33 research outputs found

    Heme oxygenase 1 improves glucoses metabolism and kidney histological alterations in diabetic rats

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    One important concern in the treatment of diabetes is the maintenance of glycemic levels and the prevention of diabetic nephropathy. Inducible heme oxygenase 1 (HO-1) is a rate-limiting enzyme thought to have antioxidant and cytoprotective roles. the goal of the present study was to analyze the effect of HO-1 induction in chronically hyperglycemic rats. the hyperglycemic rats were divided into two groups: one group, called STZ, was given a single injection of streptozotocin; and the other group was given a single streptozotocin injection as well as daily injections of hemin, an HO-1 inducer, over 60 days (STZ + HEME). A group of normoglycemic, untreated rats was used as the control (CTL).Body weight, diuresis, serum glucose levels, microalbuminuria, creatinine clearance rate, urea levels, sodium excretion, and lipid peroxidation were analyzed. Histological alterations and immunohistochemistry for HO-1 and inducible nitric oxide synthase (iNOS) were assessed. After 60 days, the STZ group exhibited an increase in blood glucose, diuresis, urea, microalbuminuria, and sodium excretion. There was no weight gain, and there was a decrease in creatinine clearance in comparison to the CTL group. in the STZ + HEME group there was an improvement in the metabolic parameters and kidney function, a decrease in blood glucose, serum urea, and microalbuminuria, and an increase of creatinine clearance, in comparison to the STZ group.There was glomerulosclerosis, collagen deposition in the STZ rats and increase in iNOS and HO-1 expression. in the STZ + HEME group, the glomerulosclerosis and fibrosis was prevented and there was an increase in the expression of HO-1, but decrease in iNOS expression and lipid peroxidation. in conclusion, our data suggest that chronic induction of HO-1 reduces hyperglycemia, improves glucose metabolism and, at least in part, protects the renal tissue from hyperglycemic injury, possibly through the antioxidant activity of HO-1.Universidade Federal de SĂŁo Paulo UNIFESP, Div Nephrol, Dept Med, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo UNIFESP, Morphol Dept, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo UNIFESP, Div Nephrol, Dept Med, SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo UNIFESP, Morphol Dept, SĂŁo Paulo, BrazilWeb of Scienc

    Effects of Topically Administered Neuroprotective Drugs in Early Stages of Diabetic Retinopathy:Results of the EUROCONDOR Clinical Trial

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    The primary objective of this study was to assess whether the topical administration of two neuroprotective drugs (brimonidine and somatostatin) could prevent or arrest retinal neurodysfunction in patients with type 2 diabetes. For this purpose, adults aged between 45 and 75 years with a diabetes duration ≥5 years and an Early Treatment of Diabetic Retinopathy Study (ETDRS) level of ≤35 were randomly assigned to one of three arms: placebo, somatostatin, or brimonidine. The primary outcome was the change in implicit time (IT) assessed by multifocal electroretinography between baseline and at the end of follow-up (96 weeks). There were 449 eligible patients allocated to brimonidine (n = 152), somatostatin (n = 145), or placebo (n = 152). When the primary end point was evaluated in the whole population, we did not find any neuroprotective effect of brimonidine or somatostatin. However, in the subset of patients (34.7%) with preexisting retinal neurodysfunction, IT worsened in the placebo group (P < 0.001) but remained unchanged in the brimonidine and somatostatin groups. In conclusion, the topical administration of the selected neuroprotective agents appears useful in preventing the worsening of preexisting retinal neurodysfunction. This finding points to screening retinal neurodysfunction as a critical issue to identify a subset of patients in whom neuroprotective treatment might be of benefit

    “The sound induced phosphene illusion”

