A structured review of placental morphology and histopathological lesions associated with SARS-CoV-2 infection.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, was first identified after a cluster of cases in Wuhan, China in December 2019. Whether vertical transmission or placental pathology might occur following maternal infection during pregnancy remains unknown. This review aimed to summarise all studies that examined the placenta or neonates following infection with SARS-CoV-2, or closely related highly pathogenic coronavirus (SARS-CoV-1, or the Middle East respiratory syndrome coronavirus (MERS-CoV)).

Morphology, histochemistry and glycosylation of the placenta and associated tissues in the European hedgehog (Erinaceus europaeus).

Introduction: There are few descriptions of the placenta and associated tissues of the European hedgehog (Erinaceus europaeus) and here we present findings on a near-term pregnant specimen.

Methods: Tissues were examined grossly and then formalin fixed and wax-embedded for histology and immunocytochemistry (cytokeratin) and resin embedded for lectin histochemistry.

Results: Each of four well-developed and near term hoglets displayed a discoid, haemochorial placenta with typical labyrinth and spongy zones.

Placental endoplasmic reticulum stress in gestational diabetes: the potential for therapeutic intervention with chemical chaperones and antioxidants.

Aims/hypothesis: The aim of this work was to determine whether placental endoplasmic reticulum (ER) stress may contribute to the pathophysiology of gestational diabetes mellitus (GDM) and to test the efficacy of chemical chaperones and antioxidant vitamins in ameliorating that stress in a trophoblast-like cell line in vitro.

Methods: Placental samples were obtained from women suffering from GDM and from normoglycaemic controls and were frozen immediately. Women with GDM had 2 h serum glucose levels > 9.

A simple histochemical method for the identification of cytotrophoblasts in tissue sections.

A simple method for the demonstration of placental cytotrophoblast cells is described, utilising the affinity of the lectin from Bandeiraea simplicifolia-II (BSA-II) for intracellular amylase-sensitive glycogen and a protocol using biotinylated BSA-II followed by an avidin-peroxidase revealing system. In early pregnancy, cytotrophoblast cells in chorionic and anchoring villi are deeply stained and with ongoing differentiation the staining gradually decreases in intensity, suggesting that this lectin can be a useful marker for these cells.

Hemangioblastic foci in human first trimester placenta: Distribution and gestational profile.

Introduction: The human placenta is a site of both hematopoiesis and vasculogenesis. There are reports of hemangioblastic foci (HAF) in the first trimester placenta, but little published information about their spatiotemporal incidence.

Methods: We have used semi-thin sections and whole mount staining techniques on archival early pregnancy hysterectomy material as well as freshly-collected termination tissue.

Functional changes in Hofbauer cell glycobiology during human pregnancy.

Introduction: This study examines the glucose metabolism and glycosylation of villous macrophages (Hofbauer cells) over the course of pregnancy.

Materials And Methods: Sections of placentae from 6 weeks to term were stained with antibodies to α-amylase, glycogen synthase, glycogen phosphorylase and glucose transporters 1 and 3 (GLUT-1 and GLUT-3) while a panel of 24 lectins was applied to resin sections from 4 weeks onwards. Hofbauer cells were identified by the binding of anti-CD 163 antibody.

The binucleate cell of okapi and giraffe placenta shows distinctive glycosylation compared with other ruminants: a lectin histochemical study.

The placenta of ruminants contains characteristic binucleate cells (BNC) with a highly conserved glycan structure which evolved early in Ruminant phylogenesis. Giraffe and Okapi placentae also contain these cells and it is not known whether they have a similar glycan array. We have used lectin histochemistry to examine the glycosylation of these cells in these species and compare them with bovine BNC which have a typical ruminant glycan composition.

Preeclampsia is associated with alterations in the p53-pathway in villous trophoblast.

Background: Preeclampsia (PE) is characterized by exaggerated apoptosis of the villous trophoblast of placental villi. Since p53 is a critical regulator of apoptosis we hypothesized that excessive apoptosis in PE is mediated by abnormal expression of proteins participating in the p53 pathway and that modulation of the p53 pathway alters trophoblast apoptosis in vitro.

