PROLIFERATION KINETICS OF CHORIONIC VILLI IN CHROMOSOMALLY NORMAL ANDABNORMAL SPONTANEOUS-ABORTIONS ANALYZED BY PREMATURE CHROMOSOME CONDENSATION AND NORTHERN BLOT

The activity of cell proliferation in human chorionic villi (CV) obtai ned from early spontaneous abortions (SAB) and from elective abortions (EAB) was determined by means of premature chromosome condensation (P CC), and by Northern blot analysis of expression of proliferation anti gens Ki67 and PCNA, The rate of chromosome aberrations among the SABs was 57%, while the EABs, taken as controls, were shown to be chromosom ally normal, PCCs were induced by fusion of the chorionic interphase c ells with mitotic Chinese hamster ovary (CHO) cells. To analyze the pr oliferation stages of the chorionic G(1)-interphases, the potential pr oliferation index (PPI) was ascertained, The PPI values found in SABs ranged from 36% to 97% as described for intensely proliferating tissue s, They did not differ from the values found in the controls (34-90%), indicating maintenance of proliferation activity of CV cells even aft er death of the embryo in missed abortions, No significant PPI differe nces were observed between the abortion groups with different cytogene tic results, The expression of proliferation associated antigens Ki67 and PCNA showed no significant: differences between mean values of the total of SABs and of the controls. However, the comparison of mean va lues of chromosomally abnormal with chromosomally normal SABs revealed a sigificantly reduced Ki67 activity in the SABs with chromosome aber rations. A similar result was obtained when comparing mean values of K i67 and PCNA expression from trisomic SABs with those of the controls. By further subdivision of chromosome aberrations a decrease for the e xpression of both antigens in chorionic villi from early lethal trisom ies, and a significantly increased Ki67- and PCNA-expression in triplo idies became evident.