The effect of N-MPP on intraerythrocytic parasite development.N-MPP (5 μM) was added to cultured P falciparum parasites synchronized at the ring (A), mature pigmented trophozoite (C), or schizont stage (D), and proportions of individual parasite stages were enumerated at the indicated time points. Cells were also treated with N-MPP for 3 hours, washed extensively, and then returned to drug-free culture medium for the remainder of the experiment (washout). Crisis-form parasites were observed at some time points. Data (±SEM) represent the mean of 1 assay performed in duplicate. *P < .05, **P < .01 comparing N-MPP vs control total percentage of infected cells; §P < .05 comparing N-MPP vs control mature trophozoites, schizonts, and crisis-form parasites. (B) Photomicrographs of different parasite stages and examples of crisis-form parasites. Healthy appearing ring (i), young trophozoite (ii), mature pigmented trophozoite (iii) and schizont (iv) stages, and crisis-form trophozoites (v and vi).