Abstract： Objective To investigate and improve the method of isolation, induction and culture, amplification in vitro of human endothelial progenitor cells (EPCs) in human bone marrow, thus establish a foundation for EPCs to participate in basic research and clinical application. Methods WHuman bone marrow mononuclear cells (hBMMNCs) were isolated by density gradient centrifugation and cultured in the 6plateds coating human fibronections(HFN group), coating gelatinum (coating gelatinum group) and coating nothing (coating nothing group) respectively. After culturing for 4-7d endothelial cell basal medium-2(EBM-2) cell colonyforming units (CFUs) appeared, then select EPCsliked CFUs for cultivation which was named the pick method, CD34+ KDR+ and CD133+ KDR+ double positive cells were detected in flow cytometry, and CD133, CD34, CD31, vWF and KDR expression were detected with cell immunochemical test. Results hBMMNCs were isolated from human bone marrow more effectively with OptiprepTM cell separating medium, and induced and obtained more EPCs, and cultured and amplificated in vitro. Flow cytometer showed CD133+ KDR+ double positive cells reaching up to 70.4%±5.4%, CD34+ KDR+ double positive cells reaching up to 69.1%±8.7%. EPCs grew vigorously in coating HFN group and coating gelatinum group, both HFN and gelatinum promote EPCs adherence and growth, but there were no statistically difference in two groups (Pgt;0.05).Surface mark of adherent cells cultured 7d such as CD133, CD31, vWF and KDR showed positive, and cells cultured 14d such as CD34 showed positive. Conclusion The method of picking CFUs can obtain more EPCs from human bone marrow with success and can amplificate EPCs in vitro, thus introducing another simple and effective method to purify EPCs, further widening range and increasing method to purify EPCs.
Objective To evaluate clinical efficacy of four-claw Ti-planes for internal fixation of multiple rib fractures and flail chest. Methods Clinical data of 93 patients with multiple rib fractures and flail chest who were admittedto Shanghai Pudong Hospital from December 2011 to November 2012 were retrospectively analyzed. There were 78 male and 15 female patients with their age of 20-80 years. All the patients received internal fixation of rib fractures using four-clawTi-planes. Finite element modeling and analysis were performed to investigate biomechanical behaviors of rib fractures after internal fixation with four-claw Ti-planes. Results The average number of rib fractures of the 93 patients was 5.9±2.1，and each patient received 3.8±1.3 four-claw Ti-planes for internal fixation. The operations were performed 6.3±3.2 days after admission. After the rib fractures were fixed with four-claw Ti-planes，rib dislocations and chest-wall collapse of flail chest were restored，and patients’ pain was relieved. Postoperative CT image reconstruction of the chest showed no dislocationor displacement at the fixation areas of the four-claw Ti-planes. Rib fractures were stabilized well，and normal contours of the chest were restored. Finite element analysis showed that the maximum bearable stress of the rib fractures after internal fixation with four-claw Ti-planes was twice as large as normal ribs. Conclusion Clinical outcomes of four-claw Ti-planesfor internal fixation of rib fractures are satisfactory with small incisions and less muscle injury of the chest wall，so this technique deserves wide clinical use.