Invasion and metastasis are the important biological features of malignant neoplasms,and are the main reasons for the death of patients with pancreatic neoplasms.Current researches find that invasion and metastasis of pancreatic neoplasms are closely related to series of molecular biological changes,including' abnormalities of tumor metastasis-related genes,degradation of extracellular matrix,tumor-induced angiogenesis,changes of the adhesion molecules and cytokines.However,the definite mechanism still remains unclear,and further researches are needed.

Objective To cultivate human retinal capillary endothelial cells (HRECs) and establish two-dimensional model of human retinal vessels in vitro. Methods In a fibronectin-coated raising pound, HRECs were cultured by non-serum human-endothelial-cells substrate and two-dimensional model of human retinal vessels was established. Horseradish peroxidase was used to detect the permeability. Some of the vascular models were cultivated with 5 ng/ml vascular endothelial growth factor (VEGF), whose changes of permeability was compared with which of the models without cultivation with VEGF. The effect of VEGF on vascular permeability was observed. Results Meshy vascular structure came into being due to the confluent HRECs after 2 to 4 days. Comparatively complete two-dimensional vascular model after about 6 days. VEGF increased vascular permeability and promoted the formation of blood vessels. Conclusion HRECs can be cultivated successfully with human-endothelial-cells substrate; standard retinal two-dimensional vascular model in vitro can be established by using cellular raising pound and non-serum human-endothelial-cells substrate.

Hemorrhage ; etiology ; surgery ; Humans ; Pancreaticoduodenectomy ; adverse effects

BACKGROUND: Embryonic stem cells (ESCs), the seed cells of all mature cells in vivo, are useful tools for nerve transplantation and developmental gene function research. Notch1 signaling pathway is the key pathway to control the ordered neural development and differentiation of many kinds of neural cells, however, there is no report on the dynamic expression of Notch1 signal during the ESC differentiation to date. OBJECTIVE: To investigate the expression of Notch1 protein, transmembrane signal transduction molecule, during directional differentiation of embryonic stem cells into neural cells. DESIGN, TIME AND SETTING: Cell research was carried out between October 2003 and October 2004 at Zhongshan Ophthalmic Center, SUN Yat-sen University, Guangzhou, Guangdong Province, China. MATERIALS: BALB/C mouse embryonic stem cell line Ⅵ (passage 11)was obtained from experimental animal center of SUN Yat-sen University, provided by professor Huang Bing. ESC culture medium was high-glucose DMEM medium with 20% bovine serum and 106 IU/L mouse leukemia inhibitory factor. Induced differentiation medium was high-glucose DMEM medium with 20% fetal bovine.serum and 5×107 mol/L retinoid acid(RA). METHODS: Passage 11 ESCs were resuscitated and incubated by ESC culture medium in incubator at 37℃ with 5% CO2. Passage 11 ESCs were subcultured after 2 or 3 days and RA was added into medium to induce differentiation. Three time points for observation were established: induced for 1, 5 and 9 days. MAIN OUTCOME MEASURES: Morphological changes were observed under inverted phase contrast microscope, MAP-2 antigen expressed in differentiated cells was detected by immunofluorescence method. Immunocytochemistry, Western Blot, flow cytometry assay were used to investigate the Notch1 protein expression. RESULTS: ESCs presented clone-like growth. After induced by RA for 9 days, single neural network was achieved around most of the cell clusters. With the prolongation of induction, MAP-2 positive neural cells increased gradually. Almost all ESC clones expressed Notch1 protein strongly or positively, but Notehl protein expression decreased gradually after induced differentiation (P < 0.01). CONCLUSION: Notch1 signal shuts off progressively during induction of ESCs into neural cells, which suggests Notch1 may play an important role in the differentiation of ESCs into neural cells.

Background Retinal Müller cells are important gliocytcs and the source of retinal stem cells.Researching the biological behavior of Müller cells is of important significance to the study on retinal physiopathological process and stem cell therapy of retinal diseases.To establish a stable culture method of Müller cells is a solid basis of relative basic research.Objective This study was to establish a simple and stable method of isolation and culture of human retinal Müller cells and provide sufficient and high-quality Müller cell source.Methods Human retinal Müller cells were isolated from healthy human donor eyes.The mixture solution of hyaluronidase (100 U) and 0.25％ trypsin were used to digest chopped retinal tissue.The DMEM/F12 medium with 20％ fetal bovine serum (FBS) was added to stop the digestion process.RPMI1640 medium with 20％ FBS was used to culture the cell for 72 hours and then replaced the half medium.The cells were passaged by the RPMI1640 medium with 20％ FBS.The morphology of the cells were examied under the optical microscope,and the expressions of glial fibrillary acidic protein (GFAP),a marker of gliocytes,and glutamine synthetase (GS),a special marker of retinal Müller cells,were detected by immunochemistry and immunofluorescence technology.Results Human retinal Müller cells were successfully isolated by enzyme mixture solution of hyaluronidase (100 U) and O.25％ trypsin.The cells were adherent to walls 24 hours after primary culture and completely merged 9-10 days after culture.The cells showed oval in shape with abundant cytoplasm,and a part of cells presented with cone-shaped bulge bilaterally and ectasia in the posterior containing large nuclei.After cells passage,the cells were enlarged and grew toward polygonal shape.The positive expression of GFAP was observed in more than 95％ cells and strongly positive expression of GS was observed in more than 90％ cells by immunohistochemstry and immunofluorescent staining.Conclusions Human retinal Müller cells can be successfully isolated by hyaluronidase combined with trypsin digestion.Abundent and pure human retinal Müller cells can be obtained by successively using RPMI1640 medium with 20％ FBS and 10％ FBS.