Methods: Fresh placental villous tissue was collected from normal pregnancies and pregnancies complicated by PE; Western blotting and real-time PCR were performed on tissue lysate for protein and mRNA expression of p53 and downstream effector proteins, p21, Bax and caspases 3 and 8.

Identification of autophagic vacuoles and regulators of autophagy in villous trophoblast from normal term pregnancies and in fetal growth restriction.

Fetal growth restriction (FGR) is a serious pregnancy complication associated with increased perinatal mortality and morbidity. Although the majority of cases with FGR result from placental dysfunction, the pathophysiology is incompletely understood. Autophagy is a physiological form of cell degradation exacerbated by nutrient and oxygen restriction, which are both thought to play a role in the aetiology of FGR.

Heightened pro-inflammatory effect of preeclamptic placental microvesicles on peripheral blood immune cells in humans.

Normal pregnancy is associated with the presence of circulating placental microvesicles (MVs). Increased MV shedding and altered immune activation are seen in patients with preeclampsia, suggesting that placental MVs may play a role in the pathophysiology of this disease. Therefore, the aim of this study was to investigate the activation of peripheral blood mononuclear cells (PBMCs) by MVs shed by first-trimester, normal term, and preeclamptic term placenta.

Fucose, placental evolution and the glycocode.

A family of 13 fucosyltransferase genes has evolved to catalyze the addition of fucose in various linkage positions to nascent glycoproteins. Null mutations in mice are unearthing unsuspected functions for glycoprotein fucosylation that affect embryo implantation and growth of the conceptus. Furthermore, as we show here, histological studies demonstrate that a variety of fucosylated structures are found within the glycan-rich interface between trophectoderm and uterine epithelium.

Mapping of CIP/KIP inhibitors, G1 cyclins D1, D3, E and p53 proteins in the rat term placenta.

As cell cycle regulation is fundamental to the normal growth and development of the placenta, the aim of the present study was to determine the immunolocalizations of cell cycle related proteins, which have key roles in proliferation, differentiation and apoptosis during the development of the rat placenta. Here immunohistochemistry has been used to localize G1 cyclins (D1, D3, E), which are major determinants of proliferation, CIP/KIP inhibitors (p21, p27, p57), p53 as a master regulator and proliferating cell nuclear antigen in all cell types of the rat term placenta. The proportion of each cell type immunolabeled was counted.

Live birth rate in fresh and frozen embryo transfer cycles in women with endometriosis.

Objectives: To test the hypothesise that the treatment protocol used for preparation of the endometrium for frozen embryo transfer (ET) has a beneficial effect on the disorganised endometrium in women with endometriosis and leads to a higher pregnancy rate.

Study Design: We performed a retrospective, database-searched cohort study. Relevant information was collected from the electronic records of women who underwent IVF/ICSI between 1/1/2000 and 31/12/2008 in our unit.

A new possible function for placental pericytes.

The pericyte is a multifunctional cell closely associated with endothelial cells and may play a role in angiogenesis and vessel stabilisation. Re-examination of over 1,100 micrographs from archival material used to investigate ultrastructural changes in placental development and pathology has identified previously undescribed structures associated with the pericyte of the human placental terminal villus. These structures take the form of outgrowths from the main body of the cell, with a narrow neck rich in cytoplasmic filaments, terminating in swollen tips which appear to bleb off the pericyte and form electron lucent stromal vesicles.

Collagen fibril organization in the pregnant endometrium of decorin-deficient mice.

In the pregnant mouse endometrium, collagen fibrillogenesis is characterized by the presence of very thick collagen fibrils which are topographically located exclusively within the decidualized stroma. This dynamic biological process is in part regulated by the small leucine-rich proteoglycans decorin and biglycan. In the present study we utilized wild-type (Dcn(+/+)) and decorin-deficient (Dcn(-/-)) time-pregnant mice to investigate the evolution of non-decidualized and decidualized collagen matrix in the uterine wall of these animals.

Three-dimensional electron microscopic reconstruction of intracellular organellar arrangements in vascular smooth muscle--further evidence of nanospaces and contacts.

