Short-term incubation with FCS or TGFβ1.

(A) Cultures initiated in the presence of TGFβ1 or FCS were washed and reseeded in control medium after 0, 1, 3, and 4 days. The percentage of F+ cells was determined on day 7 of culture. The data are from 1 representative experiment. (B) Statistics of the TGFβ1 effect in cultures from different donors, comparing various treatment timings between days 0 and 5. Measurements on day 7. The values from all individual cases (open circles) are shown to indicate range and distribution, and the median values are shown as horizontal bars. On the x-axis label, the upper row of numbers (from) indicates the starting day of treatment, and the lower row (to) the ending day of treatment. In the case of 4-day treatment, data pairs are connected. There is a strong positive correlation (r = +0.84) between the variations of TGF-induced F+ cell proportions and the variations of the corresponding baseline F+ cell proportions. The effect of 4-day treatment is statistically highly significant withP < .0001.