Fig. 5.

Quantitation of the proportion of CD31⁺ cells that develop from CD34⁺ cells in the presence of tumor-conditioned medium. CD34⁺ cells were seeded under conditions to support myeloid cell growth (GM–CSF and SCF) in the presence or absence of 40% tumor-conditioned medium. At various times, cultures were subjected to immunocytochemical staining for CD31-expressing cells. The proportion of positive-staining cells was digitally quantitated by MetaMorph microscopic analysis. Results shown are mean values from at least five fields enumerated in each of three separate analyses  ±  SEM