Objective To investigate the synthesis of heat shock protein 70 (HSP70) induced by norepinephrine preconditioning on donor heart and its effects on myocardial cell apoptosis and apoptosis related proteins. Methods 18 Wistar rats were random divided into 2 groups, with 9 in each group. The rats in the control group were intraperitoneally injected with 0.5 ml saline. After 24 hours, hearts were isolated and stored with histidine-tryptophan-ketoglutarate (HTK) solution at 4 ℃ for 3 hours to establish Langendorff isolated heart models, and then isolated hearts were perfused by Langendorff model with Krebs-Hense leit (K-H) solution for 2 hours. The rats in the experimental group received intraperitoneally 3. 1 μmol/kg (0. 53 mg/kg) noradrenaline bitartrate that was dissolved in saline and hearts were isolated and stored after 24 hours. Followed process was the same as that in the control group. Myocardial HSP70, Bcl-2, Bax content, apoptosis index were measured, cell structures were observed under light and electron microscope.Results HSP70 in the experimental group were higher [(17.78 ± 1.82)%] than those in control group [(5.22 ± 1.05)%], and biochemical indicators in texperimental group[(41.88 ± 5.09)%, (22.61 ±3. 49 ) %] were better than those in control group [(31.36 ± 3. 27 ) %, ( 40. 52 ± 4. 1 7) %]. There were alleviated ultrastructure injures in experimental group compared with those in control group. Conclusions This study demonstrated that norepinephrine preconditioning could induce high expression of HSP70 and it could play a very important role during ischemia-reperfusion. It could protect the structure and function of myocytes in isolated rat hearts and inhibited myocardial apoptosis.

BACKGROUND: Heart valve tissue engineering is aimed to construct heart valve grafts with the physiological function and biological activity by using engineering and life science principles and methods, but still in the animal experiment stage.OBJECTIVE: To summarize the commonly used tissue engineered heart valve, and to evaluate the reliability of different types of heart valve biomaterials.METHODS: Using "biological materials, heart valve, scaffolds, reviews, tissue engineering" in Chinese as the key words, a computer retrieval was performed for articles published from January 2000 to December 2010. Articles regarding the biomaterials in tissue engineered heart valve were included; the duplicated research or meta-analysis were excluded.RESULTS AND CONCLUSION: A total of 20 papers about the biomaterials and tissue engineering heart valve were screened out. Due to the superior biocompatibility and three-dimensional conformation, natural scaffold materials exhibit unparalleled bionic property compared with other materials. Synthetic biodegradable polymer materials with good mechanical properties and controllability has thus been highly favored by researchers, while the composite scaffold materials of natural materials and polymer materials provides a new strategy and direction for the investigations of tissue engineered heart valve, and has broad application prospects.

BACKGROUND:Changes of both stem cell markers and endothelial cell phenotype help understand characteristics of endothelial progenitor cells during adherent differentiation.However,there is still no specific cell marker to distinguish from mature endothelial cells.OBJECTIVE:To study the changes of stem cell markers and endothelial cell phenotype during the differentiation of rat peripheral blood rnononuclear cells into endothelial cells.DESIGN.TIME AND SETTING:Cell observation study was performed in the Laboratory of Cardiac Surgery,Qingdao Municipal Hospital between June 2004 and December 2008. MATERIALS:Peripheral blood was drawn from male SD rats to obtain mononuclear cells by Ficell density gradient centrifugation. METHODS:Mononuclear cells were in vitro cultured in fibronectin culture medium and induced by vascular endothelial growth factors(VEGF)and basic fibroblast growth factors(bFGF)in order to stimulate a differentiation into endothelial cells. MAIN OUTCOME MEASURES:Adherent cells in the culture system were identified for CD31,CD34,Rk-1 and vWF with immunochemistry within 1-7 days.RESULTS:The expressions of CD31.CD34,FIk-1.vWF on adherent cells were different in different time durations.The expressions of CD31 and CD34 started on the 2nd day of culture.reached the peak on the 4th day,gradually decreased and even disappeared on the 6thday.While.FIk-1 expressed on the 3rd day of culture,gradually increased,and reached at the peak on the 7th day.vWF expressed gradually until 100%on the 7th day. CONCLUSION:The differentiation of peripheral blood stern cells into endothelial progenitor cells is characterized by the appearance of endothelial cell phenotypes and the disappearance of stern cell markers.both in the manner of gradual progression.

Objective To study the curative effect of continuous veno-venous hemodiafiltration(CVVH)in patients with acute renal failure(ARF)after aortic dissection surgery. Methods Fifteen patients with renal dysfunction following aortic dissection surgery underwent CVVH from Feb. 2002 to Dec. 2009 in this study.The clinical data of these patients were collected,such as heart rate(HR),central vein pressure(CVP),mean artery blood pressure(MAP),PaO2,renal function,perioperative manifestations and outcomes. Results Eleven patients survived but 4 died during the course of treatment. There were significant decreases of BUN,Creatinin after CVVH (P ＜ 0. 05)treatment,and the urine volume returned to nomal after CVVH in 6 -40 days. Conclusions CVVH is an effective,convenient and safe treatment for patients with severely ARF following aortic dissection surgery.

