Objective To test the hypothesis that marrow stromal cells （MSCs）, when implanted into selfmyocardium in rabbits, can undergo milieu-dependent differentiation and express cardiomyogenic phenotypes and enhance cardiac function of ischemic hearts, through establish a clinically relevant model for autologous MSCs transplantation, Methods Thirteen New Zealand White rabbits were randomly divided into experimental group （n= 7） and control group （n= 6）. In experimental group, autotogous MSCs（3× 106 cells/30μl） labeled with Bromodeoxyuridine （BrdU） were respectively injected into superior, central and inferior sites in the periphery of the myocardial infarct region. Phosphate buffer saline （PBS） was injected into the scar of the control group hearts according to the same procedure used in the experimental group. Four weeks later, the transplanted labeled MSCs were detected by laser scanning confocal microscopy and the cardiac function were examined by echocardiogram and muhichannel physiologic recorder. Results After 4 weeks, transplanted MSCs were demonstrated myogenic differentiation with the expression of α-sarcomeric actin and connexin 43 located in intercalated disk. MSCs increased the number of vessels compared with controls in myocardial ischemia area. MSCs implantation resulted in markedly improved left ventricular contractility[left ventricular ejection fraction （LVEF）： 0. 51 ± 0.07 vs. 0. 43 ± 0.06 ,left ventricular lateral wall motion distance （LVLWMD） ：1. 75±0. 42mm vs. 1.09±0. 28mm, left ventricular systolic wall thickening ratio（LVAT） ：0. 19%±0.05% vs. 0. 11%±0.04%, left ventricular systolic pressure （LVSP）： 113. 1± 6.3mmHg vs. 99, 5 ± 5, lmmHg, left ventricular end diastolic pressure （LVEDP）： 11. 5±2. lmmHg vs, 14, 3 ±3. lmmHg, maximum rate of left ventricular pressure rise （＋dp/dtmax）：4 618. 3±365. 2 mmHg/s vs. 3 268. 1± 436.9 mmHg/s, maximum rate of left ventricular pressure fall （-dp/dtmax） ：3 008.8±346.7 mmHg/s vs. 2 536.9± 380.4 mmHg/s, P〈0.05]. Conclusion Transplanted autologous MSCs are able to undergo differentiation to form myocardial cells and improve the cardiac function of ischemia myocardium effectively. Autologous MSCs transplantation may have significant clinical potential in treatment myocardial ischemia.
Objective To study the effect of bone marrow mesenchymal stem cells(MSCs) implantation into infarcted myocardium on cytokine secretion and angiogenesis. Methods 24 Guizhou xiang porcine were equally divided into experimental group and control group randomly. Three ml bone marrow was extracted from the posterior superior iliac spine. MSCs were cultured according to the methods of Wakitani’s. After being co-cultured with 5-azacytidine for 24 hours, these cells were labeled with bromodeoxyuridine(BrdU). Autologus MSCs were implanted into the acute myocardial infarct site both via the distal segment of the ligated left anterior descending artery (LAD) and topical injection. 3 amp; 6 weeks after transplantation, the samples from experimental group and control group were collected to detect the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and Ⅷ factor by immunohistology and video image digital analysis system. Results The expression of VEGF, bFGF and the microvessel counts in the experimental group were much higher than those of control group (Plt;0.01) at 3 and 6 weeks after transplantation. Conclusion MSCs, after being implanted into infarcted myocardium, shows the ability of secreting VEGF, bFGF, with subsequent angiogenesis.
Objective To analyze longitudinal motion of infarcted myocardium and ischemic myocardium with a new echocardiographic technology of velocity vector imaging (VVI), and to assess its accuracy. Methods From December2007 to January 2008, 6 patients suffered acute anterior myocardial infarction (MI group), 9 patients had myocardial ischemia (over 70% stenosis of anterior descending branch, MS group) and 16 healthy subjects (control group) were included. The long axis view and 2-chambers view of left ventricle at the apex of heart were acquired with Siemens Sequoia 512 ultrasound system. The longitudinal velocity, displacement, strain and strain rate were analyzed with off-l ine Syngo US workplace software. Results In normal myocardial group, longitudinal peak systol ic velocity (Vs) and peak displacement (D) decreased progressively from base level to apex level in anterior wall and anterior septum (P lt; 0.05), while peak strain (S) and peak systol ic strain rate (SRs) kept the same in three levels (P gt; 0.05). S and SRs significantly decreased in all segments of infarcted myocardium (P lt; 0.05), compared with normal and ischemic myocardium. In ischemic myocardium, only base and middle segmental S of anterior wall decreased (P lt; 0.05). A myocardial S lower than —6.94% in at least one ventricular segment showed best sensitivity (100%) and specificity (100%) for detecting an infarcted left ventricle. A myocardial SRs lower than —0.81% at least in one ventricular segment showed 100% sensitivity and 80% specificity, and lower than —0.46% showed 83% sensitivity and 100% specificity. Conclusion VVI is a useful tool for assessing myocardial regional function. Especially, S and SRs are useful predictors of the presence of regional dysfunction in infarcted myocardium.