Geometrically virtual models of three-dimensional blood flow field and eight types of mesh stent (different porosity and different stent shape) were constructed using SoildWorks software, and simulation of stented models were performed respectively using finite element software ANSYS11.0 according to computation fluid dynamics method. The flow resistance of the semi-circular section stent model of blood flow from the semi-circular planar surface was greater than the reverse in a certain range of permeability. However, the result was the opposite when the porosity increased to a specific value. For both grid-stent model and sine-stent model, flow resistance of blood that flowed from the stent in both directions increased with the porosity reduction. Under the same porosity and the direction of blood flow from the same stent, the flow resistance of the grid stent model was 1.5 times greater than the sine-stent model. Results showed that there are different effects on the flow resistance in blood flow in different directions from the semi-circular section stent model.

Objective To analyze the changes of distribution and drug resistance of isolated pathogens for ventilator-associated-pneumonia (VAP) in seven intensive care units from January 2013 to December 2015,so that provides information for clinical antibiotic treatment.Methods Collected the patient records diagnosed with VAP to get the distribution and drug resistance of isolated pathogens for VAP in ICU from January 2013 to December 2015.Compared the distribution of isolated pathogens for VAP among three year with Chi-square tests,and compared the drug resistance of main isolated pathogens with Nonparametric tests.Results 177 patients were diagnosed with VAP from January 2013 to December 2015.A total of 192 strains of pathogens were isolated from the VAP patients in ICU.Among which the gram-negative bacteria were dominant.It took up 90.6％.There was no significant statistical difference for the distribution of pathogens (x2 =2.372,P=0.668＞0.05).Analyzed the drug resistance rate and trends for the primary pathogens like Acinetobacter Bauman,Pseudomonas aeruginosa and Staphylococcus aureus,among which,the drug resistance of Acinetobacter Bauman from 2013 to 2015 made statistical difference.Conclusion The major pathogen isolated from VAP patients was gram-negative bacteria from January 2013 to December 2015,especially for Acinetobacter Bauman.Drug resistance of Acinetobacter Bauman was serious.Should administrated appropriate to treat the VAP infection resulted from Acinetobacter Bauman.

Objective To compare the various surgical procedures commonly used to treat ampullary neoplasms.Methods The clinical data of 238 patients with ampullary tumor who were admitted to the Peking Union Hospital from January 1995 to June 2012 were retrospectively analyzed.There were 51 patients with benign ampullary adenomas (34 patients treated with local tumor resection,17 patients treated with pancreaticoduodenectomy) and 187 patients with ampullary cancer (25 patients treated with ampulla local excision,162 patients treated with pancreaticoduodenectomy).Results For both ampullary cancer and benign tumor,the group of patients who received local excision was superior to the group of patients who received pancreaticoduodenectomy in operative time,blood loss,hospital stay,and incidence of postoperative complications (all P＜0.05).For benign ampullary adenomas,there were no significant differences in postoperative median survival time between local resection and pancreaticoduodenectomy (P=0.071,x2 =2.003).For stage T1 or T2 ampullary cancer,there was also no significant difference in the postoperative median survival time (P=0.054,x2=3.163).However,the postoperative median survival time of the pancreaticoduodenectomy group was significantly longer than that of the local resection group for patients with stage T3 or T4 ampullary cancer (P=0.041,x2 =6.309).Conclusions Ampullary tumors are characterized by relatively good response to treatment.The results suggested that for patients with benign ampullary adenomas and stage T1 or T2 of ampullary cancer,local resection is a good surgical procedure.For patients with ampullary cancer at more advanced stages (T3 or T4),pancreaticoduodenectomy is the first choice of therapy.

This study examined the association of expression of vascular endothelial growth factor (VEGF), a promoter of angiogenesis, with endothelium dysfunction in preeclampsia. The level of VEGF protein and mRNA in the placenta and peripheral blood samples of 30 preeclampsia patients and 30 normotensive pregnant women was measured by immunohistochemistry, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. VEGF expression in the human umbilical vein endothelial cells (HUVECs) was blocked by small interfering RNAs (siRNAs). The monolayer barrier function of HUVECs was determined by measuring the fluorescence intensity of BSA that crossed the HUVEC monolayers. The cell proliferation and cell-secreted nitric oxide (NO) level were detected by MTT method and nitrate reductase assay, respectively. The results showed that VEGF was expressed in the syncytiotrophoblasts and endothelial cells of vessels and capillaries in the placenta tissue. The serum level of VEGF in the preeclampsia patients was significantly decreased as compared with that in normal pregnant subjects, although VEGF mRNA expression in the placenta tissue of preeclampsia patients remained still high. Moreover, VEGF deficit could lead to endothelium cell dysfunction, and the administration of VEGF could protect endothelium cells from injury. It was concluded that lack of VEGF contributes to endothelium dysfunction, which may lead to the occurrence and development of preeclampsia.

