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

The purpose of this study was to determine the cause of lens cataracts in hatchery trout fed diets containing white fish meal. After preliminary investigations, three experiments were conducted with fry of rainbow trout (Salmo gairdneri) that were fed practical-type diets containing either 40% herring meal (control diet) or 40% white fish meal with and without various mineral supplements. In all experiments, the trout fed herring meal grew well and had normal lenses. Those fed the diet containing white fish meal without supplement grew slowly and developed bilateral cataracts determined by using a slit-lamp biomicroscope. The severity of cataracts was increased by supplementing the diet with a mixture of minerals (phosphates and carbonates of calcium, sodium and potassium). Cataracts were prevented, however, with supplemental Na2EDTA or zinc but not by supplements of manganese, copper, iron or various other minerals. The metabolic alterations responsible for the zinc-deficiency cataract were not determined.
 ...
PMID:Influence of dietary zinc on cataracts in rainbow trout (Salmo gairdneri). 10 82

This is the first case report of cataracts in patients with thalassemia major. Desferrioxamine, an iron-chelating agent is being used with increasing frequency in the treatment of transfusion-induced iron overload. There has been some concern in the literature about possible cataract formation with use of this drug. It is therefore important to document any lens opacities seen prior to administration of desferrioxamine, or record the appearance of lens opacities after its use. The possible eitology of these lens opacities is discussed.
 ...
PMID:Lens opacities in thalassemia. 73 45

Incipient siderosis of the lens is reflected by an extremely fine granular, almost homogenous closely subcapsular brown discoloration between the anterior capsule of the lens and the epithelium. Advanced siderosis of the lens leads to subcapsular "rust spots" of varying size, especially in the region below the pupil; to increasing permeability cataract with protein breakdown and also to brown discoloration of the developing hollow spaces and clefts containing protein. In extensive siderosis of the lens, there was the following histological evidence of iron infiltration colour reactions: Between epithelium and capsule: (fusiformly) changed epithelia, intercellular substance formed by metaplasia of epithelia with connective tissue fibrillae (birefractive capsular cataract), in large, balloon-like epithelial cells freely occurring in the liquefied capsule, by decomposition of these cells in all fluid cavities containing protein (water clefts, etc.). On the other hand, there were no siderous granulations of protein: in normal epithelial cells of the lens, in unchanged fibres of the lens, in Wedl's cells and in Morgagni's or myelin droplets.
 ...
PMID:[Siderosis of the lens (author's transl)]. 96 87

Two unusual events concerning intraocular foreign bodies are presented. The first patient had an occult or unsuspected intraocular foreign body. He showed iridoplegia with mydriasis, siderosis iridis, and an intraocular piece of iron lying posteriorly near the retina. The foreign body was removed and the patient regained normal iris color and pupillary activity. His vision remains 20/15 six years postoperatively dispite ensuing retinal detachment one year after removal of the foreign body. The second patient was a young boy injured by a blasting cap explosion. He lost one eye from the injury and had a piece of intraocular brass in his left eye. In spite of the development of chalcosis and a mature cataract the lens gradually shrank in the pupillary space permitting a clear aphakic area and 20/25 vision. The brass fragment migrated forward and inferiorly and was finally extruded under the conjunctiva five years later, where it was removed and chemically analyzed by x-ray diffraction.
 ...
PMID:Two remarkable events in the field of intraocular foreign body: (1) The reversal of siderosis bulbi. (2) The spontaneous extrusion of an intraocular copper foreign body. 110 72

A single subcutaneous dose of 30 nmol of sodium selenite per gram of body weight in 13-day-old rats resulted in posterior subcapsular cataract (PSC) after 24 hr and bilateral nuclear cataracts at 72-96 hr. Within 24 hr of treatment, a 60% decrease in lens glutathione was seen. A loss of calcium homeostasis observed by 48 hr resulted in increased lens calcium (4 mumol/g dry weight), which accompanied nuclear opacification. The iron chelator, deferoxamine (DF), was evaluated as a potential protective agent against these selenite-induced changes. Three doses each consisting of 1.1 mumol DF/g body weight were administered during the initial 24 hr of selenite exposure. Within 96 hr, all lenses from animals treated only with DF remained transparent, but 50% of these lenses showed cortical cataract at 3 wk postinjection. Concurrent administration of DF and selenite protected 80% of rats against PSC after 48 hr and 25% against nuclear cataract after 96 hr. No elevation in lens calcium occurred in the protected lenses. An additional 20% of animals were not protected fully but showed substantially less nuclear opacity than with selenite alone. They had a significant but moderate increase in lens calcium. After 3 wk (animal age, 35-40 d), cataract appeared in these "protected" lenses involving both the nucleus and cortex and loss of ion homeostasis. The glutathione content remained lower in lenses from animals treated with both selenite and DF compared with those from selenite-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Deferoxamine effect on selenite-induced cataract formation in rats. 132 98

