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Sample records for retinal ischemic tolerance

  1. Protection of retinal function by sulforaphane following retinal ischemic injury.

    Science.gov (United States)

    Ambrecht, Lindsay A; Perlman, Jay I; McDonnell, James F; Zhai, Yougang; Qiao, Liang; Bu, Ping

    2015-09-01

    Sulforaphane, a precursor of glucosinolate in cruciferous vegetables such as broccoli and cauliflower, has been shown to protect brain ischemic injury. In this study, we examined the effect of systemic administration of sulforaphane on retinal ischemic reperfusion injury. Intraocular pressure was elevated in two groups of C57BL/6 mice (n = 8 per group) for 45 min to induce retinal ischemic reperfusion injury. Following retinal ischemic reperfusion injury, vehicle (1% DMSO saline) or sulforaphane (25 mg/kg/day) was administered intraperitoneally daily for 5 days. Scotopic electroretinography (ERG) was used to quantify retinal function prior to and one-week after retinal ischemic insult. Retinal morphology was examined one week after ischemic insult. Following ischemic reperfusion injury, ERG a- and b-wave amplitudes were significantly reduced in the control mice. Sulforaphane treatment significantly attenuated ischemic-induced loss of retinal function as compared to vehicle treated mice. In vehicle treated mice, ischemic reperfusion injury produced marked thinning of the inner retinal layers, but the thinning of the inner retinal layers appeared significantly less with sulforaphane treatment. Thus, sulforaphane may be beneficial in the treatment of retinal disorders with ischemic reperfusion injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Progressive retinal nonperfusion in ischemic central retinal vein occlusion.

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    Wykoff, Charles C; Brown, David M; Croft, Daniel E; Major, James C; Wong, Tien P

    2015-01-01

    Serial wide-field fluorescein angiography was performed on eyes with preproliferative (ischemic) central retinal vein occlusion to evaluate retinal perfusion. Serial wide-field fluorescein angiography was performed on 12 preproliferative central retinal vein occlusion eyes in the 3-year Rubeosis Anti-VEGF (RAVE) trial using the Staurenghi lens (Ocular Staurenghi 230SLO Retina Lens) with a scanning laser ophthalmoscope (Heidelberg HRA Spectralis). "Disk area" was defined anatomically for each eye. Mean total field of gradable retina was 290 disk areas (range, 178-452). All eyes demonstrated extensive areas of retinal nonperfusion; at baseline, mean area of retinal perfusion was 106 disk areas (range, 37-129), correlating with a mean of 46.5% perfused retinal area (range, 19.1-56.4%). The area of retinal nonperfusion increased in all eyes with a mean loss of approximately 8.1% of perfused retinal area per year (range, 4.3-12.4%), which corresponded to a mean 15-disk areas (range, 12-35) of retina evolving from perfused to nonperfused annually. The extent of baseline and final nonperfusion was not significantly different between eyes that developed neovascularization and eyes that did not. In this population of severe central retinal vein occlusion eyes, profound retinal nonperfusion was observed with wide-field fluorescein angiography at baseline and the extent of nonperfusion progressed while undergoing anti-vascular endothelial growth factor therapy.

  3. Study of retinal vessel oxygen saturation in ischemic and non-ischemic branch retinal vein occlusion

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    Lin, Lei-Lei; Dong, Yan-Min; Zong, Yao; Zheng, Qi-Shan; Fu, Yue; Yuan, Yong-Guang; Huang, Xia; Qian, Garrett; Gao, Qian-Ying

    2016-01-01

    AIM To explore how oxygen saturation in retinal blood vessels is altered in ischemic and non-ischemic branch retinal vein occlusion (BRVO). METHODS Fifty BRVO eyes were divided into ischemic (n=26) and non-ischemic (n=24) groups, based on fundus fluorescein angiography. Healthy individuals (n=52 and n=48, respectively) were also recruited as controls for the two groups. The mean oxygen saturations of the occluded vessels and central vessels were measured by oximetry in the BRVO and control groups. RESULTS In the ischemic BRVO group, the occluded arterioles oxygen saturation (SaO2-A, 106.0%±14.3%), instead of the occluded venule oxygen saturation (SaO2-V, 60.8%±9.4%), showed increases when compared with those in the same quadrant vessels (SaO2-A, 86.1%±16.5%) in the contralateral eyes (Pcentral vessels showed similar trends with those of the occluded vessels. In the non-ischemic BRVO group, the occluded and central SaO2-V and SaO2-A showed no significant changes. In both the ischemic and non-ischemic BRVOs, the central SaO2-A was significantly increased when compared to healthy individuals. CONCLUSION Obvious changes in the occluded and central SaO2-A were found in the ischemic BRVO group, indicating that disorders of oxygen metabolism in the arterioles may participate in the pathogenesis of ischemic BRVO. PMID:26949618

  4. Ischemic tolerance protects the rat retina from glaucomatous damage.

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    Nicolás Belforte

    Full Text Available Glaucoma is a leading cause of acquired blindness which may involve an ischemic-like insult to retinal ganglion cells and optic nerve head. We investigated the effect of a weekly application of brief ischemia pulses (ischemic conditioning on the rat retinal damage induced by experimental glaucoma. Glaucoma was induced by weekly injections of chondroitin sulfate (CS in the rat eye anterior chamber. Retinal ischemia was induced by increasing intraocular pressure to 120 mmHg for 5 min; this maneuver started after 6 weekly injections of vehicle or CS and was weekly repeated in one eye, while the contralateral eye was submitted to a sham procedure. Glaucoma was evaluated in terms of: i intraocular pressure (IOP, ii retinal function (electroretinogram (ERG, iii visual pathway function (visual evoked potentials, (VEPs iv histology of the retina and optic nerve head. Retinal thiobarbituric acid substances levels were assessed as an index of lipid peroxidation. Ischemic conditioning significantly preserved ERG, VEPs, as well as retinal and optic nerve head structure from glaucomatous damage, without changes in IOP. Moreover, ischemia pulses abrogated the increase in lipid peroxidation induced by experimental glaucoma. These results indicate that induction of ischemic tolerance could constitute a fertile avenue for the development of new therapeutic strategies in glaucoma treatment.

  5. Study of retinal vessel oxygen saturation in ischemic and non-ischemic branch retinal vein occlusion

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    Lei-Lei Lin

    2016-01-01

    Full Text Available AIM: To explore how oxygen saturation in retinal blood vessels is altered in ischemic and non-ischemic branch retinal vein occlusion (BRVO. METHODS: Fifty BRVO eyes were divided into ischemic (n=26 and non-ischemic (n=24 groups, based on fundus fluorescein angiography. Healthy individuals (n=52 and n=48, respectively were also recruited as controls for the two groups. The mean oxygen saturations of the occluded vessels and central vessels were measured by oximetry in the BRVO and control groups. RESULTS: In the ischemic BRVO group, the occluded arterioles oxygen saturation (SaO2-A, 106.0%±14.3%, instead of the occluded venule oxygen saturation (SaO2-V, 60.8%±9.4%, showed increases when compared with those in the same quadrant vessels (SaO2-A, 86.1%±16.5% in the contralateral eyes (P<0.05. The oxygen saturations of the central vessels showed similar trends with those of the occluded vessels. In the non-ischemic BRVO group, the occluded and central SaO2-V and SaO2-A showed no significant changes. In both the ischemic and non-ischemic BRVOs, the central SaO2-A was significantly increased when compared to healthy individuals. CONCLUSION: Obvious changes in the occluded and central SaO2-A were found in the ischemic BRVO group, indicating that disorders of oxygen metabolism in the arterioles may participate in the pathogenesis of ischemic BRVO.

  6. Immune mechanisms in cerebral ischemic tolerance

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    Lidia eGarcia-Bonilla

    2014-03-01

    Full Text Available Stressor-induced tolerance is a central mechanism in the response of bacteria, plants, and animals to potentially harmful environmental challenges. This response is characterized by immediate changes in cellular metabolism and by the delayed transcriptional activation or inhibition of genetic programs that are not generally stressor specific (cross-tolerance. These programs are aimed at countering the deleterious effects of the stressor. While induction of this response (preconditioning can be established at the cellular level, activation of systemic networks is essential for the protection to occur throughout the organs of the body. This is best signified by the phenomenon of remote ischemic preconditioning, whereby application of ischemic stress to one tissue or organ induces ischemic tolerance in remote organs through humoral, cellular and neural signaling. The immune system is an essential component in cerebral ischemic tolerance acting simultaneously both as mediator and target. This dichotomy is based on the fact that activation of inflammatory pathways is necessary to establish ischemic tolerance and that ischemic tolerance can be, in part, attributed to a subdued immune activation after index ischemia. Here we describe the components of the immune system required for induction of ischemic tolerance and review the mechanisms by which a reprogrammed immune response contributes to the neuroprotection observed after preconditioning. Learning how local and systemic immune factors participate in endogenous neuroprotection could lead to the development of new stroke therapies.

  7. Persimmon leaf flavonoid promotes brain ischemic tolerance**

    Institute of Scientific and Technical Information of China (English)

    Mingsan Miao; Xuexia Zhang; Ming Bai; Linan Wang

    2013-01-01

    Persimmon leaf flavonoid has been shown to enhance brain ischemic tolerance in mice, but its mechanism of action remains unclear. The bilateral common carotid arteries were occluded using a micro clip to block blood flow for 10 minutes. After 10 minutes of ischemic preconditioning, 200, 100, and 50 mg/kg persimmon leaf flavonoid or 20 mg/kg ginaton was intragastrical y administered per day for 5 days. At 1 hour after the final administration, ischemia/reperfusion models were estab-lished by blocking the middle cerebral artery for 2 hours. At 24 hours after model establishment, compared with cerebral ischemic rats without ischemic preconditioning or drug intervention, plasma endothelin, thrombomodulin and von Wil ebrand factor levels significantly decreased and intercel-lular adhesion molecule-1 expression markedly reduced in brain tissue from rats with ischemic pre-conditioning. Simultaneously, brain tissue injury reduced. Ischemic preconditioning combined with drug exposure noticeably improved the effects of the above-mentioned indices, and the effects of 200 mg/kg persimmon leaf flavonoid were similar to 20 mg/kg ginaton treatment. These results indicate that ischemic preconditioning produces tolerance to recurrent severe cerebral ischemia. However, persimmon leaf flavonoid can elevate ischemic tolerance by reducing inflammatory reactions and vascular endothelial injury. High-dose persimmon leaf flavonoid showed an identical effect to ginaton.

  8. Induction of ischemic tolerance as a promising treatment against diabetic retinopathy

    Institute of Scientific and Technical Information of China (English)

    Ruth E.Rosenstein; Diego C.Fernandez

    2014-01-01

    Diabetic retinopathy is a leading cause of acquired blindness, and it is the most common ischemic disorder of the retina. Available treatments are not very effective. Efforts to inhibit diabetic reti-nopathy have focused either on highly speciifc therapeutic approaches for pharmacologic targets or using genetic approaches to change expression of certain enzymes. However, it might be wise to choose innovative treatment modalities that act by multiple potential mechanisms. The resis-tance to ischemic injury, or ischemic tolerance, can be transiently induced by prior exposure to a non-injurious preconditioning stimulus. A complete functional and histologic protection against retinal ischemic damage can be achieved by previous preconditioning with non-damaging isch-emia. In this review, we will discuss evidence that supports that ischemic conditioning could help avert the dreaded consequences that results from retinal diabetic damage.

  9. Novel Neuroprotective Strategies in Ischemic Retinal Lesions

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    Szabadfi, Krisztina; Mester, Laszlo; Reglodi, Dora; Kiss, Peter; Babai, Norbert; Racz, Boglarka; Kovacs, Krisztina; Szabo, Aliz; Tamas, Andrea; Gabriel, Robert; Atlasz, Tamas

    2010-01-01

    Retinal ischemia can be effectively modeled by permanent bilateral common carotid artery occlusion, which leads to chronic hypoperfusion-induced degeneration in the entire rat retina. The complex pathways leading to retinal cell death offer a complex approach of neuroprotective strategies. In the present review we summarize recent findings with different neuroprotective candidate molecules. We describe the protective effects of intravitreal treatment with: (i) urocortin 2; (ii) a mitochondrial ATP-sensitive K+ channel opener, diazoxide; (iii) a neurotrophic factor, pituitary adenylate cyclase activating polypeptide; and (iv) a novel poly(ADP-ribose) polymerase inhibitor (HO3089). The retinoprotective effects are demonstrated with morphological description and effects on apoptotic pathways using molecular biological techniques. PMID:20386654

  10. Occurrence and predictors of persistent impaired glucose tolerance after acute ischemic stroke or transient ischemic attack

    NARCIS (Netherlands)

    S. Fonville (Susanne); H.M. den Hertog (Heleen); A.A.M. Zandbergen (Adrienne); P.J. Koudstaal (Peter Jan); H.F. Lingsma (Hester)

    2014-01-01

    textabstractBackground Impaired glucose tolerance is often present in patients with a transient ischemic attack (TIA) or ischemic stroke and doubles the risk of recurrent stroke. This impaired glucose tolerance can be transient, reflecting an acute stress response, or persistent, representing undiag

  11. Dynamic changes in DNA methylation in ischemic tolerance

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    Robert eMeller

    2015-05-01

    Full Text Available Epigenetic mediators of gene expression are hypothesized to regulate transcriptomic responses to preconditioning ischemia and ischemic tolerance. Here we utilized a methyl-DNA enrichment protocol and sequencing (ChIP-seq to identify patterns of DNA methylation in an established model of ischemic tolerance in neuronal cultures (oxygen and glucose deprivation: OGD. We observed an overall decrease in global DNA methylation at 4h following preconditioning ischemia (30min OGD, harmful ischemia (120min OGD and in ischemic tolerant neuronal cultures (30min OGD, 24h recovery, 120min OGD. We detected a smaller cohort of hypermethylated regions following ischemic conditions, which were further analyzed revealing differential chromosomal localization of methylation, and a differential concentration of methylation on genomic regions. Together these data show that the temporal profiles of DNA methylation with respect to chromatin hyper – and hypo-methylation following various ischemic conditions, are highly dynamic and may reveal novel targets for neuroprotection.

  12. Transient ischemic attack and acute ischemic stroke: associations with retinal microvascular signs.

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    Wang, Jie Jin; Baker, Michelle L; Hand, Peter J; Hankey, Graeme J; Lindley, Richard I; Rochtchina, Elena; Wong, Tien Y; Liew, Gerald; Mitchell, Paul

    2011-02-01

    Small vessel disease plays a role in cerebral events. We aimed to investigate the prevalence and patterns of retinal microvascular signs (surrogates for cerebral small vessel disease) among patients with transient ischemic attack (TIA) or acute stroke and population control subjects. Patients with TIA or acute stroke aged ≥49 years admitted to hospitals in Melbourne and Sydney, Australia, were recruited to the Multi-Centre Retina and Stroke Study (n=693, 2005 to 2007). Control subjects were Blue Mountains Eye Study participants aged ≥49 years without TIAs or stroke (n=3384, 1992 to 1994, west of Sydney). TIA, ischemic stroke, or primary intracerebral hemorrhage was classified using standardized neurological assessments, including neuroimaging. Retinal microvascular signs (retinopathy, focal arteriolar narrowing, arteriovenous nicking, enhanced arteriolar light reflex) were assessed from retinal photographs masked to clinical information. Patients with TIA or acute stroke were older than control subjects and more likely to have stroke risk factors. After adjustment for study site and known risk factors, all retinal microvascular signs were more common in patients with TIA or acute stroke than in control subjects (OR, 1.9 to 8.7; Pischemic stroke had similar prevalences of nondiabetic retinopathy (26.9% versus 29.5%; OR, 0.8; 95% CI, 0.5 to 1.6), diabetic retinopathy (55.5% versus 50.0%; OR, 1.3; 95% CI, 0.4 to 3.6), focal arteriolar narrowing (15.6% versus 18.4%; OR, 0.8; 95% CI, 0.4 to 1.5), and arteriovenous nicking (23.0% versus 17.8%; OR, 1.4; 95% CI, 0.7 to 2.7). Patients with TIA and acute stroke may share similar risk factors or pathogenic mechanisms.

  13. KUS121, a VCP modulator, attenuates ischemic retinal cell death via suppressing endoplasmic reticulum stress

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    Hata, Masayuki; Ikeda, Hanako O.; Kikkawa, Chinami; Iwai, Sachiko; Muraoka, Yuki; Hasegawa, Tomoko; Kakizuka, Akira; Yoshimura, Nagahisa

    2017-01-01

    Ischemic neural damages cause several devastating diseases, including brain stroke and ischemic retinopathies, and endoplasmic reticulum (ER) stress has been proposed to be the underlying mechanism of the neuronal cell death of these conditions. We previously synthesized Kyoto University substances (KUSs) as modulators of valosin-containing protein (VCP); KUSs inhibit VCP ATPase activity and protect cells from different cell death-inducing insults. Here, we examined the efficacy of KUS121 in a rat model of retinal ischemic injury. Systemic administration of KUS121 to rats with ischemic retinal injury significantly suppressed inner retinal thinning and death of retinal ganglion and amacrine cells, with a significant functional maintenance of visual functions, as judged by electroretinography. Furthermore, intravitreal injection of KUS121, which is the clinically preferred route of drug administration for retinal diseases, appeared to show an equal or better neuroprotective efficacy in the ischemic retina compared with systemic administration. Indeed, induction of the ER stress marker C/EBP homologous protein (CHOP) after the ischemic insult was significantly suppressed by KUS121 administration. Our study suggests VCP modulation by KUS as a promising novel therapeutic strategy for ischemic neuronal diseases. PMID:28317920

  14. Inhibition of BDNF-AS Provides Neuroprotection for Retinal Ganglion Cells against Ischemic Injury

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    Xu, Lifang; Zhang, Ziyin; Xie, Tianhua; Zhang, Xiaoyang; Dai, Tu

    2016-01-01

    Background: Brain-derived neurotrophic factor (BDNF) protects retinal ganglion cells against ischemia in ocular degenerative diseases. We aimed to determine the effect of BDNF-AS on the ischemic injury of retinal ganglion cells. Methods: The levels of BDNF and BDNF-AS were measured in retinal ganglion cells subjected to oxygen and glucose deprivation. The lentiviral vectors were constructed to either overexpress or knock out BDNF-AS. The luciferase reporter gene assay was used to determine wh...

  15. KR-31378, a potassium-channel opener, induces the protection of retinal ganglion cells in rat retinal ischemic models.

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    Choi, Anho; Choi, Jun-Sub; Yoon, Yone-Jung; Kim, Kyung-A; Joo, Choun-Ki

    2009-04-01

    KR-31378 is a newly developed K(ATP)-channel opener. To investigate the ability of KR-31378 to protect retinal ganglion cells (RGC), experiments were conducted using two retinal ischemia models. Retinal ischemia was induced by transient high intraocular pressure (IOP) for acute ischemia and by three episcleral vein occlusion for chronic retinal ischemia. KR-31378 was injected intraperitoneally and administered orally in the acute and chronic ischemia models, respectively. Under the condition of chronic ischemia, RGC density in the KR-31378-treated group was statistically higher than that in the non-treated group, and IOP was reduced. In the acute retinal ischemia model, 90% of RGC were degenerated after one week in non-treated retina, but, RGC in KR-31378-treated retina were protected from ischemic damage in a dose-dependent manner and showed inhibited glial fibrillary acidic protein (GFAP) expression. Furthermore, the KR-31378 protective effect was inhibited by glibenclamide treatment in acute ischemia. These findings indicate that systemic KR-31378 treatment may protect against ischemic injury-induced ganglion cell loss in glaucoma.

  16. Persimmon leaf flavonoid induces brain ischemic tolerance in mice

    Institute of Scientific and Technical Information of China (English)

    Mingsan Miao; Xuexia Zhang; Linan Wang

    2013-01-01

    The persimmon leaf has been shown to improve cerebral ischemic outcomes; however, its mechanism of action remains unclear. In this study, mice were subjected to 10 minutes of ischemic preconditioning, and persimmon leaf flavonoid was orally administered for 5 days. Results showed that the persimmon leaf flavonoid significantly improved the content of tissue type plasminogen activator and 6-keto prostaglandin-F1 α in the cerebral cortex, decreased the content of thromboxane B2, and reduced the content of plasminogen activator inhibitor-1 in mice. Following optical microscopy, persimmon leaf flavonoid was also shown to reduce cell swelling and nuclear hyperchromatism in the cerebral cortex and hippocampus of mice. These results suggested that persimmon leaf flavonoid can effectively inhibit brain thrombosis, improve blood supply to the brain, and relieve ischemia-induced pathological damage, resulting in brain ischemic tolerance.

  17. Calpain inhibitors reduce retinal hypoxia in ischemic retinopathy by improving neovascular architecture and functional perfusion.

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    Hoang, Mien V; Smith, Lois E H; Senger, Donald R

    2011-04-01

    In ischemic retinopathies, underlying hypoxia drives abnormal neovascularization that damages retina and causes blindness. The abnormal neovasculature is tortuous and leaky and fails to alleviate hypoxia, resulting in more pathological neovascularization and retinal damage. With an established model of ischemic retinopathy we found that calpain inhibitors, when administered in moderation, reduced architectural abnormalities, reduced vascular leakage, and most importantly reduced retinal hypoxia. Mechanistically, these calpain inhibitors improved stability and organization of the actin cytoskeleton in retinal endothelial cells undergoing capillary morphogenesis in vitro, and they similarly improved organization of actin cables within new blood vessels in vivo. Hypoxia induced calpain activity in retinal endothelial cells and severely disrupted the actin cytoskeleton, whereas calpain inhibitors preserved actin cables under hypoxic conditions. Collectively, these findings support the hypothesis that hyper-activation of calpains by hypoxia contributes to disruption of the retinal endothelial cell cytoskeleton, resulting in formation of neovessels that are defective both architecturally and functionally. Modest suppression of calpain activity with calpain inhibitors restores cytoskeletal architecture and promotes formation of a functional neovasculature, thereby reducing underlying hypoxia. In sharp contrast to "anti-angiogenesis" strategies that cannot restore normoxia and may aggravate hypoxia, the therapeutic strategy described here does not inhibit neovascularization. Instead, by improving the function of neovascularization to reduce underlying hypoxia, moderate calpain inhibition offers a method for alleviating retinal ischemia, thereby suggesting a new treatment paradigm based on improvement rather than inhibition of new blood vessel growth.

  18. Accelerated ischemic vascular retinopathy after intravitreally injected bevacizumab for central retinal vein occlusion in elderly patients

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    Isola V

    2013-03-01

    Full Text Available Vincenzo Isola,1 Alfredo Pece,1,2 Claudio Massironi,1 Simone Reposi,1 Fabio Dimastrogiovanni11Department of Ophthalmology, Melegnano Hospital, 2Fondazione Retina 3000, Milano, ItalyBackground: Ischemic changes in the retinal circulation are an uncommon but severe adverse vascular reaction to intravitreal bevacizumab (Avastin®, Genentech, San Francisco, CA, USA/Roche, Basel, Switzerland for central retinal vein occlusion (CRVO. In the two cases reported here, ischemic changes in the retina vasculature following intravitreal bevacizumab for CRVO were observed with the aim of describing the clinical and angiographic features of these changes.Methods: Two elderly patients with recent-onset CRVO received one off-label intravitreal injection of bevacizumab 0.05 mL/1.25 mg.Results: In Case 1, the patient's pre-treatment visual acuity was 20/400. At 3 weeks post injection, the patient could count fingers at a distance of 1 ft (30 cm and fluorescein angiography showed reduction in intraretinal hemorrhages and areas of retinal non-perfusion. However, at 6 weeks these were markedly increased compared with those seen in the photograph taken 3 weeks after treatment. In Case 2, the patient's pre-treatment visual acuity was 20/200. At 1 month post injection, vision had decreased to 20/400 and fluorescein angiography showed severe macular ischemia with a remarkable capillary dropout throughout the macula.Conclusion: Ischemic retinal injury may be an uncommon but severe adverse vascular reaction to intravitreal bevacizumab for CRVO. Although progression of retinal ischemia in CRVO could be observed shortly after intravitreal bevacizumab, whether this is a drug- or procedure-related effect or part of the natural history of the condition remains uncertain.Keywords: Avastin, ischemia, macular infarction, intraretinal hemorrhage, retinal non-perfusion

  19. Early retinal inflammatory biomarkers in the middle cerebral artery occlusion model of ischemic stroke

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    Ritzel, Rodney M.; Pan, Sarah J.; Verma, Rajkumar; Wizeman, John; Crapser, Joshua; Patel, Anita R.; Lieberman, Richard; Mohan, Royce

    2016-01-01

    Purpose The transient middle cerebral artery occlusion (MCAO) model of stroke is one of the most commonly used models to study focal cerebral ischemia. This procedure also results in the simultaneous occlusion of the ophthalmic artery that supplies the retina. Retinal cell death is seen days after reperfusion and leads to functional deficits; however, the mechanism responsible for this injury has not been investigated. Given that the eye may have a unique ocular immune response to an ischemic challenge, this study examined the inflammatory response to retinal ischemia in the MCAO model. Methods Young male C57B/6 mice were subjected to 90-min transient MCAO and were euthanized at several time points up to 7 days. Transcription of inflammatory cytokines was measured with quantitative real-time PCR, and immune cell activation (e.g., phagocytosis) and migration were assessed with ophthalmoscopy and flow cytometry. Results Observation of the affected eye revealed symptoms consistent with Horner’s syndrome. Light ophthalmoscopy confirmed the reduced blood flow of the retinal arteries during occlusion. CX3CR1-GFP reporter mice were then employed to evaluate the extent of the ocular microglia and monocyte activation. A significant increase in green fluorescent protein (GFP)-positive macrophages was seen throughout the ischemic area compared to the sham and contralateral control eyes. RT–PCR revealed enhanced expression of the monocyte chemotactic molecule CCL2 early after reperfusion followed by a delayed increase in the proinflammatory cytokine TNF-α. Further analysis of peripheral leukocyte recruitment by flow cytometry determined that monocytes and neutrophils were the predominant immune cells to infiltrate at 72 h. A transient reduction in retinal microglia numbers was also observed, demonstrating the ischemic sensitivity of these cells. Blood–eye barrier permeability to small and large tracer molecules was increased by 72 h. Retinal microglia exhibited enhanced

  20. Tetrandrine protects mouse retinal ganglion cells from ischemic injury

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    Li WY

    2014-03-01

    Full Text Available Weiyi Li,1,2 Chen Yang,2 Jing Lu,2 Ping Huang,1 Colin J Barnstable,2 Chun Zhang,1 Samuel S Zhang2,3 1Department of Ophthalmology, Peking University Third Hospital, Peking University Eye Center, Beijing, People's Republic of China; 2Department of Neural and Behavioral Sciences, Penn State University, Hershey, PA, USA; 3Singapore Eye Research Institute, Singapore National Eye Centre, Singapore Abstract: This study aimed to determine the protective effects of tetrandrine (Tet on murine ischemia-injured retinal ganglion cells (RGCs. For this, we used serum deprivation cell model, glutamate and hydrogen peroxide (H2O2-induced RGC-5 cell death models, and staurosporine-differentiated neuron-like RGC-5 in vitro. We also investigated cell survival of purified primary-cultured RGCs treated with Tet. An in vivo retinal ischemia/reperfusion model was used to examine RGC survival after Tet administration 1 day before ischemia. We found that Tet affected RGC-5 survival in a dose- and time-dependent manner. Compared to dimethyl sulfoxide treatment, Tet increased the numbers of RGC-5 cells by 30% at 72 hours. After 48 hours, Tet protected staurosporine-induced RGC-5 cells from serum deprivation-induced cell death and significantly increased the relative number of cells cultured with 1 mM H2O2 (P<0.01. Several concentrations of Tet significantly prevented 25-mM-glutamate-induced cell death in a dose-dependent manner. Tet also increased primary RGC survival after 72 and 96 hours. Tet administration (10 µM, 2 µL 1 day before retinal ischemia showed RGC layer loss (greater survival, which was less than those in groups with phosphate-buffered saline intravitreal injection plus ischemia in the central (P=0.005, n=6, middle (P=0.018, n=6, and peripheral (P=0.017, n=6 parts of the retina. Thus, Tet conferred protective effects on serum deprivation models of staurosporine-differentiated neuron-like RGC-5 cells and primary cultured murine RGCs. Furthermore, Tet showed

  1. Role of homocysteine in the ischemic stroke nad development of ischemic tolerance

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    Jan Lehotsky

    2016-11-01

    Full Text Available Homocysteine (Hcy is a toxic, sulfur-containing intermediate of methionine metabolism. Hyperhomocysteinemia (hHcy, as a consequence of impaired Hcy metabolism or defects in crucial co-factors that participate in its recycling, is assumed as an independent human stroke risk factor. Neural cells are sensitive to prolonged hHcy treatment, because Hcy cannot be metabolized either by the transsulfuration pathway or by the folate/vitamin B12 independent remethylation pathway. Its detrimental effect after ischemia-induced damage includes accumulation of reactive oxygen species (ROS and posttranslational modifications of proteins via homocysteinylation and thiolation. Ischemic preconditioning (IPC is an adaptive response of the CNS to sub-lethal ischemia, which elevates tissues tolerance to subsequent ischemia. The main focus of this review is on the recent data on homocysteine metabolism and mechanisms of its neurotoxicity. In this context, the review documents an increased oxidative stress and functional modification of enzymes involved in redox balance in experimentally induced hyperhomocysteinemia. It also gives an interpretation whether hyperhomocysteinemia alone or in combination with IPC affects the ischemia-induced neurodegenerative changes as well as intracellular signalling. Studies document that hHcy alone significantly increased Fluoro-Jade C- and TUNEL-positive cell neurodegeneration in the rat hippocampus as well as in the cortex. IPC, even if combined with hHcy, could still preserve the neuronal tissue from the lethal ischemic effects. This review also describes the changes in the mitogen-activated protein kinase (MAPK protein pathways following ischemic injury and IPC. These studies provide evidence for the interplay and tight integration between ERK and p38 MAPK signalling mechanisms in response to the hHcy and also in association of hHcy with ischemia/IPC challenge in the rat brain. Further investigations of the protective factors

  2. Polycomb group proteins as epigenetic mediators of neuroprotection in ischemic tolerance.

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    Stapels, Martha; Piper, Chelsea; Yang, Tao; Li, Minghua; Stowell, Cheri; Xiong, Zhi-gang; Saugstad, Julie; Simon, Roger P; Geromanos, Scott; Langridge, James; Lan, Jing-quan; Zhou, An

    2010-03-02

    Exposing the brain to sublethal ischemia affects the response to a subsequent, otherwise injurious ischemia, resulting in transcriptional suppression and neuroprotection, a response called ischemic tolerance. Here, we show that the proteomic signature of the ischemic-tolerant brain is characterized by increased abundance of transcriptional repressors, particularly polycomb group (PcG) proteins. Knocking down PcG proteins precluded the induction of ischemic tolerance, whereas in an in vitro model, overexpressing the PcG proteins SCMH1 or BMI1 induced tolerance to ischemia without preconditioning. We found that PcG proteins are associated with the promoter regions of genes encoding two potassium channel proteins that show decreased abundance in ischemic-tolerant brains. Furthermore, PcG proteins decreased potassium currents in cultured neuronal cells, and knocking down potassium channels elicited tolerance without preconditioning. These findings reveal a previously unknown mechanism of neuroprotection that involves gene repressors of the PcG family.

  3. Vitreo-Retinal Hemorrhage After Thrombolysis In A Patient With Acute Ischemic Stroke: A Case Report.

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    Mary eHormese

    2012-05-01

    Full Text Available Purpose: Bleeding is the major side effect of thrombolysis with alteplase (tissue plasminogen activator, t-PA used for the treatment of acute ischemic stroke. Life-threatening intracranial, retroperitoneal, gastrointestinal, respiratory, and genitourinary bleeding can occur with the use of t-PA. Vitreo-retinal bleeding in the context of acute ischemic stroke treatment has not been reported in the literature before and therefore is not posed as a potential risk during decision making. Here we describe the first reported case of vitreo-retinal hemorrhage due to alteplase administration in a patient with acute ischemic stroke.Summary: An 84 year old white male presented to the emergency room with complaints of right arm and leg weakness. The onset of symptoms was approximately 30 minutes prior to presentation to the emergency room. After ruling out contraindications including the presence of hemorrhage on head CT scan, patient was administered alteplase within 2 hours of symptom onset. Four hours after the administration of alteplase, the patient developed right-sided vision changes. A repeat CT scan demonstrated a newly developed right intraocular hemorrhage. Throughout the hospital course, patient’s neurological status improved, but he continued to have right-sided visual loss.Conclusion: Clinicians should be aware of the potential for ocular hemorrhage especially in high-risk patients. The likelihood of a subsequent vision-loss needs to be therefore discussed with the patient and family in such situations.

  4. Retinal protective effects of topically administered agmatine on ischemic ocular injury caused by transient occlusion of the ophthalmic artery

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    S. Hong

    2012-03-01

    Full Text Available Agmatine, an endogenous polyamine and putative neuromodulator, is known to have neuroprotective effects on various neurons in the central nervous system. We determined whether or not topically administered agmatine could reduce ischemic retinal injury. Transient ocular ischemia was achieved by intraluminal occlusion of the middle cerebral artery of ddY mice (30-35 g for 2 h, which is known to also induce occlusion of the ophthalmic artery. In the agmatine group (N = 6, a 1.0 mM agmatine-containing ophthalmic solution was administered four times daily for 2 weeks before occlusion. In the control group (N = 6, a 0.1% hyaluronic acid ophthalmic solution was instilled at the same times. At 22 h after reperfusion, the eyeballs were enucleated and the retinal sections were stained by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL. Transient ocular ischemia induced apoptosis of retinal cells in the entire retinal layer, and topically administered agmatine can significantly reduce this ischemic retinal injury. The proportion of apoptotic cells was definitely decreased (P < 0.001; Kruskal-Wallis test. Overall, we determined that topical agmatine application effectively decreases retinal damage in an in vivo ocular ischemic injury model. This implies that agmatine is a good candidate as a direct neuroprotective agent for eyes with ocular ischemic diseases.

  5. Gender-Dependent Effects of Enriched Environment and Social Isolation in Ischemic Retinal Lesion in Adult Rats

    Science.gov (United States)

    Kiss, Peter; Szabadfi, Krisztina; Horvath, Gabor; Tamas, Andrea; Farkas, Jozsef; Gabriel, Robert; Reglodi, Dora

    2013-01-01

    Exposure to an enriched environment has been shown to have many positive effects on brain structure and function. Numerous studies have proven that enriched environment can reduce the lesion induced by toxic and traumatic injuries. Impoverished environment, on the other hand, can have deleterious effects on the outcome of neuronal injuries. We have previously shown that enriched conditions have protective effects in retinal injury in newborn rats. It is well-known that the efficacy of neuroprotective strategies can depend on age and gender. The aim of the present study, therefore, was to examine the effects of environmental enrichment and social isolation in retinal ischemia. We used bilateral common carotid artery occlusion to induce retinal hypoperfusion in adult Wistar rats of both genders. Groups were housed in standard, enriched or impoverished conditions. Impoverished environment was induced by social isolation. Retinas were processed for histological analysis after two weeks of survival. In the present study, we show that (1) enriched environment has protective effects in adult ischemic retinal lesion, while (2) impoverished environment further increases the degree of ischemic injury, and (3) that these environmental effects are gender-dependent: females are less responsive to the positive effects of environmental enrichment and more vulnerable to retinal ischemia in social isolation. In summary, our present study shows that the effects of both positive and negative environmental stimuli are gender-dependent in ischemic retinal lesions. PMID:23921682

  6. Early panretinal photocoagulation for the treatment of ischemic central retinal vein occlusion

    Science.gov (United States)

    Yu, Zikui; He, Naizhen

    2005-07-01

    Objective: To evaluate the safety and efficacy of treating ischemic central retinal vein occlusion (CRVO)with early panretinal photocoagulation(PRP). Methods:24 eyes of 24 cases suffered from ischemic CRVO with history shorter than 3 months were included in this study. PRP treatments were completed through 3 to 5 times of laser therapy with total laser burns of 1000 to 2000(mean 1505+/-384).Patients were followed up 3 months to 2 years, mean 18.4+/-8.0 months.The neovascularization regression and visual acuity were compared before and after PRP, also the long-term complications were observed. Results:3 eyes of iris neovascularization (INV) regressed after PRP and there was no significant difference in visual acuity between prelaser and postlaser. No neovascular glaucoma(NVG) occurred and 2 eyes occurred vitreous hemorrhage during the follow up period.. Conclusions: Early panretinal photocoagulation is safe and efficacious in preventing and reducing complications of ischemic CRVO. It can save valuable treatment time for some patients

  7. Activation of NR2A receptors induces ischemic tolerance through CREB signaling.

    Science.gov (United States)

    Terasaki, Yasukazu; Sasaki, Tsutomu; Yagita, Yoshiki; Okazaki, Shuhei; Sugiyama, Yukio; Oyama, Naoki; Omura-Matsuoka, Emi; Sakoda, Saburo; Kitagawa, Kazuo

    2010-08-01

    Previous exposure to a nonlethal ischemic insult protects the brain against subsequent harmful ischemia. N-methyl-D-aspartate (NMDA) receptors are a highly studied target of neuroprotection after ischemia. Recently, NMDA receptor subtypes were implicated in neuronal survival and death. We focused on the contribution of NR2A and cyclic-AMP response element (CRE)-binding protein (CREB) signaling to ischemic tolerance using primary cortical neurons. Ischemia in vitro was modeled by oxygen-glucose deprivation (OGD). Ischemic tolerance was induced by applying 45-mins OGD 24 h before 180-mins OGD. Sublethal OGD also induced cross-tolerance against lethal glutamate and hydrogen peroxide. After sublethal OGD, expression of phosphorylated CREB and CRE transcriptional activity were significantly increased. When CRE activity was inhibited by CREB-S133A, a mutant CREB, ischemic tolerance was abolished. Inhibiting NR2A using NVP-AAM077 attenuated preconditioning-induced neuroprotection and correlated with decreased CRE activity levels. Activating NR2A using bicuculline and 4-aminopiridine induced resistance to lethal ischemia accompanied by elevated CRE activity levels, and this effect was abolished by NVP-AAM077. Elevated brain-derived neurotrophic factor (BDNF) transcriptional activities were observed after sublethal OGD and administration of bicuculline and 4-aminopiridine. NR2A-containing NMDA receptors and CREB signaling have important functions in the induction of ischemic tolerance. This may provide potential novel therapeutic strategies to treat ischemic stroke.

  8. Methylene blue prevents retinal damage in an experimental model of ischemic proliferative retinopathy.

    Science.gov (United States)

    Rey-Funes, Manuel; Larrayoz, Ignacio M; Fernández, Juan C; Contartese, Daniela S; Rolón, Federico; Inserra, Pablo I F; Martínez-Murillo, Ricardo; López-Costa, Juan J; Dorfman, Verónica B; Martínez, Alfredo; Loidl, César F

    2016-06-01

    Perinatal asphyxia induces retinal lesions, generating ischemic proliferative retinopathy, which may result in blindness. Previously, we showed that the nitrergic system was involved in the physiopathology of perinatal asphyxia. Here we analyze the application of methylene blue, a well-known soluble guanylate cyclase inhibitor, as a therapeutic strategy to prevent retinopathy. Male rats (n = 28 per group) were treated in different ways: 1) control group comprised born-to-term animals; 2) methylene blue group comprised animals born from pregnant rats treated with methylene blue (2 mg/kg) 30 and 5 min before delivery; 3) perinatal asphyxia (PA) group comprised rats exposed to perinatal asphyxia (20 min at 37°C); and 4) methylene blue-PA group comprised animals born from pregnant rats treated with methylene blue (2 mg/kg) 30 and 5 min before delivery, and then the pups were subjected to PA as above. For molecular studies, mRNA was obtained at different times after asphyxia, and tissue was collected at 30 days for morphological and biochemical analysis. Perinatal asphyxia produced significant gliosis, angiogenesis, and thickening of the inner retina. Methylene blue treatment reduced these parameters. Perinatal asphyxia resulted in a significant elevation of the nitrergic system as shown by NO synthase (NOS) activity assays, Western blotting, and (immuno)histochemistry for the neuronal isoform of NOS and NADPH-diaphorase activity. All these parameters were also normalized by the treatment. In addition, methylene blue induced the upregulation of the anti-angiogenic peptide, pigment epithelium-derived factor. Application of methylene blue reduced morphological and biochemical parameters of retinopathy. This finding suggests the use of methylene blue as a new treatment to prevent or decrease retinal damage in the context of ischemic proliferative retinopathy. Copyright © 2016 the American Physiological Society.

  9. Hyperhomocysteinemia, a biochemical tool for differentiating ischemic and nonischemic central retinal vein occlusion during the early acute phase.

