Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasmodium falciparum-infected erythrocytes (IRBC) synthesize 3 histidine-rich proteins: HRP-I or the knob-associated HRP, HRP-II and HRP-III or SHARP. In order to distinguish these proteins immunochemically we prepared monoclonal antibodies which react with HRP-I, HRP-II and HRP-III, and rabbit antisera against synthetic peptides derived from the HRP-II and HRP-III sequences. A comparative analysis of diverse P. falciparum parasites was made using these antibodies and immunoprecipitation or Western blotting. HRP-I (Mr 80,000-115,000) was identified in all knob-positive P. falciparum parasites including isolates examined directly from Gambian patients. However, this protein was of lower abundance in these isolates and in 6 knob-positive, culture-adapted parasites compared to Aotus monkey-adapted parasites or culture-adapted parasites studied previously. HRP-II (Mr 60,000-105,000) was identified in all P. falciparum parasites regardless of knob-phenotype, and was recovered from culture supernatants as a secreted water-soluble protein. Within IRBC, HRP-II was found as a complex of several closely spaced bands. Cell surface radio-iodination of IRBC from several isolates and immunoprecipitation with a rabbit antiserum against the HRP-II repeat sequence identified HRP-II as a surface-exposed protein. Like HRP-I, the abundance of HRP-II was lower in the Gambian isolates than with Aotus monkey-adapted parasites studied earlier. Neither HRP-I nor HRP-II were identified in a knob-positive isolate of P. malariae collected from a Gambian patient. Analogues of these HRP were also absent from asexual parasites of diverse primate and murine malaria species screened with this panel of antibodies. HRP-III (Mr 40,000-55,000) was distinguished by its lower apparent size and by specific reaction with rabbit antibody against its 5-mer repeat sequence. HRP-III was of lowest abundance compared with the other two HRP. These antibody reagents and distinguishing properties should prove useful in studies on the separate functions of the 3 P. falciparum HRP.
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PMID:Comparative analysis of the Plasmodium falciparum histidine-rich proteins HRP-I, HRP-II and HRP-III in malaria parasites of diverse origin. 332 Aug 87

With the emergence of chloroquine-resistant Plasmodium vivax (CRPV), new tests to detect P. vivax and predict response to therapy would be useful for clinical and research applications. We performed a 'blinded' evaluation of a non-isotopic (colourimetric) polymerase chain reaction (PCR) based assay (Digene SHARP Signal System) compared with microscopy and PCR/radiometric probe hybridization of ribosomal ribonucleic acid genes (RPH) for the detection of P. vivax malaria in 182 febrile travellers. Compared with PCR/RPH as the reference standard, the colourimetric assay had a sensitivity of 100% and specificity of 98%. Using microscopy as the reference standard, 84 of 87 patients with P. vivax infection had a positive colourimetric assay. The 3 patients with a negative assay were subsequently shown to be infected with P. ovale as determined by PCR/RPH. In a subset of patients followed longitudinally, the colourimetric assay was positive in 5 of 13 patients 6 or more days after initiation of therapy. Of these 5 patients, 4 were subsequently demonstrated to be infected with CRPV as determined by treatment failure in vivo and/or chloroquine blood levels. A positive assay result 6 or more days after initiation of therapy was associated with subsequent treatment failure (P < 0.01). This non-isotopic assay is a sensitive, specific, and rapid method for the detection of P. vivax PCR products and may prove useful in predicting treatment failure.
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PMID:Evaluation of a non-isotopic polymerase chain reaction-based assay to detect and predict treatment failure of Plasmodium vivax malaria in travellers. 937 34

New diagnostic tests are needed to facilitate the diagnosis of Plasmodium falciparum malaria in the returned traveler. We performed a blinded evaluation of a nonisotopic colorimetric PCR-based assay (Digene SHARP Signal System) and compared the results with those obtained by microscopy and nested PCR for the detection of P. falciparum malaria in 150 febrile travelers. By using nested PCR as the reference standard, the colorimetric assay had a sensitivity of 100% and a specificity of 95.4% for the detection of P. falciparum. This PCR-based nonisotopic assay is a rapid, sensitive, and specific method for the detection of falciparum malaria in returned travelers.
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PMID:Evaluation of a colorimetric PCR-based assay to diagnose Plasmodium falciparum malaria in travelers. 988 14