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)

We previously described the Dahl salt-sensitive rat as a potential model of cataractogenesis in which cataract formation is associated with hypertension. Cataractous lesions were characterized by a marked lenticular and aqueous humor electrolyte imbalance. In the present study the effects of chronic dietary sodium restriction on cataract formation were evaluated in salt-sensitive rats to determine whether or not modification of the hypertensive process might reduce the incidence of cataracts in this genetic model. In addition, the possibility that early cataractous lesions in adult hypertensive salt-sensitive rats might be reversed by acute sodium restriction was evaluated. Chronic dietary sodium restriction modified the development of hypertension and prevented cataract formation in salt-sensitive rats. Furthermore, acute dietary sodium restriction (1 week) completely and consistently reversed early cataractous lesions (pinpoint opacities) in adult hypertensive salt-sensitive rats. Both the prevention and reversal of cataracts were associated with normalization of the lenticular and aqueous humor parameters measured. These data suggest that cataractogenesis is not the consequence of sustained arterial hypertension, but rather that initiation of both hypertension and cataract formation in this genetic model may be the result of extracellular fluid volume state.
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PMID:Prevention and reversal of cataracts in genetically hypertensive rats through sodium restriction. 280 92

We have previously reported a high incidence of cataract formation in adult hypertensive salt-sensitive rats, suggesting that hypertension may be an important cataractogenic risk factor. Weanling salt-sensitive rats that eventually developed cataracts showed a marked increase in the pressor response to a high-sodium diet compared to salt-sensitive rats that did not develop cataracts. A lens and aqueous fluid electrolyte imbalance occurred in all adult salt-sensitive rats examined, but was greater in the salt-sensitive rats that developed cataracts, suggesting an alteration in lens and/or ciliary ion transport in cataracts associated with hypertension. In the present study, lens 86Rb uptake was measured in adult hypertensive salt-sensitive rats prior to cataract formation. 'Cataract-prone' salt-sensitive hypertensive rats (increased pressor response to a high sodium diet given at weanling age), salt-sensitive hypertensive rats unlikely to develop cataracts and control salt-resistant rats were studied at the age of 16 weeks. Total and ouabain-insensitive lens 86Rb uptake were measured for the determination of ouabain-sensitive uptake, an index of Na+,K+-ATPase activity. Lens ouabain-sensitive 86Rb uptake was low in adult hypertensive cataract-prone salt-sensitive rats before cataract formation compared with values in control resistant rats. Intermediate values were observed in hypertensive salt-sensitive rats unlikely to develop cataracts. These data suggest that altered ion transport may play a pivotal role in cataractogenesis associated with this model of hypertension. The data are also consistent with the concept of a generalized defect in epithelial ion transport, at least in salt-sensitive hypertension.
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PMID:Lenticular rubidium uptake in hypertensive 'cataract-prone' salt-sensitive rats. 285 35

In previous unrelated studies, we observed a 35 to 50% incidence of cataract formation in several groups of Dahl salt-sensitive hypertensive rats (DS) over a 4-year period. In the present study we evaluated longitudinal changes in blood pressure in DS in which cataracts eventually developed and those in which cataracts did not develop when all animals were maintained on a high sodium diet. Lenses were evaluated by slit-lamp microscopy to determine if cataractous lesions were similar among rats, to classify lesion types, and to define the age at which cataracts were detectable in DS. The possible participation of several cataractogenic risk factors as major influences on cataract formation also was evaluated. Finally, aqueous humor concentrations and lenticular content of sodium and potassium were determined to evaluate the possibility that a defect in ion transport at the lens epithelium and ciliary body might play a role in cataractogenesis in DS, since ion transport defects have been shown to lead to lens opacification in other models of genetic and experimental cataracts. Parallel studies were performed in Dahl salt-resistant control rats (DR). A high incidence of cataract formation was found in DS. Although systolic blood pressure was not consistently greater in adult DS with cataracts compared with values in age-matched DS without cataracts, the initial pressor response to a high salt diet was greatest in weanling DS in which cataractous lesions later developed. Slit-lamp analysis revealed that cataracts in this genetic model were cortical, with one mixed cortical, nuclear lesion. Posterior subcapsular lesions were not observed, suggesting that lesions were not steroid-induced.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cataracts and hypertension in salt-sensitive rats. A possible ion transport defect. 302 58

Cataracts were apparently fixed in the genome of a highly inbred strain of Dahl salt-sensitive (S/JR) rat during the course of the selection for hypertension. Cataracts were present in S/JR rats inbred for more than 40 generations, but were not present in any of the salt-resistant rats (R/JR) inbred and observed during the same time. Light and electron microscopic evaluation of 11 pairs of S/JR rat lenses revealed a large posterior capsular defect and marked degenerative changes in lens fibers in each case. While the reason for the posterior capsular break is unclear, the cataract is probably a manifestation of an abnormal recessive gene or a recent autosomal dominant mutation.
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PMID:Hereditary cataracts in the John Rapp inbred strain of Dahl salt-sensitive rat. 361 May 57

