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At least 487 records · Page 27Linked to original sources
PubMed1998

Distribution of antioxidant enzymes in the normal aged human conjunctiva: an immunocytochemical study.

BACKGROUND: The purpose of the study was to map the precise location of four antioxidant enzymes in the normal human conjunctiva. METHODS: Conjunctival tissue (seventeen specimens) from seven patients was processed for light microscopy and immunogold electron microscopy. Antibodies were used to label glutathione peroxidase, glutathione S-transferase (acidic and neutral forms) and copper/zinc superoxide dismutase. RESULTS: All layers of the epithelium exhibited labelling for all four enzymes, although there were differences in labelling intensities and distribution between the enzymes. Wing cells showed more intense labelling for glutathione peroxidase, glutathione S-transferase (neutral form) and copper/zinc superoxide dismutase than did basal and superficial cells. The strongest immunoreactivity was detected for glutathione S-transferase (acidic) and was equally strong in the superficial and wing cells. Wing cells demonstrated more immunoreactivity in the cell nuclei with antibodies against all four enzymes. A high degree of labelling was also observed in the microplicae and actin cortex of the superficial cells. Leukocytes, fibroblasts, endothelial cells and erythrocytes within the stroma exhibited minimal labelling. CONCLUSION: The subtle changes in distribution of antioxidant enzymes in the normal human conjunctival epithelium most probably reflect exposure to free radicals in the tear film and are based on the different proliferative and functional activities of each of the anatomical layers.

Aged↗
PubMed2006

Primary mantle cell lymphoma of the conjunctiva: a case report.

Primary non-Hodgkin's lymphomas of the conjunctiva are uncommon. They are almost exclusively extranodal marginal zone B-cell lymphomas/mucosa-associated lymphoid tissue lymphomas. In this study, we report an extremely rare case of conjunctival mantle cell lymphoma in a 78-year-old man, presenting as a unilateral epibulbar mass.

Aged↗
PubMed1976

Malignant melanomas of the conjunctiva.

A retrospective study of 23 conjunctival melanomas using the Clark classification revealed that the three most common forms of melanoma described in the skin--lentigo maligna melanoma (Hutchinson's freckle with melanoma), superficial spreading melanoma, and nodular melanoma--can be recognized in the conjunctiva. As in the skin, lentigo maligna melanoma appears to be associated with a good prognosis compared to the prognosis associated with superficial spreading melanoma. These two forms of melanoma are both associated with an intraepithelial stage and had previously been grouped under one designate, cancerous melanosis. They can be distinguished histologically although definite clinical differentiation will be determined in the future. Some melanomas with an intraepithelial stage, however, cannot be definitely classified. Relating all conjunctival cancerous melanoses to Hutchinson's melanotic freckle is no longer justified.

Adult↗
PubMed1976

Plasma cell infiltration of the conjunctiva associated with pancytopenia, dermatitis, and polyclonal gammopathy.

A 73-year-old man developed conjunctivitis, epiphora, pancytopenia, dermatitis, and a polyclonal gammopathy. Diffuse infiltration and thickening of the conjunctiva and lacrimal canaliculi by plasma cells was present. Histopathologic examination suggested a reactive, chronic inflammatory response rather than neoplasia. The patient's ocular manifestations appeared to be related to his pancytopenia, dermatitis, and polyclonal gammopathy.

Aged↗
PubMed1976

Beta-ray treatment of malignant epithelial tumors of the conjunctiva.

Fifteen patients with malignant epithelial tumors of the conjunctiva were treated with beta-ray ocular applicators filled with radioactive strontium and yttrium (90Sr/90Y). Histologic examination confirmed the diagnosis. There were ten squamous cell carcinomas, four carcinomas in situ, and one case of epidermidalization. In one patient, who may have received an insufficient dose, recurrence led to enucleation. Radiogenic complications-secondary glaucoma and corneal degeneration-caused visual loss in two other patients. All of the other tumors disappeared completely without seriously affecting the eyes. Beta-ray irradiation with 90Sr/90Y applicators was effective if a sufficient dose (15,000 to 18,000 rads) was applied to the tumor surface and if the height of the tumor did not exceed 5 mm.

