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PubMed1997

Phenotypic analysis of resident lymphoid cells in the conjunctiva and adnexal tissues of rat.

The conjunctival associated lymphoid tissue is considered to be an integral part of the mucosal immune system. Under normal circumstances immune mechanisms in mucosal associated lymphoid tissue of the gut and bronchus can selectively suppress, rather than enhance, immune responsiveness to encountered antigens, inducing a state of tolerance. It is possible that conjunctival associated lymphoid tissue can also induce a state of tolerance to encountered antigens. Such a response may be exploited to modulate immune mediated ocular disease. Enhanced tolerance may protect the host against foreign antigen. Alternatively, under certain circumstances when the normal immune system is altered or disrupted the mucosal tissue may act to induce sensitisation and trigger immune mediated disease. The rat is frequently used as an animal model of immune mediated eye disease, but the normal profile of immune cells in the rat conjunctiva has not been studied. This information is essential for meaningful interpretation in the experimental situation. In this study we examined the immunophenotype of lymphoid tissue associated with the conjunctiva, lacrimal gland and Harderian gland of the Lewis rat. CD4+, Ia+ and the monocyte/macrophage population of cells were found predominantly in the substantia propria of the conjuctiva and interstitial connective tissue of the glands. CD8+ cells were distributed mainly in relation to the conjunctival and glandular epithelium. Goblet cells stained strongly with the monoclonal antibody (MAb) MRC OX-39, which is a marker for IL-2 receptors. The overall pattern of distribution of immunocompetent cells in the rat was found to be similar to that reported in humans.

Animals↗
PubMed2002

Initiation and characterization of keratinocyte cultures from biopsies of normal human conjunctiva.

The purpose of the present study was to establish and characterize serum-free epithelial cultures of normal human conjunctiva using fresh biopsy tissue. To this end, small pieces of normal conjunctiva were biopsied from patients undergoing routine cataract surgery. Fragments of the tissue were placed in explant culture in medium containing fetal bovine serum for approximately 1 week to promote epithelial cell outgrowth. Cultures were then passaged multiple times into serum-free medium. Cultures generated in this way were at least 95% keratinocytes and exhibited a typical epithelial morphology, which was dependent on the extracellular Ca(2+)concentration. Immunocytochemical staining revealed that E-cadherin, P-cadherin, and involucrin were present in the cultures, with distributions consistent with their in vivo localization patterns. Distribution of keratins 19, 3, and 4 in conjunctival epithelial cultures were also consistent with in vivo patterns and distinctly different from patterns observed in epithelial cultures similarly generated from cornea and foreskin. Hence, conjunctival keratinocyte cultures retain some tissue-specific markers and do not revert to a generic, culture phenotype.

Biopsy↗
PubMed1996

The central distribution of primary afferents from the external eyelids, conjunctiva, and cornea in the rabbit, studied using WGA-HRP and B-HRP as transganglionic tracers.

We have analyzed the afferent limb of the eyeblink and nictitating membrane response of the rabbit by tracing the central distribution of primary afferents from the periorbital skin, conjunctiva, and cornea using horseradish peroxidase agglutinated to wheat germ (WGA-HRP) or conjugated to choleragenoid (B-HRP) as transganglionic tracers. Afferents in the periorbital skin and conjunctiva distribute most heavily to pars caudalis of the spinal trigeminal nucleus (Vc) and to the dorsal horn of spinal segment C1 (dhC1). These afferents terminate predominantly in laminae IIo and IIi and more weakly to the adjacent laminae I and III. There are much weaker projections to spinal segment C2, rostral Vc, and adjacent reticular formation (laminae IV and V) and to the lateral part of pars interpolaris of the spinal trigeminal nucleus (Vi). No conjunctival primary afferents were seen in the rostral divisions of the trigeminal system. Weak afferent inputs from the periorbital skin are present ventrally in pars oralis of the spinal trigeminal nucleus (Vo) and in the principal trigeminal nucleus (Vp). Corneal afferents distribute most densely in the ventral part of Vi and in islands of neuropil within the trigeminal tract at the level of Vi. They also project to caudal Vc and the adjacent dhC1 in laminae I, II, and III. There are sparse projections to the ventral and dorsal parts of Vp and to the ventral part of Vo. Reticular areas adjacent to ventral Vi also receive a few corneal afferents. WGA-HRP- and B-HRP-labeled terminals were distributed similarly in most areas, but lamina I of Vc received terminals labeled with WGA-HRP and Vp and Vo received cutaneous afferents labeled with B-HRP only. Since all subdivisions of the trigeminal system receive periocular and corneal afferent inputs, we suggest that all these subdivisions may be involved in reflex eyeblinks in the rabbit.

