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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The paper describes results after a study of pathochemical disturbances of diabetic hyperglycemia on a model of alloxan diabetes. Sugar and amino nitrogen contents in the aqueous humor of the anterior chamber, anterior and posterior segments of the crystalline lens, the iris, ciliary body, choroid and the retina were studied and the data obtained were compared with quantitative contents of sugar and amino nitrogen in the eliminate from the eyes of experimental animals. High amounts of sugar and amino nitrogen, infrequently exceeding 2-3 times in controls, were found to appear in the aqueous humor of the anterior chamber, the crystalline lens, the vitreous body. In all tests the sugar and amino nitrogen contents in the posterior segment of the lens was 10-12% higher than in its anterior segment. The data obtained about accumulation of sugar and amino nitrogen mainly in tissues and media of the eye (the lens, the vitreous) affected by diabetic process already at its early stages widen the knowledge about pathogenesis of the process and peculiarities of its pathochemistry.
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PMID:[The pathochemistry of the diabetic process in the eye based on data on experimental hyperglycemia (alloxan diabetes)]. 258 77

In this study we have investigated the oxidative metabolism of red blood cells (RBC), plasma, serum, aqueous humor, and lens of healthy subjects and of age-matched cataractous patients with and without diabetes. Reduced and oxidized glutathione (GSH GSSG) levels in RBC were similar among the three groups. Plasma levels of GSSG were higher in diabetics than in cataractous and control subjects. No differences in plasma content of GSH were noted among the three groups. The activity of the enzyme glucose-6-phosphate dehydrogenase was significantly diminished in diabetic patients. Controls and cataractous patients showed similar levels of malondialdehyde (MDA). Although not significant the MDA content in RBC from diabetics was elevated. No differences in plasma levels of vitamin E were noted among the three groups. The biological liquid oxidant activity of serum in diabetic patients was significantly higher than in controls and cataractous patients. GSH levels in aqueous humor were similar in diabetic and nondiabetic cataractous patients. The content of GSSG in aqueous humor was highest in diabetic patients. Control clear lenses showed low levels of MDA. The MDA levels in cataractous lenses from nondiabetic patients were significantly higher than those of controls. In diabetic patients the content of MDA in the lens was approximately twice as high as the cataractous values. Our results seem to demonstrate that oxidative damage could play a role in the pathogenesis of cataract in diabetes.
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PMID:Systemic human diseases as oxidative risk factors in cataractogenesis. I. Diabetes. 318 3

Insulin concentrations were measured in the aqueous humors of insulin-treated and untreated diabetic rabbits. The aqueous humor insulin concentration of diabetic rabbits after feeding was less than that of normal control animals. When diabetic rabbits were treated with insulin, the aqueous humor insulin concentration rose to concentrations much greater than in normal ones. The aqueous: plasma concentration ratios of both insulin and total protein for diabetic animals were greater than those for normal ones and suggest that the permeability of the blood-aqueous barrier was greater in the diabetic rabbits. Since insulin is known to be capable of influencing the metabolism of the lens, it is conceivable that abnormal insulin concentrations in aqueous humor may influence the development of cataract in diabetes.
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PMID:Insulin concentration in aqueous humor of rabbits: effects of alloxan-diabetes and insulin treatment. 635 95

50 patients with diabetes mellitus of 2-7 years' duration were divided by a random method into 2 equal groups, one of which received 1,500 mg of Doxium (calcium dobesilate) daily for 3 months, the other group receiving a placebo. All the patients had diabetic retinopathy, open-angle glaucoma, raised intraocular pressure, and hyperviscosity of whole blood, plasma, and aqueous humor. 10 patients in each group underwent operation for glaucoma. At the end of the trial the state of the retina, the visual acuity, and the visual fields had improved, and the intraocular pressure and the 3 viscosity values had fallen to a statistically significant extent in the Doxium group compared with the initial status and with the placebo group. These results are consistent with Doxium's known action in reducing capillary fragility, microvascular hyperpermeability, and blood viscosity.
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PMID:Hyperviscosity in whole blood, plasma, and aqueous humor decreased by doxium (calcium dobesilate) in diabetics with retinopathy and glaucoma: a double-blind controlled study. 638 3

Samples of aqueous humor obtained at cataract operations were analyzed for sodium hyaluronate by a recently developed radioassay. The mean value +/- SD of 47 samples was 1.14 +/- 0.46 micrograms/g. The samples from patients with diabetes and/or glaucoma did not differ substantially from the general distribution.
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PMID:Hyaluronate in human aqueous humor. 684 47

