AscreeningmethodforcriticalaminoacidsinEpitopesusinganti-Epitopeantibodywasdeveloped. The amino acids' frequency of occurrence in Epitopes of shrimp antigen Pen a1 was calculated using MEGA5 software and their conservative property of tropomyosin in SDAP database bank was analyzed using DNAMAN software. Potential critical amino acids based on these two methods were identified, namely Epitope 1 ( K, E, N) , Epitope 2 ( K, L, E) , Epitope 3 ( E, R, D, L, Q) , Epitope 5 ( K, L, Q) . The mutated polypeptides corresponding to these Epitopes in which these critical amino acids were substituted with alanine were synthesized. The IgG binding ability of these mutants was analyzed by competitive immunodot-blot method and indirect ELISA using Epitope antibody to screen the critical amino acids. Experimental results showed that the critical amino acids of the four Epitopes were as follows: Epitope 1 ( Gln ) , Epitope 2 ( Leu and Glu ) , Epitope 3 ( Leu and Asp) , Epitope 5 ( Leu) . The feasibility of this screening method was proved and it also offered a theoretical foundation for research on sensitization mechanism of Pen a1 and desensitization using gene modification.

ObjectiveTo compare X-ray,spiral CT and low does digital subtr,action angiongraphy technology of three dimensional reconstruction in 30 cases of the applications in the joint fractures,to study the application value of the digital subtraction angiography three- dimensional reconstruction in joint fracture.MethodsA retrospective analysis was made on 30 cases with joint fracture in Guangdong Provincial Guangzhou Development District Hospital,who were confirmed by the X-ray and spiral CT three-dimensional reconstruction and digital subtraction angiography three-dimensional reconstruction and the demonstrations three-dimensional reconstruction,spiral CT three-dimensional reconstruction and X-ray were compared.ResultsAll 30 cases fractures showed clear line,line of walk line,of the number of fracture,source and separation shift condition.Digital subtraction angiography could be clearly shows 30 cases in spiral CT could clearly show in 20 cases,10 cases not clearly show in,while X-ray clearly show in 10 cases,not show in 20 cases.Spiral CT showed clearly joint capsule and soft tissue.The SPSS 11.0 statistical soft package was used.Spearman correlation analysis,the single factor analysis of variance and the independent t test and the chi-square test were employed for data analysis,P ＜ 0.05 was considered statistical significance.Conclusions Digital subtraction angiography three-dimensional reconstruction can more clearly display fracture line,fracture pieces,walk line,source and separation shift condition compared with spiral CT and Xray essaminations,which is helpful for treatment options and prognosis estimation.