Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microbial adherence to corneal epithelial cells is the initial step in the development of infectious keratitis. In an attempt to inhibit this process, we evaluated the effects of concanavalin A (Con A) upon the adherence of Pseudomonas aeruginosa to injured rabbit corneal epithelial cells. A sterile 21-gauge needle was used to create linear epithelial injuries. Identical samples from suspensions of a pure strain of P. aeruginosa were placed on two groups of injured corneas. Prior to bacterial application, one group of corneas received topical application of Con A, a lectin that is capable of binding to alpha-D-mannose or alpha-D-glucose. The animals were sacrificed 1 hour after application of the bacteria. Scanning electron microscopy of the excised corneas revealed that, compared to the corneas that had not been exposed to Con A, those exposed to the lectin had significant fewer adherent P. aeruginosa bacilli. Additionally, only rare bacteria were noted adhering to the uninjured superficial epithelial cells. These results suggest that, by competitively binding to the exposed mannose and/or glucose groups on the surfaces of these cells, Con A is capable of inhibiting the adherence of P. aeruginosa to injured epithelial cells.
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PMID:The use of concanavalin A to competitively inhibit Pseudomonas aeruginosa adherence to rabbit corneal epithelium. 211 42

Three different commercial extended-wear soft contact lenses worn continuously by patients for at least 28 days were stained with fluorescein isothiocyanate-labeled lectins. These lectins detected the presence of alpha-linked or beta-linked D-mannose, D-glucose, D-galactose, L-fucose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and N-acetyl neuraminic acid (sialic acid) on the surfaces of the contact lenses. These saccharides are bound to other sugars that likely account for an integral part of glycoprotein and/or glycolipid deposits on lens surfaces. These tear deposits may contribute to the chemical spoilage of the lens and, furthermore, may serve as specific receptors for pathogenic microorganisms commonly implicated in extended-wear soft contact lens-associated infectious keratitis.
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PMID:Carbohydrate deposits on the surfaces of worn extended-wear soft contact lenses. 347 46

Acanthamoeba is a protist pathogen that can cause serious human infections, including blinding keratitis and a granulomatous amoebic encephalitis that almost always results in death. The current treatment for these infections includes a mixture of drugs, and even then, a recurrence can occur. Photochemotherapy has shown promise in the treatment of Acanthamoeba infections; however, the selective targeting of pathogenic Acanthamoeba has remained a major concern. The mannose-binding protein is an important adhesin expressed on the surface membranes of pathogenic Acanthamoeba organisms. To specifically target Acanthamoeba, the overall aim of this study was to synthesize a photosensitizing compound (porphyrin) conjugated with mannose and test its efficacy in vitro. The synthesis of mannose-conjugated porphyrin was achieved by mixing benzaldehyde and pyrrole, yielding tetraphenylporphyrin. Tetraphenylporphyrin was then converted into mono-nitrophenylporphyrin by selectively nitrating the para position of the phenyl rings, as confirmed by nuclear magnetic resonance (NMR) spectroscopy. The mono-nitrophenylporphyrin was reduced to mono-aminophenylporphyrin in the presence of tin dichloride and confirmed by a peak at m/z 629. Finally, mono-aminoporphyrin was conjugated with mannose, resulting in the formation of an imine bond. Mannose-conjugated porphyrin was confirmed through spectroscopic analysis and showed that it absorbed light of wavelengths ranging from 425 to 475 nm. To determine the antiacanthamoebic effects of the derived product, amoebae were incubated with mannose-conjugated porphyrin for 1 h and washed 3 times to remove extracellular compound. Next, the amoebae were exposed to light of the appropriate wavelength for 1 h. The results revealed that mannose-conjugated porphyrin produced potent trophicidal effects and blocked excystation. In contrast, Acanthamoeba castellanii incubated with mannose alone and porphyrin alone did not exhibit an antiamoebic effect. Consistently, pretreatment with mannose-conjugated porphyrin reduced the A. castellanii-mediated host cell cytotoxicity from 97% to 4.9%. In contrast, treatment with porphyrin, mannose, or solvent alone had no protective effects on the host cells. These data suggest that mannose-conjugated porphyrin has application for the targeted photodynamic therapy of Acanthamoeba infections and may serve as a model in the development of therapeutic interventions against other eukaryotic infections.
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PMID:Photochemotherapeutic strategy against Acanthamoeba infections. 2575 33