）and left bundle branch pacing（LBBP）. Methods：Fifty-nine patients with cardiac pacing were enrolled in the study between May 2017 to Nov. 2018. HBP were performed in group of 19 patients. LBBP were performed in that of 20. Additionally，another 20 patients received right ventricular septum pacing（RVSP）. The successful HBP and LBBP were defined by the characteristic intra-electrocardiograph and paced surface QRS morphology，respectively. The feasibility and the short-term safety of the LBBP’s and HBP’s approach were evaluated. The pace QRS duration was compared among three groups. Results：The successful implanting rates of three different approaches were 79% in HBP group，95% in LBBP group and 100% in RVSP group. The pacing parameters of 3 groups were stable during 3-month follow up. The sensitivity of R wave and pacing threshold in LBBP group seems better than those in HBP group. The pace QRS duration was similar between HBP and LBBP groups；however，the paced QRS duration in RVSP group was significantly broader than those in HBP and LBBP group. Neither complication occurred during this procedure nor in those of follow-up. Conclusion：HBP and LBBP appear to be safe and feasible. LBBP demonstrated with a better sensitivity of R wave and threshold than HBP. Compared to RVSP，HBP and LBBP could maintain better cardiac synchrony.

Abstract:Objective：This study aims to investigate the successful rate of the left bundle branch area pacing（LBBP），the safety and effectiveness of the technology. Methods：Thirty-six patients were divided into LBBP group and RV pacing group according to the position of the RV lead. The baseline characteristics，successful rate，procedure time，paced QRS duration and pacing parameters were investigated. Results：In the presence of accumulated of the experience，the successful rate increased up to 88.9%. The thresholds of the LBBP group were lower than those of RVP group［（0.67 ± 0.14）V vs. （0.77 ± 0.23）V，P < 0.05］. The QRS duration of the LBBP group was narrower than that of RVP group［（112.50 ± 9.96）ms vs. （164.00 ± 19.32）ms，P < 0.05］. The pacing parameters during the follow up appeared to be stable with no complication occurred. Conclusion：LBBP was safe and effective.

Abstract:Objective：To clarify the developmental status of porcine fetal kidney at different stages，and to study the expression of signaling molecules related to the development of porcine fetal kidney. Methods：The kidney tissues of porcine fetuses at different stages（fetuses on post-implantation days 21.5，27.5，35.0，45.0，75.0 and 110.0）were collected. The histological structure of pig fetal kidneys was observed by HE staining. The mRNA and protein expression levels of factors related to renal development signaling molecules（Pax2，Pax8，Six2，Six1，Sall1 and Bmp4）were detected by quantitative real-time PCR（qPCR）and Western blot，respectively. The expression and localization of Pax2 at different stages of fetal kidney were detected by immunohistochemistry. Results：The metanephros of fetal pig initiated its development starting by the 27.5th day. The early renal corpuscles appeared on the 35th day，and the renal tubules began to develop. On the 45th day，the immature glomeruli in the cortex region and the proximal matured renal corpuscles in the medulla region could be detected. The number of nephrons on the 75th day increased significantly，and kidney pyramid，renal papillae and renal pelvis were observed at this stage. On the 110th day，kidney was basically mature，the cortex and medulla could be distinguished clearly，and new nephrons kept to be produced. The mRNA and protein expression levels of Pax2，Pax8，Six2，Six1，Sall1 and Bmp4 on 75 d were higher than that on 35 d. Pax2 was widely expressed in ureteric bud，metanephric mesenchyme，cap mesenchyme，renal vesicles，comma-shaped bodies，S-shaped bodies and renal tubule，and is continuously expressed during the development of the metanephros. Conclusion：The development of metanephros of fetal pig starts the 27.5th day and basically reaches maturation on the 110th day. The signaling molecules such as Pax2，Pax8，Six2，Six1，Sall1 and Bmp4 were expressed along different stages during the kidney development，and Pax2 may be a key regulator of porcine fetal kidney development.

