ObjectivesTo systematically review the safety and efficacy of aspirin in primary prevention of cardiovascular diseases.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, CBM, WanFang Data, CNKI and VIP databases were electronically searched to collect randomized controlled trials (RCTs) of aspirin for primary prevention of cardiovascular diseases from inception to November 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, and then, meta-analysis was performed by RevMan 5.3 software.ResultsA total of 13 RCTs involving 164 225 participants were included. The results of meta-analysis showed that: aspirin reduced the risk of myocardial infarction (RR=0.85, 95%CI 0.75 to 0.97, P=0.01), ischemic stroke (RR=0.86, 95%CI 0.79 to 0.95, P=0.002) and risk of major adverse cardiovascular events (RR=0.90, 95%CI 0.86 to 0.94, P<0.000 1). However, all-cause mortality (RR=0.97, 95%CI 0.93 to 1.02, P=0.22) and cardiovascular mortality (RR=0.93, 95%CI 0.85 to 1.02, P=0.11) were not reduced. Additionally, it increased risk of hemorrhagic stroke (RR=1.29, 95%CI 1.02 to 1.64, P=0.03), major bleeding (RR=1.43, 95%CI 1.31 to 1.56, P<0.000 01) and gastrointestinal bleeding (RR=1.59, 95%CI 1.33 to 1.90, P<0.000 01).ConclusionCurrent evidence shows that aspirin can reduce the incidence of major adverse cardiovascular events and myocardial infarction during primary prevention of cardiovascular disease, while increase the risk of bleeding, especially gastrointestinal bleeding. Therefore, its potential benefits may be offset. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusion.
The purpose of this study is to reveal the protective effect of rib cage on scoliotic spine by comparing the different effect of rib cage on the stability of normal spine and Lenke1 scoliotic spine. Firstly, according to X-ray computed tomography (CT) image data, four spinal finite element models (SFEMs), including normal spine without rib cage (N1), normal spine with normal rib cage (N2), scoliotic spine without rib cage (S1) and scoliotic spine with deformed rib cage (S2), from the first thoracic vertebrae to the sacral vertebrae (T1～S) were established. Secondly, the natural vibration characteristics of the four SFEMs were obtained by modal analysis. Finally, the maximum vibration amplitudes of the four SFEMs under external excitation were obtained by steady-state analysis. As shown in results, compared with N1, the maximum deformation of N2 segment T4～T6 in the X-axis (coronal axis), Y-axis (sagittal axis) and Z-axis (vertical axis) directions decreases by 38.44%, 53.80% and 33.72%, respectively. Compared with S1, the maximum deformation of S2 segment T4～T6 in the X-axis direction, Y-axis direction and Z-axis directions decreases by 44.26%, increases by 32.80% and decreases by 49.23%, respectively. As it can be seen, for normal spine, the rib cage can improve the stability of the whole spine in three directions; for the Lenke1 scoliotic spine, the rib cage can reduce the vibration of the scoliotic spine in the X-axis and Z-axis directions and improves the stability of the whole spine in the two directions, while in the Y-axis direction, for the serious severe anteversion of scoliotic spine, the deformed rib cage exacerbates the vibration of the scoliotic spine in this direction and destroys the stability of the scoliotic spine in the Y-axis direction. This study reveals the biomechanical characteristics of rib caged influence on the stability of the scoliotic spine and it has guiding significance for the study of daily protection methods and protective tools for scoliotic patients.
Objective To investigate the protection on the intrahepatic cholangiocyte mediated by hypoxic preconditioning (HP) after liver transplantation and the role of vascular endothelial growth factor (VEGF). Methods The model of autologous liver transplantation was established, and the rats were divided into 3 groups: autologous liver transplantation group, hypoxic preconditioning before operation group (HP group) and sham operation group. At 6, 12, 24, 48 h after operation, blood samples were collected for examination of the serum total bilirubin (TBIL), direct bilirubin (DBIL) and alkaline phosphatase (ALP), and the expression of VEGF was detected by immunohistochemical method. The pathological changes of cholangiocytes were observed by light microscope. Results As compared with autologous liver transplantation group, the levels of seurm TBIL, DBIL and ALP in HP group were lower (P＜0.05), while the expression of VEGF in HP group was higher at the whole process (P＜0.05). The degrees of billiary epithelium damage and inflammatory infiltration in autologous liver transplantation group were more severe than those in HP group. Conclusion HP has protective effect on cholangiocytes after liver transplantation, in which VEGF may play an important role.