1. Human Morphology, University of Southampton, Bassett Crescent East, Southampton S016 7PX, UK,
2. Department of Pathology, University of Tübingen, Liebermeisterstrasse 8, 72076 Tübingen, FRG,
3. Department of Obstetrics and Gynaecology, University of Tübingen, Schleichstrasse 4, 72076 Tübingen, FRG