- Email: [email protected]
Morphometric estimation of the microvillus amplification factor of the trophoblastic surfaces in the term human placenta
Abstracts
INCREASED INTRAPLACENTAL ANTIFIBRINOLYTIC ACTIVITY IN TOXEMIA: RELATION TO MORPHOLOGICAL AND BIOCHEMICAL FINDINGS. A. Kanfer I, J.F. Bruch 3, C. Fondacci 3. C.J. He I, G. N g u y e n l , F . Delarue 2, C. Nessmann 3 and S. Uzan 2. iService de N~phrologie A et INSERM U64, 2Service MaternitY, H6pital Tenon, 75020 Paris, 3Laboratoire de Biologie du D~veloppement et de la Reproduction, H6pital Robert Debr~, 75019 Paris. Toxemia is characterized by systemic hypercoagulability. The aim of our study was to investigate the changes in placental hemostatic factors, in 17 toxemic compared to 17 normal term placentae. Morphological examination of villous tissue on paraffin sections showed a tendency for an increase in fibrin deposits in toxemic placentae (p = 0.08). Biochemical studies, performed on homogenates from frozen tissue, showed an increase in plasminogen activator inhibitor 2 (PAI-2) in toxemia: 124 • 8 vs 104 • 6 ng/mg protein, p = 0.046. No significant differences for functional tissue factor, thrombomodulin (TM) or PAI-I antigen were observed. However there was a negative correlation between TM activity and PAI only in toxemic placentae. In summary, toxemic placentae exhibit local alterations of hemostatic factors which may contribute to toxemic hypercoagulability.
MORPHOMETRIC ESTIMATION OF THE MICROVILLUS AMPLIFICATION FACTOR OF THE TROPHOBLASTIC SURFACES IN THE TERM HUMAN PLACENTA. A.L. Karimu and G.J. Burton, Department of Anatomy, University of Cambridge, U.K. Whilst some studies have demonstrated the absence of microvilli in the region of vasculosyncytial membrane (VSM) (eg. Fox & Agrofojo-Blanco, 1974; Eur. J. Obst. Gynee. Reprod. Biol. 4, 45-50) others have not confirmed this observation (eg. Burton, 1987, Scann. Micros. 1, 1811-1828). This study was therefore undertaken to evaluate stereologically the villous amplification factor of microvilli, in particular the differences between the regions of VSM and non-VSM. In order to achieve this, ten normal placentae from singleton pregnancies delivered by caesarian section at 38-40 weeks gestation were obtained. These were peffasion-fixed in 4% glutaraldehyde, 0.5% formaldehyde and embedded in araldite resin for thin sectioning. Trophoblastic surfaces covered with microviili were randomly photographed in both the areas of VSM and adjacent non-VSM. Morphometric estimates of the microvillas and villous surface densities were obtained by intersection counting method. For this purpose, the image of the film was projected on to a screen upon which was superimposed a quadratic test lattice. A VSM was defined as a distance between the capillary endothelium and trophoblastic apical membcane less than 41am while a non-VSM was greater than 4 ~m. A total of 15-20 films per placenta were estimated in each region. The results of the study using a paired 't' test showed that there was no significant difference in villous surface amplification factor between the regions of VSM and non-VSM (5.183 + 0.543 and 5.226 + 0.544 respectively, mean + SEM, p 9 0.05). In addition, there were no significant differences between the length and diameter of microvilli in both regions (p > 0.05 in both). These findings indicate that there are no significant differences in the morphology of the microvilli over the trophoblastic surfaces in human term placenta.
A.35
INCREASED INTRAPLACENTAL ANTIFIBRINOLYTIC ACTIVITY IN TOXEMIA: RELATION TO MORPHOLOGICAL AND BIOCHEMICAL FINDINGS. A. Kanfer I, J.F. Bruch 3, C. Fondacci 3. C.J. He I, G. N g u y e n l , F . Delarue 2, C. Nessmann 3 and S. Uzan 2. iService de N~phrologie A et INSERM U64, 2Service MaternitY, H6pital Tenon, 75020 Paris, 3Laboratoire de Biologie du D~veloppement et de la Reproduction, H6pital Robert Debr~, 75019 Paris. Toxemia is characterized by systemic hypercoagulability. The aim of our study was to investigate the changes in placental hemostatic factors, in 17 toxemic compared to 17 normal term placentae. Morphological examination of villous tissue on paraffin sections showed a tendency for an increase in fibrin deposits in toxemic placentae (p = 0.08). Biochemical studies, performed on homogenates from frozen tissue, showed an increase in plasminogen activator inhibitor 2 (PAI-2) in toxemia: 124 • 8 vs 104 • 6 ng/mg protein, p = 0.046. No significant differences for functional tissue factor, thrombomodulin (TM) or PAI-I antigen were observed. However there was a negative correlation between TM activity and PAI only in toxemic placentae. In summary, toxemic placentae exhibit local alterations of hemostatic factors which may contribute to toxemic hypercoagulability.
MORPHOMETRIC ESTIMATION OF THE MICROVILLUS AMPLIFICATION FACTOR OF THE TROPHOBLASTIC SURFACES IN THE TERM HUMAN PLACENTA. A.L. Karimu and G.J. Burton, Department of Anatomy, University of Cambridge, U.K. Whilst some studies have demonstrated the absence of microvilli in the region of vasculosyncytial membrane (VSM) (eg. Fox & Agrofojo-Blanco, 1974; Eur. J. Obst. Gynee. Reprod. Biol. 4, 45-50) others have not confirmed this observation (eg. Burton, 1987, Scann. Micros. 1, 1811-1828). This study was therefore undertaken to evaluate stereologically the villous amplification factor of microvilli, in particular the differences between the regions of VSM and non-VSM. In order to achieve this, ten normal placentae from singleton pregnancies delivered by caesarian section at 38-40 weeks gestation were obtained. These were peffasion-fixed in 4% glutaraldehyde, 0.5% formaldehyde and embedded in araldite resin for thin sectioning. Trophoblastic surfaces covered with microviili were randomly photographed in both the areas of VSM and adjacent non-VSM. Morphometric estimates of the microvillas and villous surface densities were obtained by intersection counting method. For this purpose, the image of the film was projected on to a screen upon which was superimposed a quadratic test lattice. A VSM was defined as a distance between the capillary endothelium and trophoblastic apical membcane less than 41am while a non-VSM was greater than 4 ~m. A total of 15-20 films per placenta were estimated in each region. The results of the study using a paired 't' test showed that there was no significant difference in villous surface amplification factor between the regions of VSM and non-VSM (5.183 + 0.543 and 5.226 + 0.544 respectively, mean + SEM, p 9 0.05). In addition, there were no significant differences between the length and diameter of microvilli in both regions (p > 0.05 in both). These findings indicate that there are no significant differences in the morphology of the microvilli over the trophoblastic surfaces in human term placenta.
A.35