Abnormal aggregation of amyloid-β protein (Aβ) in brain plays a vital role in the occurrence of Alzheimer's disease (AD). Hence, inhibiting Aβ aggregation is one major tactic for therapy of AD. Previous studies have found that tolcapone can inhibit Aβ42 aggregation and reduce the cytotoxicity induced by Aβ42 aggregates, but clinical studies have found that tolcapone has strong liver toxicity. To reduce the liver toxicity of tolcapone, its side chain structure was modified to obtain its derivative phenethyl (E)-2-cyano-3-(3,4 dihydroxy-5-nitrobenzene)-acrylate (PCDNA). Thioflavin T (ThT) and atomic force microscopy (AFM) assays were used to explore the inhibitory effect of PCDNA on Aβ42 fibrillogenesis. The cytotoxicity assays were used to explore the inhibitory effect of PCDNA against the cytotoxicity induced by Aβ42 aggregates. In addition, the depolymerization effect of PCDNA on mature Aβ42 fibrils was also explored. Finally, molecular docking was used to explore the interaction between PCDNA and Aβ42 pentamer. These results lay the foundation for the study of the structural analogues of tolcapone as Aβ inhibitors.

Objective    To define the patient characteristics and perioperative management, and to define the mortality and its risk factors after arterial switch operation (ASO). Methods    We conducted a bidirectional cohort study with 571 consecutive patients undergoing ASO from 1997 to 2016 in our hospital. We enrolled patients who underwent ASO before 2012 retrospectively and after 2012 prospectively and followed up all the patients prospectively. Demographic characteristics, clinical information and mortality of these patients were summarized. Joinpoint regression analysis was used to identify the time trend of the overall mortality. Kaplan-Meier survival analysis was used to evaluate the mid- and long-term survival rate after ASO. Cox proportional hazards regression models were used to explore the potential factors associated with mortality. The cumulative incidence of complications after ASO was predicted using competing risk models. Results    Several aspects of patients’ characteristics and perioperative management in our center differed from those in the developed countries. The overall mortality and in-hospital mortality after ASO was 16.3% and 15.1%, respectively. The overall cumulative survival rate at 5, 10 and 15 years after ASO was 83.3%, 82.8% and 82.8%, respectively. A significant decrease of overall mortality from 1997 to 2016 was observed. Independent risk factors of mortality included earlier ASO (1997-2006), single or intramural coronary anatomy and longer cardiopulmonary bypass time. Ten years after ASO, re-intervention, arrhythmia, pulmonary and anastomotic stenosis were the most common complications with a cumulative incidence over 10%. Conclusion    Significant improvements in the results of the ASO were observed and the postoperative mortality rate is close to reports from developed countries. Nonetheless, we have identified the need for further improvement in the early and late postoperative periods after ASO. Pulmonary stenosis, anastomotic stenosis and arrhythmia should be paid attention to during the long-term follow-up after ASO.