Animals↗
PubMedDate not supplied

The effects of antiglaucomatous agents on conjunctiva used for various durations.

PURPOSE: The effect of antiglaucomatous agents on conjunctiva used for various durations evaluated histopathologically. METHODS: Conjunctiva biopsies were taken in 19 Mayis University Faculty of Medicine Ophthalmology Department from 31 eyes of 30 patients who underwent filtration surgery after a period of antiglaucomatous agent use and examined under light microscope. The results were compared with the results of conjunctival biopsies from 10 similar aged patients undergoing retinal detachment of cataract surgery and with no other ocular pathology. RESULTS: Five of the cases were using antiglaucomatous treatment for two months (Group A), four cases for two to 12 months (Group B) and 22 cases for more than 12 months (Group C) before the surgery. Four cases were using a beta blocker only, eight cases beta blocker + sympathomimetic or beta blocker + myotic and the remaining 19 cases were using a combination of beta blocker + sympathomimetic + myotic. Histopathologic evaluation with light microscope showed no pathologic change in group A, but, subepithelial increase of lymphocytes, mast cells, macrophages and fibroblasts in group C. CONCLUSIONS: It was detected that subconjunctival inflammatory reaction increases as the number of antiglaucomatous agents and the treatment duration increase. These changes might be considered as risk factors that decrease the success rate of filtration surgery.

Administration, Topical↗
PubMed1976

[Early alterations of the conjunctiva after alkali-burning (author's transl)].

Early alterations of the conjunctiva after alkaliburning (with 0.25 N NaOH) are described. After chemical damage, there is a nearly total loss of conjunctival epithelium, with simultaneous marked edema in the lower conjunctival parts. Alterations of the surface are examined by scanning electronic microscopy (SEM). Within 24 h marked infiltration of round cells into the conjunctival stroma takes place. After burning, we find a rapid decrease in the ATP level in the conjunctiva to about one-tenth of the normal value, whereas glucose and lactate showed only small alterations before and after chemical injury.

Adenosine Triphosphate↗
PubMed1993

Adult T-cell leukemia with leukemic cell infiltration in the conjunctiva. A case report.

A 77-year-old Japanese woman who had suffered from skin eruptions since 1986 was admitted in January, 1990. A diagnosis of adult T-cell leukemia/lymphoma (ATL) was made on the basis of clinical and laboratory data. On admission, erythematous lesions were present in both eyelids. Yellowish-white elevated lesions were found along the limbal conjunctiva, and extended segmentally into the cornea of both eyes. Microscopically, leukemic infiltration into the subepithelial layer of the conjunctiva was observed. Ophthalmic manifestations in ATL have not been well described, because of a little attention paid to them.

Aged↗
PubMed1988

Ultrastructure of the paralimbal and juxtacaruncular human conjunctiva.

The epithelial fine structure of the juxtacaruncular and the medial paralimbal human conjunctiva was evaluated. In both locations the following types of cells could be identified: (1) basal cells containing numerous intermediary filaments (dark basal cells); (2) basal cells containing many mitochondria (light basal cells); (3) wing cells (spinocytes containing numerous filaments that were fewer and formed smaller bundles than those of the dark basal cells; (4) flattened, dark superficial cells; (5) wing-cell-like superficial cells. In addition, the juxtacaruncular conjunctiva contained the following cell types: goblet cells, light wing cells containing a multitude of polysomes, light wing cells containing dilated profiles of rough endoplasmic reticulum (rare), and light wing cells containing numerous microtubules (rare).

Adolescent↗
PubMed1979

[Experimental microscopy and photography of the bulbar conjunctiva capillaries].

