Abstract.We assessed an Echinococcus granulosus hydatid fluid antigen-ELISA (EgHF-ELISA) as a serologic prescreening test for E. granulosus infections, supplemented by more specific confirmatory tests, including arc-5 immunoprecipitation and antigen B subunit 8-kD immunoblotting. The diagnostic sensitivity of the EgHF-ELISA was 91%. With regard to the test specificity of the EgHF-ELISA (overall ϭ 82%), we observed relatively frequent crossreactions in tumor patients (6%) and in patients with other parasitic diseases. Cestode-related cross-reactivity can be resolved by the complementary use of E. multilocularis-specific antigens or Taenia solium cysticercosis-specific immunoblotting. Immunoblotting based upon the detection of antibody reactivity to the 8-kD antigen of EgHF, or if appropriately detectable, to the 29-kD and 34-kD bands exhibited a 91% diagnostic sensitivity and an overall specificity of 97% or 94%, respectively. Thus, immunoblotting provided a 99% discrimination between seropositive preoperative cystic hydatid disease cases and cross-reactive non-cestode parasitic infections or malignancies.For primary serologic diagnosis and for support of clinical diagnosis of cystic echinococcosis (cystic hydatid disease [CHD]), the selection of a particular immunodiagnostic test involves consideration of the diagnostic operating characteristics of the technique and the purpose for which it will be used. The diagnostic sensitivity and specificity of the tests vary according to the nature and quality of the antigen and the methodologic sensitivity of the selected technology. A concise definition of the sera used for the assessment of test parameters is essential, with special attention paid to the definition of pre-or post-operative situations respective to CHD serum sampling time point. One of the most specific conventional immunodiagnostic approaches for CHD relies upon the demonstration of serum antibodies precipitating an antigen called antigen 5 by immunoelectrophoresis or similar techniques.1 Diagnostic sensitivities with respect to hepatic CHD have been reported to vary between 50% and 80%. Antibodies to antigen 5 also occurred in serum of human patients with neurocysticercosis 3 and alveolar echinococcosis (AE). 4 Comparative studies showed that 58% of Swiss patients with AE were arc 5-positive compared with 74% of patients with CHD. 5 Resolution of E. granulosus hydatid cyst fluid by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by immunoblotting, resulted in the identification of the arc-5 subunits, including two subunits with relative molecular masses estimated by different laboratories to be between 37 and 38 kD and 20-22-24 kD, respectively. 2 Diagnostic assessment of these two antigens by immunoblotting performed in different laboratories have resulted in the publication of discrepant sensitivity and specificity parameters. 2,6,7 The second major parasite antigen in hydatid cyst fluid is a thermostable lipoprotein called antigen B. The major components of antigen B r...

We investigated a focus of highly endemic Echinococcus multilocularis infection to assess persistence of high endemicity in rural rodents, explore potential for parasite transmission to domestic carnivores, and assess (serologically) putative exposure versus infection frequency in inhabitants of the region. From spring 1993 to spring 1998, the prevalence of E. multilocularis in rodents was 9% to 39% for Arvicola terrestris and 10% to 21% for Microtus arvalis. From June 1996 to October 1997, 6 (7%) of 86 feral dogs and 1 of 33 cats living close to the region tested positive for intestinal E. multilocularis infection. Testing included egg detection by coproscopy, antigen detection by enzyme-linked immunosorbent assay (ELISA), and specific parasite DNA amplification by polymerase chain reaction. Thus, the presence of infected domestic carnivores can increase E. multilocularis exposure risk in humans. A seroepidemiologic survey of 2,943 blood donors in the area used specific Em2-ELISA. Comparative statistical analyses of seroprevalence and clinical incidence showed an increase in Em2-seroprevalence from 1986 and 1996-97 but no increase in clinical incidence of alveolar hydatid disease.

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Globoside (Gb4Cer), Ku80 autoantigen, and ␣5␤1 integrin have been identified as cell receptors/coreceptors for human parvovirus B19 (B19V), but their role and mechanism of interaction with the virus are largely unknown. In UT7/Epo cells, expression of Gb4Cer and CD49e (integrin alpha-5) was high, but expression of Ku80 was insignificant. B19V colocalized with Gb4Cer and, to a lesser extent, with CD49e. However, only anti-Gb4Cer antibodies could disturb virus attachment. Only a small proportion of cell-bound viruses were internalized, while the majority became detached from the receptor. When added to uninfected cells, the receptor-detached virus showed superior cell binding capacity and infectivity. Attachment of B19V to cells triggered conformational changes in the capsid leading to the accessibility of the N terminus of VP1 (VP1u) to antibodies, which was maintained in the receptor-detached virus. VP1u became similarly accessible to antibodies following incubation of B19V particles with increasing concentrations of purified Gb4Cer. The receptormediated exposure of VP1u is critical for virus internalization, since capsids lacking VP1 could bind to cells but were not internalized. Moreover, an antibody against the N terminus of VP1u disturbed virus internalization, but only when present during and not after virus attachment, indicating the involvement of this region in binding events required for internalization. These results suggest that Gb4Cer is not only the primary receptor for B19V attachment but also the mediator of capsid rearrangements required for subsequent interactions leading to virus internalization. The capacity of the virus to detach and reattach again would enhance the probability of productive infections.

A practical and robust process for the derivatization of Cyclosporin A was demonstrated. The processes rely on the opening of Cyclosporin A and removal of amino acid fragments via Edman degradation, with the isolation of crystalline tetrafluoroboric salts of the corresponding acyclic polypeptides.