Objective To establish an objective animal experimental model for the experimental study of clinical bone defect,detect the BMP-2 activity in bone defect area,and observe the early healing situation of rabbit radial fracture.Methods A total of 72 New Zealand rabbits [weight/ each:(2.8 ±0.2)kg] were randomly divided into four experimental groups A,B,C,and D (18/each) with corresponding 0.5 cm,1.5 cm,2.0 cm,and 3.0 cm bone defect models abolished,respectively,in the middle of the rabbit left radius.By the time of modeling,all the bone segments were retained and a small amount of bone adjacent tissues were taken as E specimens of control group.Modeling time was recorded as 0 week,and six animals of each group were killed in 1 W,3 W,4 W later.Then the bone defect surrounding tissues were taken to check BMP-2 content by Western-blot detection,and the bone-healing situation was observed at different time.Results BMP-2 composition showed a significant increase in secretory volume of each group's bone defect area tissues after modeling one week,compared with E specimens of control group (P ＜ 0.05).BMP-2 composition secretion capacity even reached its peak in the third week four groups (A,B,C,D)increased by 556.1％,385.9％,272.2％,171.2％ respectively.and BMP-2 content reduced apparently in the fourth week than before(P ＜ 0.05).At the same time,BMP-2 content decreased with the addition of bone defect length(P ＜ 0.05).Also a correlation was shown between bone healing and time with the bone defect length.Conclusions A comparable rabbit radial bone defect model was successfully established.These objective animal models,which are closer to clinical reality,provide the theoretical basis of animal experiments to explore the mechanism of human fracture healing.

BACKGROUND:It has been studied that the distribution of bone morphogenetic protein 2 is regular under bone defect situation. OBJECTIVE:To observe the expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths. METHODS:Forty-eight New Zealand rabbits were divided into two groups randomly, 0.5 cm bone defect and 3.0 cm bone defect were made by wire saw at the middle part of radius bone after anaesthesia. RESULTS AND CONCLUSION:Western blot results showed that in the 0.5 cm bone defect group, the expression of bone morphogenetic protein 2 of the tissues in the bone defect site was increased gradual y at 1, 3, 4 weeks after operation, and the expression in each defect group was increased when compared with that immediately after injury (P<0.05). In the 3.0 cm bone defect group, the expression of bone morphogenetic protein 2 of tissues in bone defect site was increased gradual y and reached to its peak at 3 weeks after the operation (P<0.05), and the peak value in the 3.0 cm bone defect group was significantly higher than that in 0.5 cm bone defect group (P<0.05). The peak value was maintained in high level. The comparison of bone cal us formation showed that the bone cal us formation of 3.0 cm bone defect group was less than that of the 0.5 cm bone defect group at 3 and 4 weeks after operation (P<0.05). The results indicate that expression of the bone morphogenetic protein 2 in 3.0 cm bone defect site is increased significantly, but the expression level cannot make the bone defect heal itself.

Lymphangioleiomyomatosis (LAM) is a rare, multisystemic, low-grade neoplasm character-ized by diffuse cystic lesions in the lung.In recent years, emerging imaging examination such as ⁶⁸Ga-NEB PET-CT scan provides efficient and precise non-invasive diagnostic methods to detect lymphatic circulation abnormalities in LAM patients. The long-term efficacy and safety of sirolimus for LAM has accumulated further evidence, and genetic profiling studies have unveiled more information of genetic mechanisms. Prognosis of LAM has been much improved. We briefly reviewed the research advances of LAM in China and other countires.