Objective To explore the incidence,clinical features,causes,treatment method and risk factors of 30-day readmission after bariatric and metabolic surgery.Methods The retrospective case-control study was conducted.The clinical data of 631 obese patients who underwent bariatric and metabolic surgery in the First Affiliated Hospital of Nanjing Medical University from May 2010 to May 2016 were collected.All the 631 patients underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB).Patients were followed up by outpatient examination and telephone interview for 1 month to detect readmission of patients up to June 2016.Observation indicators:(1) 30-day readmission situations after bariatric and metabolic surgery:cases with readmission,readmission time,clinical features,causes and treatment of readmission;(2) risk factors analysis affecting 30-day readmission after bariatric and metabolic surgery.Measurement data with skewed distribution were described as M (range).The univariate analysis and multivariate analysis were respectively done using the chi-square test and Logistic regression model.Results (1) Thirty-day readmission situations after bariatric and metabolic surgery:among 631 patients receiving postoperative 1-months follow-up,21 had 30-day readmission,with an incidence of 3.33％ (21/631),including 13 males and 8 females;10 received LSG and 11 received LRYGB.The median readmission time of 21 patients was 12 days (range,4-30 days).Of 21 patients,nausea,vomiting and dehydration of the main manifestations were detected in 11 patients,gastrointestinal bleeding in 6 patients,high fever in 2 patients,bowel obstruction in 1 patient and abdominal pain in 1 patient.The causes of the readmission of 21 patients:8 had improper food intake including 5 with premature solid food intake,1 with premature semi-fluid food intake,1 with irritating food intake and 1 with swallowing whole tablets;3 had postoperative over-anxiety;1 had Petersen hiatal hernia;1 had anastomotic ulcer;1 had anastomotic edema;1 had abdominal abscess.Of 6 patients with uncertain causes,4 had gastrointestinal bleeding and didn't receive endoscopy;1 had postoperative unexplained abdominal pain and underwent laboratory and imaging examinations and gastroscopy,showing no trouble finding;1 had high fever,and no abnormality was detected by imaging examination.Of 21 patients,19 underwent conservative treatment (rehydration and acid suppression) and then discharged from hospital after improvement,without readmission;1 with abdominal abscess was cured after emergency debridement and drainage;1 with Petersen hiatal hernia was cured by emergency surgery.The median duration of hospital stay in 21 patients with readmission was 7 days (range,3-40 days).(2) Risk factors analysis affecting 30-day readmission after bariatric and metabolic surgery:the results of univariate analysis showed that gender,preoperative adephagia habit and duration of postoperative hospital stay were related factors affecting 30-day readmission after bariatric and metabolic surgery (x2 =5.330,6.498,4.574,P＜0.05).The results of multivariate analysis showed that male and preoperative adephagia habit were independent risk factors affecting 30-day readmission after bariatric and metabolic surgery (OR=2.489,2.912,95％ confidence interval:1.006-6.161,1.196-7.088,P＜0.05).Conclusions Nausea,vomiting and dehydration are common manifestations of patients with 30-day readmission after bariatric and metabolic surgery,and it might be associated with improper food intake.Male and preoperative adephagia habit are independent risk factors affecting 30-day readmission after bariatric and metabolic surgery.

AIM: To study the function of activin receptor-like kinase Ⅰ(ALK1) gene in vascular endothelium.METHODS: The human umbilical vein endothelial cells(HUVECs) were cultured,and the change of expression of ALK1,ALK5 in activation of HUVECs was analyzed.The full-leng coding sequence of ALK1 was cloned into pcDNA3.1+using standard protocols.The constructed pcDNA3.1+ALK1 plasmid were transfected into HUVECs.The proliferation and migration of HUVECs were detected by boyden champer and flow cytometry.RESULTS: The expression of ALK1 was up-regulated in resolution.ALK1 promoted the proliferation and migration of HUVECs.CONCLUSION: ALK1 has an important function in remodeling by promoting the proliferation and migration of endothelial cells.

Objective To evaluate the effects of ischemic preconditioning(IP) on liver function,complications and hospital stays after hepatectomy under hepatic vascular exclusion by a meta-analysis.Methods Randomized controlled trials(RCTs) were identified from PUBMED,EMBASE,the Cochrane Library,VIP,CNKI and Wanfang Data according to the inclusion and exclusion criteria.Literature screening,data extraction and quality assessment were made and the meta-analysis was processed by RevMan 4.2.2.Results Eight RCTs involving a total of 511 patients were included.The methodological quality was evaluated and all the trials were in graded B.The meta-analysis revealed that the postoperative ALT peak level(weighted mean difference=-176.37;95%CI:-320.67~-30.06;P=0.02)and postoperative complications incidence(odd ratio=0.64;95%CI: 0.41~0.98;P=0.04)were lower in IP group compared with control group,but there were no significant differences in blood loss,operating time,hepatic vascular exclusion time,postoperative AST and total bilirubin peak level,and hospital stays in both groups.Conclusions IP reduces the postoperative ALT peak level and complications incidence after hepatectomy under hepatic vascular exclusion,but there is no sufficient evidence to support that the IP can protect the liver from ischemia/reperfusion injury.

Objective To investigate the correlation of serum total bile acid (TBA) levels with the inflammation grades of liver tissue in chronic liver diseases.Methods Cyclophorase assay was used to detect the serum TBA levels in 172 patients with various chronic liver diseases,and the inflammation grades of liver tissue were determined by liver biopsy.The correlation between serum TBA levels and the inflammation grades of liver tissue was evaluated using SPSS 12.0 software.Results Serum TBA level was positively correlated with the inflammation grade of liver tissue ( r =0.275,P ＜ 0.01 ).The inflammation grade reached G2 when serum TBA was 20 μmol/L.Conclusion Serum TBA level may be useful for evaluating the inflammation grade of liver tissue in chronic liver diseases.