The authors worked out a new method of in vivo observation and microphotography of the rabbit bulbar conjunctiva capillaries in this experiment. A Soviet-made luminescent contact microscope LUMAM K-1 (LOMO) was employed. In general, maximal magnification of this microscope for visual observation equals more than 600. The photographs for this experiment were made with magnifications of 150 and 200. A 10% sodium fluorescein solution was injected in the ear vein before the experiment (0.2 ml/kg of the body weight). The 500-unit, sensitive film was used for the photographs. Microvessel diameter was measured on the film with the help of a stereocamparator. As the data obtained demonstrate, conjunctival capillary diameter varied from 3 to 9 mcm, averaging 8 mcm. This method of contact biomicroscopy permits to the performance of capillarography and capillaroscopy of bulbar conjunctiva along with quantitative evaluation of capillary parameters and some reological indicators.

Animals↗
PubMed2005

Fyn regulates eosinophil infiltration into the conjunctiva by downregulating the Th2 response.

PURPOSE: Under certain circumstances, fyn may serve to negatively regulate the differentiation of naïve helper T (Th) cells into Th2 cells. This study aimed to investigate whether fyn negatively regulates the development of experimental immune-mediated blepharoconjunctivitis (EC), in which Th2 cells play an important role in C57BL/6 mice. METHODS: C57BL/6 background wild-type (WT) or fyn knockout (fyn-/-) mice were subcutaneously immunized with ragweed (RW) adsorbed in aluminum hydroxide. Ten days later the mice were challenged with RW in eye drops, and 24 h after challenge, eyes, blood and spleens were harvested for histology, measurement of serum IgE, and proliferation or cytokine assays, respectively. RW-primed splenocytes from WT and fyn-/- mice were cultured in the presence of RW. Seventy-two hours later, either whole splenocytes or isolated CD4+T cells were transferred into syngeneic WT mice. Four days after the transfer, the recipient mice were challenged with RW and evaluated as described above. RESULTS: Infiltration of eosinophils into the conjunctiva induced by active immunization was significantly increased in fyn-/- mice relative to WT mice. Total serum IgE was also significantly higher in fyn-/- mice than in WT mice. In parallel, a higher level of IL-4 production from splenocytes was induced by concanavalin A stimulation in fyn-/- mice than in WT mice. In contrast to active immunization, transfer of whole splenocytes or separated CD4+T cells derived from WT or fyn-/- mice induced similar levels of eosinophilic infiltration in WT mice. CONCLUSIONS: Fyn regulates infiltration of eosinophils into the conjunctiva through downregulation of Th2 responses. This negative regulation is exerted only during the induction phase of EC.

Animals↗
PubMed1999

Immunoelectron microscopic study of the conjunctiva in cicatricial pemphigoid.

BACKGROUND: Immune deposits can be found on the conjunctival basement membrane zone of patients affected by cicatricial pemphigoid using immunofluorescence technique. The purpose of this study was to perform direct immunoelectron microscopy on the conjunctiva of patients with scarring conjunctivitis associated with cicatricial pemphigoid. METHODS: Conjunctival and skin biopsies were performed in six patients who presented with presumed autoimmune cicatrizing conjunctivitis associated with cicatricial pemphigoid. Specimens were processed for direct immunofluorescence and direct immunoelectron microscopy. RESULTS: Direct immunofluorescence was positive in all skin samples and in three of six conjunctival samples. Direct immunoelectron microscopy showed immune deposits in the lamina lucida and the lamina densa of all skin and conjunctival samples. CONCLUSIONS: Direct immunoelectron microscopy can be performed on the conjunctiva. It shows the precise localization of cicatricial pemphigoid target antigens within the conjunctival basement membrane zone.

Aged↗
PubMed2000

Expression of fucosyltransferases in skin, conjunctiva, and cornea during human development.

During human development, type-1-precursor, sialyl-Le a, and Le x antigens were present in the periderm of skin and eye at week 6. The Le x antigen disappeared from cornea at 10 weeks and then from skin at 20 weeks. H-type-1, Le a, Le b, sialyl-Le a, H-type-2, sialyl-Le x, and Le y were found in cornea, conjunctiva, and periderm between 10 and 20 weeks. They disappear from the skin (at week 20) and progressively reappear in skin derivatives, especially in the epithelium of sweat glands. The secretory part of the sweat gland is type-1-precursor and H-type-1 positive while its excretory part is Le a, Le b, sialyl-Le a, and Le y positive. On the eye surface the disappearance of Le x at 10 weeks and of the H-type-1, sialyl-Le x, and Le y at week 35 starts in the central cornea in front of the lens. The corneal epithelium and the conjunctiva have similar antigens to those of excretory and secretory parts of the sweat gland, respectively. Invaginations and folding of the epidermis might preserve the embryonic staining. We propose that fucosylation patterns are associated with the embryonic origin and differentiation stage of tissue. The early and transient presence of Le x is associated with FUT4 or FUT9 activities, while the late appearance of Lewis antigens is related to other alpha3-fucosyltransferases.