Adult↗
PubMed1979

Allergic granulomatous nodules of the eyelid and conjunctiva. The XXXV Edward Jackson Memorial Lecture.

We studied the clinical and pathologic features of 22 cases of granulomas of the conjunctiva or eyelids. All cases showed the histologic features of the Splendore-Hoeppli phenomenon, that is, a giant cell and eosinophil granulomatous reaction to an antigen-antibody precipitate originally described in relation to parasites or fungi. In four of seven typical cases selected for detailed description unidentified nematodes were found to be the cause of the condition. In light of these findings together with a review of similar "allergic granulomas" reported both in ocular tissues and elsewhere in the body, we considered the cause in the remaining cases. All 22 cases may have been caused by nematodes, as seems, probable in 14 of them, or the causative antigens may have been of widely different kinds. Although in our cases all ocular granulomas had an identical histology, this study did not resolve the problem of those cases where no causative agent was found. Thorough investigation of such cases in the future and the demonstration of their cause may elucidate the wider problem of nonocular allergic granulomas.

Adolescent↗
PubMed1979

Application of specific red blood cell adherence test to the human cornea and conjunctiva.

We modified the specific red blood cell adherence test used in the study of blood group antigens to apply to the human cornea and conjuctiva. For the first time this test was applied to these ocular tissues with considerably specificity and sensitivity. The test revealed a concentration of blood group antigens in the epithelium of cornea and conjunctiva and along the corneal endothelium, whereas it was absent in the stroma. The test is useful in studying ABO compatibility in corneal transplants.

ABO Blood-Group System↗
PubMed1980

The clinical and morphologic characteristics of Kaposi's sarcomas of the conjunctiva.

A 77-year-old woman with known Kaposi's sarcoma of one year's duration developed nodular lesions of her right palpebral conjunctiva. Biopsy confirmed sarcomatous involvement and local resection was performed. Despite leaving residual tumor, there was complete regression of the eyelid tumor three years after the resection. Electron microscopic studies characterize this neoplasm as a proliferation of primitive endothelial cells and pericytes, the two cell lines that compose a capillary wall.

Aged↗
PubMed1995

Nitric oxide induces vascular permeability changes in the guinea pig conjunctiva.

The role of nitric oxide (NO) as an inflammatory mediator in the mechanism of increased microvascular permeability was examined in a guinea pig model of allergic conjunctivitis. Topical challenge with antigen, compound 48/80, histamine or platelet activating factor (PAF) resulted in a marked increase of the conjunctival vascular permeability. Vascular permeability was determined by measuring the albumin content in the lavage fluid of the challenged eyes after 30 min. Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME) eyedrops caused a significant inhibition of the clinical score and the vascular permeability after challenge with either antigen, histamine or PAF. Aminoguanidine prophylaxis also resulted in a significant inhibition of both the clinical score and vascular permeability in response to all the used provocative agents except PAF. Our observations indicate that NO is an important factor in the induction of the vascular permeability provoked by histamine but seems to play no role in the mechanism by which PAF exerts increased vascular permeability in the conjunctiva.

Albumins↗
PubMed1985

Biochemical transformation of bulbar conjunctiva into corneal epithelium: an electrophoretic analysis.

When the entire corneal epithelium of the rabbit is mechanically removed, the denuded corneal stroma is completely resurfaced in 5-10 days with cells of conjunctival origin. The conjunctival cells differ from the corneal epithelial cells both morphologically and biochemically; however, within approximately 6 weeks, the conjunctival cells are converted into functional cornea epithelial cells. Using high-resolution agarose-gel electrophoresis, we compared the soluble proteins from functional conjunctiva (CON), functional corneal epithelium (EPI), and 'regenerating' corneal epithelium at eight intervals ranging from 24 hr to 6 weeks post-scraping. Comparison of CON and EPI patterns shows nine major mobility classes of proteins that fall into three subgroups: A = anodal, B = intermediate, and C = cathodal. The nine major classes have marked similarity in distribution and mobility, which may account for the apparent ease with which CON can transform into EPI during regeneration. Electrophoretic patterns of soluble proteins from regenerating epithelium suggest that the regeneration process occurs in three distinct phases: 24-72 hr post-scraping is a period of de-differentiation, 72 hr to 1 week is a period of reorganization, and 1-6 weeks is a period of differentiation. Specific protein groups are identified that represent fast-transforming, slow-transforming, conjunctival-specific, and corneal-specific proteins. Certain of these protein groups can be associated with particular stages in the regenerative process.

