• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.21-29
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• 2016

The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of $Na^+$ and $H^+$ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of $Ca^{2+}$. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.

• The Korean Journal of Nuclear Medicine
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• v.35 no.3
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• pp.192-197
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• 2001

Purpose: Urinary cytology and cystoscopic exam are effective methods for diagnosis of transitional cell carcinoma(TCC). But the former shows drawbacks such as the need for a well-trained examiner, and wide imprecision related to the variability of microscopic exam; the latter is an invasive method. $UBC^{TM}$ test detects the epitope on specific cytokeratin fragments released from epithelium of bladder cancer by immunoradiometric assay. We compared $UBC^{TM}$ test with urinary cytology for diagnosis of TCC to evaluate the utility of $UBC^{TM}$ test. Materials and Methods: Eighty-four patients with hematuria were included in our study. $UBC^{TM}$ tests (IDL Biotech, Sweden) were assayed in mid-stream urine according to the ordinary assay protocol. Nineteen patients were confirmed as TCC by cystoscopic examination and underwent transurethral resection (Group A). Other patients had various benign urinary tract conditions (Group B). Samples were considered positive as the $UBC^{TM}$ concentration was greater than $12{\mu}g/L$. Results: $UBC^{TM}$ levels were significantly different between group A ($95.9{\pm}166.4\;{\mu}g/L$) and group B ($19.2{\pm}85.6{\mu}g/L$) (P<0.001). Sensitivity for diagnosis of TCC was 89.5% (17/19) in UBC test and 47.4% (9/19) in cytology (p<0.05). Specificity for diagnosis of TCC was 81.5% (53/65) in $UBC^{TM}$ test and 100% (65/65) in cytology. $UBC^{TM}$ test was significantly more sensitive in stage Ta, $T_1$ tumors (84.6 vs 38.5%, p<0.05) and in grade I (83.3% vs 16.7%, p<0.05) than cytology. $UBC^{TM}$ test showed a tendency to be more sensitive as the grade was higher (83.3% in Grade I, 90% in Grade II and 100% in Grade III). Conclusion: $UBC^{TM}$ test could be a useful method in distinguishing TCC from other benign genitourinary diseases. Moreover, $UBC^{TM}$ test could be an especially valuable marker for diagnosis of TCC in patients with early TCC of low grade TCC compared to urinary cytology. Therefore, mbined use of $UBC^{TM}$ test in association with cytology is helpful to overcome the limited sensitivity of cytology.