Browsing by Subject "Conjunctiva"

Now showing 1 - 4 of 4
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    Epithelial component and intraepithelial lymphocytes of conjunctiva-associated lymphoid tissue in healthy children
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Cano-Suárez, Magnolia T.; Reinoso, Roberto; Martín, Carmen; Calonge, Margarita; Vallelado, Ana I.; Fernández, Itziar; Corell, Alfredo
    . Conjunctiva-associated lymphoid tissue (CALT) plays a key role in protecting the eye surface by initiating and regulating immune responses. The aim of this study was to investigate in healthy children the proportion of intraepithelial lymphocytes (IELs), the degree of viability and/or apoptosis and cell proliferation in three different topographic areas of the conjunctiva. Superior tarsal, superior bulbar, and inferior tarsalbulbarfornix conjunctival cells were collected by brush cytology (BC) from 24 healthy paediatric subjects (13 boys and 11 girls, mean age 6±2 years) who were to undergo strabismus correction surgery under general anaesthesia. Subsequently, these cells were analysed phenotypically and functionally by flow cytometry (FC). Flow cytometry analysis showed that not all the cells obtained by BC were of the epithelial lineage, but that there was a population of CD45+ cells (IELs) regularly present in the conjunctiva of healthy children. These IELs were mostly T-lymphocytes (CD3+) and Blymphocytes (CD19+), with higher levels of Tlymphocytes (CD3+) in the upper areas than in the inferior tarsal-bulbar-fornix, where the highest levels of B-lymphocytes (CD19+) were found. In the apoptosis assay, two groups of cell populations were differentiated by cell size and complexity (cytoplasmic granularity), with more complex cells predominating in the upper areas of the conjunctiva and less complex cells being more abundant in the inferior tarsal-bulbar-fornix. Finally, the proliferative capacity of the conjunctival epithelium was significantly higher in the upper tarsal zone than in the rest of the zones analysed. These results suggest that the epithelial component and the IELs of CALT are also regularly present in the conjunctiva of the healthy child, varying in phenotype, viability and cell proliferation according to the different conjunctival regions analysed, which could lead us to believe that each conjunctival zone plays a different, specific role in the regulation of the immune response at the ocular level.
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    Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma
    (Murcia : F. Hernández, 2004) Chan, Ch.Ch.; Smith, J.A.; Shen, D.; Ursea, R.; LeHoang, P.; Grossniklaus, H.E.
    Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal marginal zone B-cell lymphoma that is characterized by an exaggerated clonal expansion of B cells, which implicate a pathological proliferative response to antigen(s) including bacteria. Helicobacter pylori (H. pylori) infection is recognized as one of the causative agents of gastric MALT lymphoma; however, it has not been reported in extra gastric MALT lymphoma. We studied 5 patients (4 adults and 1 child) with salmon-colored conjunctival lesions. One patient also had a history of abnormal bone marrow biopsy a year earlier with lymphoid aggregates involving 5% of the overall bone marrow. The conjunctival lesions of the 5 patients were biopsied. Histopathological diagnoses were consistent with conjunctival MALT lymphoma. Lymphoma and normal conjunctival cells were microdissected using laser capture microscopy or manual techniques. DNA was extracted and subjected to PCR amplification using H. pylori gene-specific primers from the urease B and vac/m2 gene. Cells from chronic conjunctivitis (normal lymphocytes), conjunctival human T-cell lymphotropic virus type-1/adult T-cell leukemia/lymphoma (HTLV- 1/ATL), and orbital B-cell lymphoma were also microdissected, processed and analyzed. PCR amplification and Southern blot hybridization demonstrated H. pylori DNA in the conjunctival MALT lymphoma cells of 4/5 cases. The negative case was the one with a history of abnormal bone marrow. In contrast, H. pylori gene was not detected in normal conjunctival cells from the cases of MALT lymphoma or the lymphocytes, ATL and orbital B-lymphoma cells from the controls. These data suggest that H. pylori may play a role in conjunctival MALT lymphoma.
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    The histological and the histopathological pattern of conjunctival rhinosporidiosis associated with papillomavirus infection
    (Murcia : F. Hernández, 1989) Sunbal, M. S. Noor; Al-Ali, Saad Y.
    The present study describes for the first time, the clinical, light and electron microscopic findings of two cases of conjunctival rhinosporidiosis. One was with concurrent infection of papillomavirus. Investigations at the ultrastructural leve1 have provided additional information on the development of Rhinosporidium seeberiand would suggest that the formation of the wall of this organism is a continuous morphological and biochemical spectrum throughout its cytological maturation. The current observation on the wall formation is probably a modification of the classical pattern as an environmental protection carried out by the fungus against the virus. In contradistinction to the usual histopathological picture of rhinosporidiosis, the case with the viral infection lacked the characteristic marked inflammatory reaction. This finding, together with the relatively short interval of the frequent recurrences of this lesion, have led us to postulate the presence of a localised acquired immune deficiency state. It is possible that this local immune deficiency may be caused by an immunosuppression mechanism. This is probably mediated by papillomavirus andlor due to the weak antigenicity of the host virus-infected cells which contain only copies of viral DNA in an unintegrated form.
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    Tissue and molecular events in human conjunctival scarring in ocular cicatricial pemphigoid
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Razzaque, M. S.; Foster, C. S.; Ahmed, A. R.
    Detail ed histomo rph ometric analysis of human conjunctiva l biopsy specimens has convincingly demonstrated that tissue remodeling of the extracellular matri x (EC M) is an esse nti al and dy nami c process associated with conjuncti val sca rring in ocul ar cicatricial pemphi go id (OCP). The co njun cti va l sca rring ofte n eventuall y results in impaired vision and/or blindness. The molecul ar mechanisms of conjunctival scarring are not compl etely und erstood. Acc umulating evidence indicates that the earl y phase of conjunctival fibrosis is linked with an immuno-inflammatory process medi ated by cy tokines released by ac tiva ted conjunctiv al cells and/or by infiltrating cells. Fibrogenic cytokines secreted by infl ammatory cells and fibroblasts might acti vely be in vo lve d in remode lin g o f th e matri x within th e conjunctival stroma, possibly by regul ating the altered metabolism of matrix proteins.