Objective To explore the test-retest reliability of the open field test,as a method for ethology in Kunming mice. Methods The behavior of adult male Kunming mice in the open field test was recorded twice,once for five minutes, with a one-week inter-trial interval. The following parameters were evaluated:number of central squares; number of peripheral squares; percent of central squares; number of horizontal squares; number of rearings; total score; and number of fecal boli. Subsequently,the intraclass correlation coefficient (ICC) and the agreement index (Kappa) were calculated for each of these parameters. Results Both ICC and Kappa for total score( ICC =0.902, P＜0.01; Kappa =0.680, P＜0.01; r=0.815, P＜0.01 ) showed a good reliability and correlation between the test trials. Only ICC for number of central squares ( ICC = 0. 578, P ＜ 0.01 ), number of peripheral squares( ICC =0.615, P＜0.01 ) ,percent of central squares(ICC=0.523, P＜0.01) ,number of horizontal squares( ICC = 0. 607, P ＜ 0.01 ) and number of rearings ( ICC = 0. 606, P ＜ 0.01 ) indicated a fair reliability between the test trials. Neither ICC nor Kappa for number of fecal boli displayed a significant reliability between the test trials. The difference of these parameters between test and retest, such as number of peripheral squares( t =3.01, P＜0.01 ),number of horizontal squares( t = 3.34, P ＜ 0.01 ) and total score( t = 7.86, P ＜ 0.01 ) were significant. Conclusion The parameter,total score for Kunming mice in the open field test,is found to be stable over time, and indicates a good reliability with a one-week inter-trial interval.

Objective To investigate the correlation between clinicopathological features and lymph node metastasis (LNM) in early gastric cancer (EGC).Methods From January 2006 to June 2009,the clinical data of 473 patients with EGC were collected.The data of patients including gender,age,tumor size,tumor number,general classification,differentiation degree,invasion depth,ulcer in tumor,nerve invasion,and lymphatic tumor cell embolus were analyzed.Chi-square test was performed to analyze the correlation between clinicopathological features and LNM in EGC.Logistic regression analysis was used to analyze the independent risk factor of LNM in EGC.Results Among 473 patients with EGC,77 patients had LNM and the metastasis rate was 16.3％.The metastasis rate of the female patients (24.6％,41/167) was higher than that of the male (11.8 ％,36/306).The metastasis rate of the tumors with maximum diameter over 2 cm (22.0％,39/177) was higher than that of the tumors less than 2 cm (12.8％,38/296).The metastasis rate of the elevated lesions (26.1％,6/23) was higher than that of flat and concave lesions (9.0 ％,15/167;19.8％,56/283).The metastasis rate of poorly differentiated tumors was higher than moderate differentiated and high differentiated tumors (12.7 ％,23/181; 7.1％,3/42).The metastasis rate of tumors invading into submucosa (22.9％,41/179) was higher than that of tumors invading into mucosa (12.2％,36/294).The metastasis rate of tumors with lymphatic embolus (40.7％,11/27) was higher than that of tumors without lymphatic embolus (14.8％,66/446) and the differences were statistically significant (x2 =12.960,6.873,10.704,7.382,9.277 and 12.572,all P＜0.05).The results of multifactor analyzed by Logistic regression analysis revealed that female,maximum diameter over 2 cm,poorly differentiated type and invasion to submucosa were the independent risk factors of LNM in EGC (relative risk (RR)=2.53,2.14,1.63 and 2.39,all P＜0.01).Conclusion Female,maximum diameter over 2 cm,poorly differentiated type and invasion to submucosa are the independent risk factors of LNM in EGC.

Objective To investigate the clinical efficacy of the superior pancreatic region approach guided by pancreatic capsule in laparoscopic radical gastrectomy of 438 patients.Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 438 patients who underwent laparoscopic radical gastrectomy of gastric cancer in the Second Hospital of Jilin University between April 2013 and April 2017were collected.Patients were confirmed with stage T2 and above by postoperative pathological examination and then underwent adjuvant chemotherapy of XELOX regimen.Observation indicators:(1) surgical situation;(2)postoperative recovery situation;(3) postoperative pathological examination;(4) follow-up situation.Follow-up using outpatient examination and telephone interview was performed to detect the postoperative adjuvant chemotherapy,postoperative long-term complications and tumor metastasis or recurrence up to May 2017.Measurement data with normal distribution were represented as x±s.Results (1) Surgical situation:all the 438patients underwent laparoscopic radical gastrectomy of gastric cancer through the superior pancreatic region approach guided by pancreatic capsule,including 295 undergoing distal gastrectomy and 143 undergoing total gastrectomy.There were no conversion to open surgery.Operation time and volume of intraoperative blood loss were respectively (178 ±32) minutes and (39± 11)mL.There were no intraoperative complications and death in perioperative period.(2) Postoperative recovery situation:time to anal exsufflation,time for fluid diet intake and duration of hospital stay were (32±6) hours,(26±3) hours and (8.7±2.3) days,respectively.Volume of amylase drainage was (157±35) U/L at postoperative day 1,(68±25) U/L at postoperative day 2 and (43±17) U/L at postoperative day 3,respectively.No pancreatic fistula occurred postoperatively.(3) Postoperative pathological examination:results of postoperative pathological examination showed that 218,209 and 11 patients were detected in T2,T3 and T4a staging,respectively.Numbers of lymph node dissected and lymph node metastases were respectively 27.0± 6.0 and 4.2-± 2.9.Pathological typing:high-or moderate-differentiated adenocarcinoma,lowdifferentiated adenocarcinoma and undifferentiated carcinoma or signet-ring cell carcinoma were detected in 67,279 and 92 patients,respectively.(4) Follow-up situation:of 438 patients,415 were followed up for 1-48months,with a median time of 33 months of 438 patients,293 received postoperative adjuvant chemotherapy of XELOX regimen,122 received unknown adjuvant chemotherapy or refused chemotherapy.During the follow-up,there was no oecurrence of tumor-related complications,13 patients had tumor metastases or recurrence and 5patients died of tumor recurrence or metastases.Conclusion The superior pancreatic region approach guided by pancreatic capsule is safe and feasible in laparoscopic radical gastrectomy.

