Circulating excretory-secretory antigen levels and specific antibody responses in @entity19 infected with XXXX .

@entity19 @entity281 @entity5603 @entity1885
Circulatory excretory-secretory antigen levels and IgM and IgG responses to larval antigens were monitored in the serum of 20 BALB/c @entity19 that had been given approximately 500 infective eggs of @entity5603 by stomach tube. Other groups of @entity19 received different doses of infective eggs, ranging from 5 to 1,250 eggs. Excretory-secretory antigens were collected from culture fluid in which mechanically hatched larvae of @entity5603 were maintained. An indirect enzyme-linked immunosorbent assay was used to monitor specific antibody responses. Circulating antigen levels were monitored using a direct ELISA which incorporated an IgG fraction of a rabbit antiserum to the excretory-secretory antigens as a capture antibody and a @entity1885 -conjugated form of the same rabbit IgG as the second antibody. The antigen-specific IgM response was evident the first week of @entity281 and peaked 3 to 6 weeks post- @entity281 . The antigen-specific IgG response first appeared the second week of @entity281 and peaked at 6 to 8 weeks post- @entity281 . Both isotype levels stayed near their peak values for the remainder of the study. In the untreated sera, circulating antigen was initially evident and highest the first week of @entity281 ; the antigen concentrations dropped by the third month of @entity281 to low, but significant, levels that persisted for the duration of the study. The administration of greater than 25 eggs produced antigenemias. There appeared to be a positive linear trend between the number of eggs given and the amount of antigen in the circulation.
