Plasmodium falciparum can now be maintained in continuous culture in human erythrocytes incubated at 38 degrees C in RPMI 1640 medium with human serum under an atmosphere with 7 percent carbon dioxide and low oxygen (1 or 5 percent). The original parasite material, derived from an infected Aotus trivirgatus monkey, was diluted more than 100 million times by… (More)
The method for continuous cultivation of Plasmodium falciparum has now been successfully applied to several strains from different geographical areas. It has been used for tests of antimalarial drugs, for studies of parasite-host cell interactions with special reference to sickle haemoglobin, and for the production of amounts of parasite sufficient for… (More)
The kinetics of sickling of malaria-infected red cells from humans with sickle cell trait were studied in vitro in an attempt to obtain direct experimental evidence for a selective advantage of the hemoglobin S heterozygote in a malarious region. The sickling rates of cells infected with Plasmodium falciparum and of non-infected cells were studied both in… (More)
Aromatase is a microsomal cytochrome P450 that converts androgens to estrogens by three sequential oxidations. The isolation of the 19-hydroxy and 19-oxo androgens suggests that the first two oxidations occur at the C19 carbon. However, the mechanism of the third oxidation, which results in C10--C19 bond cleavage, has not been determined. Two proposed… (More)
A medium has been developed in which certain cells from the gonads of female silkworms multiply and live for periods of 2 to 3 weeks. In such tissue cultures, strains of silkworm grasserie virus were maintained in successive passages up to the number of ten. The virus multiplied greatly and typical polyhedral bodies formed in the cells of infected cultures.
After condinous cultivation in the presence of chloroquine, an African strain of the malaria parasite, Plasmodium falciparu, acquired resistance to the drug. The resistance was stable and comparable in vitro to that occurring naturally in a strain from Southeast Asia. This suggests that chloroquine resistance, absent until now in Africa, might arise in the… (More)
The theoretical basis for the direct linear plot [Eisenthal & Cornish-Bowden (1974) Biochem. J. 139, 715-720], a non-parametric statistical method for the analysis of data-fitting the Michaelis-Menten equation, was reinvestigated in order to accommodate additional experimental designs and to provide estimates of precision more directly comparable with those… (More)
Monte Carlo experiments have been used to test the robustness of distribution-free confidence limits for the parameters of the Michaelis-Menten equation (Porter & Trager, 1977). When used in conjunction with the modified form of the direct linear plot (Cornish-Bowden & Eisenthal, 1978), they prove to be more robust than least-squares confidence limits. In… (More)