TABLE 1.

Summary of histological findings in lungs of test mice and comparison of cytokine levels in the lungs of test and control mice

Day postinfection	Histopathology			Median cytokine level (pg/100 mg tissue) in test mice compared with that in control micea
	Inflammation	Histology	Intracellular bacteriumlike structures	TNF-α	IFN-γ	IL-1β	IL-2	IL-4	IL-6	IL-10
1	Interstitial inflammation	Polymorphonuclear cells	No	1,086*	373*	−42*	37*	−3,927*	−2	113
3	Peribronchial pneumonia	Macrophages and epithelioid cells	Yes	76	−214	109*	−58*	1,629	−6	−113*
5	Bronchopneumonia	Macrophages and epithelioid cells	Yes	−478	602	85*	−11	9,600	36*	311

^aDifference in median test levels from median control levels (pg/100 mg tissue). A minus sign indicates that the median test levels were lower than the median control levels. An asterisk indicates the median test levels were significantly different from (i.e., significantly higher than or significantly lower than) the median control levels (P ≤ 0.05, Mann-Whitney U test).