Objective To evaluate the accuracy of pedicle guide device for the placement of the pedicle screws. Methods Pedicle guide device was designed and made for the anatomical trait of pedicle. The 3-Danatomical data of the thoracic pedicles were measured by multislice spiral CT in two embalmed human cadaveric thoracic pedicles spine(T1 -T10). Depending on transverse section angle(TSA) and sagittal section angle(SSA) of pedicle axis, the degree of horizontal dial and sagittal dial were adjusted in the guide device. The screws wereinserted bilaterally in the thoracic pedicles by using the device. After pulling the screws out, the pathways were filled with contrast media. The TSA and SSA of developed pathways were measured. Results Analysis of the difference between pedicle axis and developed pathway was of no statistical significance(P＞0.05). Conclusion The guide device could be easilyoperated and guarantee high accuracy of the pathways of screws and the incidence of pedicle penetration could be significantly reduced.
Objective To investigate the early change of brain-derived neurotrophic factor (BDNF) in denervated red and white muscles and the regeneration of nerves innervating the muscles and to discuss the effect of the target organs on regeneration of the injured nerves.Methods Forty Wistar rats were divided into 5 groups. The sciatic nerves in 4 groups were sheared to make the models of the denervated muscles and the other one as control group. The amount of BDNF in muscles was measured with immunohistochemistry 1 day, 3 days, 7 days and 14 days after injury. The models of the regeneration of the nerves were made in another 15 rats whose sciatic nerves were disconnected with forceps. The nerve conduction velocity and electromyogram were tested with neuroelectrophysiology7 days and 14 days after injury. Results The expression of BDNF in soleus increased significantly on the 1st day, the 3rd day and the 7th day (P＜0.01); theexpression ingastrocnemius was lower, but there was no significant difference(P＞0.05) on the 1st day, the 3rd day,the 7th day and the 14th day when compared with control group. After 14 days of injury in the nerves innervating GAS and SOL, the nerve conduction velocities and the amplitudes of wave M recovered to (36.60±7.40)% and (19.9±6.4)% of normal value, and (42.50±3.50)% and (13.7±4.0)% of normal value respectively; there were no significant differences between the two muscles(P＞0.05).Conclusion There is- difference in BDNF amount between the denervated red and white muscles, but the recovery of the two kinds of the motornerves is similar,and the neurotrophism of denervated muscles was determined by all kinds of neurotrophic factors.
Objective To study the mRNA expressions of protein kinase C(PKC) and nerve growth factor (NGF) in rat sciatic nerve and the number ofaxons after phorbol-12-myristate-13-acetate (PMA) was injected into silicone chamber. Methods Forty-two SD adult rats were divided into six groups depending on the time of injury (1 day, 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks). A 0.5 cm nerve was cut in doublerat sciatic nerves and “T” type silicone chamber was sutured. PMA at the concentration of 1×10-9mol/L was injected discontinuously into the right side of Ttype silicone chamber(PMA group) and saline was injected into the left side(control group). Nucleic acid in situ hybridization histochemistry technique and thecomputer imagine analysis were employed to detect dynamic changes of PKC mRNA and NGF mRNA in rat sciatic nerves. The number of axons was measured. Results The expressions of PKC mRNA and NGF mRNA increased after injury, and the expressions of PKC mRNA and NGF mRNA reached the peak 2 weeks and3 weeks after injury respectively in control group. The expressions of PKC mRNA and NGF mRNA in PMA group were significantly increased than those in control group 2,3 and 4 weeks after injury(Plt;0.01).The number of axons in PMA group significantly increased than that in control group(Plt;0.01). Conclusion PKC involved inthe expression of NGF mRNA and nerve regeneration after injury. During the regenerated course, PMA can promote the expression of NGF mRNA and the number of axons after injury.