Zhi-Yun Xu

Second Military Medical University, Shanghai, Shanghai, Shanghai Shi, China

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Publications (80)64.92 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The Society of Thoracic Surgeons 2008 cardiac surgery risk models have been developed for heart valve surgery with and without coronary artery bypass grafting. The aim of our study was to evaluate the performance of Society of Thoracic Surgeons 2008 cardiac risk models in Chinese patients undergoing single valve surgery and the predicted mortality rates of those undergoing multiple valve surgery derived from the Society of Thoracic Surgeons 2008 risk models.
    Journal of Thoracic and Cardiovascular Surgery 07/2014; DOI:10.1016/j.jtcvs.2013.09.081 · 3.99 Impact Factor
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    ABSTRACT: Intra-aortic balloon pump (IABP) in heart valve surgical patients is associated with a higher mortality than coronary artery bypass grafting (CABG). The study aim was to analyze the early outcome of heart valve surgical patients requiring IABP support, and to assess the risk factors for early mortality. Among a cohort of 5,786 patients undergoing heart valve replacement without CABG, 81 (1.4%) required IABP support. Data from these latter patients were collected and analyzed retrospectively, and univariate and multivariate logistic regression were applied to identify risk factors for early mortality in patients requiring IABP support. IABP was inserted in 30 patients intraoperatively, and in 51 patients postoperatively. The overall mortality was 50.6%. Mortality in the intraoperative IABP subgroup was significantly lower than in the postoperative IABP subgroup (26.7% versus 64.7%, p = 0.001). The independent risk factors for early mortality were: age increasing by 10 years (OR 1.906, 95% CI: 1.165-3.116, p = 0.010) and pulmonary hypertension (OR 4.153, 95% CI: 1.380-12.499, p = 0.011). Intraoperative IABP insertion (OR 0.297, 95% CI: 0.100-0.876, p = 0.028) was identified as a protective factor compared to postoperative insertion. The mortality of patients requiring IABP support after heart valve replacement was high. The efficacy of intraoperative IABP insertion was better than a postoperative mandatory use. Clearly, more attention should be paid to older patients or those with pulmonary hypertension, who may benefit less from IABP.
    The Journal of heart valve disease 07/2014; 23(4):458-62. · 0.73 Impact Factor
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    ABSTRACT: Since 2000, transcatheter pulmonary valve replacement has steadily advanced. However, the available prosthetic valves are restricted to bioprosthesis which have defects like poor durability. Polymeric heart valve is thought as a promising alternative to bioprosthesis. In this study, we introduced a novel polymeric transcatheter pulmonary valve and evaluated its feasibility and safety in sheep by a hybrid approach.
    PLoS ONE 06/2014; 9(6):e100065. DOI:10.1371/journal.pone.0100065 · 3.53 Impact Factor
    This article is viewable in ResearchGate's enriched format
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    ABSTRACT: Inconsistent results regarding the relations between consumption of dairy products and the risk of esophageal squamous cell carcinoma (ESCC) have been reported. In this report, we summarized the evidence by a meta-analysis of observational studies. Eligible studies published up to January 31, 2013 were retrieved via both computer searches and a manual review of references. Random-effects models were used to calculate the summary relative risk (SRR) based on high versus low and dose-response analysis. A total of 19 studies with 4315 ESCC cases were included in this meta-analysis. Overall, there were no significant associations between intakes of total dairy products, milk, cheese and butter and ESCC for the highest versus lowest intake categories (total dairy products: SRR 1.03, 95% confidence interval [CI]: 0.60-1.77; milk: SRR 0.93, 95% CI: 0.74-1.16; cheese: SRR 0.84, 95% CI: 0.61-1.15; butter: SRR 1.77, 95% CI 0.85-3.75). A significant inverse association was found for yogurt consumption (SRR 0.73, 95% CI: 0.54-0.98). There was high heterogeneity among studies on total dairy products, milk and butter; however, little or no heterogeneity was observed among studies on cheese and yogurt. No associations between consumption of milk, dairy products, butter or cheese and risk of ESCC were found, while yogurt consumption may have a protective effect. However, these associations may be subject to high levels of heterogeneity or confounding, and further efforts should be made to confirm these findings.
