There are many methods for internal and external fixation of limbs fractures,such as plaster,splint,and traction.But the disadvantages such as destroyed local blood supply,unreliable fixation,inappropriate dynamic and static combination,postoperative nursing,delayed functional recovery and complications limit their application.Multifunctional external fixation apparatus has been used to treat limbs fractures.It avoids to dissect surrounding tissues and does not damage blood supply out of medullary cavity,which benefits wound treatment,early functional exercise,prevents joint adherence,improves cure rate,reduces complications and avoids second surgery.Moreover,this method is an effective fixation,saves treatment time and prevents adverse results due to treatment for other wounds.In addition.it can also be used to treat bone nonunion,infective fracture,bone defect and other fracture complications.

Objective To investigate the effect of sertraline on the viability and the expression of tyrosine hydroxylase (TH) and phosphorylated ERK1/2 in NGF-induced rat pheochromocytoma (PC12) cells.Methods NGF-induced PC12 cells were pretreated or directly treated with different concentrations of sertraline for 24 or 48 hours and the pretreated groups were then subjected to serum withdrawal condition. Then cell viability was determined by the cell counting Kit-8 (CCK-8). The expression of Tyrosine hydroxylase (TH) and pERK1/2in NGF-induced PC12 cells was determined by immunohistochemistry and western blot respectively. Results The viability of NGF-induced PC12 was improved after administration with sertra]ine. After 24h sertraline administration, the cells activity of PC 12 cells at 20μM ( 1.32 ± 0. 11 ) , 10μM ( 1. 17 ± 0.05 ) of direct effect, and 20μM ( 1.15 ±0.11 ) of protect effect increased dramatically as compared with control group. But high dose ( 50μM )sertraline express high toxic effect to PC12 cells. The expression of TH was increased by sertraline 20 μM at both 24h(ratio of TH/β-actin = 1.27 ±0.05) and 48h(ratio of TH/β-actin = 1. 23 ±0.08) compare with control group,and the expression of pERK1/2 also increased dramatically by sertraline 20 μM at both 24h (ratio of (pERK1/2)/β-actin = 1.41±0.05) and 48h( ratio of (pERK1/2)/β-actin = 1.40 ±0.06) compare with control group(P＜0. 01, P ＜ 0. 05). Immunohistochemistry showed similar results. Conclusion These data suggest that the neuroprotective effect of sertraline may play an important role in depression therapy, and this effect might be mediated by TH and pERK1/2 up-regulation.