Metacercarial proteins interacting with WD40-repeat protein of Clonorchis sinensis

The WD40-repeat proteins serve as a platform coordinating partner proteins and are involved in a range of regulatory cellular functions. A WD40-repeat protein (CsWD1) of Clonorchis sinensis previously cloned is expressed stage-specifically in the tegumental syncytium of C. sinensis metacercariae. In the present study, interacting proteins with the CsWD1 protein was purified by immunoprecipitation and 2 dimension gel electrophoresis from the C. sinensis metacercaria soluble extract, and tryptic peptides were analyzed by LC/ESI-MS. Putative partner proteins were annotated to be actin-2, glyceraldehyde-3-phosphate dehydrogenase, and hypothetical and unmanned proteins. The CsWD1 protein was predicted to contain 3 conserved actin-interacting residues on its functional surface. With these results, the CsWD1 protein is suggested to be an actin-interacting protein of C. sinensis.

Immunoperoxidase staining of alveolar hydatid cyst from an experimentally infected gerbil.

Echinococcus multilocularis, the small fox tapeworm, has an extensive geographical range in the northern hemisphere where foxes and small rodents represent natural hosts. The larval stage of this parasite, alveolar echinococcosis (AE), is an emerging zoonosis of increasing importance. It is a serious human illness which is often misdiagnosed as hepatic cancer. If not identified at an early stage of parasite development it can lead to the death of patients. Histological examination of biopsies is one of the classical methods of diagnosis. In this study, in order to gain unequivocal histopathological diagnosis of AE, the immunoperoxidase staining technique was performed on routinely processed histological sections of an experimentally infected gerbil, using rabbit anti-E. multilocularis protoscolex IgG labelled with horseradish peroxidase. Demonstration of AE antigen was achieved by dark brown stain of cyst membranes against a blue background of the host liver cells stained with hematoxylin.

Effect of praziquantel treatment on antibody levels and lymphoproliferative responses in patients with opisthorchiasis.

The purpose of this study was to explore alternative method(s) to monitor the efficacy of anthelmintic treatment of patients with opisthorchiasis. Therefore, in our initial attempt, we studied the changes in antibody levels and lymphoproliferative responses in O. viverrini infected patients before and 2 months after successful praziquantel treatment. The results showed that although a substantial reduction of the antibody levels occurred after such a treatment, it did not occur in all patients. In those showing reduction, the final level were still above 2 standard deviations of the normal mean value. The reduction was more profound for IgG antibody. With regard to the IgA antibody isotype, the reduction was not as marked. In contrast, IgE antibody levels in most patients not only failed to decline, but instead, showed a tendency to be elevated after praziquantel treatment. Unlike the antibody levels, there was no alteration in the lymphoproliferative response to PHA stimulation and therefore this parameter is not useful for our intended objective. It was suggested that studies of a more specific O. viverrini component may be more reliable than the current method of parasitological examination of eggs in the feces of suspected individuals.