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)

Lipid extracts of the human cataractous and normal lenses were analyzed by thin-layer chromatography (TLC) using a solvent system consisting of CHCl3/CH3OH/CH3COOH/H2O (50:25:7:3 by vol.). A novel phospholipid having a Rf intermediate between phosphatidyl ethanolamine (PE) and phosphatidyl serine (PS) was detected besides the four major phospholipids viz., PE, PS, phosphatidyl choline (PC) and sphingomyelin (SP). The novel phospholipid was found to be molybdenum positive and ninhydrin negative having a characteristic fluorescence of Schiff-base conjugate formed between PE, malondialdehyde (MDA) and PS. It was possible to resolve this adduct into PE and PS after acid hydrolysis using two dimensional TLC with CHCl3/CH3OH/NH3 (7 M) (65:25:4 by vol.) as the second solvent. In cataract PE . MDA . PS adduct increased significantly as did diene conjugates and MDA. In plasma membrane lipid extract of cataractous lenses there was a marked increase in fluorescence at 460 nm when excited at 365 nm showing a characteristic fluorescence of a typical Schiff-base conjugate. The evidence suggests that peroxidation of lenticular plasma membrane lipids is one of the molecular mechanisms involved in cataract in the human.
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PMID:Molecular mechanisms of cataractogenesis: IV. Evidence of phospholipid . malondialdehyde adduct in human senile cataract. 372 54

Agricultural evaporation basins are used as a means to dispose of highly saline underground-tile-drainage water in the San Joaquin Valley (California, USA). The hypersaline water conditions encourage high aquatic invertebrate production, primarily brine shrimp (Artemia franciscana), which attract birds to these sites. Cool winter temperatures (< 4 C) and hypersaline water conditions (> 70,000 mumhos/cm) resulted in feather salt encrustation and salt toxicosis in ruddy ducks (Oxyura jamaicensis). During December 1998 and January 1999, approximately 200 dead and sick ruddy ducks were collected from an evaporation basin and five healthy control ruddy ducks were collected from a freshwater wetland. Brains contained > or = 1,890 ppm sodium (wet tissue mass) in seven dead birds and contained < or = 1,150 ppm sodium in the control birds. Liver arsenic, lead, and mercury concentrations were < 1 ppm in all birds examined. Manganese, molybdenum, and copper liver concentrations did not differ significantly (P > 0.05) between the two groups of ducks. The dead ducks had significantly higher liver selenium, cadmium, iron, and zinc than the controls, but the concentrations were not sufficient to cause toxicity. Significant gross and microscopic lesions in most of the dead birds included conjunctivitis, lens opacity and cataract formation, vascular congestion in various organs most notably in the meninges of the brain, and myocardial and skeletal muscle degeneration.
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PMID:Salt toxicosis in ruddy ducks that winter on an agricultural evaporation basin in California. 1183 3

Age-related cataract (ARC) is the leading cause of blindness in the world, particularly in developing countries. In contrast, cataract surgery has become the most frequent surgical procedure in people aged 65 years or older in the Western world, causing a considerable financial burden to the health care system. The development of cataracts is mainly an age-related phenomenon, although socioeconomic and lifestyle factors appear to influence their development, e.g. smoking has been found to directly influence ARC. A key role in the pathomechanism of the crystalline lens alteration is played by glucose metabolism and associated effected redox potential, which may induce oxidative damages. Aldose reductase blockers were able to prevent the development of diabetic cataracts in experimental studies, however clinical trials were interrupted due to unclear side effects. Other drugs with radical scavenging properties were effective in in vitro and in vivo experiments, but could not be proven to be efficient and safe in preclinical human trials. A number of epidemiological studies showed an increased risk of nuclear or cortical cataract in people with low blood levels of vitamin E. It is also known that the measured levels of ascorbic acid decline with increasing age in the lens. Beta-Carotin and other non-polar carotenoids seem to be missing and may therefore only play a minor role. Polarized carotenoid lutein and zeaxanthin are available in low concentrations and may therefore have some direct effects. The results of the present interventional studies are still controversial. While the Linxian studies indicated that the prevalence for nuclear cataract was reduced by the supplementation with retinol/zinc or vitamin C/molybdenum, the AREDS trial showed no effect of the antioxidant formulation on the development or progression of ARC. Again, while the REACT study demonstrated a statistically significant positive treatment effect 2 years after treatment for the US patients and for both subgroups (US & UK) after 3 years, no effect was observed in UK patients alone. In another US study, the Physician Health Study, no positive or negative effect of Beta-carotin was observed. Taken together, these studies suggest that any effect of antioxidants on cataract development is likely to be very small and probably is of no clinical or public health significance, thus removing a major rationale for 'anticataract' vitamin supplementation among health-conscious individuals.
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PMID:Nutritional supplementation to prevent cataract formation. 1560 20