Browsing by Subject "Urothelium"

Now showing 1 - 4 of 4
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    Cytokeratin expression patterns in normal and malignant urothelium, a review of the biological and diagnostic implications
    (Murcia : F. Hernández, 1999) Southgate, J.; Harnden, P.; Trejdosiewicz, L.K.
    The cytokeratins are the intermediate filament proteins characteristic of epithelial cells. In human cells, some 20 different cytokeratin isotypes have been identified. Epithelia1 cells express between two and ten cytokeratin isotypes and the consequent profile which reflects both epithelial type and differentiation status may be useful in tumour diagnosis. The transitional epithelium or urothelium of the urinary tract shows alterations in the expression and configuration of cytokeratin isotypes related to stratification and differentiation. In transitional cell carcinoma, changes in cytokeratin profile may provide information of potential diagnostic and prognostic significance. The intensification of immunolabelling with some CK8 and CK18 antibodies may underly an active role in tumour invasion and foci of CK17-positive cells may represent proliferating populations. Loss of CK13 is a marker of grade and stage and de novo expression of CK14 is indicative of squamous differentiation and an unfavourable prognosis. However, perhaps the most important recent finding is the demonstration that a normal CK20 expression pattern is predictive of tumour non-recurrence and can be used to make an objective differential diagnosis between transitional cell papilloma and carcinoma. This review will consider cytokeratin expression in urothelium and discuss the application of cytokeratin typing to the diagnosis and prognosis of patients with TCC.
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    lmmunohistochemical demonstration of secretory IgA in human urothelium
    (Murcia : F. Hernández, 1995) Sirigu, P.; Perra, M. T.; Turno, F.; Usai, E.
    The mucosal surface of the human urothelium represents a very large exposure area to exogeoous agents, including potentially harmful microorganisms. Male human urothelium was treated for the immunohistochemical demonstration of secretory IgA (sIgA) in order to verify its own possible antimicrobial properties. An intense immunoreactivity for sIgA was observed in the apical cells of the urethral and vesical epithelia. The ureteric epithelium, at the lumina1 surface, showed discontinuous areas of less dense or completely absent reaction product. A less intense immunoreactivity was observed in the pelvic apical epithelial cells. The results suggest that sIgA play a prominent role in the local defence mechanisms of the lower urinary tract against ascending infectqns, whereas in the upper urinary tract the immuno-specific local defences seem reduced.
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    Staining patterns of keratins in the human urinary tract
    (Murcia : F. Hernández, 2009) Alonso, Angélica; Ikinger, Uwe; Kartenbeck, Jürgen
    The keratins, members of the intermediate filament family, are characteristically expressed in epithelial cells. In the various types of epithelia, the keratin expression pattern is characterized by cell-type specific combinations of the keratin isotypes with a plain pattern in monolayered (simple) epithelia and more complex patterns in stratified and pseudostratified epithelia. Here we demonstrate that the transitional epithelium of the human urinary tract holds an exceptional position between the pseudostratified and stratified epithelia. We show that the simple epithelia keratins 7, 8, 18 and 19 are expressed throughout the whole epithelium as known from pseudostratified epithelia. In addition, we demonstrate expression of keratins 5, 14 and 17, otherwise present in basal cells of multilayered epithelia, and keratins 4 and 13, present in suprabasal areas of non cornified multilayered epithelia. Moreover, we report differences in expression in the various morphological parts of the urinary tract which might be related to their specific functions. Keratin 20, a typical component of the simple epithelia of the digestive tract, is present in bladder and ureter but not in the renal pelvis. Keratin 6, typical for stratified epithelia, is found only in parts of the renal pelvis. We further show that changes in keratin pattern occur during the development from embryonic to adult bladder urothelium. In contrast to adult tissue, the simple type keratins 7, 8 and 18 are not synthesized in basal embryonic cells. Further, keratin 20, present in cells facing the bladder lumen in adult urothelium, is expressed in all but the basal cells in embryonic bladder.
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    Transitional papillary cell carcinoma of the ureter, a histological and ultrastructural study
    (Murcia : F. Hernández, 1994) Melis, M.; Petrozza, V.; Pulvirenti, S.; Eleuteri, E.; Mosca, A.; Angelini, L.; Carpino, F.
    We report a case of transitional papillary carcinoma of the distal left ureter. The histological and ultrastructural features were seen and compared by SEM and TEM. Observations confirm the data of literature that the deep cells of neoplasm are a normal morphological finding while the superficial cells do not have the characteristics present in normal transitional cells. In addition, SEM shows small groups or single cells with ccpleomorphic microvilli>, on the cell surface. These, in ureter, confirm the studies of many authors who have observed these abnormalities in carcinomas of several organs like breast, colon, liver and mesothelium.