Chitin/Chitosan oligomers were prepared by the concentrated hydrochloric acid or enzymatic hydrolysis with chitinase and chitosanase and its transglycosylation reaction. Their preparation,isolation and analytical methods are reviewed.

In this article， several kinds of common immunosensors and the development of their transducers are introduced． Meanwhile， some problems in the fabrication of immunosensor such as immobilization method and reproduction are discussed．

Objective To obtain the short peptides mimicking antigenic epitopes of Trichinella spiralis ( T\^s\^ ), and explore their cross protective immunity against Schistosoma japonicum ( S\^j. ) in mice. Methods IgG antibodies were purified from sera of mice infected with T\^s\^ . The purified IgG was used to immunoscreen a phage random peptide library of 7 amino\|acid residues displayed as a fusion to protein of filamentous phage. Positive clones were obtained by affinity selection, the reactivity of each clone binding to specific IgG was detected by ELISA. Kunming mice were immunized subcutaneously three times with mixed phage clones. The mice were sacrificed 45 days after challenge. The worms and the liver eggs were counted. Results After three rounds of panning, the relevant phages had been enriched approximately 150 times in production as compared to those from the first round. Of 24 phage clones randomly selected from the third round biopanning, 21 clones were shown to actually bind to the specific IgG. As compared with the control group, the worm and the liver egg reduction rates in vaccination group were 42\^8% and 66\^3% ( P

0. 05) and the specificity is higher than that of the SEA-ELISA (P

0.05). Conclusion pcDNA3.1/SjTs-1 induced the mucosal and systemic immune response and partial protection against the challenge of S.japonicum by the intranasal vaccinations of mice.

OBJECTIVETo obtain peptide mimicking epitopes of Schistosoma japonicum (S. japonicum) through screening of a phage peptide library and to test their potential for induction of protection.

METHODSS. japonicum infected sera from Microtus fortis (IMFS) and normal sera from Microtus fortis (NMFS) were used respectively to screen a 12-mers random peptide library by testing the reactivity of anti-S. japonicum serum with the phagotopes. After three rounds of biopanning, the pooled phages were used to immunize mice, after which challenge infection was performed.

RESULTSOf 12 randomly picked clones, 10 clones selected using IMFS and 7 clones selected using NMFS were shown to be antigenic. Significant reduction in adult worms (22.6%) and a high reduction (68.9%) in liver eggs were achieved following immunization with phages screened with IMFS. However, no protection was elicited by those selected with NMFS.

CONCLUSIONThe results show that the phagotopes are both antigenic and immunogenic, suggesting a potential use of phage displayed peptide as novel vaccines against S. japonicum.

Animals ; Arvicolinae ; parasitology ; Epitopes ; Helminth Proteins ; immunology ; Peptide Library ; Schistosoma japonicum ; immunology ; Schistosomiasis japonica ; prevention & control ; Vaccines ; immunology