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

A study was made of diabetic retinopathy in acromegaly. 10 of 15 patients with acromegaly had diabetes mellitus, and 3 of the 10 showed diabetic retinopathy. 2 of them had a diabetic family history. 1 patient with a diabetic family history had retinopathy of state IIIa in Scott's classification, and the other 2 showed a few microaneurysms and/or punctate hemorrhages in the macula. Diabetes mellitus and diabetic retinopathy in acromegaly showed no correlation with the duration of acromegaly and diabetes mellitus, age, or growth hormone level. No diabetic cataract was found in the present series. It was concluded that diabetic retinopathy due to secondary diabetes mellitus is usually slight or moderate. Diabetes mellitus with severe retinopathy is probably primary diabetes due to a genetic defect, and secondary diabetes may be different in nature from the primary disease.
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PMID:Diabetic retinopathy in acromegaly. 63 58

214 patients who underwent cataract-extraction in 1973 were examined for systemic diseases. The average age of patients with (70%) and without (30%) general diseases was 67 years. The frequency of cardio-vascular and respiratory diseases corresponded to that observed in the general population of the same age. In contrast, the rate of diabetes mellitus was four times higher than to be expected statistically. The importance of an adequate clinical management of diabetic cataract patients is discussed.
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PMID:[Systemic diseases in patients with cataract-extraction (author's transl)]. 73 2

Cataract is the major cause of blindness worldwide and at present the only approved treatment in many countries including the UK and USA is surgical removal of the lens. In other countries various anti-cataract drugs are available without proof of their efficacy. Research is continuing into the possible benefits of several groups of drugs and some vitamins. The first to be studied were sorbitol-lowering agents (aldose reductase inhibitors) based on the sorbitol hypothesis for diabetic cataract. Sorbitol-lowering agents have distinct effects in vitro and many of them delay the development of cataract in galactose-fed rats. A few delay cataract in diabetic rats but none have been proved effective in clinical trials, although these continue. Aspirin, paracetamol (acetaminophen) and ibuprofen delay diabetic cataract in rats, and have been shown to delay other experimental cataracts. Case-control studies from 3 continents indicate that these drugs, or at least aspirin, protect against cataract. Results of studies on all 3 drugs indicate a benefit even at low doses. Population-based studies did not identify any protection against early lens opacities but tiny opacities that do not impair vision are not a problem. Bendazac protects lens proteins in vitro and delays cataractogenesis in x-irradiated rats. In humans, it reached the clinical trial stage but most trials have been small and with subjective criteria of opacification. One objectively monitored trial suffered from a high drop-out rate. Other preparations studied less extensively include vitamins, aminoguanidine to prevent protein cross-linking in diabetes and agents designed to boost glutathione levels. It is probable that some agents which may delay or prevent cataract will be proved effective soon, and in the end there may be different drugs to delay cataract in different high risk groups. This is what might be expected of a multifactorial disease, although compounds that intervene in the final common pathways to cataract could have a broad efficacy.
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PMID:Pharmacological treatment strategies in age-related cataracts. 150 43

The effect of the instillation of gamma-glutamylcysteinylethyl ester (gamma-GCE), which has been reported to function as a precursor of glutathione, on cataract formation was examined in rats in which diabetes had been induced by Streptozotocin (STZ). Three days after i.p. treatment with 50 mg/kg body weight of STZ, male Wistar rats aged 6 weeks received instillations of gamma-GCE in solution or liposomes prepared with dipalmitoylphosphatidylcholine (DPPC) for a period of 9 weeks. Cataract formation and development were observed by use of a cataract camera every week. After 9 weeks' observation, the lenses were enucleated and the content of the lens GSH was measured. Instillation of gamma-GCE in solution or liposomes to STZ-diabetic rats not only inhibited cataract formation but also kept lens GSH level almost at the control level. In addition, the inhibitory effect of the instillation of gamma-GCE in liposome was stronger than that of gamma-GCE in solution. The present results indicate that the administration of gamma-GCE in solution or in liposomes inhibits diabetic cataract formation, possibly by preventing lens GSH depletion.
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PMID:[The inhibitory effect of gamma-glutamylcysteinylethyl ester (gamma-GCE) instillation on experimental diabetic cataract formation in rats]. 183 18

