Fig. 5. Natural killer cell–mediated cytotoxicity in 51 patients against 51Cr-labeled K 562 tumor cells at an effector:target cell ratio of 50:1 versus time after infusion of 4 ml/kg NaCl, 7.5% (○); 4 ml/kg NaCl, 0.9% (▿); or 32 ml/kg NaCl, 0.9% (▵). Numbers in parentheses indicate the number of patients in each group. The activity changed over time (P < 0.001, multivariate analysis of variance, within groups) but with no difference between groups (P = 0.45). Data are presented as geometric mean with 95% confidence interval. 1, 24, and 48 h = hours after surgery; Inc = 5 min after incision; Pre = baseline.