ABSTRACT
Objective To compare of the difference about ectopic activation between autogenous bone graft and allograft from large segment tibia of rabbits.Methods Eighty healthy adult Chinese rabbits (6 months of age),weighing (2.5 ±-0.5)kg,were randomly divided into experimental group (allogeneic bone group) and the control group (autograft group),40 rabbits in each group.Another 10 rabbits were allogeneic bone donor.In experimental group,when 1.5 cm long rabbit tibial allograft were finishied,they were implanted into spatium intermusculare between the musculus rectus femoris and medial vastus muscle of the rabbit around the saphenous artery and were fastened to the femur by 1.0 mm Kirschner-wire.In control group,autologous tibias were done,the same as experimental group including length and position and method.Four weeks and 8 weeks and 12 weeks postoperative,respectively,the postmortem specimens were examined gross and immunohistochemistry and the expression of BMP-2 and collagen type Ⅰ of transplanted bone tissue were detected.Results BMP-2 mainly exist in cytoplasm of osteoblasts and chondrocytes undifferentiated mesenchymal cells.Collagen type Ⅰ primarily exist in the bone matrix around the pit of bone.The expression level of BMP-2 of experimental group in postoperative 4,8,12 and 16 weeks were 85.25 ± 4.47,109.44 ± 14.69,141.85 ± 9.45,116.25 ± 14.18,respectively,and the expression level of BMP-2 of control group were 103.78 ±-6.59,124.95 ± 14.94,145.46 ± 8.10,112.48 ± 13.27,respectively.The expression level of collagen type Ⅰ of experimental group in postoperative 4,8,12 and 16 weeks were 78.74 ± 7.99,95.95 ± 6.99,139.91 ± 4.32,137.76 ± 3.48,respectively,and the expression level of BMP-2 of control group were 88.87 ± 11.26,102.45 ± 2.82,140.76 ± 4.62,139.05 ± 4.55.Compared with control group,there was a significant difference in the expression level of the BMP-2 and collagen type Ⅰ of experimental group in postoperative 4,8 weeks (P ＜ 0.05),but,there was no significant difference in the expression level of the BMP-2 and collagen type Ⅰ of experimental group in postoperative 12,16 weeks (P ＞ 0.05).The amount increased gradually during 4 weeks,8 weeks,12weeks,peaked at 12 weeks,BMP-2 displayed a downward trend at 16 weeks,and collagen type Ⅰ basiclly maintain the level of 12 weeks.Conclusion Allograft segment could complete activation while they are implanted into spatium intermusculare containing famous blood supply within 3 months,there is no significant difference between autologous bone and allograft,it shows the feasibility of ectopic activation about allograft segment.
ABSTRACT
Objective To design a complex hepatitis C vires(HCV)=E1 antigen,and to search its application in HCV vaccine and diagnosis test.Methods Through consulting the database and widely comparison of sequences from HCV E1 of different genotype,the representative immunodominant epitope sequences were selected from all the six genotypes.Their genes were deduced according to the preference codon in E.coli and three fragments were designed to contain the six epitopes.They were chemically synthesized and cloned into pBVIL1 vector separately.The cloned fragments were conjugated together profiting from pBVIL1's property,and then a doubled pan-DR helper T cell epitopes(PADRE)gene was inserted to form a complex expression plasmid.The transformed E.coli cells with this plasmid were cultured and induced to express recombinant protein and the antigenic activity of the product was tested.Results An expressing plasmid containing 8 epitopes from HCV genotype 1a,1b,2a,3a,4a,6a and a doubled PADRE sequences was constructed successfully and the engineering E.coli transformed with this plasmid highly expressed after inducing culture at 42℃ in an inclusion manner.The immunological activity of the purified recombinsnt multi-epitope antigen shows that:(1)It can react with a great part of sera from HCV positive patients by indirect ELISA.(2)It can induce notable specific humoral immunity in injected mice.Conclusion The novel constructed expressing plasmid and its product may be useful in study of a newly HCV vaccine as well as an antigen for HCV immunoassays.