Objective To investigate the protective mechanism of ischemic preconditioning for myocardial ischemic reperfusion injury (MI/RI) rats. Methods Eighteen male Sprague–Dawley (SD) rats were randomly separated into Sham operation,ischemic reperfusion (IR) and ischemic preconditioning (IP) groups (6 rats in each group). Peripheral blood and cardiac muscle were collected after the establishment of the above 3 animal models. ELISA was employed to determine proinflammatory cytokines TNF-? and IL-1? production in sera of these animals. RT-PCR and Western blot analysis was used to assay the transcriptional level and protein level of Toll-like receptor 4 (TLR4) in cardiac muscle tissue with pathological change,respectively. Results Compared with IR group,ischemic preconditioning effectively decreased the expression levels of TNF-? and IL-1? in sera of rats in IP group (P

Background and purpose:Differentiation of tumor tissue is an important factor on determining the prognosis of gastric cancer. This study aimed to investigate the expression levels and clinical signiifcance of gender determining region Y-box 2 (SOX2) gene and octamer binding factor 4 (OCT4) gene in gastric cancer tissues varying different differentiation degrees. Methods: Sixty cases with gastric cancer were recruited in this study. The gastric cancer tissues and corresponding normal mucosa of the 60 cases were obtained. The mRNA and protein level of SOX2, OCT4 gene are evaluated by the quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry, respectively. The relationship between the expression levels of SOX2, OCT4 gene and clinical pathological parameters were also analyzed in this study. Results:The expression of SOX2 in both mRNA and protein levels had no signiifcant difference between the well-differentiated gastric cancer tissues and normal gastric mucosa (mRNA levels:t=0.1033, P>0.05;protein levels:t=0.116, P>0.05). However, both the mRNA and protein expression of SOX2 in patients with well-differentiated gastric cancer tissues were signiifcant higher than not only in patients with moderately differentiated gastric carcinoma (mRNA levels: t=12.48, P<0.05; protein levels: t=22.78, P<0.05) but also in patients with than poorly differentiated gastric carcinoma (mRNA levels:t=17.56, P<0.05;protein levels:t=30.00, P<0.05). In contrast to SOX2, both the mRNA and protein expression of OCT4 in patients with well-differentiated gastric cancer tissues were signiifcant lower than not only in patients with moderately differentiated gastric carcinoma (mRNA levels:t=13.23, P<0.05; protein levels: t=25.56, P<0.05) but also in patients with poorly differentiated gastric carcinoma (mRNA levels: t=12.10, P<0.05; protein levels: t=69.48, P<0.05). There was no significance of OCT4 mRNA and protein expression between the well-differentiated gastric cancer tissues and normal gastric mucosa (mRNA levels:t=2.436, P>0.05;protein levels:t=1.064, P>0.05). Immunohistochemical study demonstrated that the positive rate of SOX2 in patients with well-differentiated gastric cancer tissues (10/21) were higher than in patients with not only moderately differentiated gastric carcinoma (7/20) but also poorly differentiated gastric carcinoma (2/19, P<0.05), while the positive rate of OCT4 in cases with well-differentiated gastric cancer tissues (2/21) were lower than in cases with not only moderately differentiated gastric carcinoma (6/20) but also the poorly differentiated gastric carcinoma (12/19, P<0.05). There was no correlation between the expression of SOX2, OCT4 in gastric cancer and gender or age (P>0.05). Nevertheless, the expression of SOX2, OCT4 were positive or negative correlated with the pathological staging, the degree of inifltration and lymph node metastasis (P<0.05). Conclusion:Decreased SOX2 expression and increased expression level of OCT4 can promote the formation, development and invasion of gastric cancer and they may become biomarkers or the diagnosis, treatment and prognosis evaluation in gastric carcinoma.

