Analysis of monoclonal antibody binding sites in ovine prion protein / 生物工程学报

Binding sites of five monoclonal antibodies were obtained by reinforceable method of overlapping recombinant prion protein and synthetic peptide. Overlapping peptides of PrP core were expressed in Escherichia coli by insertion of serial PCR amplicons of ovine PrP gene fragments into pET32a. The expressed fusion peptides were then tested for the binding activity to PrP monoclonal antibodies in Western blotting. The binding sites of 5 monoclonal antibodies of ovine PrP were located respectively as follows: 2H3 in 199 aa-213 aa, 4C6, 5F11 and 7F11 in 139 aa-168 aa and 7F1 in 214 aa-227 aa. There oligo peptides were synthesized and used in ELISA test for more accurate localization of the binding sites. The binding sites of 4C6, 5F11 and 7F11 were further confirmed to be in 149 aa-158 aa. This conclusion may contribute to the research for pathogenesis and diagnostic method of scrapie and bovine transmissible spongiform encephalopathy.

Treatment of thoracolumbar vertebrate fracture by transpedicular morselized bone grafting in vertebrae for spinal fusion and pedicle screw fixation / 华中科技大学学报（医学）（英德文版）

To enhance the fusion of graft bone in thoracolumbar vertebrae and minimize the postoperative loss of correction, short-segment pedicle screw fixation was reinforced with posterior moselizee bone grafting in vertebrae for spinal fusion in patients with thoracrolumbar vertebrate fractures. Seventy patients with thoracrolumbar vertebrate fractures were treated by short-segment pedicle screw fixation and were randomly divided into two groups. Fractures in group A (n=20) were reinforced with posterior morselized bone grafting in vertebrae for spinal fusion, while patients group B (n=50) did not receive the morselized bone grafting for bone fusion. The two groups were compared in terms of kyphotic deformity, anterior vertebral height, instrument failure and neurological functions after the treatment. Frankel grading system was used for the evaluation of neurological evaluation and Denis scoring scale was employed for pain assessment. The results showed that the kyphosis correction was achieved in both group A and group B (group A: 6.4 degree; group B: 5.4 degree)/ At the end of follow-up, kyphosis correction was maintained in group A but lost in group B (P=0.0001). Postoperatively, greater anterior height was achieved in group A than in group B (P<0.01). During follow-up study, anterior vertebral height was maintained only in Group A (P<0.001). Both group A and group B showed good Denis pain scores (P1 and P2) but group A outdid group B in terms of control of severe and constant pain (P4 and P5). By Frankel criteria, the changes in neurological functions in group A was better than those of group B (P<0.001). It is concluded that reinforcement of short-segment pedicle fixation with morselized bone grafting for the treatment of patients with thoracolumbar vertebrae fracture could achieve and maintain kyphosis correction, and it may also increase and maintain anterior vertebral height. Morselized bone grafting in vertebrae offers immediate spinal stability in patients with thoracolumbar vertebrate fractures, decreases the instrument failure and provides better postoperative pain control than without the morselized bone grafting.