Search results for "epithelium"
showing 10 items of 505 documents
Echovirus 1 Entry into Polarized Caco-2 Cells Depends on Dynamin, Cholesterol, and Cellular Factors Associated with Macropinocytosis
2013
ABSTRACT Enteroviruses invade their hosts by crossing the intestinal epithelium. We have examined the mechanism by which echovirus 1 (EV1) enters polarized intestinal epithelial cells (Caco-2). Virus binds to VLA-2 on the apical cell surface and moves rapidly to early endosomes. Using inhibitory drugs, dominant negative mutants, and small interfering RNAs (siRNAs) to block specific endocytic pathways, we found that virus entry requires dynamin GTPase and membrane cholesterol but is independent of both clathrin- and caveolin-mediated endocytosis. Instead, infection requires factors commonly associated with macropinocytosis, including amiloride-sensitive Na + /H + exchange, protein kinase C, …
Interaction between mesenchymal cells and the posterior iris epithelium in chicken embryos
1977
The iris anlage of 3--10 day old chicken embryos was studied by both light and electron microscopy. Serial semithin sections showed that some of the mesenchymal cells overlying the eye cup moved into the primitive eye cavity by the 3rd day of incubation. On the 4th day some of these cells came into close contact with the basement membrane of the dorsal iris epithelium. The bases of the epithelial cells were flat at this stage. Towards the 10th day they formed cytoplasmic processes which did not penetrate the basement membrane. Fine mesenchymal cytoplasmic processes and a large number of extracellular fibrils developed in the epithelial--mesenchymal interface. The fine mesenchymal processes …
A novel model of human implantation: 3D endometrium-like culture system to study attachment of human trophoblast (Jar) cell spheroids.
2011
There is an urgent need to develop optimized experimental models to examine human implantation. These studies aimed to (i) establish a human endometrium-like three-dimensional (3D) culture system, and (ii) examine the attachment of trophoblast-like Jar spher- oids to the culture. In the present work, 3D endometrial cultures were constructed with fibrin-agarose as matrix scaffold, and using epithelial and stromal cells from both human primary cultures and established cell lines. An attachment assay between trophoblast cells and the 3D culture was developed. Epithelial cells (cytokeratin + ) concentrated on top of the matrix forming a monolayer, and stromal cells (vimentin + ) resided within …
Rat fetuin: distribution of protein and mRNA in embryonic and neonatal rat tissues
1998
Fetuin is a serum protein widely distributed in the animal kingdom and found in all mammalian species so far investigated. It is mainly a fetal protein, in the sense that the highest concentrations are found in serum and body fluids of embryos and fetuses. In order to elucidate possible biological functions of fetuin, we have studied its synthesis and distribution during the prenatal development of the rat with immunohistochemistry and in situ hybridization. We have isolated fetuin from rat serum and produced an antibody against this protein. In situ hybridization was performed using a 375-nucleotides-long digoxigenin-labeled riboprobe. Fetuin was unevenly distributed in all organ systems d…
Face-selective adhesion of calcium oxalate dihydrate crystals to renal epithelial cells
1996
The interaction between the most common urinary crystal, calcium oxalate dihydrate (COD) and the surface of monkey renal epithelial cells of the BSC-1 line was investigated. The [100] face of exogenous COD crystals bound selectively and rapidly to the kidney cell surface. Cellular processes extended preferentially over the [100] face initially, and then progressively covered the crystal so that by 24 hours some crystals were observed beneath the plasma membrane. When nucleated from solution onto the surface of the cell monolayer, COD crystals oriented preferentially so that their [100] faces were in direct contact with the cell surface. In contrast, when siliconized glass was used as a subs…
Mechanosensory Genes Pkd1 and Pkd2 Contribute to the Planar Polarization of Brain Ventricular Epithelium
2015
Directional beating of ependymal (E) cells9 cilia in the walls of the ventricles in the brain is essential for proper CSF flow. E cells display two forms of planar cell polarity (PCP): rotational polarity of individual cilium and translational polarity (asymmetric positioning of cilia in the apical area). The orientation of individual E cells varies according to their location in the ventricular wall (location-specific PCP). It has been hypothesized that hydrodynamic forces on the apical surface of radial glia cells (RGCs), the embryonic precursors of E cells, could guide location-specific PCP in the ventricular epithelium. However, the detection mechanisms for these hydrodynamic forces hav…
Regionalization of epididymal duct and epithelium in rats and mice by automatic computer-aided morphometric analysis.
2005
Aim: To establish a rat and mouse epididymal map based on the use of the Epiquatre automatic software for histologic image analysis. Methods: Epididymides from five adult rats and five adult mice were fixed in alcoholic Bouin’s fixative and embedded in paraffin. Serial longitudinal sections through the medial aspect of the organ were cut at 10 µm and stained with hematoxylin and eosin. As determined from major connective tissue septa, nine subdivisions of the rat epididymis and seven for the mouse were determined, consisting of five sub-regions in the caput (rat and mouse), one (mouse) or three (rat) in the corpus and one in the cauda (rat and mouse). Using the Epiquatre software, several t…
Reproducibility of grading systems in oral epithelial dysplasia
2012
Objective: To assess inter and intra observer variability in grading oral epithelial dysplasia (OED) using Smith and Pindborg grading system, WHO classification system and Brothwell DJ et al. classification system. Study design: In the study 45 histological tissues of dysplasia, 15 each of mild, moderate and severe dysplasia were coded and blindly graded by three observers in three grading systems. Further on the same observers graded 15 slides again of the previous 45 for analyzing the reproducibility in the three grading systems. The individual significance of various indicators of dysplasia among various grades of dysplasia was also assessed. Result: Inter observer agreement was signific…
Encapsulation Response ofCiona intestinalis(Ascidiacea) to Intratunical Erythrocyte Injection
1997
Abstract Electron microscopic studies on the encapsulation induced by erythrocyte injection into the tunic of the ascidian Ciona intestinalis were carried out. The observations reported in the present paper complete the description previously given of capsule architecture and contribute to the characterization of the cells involved in the inflammatory reaction. The inflamed area is surrounded by an ample and peculiar “three-layered coat” respectively composed of flattened and packed extratunical hemocytes, the monolayered epithelium, and a layer of intratunical electron-dense particles. The latter are also clustered, variously arranged, and distributed in the tunic ground substance. The epi…
Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on …
2015
This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence.-- et al.