0.05). In the control test against tne sera of normal persons, the false positive rate of the two antigens was both 7.7%(4/52).It is suggested that O. armillata adult worm may be used as a heteroantigen for diagnosis of filariasis.

The common antigen component between B. malayi and O. armillata was demonstra-ted by cross immunoelectrophoresis(XIE) with antigens from these 2 species of filariae against the sera from patients infected with B. malayt. When the two antigens were subjected to SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme linked im-munoblotting (ELIB), the component of approximately 43 KD was identified to be the common antigen component.

Objective To explore the presence of biliverdin reductase (BR) activity in adult worms of Schistosoma japonicum in vitro. Methods The soluble fraction was isolated from homogenates of adult worms of S. japonicum, and incubated with biliverdin under different pH conditions and buffers. The time dependency of this enzymatic reaction was also detected. ResultsThe soluble fraction of the homogenates of adult worms could degrade biliverdin in vitro, the BR activity was 43.30 nmol/(mg?min), with its optimal condition at pH 8.7. The rate of reaction peaked at 15 min of incubation for the BR activity. Conclusion The presence of BR activity in adult worms of S. japonicum was firstly demonstrated.

Objective To explore the activity of heme oxygenase and immunolocate the enzyme in the adult worms of Schistosoma japonicum .Methods Microsomal protein was isolated from the homogenate of adult S\^japonicum , heme degradation and effect of different pH conditions and buffers on degrading reaction were investigated by incubating microsomal protein with hemin. The slices of whole worm and cells of S\^japonicum were prepared, distribution of HO in schistosome was studied by immunofluorescent and alkaline phosphatase(AP) \|immunocytochemical assays.Results Microsomal protein of adult worms can degrade the heme in vitro , the activity being 56\^7 nmol bilirubin/(mg?min).The optimal pH was 8\^7. Immunofluorescent and AP\|immunocytochemical assays revealed that the HO distributed dispersively in the worm, and located in cytoplasm.Conclusion The presence of HO was firstly proved in S\^japonicum .

Objective To detect the infection of Schistosoma japonicum in mice with a novel test based on agglutination of hybridoma cells and to study the mechanism of the hybridoma cells agglutination. Methods The procedure was developed with a murine cell line H226 producing a monoclonal antibody specific to schistosome 31/32 kDa antigen and sera collected from mice infected with different numbers (10,30,50) of S. japonicum cercariae in different period. Immunofluorescent test was carried out with the hybridoma cells and schistosome-infected sera. Results The circulating antigen was detected by the test as early as 2 weeks after a heavy infection and all mice showed positive results in the test by 5 weeks after infection. The titers of antigen rose along with the lime post infection, and the tilers of sera from heavy infection were statistically higher than that from the mice receiving a lower number of cercariae. Specific yellowish green fluorescence appeared on the membrane of the hybridoma cells; no signal was detected inside. Conclusion Hybridoma cell agglutination test (HCAT) may become useful to diagnose schistosomiasis.

Objective To study the expression of inducible nitric oxide synthase (iNOS) in livers of mice infected with Schistosoma japonicum. Methods The livers of NMRI mice infected with S. japonicum were collected on day 21, 28, 38, 45 post infection(p.i.), total RNA of livers were extracted and kinetics of the mRNA expression of iNOS were detected by RT-PCR, the protein expression of iNOS was then confirmed by Western blotting and the distribution of iNOS in the infected liver was determined by immunohistochemical methods. Results The mRNA expression of iNOS was not detectable in the uninfected liver, iNOS mRNA expression was detected on day 21 p.i, the expression increased on day 28 p.i and peaked on day 38 p.i, then decreased slightly on day 45 p.i. Western blotting showed an iNOS expression in the livers only on day 38, 45 p.i. IFA test showed that the expression of iNOS was maily distributed in the granuloma of the livers. Conclusion S. japonicum infection can induce the expression of iNOS in a time-dependent manner in the liver of the host,and eggs may be the main factor in inducing the expression.