Abstract:Objective：Porcine naive-like embryonic stem cells were induced to differentiate into neural cells in vitro，which provided basic information for the repair and treatment of the neurological disease. Methods：The neural-inducing culture medium with small molecule compounds β-mercaptoethanol，B-27 and heparin was used to differentiate the porcine naive-like embryonic stem cells towards the neural-like cells. We have derived neural-like cells with identification of the neural specific gene expression. We detected whether these cells could show limited pluripotency. Results：The neural-like cells had obvious neuronal cell structure. RT-PCR and immunofluorescence data showed that the differentiated neurons expressed a variety of neural cell-specific genes. QPCR results showed that the expression of pluripotent factors was decreased significantly after differentiation process and the expression of nerve-specific genes was significantly increased. The results of immunofluorescence showed that the rate of light neurofilament protein（NF-L）positive cells reached 79%. Conclusion：Neural cells could be directly induced from porcine naive-like embryonic stem cells in vitro.

Abstract:Objective：This study aims to build inbred Wuzhishan miniature pigs with GGTA1/β4GalNT2 double gene knockout by CRISPR/Cas9 mediated targeting. Methods: Single-guide RNAs（sgRNAs） specific for the pig GGTA1 and β4GalNT2 were designed and synthesized，then cloned into the pX330 plasmid containing a Cas9 skeleton，respectively. The resulting targeting vectors for GGTA1 and β4GalNT2 were transfected into the primary porcine fetal fibroblasts（PFFs） derived from Wuzhishan miniature inbred pigs. G418 drug screening and Sanger sequencing were used to identify the monoclonal cells with GGTA1/β4GalNT2 double gene knockout. Somatic cell nuclear transfer（SCNT） was employed to generate Wuzhishan miniature inbred pigs using the obtained colonies as donor cells. Flow cytometry analysis was conducted to examine the αGal and Sd（a） antigen expression in peripheral blood mononuclear cell（PBMC） of the cloned piglets. Results：Cas9/sgRNA expression vectors targeting pig GGTA1 and β4GalNT2 genes were successfully constructed. After transfection into PFFs，9 cell colonies were obtained with biallelic modifications in both GGTA1 and β4GalNT2 loci. Ten cloned piglets were produced by SCNT. The expression of αGal and Sd（a）antigens on these cloned knockout piglets was negative. Conclusion：The CRISPR/Cas9 system showed high efficiency in pig gene targeting. The GGTA1/β4GalNT2 double gene knockout inbred Wuzhishan miniature pigs were successfully produced in the present study，which could serve as newly ideal materials for xenotransplantation.

Abstract:Objective：This study aims to construct the lentiviral vector carrying the cDNA encoding neuronal nitric oxide synthase（nNOS）of rat and to detect its expression and catalytic function. Methods：The cDNA of nNOS was extracted by RT-PCR followed by eukaryotic expression vector of CDH-GFP for cloning．After confirming the cDNA of nNOS by sequencing，cDNA of nNOS was cloned into the lentiviral vector pCDH-GFP for constructing recombinant vector pCDH-GFP/nNOS．The plasmid pCDH-GFP/nNOS was then transfected into 293T cells in the presence ofhelper plasmids by Lipofectamine 2000 mediation for packing lentiviral particles LV-nNOS-GFP．The cultured neuronal stem cells（NSCs）were used to verify whether LV-nNOS-GFP can infect NSCs by co- incubation with LV-nNOS-GFP Afterwards，LV-nNOS-GFP was injected into the dentate gyrys（DG）of the hippocampus to measure the expression of nNOS and the generation of nitric oxide（NO）. Results：The full length cDNA of nNOS could besuccessfully amplified and constructed into the recombinant lentiviral vector pCDH-GFP/nNOS. The packaged LV-nNOS-GFP successfully infected cultured NSCs and neurons in the hippocampal DG. The expressed nNOS was catalytic effective in catalyzing NO generation. Conclusion：The lentiviral vector of LV-nNOS-GFP was constructed successfully with functional nNOSexpression after infection.

Abstract:Objective：This study aims to investigate the role of N6-methyladenosine（m6A）reader protein Ythdf3 during spermatogenesis in knockout mouse model. Methods：We generated Ythdf3 knockout mice by CRISPR/Cas9 technology，and detected the role of Ythdf3 in spermatogenesis by immunofluorescence，HE staining. Results：Immunohistochemistry results showed that Ythdf3 expressed in the nuclear of spermatogonia and spermatocytes；Ythdf3 knockout mice were constructed successfully；HE staining results revealed spermatogenic wave and the morphology of epididymis cauda in Ythdf3 knockout mice were normal compared with control. Conclusion：Depletion of Ythdf3 did not affect mouse spermatogenesis in normal physiological condition.

