Trichinella spiralis zinc metalloproteinase NAS-36 gene(TsNas36)is a member of the zinc metalloproteinase family found in excretory secretory products(ESP)of T.spiralis.In this study,TsNas36 gene was cloned and expressed,and its biological characteristics and temporal and spatial characteristics were identified.These results provide a theoretical and material basis for ex-ploring the biological function of TsNas36 gene.Bioinformatics analysis showed that TsNas36 was 470 amino acids(AA)in length with a molecular weight of about 54.69 kDa,no transmembrane region,and contained a signal peptide(1-20 AA),an Astacins domain(116-320 AA)and a CUB domain(355-470 AA).There were five active site residues located at amino acids 216(His),217(Glu),220(His),226(His)and 275(Tyr).The expression plasmid pET-28a(+)/TsNas36 was constructed and induced to express in E.coli BL21(DE3)to obtain the recombinant protein rTs-Nas36.The recombinant protein was used to immunize rabbits to obtain anti-rTsNas36 polyclonal antibody serum.Indirect ELISA results showed that the antibody titer reached 1∶105.qRT-PCR and Western blot results showed that the transcription levels of TsNas36 were significantly higher in newborn larvae(NBL)than in adult worm(AW)and muscle larva(ML)stages.Immunofluo-rescence results showed that TsNas36 was only localized in the epidermis of NBL.In summary,this study characterized the biological characteristics of the TsNas36 gene and found that this gene is highly period-specific and may be involved in the unique developmental process of NBL.

Trichinella spiralis zinc metalloproteinase NAS-36 gene(TsNas36)is a member of the zinc metalloproteinase family found in excretory secretory products(ESP)of T.spiralis.In this study,TsNas36 gene was cloned and expressed,and its biological characteristics and temporal and spatial characteristics were identified.These results provide a theoretical and material basis for ex-ploring the biological function of TsNas36 gene.Bioinformatics analysis showed that TsNas36 was 470 amino acids(AA)in length with a molecular weight of about 54.69 kDa,no transmembrane region,and contained a signal peptide(1-20 AA),an Astacins domain(116-320 AA)and a CUB domain(355-470 AA).There were five active site residues located at amino acids 216(His),217(Glu),220(His),226(His)and 275(Tyr).The expression plasmid pET-28a(+)/TsNas36 was constructed and induced to express in E.coli BL21(DE3)to obtain the recombinant protein rTs-Nas36.The recombinant protein was used to immunize rabbits to obtain anti-rTsNas36 polyclonal antibody serum.Indirect ELISA results showed that the antibody titer reached 1∶105.qRT-PCR and Western blot results showed that the transcription levels of TsNas36 were significantly higher in newborn larvae(NBL)than in adult worm(AW)and muscle larva(ML)stages.Immunofluo-rescence results showed that TsNas36 was only localized in the epidermis of NBL.In summary,this study characterized the biological characteristics of the TsNas36 gene and found that this gene is highly period-specific and may be involved in the unique developmental process of NBL.

ObjectiveTo investigate the safety and early clinical efficiency of dynamic cervical implant (DCI) internal fixation to treat cervical disc herniation.Methods From September 2009 to December 2010,31 patients with herniation of cervical disc underwent DCI implantation.The operation time and blood loss were recorded and analyzed.Neck disability index (NDI),Japanese Orthopaedic Association (JOA) score,and visual analogue scale(VAS) score were used to evaluate neurofunctional recovery pre- and post-operation.Routinely,the patients accepted X-ray examination preoperatively and postoperatively.We used White's measurement to measure the range of motion(ROM) and height ratio of implant segment and the superior vertebra pre- and post-operation.ResultsThe average operation time and amount of bleeding were 45 (30-60) min and (100±30) ml respectively.The average postoperative follow-up was 14 months (range,6-20).The average NDI (50.5±16.2 vs.19.6±4.3,P＜0.05),JOA score (12.3±1.6 vs.13.9±1.8,P＜0.05) and VAS score (6.3±2.6 vs.3.1±2.2,P＜0.05) changed significantly at the last follow-up compared with those pre-operation.There were no significant differences in the average ROM of implant segment (9.6°±4.2° vs.6.9°±5.3°,P＞0.05),the height ratio of implant segment and the superior vertebra(2.6±0.1 vs.2.5±0.1,P＞0.05) and the angle of functional spine unit(2.6°±5.2° vs.1.7°±2.9°,P＞0.05) at last follow-up compared with those preoperation.ConclusionUsing DCI to treat cervical disc herniation had shorter operation time and less bleeding advantages,and the early clinical effect was satisfactory.It may retain the cervical biomechanical movement in some degree,maintain the cervical stability.