ABSTRACT
BACKGROUND:Simple pedicle screw fixation for thoracolumbar fractures has better outcomes, but there are some deficiencies, such as poor applicability for severe compression or burst fractures, strong vertebral pain, easy to cause vertebral wound denervation and paraspinal muscle injury, and slow recovery. OBJECTIVE:To investigate the clinical effects of pedicle screw fixation combined with artificial bone graft for the treatment of thoracolumbar fractures. METHODS:A total of 126 patients with thoracolumbar vertebral compression fractures, who had undergone pedicle screw fixation without bone graft (control group,n=62) and with bone graft (test group,n=64) were enroled. The fracture healing, anterior vertebral height ratio, sagittal Cobb angle, and loss rate of vertebral height after 6 months were observed by X-ray in the two groups. RESULTS AND CONCLUSION:Al patients were folowed up, and had complete fracture healing after 12-16 months. The anterior vertebral height and Cobb angle were both improved in the two groups at 1 week after operation (P 0.05). New bone formation was observed in the test group at 6 months after operation, and patients were pain-free; but the speed of bone formation was slower in the control group, and patients stil suffered from painful thoracolumbar fractures. There was no difference in the loss of anterior vertebral height and Cobb angle between the two groups (P> 0.05). These findings indicate that pedicle screw fixation combined with artificial bone graft lead to a better recovery in thoracolumbar fractures.
ABSTRACT
AIM: To clone and express the metalloproteinase domain of human von Willebrand factor-cleaving protease (vWF-cp). METHODS: The metalloproteinase domain of human vWF-cp, amplified from the plasmid containing the vWF-cp cDNA gene by using polymerase chain reaction, was cloned into pUC18, and its accuracy was verified by sequencing. Then the domain was inserted into the multiclone site of pET28a(+) and included a 6?His Tag at its amino terminal. After induced by IPTG, the recombinant protein was purified by using a Ni-NTA column and confirmed by Western blot. RESULTS: Comparison of the nucleotide sequence of our cloned domain with the GenBank sequence revealed no difference. High-level expression of the recombinant protein was yielded after 5-hour induction, which amounted to 28% of total bacteria protein in inclusion body. Western blot demonstrated that it possessed high specificity. CONCLUSION: The metalloproteinase domain of vWF-cp was high efficiently expressed in Escherichia coli. This might contribute to the further study of the relationship between its structure and function. [