BACKGROUND:We previously demonstrated that the acid fibroblast growth factor/fibrin gelatin implantation could greatly relieve denervated motor end-plate degeneration and myatrophy. OBJECTIVE:To study the effect of acid fibroblast growth factor/fibrin gelatin on preventing denervated motor end-plate degeneration using immunohistochemical method. DESIGN,TIME AND SETTING:A randomized controlled animal experiment was performed in Zhujiang Hospital,Southern Medical University from June to December 2006. MATERIALS:A total of 24 SD rats of clean grade were randomly divided into three groups:acid fibroblast growth factor/fibrin gelatin group,fibrin gelatin group,and blank control group,with 8 rats for each group. METHODS:Under the general anesthesia,right common peroneal nerves of rats in each group were cut off 1 cm away from the nerve muscle entry point. Acid fibroblast growth factor/fibrin gelatin group,perilemma was sutured and the compound was implanted into spatium intermusculare around denervated tibial muscle nerve region;fibrin gelatin group,perilemma was sutured and fibrin gelatin was implanted;perilemma was sutured without medication in the blank control group. MAIN OUTCOME MEASURES:After 6 weeks,neuromuscular junction of tibial muscle branch of common peroneal nerve and its peripheral muscles were separated. Acidic fibroblast growth factor receptor was detected by SP immunohistochemistry to observe expressive site of acidic fibroblast growth factor receptors,and count positive blood capillary. Gray scale of the acidic fibroblast growth factor receptor was detected using image analysis system. RESULTS:The acidic fibroblast growth factor receptor was mainly located in capillary vessel wall. High density of expressing area of acidic fibroblast growth factor receptor and intensive capillary vessels were in acid fibroblast growth factor/fibrin gelatin group. In contrast,low density of masculine expressing site of acidic fibroblast growth factor receptor in capillary vessel and rare capillary vessels were in fibrin gelatin group and blank control group. The positive percentage of acidic fibroblast growth factor receptor expression of capillary vessels in acid fibroblast growth factor/fibrin gelatin group was higher than fibrin gelatin group and blank control group. The expressing amount of acidic fibroblast growth factor receptor in acid fibroblast growth factor/fibrin gelatin group was also higher than fibrin gelatin group and blank control group CONCLUSION:Acidic fibroblast growth factor can protect motor end-plate by improving the surrounding blood circulation.

Objective To determine the factors influencing the indication for tracheostomy following cervical spinal cord injury.Methods A retrospective study was performed to analyze the 118 patients who had been treated for cervical fracture/dislocation along with cervical spinal cord injury from July 2004 to June 2014 and whose abbreviated injury scale score (AISS) was lower than 3.They were 96 men and 22 women,19 to 68 years of age (average,45.2 years).The patients were divided into a tracheostomy group (n ＝ 28) and a non-tracheostomy group (n =90).The 2 groups were compared in terms of gender,age,presence or absence of complete spinal cord injury at admission,injured segment,injury mechanism,smoking history,injury severity score (ISS),motor AISS,systolic pressure at admission,hospital stay,and ICU stay to determine the factors influencing allocation of tracheostomy.Results Compared with the non-tracheostomy group,the tracheostomy group had a higher rate of complete spinal cord injury at admission,a higher rate of smoking,a higher ISS at admission,a lower motor AISS,and longer hospital and ICU stay,with statistically significant differences (P ＜ 0.05).There were no significant differences between the 2 groups in gender,age,injured segment,injury mechanism,or systolic pressure at admission (P ＞ 0.05).Increased severity of cervical spinal cord injury was associated with significantly decreased motor AISA,increased rate of tracheostomy and increased ISS (P ＜ 0.05).Conclusion The influencing factors for indication of tracheostomy after cervical spinal cord injury are complete cervical spinal cord injury irrespective of the level of injury,ISS,motor AISS,and history of smoking.

This article introduces a new technology of prosthetic disc nucleus replacement to treat lumbar disc herniation. The preliminary clinic experience, short time following ups, indications, contraindications, size and method of the technique were discussed. It was noted that some patients had short but heavy lumbago after the operation but the pain was relieved after oral medication. It will be a trend in the future spine surgery to restore the functions of spine unit. The prosthetic disc nucleus is a good choice before a total disc prosthesis replacing or spine fusion.

[Objective]To evaluate the feasibility of the minic microgravity as a method and the layered cylindric collagen-chitosan-?-tricalcium phosphate composite as a scaffold for the cartilage tissue engineering after an observation of how it absorbs the chondrocytes and affects the cell behavior.[Method]The chondrocytes were isolated and multiplied in vitro,and then the chondrocytes were seeded onto the porous collagen-chitosan-?-tricalcium phosphate composite scaffold and were cultured in both minic microgravity and ordinary environment for 3 weeks.The effects of the composite scaffold on the cell adhesivity,proliferation,morphological changes and synthesis of the extracellularmatrix were observed by the growth curve,phase-contrast microscopy,histology,scanning electron microscopy and immunohistochemistry.[Result]The chondrocytes that adhered to the scaffold increased significantly and secreted extracellular matrix in the center of the porous scaffold around the chondrocytes under minic microgravity compared with ordinary environment.Immunohistochemistry of type Ⅱ collagen was positive.[Conclusion]The minic microgravity environment will be a good method for the cartilage tissue engineering.And the layered cylindric collagen-chitosan-?-tricalcium phosphate composite scaffold has a good cellular compatibility.It will be an ideal scaffold for the cartilage tissue engineering.

