Detection of gene expression pattern in the early stage after spinal cord injury by gene chip.

OBJECTIVE: To study the changes of the gene expression pattern of spinal cord tissues in the early stage after injury by DNA microarray (gene chip). METHODS: The contusion model of rat spinal cord was established according to Allen's falling strike method and the gene expression patterns of normal and injured spinal cord tissues were studied by gene chip. RESULTS: The expression of 45 genes was significantly changed in the early stage after spinal cord injury, in which 22 genes up-regulated and 23 genes down-regulated. CONCLUSIONS: The expression of some genes changes significantly in the early stage after spinal cord injury, which indicates the complexity of secondary spinal cord injury.

[Treatment of lumbar spondylolisthesis by Socon internal fixator: report of 18 cases].

OBJECTIVE: To evaluate the therapeutic effect of Socon transpedicle internal fixators in the treatment of spondylolisthesis in the lumbar spine. METHODS: Fixation with Socon internal fixators along with posterior decompression and fusion was performed in 18 patients with degenerative spondylolisthesis in the lumbar spine. The symptoms, signs and X-ray manifestations observed preoperatively and postoperatively were compared, and a follow-up study of all cases lasting for 6 to 18 month was conducted. RESULTS: Anatomical restoration of the involved vertebrae was achieved in all the cases, of them 15 had out-standing and 2 had fairly good clinical results without incidences of any complications during or after the operation. CONCLUSION: Socon internal fixator is an excellent modality for treatment of lumbar spondylolithesis.

Three-dimensional porous poly-DL-lactide/basic fibroblast growth factor composites for bone defect repair: an experimental study.

OBJECTIVE: To investigate the osteoinductive ability of the composites consisting of basic fibroblast growth factor (bFGF) and porous poly-DL-lactide (PDLLA) for the development of a new absorbable osteosynthesis material. METHODS: Highly porous foams of PDLLA with the pore size ranging from 150 to 300 microm were prepared by a solvent-casting, particulate-leaching technique with NaCl as the leachable component. Animal models of radial diaphyseal defects of 1.0 cm with complete removal of the periosteum were induced in 45 rabbits, which were randomly divided into 3 groups to receive the defect repair with PDLLA and PDLLA/bFGF respectively, leaving one group untreated to serve as the control group. The implant specimens were harvested at 2, 4, 8, and 12 weeks respectively after the surgery and X-ray, histological and scanning electron microscopic (SEM) examinations were performed to evaluate the effectiveness of defect repair. At 8 and 12 weeks after implantation, biomechanical test (for three-point bending strength) was employed to study the quality of bone formation. RESULTS: PDLLA/bFGF composite stimulated more bone formation and had higher bending strength than PDLLA (P<0.05), and the bone formation induced by both materials was significantly more than that observed in the control group in every postoperative stage (P<0.05). CONCLUSION: PDLLA possesses good biocompatibility and absorbability, and when prepared into a porous material, it exhibits good osteoconductibility. As a good bFGF carrier, the foam of PDLLA with three- dimensional structure shows good osteoinductive ability with regard to the rapidity, quantity and quality of the bone formation.