Fig. 4. [³H]Thymidine incorporation in fibroblasts from non-AD and AD patients after H₂O₂ treatment. [³H]Thymidine was added to the culture media at the times indicated by the white arrows. Cells were exposed to H₂O (circles) or 1 mM H₂O₂ (triangles) for 15 minutes at time 0 as indicated by black arrows, then washed and cultured for additional 6 hours or 24 hours. Data are from six non-AD and six AD different cell lines and are expressed as mean±s.e.m. of at least three separate experiments for each sample.