[Objective]To analyze the change of intervertebral disc Von Mises stress on the adjacent segment after "U" shape dynamic fixation for lumbar with finite element method. [Method]The three-dimensional finite element models of the lumbar dynamic fixation and rigid fixation were established by using Mimics11.11 and Abaqus6.51 softwares.Loads used in this study were axial compressive,flexion,extension,lateral bending,and rotation forces.The intervertebral disc Von Mises stress of the adjacent segment was analyzed and compared.[Result]In the same shearing load of 500 N,the intervertebral disc Von Mises stress of the adjacent segment in the dynamic fixation model was lower than rigid fixation model under axial compressive,flexion,extension,lateral bending,and rotation forces,especially at lateral of the intervertebral disc,and there were significant difference between dynamic fixation group and rigid fixation group(P

[Objective]To evaluate the effectiveness of recombinant human bone morphogenetic protein-2 in the repair of rabbit rotator cuff injury.[Method]Forty-eight male New Zealand rabbits,aged 8 months,received an rotator cuff acute injury and reconstruction of the insertion of supraspinatus tendon on greater tuberosity of humerus.The rabbits were randomly divided into 3 groups postoperatively:(1) rhBMP-2 group:fibrin sealant(FS) containing rhBMP-2 was applied to the interface between the bone-tendon interface; (2)FS control group:only FS was applied;(3)blank control group:untreated after the surgery.Harvested 36 specimens underwent biomechanical analysis at the 2nd,4th,8th postoperative weeks respectively.Harvested 12 specimens underwent histological analysis at the 8th postoperative week.[Result]Histological examination showed that Sharpey's fibers were found in the interface with the formation of four-layer indirect insertion in the rhBMP-2 group at the 8th postoperative week.In the FS control group and blank group,the tendon-bone interface was filled with granulation tissue and part of Sharpey's fibers and the newly generated bone tissue.Biomechanical analysis displayed that the tensile strength and stiffness of bone-tendon interface increased time-dependently in all groups,and it in the rhBMP-2 group was significantly higher than those in the other two groups at any time-points (both P

To investigate the degradation features of HA and PDLLA/HA composites in different proportion in vitro. Four kinds of foams consisting of PDLLA, PDLLA/HA (5%wt), PDLLA/HA (20%wt), and PDLLA/HA (35%wt) were immersed in distilled water. Changes in pH, mass loss, viscosity-average molecular weight, and strength against pressure were observed and compared to study degradation features of specimens in vitro. There were statistically differences in the indexes between the PDLLA/HA (20%wt) composite and the other foams after 12 weeks (P

[Objective]To investigate the compatibility of tissue and cell in the three-dimensional porous bioactive glass/recombine human Bone Morphogenetic Protein-2 (BG /rhBMP2)materialscaffolds and provide a reference for improving the constitution of composite material.[Method]The material of BG and BG/rhBMP2 were cultured in vitro with rabbit osteoblasts respectively. The morphology and adhesion were examined by inverted microscope and scanning electron microscope, and the cell proliferation was detected by MTT assay. The composite materialscaffold were embeded in rabbit's muscle and incisions were observed. The specimens were harvested in 2, 4, 8 and 12 weeks respectively and examined by histology to evaluate the tissue response.[Result]The results showed the cells on BG and BG /rhBMP2 were good adhension and activity, the two materialscaffolds had no apparent inflammatory reaction in vivo. MTT assay showed the number of the cells in each group were significantly increased along with the culture time prolonged. The number of cells in the BG and rhBMP2 group was higher than that of the control group at different intervals, with a significant difference. The number of cells in the BG/rhBMP2 was not evidently higher than that of the BG with a significant difference.[Conclusion]The porous composite materialscaffold of BG/rhBMP2 has good biocompatibility with the hope to wide use in bone tissue engineering.

[Objective]To investigate the influence of wing-like memory alloy intrasegmental fixator(WMAIF)on healing of lumbar spondylolysis.[Method]Eighteen healthy hybrid adult dogs were used in the experiment,regardless of gender,the L_6 isthmic portion were injured by operation randomly and equally divided into three groups.Group Ⅰ were fixed with WMAIF,groupⅡ were fixed with steel wire,group Ⅲ were treated with nothing.Every group was examined through CT at 2,4,6,8 and 10 weeks.[Result]In group Ⅰ,the fracture achieved healing at 6 weeks after operation.In group Ⅱ,the fracture achieved healing at 10 weeks after operation,while no repair of fracture was found in group Ⅲ.[Conclusion]Lumber spondylolysis fixation with WMAIF has stable and continued axial stress,WMAIF is beneficial to fracture healing,and is a new and reliable intrasegmental instrument for direct repair of lumbar spondylolysis.

Objective To test the releasing property of a self-developed plastic drug delivery implant of anti-infective nano-hydroxyapatite(nano-HA)so as to provide a new local drug delivery system(LDDS)for treatment of osteomyelitis.Methods The nano-HA was used as the core carrier to load gentamicin(GM).It was coated with poly hydroxybutyrate-co-hydroxyvalerate /polyethylene glycol(PHBV/PEG)to prepare the nano-HA-PHBV/PEG-GM microspheres which were mixed with the fibrin sealant(FS)to develop a plastic implant.Then its antibacte rial and in vitro releasing properties were investigated.Results The plastic LDDS implant was found to have a fine drug delivery capability.The bacterial growth inhibition zone was found around the LDDS for 56 days in the antibacterial test.Three samples were soaked with liquid of PBS(phosphate buffered saline).The titer of GM released within the first day was 154.3 ?g/mL,and then the releasing maintained a slow level in the following days.After 49 days'releasing,the titer was 6.9 ?g/mL which was still higher than the MIC(2 ?g/mL)(minima l inhibitory concentration)of GM.Conclusion The plastic LDDS has a fine in vitro releasing property and may have a widespread application in treatment of osteomyelitis.