    Science.gov (United States)

    Lahiri, Kapil Deb; Mukherjee, Somnath; Ghosh, Sambuddha; Mukherjee, Suman; Dutta, Jayanta; Datta, Himadri; Das, Harendra Nath

    2015-04-01

    The purpose of the study was to differentiate ischemic central retinal vein occlusion (CRVO) from nonischemic CRVO during the early acute phase using plasma homocysteine as a biochemical marker. Fasting plasma homocysteine, serum vitamin B12, and folate levels were measured in 108 consecutive unilateral elderly adult (age >50 years) ischemic CRVO patients in the absence of local and systemic disease and compared with a total of 144 age and sex matched nonischemic CRVO patients and 120 age and sex matched healthy control subjects. Homocysteine level was significantly increased in the patients with ischemic CRVO in comparison with nonischemic CRVO patients (p = 0.009) and also in comparison with control subjects (p 0.1). Hyperhomocysteinemia can be regarded as useful in differentiating nonischemic and ischemic CRVO during the early acute phase in absence of local and systemic disease in the elderly adult (age >50 years) population.

  10. Central retinal artery occlusion following laser treatment for ocular ischemic aortic arch syndrome

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    Shah, Payal J.

    2015-12-01

    Full Text Available Objective: Ocular ischemic syndrome is a rare blinding condition generally caused by disease of the carotid artery. We describe a 69-year-old female with a 50 pack-year smoking history with aortic arch syndrome causing bilateral ocular ischemic syndrome. Methods: The patient presented with progressive visual loss and temple pain. Slit lamp biomicroscopy revealed bilateral iris neovascularization. This finding prompted a cardiovascular work up. Panretinal photocoagulation with retrobulbar block was performed in the right eye. Results: A temporal artery biopsy was negative. The carotid duplex sound showed only a 1–39% stenosis. MRA revealed a more proximal occlusion of the aortic branch for which she underwent subclavian carotid bypass surgery. At the one month follow up, the right eye suffered profound vision loss secondary to a central retinal artery occlusion. Conclusion: Ocular neovascularization may be one of the clinical manifestations of aortic arch syndrome. This case also illustrates the limitations of relying solely on carotid duplex ultrasound testing. We caution against overly aggressive panretinal photocoagulation utilizing retrobulbar anesthesia.

  11. The Retinal Nerve Fiber Layer Defects in Patients with Anterior Ischemic Optic Neuropathy

    Institute of Scientific and Technical Information of China (English)

    HaiLu; QiZang

    1995-01-01

    Purpose:To demonstrate the effects of optic nerve ischemia on retinal nerve fiber layer(RNFL)and the associated visual dysfunction.Methods:23patients(25eyes)wits anterior ischemic optic neuropathy(AION)un derwent fundus fluorescein angiography(FFA),and then red-foree light pic-tures were taken via SE-40exceiter filter.All pictures were printed for RNAFL analysis,Humphrey central field analysis was conducted.All dataobtained fromFFA and visual field defects were analysed statistically.Results:The RNFL defects and the corresponding visual field edfects were pre-sented in 23of 25eyes(92%),The optic disc filling defects,RNAL edfects and visual field defects were found to be highly correspondent to each other.The RNFL defects were mainly the local losses of RNFL which were correspondent to the ischemic regions.Conclusion:The poor optic disc filling or ischemia can result in the RNFL defects which cause the associated visual dysfunction.Because RNFLdefects are irrever-siable changes,the potential values in predicting the prognosis of visual field de-fects caused by RNFL damages were suggested.Eye Science1995;11:165-167.

  12. Expression of hypoxia inducible factor-1 alpha and ischemic erythropoietin tolerance in the brain of cerebral ischemic tolerance model rats

    Institute of Scientific and Technical Information of China (English)

    Renliang Zhao; Ruijian Dong; Zhongling Sun

    2006-01-01

    BACKGROUND: Hypoxia inducible factor-1 alpha (HIF-1 α) and erythropoietin(EPO), possessing neuroprotective effect in the cerebral ischemia, might play an important role in the formation of cerebral ischemic tolerance (IT).OBJECTIVE:To observe the neuroprotective effect of cerebral ischemic preconditioning(IPC) of rats, and the expression and mechanism of HIF-1α and target gene erythropoietin in the brain tissue following the formation of cerebral IT.DESIGN :A randomized and controlled observation.SETTING: Department of Neurology, the Affiliated Hospital of Medical College, Qingdao University.MATERIALS: Totally 84 enrolled adult healthy male Wistar rats of clean grade, weighing 250 to 300 g, were provided by the Animal Experimental Department, Tongji Medical College of Huazhong University of Science and Technology. Ready-to-use SABC reagent kit and rabbit anti-rat HIF-1α monoclonal antibody were purchased from Boshide Bioengineering Co. Ltd (Wuhan); Rabbit anti-rat EPO monoclonal antibody was purchased from Santa Cruz Company (USA).METHODS: This experiment was carried out in the Department of Anatomy, Medical College, Qingdao University during March 2005 to March 2006. ① The 84 rats were divided into 3 groups by a lot: IPC group (n=40),sham-operation group (n=40) and control group (n=4). In the IPC group, middle cerebral artery was occluded for 2 hours respectively on the 1st, 3rd, 7th, 14th and 21st days of the reperfusion following 10-minute preischemia was made using a modified middle cerebral artery second suture method from Zea-Longa. The rats were sacrificed 22 hours after reperfusion in the end of middle cerebral artery occlusion (MCAO). That was to say,after 10-minute preischemia, suture was exited to the external carotid artery and embedded subcutaneously.Middle cerebral artery was occluded again to form the second reperfusion at the set time point after reperfusion. Twenty-two hours later, rats were sacrificed; In the sham-operation group

  13. Ranibizumab in preproliferative (ischemic) central retinal vein occlusion: the rubeosis anti-VEGF (RAVE) trial.

    Science.gov (United States)

    Brown, David M; Wykoff, Charles C; Wong, Tien P; Mariani, Angeline F; Croft, Daniel E; Schuetzle, Karri L

    2014-09-01

    To analyze the efficacy and safety of ranibizumab in eyes with preproliferative (ischemic) central retinal vein occlusion. In this prospective, phase I/II, open-label clinical trial, eyes at high risk of neovascular complications were identified; all eyes met ≥ 3 of 4 high-risk criteria: 1) the best-corrected visual acuity being ≤ 20/200, 2) loss of the 1-2e isopter on Goldmann visual field, 3) relative afferent pupillary defect being ≥ 0.9 log units, and 4) electroretinogram B-wave reduction to ≤ 60% of the corresponding A-wave. Monthly intravitreal ranibizumab treatment for 9 months, monthly monitoring for 3 months, and then monthly examination with pro re nata retreatment on evidence of disease activity for 24 months were performed. Therefore, the total study duration was 36 months. The main outcome measures were mean change in the best-corrected visual acuity and central macular thickness by optical coherence tomography, proportion of patients with neovascular complications, and the incidence and severity of ocular and nonocular adverse events. Twenty patients were enrolled in the Rubeosis Anti-VEgf trial, and the mean number of intravitreal treatments administered through Months 24 and 36 were 14.1 and 17.2, respectively. The mean best-corrected visual acuity letters gained were +21.1 and +21.4 at 9 and 36 months, respectively. The mean central macular thickness improved -294 μm from baseline after 9 monthly treatments. Subsequently, after 3 months of observation, the mean central macular thickness increased +203 μm. On initiation of pro re nata ranibizumab retreatment, the mean central macular thickness then improved -191 μm at Month 36 compared with Month 12. Nine patients developed neovascular complications, being diagnosed after a mean of 24-month follow-up (range, 3-44 months), with 2 patients developing neovascularization after completion of the 36-month trial endpoint (at Months 42 and 44 after study enrollment). Intravitreal ranibizumab

  14. Excitatory and inhibitory amino acid neurotransmitters in stroke: from neurotoxicity to ischemic tolerance.

    Science.gov (United States)

    Amantea, Diana; Bagetta, Giacinto

    2017-08-17

    The search for neuroprotection in acute ischemic stroke has been dramatically disappointing, with virtually all clinical trials failed for excessive toxicity or lack of efficacy of the tested drug; whereby, current treatments are exclusively based on reperfusion. Given the crucial role of amino acid neurotransmission in ischemic pathobiology, numerous failed strategies were aimed at blocking ionotropic glutamate receptor-mediated excitotoxicity or potentiating GABA-mediated inhibition. Recent work has revived the interest of pharmacologists toward glutamate and GABA receptors, due to a better understanding of subtype-specific toxicity and their involvement in ischemic tolerance. Thus, blocking receptor stimulation through glutamate grabbing, inhibiting downstream transduction pathways or selectively antagonizing detrimental NMDA receptor subpopulations represent promising strategies to rescue ischemic brain injury with limited side effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Selective over-expression of endothelin-1 in endothelial cells exacerbates inner retinal edema and neuronal death in ischemic retina.

    Directory of Open Access Journals (Sweden)

    Simon S F Cheung

    Full Text Available The level of endothelin-1 (ET-1, a potent vasoconstrictor, was associated with retinopathy under ischemia. The effects of endothelial endothelin-1 (ET-1 over-expression in a transgenic mouse model using Tie-1 promoter (TET-1 mice on pathophysiological changes of retinal ischemia were investigated by intraluminal insertion of a microfilament up to middle cerebral artery (MCA to transiently block the ophthalmic artery. Two-hour occlusion and twenty-two-hour reperfusion were performed in homozygous (Hm TET-1 mice and their non-transgenic (NTg littermates. Presence of pyknotic nuclei in ganglion cell layer (GCL was investigated in paraffin sections of ipsilateral (ischemic and contralateral (non-ischemic retinae, followed by measurement of the thickness of inner retinal layer. Moreover, immunocytochemistry of glial fibrillary acidic protein (GFAP, glutamine synthetase (GS and aquaporin-4 (AQP4 peptides on retinal sections were performed to study glial cell reactivity, glutamate metabolism and water accumulation, respectively after retinal ischemia. Similar morphology was observed in the contralateral retinae of NTg and Hm TET-1 mice, whereas ipsilateral retina of NTg mice showed slight structural and cellular changes compared with the corresponding contralateral retina. Ipsilateral retinae of Hm TET-1 mice showed more significant changes when compared with ipsilateral retina of NTg mice, including more prominent cell death in GCL characterized by the presence of pyknotic nuclei, elevated GS immunoreactivity in Müller cell bodies and processes, increased AQP-4 immunoreactivity in Müller cell processes, and increased inner retinal thickness. Thus, over-expression of endothelial ET-1 in TET-1 mice may contribute to increased glutamate-induced neurotoxicity on neuronal cells and water accumulation in inner retina leading to edema.

  16. Safety and Tolerability of Desmoteplase Within 3 to 9 Hours After Symptoms Onset in Japanese Patients With Ischemic Stroke

    DEFF Research Database (Denmark)

    Mori, Etsuro; Minematsu, Kazuo; Nakagawara, Jyoji

    2015-01-01

    BACKGROUND AND PURPOSE: This study investigated the safety and tolerability of desmoteplase administered within 3 to 9 hours after stroke symptoms onset in Japanese patients with acute ischemic stroke. METHODS: Patients were randomized to treatment with either desmoteplase or placebo in a 2:1 rat...... tolerated in Japanese patients with acute ischemic stroke when administered 3 to 9 hours after stroke symptoms onset. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01104467....

  17. [CREB activation is a key player for ischemic tolerance in the brain].

    Science.gov (United States)

    Kitagawa, Kazuo; Sasaki, Tsutomu; Terasaki, Yasukazu; Yagita, Yoshiki; Mochizuki, Hideki

    2012-01-01

    Ischemic tolerance is as powerful and reproducible for neuro-protection as hypothermia. Several pathways could be involved in acquisition of ischemic tolerance. CREB is an abundant transcription factor in the brain and plays critical role on synaptic plasticity and neuronal survival. CREB activation has been also shown to be involved in ischemic tolerance. Ischemia or oxygen-glucose deprivation leads to release of glutamate, which binds to synaptic NMDA receptor. Then, influx of calcium ions into intracellular space activates calcium-calmodulin dependent protein kinase (CaMK). CaMK I/IV phosphorylates Ser 133 of CREB, and Thr 484 of salt-inducible kinase (SIK). Phosphorylation of SIK2 at Thr 484 triggers degradation of SIK2 through ubiquitin proteasome system. SIK2 maintains the phosphorylation level of CREB-regulated transcriptional co-activator (CRTC). Degradation of SIK2 induces dephosphorylation of CRTC1, and moves CRTC1 from cytoplasm into nucleus. Thus CRTC1 binds to basic ZIP domain of CREB. Both Ser133 phosphorylation and CRTC1 bound to the basic ZIP domain of CREB enhances CRE-mediated transcription, induces gene expression of survival factors, and renders the neurons resistant to subsequent severe ischemia.

  18. Increased expression of angiogenic and inflammatory proteins in the vitreous of patients with ischemic central retinal vein occlusion.

    Directory of Open Access Journals (Sweden)

    Christoph Ehlken

    Full Text Available Central retinal vein occlusion (CRVO is a common disease characterized by a disrupted retinal blood supply and a high risk of subsequent vision loss due to retinal edema and neovascular disease. This study was designed to assess the concentrations of selected signaling proteins in the vitreous and blood of patients with ischemic CRVO.Vitreous and blood samples were collected from patients undergoing surgery for ischemic CRVO (radial optic neurotomy (RON, n = 13, epiretinal gliosis or macular hole (control group, n = 13. Concentrations of 40 different proteins were determined by an ELISA-type antibody microarray.Expression of proteins enriched in the vitreous (CCL2, IGFBP2, MMP10, HGF, TNFRSF11B (OPG was localized by immunohistochemistry in eyes of patients with severe ischemic CRVO followed by secondary glaucoma. Vitreal expression levels were higher in CRVO patients than in the control group (CRVO / control; p < 0.05 for ADIPOQ (13.6, ANGPT2 (20.5, CCL2 (MCP1 (3.2, HGF (4.7, IFNG (13.9, IGFBP1 (14.7, IGFBP2 (1.8, IGFBP3 (4.1, IGFBP4 (1.7, IL6 (10.8, LEP (3.4, MMP3 (4.3, MMP9 (3.6, MMP10 (5.4, PPBP (CXCL7 or NAP2 (11.8, TIMP4 (3.8, and VEGFA (85.3. In CRVO patients, vitreal levels of CCL2 (4.2, HGF (23.3, IGFBP2 (1.23, MMP10 (2.47, TNFRSF11B (2.96, and VEGFA (29.2 were higher than the blood levels (vitreous / blood, p < 0.05. Expression of CCL2, IGFBP2, MMP10, HGF, and TNFRSF11B was preferentially localized to the retina and the retinal pigment epithelium (RPE.Proteins related to hypoxia, angiogenesis, and inflammation were significantly elevated in the vitreous of CRVO patients. Moreover, some markers known to indicate atherosclerosis may be related to a basic vascular disease underlying RVO. This would imply that local therapeutic targeting might not be sufficient for a long term therapy in a systemic disease but hypothetically reduce local changes as an initial therapeutic approach.

  19. Photodynamic impact induces ischemic tolerance in models in vivo and in vitro

    Science.gov (United States)

    Demyanenko, Svetlana; Sharifulina, Svetlana; Berezhnaya, Elena; Kovaleva, Vera; Neginskaya, Maria; Zhukovskaya, Ludmila

    2016-04-01

    Ischemic tolerance determines resistance to lethal ischemia gained by a prior sublethal stimulus (i.e., preconditioning). We reproduced this effect in two variants. In vitro the preliminary short (5 s) photodynamic treatment (PDT) (photosensitizer Photosens, 10 nM, 30 min preincubation; laser: 670 nm, 100 mW/cm2) significantly reduced the necrosis of neurons and glial cells in the isolated crayfish stretch receptor, which was caused by following 30-min PDT by 66% and 46%, respectively. In vivo PDT of the rat cerebral cortex with hydrophilic photosensitizer Rose Bengal (i.v. administration, laser irradiation: 532 nm, 60 mW/cm2, 3 mm beam diameter, 30 min) caused occlusion of small brain vessels and local photothrombotic infarct (PTI). It is a model of ischemic stroke. Cerebral tissue edema and global necrosis of neurons and glial cells occurred in the infarction core, which was surrounded by a 1.5 mm transition zone, penumbra. The maximal pericellular edema, hypo- and hyperchromia of neurons were observed in penumbra 24 h after PTI. The repeated laser irradiation of the contralateral cerebral cortex also caused PTI but lesser as compared with single PDT. Preliminary unilateral PTI provided ischemic tolerance: at 14 day after second exposure the PTI volume significantly decreased by 24% than in the case of a single exposure. Sensorimotor deficits in PDT-treated rats was registered using the behavioral tests. The preliminary PTI caused the preconditioning effect.

  20. Long-term window of ischemic tolerance: An evolutionarily conserved form of metabolic plasticity regulated by epigenetic modifications?

    Science.gov (United States)

    Khoury, Nathalie; Koronowski, Kevin B.; Perez-Pinzon, Miguel A.

    2016-01-01

    In the absence of effective neuroprotective agents in the clinic, ischemic and pharmacological preconditioning are gaining increased interest in the field of cerebral ischemia. Our lab recently reported that resveratrol preconditioning affords tolerance against a focal cerebral ischemic insult in mice that can last for at least 14 days in vivo making it the longest window of ischemic tolerance discovered to date by a single administration of a pharmacological agent. The mechanism behind this novel extended window of ischemic tolerance remains elusive. In the below commentary we discuss potential mechanisms that could explain this novel extended window of ischemic tolerance in the context of previously identified windows and the known mechanisms behind them. We also draw parallels from the fields of hibernation and hypoxia-tolerance, which are chronic adaptations to severe conditions of hypoxia and ischemia known to be mediated by a form of metabolic depression. We also briefly discuss the importance of epigenetic modifications in maintaining this depressed state of metabolism. PMID:27796011

  1. Impending anterior ischemic optic neuropathy with elements of retinal vein occlusion in a patient on interferon for polycythemia vera

    Directory of Open Access Journals (Sweden)

    Rue KS

    2012-10-01

    Full Text Available Kelly S Rue, Louis K Hirsch, Alfredo A SadunDepartment of Neuro-Ophthalmology, Doheny Eye Institute and Keck School of Medicine, University of Southern California, Los Angeles, CA, USAAbstract: We describe the course and likely pathophysiology of impending anterior ischemic optic neuropathy (AION and retinal vein occlusion in a 56-year-old man with polycythemia vera managed with interferon alpha for 2 years. Our patient presented with decreased vision, scintillating scotomata, and floaters. Fundus examination findings and results of a fluorescein angiogram led to the diagnosis of impending AION and retinal vein occlusion. Considering that both polycythemia vera and interferon have possible influences on vascular occlusion and optic disc edema, we stopped interferon treatment and immediately attempted to treat the polycythemia vera empirically with pentoxifylline and any interferon-associated inflammation with prednisone. Our patient experienced complete resolution of fundus abnormalities and return of normal vision within 3 weeks, which may be attributed to our successful treatment of both etiologies. Thus, further study is warranted to elucidate the treatment of both polycythemia vera and interferon-induced impending AION.Keywords: optic disc edema, interferon alpha, vascular occlusion, Roth spot, autoantibody, pentoxifylline

  2. RESVERATROL PRECONDITIONING INDUCES A NOVEL EXTENDED WINDOW OF ISCHEMIC TOLERANCE IN THE MOUSE BRAIN

    Science.gov (United States)

    Koronowski, Kevin B.; Dave, Kunjan R.; Saul, Isabel; Camarena, Vladimir; Thompson, John W.; Neumann, Jake T.; Young, Juan I.; Perez-Pinzon, Miguel A.

    2015-01-01

    Background and Purpose Prophylactic treatments that afford neuroprotection against stroke may emerge from the field of preconditioning. Resveratrol mimics ischemic preconditioning, reducing ischemic brain injury when administered two days prior to global ischemia in rats. This protection is linked to Sirt1 and enhanced mitochondrial function possibly through its repression of UCP2. BDNF is another neuroprotective protein associated with Sirt1. In this study we sought to identify the conditions of resveratrol preconditioning (RPC) that most robustly induce neuroprotection against focal ischemia in mice. Methods We tested four different RPC paradigms against a middle cerebral artery occlusion (MCAo) model of stroke. Infarct volume and neurological score were calculated 24 hours following MCAo. Sirt1-chromatin binding was evaluated by ChIP-qPCR. Percoll gradients were used to isolate synaptic fractions and changes in protein expression were determined via Western blot analysis. BDNF concentration was measured using a BDNF-specific ELISA assay. Results While repetitive RPC induced neuroprotection from MCAo, strikingly one application of RPC 14 days prior to MCAo showed the most robust protection, reducing infarct volume by 33% and improving neurological score by 28%. Fourteen days following RPC, Sirt1 protein was increased 1.5 fold and differentially bound to the UCP2 and BDNF promoter regions. Accordingly, synaptic UCP2 protein decreased by 23% and cortical BDNF concentration increased 26%. Conclusions RPC induces a novel extended window of ischemic tolerance in the brain that lasts for at least 14 days. Our data suggest that this tolerance may be mediated by Sirt1, through upregulation of BDNF and downregulation of UCP2. PMID:26159789

  3. Improving mitochondrial bioenergetics under ischemic conditions increases warm ischemia tolerance in the kidney.

    Science.gov (United States)

    Szeto, Hazel H; Liu, Shaoyi; Soong, Yi; Birk, Alexander V

    2015-01-01

    Ischemia time during partial nephrectomy is strongly associated with acute and chronic renal injury. ATP depletion during warm ischemia inhibits ATP-dependent processes, resulting in cell swelling, cytoskeletal breakdown, and cell death. The duration of ischemia tolerated by the kidney depends on the amount of ATP that can be produced with residual substrates and oxygen in the tissue to sustain cell function. We previously reported that the rat can tolerate 30-min ischemia quite well but 45-min ischemia results in acute kidney injury and progressive interstitial fibrosis. Here, we report that pretreatment with SS-20 30 min before warm ischemia in the rat increased ischemia tolerance from 30 to 45 min. Histological examination of kidney tissues revealed that SS-20 reduced cytoskeletal breakdown and cell swelling after 45-min ischemia. Electron microscopy showed that SS-20 reduced mitochondrial matrix swelling and preserved cristae membranes, suggesting that SS-20 enhanced mitochondrial ATP synthesis under ischemic conditions. Studies with isolated kidney mitochondria showed dramatic reduction in state 3 respiration and respiratory control ratio after 45-min ischemia, and this was significantly improved by SS-20 treatment. These results suggest that SS-20 increases efficiency of the electron transport chain and improves coupling of oxidative phosphorylation. SS-20 treatment after ischemia also significantly reduced interstitial fibrosis. These new findings reveal that enhancing mitochondrial bioenergetics may be an important target for improving ischemia tolerance, and SS-20 may serve well for minimizing acute kidney injury and chronic kidney disease following surgical procedures such as partial nephrectomy and transplantation.

  4. Optic Disc and Retinal Nerve Fiber Layer Thickness Evaluation of the Fellow Eyes in Non-Arteritic Ischemic Optic Neuropathy

    Directory of Open Access Journals (Sweden)

    Medine Yılmaz Dağ

    2015-05-01

    Full Text Available Objectives: To examine the fellow eyes in unilateral non-arteritic ischemic optic neuropathy (NAION and to compare their optic disc parameters and peripapillary retinal nerve fiber layer (RNFL thickness with age-and refraction-matched normal controll subjects, using Heidelberg Retinal Tomograph 2 (HRT II. Materials and Methods: The fellow eyes of 40 patients with typical unilateral NAION (study group and one randomly chosen eye of 42 age-, sex-, and refraction-matched normal control subjects were enrolled in the study. Optic disc morphologic features (average disc area, cup area, rim area, disc volume, rim volume, cup/disc area ratio, cup depth and peripapillary RNFL thickness were evaluated using HRT II, a confoal scanning ophtalmoscopy. Results: In the study group, there were 26 (65% men and 14 (35% women, whereas there were 27 (64% men and 15 (36% women in the control group (Chi square test, p=0.89. Mean age of the patients in the study and control groups was 59.4±10.3 and 57.7±9.1 years, respectively (T test, p=0.72. There was not any statistically significant difference regarding mean spheric equivalent between the two groups (Mann-Whitney U-test, p=0.203. The NAION unaffected fellow eyes had significantly smaller disc areas, cup areas, cup volumes, cup-disc area ratios (vertical and lineer, and cup depths than the control eyes (Mann-Whitney U-test; p<0.05, whereas there was no significant difference in the RNFL thickness between the two. Conclusion: A comparison of the fellow eyes in patients with unilateral NAION and the control eyes showed a significant difference in optic disc parameters and the morphology of RNFL. These differences could be important in the pathogenesis of NAION and needs to have further investigated. (Turk J Ophthalmol 2015; 45: 111-114

  5. Moderate GSK-3β inhibition improves neovascular architecture, reduces vascular leakage, and reduces retinal hypoxia in a model of ischemic retinopathy.

    Science.gov (United States)

    Hoang, Mien V; Smith, Lois E H; Senger, Donald R

    2010-09-01

    In ischemic retinopathies, unrelieved hypoxia induces the formation of architecturally abnormal, leaky blood vessels that damage retina and ultimately can cause blindness. Because these newly formed blood vessels are functionally defective, they fail to alleviate underlying hypoxia, resulting in more pathological neovascularization and more damage to retina. With an established model of ischemic retinopathy, we investigated inhibition of glycogen synthase kinase-3β (GSK-3β) as a means for improving the architecture and functionality of pathological blood vessels in retina. In vitro, hypoxia increased GSK-3β activity in retinal endothelial cells, reduced β-catenin, and correspondingly impaired integrity of cell/cell junctions. Conversely, GSK-3β inhibitors restored β-catenin, improved cell/cell junctions, and enhanced the formation of capillary cords in three-dimensional collagen matrix. In vivo, GSK-3β inhibitors, at appropriately moderate doses, strongly reduced abnormal vascular tufts, reduced abnormal vascular leakage, and improved vascular coverage and perfusion during the proliferative phase of ischemia-driven retinal neovascularization. Most importantly, these improvements in neovasculature were accompanied by marked reduction in retinal hypoxia, relative to controls. Thus, GSK-3β inhibitors offer a promising strategy for alleviating retinal hypoxia by correcting key vascular defects typically associated with ischemia-driven neovascularization.

  6. Safety and tolerability of early noninvasive ventilatory correction using bilevel positive airway pressure in acute ischemic stroke.

    Science.gov (United States)

    Tsivgoulis, Georgios; Zhang, Yi; Alexandrov, Anne W; Harrigan, Mark R; Sisson, April; Zhao, Limin; Brethour, Mary; Cava, Luis; Balucani, Clotilde; Barlinn, Kristian; Patterson, Damon E; Giannopoulos, Sotirios; DeWolfe, Jennifer; Alexandrov, Andrei V

    2011-04-01

    Hypercapnia can induce intracranial blood-flow steal from ischemic brain tissues, and early initiation of noninvasive ventilator correction (NIVC) may improve cerebral hemodynamics in acute ischemic stroke. We sought to determine safety and tolerability of NIVC initiated on hospital admission without polysomnography study. Consecutive acute ischemic stroke patients were evaluated for the presence of a proximal arterial occlusion, daytime sleepiness, or history of obstructive sleep apnea, and acceptable pulse oximetry readings while awake (96%-100% on 2 to 4 L supplemental oxygen delivered by nasal cannula). NIVC was started on hospital admission as standard of care when considered necessary by treating physicians. NIVC was initiated using bilevel positive airway pressure at 10 cmH(2)O inspiratory positive airway pressure and 5 cmH(2)O expiratory positive airway pressure in combination with 40% fraction of inspired oxygen. All potential adverse events were prospectively documented. Among 356 acute ischemic stroke patients (median NIHSS score, 5; interquartile range, 2-13), 64 cases (18%) received NIVC (median NIHSS score, 12; interquartile range, 6-17). Baseline stroke severity was higher and proximal arterial occlusions were more frequent in NIVC patients compared to the rest (Pacute ischemic stroke patients with proximal arterial occlusion and excessive sleepiness or obstructive sleep apnea, NIVC can be initiated early with good tolerability and a relatively small risk of serious complications.

  7. Dietary boron intake does not change the ischemic tolerance and preconditioning response in isoproterenol-induced myocardial injury in healthy rats

    OpenAIRE

    Karakaş, Mehmet Fatih; Kurt, Mustafa; ARSLANTAŞ, Uğur; İpek, Göktürk; Karakaş, Esra; BİLEN, Emine; Erdamar, Hüsamettin

    2011-01-01

    Boron is important for many enzymes, most of which also have a role in the ischemic tolerance of the myocardium. We aimed to evaluate the influence of dietary boron intake on ischemic tolerance in a rat model. Materials and methods: Rats were divided into 3 groups according to the ischemia protocol: Sham (S) (n = 20 total), ischemia only (Isc-only) (n = 40 total), and remote ischemic preconditioning + ischemia (RIPC+Isc) (n = 40 total) groups. These 3 groups were further divided into 4 accor...

  8. Pre-Ischemic Treadmill Training Induces Tolerance to Brain Ischemia: Involvement of Glutamate and ERK1/2

    Directory of Open Access Journals (Sweden)

    Yong-Shan Hu

    2010-08-01

    Full Text Available Physical exercise has been shown to be beneficial in stroke patients and animal stroke models. However, the exact mechanisms underlying this effect are not yet very clear. The present study investigated whether pre-ischemic treadmill training could induce brain ischemic tolerance (BIT by inhibiting the excessive glutamate release and event-related kinase 1/2 (ERK1/2 activation observed in rats exposed to middle cerebral artery occlusion (MCAO. Sprague–Dawley rats were divided into three groups (n = 12/group: sham surgery without prior exercise, MCAO without prior exercise and MCAO following three weeks of exercise. Pre-MCAO exercise significantly reduced brain infarct size (103.1 ± 6.7 mm3 relative to MCAO without prior exercise (175.9 ± 13.5 mm3. Similarly, pre-MCAO exercise significantly reduced neurological defects (1.83 ± 0.75 relative to MCAO without exercise (3.00 ± 0.63. As expected, MCAO increased levels of phospho-ERK1/2 (69 ± 5% relative to sham surgery (40 ± 5%, and phospho-ERK1/2 levels were normalized in rats exposed to pre-ischemic treadmill training (52 ± 6% relative to MCAO without exercise (69% ± 5%. Parallel effects were observed on striatal glutamate overflow. This study suggests that pre-ischemic treadmill training might induce neuroprotection by inhibiting the phospho-ERK1/2 over-activation and reducing excessive glutamate release.

  9. An autosomal recessive leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa maps to chromosome 17q24.2-25.3

    Directory of Open Access Journals (Sweden)

    Bouhouche Ahmed

    2012-03-01

    Full Text Available Abstract Background Single-gene disorders related to ischemic stroke seem to be an important cause of stroke in young patients without known risk factors. To identify new genes responsible of such diseases, we studied a consanguineous Moroccan family with three affected individuals displaying hereditary leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa that appears to segregate in autosomal recessive pattern. Methods All family members underwent neurological and radiological examinations. A genome wide search was conducted in this family using the ABI PRISM linkage mapping set version 2.5 from Applied Biosystems. Six candidate genes within the region linked to the disease were screened for mutations by direct sequencing. Results Evidence of linkage was obtained on chromosome 17q24.2-25.3. Analysis of recombination events and LOD score calculation suggests linkage of the responsible gene in a genetic interval of 11 Mb located between D17S789 and D17S1806 with a maximal multipoint LOD score of 2.90. Sequencing of seven candidate genes in this locus, ATP5H, FDXR, SLC25A19, MCT8, CYGB, KCNJ16 and GRIN2C, identified three missense mutations in the FDXR gene which were also found in a homozygous state in three healthy controls, suggesting that these variants are not disease-causing mutations in the family. Conclusion A novel locus for leucoencephalopathy with ischemic stroke, dysmorphic syndrome and retinitis pigmentosa has been mapped to chromosome 17q24.2-25.3 in a consanguineous Moroccan family.

  10. [Radiation preconditioning of mouse retina results in tolerance to MNU-induced degeneration and stimulates retinal recovery].

    Science.gov (United States)

    Tronov, V A; Vinogradova, Yu V; Poplinskaya, V A; Nekrasova, E I; Ostrovsky, M A

    2015-01-01

    Emerging body of data indicate protecting effect of low level of stress (preconditioning) on retina. Our previous studies have revealed a non-linear dose-response relationship for cytotoxic effect of both ionizing radiation and N-methyl-N-nitrosourea (MNU) on mouse retina. Moreover, non-cytotoxic dose of MNU increased tolerance of retina to following challenge dose of MNU. This result displays protection of retina through mechanism of recovery. In the present study we used the mouse model for MNU-induced retinal degeneration to evaluate the adaptive response of the retina to proton irradiation and implication of glial Muller cells in this response. In this paper, we have shown that the recovery of the retina after exposure to genotoxic agents is associated with an increased efficiency of DNA damage repair and lowered death of retinal photoreceptors.

  11. The Neuroprotective Effect of Rosemary (Rosmarinus officinalis L.) Hydro-alcoholic Extract on Cerebral Ischemic Tolerance in Experimental Stroke

    Science.gov (United States)

    Seyedemadi, Parisa; Rahnema, Mehdi; Bigdeli, Mohammad Reza; Oryan, Shahrebano; Rafati, Hassan

    2016-01-01

    The prevention of BBB breakdown and the subsequent vasogenic edema are important parts of the medical management of ischemic stroke. The purpose of this study was to investigate the ischemic tolerance effect of Rosmarinus officinalis leaf hydro-alcoholic extract (RHE). Five groups of animals were designed: sham (underwent surgery without MCAO) and MCAO groups, the MCAO groups were pretreated orally by gavages with RHE (50, 75, and 100 mg/Kg/day), daily for 30 days. Two hours after the last dose, serum lipid levels were determined and then the rats were subjected to 60 min of middle cerebral artery occlusion followed by 24 h of reperfusion. Subsequently, brain infarct size, brain edema and Evans Blue dye extravasations were measured and neurological deficits were scored. Dietary RHE could significantly reduce cortical and sub-cortical infarct volumes (211.55 ± 24.88 mm3 vs. 40.59 ± 10.04 mm3 vs. 29.96 ± 12.19 mm3vs. 6.58 ± 3.2 mm3), neurologic deficit scores, cerebral edema (82.34 ± 0.42% vs. 79.92 ± 0.49% vs. 79.45 ± 0.26% vs. 79.30 ± 0.19%), blood–brain barrier (BBB) permeability (7.73 ± 0.4 μg/g tissue vs. 4.1 ± 0.23 μg/g tissue vs. 3.58 ± 0.3 μg/g tissue vs. 3.38 ± 0.25 μg/g tissue) in doses of 50, 75 and 100 mg/Kg/day as compared with the control group in the transient model of focal cerebral ischemia. Although pretreatment with RHE plays an important role in the generation of tolerance against cerebral I/R injury, further studies are needed to clarify the mechanism of the ischemic tolerance. PMID:28243285

  12. Physiologically tolerable insulin reduces myocardial injury and improves cardiac functional recovery in myocardial ischemic/reperfused dogs.

    Science.gov (United States)

    Zhang, Hang-Xiang; Zang, Yi-Min; Huo, Jian-Hua; Liang, Shao-Jun; Zhang, Hai-Feng; Wang, Yue-Min; Fan, Qian; Guo, Wen-Yi; Wang, Hai-Chang; Gao, Feng

    2006-12-01

    This study was designed to examine whether physiologically tolerable insulin, which maintains lower blood glucose, can protect the myocardium against ischemia/reperfusion (I/R) injury in a preclinical large animal model. Adult dogs were subjected to 50 minutes of myocardial ischemia (80% reduction in coronary blood flow) followed by 4 hours of reperfusion and treated with vehicle, glucose-insulin-potassium (GIK; glucose, 250 g/L; insulin, 60 U/L; potassium, 80 mmol/L), GK, or low-dose insulin (30 U/L) 10 minutes before reperfusion. Treatment with GIK exerted significant cardioprotective effects as evidenced by improved cardiac function, improved coronary blood flow, reduced infarct size, and myocardial apoptosis. In contrast, treatment with GK increased blood glucose level and aggravated myocardial I/R injury. It is interesting that treatment with insulin alone at the dose that reduced blood glucose to a clinically tolerable level exerted significant cardioprotective effects that were comparable to that seen in the GIK-treated group. This low-dose insulin had no effect on coronary blood flow after reperfusion but markedly reduced coronary reactive hyperemia and switched myocardial substrate uptake from fat to carbohydrate. Our results suggest that lower glucose supply to the ischemic myocardium at early reperfusion may create a "metabolic postconditioning" and thus reduce myocardial ischemia/reperfusion injury after prolonged reperfusion.

  13. Protein Kinase C Epsilon Promotes Cerebral Ischemic Tolerance Via Modulation of Mitochondrial Sirt5

    Science.gov (United States)

    Morris-Blanco, Kahlilia C.; Dave, Kunjan R.; Saul, Isabel; Koronowski, Kevin B.; Stradecki, Holly M.; Perez-Pinzon, Miguel A.

    2016-01-01

    Sirtuin 5 (SIRT5) is a mitochondrial-localized NAD+-dependent lysine desuccinylase and a major regulator of the mitochondrial succinylome. We wanted to determine whether SIRT5 is activated by protein kinase C epsilon (PKCε)-mediated increases in mitochondrial Nampt and whether SIRT5 regulates mitochondrial bioenergetics and neuroprotection against cerebral ischemia. In isolated mitochondria from rat cortical cultures, PKCε activation increased SIRT5 levels and desuccinylation activity in a Nampt-dependent manner. PKCε activation did not lead to significant modifications in SIRT3 activity, the major mitochondrial lysine deacetylase. Assessments of mitochondrial bioenergetics in the cortex of wild type (WT) and SIRT5−/− mice revealed that SIRT5 regulates oxygen consumption in the presence of complex I, complex II, and complex IV substrates. To explore the potential role of SIRT5 in PKCε-mediated protection, we compared WT and SIRT5−/− mice by employing both in vitro and in vivo ischemia paradigms. PKCε-mediated decreases in cell death following oxygen-glucose deprivation were abolished in cortical cultures harvested from SIRT5−/− mice. Furthermore, PKCε failed to prevent cortical degeneration following MCAO in SIRT5−/− mice. Collectively this demonstrates that SIRT5 is an important mitochondrial enzyme for protection against metabolic and ischemic stress following PKCε activation in the brain. PMID:27435822

  14. The effect of endurance training on cell metabolism and exercise tolerance in patients with ischemic heart disease

    Directory of Open Access Journals (Sweden)

    T Rychlewski

    2003-03-01

    Full Text Available We have investigated the effect of endurance training on cell metabolism and exercise tolerance in patients with ischemic heart disease. Study population consisted of 24 survivors of myocardial infarction. Patients were assigned to the training group (n=18, mean age 48.2 years or to the control group (n=6, mean age 42.6 years. Directly before (ExTest I and after completing a 3-week endurance training program (ExTest II patients performed bicycle ergometry with computer analysis of ventilatory expired gas (CardioO2, Medical Graphics Corporation. The exercise intensity increased gradually until ventilatory threshold was reached. ExTest II was finished at the same workload level as ExTest I. ECG was recorded and blood pressure was assessed during each ergometry. Prior to and 3 minutes after finishing each test, capillary blood samples were taken for measurements of acid-base equilibrium parameters and lactate concentrations and venous blood samples were collected for assessment of oxypurines and uric acid levels (HPLC method. The training consisted of five 40-min sessions of continuos working on a bicycle ergometer weekly. The workload was 25 W lower than the load at which ventilatory threshold had been reached by the patient. Subjects in the control group did not participate in endurance training. During exercise tests performed after the rehabilitation program, heart rate and rate-pressure product at particular workload were lower than on admission. Similarly, the increases in lactate concentrations and changes in base excess were reduced during ExTest II. The oxypurines pool was reduced after the training, which reflects improvement in cell metabolism. No influence of training on uric acid concentrations was observed.

  15. Ischemic preconditioning

    Directory of Open Access Journals (Sweden)

    Ristić-Anđelkov Anđelka

    2005-01-01

    Full Text Available Background. Ischemic preconditioning is a phenomenon during which myocardium, subjected to brief episodes of ischemia followed by reperfusion, tolerates better the subsequent, more prolonged episode of this ischemia, thus reducing the infarction size substantially. Case report. Two patients with acute left anterior descendent artery occlusion received fibrinolytic therapy (alteplase within 6 hours of the onset of chest pain, but developed myocardial infarctions of different sizes. The first patient, without the history of preinfarction angina, developed large anterior infarct, because there was no time either for ischemic preconditioning or for the coronary collateral vessels development. In the second patient, with 4-day history of preinfarction angina, the more favorable outcome was seen he developed smaller apical necrosis, with the great degree of myocardial viability in the infarct-related area. Conclusion. Ischemic preconditioning in patients with acute myocardal infarction results in the reduction of mortality, infarction size, as well as in the frequency of malignant arrhythmias.

