Evaluation of topical cysteamine therapy in the CTNS(-/-) knockout mouse using in vivo confocal microscopy.
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PURPOSE: The purpose of this study was to assess the ability of quantitative in vivo confocal microscopy (CM) to detect changes in cystine crystal volume in the cystinosisn (Ctns(-/-))mouse cornea following topical cysteamine therapy. METHODS: Fifteen Ctns(-/-) mice were sequentially followed using in vivo CM from 3 to 10 months of age. In a second experiment, five mice receiving topical cysteamine eyedrops (0.55%) for 4 weeks were compared to five untreated mice. The volume of corneal cystine crystals was determined by thresholding and counting high intensity pixels in the in vivo CM scans and dividing by the stromal volume to calculate a crystal volume index (CVI). RESULTS: Corneal crystals progressively increased in density with age, reaching a peak density at 6-8 months and showing a 70 fold increase in CVI. Eyes treated with cysteamine drops showed significantly less crystal accumulation compared to control eyes (p<0.001) with only a 15% increase in treated eyes (p=ns) compared to 173% increase (p<0.04) for untreated eyes. CONCLUSIONS: Measurement of CVI shows that there is a progressive increase in cystine crystal volume up to 8 months of age and that cysteamine eyedrops significantly inhibits progression in the Ctns(-/-) mouse. These findings are similar to those seen clinically in patients with cystinosis, and suggest that measurement of CVI in the Ctns(-/-) mouse may be used as a model to develop novel therapeutic strategies for treating corneal cystinosis. (+info)
Removal of the basement membrane enhances corneal wound healing.
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Eosinophil as a cellular target of the ocular anti-allergic action of mapracorat, a novel selective glucocorticoid receptor agonist.
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PURPOSE: Glucocorticoids can either suppress gene transcription (transrepression) or activate it (transactivation). This latter process may contribute to certain side effects caused by these agents. Mapracorat (also known as BOL-303242-X or ZK 245186) is a novel selective glucocorticoid receptor agonist that maintains a beneficial anti-inflammatory activity but seems to be less effective in transactivation, resulting in a lower potential for side effects; it has been proposed for the topical treatment of inflammatory skin disorders. This study assessed the anti-allergic activity of mapracorat at the ocular level and whether eosinophils and mast cells are targets of its action. METHODS: With in vitro studies apoptosis was evaluated in human eosinophils by flow cytometry and western blot of caspase-3 fragments. Eosinophil migration toward platelet-activating factor was evaluated by transwell assays. Interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and the chemokine (C-C motif) ligand 5 (CCL5)/regulated upon activation normal T cell expressed, and presumably secreted (RANTES) were measured using a high-throughput multiplex luminex technology. Annexin I and the chemochine receptor C-X-C chemokine receptor 4 (CXCR4) were detected by flow cytometry. With in vivo studies, allergic conjunctivitis was induced in guinea pigs sensitized to ovalbumin by an ocular allergen challenge and evaluated by a clinical score. Conjunctival eosinophils were determined by microscopy or eosinophil peroxidase assay. RESULTS: In cultured human eosinophils, mapracorat showed the same potency as dexamethasone but displayed higher efficacy in increasing spontaneous apoptosis and in counteracting cytokine-sustained eosinophil survival. These effects were prevented by the glucocorticoid receptor antagonist mifepristone. Mapracorat inhibited eosinophil migration and IL-8 release from eosinophils or the release of IL-6, IL-8, CCL5/RANTES, and TNF-alpha from a human mast cell line with equal potency as dexamethasone, whereas it was clearly less potent than this glucocorticoid in inducing annexin I and CXCR4 expression on the human eosinophil surface; this was taken as a possible sign of glucocorticoid-dependent transactivation. In the guinea pig, mapracorat or dexamethasone eye drops induced an analogous reduction in clinical symptoms of allergic conjunctivitis and conjunctival eosinophil accumulation. CONCLUSIONS: Mapracorat appears to be a promising candidate for the topical treatment of allergic eye disorders. It maintains an anti-allergic profile similar to that of dexamethasone but seems to have fewer transactivation effects in comparison to this classical glucocorticoid. Some of its cellular targets may contribute to eosinophil apoptosis and/or to preventing their recruitment and activation and to inhibiting the release of cytokines and chemokines. (+info)
Avian paramyxovirus serotypes 2-9 (APMV-2-9) vary in the ability to induce protective immunity in chickens against challenge with virulent Newcastle disease virus (APMV-1).
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