R W Richle

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The late blood stages of the human malaria parasite, Plasmodium falciparum, carry a major surface antigen, p190, of molecular weight (Mr) 190,000. This antigenically variable protein is actively processed, first as the parasite matures and again when it is released into the blood stream and invades a new erythrocyte to initiate a cycle of growth. It elicits(More)
Saimiri monkeys immunized with a Plasmodium falciparum merozoite polypeptide of 41 kD mol wt are resistant to a blood challenge infection that induces a fulminant infection in control monkeys. The sera of the immunized monkeys reacted, as shown by the indirect immunofluorescence technique, with the apical part of the merozoites from five isolates or clones(More)
Plasmodium falciparum polypeptides of 200 and 140 K mol wt exposed at the surface of merozoites and/or schizonts were purified by affinity chromatography and by electroelution from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Monkeys were separated into three groups of four and immunized either with one of the two polypeptides or with saline(More)
A total of 17 monensin urethanes, including two naturally produced phenethylurethanes (Streptomyces sp.), were evaluated for antiparasitic activity. All of the compounds had the characteristic properties of the polyether antibiotics including their ability to transport cations across membranes. Several of the semisynthetic derivatives demonstrated in vitro(More)