Objective:To study the toxicity of dioctyl phthalate (DOP) on adrenal pheochromocytoma (PC12) cells and its effect on processing of amyloid precursor protein (APP) -enzymolysis.Methods:In vitro experiments, PC12 cells were divided into blank control (CT) , low DOP (DOP1) , medium DOP (DOP2) , high DOP (DOP3) , low DOP+Aβ 25-35 (DOP1+Aβ) , medium DOP+Aβ 25-35 (DOP2+Aβ) , high DOP+Aβ 25-35 (DOP3+Aβ) , Aβ 25-35 (Aβ) , a total of 8 groups, each with 4 samples. The cell viability was measured by MTT assay, the contents of lactate dehydrogenase (LDH) , malondialdehyde (MDA) and nitric oxide (NO) were measured, and cysteine protease 3 (Caspase-3) was determined by Western blot. In the transfection experiment, the hamster ovary (CHO) cells were transfected with APP695 and treated with different concentrations of DOP. They were divided into V-Flag control (V-Flag) , APP695-Flag (APP695) , low DOP (DOP1+APP695) , medium DOP (DOP2+APP695) , high DOP (DOP3+APP695) , a total of 5 groups, each with 4 samples. Enzyme-linked immunosorbent assay (ELISA) was used to determine the content of Aβ 1-40 and the activity of γ-secretase. In vivo experiment, 50 male Kunming mice of SPF grade, weighing (20±2) g, were selected and randomly divided into control, lead (Pb) , low DOP (DOP1＇) , medium DOP (DOP2＇) , high DOP (DOP3＇) consisted of 5 groups, each with 10 mice, continuously gavage for 6 weeks. Morris water maze method was used to detect the effect of different concentrations of DOP on learning and memory in mice, and ELISA method was used to detect β-secretase, γ-secretase activity and Aβ 1-40 content in brain tissue. Results:Compared with the CT group, the cell viabilities of the DOP2 and DOP3 groups were decreased, and the contents of LDH, MDA, and NO were increased, and the differences were statistically significant ( P<0.05) . Compared with the CT group, the cell viabilities of DOP1+Aβ, DOP2+Aβ and DOP3+Aβ groups were decreased, the contents of LDH, MDA, NO were increased, the differences were statistically significant ( P<0.05) . Compared with the Aβ group, the cell viability of DOP3+Aβ group was decreased, the contents of LDH, MDA, NO were increased, the differences were statistically significant ( P<0.05) . Compared with the Aβ group, the contents of LDH and NO in the DOP2+Aβ group were increased, and the differences were statistically significant ( P<0.05) . Compared with the CT group, the expression levels of Caspase-3 in the DOP2 and DOP3 groups were increased, and the differences were statistically significant ( P<0.05) . Compared with the Aβ group, the expression levels of Caspase-3 in the DOP2+Aβ and DOP3+Aβ groups were increased, and the differences were statistically significant ( P<0.05) . Compared with the APP695 group, the contents of Aβ 1-40 and the activities of γ-secretase of the DOP2+APP695 and DOP3+APP695 groups were increased ( P<0.05) . Compared with the control group, the activities of β-secretase, γ-secretase and the content of Aβ 1-40 in the brain tissue of DOP3＇group were increased, and the differences were statistically significant ( P<0.05) . Compared with the Pb group, the activities of β-secretase, γ-secretase and the content of Aβ 1-40 of the DOP3＇group were increased, and the differences were statistically significant ( P<0.05) . Compared with the control group, the target quadrant stay time and the number of crossings in the DOP2＇and DOP3＇groups were reduced, and the differences were statistically significant ( P<0.05) . Conclusion:DOP has a certain toxic effect on PC12 cells, causing learning and memory impairment in mice, and may promote the pathological progression of Alzheimer＇s disease.