    Asia-Pacific Journal of Clinical Oncology 03/2014; DOI:10.1111/ajco.12183 · 0.91 Impact Factor
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    ABSTRACT: Valve calcification involves transdifferentiation of valve interstitial cells (VICs) into osteoblasts. Twist-related protein 1 (TWIST1) has been established as a negative regulator of osteoblast differentiation in both mouse and human mesenchymal stem cells, but its function in human aortic VICs is unknown. In our study, we determined the mechanism of TWIST1 action in regulating osteoblastic transdifferentiation of human aortic VICs. Human calcified and noncalcified aortic valves were examined for TWIST1 expression. Human aortic VICs were isolated and cultured. The data showed that calcified aortic valves express lower levels of TWIST1. In vitro experiments showed that TWIST1 overexpression inhibited the transdifferentiation of VICs into osteoblasts by decreasing the expression of runt-related transcription factor 2 (RUNX2) and its downstream osteoblastic markers. Through chromatin immunoprecipitation and dual luciferase assays, we found that TWIST1 repressed the expression of RUNX2 by directly binding to an E-box located at -820 bp of the RUNX2 P2 promoter region and inhibiting its activity. Our study results suggest that TWIST1 could play an important role in preventing human aortic valve calcification by negatively regulating osteoblastic transdifferentiation of human aortic VICs through direct inhibition of RUNX2.
    The Journal of thoracic and cardiovascular surgery 03/2014; 148(4). DOI:10.1016/j.jtcvs.2014.02.084 · 3.41 Impact Factor
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    ABSTRACT: Objective Valve calcification involves transdifferentiation of valve interstitial cells (VICs) into osteoblasts. Twist1 has been established as a negative regulator of osteoblast differentiation in both mouse and human mesenchymal stem cells, but its function in human aortic VICs is unknown. In this study, we aimed to determine the mechanism of TWIST1 action in regulating osteoblastic transdifferentiation of human aortic VICs. Methods and Results Human calcified and non-calcified aortic valves were examined for the expression of TWIST1. Data showed that calcified aortic valves expressed lower levels of TWIST1. Human aortic VICs were isolated and cultured. In vitro experiments showed that TWIST1 overexpression inhibited the transdifferentiation of VICs into osteoblasts by decreasing the expression of RUNX2 and its downstream osteoblastic markers. Through chromatin immunoprecipitation and dual luciferase assays, we found that TWIST1 repressed the expression of RUNX2 by directly binding to an E-box located at -820bp of the RUNX2 P2 promoter region and inhibiting its activity. Conclusion Our study suggests that TWIST1 may play an important role in preventing human aortic valve calcification by negatively regulating osteoblastic transdifferentiation of human aortic VICs through direct inhibition of RUNX2.
  • Academic Journal of Second Military Medical University 11/2013; 33(11):1267-1270. DOI:10.3724/SP.J.1008.2013.01267
  • Academic Journal of Second Military Medical University 09/2013; 33(9):1021-1024. DOI:10.3724/SP.J.1008.2013.01021
  • Academic Journal of Second Military Medical University 09/2013; 33(9):965-968. DOI:10.3724/SP.J.1008.2013.00965
  • Academic Journal of Second Military Medical University 09/2013; 33(9):946-948. DOI:10.3724/SP.J.1008.2013.00946
  • Academic Journal of Second Military Medical University 06/2013; 32(6):629-632. DOI:10.3724/SP.J.1008.2012.00629
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    ABSTRACT: There are debates regarding the optimal approach for AAAD involving the aortic root. We described a modified reinforced aortic root reconstruction approach for treating AAAD involving the aortic root. A total of 161 patients with AAAD involving the aortic root were treated by our modified reinforced aortic root reconstruction approach from January 1998 to December 2008. Key features of our modified approach were placement of an autologous pericardial patch in the false lumen, lining of the sinotubular junction lumen with a polyester vascular ring, and wrapping of the vessel with Teflon strips. Outcome measures included post-operative mortality, survival, complications, and level of aortic regurgitation. A total of 161 patients were included in the study (mean age: 43.3 1 15.5 years). The mean duration of follow-up was 5.1 1 2.96 years (2-12 years). A total of 10 (6.2%) and 11 (6.8%) patients died during hospitalization and during follow-up, respectively. Thirty-one (19.3%) patients experienced postoperative complications. The 1-, 3-, 5-, and 10-year survival rates were 99.3%, 98%, 93.8%, and 75.5%, respectively. There were no instances of recurrent aortic dissection, aortic aneurysm, or pseudoaneurysm during the entire study period. The severity of aortic regurgitation dramatically decreased immediately after surgery (from 28.6% to 0% grade 3-4) and thereafter slightly increased (from 0% to 7.2% at 5 years and 9.1% at 10 years). This modified reinforced aortic root reconstruction was feasible, safe and durable/effective, as indicated by its low mortality, low postoperative complications and high survival rate.
