Search results for "epithelium"
showing 10 items of 505 documents
Determination of cytokeratins 1, 13 and 14 in oral lichen planus
2014
Cytokeratins (CK) are molecules of the cytoskeleton that contribute to the cellular differenciation. We studied the expression of CK1, CK13 and CK14 in thirty-three patients with OLP. The biopsied lesions were located in the dorsal surface of the tongue, the palatal keratinized mucosa and the nonkeratinized buccal mucosa. Objectives: This study aimed to determine the expression of CK1, CK13 and CK14 in oral lichen planus (OLP) and its relations with: clinical patterns, prognosis, drugs and tobacco intake and histopathological features. Study Design: Immunohistochemical analysis, retrospective, descriptive, observational and no randomized study. Results: No significant difference was observe…
Distribution and density of CD1a+ and CD83+ dendritic cells in HPV-associated laryngeal papillomas.
2009
Summary Background Respiratory papillomatosis associated with human papilloma virus (HPV) infection is the most common benign laryngeal neoplasm. The age of patients at disease onset, HPV type, number of surgeries are well known prognostic factors of the disease course. The correlation between dendritic cell (DC) density in tumor tissue and clinical prognosis was established. Aim The aim of our study was to estimate the density of DC in laryngeal papillomas associated with HPV types 6/11 infection and to evaluate the relationship between the number of DC and the disease severity. Materials and methods Our study included 40 randomly selected biopsy specimens from patients with HPV-positive l…
Bile duct epithelia as target cells in primary biliary cirrhosis and primary sclerosing cholangitis.
1997
Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are chronic autoimmune-mediated diseases of the biliary tree, resulting in a loss of bile ducts. There are morphological features that clearly distinguish them from each other: in PBC, there is overt destruction of the bile ducts with disruption of the basement membrane; in PSC there is abundant periductular fibrosis with shrinkage and subsequent loss of the bile ducts. In order to see if the disparate histopathology is paralleled by different immunohistology we looked at a panel of epitopes on bile duct epithelia especially to see if biliary epithelial cells may present as targets for cell mediated immune response. In…
Ultrastructural Pathology of Eccrine Sweat Gland Epithelial Cells in Globoid Cell Leukodystrophy
1993
Three of four children were recognized by deficient β-galactocerebrosidase activities as having globoid cell leukodystrophy inclusions in sweat gland epithelial cells, similar in ultrastructure to those seen in Schwann cells. This observation in globoid cell leukodystrophy emphasizes the need to include sweat gland epithelial cells in examinations of skin in globoid cell leukodystrophy, as well as in any neurometabolic disorder. ( J Child Neurol 1993;8:171-174).
Gap junctional intercellular communication of cultured rat liver parenchymal cells is stabilized by epithelial cells and their isolated plasma membra…
1994
The gap junctional intercellular communication (GJIC) determined by measuring dye coupling with Lucifer yellow, decreased within 3 d from 66% to 28% in monocultures of rat liver parenchymal cells. Coculturing of the parenchymal cells with a nonparenchymal epithelial cell line from rat liver resulted in increased and stabilized intercellular communication (83% after 3 d). The presence of isolated plasma membrane vesicles of the nonparenchymal epithelial cells also stabilized the intercellular communication between the liver parenchymal cells (70% after 3 d). When liver parenchymal cells were cocultured with a rat liver fibroblast cell line the gap junctional communication between the parench…
The mechanism of epithelial shedding after ischemic damage to the small intestinal mucosa
1979
The intestinal mucosa of the rat was examined by light and electron microscopy 15, 30, 60 and 120 min after complete ligation of the vessel arcades of the proximal jejunum. The characteristic sign of ischemic damage to the small intestinal mucosa and the reason for epithelial shedding is the appearance of membrane enclosed cytoplasmic blebs which arise at the cell base of the enterocytes and detach the epithelium from the basement membrane. This process begins at the tip of the villi before the enterocytes display signs of irreversible damage and progress to the base of the villi with continuation of the ischemia.
Clinicopathological evaluation of 164 dental follicles and dentigerous cysts with emphasis on the presence of odontogenic epithelium in the connectiv…
2012
Objectives: Some ameloblastomas presumably originate from odontogenic epithelium within the connective tissue of dental follicles and dentigerous cysts. Therefore, it would seem reasonable to discuss as whether odontogenic epithelium proliferations, frankly displaying ameloblastomatous features (“focal ameloblastoma”), should be considered as an “early” ameloblastoma. Study Design: Histopathological reports from 164 dental follicles and dentigerous cysts from the Department of Oral and Maxillofacial Surgery/Oral Pathology of the VU Free University medical center in Amsterdam, The Ne-therlands, were reviewed. Histopathological slides from 39 cases reporting the presence of odontogenic epithe…
TWIST and p-Akt immunoexpression in normal oral epithelium, oral dysplasia and in oral squamous cell carcinoma
2010
Objectives: The aim of this study was to evaluate the immunoexpression of TWIST and p-Akt proteins in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC), correlating their expressions with the histological features of the lesions. Study design: Immunohistochemical studies were carried out on 10 normal oral epithelium, 30 OL and 20 OSCC formalin-fixed, paraffin-embedded tissue samples. Immunoperoxidase reactions for TWIST and p-Akt proteins were applied on the specimens and the positivity of the reactions was calculated for 1000 epithelial cells. Results: Kruskal-Wallis and Dunn’s post tests revealed a significant difference in TWIST and p-Akt immunoexpression among normal oral mu…
Pathogenesis of Paraneoplastic Follicular Hyperkeratotic Spicules in Multiple Myeloma
1990
• We describe a 62-year-old man with multiple myeloma who developed horny spicules on his face, particularly on his nose. IgG-λ monoclonal gammopathy was detected, and the serum dysprotein was shown to be a cryoglobulin, which forms a cryogel at low temperatures. Light and electron microscopic and immunohistochemical examinations showed an intercellular precipitation and massive accumulation of the IgG dysprotein and cryoglobulin between the keratinocytes of the upper epidermis and the infundibular epithelium. The follicles were dilated and filled with parakeratotic cells, the protein deposits between them and a rudimentary hair thus resulting in the clinically visible symptoms of horny spi…
Epithelium modulates the reactivity of sensitized guinea-pig trachea: influence of the surface of drug entry.
1991
Abstract A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings isolated from sensitized guinea-pigs was applied to study the role of the epithelium in modulating responses to KCl, acetylcholine, histamine and antigen (bovine serum albumin, BSA). Epithelium removal did not alter the responsiveness or sensitivity of tracheal rings to KCl. In contrast, a leftward shift occurred for concentration-response curves to acetylcholine (concentration ratio (CR) = 4·1), histamine (CR = 2·9) and BSA (CR = 33·9) entering from the mucosal surface of de-epithelialized trachea. This shift was not associated with changes in the maximal effect of th…