Abstract:Objective：This study aims to construct a recombinant plasmid expressing fat mass and obesity associated（FTO）gene and to detect its effects on m6A modification and proliferation of mouse mesangial cells（MMCs）. Methods：The FTO gene fragment was amplified by PCR and inserted into the expression vector pCMV-MCS-EGFP plasmid to construct the recombinant plasmid pCMV-FTO. The target plasmid pCMV-FTO and the control plasmid pCMV were transfected into MMCs，respectively，and the mRNA expression of FTO was measured with real-time quantitative PCR（RT-qPCR）. The total protein was extracted，and FTO，EGFP，proliferation markers of Cyclin D1 and PCNA were detected by Western blotting. The proliferation of MMCs were studied with CCK8 method. The m6A content was measured using the m6A RNA methylation quantification kit. Results：Colony PCR identification and sequencing confirmed that the recombinant plasmid pCMV-FTO was successfully constructed. The results showed that the mRNA and protein level of FTO was significantly increased after transfection of the target plasmid pCMV-FTO. After overexpression of FTO，m6A content，the proliferation of MMCs and Cyclin D1，PCNA protein levels decreased significantly. Conclusion：FTO can reduce the level of m6A modification and inhibit cell proliferation in MMCs.

Abstract:Objective：This study aims to construct the promoter of human cyclic guanosine monophosphate-adenosine monophosphate synthase（cGAS）gene，and explore its promoter activity and transcriptional regulation mechanism. Methods：The 1 254 bp（-1 178~+76 bp）fragment of 5′ upstream of human cGAS gene was amplified by PCR and subcloned into pGL3-basic plasmid. By a series of 5′ deletion and promoter constructions，the core region of cGAS promoter was founded. Luciferase assays were used to detect the activity of recombinant plasmids in Hela cells. Then，the transcription factor binding sites in promoter region were predicted by bioinformatics. Finally，potential transcription factor binding sites were verified by point mutation experiments. Resluts：The luciferase reporter gene recombinant plasmids of cGAS gene promoter were successfully constructed. In comparison with the pGL3-basic plasmid，the relative luciferase activities of recombinant palsmids of cGAS promoter were much higher（P < 0.05）. What’s more，bioinformatics software predicts that the proximal promoter region of human cGAS（-414~+76 bp） may contain binding sites of transcription factors such as Sp1，CREB，USF1，RAP1，C-JUN and OCT-1. Sp1 and CREB positively regulated promoter region，which was confirmed by point mutation experiment. Conclusion：It is concluded that the proximal promoter core region of human cGAS has strong promoter activity，which contains many potential transcription factors binding sites. The transcription factor Sp1 and CREB regulates the human cGAS promoter region.

Abstract:Objective：To clone the promoter sequences of fat atypical cadherin 1（FAT1），and to preliminarily analyze the transcriptional regulatory mechanism of the promoter. Methods：Promoter region was consructed by bioinformatic methods，and the application of 1 163 bp（-1 029~+134 bp）fragment of 5′upstream sequence of FAT1 gene by PCR was conducted，followed by cloning to pGL3-basic vector to establish the luciferase report gene recombinant plasmid. Another four recombinant plasmids of different lengths were obtained through walking deletion and then cloned to pGL3-basic plasmid as before. The resultant plasmids were transfected into A549 cells and HEK293T cells respectively together with pGL3-basic vector. After this their activities were detected via dual-luciferase reporter assay. Bioinformatic methods was performed to predict the sequences of the potential transcriptional factor binding sites of the core region found in the promoter. Results：The lusiferase reporter gene recombinant plasmids of human FAT1 promoter were successfully conducted. The relative luciferase activities of recombinant promoters，in contrast to pGL3-basic vector，were much higher（P < 0.05）. Note the sequences of the binding sites such as TFAP2C、KLF5 were possibly included in the promoter region（-233~-110 bp）of FAT1 gene，which could bepredicted through bioinformatic means. Conclusion：The construction of the luciferase report recombinant plasmids of FAT1 gene were successfully done，and four of these plasmids had strong luciferase activities in A549 cells and HEK293T cells，comparing to the activities of pGL3-basic plasmid. Through this the core region was probably found. It is concluded the core promoter region of FAT1 gene was possibly located in the（-233~+134 bp）region，in which may preserve potential important transcriptional binding sites.

