Search results for "CYTOKERATIN"
showing 10 items of 92 documents
Immunohistochemical expression of Cytokeratins in periapical lesions
2011
Objective. This study seeks to clarify the histological origin of apical lesions, through the expression of certain cytokeratins.Study design. In 3 years 30 patients were selected. After clinical and radiological exams were chosen patients who had severe apical lesions and tooth decay with exposure of the pulp chamber left untreated for very long periods (more the 12 months). Serial slides were prepared both for immunohistochemistry and Hematoxylin- Eosin. Material and methods. Twenty specimens coming from the 30 patients were used for our purpose. All periapical lesions were surgically extracted and fixed in Bouin mixture, and embedded in paraffin. Samples were processed immunohistochemica…
Cytokeratins identification in human Umbilical Cord at Term
2009
Expression of cytokeratins in human umbilical cord at term
2009
Background. Cytokeratins are the proteins that costitute intermediate filaments. In the cytoplasm, keratin filaments extend from the nucleus to the plasma membrane. This link is important for the structural organization of the cytoplasm and for many cellular processes such as mitosis, cell movement, cell differentiation and adhesion. The pattern of expression of cytokeratins is frequently organ or tissue specific and depends mainly on the type of epithelium, the level of differentiation and the stage of development. The expression of cytokeratins in umbilical cord has been investigated by many groups, but these previous studies gave only fragmentary informations: each single study focused o…
Desmosomes: interconnected calcium-dependent structures of remarkable stability with significant integral membrane protein turnover
2002
Desmosomes are prominent cell adhesion structures that are major stabilizing elements, together with the attached cytoskeletal intermediate filament network, of the cytokeratin type in epithelial tissues. To examine desmosome dynamics in tightly coupled cells and in situations of decreased adhesion, fluorescent desmosomal cadherin desmocollin 2a (Dsc2a) chimeras were stably expressed in human hepatocellular carcinoma-derived PLC cells (clone PDc-13) and in Madin-Darby canine kidney cells (clone MDc-2) for the continuous monitoring of desmosomes in living cells. The hybrid polypeptides integrated specifically and without disturbance into normal-appearing desmosomes that occurred in associati…
Induction of rapid and reversible cytokeratin filament network remodeling by inhibition of tyrosine phosphatases
2002
The cytokeratin filament network is intrinsically dynamic, continuously exchanging subunits over its entire surface, while conferring structural stability on epithelial cells. However, it is not known how cytokeratin filaments are remodeled in situations where the network is temporarily and spatially restricted. Using the tyrosine phosphatase inhibitor orthovanadate we observed rapid and reversible restructuring in living cells, which may provide the basis for such dynamics. By examining cells stably expressing fluorescent cytokeratin chimeras, we found that cytokeratin filaments were broken down and then formed into granular aggregates within a few minutes of orthovanadate addition. After …
Light-induced resistance of the keratin network to the filament-disrupting tyrosine phosphatase inhibitor orthovanadate.
2003
Epidermal keratinocytes respond to low-dose light irradiation by inducing signaling cascades that lead to long-term effects on gene transcription thereby protecting cells against damage. In contrast, little is known about immediate light-induced alterations of structural proteins. We have made the intriguing observation that light produces fundamental changes in the properties of the keratin filament system of cultured epidermoid A-431 cells. A short light exposure (1–10 min) causes the keratin cytoskeleton to become immediately resistant to the tyrosine phosphatase inhibitor orthovanadate, which otherwise disrupts the keratin filament network completely in just a few minutes. This protecti…
The Level of Cytokeratin 18 in Patients with HIV and Viral Hepatitis C Co-Infection in Latvia
2020
Abstract Cytokeratin 18 (CK18) is a specific marker of hepatocellular apoptosis, which is a useful noninvasive indicator of liver fibrosis in the HIV/HCV group. However, data on the CK18 level in serum are limited for this group. This study demonstrated CK18 levels in serum in HIV/HCV co-infected and HIV mono-infected patients; investigated the association of CK18 levels with other non-invasive markers of liver fibrosis; and presents CK18 dynamics in a four-month-long period. The sample included 273 patients with HIV infection (128 of them were with HIV/HCV co-infection) aged from 23 to 65 (35% females). Levels of hyaluronic acid, CK18, ALT, and AST were determined in serum, and the FIB4 in…
Patterns of expression of trichocytic and epithelial cytokeratins in mammalian tissues
1988
Abstract Cells forming hair and nail material are characterized by the synthesis of members of a particular group of α-keratin polypeptides (trichocytic cytokeratins, “T cytokeratins”) different from epithelial cytokeratins (“E cytokeratins”). As the precursor cells to trichocytes are derived from fetal epidermal keratinocytes expressing only E cytokeratins, we have studied the patterns of expression of both T and E cytokeratins in developing human hair-and nailforming tissues of different fetal stages, by immunocyto-chemistry using antibodies specific for certain T or E cytokeratins and by two-dimensional gel electrophoresis and immunoblotting. In developing hair follicles up to the early …
Expression of Cytokeratin 7 and 20 in Pathological Conditions of the Bile Tract
2003
Expression of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) helps to establish the origin of biliary and metastatic carcinomas. We investigated the expression of CK7 and CK20 in inflammatory, metaplastic and neoplastic conditions of the bile ducts, and evaluated possible relationships between the CK expression pattern and extrahepatic bile duct/gallbladder carcinomas (EBDCs) or intrahepatic bile duct carcinomas (IBDCs). We used immunohistochemistry for the investigation of 48 formalin-fixed, paraffin-embedded specimens grouped as: A) lithiasic or inflamed surgically resected extrahepatic bile ducts/gallbladders: all were CK7+/CK20+; B) percutaneous liver biopsies from patients with chronic …
Chromophobe Renal Cell Carcinoma
1996
SUMMARY A case ofchromophobe renal cell carcinoma is reported in a 73 year-old man. Light microscopically, the tumor was composed of polygonal cells with a slightly eosinophilic and a fine reticular pattern, and a reaction of the cytoplasm with Hale's acid iron colloid. Ultrastructural analysis showed membranous microuesicles within the tumor cells, with degenerated mitochondria. Immunohistochemical profile against intermediate filaments was positive to cytokeratin 18 and negative against uimentin. Flow cytometry and cytogenetics revealed a predominant bypertriploid population. Few cases have been published with flow cytometry and cytogenetic findings. We report a new case.