Browsing by Subject "Cytokeratins"

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    An immunohistochemical study of cytokeratins distribution of the human adult male and female urethra
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Herrera Imbroda, B.; Aragón, I.M.; Hierro, M.I.; Álvarez, M.; Alaminos, M.; Campos, A.; Izeta, A.; Machuca, J.; Lara, M.F.
    Surgical treatment of diseases affecting long urethral areas represents a challenge in urology. Recent developments of tissue-engineered urethral substitutes represent a hope for patients. However finding an ideal tissue source for urethral reconstruction first requires proper understanding of the native human urethra physiology and a deep knowledge of the histological and molecular features of the native human urethra. Here we present a comprehensive characterization of male and female urethra by histological, histochemical and immunohistochemical methods with a panel of 15 antibodies. The results demonstrated that the histology of the male and female urethra depend on the area where the sample is taken along its length. Proximal areas of male and female urethra have differential expression of the epithelial basal and suprabasal layer markers CK14 and CK10 which distinguished the prostatic/ membranous and proximal female urethra from the bulbar/penile and distal female areas of the urethra. The distal male (penile) and female may be further divided by the distinct expression pattern of CK19. On the other hand, the expression of CK5/6 and CK19 also make a distinction of the proximal and distal female urethra. These results should facilitate a more informed selection of donor graft tissues for urethral replacement. Besides, novel bioengineered urethral tissue approaches should take into account the characterization of the different areas of the urethra presented in this work.
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    Bronchial epithelium associated to lymphoid tissue does not selectively express vimentin
    (Murcia : F. Hernández, 1997) Alonso, L.M.; Cortés, A.; Barrutia, M.G.; Romo, T.; Varas, A.; Zapata, A.G.
    The existence of a lymphoepithelium containing M cells in the bronchus-assmiated lymphoid tissue (BALT) of severa1 species has repeatedly been questioned. In previous electron microscopical studies we failed to ultrastmcturally identify these cells in the epithelium covering bronchial lymphoid tissue of adult rats. In the present study, we analyze immunohistochemically the expression of vimentin, an intermediate filament, reported to be a sensitive marker for rabbit M cells, in both BALT and Peyer's patches. Our results demonstrate, however, the absence of vimentin expression in the epithelium covering the bronchial lymphoid aggregates as well as in the lymphoepithelium of the Peyer's patches. On the contrary, both epithelia are strongly cytokeratin positive. Furthermore, numerous vimentin-positive lymphocytes appear in both lymphoid organs. Results are discussed from a view of the possible relationship between BALT and the so-called mucosaeassociated lymphoid tissue (MALT).
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    Changing pattern of cytokeratin 7 and 20 expression from normal epithelium to intestinal metaplasia of the gastric mucosa and gastroesophageal junction
    (Murcia : F. Hernández, 2002) Jovanovic, I.; Tzardi, M.; Mouzas, I.A.; Micev, M.; Pesko, P.; Milosavljevic, T.; Zois, M.; Sgantzos, M.; Delides, G.; Kanavaros, Panagiotis
    It is currently unclear whether intestinal metaplasia at the esophagogastric junction and in the distal esophagus represent a continuum of the same underlying disease process, i.e., gastroesophageal reflux, or constitute different entities with a diff e r e n t pathogenesis. Biopsies below the Z line might show specialized epithelium in some patients and the question is whether this is another form of short segment Barrett’s esophagus or whether it is related to a generalized atrophic process of the stomach. Data from recent studies regarding the expression of cytokeratin CK7 and CK20 in intestinal metaplasia (IM) found at the gastroesophageal junction are conflicting. Prompted by these data we undertook the present study: a) to evaluate the expression of CK7 and CK20 in IM of the gastric cardia and to compare the findings with those in patients with Barrett’s esophagus and IM of the gastric corpus and antrum mucosa; and b) to evaluate the immunophenotype of non-intestinalized cardiac mucosa and to compare it with that of normal gastric epithelium. We studied the expression of CK7 and CK20 on biopsy specimens from patients with long-seg m e n t B a r r e t t ’s esophagus (n=17) and surgical resection and biopsy specimens of gastric cardia (n=15), corpus (n=14) and antrum (n=22) from patients with histological evidence of IM. Eighty-four biopsy specimens from 42 patients (antrum n=15, corpus n=20, cardia n=7) without evidence of IM were studied as a control group. We observed an immunophenotype characterised by diffuse moderate to strong CK7 staining on the surface and crypt epithelium combined with strong CK20 staining on the surface and superficial part of the crypts in 94.1% (16/17) of the cases with long-se g m e n t Barrett’s esophagus, but in none of the 36 cases with IM in distal stomach (antrum and corpus). IM in the gastric cardia expressed the immunophenotype seen in IM of the gastric mucosa in 93.3% (14/15) of the cases. On the other hand, normal cardiac epithelium expressed patchy strong CK7 staining on the surface epithelium and on both, superficial and deep parts of the pits combined with patchy strong CK20 staining on the surf a c e epithelium and superficial pits, a feature permitting distinction of the normal cardiac epithelium from those of the normal gastric antrum and corpus epithelium. We conclude that the expression of cy t o keratins 7 and 20 can be used to distinguish the origin of IM of the gastroesophageal junction. The CK7/20 immunophenotype of IM in the gastric cardia closely resembles that of the IM in the gastric antrum and corpus and is different from IM in long-segment Barrett's esophagus. In contrast, the CK7/20 immunophenotype of the cardiac epithelium is different from that of the gastric antrum and corpus mucosa, suggesting that cardiac epithelium might not be a native normal g a s t r i c epithelium but one that is acquired as a consequence of longstanding inflammation. Changing pattern of CK7 and CK20 expression from normal to intestinalized epithelium suggests that IM arising from cardiac epithelium might have distinctive features.