    Brazilian Journal of Cardiovascular Surgery 06/2013; 28(2):190-9. DOI:10.5935/1678-9741.20130028
  • Academic Journal of Second Military Medical University 05/2013; 32(5):497-500. DOI:10.3724/SP.J.1008.2012.00497
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    ABSTRACT: OBJECTIVES: The EuroSCORE II is an updated version of the EuroSCORE. This multicentre study validated the EuroSCORE II and logistic EuroSCORE in Chinese patients who underwent heart valve surgery. METHODS: A total of 11 170 adult patients underwent heart valve surgery from January 2008 to December 2011. Model discrimination and calibration were assessed for both EuroSCORE II and logistic EuroSCORE. The patients were divided into three subgroups according to the weight of the procedures, and the performance of EuroSCORE II for each group was assessed. A correlation analysis was performed for operative complications and EuroSCORE II. RESULTS: The in-hospital mortality of this series was 2.02% (226 of 11 170), and the predicted mortality rate was 2.62 ± 5.75% by EuroSCORE II and 2.55 ± 6.51% by logistic EuroSCORE (LES). The C-statistics of EuroSCORE II and LES were 0.72 [95% confidence interval (CI) 0.69-0.75] and 0.67 (95% CI 0.63-0.70), respectively. Both models failed the Hosmer-Lemeshow goodness-of-fit test, with a P < 0.05. According to the weight of the procedure, the isolated non-CABG subgroup had the best discrimination (C-statistics: 0.76 in the non-CABG group, 0.67 in the 2 procedures group and 0.73 in the 3+ procedures group). The complication ratio was strongly related to the EuroSCORE II-predicted mortality (Pearson correlation coefficient: 0.90 for ARDS, 0.97 for acute renal failure, 0.97 for prolonged ventilation and 0.94 for a prolonged ICU stay). CONCLUSIONS: EuroSCORE II was an improvement upon its original logistic model for Chinese patients who underwent heart valve surgery, particularly for a single-valve procedure. The EuroSCORE II-predicted mortality correlated with the operative complications.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 05/2013; 45(2). DOI:10.1093/ejcts/ezt264 · 2.40 Impact Factor
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    ABSTRACT: BACKGROUND: To compare six risk scores with regard to their validity to predict in-hospital mortality after heart valve surgery in a single-centre patient population of China. METHODS: From January 2006 to December 2011, 3479 consecutive patients who underwent heart valve surgery at our centre were collected and scored according to the EuroSCORE II, VA risk score, NNE risk score, Ambler risk score, NYC risk score, and STS risk score. Calibration of the six risk scores was assessed by the Hosmer-Lemeshow (H-L) test. Discrimination was tested by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: Observed mortality was 3.32% overall. The STS score showed good calibration in predicting in-hospital mortality (H-L: P=0.126). The EuroSCORE II, VA score, NNE score, and NYC score underpredicted observed mortality (H-L: P<0.0001, P<0.0001, P=0.001, and P<0.0001, respectively) and the Ambler score overpredicted observed mortality (H-L: P=0.005). The discriminative power (i.e. the area under the ROC curve) for in-hospital mortality was highest for the STS score (0.706), followed by the EuroSCORE II model (0.693), NNE score (0.684), NYC score (0.682), Ambler score (0.677) and VA score (0.643). CONCLUSION: Compared with the EuroSCORE II, VA score, NNE score, NYC score, and the Ambler score, the STS score gives an accurate prediction for individual operative risk in patients undergoing heart valve surgery at our centre. Therefore, the use of the STS score for risk evaluation maybe suitable in patients undergoing heart valve surgery at our centre in the future.