  16. Metformin and sitAgliptin in patients with impAired glucose tolerance and a recent TIA or minor ischemic Stroke (MAAS): study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    E. Osei; S. Fonville (Susanne); A.A.M. Zandbergen (Adrienne); P.J. Brouwers (Paul); L.J.M.M. Mulder (Laus J. M.); H.F. Lingsma (Hester); D.W.J. Dippel (Diederik); P.J. Koudstaal (Peter Jan); H.M. den Hertog (Heleen)

    2015-01-01

    textabstractBackground: Impaired glucose tolerance is present in one third of patients with a TIA or ischemic stroke and is associated with a two-fold risk of recurrent stroke. Metformin improves glucose tolerance, but often leads to side effects. The aim of this study is to explore the feasibility,

  17. Involvement of δ-and μ-opioid receptors in the delayed cerebral ischemic tolerance induced by repeated electroacupuncture preconditioning in rats

    Institute of Scientific and Technical Information of China (English)

    XIONG Li-ze; YANG Jing; WANG Qiang; LU Zhi-hong

    2007-01-01

    Background Preconditioning with repeated electroacupuncture (EA) could mimic ischemic preconditioning to induce cerebral ischemic tolerance in rats. The present study was designed to investigate whether mu(μ)-, delta(δ)- or kappa(κ)-opioid receptors are involved in the neuroprotection induced by repeated EA preconditioning.Methods The rats were pretreated with naltrindole (NTI), nor-binaltorphimine (nor-BNI) or D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), which is a highly selective δ-, κ- or μ-opioid receptor antagonist respectively, before each EA preconditioning (30 minutes per day, 5 days). Twenty-four hours after the last EA treatment, the middle cerebral artery occlusion (MCAO) was induced for 120 minutes. The brain infarct volume was determined with 2,3,5-triphenyltetrazolium chloride staining at 24 hours after MCAO and compared with that in rats which only received EA preconditioning. In another experiment, the met-enkephalin-like immunoreactivity in rat brain was investigated by immunohistochemistry in both EA preconditioning and control rats.Results The EA preconditioning reduced brain infarct volume compared with the control rats (P=0.000). Administration of both NTI and CTOP attenuated the brain infarct volume reduction induced by EA preconditioning, presenting with larger infarct volume than that in the EA preconditioning rats (P<0.001). But nor-BNI administration did not block the infarct volume reduction induced by EA preconditioning, presenting with smaller infarct volume than the control group rats(P=0.000). The number of met-enkephalin-like immunoreactivity positive neurons in the EA preconditioning rats was more than that of the control rats (P=0.000).Conclusion Repeated EA preconditioning stimulates the release of enkephalins, which may bind δ- and μ-opioid receptors to induce the tolerance against focal cerebral ischemia.

  18. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

    Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated by the d...... these alternatives by returning to the notion of tolerance as the endurance of pain, linking this notion to exemplars and theories relevant to the politics of multiculturalism, religious freedom, and free speech....

  19. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

    Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated by the d...... these alternatives by returning to the notion of tolerance as the endurance of pain, linking this notion to exemplars and theories relevant to the politics of multiculturalism, religious freedom, and free speech....

  20. Induction of ischemic tolerance in rat liver via reduced nicotinamide adenine dinucleotide phosphate oxidase in Kupffer cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To elucidate the mechanisms of hepatocyte preconditioning by H2O2 to better understand the pathophysiology of ischemic preconditioning.METHODS: The in vitro effect of H2O2 pretreatment was investigated in rat isolated hepatocytes subjected to anoxia/reoxygenation. Cell viability was assessed with propidium iodide fluorometry. In other experiments, rat livers were excised and subjected to warm ischemia/reperfusion in an isolated perfused liver system to determine leakage of liver enzymes. Preconditioning was performed by H2O2 perfusion, or by stopping the perfusion for 10 min followed by 10 min of reperfusion.To inhibit Kupffer cell function or reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase,gadolinium chloride was injected prior to liver excision, or diphenyleneiodonium, an inhibitor of NADPH oxidase, was added to the perfusate, respectively. Histological detection of o~gen radical formation in Kupffer cells was performed by perfusion with nitro blue tetrazolium.RESULTS: Anoxia/reoxygenation decreased hepatocyte viability compared to the controls. Pretreatment with H2O2 did not improve such hepatocyte injury. In liver perfusion experiments, however, H2O2 preconditioning reduced warm ischemia/reperfusion injury, which was reversed by inhibition of Kupffer cell function or NADPH oxidase. Histological examination revealed that H2O2 preconditioning induced oxygen radical formation in Kupffer cells. NADPH oxidase inhibition also reversed hepatoprotection by ischemic preconditioning.CONCLUSION: H2O2 preconditioning protects hepatocytes against warm ischemia/reperfusion injury via NADPH oxidase in Kupffer cells, and not directly. NADPH oxidase also mediates hepatoprotection by ischemic preconditioning.

  1. Retino-choroidal ischemia in central retinal vein occlusion

    OpenAIRE

    Hussain, Nazimul; Hussain, Anjli

    2014-01-01

    A 41-year-old gentleman with insulin dependent diabetes had decreased vision in the right eye due to non-ischemic central retinal vein occlusion with macular edema. One month following intravitreal ranibizumab, he developed retino-choroidal ischemia with further loss of vision. Authors show the fluorescein angiographic transition from non-ischemic central retinal vein occlusion to retino-choroidal ischemia.

  2. ASSOCIATION BETWEEN RETINAL HEMORRHAGIC PATTERNS AND PERFUSION STATUS IN EYES WITH ACUTE CENTRAL RETINAL VEIN OCCLUSION.

    Science.gov (United States)

    Muraoka, Yuki; Uji, Akihito; Tsujikawa, Akitaka; Murakami, Tomoaki; Ooto, Sotaro; Suzuma, Kiyoshi; Takahashi, Ayako; Iida, Yuto; Miwa, Yuko; Hata, Masayuki; Yoshimura, Nagahisa

    2017-03-01

    To evaluate peripheral retinal hemorrhagic patterns in eyes with acute central retinal vein occlusion, and to explore their clinical relevance in differentiating for the retinal perfusion status, through a prospective, and cross-sectional study. Fifty eyes with acute central retinal vein occlusion were included. Retinal hemorrhagic patterns at the equator and retinal perfusion status were evaluated by ultra-wide field fundus photography and fluorescein angiography. Retinal perfusion was categorized as nonischemic in 29 eyes, ischemic in 18 eyes, and undeterminable in 3 eyes. None of the examined eyes had flame-shaped retinal hemorrhages in the periphery. All hemorrhages were rounded-dot or blot and were variable in size. Particle analysis was performed to quantify hemorrhage size, and showed higher values in eyes having larger blot hemorrhages, and lower values in eyes having dot or smaller blot hemorrhages. Mean size of maximum peripheral dot or blot hemorrhage was larger in eyes classified as ischemic (10,763.0 ± 5,946.3 pixels) than as nonischemic (2,839.9 ± 1,153.6 pixels, P retinal perfusion status, which was 0.963 (P retinal hemorrhagic patterns at the equator in eyes with acute central retinal vein occlusion using particle analysis. The resulting hemorrhage size measurement was considered to be often useful in determining retinal perfusion status. Because they can be noninvasively evaluated with readily available equipment, peripheral hemorrhagic patterns might be good clinical markers of retinal perfusion.

  3. Ischemic conditioning protects from axoglial alterations of the optic pathway induced by experimental diabetes in rats.

    Directory of Open Access Journals (Sweden)

    Diego C Fernandez

    Full Text Available Diabetic retinopathy is a leading cause of blindness. Visual function disorders have been demonstrated in diabetics even before the onset of retinopathy. At early stages of experimental diabetes, axoglial alterations occur at the distal portion of the optic nerve. Although ischemic conditioning can protect neurons and synaptic terminals against ischemic damage, there is no information on its ability to protect axons. We analyzed the effect of ischemic conditioning on the early axoglial alterations in the distal portion of the optic nerve induced by experimental diabetes. Diabetes was induced in Wistar rats by an intraperitoneal injection of streptozotocin. Retinal ischemia was induced by increasing intraocular pressure to 120 mm Hg for 5 min; this maneuver started 3 days after streptozotocin injection and was weekly repeated in one eye, while the contralateral eye was submitted to a sham procedure. The application of ischemia pulses prevented a deficit in the anterograde transport from the retina to the superior colliculus, as well as an increase in astrocyte reactivity, ultraestructural myelin alterations, and altered morphology of oligodendrocyte lineage in the optic nerve distal portion at early stages of experimental diabetes. Ischemia tolerance prevented a significant decrease of retinal glutamine synthetase activity induced by diabetes. These results suggest that early vision loss in diabetes could be abated by ischemic conditioning which preserved axonal function and structure.

  4. ACUTE RETINAL ARTERIAL OCCLUSIVE DISORDERS

    Science.gov (United States)

    Hayreh, Sohan Singh

    2011-01-01

    The initial section deals with basic sciences; among the various topics briefly discussed are the anatomical features of ophthalmic, central retinal and cilioretinal arteries which may play a role in acute retinal arterial ischemic disorders. Crucial information required in the management of central retinal artery occlusion (CRAO) is the length of time the retina can survive following that. An experimental study shows that CRAO for 97 minutes produces no detectable permanent retinal damage but there is a progressive ischemic damage thereafter, and by 4 hours the retina has suffered irreversible damage. In the clinical section, I discuss at length various controversies on acute retinal arterial ischemic disorders. Classification of acute retinal arterial ischemic disorders These are of 4 types: CRAO, branch retinal artery occlusion (BRAO), cotton wools spots and amaurosis fugax. Both CRAO and BRAO further comprise multiple clinical entities. Contrary to the universal belief, pathogenetically, clinically and for management, CRAO is not one clinical entity but 4 distinct clinical entities – non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, arteritic CRAO associated with giant cell arteritis (GCA) and transient non-arteritic CRAO. Similarly, BRAO comprises permanent BRAO, transient BRAO and cilioretinal artery occlusion (CLRAO), and the latter further consists of 3 distinct clinical entities - non-arteritic CLRAO alone, non-arteritic CLRAO associated with central retinal vein occlusion and arteritic CLRAO associated with GCA. Understanding these classifications is essential to comprehend fully various aspects of these disorders. Central retinal artery occlusion The pathogeneses, clinical features and management of the various types of CRAO are discussed in detail. Contrary to the prevalent belief, spontaneous improvement in both visual acuity and visual fields does occur, mainly during the first 7 days. The incidence of spontaneous visual

  5. Efficacy and tolerability of bilateral sustained-release dexamethasone intravitreal implants for the treatment of noninfectious posterior uveitis and macular edema secondary to retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    Ryder SJ

    2015-06-01

    Full Text Available Steven J Ryder,1 Danilo Iannetta,1 Swetangi D Bhaleeya,2 Szilárd Kiss1 1Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA; 2Department of Ophthalmology, University of South Florida, Tampa, FL, USA Purpose: To report our experience with bilateral placement of dexamethasone 0.7 mg (DEX sustained-release intravitreal implant in the management of noninfectious posterior uveitis or macular edema secondary to retinal vein occlusion.Methods: A retrospective chart review of patients with bilateral noninfectious posterior uveitis and macular edema secondary to retinal vein occlusion who were treated with DEX intravitreal implant was performed. Ocular side effects such as intraocular pressure (IOP, cataract, and tolerability of bilateral injections was reviewed.Results: Twenty-two eyes of eleven patients treated with a total of 32 DEX implants were included. Ten of eleven patients received bilateral implants due to active noninfectious uveitis while the other demonstrated macular edema in both eyes following separate central retinal vein occlusions. Among the patients with bilateral uveitis, the mean interval between DEX implant in the initial eye and the subsequent DEX in the fellow eye was 15.6 days (range 2–71 days. Seven of the ten patients received the second implant in the fellow eye within 8 days of the initial implantation. None of the patients had bilateral implantations on the same day. Seven eyes required reimplantation for recurrence of inflammation (mean interval between first and repeat implantation was 6.00±2.39 months. Following single or, in the case of the aforementioned seven eyes, repeat DEX implantation, all 20 uveitic eyes demonstrated clinical and/or angiographic evidence of decreased inflammation in the form of reduction in vitreous cells on slit lamp ophthalmoscopy, macular edema on ophthalmoscopy, or optical coherence tomography and/or disc and vascular leakage on fluorescein angiography. The mean

  6. Central Retinal Artery Occlusion With Subsequent Central Retinal Vein Occlusion in Biopsy-Proven Giant Cell Arteritis.

    Science.gov (United States)

    Williams, Zoë R; Wang, Xiaofei; DiLoreto, David A

    2016-09-01

    Central retinal artery occlusion with subsequent central retinal vein occlusion in the same eye is a rare entity. We present a 72-year-old man with biopsy-proven giant cell arteritis who developed bilateral arteritic anterior ischemic optic neuropathy and a left central retinal artery occlusion. Subsequently, he developed a left central retinal vein occlusion within 2 weeks of his initial vision loss. His vision did not improve with corticosteroids.

  7. Ischemic Stroke

    Science.gov (United States)

    A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Ischemic stroke is the most common type. It is usually ... are at risk for having a more serious stroke. Symptoms of stroke are Sudden numbness or weakness ...

  8. Effects of C-nitropyrazoles and C-nitroazoles on ocular blood flow and retinal function recovery after ischemic insult%C-硝基吡唑类和C-硝基吡咯类对局部缺血损伤后眼血流量和视网膜功能恢复的作用

    Institute of Scientific and Technical Information of China (English)

    Bo XUAN; Tao WANG; George CY CHIOU; Igor L'vovich DALINGER; Tatyana Konstantinovna SHKINEVA; Svyatoslav Arkadievich SHEVELEV

    2002-01-01

    AIM: Effects of C-nitropyrazoles and C-nitroazoles on ocular blood flow and retinal.function recovery after ischemia have been studied. METHODS: The compounds were tested on ocular blood flow of ocular hyperten sive (40 mmHg) rabbit eyes with colored microsphere technique. They were also tested on the retinal function recovery after ischemia of rat eyes with electroretinography. RESULTS: All compounds (DC-1 through DC-17)showed significant increase in retinal function recovery after ischemia in the range of 26 % to 120 %(P<0.05). Among five compounds (DC-1 through DC-5) studied, four compounds (DC-2 through DC-5) in creased the blood flow in ehoroid, iris, and ciliary body, but not in retina. DC-1 did not show significant increase of blood flow in any of these ocular tissues. CONCLUSION: C-Nitropyrazoles can facilitate significant retinal function recovery after ischemic insult through the increase of ocular blood flow. Since rabbit's retina is scarce in vasculature, it did not show significant change in blood flow by C-nitropyrazoles as expected. Among all 17 compounds, DC-5 seems to be the most potent compound.

  9. Ocular neovascularization associated with central and hemicentral retinal vein occlusion.

    Science.gov (United States)

    Hayreh, Sohan Singh; Zimmerman, M Bridget

    2012-09-01

    To investigate the incidence of ocular neovascularization (NV) in central and hemicentral retinal vein occlusion. The study comprised consecutive 912 (673 nonischemic and 239 ischemic) central retinal vein occlusion and 190 (147 nonischemic, 43 ischemic) hemicentral retinal vein occlusion eyes. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. In ischemic central retinal vein occlusion, within 6 months from time of onset, the cumulative probability of development of iris NV was 49%, angle NV 37%, NV glaucoma 29%, retinal NV 9%, and disk NV 6%. More severe peripheral retinal hemorrhages were significantly associated with iris NV (P = 0.005), angle NV (P = 0.0004), and NV glaucoma (P = 0.012). Eyes that developed disk NV had more cotton wool spots (P = 0.058) than those without. In ischemic hemicentral retinal vein occlusion, within 12 months of onset, the cumulative probability of development of retinal NV was 29%, disk NV 12%, and iris NV 12%; within 6 months of onset, angle NV was found in 10% and NV glaucoma in 5%. Anterior chamber flare was associated with anterior segment NV and may precede the development of NV. Patients who developed NV were significantly younger, and there was a greater prevalence of NV glaucoma in patients with primary open angle glaucoma. In ischemic central retinal vein occlusion, anterior segment NV is much more common than posterior segment NV, and the cumulative chance of developing anterior segment NV is maximum during the first 6 months. In ischemic hemicentral retinal vein occlusion, posterior segment NV is much more common than anterior segment NV.

  10. Retinal Vasculitis

    Science.gov (United States)

    Rosenbaum, James T.; Sibley, Cailin H.; Lin, Phoebe

    2016-01-01

    Purpose of review Ophthalmologists and rheumatologists frequently miscommunicate in consulting on patients with retinal vasculitis. This report seeks to establish a common understanding of the term, retinal vasculitis, and to review recent papers on this diagnosis. Recent findings 1) The genetic basis of some rare forms of retinal vascular disease have recently been described. Identified genes include CAPN5, TREX1, and TNFAIP3; 2) Behçet’s disease is a systemic illness that is very commonly associated with occlusive retinal vasculitis; 3) retinal imaging including fluorescein angiography and other newer imaging modalities has proven crucial to the identification and characterization of retinal vasculitis and its complications; 4) although monoclonal antibodies to IL-17A or IL-1 beta failed in trials for Behçet’s disease, antibodies to TNF alpha, either infliximab or adalimumab, have demonstrated consistent benefit in managing this disease. Interferon treatment and B cell depletion therapy via rituximab may be beneficial in certain types of retinal vasculitis. Summary Retinal vasculitis is an important entity for rheumatologists to understand. Retinal vasculitis associated with Behçet’s disease responds to monoclonal antibodies that neutralize TNF, but the many other forms of non-infectious retinal vasculitis may require alternate therapeutic management. PMID:26945335

  11. Preclinical models to investigate retinal ischemia: Advances and drawbacks

    Directory of Open Access Journals (Sweden)

    Gillipsie eMinhas

    2012-05-01

    Full Text Available Retinal ischemia is a frequent source of irreparable visual impairment affecting over a hundred million individuals in the world. It is associated with a wide range of retinal disorders like ischemic optic neuropathies, obstructive retinopathies, carotid occlusive disorders, diabetic retinopathy and glaucoma. Compared to other tissues retina has a higher metabolic rate; any disruption in blood supply can have an effect on the supply of oxygen leading to retinal ischemia. If occlusion is not rescued the outcome is irreversible with ischemic and apoptotic cascades resulting in cell death. In addition to in-vitro models, animal models are necessary to further our understanding of the etiology, pathology, and evolution of retinal ischemia besides the evaluation, development, and improvement of therapeutic strategies. The various existing animal models of retinal ischemia are characterised by obstruction of retinal circulation that allows the study of neurovascular changes. In this review we provide an overview of major models and emerging preclinical therapeutic strategies.

  12. Modulation of valosin-containing protein by Kyoto University Substances (KUS as a novel therapeutic strategy for ischemic neuronal diseases

    Directory of Open Access Journals (Sweden)

    Masayuki Hata

    2017-01-01

    Full Text Available Retinal ischemia causes several vision-threatening diseases, including diabetic retinopathy, retinal artery occlusion, and retinal vein occlusion. Intracellular adenosine triphosphate (ATP depletion and subsequent induced endoplasmic reticulum (ER stress are proposed to be the underlying mechanisms of ischemic retinal cell death. Recently, we found that a naphthalene derivative can inhibit ATPase activity of valosin-containing protein, universally expressed within various types of cells, including retinal neural cells, with strong cytoprotective activity. Based on the chemical structure, we developed novel valosin-containing protein modulators, Kyoto University Substances (KUSs, that not only inhibit intracellular ATP depletion, but also ameliorate ER stress. Suppressing ER stress by KUSs is associated with neural cell survival in animal models of several neurodegenerative diseases, such as glaucoma and retinal degeneration. Given that a major pathology of ischemic retinal diseases, other than intracellular ATP depletion, is ER stress-induced cell death, KUSs may provide a novel strategy for cell protection in ischemic conditions. Hence, we investigated the efficacy of KUS121 in a rat model of retinal ischemic injury. Intravitreal injections of KUS121, which is clinically preferable route of drug administration in retinal diseases, significantly suppressed inner retinal thinning and retinal cell death, and maintained visual functions. Valosin-containing protein modulation by KUS is a promising novel therapeutic strategy for ischemic retinal diseases.

  13. Cell Therapy Applications for Retinal Vascular Diseases: Diabetic Retinopathy and Retinal Vein Occlusion.

    Science.gov (United States)

    Park, Susanna S

    2016-04-01

    Retinal vascular conditions, such as diabetic retinopathy and retinal vein occlusion, remain leading causes of vision loss. No therapy exists to restore vision loss resulting from retinal ischemia and associated retinal degeneration. Tissue regeneration is possible with cell therapy. The goal would be to restore or replace the damaged retinal vasculature and the retinal neurons that are damaged and/or degenerating from the hypoxic insult. Currently, various adult cell therapies have been explored as potential treatment. They include mesenchymal stem cells, vascular precursor cells (i.e., CD34+ cells, hematopoietic cells or endothelial progenitor cells), and adipose stromal cells. Preclinical studies show that all these cells have a paracrine trophic effect on damaged ischemic tissue, leading to tissue preservation. Endothelial progenitor cells and adipose stromal cells integrate into the damaged retinal vascular wall in preclinical models of diabetic retinopathy and ischemia-reperfusion injury. Mesenchymal stem cells do not integrate as readily but appear to have a primary paracrine trophic effect. Early phase clinical trials have been initiated and ongoing using mesenchymal stem cells or autologous bone marrow CD34+ cells injected intravitreally as potential therapy for diabetic retinopathy or retinal vein occlusion. Adipose stromal cells or pluripotent stem cells differentiated into endothelial colony-forming cells have been explored in preclinical studies and show promise as possible therapies for retinal vascular disorders. The relative safety or efficacy of these various cell therapies for treating retinal vascular disorders have yet to be determined.

  14. Area of peripheral retinal nonperfusion and treatment response in branch and central retinal vein occlusion.

    Science.gov (United States)

    Singer, Michael; Tan, Colin S; Bell, Darren; Sadda, Srinivas R

    2014-09-01

    To evaluate the extent of peripheral retinal nonperfusion in retinal vein occlusion and to determine its effect on the severity of macular edema and response to treatment. This prospective clinic-based cohort study included 32 consecutive patients with retinal vein occlusion and refractory macular edema evaluated using spectral domain optical coherence tomography and wide-field fluorescein angiography. Areas of ischemia were calculated as a percentage of the total visible retina (ischemic index), which was evaluated when macular edema was present (foveal central subfield >300 μm) and when edema had resolved (foveal central subfield ≤ 300 μm). Ischemic index was the main outcome measure. The mean ischemic index at study enrollment was 14.8% and was larger when macular edema was present compared with when edema had resolved (14.8 vs. 10.3%, P 10% had thicker mean foveal central subfield on optical coherence tomography (520.8 vs. 424.5 μm, P = 0.029) and worse visual acuity (56.3 vs. 59 letters) with the presence of macular edema and experienced greater decrease in optical coherence tomography (296.1 vs. 165.3 μm, P = 0.019) and gain in visual acuity (12.4 vs. 0.9 letters, P = 0.036) in response to treatment. The area of peripheral retinal nonperfusion is variable in patients with retinal vein occlusion and affects its clinical course and response to treatment.

  15. Laser photocoagulation for retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    K. A. Mirzabekova

    2015-03-01

    Full Text Available Retinal vein occlusion (RVO is one of the leading causes of permanent vision loss. In adults, central retinal vein occlusion (CRVO occurs in 1.8% while branch retinal vein occlusion (BRVO occurs in 0.2%. Treatment strategy and disease prognosis are determined by RVO type (ischemic/non-ischemic. Despite numerous studies and many current CRVO and BRVO treatment approaches, the management of these patients is still being debated. Intravitreal injections of steroids (triamcinolone acetate, dexamethasone and vascular endothelial growth factor (VEGF inhibitors (bevacizumab, ranibizumab were shown to be fairly effective. However, it is unclear whether anti-VEGF agents are reasonable in ischemic RVOs. Laser photocoagulation remains the only effective treatment of optic nerve head and/or retinal neovascularization. Laser photocoagulation is also indicated for the treatment of macular edema. Both threshold and sub-threshold photocoagulation may be performed. Photocoagulation performed with argon (514 nm, krypton (647 nm, or diode (810 nm laser for macular edema provides similar results (no significant differences. The treatment may be complex and include medication therapy and/or surgery. Medication therapy includes anti-aggregant agents and antioxidants, i.e., emoxypine which may be used in acute RVO as well as in post-thrombotic retinopathy. 

  16. Effect of retinal ischemia on the non-image forming visual system.

    Science.gov (United States)

    González Fleitas, María Florencia; Bordone, Melina; Rosenstein, Ruth E; Dorfman, Damián

    2015-03-01

    Retinal ischemic injury is an important cause of visual impairment. The loss of retinal ganglion cells (RGCs) is a key sign of retinal ischemic damage. A subset of RGCs expressing the photopigment melanopsin (mRGCs) regulates non-image-forming visual functions such as the pupillary light reflex (PLR), and circadian rhythms. We studied the effect of retinal ischemia on mRGCs and the non-image-forming visual system function. For this purpose, transient ischemia was induced by raising intraocular pressure to 120 mm Hg for 40 min followed by retinal reperfusion by restoring normal pressure. At 4 weeks post-treatment, animals were subjected to electroretinography and histological analysis. Ischemia induced a significant retinal dysfunction and histological alterations. At this time point, a significant decrease in the number of Brn3a(+) RGCs and in the anterograde transport from the retina to the superior colliculus and lateral geniculate nucleus was observed, whereas no differences in the number of mRGCs, melanopsin levels, and retinal projections to the suprachiasmatic nuclei and the olivary pretectal nucleus were detected. At low light intensity, a decrease in pupil constriction was observed in intact eyes contralateral to ischemic eyes, whereas at high light intensity, retinal ischemia did not affect the consensual PLR. Animals with ischemia in both eyes showed a conserved locomotor activity rhythm and a photoentrainment rate which did not differ from control animals. These results suggest that the non-image forming visual system was protected against retinal ischemic damage.

  17. Anterior ischemic optic neuropathy following dengue fever.

    Science.gov (United States)

    Ramakrishnan, Reshma; Shrivastava, Saurabh; Deshpande, Shrikant; Patkar, Priyanka

    2016-01-01

    Dengue fever is caused by a flavivirus. This infection is endemic in the tropics and warm temperate regions of the world. Ocular manifestations of dengue fever include subconjunctival, vitreous, and retinal haemorrhages; posterior uveitis; optic neuritis; and maculopathies, haemorrhage, and oedema. However anterior ischemic optic neuropathy is a rare presentation. Optic nerve ischemia most frequently occurs at the optic nerve head, where structural crowding of nerve fibers and reduction of the vascular supply may combine to impair perfusion to a critical degree and produce optic disc oedema. Here we present a case of anterior ischemic optic neurapathy associated with dengue fever.

  18. Fundus changes in central retinal vein occlusion.

    Science.gov (United States)

    Hayreh, Sohan Singh; Zimmerman, M Bridget

    2015-01-01

    To investigate systematically the retinal and optic disk changes in central retinal vein occlusion (CRVO) and their natural history. This study comprised 562 consecutive patients with CRVO (492 nonischemic [NI-CRVO] and 89 ischemic CRVO [I-CRVO] eyes) seen within 3 months of onset. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. Retinal and subinternal limiting membrane hemorrhages and optic disk edema in I-CRVO were initially more marked (P retinal epithelial pigment degeneration, serous macular detachment, and retinal perivenous sheathing developed at a higher rate in I-CRVO than that in NI-CRVO (P retinal venous engorgement than NI-CRVO (P = 0.003). Fluorescein fundus angiography showed significantly more fluorescein leakage, retinal capillary dilatation, capillary obliteration, and broken capillary foveal arcade (P < 0.0001) in I-CRVO than NI-CRVO. Resolution time of CRVO was longer for I-CRVO than NI-CRVO (P < 0.0001). Characteristics and natural history of fundus findings in the two types of CRVO are different.

  19. Retinitis pigmentosa

    NARCIS (Netherlands)

    Hartong, Dyonne T.; Berson, Eliot L.; Dryja, Thaddeus P.

    2006-01-01

    Hereditary degenerations of the human retina are genetically heterogeneous, with well over 100 genes implicated so far. This Seminar focuses on the subset of diseases called retinitis pigmentosa, in which patients typically lose night vision in adolescence, side vision in young adulthood, and centra

  20. Central retinal vein occlusion concomitant with dengue fever

    OpenAIRE

    Velaitham, Punithamalar; Vijayasingham, Nandini

    2016-01-01

    Background Dengue virus infection is on the rise and there is increasing number of ocular complications that are being reported. Most common ocular complications are macular edema, macular hemorrhages, and foveolitis. There are case reports on branch retinal vessel occlusions. Most of the ocular complications are attributed to the bleeding tendency and transudative process in dengue viral infection. This is a case report of ischemic central retinal vein occlusion (CRVO) concomitant with dengu...

  1. Advances in bone marrow stem cell therapy for retinal dysfunction.

    OpenAIRE

    Park, SS; Moisseiev, E; Bauer, G.; Anderson, JD; Grant, MB; Zam, A; Zawadzki, RJ; Werner., JS; Nolta, JA

    2017-01-01

    The most common cause of untreatable vision loss is dysfunction of the retina. Conditions, such as age-related macular degeneration, diabetic retinopathy and glaucoma remain leading causes of untreatable blindness worldwide. Various stem cell approaches are being explored for treatment of retinal regeneration. The rationale for using bone marrow stem cells to treat retinal dysfunction is based on preclinical evidence showing that bone marrow stem cells can rescue degenerating and ischemic ret...

  2. Central retinal vein occlusion concomitant with dengue fever

    OpenAIRE

    Velaitham, Punithamalar; Vijayasingham, Nandini

    2016-01-01

    Background Dengue virus infection is on the rise and there is increasing number of ocular complications that are being reported. Most common ocular complications are macular edema, macular hemorrhages, and foveolitis. There are case reports on branch retinal vessel occlusions. Most of the ocular complications are attributed to the bleeding tendency and transudative process in dengue viral infection. This is a case report of ischemic central retinal vein occlusion (CRVO) concomitant with dengu...

  3. [Ocular ischemic syndrome--a case report].

    Science.gov (United States)

    Zemba, M; Avram, Corina Ioana; Ochinciuc, Uliana; Stamate, Alina Cristina; Camburu, Raluca Lăcrămioara

    2013-01-01

    Ocular ischemic syndrome, also known as hypoperfusion/ hypotensive retinopathy or as ischemic oculopathy is a rare ocular disease determined by chronic arterial hypoperfusion through central retinal artery, posterior and anterior ciliary arteries. It is bilateral in 20% of the cases. Most often it appears due to severe occlusion of the carotid arteries (ICA, MCA>ECA), described in 1963 by Kearns and Hollenhorst. Occasionally it can be determined by the obstruction of ophtalmic artery or some arterities (Takayasu, giant cell arteritis). The risk factors are: age between 50-80 years, males (M:F = 2:1), arterial hypertension, diabetes, coronary diseases (5% of the cases develop ocular ischemic syndrome), vascular stroke, hemodialysis. The case we present is of an 63 years old man known with primary arterial hypertension, hypercholesterolemia, diabetes type 2 non insulin dependent and diagnosticated with ischemic cerebral stroke and bilateral obstruction of internal carotid arteries in march 2010, who is presenting for visual impairment in both eyes. The imaging investigations show important carotid occlusion and at the ophthalmologic evaluation there are ocular hypertension and rubeosis iridis at the right eye, optic atrophy at both eyes (complete in the right eye and partial in the left eye), with superior altitudinal visual field defect in left eye. The following diagnosis was established: Chronic ocular ischemic syndrome in both eyes with Neovascular glaucoma at the right eye, Anterior ischemic optic neuropathy at the left eye and laser panphotocoagulation at the right eye was started.

  4. Volkmann ischemic contracture

    Science.gov (United States)

    Ischemic contracture - Volkmann; Compartment syndrome - Volkmann ischemic contracture ... Volkmann contracture occurs when there is a lack of blood flow (ischemia) to the forearm. This occurs when there ...

  5. RETINAL BLOOD FLOW CORRELATES TO AQUEOUS VASCULAR ENDOTHELIAL GROWTH FACTOR IN CENTRAL RETINAL VEIN OCCLUSION.

    Science.gov (United States)

    Yamada, Yoshihisa; Suzuma, Kiyoshi; Matsumoto, Makiko; Tsuiki, Eiko; Fujikawa, Azusa; Harada, Takafumi; Kitaoka, Takashi

    2015-10-01

    As laser speckle flowgraphy can measure blood flow distribution in the ocular fundus, the authors analyzed the relationship between retinal blood flow and aqueous vascular endothelial growth factor (VEGF) concentration in central retinal vein occlusion. This prospective observational study examined 45 eyes of 45 patients with central retinal vein occlusion before treatment. Blood flow in large vessels around and at the optic disk, aqueous VEGF concentration, and arteriovenous passage time were examined. Blood flow was evaluated as mean blur rate by laser speckle flowgraphy. Fluorescein angiography found 20 ischemic and 25 nonischemic type eyes. Aqueous VEGF concentration in the ischemic type was significantly higher than that in the nonischemic type (P = 0.01). Arteriovenous passage time was significantly correlated to the logarithm of the aqueous VEGF concentration (P = 0.0001). Mean blur rate of the affected eye/mean blur rate of the unaffected eye of the ischemic type was significantly lower than the nonischemic type (P = 0.039). Additionally, mean blur rate was significantly correlated both to the logarithm of the aqueous VEGF concentration (P central retinal vein occlusion.

  6. Retinitis pigmentosa

    Directory of Open Access Journals (Sweden)

    Hamel Christian

    2006-10-01

    Full Text Available Abstract Retinitis pigmentosa (RP is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms. Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema, and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis.

  7. Ischemic postconditioning protects against ischemic brain injury by up-regulation of acid-sensing ion channel 2a

    Institute of Scientific and Technical Information of China (English)

    Wang-sheng Duanmu; Liu Cao; Jing-yu Chen; Hong-fei Ge; Rong Hu; Hua Feng

    2016-01-01

    Ischemic postconditioning renders brain tissue tolerant to brain ischemia, thereby alleviating ischemic brain injury. However, the exact mechanism of action is still unclear. In this study, a rat model of global brain ischemia was subjected to ischemic postconditioning treat-ment using the vessel occlusion method. After 2 hours of ischemia, the bilateral common carotid arteries were blocked immediately for 10 seconds and then perfused for 10 seconds. This procedure was repeated six times. Ischemic postconditioning was found to mitigate hippocampal CA1 neuronal damage in rats with brain ischemia, and up-regulate acid-sensing ion channel 2a expression at the mRNA and protein level. These ifndings suggest that ischemic postconditioning up-regulates acid-sensing ion channel 2a expression in the rat hippo-campus after global brain ischemia, which promotes neuronal tolerance to ischemic brain injury.

  8. Hypoxia-ischemia and retinal ganglion cell damage

    Directory of Open Access Journals (Sweden)

    Charanjit Kaur

    2008-08-01

    Full Text Available Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of retinal ganglion cells (RGCs occurring in such conditions. RGC death occurs by apoptosis or necrosis. Hypoxia-ischemia induces the expression of hypoxia inducible factor-1α and its target genes such as vascular endothelial growth factor (VEGF and nitric oxide synthase (NOS. Increased production of VEGF results in disruption of the blood retinal barrier leading to retinal edema. Enhanced expression of NOS results in increased production of nitric oxide which may be toxic to the cells resulting in their death. Excess glutamate release in hypoxic-ischemic conditions causes excitotoxic damage to the RGCs through activation of ionotropic and metabotropic glutamate receptors. Activation of glutamate receptors is thought to initiate damage in the retina by a cascade of biochemical effects such as neuronal NOS activation and increase in intracellular Ca2+ which has been described as a major contributing factor to RGC loss. Excess production of proinflammatory cytokines also mediates cell damage. Besides the above, free-radicals generated in hypoxic-ischemic conditions result in RGC loss because of an imbalance between antioxidant- and oxidant-generating systems. Although many advances have been made in understanding the mediators and mechanisms of injury, strategies to improve the damage are lacking. Measures to prevent neuronal injury have to be developed.Keywords: retinal hypoxia, retinal ganglion cells, glutamate receptors, neuronal injury, retina

  9. Length of warm ischemic tolerance for epithelial regeneration in heterotopic rat tracheal isografts%大鼠气管上皮耐受热缺血时限的研究

    Institute of Scientific and Technical Information of China (English)

    韩敬泉; 张凯; 崔键; 刘成; 赵桂彬; 辛衍忠; 郭庆凤

    2011-01-01

    Objective To determine the length of warm ischemic (WI) tolerance in bronchial graft from non-heart-beating donors. Methods Forty-eight rats were randomly divided into 4 groups (each group having 12 rats) according to different WI durations including WI-0 min (group A), WI-30 min (group B), WI-45 min (group C) and WI-60 min (group D). In each group, the tracheae from 6 rats were respectively imbedded in greater omentum of other 6 rats, and 14 days later, the transplanted tracheae were taken from recipients to evaluate epithelial thickness and regeneration. Results Epithelial thickness and the degree of epithelial regeneration had no significant difference (P >0. 05) between the syngeneic control group and the WI-30 minutes group. All of the grafts with WI duration of 45 min were viable, but the epithelium was significantly thinner than that in the syngeneic control group (P0.05);虽然45 min组与对照组相比,上皮厚度的差异有统计学意义(P<0.05),但45 min组的气管上皮有正常黏膜结构,并且与对照组相比,上皮细胞层数差异无统计学意义(P<0.05);而热缺血60min组,看不到正常的上皮结构,上皮也仅由1~2层黏膜上皮细胞覆盖.结论 气管耐受热缺血的时限可能为45 min.

  10. Relationship between carotid artery stenosis and ischemic ocular diseases

    Directory of Open Access Journals (Sweden)

    Qian Chen

    2015-01-01

    Full Text Available AIM: To investigate the relationship between carotid artery stenosis and ischemic ocular diseases.METHODS: The clinical data of 30 cases(37 eyesof patients with ischemic eye diseases were collected from November 2010 to May 2014, and they were accepted the fundus fluorescein angiography(FFA, transcranial Doppler(TCDultrasonic blood vessels of the eye, neck vascular color Doppler flow imaging(CDFI, the neck CT angiography(CTAand carotid artery digital subtraction angiography(DSAexamination, and then the ischemic eye disease patients with ocular symptoms were analyzed. The peak systolic velocity(PSVand resistance index(RIof ophthalmic artery and central retinal artery were compared. Correlation between the internal carotid artery intima-media thickness(IMTand ophthalmic artery, central retinal artery PSV and RI correlation risk; ipsilateral internal carotid artery plaque and ophthalmic artery PSV and RI; PSV and RI associated ipsilateral internal carotid artery plaque and central retinal artery were analyzed. RESULTS: Eye symptoms: a black dim, reduced vision, the eyes flash, and around the eye pain were 75.7%, 83.8%, 51.4% and 32.4%; The eye signs: the dilatation of retinal vein, retinal hemorrhage, arterial stenosis and cotton spot and the contralateral side were regarded as main signs. Ophthalmic artery PSV and RI value of the differences were statistically significant(PPP>0.05; The ipsilateral internal carotid artery plaque and ophthalmic artery PSV had no correlation with RI values(P>0.05; PSV and RI and the ipsilateral internal carotid artery plaque and central retinal artery had no correlation(P>0.05.CONCLUSION: The incidence of ischemic eye diseases and internal carotid artery stenosis is associated with very close, the clinical can regard the degree of internal carotid artery stenosis as an important basis for diagnosis and treatment of eye diseases.

