FIG. 1.

Comparison of the results of the Griess reaction with those of HPIC for the measurement of nitrite in 48-h culture supernatants. The measurements (n = 49) utilized in this analysis were from four time points (prechallenge [day 0] and 34, 68, and 124 days postchallenge) and stimuli (nonstimulated [medium alone] and stimulated with PPDa, PPDb, or PWM). The symbols (+) represent individual responses, and the line was generated by linear regression analysis (r = 0.94, P < 0.0001; y = 0.57x + 70.87).