Table 1

Variation of CIs at different effect levels

Treatment
CI at ED50
CI at ED75
CI at ED90

X-rays + wortmannin
+
+++
+++
X-rays + CisPt
-
--
--
X-rays + vinblastine
--
---
----
Vinblastine + wortmannin
±
+++
+++
CisPt + wortmannin
--
---
---
CisPt + vinblastine
--
---
----

CI < 1, = 1, and > 1 indicates synergism, additivity and antagonism, respectively. More precisely, symbols +, ++ and +++ describe slight synergism (CI between 0.85 and 0.90), moderate synergism (CI between 0.7 and 0.85) and synergism (CI between 0.3 and 0.7), respectively. Symbols -, --, --- and ---- indicate slight antagonism (CI between 1.10 and 1.20), moderate antagonism (CI between 1.20 and 1.45), antagonism (CI between 1.45 and 3.3) and strong antagonism (CI > 3.3), respectively. Nearly additive effects (CI in the range 0.90 and 1.10) are represented by the symbol ±. ED50, ED75 and ED90 indicate 50%, 75% and 90% inhibition of growth, respectively. Equipotent amounts of the two agents were combined. In most experiments employing X-rays, various ratios were tested. Each CI determination resulted from at least three independent experiments evaluating at least five different doses or dilutions of the two agents.

Nocentini Cancer Cell International 2003 3:11   doi:10.1186/1475-2867-3-11