Objective To investigate the extent intravenously transplantation of mesenchymal stem cells (MSCs) mediated by magnetic targeting material arrive in the myocardial infarction region and its effects on the recovery of myocardial infarction. Methods Identify the phenotype of the fourth genet of ex vivo expanded MSCs, stain with DAPI after inducing with 10μmol/L 5-aza, then preserve the MSCs for transplantation. 28 SD rats were divided into three groups: group A (n=10), delivered MSCs combined with magnetic targeting material for 30 minutes to rats through tail vein,and kept on raising after placing magnets on the corresponding skin region to myocardial infarction area for 30min; group B (n=9), administration MSCs not conjuncted with magnetic targeting material through tail vein; group C (n=9), direct intramyocardial transplantation of MSCs. Two days after transplantation, evaluate the aggregation state of MSCs in the area of myocardial infarction; 30d later, estimate the functional and morphological changes in myocardial infarction region. Results We observed that each MSCs had 3-5 molecules of magnetic targeting material attached to its membrane under transmission electron microscope. The homing rates of MSCs respectively were group A 38%, group B 6%, group C 53%.The number of aggregating MSCs of group A and group C was apparently more than that of group B（Plt;0.01）. After transplantation, the contraction indices of left ventricle in group A and group C had significant improvement as compared with that of pretransplantation (LVEF 46%±6% vs. 38%±8%, 51%±5% vs. 35%±4%; LVFS 28%±6% vs. 20%±7%, 32%±4% vs. 20%±5%, Plt;0.05) and administrated cells stained with DAPI could be detected in infarction region under optical microscope. After transplantation, the contraction indices of left ventricle in group B hadn’t conspicuous improvement, and the transplanted cells labeled with DAPI could not be identified in infarction region under optical microscope (homing rate of MSCs 38%). There was no statistically difference of results between group A and group C, but in experiment process, there was a high mortality in group C. Conclusion The method that intravenously delivery of MSCs mediated by magnetic targeting material could accumulate much more MSCs in infarction region, reduce infarction size, and effectively improve the cardiac function after infarction.
Objective To study palliative surgical strategies for patients with complex congenital heart diseases， and improve their clinical outcomes and survival rate.?Methods We retrospectively analyzed clinical data of 95 patients with complex congenital heart diseases who underwent palliative surgical repair in Union Hospital of Tongji Medical College，Huazhong University of Science and Technology from January 2004 to May 2011. There were 68 male patients and 27female patients with their age ranging from 1 month to 37 years. Modified Blalock-Taussig shunt （B-T shunt） was performed in 12 patients， modified Brock’s procedure in 23 patients， bidirectional Glenn procedure in 55 patients and pulmonary artery banding in 5 patients. Surgical strategies and influential factors of treatment outcomes were analyzed.?Results There were 10 in-hospital death with the overall mortality of 10.5% （10/95）. All the surviving patients were discharged successfully. Main postoperative complications included low cardiac output syndrome， hypoxemia and pneumonia. All the surviving patients were followed up for 5 months to 6 years， and in New York Heart Association （NYHA） functional class ⅠorⅡduring follow-up. During follow-up， nine patients after modified Brock’s procedure received radical repair， and 6 patients after bidirectional Glenn procedure received total cavopulmonary connection.?Conclusion A considerable numberof patients with complex congenital heart diseases may miss their best timing for surgical repair， which significantlyinfluences their surgical outcomes. We need to choose best palliative surgical strategy for these patients according to their pulmonary artery development condition， heart malformation characteristics and final treatment goal.