TABLE 2.

iNOS expression by uninfected and infected colonic epithelial cells

Cell status	% iNOS-expressing cellsa at day:
	6	10	14
Uninfected	75 ± 7	87 ± 10	90 ± 15
Mildly infectedb	21 ± 5	23 ± 6	29 ± 4
Heavily infectedb	14 ± 3	13 ± 4	18 ± 6

^aInfected cells were separated into groups of mildly infected cells (<10 foci of Tir/cell) and heavily infected cells (>10 foci of Tir/cell). Values represent the mean percentage of epithelial cells that express detectable iNOS ± 1 SEM from three independent experiments, each with groups of four mice.

^bSignificantly lower percentages of iNOS-expressing cells at days 6, 10, and 14 than those of uninfected cells at the same time points (P < 0.05).