Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gangliosides were isolated from human senile cataractous lenses by solvent extraction, DEAE-Sephadex column chromatography, and thin-layer chromatography. The content and composition of gangliosides were examined in individual lens tissues. Three predominant gangliosides, GM3, GM1, and GD1a, were tentatively identified in comparison with authentic brain gangliosides, and several unidentified gangliosides were also recognized. The increase in ganglioside content per mg of protein content in cataractous lenses was found to be influenced by two physiologic parameters: aging and cataract progression. The mature cataractous lenses showed a higher ganglioside level on a protein basis than the immature lenses compared with the same age group. On the basis of statistical analysis, an age-dependent increase in ganglioside concentration was recognized in both mature and immature lens groups. The relative increase in slow-moving polysialogangliosides on thin-layer chromatography seemed to be caused by the maturation of cataract. The sugar composition of one of the polysialogangliosides was found to be glucose, galactose, and sialic acid in the molar ratio of 2:1:4; this suggests the presence of a unique ganglioside species in human cataractous lens.
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PMID:Increase in lens gangliosides due to aging and cataract progression in human senile cataract. 221 Oct 13

Human lens accumulates gangliosides in association with aging and senile cataract progression. In this study we purified and characterized five major gangliosides in human cataractous lenses. Structural analyses and immunological studies revealed the presence of ganglio-series gangliosides, GM3, GM2, GM1 and GD1a, and a sialyl-Lewisx-containing neolacto-series ganglioside, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1ceramide (IV3NeuAcIII3FucnLc4). Slow-moving gangliosides, although minor components, were also found to have sialyl-Lewisx-related structures, based on anti-Lewisx antiserum binding to their asialo forms. However, sialyl-paragloboside, a possible precursor of the sialyl-Lewisx ganglioside, was not identified.
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PMID:Identification and synthetic pathway of sialyl-Lewisx-containing neolacto-series gangliosides in lens tissues. 1. Characterization of gangliosides in human senile cataractous lens. 776 94

Rat lens was found to contain several neutral and acidic glycosphingolipids in lens epithelia, cortex and nucleus, and showed developmental changes in their content and localization. TLC-immunostaining of gangliosides revealed the enrichment of some ganglio-series gangliosides (GM3, GM1, GD3 and GD1b) in lens epithelia and the presence of GM3 and GD3 in the lens nucleus. Immunohistochemical studies confirmed the distribution of GM3 and GM1 in anterior lens epithelial cells and the cortex, with expression decreasing toward the lens nucleus. Immunoreaction to GD3 was more intense in the lens nucleus than in epithelial cells. In contrast, the expression of neolacto-series glycosphingolipids was restricted to the lens nucleus. In order to investigate the pathological changes of glycosphingolipids in cataract, galactose-induced cataractous lenses were examined. However, no significant changes were observed in the content and composition of glycosphingolipids. In addition, Lewisx epitopes found in human cataractous lenses were not detected in the cataractous lenses of galactosaemic rats and hereditary cataractous Emory mice.
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PMID:Localization of neutral and acidic glycosphingolipids in rat lens. 778 Jan 93

We previously reported that human lens accumulates gangliosides in association with aging and senile cataract progression. Structural analysis revealed that gangliosides in human cataractous lenses were composed of ganglio-series gangliosides, such as GM3, GM2, GM1 and GD1a, and sialyl-Lewisx-containing neolacto-series gangliosides. Although Lewisx-containing neolacto-series glycolipid was found to accumulate in association with aging and cataract progression, the sialyl-Lewisx gangliosides did not show much accumulation in individual lenses from subjects between 16 and 80 years old. The content of sialyl-Lewisx gangliosides was about two to four times higher than that of Lewisx glycolipids, suggesting the possibility that the increase in Le(x) glycolipid is partly due to the desialylation of sialyl-Le(x) gangliosides. On the other hand, the expression of ganglio-series gangliosides increased in an age-related manner. Thus, age-related changes in lens glycolipids may modify the cell-to-cell interaction induced by cell surface sugar chains, leading to the initiation and progression of cataract.
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PMID:Age-related changes in ganglioside composition in human lens. 778 11

We have studied the glycolipid composition of human cataractous lenses. Neutral and acidic lipid fractions were isolated by column chromatographies on DEAE-Sephadex and Iatrobeads. The neutral glycolipid fraction and acidic glycolipid fraction contained 0.6-0.9 micrograms of lipid-bound glucose (Glc) per mg of protein and 0.8-1.3 micrograms of lipid-bound sialic acid (NeuAc) per mg of protein, respectively. The neutral glycolipid fraction was found to contain LacCer (39.0% of total neutral glycolipids), Gb3 (16.2%), Gb4 (1.1%), nLc4 (5.0%), X (29.0%), and Y (9.2%). The acidic lipid fraction was found to contain mainly GM3 (33.1% of the total ganglioside fraction), GM1 (8.3%), LM1 (7.3%), GD1a (16.0%), and G (30.1%). The structures of neutral glycolipids X and Y and ganglioside G were elucidated by high performance thin-layer chromatography overlay method of glycolipids, gas-liquid chromatography, proton NMR spectrometry, and liquid secondary ion mass spectrometry as follows: 1) X, Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer, III3FucnLc4 (Lex); 2) Y, Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4(Fuc alpha 1- 3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer, V3FucIII3FucnLc6; and 3) G, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3 Gal-beta 1-4Glc beta 1-1'Cer, IV3NeuAcIII3FucnLc4 (sialosyl-Le(x)). A minor neutral glycolipid Z was isolated and tentatively characterized as GlcNAc beta 1-3?Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer (GlcNAc-Le(x)), suggesting that it may be the precursor of glycolipid Y. The major long-chain base of these human cataract glycolipids was C18:0 sphingosine (sphinganine). The major fatty acids were C16:0, C24:1 and C24:0, and monounsaturated fatty acids accounted for 40-55% of the total fatty acids.
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PMID:Glycolipid composition of human cataractous lenses. Characterization of Lewisx glycolipids. 790 80

Administration of glucocorticoids induces transient cataract in 15-day-old chick embryos within 48 hr, and the opaque lens again becomes clear within the subsequent 48 hr. Oxidative stress is likely to be involved in the process of cataract formation, resulting in the appearance of numerous vacuoles around the perinuclear region. Chick lens contained low amounts of glycosphingolipids, which mainly consists of GM3, GD3, sialyl-LewisX gangliosides and glucosylceramide. Most lens gangliosides were immunohistochemically detected in lens epithelia, annular pads and developing fibers, but not in perinuclear and nuclear regions. Since cell surface gangliosides, for example GM3 and sialyl-LewisX gangliosides, are involved in cell adhesion, weak cell-to-cell interactions in the perinuclear and nuclear regions may allow vacuole formation in steroid-induced cataractogenesis.
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PMID:Neutral and acidic glycosphingolipids in glucocorticoid-induced cataract in chick lens. 1006 88