  11. CLINICAL STUDY OF RETINAL VEIN OCCLUSIONS AND MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Satyavathi

    2015-01-01

    Full Text Available Retinal vein occlusion is the most common retinal occlusive disorder encountered by Ophthalmologists and is usually associated with a variable amount of visual loss. This is the second most common retinal vascular disease next to diabetic retinopathy. Liebreich initially described dramatic obstruction of veins as retinal apoplexy. Leber ( 1 (1877 reported the first case of BRVO and called it Hem orrhagic retinitis. RVO most commonly affects the venous blood supply of the entire retina (CRVO or a quadrant drained by one of the branches (BRVO or less commonly the superior or inferior half of the retina alone is affected (HCRVO. For discussion and management purpose RVO is broadly classified into six clinical entities includes (1 Non - ischemic CRVO (2 Ischemic CRVO (3 Non ischemic HCRVO (4Ischemic HCRVO (5 Major BRVO (6Macular BRVO. So much of confusion still exists regarding its natural histo ry, degree of severity, management and its progression. The clinical study of RVO is taken up mainly with a view to study the importance of systemic risk factors in etiopathogenisis of RVO, to study the clinical features and effectiveness of treatment in m odification of the natural course and complications of RVO. Depending on type of venous occlusion patient may present with loss of central vision frequently noticed on waking up in the morning, or field contraction, erythropsia, floates, black spots. Episo des of amaurosis fugax lasts for minutes to hours may be present. There may be metamor - phopsia. Signs of decreased visual acuty, RAPD, visual field defects are observed. Fundus picture shows Retinal hemorrhages distributed based on type of venous occlusion . In ischemic CRVO the picture shows “berries on a twig”. Various sequel & complications include macular edema, anterior segment and retinal neovascularisation, vitreous hemorrhage, retinal detachment may be encountered. Various risk factors include Hypert ension, Diabetes, Hyper lipidemia, IHD

  12. Ischemic preconditioning protects against ischemic brain injury

    Directory of Open Access Journals (Sweden)

    Xiao-meng Ma

    2016-01-01

    Full Text Available In this study, we hypothesized that an increase in integrin αv ß 3 and its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αv ß 3, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αv ß 3 and vascular endothelial growth factor levels in the brain following ischemia.

  13. Unilateral anterior ischemic optic neuropathy

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik

    2013-01-01

    The intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin, which is sensitive to blue light. Previous chromatic pupillometry studies have shown that the post-illumination response is considered an indicator of the melanopsin activation. The aim......-affected eyes, compared with the non-affected fellow eyes, suggesting dysfunction of the ipRGCs. Compared with the responses of the healthy controls, the blue light post-illumination pupil responses were similar in the affected eyes and increased in the fellow non-affected eyes. This suggests a possible...... of this study was to investigate the ipRGC mediated pupil response in patients with a unilateral non-arteritic anterior ischemic optic neuropathy (NAION). Consensual pupil responses during and after exposure to continuous 20 s blue (470 nm) or red (660 nm) light of high intensity (300 cd/m(2)) were recorded...

  14. Transient Ischemic Attack

    Medline Plus

    Full Text Available Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood ... The only difference between a stroke and TIA is that with TIA the blockage is transient (temporary). ...

  15. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only difference between a stroke ...

  16. Targeting Neovascularization in Ischemic Retinopathy: Recent Advances

    Science.gov (United States)

    Al-Shabrawey, Mohamed; Elsherbiny, Mohamed; Nussbaum, Julian; Othman, Amira; Megyerdi, Sylvia; Tawfik, Amany

    2014-01-01

    Pathological retinal neovascularization (RNV) is a common micro-vascular complication in several retinal diseases including retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration and central vein occlusion. The current therapeutic modalities of RNV are invasive and although they may slow or halt the progression of the disease they are unlikely to restore normal acuity. Therefore, there is an urgent need to develop treatment modalities, which are less invasive and therefore associated with fewer procedural complications and systemic side effects. This review article summarizes our understanding of the pathophysiology and current treatment of RNV in ischemic retinopathies; lists potential therapeutic targets; and provides a framework for the development of future treatment modalities. PMID:25598837

  17. Hypoxemic and ischemic tolerance in emperor penguins.

    Science.gov (United States)

    Zenteno-Savin, T; St Leger, J; Ponganis, P J

    2010-06-01

    Oxygen store depletion and a diving bradycardia in emperor penguins (Aptenodytes forsteri) expose tissues to critical levels of hypoxemia and ischemia. To assess the prevention of re-perfusion injury and reactive oxygen species (ROS) damage in emperor penguins, superoxide radical production, lipid peroxidation (thiobarbituric acid reactive substances (TBARS)), and antioxidant enzyme activity profiles in biopsy samples from muscle and liver were determined and compared to those in the chicken and 8 species of flighted marine birds (non-divers and plunge divers). In muscle of emperor penguins, superoxide production and TBARS levels were not distinctly different from those in the other species; among the antioxidant enzymes, catalase (CAT) and glutathione-S-transferase (GST) activities were significantly elevated above all species. In the liver of emperor penguins, TBARS levels were not significantly different from other species; only CAT activity was significantly elevated, although GST and glutathione peroxidase (GPX) activities were 2-3 times higher than those in other species. The potential for ROS formation and lipid peroxidation is not reduced in the pectoral muscle or liver of the emperor penguin. Scavenging of hydrogen peroxide by CAT and the conjugation of glutathione with reactive intermediates and peroxides by GST and GPX appear to be important in the prevention of ROS damage and re-perfusion injury in these birds.

  18. Acute Ischemic Stroke and Transient Ischemic Attack

    OpenAIRE

    Staykov, Dimitre; Schwab, Stefan

    2014-01-01

    This short review focuses on recent practically relevant studies in stroke treatment and prevention and discusses their implications on clinical practice and future research, including 3 shortly published randomized controlled trials investigating interventional treatment in acute ischemic stroke (The Interventional Management of Stroke phase III trial [IMS III], Synthesis Expansion: A Randomized Controlled Trial on Intra-Arterial Versus Intravenous Thrombolysis in Acute Ischemic Stroke, and ...

  19. 吗啡预处理诱导小鼠离体海马脑片氧糖剥夺耐受中PKCδ的作用%Effect of PKCdeta on cerebral ischemic/hypoxic tolerance induced by morphine preconditioning

    Institute of Scientific and Technical Information of China (English)

    刘雅; 韩松; 李俊发; 纪方; 张炳熙

    2011-01-01

    目的 探讨吗啡预处理诱导小鼠离体海马脑片氧糖剥夺耐受形成的机制.方法 以离体小鼠海马脑片氧糖剥夺(OGD)模拟脑缺血再灌注损伤模型,以孵育液乳酸脱氢酶(LDH)漏出率及脑片细胞存活率为指标,探讨吗啡3 μmol/L预处理对不同程度OGD损伤小鼠海马脑片神经元的保护作用,用Western blot检测PKCδ表达.结果 吗啡预处理明显提高OGD 5、10及20 min脑片细胞存活率,使孵育液LDH漏出减少(P<0.05).OGD后即刻和再灌注2 h后,缺糖缺氧组PKCδ膜相关成分蛋白表达明显增高,同时胞质部分蛋白表达明显减少(P<0.05),吗啡预处理对PKCδ膜转位变化无明显影响.结论 吗啡预处理减轻小鼠离体海马脑片20 min以内氧糖剥夺损伤,其机制可能与PKCδ的膜转位激活无关.%Objective To determine the mechanism of morphine preconditioning(MP) on brain ischemic/hypoxic tolerance in the hippocampus slices of mouse.Methods Hippocampus slices were exposed to oxygen-glucose deprivation(OGD) to mimic ischemia-reperfusion injury in vitro.The injuries were assessed by lactic dehydrogenase (LDH) release rate and cell survival rate of slices 2,3,5-triphenyltetrazolium chloride (TTC) to evaluate the protective effects of MP.Western blot analysis was used to identify the expression of PKCδ.Results In hippocampal slices preconditioned with morphine, cell survival rate was increased and LDH release rate was decreased significantly compared with OGD 5 min, 10 min and 20 min (P < 0.05 ).Immediately and at the end of 2 h reperfusion after OGD 10 min, the particulate fraction of PKCδ increased significantly, concomitantly with a corresponding decrease in the cytosolic fraction (P < 0.05).The increased membrane translocation of PKCδ was not inhibited by MP.Conclusion MP can reduce OGD-induced neuronal injuries, the protective effects were observed for periods of OGD equal to or shorter than 20 min.PKCδ membrane translocation might not be

  20. Retinal remodeling in human retinitis pigmentosa.

    Science.gov (United States)

    Jones, B W; Pfeiffer, R L; Ferrell, W D; Watt, C B; Marmor, M; Marc, R E

    2016-09-01

    Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.

  1. Citicoline and Retinal Ganglion Cells: Effects on Morphology and Function.

    Science.gov (United States)

    Parisi, Vincenzo; Oddone, Francesco; Ziccardi, Lucia; Roberti, Gloria; Coppola, Gianluca; Manni, Gianluca

    2017-07-03

    Retinal ganglion cells (RGCs) are the nervous retinal elements that connect the visual receptors to the brain forming the nervous visual system. Functional and/or morphological involvement of RGCs occurs in several ocular and neurological disorders and therefore these cells are targeted in neuroprotective strategies. Cytidine 5-diphosphocholine or Citicoline is an endogenous compound that acts in the biosynthesis of phospholipids of cell membranes and increases neurotransmitters' levels in the Central Nervous System. Experimental studies suggested the neuromodulator effect and the protective role of Citicoline on RGCs. In particular, in rodent retinal cultures and animal models Citicoline induces antiapoptotic effects, increases the dopamine retinal level and counteracts retinal nerve fibers layer thinning. Human studies in neurodegenerative visual pathologies such as glaucoma or non-arteritic ischemic neuropathy showed a reduction of the RGCs impairment after Citicoline administration. By reducing the RGCs' dysfunction, a better neural conduction along the post-retinal visual pathways with an improvement of the visual field defects was observed. Therefore, actually Citicoline, with a solid history of experimental and clinical studies, may be considered a very promising molecule for neuroprotective strategies. In this review, we will present the current evidences on the effects of Citicoline in experimental or human models of neurodegenerative disorders involving the RGCs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. What can we learn about stroke from retinal ischemia models?

    Institute of Scientific and Technical Information of China (English)

    Philippe M D'ONOFRIO; Paulo D KOEBERLE

    2013-01-01

    Retinal ischemia is a very useful model to study the impact of various cell death pathways,such as apoptosis and necrosis,in the ischemic retina.However,it is important to note that the retina is formed as an outpouching of the diencephalon and is part of the central nervous system.As such,the cell death pathways initiated in response to ischemic damage in the retina reflect those found in other areas of the central nervous system undergoing similar trauma.The retina is also more accessible than other areas of the central nervous system,thus making it a simpler model to work with and study.By utilizing the retinal model,we can greatly increase our knowledge of the cell death processes initiated by ischemia which lead to degeneration in the central nervous system.This paper examines work that has been done so far to characterize various aspects of cell death in the retinal ischemia model,such as various pathways which are activated,and the role neurotrophic factors,and discusses how these are relevant to the treatment of ischemic damage in both the retina and the greater central nervous system.

  3. 三七三醇皂苷与脑缺血耐受对脑自体神经干细胞增殖的作用%Research about panaxtrial saponins on the relationship between cerebral ischemic tolerance and proliferation of endogenous neural stem cells

    Institute of Scientific and Technical Information of China (English)

    姜晓锋; 张杰文; 罗祖明

    2014-01-01

    BACKGROUND:Cerebral ischemia tolerance can promote proliferation of autologous neural stem cells in the hippocampus of cerebral infarction rats, but panaxtrial saponins effects on the proliferation of autologous neural stem cells in the brain have not been reported. OBJECTIVE:To explore the relationship of panaxtrial saponins, ischemic preconditioning and proliferation of endogenous neural stem cells in the hippocampus of rats at 7 days after cerebral infarction, and to observe the effect on neurobehavioral scores of rats after cerebral infarction. METHODS:Fifty Sprague-Dawley rats were included and randomly divided into five groups:sham group, ischemia group, ischemic control group, ischemic preconditioning group, and panaxtrial saponins group. In the latter four groups, acute models of cerebral infarction were established using Zea-Longa method. In the sham group, only an incision was made on the neck. The focal-focal ischemic tolerance models were established with twice suture method in the ischemic preconditioning and panaxtrial saponins groups. Sham operation was instead of ischemic preconditioning in the ischemic control group. In the panaxtrial saponins group, rats were given intraperitoneal injection of 100 mg/kg panaxtrial saponins at 7 days before modeling. RESULTS AND CONCLUSION:After 7 days of cerebral infarction, the neurobehavioral score and the number of neural stem cells in the hippocampus were significantly increased in the ischemia group (P0.05). In addition, differences in the neurobehavioral scores and the number of neural stem cells in the hippocampus were insignificant between the ischemic control group and ischemia group (P>0.05). These findings indicate that panaxtrial saponins can play a role similar to ischemic tolerance, and thus improve neurologic impairment in rats with cerebral infarction.%背景:脑缺血耐受可促进大鼠脑梗死后海马区自体神经干细胞的增殖,但传统中药三七通舒对脑自体神经干细

  4. Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Anusha; Srinivasan, Sivasubramanian [Khoo Teck Puat Hospital, Singapore (Singapore)

    2012-09-15

    We read with great interest, the case report on ischemic optic neuropathy (1). We would like to add a few points concerning the blood supply of the optic nerve and the correlation with the development of post-operative ischemic neuropathy. Actually, the perioperative or post-operative vision loss (postoperative ischemic neuropathy) is most likely due to ischemic optic neuropathy. Ischemic optic neuropathy (2) is classified as an anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). This classification is based on the fact that blood supply (2) to the anterior segment of the optic nerve (part of the optic nerve in the scleral canal and the optic disc) is supplied by short posterior ciliary vessels or anastamotic ring branches around the optic nerve. The posterior part of the optic canal is relatively less perfused, and is supplied by ophthalmic artery and central fibres are perfused by a central retinal artery. So, in the post-operative period, the posterior part of the optic nerve is more vulnerable for ischemia, especially, after major surgeries (3), one of the theories being hypotension or anaemia (2) and resultant decreased perfusion. The onset of PION is slower than the anterior ischemic optic neuropathy. AION on the other hand, is usually spontaneous (idiopathic) or due to arteritis, and is usually sudden in its onset. The reported case is most likely a case of PION. The role of imaging, especially the diffusion weighted magnetic resonance imaging, is very important because the ophthalmoscopic findings in early stages of PION is normal, and it may delay the diagnosis. On the other hand, edema of the disc is usually seen in the early stages of AION.

  5. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik;

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  6. Molecular pathogenesis of retinal and choroidal vascular diseases.

    Science.gov (United States)

    Campochiaro, Peter A

    2015-11-01

    There are two major types of ocular neovascularization that affect the retina, retinal neovascularization (NV) and subretinal or choroidal NV. Retinal NV occurs in a group of diseases referred to as ischemic retinopathies in which damage to retinal vessels results in retinal ischemia. Most prevalent of these are diabetic retinopathy and retinal vein occlusions. Subretinal and choroidal NV occur in diseases of the outer retina and Bruch's membrane, the most prevalent of which is age-related macular degeneration. Numerous studies in mouse models have helped to elucidate the molecular pathogenesis underlying retinal, subretinal, and choroidal NV. There is considerable overlap because the precipitating event in each is stabilization of hypoxia inducible factor-1 (HIF-1) which leads to upregulation of several hypoxia-regulated gene products, including vascular endothelial growth factor (VEGF), angiopoietin 2, vascular endothelial-protein tyrosine phosphatase (VE-PTP), and several others. Stimulation of VEGF signaling and suppression of Tie2 by angiopoietin 2 and VE-PTP are critical for sprouting of retinal, subretinal, and choroidal NV, with perturbation of Bruch's membrane also needed for the latter. Additional HIF-1-regulated gene products cause further stimulation of the NV. It is difficult to model macular edema in animals and therefore proof-of-concept clinical trials were done and demonstrated that VEGF plays a central role and that suppression of Tie2 is also important. Neutralization of VEGF is currently the first line therapy for all of the above disease processes, but new treatments directed at some of the other molecular targets, particularly stabilization of Tie2, are likely to provide additional benefit for subretinal/choroidal NV and macular edema. In addition, the chronicity of these diseases as well as the implication of VEGF as a cause of retinal nonperfusion and progression of background diabetic retinopathy make sustained delivery approaches for VEGF

  7. Molecular Pathogenesis of Retinal and Choroidal Vascular Diseases

    Science.gov (United States)

    Campochiaro, Peter A.

    2015-01-01

    There are two major types of ocular neovascularization that affect the retina, retinal neovascularization (NV) and subretinal or choroidal NV. Retinal NV occurs in a group of diseases referred to as ischemic retinopathies in which damage to retinal vessels results in retinal ischemia. Most prevalent of these are diabetic retinopathy and retinal vein occlusions. Subretinal and choroidal NV occur in diseases of the outer retina and Bruch’s membrane, the most prevalent of which is age-related macular degeneration. Numerous studies in mouse models have helped to elucidate the molecular pathogenesis underlying retinal, subretinal, and choroidal NV. There is considerable overlap because the precipitating event in each is stabilization of hypoxia inducible factor-1 (HIF-1) which leads to upregulation of several hypoxia-regulated gene products, including vascular endothelial growth factor (VEGF), angiopoietin 2, vascular endothelial-protein tyrosine phosphatase (VE-PTP), and several others. Stimulation of VEGF signaling and suppression of Tie2 by angiopoietin 2 and VE-PTP are critical for sprouting of retinal, subretinal, and choroidal NV, with perturbation of Bruch’s membrane also needed for the latter. Additional HIF-1-regulated gene products cause further stimulation of the NV. It is difficult to model macular edema in animals and therefore proof-of-concept clinical trials were done and demonstrated that VEGF plays a central role and that suppression of Tie2 is also important. Neutralization of VEGF is currently the first line therapy for all of the above disease processes, but new treatments directed at some of the other molecular targets, particularly stabilization of Tie2, are likely to provide additional benefit for subretinal/choroidal NV and macular edema. In addition, the chronicity of these diseases as well as the implication of VEGF as a cause of retinal nonperfusion and progression of background diabetic retinopathy make sustained delivery approaches for

  8. The neuroprotective mechanism of brain ischemic preconditioning

    Institute of Scientific and Technical Information of China (English)

    Xiao-qian LIU; Rui SHENG; Zheng-hong QIN

    2009-01-01

    Brain ischemia is one of the most common causes of death and the leading cause of adult disability in the world. Brain ischemic pre- conditioning (BIP) refers to a transient, sublethal ischemia which results in tolerance to later, otherwise lethal, cerebral ischemia. Many attempts have been made to understand the molecular and cellular mechanisms underlying the neuroprotection offered by ischemic preconditioning. Many studies have shown that neuroprotective mechanisms may involve a series of molecular regulatory pathways including activation of the N-methyI-D-aspartate (NMDA) and adenosine receptors; activation of intracellular signaling pathways such as mitogen activated protein kinases (MAPK) and other protein kinases; upregulation of Bcl-2 and heat shock proteins (HSPs); and activation of the ubiquitin-proteasome pathway and the autophagic-lysosomal pathway. A better understanding of the processes that lead to cell death after stroke as well as of the endogenous neuroprotective mechanisms by which BIP protects against brain ischemic insults could help to develop new therapeutic strategies for this devastating neurological disease. The purpose of the present review is to summarize the neuroprotective mechanisms of BIP and to discuss the possibility of mimicking ischemic preconditioning as a new strategy for preventive treatment of ischemia.

  9. Full-Thickness Retinochoroidal Incision in the Management of Central Retinal Vein Occlusion

    Directory of Open Access Journals (Sweden)

    San-Ni Chen

    2015-01-01

    Full Text Available Purpose. To evaluate the clinical outcomes in patients with central retinal vein occlusion (CRVO treated with full-thickness retinochoroidal incisions and to compare whether there is difference in treatment response in ischemic and nonischemic CRVO. Methods. Retrospective study of patients of CRVO receiving full-thickness retinochoroidal incisions in Changhua Christian Hospital. Fluorescein angiography (FA, slit-lamp biomicroscopy, indirect funduscopy, best corrected visual acuity, and central macular thickness (CMT measured by optical coherence tomography were performed pre- and postoperatively. Patients were divided into an ischemic and nonischemic group according to the findings of FA. Patients were followed up for at least 1 year. Results. Twenty-eight eyes (14 ischemic and 14 nonischemic CRVO were included. Functional retinochoroidal venous anastomosis (RCVA was achieved in 48 of the 65 retinochoroidal incisions (73.8%. Central macular thickness (CMT and retinal hemorrhage decreased significantly after the surgery. Significant visual gain was observed postoperatively in the nonischemic group, but not in the ischemic group. Postoperative complications included vitreous hemorrhage (17.8%, neovascular glaucoma (7.1%, and preretinal fibrovasular membrane (10.7%, all of which were in the ischemic group. Conclusions. RCVA formation induced by retinochoroidal incisions could improve venous flow, and decrease CMT and retinal hemorrhage. However, only eyes with nonischemic CRVO showed visual improvement.

  10. Lubiprostone induced ischemic colitis.

    Science.gov (United States)

    Sherid, Muhammed; Sifuentes, Humberto; Samo, Salih; Deepak, Parakkal; Sridhar, Subbaramiah

    2013-01-14

    Ischemic colitis accounts for 6%-18% of the causes of acute lower gastrointestinal bleeding. It is often multifactorial and more commonly encountered in the elderly. Several medications have been implicated in the development of colonic ischemia. We report a case of a 54-year old woman who presented with a two-hour history of nausea, vomiting, abdominal pain, and bloody stool. The patient had recently used lubiprostone with close temporal relationship between the increase in the dose and her symptoms of rectal bleeding. The radiologic, colonoscopic and histopathologic findings were all consistent with ischemic colitis. Her condition improved without any serious complications after the cessation of lubiprostone. This is the first reported case of ischemic colitis with a clear relationship with lubiprostone (Naranjo score of 10). Clinical vigilance for ischemic colitis is recommended for patients receiving lubiprostone who are presenting with abdominal pain and rectal bleeding.

  11. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an ... a short time. The only difference between a stroke and TIA is that with TIA the blockage ...

  12. Preterm Hypoxic Ischemic Encephalopathy

    Directory of Open Access Journals (Sweden)

    Krishna G Gopagondanahalli

    2016-10-01

    Full Text Available Hypoxic ischemic encephalopathy (HIE is a recognizable and defined clinical syndrome in term infants that results from a severe or prolonged hypoxic ischemic episode before or during birth. However, in the preterm infant, defining hypoxic ischemic injury, its clinical course, monitoring and outcomes remains complex. Few studies examine preterm HIE, and these are heterogeneous, with variable inclusion criteria and outcomes reported. We examine the available evidence that implies that the incidence of hypoxic ischemic insult in preterm infants is probably higher than recognized, and follows a more complex clinical course, with higher rates of adverse neurological outcomes, compared to term infants. This review aims to elucidate the causes and consequences of preterm hypoxia ischemia, the subsequent clinical encephalopathy syndrome, diagnostic tools and outcomes. Finally, we suggest a uniform definition for preterm HIE that may help in identifying infants most at risk of adverse outcomes and amenable to neuroprotective therapies.

  13. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an ... a short time. The only difference between a stroke and TIA is that with TIA the blockage ...

  14. Tolerating Zero Tolerance?

    Science.gov (United States)

    Moore, Brian N.

    2010-01-01

    The concept of zero tolerance dates back to the mid-1990s when New Jersey was creating laws to address nuisance crimes in communities. The main goal of these neighborhood crime policies was to have zero tolerance for petty crime such as graffiti or littering so as to keep more serious crimes from occurring. Next came the war on drugs. In federal…

  15. Ischemia reperfusion injury, ischemic conditioning and diabetes mellitus.

    Science.gov (United States)

    Lejay, Anne; Fang, Fei; John, Rohan; Van, Julie A D; Barr, Meredith; Thaveau, Fabien; Chakfe, Nabil; Geny, Bernard; Scholey, James W

    2016-02-01

    Ischemia/reperfusion, which is characterized by deficient oxygen supply and subsequent restoration of blood flow, can cause irreversible damages to tissue. Mechanisms contributing to the pathogenesis of ischemia reperfusion injury are complex, multifactorial and highly integrated. Extensive research has focused on increasing organ tolerance to ischemia reperfusion injury, especially through the use of ischemic conditioning strategies. Of morbidities that potentially compromise the protective mechanisms of the heart, diabetes mellitus appears primarily important to study. Diabetes mellitus increases myocardial susceptibility to ischemia reperfusion injury and also modifies myocardial responses to ischemic conditioning strategies by disruption of intracellular signaling responsible for enhancement of resistance to cell death. The purpose of this review is twofold: first, to summarize mechanisms underlying ischemia reperfusion injury and the signal transduction pathways underlying ischemic conditioning cardioprotection; and second, to focus on diabetes mellitus and mechanisms that may be responsible for the lack of effect of ischemic conditioning strategies in diabetes.

  16. Acute ischemic cerebral attack

    OpenAIRE

    Franco-Garcia Samir; Barreiro-Pinto Belis

    2010-01-01

    The decrease of the cerebral blood flow below the threshold of autoregulation led to changes of cerebral ischemia and necrosis that traduce in signs and symtoms of focal neurologic dysfunction called acute cerebrovascular symdrome (ACS) or stroke. Two big groups according to its etiology are included in this category the hemorragic that constitue a 20% and the ischemic a 80% of cases. Great interest has wom the ischemic ACS because of its high social burden, being the third cause of no violen...

  17. Recombinant Human Erythropoietin in the Treatment of Acute Ischemic Stroke

    NARCIS (Netherlands)

    Ehrenreich, Hannelore; Weissenborn, Karin; Prange, Hilmar; Schneider, Dietmar; Weimar, Christian; Wartenberg, Katja; Schellinger, Peter D.; Bohn, Matthias; Becker, Harald; Wegrzyn, Martin; Jaehnig, Peter; Herrmann, Manfred; Knauth, Michael; Baehr, Mathias; Heide, Wolfgang; Wagner, Armin; Schwab, Stefan; Reichmann, Heinz; Schwendemann, Guenther; Dengler, Reinhard; Kastrup, Andreas; Bartels, Claudia

    2009-01-01

    Background and Purpose-Numerous preclinical findings and a clinical pilot study suggest that recombinant human erythropoietin (EPO) provides neuroprotection that may be beneficial for the treatment of patients with ischemic stroke. Although EPO has been considered to be a safe and well-tolerated dru

  18. Fifty-eight cases of ocular ischemic diseases caused by carotid artery stenosis

    Institute of Scientific and Technical Information of China (English)

    LUO Rong-jiang; LIU Shao-rui; LI Xiao-min; ZHUO Ye-hong; TIAN Zhen

    2010-01-01

    Background The blood supply to the eye comes from the retinal central vascular system of the ophthalmic artery and the ciliary vascular system. The ophthalmic artery stems from the ipsilateral internal carotid artery. If occlusion or stenosis occurs in the carotid artery, the blood perfusion to the ophthalmic artery becomes insufficient, leading to signs and symptoms of anterior and posterior ocular ischemia. The objective of this study was to evaluate the clinical characteristics and risk factors of ocular ischemic diseases caused by carotid artery stenosis.Methods This study was a retrospective review of 145 patients with carotid artery stenosis. Fifty-eight patients who had symptoms of ocular ischemic disease caused by carotid artery stenosis formed group A and the other 87 patients who only had carotid artery stenosis formed group B. We analyzed the causes and course of disease, and relative risk factors,by comparing the two groups.Results The degree of carotid artery stenosis in group A was higher than that in group B. And group A had a greater decrease of ophthalmic artery flow. Male, hypertension, hyperlipidemia, and smoking were significantly related to carotid artery stenosis. Amaurosis fugax was the most common ocular symptom in group A. The ocular ischemic diseases mainly included ischemic optic neuropathy, central/branch retinal artery occlusion, ophthalmoplegia externa, and ocular ischemic syndrome.Conclusions Carotid artery stenosis correlates with ocular ischemic diseases. Ophthalmologists must observe for ocular symptoms, which were the onset symptoms in some patients.

  19. Association of aqueous humor cytokines with the development of retinal ischemia and recurrent macular edema in retinal vein occlusion.

    Science.gov (United States)

    Jung, Sang Hoon; Kim, Kyung-A; Sohn, Sea Woon; Yang, Sung Jae

    2014-04-09

    We evaluated the association of angiogenic and inflammatory cytokine levels in the aqueous humor with development of retinal ischemia and recurrent macular edema in retinal vein occlusion (RVO) patients. This was a retrospective cross-sectional study, and patients with RVO (n = 41) and age-matched control subjects (n = 25) were included. The concentrations of angiogenic and inflammatory cytokines, including VEGF, PDGF-AA, IL-1a, IL-6, IL-8, MCP-1, TNF-α, and IP-10, in the aqueous humor were measured before intravitreal injection of bevacizumab using suspension array technology. After retinal hemorrhage disappeared, fluorescein angiography (FA) images were obtained. Based on FA data, RVO patients were divided into a nonischemic group and an ischemic group. We investigated the presence of recurrent macular edema using optical coherent tomography (OCT) during the follow-up period. We compared the levels of cytokines between RVO patients and control subjects, between nonischemic and ischemic groups, and between patients with and without recurrent macular edema. The levels of VEGF, PDGF-AA, IL-1a, IL-6, IL-8, MCP-1, TNF-α, and IP-10 in the aqueous humor were higher in the RVO group than in the control group. The levels of IL-8, PDFGF-AA, TNF-α, and VEGF in the aqueous humor were significantly higher in the ischemic RVO group than in the nonischemic RVO group. We did not observe any association between cytokine levels and recurrent macular edema. Angiogenic and inflammatory cytokines were overexpressed in RVO patients. Additionally, increased levels of IL-8, PDFGF-AA, TNF-α, and VEGF in the aqueous humor at the onset of RVO were associated with the development of future retinal ischemia in RVO patients.

  20. The Desmoteplase in Acute Ischemic Stroke (DIAS) clinical trial program.

    Science.gov (United States)

    von Kummer, Rüdiger; Albers, Gregory W; Mori, Etsuro

    2012-10-01

    Desmoteplase is a novel, highly fibrin-specific thrombolytic agent in phase III of clinical development. In comparison to alteplase, it has high fibrin selectivity, is associated with minimal or no neurotoxicity, and has no apparent negative effect on the blood-brain barrier. The safety and efficacy of desmoteplase is being studied in the Desmoteplase in Acute Ischemic Stroke clinical trial program. Three studies (Dose Escalation Study of Desmoteplase in Acute Ischemic Stroke, Desmoteplase in Acute Ischemic Stroke, and Desmoteplase in Acute Ischemic Stroke-2) have been completed, two large randomized, double-blind, placebo-controlled, phase III trials are ongoing at >200 sites worldwide (Desmoteplase in Acute Ischemic Stroke-3 and Desmoteplase in Acute Ischemic Stroke-4, n = 800; DIAS-3 and DIAS-4), and a randomized, double-blind, placebo-controlled, dose-escalation phase II trial is ongoing in Japan (Desmoteplase in Acute Ischemic Stroke-Japan, n = 48; DIAS-J). The objective of DIAS-3 and DIAS-4 is to evaluate the safety and efficacy of a single IV bolus injection of 90 μg/kg desmoteplase given three- to nine-hours after onset of ischemic stroke (National Institutes of Health Stroke Scale 4-24, age 18-85 years). The objective of DIAS-J is to evaluate the safety and tolerability of desmoteplase 70 and 90 μg/kg three- to nine-hours after ischemic stroke onset in Japanese patients. Patients are included with occlusion or high-grade stenosis (thrombolysis in myocardial infarction 0-1) in proximal cerebral arteries on magnetic resonance or computed tomography angiography but excluded with extended ischemic edema on computed tomography or diffusion-weighted imaging. Desmoteplase is the only thrombolytic agent in late-stage development for acute ischemic stroke that is now tested in patients with proven stroke pathology. The results of the Desmoteplase in Acute Ischemic Stroke clinical trial program will show whether patients with major artery occlusions

  1. Macular edema in central retinal vein occlusion: correlation between optical coherence tomography, angiography and visual acuity.

    Science.gov (United States)

    Martinet, Virginie; Guigui, Benjamin; Glacet-Bernard, Agnès; Zourdani, Alain; Coscas, Gabriel; Soubrane, Gisèle; Souied, Eric H

    2012-08-01

    To analyze the characteristics and the course of macular edema secondary to central retinal vein occlusion (CRVO) using optical coherence tomography (OCT) and to determine correlations between clinical, tomographic and angiographic data, in particular including retinal ischemia. In this retrospective study, 53 consecutive patients with CRVO were included. At each follow-up visit, patients underwent complete ophthalmological examination, including best-corrected visual acuity (BCVA) and OCT. Fluorescein angiography was performed at baseline and on demand during follow-up. 243 OCTs were analyzed. Mean age was 61 years and mean follow-up 13 months. The first structural change, observed very early after the onset of the occlusion, was a diffuse increase at the level of the outer nuclear layer without change at the level of the inner retina. This early change seemed characteristic of retinal vein occlusion. Cystoid spaces were subsequently observed in all retinal layers and were combined with serous retinal detachment in 51 %. During the first 6 months, central retinal thickness was higher in ischemic CRVO (mean, 691 μm) than in non-ischemic CRVO (mean, 440 μm, p central retinal thickness without subretinal fluid) of 700 μm or greater, peripheral ischemia was present in 69 % of eyes, final BCVA was 20/200 or less in 75 % and never reached 20/40 during follow-up. The integrity of the junction of the photoreceptors' inner and outer segments was correlated with a better prognosis (p < 0.05). Foveal thickness was inversely correlated to BCVA at each visit and could have a prognostic value. OCT examination in CRVO revealed useful data for the diagnosis of CRVO and its prognosis. The largest macular edemas seemed to be the hallmark of ischemic CRVO.

  2. Metabolic Prosthesis for Oxygenation of Ischemic Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Elias [ORNL

    2009-01-01

    This communication discloses new ideas and preliminary results on the development of a "metabolic prosthesis" for local oxygenation of ischemic tissue under physiological neutral conditions. We report for the first time the selective electrolysis of physiological saline by repetitively pulsed charge-limited electrolysis for the production of oxygen and suppression of free chlorine. For example, using 800 A amplitude current pulses and <200 sec pulse durations, we demonstrated prompt oxygen production and delayed chlorine production at the surface of a shiny 0.85 mm diameter spherical platinum electrode. The data, interpreted in terms of the ionic structure of the electric double layer, suggest a strategy for in situ production of metabolic oxygen via a new class of "smart" prosthetic implants for dealing with ischemic disease such as diabetic retinopathy. We also present data indicating that drift of the local pH of the oxygenated environment can be held constant using a feedback-controlled three electrode electrolysis system that chooses anode and cathode pair based on pH data provided by local microsensors. The work is discussed in the context of diabetic retinopathy since surgical techniques for multielectrode prosthetic implants aimed at retinal degenerative diseases have been developed.

  3. Myocardial ischemic conditioning: Physiological aspects and clinical applications in cardiac surgery.

    Science.gov (United States)

    Bousselmi, Radhouane; Lebbi, Mohamed Anis; Ferjani, Mustapha

    2014-04-01

    Ischemia-reperfusion is a major determinant of myocardial impairment in patients undergoing cardiac surgery. The main goal of research in cardioprotection is to develop effective techniques to avoid ischemia-reperfusion lesions. Myocardial ischemic conditioning is a powerful endogenous cardioprotective phenomenon. First described in animals in 1986, myocardial ischemic conditioning consists of applying increased tolerance of the myocardium to sustained ischemia by exposing it to brief episodes of ischemia-reperfusion. Several studies have sought to demonstrate its effective cardioprotective action in humans and to understand its underlying mechanisms. Myocardial ischemic conditioning has two forms: ischemic preconditioning (IPC) when the conditioning stimulus is applied before the index ischemia and ischemic postconditioning when the conditioning stimulus is applied after it. The cardioprotective action of ischemic conditioning was reproduced by applying the ischemia-reperfusion stimulus to organs remote from the heart. This non-invasive manner of applying ischemic conditioning has led to its application in clinical settings. Clinical trials for the different forms of ischemic conditioning were mainly developed in cardiac surgery. Many studies suggest that this phenomenon can represent an interesting adjuvant to classical cardioprotection during on-pump cardiac surgery. Ischemic conditioning was also tested in interventional cardiology with interesting results. Finally, advances made in the understanding of mechanisms that underlie the cardioprotective action of ischemic conditioning have paved the way to a new form of myocardial conditioning which is pharmacological conditioning.

  4. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    Science.gov (United States)

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-08-10

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids.

  5. Thrombophilic screening in retinal artery occlusion patients

    Directory of Open Access Journals (Sweden)

    Valeria Nagy

    2008-10-01

    Full Text Available Valeria Nagy1, Lili Takacs1, Zita Steiber1, György Pfliegler2, Andras Berta11Department of Ophthalmology, 2Division of Rare Diseases, University of Debrecen Medical and Health Science Center, Debrecen, HungaryBackground: Retinal artery occlusion (RAO is an ischemic vascular damage of the retina, which frequently leads to sudden, mostly irreversible loss of vision. In this study, blood thrombophilic factors as well as cardiovascular risk factors were investigated for their relevance to this pathology. Thrombophilic risk factors so far not evaluated were included in the study.Patients and methods: 28 RAO patients and 81 matched control subjects were examined. From blood samples, protein C, protein S, antithrombinopathy, and factor V (Leiden mutation (FV, factor II gene polymorphism, factor VIII C level, plasminogen activity, lipoprotein(a and fibrinogen levels, hyperhomocysteinemia and presence of anticardiolipin – antiphospholipid antibodies were investigated. Possibly relevant pathologies such as diabetes mellitus, hypertension, and ischemic heart disease were also registered. Statistical analysis by logistic regression was performed with 95% confidence intervals.Results: In the group of patients with RAO only the incidence of hypertension (OR: 3.33, 95% CI: 1.30–9.70, p = 0.014 as an average risk factor showed significant difference, but thrombophilic factors such as hyperfibrinogenemia (OR: 2.9, 95% CI: 1.29–6.57, p = 0.010 and the presence of FV (Leiden mutation (OR: 3.9, 95% CI: 1.43–10.96, p = 0.008 increased the chances of developing this disease.Conclusions: Our results support the assumption that thrombophilia may contribute to the development of RAO besides vascular damage due to the presence of cardiovascular risk factors. Further studies are needed, however, to justify the possible use of secondary prophylaxis in form of anticoagulant/antiplatelet therapy.Keywords: retinal arterial occlusion, risk factors, thrombophilia

  6. [Ischemic heart disease].

    Science.gov (United States)

    Yamamuro, Megumi; Ogawa, Hisao

    2009-04-01

    It has been reported that antihypertensive therapy reduces the risk of ischemic heart disease. Except for the antihypertensive effects, the angiotensin converting enzyme (ACE) inhibitors are proved to be very effective in primary and secondary event onset prophylaxis by many clinical trials. The angiotensin II receptor antagonists (ARBs) used briskly in recent years inhibits angiotensin II type 1 receptor alternatively. Although ARBs protect organs, especially blood vessel, heart, brain and kidney in sites of pharmacology, ARBs are still not much as effective results as ACE inhibitors for the patients with ischemic heart disease, by many clinical trials.

  7. Interleukin-1beta mediates ischemic injury in the rat retina.

    Science.gov (United States)

    Yoneda, S; Tanihara, H; Kido, N; Honda, Y; Goto, W; Hara, H; Miyawaki, N

    2001-11-01

    Two types of experiment were performed to examine the role of interleukin-1beta in ischemia-induced damage in the rat retina. In the in vivo study, enzyme-linked immunosorbent assay was used to investigate the expression of immunoreactive interleukin-1beta in the rat retina following a hypertension-induced ischemia/reperfusion, while the effect of a recombinant human interleukin-1 receptor antagonist or an anti-interleukin-1beta neutralizing antibody on the ischemia-induced damage was examined histologically. A transient increase in the expression of immunoreactive interleukin-1beta was observed in the retina 3-12 hr after reperfusion, and morphometric evaluation at 7 days after the ischemia showed a decrease in cell numbers in the ganglion cell layer and a decreased thickness of the inner plexiform layer with no change in the other retinal layers. Intravitreal injection of interleukin-1 receptor antagonist (1 or 10 ng per eye) or anti-interleukin-1beta antibody (50 or 500 ng per eye) 5 min before the onset of the ischemia reduced the damage. In the in vitro study, interleukin-1 receptor antagonist (500 ng ml(-1)) significantly reduced glutamate-induced neurotoxicity in rat cultured retinal neurons. These results suggest that interleukin-1 plays an important role in mediating ischemic and excitotoxic damage in the retina, and that interleukin-1 inhibitors may be therapeutically useful against neuronal injury caused by optic nerve or retinal diseases such as glaucoma and central retinal artery or vein occlusion.