BACKGROUND: How to successfully obtain compact endothelium layers on smooth muscle cells is the most crucial part for the tissue-engineered vessels. OBJECTIVE: To explore the effects of different cell implantation concentrations on the construction of the complete biological tissue-engineered blood vessels.METHODS: Different concentrations of porcine vascular smooth muscle cells (5×105, 5×107 cells/L) were implanted on the porcine acellular vascular matrix to culture for 3 days. Then different concentrations of endothelial progenitor cells (5×105, 5×107 cells/L) were implanted on the smooth muscle cell-vascular matrix composite to construct lamellar complete biological tissue-engineered blood vessels.RESULTS AND CONCLUSION: The growth curves of high concentrations of smooth muscle cells on the acellular vascular matrix were similar to that of low concentrations. Moreover, the growth curves of cells implanted in the culture plates were similar to that implanted on the acellular matrix. However, cells in the low concentration groups have relatively low proliferation activity and low coverage rate. The cell coverage rate decreased as follows: high concentrations of endothelial progenitor cells+acellular matrix containing high concentrations of smooth muscle cells > high concentrations of endothelial progenitor cells+acellular matrix containing low concentrations of smooth muscle cells > low concentrations of endothelial progenitor cells+acellular matrix containing high concentrations of smooth muscle cells > low concentrations of endothelial progenitor cells+acellular matrix containing low concentrations of smooth muscle cells. Moreover, high concentrations of endothelial progenitor cells form relatively compact layers on the acellular matrix and show cobble-like growth. These findings indicate that an increase in the cell implantation concentrations is beneficial to the rapid formation of compact cell layers on the material surface.

To investigate the effect of preoperative uses of levosimendan in patients with low LVEF(≤0. 40) undergoing off-pump coronary artery bypass grafting(OPCABG). Methods 63 patients with low LVEF coronary artery diseases were prospectively enrolled during June 2015 to May 2018, randomized to levosimendan-treated group(n =32) and control group(n =31)preoperatively. Patients in levosimendan-treated group underwent levosimendan intravenous infusion 24 h before OPCABG. All patients underwent OPCABG at normal temperature. Internal mammary artery and great saphenous vein were used as bypass materials. Hemodynamics and cardiac function were compared between the two groups after OPCABG. Results Compared to control group, the systemic vascular resistance(SVR) and central venous pressure(CVP) of levosimendan- treated group were decreased significantly and the CO and LVEF increased significantly at 12h and 24h after surgery(P < 0. 05). The heart rate and mean artery pressure had no statistical difference between the two groups(P >0. 05). The dosage and administration time of vasoactive agents in levosimendan-treated group were significantly smaller than those in control group (P <0. 05). The time of mechanical ventilation, the ICU stay length, the BNP level in the first two days after operation, and the incidence of new atrial fibrillation were less than those of the control group(P <0. 05). The perioperative intra-aortic balloon pump implantation rate in levosimendan-treated group was significantly lower than that of the control group(P < 0. 05). Conclusion Preoperative use of levosimendan can significantly improve the hemodynamic and cardiac function status of patients with low LVEF after OPCABG, shorten the time of ventilator assisted and ICU hospitalization, and reduce the incidence of adverse events.

To identify the predictors of prolonged mechanical ventilation in patients undergoing surgery for stanford type A acute aortic dissection. Methods 202 patients who underwent surgery for acute aortic dissection type A from May 2009 to May 2016 were divided into two groups based on their mechanical ventilation time after surgery, including 70 patients with mechanical ventilation 48 hours or more(group A), 132 patients with mechanical ventilation less than 48 hours (group B). Univariate and multivariate analysis(logistic regression) were used to identify the predictive risk factors. Results The mechanical ventilation time was(146. 8 ±78. 5)h and(21. 7 ±9. 5)h in group A and group B respectively. Overall inhospital mortality was 8. 6％ and 2. 3％. Multivariate logistic analysis showed that BMI(OR = 5. 956, 95％ CI: 2. 585 - 13. 723, P =0. 000), CPB time(OR =1. 108, 95％CI: 1. 052 -1. 166, P =0. 000), DHCA(OR =4. 562, 95％ CI: 1. 250 - 16. 640, P =0. 022), red blood cell transfusion intraoperative and in 24 hours postoperatively(OR =2. 625, 95％ CI: 1. 515 -4. 549, P =0. 001) were the independent predictors for prolonged mechanical ventilation. Conclusion The incidence of prolonged mechanical ventilation is high after surgery for stanford type A acute aortic dissection. It can be predicted based on above factors, for patients with these risk factors, more perioperative care strategies are needed in order to shorten the mechanical ventilation time.