To assess the significance of glycation, nonenzymatic browning, and oxidation of lens crystallins in cataract formation in elderly diabetic patients, we measured three distinct products of glycation, browning, and oxidation reactions in cataractous lens crystallins from 29 diabetic patients (mean +/- SD age 72.8 +/- 8.8 yr) and 24 nondiabetic patients (age 73.5 +/- 8.3 yr). Compounds measured included 1) fructoselysine (FL), the first stable product of glycation; 2) pentosidine, a fluorescent, carbohydrate-derived protein cross-link between lysine and arginine residues formed during nonenzymatic browning; and 3) N epsilon-(carboxymethyl)lysine (CML), a product of autoxidation of sugar adducts to protein. In diabetic compared with nondiabetic patients, there were significant increases (P less than 0.001) in HbA1 (10.2 +/- 3.1 vs. 7.1 +/- 0.7%), FL (7.6 +/- 5.4 vs. 1.7 +/- 1.2 mmol/mol lysine), and pentosidine (6.3 +/- 2.8 vs. 3.8 +/- 1.9 mumol/mol lysine). The disproportionate elevation of FL compared with HbA1 suggests a breakdown in the lens barrier to glucose in diabetes, whereas the increase in pentosidine is indicative of accelerated nonenzymatic browning of diabetic lens crystallins. CML levels were similar in the two groups (7.1 +/- 2.4 vs. 6.8 +/- 3.0 mmol/mol lysine), providing no evidence for increased oxidative stress in the diabetic cataract. Thus, although the modification of lens crystallins by autoxidation reactions was not increased in diabetes, the increase in glycation and nonenzymatic browning suggests that these processes may acclerate the development of cataracts in diabetic patients.
Diabetes 1991 Aug
PMID:Role of glycation in modification of lens crystallins in diabetic and nondiabetic senile cataracts. 190 46

As the UV-B cataract and early stages of diabetic cataract in rats only touches the epithelium and anterior superficial cortex, a whole lens analysis is not meaningful, but a regional analysis with the freeze-sectioning device has to be performed. Scheimpflug photography with microdensitometric image analysis enables the scientist to discern in vivo single layers along the optical axis of the lens. UV-B cataracts (0.2 J/cm2, every 2nd day) and diabetic cataracts (Streptozotocin (STZ), 70 mg/kg BW) were induced in Brown-Norway rats. The stages of lens opacification were documented by Scheimpflug photography. 8 weeks after start of UV-B treatment and at several dates before onset of visible diabetic cataractous changes, the animals were sacrificed. The lenses were divided reproducibly into 4 or 7 parts such as an equatorial ring and several layers of the central cylinder from anterior to posterior part. The enzyme activity spectrum shows highly region related pattern that would not have been found in a whole lens analysis. Aldose reductase was activated before appearance of visible cataractous changes due to diabetes compared to normal lenses. In contrast Fructose-1,6-biphosphate-aldolase activity was lower before onset of visible changes than in normal lenses, but only within the 1st section where later visible cataractous changes of UV-B cataract could be detected.
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PMID:Regional enzymatic analysis of UV-B and streptozotocin induced diabetic cataract lens. 196 39

