Figure 1.

Inhibition of clonal outgrowth of ECFCs from cord and peripheral blood MNCs by hypoxia. (A,B) Primary colony of CB-ECFCs isolated at 1% of oxygen. Bars are 500 μm (A) and 100 μm (B), respectively. (C) Staining of VE-cadherin (green), f-actin (red), and nuclei (DAPI) of a primary colony of CB-ECFCs. Note two dividing cells in the middle top part. Bar = 100 μm (D) Enumeration of outgrowth colonies from umbilical cord blood-derived MNCs at 20 and 1% O₂ expressed as average number ± SEM (n = 14) of counted colonies per donor. Statistical significance was determined by Wilcoxon matched-pairs signed rank test; ^***p < 0.005. (E) Enumeration of outgrowth colonies from peripheral blood-derived MNCs at 20 and 1% O₂ expressed as average number ± SEM (n = 9) of counted colonies per donor. Statistical significance was determined by Wilcoxon matched-pairs signed rank test; ^**p < 0.01.