Objective:To investigate the expression of transforming growth factor ?1(TGF-?1) in dog mandibular distraction osteogenensis (DO). Methods: Mandibular DO model was established in 12 dogs and nonunion model in another 12 dogs, 4 dogs were used as the no-treatment control. Tissue samples were obtained 6 d,2 and 8 weeks after operation respectively.Immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were used to determine the expressions of TGF-?1 in the samples.Results: TGF-?1 (ng/g) in control group was 1394.3?20.1,6 d after operation that in DO and nonunion groups was 1928.5?33.5(vs control,P

Antibiotics can not only combine with specific targets, but also induce a cascade of re-active oxygen species ( ROS) in bacteria. Antioxidant defense system plays an important role in scavenging ROS and repairing injury against oxidative stress. However, the mechanism of ROS accumulation in bacteria and the action of ROS are very complicated. Therefore, this paper reviewed the mechanisms of bacterial re-sponding to oxidative stress in the existence of antibiotics. In addition, we analyzed the main problems lying in the current study and the issues needing further consideration.

Purpose To investigate the reproducibility and risk factors of aortic distensibility quantification in patients with abdominal aortic aneurysm using multi-slice spiral CT.Materials and Methods The abdominal aortic computed tomography angiography data of 54 patients with infrarenal abdominal aortic aneurysm were prospectively studied.64-muti detector spiral CT,retrospective ECG-gating and segment data collecting scanning were all carried out.The aortic distensibility,D value,and pulse wave velocity at renal artery level and infrarenal artery level were calculated using semiautomatic segmentation software.The difference of aortic distensibility at different levels was compared,and consistency test was performed.Results The D value at renal artery level and infrarenal artery level of abdominal aortic aneurysm was (1.05 ±0.22)×10-5/Pa and (0.49± 0.18)× 10-5/Pa,respectively;and the corresponding pulse wave velocity was (9.68± 1.09) m/s and (14.96 ±4.01) m/s,respectively.The intraclass correlation coefficient of intra-and interobserver at renal level was 0.92 and 0.79,while it was 0.85 and 0.79 at inffa level.The Bland-Altman graph showed that the vast majority of points were within the 95％ CI,the difference of intraobserver between the two positions was 0.017×105/pa and 0.010×10-5/Pa,and the difference of interobserver was 0.013×105/Pa and 0.018×10-5/Pa.Multivariate analysis of all these variables showed aortic distensibility to be independently correlated to body mass index,pulse pressure,diastolic pressure and abdominal aortic aneurysm diameter (R2=0.68).Conclusion The quantification of aortic distensibility using multi-slice spiral in patients with abdominal aortic aneurysm shows high stability.Taking into consideration of the relationship between different risk factors and the incidence of abdominal aortic aneurysm can lead to a better clinical approach.