ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Interleukin-1 receptor and glucocorticoid receptor messenger ribonucleic acid (RNA) sequences coding for the corresponding proteins were detected in corneal epithelium, stromal fibroblast, and endothelial cells using the polymerase chain reaction and hot blotting. Identification of interleukin-1 receptor mRNA in each of the three major cell types of the cornea suggests that interleukin-1 α has autocrine and/or paracrine roles in the cornea, since previous studies have found that interleukin-1 α mRNA is produced in corneal epithelial, stromal fibroblast, and endothelial cells. Further investigation is needed to determine the functions regulated by the interleukin-1 receptor and glucocorticoid receptor in the cornea and the role of each in corneal wound healing.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

We have documented the inability of human corneal epithelial−like cells to suppress proliferation of peripheral blood leukocytes (PBLs) induced by allogeneic PBLs in a mixed leukocyte reaction (MLR). Instead, enhanced proliferation of PBLs, albeit small, was consistently noted as indicated by uptake of radiolabeled thymidine. Maximum proliferation of PBLs was detected when a mixed leukocyte reaction (MLR) was conducted in the presence of corneal cells. High levels of interleukin-1β(IL-1β) were found during MLR irrespective of the presence of corneal cells. High levels of IL-1β correlated well with observed synergistic stimulation of PBL proliferation by corneal cells and stimulating allogeneic PBLs. In PBL-corneal cell cocultures, PBLs produced IL-1β corneal cells contributed large amounts of prostaglandin E2(PGE2). Although indomethacin completely blocked prostaglandin E2production, it did not significantly alter the results. Our data show that PBLs and corneal cells can reciprocate each other's presence, and, under appropriate conditions, corneal cells can deliver at least one signal to enhance rather than suppress antigen-driven PBL proliferation. Our data suggest a role for immunoregulatory cytokines and prostanoids such as IL-1β and PGE2in these interactions.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Adherent leukomatous corneal opacities constitute the bulk of cases undergoing keratoplasty in developing countries. Surgical trauma to the iris resulting in a large iris coloboma, iridodialysis, and bleeding are the imminent intraoperative complications in such cases. We have evolved a technique of lamellar separation of corneal layers and gentle separation of adherent iris after partial trephination in such cases. We have successfully used this technique in six cases of adherent leukoma. No intraor postoperative complication related to lamellar separation was encountered, and all the grafts remained clear at the end of 3 months.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

94.6 nm) and variable up to 21 days postoperatively. Because the changes in interfibrillar spacing did not always mirror pachymetry changes in the frozen cases, we suspect occasional graft malapposition or the formation of intrastromal, fluid-filled, collagen-free “lakes.”