Objective:To study the toxicity of dioctyl phthalate (DOP) on adrenal pheochromocytoma (PC12) cells and its effect on processing of amyloid precursor protein (APP) -enzymolysis.Methods:In vitro experiments, PC12 cells were divided into blank control (CT) , low DOP (DOP1) , medium DOP (DOP2) , high DOP (DOP3) , low DOP+Aβ 25-35 (DOP1+Aβ) , medium DOP+Aβ 25-35 (DOP2+Aβ) , high DOP+Aβ 25-35 (DOP3+Aβ) , Aβ 25-35 (Aβ) , a total of 8 groups, each with 4 samples. The cell viability was measured by MTT assay, the contents of lactate dehydrogenase (LDH) , malondialdehyde (MDA) and nitric oxide (NO) were measured, and cysteine protease 3 (Caspase-3) was determined by Western blot. In the transfection experiment, the hamster ovary (CHO) cells were transfected with APP695 and treated with different concentrations of DOP. They were divided into V-Flag control (V-Flag) , APP695-Flag (APP695) , low DOP (DOP1+APP695) , medium DOP (DOP2+APP695) , high DOP (DOP3+APP695) , a total of 5 groups, each with 4 samples. Enzyme-linked immunosorbent assay (ELISA) was used to determine the content of Aβ 1-40 and the activity of γ-secretase. In vivo experiment, 50 male Kunming mice of SPF grade, weighing (20±2) g, were selected and randomly divided into control, lead (Pb) , low DOP (DOP1＇) , medium DOP (DOP2＇) , high DOP (DOP3＇) consisted of 5 groups, each with 10 mice, continuously gavage for 6 weeks. Morris water maze method was used to detect the effect of different concentrations of DOP on learning and memory in mice, and ELISA method was used to detect β-secretase, γ-secretase activity and Aβ 1-40 content in brain tissue. Results:Compared with the CT group, the cell viabilities of the DOP2 and DOP3 groups were decreased, and the contents of LDH, MDA, and NO were increased, and the differences were statistically significant ( P<0.05) . Compared with the CT group, the cell viabilities of DOP1+Aβ, DOP2+Aβ and DOP3+Aβ groups were decreased, the contents of LDH, MDA, NO were increased, the differences were statistically significant ( P<0.05) . Compared with the Aβ group, the cell viability of DOP3+Aβ group was decreased, the contents of LDH, MDA, NO were increased, the differences were statistically significant ( P<0.05) . Compared with the Aβ group, the contents of LDH and NO in the DOP2+Aβ group were increased, and the differences were statistically significant ( P<0.05) . Compared with the CT group, the expression levels of Caspase-3 in the DOP2 and DOP3 groups were increased, and the differences were statistically significant ( P<0.05) . Compared with the Aβ group, the expression levels of Caspase-3 in the DOP2+Aβ and DOP3+Aβ groups were increased, and the differences were statistically significant ( P<0.05) . Compared with the APP695 group, the contents of Aβ 1-40 and the activities of γ-secretase of the DOP2+APP695 and DOP3+APP695 groups were increased ( P<0.05) . Compared with the control group, the activities of β-secretase, γ-secretase and the content of Aβ 1-40 in the brain tissue of DOP3＇group were increased, and the differences were statistically significant ( P<0.05) . Compared with the Pb group, the activities of β-secretase, γ-secretase and the content of Aβ 1-40 of the DOP3＇group were increased, and the differences were statistically significant ( P<0.05) . Compared with the control group, the target quadrant stay time and the number of crossings in the DOP2＇and DOP3＇groups were reduced, and the differences were statistically significant ( P<0.05) . Conclusion:DOP has a certain toxic effect on PC12 cells, causing learning and memory impairment in mice, and may promote the pathological progression of Alzheimer＇s disease.

Objective To explore the effect of the surgical treatment in neonates with congenital heart disease(CHD) and the factors related to the perioperative mortality during cardiopulmonary bypass. Methods Totally,666 neonates undergo-ing CHD operation were reviewed in a single center from Jan 2006 to Dec 2014,of which,431 cases had complete cardiopul-monary bypass records. Analysis was performed to investigate the association between perioperative mortality and potential fac-tors,especially the cardiopulmonary bypass factors during different periods. In the multivariate Cox proportional hazard model, factors with statistical significance(P < 0. 1)in the univariate analysis were included in the model,such as,surgeon grouping, year of surgery,Aristotle score,preoperative weight,preoperative and intraoperative sodium bicarbonate volume and postopera-tive low cardiac output. Results The neonates enrolled ranged 8 - 22 days after birth,and 2. 7 - 3. 6 kg at weight. The mor-tality rate decreased from 23. 7％ in 2006 to 12. 4％ in 2014,showing a gradual decline(P = 0. 02). The mortalities of differ-ent CHDs were:pulmonary atresia(24. 4％),coarctation of the aorta( 16. 7％),transposition of the great arteries( 13. 1％), total anomalous pulmonary venous connection( 11. 0％),ventricular septal defect( 10. 6％),and so on. The volume of preop-erative and intraoperative 5％ sodium bicarbonate was 30(20 - 50)mL in death group,higher than that in survival group[23 ( 15 - 30)ml]. While the preoperative weight was 3. 1(2. 7 - 3. 5)kg,lower than that in survival group[3. 3(3. 0 - 3. 6) kg]. The total amount of Plasmalyte/ Ringer,erythrocytes,ultrafiltration volume and the cardiac assist ratio were higher in the death group than in the survival group. After controlling the confounding effect of surgeons,the multivariable Cox proportional hazard model showed that:the independent risk factors for perioperative mortality were pulmonary atresia[aHR = 3. 89( 1. 78 -8. 42)],5％ sodium bicarbonate volume ≥50 ml[aHR = 2. 62( 1. 14 - 6. 04)],erythrocytes volume > 200 ml[aHR = 2. 26 ( 1. 1 - 4. 06)]and postoperative low cardiac output[aHR = 6. 76(3. 30 - 13. 87)]. Conclusion During the study period, the preoperative mortality for neonates with CHD had a dramatical decrease,although the preoperative risk factors for the pa-tients increased. Pulmonary atresia repair surgery had the highest mortality in neonates. Factors associated with the periopera-tive mortality includedpreoperative acidosis and postoperative low cardiac output. There is a significant association between the improvement of perioperative mortality and the improvement of the technology of minimized cardiopulmonary bypass circuit dur-ing neonatal operation. It is suggested that the total erythrocytes volume maintains less than 200 ml.

