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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-7-10
pubmed:abstractText
Epidemiological and clinical studies have indicated that the thalassaemias may confer protection against malaria. The study reported here investigated this protective effect in vitro, using a new approach which controls for the potential effect of red cell size and age on the virulence of the parasite. A Percoll density gradient method was used to separate alpha- and beta-thalassaemic trait, haemoglobin H and normal red blood cells (RBC) into fractions of different density. Correlations between RBC density, age and size in fractions of all genotypes were established using red cell creatine as an index of cell age. The development of Plasmodium falciparum over 3 erythrocytic cycles (144 h) in whole blood as well as fractionated samples was monitored by slide microscopy and flow cytometry. A significantly reduced rate of parasite invasion and growth was demonstrated in RBC from all thalassaemic genotypes tested. Poor reinvasion rates were noted in the second and third cycles. Increased duration of culture and red cell age also had a greater negative impact on parasite growth in thalassaemic RBC. This poor growth rate was also associated with the arrest of parasite growth at the schizont stage (schizont maturation arrest) and the accumulation of abnormal, trophozoite/schizont stage parasites in the older thalassaemic RBC fractions. These findings suggest a defect in the number and viability of merozoites generated by parasites growing in thalassaemic RBC. Age related factors such as oxidant stress may play a key role in mediating this kind of protective mechanism and deserve further investigation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0035-9203
pubmed:author
pubmed:issnType
Print
pubmed:volume
91
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
138-43
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Invasion and growth of Plasmodium falciparum is inhibited in fractionated thalassaemic erythrocytes.
pubmed:affiliation
Department of Paediatrics, Chinese University of Hong Kong, Shatin, NT, Hong Kong.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't