Abstract:Objective：This study aims to investigate the role of HOXA5 in HCC progression. Methods：RT-qPCR，Western blot，IHC were carried out to detect the expression of HOXA5 in HCC tissues and adjacent peritumor tissues. Hep3B and MHCC97H cells were chosen to establish the knockdown model. Colony formation assay，EdU assay，and CCK8 assay were performed to demonstrate the proliferation ability of HCC cells. Transwell assay and FACS technology were used to detected invasion and anti-apoptosis ability of HCC cells separately. Finally，Western blot was carried out to further confirm the possibile role that HOXA5 played in PI3K-AKT signal pathway. Results：Expression of HOXA5 at mRNA and protein level in HCC tissues were significantly higher than that in adjacent peritumor tissues. Knockdown of HOXA5 could reduce the proliferation，invasion and anti-apoptosis ability of HCC cells. Knockdown of HOXA5 could decrease the expression of phosphorylated PI3K and phosphorylated AKT，while ectopic expression of HOXA5 promoted the activation of this pathway. Conclusion：The expression of HOXA5 in HCC tissues is higher than that in adjacent tissues. Manipulation of HOXA5 expression in HCC cells had an impact on their proliferation，anti-apoptosis ability，invasion ability and activation of the PI3K-AKT signaling pathway in vitro.

Abstract:Objective：This study aims to explore the function of miR-590-3p in papillary thyroid cancer（PTC）. Methods：We examined the miR-590-3p expression in human PTC tissues and cell lines by RT-PCR. CCK-8，EdU，wound healing，Transwell，flow cytometry were performed to analyze PTC cell function. Changes of epithelial-mesenchymal transition（EMT）signaling proteins were detected by Western blot. Results：The expression of miR-590-3p was decreased in PTC tissues and cell lines. Compared with the normal control，knockdown of miR-590-3p promoted cell proliferation，migration，invasion and inhibited cell apoptosis in PTC cells（P < 0.01）. However，overexpression of miR-590-3p inhibited cell proliferation，migration，invasion and promoted cell apoptosis in PTC cells（P < 0.01）. And miR-590-3p significantly inhibited EMT process. Conclusion：MiR-590-3p acts as a tumor suppressor in PTC carcinogenesis and metastasis，and may be a therapeutic target for PTC.

Abstract:Objective：This study aims to detect the effect of mitochondria from high fat diet mice heart，and the effects of hypoxia-reoxygenation. Methods：A total of 12 2-week-old mice（male，C57B6）were randomly divided into high-fat-diet（HFD，n=6）group and control（CTR，n=6）group，and they were fed with high fat diet and normal diet respectively for 20 weeks. Hearts were used to isolate pure mitochondria. After the oxygen used up in the chamber，the mitochondria were subjected to 30 minutes of hypoxia-reoxygenation to simulate ischemia-reperfusion. Mitochondrial oxygen consumption rate（OCR）was measured using oxygen monitor system. Mitochondrial complex enzyme activity was assessed using microplate colorimetric assay kit. Reactive oxygen species（ROS）was measured by fluorimeter. Results：The mitochondrial OCR was greater in HFD group compared to that of CTR group（P < 0.05）. Similarly，mito-complex Ⅱ activity was significantly increased in HFD group compared to that of CTR group（P < 0.05）. Furthermore，reoxygenation of purified mitochondria following 30 min hypoxia transiently increased OCR，with significantly higher increase in HFD group. Pre-treatment of mito-complex Ⅱ inhibitor，malonate diminished reoxygenation-induced OCR increase in both groups. The similar tendency was also detected in ROS. Conclusion：Mito-complex Ⅱ activity was totally enhanced in the HFD model，which could be involved in the injury of hypoxia-reoxygenation（which simulated ischemia-reperfusion）in heart.