Objective To explore the effect of postnatal infection on SOX10 expression in cerebral white matter in immature rats. Methods A total of 96 newborn SD rats were randomly divided into hypoxia group, lipopolysaccharide (LPS) group, and control group. At day 3 and 6 after birth, the rats in LPS group and hypoxia group were intraperitoneally injected with 0.25 mg/kg of LPS while the rats in control group were injected with normal saline. Meanwhile the rats in hypoxia group were maintained in a hypoxic tank under atmospheric pressure and thermostatic water bath at 37℃for 2 hours of ventilation with mixed gas con-taining 8%O2 and 92%N2 at a rate of 2 L/min starting 3 days after birth. At day 7, 10, 14, 21 after birth, eight rats in each groups were sacriifced and the cerebral white matter was extracted. HE staining was performed to observe the pathological changes of cerebral white matter by light microscopy. The expression of SOX10 in cerebral white matter was determined by immunohisto-chemical and Western blotting analysis. The expression of TLR-4 was determined by Western blotting. Results In LPS group and hypoxia group, the SOX10 positive cells and expressions of SOX 10 and TLR-4 were increased at day 7, reached the peak at day 10, and then gradually declined. There were signiifcant differences between any two time points (P<0.05). In control group, there were a few positive cells and limited expressions of SOX 10 and TLR-4 and there were no differences between any two time points (P>0.05). At each time point, the difference in the SOX10 positive cells and the expressions of SOX 10 and TLR-4 were statistically signiifcant among three groups (P<0.05) in the order of hypoxia group>LPS group>control group and there were signiifcantly differences between each groups (P<0.05). Conclusions Postnatal infections can lead to cerebral white mat-ter lesions in immature rats. The existence of both hypoxia and infection can aggravate the brain injury. The high expression of SOX 10 may have the protective effect.

Objective To study the risk factors and to provide preventive measures of pulmonary infection for patients with severe brain injury.Methods A total of 320 patients with severe brain injury were analyzed with hospital-based case-control study method.A total of 101 patients complicated with lung infection were set as the experimental group.Another 101 patients with no pulmonary infection according to the proportion of 1:1 choice over the same period were set as the control group.The related factors were analyzed with the univariate analysis and the multiple factors Logistic regression analysis.Results Univariate analysis showed that the occurrence of pulmonary infection of patients with severe brain injury was closely related to the old age,low GCS score,long time stay in the bed,long time hormone application,long time antibiotic application,the combined underlying disease,use of mechanic ventilation,long-term smoking history and indwelling gastric tube.Multivariable Logistic regression analysis showed that the application of mechanic ventilator,the combined underlying disease and long time stay in bed were the independent risk factors for pulmonary infection of patients with severe brain injury,but GCS score was a protective factor.Conclusions The occurrence of lung infection were related to the ventilator application,the combined underlying disease,long time stay in bed and low GCS score.Considering these risk factors,the medical staffs should take preventive measures early to control lung infection.

Objective:By comparing the expression levels of retinoic acid-related orphan nuclear receptorγt( RORγt) and in-terleukin-17 ( IL-17 ) in newborn rats′spleen tissue with cytomegalovirus infection with normal newborn to provide experimental evidence for the pathogenesis of CMV infection.Methods:Forty-eight newborn BALB/c mice were randomly divided into control group and MCMV group.Mice in virus group was given intraperitoneal injection of MCMV virus suspension,while the control group were given the same dose of normal saline as controls.Eight mice in the two groups were killed at day 3,7 and 14.The animal were sacrificed at day 3,7 and 14( n=8 for each interval) and spleens were obtained from the two groups.MCMV DNA,RORγt mRNA,IL-17 mRNA and protein of RORγwere detected by using RT-PCR and Western blot between the two groups.Results:Expression of MCMV DNA was in-creased in the MCMV group but absent in the control group.RORγt mRNA, IL-17 mRNA and protein expression of RORγt were significantly higher than the normal control group,with the extension of the infection time gradually increased( P<0.05 ) .Conclusion:The IL-17 and RORγt in spleen tissue may take part in the inflammatory response induced by MCMV, and may be involved in the pathogeneses of MCMV injury.