| polymorphism in the circumsporozoite protein of the human malaria parasite plasmodium vivax. | the circumsporozoite (cs) protein that covers the surface of infectious sporozoites is a candidate antigen in malaria vaccine development. to determine the extent of b- and t-epitope polymorphism and to understand the mechanisms of antigenic variability, we have characterized the cs protein gene of plasmodium vivax from field isolates representing geographically distant regions of papua new guinea (png) and brazil. in the central repeat region of the cs protein, in addition to variation in the n ... | 1992 | 1279418 |
| evidence for limited activation of distinct cd4+ t cell subsets in response to the plasmodium falciparum circumsporozoite protein in papua new guinea. | both cd4+ and cd8+ t cells, as well as antibody, are known to be important in sporozoite immunity. data from animal studies suggest that cytokines, in particular gamma-interferon and interleukin-6, are involved. the interplay of these various factors and their importance in vaccine development has, however, not yet been elucidated. in this study, we have studied cellular and humoral responses of individuals naturally exposed to malaria in a highly endemic region of papua new guinea to the circum ... | 1994 | 7911566 |
| relationship between humoral response to plasmodium falciparum merozoite surface antigen-2 and malaria morbidity in a highly endemic area of papua new guinea. | the prevalence and concentration of antibodies to merozoite surface antigen-2 (msa-2) were measured in blood samples collected during a cross-sectional survey. antibodies were measured by enzyme-linked immunosorbent assay using two recombinant proteins that closely approximated the full-length mature msa-2 polypeptides expressed by the plasmodium falciparum isolate fc27 and the cloned line 3d7 and that were representative of the dimorphic forms of msa-2. antibodies were also measured to a form o ... | 1994 | 7985752 |
| clinical malaria in the tropics. | although malaria has been largely eradicated from temperate countries, it is on the increase in the tropics. infection with plasmodium falciparum affects a vast number of people and kills over a million annually. severe malaria is a multisystem disease affecting particularly the central nervous system (causing coma and convulsions), the kidneys (resulting in acute tubular necrosis), and the liver (contributing to lactic acidosis and hypoglycaemia). acute pulmonary oedema (acute respiratory distr ... | 1993 | 8336622 |
| cellular immunity to merozoite surface protein 2 (fc27 and 3d7) in papua new guinean children. temporal variation and relation to clinical and parasitological status. | a prospective study in 207 children aged 0.5-15 years was carried out in a highly endemic area of papua new guinea to examine the relationship between cellular responses to plasmodium falciparum merozoite surface protein 2 (msp2) and malaria infection and morbidity. in vitro proliferation, ifn-gamma and il-4 induction were measured against two recombinant proteins of msp2, fc27 and 3d7 as well as against a form of the 3d7 msp2 lacking the central repetitive sequences (d3d7). the prevalence of pr ... | 1997 | 9194097 |
| in vitro susceptibility of plasmodium falciparum isolates to halofantrine in the central province of papua new guinea. | halofantrine is a newer antimalarial drug which has not been approved for clinical use in papua new guinea. we assessed 21 central province isolates of plasmodium falciparum for their in vitro susceptibility to halofantrine. the concentration required to inhibit 50% of parasite growth (ic50) ranged from 0.05 to 7.0 nm with a mean of 1.90 nm and a median of 1.50 nm. the minimum inhibitory concentration (mic) values ranged from 2.5 to 50 nm with a median of 5.0 nm. all but one isolate had an mic o ... | 1998 | 10741175 |
| in vitro susceptibility of plasmodium falciparum to four antimalarial drugs in the central province of papua new guinea. | the susceptibility of plasmodium falciparum to chloroquine, quinine, mefloquine and halofantrine was investigated in the central province of papua new guinea between march 1995 and september 1996, when chloroquine resistance was widely present in the country. the standard world health organization in vitro microtest methodology was used in the study. of the 30 isolates tested for chloroquine susceptibility all were resistant to chloroquine with median ic50 of 1.15 mumol/l (range 0.54 to 4.24), i ... | 1998 | 10934544 |
| force of infection is key to understanding the epidemiology of plasmodium falciparum malaria in papua new guinean children. | genotyping plasmodium falciparum parasites in longitudinal studies provides a robust approach to estimating force of infection (foi) in the presence of superinfections. the molecular parameter (mol)foi, defined as the number of new p. falciparum clones acquired over time, describes basic malaria epidemiology and is suitable for measuring outcomes of interventions. this study was designed to test whether (mol)foi influenced the risk of clinical malaria episodes and how far (mol)foi reflected envi ... | 2012 | 22665809 |