Abstract:Objective：This study aims to investigate the concentrations of interleukin（IL）-8 and IL-17 in bronchoalveolar lavage fluid of patients with stable chronic obstructive pulmonary disease（COPD），and analyze their correlations with clinical parameters. Methods：We recruited 109 patients with lung peripheral nodules who visited the Zhongda Hospital Affiliated to Southeast University between Dec.1st 2017 and May 30th 2018，including 79 patients with stable COPD，17 smokers with normal lung function，and 20 healthy non-smokers. Smoking history inquiry，COPD assessment test（CAT），modified Medical Research Council（mMRC）dyspnea index score were collected while spirometry，chest computed tomography and bronchoscopy were performed in all subjects. The levels of IL-8 and IL-17 in BALF were analyzed by enzyme linked immunosorbent assay（ELISA）. Results：The levels of IL-8 and IL-17 in the patients with stable COPD were significantly higher than those of the smokers and the healthy non-smokers（P < 0.01）. The concentration of IL-8 was correlated with IL-17 in all subjects（r=0.929，P < 0.001）and in the COPD patients（r=0.865，P < 0.001）. The levels of IL-8 and IL-17 were negatively correlated with forced expiratory volume in one second（FEV1）and maximum midexpiratory flow（MMEF），while positively correlated with CAT and mMRC. The correlations of IL-8 and IL-17 with emphysema index were significant in the COPD patients with mild emphysema（r=0.559，P < 0.001；r=0.627，P < 0.001），however with no indication among COPD patients with severe emphysema. Conclusion： In stable COPD patients，the levels of IL-8 and IL-17 in bronchoalveolar lavage fluid are increased significantly and correlated with the disease severity. IL-8 and IL-17 have correlation with clinical indicators such as CAT，mMRC，FEV1 and MMEF. The correlations of IL-8 and IL-17 with emphysema index are not significant in COPD patients with mild emphysema.

Abstract:Objective：A predictive value of neutrophil to lymphocyte ratio（NLR）for intracranial and extracranial artery stenosis in patients with acute cerebral infarction was explored to provide a reference for prediction and prevention of intracranial and extracranial artery stenosis in acute cerebral infarction. Methods：In this study，a total of 145 patients were enrolled in the Department of Neurology of the First Affiliated Hospital of Nanjing Medical University. Patients with ntracranial and extracranial artery stenosis were separated into 2 groups. The rate of intracranial and extracranial artery stenosis <50% was 95，and the stenosis rate of >50% was 50. Collection of baseline data and blood test indicators. All data were statistically analyzed by SPSS 19 software. Results：The age，white blood cell count，neutrophil count and NLR level in the patients with acute cerebral infarction were significantly higher than those in the control group，the differences were statistically significant. Lymphocyte count in the stenosis group was lower than that in the control group，the difference was statistically significant（P < 0.05）. Logistic regression showed that NLR（OR=1.492，P < 0.001）accounts for a risk factor for intracranial and extracranial atherosclerotic stenosis in patients with acute cerebral infarction. The ROC curve analysis showed that the area under the curve of leucocyte was 0.658，the AUC of neutrophils was 0.718，the lymphocyte AUC was 0.631，the combined index AUC is 0.725，and the NLR level AUC was 0.739. The best diagnostic value of NLR was 2.23. Conclusion：NLR plays a predictive role in intracranial and extracranial artery stenosis in patients with acute cerebral infarction.

Abstract:Objective：This study aims to analyze the severity of left ventricular posterior wall（LVPW） in patients with calcific aortic valve disease，and to evaluate the severity of the lesion and prognosis. Methods：Immunohistochemical staining，semi-quantitative analysis of optical density and RT-PCR were used to detect the calcification degree of valvular tissue in 60 patients with aortic valve calcification，who were divided into mild，moderate and severe aortic stenosis groups. The changes of ejection fraction（EF） before and after operation were compared，and the role of left ventricle post wall（LVWP） in judging the indication of operation and prognosis was evaluated. Results：LVWP in different degree of stenosis group was analyzed，and LVWP in mild，moderate and severe stenosis group was increased in turn，the difference was statistically significant. Through the semi-quantitative analysis of Von Kossa staining of valve tissue and RT-PCR analysis，the calcification degree of LVPW mild，medium and severe thickening group increased in turn，and the difference was statistically significant. The EF difference before and after surgery of patients with LVPW medium thickening was more than that of patients with LVPW mild thickening，and the difference was statistically significant. There was no significant difference in the EF increase in patients with LVPW severe thickening and patients with LVPW medium thickening. Conclusion：LVPW can be used to estimate the approximate degree of aortic valve calcification. For patients with severe calcification of non-aortic valve，the greater the LVPW value，the greater the benefit of surgery.