  8. Investigation of PACAP Fragments and Related Peptides in Chronic Retinal Hypoperfusion

    Directory of Open Access Journals (Sweden)

    Dora Werling

    2014-01-01

    Full Text Available Pituitary adenylate cyclase activating polypeptide (PACAP has neuroprotective effects in different neuronal and retinal injuries. Retinal ischemia can be effectively modelled by permanent bilateral common carotid artery occlusion (BCCAO, which causes chronic hypoperfusion-induced degeneration in the entire rat retina. The retinoprotective effect of PACAP 1-38 and VIP is well-established in ischemic retinopathy. However, little is known about the effects of related peptides and PACAP fragments in ischemic retinopathy. The aim of the present study was to investigate the potential retinoprotective effects of different PACAP fragments (PACAP 4-13, 4-22, 6-10, 6-15, 11-15, and 20-31 and related peptides (secretin, glucagon in BCCAO-induced ischemic retinopathy. Wistar rats (3-4 months old were used in the experiment. After performing BCCAO, the right eyes of the animals were treated with PACAP fragments or related peptides intravitreal (100 pM, while the left eyes were injected with saline serving as control eyes. Sham-operated (without BCCAO rats received the same treatment. Routine histology was performed 2 weeks after the surgery; cells were counted and the thickness of retinal layers was compared. Our results revealed significant neuroprotection by PACAP 1-38 but did not reveal retinoprotective effect of the PACAP fragments or related peptides. These results suggest that PACAP 1-38 has the greatest efficacy in ischemic retinopathy.

  9. Investigation of PACAP Fragments and Related Peptides in Chronic Retinal Hypoperfusion

    Science.gov (United States)

    Werling, Dora; Reglodi, Dora; Kiss, Peter; Toth, Gabor; Szabadfi, Krisztina; Tamas, Andrea; Biro, Zsolt; Atlasz, Tamas

    2014-01-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) has neuroprotective effects in different neuronal and retinal injuries. Retinal ischemia can be effectively modelled by permanent bilateral common carotid artery occlusion (BCCAO), which causes chronic hypoperfusion-induced degeneration in the entire rat retina. The retinoprotective effect of PACAP 1-38 and VIP is well-established in ischemic retinopathy. However, little is known about the effects of related peptides and PACAP fragments in ischemic retinopathy. The aim of the present study was to investigate the potential retinoprotective effects of different PACAP fragments (PACAP 4-13, 4-22, 6-10, 6-15, 11-15, and 20-31) and related peptides (secretin, glucagon) in BCCAO-induced ischemic retinopathy. Wistar rats (3-4 months old) were used in the experiment. After performing BCCAO, the right eyes of the animals were treated with PACAP fragments or related peptides intravitreal (100 pM), while the left eyes were injected with saline serving as control eyes. Sham-operated (without BCCAO) rats received the same treatment. Routine histology was performed 2 weeks after the surgery; cells were counted and the thickness of retinal layers was compared. Our results revealed significant neuroprotection by PACAP 1-38 but did not reveal retinoprotective effect of the PACAP fragments or related peptides. These results suggest that PACAP 1-38 has the greatest efficacy in ischemic retinopathy. PMID:24900914

  10. Ischemic strokes and migraine

    Energy Technology Data Exchange (ETDEWEB)

    Bousser, M.G.; Baron, J.C.; Chiras, J.

    1985-11-01

    Lasting neurological deficits, though most infrequent, do occur in migrainous subjects and are well documented by clinical angiographic computed tomographic (CT scan) and even pathological studies. However the mechanism of cerebral ischemia in migraine remains widely unknown and the precise role of migraine in the pathogenesis of ischemic strokes is still debated. (orig./MG).

  11. Retinal Detachment in Preeclampsia

    Directory of Open Access Journals (Sweden)

    Prado Renata Silva do

    2002-01-01

    Full Text Available Preeclampsia is an obstetric disease of unknown cause that affects approximately 5% of pregnant women. The visual system may be affected with variable intensity, being the retinal detachment a rare complication. The retinal detachment in preeclampsia is usually bilateral and serous, and its pathogenesis is related to the choroidal ischemia secondary to an intense arteriolar vasospasm. The majority of patients have complete recovery of vision with clinical management, and surgery is unnecessary. This is a case report of a 27 year old patient who developed the severe form of preeclampsia on her first pregnancy. She had progressive blurred vision, until she could see only shadows. Ophthalmic examination diagnosed spread and bilateral retinal detachment. With blood pressure control at postpartum, the patient had her retina reattached, and recovery of vision.

  12. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  13. Bioelectronic retinal prosthesis

    Science.gov (United States)

    Weiland, James D.

    2016-05-01

    Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

  14. Retinal flow cytometer.

    Science.gov (United States)

    Alt, C; Veilleux, I; Lee, H; Pitsillides, C M; Côté, D; Lin, C P

    2007-12-01

    The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery-vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerve head. We demonstrate that the retinal flow cytometer detects about five times more cells per minute than the original in vivo flow cytometer does in the ear.

  15. [Retinal pneumopexy in the treatment of rhegmatogenous retinal detachment].

    Science.gov (United States)

    Levai, L; Gavriş, Monica; Gábor, Radó; Bagosi, P

    2014-01-01

    To evaluate the efficiency of retinal pneumopexy in patients with rhegmatogenous retinal detachment. This clinical prospective study unrolled between november 2010-june 2012 in the Ophthalmology Department of the Military Hospital in Cluj-Napoca and Satu Mare Emergency Hospital included 20 patients (20 eyes) with rhegmatogenous retinal detachment. Patients were treated with retinal pneumopexy followed by laser photocoagulation. Anatomical and functional results were evaluated 1, 3, 6, 12 and 19 months after treatment. In 17 eyes out of 20, we achieved retinal reattachment and visual recovery. Three cases yelded no success, these being further treated with posterior vitrectomy. Retinal pneumopexy is a minimally invasive treatment method of rhegmatogenous retinal detachment with very good results in well selected cases.

  16. Hypoxic-Preconditioned Bone Marrow Stem Cell Medium Significantly Improves Outcome After Retinal Ischemia in Rats.

    Science.gov (United States)

    Roth, Steven; Dreixler, John C; Mathew, Biji; Balyasnikova, Irina; Mann, Jacob R; Boddapoti, Venkat; Xue, Lai; Lesniak, Maciej S

    2016-06-01

    We have previously demonstrated the protective effect of bone marrow stem cell (BMSC)-conditioned medium in retinal ischemic injury. We hypothesized here that hypoxic preconditioning of stem cells significantly enhances the neuroprotective effect of the conditioned medium and thereby augments the protective effect in ischemic retina. Rats were subjected to retinal ischemia by increasing intraocular pressure to 130 to 135 mm Hg for 55 minutes. Hypoxic-preconditioned, hypoxic unconditioned, or normoxic medium was injected into the vitreous 24 hours after ischemia ended. Recovery was assessed 7 days after injections by comparing electroretinography measurements, histologic examination, and apoptosis (TUNEL, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay). To compare proteins secreted into the medium in the groups and the effect of hypoxic exposure, we used rat cytokine arrays. Eyes injected with hypoxic BMSC-conditioned medium 24 hours after ischemia demonstrated significantly enhanced return of retinal function, decreased retinal ganglion cell layer loss, and attenuated apoptosis compared to those administered normoxic or hypoxic unconditioned medium. Hypoxic-preconditioned medium had 21 significantly increased protein levels compared to normoxic medium. The medium from hypoxic-preconditioned BMSCs robustly restored retinal function and prevented cell loss after ischemia when injected 24 hours after ischemia. The protective effect was even more pronounced than in our previous studies of normoxic conditioned medium. Prosurvival signals triggered by the secretome may play a role in this neuroprotective effect.

  17. Contrast sensitivity, ocular blood flow and their potential role in assessing ischaemic retinal disease.

    Science.gov (United States)

    Shoshani, Yochai Z; Harris, Alon; Rusia, Deepam; Spaeth, George L; Siesky, Brent; Pollack, Ayala; Wirostko, Barbara

    2011-08-01

    To examine the definition, evaluation methodology, association to ocular blood flow and potential clinical value of contrast sensitivity (CS) testing in clinical and research settings, focusing in patients with ischemic retinal disease. A review of the medical literature focusing on CS and ocular blood flow in ischemic retinal disease. CS may be more sensitive than other methods at detecting subtle defects or improvements in primarily central retinal ganglion cell function early on in a disease process. CS testing attempts to provide spatial detection differences which are not directly assessed with standard visual acuity chart testing. Analyzing all studies that have assessed both CS change and ocular blood flow, it is apparent that both choroidal circulation and retinal circulation may have an important role in influencing CS. The concept that CS is directly influenced by ocular blood flow is supported by reviewing the studies involving both. Although the studies in the literature have not established a direct cause and effect relationship per se, the literature review makes it logical to assume that changes in retinal and choroidal blood flow influence CS. This raises the possibility that a subjective visual characteristic, specifically CS, may be able to be evaluated more objectively by studying blood flow. It appears appropriate to study the relationship between blood flow and CS more extensively to develop improved ways of measuring various aspects of blood flow to the eye and to best quantify early changes in visual function. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  18. Retinal locus for scanning text.

    Science.gov (United States)

    Timberlake, George T; Sharma, Manoj K; Grose, Susan A; Maino, Joseph H

    2006-01-01

    A method of mapping the retinal location of text during reading is described in which text position is plotted cumulatively on scanning laser ophthalmoscope retinal images. Retinal locations that contain text most often are the brightest in the cumulative plot, and locations that contain text least often are the darkest. In this way, the retinal area that most often contains text is determined. Text maps were plotted for eight control subjects without vision loss and eight subjects with central scotomas from macular degeneration. Control subjects' text maps showed that the fovea contained text most often. Text maps of five of the subjects with scotomas showed that they used the same peripheral retinal area to scan text and fixate. Text maps of the other three subjects with scotomas showed that they used separate areas to scan text and fixate. Retinal text maps may help evaluate rehabilitative strategies for training individuals with central scotomas to use a particular retinal area to scan text.

  19. The tole of ischemic preconditioning in acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Ristić Anđelka

    2005-01-01

    Full Text Available Introduction Ischemic preconditioning is a phenomenon in which brief episodes of ischemia and reperfusion increase myocardial tolerance and substantially reduce the infarction size. Case report Two patients with acute left anterior descending artery occlusion received fibrinolytic therapy within 6 hours of symptom onset, but nevertheless developed myocardial infarctions of different size. The first patient, without a history of preinfarction angina, developed a large anterior infarction, because there was no time for ischemic preconditioning or development of coronary collateral vessels. The second patient, with a 4-day history of preinfarction angina, had a more favorable outcome-he developed apical necrosis, with greater myocardial viability in the infarct-related area. Conclusion The beneficial effects of angina occurring 24-48h before infarction are resulting from ischemic preconditioning, which reduces cardiac mortality, infarct size and occurrence of life-threatening ventricular arrhythmias. .

  20. Learning about Retinitis Pigmentosa

    Science.gov (United States)

    ... that detect light). Photoreceptor cells capture and process light helping us to see. As these cells breakdown and die, patients experience progressive vision loss. The most common feature of all forms of RP is a ... cells that detect dim light) and cones (retinal cells that detect light and ...

  1. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  2. Retinal vein occlusion

    Science.gov (United States)

    ... decrease the risk of retinal vein occlusion. These measures include: Eating a low-fat diet Getting regular exercise Maintaining an ideal weight Not smoking Aspirin or other blood thinners may help prevent blockages in the other eye. Controlling diabetes may ...

  3. Retinal imaging with smartphone.

    Science.gov (United States)

    Ademola-Popoola, D S; Olatunji, V A

    2017-03-01

    The use of smartphones for various purposes among health professionals is increasing, especially with the availability of different applications. On account of cost, fundus cameras are not readily available in ophthalmic practice in developing countries. Since smartphones are readily available, easy to use and portable, they may present a cheap alternative in a resource-limited economy. to explore the use of smartphone (Blackberry Z-10) for retinal imaging in a resource-limited economy. A smartphone (Blackberry Z-10) was used to acquire retinal images with the use of +20D lens in patients with dilated pupils by activating the video mode of the camera. Clear retinal images were obtained in different clinical conditions in adults and children including branch retinal vein occlusion with fibrovascular proliferation, chorioretinal scarring from laser photocoagulation, presumed ocular toxoplasmosis, diabetic retinopathy, retinoblastoma, ocular albinism with fundus hypopigmentation. The ability to have low cost fundus imaging from readily available smartphones in an eye clinic in Nigeria presents a major boost to patient care and also offers an innovative role in research, education, and information sharing.

  4. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  5. Retinal Imaging with Smartphone

    African Journals Online (AJOL)

    2017-03-06

    Mar 6, 2017 ... Aim and Objectives: to explore the use of smartphone (Blackberry. Z-10) for retinal imaging in ... Samsung phones with additional apps/software such as the Filmic pro to ... in Nigeria also compared the iPhone with the Android.

  6. Duration of rhegmatogenous retinal detachment predicts recovery of retinal sensitivity

    Directory of Open Access Journals (Sweden)

    Rose Rose

    2016-02-01

    Full Text Available The decision to treat a disease is often based on the presence or absence of symptoms, one prototype case being rhegmatogenous retinal detachment. Detachment of the neural retina from the pigment epithelium is a major cause of anatomical and functional dysfunction of the retina, where retinal recovery is inversely related to duration of detachment. The purpose of retinal reattachment is to effect recovery of the photoreceptors and pigment epithelium from degeneration. The aim of this study was to determine the critical duration of rhegmatogenous retinal detachment resulting in optimal retinal recovery after reattachment. A prospective study was conducted at a private hospital in Yogyakarta. Thirty five eyes were involved in this study. Three months after reattachment, central retinal recovery was measured by means of a Goldmann manual kinetic perimeter. The results showed that retinal recovery developed three months after surgery if the onset of rhegmatogenous retinal detachment was less than 28 days before surgery. The results were not significant if the onset of rhegmatogenous retinal detachment was more than 35 days. Although the Goldmann manual kinetic perimeter can efficiently detect central retinal sensitivity, it should be supported by more sensitive tools to evaluate the anatomy and function of the retina.

  7. Recent Advances towards the Clinical Application of Stem Cells for Retinal Regeneration

    Directory of Open Access Journals (Sweden)

    G. Astrid Limb

    2012-10-01

    Full Text Available Retinal degenerative diseases constitute a major cause of irreversible blindness in the world. Stem cell-based therapies offer hope for these patients at risk of or suffering from blindness due to the deterioration of the neural retina. Various sources of stem cells are currently being investigated, ranging from human embryonic stem cells to adult-derived induced pluripotent stem cells as well as human Müller stem cells, with the first clinical trials to investigate the safety and tolerability of human embryonic stem cell-derived retinal pigment epithelium cells having recently commenced. This review aims to summarize the latest advances in the development of stem cell strategies for the replacement of retinal neurons and their supportive cells, the retinal pigment epithelium (RPE affected by retinal degenerative conditions. Particular emphasis will be given to the advances in stem cell transplantation and the challenges associated with their translation into clinical practice.

  8. Peripapillary retinal thermal coagulation following electrical injury

    Directory of Open Access Journals (Sweden)

    Manjari Tandon

    2013-01-01

    Full Text Available In this study, we have presented the case report of a 20 year old boy who suffered an electric injury shock, following which he showed peripapillary retinal opacification and increased retinal thickening that subsequently progressed to retinal atrophy. The fluorescein angiogram revealed normal retinal circulation, thus indicating thermal damage to retina without any compromise to retinal circulation.

  9. Adenosine A3 receptor activation is neuroprotective against retinal neurodegeneration.

    Science.gov (United States)

    Galvao, Joana; Elvas, Filipe; Martins, Tiago; Cordeiro, M Francesca; Ambrósio, António Francisco; Santiago, Ana Raquel

    2015-11-01

    Death of retinal neural cells, namely retinal ganglion cells (RGCs), is a characteristic of several retinal neurodegenerative diseases. Although the role of adenosine A3 receptor (A3R) in neuroprotection is controversial, A3R activation has been reported to afford protection against several brain insults, with few studies in the retina. In vitro models (retinal neural and organotypic cultures) and animal models [ischemia-reperfusion (I-R) and partial optic nerve transection (pONT)] were used to study the neuroprotective properties of A3R activation against retinal neurodegeneration. The A3R selective agonist (2-Cl-IB-MECA, 1 μM) prevented apoptosis (TUNEL(+)-cells) induced by kainate and cyclothiazide (KA + CTZ) in retinal neural cultures (86.5 ± 7.4 and 37.2 ± 6.1 TUNEL(+)-cells/field, in KA + CTZ and KA + CTZ + 2-Cl-IB-MECA, respectively). In retinal organotypic cultures, 2-Cl-IB-MECA attenuated NMDA-induced cell death, assessed by TUNEL (17.3 ± 2.3 and 8.3 ± 1.2 TUNEL(+)-cells/mm(2) in NMDA and NMDA+2-Cl-IB-MECA, respectively) and PI incorporation (ratio DIV4/DIV2 3.3 ± 0.3 and 1.3 ± 0.1 in NMDA and NMDA+2-Cl-IB-MECA, respectively) assays. Intravitreal 2-Cl-IB-MECA administration afforded protection against I-R injury decreasing the number of TUNEL(+) cells by 72%, and increased RGC survival by 57%. Also, intravitreal administration of 2-Cl-IB-MECA inhibited apoptosis (from 449.4 ± 37.8 to 207.6 ± 48.9 annexin-V(+)-cells) and RGC loss (from 1.2 ± 0.6 to 8.1 ± 1.7 cells/mm) induced by pONT. This study demonstrates that 2-Cl-IB-MECA is neuroprotective to the retina, both in vitro and in vivo. Activation of A3R may have great potential in the management of retinal neurodegenerative diseases characterized by RGC death, as glaucoma and diabetic retinopathy, and ischemic diseases.

  10. Reversibility of retinal ischemia due to central retinal artery occlusion by hyperbaric oxygen

    Directory of Open Access Journals (Sweden)

    Hadanny A

    2016-12-01

    Full Text Available Amir Hadanny,1,2 Amit Maliar,1 Gregory Fishlev,1 Yair Bechor,1 Jacob Bergan,1 Mony Friedman,1 Isaac Avni,2,3 Shai Efrati1,2,4,5 1Sagol Center for Hyperbaric Medicine and Research, Assaf Harofeh Medical Center, Zerifin, Israel; 2Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel; 3Opthalmology Department, Assaf Harofeh Medical Center, Zeirifin, Israel; 4Research and Development Unit, Assaf Harofeh Medical Center, Zerifin, Israel; 5Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel Purpose: Ischemic retinal damage can be reversed by hyperbaric oxygen therapy (HBOT as long as irreversible infarction damage has not developed. However, the time window till irreversible damage develops is still unknown. The study aim was to evaluate the effect of HBOT and determine possible markers for irreversible retinal damage.Materials and methods: Retrospective analysis of 225 patients treated with HBOT for central retinal artery occlusion (CRAO in 1999–2015. One hundred and twenty-eight patients fulfilled inclusion/exclusion criteria: age >18 years, symptoms <20 hours, and best-corrected visual acuity (BCVA <0.5 logMAR.Results: Time delay from symptoms to treatment was 7.8±3.8 hours. The BCVA was significantly improved after HBOT, from 2.14±0.50 to 1.61±0.78 (P<0.0001. The proportion of patients with clinically meaningful visual improvement was significantly higher in patients without cherry-red spot (CRS compared to patients with CRS at presentation (86.0% vs 57.6%, P<0.0001. The percentage of patients with final BCVA better than 1.0 was also significantly higher in patients without CRS vs patients with CRS at presentation (61.0% vs 7.1%, P<0.0001. There was no correlation between CRS and the time from symptoms. HBOT was found to be safe, and only 5.5% of patients had minor, reversible, adverse events.Conclusion: HBOT is an effective treatment for non-arteritic CRAO as long as CRS has not formed. The fundus findings, rather

  11. Short-term results of endovascular surgery with tissue plasminogen activator injection for central retinal vein occlusion.

    Science.gov (United States)

    Ishida, Masaaki; Abe, Shinya; Nakagawa, Takuya; Hayashi, Atsushi

    2017-08-12

    To examine the effects of retinal endovascular surgery (REVS) with tissue plasminogen activator injection into the retinal vein in central retinal vein occlusion (CRVO) eyes. Sixteen consecutive CRVO patients with macular edema and decreased visual acuity who were referred to Toyama University Hospital between March 2014 and February 2016 were included in this study. Changes in visual acuity (VA) and central retinal thickness (CRT) were evaluated up to 6 months after REVS. Staining and leakage of the retinal veins in fluorescein angiography (FA) was graded in nine patients. Ten of 16 eyes were determined to be non-ischemic while the remaining six were ischemic. The mean logarithm of the minimum angle of resolution (logMAR) of VA was significantly improved from 0.98 ± 0.58 (mean ± standard deviation) at baseline to 0.78 ± 0.61 at 3 months (p = 0.002), and 0.64 ± 0.60 at 6 months (p = 0.003) after REVS. At 6 months, VA was improved in eight eyes (50%), while the other eight (50%) showed no change; none showed worsening. In the 10 eyes with non-ischemic CRVO, the mean VA was significantly improved at 6 months (p = 0.002), whereas no improvement was found in the six eyes with ischemic CRVO, . In all eyes, the mean CRT was significantly improved from 804 ± 343 μm at baseline to 506 ± 304 μm at 2 months (p = 0.014), 332 ± 229 μm at 3 months (p = 0.0001), and 305 ± 235 μm at 6 months (p = 0.00001). The postoperative complications observed were prolonged vitreous hemorrhage in one eye and neovascular glaucoma in two eyes. For postoperative recurrence of macular edema, sub-tenon injection of triamcinolone acetonide was given to five eyes, and intravitreal injection of an anti-VEGF agent was given to five eyes. Pan-retinal photocoagulation was performed on six eyes with ischemic type CRVO. The FA score was significantly improved after REVS (p = 0.018). REVS using a specially made micro-needle may be a surgical treatment

  12. Retinal flow cytometer

    OpenAIRE

    Alt, C.; Veilleux, I.; H. Lee; Pitsillides, C. M.; Côté, D.; Lin, C.P.

    2007-01-01

    The in vivo flow cytometer is an instrument capable of continuous, real-time monitoring of fluorescently labeled cells in the circulation without the need to draw blood samples. However, the original system probes a single vessel in the mouse ear; the small sample volume limits the sensitivity of the technique. We describe an in vivo retinal flow cytometer that simultaneously probes five artery–vein pairs in the mouse eye by circularly scanning a small laser spot rapidly around the optic nerv...

  13. Inherited Retinal Degenerative Disease Registry

    Science.gov (United States)

    2016-03-21

    Eye Diseases Hereditary; Retinal Disease; Achromatopsia; Bardet-Biedl Syndrome; Bassen-Kornzweig Syndrome; Batten Disease; Best Disease; Choroidal Dystrophy; Choroideremia; Cone Dystrophy; Cone-Rod Dystrophy; Congenital Stationary Night Blindness; Enhanced S-Cone Syndrome; Fundus Albipunctatus; Goldmann-Favre Syndrome; Gyrate Atrophy; Juvenile Macular Degeneration; Kearns-Sayre Syndrome; Leber Congenital Amaurosis; Refsum Syndrome; Retinitis Pigmentosa; Retinitis Punctata Albescens; Retinoschisis; Rod-Cone Dystrophy; Rod Dystrophy; Rod Monochromacy; Stargardt Disease; Usher Syndrome

  14. 吗啡后处理诱导小鼠海马脑片氧糖剥夺/再灌注耐受和对cPKCβⅡ/γ膜转位的影响%Effects of cPKCβⅡ/γ membrane translocation ischemic/hypoxic tolerance induced by morphine postconditioning in hippocampal slices

    Institute of Scientific and Technical Information of China (English)

    胡海立; 杨静; 纪方; 李天佐; 李俊发

    2011-01-01

    Objective To determine whether or not morphine postconditioning can induce ischemic/hypoxic tolerance in neurons subjected to reperfusion injury after oxygen-glucose deprivation (OGD). Methods Hippocampal slices of 400 μm thickness were prepared from healthy adult male BALB/c mice. The slices were incubated in oxygen-saturated ACSF without or with calcium, then were subjected to OGD for 20 min. After recovery, the samples were immersed in oxygenated artificial fluid for 2 hours in the presence or absence of morphine postconditioning at 3 μmol/L during the first 5-60 min. The assessment of slices injury was performed by a determination of the intensity of slice stain incubated with TTC (2% 2, 3, 5-triphenyltetrazolium chloride) and the leakage rate of LDH also evaluated. At the designated periods during incubation, some slices were immersed into liquid nitrogen for a later analysis of Western blot. The frozen slices were homogenized, sonicated and centrifuged to separate soluble and particulate proteins. 10% SDS-PAGE Western blot was used to identify the changes of membrane-specific translocation of cPKCβⅡ/γ. Results After reperfusion, the cell survival significantly decreased with the elongation of OGD (51.4%). The release rate of LDH (184.05%) significantly increased simultaneously. In hippocampal slices postconditioned with morphine for 20-60 min, the release rate of LDH (136%, 142%, 144%) significantly decreased as compared with the group OGD. In the hippocampal slices postconditioned with morphine for 10-30 min, the cell survival rate (64.9%, 69.9%, 63.5%) significantly increased as compared with reperfusion alone. cPKCγ of particulate fraction increased versus the control. And there was a corresponding decrease of cytosolic fraction. Morphine postconditioning significantly inhibited the cPKCγ isoform-specific membrane translocation. It declined from 136% in the group OGD to 123%, 118%, 114% in the group morphine 20-60 min. c

  15. Retinal hypoxia induces vascular endothelial growth factor through induction of estrogen-related receptor γ

    Energy Technology Data Exchange (ETDEWEB)

    Do, Ji Yeon; Choi, Young Keun [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Kook, Hyun [Department of Pharmacology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Suk, Kyoungho [Department of Pharmacology, Brain Science & Engineering Institute, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, In-Kyu [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Aging and Metabolism, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Park, Dong Ho, E-mail: sarasate2222@gmail.com [Department of Ophthalmology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2015-05-01

    Ischemic retinopathies causing overexpression of pro-angiogenic factors, including vascular endothelial growth factor (VEGF), are the most common cause of blindness. Thus, understanding the pathophysiology of targetable pathways that regulate retinal VEGF is of great interest. A conserved binding site for estrogen-related receptor γ (ERRγ) has been identified in the promoter of the Vegfa gene. ERRγ is a constitutively active orphan nuclear receptor and its expression is increased by hypoxic stimuli in metabolically active tissues. This study evaluated the role of ERRγ in the ischemic retina and the anti-VEGF potential of GSK5182, a selective inverse agonist of ERRγ. In an oxygen-induced retinopathy (OIR) mouse model, immunohistochemistry showed significantly increased ERRγ expression in the ganglion cell layer at postnatal day (P) 17. In a ganglion cell line (RGC-5), mRNA and protein levels of ERRγ were increased by desferrioxamine treatment and hypoxic conditions (1% O{sub 2}). Transient transfection of RGC-5 cells revealed that ERRγ regulated Vegfa expression and this was inhibited by GSK5182. Intravitreal injection of GSK5182 into the OIR model at P14 inhibited retinal Vegfa mRNA expression at P17. GSK5182 suppresses hypoxia-induced VEGF expression via ERRγ; therefore, ERRγ could be a treatment target for ischemic retinopathies. - Highlights: • OIR mice exhibited increased ERRγ expression in the ganglion cell layer. • Hypoxia-induced ERRγ expression was observed in retinal ganglion cells. • ERRγ overexpression increased VEGFA expression in retinal ganglion cells. • An ERRγ inverse agonist suppressed VEGFA expression in retinal ganglion cells. • Intravitreal injection of an ERRγ inverse agonist suppressed VEGFA in OIR mice.

  16. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants

    Science.gov (United States)

    Olivares-González, Lorena; Martínez-Fernández de la Cámara, Cristina; Hervás, David; Marín, María Pilar; Lahoz, Agustin; Millán, José María

    2016-01-01

    Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP) has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE) with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2) for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation) mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities) and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions. PMID:27861632

  17. Influence of ischemia on visual function in patients with branch retinal vein occlusion and macular edema

    Directory of Open Access Journals (Sweden)

    Noma H

    2011-05-01

    Full Text Available Hidetaka Noma¹, Hideharu Funatsu¹, Tatsuya Mimura², Katsunori Shimada³¹Department of Ophthalmology, Yachiyo Medical Center, Tokyo Women's Medical University, Owada-shinden, Chiba, Japan; ²Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan; ³Department of Hygiene and Public Health II, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, JapanAbstract: Visual function and retinal morphology were investigated to elucidate the influence of ischemia in patients with branch retinal vein occlusion (BRVO and macular edema. In 41 consecutive patients with BRVO aged 68.9 ± 10.0 years (22 women and 19 men, the area of capillary nonperfusion was measured by fluorescein angiography. Retinal thickness and retinal volume were measured by optical coherence tomography, and mean retinal sensitivity was calculated for each of 9 macular subfields. Mean visual acuity and macular sensitivity within the central subfield were not significantly correlated with the nonperfused area. However, the macular sensitivity within the central 5 subfields and all 9 subfields showed significant negative correlations with the nonperfused area. Also, macular thickness and volume within all 9 subfields were significantly correlated with the nonperfused area. In conclusion, evaluation of both the fovea and the entire macular region may be important in patients with ischemic BRVO.Keywords: branch retinal vein occlusion, macular edema, macular sensitivity, ischemia

  18. Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis.

    Directory of Open Access Journals (Sweden)

    Cheryl A Arcinue

    Full Text Available To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula compared with age-matched HIV-negative controls.Cohort of patients with known HIV under CART (combination Antiretroviral Therapy treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT to assess retinal layers and retinal thickness.Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior, the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308-6,872 cones/mm2. A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea. We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer was also significantly thickened in all the different locations scanned compared with HIV-negative controls.Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.

  19. Blood Biomarkers of Ischemic Stroke

    National Research Council Canada - National Science Library

    Jickling, Glen C; Sharp, Frank R

    2011-01-01

    .... Though many candidate blood based biomarkers for ischemic stroke have been identified, none are currently used in clinical practice. With further well designed study and careful validation, the development of blood biomarkers to improve the care of patients with ischemic stroke may be achieved.

  20. [Application of retinal oximeter in ophthalmology].

    Science.gov (United States)

    Li, Jing; Ma, Jianmin; Wang, Ningli

    2015-11-01

    Retinal oximeter is a new machine which has been used in the diagnose, treatment and research of several ophthalmic diseases for recent years. It allows ophthalmologists to gain retinal oxygen saturation directly. Therefore, retinal oximeter might be useful for ophthalmologists to understand ophthalmic diseases more deeper and clarify the impact of ischemia on retinal function. It has been reported in the literatures that retinal oximeter has potentially useful diagnostic and therapeutic indications in various eye diseases such as diabetic retinopathy, central retinal vein and artery occlusion, retinitis pigmentosa, glaucomatous optic neuropathy, et al. In this thesis, the application of retinal oximeter in ophthalmology is reviewed.

  1. Retinal oximetry in patients with ischaemic retinal diseases

    DEFF Research Database (Denmark)

    Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

    2017-01-01

    increased retinal arterial oxygen saturation (raSatO2 ) in patients with DR. In patients with central retinal vein occlusion (CRVO), all studies found that rvSatO2 was reduced, but raSatO2 remained unchanged. Branch retinal vein occlusion was not associated with changes in retinal oxygen saturation......, but this was based on a single study. In conclusion, DR is associated with increased rvSatO2 and might also be related to increased raSatO2 . Central retinal vein occlusion (CRVO) is correlated with increased rvSatO2 but unrelated to raSatO2 . Prospective studies are needed to expand these findings. These would tell...... retinopathy (DR) and four about retinal vein occlusion. No studies about retinal artery occlusion were included. In diabetes, all studies found that increases in retinal venous oxygen saturation (rvSatO2 ) were associated with present as well as increasing levels of DR. Four of six studies also found...

  2. Imaging acute ischemic stroke.

    Science.gov (United States)

    González, R Gilberto; Schwamm, Lee H

    2016-01-01

    Acute ischemic stroke is common and often treatable, but treatment requires reliable information on the state of the brain that may be provided by modern neuroimaging. Critical information includes: the presence of hemorrhage; the site of arterial occlusion; the size of the early infarct "core"; and the size of underperfused, potentially threatened brain parenchyma, commonly referred to as the "penumbra." In this chapter we review the major determinants of outcomes in ischemic stroke patients, and the clinical value of various advanced computed tomography and magnetic resonance imaging methods that may provide key physiologic information in these patients. The focus is on major strokes due to occlusions of large arteries of the anterior circulation, the most common cause of a severe stroke syndrome. The current evidence-based approach to imaging the acute stroke patient at the Massachusetts General Hospital is presented, which is applicable for all stroke types. We conclude with new information on time and stroke evolution that imaging has revealed, and how it may open the possibilities of treating many more patients. © 2016 Elsevier B.V. All rights reserved.

  3. [Ischemic hepatitis. Case report].

    Science.gov (United States)

    Squella, Freddy; Zapata, Rodrigo

    2003-06-01

    Ischemic hepatitis or shock liver is defined as an extensive hepatocellular necrosis associated with a decrease in hepatic perfusion due to systemic hypotension. Serum aminotransferase levels (ALAT and ASAT) increase rapidly after the ischemic episode and peak within 1 to 3 days to at least 20 times the upper normal limit. After recovery, aminotransferases return to near normal levels in 7-10 days of the initial insult. Histological it is characterized by centrolobular necrosis without inflammation. We report a 47 years old woman with a rheumatic mitral valve disease, atrial fibrillation on anticoagulation and congestive heart failure. She was admitted due to a rapid auricular arrhythmia and secondary severe hypotension. She developed rapidly progressive jaundice (bilirubin up to 8.9 mg/dl) and her aminotransferases (ALAT and ASAT) increased rapidly to levels near 100 times the upper normal limit. Other causes of liver disease were excluded. With hemodynamic support and after heart rate control she improved rapidly within the following 10 days with normalization of liver function tests and complete clinical recovery.

  4. The Feasibility of Central Retinal Artery Doppler Ultrasonography in Patients with Sudden Visual Disturbance that's Caused by Retinal Vascular Occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Won; Lee, Hui Joong; Lee, Jong Min [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2009-03-15

    We evaluated the usefulness of central retinal artery Doppler ultrasonography for assessing the patients with sudden visual disturbance that's caused by retinal vascular occlusion. The blood flow velocity and the resistive and pulsatile indexes were measured at the central retinal arteries of 65 patients with sudden visual disturbance. For all the subjects, the patient's affected eye was compared with the non-affected eye. We investigated the efficacy of the Doppler ultrasonography parameters to predict a significant visual loss on the Snellen test (<20/400). A significantly lower central retinal arterial flow velocity was measured in the affected eye as compared with the unaffected normal eye for all the subjects (p < 0.05). The ROC curves showed that the mean velocity was the best parameter to predict significant visual loss (p < 0.05). If a mean velocity of 4.3 cm/sec was chosen as the cutoff value to predict significant visual loss, then the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 89%, 95%, 95%, 88% and 92%, respectively (estimated area = 0.958, p-value <0.01). Central retinal artery Doppler ultrasonography was helpful for predicting significant visual loss in patients who complain of sudden visual disturbance. In addition to the other ophthalmologic diagnostic modalities, Doppler ultrasonography may be a feasible modality to depict impending further visual loss of an ischemic origin.

  5. Central retinal vein occlusion concomitant with dengue fever.

    Science.gov (United States)

    Velaitham, Punithamalar; Vijayasingham, Nandini

    2016-01-01

    Dengue virus infection is on the rise and there is increasing number of ocular complications that are being reported. Most common ocular complications are macular edema, macular hemorrhages, and foveolitis. There are case reports on branch retinal vessel occlusions. Most of the ocular complications are attributed to the bleeding tendency and transudative process in dengue viral infection. This is a case report of ischemic central retinal vein occlusion (CRVO) concomitant with dengue fever. A 41 year old Malay female was admitted to medical ward and diagnosed to have "dengue fever with warning signs". On the day of admission she noted sudden onset of right eye blurring of vision. She presented to our clinic 1 week later. Ocular examination revealed right eye visual acuity of <20/1000 and ischaemic CRVO with macular edema. She had no other risk factors to develop retinal vein occlusion. She progressively developed proliferative retinopathy and received multiple laser therapy. There was no anterior segment neovascularization. However, her vision improved to only 20/400 despite of resolution of macular edema and new vessels elsewhere. Dengue virus infection is known to cause thrombocytopenia which can result in hemorrhagic events. It can also cause procoagulant state which can result in thrombotic events secondary to immune reaction. Awareness among treating physicians of such ocular complication which can result in significant morbidity for patient is necessary.

  6. Retinal detachment surgery without cryotherapy.

    OpenAIRE

    Chignell, A H; Markham, R H

    1981-01-01

    A series of cases of retinal detachment treated without the application of cryotherapy at the time of surgery has been studied. The omission of cryotherapy while not interfering with retinal reattachment, carries the risk of redetachment at a later date. Macular pucker may still occur in spite of the absence of cryotherapy.

  7. Perceptual Fading without Retinal Adaptation

    Science.gov (United States)

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  8. Spectrophotometric retinal oximetry in pigs

    DEFF Research Database (Denmark)

    Traustason, Sindri; Kiilgaard, Jens Folke; Karlsson, Robert

    2013-01-01

    PURPOSE: To assess the validity of spectrophotometric retinal oximetry, by comparison to blood gas analysis and intra-vitreal measurements of partial pressure of oxygen (pO2). METHODS: Female domestic pigs were used for all experiments (n=8). Oxygen fraction in inspired air was changed using...... a mixture of room air, pure oxygen and pure nitrogen, ranging from 5% to 100% oxygen. Femoral arterial blood gas analysis and retinal oximetry was performed at each level of inspiratory oxygen fraction. Retinal oximetry was performed using a commercial instrument, the Oxymap Retinal Oximeter T1 (Oxymap ehf......, Reykjavik, Iceland). The device simultaneously acquires images at two wavelengths (570 nm and 600 nm) and specialized software automatically detects retinal blood vessels. In three pigs, invasive pO2-measurements were performed after the initial non-invasive measurements. RESULTS: Comparison of femoral...

  9. Bilateral retinitis following typhoid fever.

    Science.gov (United States)

    Prabhushanker, M; Topiwalla, Tasneem T; Ganesan, Geetha; Appandaraj, Sripal

    2017-01-01

    Post typhoid fever immune related reactions affecting the eye is a rare finding which can have various presentations in which typhoid retinopathy is not a well recognized sequelae. Here we present a case of 59 year old male who presented with right eye sudden painless loss of vision 4 weeks after typhoid fever which was diagnosed and treated successfully. His BCVA was 2/60 in right eye and 6/6 in left eye. Fundus examination showed retinitis along with macular serous detachment in right eye and retinitis in left eye. Significant improvement in BCVA in right eye was observed after treatment with oral steroid with resolving retinitis lesions. Diagnosis of post typhoid immune mediated retinitis was made with good resolution following treatment. Immune mediated retinitis is a rare sequelae to typhoid infection which can be successfully treated with systemic steroids with good resolution of the lesions.

  10. RETINAL BLOOD FLOW AFTER INTRAVITREAL BEVACIZUMAB IS A PREDICTIVE FACTOR FOR OUTCOMES OF MACULAR EDEMA ASSOCIATED WITH CENTRAL RETINAL VEIN OCCLUSION.

    Science.gov (United States)

    Matsumoto, Makiko; Suzuma, Kiyoshi; Yamada, Yoshihisa; Tsuiki, Eiko; Fujikawa, Azusa; Kitaoka, Takashi

    2017-02-01

    To investigate whether retinal blood flow levels after intravitreal bevacizumab (IVB) treatment are correlated with the outcomes of patients with macular edema secondary to central retinal vein occlusion. This retrospective observational case study enrolled 44 cases nonischemic central retinal vein occlusion. In each patient, visual acuity, central retinal thickness, and mean blur rate, which was measured by laser speckle flowgraphy and represents retinal blood flow velocity, were examined. At the end of the follow-up period (19.8 ± 8.8 months), 4 of 44 eyes (9.1%) converted to the ischemic type (converted group), whereas 40 (90.9%) remained unchanged (nonischemic group). Mean central retinal thickness significantly decreased and mean visual acuity significantly improved at 1 month after the first IVB injection in each group. Mean mean blur rate in the nonischemic group significantly increased, whereas it was unchanged in the converted group. The difference between the two groups was already significant after the first IVB injection. Subsequently, visual acuity worsened in the converted group. Multiple linear regression analysis indicated that the strongest correlation was between the last visual acuity and the last mean blur rate. Blood flow measurements are useful for evaluating IVB treatments. Blood flow after IVB can predict outcomes in patients with central retinal vein occlusion.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  11. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    Science.gov (United States)

    Ayhan, Ziya; Yaman, Aylin; Söylev Bajin, Meltem; Saatci, A. Osman

    2015-01-01

    Optic disc drusen (ODD) are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION) who received the diagnosis of bilateral optic disc drusen five years earlier and thereby reiterated the association of ODD and acute NAION. PMID:26550507

  12. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    Directory of Open Access Journals (Sweden)

    Ziya Ayhan

    2015-01-01

    Full Text Available Optic disc drusen (ODD are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION who received the diagnosis of bilateral optic disc drusen five years earlier and thereby reiterated the association of ODD and acute NAION.

