Objective To explore the human stromal cell-derived factor 1α (hSDF-1α) and human vascular endothel ial growth factor 165 (hVEGF165) mRNA expressions of the transfected cells after hSDF-1α gene and hVEGF165 gene were transfected into rat myoblasts in vitro so as to lay a foundation for further study on the synergistic effects of 2 genes on tissue engineered skeletal muscle vascularization. Methods The myoblasts of 1-day-old Sprague Dawley rats were cultured and purified by trypsin digestion assay in vitro and were identified by immunohistochemistry staining of Desmin. pproximately 70%-80% of confluent myoblasts were transfected with enhanced green fluorescent protein (EGFP)-hSDF-1α and EGFP-hVEGF165 genes in vitro (transfected group) and were not transfected (control group). The expressions of hSDF-1αand hVEGF165 mRNA and protein in the transfected cells were detected by RT-PCR, ELISA, and Western blot espectively.Results The cultured cells were identified as myoblasts by immunohistochemistry staining of Desmin. The expression ofgreen fluorescent protein was observed in transfected cells, indicating that hSDF-1α and hVEGF165 genes were transfected into myoblasts successfully. The mRNA and protein expressions of the 2 genes were positive in the transfected group by RT-PCR and Western bolt assay at 2, 4, 6, and 8 days after transfection, and were negative in the control group. The expressions of hSDF- 1α and hVEGF165 showed a stable low level in the control group, but the expressions of the proteins increased at 2 days and then showed gradual downtrend with time in the transfected group by ELISA assay. There were significant differences in the expressions of hSDF-1α and hVEGF165 proteins between different time points in the transfected group, and between 2 groups (P lt; 0.05). Conclusion hSDF-1α and hVEGF165 genes are successfully transfected into myoblasts in vitro, and mRNA and proteins of hSDF-1α and hVEGF165 can be expressed in the transfected myoblasts, which may provide the experimental evidence for the expressions of hSDF-1α and hVEGF165 mRNA and proteins in vivo successfully.
Objective To systematically review the effectiveness and safety of power chain vs. nickel titanium coil springs in closing dental extraction space. Methods Databases including PubMed, EMbase, The Cochrane Library, Chinese Biomedicine Literature Database, Chinese Scientific Journals Full-text Database, and Chinese Journal Full-text Database were searched to collect the randomized controlled trials (RCTs) on comparing power chain with nickel titanium coil springs published before February 2012. Two reviewers independently screened literature, extracted data and assessed the quality of the included studies. Then meta-analysis was conducted using RevMan 5.0 software. Results A total of 4 RCTs involving 122 patients were included. The results of meta-analyses showed that there was a significant difference in the rate of space closure between the two groups (MD=0.30 mm per month, 95%CI 0.17 to 0.44, Plt;0.000 1); The results of subgroup analyses indicated that, both high-quality trials (MD=0.20, 95%CI 0.07 to 0.34, P=0.003) and low quality trials (MD=0.40, 95%CI 0.30 to 0.50, Plt;0.000 01) showed no significant difference in the rate of space closure. Conclusion Current clinical evidence indicates nickel titanium coil spring is superior to power chain in the rate of space closure, but its long-term effect still needs to be proved by more large-scale RCTs.