Biomedical subjects

S Baur-Aubele

Publications and source records attributed to S Baur-Aubele.

3 recordsLinked to original sources

PubMed1992

First trimester amniocentesis between the seventh and 13th weeks: evaluation of the earliest possible genetic diagnosis.

Amniocentesis performed at the 12th week and later gives reliable results. The procedure can be performed using regimens developed for mid-trimester amniotic fluid (AF) cells. Extension to the 10th-11th week is, in principle, feasible. However, the high cytogenetic failure rate is a difficulty and despite a high clone count, the culture time is prolonged. The problem of the relatively high loss of AF could be overcome by cell filtration techniques and replacement of the fluid. Because of the short turnover rate of the AF, this may be unnecessary or replacement with an isotonic solution may be sufficient. (Pseudo)mosaicism appears to occur more frequently in early than in late amniocentesis. As yet, data are too sparse to allow a comparison with chorionic villus sampling. There are no reliable follow-up data from which to estimate the abortion rate and the number of embryonic malformations.

Amniocentesis↗

PubMed1992

Nuclear and chromosomal replication patterns in chorionic villi cells by bromodeoxyuridine labelling and DNA flow cytometry.

Cell kinetics of chorionic villi (CV) were studied by BrdUrd-incorporation detected by fluorescence-plus-Giemsa and BrdUrd-antibody techniques, and by DNA flow cytometry. Growth characteristics of long-term cultures of CV resembled fibroblasts with a total cell cycle time of 26 h, final S phase of 9 h, penultimate S phase of 16 h and G2/M phase of 3-4 h. Especially useful for a quick routine diagnostic approach, Ultroser RG, a commercially available serum supplement, significantly increased cell proliferation and stabilized cell cycle lengths to a total cell cycle time of 14 h, final S phase of 7 h, penultimate S phase of 6 h and G2/M phase of 4 h. Moreover, mitotic activity steadily increased in cultured CV, when studying six successive subculturings. This reflects adaptation to the culture conditions rather than an inherent response of cultured CV cells of increasing passage numbers. Native villi exposed to BrdUrd immediately after biopsy show lower rates of uptake than do aliquots after overnight incubation. As shown by BrdUrd-pulse labelling studies, more than 7 h are required to overcome the proposed 'biopsy stress'. This correlates with routine diagnostic techniques, in which many more metaphase cells are observed in short-term cultures than in direct preparations.

Bromodeoxyuridine↗

PubMed1991

Proliferation kinetics in native chorionic villus cells.

In accordance with observations by other groups direct CVS preparations reveal only a few mitoses, whereas semi-direct cultures (overnight incubation) give good results. By monitoring the BrdU uptake with an immunological method, a delay in the proliferation activity in native villi could be observed up to 7 h after biopsy.

Bromodeoxyuridine↗