  13. [Cerebrolysin for acute ischemic stroke].

    Science.gov (United States)

    iganshina, L E; Abakumova, T R

    2013-01-01

    The review discusses existing evidence of benefits and risks of cerebrolysin--a mixture of low-molecular-weight peptides and amino acids derived from pigs' brain tissue with proposed neuroprotective and neurotrophic properties, for acute ischemic stroke. The review presents results of systematic search and analysis of randomised clinical trials comparing cerebrolysin with placebo in patients with acute ischemic stroke. Only one trial was selected as meeting quality criteria. No difference in death and adverse events between cerebrolysin and placebo was established. The authors conclude about insufficiency of evidence to evaluate the effect of cerebrolysin on survival and dependency in people with acute ischemic stroke.

  14. Hemichorea after ischemic stroke

    Directory of Open Access Journals (Sweden)

    Sadullah Saglam

    2016-03-01

    Full Text Available The deterioration of the balance between direct and indirect ways in the basal ganglia causes chorea. The lesions of contralateral basal ganglia, thalamus or the connection of them all together are responsible for this. Chorea can be observed during the course of metabolic and vascular diseases, neurodegenerative or hereditary diseases. Hyperkinetic movement disorders after acute ischemic stroke are reported as rare; however, hemichorea is the most frequent developing disorder of hyperkinetic movement as a result of cerebrovascular disease. In this case report, we presented two case who applied us with choreiform movements in his left half of the body after acute thalamic stroke. [Cukurova Med J 2016; 41(0.100: 29-32

  15. Ketogenic diet may improve ischemic tolerance of middle cerebral artery occlusion mice through up-regulation of hypoxia inducible factor-1 target genes%缺氧诱导因子-1靶基因参与生酮饮食提高大脑中动脉闭塞模型小鼠脑缺血耐受作用

    Institute of Scientific and Technical Information of China (English)

    国敏; 崔梅; 董强

    2016-01-01

    Objective To explore the effects of ketogenic diet on middle cerebral artery occ-lusion ( MCAO ) mice and the role of hypoxia inducible factor-1 ( HIF-1 ) target genes in this process. Methods C57BL/6 mice were randomly allocated into four groups: standard diet group, high carbohydrate diet group, ketogenic diet group and control group. Mice of the 3 intervention groups were fed with corresponding diets for 3 weeks and were afterwards made into MCAO mice models. Control group was fed with standard diet for 3 weeks without MCAO treatment. Stroke vo-lume was measured by 2,3,5-triphenyl tetrazolium chloride ( TTC) staining. Neurological function was accessed by Longa scoring method. Polymerase chain reaction ( PCR) was used to detect mRNA expression quantity of HIF-1 downstream target genes including erythropoietin ( EPO) , vascular en-dothelial growth factor ( VEGF ) , glucose transport 1 ( GLUT1 ) and monocarboxylic transporter 4 ( MCT4) in the ischemic region. Results Compared with the other 3 groups, ketogenic diet group showed smaller stroke volume, better neurological score and higher mRNA expression quantity of HIT-1 downstream target genes. Conclusion Ketogenic diet may improve brain ischemic tolerance of MCAO mice through up-regulation of HIF-1 target genes.%目的:探究生酮饮食对大脑中动脉闭塞( middle cerebral artery occlusion,MCAO)模型小鼠的作用及缺氧诱导因子-1靶基因参与机制。方法小鼠随机分为正常对照组及标准饮食组、高碳水化合物饮食组、生酮饮食组,建模前通过3周饮食干预后,饮食干预的3组小鼠建造MCAO模型,正常对照组给予标准饮食但不进行MCAO造模。2,3,5-三苯基氯化四氮唑染色观察脑梗死体积,Longa评分法对模型鼠进行神经功能评分,聚合酶链反应检测缺血区脑组织缺氧诱导因子-1下游靶基因红细胞生成素、血管内皮生长因子、葡萄糖转运体1、单羧酸转运体4的mRNA表达量。结果生酮饮食

  16. Acute retinal necrosis

    Directory of Open Access Journals (Sweden)

    Hugo Hernán Ocampo

    2009-12-01

    Full Text Available Purpose: Clinical features in a case of acute retinal necrosis are described as well as its diagnostic approach and response to early treatment. Methods: This is a descriptive and retrospective study case report of a 26 year old male patient who arrived to the emergency room with a three day history of sudden visual loss in the right eye (RE. At initial evaluation a visual acuity of hand movements in the RE, 20/15 in the left eye (LE and a right relative afferent pupillary defect were found. Fundoscopy revealed profuse soft exudates and hemorrhages involving posterior pole, inferior hemiretina and superotemporal periphery. Infectious workup and fluoresceinic angiography were made and positive serologies for herpes virus types 1 and 2, without HIV, were found. A diagnosis of acute retinal necrosis was made and treatment with intravenous valgancyclovir for two weeks and intra-vitreous triamcinolone for severe vasculitis, was given. Then a 3 months treatment with oral antiviral agents was prescribed. Results: Patient’s evolution showed improvement with treatment and at two and a half months of follow up, visual acuity was 20/50 in the right eye, normal slit lamp examination, tonometry of 12 mm Hg and fundoscopy improved when compared to initial pictures.Conclusions: A high index of suspicion is needed for diagnosing ARN taking into account clinical findings. Prompt intravenous and intra-vitreous treatments are needed to achieve good clinical and functional outcomes and to avoid central nervous system complications.

  17. Enhanced Endothelin-1 Mediated Vasoconstriction of the Ophthalmic Artery May Exacerbate Retinal Damage after Transient Global Cerebral Ischemia in Rat

    DEFF Research Database (Denmark)

    Blixt, Frank W; Johansson, Sara Ellinor; Johnson, Leif

    2016-01-01

    Cerebral vasculature is often the target of stroke studies. However, the vasculature supplying the eye might also be affected by ischemia. The aim of the present study was to investigate if the transient global cerebral ischemia (GCI) enhances vascular effect of endothelin-1 (ET-1) and 5...... decreased function at 72 hours, but recovered almost completely after 7 days. In conclusion, we propose that the increased contractile response via ET-1 receptors in the ophthalmic artery after 48 hours may elicit negative retinal consequences due to a second ischemic period. This may exacerbate retinal...

  18. Let's Talk about Ischemic Stroke

    Science.gov (United States)

    ... Thromboembolism Aortic Aneurysm More Let's Talk About Ischemic Stroke Updated:Dec 9,2015 The majority of strokes ... Should I Limit Sodium? How Do I Understand "Nutrition Facts" Labels? How Can I Quit Smoking? How ...

  19. Thrombolysis for Acute Ischemic Stroke

    NARCIS (Netherlands)

    Uyttenboogaart, Maarten; De Keyser, J.; Luijckx, G. J.

    2009-01-01

    In the last decennium, thrombolytic therapy has changed the management of acute ischemic stroke. Randomized clinical studies have demonstrated that intravenous thrombolysis with tissue plasminogen activator improves functional outcomes. Recently the time window for intravenous thrombolysis has been

  20. Cryoglobulins in Acute Ischemic Stroke

    Science.gov (United States)

    Manukyan, L. A.; Ayvazyan, V. A.; Boyajyan, A. S.

    Cryoglobulins (Cgs) are pathogenic immune complexes, non specific markers of the inflammatory and autoimmune responses. In this study we for the first time, revealed Cgs in the blood of ischemic stroke patients and analyze their composition.

  1. Treatment of Laser-Induced Retinal Injuries

    Science.gov (United States)

    1989-06-29

    Distribution List (enclosed) bI’TF rruIoN STATEMEN A Approved for publi reljaso Disatbunon Unlimited TREATMENT OF LASER-INDUCED RETINAL INJURIES FINAL...suprathreshold retinal laser lesions II. Subthreshold retinal laser lesions III. Effect of steroid treatment on laser-induced retinal injury Discussion and...In the present study we investigated the effect of corticosteroid treatment of argon laser-induced retinal injury on vitreal accumulation of both

  2. Ethyl Pyruvate Inhibits Retinal Pathogenic Neovascularization by Downregulating HMGB1 Expression

    Directory of Open Access Journals (Sweden)

    Yun Mi Lee

    2013-01-01

    Full Text Available Retinal pathogenic angiogenesis in the eyes is a causative factor in retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration. This study was designed to examine the pathogenic role of the high-mobility group box-1 (HMGB1 protein and the inhibitory effect of ethyl pyruvate (EP, a well-known antioxidant substance, in retinal pathogenic angiogenesis in mice with oxygen-induced retinopathy (OIR, one of the animal models of proliferative ischemic retinopathy. The OIR mouse model was used for our in vivo studies. The mice were exposed to 75% oxygen from postnatal day 7 (P7 to P11, after which the mice were brought to room air and intraperitoneally injected with EP (50 mg/kg, or 100 mg/kg for five days. At P17, the mice were perfused with fluorescein isothiocyanate-dextran, and flat-mounted retinas were used to measure nonperfused and neovascular tufts. In OIR mice, an intraperitoneal injection of EP reduced the nonperfused retinal area in the treatment group and significantly reduced the retinal neovascular tufts. In addition, EP inhibited the overexpression of HMGB1 in the retinas of OIR mice. These data suggest that EP could serve as an innovative pharmaceutical agent to prevent retinal neovascularization through inhibiting HMGB1 expression.

  3. Ethyl pyruvate inhibits retinal pathogenic neovascularization by downregulating HMGB1 expression.

    Science.gov (United States)

    Lee, Yun Mi; Kim, Junghyun; Jo, Kyuhyung; Shin, So Dam; Kim, Chan-Sik; Sohn, Eun Jin; Kim, Seon Gi; Kim, Jin Sook

    2013-01-01

    Retinal pathogenic angiogenesis in the eyes is a causative factor in retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration. This study was designed to examine the pathogenic role of the high-mobility group box-1 (HMGB1) protein and the inhibitory effect of ethyl pyruvate (EP), a well-known antioxidant substance, in retinal pathogenic angiogenesis in mice with oxygen-induced retinopathy (OIR), one of the animal models of proliferative ischemic retinopathy. The OIR mouse model was used for our in vivo studies. The mice were exposed to 75% oxygen from postnatal day 7 (P7) to P11, after which the mice were brought to room air and intraperitoneally injected with EP (50 mg/kg, or 100 mg/kg) for five days. At P17, the mice were perfused with fluorescein isothiocyanate-dextran, and flat-mounted retinas were used to measure nonperfused and neovascular tufts. In OIR mice, an intraperitoneal injection of EP reduced the nonperfused retinal area in the treatment group and significantly reduced the retinal neovascular tufts. In addition, EP inhibited the overexpression of HMGB1 in the retinas of OIR mice. These data suggest that EP could serve as an innovative pharmaceutical agent to prevent retinal neovascularization through inhibiting HMGB1 expression.

  4. Retinal Microvascular Abnormalities in Neurofibromatosis Type 1 Associated with Congenital Retinal Macrovessels

    Science.gov (United States)

    Makino, Shinji; Endoh, Katsuhisa; Tampo, Hironobu

    2013-01-01

    Here, we report a case of retinal microvascular abnormalities in a patient with neurofibromatosis type 1 (NF1) associated with congenital retinal macrovessels. An abnormal retinal macrovessel, crossing the macula horizontally, was detected in the right eye. Additionally, retinal microvascular abnormalities were detected. Eight years after the initial visit, the retinal microvascular abnormalities were noted to have changed substantially. We speculate that retinal microvascular abnormalities in NF1 may change dynamically over the years. PMID:23781366

  5. Retinal Microvascular Abnormalities in Neurofibromatosis Type 1 Associated with Congenital Retinal Macrovessels

    Directory of Open Access Journals (Sweden)

    Shinji Makino

    2013-01-01

    Full Text Available Here, we report a case of retinal microvascular abnormalities in a patient with neurofibromatosis type 1 (NF1 associated with congenital retinal macrovessels. An abnormal retinal macrovessel, crossing the macula horizontally, was detected in the right eye. Additionally, retinal microvascular abnormalities were detected. Eight years after the initial visit, the retinal microvascular abnormalities were noted to have changed substantially. We speculate that retinal microvascular abnormalities in NF1 may change dynamically over the years.

  6. Bilateral patching in retinal detachment: fluid mechanics and retinal "settling".

    Science.gov (United States)

    Foster, William J

    2011-07-20

    When a patient suffers a retinal detachment and surgery is delayed, it is known clinically that bilaterally patching the patient may allow the retina to partially reattach or "settle." Although this procedure has been performed since the 1860s, there is still debate as to how such a maneuver facilitates the reattachment of the retina. Finite element calculations using commercially available analysis software are used to elucidate the influence of reduction in eye movement caused by bilateral patching on the flow of subretinal fluid in a physical model of retinal detachment. It was found that by coupling fluid mechanics with structural mechanics, a physically consistent explanation of increased retinal detachment with eye movements can be found in the case of traction on the retinal hole. Large eye movements increase vitreous traction and detachment forces on the edge of the retinal hole, creating a subretinal vacuum and facilitating increased subretinal fluid. Alternative models, in which intraocular fluid flow is redirected into the subretinal space, are not consistent with these simulations. The results of these simulations explain the physical principles behind bilateral patching and provide insight that can be used clinically. In particular, as is known clinically, bilateral patching may facilitate a decrease in the height of a retinal detachment. The results described here provide a description of a physical mechanism underlying this technique. The findings of this study may aid in deciding whether to bilaterally patch patients and in counseling patients on pre- and postoperative care.

  7. Bioactivation of organic nitrates and the mechanism of nitrate tolerance.

    Science.gov (United States)

    Klemenska, Emila; Beresewicz, Andrzej

    2009-01-01

    Organic nitrates, such as nitroglycerin, are commonly used in the therapy of cardiovascular disease. Long-term therapy with these drugs, however, results in the rapid development of nitrate tolerance, limiting their hemodynamic and anti-ischemic efficacy. In addition, nitrate tolerance is associated with the expression of potentially deleterious modifications such as increased oxidative stress, endothelial dysfunction, and sympathetic activation. In this review we discuss current concepts regarding the mechanisms of organic nitrate bioactivation, nitrate tolerance, and nitrate-mediated oxidative stress and endothelial dysfunction. We also examine how hydralazine may prevent nitrate tolerance and related endothelial dysfunction.

  8. AUTOMATIC RETINAL VESSEL TORTUOSITY MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Nidhal Khdhair El Abbadi

    2013-01-01

    Full Text Available Retinal vascular vessels have the role to indicate the retinal diseases and for systematic diseases when there are any abnormalities in retinal vascular pattern. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e., how curved or kinked a blood vessel, either vein or artery, appears along its course. In this study we suggest a novel mask filter to track the blood vessel along its course and measuring the blood vessels tortuosity over the entire human retinal vessel network in fundus eye image, by using the arc to chord ratio. The suggested algorithm tested with straight and curve hand drawing lines and gives high accurate results.

  9. [Retinal vasculitis in lupic disease].

    Science.gov (United States)

    Brissaud, P; Laroche, L; Krulik, M; Prier, A M; Saraux, H; Canuel, C; Debray, J

    1985-01-01

    Three cases of retinal vasculitis in SLE-type diseases are reported. The first was central retinal vein occlusion occurring during clinical remission of SLE in a 55 year old black female. Prednisone maintenance therapy was unchanged and visual loss rapidly regressed with heparin therapy. The second case was a 33 year old black female in whom SLE was discovered following relapsing bilateral optic neuritis. A progressive visual improvement was obtained with high dose of prednisone (1 mg/kg/day). The third cas was a 17 year old white girl with retinal vasculitis. She had an unclassified connective tissue disease inaugurated by optic neuritis at the age of 10. High dose prednisone (1 mg/kg/day) was effective on the visual loss. Retinal vasculitis lesions in SLE and their therapy are reviewed.

  10. Outcomes of Patients Initially Treated with Intravitreal Bevacizumab for Central Retinal Vein Occlusion: Long-Term Follow-Up.

    Science.gov (United States)

    Bajric, Jasmina; Bakri, Sophie J

    2016-01-01

    To assess outcomes of visual acuity (VA) and central retinal thickness (RT) in patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO) who were initially treated with bevacizumab and followed for up to four years. In this observational case series, 51 patients with non-ischemic and ischemic CRVO who had initial treatment with bevacizumab were included. Main outcome measures were VA and RT at one year, with follow-up of up to four years. Mean VA improved from 20/214 at baseline to 20/107 at one year (p = 0.0009) and this improvement was maintained clinically at four years. RT decreased from 595 μm to 339 μm at one year (p = 0.0027) and this was maintained at four years. Patients who received bevacizumab as initial therapy for ME from CRVO maintained VA and RT improvement for up to four years.

  11. Honokiol inhibits pathological retinal neovascularization in oxygen-induced retinopathy mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Vavilala, Divya Teja [Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, MO (United States); O’Bryhim, Bliss E. [Department of Ophthalmology, University of Kansas Medical Center, Kansas City, KS (United States); Ponnaluri, V.K. Chaithanya [Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, MO (United States); White, R. Sid; Radel, Jeff [Department of Ophthalmology, University of Kansas Medical Center, Kansas City, KS (United States); Symons, R.C. Andrew [Department of Ophthalmology, University of Kansas Medical Center, Kansas City, KS (United States); Ophthalmology Department, Royal Melbourne Hospital, University of Melbourne, Victoria (Australia); Department of Surgery, Royal Melbourne Hospital, University of Melbourne, Victoria (Australia); Mukherji, Mridul, E-mail: mukherjim@umkc.edu [Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, MO (United States)

    2013-09-06

    Highlights: •Aberrant activation of HIF pathway is the underlying cause of ischemic neovascularization. •Honokiol has better therapeutic index as a HIF inhibitor than digoxin and doxorubicin. •Daily IP injection of honokiol in OIR mouse model reduced retinal neovascularization. •Honokiol also prevents vaso-obliteration, the characteristic feature of the OIR model. •Honokiol enhanced physiological revascularization of the retinal vascular plexuses. -- Abstract: Aberrant activation of the hypoxia inducible factor (HIF) pathway is the underlying cause of retinal neovascularization, one of the most common causes of blindness worldwide. The HIF pathway also plays critical roles during tumor angiogenesis and cancer stem cell transformation. We have recently shown that honokiol is a potent inhibitor of the HIF pathway in a number of cancer and retinal pigment epithelial cell lines. Here we evaluate the safety and efficacy of honokiol, digoxin, and doxorubicin, three recently identified HIF inhibitors from natural sources. Our studies show that honokiol has a better safety to efficacy profile as a HIF inhibitor than digoxin and doxorubicin. Further, we show for the first time that daily intraperitoneal injection of honokiol starting at postnatal day (P) 12 in an oxygen-induced retinopathy (OIR) mouse model significantly reduced retinal neovascularization at P17. Administration of honokiol also prevents the oxygen-induced central retinal vaso-obliteration, characteristic feature of the OIR model. Additionally, honokiol enhanced physiological revascularization of the retinal vascular plexuses. Since honokiol suppresses multiple pathways activated by HIF, in addition to the VEGF signaling, it may provide advantages over current treatments utilizing specific VEGF antagonists for ocular neovascular diseases and cancers.

  12. Protective Effects of Focal Ischemic Preconditioning and HSP70 Expression on Middle Cerebral Artery Occlusion in Rats

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jianhua; SUN Senggang; CHEN Xiaowu

    2006-01-01

    To systematically evaluate the importance of protein synthesis in ischemic preconditioning (PC)-induced ischemic tolerance (IT), temporary middle cerebral artery occlusion (MCAO)by Longa (20 min) was used for PC (ischemic precondioning). Twenty-four hours of reperfusion was allowed after PC and before permanent MCAO to establish ischemic tolerance (IT) to compare with non-PC (sham-operated) rats (n=5 for each group). Infarct size and neurological deficits were measured 24 h after PMCAO. Samples of brain were taken for the determination of HSP70 expression by Western blot analysis. The effects of the protein synthesis inhibitor cycloheximide administered just before PC or administered long after PC but just before PMCAO on IT were also determined (n=5 for each group). Our results showed that hemispheric infarct was significantly reduced (P<0.01) only if PC was performed after 24 h, and PC significantly (P<0.05) reduced neurological deficits (similar to reductions in infarct size). Cycloheximide eliminated ischemic PC-induced IT effects on both brain injury and neurological deficits if administered before PC but not if administered long after PC but before PMCAO. PC produced no brain injury but did increase HSP70 protein 24 h after PC. Cycloheximide eliminated that effect. The results suggest that PC is a powerful inducer of ischemic brain tolerance as reflected by the preservation of brain tissue and motor function. PC induces IT that is dependent on de novo protein synthesis.

  13. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit

    2006-01-01

    PURPOSE: To assess the relative influence of genetic and environmental effects on retinal vessel diameters and blood pressure in healthy adults, as well as the possible genetic connection between these two characteristics. METHODS: In 55 monozygotic and 50 dizygotic same-sex healthy twin pairs......%-80%) for CRAE, 83% (95% CI: 73%-89%) for CRVE, and 61% (95% CI: 44%-73%) for mean arterial blood pressure (MABP). Retinal artery diameter decreased with increasing age and increasing arterial blood pressure. Mean vessel diameters in the population were 165.8 +/- 14.9 microm for CRAE, 246.2 +/- 17.7 microm...... for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...

  14. RANIBIZUMAB FOR RETINAL VEIN OCCLUSION: Predictive Factors and Long-Term Outcomes in Real-Life Data.

    Science.gov (United States)

    Chatziralli, Irini; Theodossiadis, George; Chatzirallis, Alexandros; Parikakis, Efstratios; Mitropoulos, Panagiotis; Theodossiadis, Panagiotis

    2017-02-28

    The purpose of the study was to evaluate the long-term anatomical and functional outcomes in patients with retinal vein occlusion (RVO), either central retinal vein occlusion or branch retinal vein occlusion, treated with intravitreal ranibizumab and to determine the predictive factors of the final visual outcome. This retrospective study included 54 treatment-naive patients with macular edema due to RVO (25 with central retinal vein occlusion and 29 with branch retinal vein occlusion), who were treated with intravitreal ranibizumab (3 monthly injections and pro re nata). Predictive factors for visual outcome were assessed. In addition, the best-corrected visual acuity change and the percentage of patients with edema resolution were evaluated. The mean follow-up time was 47.4 ± 11.1 months. At the end of the follow-up, patients with central retinal vein occlusion gained +6.9 letters (∼1 Snellen line), whereas patients with branch retinal vein occlusion gained +15.1 letters (3 Snellen lines). Forty-eight percent of patients in central retinal vein occlusion group and 69.0% in branch retinal vein occlusion group presented resolution of macular edema. Negative predictive factors for the final visual outcome were found to be increasing age, increasing macular thickness, the presence of intraretinal fluid, the duration of RVO >3 months, the ischemic type of RVO, the cystoid type of edema, and the external limiting membrane and ellipsoid zone disruption. The various predictive factors that determine the visual outcome and possibly define the patients' prognosis after ranibizumab treatment in RVO have been studied. The long follow-up period showed that ranibizumab seems to be safe and effective in the treatment of the disease.

  15. Retinal prosthesis for the blind.

    Science.gov (United States)

    Margalit, Eyal; Maia, Mauricio; Weiland, James D; Greenberg, Robert J; Fujii, Gildo Y; Torres, Gustavo; Piyathaisere, Duke V; O'Hearn, Thomas M; Liu, Wentai; Lazzi, Gianluca; Dagnelie, Gislin; Scribner, Dean A; de Juan, Eugene; Humayun, Mark S

    2002-01-01

    Most of current concepts for a visual prosthesis are based on neuronal electrical stimulation at different locations along the visual pathways within the central nervous system. The different designs of visual prostheses are named according to their locations (i.e., cortical, optic nerve, subretinal, and epiretinal). Visual loss caused by outer retinal degeneration in diseases such as retinitis pigmentosa or age-related macular degeneration can be reversed by electrical stimulation of the retina or the optic nerve (retinal or optic nerve prostheses, respectively). On the other hand, visual loss caused by inner or whole thickness retinal diseases, eye loss, optic nerve diseases (tumors, ischemia, inflammatory processes etc.), or diseases of the central nervous system (not including diseases of the primary and secondary visual cortices) can be reversed by a cortical visual prosthesis. The intent of this article is to provide an overview of current and future concepts of retinal and optic nerve prostheses. This article will begin with general considerations that are related to all or most of visual prostheses and then concentrate on the retinal and optic nerve designs. The authors believe that the field has grown beyond the scope of a single article so cortical prostheses will be described only because of their direct effect on the concept and technical development of the other prostheses, and this will be done in a more general and historic perspective.

  16. Retinal implants: a systematic review.

    Science.gov (United States)

    Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B

    2014-07-01

    Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability.

  17. Filling in the retinal image

    Science.gov (United States)

    Larimer, James; Piantanida, Thomas

    1990-01-01

    The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

  18. The mechanics of retinal detachment

    Science.gov (United States)

    Chou, Tom; Siegel, Michael

    2013-03-01

    We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular, and retinal pigment epithelium (RPE) pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed tissue within which e.g., the hydraulic conductivities of the retina or choroid increase, the RPE pumps fail, or the adhesion properties change. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing. This work supported by the Army Research Office through grant 58386MA

  19. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Broe, Rebecca; Kessel, Line

    2017-01-01

    Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension. Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs, the reti......Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension. Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs......, the retinal vascular fractal dimension was measured using the box-counting method and compared within monozygotic and dizygotic twin pairs using Pearson correlation coefficients. Falconer's formula and quantitative genetic models were used to determine the genetic component of variation. Results: The mean......, the branching pattern of the retinal vessels demonstrated a higher structural similarity in monozygotic than in dizygotic twin pairs. The retinal vascular fractal dimension was mainly determined by genetic factors, which accounted for 54% of the variation. The genetically predetermination of the retinal...

  20. Om tolerance

    DEFF Research Database (Denmark)

    Huggler, Jørgen

    2007-01-01

    Begrebet tolerance og dets betydninger diskuteres med henblik på en tydeliggørelse af begrebets forbindelse med stat, religion, ytringsfrihed, skeptisk erkendelsesteori, antropologi og pædagogik.......Begrebet tolerance og dets betydninger diskuteres med henblik på en tydeliggørelse af begrebets forbindelse med stat, religion, ytringsfrihed, skeptisk erkendelsesteori, antropologi og pædagogik....

  1. Om tolerance

    DEFF Research Database (Denmark)

    Huggler, Jørgen

    2007-01-01

    Begrebet tolerance og dets betydninger diskuteres med henblik på en tydeliggørelse af begrebets forbindelse med stat, religion, ytringsfrihed, skeptisk erkendelsesteori, antropologi og pædagogik.......Begrebet tolerance og dets betydninger diskuteres med henblik på en tydeliggørelse af begrebets forbindelse med stat, religion, ytringsfrihed, skeptisk erkendelsesteori, antropologi og pædagogik....

  2. Age-related reduction of cerebral ischemic preconditioning: myth or reality?

    Directory of Open Access Journals (Sweden)

    Della-Morte D

    2013-08-01

    Full Text Available David Della-Morte,1,2 Francesco Cacciatore,3 Elisa Salsano,4 Gilda Pirozzi,4 Maria Teresa Del Genio,4 Iole D'Antonio,4 Gaetano Gargiulo,5 Raffaele Palmirotta,2 Fiorella Guadagni,2 Tatjana Rundek,1 Pasquale Abete41Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, USA; 2Department of Advanced Biotechnologies and Bioimaging, IRCCS San Raffaele, Rome, Italy; 3Istituto Scientifico di Campoli/Telese, Fondazione Salvatore Maugeri, IRCCS, Benevento, Italy; 4Dipartimento di Scienze Mediche Traslazionali, Università di Napoli "Federico II," Naples, Italy; 5AON, SS Antonio e Biagio e Cesare Arrigo, Struttura Complessa di Geriatria, Alessandria, ItalyAbstract: Stroke is one of the leading causes of death in industrialized countries for people older than 65 years of age. The reasons are still unclear. A reduction of endogenous mechanisms against ischemic insults has been proposed to explain this phenomenon. The “cerebral” ischemic preconditioning mechanism is characterized by a brief episode of ischemia that renders the brain more resistant against subsequent longer ischemic events. This ischemic tolerance has been shown in numerous experimental models of cerebral ischemia. This protective mechanism seems to be reduced with aging both in experimental and clinical studies. Alterations of mediators released and/or intracellular pathways may be responsible for age-related ischemic preconditioning reduction. Agents able to mimic the “cerebral” preconditioning effect may represent a new powerful tool for the treatment of acute ischemic stroke in the elderly. In this article, animal and human cerebral ischemic preconditioning, its age-related difference, and its potential therapeutical applications are discussed.Keywords: ischemic preconditioning, stroke, transient cerebral ischemic attack, mortality, elderly

  3. Effects of hypnotic analgesia and hypnotizability on experimental ischemic pain.

    Science.gov (United States)

    DeBenedittis, G; Panerai, A A; Villamira, M A

    1989-01-01

    Mechanisms of hypnotic analgesia are still poorly understood and conflicting data are reported regarding the underlying neurochemical correlates. The present study was designed to investigate the effects of hypnotically induced analgesia and hypnotizability on experimental ischemic pain, taking into account pain and distress tolerance as well as the neurochemical correlates. 11 high hypnotizable Ss and 10 low hypnotizable Ss, as determined by scores on the Stanford Hypnotic Susceptibility Scale, Form C (Weitzenhoffer & E. R. Hilgard, 1962), were administered an ischemic pain test in both waking and hypnotic conditions. The following variables were measured: (a) pain and distress tolerance, (b) anxiety levels, and (c) plasma concentrations of beta-endorphin and adrenocorticotropic hormone (ACTH). Results confirmed significant increases of pain and distress tolerance during hypnosis as compared to the waking state, with positive correlations between pain and distress relief and hypnotizability. Moreover, a hypnotically induced dissociation between the sensory-discriminative and the affective-motivational dimensions of pain experience was found, but only in high hypnotizable Ss. Hypnotic analgesia was unrelated to anxiety reduction and was not mediated either by endorphins or by ACTH.

  4. Determination of retinal surface area.

    Science.gov (United States)

    Nagra, Manbir; Gilmartin, Bernard; Thai, Ngoc Jade; Logan, Nicola S

    2017-09-01

    Previous attempts at determining retinal surface area and surface area of the whole eye have been based upon mathematical calculations derived from retinal photographs, schematic eyes and retinal biopsies of donor eyes. 3-dimensional (3-D) ocular magnetic resonance imaging (MRI) allows a more direct measurement, it can be used to image the eye in vivo, and there is no risk of tissue shrinkage. The primary purpose of this study is to compare, using T2-weighted 3D MRI, retinal surface areas for superior-temporal (ST), inferior-temporal (IT), superior-nasal (SN) and inferior-nasal (IN) retinal quadrants. An ancillary aim is to examine whether inter-quadrant variations in area are concordant with reported inter-quadrant patterns of susceptibility to retinal breaks associated with posterior vitreous detachment (PVD). Seventy-three adult participants presenting without retinal pathology (mean age 26.25 ± 6.06 years) were scanned using a Siemens 3-Tesla MRI scanner to provide T2-weighted MR images that demarcate fluid-filled internal structures for the whole eye and provide high-contrast delineation of the vitreous-retina interface. Integrated MRI software generated total internal ocular surface area (TSA). The second nodal point was used to demarcate the origin of the peripheral retina in order to calculate total retinal surface area (RSA) and quadrant retinal surface areas (QRSA) for ST, IT, SN, and IN quadrants. Mean spherical error (MSE) was -2.50 ± 4.03D and mean axial length (AL) 24.51 ± 1.57 mm. Mean TSA and RSA for the RE were 2058 ± 189 and 1363 ± 160 mm(2) , respectively. Repeated measures anova for QRSA data indicated a significant difference within-quadrants (P area/mm increase in AL. Although the differences between QRSAs are relatively small, there was evidence of concordance with reported inter-quadrant patterns of susceptibility to retinal breaks associated with PVD. The data allow AL to be converted to QRSAs, which will assist further

  5. Retinal vascular changes in hypertensive patients in Ibadan, Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Oluleye ST

    2016-08-01

    Full Text Available Sunday Tunji Oluleye,1 Bolutife Ayokunu Olusanya,1 Abiodun Moshood Adeoye2 1Department of Ophthalmology, 2Department of Medicine, College of Medicine, University of Ibadan and University College Hospital, Ibadan, Nigeria Background: Earlier studies in Nigeria reported the rarity of retinal vascular changes in hypertensives. The aim of this study was to describe the various retinal vascular changes in the hypertensive patients of Nigeria.Patients and methods: Nine hundred and three hypertensive patients were studied. This study was approved by the ethical and research committee of the University of Ibadan and University College Hospital, Ibadan, Nigeria. Blood pressure and anthropometric measurements were measured. Cardiac echocardiography was performed on 156 patients. All patients had dilated fundoscopy and fundus photography using the Kowa portable fundus camera and an Apple iPhone with 20 D lens. Statistical analysis was done with Statistical Packages for the Social Sciences (Version 21.Results: The mean age of patients was 57 years with a male:female ratio of 1. No retinopathy was found in 556 (61.5% patients. In all, 175 (19.4% patients had features of hypertensive retinopathy. Retinal vascular occlusion was a significant finding in 121 patients (13.4%, of which branch retinal vein occlusion, 43 (4.7%, and central retinal vein occlusion, 30 (3.3%, were the most prominent ones in cases. Hemicentral retinal vein occlusion, 26 (2.9%, and central retinal artery occlusion, 17 (1.9%, were significant presentations. Other findings included nonarteritic anterior ischemic optic neuropathy in five (0.6% patients, hypertensive choroidopathy in seven (0.8% patients, and hemorrhagic choroidal detachment in five (0.6% patients. Left ventricular (LV geometry was abnormal in 85 (55.5% patients. Concentric remodeling, eccentric hypertrophy, and concentric hypertrophy were observed in 43 (27.6%, 26 (17.2%, and 15 (9.7% patients, respectively. LV

  6. A case of anterior ischemic optic neuropathy associated with uveitis

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    Sugahara M

    2013-05-01

    Full Text Available Michitaka Sugahara, Takayuki Fujimoto, Kyoko Shidara, Kenji Inoue, Masato Wakakura Inouye Eye Hospital, Tokyo, Japan Introduction: Here, we describe a patient who presented with anterior ischemic optic neuropathy (AION and subsequently developed uveitis. Case: A 69-year-old man was referred to our hospital and initially presented with best-corrected visual acuities (BCVA of 20/40 (right eye and 20/1000 (left eye and relative afferent pupillary defect. Slit-lamp examination revealed no signs of ocular inflammation in either eye. Fundus examination revealed left-eye swelling and a pale superior optic disc, and Goldmann perimetry revealed left-eye inferior hemianopia. The patient was diagnosed with nonarteritic AION in the left eye. One week later, the patient returned to the hospital because of vision loss. The BCVA of the left eye was so poor that the patient could only count fingers. Slit-lamp examination revealed 1+ cells in the anterior chamber and the anterior vitreous in both eyes. Funduscopic examination revealed vasculitis and exudates in both eyes. The patient was diagnosed with bilateral panuveitis, and treatment with topical betamethasone was started. No other physical findings resulting from other autoimmune or infectious diseases were found. No additional treatments were administered, and optic disc edema in the left eye improved, and the retinal exudates disappeared in 3 months. The patient's BCVA improved after cataract surgery was performed. Conclusion: Panuveitis most likely manifests after the development of AION. Keywords: anterior ischemic optic neuropathy, uveitis

  7. Integrity of Cerebellar Fastigial Nucleus Intrinsic Neurons Is Critical for the Global Ischemic Preconditioning

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    Eugene V. Golanov

    2017-09-01

    Full Text Available Excitation of intrinsic neurons of cerebellar fastigial nucleus (FN renders brain tolerant to local and global ischemia. This effect reaches a maximum 72 h after the stimulation and lasts over 10 days. Comparable neuroprotection is observed following sublethal global brain ischemia, a phenomenon known as preconditioning. We hypothesized that FN may participate in the mechanisms of ischemic preconditioning as a part of the intrinsic neuroprotective mechanism. To explore potential significance of FN neurons in brain ischemic tolerance we lesioned intrinsic FN neurons with excitotoxin ibotenic acid five days before exposure to 20 min four-vessel occlusion (4-VO global ischemia while analyzing neuronal damage in Cornu Ammoni area 1 (CA1 hippocampal area one week later. In FN-lesioned animals, loss of CA1 cells was higher by 22% compared to control (phosphate buffered saline (PBS-injected animals. Moreover, lesion of FN neurons increased morbidity following global ischemia by 50%. Ablation of FN neurons also reversed salvaging effects of five-minute ischemic preconditioning on CA1 neurons and morbidity, while ablation of cerebellar dentate nucleus neurons did not change effect of ischemic preconditioning. We conclude that FN is an important part of intrinsic neuroprotective system, which participates in ischemic preconditioning and may participate in naturally occurring neuroprotection, such as “diving response”.

  8. Pathogenic mechanisms following ischemic stroke.

    Science.gov (United States)

    Khoshnam, Seyed Esmaeil; Winlow, William; Farzaneh, Maryam; Farbood, Yaghoob; Moghaddam, Hadi Fathi

    2017-07-01

    Stroke is the second most common cause of death and the leading cause of disability worldwide. Brain injury following stroke results from a complex series of pathophysiological events including excitotoxicity, oxidative and nitrative stress, inflammation, and apoptosis. Moreover, there is a mechanistic link between brain ischemia, innate and adaptive immune cells, intracranial atherosclerosis, and also the gut microbiota in modifying the cerebral responses to ischemic insult. There are very few treatments for stroke injuries, partly owing to an incomplete understanding of the diverse cellular and molecular changes that occur following ischemic stroke and that are responsible for neuronal death. Experimental discoveries have begun to define the cellular and molecular mechanisms involved in stroke injury, leading to the development of numerous agents that target various injury pathways. In the present article, we review the underlying pathophysiology of ischemic stroke and reveal the intertwined pathways that are promising therapeutic targets.

  9. Retrograde degeneration of retinal ganglion cells in homonymous hemianopsia

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    Herro AM

    2015-06-01

    Full Text Available Angela M Herro, Byron L Lam Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA Background: The aim of this study was to demonstrate the relationship between topographic reduction in macular ganglion cell complex (GCC thickness as detected with spectral-domain optical coherence tomography and visual field defects caused by ischemic occipital cortical injury.Methods: This study was a retrospective review of all patients who presented to our eye institution between January 2012 and July 2014 with visual field defects secondary to ischemic cortical injury. The visual field defect pattern and mean deviation were analyzed. Retinal nerve fiber layer (RNFL and macular GCC were both assessed with spectral-domain optical coherence tomography. Patients with any ocular pathology that could affect these measurements were excluded. The topographic relationship of visual field defect to reduction in GCC was specifically analyzed. Results: Nine patients met the inclusion criteria. Their average age was 65 (57–73 years; eight were men and six had right hemianopsias. The laterality of the visual field defect was used to assign an affected and unaffected side of analysis for RNFL and GCC layer thickness. A right hemianopsia meant that the nasal fibers of the right eye and temporal fibers of the left eye were assigned as the “affected side”, and the temporal fibers of the right eye and nasal fibers of the left eye were assigned as “unaffected”. There was no statistically significant difference between affected and unaffected RNFL. However, there was a significant difference in GCC layer reduction between the affected and unaffected sides (P=0.029.Conclusion: There is evidence of retrograde trans-synaptic retinal ganglion cell loss in patients with homonymous hemianopsias from cortical visual impairment. This relationship is reflected in thinning of the GCC and maintains the topographic

  10. RECAST (Remote Ischemic Conditioning After Stroke Trial): A Pilot Randomized Placebo Controlled Phase II Trial in Acute Ischemic Stroke.

    Science.gov (United States)

    England, Timothy J; Hedstrom, Amanda; O'Sullivan, Saoirse; Donnelly, Richard; Barrett, David A; Sarmad, Sarir; Sprigg, Nikola; Bath, Philip M

    2017-05-01

    Repeated episodes of limb ischemia and reperfusion (remote ischemic conditioning [RIC]) may improve outcome after acute stroke. We performed a pilot blinded placebo-controlled trial in patients with acute ischemic stroke, randomized 1:1 to receive 4 cycles of RIC within 24 hours of ictus. The primary outcome was tolerability and feasibility. Secondary outcomes included safety, clinical efficacy (day 90), putative biomarkers (pre- and post-intervention, day 4), and exploratory hemodynamic measures. Twenty-six patients (13 RIC and 13 sham) were recruited 15.8 hours (SD 6.2) post-onset, age 76.2 years (SD 10.5), blood pressure 159/83 mm Hg (SD 25/11), and National Institutes of Health Stroke Scale (NIHSS) score 5 (interquartile range, 3.75-9.25). RIC was well tolerated with 49 out of 52 cycles completed in full. Three patients experienced vascular events in the sham group: 2 ischemic strokes and 2 myocardial infarcts versus none in the RIC group (P=0.076, log-rank test). Compared with sham, there was a significant decrease in day 90 NIHSS score in the RIC group, median NIHSS score 1 (interquartile range, 0.5-5) versus 3 (interquartile range, 2-9.5; P=0.04); RIC augmented plasma HSP27 (heat shock protein 27; Pacute stroke is well tolerated and appears safe and feasible. RIC may improve neurological outcome, and protective mechanisms may be mediated through HSP27. A larger trial is warranted. URL: http://www.isrctn.com. Unique identifier: ISRCTN86672015. © 2017 American Heart Association, Inc.