Objective To study the in vitro larvicidal activity of nitric oxide (NO) to the juvenile Schistosoma japoni-cum. Methods Macrophages were induced by LPS or LPS + IFN-? to produce NO, schistosomula obtained mechanically from cercariae were added to the medium with activated macrophages, the larvicidal activity was observed within 48 h . In order to further confirm the effect of NO, an inhibitor of iNOS,L-NNA (N?-nitro-L-arginine), was used to inhibit the production of NO, larvicidal activity was measured by the same methods and the difference of dead larvae ratio was compared between the inhibited and uninhibited groups. Results LPS and LPS + IFN-? can induce macrophages effectively, with the NO production of (109.96?3.70)?mol/L and (113.50?7.38) ?mol/L respectively, accordingly the larvicidal effect reached to 91.07% ?2.92% and 96.86%?2.36% respectively. This activity can be inhibited by L-NNA. NO production and dead larvae ratio were reduced significantly in the inhibited group than in the uninhibited one. Conclusion NO produced by activated macrophages can kill schistosomula of Schistosoma japonicum.

Objective To explore the mechanism of protective immunity against Schistosoma japonicum infection induced by Sj26 gene transfected dendritic cell(DC).Methods 48 BALB/c mice were divided randomly into 4 groups with 12 each.The mice were injected through auricle for three times with Sj26 gene transfected DC(Group A),pcDNA3 transfected DC(Group B),untreated DC(Group C) and RPMI-1640(Group D) respectively,and challenged with 40?2 cercariae of S.japonicum per mouse 2 weeks after the last immunization.Sera from mice were examined for IgG antibody,IFN-? and IL-4 by ELISA.Western blot was used for detecting specific anti-Sj26 IgG antibody.The production of IFN-? and IL-4 in the supernatant of spleen cells stimulated with soluble egg antigen(SEA) and ConA was quantified by sandwich ABC-ELISA.The proliferation of spleen cells were measured with MTT method.Results IgG antibody increased significantly in the mice of group A at 2 weeks after the last immunization(absorbency A491=0.117),higher than that of group B(A491=0.061) and group C(A491=0.058)(P

Objective To investigate the effect of nitric oxide on the liver fibrosis of mice infected with Schistosoma japonicum during the early stage of schistosomiasis. Methods NMRI mice were treated with AMG-an iNOS inhibitor from day 23 post infection(p.i) to the sacrificed and the livers were collected at 38 days, 45 days p.i respectively. The expression and distribution of collagen typeⅠ, Ⅲ (ColⅠand ColⅢ) in liver tissues were investigated with the Picric acid-Sirius red staining techniques and differentiated with the polarization microscopy combining with picture analysis system. Hydroxyproline concentration in liver homogenate was measured by the biochemical methods. Results At 38 day p.i, the Picric acid-Sirius red staining showed that the hyperplasia of Col Ⅰ and ColⅢ in the livers of AMG treated mice increased significantly compared with the control livers, but there was no significant difference of hydroxyproline content between the two groups. At 45 days p.i, only the hyperplasia of Col Ⅰ in AMG treated group increased significantly compared with the control livers, and moreover, content of hydroxyproline of the inhibited mice was significantly higher than that of the control mice (P

Objective To construct and express recombinant plasmid containing the structural gene encoding {Mr 31 000} antigen of Trichinella spiralis muscle larvae. MethodsThe target gene TspE1 was amplified by RT_PCR, cloned into pUC18 vector, and sub_cloned into the eukaryotic expression vector pcDNA3. BALB/c mice were immunized with the purified recombinant plasmid pcDNA3_TspE1 by gene_gun bombardment. The expression of recombinant plasmid in the skin tissue was observed by HE staining and immunohistochemical staining. Results and Conclusion The recombinant plasmid pcDNA3_TspE1 was successfully constructed and expressed in the BALB/c mice.