Detection of the viscoelasticity of relaxed myocardium in vivo by intervention ultrasound indentation system / 解放军医学杂志

Objective To explore the viscoelasticity of relaxed myocardium in vivo through indentation method with an intervention ultrasound indentation system (IUIS). Methods Old myocardial infarction (OMI) models of canine were established by ligating left anterior descending branch of coronary artery for 3 months. The indentation creep tests were used respectively in OMI group and shame group (n=8, each) by IUIS in middle and advanced diastole stage in vivo. Test data were processed with three-parameter solid viscoelasticity model, and the viscoelastic parameters, such as instantaneous elastic modulus (E1), relaxation modulus (E∞), creep elastic modulus (E2) and viscous damping coefficient (η) in normal and infarcted myocardium were obtained and compared. Results All the parameters of E1, E∞, E2 and η increased obviously in OMI group than in sham group shown as follows: 27.81±6.74kPa vs. 6.78±2.43kPa; 17.87±3.59kPa vs. 4.52±1.56kPa; 49.54±14.35kPa vs. 16.82±12.37kPa and 1.97±0.78Pa.s vs. 0.66±0.40Pa.s. The differences were statistically significant (P<0.05). Conclusions IUIS is a feasible method to assess the viscoelasticity of relaxed myocardium in vivo. Three-parameter viscoelasticity model can be used to describe creep properties of relaxed myocardium. Both elastic modulus and viscosity resistance have increased in infarcted myocardium.

Application of vitamin D in the treatment of patients with chronic obstructive pulmonary disease / 国际检验医学杂志

Objective To investigate the effect of vitamin D on pulmonary function in patients with chronic obstructive pulmona-ry disease,and to explore its possible mechanism.Methods Patients with chronic obstructive pulmonary disease admitted in the hospital were randomly divided into 2 groups,one group of patients were given regular COPD treatment (control group,30 cases), the other group of patients were given vitamin D on the basis of conventional therapy(experimental group,30 cases).Pulmonary function test and C reaction protein (CRP)determination in the 2 groups were performed,the contents of PaO2 ,PaCO2 were also determined.Results Compared with the control group,lung function improvement in experimental group were more obvious,and the the number of acute attack significantly reduced(P 0.05).Conclusion Vitamin D contributes to the improvement of pulmonary function in patients with COPD,and its mecha-nism might relate to the reduction of inflammatory reaction.

Effect of injection with hepatocyte growth factor on angiogenesis in myocardium of dogs with myocardial ischemia / 第三军医大学学报

Objective To study the molecular mechanism of injection with hepatocyte growth factor (HGF) at different doses on angiogenesis in myocardium of dogs with acute myocardial infarction (MI).Methods Sixteen 1.5-year-old male hybrid dogs,weighing 11-13 kg,were divided into 500 ?g HGF treatment group,1 000 ?g HGF treatment group,sham operation group,and no MI interference group,4 dogs in each group.Expressions of VEGF,HGF,CD31,and platelet factor Ⅷ in myocardium of dogs with MI were detected,the number of micro blood vessels was calculated,and correlation between angiogenesis and expression of HGF and VEGF was analyzed in 28 d after the model was established.Results HGF gene therapy could up-regulate the expression of CD31 and VEGF.The expression of CD31 and VEGF mRNA was 0.82 and 0.39 respectively in 1 000 ?g HGF group,and 0.47 and 0.21 respectively in 500 ?g HGF group.The expression of VEGF mRNA was 0.09 and no expression of CD31 mRNA was found in MI group.HGF could increase the angiogenesis in infracted myocardium.The microvascular density was 126.4?10.6,79.8?6.0,and 21.7?2.5/mm2,respectively,in 1 000 ?g HGF group,500 ?g HGF group,and MI group (P

Effect of simvastatin on RhoA expression and cardiac remodeling with in acute myocardiac infarction rats / 第三军医大学学报

Objective To investigate the effects of simvastatin on the abatement of the mRNA,protein expression of RhoA and the improvement of the cardiac remodeling and cardiac disfunction after the myocardiac infarction in rats.Methods Rats were divided into 3 groups: the control group,the myocardiac infarction group and Simvastatin intervened group.After 8 weeks,cardiac weight index and hemodynamics were observed,mRNA and protein expression of RhoA in cardiac muscles was measured. Results Compared with the control group,the cardiac weight index and the mRNA and protein expression were increased in rats with myocardiac infarction and the hemodynamics was worsened(P

Experimental study of improved cardiac remodeling and cardiac dysfunction by Simvastatin / 重庆医科大学学报

Objective:To investigate the beneficial effects of Simvastatin on cardiac remodeling and cardiac dysfunction after myocardial infarction and its possible mechanisms.Methods:Simvastatin was administered to the rats with myocardial infarction rats by left anterior descending coronary artery ligation.After 8 weeks,cardiac remodeling was observed through right ventricular weight index (RVWI),and left ventricular weight index (LVWI).Changes in hemodynamics were observed.The activity of nitric oxide synthase (NOS) and inducible nitric oxide synthase (iNOS) in left ventricle and serum were measured.Results:In the rat model of myocardial infarction RVWI,LVWI increased and activity of NOS and iNOS in ventricle and serum decreased(P