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

We tested the ability of 15-deoxyspergualin (DSG), a new immunosuppressant, to inhibit corneal allograft rejection in the rat penetrating keratoplasty model. Fifty-six inbred Lewis rats were recipients of orthotopic corneal allografts from Brown Norway rats. Allogeneic groups received daily intramuscular injections of DSG 2, 3, 4, or 10 mg/ kg/day. The animals treated with 2 mg/kg/day had four out of 10 grafts rejected; in the 3 mg/kg/day group none of the six grafts rejected; whereas in the 4 mg/kg/day group one out of 15 grafts rejected. The animals treated with 10 mg/kg/day became emaciated and died during the second and third postoperative weeks with relatively clear grafts. All corneas rejected following discontinuation of the drug. We conclude that the systemic administration of DSG at 3 or 4 mg/kg/day results in effective suppression of corneal allograft rejection in the rat penetrating keratoplasty model.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The corneal findings in 60 patients with floppy eyelid syndrome seen at the Bascom Palmer Eye Institute over a 10-year period were determined by review of their medical records. Punctate epithelial keratopathy (45%), and both clinical (10%) and subclinical keratoconus were the most commonly encountered corneal disorders. Two patients developed progressive endotheliopathy (Chandler's syndrome and nonguttate endothelial dystrophy) during the period of observation. In contrast to previous reports in which almost all patients were obese men, 37% (n=22) of our patients were women and only 29% of all patients were obese. All patients slept face down, usually on the most severely affected eye. Treatment by lid shortening surgery and/or an eye shield provided symptomatic relief. A pathogenetic theory is advanced that the degenerative changes in the tarsus result from the combination of local pressure-induced lid ischemia and systemic hypoventilation followed by reperfusion oxidation injury.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Rose bengal and fluorescein are photosensitive dyes in widespread use in the evaluation of ocular surface diseases, including herpes simplex virus (HSV) keratitis. These dyes have recently been shown to penetrate living cells, and rose bengal was previously reported to possess antiviral activity. Several experiments reported herein suggest that these dyes do possess the potential for potent antiviral activity against extracellular virus, but only in the presence of light. Rose bengal is substantially more effective in vitro than fluorescein, and the effect is greater with increasing concentration of dye and duration of light exposure. Electron microscopic evaluation of treated virus showed no structural difference from untreated virus, in spite of 4- to 5-log decreases in virus titer. Intracellular virus was found to be markedly resistant to photoinactivation. In a rabbit model of acute primary HSV keratitis, daily application of topical rose bengal followed by light exposure had no therapeutic effect, although an adverse effect on culture sensitivity testing was seen.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Cytochalasins B (CB), dihydroB (H2CB), and D (CD) were found to cause loss of fibronectin (Fn) from the cell surface of normal rabbit corneal fibroblasts, breakdown of F-actin-containing microfilament bundles ("stress fibers"), and increase levels of type 1 interstitial collagenase (MMP-1) in the medium. In contrast to the effects of plasmin, the cytochalasins caused withdrawal of cells from the Fn mesh but not total loss of the mesh, and the collagenase was essentially all in latent form. The results are consistent with the possibility that cytochalasins, like plasmin, perturb the α5β1integrin (Fn) receptor. Unlike plasmin, which degrades Fn to result in such a perturbation, however, the cytochalasins are thought to do so by directly disrupting cytoplasmic F-actin microfilaments associated with focal contact adhesive structures, to result in changes in the Fn receptor that cause loss of Fn. Thus, plasmin acting extracellularly and cytochalasins acting intracellularly are both thought to be able to modulate the secretion (and possibly also the synthesis) of MMP-1 by corneal fibroblasts by perturbing the Fn receptor located in the focal contact. The presence of all active collagenase after treatment with plasmin, as opposed to latent collagenase after treatment with cytochalasin, supports the interpretation that the events of secretion and activation of collagenase can be uncoupled.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Dried tears from keratoconjunctivitis sicca eyes fail to exhibit the fern-like crystallization patterns observed with tears from eyes with normal tear function. To test our hypothesis that the extent of ferning depends on the ratio of salts to protein and mucin in the tear sample, dried tears from six normal subjects were subjected to scanning electron microscopy (SEM) and X-ray analyses. X-ray diffraction identified sodium chloride and potassium chloride as the major components of tear fern crystals. X-ray fluorescence detected the elements potassium, chlorine, calcium, and sulfur in the dried tear samples, with sulfur indicating the presence of protein and/or mucin. As well as confirming the presence of cubic fern nuclei, SEM revealed two kinds of material, having crystalline and globular appearances, that are hypothesized to be composed of salts and protein/mucin, respectively. Globular material appeared to block extension of crystal fern arms or to coat crystalline material, but did not crystallize. These findings suggest that tear fern crystals are composed of sodium and potassium chloride, with proteinaceous material controlling crystallization indirectly by coating crystal faces and blocking fern extension. This structural composition is consistent with the hypothesis that the ratio of salt to macromolecular species is an important determinant of tear ferning.

ISSN:0277-3740    

出版商:OVID    

年代:1994

数据来源: OVID