  11. Salvia miltiorrhiza and ischemic diseases

    Institute of Scientific and Technical Information of China (English)

    Xin-Yan JI; Benny K-H TAN; Yi-Zhun ZHU

    2000-01-01

    The demonstration of beneficial effects of salvia miltiorrhiza (DanShen) on ischemic diseases has revolutionized the management of angina pectoris, myocardial infarction (MI) or stroke in Chinese society. Experimental studies have shown that DanShen dilated coronary arteries, increased coronary blood flow, and scavenged free radicals in ischemic diseases, so that it reduced the cellular damage from ischemia and improved heart functions. Clinical trials also indicated that DanShen was an effective medicine for angina pectoris, MI, and stroke. This review will focus on DanShen's effects in angina pectoris, MI and stroke.

  12. [Pregnancy and acute ischemic stroke].

    Science.gov (United States)

    Bereczki, Dániel

    2016-05-15

    Pregnancy-related ischemic strokes play an important role in both maternal and fetal morbidity and mortality. Changes in hemostaseology and hemodynamics as well as risk factors related to or independent from pregnancy contribute to the increased stroke-risk during gestation and the puerperium. Potential teratogenic effects make diagnostics, acute therapy and prevention challenging. Because randomized, controlled trials are not available, a multicenter registry of patients with gestational stroke would be desirable. Until definite guidelines emerge, management of acute ischemic stroke during pregnancy remains individual, involving experts and weighing the risks and benefits.

  13. Central retinal vessel blood flow after surgical treatment for central retinal vein occlusion.

    NARCIS (Netherlands)

    Crama, N.; Gualino, V.; Restori, M.; Charteris, D.G.

    2010-01-01

    PURPOSE: The purpose of this study was to determine the effect of radial optic neurotomy and retinal endovascular surgery on retinal blood flow velocity in patients with central retinal vein occlusion. METHODS: A prospective interventional case series. RESULTS: Six patients with a central retinal

  14. Retinal vascular and structural dynamics during acute hyperglycaemia

    DEFF Research Database (Denmark)

    Klefter, Oliver N; Lauritsen, Tina Vilsbøll; Knop, Filip K

    2015-01-01

    oximetry, macular perfusion velocities and optical coherence tomographic measurement of subfoveal choroidal thickness every 30 min during a 3-hr 75 g oral glucose tolerance test (OGTT). Patients paused antidiabetic therapy for 1 week prior to the OGTT. RESULTS: Plasma glucose (PG) and fluctuations in PG......, narrowed retinal veins and increased arteriovenous diameter ratios. No effect of age, gender or diabetes status was observed. Choroidal thickness was transiently reduced in controls and unchanged in patients with diabetes (p = 0.021). Macular perfusion velocities increased after 150 min in patients...

  15. [Congenital retinal folds in different clinical cases].

    Science.gov (United States)

    Munteanu, M

    2005-01-01

    We present 12 clinical cases of congenital retinal folds with different etiologies: posterior primitive vitreous persistency and hyperplasia (7 cases),retinocytoma (1 case). retinopathy of prematurity (1 case), astrocytoma of the retina (1 case), retinal vasculitis (1 case), Goldmann-Favre syndrome (1 case). Etiopathogenic and nosological aspects are discussed; the congenital retinal folds are interpreted as a symptom in a context of a congenital or acquired vitreo-retinal pathology.

  16. Distribution, markers and functions of retinal microglia

    NARCIS (Netherlands)

    Chen, L.; Yang, P.Z.; Kijlstra, A.

    2002-01-01

    Retinal microglia originate from hemopoietic cells and invade the retina from the retinal margin and the optic disc, most likely via the blood vessels of the ciliary body and iris, and the retinal vasculature, respectively. The microglial precursors that appear in the retina prior to vascularization

  17. Choroidal melanoma clinically simulating a retinal angioma

    Energy Technology Data Exchange (ETDEWEB)

    Shields, J.A.; Joffe, L.; Guibor, P.

    1978-01-01

    An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

  18. Choroidal melanoma clinically simulating a retinal angioma.

    Science.gov (United States)

    Shields, J A; Joffe, L; Guibor, P

    1978-01-01

    An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

  19. Noninvasive Retinal Markers in Diabetic Retinopathy

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Torp, Thomas Lee; Lundberg, Kristian

    2017-01-01

    The retinal vascular system is the only part of the human body available for direct, in vivo inspection. Noninvasive retinal markers are important to identity patients in risk of sight-threatening diabetic retinopathy. Studies have correlated structural features like retinal vascular caliber and ...

  20. Exploring the retinal connectome

    Science.gov (United States)

    Anderson, James R.; Jones, Bryan W.; Watt, Carl B.; Shaw, Margaret V.; Yang, Jia-Hui; DeMill, David; Lauritzen, James S.; Lin, Yanhua; Rapp, Kevin D.; Mastronarde, David; Koshevoy, Pavel; Grimm, Bradley; Tasdizen, Tolga; Whitaker, Ross

    2011-01-01

    Purpose A connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings. Methods We acquired and assembled a 16.5 terabyte connectome data set RC1 for the rabbit retina at ≈2 nm resolution using automated transmission electron microscope imaging, automated mosaicking, and automated volume registration. RC1 represents a column of tissue 0.25 mm in diameter, spanning the inner nuclear, inner plexiform, and ganglion cell layers. To enhance ultrastructural tracing, we included molecular markers for 4-aminobutyrate (GABA), glutamate, glycine, taurine, glutamine, and the in vivo activity marker, 1-amino-4-guanidobutane. This enabled us to distinguish GABAergic and glycinergic amacrine cells; to identify ON bipolar cells coupled to glycinergic cells; and to discriminate different kinds of bipolar, amacrine, and ganglion cells based on their molecular signatures and activity. The data set was explored and annotated with Viking, our multiuser navigation tool. Annotations were exported to additional applications to render cells, visualize network graphs, and query the database. Results Exploration of RC1 showed that the 2 nm resolution readily recapitulated well known connections and revealed several new features of retinal organization: (1) The well known AII amacrine cell pathway displayed more complexity than previously reported, with no less than 17 distinct signaling modes, including ribbon synapse inputs from OFF bipolar cells, wide-field ON cone bipolar cells and rod bipolar cells, and extensive input from cone-pathway amacrine cells. (2) The axons of most cone bipolar cells formed a distinct signal integration compartment, with ON cone bipolar cell axonal synapses targeting diverse cell types. Both ON and OFF bipolar cells receive

  1. Advances in understanding ischemic acute kidney injury

    Directory of Open Access Journals (Sweden)

    Himmelfarb Jonathan

    2011-02-01

    Full Text Available Abstract Acute kidney injury (AKI is independently associated with increased morbidity and mortality. Ischemia is the leading cause of AKI, and short of supportive measures, no currently available therapy can effectively treat or prevent ischemic AKI. This paper discusses recent developments in the understanding of ischemic AKI pathophysiology, the emerging relationship between ischemic AKI and development of progressive chronic kidney disease, and promising novel therapies currently under investigation. On the basis of recent breakthroughs in understanding the pathophysiology of ischemic AKI, therapies that can treat or even prevent ischemic AKI may become a reality in the near future.

  2. Sex Hormones and Ischemic Stroke

    DEFF Research Database (Denmark)

    Holmegard, Haya N; Nordestgaard, Børge G; Jensen, Gorm B

    2016-01-01

    CONTEXT AND OBJECTIVE: Whether endogenous sex hormones are associated with ischemic stroke (IS) is unclear. We tested the hypothesis that extreme concentrations of endogenous sex hormones are associated with risk of IS in the general population. DESIGN, SETTING, AND PARTICIPANTS: Adult men (n...

  3. Olanzapine-induced ischemic colitis

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    Esteban Sáez-González

    Full Text Available Background: Ischemic colitis (IC is an uncommon adverse event associated with antipsychotic agents, more commonly found with phenothiazine drugs and atypical neuroleptics such as clozapine. The risk of developing ischemic colitis increases when anticholinergic drugs are associated. Case report: We report the case of a 38-year-old woman with a history of schizoaffective disorder who had been on chronic quetiapine for 3 years, and presented to the ER because of diarrhea for 5 days. Four months previously, olanzapine had been added to her psychiatric drug regimen. Physical examination revealed abdominal distension with abdominal tympanic sounds and tenderness. Emergency laboratory tests were notable for increased acute phase reagents. Tomography revealed a concentric thickening of the colonic wall in the transverse, descending and sigmoid segments, with no signs of intestinal perforation. Colonoscopy demonstrated severe mucosal involvement from the sigmoid to the hepatic flexure, with ulcerations and fibrinoid exudate. Biopsies confirmed the diagnosis of ischemic colitis. The only relevant finding in her history was the newly added drug to her baseline regimen. An adverse effect was suspected because of its anticholinergic action at the intestinal level, and the drug was withdrawn. After 6 months of follow-up clinical, laboratory and endoscopic recovery was achieved. Discussion: Antipsychotic medication should be considered as a potential cause of ischemic colitis, particularly atypical antipsychotics such as clozapine and olanzapine; despite being uncommon, this adverse event may result in high morbidity and mortality.

  4. Neuroprotection in acute ischemic stroke

    NARCIS (Netherlands)

    De Keyser, Jacques; Uyttenboogaart, Maarten; Koch, Marcus W; Elting, Jan Willem; Sulter, Geert; Vroomen, Patrick C; Luijckx, Gert Jan

    2005-01-01

    Neuroprotection of patients with acute ischemic stroke should start at the scene and continue in the ambulance with the assessment and treatment of the airway, breathing, circulation, body temperature, and blood glucose. The key goal in eligible patients should be fast vessel recanalization with int

  5. Ischemic glans penis after circumcision

    Institute of Scientific and Technical Information of China (English)

    Yuan-ShengTzeng; Shou-HungTang; EnMeng; Teng-FuLin; Guang-HuanSun

    2004-01-01

    A 33-year-old male receiving dorsal penile nerve block (DPNB) for circumcision exhibited a postoperative ischemic change over the glans penis. The event occurred nearly 24 hours after the procedure. The patient was treated with intravenous pentoxifyllin and hyperbaric oxygenation. Total reverse of the ischemia was observed. The complications associated with circumcision and DPNB were reviewed and discussed.

  6. Evaluation of the Retinal Vasculature in Hypertension and Chronic Kidney Disease in an Elderly Population of Irish Nuns.

    Directory of Open Access Journals (Sweden)

    Amy McGowan

    Full Text Available Chronic kidney disease (CKD and hypertension are global public health problems associated with considerable morbidity, premature mortality and attendant healthcare costs. Previous studies have highlighted that non-invasive examination of the retinal microcirculation can detect microvascular pathology that is associated with systemic disorders of the circulatory system such as hypertension. We examined the associations between retinal vessel caliber (RVC and fractal dimension (DF, with both hypertension and CKD in elderly Irish nuns.Data from 1233 participants in the cross-sectional observational Irish Nun Eye Study (INES were assessed from digital photographs with a standardized protocol using computer-assisted software. Multivariate regression analyses were used to assess associations with hypertension and CKD, with adjustment for age, body mass index (BMI, refraction, fellow eye RVC, smoking, alcohol consumption, ischemic heart disease (IHD, cerebrovascular accident (CVA, diabetes and medication use.In total, 1122 (91% participants (mean age: 76.3 [range: 56-100] years had gradable retinal images of sufficient quality for blood vessel assessment. Hypertension was significantly associated with a narrower central retinal arteriolar equivalent (CRAE in a fully adjusted analysis (P = 0.002; effect size = -2.16 μm; 95% confidence intervals [CI]: -3.51, -0.81 μm. No significant associations between other retinal vascular parameters and hypertension or between any retinal vascular parameters and CKD were found.Individuals with hypertension have significantly narrower retinal arterioles which may afford an earlier opportunity for tailored prevention and treatment options to optimize the structure and function of the microvasculature, providing additional clinical utility. No significant associations between retinal vascular parameters and CKD were detected.

  7. Hypoxic-Ischemic Neonatal Encephalopathy: Animal Experiments for Neuroprotective Therapies

    Directory of Open Access Journals (Sweden)

    Hiroshi Sameshima

    2013-01-01

    Full Text Available Hypoxic-ischemic neonatal encephalopathy and ensuing brain damage is still an important problem in modern perinatal medicine. In this paper, we would like to share some of the results of our recent studies on neuroprotective therapies in animal experiments, as well as some literature reviews. From the basic animal studies, we have now obtained some possible candidates for therapeutic measures against hypoxic-ischemic neonatal encephalopathy. For example, they are hypothermia, rehabilitation, free radical scavenger, neurotrophic factors and growth factors, steroid, calcium channel blocker, vagal stimulation, some anti apoptotic agents, pre- and post conditioning, antioxidants, cell therapy with stem cells, modulators of K(+-ATP channels, and so on. Whether combination of these therapies may be more beneficial than any single therapy needs to be clarified. Hypoxia-ischemia is a complicated condition, in which the cause, severity, and time-course are different in each case. Likewise, each fetus has its own inherent potentials such as adaptation, preconditioning-tolerance, and intolerance. Therefore, further extensive studies are required to establish an individualized strategy for neuroprotection against perinatal hypoxic-ischemic insult.

  8. Therapeutic Potential of Non-Psychotropic Cannabidiol in Ischemic Stroke.

    Science.gov (United States)

    Hayakawa, Kazuhide; Mishima, Kenichi; Fujiwara, Michihiro

    2010-07-08

    Cannabis contains the psychoactive component delta⁸-tetrahydrocannabinol (delta⁸-THC), and the non-psychoactive components cannabidiol (CBD), cannabinol, and cannabigerol. It is well-known that delta⁸-THC and other cannabinoid CB₁ receptor agonists are neuroprotective during global and focal ischemic injury. Additionally, delta⁸-THC also mediates psychological effects through the activation of the CB₁ receptor in the central nervous system. In addition to the CB₁ receptor agonists, cannabis also contains therapeutically active components which are CB₁ receptor independent. Of the CB₁ receptor-independent cannabis, the most important is CBD. In the past five years, an increasing number of publications have focused on the discovery of the anti-inflammatory, anti-oxidant, and neuroprotective effects of CBD. In particular, CBD exerts positive pharmacological effects in ischemic stroke and other chronic diseases, including Parkinson's disease, Alzheimer's disease, and rheumatoid arthritis. The cerebroprotective action of CBD is CB₁ receptor-independent, long-lasting, and has potent anti-oxidant activity. Importantly, CBD use does not lead to tolerance. In this review, we will discuss the therapeutic possibility of CBD as a cerebroprotective agent, highlighting recent pharmacological advances, novel mechanisms, and therapeutic time window of CBD in ischemic stroke.

  9. Therapeutic Potential of Non-Psychotropic Cannabidiol in Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Michihiro Fujiwara

    2010-07-01

    Full Text Available Cannabis contains the psychoactive component delta9-tetrahydrocannabinol (delta9-THC, and the non-psychoactive components cannabidiol (CBD, cannabinol, and cannabigerol. It is well-known that delta9-THC and other cannabinoid CB1 receptor agonists are neuroprotective during global and focal ischemic injury. Additionally, delta9-THC also mediates psychological effects through the activation of the CB1 receptor in the central nervous system. In addition to the CB1 receptor agonists, cannabis also contains therapeutically active components which are CB1 receptor independent. Of the CB1 receptor-independent cannabis, the most important is CBD. In the past five years, an increasing number of publications have focused on the discovery of the anti-inflammatory, anti-oxidant, and neuroprotective effects of CBD. In particular, CBD exerts positive pharmacological effects in ischemic stroke and other chronic diseases, including Parkinson’s disease, Alzheimer’s disease, and rheumatoid arthritis. The cerebroprotective action of CBD is CB1 receptor-independent, long-lasting, and has potent anti-oxidant activity. Importantly, CBD use does not lead to tolerance. In this review, we will discuss the therapeutic possibility of CBD as a cerebroprotective agent, highlighting recent pharmacological advances, novel mechanisms, and therapeutic time window of CBD in ischemic stroke.

  10. Towards Tolerance

    NARCIS (Netherlands)

    Lisette Kuyper; Jurjen Iedema; Saskia Keuzenkamp

    2013-01-01

    Across Europe, public attitudes towards lesbian, gay and bisexual (LGB) individuals range from broad tolerance to widespread rejection. Attitudes towards homosexuality are more than mere individual opinions, but form part of the social and political structures which foster or hinder the equality

  11. Repressive Tolerance

    DEFF Research Database (Denmark)

    Pedersen, Morten Jarlbæk

    2016-01-01

    to an administrative culture of repressive tolerance of organised interests: authorities listen but only reacts in a very limited sense. This bears in it the risk of jeopardising the knowledge transfer from societal actors to administrative ditto thus harming the consultation institutions’ potential for strengthening...

  12. Retinal Optical Coherence Tomography Imaging

    Science.gov (United States)

    Drexler, Wolfgang; Fujimoto, James G.

    The eye is essentially transparent, transmitting light with only minimal optical attenuation and scattering providing easy optical access to the anterior segment as well as the retina. For this reason, ophthalmic and especially retinal imaging has been not only the first but also most successful clinical application for optical coherence tomography (OCT). This chapter focuses on the development of OCT technology for retinal imaging. OCT has significantly improved the potential for early diagnosis, understanding of retinal disease pathogenesis, as well as monitoring disease progression and response to therapy. Development of ultrabroad bandwidth light sources and high-speed detection techniques has enabled significant improvements in ophthalmic OCT imaging performance, demonstrating the potential of three-dimensional, ultrahigh-resolution OCT (UHR OCT) to perform noninvasive optical biopsy of the living human retina, i.e., the in vivo visualization of microstructural, intraretinal morphology in situ approaching the resolution of conventional histopathology. Significant improvements in axial resolution and speed not only enable three-dimensional rendering of retinal volumes but also high-definition, two-dimensional tomograms, topographic thickness maps of all major intraretinal layers, as well as volumetric quantification of pathologic intraretinal changes. These advances in OCT technology have also been successfully applied in several animal models of retinal pathologies. The development of light sources emitting at alternative wavelengths, e.g., around #1,060 nm, not only enabled three-dimensional OCT imaging with enhanced choroidal visualization but also improved OCT performance in cataract patients due to reduced scattering losses in this wavelength region. Adaptive optics using deformable mirror technology, with unique high stroke to correct higher-order ocular aberrations, with specially designed optics to compensate chromatic aberration of the human eye, in

  13. [Study on preferred retinal locus].

    Science.gov (United States)

    Dai, Bing-Fa; Hu, Jian-Min; Xu, Duan-Lian

    2012-03-01

    Preferred retinal locus (PRL) is always found in the age-related macular degeneration and other macular damages in patients with low vision, and it is a very important anatomic position in patients with central vision impairment to achieve the rehabilitation. In recent years, the training of preferred retinal locus (PRL) has become a research hotspot of low vision rehabilitation, it can clearly improve functional vision and quality of life. The authors reviewed relevant literatures, and summarized the definition, position, characteristics, training and clinical implications of the PRL.

  14. Angiographic results of retinal-retinal anastomosis and retinal-choroidal anastomosis after treatments in eyes with retinal angiomatous proliferation

    Directory of Open Access Journals (Sweden)

    Saito M

    2012-08-01

    Full Text Available Masaaki Saito,1 Tomohiro Iida,1,2 Mariko Kano,1 Kanako Itagaki11Department of Ophthalmology, Fukushima Medical University School of Medicine, Fukushima, 2Department of Ophthalmology, Tokyo Women's Medical University School of Medicine, Tokyo, JapanBackground: The purpose of this study was to evaluate the angiographic results of retinal-retinal anastomosis (RRA and retinal-choroidal anastomosis (RCA for eyes with retinal angiomatous proliferation (RAP after treatment with intravitreal bevacizumab injections as monotherapy or intravitreal bevacizumab combined with photodynamic therapy.Methods: In this interventional, consecutive case series, we retrospectively reviewed five naïve eyes from four patients (mean age 80 years treated with three consecutive monthly intravitreal bevacizumab (1.25 mg/0.05 mL injections as initial treatment, and followed up for at least 3 months. In cases with over 3 months of follow-up and having recurrence of RAP or leakage by fluorescein angiography, retreatment was performed with a single intravitreal bevacizumab injection and photodynamic therapy.Results: Indocyanine green angiography showed RRA in three eyes with subretinal neovascularization and RCA in two eyes with choroidal neovascularization at baseline. At 3 months after baseline (month 3, neither the RRA nor RCA was occluded in any eye on indocyanine green angiography. Retreatment with intravitreal bevacizumab plus photodynamic therapy was performed in three eyes at months 3 (persistent leakage on fluorescein angiography, 6, and 7 (recurrence of RAP lesion, which achieved obvious occlusion of the RRA and RCA. Mean best-corrected visual acuity improved from 0.13 to 0.21 at month 3 (P = 0.066. No complications or systemic adverse events were noted.Conclusion: Although intravitreal bevacizumab for RAP was effective in improving visual acuity during short-term follow-up, intravitreal bevacizumab could not achieve complete occlusion of RRA and RCA, which could

  15. Ischemic optic neuropathy as a model of neurodegenerative disorder: A review of pathogenic mechanism of axonal degeneration and the role of neuroprotection.

    Science.gov (United States)

    Khalilpour, Saba; Latifi, Shahrzad; Behnammanesh, Ghazaleh; Majid, Amin Malik Shah Abdul; Majid, Aman Shah Abdul; Tamayol, Ali

    2017-04-15

    Optic neuropathy is a neurodegenerative disease which involves optic nerve injury. It is caused by acute or intermittent insults leading to visual dysfunction. There are number of factors, responsible for optic neuropathy, and the optic nerve axon is affected in all type which causes the loss of retinal ganglion cells. In this review we will highlight various mechanisms involved in the cell loss cascades during axonal degeneration as well as ischemic optic neuropathy. These mechanisms include oxidative stress, excitotoxicity, angiogenesis, neuroinflammation and apoptosis following retinal ischemia. We will also discuss the effect of neuroprotective agents in attenuation of the negative effect of factors involve in the disease occurrence and progression.

  16. Protection of retinal ganglion cells and retinal vasculature by Lycium barbarum polysaccharides in a mouse model of acute ocular hypertension.

    Directory of Open Access Journals (Sweden)

    Xue-Song Mi

    Full Text Available Acute ocular hypertension (AOH is a condition found in acute glaucoma. The purpose of this study is to investigate the protective effect of Lycium barbarum polysaccharides (LBP and its protective mechanisms in the AOH insult. LBP has been shown to exhibit neuroprotective effect in the chronic ocular hypertension (COH experiments. AOH mouse model was induced in unilateral eye for one hour by introducing 90 mmHg ocular pressure. The animal was fed with LBP solution (1 mg/kg or vehicle daily from 7 days before the AOH insult till sacrifice at either day 4 or day 7 post insult. The neuroprotective effects of LBP on retinal ganglion cells (RGCs and blood-retinal-barrier (BRB were evaluated. In control AOH retina, loss of RGCs, thinning of IRL thickness, increased IgG leakage, broken tight junctions, and decreased density of retinal blood vessels were observed. However, in LBP-treated AOH retina, there was less loss of RGCs with thinning of IRL thickness, IgG leakage, more continued structure of tight junctions associated with higher level of occludin protein and the recovery of the blood vessel density when compared with vehicle-treated AOH retina. Moreover, we found that LBP provides neuroprotection by down-regulating RAGE, ET-1, Aβ and AGE in the retina, as well as their related signaling pathways, which was related to inhibiting vascular damages and the neuronal degeneration in AOH insults. The present study suggests that LBP could prevent damage to RGCs from AOH-induced ischemic injury; furthermore, through its effects on blood vessel protection, LBP would also be a potential treatment for vascular-related retinopathy.

  17. Retinal vein thrombosis associated with pegylated-interferon and ribavirin combination therapy for chronic hepatitis C

    Institute of Scientific and Technical Information of China (English)

    Iman Zandieh; Mohamed Adenwalla; Cindy Cheong-Lee; Patrick E Ma; Eric M Yoshida

    2006-01-01

    An estimated 300 million people worldwide suffer fromchronic hepatitis C with a prevalence of 0.8%-1.0% of the general population in Canada. An increasing pool of evidence exists supporting the use of pegylatedinterferon (pegIFN) and ribavirin combination therapy for hepatitis C. We report a 49-year old male of North American aboriginal descent with chronic hepatitis C (genotype 2b). Biopsy confirmed that he had cirrhosis with a 2-wk history of left eye pain and decreased visual acuity. He developed retinal vein thrombosis after 16 of 24 wk of pegIFN-α 2a and ribavirin combination therapy. He was urgently referred to a retinal specialist and diagnosed with non-ischemic central retinal vein occlusion of the left eye. PegIFN and ribavirin combination therapy was discontinued and HCV RNA was undetectable after 16 wk of treatment. Hematologic investigations revealed that the patient was a factor V Leiden heterozygote with mildly decreased protein C activity. Our patient had a number of hypercoagulable risk factors, including factor V Leiden heterozygosity, cirrhosis, and hepatitis C that alone would have most likely remained clinically silent. We speculate that in the setting of pegIFN treatment, these risk factors may coalesce and cause the retinal vein thrombosis.

  18. Stress hyperglycemia and acute ischemic stroke in-hospital outcome.

    Science.gov (United States)

    Tziomalos, Konstantinos; Dimitriou, Panagiotis; Bouziana, Stella D; Spanou, Marianna; Kostaki, Stavroula; Angelopoulou, Stella-Maria; Papadopoulou, Maria; Giampatzis, Vasilios; Savopoulos, Christos; Hatzitolios, Apostolos I

    2017-02-01

    Stress hyperglycemia is frequent in patients with acute ischemic stroke. However, it is unclear whether stress hyperglycemia only reflects stroke severity or if it is directly associated with adverse outcome. We aimed to evaluate the prognostic significance of stress hyperglycemia in acute ischemic stroke. We prospectively studied 790 consecutive patients who were admitted with acute ischemic stroke (41.0% males, age 79.4±6.8years). The severity of stroke was assessed at admission with the National Institutes of Health Stroke Scale (NIHSS). Stress hyperglycemia was defined as fasting serum glucose levels at the second day after admission ≥126mg/dl in patients without type 2 diabetes mellitus (T2DM). The outcome was assessed with adverse outcome rates at discharge (modified Rankin scale between 2 and 6) and with in-hospital mortality. In the total study population, 8.6% had stress hyperglycemia. Patients with stress hyperglycemia had more severe stroke. Independent predictors of adverse outcome at discharge were age, prior ischemic stroke and NIHSS at admission whereas treatment with statins prior to stroke was associated with favorable outcome. When the NIHSS was removed from the multivariate model, independent predictors of adverse outcome were age, heart rate at admission, prior ischemic stroke, log-triglyceride (TG) levels and stress hyperglycemia, whereas treatment with statins prior to stroke was associated with favorable outcome. Independent predictors of in-hospital mortality were atrial fibrillation (AF), diastolic blood pressure (DBP), serum log-TG levels and NIHSS at admission. When the NIHSS was removed from the multivariate model, independent predictors of in-hospital mortality were age, AF, DBP, log-TG levels and stress hyperglycemia. Stress hyperglycemia does not appear to be directly associated with the outcome of acute ischemic stroke. However, given that patients with stress hyperglycemia had higher prevalence of cardiovascular risk factors than

  19. Aqueous levels of erythropoietin in acute retinal vein occlusion with macular edema

    Directory of Open Access Journals (Sweden)

    Hyun Jin Shin

    2014-06-01

    Full Text Available AIM: To investigate the aqueous erythropoietin (EPO levels and associated factors in patients with acute retinal vein occlusion (RVO.METHODS:The aqueous EPO level was measured in patients with macular edema (ME secondary to acute branched retinal vein occlusion (BRVO or central retinal vein occlusion (CRVO. Aqueous fluid from cataract patients served as the control. We also evaluated whether aqueous level of EPO was associated with factors such as serum EPO level, non-perfusion area, central macular thickness (CMT, and arterio-venous (AV transit timeRESULTS:Twenty-seven RVO patients (16 BRVO, 11 CRVO and 9 control subjects were enrolled in the study. The aqueous EPO level (mU/mL was higher in RVO (68.2±54.3 than that in the control subjects (12.9±5.9. More specifically, the aqueous EPO level was higher in CRVO (118.9±52.1 than that in BRVO (33.3±10.8. However, no differences were found in serum EPO levels among three groups. CMT in RVO patients had a positive correlation with the aqueous EPO level (r=0.66. Also, in terms of non-perfusion area, the aqueous EPO levels were more elevated in the ischemic subgroup than in the non-ischemic subgroup in both BRVO and CRVO.CONCLUSION:Aqueous EPO levels are elevated in patients with macular edema secondary to recent onset RVO. Patients with CRVO have higher EPO levels than those with BRVO. The aqueous EPO level in RVO has a positive correlation with CMT and is associated with non-perfusion area. These results suggest that the aqueous EPO level could be associated with retinal ischemia and may be involved in the pathogenesis of macular edema secondary to RVO.

  20. A study of evaluation of various risk factors of retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    Vaishali Amrutlal Prajapati

    2014-06-01

    Full Text Available Background: A study of various ocular and systemic risk factors in Retinal Vein Occulation (RVO at tertiary eye care centre. Methods: A prospective study included 50 eyes of 50 patients, in period of September 2010 to August 2012. Inclusion criteria: 1. Age >25 years, 2. All newly diagnosed cases of vein occlusion. Exclusion criteria: 1. Age Ischemic (24%. In risk factors - most common was hypertension - in 38 (76% patients. Followed by descending order, hyperlipidemia 27 (54% >diabetes mellitus 16 (32% >tobacco 14 (28% >hyper homocystinemia 4 (8% >severe alcohol 2 (4%. The complications were more in ischemic than Nonischemic-CRVO >BRVO - they were macular edema 43 (86% >neovascularization at iris - 14 (28% >neovascularization at angle - 10 (20% >neovascular glaucoma and #8211; 4 (8%. Conclusion: RVOs are more common with increasing age, in males and most common risk factor is hypertensive. Most common cause for vision loss is macular edema - ischemic >non-ischemic. [Int J Res Med Sci 2014; 2(3.000: 1054-1057

  1. Human Data Supporting Glyburide in Ischemic Stroke

    Science.gov (United States)

    Sheth, Kevin N.; Simard, J. Marc; Elm, Jordan; Kronenberg, Golo; Kunte, Hagen; Kimberly, W. Taylor

    2016-01-01

    The SUR1-TRPM4 channel is a critical determinant of edema and hemorrhagic transformation after focal ischemia. Blockade of this channel by the small molecule glyburide results in improved survival and neurological outcome in multiple preclinical models of ischemic stroke. A robust, compelling body of evidence suggests that an intravenous (IV) formulation of glyburide, RP-1127, can prevent swelling and improve outcome in patients with stroke. Retrospective studies of diabetic stroke patients show improved outcomes in patients who are continued on sulfonylureas after stroke onset. Early phase II study of MRI and plasma biomarkers support the conclusion that RP-1127 may decrease swelling and hemorrhagic transformation. Finally, the ongoing phase II RP-1127 development program has demonstrated continued safety as well as feasibility of enrollment and tolerability of the intervention. Continued efforts to complete the ongoing phase IIb study and definitive efficacy studies are urgently needed to bring a candidate pharmacotherapy to a population of severe stroke patients that currently have no alternative. PMID:26463916

  2. [Progress of research in retinal image registration].

    Science.gov (United States)

    Yu, Lun; Wei, Lifang; Pan, Lin

    2011-10-01

    The retinal image registration has important applications in the processes of auxiliary diagnosis and treatment for a variety of diseases. The retinal image registration can be used to measure the disease process and the therapeutic effect. A variety of retinal image registration techniques have been studied extensively in recent years. However, there are still many problems existing and there are numerous research possibilities. Based on extensive investigation of existing literatures, the present paper analyzes the feature of retinal image and current challenges of retinal image registration, and reviews the transformation models of the retinal image registration technology and the main research algorithms in current retinal image registration, and analyzes the advantages and disadvantages of various types of algorithms. Some research challenges and future developing trends are also discussed.

  3. Regarding optical coherence tomography grading of ischemia in central retinal venous occlusion

    Directory of Open Access Journals (Sweden)

    Tripathy K

    2017-02-01

    Full Text Available Koushik TripathyDepartment of Vitreoretina and Uvea, ICARE Eye Hospital & Postgraduate Institute, Noida, Uttar Pradesh, IndiaThe author read with interest the article by Browning et al.1 The author humbly wants to discuss a few facts.1. The article1 discusses grading of retinal ischemia based on optical coherence tomography features in central retinal venous occlusion. As coexisting central retinal arterial occlusion or cilioretinal arterial occlusion may also cause inner retinal hyper-reflectivity, exclusion of such cases is an important consideration before implicating central retinal venous occlusion for the ischemia. Extensive intraretinal hemorrhages are other important hindrances to the evaluation of the perfusion status of the retina using both fluorescein angiogram and optical coherence tomography.2. It would be interesting to know the gonioscopic findings, especially neovascularization of the anterior chamber angle if it was performed at presentation and during the follow-ups.3. The manuscript documented that the incidence of anterior segment neovascularization at 1 year was 8.9% in severe ischemia group.1 The incidence of anterior segment neovascularization in perfused groups was higher (15.4% and 17.6% for mild and moderate ischemia, respectively. Although the sample size was low, such findings are contrary to the literature2 and require further discussion. Authors' replyDavid J Browning, Omar S Punjabi, Chong LeeDepartment of Ophthalmology, Charlotte Eye, Ear, Nose and Throat Associates, P.A., Charlotte, NC, USA We thank Dr Tripathy for his interest in our article and would respond to his above-mentioned points.1. We agree that excluding eyes with cilioretinal artery and central retinal artery occlusions is necessary to be able to attribute inner retinal reflectivity changes to central retinal vein occlusion. Cilioretinal artery occlusion is associated with a band of ischemic retinal whitening and central retinal artery occlusion

  4. Retinal imaging and image analysis

    NARCIS (Netherlands)

    Abramoff, M.D.; Garvin, Mona K.; Sonka, Milan

    2010-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindne

  5. [Surgical managment of retinal detachment].

    Science.gov (United States)

    Haritoglou, C; Wolf, A

    2015-05-01

    The detachment of the neurosensory retina from the underlying retinal pigment epithelium can be related to breaks of the retina allowing vitreous fluid to gain access to the subretinal space, to exudative changes of the choroid such as tumours or inflammatory diseases or to excessive tractional forces exerted by interactions of the collagenous vitreous and the retina. Tractional retinal detachment is usually treated by vitrectomy and exudative detachment can be addressed by treatment of the underlying condition in many cases. In rhegmatogenous retinal detachment two different surgical procedures, vitrectomy and scleral buckling, can be applied for functional and anatomic rehabilitation of our patients. The choice of the surgical procedure is not really standardised and often depends on the experience of the surgeon and other more ocular factors including lens status, the number of retinal breaks, the extent of the detachment and the amount of preexisting PVR. Using both techniques, anatomic success rates of over 90 % can be achieved. Especially in young phakic patients scleral buckling offers the true advantage to prevent the progression of cataract formation requiring cataract extraction and intraocular lens implantation. Therefore, scleral buckling should be considered in selected cases as an alternative surgical option in spite of the very important technical refinements in modern vitrectomy techniques. Georg Thieme Verlag KG Stuttgart · New York.

  6. Blood microRNAs as potential diagnostic and prognostic markers in cerebral ischemic injury

    Institute of Scientific and Technical Information of China (English)

    Bridget Martinez; Philip V Peplow

    2016-01-01

    MicroRNAs are a family of small, genome-encoded endogenous RNAs that are transcribed but are not translated into proteins. They serve essential roles in virtually every aspect of brain function, including neurogenesis, neural development, and cellular responses leading to changes in synaptic plasticity. They are also implicated in neurodegeneration and neurological disorders, in responses to hypoxia and ischemia, and in ischemic tolerance induced by ischemic preconditioning. In recent developments, miRNA expres-sion proifling has been examined in stroke, and these studies indicate that miRNAs have emerged as key mediators in ischemic stroke biology. Both increased and decreased miRNA levels may be needed either as prevention or treatment of stroke. Novel approaches are being developed to get miRNA related therapeu-tics into the brain across an intact blood-brain barrier, including chemical modiifcation, use of targeting molecules and methods to disrupt the blood-brain barrier.

  7. A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease

    OpenAIRE

    Ahrén Bo; Erlanson-Albertsson Charlotte; Granfeldt Yvonne; Jönsson Tommy; Lindeberg Staffan

    2010-01-01

    Abstract Background We found marked improvement of glucose tolerance and lower dietary energy intake in ischemic heart disease (IHD) patients after advice to follow a Paleolithic diet, as compared to a Mediterranean-like diet. We now report findings on subjective ratings of satiety at meals and data on the satiety hormone leptin and the soluble leptin receptor from the same study. Methods Twenty-nine male IHD patients with impaired glucose tolerance or diabetes type 2, and waist circumference...

  8. A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease.

    OpenAIRE

    Ahrén Bo; Erlanson-Albertsson Charlotte; Granfeldt Yvonne; Jönsson Tommy; Lindeberg Staffan

    2010-01-01

    Abstract Background We found marked improvement of glucose tolerance and lower dietary energy intake in ischemic heart disease (IHD) patients after advice to follow a Paleolithic diet, as compared to a Mediterranean-like diet. We now report findings on subjective ratings of satiety at meals and data on the satiety hormone leptin and the soluble leptin receptor from the same study. Methods Twenty-nine male IHD patients with impaired glucose tolerance or diabetes type 2, and waist circumference...

  9. Depolarization thresholds for hippocampal damage, ischemic preconditioning, and changes in gene expression after global ischemia in the rat.

    Science.gov (United States)

    Halaby, Issam A; Takeda, Yoshimasa; Yufu, Katsumi; Nowak, Thaddeus S; Pulsinelli, William A

    2004-11-30

    Induced ischemic tolerance in rat hippocampus was investigated in a forebrain ischemia model of repeated 4-vessel occlusion (4-VO). Ischemic insult variability was reduced by the use of dc potential measurements to determine the duration of ischemic depolarization in hippocampus. The results demonstrate a depolarization threshold for ischemic injury to CA1 neurons of 4-6 min and a window for optimal preconditioning of 2.5-3.5 min. Levels of induced mRNAs encoding hsp72 and several immediate-early genes were also shown to vary with depolarization interval. Immediate-early genes were maximally induced after depolarization periods inducing optimal preconditioning, while hsp72 expression increased with insult severity over the range leading to neuron loss. These results are similar to those obtained in gerbil studies indicating that preconditioning does not require large increases in hsp72 expression, and demonstrate the fundamental comparability of rodent global ischemia models when monitored by this approach.

  10. Epsilon PKC increases brain mitochondrial SIRT1 protein levels via heat shock protein 90 following ischemic preconditioning in rats.

    Directory of Open Access Journals (Sweden)

    John W Thompson

    Full Text Available Ischemic preconditioning is a neuroprotective mechanism whereby a sublethal ischemic exposure is protective against a subsequent lethal ischemic attack. We previously demonstrated that SIRT1, a nuclear localized stress-activated deacetylase, is vital for ischemic preconditioning neuroprotection. However, a recent study demonstrated that SIRT1 can also localize to the mitochondria. Mitochondrial localized SIRT1 may allow for a direct protection of mitochondria following ischemic preconditioning. The objective of this study was to determine whether ischemic preconditioning increases brain mitochondrial SIRT1 protein levels and to determine the role of PKCɛ and HSP90 in targeting SIRT1 to the mitochondria. Here we report that preconditioning rats, with 2 min of global cerebral ischemia, induces a delayed increase in non-synaptic mitochondrial SIRT1 protein levels which was not observed in synaptic mitochondria. This increase in mitochondrial SIRT1 protein was found to occur only in neuronal cells and was mediated by PKCε activation. Inhibition of HSP90, a protein chaperone involved in mitochondrial protein import, prevented preconditioning induced increases in mitochondrial SIRT1 and PKCε protein. Our work provides new insights into a possible direct role of SIRT1 in modulating mitochondrial function under both normal and stress conditions, and to a possible role of mitochondrial SIRT1 in activating preconditioning induced ischemic tolerance.