Animals↗
PubMed1991

The distribution and origin of substance P immunoreactive nerve fibres in the rat conjunctiva.

Indirect immunohistochemistry was used to examine the presence and origin of substance P immunoreactive nerve fibres in the rat conjunctiva. Fluorescent substance P immunoreactive nerve fibres were visualized both in the epithelium and stroma, their number being higher in the stroma where they were associated with blood vessels, the smooth muscle of Müller and the Meibomian glands. Ten to twenty percent of the ganglion cells in the trigeminal ganglion were immunoreactive to substance P, most of them being small in size. Sensory denervation by electrocoagulating the ophthalmic and maxillary branches of the trigeminal nerve caused a complete disappearance of the epithelial fibres and greatly reduced the number of the stromal fibres. These results indicate that the majority of the demonstrated fibres are sensory nerves originating from the trigeminal ganglion. Since sympathectomy had no detectable effect on the number or distribution of substance P immunoreactive nerve fibres, and since some of the fibres remained after sensory denervation it is suggested that at least some of the remaining fibres could be of parasympathetic origin.

Animals↗
PubMedDate not supplied

Squamous cell carcinoma of the conjunctiva. Value of exfoliative cytology in diagnosis.

Cytologic examination is of potential value to the practicing ophthalmologist in confirming the clinical impression of cancer of the eye. Scrapings of conjunctival lesions can be prepared in the office, stained with Giemsa stain and rapidly examined. Carcinoma in situ and squamous cell carcinoma of the bulbar conjunctiva were presented as illustrations of the usefulness of exfoliative cytology in clinical ophthalmology.

Adult↗
PubMed1991

Mast cell numbers and staining characteristics in the normal and allergic human conjunctiva.

In this study we report the numbers and metachromatic dye-staining characteristics of mast cells (MCs) in the conjunctiva of normal subjects and patients with seasonal allergic conjunctivitis caused by pollenosis. In addition, we have used a monoclonal antibody to the MC-specific enzyme, tryptase, to enumerate tryptase-positive cells immunohistochemically. Tarsal conjunctival MCs were found to be present in increased numbers in the allergic compared to the nonallergic subjects. Most of the MCs exhibited staining that was formaldehyde resistant, compatible with their identification as connective tissue MCs or basophils. The high positive staining for tryptase confirmed that the metachromatic cells stained with toluidine blue were MCs and not basophils, both in normal and allergic subjects.

Adult↗
PubMed1993

Allergic subjects express intercellular adhesion molecule--1 (ICAM-1 or CD54) on epithelial cells of conjunctiva after allergen challenge.

BACKGROUND: Allergic inflammation can be experimentally reproduced in vivo in humans, by means of the conjunctival provocation test with allergen. The allergen stimulation triggers an early clinical response and an almost simultaneous cellular infiltrate. Among the factors that can contribute to the local cellular recruitment, we postulate a possible early involvement of CD54 in the development of inflammation caused by the allergic reaction. METHODS: We used a sensitive immunocytochemical immunoenzymatic alkaline phosphatase-monoclonal antialkaline phosphatase technique to detect the possible expression of CD54 molecule on epithelial cells of conjunctiva in 15 allergic subjects and in 15 healthy individuals in basal conditions and after allergen challenge (Parietaria judaica) during the off-pollen season. RESULTS: At baseline all studied individuals did not evidence CD54 expression on epithelial cells; 30 minutes after allergen challenge, all the allergic individuals showed a marked expression of CD54 on conjunctival epithelium, whereas none of healthy subjects showed any CD54 expression. First, CD54 expression on conjunctival epithelium after specific provocation test appeared as a specific phenomenon occurring only in sensitized subjects; moreover, it is an immediate event concomitant with the local inflammatory infiltrate. Therefore conjunctival epithelium unexpectedly appeared to be more than a bystander in the allergic reaction; it may be perceived as an active participant interacting with the inflammatory infiltrate. CONCLUSIONS: These findings indicate that CD54 may play a central role in the allergic inflammation and strongly support the concept that maneuvers designed to interact with the adhesion machinery expressed on inflammatory cells and epithelium may be a helpful therapeutic approach.

