Table 1.

Effect of removal of nonadherent monocytes on PCA of cocultures of monocytes and bacterium-infected ECa

Time of culture (h)bPCA (mU of FXa/well) in cocultures of monocytes and EC infected with:
S. aureusS. sanguisS. epidermidis
0 (no monocytes)21.37 ± 14.01.67 ± 0.51.57 ± 0.8
124.28 ± 4.613.48 ± 2.923.45 ± 4.7
453.42 ± 18.527.31 ± 7.850.18 ± 15.5
676.68 ± 13.857.89 ± 7.191.99 ± 16.9
  • a Monolayers of 2 × 105EC/well were incubated for 24 h with 4 × 107 to 5 × 107 organisms of the indicated bacterium, washed, and incubated for 1 h with 2.5 × 105 monocytes. Then, nonadherent monocytes were removed by washing, EC with membrane-bound monocytes were cocultured for an additional period of time; and PCA was determined. Values represent the means ± standard deviations for three individual experiments.

  • b At time zero, the levels of PCA were determined 24 h after bacterial infection just before the addition of monocytes. At 1 h of culture, nonadherent monocytes were removed and PCA was assessed 1 h after continuous incubation of bacterium-infected EC with monocytes. At 4 and 6 h after the addition of monocytes (i.e., 3 and 5 h, respectively, after the removal of nonadherent monocytes from the coculture, PCA was determined.