48 KB162 KB33 KB200020242003Mayhew, Terry M.številka:1letnik:228 stranistr. 49-56ISSN:1580-3139COBISSID:16050649URN:URN:NBN:SI:doc-B0R0YNDSenDruštvo za stereologijo in kvantitativno analizo slike, Medicinska fakultetaImage analysis and stereologyAnatomy And HistologyChorionic VilliHorionske resicehuman pregnancyImage Processing, Computer-AssistedNosečnostPlacentaPregnancySlika, obdelava z računalnikomUltrastructureStereological studies on fetal vascular development in human placental villi|In human pregnancy, fetal well-being depends on the development of placental villi and the creation and maintenance of fetal microvessels within them. The aim of this study was to define stereological measures of the growth, capillarization and maturation of villi and of fetoplacental angiogenesis and capillary remodelling. Placentas were collected at 12-41 weeks of gestation and assigned to six age groups spanning equal age ranges. Tissue samples were randomised for position and orientation. Overall growth of peripheral (intermediate and terminal) villi and their capillaries was evaluated using total volumes, surface areas and lengths. Measures of villous capillarization comprised capillary volume, surface and length densities and capillary:villus surface and length ratios. Size and shape remodelling of villi and capillarieswas assessed using mean cross-sectional areas, perimeters and shapecoefficients (perimeter2/area). Group comparisons were drawn by analysis of variance. Villous and capillary volumes, surfaces and lengths increased significantly throughout gestation. Villous maturation involved phasic (capillary:villus surface and length ratios) or progressive (volume, surface and length densities) increases in indices of villous capillarization. It alsoinvolved isomorphic thinning (cross-sectional areas and perimeters declined but shape coefficients did not alter). In contrast, growth of capillaries did not involve changes in luminal areas or perimeters. The results show that villous growth and fetal angiogenesis involve increases in overall length rather than calibre and that villous differentiation involves increased capillarization. Although they do not distinguish between increases in the lengths versus numbers of capillary segments, other studies have shown that capillaries switch from branching to non-branching angiogenesis during gestation. (Abstract truncated at 2000 characteristics)TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaDruštvo za stereologijo in kvantitativno analizo slike