OBJECTIVEThis research aimed to investigate the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in mandibular distraction osteogenesis (DO) regulated by parathyroid hormone (PTH) and to explore the mechanism by which PTH promotes DO.

METHODSA rabbit mandibular DO model was established. The rabbits were randomly divided into experimental group and control group. The former were subcutaneously injected with different doses of PTH on alternate days, the latter was injected with normal saline every other day. Serum OPG levels were detected through enzyme-linked immunosorbent assay. The OPG and RANKL expression levels in the DO-induced formation of a new bone tissue were examined through immunohistochemistry staining.

RESULTSThe serum OPG levels gradually increased during distraction. At the end of the stretch, the OPG expression in the experimental group was significantly stronger than that in the control group. As the fixed period was extended, the OPG expression in the new bone gradually decreased, but the RANKL expression increased.

CONCLUSIONIntermittent subcutaneous PTH injection can upregulate the OPG expression and accelerate bone metabolism. Thus, this procedure promotes the early generation of a new bone in the mandible through DO.

Animals ; Enzyme-Linked Immunosorbent Assay ; Mandible ; NF-kappa B ; metabolism ; Osteogenesis, Distraction ; methods ; Osteoprotegerin ; metabolism ; Parathyroid Hormone ; metabolism ; RANK Ligand ; metabolism ; RNA, Messenger ; Rabbits ; Random Allocation

Objectives Through analyzing the published scientific papers from 2001 to 2010 by the professionals of the 31 provincial Center for Disease Control and Prevention in China,offer reference for making plan about scientific research,disciplinary areas,personnel training.Methods Literature quantitative analysis and health statistics methods were used to analyze these papers.Results The professionals in 31 provincial CDC published a total of 22079 papers,Zhejiang 1669(7.56％),Guangxi 1579 (7.15 ％),Jiangsu 1410 (6.39 ％) are the top 3 provinces.The ratio of published papers in Zhonghua medical journal among all the papers are 1366(6.19％),the first three provinces Tianjinlll (13.67％).Beijing160 (13.57％).Shaanxi34 (10.59％).Average papers published by the eastern,central and western regions are 1131,452,444,eastern above western regions (P =0.0065.P =0.0028).Conclusion In recent ten years,the quantity and quality of papers published by the professionals of provincial CDC in China were improved.The unbalanced development exist among eastern,central and western regions,But the majority CDC's papers should be strengthened further.