“…These epithelial cells were cultured in WAJC 404 medium (GIBCO) supplemented with 10% heatinactivated FBS, 25 U/mL of penicillin, 25 g/mL of streptomycin, 28 mM of N-2-hydroxyethyl piperazine-NЈ-2-ethane sulphonate, 14.2 mM of NaHCO 3, 20 ng/mL of cholera toxin, 1 M of dexamethazone, 25 ng/mL of zinc-stabilized insulin, 2.5 M of hydrocortisone, and 250 g/mL of amphotericin B. Fibroblast aggregates, which were removed from the supernatant fluid by an additional centrifugation step at 2000 revolutions per minute for 10 minutes, then were grown in RPMI-1640 medium supplemented with 10% heatinactivated FBS, 50 U/mL of penicillin, 50 g/mL of streptomycin, 10 mM of L-glutamine, and 500 g/mL of amphotericin B. The established primary cell lines were sustained only from 6 to 8 weeks and were passaged either 25-cm 3 or 75-cm…”