Petersen E
Trans R Soc Trop Med Hyg. 1987;81(2):238-41. doi: 10.1016/0035-9203(87)90226-4.
Two isolates of Plasmodium falciparum (F 32 and K 1) were tested against sulfadoxine (SDX), sulfamethoxazole (SMZ), pyrimethamine (PYR) and trimethoprim (TMP), using a 48 h microtest, with RPMI-1640 low in PABA and folic acid. The IC50 for F 32 was: PYR 6.1 X 10(-9) M (mol/litre), TMP 1.3 X 10(-7) M, Fansidar (SDX/PYR 80:1) less than 10(-8) to 1.3 X 10(-10) M and cotrimoxazole (SMZ/TMP 20:1) 2.6 X 10(-7) to 1.3 X 10(-8) M. The IC50 for K 1 was: PYR greater than 10(-6) M, TMP 8.2 X 10(-7) M, Fansidar 4.1 X 10(-7) to 1.1 X 10(-9) M and cotrimoxazole 1.8 X 10(-6) to 9.0 X 10(-8) M. The difference in IC50 between F 32 and K 1 against TMP and cotrimoxazole is much less than the difference between the IC50 values against PYR and Fansidar, indicating that cross-resistance between PYR and TMP exists, but is not complete. A method for calculating the IC50 by linear regression analysis is described.
使用含低对氨基苯甲酸（PABA）和叶酸的RPMI - 1640培养基，通过48小时微量试验，对两株恶性疟原虫（F 32和K 1）进行了磺胺多辛（SDX）、磺胺甲恶唑（SMZ）、乙胺嘧啶（PYR）和甲氧苄啶（TMP）的测试。F 32的半数抑制浓度（IC50）为：PYR 6.1×10⁻⁹ M（摩尔/升），TMP 1.3×10⁻⁷ M，Fansidar（SDX/PYR 80:1）小于10⁻⁸至1.3×10⁻¹⁰ M，复方新诺明（SMZ/TMP 20:1）2.6×10⁻⁷至1.3×10⁻⁸ M。K 1的IC50为：PYR大于10⁻⁶ M，TMP 8.2×10⁻⁷ M，Fansidar 4.1×10⁻⁷至1.1×10⁻⁹ M，复方新诺明1.8×10⁻⁶至9.0×10⁻⁸ M。F 32和K 1对TMP和复方新诺明的IC50差异远小于对PYR和Fansidar的IC50值差异，表明PYR和TMP之间存在交叉耐药性，但并不完全。描述了一种通过线性回归分析计算IC50的方法。
