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)

To evaluate accumulation of advanced glycation end-products (AGE) in diabetes and its possible correlation with late diabetic complications, AGE levels were measured by spectrofluorimetry in eye lens and sciatic nerve proteins and isolated tail tendon collagen of rats with experimental diabetes of 3- and 6-month duration. The values obtained were compared to those from age-matched control rats and correlated with cataract presence and somatosensory evoked potential (SEP) alterations. Diabetic animals had increased AGE levels in all tissues at both times; cataract developed in 29% of diabetic rats at 3 months and in 57% at 6 months; SEP conduction velocity was reduced in diabetic animals both at 3 (54.5 +/- 1.8 S.E.M. m/s vs. 73.9 +/- 1.0, P < 0.0001) and 6 months (59.5 +/- 1.4 vs. 71.5 +/- 1.6, P < 0.0001) from diabetes induction. No eye lens AGE level differences were observed when cataract presence was considered. Interestingly, in diabetic rats, increased sciatic nerve AGE levels were associated with reduced SEP. These data show that: (1) AGE levels are increased as early as 3 months from development of hyperglycemia; (2) other factors, in addition to an enhanced rate of fluorescent AGE formation, might play important roles in the pathogenesis of diabetic cataract; (3) increased peripheral nerve AGE levels are associated with SEP alterations.
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PMID:Role of advanced glycation end-products (AGE) in late diabetic complications. 758 17

Using a biomechanical wound strength model, we compared the efficacy of cyanoacrylate and fibrin glues used to close scleral tunnel incisions. Scleral tunnel incisions were made in four groups of rabbits: (1) traditional self-sealing incision, (2) modified non-self-sealing incision, (3) method 2, closed with cyanoacrylate glue, or (4) method 2, closed with fibrin glue. Overall, Groups 1 and 4 showed the least clinical reaction, the slightest decrease in intraocular pressure (which recovered to baseline by day 7), and the most significant recovery of postoperative astigmatism. Initially, the bursting pressure in Groups 1 and 3 was statistically the highest (P < .005). By day 3, wound strengths in Groups 1 and 4 were comparable. Bursting pressure decreased in Groups 2 and 3 by day 7. Our results indicate that clinical responses, intraocular pressure, induced astigmatism, and ultimately wound strength were comparable in fibrin-glue-closed scleral pocket and sutureless self-sealing cataract incisions. Although cyanoacrylate glue cures immediately and initially demonstrates a strong adhesive quality, it causes a severe inflammatory response that inhibits subsequent collagen remodeling. Fibrin tissue adhesives may have an application as adjunctive means of closing scleral tunnel incisions.
J Cataract Refract Surg 1995 May
PMID:Evaluation of tissue adhesives in closure of scleral tunnel incisions. 767 71

We used a disposable bandage soft contact lens piggybacked onto a medicated, 12-hour corneal collagen shield to promote postoperative corneal epithelial healing and to provide sustained delivery of high levels of medications after corneal surgery in patients known to have poor corneal epithelial wound healing characteristics. Our experience with three patients indicates that the collagen shield dissolves completely by the first postoperative day and that the bandage lens remains in place with good mobility until it is removed when epithelialization is complete. This system eliminates the need for painful manipulation and placement of a bandage soft contact lens in an edematous, inflamed eye during the immediate postoperative period.
J Cataract Refract Surg 1995 Mar
PMID:A corneal lens/shield system to promote postoperative corneal epithelial healing. 779 Oct 49

The fibrous type of human posterior capsule opacification was examined by electron microscopy and immunoelectron microscopy to determine which types of collagen were present. The opacification consisted of lens epithelial cells and a large amount of extracellular matrix. The extracellular matrix comprised collagen fibrils and basal lamina-like material. Immunoelectron microscopy revealed that collagen types I, III, and IV were present. Types I and III were localized to the collagen fibrils. Type IV was present in the basal lamina of the lens epithelial cells and in the basal lamina-like material of the extracellular matrix.
J Cataract Refract Surg 1994 Nov
PMID:Collagen types in human posterior capsule opacification. 783 77

A better understanding of the functions of ascorbic acid would help clarify the magnitude of the influence of this vitamin on health-related conditions. Many of the purported benefits require confirmation as well as a knowledge of the mechanism of action. The majority of investigations of the association of vitamin C with various types of cancer, with cardiovascular risk, and with cataract formation were epidemiologic studies. Often it was not possible to discern whether the apparent protective effect was due to vitamin C, vitamin E, or carotene, or to a combined effect of these nutrients or of additional factors. Human intervention trials may provide definitive and quantitative assessments of the role of vitamin C in health maintenance. We need to gain a more thorough understanding of the interactions of vitamin C with other nutrients, such as vitamin E and carotenoids, in order to appreciate the role of vitamin C in disease prevention. Investigators are increasingly recognizing the diverse functions of vitamin C in the body in addition to its role in collagen synthesis. However, the functional consequences of these many important roles of vitamin C remain essentially unknown. Excluding scurvy, the health consequences of inadequate vitamin C status are not well characterized. Nonetheless, epidemiologic evidence suggests a role for vitamin C in cancer and heart disease as well as in a number of other diseases.
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PMID:Pharmacology of vitamin C. 794 25