    Heart, Lung and Circulation 04/2013; 22(8). DOI:10.1016/j.hlc.2013.03.084 · 1.17 Impact Factor
  • Academic Journal of Second Military Medical University 02/2013; 33(2):172-176. DOI:10.3724/SP.J.1008.2013.00172
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    ABSTRACT: BACKGROUND: To assess the performance of the The European System for Cardiac Operative. Risk Evaluation II (EuroSCORE II) in Chinese patients undergoing heart valve surgery at our centre. METHODS: From January 2006 to December 2011, 3479 consecutive patients who underwent heart valve surgery at our centre were collected and scored according to the original EuroSCORE and EuroSCORE II model. All patients were divided into single valve surgery and multiple valve surgery subgroup. The entire cohort and each subgroup were analysed. Calibration of the original EuroSCORE and EuroSCORE II model was assessed by the Hosmer-Lemeshow (H-L) test. Discrimination was tested by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: Observed mortality was 3.32% overall, compared to expected mortality 3.84% for the original additive EuroSCORE (H-L: P=0.013), 3.33% for the original logistic EuroSCORE (H-L: P=0.08), and 2.52% for the EuroSCORE II (H-L: P<0.0001). The EuroSCORE II model showed good calibration in predicting in-hospital mortality for patients undergoing single valve surgery (H-L: P=0.103) and poor calibration for patients undergoing multiple valve surgery (H-L: P<0.0001). The discriminative power of the original EuroSCORE model (area under the ROC curve of 0.684 and 0.673 for the additive and logistic model, respectively) and EuroSCORE II model (area under the ROC curve of 0.685) for the entire cohort was poor. The discriminative power of the EuroSCORE II model was good for the single valve surgery group (area under the ROC curve of 0.792) and was poor for the multiple valve surgery group (area under the ROC curve of 0.605). CONCLUSION: The EuroSCORE II model give an accurate prediction for individual operative risk in patients undergoing single valve surgery but an imprecise prediction in patients undergoing multiple valve surgery at our centre. Therefore, the use of the EuroSCORE II model for risk evaluation maybe suitable in patients undergoing single valve surgery, and creation of a new model which accurately predicts outcomes in patients undergoing multiple valve surgery is maybe required at our centre in the future.
    Heart, Lung and Circulation 01/2013; 22(8). DOI:10.1016/j.hlc.2012.12.012 · 1.17 Impact Factor
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    ABSTRACT: The cancer stem cell (CSC) model depicts that tumors are hierarchically organized and maintained by CSCs lying at the apex. CSCs have been "identified" in a variety of tumors through the tumor-forming assay, in which tumor cells distinguished by a certain cell surface marker (known as a CSC marker) were separately transplanted into immunodeficient mice. In such assays, tumor cells positive but not negative for the CSC marker (hereby defined as CSC(+) and CSC(-) cells, respectively) have the ability of tumor-forming and generating both progenies. However, here we show that CSC(+) and CSC(-) cells exhibit similar proliferation in the native states. Using a cell tracing method, we demonstrate that CSC(-) cells exhibit similar tumorigenesis and proliferation as CSC(+) cells when they were co-transplanted into immunodeficient mice. Through serial single-cell derived subline construction, we further demonstrated that CSC(+) and CSC(-) cells from CSC marker expressing tumors could invariably generate both progenies, and their characteristics are maintained among different generations irrespective of the origins (CSC(+)-derived or CSC(-)-derived). These findings demonstrate that tumorigenic cells cannot be distinguished by common CSC markers alone and we propose that cautions should be taken when using these markers independently to identify cancer stem cells due to the phenotypic plasticity of tumor cells.
    PLoS ONE 01/2013; 8(1):e54579. DOI:10.1371/journal.pone.0054579 · 3.53 Impact Factor
  • Academic Journal of Second Military Medical University 01/2013; 33(1):46-49. DOI:10.3724/SP.J.1008.2013.00046
  • Academic Journal of Second Military Medical University 01/2013; 33(1):11-16. DOI:10.3724/SP.J.1008.2013.00011

Publication Stats

201 Citations
64.92 Total Impact Points

Institutions

  • 2006–2014
    • Second Military Medical University, Shanghai
      Shanghai, Shanghai Shi, China
  • 2003–2014
    • Changhai Hospital, Shanghai
      Shanghai, Shanghai Shi, China
  • 2013
    • Government of the People's Republic of China
      Peping, Beijing, China
  • 2011
    • Renji Hospital
      Shanghai, Shanghai Shi, China
  • 2008
    • Shanghai University of Traditional Chinese Medicine
      Shanghai, Shanghai Shi, China