Objective To investigate the assessment of multi-detector spiral CT on the cardiac function after bioprosthetic valve replacement with mitral valve preservation.Methods Thirty-five patients suitable for undergoing bioprosthetic mitral valve replacement in our hospital from May 2012 to February 2014 were randomly divided into 2 groups:group A(experimental group,intraoperative preservation of mitral valve and subvalvular structure during,n=16) and group B (control group,without intraoperative preservation of subvalvular structure of mitral valve,n=19).MDCT before operation and on postoperative 10 d was performed for evaluating the left ventricular function.Results In the comparison of preoperative MDCT,the end diastolic velocity(EDV),end systolic velocity(ESV),ejection fraction(EF) and stroke volume(SV) had no statistical difference between the group A and B.In MDCT results on postoperative 10 d,EDV,ESV and EF in the group A were 113.42±9.22)mL,(38.63±3.40)mL and (51.63±4.71) ％,which in the group B were(113.42 ± 9.22) mL,(38.63 ± 3.40) mL and (51.63 ± 4.71) ％ respectively,the difference was statistically significant(P＜0.05),but SV had no statistical difference between the two groups(P＞0.05).Conclusion The bioprosthetic valve replacement with mitral valve preservation is safe and feasible in technology,moreover effectively protects the postoperative left ventricular function.

Objective Studies of the positioning,framework and weight of the performance of directors of third-grade public hospitals will pave the way for launching a study of the performance of these directors,and for the performance appraisal of the directors of third grade public hospitals.Methods The following methods are called into play:Meta-analysis of literature to summarize the research outcomes of the appraisal thinking and modeling for managers of public hospitals;the balance score card to design the theoretical base of public hospital performance framework;the Delphi Method to identify the functionality expected of public hospitals,and the thinking and framework for performance appraisal;in addition to experts consultancy to demonstrate via questionnaires.Results Positioning of directors performance appraisal of third-grade public hospitals comprises both desirable social effect outcomes and desirable operating status.This performance appraisal consists of such five dimensions as social satisfaction,effective management,asset operation,development sustainability,and employee recognition,totaling 12 performance objectives.Conclusion Scientific and reasonable design of the framework and weight of the perfofinance appraisal for managers of public hospitals is conducive to assuring the public interest nature for public hospitals.

Objective To observe the effects of remote ischemic preconditioning(RIPC) on Na+-K+-ATP enzyme and Ca2+-Mg2+-ATP enzyme in thoracoscopic heart operation.Methods One hundred and twenty patients with thoracoscopic heart operation were randomly divided into the thoracoscopic extracorporeal circulation control group (C)and RIPC plus thoracoscopic extracorporeal circulation group(RIPC).The acidity and alkalinity change of arterial blood before and after treatment was abserved in the RIPC group;the changes of myocardial enzymes spectrum,cTnI and oxidation indicators(SOD,MDA) were compared among different time periods,and preoperative and postoperative Na+-K+-ATP enzyme and Ca2+-Mg2+-ATP enzyme levels were also compared.Results Compared with the group C,the acidity and alkalinity of artery blood were lower after RIPC(P＜0.05);the levels of CK-MB and cTnI at postoperative 6,24 h in the RIPC group were lower than those in those in the group C(P＜0.05);the SOD activity was higher than that in the group C,while the MDA level was lower than that in the group C(P＜0.05);the postoperative Na+-K+-ATP enzyme and Ca2+-Mg2+-ATP enzyme levels were higher than those in the group C at different degrees.Conclusion RIPC can alleviate myocardial injury in the patients with thoracoscopic heart operation and this effect may be related with activation of corresponding ATP enzyme.