Adult↗
PubMed2004

Resuturing the scleral flap through conjunctiva for treatment of excess filtration.

PURPOSE: To elevate the intraocular pressure (IOP) in eyes with persistent hypotony caused by excess filtration after trabeculectomy. DESIGN: Interventional case series. METHODS: The scleral flap was sutured directly through the conjunctival flap using a round, tapered needle with a 10-0 nylon suture. This procedure has been performed in 10 eyes. RESULTS: The IOP elevated from 2.6 (+/- 1.0) mm Hg to 8.8 (+/- 3.7) mm Hg in 1 week and has been maintained between 6 to 14 mm Hg during the follow-up. Hypotony maculopathy has disappeared in nine eyes. The suture was buried in the conjunctiva spontaneously in 1 week in all cases. No complications developed. CONCLUSIONS: Suturing the scleral flap directly through the conjunctival flap is a simple and effective modality to treat the hypotony caused by excess filtration after trabeculectomy.

Conjunctiva↗
PubMed2003

Nadroparine inhibits the hypersensitivity response in the conjunctiva.

This study sought to investigate the effects of nadroparine on an in vivo experimental model of type I hypersensitivity response in the rat conjunctiva. Following drug application onto the eye, either before or after challenge with the mast cell degranulator, basic polyamine compound 48/80, the conjunctival histamine content and the nitrite levels in the conjunctival lavage fluid were quantified fluorometrically and spectrophotometrically, respectively. Instillation into the eye of nadroparine inhibited the C48/80-induced decreases in conjunctival histamine and the delayed increases in nitrite levels, without influencing basal mediator levels. Protamine did not induce histamine release and only partially reversed the effects of nadroparine post-challenge, yet it had no effect on the protective action of the drug when administered prior to degranulation. The results showed that nadroparine was equally effective in attenuating the effects of compound 48/80 in the eye when administered topically either before or after challenge.

Analysis of Variance↗
PubMed2006

Expression of bone morphogenetic proteins (BMPs), their receptors, and activins in normal and scarred conjunctiva: role of BMP-6 and activin-A in conjunctival scarring?

Bone morphogenetic proteins (BMPs) and activins are multifunctional growth factors, which also affect wound healing and tissue fibrosis. To determine their putative role in conjunctival wound healing and scarring, we investigated the expression of various BMPs, BMP receptors, and activins in normal and scarred human conjunctival tissue and in cultured human Tenon's capsule fibroblasts on the mRNA and protein level. Messenger RNA expression of BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, BMP-7, the BMP receptors type I (BMPR-IA, BMPR-IB) and II (BMPR-II), and of activin A and B was investigated by semi-quantitative RT-PCR in normal conjunctival specimens and in scarred filtering blebs as well as in cultured Tenon's capsule fibroblasts obtained from patients with primary open-angle glaucoma (POAG), pseudoexfoliation (PEX) glaucoma and cataract. Immunohistochemistry was used to study the protein expression of BMP-2, BMP-4, BMP-6, BMP-7, and activin A in normal and scarred conjunctival tissue as well as in cultured Tenon's capsule fibroblasts. BMP-2, BMP-3, BMP-4, BMP-6, BMP-7, all BMP receptors, and activin A were expressed on the mRNA and protein level in conjunctival biopsies without showing any differences between groups of patients. The mRNA and protein expression of both BMP-6 and activin A was found to be significantly increased in scar tissue compared with normal conjunctiva and could be immunolocalized to epithelial cells, vascular endothelia, stromal fibroblasts, and macrophage-like cells. However, no significant increase in receptor gene expression was observed in scar tissue. With the exception of BMP-7, all growth factors and receptors were also expressed in cultured Tenon's fibroblasts without showing any differences between cultures derived from normal and scarred conjunctival specimens. These findings suggest various BMPs and activin A as components of the conjunctival cytokine meshwork regulating tissue homeostasis and wound healing and provide evidence that alterations in the expression of BMP-6 and activin A, in particular, are associated with conjunctival scarring. Modulation of BMP/activin activities may, therefore, be explored as new approaches for managing postoperative conjunctival scarring responses in glaucoma patients.

Activins↗