Crystallin glycation seems to play an important role in the development of diabetic cataract. In order to understand the role of glycation in cataractogenesis, levels of glycation of different crystallins were determined by in vitro glycation of rat lens soluble fraction with 50 mM glucose or glucose-6-phosphate (G6P) for up to 5 days and in streptozotocin-diabetic rats during various stages of cataract development. All samples were reduced with [3H]NaBH4 and the tritium incorporation was taken as a measure of glycation. Proteins were routinely separated by molecular sieve HPLC. In vitro studies with glucose showed that gamma-crystallin was readily glycated and reached a plateau by 3 days, while alpha- and beta-crystallins were glycated slowly initially up to 3 days followed by a steep increase as seen on the fifth day. Incubation with 50 mM G6P resulted in an approximately two fold increase in glycation compared to glucose of all crystallins. In the diabetic animals also gamma-crystallin glycation increased approximately twofold within 15 days after the onset of diabetes and an additional threefold within the next 45 days followed by a slight decrease during the following 90-120 days. Increase in glycation, on the contrary, was very slow up to 30 days for alpha-crystallin and up to 60 days for beta-crystallin, followed by a steep increase during the remainder of the experimental period. The high molecular weight (HMW) aggregates had higher levels of glycation than other proteins; the insoluble HMW aggregates contained higher levels of glycation than the soluble HMW aggregates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential glycation of rat alpha-, beta- and gamma-crystallins. 203 22

The WBN/Kob rat is an animal model of spontaneously occurring diabetes only in males at the age of around one year. The diabetic cataract develops about a half year after the onset of diabetes. Using laser Raman spectroscopy we monitored WBN/Kob rat lenses which had chronic hyperglycemic stress and streptozotocin-induced diabetic rat lenses which showed relatively acute cataract formation. WBN/Kob rat lenses revealed a marked increase in the lens water content only in the cortical portion. On the other hand, streptozotocin-induced diabetic rat lenses showed a pronounced increase in the lens water content both in the cortical and the nuclear portion.
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PMID:Raman study of the lenses of spontaneously-occurring and streptozotocin-induced diabetic rats. 215 May 37

Diabetes causes cataract and certain physical changes in the lens. The diabetic lens is larger than the non-diabetic and shows greater light scatter and fluorescence. Both hyperglycaemia and lowering of blood glucose case refractive changes and hypermetropia is the most common. Classical 'snow-flake' juvenile cataract associated with hyperglycaemia is now rare. It has an osmotic mechanism. Diabetes is a risk factor for cataract in adults which is duration dependent, more frequent in women and leads to earlier surgery. It resembles non-diabetic senile cataract. Extracapsular cataract extraction is the method of choice for diabetic cataract with a better visual result and less risk of rubeosis iridis. A posterior chamber implant may still permit retinal photocoagulation if necessary. Diabetic retinopathy is still the leading cause of blindness in the working age group. The beneficial effect of photocoagulation has been shown by randomized controlled trials to be long-lasting for both proliferative retinopathy and maculopathy. Therefore there is a need for screening, especially for those with proliferative disease which may be present without symptoms. A knowledge of risk factors will enhance detection rate with duration as the strongest determinant for retinopathy. Any screening modality should be highly sensitive as well as specific. The role of different professionals as potential screeners should be considered. Adequate provisions include facilities for checking vision and for dimming ambient lighting. Mydriasis and a good ophthalmoscope light will increase detection rate. The use of a 45 degrees non-mydriatic camera is unlikely to supplant the use of an ophthalmoscope as a single field is likely to miss important lesions. A 60 degrees camera may confer a large enough field and the use of transparencies will provide magnification when films are projected but the camera is more difficult to use. A list of features chosen by a recent study to characterize sight-threatening retinopathy is included and their presence indicates the need for referral to an ophthalmic clinic for treatment or close observation.
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PMID:Cataract and retinopathy: screening for treatable retinopathy. 309 17

Increased blood sugar levels may influence the refractive power of the lens in juvenile diabetics, and can lead to the rare true diabetic cataract ("snow-storm cataract"). Surplus glucose induces accumulation of the sugar alcohol within the cells, thus generating disturbances of the osmotic balance and finally causing cataract. The enzyme aldose reductase catalyzes the formation of sorbitol. Experiments with animals have shown that aldose reductase inhibitors can prevent the formation of such opacities with streptozotocin-induced diabetes in rats. Numerous aldose reductase inhibitors are now known, but we still have insufficient knowledge to determine whether systemic or local administration is preferable. The mechanisms reported here are not relevant with respect to the frequent occurrence of senile cataract in older diabetics, which has often been described.
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PMID:[Aldose reductase inhibitor--a new way for preventing diabetic lens changes?]. 310 Aug 60


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