Objective    To investigate the effect of postoperative use of levosimendan on patients with valve replacement. Method    Patients with valvular diseases who underwent valve replacement were prospectively enrolled during Jan 2014 to May 2018 in Qingdao Municipal Hospital, randomized to a levosimendan-treated group (n=93) and a control group (n=92) preoperatively. Patients in both groups underwent the same routine treatment preoperatively and postoperatively. In addition, patients in the levosimendan-treated group underwent levosimendan intravenous infusion 24 hours after entering ICU postoperatively. The clinical effect of the two groups was compared. Results    Compared to the control group, the cardiac output(CO, 5.2±1.0 L/min vs. 4.4±1.1 L/min on the seventh day after surgery) and left ventricular ejection fraction (LVEF, 55.7%±2.5% vs. 50.5%±2.2% on the seventh day after surgery) of levosimendan-treated group were increased significantly at different time points(1 day, 3 days and 7 days after surgery)(P<0.05), and the brain natriuetic peptid (BNP) level (312.5±34.6 pg/ml vs. 455.4±45.2 pg/ml on the seventh day after surgery) was less than that of the control group (P<0.05). The dosage (11.5±1.8 mg/kg vs. 20.4±2.1 mg/kg) and administration time of vasoactive agents in the levosimendan-treated group were significantly lower or shorter than those in the control group (70.4±11.2 h vs. 110.5±12.1 h, P<0.05). The ICU stay length, and the total incidence of adverse events were less than those of the control group (P<0.05). Conclusion    Postoperative use of levosimendan immediately after surgery can significantly improve the   cardiac function status of patients who underwent valve replacement, reduce the dosage of vasoactive agents, shorten the time of ICU hospitalization, reduce the incidence of adverse events and enhance the patient’s recovery after valve replacement.

Objective To identify the predictors of postoperative acute kidney injury in patients undergoing surgery for Stanford type A acute aortic dissection. Methods A total of 220 patients who underwent surgery for type A acute aortic dissection in Qingdao Municipal Hospital from September 2010 to September 2017 were divided into two groups including a group A and a group B based on whether acute kidney injury occurred or not after surgery. There were 40 patients with 29 males and 11 females with the mean age of 54.6±9.2 years in the group A, 180 patients with 133 males and 47 females with the mean age of 48.5±7.9 years in the group B. Univariate and multivariate analyses (logistic regression) were used to identify the predictive risk factors. Results Overall in-hospital mortality was 5.5%. In univariate analysis, there were statistically significant differences with respect to the age, preoperative creatinine, preoperative white blood cell, the European system for cardiac operative risk evaluation (EuroSCORE), total cardiopulmonary bypass (CPB) time, deep hypothermic circulatory arrest (DHCA) time, arch replacement, red blood cell transfusion intraoperative and in 24 hours postoperatively, postoperative mechanical ventilation time, ICU stay duration, hospital stay duration and in hospital mortality. Multivariate logistic analysis showed that preoperative creatinine, preoperative white blood cell, CPB time, and red blood cell transfusion intraoperative and in 24 hours postoperatively were the independent predictors for postoperative acute kidney injury. Conclusion The incidence of acute kidney injury is high after surgery for acute Stanford type A aortic dissection. It can be predicted based on above factors, for patients with these risk factors, more perioperative care strategies are needed in order to induce the incidence of acute kidney injury.

Objective    To investigate the feasibility and safety of hybrid coronary revascularization (HCR) in patients with multivessel coronary artery disease (MVCAD). Methods    A total of 50 patients with MVCAD who underwent HCR technique in our heart center from May 2016 to April 2019 were included in this study (a HCR group), including 38 patients who underwent two-stage HCR and 12 patients one-stop HCR. There were 39 males and 11 females, with an average age of 62.4 (46-82) years. Another 482 patients who underwent conventional median incision under off-pump coronary artery bypass grafting (OPCAB) at the same period were selected as control (an OPCAB group), including 392 males and 90 females, with an average age of 64.2 (48-84) years. The safety and feasibility of HCR were evaluated and compared with conventional OPCAB technique. Results    There was no perioperative death in both groups. Compared with the OPCAB, HCR was associated with shorter operation time, less chest tube drainage, lower requirement of blood transfusion, shorter mechanical ventilation time and shorter postoperative intensive care unit (ICU) stay (P<0.05). There was no statistical difference in the incidence of major adverse cardiac or cerebrovascular events during the follow-up of 6 to 36 months between the two groups. Conclusion    HCR provides favorable short and mid-term outcomes for selected patients with MVCAD compared with conventional OPCAB.