BACKGROUND: Bone morphogenetic protein (BMP) is a protein possesses potential activity, which can increase and enhance its activity when the bone issues are damaged, so it can be used to repair the bone defects when combined with carrier. However,there are few reports concerning it as gene therapy.OBJECTIVE: To construct recombinant retroviral vector expressing human BMP2 gene and to discuss its biological function in ostecblasts.METHODS: BMP2-specific primers were designed and synthesized according gene sequence of human BMP2 gene in Genbank, then BMP2 gena was amplified by Hifi PCR, which was recombined with cloning vector pDNR-CMV homologousiy into pDNR-CMV-BMP2 plasmid identified by BMP2 PCR and enzyme digestion of Sail and EcoRI as well as gene sequencing; recombinant plasmid pDNR-CMV-BMP2 and retroviral plasmid pLP-LNCX were recombined homologously in IoxP sites into pLP-LNCX-BMP2 plasmid transferred into packing cell line PT67 and the supernatant was collected to assay viral titre. Human osteoblast was infected with retrovirus, then the growth of cells were observed by MTT, and the expression of BMP2 protein was detected by Western blotting at 48 hours transfectionRESULTS AND CONCLUSION: Digestion, BMP2 PCR and gene sequencing of pDNR-CMV-BMP2 were coincided with expected. After transfected with plasmid pLP-LNCX-BMP2, PT67 cells could be screened with G418 only to get stably integrated in BMP2, of whose supemanant viral titra amounted to 5×10~8 pfu/mL. MTT assay showed that there had no evident difference in cellular inhibition between the normal and retrovirus groups at 72 hours after transfection (P ＞ 0.05); Western blotting showed that the BMP2 was strong expressed at 48 hours after transfection. It demonstrated that BMP2 gene was successful cloned and its retrovirus vector was constructed.

Objective To investigate the prevalence of musculoskeletal disorders (MSD) in dentists and to analyze the risk factors of MSD to provide suggestions for preventing and reducing MSD in dentists. Methods Through stratified cluster random sampling, 373 dentists were selected from one Hospital of Stomatolagy and five general hospitals among Three-A hospitals in Wuhan as the research objects. The prevalence of MSD was surveyed using the Nordic musculoskeletal disorders standard questionnaire (NMQ) and Numerical Rating Scale (NRS) of pain measurement, and the risk factors of MSD was analyzed with binary Logistic regression. Results The total MSD annual prevalence rate of dentists was 93.3%, with a prevalence rate in neck, shoulder and back, waist and wrist at 78.3%, 70.0%, 56.0% and 36.2% respectively. Through Binary Logistic regression analysis, it was found that the risk factors associated with neck MSD were work fatigue（χ²=24.00，P=0.000）, neck hunching（χ²=23.55，P=0.000）, and shoulder side lift（χ²=24.52，P=0.000）. The risk factors associated with MSD in shoulder and back were work fatigue（χ²=34.64，P=0.000）, neck twisting（χ²=21.68，P=0.000） and wrist bending（χ²=45.87，P=0.000）. The risk factors associated with waist MSD were age（χ²=29.83，P=0.000）, majors（χ²=16.68，P=0.028）, work fatigue（χ²=21.08，P=0.000）, waist bending（χ²=22.88，P=0.000）. The risk factors associated with wrist MSD were gender（χ²=4.17，P=0.041）, majors（χ²=23.47，P=0.001）, working years（χ²=11.63，P=0.009）, physical activities（χ²=9.14，P=0.028）, number of patient visits per day（χ²=18.41，P=0.000）, bending and twisting（χ²=24.12，P=0.000）, wrist twisting（χ²=34.41，P=0.000）, and prevalence of microscope using（χ²=12.09，P=0.020）, while physical exercise was a protective factor for wrist MSD.The differences of the above-mentioned risk factors were statistically significant (P<0.05). Conclusion The prevalence of MSD in dentists is relatively high, and hospital management should strengthen organizational training to help dentists to realize the importance of adopting correct operating posture, a 5-minute breaks during work, prevent MSD at an early stage.