The sarcoplasmic reticulum (SR) of smooth muscle is crucial for appropriate regulation of Ca(2+) signalling. In visceral and vascular smooth muscles the SR is known to periodically lie in close register, within a few nanometres, to the plasma membrane. Recent work has focussed on reconstructions of the ultrastructural arrangement of this so-called peripheral SR that may be important for the genesis of phenomena such as Ca(2+) sparks.

Comparison of lectin binding of drusen, RPE, Bruch's membrane, and photoreceptors.

Purpose: Drusen are deposits located between the retinal pigment epithelium and Bruch's membrane in age-related maculopathy. They are believed to be photoreceptor byproducts that are incompletely metabolized by the retinal pigment epithelium. This study therefore compares the lectin histochemistry of drusen, photoreceptors, retinal pigment epithelium, and Bruch's membrane.

Syncytial knots, sprouts, apoptosis, and trophoblast deportation from the human placenta.

The syncytiotrophoblast (STB) that forms the epithelial covering of the placental villous tree has a unique cell biology on account of its syncytial nature. The tissue is in a terminally-differentiated, postmitotic state, and expands through the recruitment by fusion of underlying progenitor cytotrophoblast cells. This process occurs from the time of implantation until term, and so its nuclei will be of various ages, producing a spectrum of contrasting appearances; whilst some are euchromatic, others display dense condensations of heterochromatin, the latter often aggregating to form clusters referred to as syncytial knots.

Eutopic endometrium from women with endometriosis shows altered ultrastructure and glycosylation compared to that from healthy controls--a pilot observational study.

Endometrial curettings from a cohort of 24 women with endometriosis were compared with matched biopsies from 14 healthy, fertile women and examined for ultrastructural changes and the secretion of glycans bound by the lectin from Dolichos biflorus. Ultrastructural analysis of glandular endometrial tissue from women with stages I to III endometriosis showed heterogeneous responses to the disease, biopsies often showing a mixture of features, combining delays in the maturation sequence with characteristics of later phenotypes particularly in the mid-late secretory phase of the menstrual cycle. Expression of glycans bound by Dolichos biflorus agglutinin was very variable in these cases but generally matched the observed ultrastructure.

Oligosaccharide composition is similar in drusen and dense deposits in membranoproliferative glomerulonephritis type II.

Drusen are a feature of age-related macular degeneration (AMD). Lesions similar in appearance to drusen are also found in the fundi of patients with membranoproliferative glomerulonephritis type II (dense deposit disease, DDD). The lamina densa of the glomerular basement membrane, in DDD, is transformed into an electron-dense structure by deposition of microscopically homogeneous material.

Peritoneal ectopic lesions from women with endometriosis show abnormalities in progesterone-dependent glycan expression.

Examination of 12 paired peritoneal ectopic and eutopic endometria for histochemical binding of Dolichos biflorus agglutinin, normally found in the mid-late secretory part of the cycle, showed a failure of lectin binding in 9 of 11 secretory-phase lesions although the eutopic specimens generally stained normally. This failure of glycan expression in the secretory phase may result from various anomalies, including an inability to respond to progesterone, possibly due to a lack of, or to nonfunctional, progesterone receptors, suggesting that an ectopic environment may produce changes in tissue cell biology and hormonal responsiveness compared with that of eutopic endometrium.

Ultrastructure of ectopic peritoneal lesions from women with endometriosis, including observations on the contribution of coelomic mesothelium.

Following a study in a baboon model of endometriosis, we here describe the morphology of ectopic peritoneal lesions in the human to examine the effects of an ectopic site on glandular structure and function. Ectopic biopsies from 17 women with endometriosis were fixed and processed for electron microscopy. Certain biopsies were also probed for intermediate filaments using immunohistochemistry.

Glycosylation at the fetomaternal interface: does the glycocode play a critical role in implantation?

During pregnancy, the heavily glycosylated surfaces of the implanting blastocyst and maternal uterine epithelium interact in a highly controlled and specific manner. Examination of this interface in species that show interdigitation of embryonic and maternal surfaces (epitheliochorial placentation) shows that each has its own particular pattern of glycosylation or glycotype, and that closely related and/or interbreeding species e.g.