Figure 1.

XDH/XO expression is increased in floating and anchoring villi from placentas of patients with preeclampsia. A–D: Tissue sections obtained from control placentas at the gestational ages indicated in weeks (wk). E and F: Tissue sections obtained from the placenta of a patient diagnosed at 32 weeks of gestation with preeclampsia (PE). Panels show staining with anti-cytokeratin (CK; A, C, and E) and anti-XO (B, D, and F). In general, control first- (data not shown) and second-trimester (B) villi did not express XO. By the third trimester, the cellular components of the villi stained weakly (D), but never as intensely as when the pregnancy was complicated by preeclampsia (F). In the latter situation immunoreactive cells were detected in the villous stromal core, particularly evident in association with blood vessels (arrowheads), and the trophoblast syncytium. Essentially the same results were obtained in analyses of 10 of 10 control samples and 10 of 10 samples obtained from women with preeclampsia.