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    Crossmodal illusions clearly show how perception, rather than being a modular and self-contained function, can be dramatically altered by interactions between senses. Here, we provide evidence for a novel crossmodal "physiological" illusion, showing that sounds can boost visual cortical responses in such a way to give rise to a striking illusory visual percept. In healthy participants, a single-pulse transcranial magnetic stimulation (sTMS) delivered to the occipital cortex evoked a visual percept, i.e., a phosphene. When sTMS is accompanied by two auditory beeps, the second beep induces in neurologically unimpaired participants the perception of an illusory second phosphene, namely the sound-induced phosphene illusion. This perceptual "fission" of a single phosphene, due to multiple beeps, is not matched by a "fusion" of double phosphenes due to a single beep, and it is characterized by an early auditory modulation of the TMS-induced visual responses (~80 ms). Multiple beeps also induce an illusory feeling of multiple TMS pulses on the participants' scalp, consistent with an audio-tactile fission illusion. In conclusion, an auditory stimulation may bring about a phenomenological change in the conscious visual experience produced by the transcranial stimulation of the occipital cortex, which reveals crossmodal binding mechanisms within early stages of visual processing

    Final versus referral diagnosis of childhood visual impairment in an Italian tertiary low vision rehabilitation centre

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    Purpose: To compare the final diagnosis of the causes of low vision in children attending a tertiary rehabilitation centre for visually impaired children versus referral diagnosis. Methods: Retrospective review of clinical charts of all children referred to the Robert Hollman Foundation, a tertiary centre for visually impaired children, between January 2010 and June 2011. The following clinical data were analysed: entry diagnosis made by the referral ophthalmologist and final diagnosis made at Robert Hollman Foundation based on a complete ophthalmic evaluation. Results: Ninety-two consecutive children (mean age = 2.37 \ub1 1.98 years, range = 0\u20139) were included. A referral diagnosis was retrieved in 76 cases (82.6%), including cerebral visual impairment (14.1%), retinopathy of prematurity (14.1%), hereditary retinal diseases (10.9%), nystagmus (8.7%) and other rarer diseases (34.8%). In the remaining 16 children (17.4%), a precise referral diagnosis was unavailable. Final clinical diagnosis made at Robert Hollman Foundation was normal visual function in 8.7%, cerebral visual impairment in 30.4%, retinopathy of prematurity in 10.9%, hereditary retinal disease in 9.8% and other in 40.2%. In 17 cases (18.5%), the diagnosis made at the Robert Hollman Foundation did not confirm the entry diagnosis. Among patients where measurement of visual acuity was possible (84), 66.7% were blind or seriously visual impaired, and the main causes were cerebral visual impairment (32.1%) and retinopathy of prematurity (16.1%). Conclusion: The most frequent diseases were cerebral visual impairment, retinopathy of prematurity and hereditary retinal diseases. Approximately one-third of referred children had not a correct diagnosis at baseline. The activity of an ophthalmic tertiary centre is essential to offer a precise diagnosis to visually impaired (sometimes with other deficits) children

    Single retinal layer changes after subthreshold micropulse yellow laser in diabetic macular edema

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    A pilot prospective, interventional study has been conducted on 10 patients with diabetic macular edema (DME) treated with subthreshold micropulse laser (SMPL) to evaluate changes of individual retinal layers and to correlate with functional changes. All patients underwent complete ophthalmologic evaluation including spectral-domain optical coherence tomography (OCT) and microperimetry at baseline, 3 months, 6 months, 9 months, and 12 months. Compared with baseline, a significant decrease was found in inner nuclear layer (INL) and outer retinal layer (ORL) thickness in the central 1 mm (P < .05). Increase in best-corrected visual acuity was significantly and inversely correlated to central retinal thickness (CRT) (P = .0027), INL (P = .0167), and outer nuclear layer (ONL) thickness (P = .0107). Increase in retinal sensitivity was significantly and inversely correlated to CRT and ONL thickness (P < .01). Therefore, SMPL showed to improve firstly functional parameters and then morphologic parameters. Functional parameters were inversely correlated to CRT, INL, and ONL thickness. The exact mechanism of reduction of INL thickness induced by SMPL remains to be further evaluated
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