Figure 7.

Human tears inhibit Acanthamoeba-induced cytopathic effect. . Epithelial cells were incubated overnight alone (Cont) or with Acanthamoebae in the absence (A) or presence (A+tears) of pooled tear fluid. At the end of the incubation period, the monolayers were stained with Giemsa, photographed and scanned to estimate approximate cell density. Clear, unstained regions indicate loss of epithelial cells; dark, stained areas indicate presence of cells. A value of 1.0 was assigned to the cell density of the plates incubated in media alone without amoebae (Cont). The values for cultures incubated in the presence of tears are expressed as the change in the density with respect to control plates. *P<.05 compared with all other groups. Data are expressed as mean ± SE (n=4 or 6 per group except for 45- and 75-μg/well groups, where n=2 owing to limited availability of tear samples). Representative photographs of the plates are shown in the right panel. For A+tears, the number of micrograms of protein per well indicates tear protein concentration used for the assay. (Reprinted with permission from Cao Z ET al.⁶⁰)