The effects of bendazac-L-lysine salt (bendazac-lysine) on some biochemical parameters (soluble and insoluble proteins, reduced glutathione, sulphydryl and disulphide groups, water content) in rabbit lens at different times after X-rays (2000 rads) were studied. The mature cataract (swelling and total lens opacity) developed 11-12 weeks after irradiation. In the mature cataract, the irradiated lenses not treated with bendazac-lysine (ILNTB) show a 32% increase in water content compared with controls; this increase is 12% in irradiated lens treated with bendazac-lysine (ILTB). Twelve weeks after irradiation the concentration of insoluble proteins in the controls, ILNTB and ILTB is 7.6%, 52.3% and 18.3% respectively. After 6, 8 and 12 weeks the concentration of reduced glutathione in ILNTB decreases by 23%, 81% and 92% as compared with the controls. In the ILTB the decrease is present only 8 and 12 weeks after X-irradiation and is of 55% and 69%, respectively. The sulphydryl-group content in the soluble proteins in ILNTB compared with the controls decreases by 26%, 38% and 47% after 6, 8 and 12 weeks, while in the ILTB a decrease is observed only after 8 and 12 weeks and is 6% and 12%, respectively. The decrease of the sulphydryl groups parallels the increase of the disulphide groups. This increase is already significant (P less than 0.01) after 6 weeks in the ILNTB, whereas it becomes significant in the ILTB only after 8 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of bendazac L-lysine salt on X-ray-induced cataract in the rabbit lens. 369 6

Meticulous studies of the pathophysiology of postoperative eyes are mandatory to find the means of reducing the risks of intraocular surgery. Various methods of examination developed for this purpose are described and their clinical significance discussed. The corneal endothelium shows no proliferative capacity even after injury and great care must be taken to protect this vulnerable cell layer. Drugs may be toxic to the corneal endothelium and their use during surgery must be exercised with caution. The intraocular irrigating solutions must contain calcium and have an appropriate salt composition. Pupillary constriction that occurs during extracapsular cataract extraction is due mainly to prostaglandins synthesized as a result of surgical trauma; this can be prevented by the preoperative use of topical indomethacin. Breakdown of the blood-aqueous barrier after intraocular surgery may also be due to a similar mechanism, and preoperative topical non-steroidal anti-inflammatory agents (indomethacin, flurbiprofen and diclofenac) can prevent this phenomenon, as studied by fluorophotometry. Topical indomethacin also prevents cystoid macular oedema after cataract surgery. Based on the biochemical findings on inflammation after tissue injury, a protocol for the preoperative and postoperative use of corticosteroid and non-steroidal anti-inflammatory agents is proposed for anterior segment surgery.
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PMID:Pathophysiology and pharmacology of intraocular surgery. 390 61

Quantification and biosynthesis of type I and type III collagens were determined in skin of control and Fraser mice (CatFraser mutation), which exhibit a genetically determined cataract. Skin organ cultures were labelled with [3H]proline. Pepsin-solubilized collagens were studied using three different approaches: (a) differential salt precipitation at neutral pH, followed by SDS-polyacrylamide gel electrophoresis; (b) differential salt precipitation at acid pH followed by SDS-polyacrylamide gel electrophoresis. (c) CNBr peptide analysis. These methods gave consistent and reproducible results, indicating a selective decrease of type I collagen in Fraser mouse skin as compared to control mouse skin. Metabolic labelling of skin organ cultures showed a decreased specific radioactivity of hydroxy[3H]proline in type I collagen of Fraser mouse skin. The concordant results of these experiments suggest a genetically determined alteration of interstitial collagen metabolism in the Fraser mutation apparently specifically concerning the expression of type I collagen gene(s).
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PMID:Selective decrease of type I collagen synthesis in Fraser mice skin. 393 69

Simplified manual forms of extracapsular cataract extraction appear to be more economical, yet as safe and simple as techniques employing more complex instrumentation. The following method, employed in 40,000 cases, seems to the author to be an efficient and effective way of performing cataract extraction. One hour prior to surgery, modified retrobulbar anesthesia alone is employed using the technique described, and provides adequate akinesia as well as anesthesia. Positive pressure is applied to the eye preoperatively to assure softness of the globe at the time of surgery. An anterior capsulectomy is made with scissors, using the open-sky technique. Following the delivery of the lens nucleus and as much cortex as possible with a lens loop, the remaining cortex is removed with an angled, 23-gauge, double irrigation-aspiration cannula. Filtered balance salt solution, containing gentamycin flows into the eye through the side port (inflow) and a 3-cc syringe with 2 cc BSS for irrigation-aspiration is connected to the other (aspiration) port. A single, 25-gauge, angled irrigation cannula is used to clean up the finger cortical remains. A firm-loop intraocular lens is inserted into the capsular bag. The posterior capsule is left intact.
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PMID:My method of extracapsular cataract extraction with implantation of a posterior chamber intraocular lens. 402 61

The use of sodium hyaluronate in 383 cases of Cataract extraction with primary lens implantation has been to be effective, non-toxic and safe. Chief uses are to protect the corneal endothelium during nucleus extraction and to maintain the anterior chamber depth during lens implantation and during iris suturing. It is important not to use excessive amounts and to dilute with miochol or salt solution during wound closure. Using these techniques sodium hyaluronate was found to be free from side effects and when timolol maleate was used b.d. from the close of surgery the incidence of postoperative ocular hypertension was found to be no different from that in a control group. Endothelial cell studies showed a cell loss of 13 per cent to be within the range previously established for intracapsular cataract surgery without lens implantation, and support a widening conviction that lens implantation may now be regarded as a safe procedure.
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PMID:Sodium hyaluronate in cataract and intraocular lens surgery. 658 65

Bendazac, as such or in the form of its l-lysine salt, has a protective effect against lens protein denaturation both in vitro and in vivo. In vitro this effect has been documented on the lens proteins of rats, rabbits and pigs by using nephelometry, electrophoresis and electron microscopy. In vivo the protective effect has been observed after treatments ranging in duration from 3 to 14 days depending on the dosage used; the minimal effective dose produced a serum level of 35 micrograms/ml of bendazac. The penetration of the drug into the lens has been shown by both radioassay and HPLC; the lens concentration of bendazac increases with the duration of treatment. The mechanism of the protective action of bendazac against lens protein denaturation is discussed together with the implications of such protective action in the treatment of cataract.
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PMID:Basic data supporting the use of the l-lysine salt of bendazac in cataract. 661 87


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