AIM To obtain some insight into the extracellular matrix in the placenta, changes in the composition of collagens during placental development were investigated. METHODS Collagen was extracted from placentas (group 1, 25-30 weeks, n = 21; group 2, 31-36 weeks, n = 32; and group 3, 37-41 weeks of gestation, n = 40) and the relative concentrations of various collagens were evaluated by SDS-PAGE...

We employed a novel mouse line that expresses low levels of human tissue factor (TF) in the absence of murine TF to analyze the role of TF in gestation. Low-TF female mice had a 14-18% incidence of fatal postpartum uterine hemorrhage, suggesting that TF plays an important role in uterine hemostasis. Low-TF female mice mated with low-TF male mice had a 42% incidence of fatal midgestational hemor...

Adenosine, inosine, and hypoxanthine were isolated from human term placentas by paper chromatography of the diaJyzates of aqueous placental homogenates and quantified by ultraviolet spectroscopy. Placentas obtained upon vaginal delivery contained 230 ± 18 nmoles adenosine/g tissue, 300 ± 29 nmoles inosine/g, and 250 ± 19 nmoles hypoxanthine/g. Three prelabor placentas obtained by cesarean secti...

Vascularity is increased in placentas from high- compared with low-altitude pregnancies. An angiogenic response to hypoxia may protect an organ from further hypoxic insult by increasing blood flow and oxygen delivery to the tissue. We hypothesized that increased placental vascularity is sufficient to adapt to high altitude. Therefore, indexes of hypoxic stress would not be present in placentas ...

BACKGROUND The rationale for this study was to assess the expression, activity and localization of the enzymes uridine diphosphate glucuronosyltransferase (UGT), beta-glucuronidase, cytochrome P450 1A (CYP1A) and cytochrome P450 2E1 (CYP2E1) in first trimester human placenta and to gauge the effects of maternal variables on placental metabolism. METHODS CYP1A, CYP2E1, UGT and beta-glucuronida...

Previous studies by others and ourselves have suggested that the methylation pattern of imprinted genes in oocytes is altered during postovulatory aging. The purpose of the current study was to evaluate the effects of postovulatory aging of mouse oocytes on methylation and expression of imprinted genes at the mid-gestation development stages. Proestrous females were artificially inseminated at ...

This study investigates the validity of retrospective determination of chorion type by asking the question to the mother about the number of placentas. In the "East Flanders Prospective Twin Survey" (EFPTS), accurate information on the placentation and zygosity of the multiples was collected prospectively. The mothers of 231 monozygotic (95 dichorionic and 136 monochorionic) twins and 255 dizyg...

AIMS Our objective was to elucidate the pathogenesis of twin discordance in four dizygotic pregnancies where only one of the twins had IUGR due to chronic villitis. METHODS We identified four cases of dizygotic twin placentas over a period of four years with evidence of chronic villitis. There was no clinical or pathologic evidence of TORCH, bacterial infection, preeclampsia or autoimmune dis...

BACKGROUND Placental malfunction in preeclampsia is believed to be a consequence of aberrant differentiation of trophoblast lineages and changes in utero-placental oxygenation. The transcription factor Snail, a master regulator molecule of epithelial-mesenchymal transition in embryonic development and in cancer, is shown to be involved in trophoblast differentiation as well. Moreover, Snail can...

Preeclampsia (PE) is a leading cause of maternal mortality worldwide. Several studies have detected some differentially expressed microRNAs in the preeclamptic placenta, but few of the identified microRNAs demonstrated consistent findings among different research studies. In this study, high-throughput microRNA sequencing (HTS) of 9 preeclamptic and 9 normal placentas was performed. Seventeen m...