We have discussed the nature of a scleral lens that will allow us to follow changes in aqueous humor glucose levels in animals by a method based on optical rotation and a technique described in an earlier paper. We have shown how this lens can be micro-miniaturized and can be used in humans as a non-invasive glucose monitor. We have described preliminary experiments designed to show the correlation between the blood glucose assay (BGA) and the aqueous humor glucose concentration as determined by chemical assay (AGA) and by optical rotation determination (ARD). The last mentioned has been obtained by paracentesis directly into a microcell used in conjunction with instrumentation capable of measuring optical rotations as low as 0.0013 degrees (4.5") corresponding to 20 mg/dl glucose with a sensitivity of 0.0001 degrees (0.36"). The variability among normal rabbits as a function of individuality and diurnal changes is described, and the correlation between AGA and ARD shown to be essentially 1.0. Such rabbits are examined when undergoing very rapid decreases in BGA (insulin treatment) or very rapid increases in BGA (bolus of glucose). The AGA and ARD are shown to lag behind the BGA, and this is discussed in terms of the rate of change of BGA with respect to time and its concomitant change in AGA/ARD as well as a simple procedure that would materially reduce this lag.
Diabetes Care
PMID:Noninvasive glucose monitoring of the aqueous humor of the eye: Part II. Animal studies and the scleral lens. 689 Aug 93

We have described the concept of using the aqueous humor glucose as a measure of the blood glucose concentration, with a view to developing a noninvasive glucose monitor for diabetic individuals. We have conceived of a scleral lens that houses a light source, polarizers, other electro-optic units, and a light detector, and which measures the optical rotation of the aqueous humor continuously. We have built an optical bench mock-up of the glucose sensor and assessed the limits of its capabilities. We have described a physical method, employing the Faraday effect, that modulates the incident light and uses a compensator to introduce a feedback mechanism giving a null-point technique capable of measuring extremely small rotations with an accuracy of 0.4 s of arc. We have used this and have measured the optical rotations of glucose solutions from 0.02 to 0.1%, and have demonstrated linearity in both cases. Miniaturization of the technique is discussed.
Diabetes Care
PMID:Noninvasive glucose monitoring of the aqueous humor of the eye: Part I. Measurement of very small optical rotations. 717 92

The concentration of over 20 biochemicals in bovine aqueous humor was determined by conventional means, and the contribution of each to the observed optical rotation was estimated. Of those studied, only glucose and the total proteins made a significant contribution. However, other unidentified chemicals apparently also contribute to the optical activity since it was not possible to reconstruct the actual aqueous humor optical rotation based on the chemicals included. Alternative experimental approaches that may yield more complete results are discussed. With further work, optical rotation might be used as the basis of a noninvasive sensor for measuring the glucose concentration of aqueous humor in the intact eye.
Diabetes Care
PMID:The composition and optical rotary dispersion of bovine aqueous humor. 717 93

The etiology of diabetic cataract is usually explained by the following process; the conversion of glucose and galactose to polyol by aldose reductase, then the accumulation of polyol in lens, and the opacity of lens. Another explanation is that the hyperoxidation of lens membrane due to an increase of active oxygen and lipid peroxide in lens induces diabetic cataract. The experimental animals used in the present study were rats with galactose cataract and streptozotocin cataract. We measured the levels of antioxidants (glutathione, ascorbic acid) and lipid peroxide (malonodialdehyde) in lens, aqueous humor and vitreous body. Furthermore we studied the effects of aldose reductase inhibitor (TAT) on these levels. In streptozotocin diabetes rats, the increased malonodialdehyde levels in lens, aqueous humor and serum were suppressed by TAT administration. In galactose and streptozotocin diabetes rats, the decreased levels of glutathione and ascorbic acid were suppressed by TAT administration.
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PMID:[Biochemical changes in lens, aqueous humor and vitreous body and effects of aldose reductase inhibitor (TAT) on rats with experimental diabetes]. 755 22

Studies of ocular immunity showed that incubation of peritoneal exudate cells with antigen in the presence of aqueous humor containing TGF-beta, conferred upon them the ability to systemically inhibit antigen-specific cellular immunity when injected into naive recipients. Since cell mediated immunity has been implicated in the destruction of the islets of Langerhans in diabetes, it was theorized that injection of naive diabetes prone BB/W or rats with peritoneal exudate cells pre-cultured in the presence of islet antigen and TGF-beta might similarly inhibit their anti-islet immune reactions and prevent their development of diabetes. 34.2% (13 of 38) of experimental recipient diabetes prone rats developed diabetes while 78.4% (29 of 37; p < 0.0005 compared to experimentals), 72.2% (13 of 18; p < 0.03 compared to experimentals), 68.8% (11 of 16; p < 0.09 compared to experimentals), and 77.7% (7 of 9; p < 0.08 compared to experimentals) of controls receiving peritoneal exudate cells pre-cultured alone, with TGF-beta, with TGF-beta and pheochromocytoma (PC12) cells, or with islets + TGF-beta + anti-TGF-beta antibody, respectively, became diabetic. Experimental treatment did not markedly alter recipient spleen cell subsets, and spleen cells from protected rats did not confer disease protection when transferred into naive recipients. These data demonstrate that the above approach is efficacious and represents a unique strategy for preventing the development of autoimmune type I diabetes in an animal model.
Diabetes Res 1994
PMID:Prevention of diabetes in BB/Wor rats by injection of peritoneal exudate cells cultured in the presence of transforming growth factor beta (TGF-beta) and islet cells. 764 92


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