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    Comparative cytokeratin distribution patterns in cholesteatoma epithelium
    (Murcia : F. Hernández, 2007) Olszewska, E.; Sudhoff, H.
    Cytokeratins (CKs) are known as the intermediate filament proteins of epithelial origin. Their distribution in human epithelia is different according to the type of epithelium, state of growth and differentiation. We used monoclonal mouse antibodies against cytokeratins to study CK expression in the following human tissues: cholesteatoma, middle ear mucosa, glandular epithelium, and meatal ear canal epithelium. Immunohistochemical processing was performed using the labeled steptavidin peroxidase method to demonstrate the presence of CKs in cells of human epidermis. Positive reaction was obtained for CK4, CK34ßE12, CK10, CK14 in skin and cholesteatoma epithelium. However, a more extensive positive reaction with those CKs was observed in cholesteatoma epithelium. Positive immunoreactivity was seen with anti- CK19 in the glandular epithelium. Middle ear mucosa specimens revealed positive immunoreactivity with the antibodies against CK4. The expression of CK4 was definitely positive within the basal layers of the epidermis. The glandular epithelium showed no positive reaction with anti- CK4, anti- CK34ßE12, anti- CK14 and anti-CK10. Immunohistochemistry for CK18 showed no reaction in all examined tissues. Cholesteatoma is known as a proliferative disease in the middle ear which pathogenesis is not completely understood. Keratinocytes express hyperproliferation- associated CKs and after reaching the suprabasal layers they finally undergo apoptosis creating keratinous debris. Cytokeratin expression observed in the epithelium explains proliferative behavior of cholesteatoma which is associated with increased keratinocyte migration. Cytokeratins can be used as potential proliferative markers. It can also allow for searching the usefulness of inhibiting regulators in the treatment of hyperproliferative diseases.
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    Immunohistochemical and lectin histochemical analysis of the alpaca efferent ducts
    (Murcia : F. Hernández, 2009) Parillo, F.; Magi, G.E.; Diverio, S.; Catone, G.
    An immunohistochemical and lectin histochemical study of the efferent ducts was performed in the alpaca. Two types of epithelium, consisting of principal and ciliated cells, were detected on the basis of the different cytokeratins expression and lectin binding pattern. AE1/AE3 and 13 cytokeratin antibodies intensely immunostained the entire cytoplasm of type I PCs, whereas AE1/AE3, but not anti cytokeratin 13, immunoreacted in type II principal cells along the apical, lateral and basal plasma-membrane. The histochemical characterization of the epithelial cells was carried out using a battery of different lectins: Con-A, UEA-I, LTA, WGA, GSA-II, GSA-IB4, SBA, PNA, ECA, DBA, MAL-II and SNA. Sialidase digestion and deglycosilation pre-treatments were also employed. In type I principal cells, the staining of the Golgi zone was interpreted giving evidence for the synthesis and secretion of O- and N-linked oligosaccharides. In particular, a-Man/a-Glc, GlcNAc, ß-Gal-(1-4)-GlcNAc, Neu5Aca2,3Gal and Neu5Aca2,6Gal/GalNAc residues were included in both O- and N-linked glycans, whereas a-Fuc, ß-GalNAc and a-Gal were only found in Olinked oligosaccharides; a-GalNac and ß-Gal-(1-3)-DGalNAc were found subterminal to sialic acid moieties and they were included in O- and N-glycans. In type II principal cells, the lectin staining was observed in the apical cytoplasmic granules and in vacuoles that were interpreted as components of an elaborate endocytotic apparatus specialized for the uptake of particulate material and fluid from the lumen. These results suggest the existence of two structurally different epithelial segments along the ductuli efferentes of the alpaca, with a high degree of compartmentalization of the secretory and absorptive activities.
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    Recent advances in the biology of colorectal cancer
    (Murcia : F. Hernández, 1996) Grogan, L.; Behan, K.A.; Johnston, P.G.
    The identification of the precise molecular defects responsible for the common forms of inherited colorectal cancer has significantly advanced our understanding of both inherited and sporadic disease. These advances coupled with a rapid accumulation of information on the molecular genotype and biological phenotype of colorectal cancer have identified potential markers that may prove to be not only of prognostic value but also important as screening tools and therapeutic targets. These molecular and biological features include replication errors, mutations of oncogenes and tumor suppressor genes and expression of tumor specific antigens and cytokeratins. This review highlights important recent advances that further our understanding of the biology and genetics of colorectal cancer.