Table 1.

Production of NO and IL1B in vitro by PBMCs isolated from E. coli(−) and E. coli(+) cows with or without stimulation with 500 ng/mL LPS for 2 h.

	E. coli(−) * CONT	E. coli(+) EARLY ‡	E. coli(+) LATE ‡
n	6	6	3
Control NO production (µM)	8.7 ± 0.37	10.3 ± 1.72	8.6 ± 0.06
LPS stimulated NO production (µM)	8.5 ± 0.18 #	8.5 ± 0.13	9.4 ± 0.56 #
Control IL1B production (pg/mL)	87.0 ± 18.58 a	59.8 ±11.87 a	61.3 ± 14.83 a
LPS stimulated IL1B production (pg/mL)	258.3 ± 86.90 b	195.5 ± 40.08 b	205.7 ± 38.84 b

* The 3 control cows which had evidence of subclinical mastitis were omitted from the analysis. ^‡ EARLY cows were sampled at 10 ± 1.8 days after diagnosis of clinical mastitis and LATE cows at 47 ± 11.0 days. Values are mean ± SEM. Within columns, b > a, p < 0.01. Within rows, ^# indicates a trend towards difference, p = 0.058.