The Lens Opacities Case-Control Study evaluated risk factors for age-related nuclear, cortical, posterior subcapsular, and mixed cataracts. The 1380 participants were ophthalmology outpatients, aged 40 to 79 years, classified into the following groups: posterior subcapsular only, 72 patients; nuclear only, 137 patients; cortical only, 290 patients; mixed cataract, 446 patients; and controls, 435 patients. In polychotomous logistic regression analyses, low education increased risk (odds ratio [OR] = 1.46) and regular use of multivitamin supplements decreased risk (OR = 0.63) for all cataract types. Dietary intake of riboflavin, vitamins C, E, and carotene, which have antioxidant potential, was protective for cortical, nuclear, and mixed cataract; intake of niacin, thiamine, and iron also decreased risk. Similar results were found in analyses that combined the antioxidant vitamins (OR = 0.40) or considered the individual nutrients (OR = 0.48 to 0.56). Diabetes increased risk of posterior subcapsular, cortical, and mixed cataracts (OR = 1.56). Oral steroid therapy increased posterior subcapsular cataract risk (OR = 5.83). Females (OR = 1.51) and nonwhites (OR = 2.03) were at increased risk only for cortical cataract. Risk factors for nuclear cataract were a nonprofessional occupation (OR = 1.96), current smoking (OR = 1.68), body mass index (OR = 0.76), and occupational exposure to sunlight (OR = 0.61). Gout medications (OR = 2.48), family history (OR = 1.52), and use of eyeglasses by age 20 years, which is an indicator of myopia (OR = 1.44), increased risk of mixed cataract. The results support a role for the nutritional, medical, personal, and other factors in cataractogenesis. The potentially modifiable factors suggested by this study merit further evaluation.
 ...
PMID:The Lens Opacities Case-Control Study. Risk factors for cataract. 184 56

The evidence reviewed here supports the hypothesis that metal catalyzed oxidation reactions occur in the lens and may make a significant contribution to the changes seen in the lens with age and in cataract formation. The major support for this hypothesis is as follows. (1) All of the components of the non-enzymic metal catalyzed oxidation systems are present in the lens normally. Ascorbate, glutathione and oxygen are present in much lower concentrations. Although, even at low concentrations, the reactions could occur over many years with significant consequences. Components of some of the enzymic systems are also present, although primarily in the epithelial layer and outer cortical region. Copper and iron levels may be increased in some cataracts. (2) Protein carbonyl derivatives are increased in both aging and cataractous lenses. Amino acid-derived protein carbonyl derivatives have only been demonstrated in oxidative reactions derived from oxygen radical generation, particularly those catalyzed by metal-catalyzed oxidation systems. (3) Treatment of isolated bovine crystallins with metal catalyzed oxidation systems generates modifications similar to those found in vivo. The proposed mechanism of site-specific metal catalyzed oxidation appears to be a feasible mechanism of oxidation in the lens, and verification of the mechanism requires further study. Although the focus of this manuscript has been on the oxidative modification induced in proteins,m oxidative damage to DNA or membrane resulting from similar mechanisms may also play an important role in alteration of lens function during aging and cataractogenesis.
 ...
PMID:Role of site-specific, metal-catalyzed oxidation in lens aging and cataract: a hypothesis. 219 8

The authors report their experience in managing 14 cases of siderosis bulbi secondary to a retained iron-containing intraocular foreign body (IOFB). The IOFB was removed in 12 of the 14 eyes. The IOFB was removed with a sclerotomy and external magnet (5 eyes), a pars plana vitrectomy (PPV) and intraocular forceps (5 eyes), a PPV and intraocular magnet (1 eye), and a PPV with aspiration using the suction mode of the vitrectomy instrument (1 eye). A siderotic cataract developed in 11 eyes and cataract extraction resulted in postoperative visual acuity ranging from 20/15 to 20/40. The most recent siderotic cataracts have been managed with cataract extraction and posterior chamber intraocular lens (PC IOL) implantation. No patient in this series experienced visual deterioration after receiving medical attention. The current management of siderosis bulbi is discussed.
 ...
PMID:Management of siderosis bulbi due to a retained iron-containing intraocular foreign body. 233 77

The lenses of mice exposed to 600 MeV/amu iron ions were evaluated by slit-lamp biomicroscopy and cytopathological analyses. The doses ranged from 0.05 to 1.6 Gy, and the lenses were assessed at several intervals postirradiation. Cataract, the development of which is dependent on both time and dose, is significantly more advanced in all of the exposed mice when compared to the unirradiated controls. The great difference between the severity of the cataracts caused by 0.05 Gy (the lowest dose used) and those that developed spontaneously in the control animals is an indication that 0.05 Gy may far exceed the threshold dose for the production of cataracts by accelerated iron ions. Cytopathologically, a similar dose dependence was observed for a number of end points including micronucleation, interphase death, and meridional row disorganization. In addition the exposure to the 56Fe ions produced a long-term effect on the mitotic population and a pronounced "focal" loss of epithelial cytoarchitecture. The microscopic changes support the view that the mechanism of heavy-ion-induced cataractogenesis is the same as that for cataracts caused by low-LET radiation.
 ...
PMID:Accelerated heavy ions and the lens. IV. Biomicroscopic and cytopathological analyses of the lenses of mice irradiated with 600 MeV/amu 56Fe ions. 269 15

A 43-year-old man had a silent intraocular foreign body at the ciliary body that was composed of iron. Siderosis bulbi was observed after an extracapsular cataract extraction with intraocular lens implantation was performed. The mechanical forces applied during the surgery might have been responsible for liberating the ferrous ion into the globe.
 ...
PMID:Siderosis bulbi induced by intraocular lens implantation. 272 57


1 2 3 4 5 6 7 8 9 10 Next >>