Objective:To propose a machine learning-based markerless beam′s eye view (BEV) tumor tracking algorithm that can be applied to low-quality megavolt (MV) images with multileaf collimator (MLC)-induced occlusion and non-rigid deformation.Methods:This study processed the registration of MV images using the window template matching method and end-to-end unsupervised network Voxelmorph and verified the accuracy of the tumor tracking algorithm using dynamic chest models. Phantom QA plans were executed after the treatment offset was manually set on the accelerator, and 682 electronic portal imaging device (EPID) images obtained during the treatment were collected as fixed images. Moreover, the digitally reconstructed radiography (DRR) images corresponding to the portal angles in the planning system were collected as floating images for the study of target volume tracking. In addition, 533 pairs of EPID and DRR images of 21 lung tumor patients treated with radiotherapy were collected to conduct the study of tumor tracking and provide quantitative result of changes in tumor locations during the treatment. Image similarity was used for third-party validation of the algorithm.Results:The algorithm could process images with different degrees (10%-80%) of data missing and performed well in non-rigid registration of images with data missing. As shown by the phantom verification, 86.8% and 80% of the tracking errors were less than 3 mm and less than 2 mm, respectively, and the normalized mutual information (NMI) varied from 1.18 ± 0.02 to 1.20 ± 0.02 after registration ( t = -6.78, P = 0.001). The tumor motion of the clinical cases was dominated by translation, with an average displacement of 3.78 mm and a maximum displacement of 7.46 mm. The registration result of the cases showed the presence of non-rigid deformations, and the corresponding NMI varied from 1.21 ± 0.03 before registration to 1.22 ± 0.03 after registration ( t = -2.91, P = 0.001). Conclusions:The tumor tracking algorithm proposed in this study has reliable tracking accuracy and high robustness and can be used for non-invasive and real-time tumor tracking requiring no additional equipment and radiation dose.

Objective:To evaluate the feasibility of predicting lung cancer target position by online optical surface motion monitoring.Methods:CT images obtained in different ways of stereotactic body radiotherapy (SBRT) plans from 16 lung cancer cases were selected for experimental simulation. The planned CT and the original target position were taken as the reference, and the 10 phases of CT in four dimension CT and each cone beam (CBCT) were taken as the floating objects, on which the floating target location was delineated. The binocular visual surface imaging method was used to obtain point cloud data of reference and floating image body surface, while the point cloud feature information was extracted for comparison. Based on the random forest algorithm, the feature information difference and the corresponding target area position difference were fitted, and an online prediction model of the target area position was constructed.Results:The model had a high prediction success rate for the target position. The variance explainded and root mean squared error ( RMSE) of left-right, superior-inferior, anterior-posterior directions were 99.76%, 99.25%, 99.58%, and 0.0447 mm, 0.0837 mm, 0.0616 mm, respectively. Conclusion:The online monitoring of lung SBRT target position proposed in this study is feasible, which can provide reference for online monitoring and verification of target position and dose evaluation in clinical radiotherapy.

Objective:To propose a markerless beam's eye view (BEV) tumor tracking algorithm, which can be applied to megavolt (MV) images with poor image quality, multi-leaf collimator (MLC) occlusion and non-rigid deformation.Methods:Window template matching, image structure transformation and demons non-rigid registration method were used to solve the registration problem in MV images. The quality assurance (QA) plan was generated in the phantom and executed after manually setting the treatment offset on the accelerator, and 682 electronic portal imaging device (EPID) images in the treatment process were collected as fixed images. Meanwhile, the digitally reconstructured radiograph (DRR) images corresponding to the field angle in the planning system were collected as floating images to verify the accuracy of the algorithm. In addition, a total of 533 images were collected from 21 cases of lung tumor treatment data for tumor tracking study, providing quantitative results of tumor location changes during treatment. Image similarity was used for third-party verification of tracking results.Results:The algorithm could cope with different degrees (10%-80%) of image missing. In the phantom verification, 86.8% of the tracking errors were less than 3 mm, and 80% were less than 2 mm. Normalized mutual information (NMI) varied from 1.182±0.026 to 1.202±0.027 ( P<0.005) before and after registration and the change of Hausdorff distance (HD) was from 57.767±6.474 to 56.664±6.733 ( P<0.005). The case results were predominantly translational (-6.0 mm to 6.2 mm), but non-rigid deformation still existed. NMI varied from 1.216±0.031 to 1.225±0.031 ( P<0.005) before and after registration and the change of HD was from 46.384±7.698 to 45.691±8.089 ( P<0.005). Conclusions:The proposed algorithm can cope with different degrees of image missing and performs well in non-rigid registration with data missing images which can be applied in different radiotherapy technologies. It provides a reference idea for processing MV images with multi-modality, partial data and poor image quality.