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)

In the lens, disorders of the metabolism occur, and, with them, active permeability (the cation pump with uptake of K and release of Na) changes to passive permeability and consequently Na ions enter with water. As a result, the lens increases in weight and a subcapsular (permeability) cataract develops. It is shown that the cattle lens in vitro increases in weight the lower the pH (6.5 greater than 7.5 greater than 8.5) of the surrounding fluid becomes. In a further experiment, 1 ml of buffered liquids with different pH were injected into the anterior chamber of the eyes of freshly slaughtered cattle. Here, too, the mechanically undamaged, untouched lens increased in weight more greatly as the pH (5.5 greater than 6.5 greater than 7.5 greater than 8.5) of the injected fluid was lowered. The significance of the lowering of the pH, e.g., in local inflammation (iritis, cyclitis, retinitis, etc.) or general acidoses (diabetes mellitus, galactosemia, hunger, extracorporeal circulation for atrophic kidney. Albright-, Love-, Fanconi-syndrome) for the appearance of incipient subcapsular clouding of the lens is pointed out.
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PMID:[Lens changes occuring as a result of lowered pH (acidosis) (author's transl)]. 1 65

1. Cataract formation in streptozotocin-induced diabetes in rats was reduced by approximately 85% when a diet rich in maize oil (300 g/kg diet) (fat diet) was given, thus confirming results of earlier studies. However, the concentration of sorbitol in the lens of diabetic animals remained high, the values for diabetic rats given the standard diet and the fat died being 65 and 40 mumol/g protein respectively. 2. With the standard diet, the fatty acid profile of the triglycerides of the epididymal fat pads was characterized by a greater relative proportion of saturated fatty acids for the diabetic animals compared to that for the normal animals. The fat diet moderated the tendency towards saturation in the diabetic animals. 3. The fat diet had other effects on the diabetic animals; these included a reduced mortality rate, increased body-weight, a decrease in the daily water intake, and in the daily urinary excretion of glucose and urea. 4. In the diabetic animals the fat diet had no effect on the specific activities in the liver of hexokinase (EC 2.7.1.1), glucokinase (EC 2.7.1.2), phosphofructokinase (EC 2.7.1.11) and pyruvate kinase (EC 2.7.1.40). However, the specific activity of glucose-6-phosphatase (EC 3.1.3.9) was reduced, while that of malate dehydrogenase (decarboxylating) (NADP) (EC 1.1.1.40) was increased. The NAD+:NADH ratio, as calculated from liver pyruvate and lactate concentrations, tended to increase. 5. The results suggested that the fat diet moderated the long-term metabolic effects of diabetes.
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PMID:The effect of an unsaturated-fat diet on cataract formation in streptozotocin-induced diabetic rats. 13 11

Fresh calf lesnses incubated in nutritive media containing dexamethasone phosphate or ouabain in concentrations ranging from 1 X 10(-4) M to 1 X 10(-8) M developed cortical opacification and showed significant inhibition of Na(+)-K(+) ATP'ase activity. Over a 3-day incubation period the decrease in Na+-K+ ATP'ase activity correlated well with the observed decrease in light transmission. The degree of enzyme inhibition and decrease in light transmission varied directly with the concentration of dexamethasone phosphate and ouabain, with significant changes observed at 'physiologic' and 'pharmacologic' concentrations of these agents. Lenses incubated for 4 days in dexamethasone phosphate or ouabain showed substantial increases in water content as well as an increase in Na+ and a decrease in K+ concentration. These data suggest that inhibition of the cation pump may play a significant role in the formation of steroid cataract in vitro.
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PMID:In vitro production of steroid cataract in bovine lens. Part II: measurement of sodium-potassium adenosine triphosphatase activity. 23 7

A series of 91 cryoextractions was performed on autopsy material. The scleral section was placed near to the chamber angle and was nearly circumferential (about 330 degrees). Cornea and adjacent sclera could be flapped over this way, and did not interfere with a straightforward lens extraction. The pupil was medically dilated. A cryoprobe was fixed to a specially constructed scale, and frozen to the anterior pole of the lens. Its weight was counterbalanced by a plastic water container at the other end of the scale. The extraction was performed by filling additional water into the counterbalancing container. The statistical evaluation of the results showed a very significant dependence of the average tensile strength on age. However, a considerable standard deviation was found throughout all ages. The nutritional state of the autopsy bodies and the time interval between death and start of the measurement had no significant influence. The differences between right and left eyes were also not significant, as could be expected. The methodological error remained small. Age proved to be an unreliable indicator for the tensile strength of the zonule. All results apply to clear lenses. We known from clinical experience that the tenacity of the zonule may also be different in the various types of cataract.
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PMID:[The tensile strength of human zonule and its alteration with age (author's transl)]. 30 83