Carbohydrate Sequence↗
PubMedDate not supplied

Histological study on mast cells in conjunctiva of NC/Nga mice.

PURPOSE: To investigate the pathological findings in conjunctiva of NC/Nga mice, which develop atopic dermatitis spontaneously, we focused our study on the density of mast cells as determined by histological methods. METHODS: NC/Nga mice were divided into five groups; the 4W-group comprised four 4-week-old mice without treatment, the 10W-group comprised four 10-week-old mice without treatment, the 16W-group comprised four 16-week-old mice without treatment, the Dx group comprised three 16-week-old mice undergoing topical 0.1% dexamethasone (Dx) ointment treatment, and the FK506 group comprised three 16-week-old mice undergoing topical 0.1% FK506 ointment treatment. For the histological examination, the lids and eyeballs of the mice were removed and fixed with Carnoy's solution and thin sections were made. The Carnoy-fixed specimens were stained with toluidine blue or H&E and examined histologically. Toluidine blue-stained tissue sections were examined for the density per square millimeter of mast cells, which were identified as metachromatic cells in the conjunctival tissue and lid cutaneous tissue by light microscopy. RESULTS: Mast cell density in the conjunctiva was 8.6 +/- 8.2 cells/mm(2) in the 4W-group, 29.2 +/- 22.0 cells/mm(2) in the 10W-group, 41.0 +/- 21.1 cells/mm(2) in the 16W-group, 22.7 +/- 17.1 cells/mm(2) in the Dx group, and 33.6 +/- 27.7 cells/mm(2) in the FK506 group. Mast cell density increased significantly with age among the 4W-, 10W-, and 16W-groups ( P < 0.001). The mast cell density of lid cutaneous tissue was higher than the conjunctival mast cell density. Mast cell density was significantly higher in the 16W-group than in the Dx group, but not significantly higher than in the FK506 group. CONCLUSIONS: An increase in mast cell density with age indicates that NC/Nga mice develop atopic keratoconjunctivitis-like signs. Dexamethasone ointment has a suppressive effect on the increase in mast cell density.

Aging↗
PubMedDate not supplied

The effect of octreotide against oxidative damage in photosensitized conjunctiva and cornea of rabbits.

The purpose of this study was to determine the protective effect of octreotide against oxidative damage in rabbit conjunctiva and cornea exposed to ultraviolet radiation. Twenty rabbits weighing 2,500-3,000 g were used and we divided them into 4 groups with randomly selected 5 rabbits. Rabbits were exposed to 2 J/cm(2)/h of ultraviolet A radiation (UVA) in the range 320-405 nm for 12 h per day for 90 days. Group 1 did not receive any treatment or UVA exposure (control group). Group 2 was only exposed to UVA radiation (UVA group). Group 3 received 8-methoxypsoralen and UVA (PUVA group). Group 4 was treated with 8-methoxypsoralen + UVA + octreotide (octreotide group). At the end of 90 days the rabbits were killed by decapitation and then eyes were enucleated. Both eyes of each rabbit were used for histopathologic evaluation. Histopathologic analysis of each group indicated that UVA group and PUVA group showed increasing edema (p<0.01), inflammation (p<0.05), fibroblast proliferation (p<0.05), dysplasia (p<0.05), hyperchromasia (p<0.01) in the conjunctiva. Octreotide group had significant protective effect in comparison with the UVA group and PUVA group. The UVA group and PUVA group showed increasing proliferation (p<0.01), dysplasia (p<0.01), hyperchromasia (p<0.01), pyknosis (p<0.001) and parakeratosis (p<0.01) in the corneal epithelium. Octreotide group showed similar results with control group. We conclude that octreotide which is considered as free radical scavenger protects the eye from the damaging effect of UV exposure.

Animals↗
PubMed1975

Kaposi's sarcoma of the conjunctiva.

