TABLE 1.
Recrudescences after pyrimethamine treatment
| Treatment duration (days) | Recrudescence for the following initial no. of parasitized erythrocytesa:
|
|||||
|---|---|---|---|---|---|---|
| 104 | 105 | 106 | 107 | 108 | 109 | |
| 4 | − | ++ | ++ | ND | ND | ND |
| 6 | ND | − | ++ | ++ | ND | ND |
| 8 | ND | ND | − | − | + | ++ |
| 10 | ND | ND | ND | − | − | + |
a
The indicated numbers of parasitized erythrocytes were exposed to 10−6 M pyrimethamine for the indicated numbers of days, washed, and returned to standard medium. Experiments were carried out in triplicate. −, no recrudescences were observed for 2 months after treatment or recrudescence was observed in one of three flasks; +, recrudescences were observed in two of three flasks or in all three flasks; ++, recrudescences were observed in all three flasks; ND, not done. The same experiments were repeated six times, and the accumulated data are presented.