Abstract:Objective：To explore the application of SARIMA-ERNN combination model in predicting the incidence of bacterial dysentery in China. Methods：Using the monthly incidence data of bacterial dysentery in China from January 2005 to December 2016 as the training set，the SARIMA model，the ERNN model，and the SARIMA-ERNN combination model were established respectively. The monthly incidence of bacterial dysentery in China in 2017 which was used to test the efficacy of the above models was used as a test set. Results：The MRE，MER，RMSE and MAE fitted and forecasted by SARIMA model were 5.661 37，0.061 81，0.001 45，0.000 94 and 5.596 40，0.051 77，0.004 54，0.000 34 respectively. The MRE，MER，RMSE and MAE fitted and forecasted by ERNN model fit and predicted were 5.348 57，0.056 05，0.017 08，0.000 79 and 5.544 30，0.044 55，0.000 36，0.000 30 respectively；The MRE，MER，RMSE and MAE fitted and forecasted by SARIMA-ERNN combination model were 4.924 25，0.047 33，0.001 15，0.000 72 and 4.251 30，0.044 19，0.000 38，0.000 29 respectively. Conclusion：The SARIMA-ERNN combination model has high validity and reasonability that can be used for short-term forecasting and early warning of bacterial dysentery in China.

Abstract:Objective：To present a meta-analysis of high-quality published and classic randomized controlled trials（RCTs）in the past decade in comparison to laparoscopic surgery（LS）and open surgery（OS）for rectal cancer. Methods：Electronic literature search was performed on PubMed，EMBASE，Web of Science，OVID，CNKI，Wanfang Data and Cochrane Library from January 1，2007 to November 1，2018. All eligible RCTs were evaluated based on the Jadad score. We used the fixed effect model（FE）and the random effect model（RE）to analyze this cohort. Results：Among all the 14 included studies，a total of 3 288 cases were reported，including 1 779 patients in the LS group and 1 509 patients in the OS group. The results of the Meta-analysis demonstrated the operative time of the LS group was obviously longer than that of the OS group（MD=40.04，95%CI［24.07，56.01］，P < 0.05），LS was associated with less blood loss（MD=-98.48，95%CI［-148.72，-48.25］，P < 0.05），fewer blood transfusions（OR=0.30，95%CI［0.16，0.55］，P < 0.05），shorter bowel function recovery times（MD=-0.68，95%CI［-0.98，-0.38］，P < 0.05），shorter postoperative hospital stays（MD=-1.08，95%CI［-1.49，-0.66］，P < 0.05），fewer postoperative complications（OR=0.67，95%CI［0.46，0.97］，P < 0.05）and fewer wound infections（OR=0.52，95%CI［0.36，0.77］，P < 0.05）. However，no significant differences between the LS and OS groups were proximal resection margin，radial distal margin，the number of harvested lymph nodes，positive circumferential resection margin（CRM），reoperation，other postoperative complications（ileus，abdominal infection，lung infection，anastomotic fistula，anastomosis bleeding and anastomosis stenosis），local recurrence，3-year overall survival，5-year overall survival or 5-year disease-free survival. Conclusion：There are no significant differences between LS and OS in terms of the number of harvested lymph nodes，positive CRM，local recurrence or overall survival. More，LS for rectal cancer appears to be safer in blood loss，blood transfusions，bowel function recovery times and wound infections in comparison to OS.

Abstract:Objective：This study aims to assess the association between excision repair cross complementing 1（ERCC1）gene polymorphisms（rs3212986、rs11615）and susceptibility to pancreatic ductal adenocarcinoma. Methods：Evidence for this association was obtained by searching PubMed，Web of Science，EMBASE and CNKI. Data were extracted using standardized forms and odds ratios（ORs）with 95% confidence intervals（CIs）were used to assess the strength of association. All statistical analyses were performed using Stata 12.0. Results：Eight studies were enrolled in our final combined analysis. The results showed evidence for significant association between rs3212986 polymorphism and PDAC risk（CA vs. AA：OR=1.34，95% CI：1.11-1.63；CC vs. AA：OR=2.33，95% CI：1.73-3.14；AC+CC vs. AA：OR=1.50，95% CI：1.25-1.80；CC vs. CA+AA：OR=1.98，95% CI：1.50-2.62；C vs. A：OR=1.45，95% CI：1.27-1.66）. However，no association was observed between rs11615 and PDAC risk（CT vs. TT：OR=1.02，95% CI：0.87-1.21；CC vs. TT：OR=1.21；95% CI：0.93-1.56；TC+CC vs. TT：OR=1.06，95% CI：0.91-1.24；CC vs. CT+TT：OR=1.20，95% CI：0.94-1.53；C vs. T：OR=1.08，95% CI：0.96-1.21）. Conclusion：The allele gene C of ERCC rs3212986 is significantly associated with the risk of PDAC，while rs11615 might not contribute to the risk of PDAC.