A 75-year-old man with known Kaposi's sarcoma of three-years' duration developed chronic hemorrhagic thickening of the conjunctiva. Biopsy demonstrated histopathologically that the conjunctiva thickening represented sarcoma involvement. Although surgically untenable, the conjunctival lesion responds satisfactorily to radiotherapy.

Aged↗
PubMed1979

Number of type of inflammatory cells in conjunctiva of asymptomatic contact lens wearers.

Biopsy specimens were taken from the upper tarsal conjunctiva of eight asymptomatic contact lens wearers and quantitative histology was determined and compared to histology from 15 normals and 55 patients with contact lens-induced giant papillary conjunctivitis. No abnormalities were detected in the asymptomatic contact lens wearers. One or more of the three tissue characteristics of giant papillary conjunctivitis--(1) mast cells in the epithelium, (2) eosinophils in epithelium or substantia propria, and (3) basophils in epithelium or substantia propria--was found in all patients with this syndrome, but none was present in any of the eight asymptomatic lens wearers. Trauma occurring over months or even years does not induce histologic alteration in the upper tarsal conjunctiva; the surface changes seen previously by scanning electron microscopy in asymptomatic lens wearers are secondary to trauma, not early aspects of the giant papillary conjunctivitis syndrome.

Adult↗
PubMed1991

High expression levels of the "erythroid/brain" type glucose transporter (GLUT1) in the basal cells of human eye conjunctiva and oral mucosa reconstituted in culture.

The expression of the "erythroid/brain" type glucose transporter (GLUT1) seems to be a feature of "barrier" tissues, at least in humans. Recently, we reported that GLUT1 is highly expressed in the basal layers of either "authentic" human epidermis or human epidermis reconstituted in culture and that its expression seems to be related to keratinocyte differentiation. In this paper we demonstrate that GLUT1 is selectively expressed in the basal layers of either eye conjunctiva epithelia or oral mucosa, reconstituted in culture starting from 1-2 mm2 bioptic specimens of normal human tissue. GLUT1 mRNA and protein levels are very high in conjunctiva and oral mucosa, 2-3 times higher than in epidermis reconstituted in culture. Taking into account its localization at the border of tissues not directly vascularized, but metabolically active, GLUT1 could play an important role in controlling the entry of glucose into these firmly guarded tissues.

Blotting, Northern↗
PubMed1987

Accumulation of unesterified cholesterol in limbal cornea and conjunctiva of rabbits fed a high-cholesterol diet. Detection with filipin.

Progressive cholesterol deposition frequently occurs in the corneas, tendons, and arteries of those individuals who have hypercholesterolemia. Many investigators have noted histochemical and chemical similarities in the nature of the lipid that accumulates in these tissues. Lipid-soluble dyes have been used to stain hydrophobic lipids such as cholesteryl ester and triglyceride in previous studies of corneal lipid deposits. In this report, deposits of unesterified cholesterol have been detected in the limbal cornea and conjunctiva of hypercholesterolemic rabbits using the fluorescent dye filipin. Whereas, oil red O-stained lipid accumulated both intra- and extracellularly, unesterified cholesterol accumulated extracellularly, similar to its predominant location in tendon xanthoma and atherosclerotic lesions. The source and mechanism by which unesterified cholesterol accumulates in limbal cornea and conjunctiva, tendons, and arteries remains to be determined.

Animals↗
PubMed1995

Possible existence of Na(+)-coupled amino acid transport in the pigmented rabbit conjunctiva.

The objective of the present study was to determine whether Na(+)-amino acid cotransport contributed to the short-circuit current (ISC) in the isolated pigmented rabbit conjunctiva. Glycine, L-arginine, D-arginine, and L-glutamic acid were the amino acids tested, and bioelectric measurements were made in the Using chamber. The ISC was increased from 4% (L-glutamic acid) to 44% (L-arginine). The EC50 was 0.35 mM for glycine, 0.06 mM for L-arginine, 0.16 mM for D-arginine, and 1 mM for L-glutamic acid. No elevation in ISC was seen in the absence of Na+ in the mucosal bathing fluid. The above findings are consistent with the possible existence of a Na(+)-amino acid cotransport process on the apical side of the pigmented rabbit conjunctiva.

Amino Acids↗