TNF and acute respiratory distress syndrome: We observed typical histological changes in our LPS-induced model of ALI, including increased inflammatory cell infiltration, focal areas of fibrosis with collapsed air alveoli, thickening of the alveolar wall in lung tissue, and increased expression of the proinflammatory cytokines TNF-α, IL-1β, and IL-6 (see Figures 6(a) and 6(d)).