Objective To explore the feasibility and option of different surgeries for neonates with pulmonary atresia and ventricular septal defect (PA/VSD) through assessing the effect of common surgeries. Methods Fourteen neonates who underwent their first surgery in our center from July 2004 to October 2014 were included. Their basic characteristics, operation and pre- and postoperative clinical information were extracted. Follow up was conducted and the last visit was on October 10, 2016. Short- and midterm survival and total correction rate were compared among different surgeries. Results Among the 14 patients, there were 4 (28.6%) patients, 6 (42.9%) and 4 (28.6%) who underwent one-stage repair, right ventricular outflow tract (RVOT) reconstruction, and systemic to PA shunt operation respectively. The overall in-hospital mortality after the first operation was 28.6% (4/14). At last visit, no death occurred resulting the 5-year survival rate of 71.4% (10/14). The overall total correction rate for all neonates was 64.3% (9/14). Although no statistical difference was found in the mortality among the one-stage repair , RVOT reconstruction and systemic to PA shunt group(50.0% vs. 33.3% vs. 0.0%, P=0.280), the survival and hazard analysis implied better outcomes of the systemic to PA shunt palliation operation. There was no statistical difference in the total correction rate and months from the first palliative operation to correction between those who underwent RVOT reconstruction and systemic to PA shunt (75.0% vs. 50.0%, P=0.470; 32.0 months vs. 18.0 months, P=0.400). Conclusion Performing surgeries for neonates with PA/VSD is still a great challenge. However, the midterm survival rate was optimistic for the early survivors. Systematic to PA shunt seemed to be a better choice with lower mortality for the neonates with PA/VSD who need the surgery to survive.

[Objective]To evaluate the effects of sutureless technique in comparison to conventional techniques for repair of total anomalous pulmonary venous connection(TAPVC)with the method of propensity score analysis.[Methods]From October 2007 to December 2013,179 consecutive patients were enrolled in this study. Patients were operated with sutureless technique(n = 81)or Conventional technique(n=98),and followed up at an interval of 1 month,3 months,6 months and then once a year post-operation. During analysis,three type of propensity-score matching methods,including nearest neighbor caliper matching,Mahalanobis metric matching with propensity score ,optimal full matching were used to create balanced groups of patients receiving each treatment. Surgeons’performance difference was assessed with random frailty proportional hazards models with gamma. Composite endpoints was defined by postoperative death or late death or postoperative pulmonary venous obstruction(PVO),which was evaluated with Kaplan-Meier curve and multivariable Cox proportional hazard model,adjusted by Preoperative-PVO,age,gender,weight and TAPVC type.[Results]Nearest neighbor caliper matching method was the best choice during propensity score analysis. After matching ,sutureless group included 73 patients and Conventional group73 patients. In sutureless group,cardiopulmonary bypass(CPB)time(Z=2.18, P=0.030),cross-clamp time(Z=3.63,P<0.001),rate of composite endpoints(HR 95%CI=0.20(0.06~0.61),P=0.005),late death(HR 95%CI=0.03(0.01~0.55),P=0.017)were significantly better than that in Conventional group. In subgroup analysis ,for patients with pre-PVO,decreased composite endpoints was seen in sutureless group.[Conclusion]Comparison using thepropensity score analysis demonstrated that sutureless strategy for primary repair of TAPVC may associate with decreased mortality rate of post-PVO and CPB time and cross-clamp time.

