The synthetic typing and its clinical application in atlantoaxial dislocation / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the synthetic typing and the treatment strategy for atlantoaxial dislocation.</p><p><b>METHODS</b>The synthetic typing of atlantoaxial dislocation was worked out on the base of pathogenesis typing, Fielding imaging typing, and clinical typing, named PIR typing system (Pathogenesis, Imaging, and Reduction). Ninety-three patients with atlantoaxial dislocation were treated according to this typing system.</p><p><b>RESULTS</b>Nine cases of type-II dens fracture were treated with hollow screw fixation. Bone union was accomplished at the follow-up of three months in all the patients, only with slight limitation of cervical motion. Un-retrieved Fielding I -degree dislocation was found in one case. Among the thirty-four patients treated with trans-oropharyngeal atlantoaxial reduction plate system (TARP), 32 obtained complete atlantoaxial reduction and fusion three months after operation. Atlantoaxial dislocation recurred in the other two cases because of screw loosening and the problem was solved through revision operations. Four patients in non-reducible type underwent anterior and/or posterior decompression. T heir neurological improved after operation but their atlantoaxial joints remained dislocated, and one case complicated with intracranial infection.</p><p><b>CONCLUSIONS</b>Via the synthetic PIR typing system, atlantoaxial dislocation can be better classified according to its pathogenesis, imaging manifestation and mechanic stability. This system can also be served as a guide for clinical treatment. Anterior TARP operation and posterior atlantoaxial trans-pedicle screw-rod fixation are the main methods for the treatment of atlantoaxial dislocation.</p>

The Functional Motif of SARS-CoV S Protein Involved in the Interaction with ACE2 / 中国病毒学

SARS-CoV is a newly discovery pathogen causing severe acute respiratory problems.It has been established that the S protein in this pathogen plays an important rule in the adsorption and penetration of SARS-CoV into the host cell by interaction with the ACE2 receptor.To determinant which functional motif of the S protein was involved in the interaction with ACE2,seven truncated S proteins deleted from the N or C terminal were obtained by an E.coli expression system and purified by column chromatography to homogeneity.Each truncated S protein was fixed on to the well of an ELISA plate and an interaction was initiated with the ACE2 protein.The adsorption were quantified by ELISA,and the results indicated that amino acids from 388 to 496 of the S protein was responsible for the interaction with the ACE2 receptor,and the interaction could be completely disrupted by an antibody specific to these amino acids.Deletions adjacent to this domain did not appear to have a significant impact on the interaction with ACE2,suggesting that the S protein of SARS-CoV could be developed as a vaccine to prevent the spread of SARS-CoV.

The purification of HBV full-length PreS protein in Pichia pastoris / 生物工程学报

The Pichia pastoris strain GS115-PreS could produce a high expression level of full-length PreS protein that secreted to the supernatant after methanol induction in the fermentation. The Western blot analysis showed a single band with expected molecular mass of 48kD and that the major component of the particles was the full-length PreS protein (PreS1 + PreS2 + S) and small envelope protein (S) of 48 and 28 kD, respectively. Electron microscopy image showed PreS particles with 30 nm in diameter. The supernatants of the fermentation were desalted and concentrated. Purified PreS protein was obtained by DEAE-SFF anion exchange column chromatography and the PreS particles were obtained by ultracentrifugation and sucrose density gradient. The ELISA assay results proved that both full-length PreS protein and particles showed high immunogenicity and specificity. P/N ratio further demonstrated that the immunogenicity of the particles is higher than the full-length PreS protein.

Expression of Hepatitis C Virus NS5A Gene In E.coli and Its Application in HCV Antibody Detection / 中国病毒学

Full-length NS5A gene of the hepatitis C virus was amplified by PCR using plasmid pBAC25 containing HCV nonstructural gene as template. The amplified fragment (about 1.34 kb) was cloned into plasmid pQE32, and the recombinant plasmid pQENS5A was expressed in JM109 strain. The NS5A protein was purified by NiSO4 metal chelating resin, and characterized by Western-blot. Its antigenecity was determined by ELISA. The positive detection rate of anti-NS5A was 75% (69/92) in ninety-two clinic sera. The positive rate of anti-NS5A was 82.5% (33/40) in fourty positive standand sera, and the negative rate of anti-NS5A was 100% (40/40) in fourty negative standand sera. The results showed that the Full-length NS5A proteinn had the higher sensitivity and specificity in the detection of HCV antibody in sera, we suggested that NS5A protein was a useful antigen for blood screening.