Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-7-17
pubmed:abstractText
Plasmodium vivax malaria infections in non-immune individuals manifest as periodic clinical episodes of fever with chills and rigors known as paroxysms. We have demonstrated that in non-immune patients the period of paroxysm is associated with the transient presence of plasma factors which kill gametocytes, the intra-erythrocytic sexual stages of the malaria parasite which transmit the infection from humans to mosquito, rendering them non-infectious to mosquitoes. Gametocyte killing in paroxysm plasma is mediated by tumour necrosis factor (TNF) acting in conjunction with other essential serum factor(s). Plasma TNF levels were elevated during a paroxysm. In semi-immune individuals from a P. vivax-endemic area clinical symptoms of malaria are mild and the parasite killing factors are not induced during paroxysm. Serum TNF levels were correspondingly lower in endemic patients during a paroxysm. Human peripheral blood mononuclear cells (PBMC) can be stimulated in vitro by extracts of P. vivax blood stage parasites to produce TNF and associated parasite killing factor(s), thus simulating in vitro the events that occur during a paroxysm, this being the release of parasite exo-antigens by rupturing schizonts and the subsequent induction of PBMC to produce TNF and other parasite-killing factors. We were able to show that convalescent serum from P. vivax semi-immune individuals block the induction of TNF and parasite-killing factors by malaria antigens in vitro, presumably through antibodies that neutralize parasite exo-antigens. Thus, individuals living in malaria-endemic areas appear to acquire clinical immunity to malaria by avoiding their induction during infection; we have shown that one such mechanism is the neutralization of parasite exo-antigens that induce the production of parasite killing factors.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-13356045, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-1692862, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-1900073, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2126526, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2184688, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2196178, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2379940, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2405875, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2501793, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2657427, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-2957445, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-3049913, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-3119710, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-3328333, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-3621669, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-3661678, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-6166564, http://linkedlifedata.com/resource/pubmed/commentcorrection/1351432-78300
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0009-9104
pubmed:author
pubmed:issnType
Print
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
499-505
pubmed:dateRevised
2010-9-7
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Tumour necrosis factor-dependent parasite-killing effects during paroxysms in non-immune Plasmodium vivax malaria patients.
pubmed:affiliation
Department of Parasitology, Faculty of Medicine, University of Colombo, Sri Lanka.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't