Mayhew T M, Wadrop E
Department of Human Morphology, University of Nottingham, Queen's Medical Centre, UK.
Placenta. 1994 Feb-Mar;15(2):209-17. doi: 10.1016/s0143-4004(05)80457-6.
In 27 human placentae collected at 13-39 weeks, the growth and morphogenesis of villi and of the maternal intervillous space were assessed using a design-based stereological approach for estimating star volume. The purpose was to quantify changes occurring during these processes and to derive parameters pertinent to physiological performance (notably transport capability and haemodynamics). Placentae were sampled by cutting paraffin sections at random locations and orientations. Estimates of the global volumes of peripheral (terminal and intermediate) villi and intervillous space were derived from placental volumes via point counting. Total villous surface was estimated by intersection counting and length by transection counting. Treating villi like the branches of tree-like networks and the intervillous space as a system of confluent pores, estimates of the star volumes of these compartments were also made. These volumes were calculated by measuring point-sampled intercept lengths. The total volumes of villi and intervillous space increased steadily throughout gestation. After the second trimester, the increase in volume of villi was accompanied by a decrease in villous star volume. This can be explained by the continued elaboration and maturation of terminal villi, the combined length of which increased whilst mean diameter declined. The star volume of the intervillous space also declined and this, too, is consistent with villous growth and proliferation.
在收集的27例孕13 - 39周的人胎盘标本中，采用基于设计的体视学方法评估绒毛及母体绒毛间隙的生长和形态发生，来估计星体积。目的是量化这些过程中发生的变化，并得出与生理功能（尤其是转运能力和血流动力学）相关的参数。通过在随机位置和方向切割石蜡切片对胎盘进行采样。通过点计数从胎盘体积得出外周（终末和中间）绒毛及绒毛间隙的总体积估计值。通过相交计数估计绒毛总表面积，通过横切计数估计长度。将绒毛视为树状网络的分支，将绒毛间隙视为汇合孔隙系统，还对这些隔室的星体积进行了估计。这些体积通过测量点采样截距长度来计算。绒毛和绒毛间隙的总体积在整个妊娠期稳步增加。孕中期之后，绒毛体积的增加伴随着绒毛星体积的减小。这可以通过终末绒毛的持续细化和成熟来解释，终末绒毛的总长度增加而平均直径减小。绒毛间隙的星体积也减小，这也与绒毛的生长和增殖一致。