There is an enormous amount of literature on vitamin C intake and health in animals, cell cultures, and humans. Beyond its function in collagen formation, ascorbic acid is known to increase absorption of inorganic iron, to have essential roles in the metabolism of folic acid and of some amino acids and hormones, and to act as an antioxidant. In recent years, research has increasingly focused on this latter function, stimulated by suggestions that "oxidative stress" may be a causal factor in the etiology of such diverse and important disorders of aging as cancer, cardiovascular disease, and cataract formation. The present evidence is strong enough to have convinced nutritionists that daily vitamin C intake should be many times higher than the amount needed to protect against scurvy, and this is reflected in the present Recommended Dietary Allowances. Suggestions that the recommended levels should be higher still are largely based on extrapolations from results of animal and tissue culture studies. How much ascorbic acid is necessary to achieve in humans the effects seen in animal studies is not clear. In general, the limited human studies have not been persuasive. The data are incomplete, and many of the studies have serious flaws. There are no toxicity studies of the type done for new compounds being considered for approval as therapy for major disease conditions. Intervention studies will be difficult, but are essential, and methods for tissue saturation measurement must be defined before new recommendations for the public are designed.
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PMID:Vitamin C (ascorbic acid): new roles, new requirements? 805 61

We evaluated the influence of age upon conjunctival structure and number of inflammatory cells by studying perioperative conjunctival biopsies from 54 consecutive primary open-angle glaucoma patients undergoing initial filtering surgery (trabeculectomy alone or combined cataract extraction and trabeculectomy). All patients had received chronic topical glaucoma therapy for > 1 year. We divided the patients into three age groups for analysis: 40-60 (n = 10), 61-74 (n = 28), and > 75 (n = 16) years. We found no statistical difference (p > 0.05, chi-square) in cell counts of neutrophils, eosinophils, mast cells, macrophages, fibroblasts, lymphocytes, plasma cells and goblet cells across the three age groups. In addition, no statistical differences were observed between age groups in vascular density, epithelial thickness as well as mucopolysaccharide and collagen composition (p > 0.05, chi square). This study suggests that conjunctival structure and inflammatory cell counts change little with advancing age in primary open-angle glaucoma patients.
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PMID:The influence of age upon inflammatory cell counts and structure of conjunctiva in chronic open-angle glaucoma. 810 16

A randomized, prospective, multicenter study evaluated the efficacy and safety of using collagen shields to deliver drugs after cataract surgery. Collagen shields saturated with an antibiotic and a steroid were placed in 90 eyes postoperatively. A control group of 93 eyes received the same drugs through a peribulbar/retrobulbar injection. One day after surgery, the shield group had significantly less corneal edema, conjunctival hemorrhaging, and postoperative pain and fewer corneal opacities. All symptoms except the conjunctival hemorrhaging disappeared by day seven. Our study suggests that using collagen shields for drug delivery after cataract surgery decreases tissue damage and increases patient comfort without adverse side effects.
J Cataract Refract Surg 1994 Mar
PMID:Use of collagen shields in cataract surgery. 783 90

In studies conducted by numerous investigators for 150 years, lenses regenerated following endocapsular lens extraction in New Zealand albino rabbits have been irregular in shape, appearing primarily doughnut-shaped as a result of lack of lens growth at the site of the anterior capsulotomy and its adhesion to the posterior capsule. In the present study, we restored the lens capsule integrity by inserting a collagen patch at the time of surgery to seal the anterior capsulotomy and to improve the shape and structure of the regenerated lenses. We then filled the capsule bag with air to prevent adhesions between the anterior and posterior capsule and maintain capsule tautness and shape. Lens regeneration was first noted as early as one to two weeks. Regenerated lens filled approximately 50% of the capsule bag at two weeks and 100% by five weeks. Subsequent growth was in the anterior-posterior direction and measured by A-scan biometry. Lens thickness increased by 0.3 mm per month. The regenerated lenses were spherical with normal cortical structure and a nuclear opacity. In conclusion, restoration of lens capsular integrity with a collagen patch following endocapsular lens extraction enhanced the shape, structure, and growth rate of the regenerated lenses. In addition, lens regeneration was shown to occur in two cats.
J Cataract Refract Surg 1993 Nov
PMID:Restoring lens capsule integrity enhances lens regeneration in New Zealand albino rabbits and cats. 827 Nov 70

The arrangement of the collagen fibrils of the sclera was analyzed at defined areas by using SEM with regard to morphological alterations in cases of glaucoma and to postoperative astigmatism after cataract operations. Adult eyes with no apparent pathological changes were studied. In the lamina cribrosa the collagen fibrils are arranged circularly around the points of passage of the axons and vessels. In the region of the muscle attachments the tendinous collagen fibrils intersect the bundles of collagen fibrils of the sclera at right angles. The collagen fibrils form a reticular structure on the external surface of the sclera. A main route of alignment can only be identified in a few places. The collagen fibrils are aligned in a rhombic pattern on the internal surface of the sclera. The immunohistochemical analysis revealed collagen types I and III in the sclera, while collagen types I, III and IV were found in the lamina cribrosa.
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PMID:The collagen architecture of the sclera--SEM and immunohistochemical studies. 833 19


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