Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042961 (volvulus)
 4,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Specific diagnosis of antibodies to Onchocerca was achieved through (1) the construction of direct and indirect ELISA systems, and (2) restricting ELISA assays to the IgG4 class. The direct ELISA was based on the isolation of a surface derived, low molecular weight surface antigen preparation containing two main antigens (M. wt. 16.2 and 12.8 kDA) as defined by Western blot analysis. The direct ELISA system detected antibodies in children of six years old, and may therefore be applicable to detecting reinvasion in OCP areas of Onchocerca volvulus control. The indirect ELISA system was a competitive binding ELISA-based assay using a monoclonal antibody recognising two Onchocerca components (M. wts. 15.6 and 25.9) on a Western blot. The direct and indirect ELISA systems were similarly specific and sensitive when evaluated in a preliminary survey. The direct ELISA system yielded a specificity and sensitivity of: 100% and 100% respectively, using Mexican endemic and Mexican intestinal nematode infection sera as positive and negative controls respectively: 91% and 96% respectively, using Venezuelan endemic and Venezuelan Mansonella ozzardi infection sera as positive and negative controls, respectively: 87% and 93% respectively, using African endemic and Papuan (New Guinea) Wuchereria bancrofti infection sera as positive and negative controls respectively: 93% and 93% respectively, using African endemic and Indian W. bancrofti infection sera as positive and negative controls respectively. Similar specificity and sensitivity levels were obtained when the same comparisons were made using the indirect (inhibition) ELISA assay. These values may be contrasted with the currently used PBS extract of O. volvulus which yielded specificities of less than 10% in all the above comparisons.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Specific detection of human antibodies to Onchocerca volvulus. 269 81

Crude phosphate-buffered extracts of adult Onchocerca volvulus from savanna (Mali) and rain forest (Cameroon) areas were comparatively analysed using biochemical and immunological methods. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing revealed only minor differences between the two extracts. Out of 42 bands detectable by SDS-PAGE at least 21 were identified as glycoproteins by their affinity to concanavalin A. High resolution analysis using two dimensional gel electrophoresis (2D-G) showed marked differences in the polypeptide patterns of the two extracts. Some of the over 100 polypeptides demonstrable by Coomassie blue staining (especially at pIs between 4.3 and 5.6 and mol. wts over 64kD) were clearly different when the two extracts were compared. Antigenic differences between the two extracts could be detected by crossed immunoelectrophoresis using a rabbit anti-O. volvulus hyperimmune serum. The comparison by tandem crossed immunoelectrophoresis demonstrated clearly the existence of at least three antigenic differences, four partial identities and 13 antigenic identities between the extracts. For the identification of O. volvulus antigens serologically recognized by infected patients, we combined the 2D-G with an immunoblotting technique using a pool of highly reactive onchocerciasis sera from Mali. IgG binding antigens were then identified by incubating the blot membrane with this serum pool and with 125I-labelled protein A followed by autoradiography. IgE binding antigens were detected using a 125I-labelled anti-human IgE antiserum. Whilst the overall antigenic patterns were similar, there were, however, clear differences between the antigen preparations which gives further evidence for antigenic diversity of O. volvulus from savanna and rain forest areas.
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PMID:Immunochemical comparison between worm extracts of Onchocerca volvulus from savanna and rain forest. 401 3