Although pre-eclampsia (PE) is often associated with fetal hypoxia, hypertension and/or disturbed function of the fetal circulation, the effect of these altered hemodynamic parameters on the structure and composition of umbilical vessels has not been systematically investigated before. Therefore, this study focuses on PE-associated changes of the elastic fibre system in umbilical cord vessels investigated by light and electron microscopy, immunocytochemistry and biochemistry. In umbilical cord veins, no changes in thickness of the vessel wall or of any sublayer were observed. However, the internal elastic lamina of the veins was split in 80% of the PE-group in contrast to 20% in uncomplicated pregnancies. This effect was significant (alpha <0.01) from 36 weeks of gestation onwards. In umbilical cord arteries, the entire arterial vessel wall was found to be 15% thicker in PE than in uncomplicated pregnancies. The enlargement was caused by an increase of both the tunica intima and tunica media. The thickening of the tunica intima was attributed to a migration of smooth muscle cells towards the endothelium, accompanied by a splitting of the internal elastic lamina. Compared to uncomplicated pregnancies, smooth muscle cells of arteries and veins in PE showed a metabolic activation demonstrated by highly dilated endoplasmic reticulum. A semiquantitative score method as well as a quantitative dot blot assay indicated a PE-associated reduction of elastin expression in the arterial vessel walls. In summary, PE obviously induces a decrease of the elastin content accompanied by a thickening of the vessel wall in umbilical cord arteries. This remodeling of the elastic fibre system, together with an increased migration of smooth muscle cells, might represent part of the functional adaptation system of the umbilical cord arteries on the altered hemodynamic conditions in PE.

und W. A. GALE e n t h a b n . W. A. GALE hebt die beiden weeentlichen Entwicklungsrichtungen hervor : Einerseita werden die Methoden der ,,Kunstlichen Intelligenz", die symbolische Infomtionwerarbeitung zur Entscheidungsfindung in der statistischen Probleml~ung, ah3 Werkzeuge eingesetzt. Die bekannten Statktikverfahren wurden hierbei in entaprechende Strategien eingebettet. Andererseita bedient sich die kunstliche Intelligenz zunehmend statistisoher Betrachtungeweiaen, da empirische Beziehungen eine gewisee Unsicherheit besitzen und beatimmte statistkche Verfahren. z. B. die Clusteranalyse, fiir die Wissensakkumulation und Hypotheeenbildung Bedeutung haben. Drei Beitrage sollen beaonders hervorgehoben werden. William A. GALB gibt einen Bericht uber dae wit COMPSTAT 84 bekannte Expertensystem der Regreasioneanalyse. (REX), dem in einem spiiteren Kapitel recht detaillierte Aiisfiihrungen uber die 1. Ausbaustufe des Nachfolgesptem ,,STUDENT" folgen. Wiihrend REX die Ein-und Ausgangedaten der Regreasion h t e t und interpretiert, kann mit Hilfe von STUDENT anhand von Beispielen die Strategie der statistischen Arbeit erlernt werden.Anknupfend an die von W. A. GALE in der Einleitung geaetzten Schwerpunkte gibt D. J. HAND

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