A 43,000-dalton polypeptide has been isolated from the high-molecular-weight disulfide-rich fraction of the water-insoluble protein of human cataractous lenses. On the basis of immunochemical reactivity and fluorescent antibody binding, this polypeptide is localized in the membrane region of the lens cell. This observation suggests an interaction between the soluble lens proteins and membrane-associated polypeptides in the formation of large protein aggregates which may cause cataract.
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PMID:An extrinsic membrane polypeptide associated with high-molecular-weight protein aggregates in human cataract. 37 84

Tetracycline hydrochloride--as a 1% suspension in oil, 1 and 2% suspension in ointment, and 1 and 2% solution in water or balanced salt solution USP--was applied once to the conjunctival cul-de-sacs of volunteers and patients before cataract extraction. The tear film concentrations of drug were maintained above a bacteriostatic level in excess of six hours for 1 and 2% tetracycline in ointment, less than two hours for 1% tetracycline in oil, and less than 30 minutes for 1 and 2% tetracycline in water or balanced salt solution. The 2% tetracycline in ointment produced the highest tear film levels of drug. The 1% tetracycline in oil induced excessive lacrimation and much of the drug was washed from the conjunctival surface. The tear film levels of the drug were mirrored by the maintenance of bacteriostatic levels of tetracycline in the aqueous humor for 1 1/2 hours with 2% tetracycline in ointment. Whereas 1% tetracycline in ointment produced drug levels approaching bacteriostasis in the aqueous humor, 1% tetracycline in oil produced only trace levels of the drug within the anterior chamber. The ointment acted as a depot for the suspended drug and most of the drug in the absence of excessive tearing was lost from the conjunctiva via the lacrimal system.
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PMID:Effect of drug vehicle on human ocular retention of topically applied tetracycline. 76 37

Ultrasonography can provide priceless information about a retinal detachment when the fundus is invisible because of a cataract or an unclear vitreous. The exploration of an eye with A-scan ultrasonography is a long and careful procedure which is made step by step along the meridians, then along the parallels of the eyeball. Quantitative ultrasonography is necessary to separate the echoes of the vitreous opacities and of the detached retina. The B-scan gives the same information - except the biometric data - in a much shorter time and is now available without the interposition of water between the patient and the probe. It also permits an easy diagnosis of the choroidal detachment. After the operation, when the media are not clear, A-and B-scan ultrasonography can give an early indication of whether the retina is reattached or not. But at that time a mistake may be made due to the edge of buckling and everyone should be aware of this.
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PMID:[Possibilities and limits of echographic examination of retinal detachment before and after surgery]. 87 79

A remarkable resemblance between the appearance of opacity in lysozyme--salt water mixtures and the development of opacity in cold cataract in the young rat lens is strong evidence that cold cataract is fundamentally a phase separation of the "protein-water binary mixture" in the lens.
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PMID:Phase separation of a protein-water mixture in cold cataract in the young rat lens. 88 36

A 63-year-old patient suffering from old sclerokeratitis was fitted with a therapeutic soft contact lens one and a half years after corneal transplantation and half a year after cataract surgery. The patient was on oral and local cortisone treatment. The first three months were uneventful with an aphakic high water content lens worn continuously. This lens was lost and she was given a B-L plano T. One month later the patient was admitted to the hospital with a red eye and a large corneal ulcer. Two white spots were noted on the contact lens. In a frozen section yeast-like structures were seen on the lens that partly invaded the lens material. Fungal culture from the other deposit revealed candida tropicalis and fusarium. The corneal ulcer healed with antimycotic therapy. The possible relationship between cortisone treatment, corneal ulcer and fungal contamination of the lens is discussed.
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PMID:[Mykosis of soft contact lenses (author's transl)]. 89 93

Senile nuclear cataractous lenses were divided into three groups of increasing nuclear color. These groups were considered as successive stages in the development of senile nuclear cataract. The cortex and the nucleus of normal and cataractous lenses were separated into water-soluble, urea-soluble and urea-insoluble fractions. Fractionation on a Sephadex G-200 column of the water-soluble components revealed five protein fractions for both cortex and nucleus. Only minor quantitative differences in polypeptide chain composition were found by isoelectric focusing between corresponding protein fractions isolated from normal and cataractous lenses. The weight percentages of the water-soluble, urea-soluble, and urea-insoluble fractions of cortex and nucleus from the normal and cataractous lenses were determined. A decrease of the amounts of the water-soluble and urea-soluble fractions and a concomitant increase of the urea-insoluble fraction were observed in the nucleus as a function of cataract development. Lens wet weight and protein content did not change significantly. The carbohydrate content of the urea-soluble fractions increased, that of the urea-insoluble fraction decreased. A striking decrease of the phospholipid content in the urea-insoluble fraction was found.
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PMID:Protein changes in the human lens during development of senile nuclear cataract. 93 70


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