Objective This retrospective cohort study aims to evaluate and compare the prognosis of surgical repair for total anomalous pulmonary venous connection(TAPVC) with different drainage type.Methods From January 2006 to Decem-ber 2013, 328 consecutive patients were enrolled in this study .The distribution of the defects was 109 cases with cardiac, 161 with supracardiac, 32 with infracardiac, and 26 with mixed type of the drainage into the systemic circulation .The clinical re-cords of all the patients were reviewed.Studied variables were extracted from the clinical records.Followed-up was conducted at an interval of 1 month, 3 months, 6 months and then once a year post-operation.Prevalence of peri-operative conditions were compared among four different types.Studied endpoints was defined by postoperative total death or pulmonary venous obstruc-tion(PVO), which was evaluated with Kaplan-Meier curve and multivariable Cox proportional hazard model, adjusted by differ-ent surgical strategy, emergency operation, preoperative-PVO, neonates, weight, combing with other complex cardiac defects,NYHA cardiac function, severe pulmonary hypertension and severe tricuspid regurgitation.Results There were significant discrepancyof preoperative conditions among four types of TAPVC.Patients with infracardiac TAPVC presented the most criticalsymptoms and clinical indexes, which included having largest proportion of neonates, preoperative PVO, severe NYHA grading,pulmonary hypertension and tricuspid regurgitation, having lowest body weight at operation and youngest age.The cardiopulmonarybypass time, aortic crossclamp time and mechanical ventilation time were significantly longer in infracadiac and mixedTAPVC comparing to the other two types.For early mortality(death in hospital), infracadiac(9.4%) and mixed(11.5%)TAPVC demonstrated higher rates of death than cardiac(4.6%) and supracardiac(7.5%)TAPVC, although had no statisticalsignificance.For intermediate-term results, mortality in infracadiac(21.9%) and mixed(30.8%) TAPVC were significantlyhigher than cardiac ( 8.3%) and supracardiac (11.8%) TAPVC.Reoperation was more frequently required in mixed(19.2%), then infracadiac(15.6%)TAPVC.Mixed and infracadiac types are independent risk factors for TAPVC prognosis,after adjusting by the confounding factors.Conclusion Mixed and infracadiac types are independent risk factors for postoperativedeath and PVO among TAPVC patients.This study provided evidence for clinical assessment and management strategy fordifferent types of TAPVC.

Competing risks occur frequently in the analysis of survival data that should be dealt with competing risk models.Competing risk is an event whose occurrence precludes the occurrence of the primary event of interest.Previous commonly used Kaplan-Meier method tends to overestimate the cumulative survival functions,while the traditional Cox proportional hazards model falsely evaluates the effects of covariates on the hazard related to the occurrence of the event.There are few domestic reports mentioning the concept,application and methodology of competing risk model as well as the implementation procedures or resolution of model conditions and parameters.The current work aims to explain the core concept and methodology of the competing risk model and to illustrate the process of analysis on cumulative incidence rate,using both the cause-specific hazard function model and the sub-distribution hazard function model.Software macro code in SAS 9.4 is also provided to assist clinical researchers to further understand the application of the model so to properly analyze the survival data.

Conditional logistic regression analysis and unconditional logistic regression analysis are commonly used in case control study,but Cox proportional hazard model is often used in survival data analysis.Most literature only refer to main effect model,however,generalized linear model differs from general linear model,and the interaction was composed of multiplicative interaction and additive interaction.The former is only statistical significant,but the latter has biological significance.In this paper,macros was written by using SAS 9.4 and the contrast ratio,attributable proportion due to interaction and synergy index were calculated while calculating the items of logistic and Cox regression interactions,and the confidence intervals of Wald,delta and profile likelihood were used to evaluate additive interaction for the reference in big data analysis in clinical epidemiology and in analysis of genetic multiplicative and additive interactions.