  11. Retinal detachment in a patient with extensive myelinated retinal nerve fibers.

    Science.gov (United States)

    Chen, Muh-Shy; Ho, Tzyy-Chang; Chang, Ching-Chung; Hou, Ping-Kang

    2007-01-01

    We report extensive myelinated retinal nerve fibers in a 42-year-old patient with retinal detachment. Fundus examination revealed a horseshoe-shaped tear near the temporal edge. Pars plana vitrectomy was performed and firm vitreo-retinal adhesion was noticed in the area of extensive myelinated retinal nerve fibers. Following vitrectomy with silicone oil tamponade, the retina was reattached successfully. In conclusion, retinal detachment may develop in patients with extensive myelinated retinal nerve fibers. Vitrectomy may be performed to treat this condition.

  12. Rational modulation of the innate immune system for neuroprotection in ischemic stroke

    Directory of Open Access Journals (Sweden)

    Diana eAmantea

    2015-04-01

    Full Text Available The innate immune system plays a dualistic role in the evolution of ischemic brain damage and has also been implicated in ischemic tolerance produced by different conditioning stimuli. Early after ischemia, perivascular astrocytes release cytokines and activate metalloproteases (MMPs that contribute to blood–brain barrier (BBB disruption and vasogenic oedema; whereas at later stages, they provide extracellular glutamate uptake, BBB regeneration and neurotrophic factors release. Similarly, early activation of microglia contributes to ischemic brain injury via the production of inflammatory cytokines, including tumor necrosis factor (TNF and interleukin (IL-1, reactive oxygen and nitrogen species and proteases. Nevertheless, microglia also contributes to the resolution of inflammation, by releasing IL-10 and tumor growth factor (TGF-beta, and to the late reparative processes by phagocytic activity and growth factors production. Indeed, after ischemia, microglia/macrophages differentiate towards several phenotypes: the M1 pro-inflammatory phenotype is classically activated via toll-like receptors or interferon-γ, whereas M2 phenotypes are alternatively activated by regulatory mediators, such as ILs 4, 10, 13 or TGF-beta. Thus, immune cells exert a dualistic role on the evolution of ischemic brain damage, since the classic phenotypes promote injury, whereas alternatively activated M2 macrophages or N2 neutrophils prompt tissue remodeling and repair.Moreover, a subdued activation of the immune system has been involved in ischemic tolerance, since different preconditioning stimuli act via modulation of inflammatory mediators, including toll-like receptors and cytokine signaling pathways. This further underscores that the immuno-modulatory approach for the treatment of ischemic stroke should be aimed at blocking the detrimental effects, while promoting the beneficial responses of the immune reaction.

  13. Peculiarities of Ischemic Heart Disease Course and Treatment in Patients with Glucose Metabolism Impairment and Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    O.M. Radchenko

    2015-11-01

    Full Text Available Combination of ischemic heart disease and diabetes mellitus is characterized by certain features of clinical picture and insufficient effectiveness of treatment of ischemic heart disease. With the aim of investigation of pathogenic mechanisms and features of the clinical course of ischemic heart disease associated with glucose homeostasis violation we examined 116 patients (51 women, 65 men, median of age 63 years old with normal regulation of glucose metabolism (NRG, n = 24, changes in fasting glucose (n = 23, violated glucose tolerance (n = 21, combined violation (n = 24 and diabetes mellitus (n = 24. We also conducted their prospective observation for 40 months with the following endpoints — hospitalization because of cardiovascular complications, death from them and the emergence of diabetes. It was established that ischemic heart disease associated with prediabetic disorders and diabetes mellitus has the following peculiarities: earlier clinical manifestation in women; more frequent and severe heart failure; lower tolerance to physical load in patients with angina pectoris; atypical manifestation of ischemic pain: longer attacks, atypical localization or absent pain; frequent combination with arrhythmias and conduction disorders; frequent affection of multiple coronary arteries, which leads to myocardial infarction with complicated course; eccentric type of left ventricle remodeling; significant calcification of mitral and aortic valves of heart. The main principles of treatment of ischemic heart disease: weight loss; active correction of glucose metabolism violations using medications (metformin even at the stage of prediabetes, because in chronic stable forms of ischemic heart disease metformin significantly improves glucose metabolism, decreases insulin resistance and does not increase the incidence of cardiovascular complications and decompensations of heart failure; the basic drugs for treatment of ischemic heart disease should be

  14. Ischemic stroke and incomplete infarction

    DEFF Research Database (Denmark)

    Garcia, Javier; Lassen, N A; Weiller, C

    1996-01-01

    The concept of selective vulnerability or selective loss o f individual neurons, with survival of glial and vascular elements as one of the consequences of a systemic ischemic-hypoxic insult (eg, transient cardiac arrest or severe hypotension), has been recognized for decades. In contrast, select......, selective neuronal death as one of the lesions that may develop in the brain after occluding an intracranial artery is an idea not readily acknowledged in the current medical literature dealing with human stroke....

  15. Type 2 diabetes is not a risk factor for asymptomatic ischemic brain lesion. The Funagata study

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Tamotsu; Daimon, Makoto; Eguchi, Hideyuki; Hosoya, Takaaki; Kawanami, Toru; Kurita, Keiji; Tominaga, Makoto; Kato, Takeo [Yamagata Univ. (Japan). School of Medicine

    2002-05-01

    The purpose of this study is to clarify whether type 2 diabetes (DM) is a risk factor for asymptomatic (silent) ischemic brain lesion, which is controversial at present. The subjects (n=187), who showed normal results on both neurological and neuropsychological examinations, underwent a 75-g OGTT and were examined by brain MRI on T1-weighted, T2-weighted, and FLAIR (fluid-attenuated inversion recovery) images. Their brain MRIs were evaluated quantitatively with the ischemia rating scale defined here. The subjects were grouped based on their glucose tolerance: normal glucose tolerance (NGT) (n=48), impaired glucose tolerance (IGT) (n=62), and DM (n=65). The subjects with DM were further divided based on their duration of illness: 20 with short duration (short DM: 1.3{+-}0.8 years) and 45 with long duration (long DM; 8.9{+-}5.4 years). Ages were matched among the groups. The percentages of individuals with asymptomatic ischemic brain lesion were 81% in NGT, 74% in IGT, 65% in short DM, and 78% in long DM. No significant difference was observed among the groups in terms of the percentage. Namely, even in individuals with a long history of DM without clinical stroke, the prevalence of asymptomatic ischemic brain lesion was not different from that of the other groups. Multiple regression and multiple logistic regression analyses showed that age and hypertension were significant independent risk factors for asymptomatic ischemic brain lesion, whereas hypercholesterolemia, smoking, and glucose intolerance, including IGT, short DM and long DM, were not. DM is not a risk factor for asymptomatic ischemic brain lesion. (author)

  16. Cytomegalovirus retinitis associated with acquired immunodeficiency syndrome

    Institute of Scientific and Technical Information of China (English)

    GENG Shuang; YE Jun-jie; ZHAO Jia-liang; LI Tai-sheng; HAN Yang

    2011-01-01

    Background Cytomegalovirus (CMV) retinitis is the most severe intraocular complication that results in total retinal destruction and loss of visual acuity in patients with acquired immunodeficiency syndrome (AIDS). This study aimed to investigate the fundus characteristics, systemic manifestations and therapeutic outcomes of CMV retinitis associated with AIDS.Methods It was a retrospective case series. CMV retinitis was present in 39 eyes (25 patients). Best corrected visual acuities, anterior segment, fundus features, fundus fluorescence angiography (FFA) and CD4+ T-lymphocyte counts of the patients with CMV retinitis associated with AIDS were analyzed. Intravitreal injections of ganciclovir (400 μg) were performed in 4 eyes (2 patients).Results Retinal vasculitis, dense, full-thickness, yellow-white lesions along vascular distribution with irregular granules at the border, and hemorrhage on the retinal surface were present in 28 eyes. The vitreous was clear or mildly opaque.Late stage of the retinopathy was demonstrated in 8 eyes characterized as atrophic retina, sclerotic and attenuated vessels, retinal pigment epithelium (RPE) atrophy, and optic nerve atrophy. Retinal detachment was found in 3 eyes. The average CD4+ T-lymphocyte count in peripheral blood of the patients with CMV retinitis was (30.6±25.3) ×106/L (range,(0-85) × 106/L). After intravitreal injections of ganciclovir, visual acuity was improved and fundus lesions regressed.Conclusions CMV retinitis is the most severe and the most common intraocular complication in patients with AIDS. For the patients with yellow-white retinal lesions, hemorrhage and retinal vasculitis without clear cause, human immunodeficiency virus (HIV) serology should be performed. Routine eye examination is also indicated in HIV positive patients.

  17. Retinal vascular changes in hypertensive patients in Ibadan, Sub-Saharan Africa

    Science.gov (United States)

    Oluleye, Sunday Tunji; Olusanya, Bolutife Ayokunu; Adeoye, Abiodun Moshood

    2016-01-01

    Background Earlier studies in Nigeria reported the rarity of retinal vascular changes in hypertensives. The aim of this study was to describe the various retinal vascular changes in the hypertensive patients of Nigeria. Patients and methods Nine hundred and three hypertensive patients were studied. This study was approved by the ethical and research committee of the University of Ibadan and University College Hospital, Ibadan, Nigeria. Blood pressure and anthropometric measurements were measured. Cardiac echocardiography was performed on 156 patients. All patients had dilated fundoscopy and fundus photography using the Kowa portable fundus camera and an Apple iPhone with 20 D lens. Statistical analysis was done with Statistical Packages for the Social Sciences (Version 21). Results The mean age of patients was 57 years with a male:female ratio of 1. No retinopathy was found in 556 (61.5%) patients. In all, 175 (19.4%) patients had features of hypertensive retinopathy. Retinal vascular occlusion was a significant finding in 121 patients (13.4%), of which branch retinal vein occlusion, 43 (4.7%), and central retinal vein occlusion, 30 (3.3%), were the most prominent ones in cases. Hemicentral retinal vein occlusion, 26 (2.9%), and central retinal artery occlusion, 17 (1.9%), were significant presentations. Other findings included nonarteritic anterior ischemic optic neuropathy in five (0.6%) patients, hypertensive choroidopathy in seven (0.8%) patients, and hemorrhagic choroidal detachment in five (0.6%) patients. Left ventricular (LV) geometry was abnormal in 85 (55.5%) patients. Concentric remodeling, eccentric hypertrophy, and concentric hypertrophy were observed in 43 (27.6%), 26 (17.2%), and 15 (9.7%) patients, respectively. LV hypertrophy was found in 42 (27%) patients, while 60 (39%) patients had increased relative wall thickness. In this study, bivariate analysis showed a correlation between LV relative wall thickness and severity of retinopathy in both eyes

  18. Risk factors for ischemic stroke and transient ischemic attack in patients under age 50

    NARCIS (Netherlands)

    Janssen, A.W.M.; Leeuw, F.E. de; Janssen, M.C.H.

    2011-01-01

    To analyze risk factors for ischemic stroke and transient ischemic attack (TIA) in young adults under the age of 50. To make recommendations for additional research and practical consequences. From 97 patients with ischemic stroke or TIA under the age of 50, classical cardiovascular risk factors, co

  19. Characteristics of Misclassified CT Perfusion Ischemic Core in Patients with Acute Ischemic Stroke

    NARCIS (Netherlands)

    Geuskens, R.R.; Borst, J.; Lucas, M.; Boers, A.M.; Berkhemer, O.A.; Roos, Y.B.; Walderveen, M.A. van; Jenniskens, S.F.M.; Zwam, W.H. van; Dippel, D.W.; Majoie, C.B.; Marquering, H.A.

    2015-01-01

    BACKGROUND: CT perfusion (CTP) is used to estimate the extent of ischemic core and penumbra in patients with acute ischemic stroke. CTP reliability, however, is limited. This study aims to identify regions misclassified as ischemic core on CTP, using infarct on follow-up noncontrast CT. We aim to

  20. [Vitreo-retinal surgery for complicated retinal detachment].

    Science.gov (United States)

    Wang, J Z

    1993-07-01

    93 eyes (93 patients) of complicated retinal detachment were treated with vitreo-retinal surgery. Among the series, 75 eyes were rhegmatogenous with PVR C3-D3 in 66 eyes (88.0%), while the remaining 18 eyes were traction induced. None of the cases had giant tears or complicating diabetes. On discharge from the hospital, the operation was effective in 62 cases (66.7%), in whom the retina was totally reattached or only a small amount of subretinal fluid remained. In a group of 40 eyes where the inert gas SF6 was used, the operation was effective in 30 cases (75.0%). 41 cases were followed up postoperatively for over 3 months, averaging 13.7 months, to find the operative results stable in 33 eyes (80.5%), with the visual acuity improved in 22 cases (66.7%), unchanged in 9 cases (27.3%), and decreased in 2 cases (6.0%). The operative procedures, the peeling of pre-retinal membrane, the effect of PVR severity on the operative results, and the promotion of operative efficacy by application of wide encircling buckle and inert gas tamponade were discussed.

  1. Anti-Vascular Endothelial Growth Factor Agents in the Treatment of Retinal Disease: From Bench to Bedside.

    Science.gov (United States)

    Campochiaro, Peter A; Aiello, Lloyd Paul; Rosenfeld, Philip J

    2016-10-01

    The association of retinal hypoxia with retinal neovascularization has been recognized for decades, causing Michaelson to postulate in 1948 that a factor secreted by hypoxic retina was involved. The isolation of vascular endothelial growth factor (VEGF), characterization of its angiogenic activity, and demonstration that its expression was increased in hypoxic tissue made it a prime candidate. Intraocular levels of VEGF are elevated in patients with retinal or iris neovascularization, and VEGF-specific antagonists markedly suppress retinal neovascularization in mice and primates with ischemic retinopathy. Vascular endothelial growth factor antagonists also suppress choroidal neovascularization, and transgenic expression of VEGF in the retina of mice causes subretinal neovascularization. Clinical trials using a VEGF antagonist that blocks all isoforms of VEGF-A in patients with neovascular age-related macular degeneration (nAMD) demonstrated dramatic benefit. Similar results have been obtained with 2 other VEGF antagonists. Retinal hypoxia also contributes to diabetic macular edema (DME), and because of the absence of good animal models, small clinical trials were used to test the role of VEGF. The results clearly implicated VEGF as a major contributor to DME and have been confirmed by several large multicenter trials. A similar strategy demonstrated that VEGF is a major contributor to macular edema resulting from retinal vein occlusion, also confirmed in multicenter trials. Secondary outcomes in these large clinical trials have shown that VEGF inhibition improves retinal hemorrhages, retinal vessel closure, and progression of nonproliferative diabetic retinopathy. Anti-VEGF agents also provide therapeutic benefits in proliferative diabetic retinopathy. Thus, the development of VEGF antagonists has revolutionized the treatment of nAMD, diabetic retinopathy, and other ischemic retinopathies, but in many patients, the upregulation of VEGF is prolonged. Although the

  2. Astrocytic Toll-like receptor 3 is associated with ischemic preconditioning-induced protection against brain ischemia in rodents.

    Directory of Open Access Journals (Sweden)

    Lin-na Pan

    Full Text Available BACKGROUND: Cerebral ischemic preconditioning (IPC protects brain against ischemic injury. Activation of Toll-like receptor 3 (TLR3 signaling can induce neuroprotective mediators, but whether astrocytic TLR3 signaling is involved in IPC-induced ischemic tolerance is not known. METHODS: IPC was modeled in mice with three brief episodes of bilateral carotid occlusion. In vitro, IPC was modeled in astrocytes by 1-h oxygen-glucose deprivation (OGD. Injury and components of the TLR3 signaling pathway were measured after a subsequent protracted ischemic event. A neutralizing antibody against TLR3 was used to evaluate the role of TLR3 signaling in ischemic tolerance. RESULTS: IPC in vivo reduced brain damage from permanent middle cerebral artery occlusion in mice and increased expression of TLR3 in cortical astrocytes. IPC also reduced damage in isolated astrocytes after 12-h OGD. In astrocytes, IPC or 12-h OGD alone increased TLR3 expression, and 12-h OGD alone increased expression of phosphorylated NFκB (pNFκB. However, IPC or 12-h OGD alone did not alter the expression of Toll/interleukin receptor domain-containing adaptor-inducing IFNβ (TRIF or phosphorylated interferon regulatory factor 3 (pIRF3. Exposure to IPC before OGD increased TRIF and pIRF3 expression but decreased pNFκB expression. Analysis of cytokines showed that 12-h OGD alone increased IFNβ and IL-6 secretion; 12-h OGD preceded by IPC further increased IFNβ secretion but decreased IL-6 secretion. Preconditioning with TLR3 ligand Poly I:C increased pIRF3 expression and protected astrocytes against ischemic injury; however, cells treated with a neutralizing antibody against TLR3 lacked the IPC- and Poly I:C-induced ischemic protection and augmentation of IFNβ. CONCLUSIONS: The results suggest that IPC-induced ischemic tolerance is mediated by astrocytic TLR3 signaling. This reprogramming of TLR3 signaling by IPC in astrocytes may play an important role in suppression of the post-ischemic

  3. Advances in Retinal Stem Cell Biology

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    Andrea S Viczian

    2013-01-01

    Full Text Available Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different groups, which has culminated in the generation of laminated retinal tissue from both embryonic and induced pluripotent cells. The review also briefly describes advances made in transplantation studies using donor retinal progenitor and cultured retinal cells.

  4. Automatic Vessel Segmentation on Retinal Images

    Institute of Scientific and Technical Information of China (English)

    Chun-Yuan Yu; Chia-Jen Chang; Yen-Ju Yao; Shyr-Shen Yu

    2014-01-01

    Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hyper-tension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm. In this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE (digital retinal images for vessel extraction) retinal database, which is much better than other methods.

  5. Acute effects of remote ischemic preconditioning on cutaneous microcirculation - a controlled prospective cohort study

    OpenAIRE

    Kraemer Robert; Lorenzen Johan; Kabbani Mohammad; Herold Christian; Busche Marc; Vogt Peter M; Knobloch Karsten

    2011-01-01

    Abstract Background Therapeutic strategies aiming to reduce ischemia/reperfusion injury by conditioning tissue tolerance against ischemia appear attractive not only from a scientific perspective, but also in clinics. Although previous studies indicate that remote ischemic intermittent preconditioning (RIPC) is a systemic phenomenon, only a few studies have focused on the elucidation of its mechanisms of action especially in the clinical setting. Therefore, the aim of this study is to evaluate...

  6. Retinal Cell Degeneration in Animal Models

    OpenAIRE

    Masayuki Niwa; Hitomi Aoki; Akihiro Hirata; Hiroyuki Tomita; Green, Paul G.; Akira Hara

    2016-01-01

    The aim of this review is to provide an overview of various retinal cell degeneration models in animal induced by chemicals (N-methyl-d-aspartate- and CoCl2-induced), autoimmune (experimental autoimmune encephalomyelitis), mechanical stress (optic nerve crush-induced, light-induced) and ischemia (transient retinal ischemia-induced). The target regions, pathology and proposed mechanism of each model are described in a comparative fashion. Animal models of retinal cell degeneration provide insi...

  7. Intrinsically photosensitive retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    Gary; E.PICKARD; Patricia; J.SOLLARS

    2010-01-01

    A new mammalian photoreceptor was recently discovered to reside in the ganglion cell layer of the inner retina.These intrinsically photosensitive retinal ganglion cells(ipRGCs) express a photopigment,melanopsin,that confers upon them the ability to respond to light in the absence of all rod and cone photoreceptor input.Although relatively few in number,ipRGCs extend their dendrites across large expanses of the retina making them ideally suited to function as irradiance detectors to assess changes in ambient light levels.Phototransduction in ipRGCs appears to be mediated by transient receptor potential channels more closely resembling the phototransduction cascade of invertebrate rather than vertebrate photoreceptors.ipRGCs convey irradiance information centrally via the optic nerve to influence several functions.ipRGCs are the primary retinal input to the hypothalamic suprachiasmatic nucleus(SCN),a circadian oscillator and biological clock,and this input entrains the SCN to the day/night cycle.ipRGCs contribute irradiance signals that regulate pupil size and they also provide signals that interface with the autonomic nervous system to regulate rhythmic gene activity in major organs of the body.ipRGCs also provide excitatory drive to dopaminergic amacrine cells in the retina,providing a novel basis for the restructuring of retinal circuits by light.Here we review the ground-breaking discoveries,current progress and directions for future investigation.

  8. Mitochondrial dysfunction underlying outer retinal diseases

    DEFF Research Database (Denmark)

    Lefevere, Evy; Toft-Kehler, Anne Katrine; Vohra, Rupali

    2017-01-01

    Dysfunction of photoreceptors, retinal pigment epithelium (RPE) or both contribute to the initiation and progression of several outer retinal disorders. Disrupted Müller glia function might additionally subsidize to these diseases. Mitochondrial malfunctioning is importantly associated with outer...... retina pathologies, which can be classified as primary and secondary mitochondrial disorders. This review highlights the importance of oxidative stress and mitochondrial DNA damage, underlying outer retinal disorders. Indeed, the metabolically active photoreceptors/RPE are highly prone to these hallmarks...... of mitochondrial dysfunction, indicating that mitochondria represent a weak link in the antioxidant defenses of outer retinal cells....

  9. RETINAL VASCULITIS ASSOCIATED WITH NEUROMYELITIS OPTICA.

    Science.gov (United States)

    Mikhail, Mikel; Khan, Ayesha

    2017-01-01

    To report a case of retinal vasculitis in a patient with neuromyelitis optica. Clinical case report, imaging was obtained with photographs, fluorescein angiography, spectral domain optical coherence tomography, and magnetic resonance imaging. The aforementioned patient presented with urinary incontinence and spastic paraparesis. She was found to have a transverse myelitis on magnetic resonance imaging and positive anti-aquaporin-4 (AQP4-Ab) testing. She had no associated visual symptoms. Examination revealed a retinal vasculitis. There have been no previous reports of retinal vasculitis associated with neuromyelitis optica or neuromyelitis optica spectrum disorder. Retinal vasculitis can be associated with neuromyelitis optica.

  10. Retinal Macroglial Responses in Health and Disease

    Directory of Open Access Journals (Sweden)

    Rosa de Hoz

    2016-01-01

    Full Text Available Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB, play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD, diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.

  11. Retinal occlusive vasculer disorder and rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Huseyin Ortak

    2013-03-01

    Full Text Available Rheumatoid arthritis is a systemic inflammatory disease that affected older women with many ocular manifestations. Also, these systemic diseases can cause retinal vein occlusion and arterial occlusion that lead to serious and permanent visual loss. Rheumatoid arthritis's the most common manifestation is that retinal vasculitis and retinal vascular complications are associated with this complication. In this review, retinal vascular occlusive diseases are presented to associated with rheumatoid arthritis in literature. Rheumatoid arthritis and its complications have been outlined and was made to create a new perspective. [J Contemp Med 2013; 3(1.000: 71-73

  12. Retinal vascular occlusion: a window to diagnosis of familial and acquired thrombophilia and hypofibrinolysis, with important ramifications for pregnancy outcomes

    Directory of Open Access Journals (Sweden)

    Dixon SG

    2016-08-01

    Full Text Available Stephan G Dixon,1 Carl T Bruce,1 Charles J Glueck,1 Robert A Sisk,2,3 Robert K Hutchins,2,3 Vybhav Jetty,1 Ping Wang1 1Cholesterol, Metabolism, and Thrombosis Center, Jewish Hospital of Cincinnati, 2Cincinnati Eye Institute, 3Department of Ophthalmology, University of Cincinnati College of Medicine, Cincinnati, OH, USA Aim: Our specific aim was to document the pathoetiologic importance of thrombophilia among females presenting with severe ischemic retinal vein (RVO or retinal artery (RAO occlusion, without typical risk factors, and to emphasize that the ophthalmologists’ diagnosis of thrombophilia has important diagnostic and therapeutic downstream ramifications for nonocular thrombosis, including reproductive outcomes. Methods: We evaluated familial and acquired thrombophilia in 60 females with RVO (central RVO, n=52; branch RVO, n=8 and 16 with RAO (central RAO, n=11; branch RAO, n=5. They were referred by retinologists, without typical risk factors for RVO/RAO and/or severe ocular ischemic presentation. We focused on extraocular thrombotic events, particularly pregnancy complications, including unexplained spontaneous abortion, pre-eclampsia–eclampsia. Thrombophilia measurements in the 76 females were compared with 62 healthy normal females without ocular vascular occlusions (OVOs. Results: The 76 females with OVO were more likely than 62 normal female controls to have high homocysteine (24% vs 0%, P<0.0001, high anticardiolipin antibody (immunoglobulin M, 17% vs 3%, P=0.012, high (>150% factor VIII (42% vs 11%, P<0.0001, and high (>150% factor XI (22% vs 4%, P=0.004. Of the 76 females, 26 (34% had ≥1 spontaneous abortion; 17 (22% had ≥2 spontaneous abortions and/or pre-eclampsia–eclampsia. Compared to 62 healthy female controls, these 17 females with pregnancy complications had high homocysteine (29% vs 0%, P=0.0003, high anticardiolipin antibody immunoglobulin M (24% vs 3%, P=0.02, high factor VIII (38% vs 11%, P=0.02, and were

  13. Intravitreal Fluorinated Gas Preference and Occurrence of Rare Ischemic Postoperative Complications after Pars Plana Vitrectomy: A Survey of the American Society of Retina Specialists

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    Eric J. Sigler

    2012-01-01

    Full Text Available Objective. To perform a survey of the American Society of Retina Specialists (ASRS regarding the use of vitreous cavity fluorinated gas as an adjunct to pars plana vitrectomy for retinal detachment or macular hole repair. Methods. A multiple-choice online questionnaire was administered to members of ASRS. Physician experience, gas preference for vitrectomy, and categorical estimate of observation of blinding postoperative ischemic events were recorded. Results. 282 questionnaires were completed. Mean years in vitreoretinal practice were 15±10. A decrease in yearly vitrectomy volume was associated with increased number of years in practice (P=0.011. Greater than 95% of respondents preferred fluorinated gas to air alone for both retinal detachment and macular hole repair. 38% of respondents reported at least one observation of a blinding ischemic postoperative event. Overall estimated incidence of blinding postoperative ischemic event was 0.06 events/year in practice. Conclusions. Currently, C3F8 and SF6 are the postoperative gas preference for ASRS respondents, in contrast to previous North American surveys. The occurrence of blinding ischemic events appears unrelated to number of years in practice, was reported by less than half of those surveyed, and has occurred at an infrequent rate of approximately once for every ten years of practice for those observing the phenomena.

  14. Ischemic injury leads to extracellular matrix alterations in retina and optic nerve

    Science.gov (United States)

    Reinhard, Jacqueline; Renner, Marina; Wiemann, Susanne; Shakoor, Daniel A.; Stute, Gesa; Dick, H. Burkhard; Faissner, Andreas; Joachim, Stephanie C.

    2017-01-01

    Retinal ischemia occurs in a variety of eye diseases. Restrained blood flow induces retinal damage, which leads to progressive optic nerve degeneration and vision loss. Previous studies indicate that extracellular matrix (ECM) constituents play an important role in complex tissues, such as retina and optic nerve. They have great impact on de- and regeneration processes and represent major candidates of central nervous system glial scar formation. Nevertheless, the importance of the ECM during ischemic retina and optic nerve neurodegeneration is not fully understood yet. In this study, we analyzed remodeling of the extracellular glycoproteins fibronectin, laminin, tenascin-C and tenascin-R and the chondroitin sulfate proteoglycans (CSPGs) aggrecan, brevican and phosphacan/RPTPβ/ζ in retinae and optic nerves of an ischemia/reperfusion rat model via quantitative real-time PCR, immunohistochemistry and Western blot. A variety of ECM constituents were dysregulated in the retina and optic nerve after ischemia. Regarding fibronectin, significantly elevated mRNA and protein levels were observed in the retina following ischemia, while laminin and tenascin-C showed enhanced immunoreactivity in the optic nerve after ischemia. Interestingly, CSPGs displayed significantly increased expression levels in the optic nerve. Our study demonstrates a dynamic expression of ECM molecules following retinal ischemia, which strengthens their regulatory role during neurodegeneration. PMID:28262779

  15. Diabetes and ischemic heart disease

    DEFF Research Database (Denmark)

    Bergmann, Natasha; Ballegaard, Søren; Holmager, Pernille

    2014-01-01

    The aim of this study was to test i) whether patients having diabetes and ischemic heart disease (IHD), i.e., patients suffering from two chronic diseases, demonstrate a higher degree of chronic stress when compared with patients suffering from IHD alone, and ii) whether suffering from the two...... chronic diseases results in an elevation in specific elements of the chronic stress concept. A total of 361 participants with IHD were included, of whom 47 suffered from concomitant diabetes. Stress was measured by pressure pain sensitivity (PPS) and by the following questionnaires: the Major Depression...

  16. Remote Ischemic Conditioning: Its Benefits and Limitations.

    Science.gov (United States)

    Kloner, Robert A

    2016-03-01

    This editorial describes benefits and limitations of remote ischemic conditioning. Remote ischemic conditioning was shown to reduce myocardial intact size in at least 4 sizeable clinical trials of acute myocardial infarction. It was not effective in recent studies of cardiac surgery. Reasons for these differences are discussed.

  17. Genetically determined coagulation disorders in ischemic stroke

    NARCIS (Netherlands)

    M.P.J. van Goor (Marie-Louise)

    2004-01-01

    textabstractThe aim of the research described in this thesis was to investigate the role of genetically determined coagulation disorders in ischemic stroke. We therefore performed several retrospective studies and one prospective case-control study of patients with recent ischemic stroke (the COCOS

  18. Persistent cognitive impairment after transient ischemic attack

    NARCIS (Netherlands)

    Rooij, F.G. van; Schaapsmeerders, P.; Maaijwee, N.A.; Duijnhoven, D.A. van; Leeuw, F.E. de; Kessels, R.P.; Dijk, E.J. van

    2014-01-01

    BACKGROUND AND PURPOSE: By definition, the symptoms of a transient ischemic attack (TIA) subside completely within 24 hours. Imaging studies show signs of persistent ischemic tissue damage in a substantial amount of patients with TIA. Cerebral infarction can cause permanent cognitive impairment. Whe

  19. Persistent Cognitive Impairment After Transient Ischemic Attack

    NARCIS (Netherlands)

    Rooij, F.G. van; Schaapsmeerders, P.; Maaijwee, N.A.M.M.; Duijnhoven, D.A. van; de Leeuw, F.E.; Kessels, R.P.C.; Dijk, E.J. van

    2014-01-01

    Background and Purpose—By definition, the symptoms of a transient ischemic attack (TIA) subside completely within 24 hours. Imaging studies show signs of persistent ischemic tissue damage in a substantial amount of patients with TIA. Cerebral infarction can cause permanent cognitive impairment. Whet

  20. The relation between BMI with exercise test in individuals with cardiac ischemic pains

    Directory of Open Access Journals (Sweden)

    Ravanbakhsh Esmaeili1

    2009-01-01

    Full Text Available (Received 19 Nov, 2008; Accepted 28 Jan, 2009AbstractBackground and purpose: Prevalence of over weight and obesity is increasing in the world. Those over weight are more susceptible to cardiovascular diseases than other individual's. Studies indicate that body fat distribution has a determining role in the identification of risk factors. Also, the relation between BMI, cardiac ischemic pains and exercise test condition in such patients, is in need further investigation. The aim of this study was to determine the relation between BMI with exercise tolerance test in patients with cardiac ischemic pains, who were referred to the Cardiac Center of Mazandaran Province, in Sari Township.Materials and methods: In this case control study considering the BMI in ischemic patients, 65 were selected as case and 65 persons as control using Tread mill and according to Bruce Protocol, results and tolerance test time was recorded. Independent T test was used for comparison of quantitative indexes mean, while x2 test using SPSS soft ware was used for comparison of the ratio of persons with the qualitative features.Results: Data indicated mean weight of 57.1 kg and height of 1.64m in the case group. Also, 58.5% had history of hyperlipidemia (Cholesterol higher than 200mg/dl and 78.8% with history of blood sugar (higher than 120mg/dl (P<0.001. Even 63.6% had hypertension of 140/9o mm Hg. Our findings showed that BMI in the case and control groups were (26.95±3.94 and (25.95±3.49 respectively. Moreover, a significant relationship between high BMI with cardiac ischemic pains and exercise tolerance test (P<0.001 were demonstrated.Conclusion: Cardiac ischemic pains in individuals with high BMI is common. Exercise tolerance test as one of the non invasive and less expensive procedures, can be an indicator of cardiac ischemic disease.J Mazand Univ Med Sci 2009; 19(68: 64-69 (Persian

  1. Zinc transporter 8 (ZnT8 expression is reduced by ischemic insults: a potential therapeutic target to prevent ischemic retinopathy.

    Directory of Open Access Journals (Sweden)

    Michael Deniro

    Full Text Available The zinc (Zn(++ transporter ZnT8 plays a crucial role in zinc homeostasis. It's been reported that an acute decrease in ZnT8 levels impairs β cell function and Zn(++ homeostasis, which contribute to the pathophysiology of diabetes mellitus (DM. Although ZnT8 expression has been detected in the retinal pigment epithelium (RPE, its expression profile in the retina has yet to be determined. Furthermore, the link between diabetes and ischemic retinopathy is well documented; nevertheless, the molecular mechanism(s of such link has yet to be defined. Our aims were to; investigate the expression profile of ZnT8 in the retina; address the influence of ischemia on such expression; and evaluate the influence of YC-1; (3-(50-hydroxymethyl-20-furyl-1-benzyl indazole, a hypoxia inducible factor-1 (HIF-1 inhibitor, on the status of ZnT8 expression. We used real-time RT-PCR, immunohistochemistry, and Western blot in the mouse model of oxygen-induced retinopathy (OIR and Müller cells to evaluate the effects of ischemia/hypoxia and YC-1 on ZnT8 expression. Our data indicate that ZnT8 was strongly expressed in the outer nuclear layer (ONL, outer plexiform layer (OPL, ganglion cell layer (GCL, and nerve fiber layer (NFL, whereas the photoreceptor layer (PRL, inner nuclear layer (INL and inner plexiform layer (IPL showed moderate ZnT8 immunoreactivity. Furthermore, we demonstrate that retinal ischemic insult induces a significant downregulation of ZnT8 at the message and protein levels, YC-1 rescues the injured retina by restoring the ZnT8 to its basal homeostatic levels in the neovascular retinas. Our data indicate that ischemic retinopathy maybe mediated by aberrant Zn(++ homeostasis caused by ZnT8 downregulation, whereas YC-1 plays a neuroprotective role against ischemic insult. Therefore, targeting ZnT8 provides a therapeutic strategy to combat neovascular eye diseases.

  2. [Acute ischemic proctitis following an epileptic attack

    DEFF Research Database (Denmark)

    Klintmann, C.K.; Hillingso, J.G.; Glenthøj, Andreas

    2008-01-01

    Acute ischemic proctitis is a rare diagnosis mainly because the rectum is supplied by an extensive arterial network. Consequently, in more than 90% of patients with ischemic colitis the rectum is spared. Previously reported cases are related to severe vascular insufficiency of the rectal circulat......Acute ischemic proctitis is a rare diagnosis mainly because the rectum is supplied by an extensive arterial network. Consequently, in more than 90% of patients with ischemic colitis the rectum is spared. Previously reported cases are related to severe vascular insufficiency of the rectal...... circulation caused by systemic atherosclerosis, usually following aortic or aortoiliac operations. We report one case of acute ischemic proctitis following an epileptic attack Udgivelsesdato: 2008/9/29...

  3. Retinal vessel tortuosity associated with central retinal vein occlusion: an optical coherence tomography study.

    Science.gov (United States)

    Muraoka, Yuki; Tsujikawa, Akitaka; Kumagai, Kyoko; Akagi-Kurashige, Yumiko; Ogino, Ken; Murakami, Tomoaki; Miyamoto, Kazuaki; Yoshimura, Nagahisa

    2014-01-07

    We studied morphologic changes of the retinal vasculature in eyes with central retinal vein occlusion (CRVO) through the use of optical coherence tomography (OCT). Major retinal vessels in 35 eyes from 35 consecutive patients with acute CRVO were examined prospectively and longitudinally with sequential thin sectioning and circumpapillary scanning. Anteroposterior venous tortuosity associated with CRVO was quantified on longitudinal OCT images of a randomly selected major temporal vein. On OCT sections of a given vein, we identified the innermost and outermost points of the vessel wall. The degree of anteroposterior venous tortuosity was defined as the difference between the vertical distances from the retinal pigment epithelium to the center of the venous lumen at these two points. The OCT images revealed that the major retinal veins traveled tortuously through the swollen neurosensory retina from the inner retinal surface to the retinal pigment epithelium. The degree of anteroposterior venous tortuosity was correlated with poor visual acuity (r = 0.457, P = 0.017), increased mean foveal thickness (r = 0.671, P retinal detachment was detected around the optic disc, which correlated with anteroposterior venous tortuosity. In 14 (40%) eyes, elongated major retinal veins disrupted the boundary between retinal vessels and parenchyma, which resulted in juxtavenous splitting of the neurosensory retina. In eyes with CRVO, OCT can be used to visualize anteroposterior venous tortuosity and associated structural changes to the retinal parenchyma.

  4. Swallowing disorders after ischemic stroke

    Directory of Open Access Journals (Sweden)

    Gabriela Camargo Remesso

    2011-10-01

    Full Text Available OBJECTIVE: To investigate occurrences of swallowing disorders after ischemic stroke. METHOD: This was a retrospective study on 596 medical files. The inclusion criterion was that the patients needed to have been hospitalized with a diagnosis of ischemic stroke; the exclusion criteria were the presence of associated cardiac problems and hospital stay already more than 14 days. RESULTS: 50.5% were men and 49.5% women; mean age 65.3 years (SD=±11.7 (p<0.001. Among the risk factors, 79.4% had hypertension, 36.7% had diabetes (p<0.001 and 42.7% were smokers. 13.3% of the patients died. Swallowing disorders occurred in 19.6%, among whom 91.5% had mild difficulty and 8.5% had severe difficulty. 87.1% had spontaneous recovery after a mean of 2.4 months. A lesion in the brainstem region occurred in 6.8% (p<0.001. CONCLUSION: Swallowing disorders occurred in almost 20% of the population and most of the difficulty in swallowing found was mild. The predictors for swallowing disorders were older age, diabetes mellitus and lesions in the brainstem region.

  5. Morbidity predictors in ischemic stroke

    Directory of Open Access Journals (Sweden)

    Panicker J

    2003-01-01

    Full Text Available Background: Although ischemic CVA is one of the leading causes for death and disability, parameters for predicting long-term outcome in such patients have not been clearly delineated, especially in the Indian context. Methods: A prospective hospital-based study of 105 patients of ischemic stroke, focal neurological deficits and functional score was assessed and the C-reactive protein level (CRP was measured. A follow-up was done at 5 days and at 6 months and outcome variable was the functional status at 6 months using Barthel Index of Activities of Daily Living. Accordingly, patients were grouped into 3 - Barthel Index < 41: Severely disabled, Barthel Index 41-60: Moderately disabled and Barthel Index > 60: Mildly disabled. Results: At admission, if upper limb power was less than Medical Research Council (MRC grade 4, or aphasia was present or CRP assay was positive, then at 6 months, these patients most likely belonged to the severely disabled group. If upper limb or lower limb power was greater than MRC grade 3 or there was no aphasia or conjugate gaze deviation or CRP assay was negative, these patients most likely belonged to the mildly disabled group at 6 months. Follow-up rate was 86%. Conclusion: Patients can be stratified according to the predicted prognosis. The treatment and rehabilitation can be properly planned and strictly adhered to in patients predicted to have worse prognosis.

  6. Retinal vascular oximetry during ranibizumab treatment of central retinal vein occlusion

    DEFF Research Database (Denmark)

    Traustason, Sindri; la Cour, Morten; Larsen, Michael

    2014-01-01

    PURPOSE: To investigate the effect of intravitreal injections of the vascular endothelial growth factor inhibitor ranibizumab on retinal oxygenation in patients with central retinal vein occlusion (CRVO). METHODS: Retinal oxygen saturation in patients with CRVO was analysed using the Oxymap Retinal...... in eyes with CRVO than in the fellow eyes (95%±8% and 91%±3%, p=0.04). Mean visual acuity increased from 51±24 letters ETDRS at baseline to 66±24 and 69±20 letters ETRDS, respectively, at 3 months and 6 months treatment (mean±SD, pcentral retinal...... Oximeter P3, before and during 6 months of treatment with intravitreal injections of ranibizumab. RESULTS: At presentation, retinal venous oxygen saturation was lower in eyes with CRVO than in the healthy fellow eyes (32±13% vs 59±10%, respectively, p=0.001) whereas retinal arterial saturation was higher...

  7. Microcystic Changes in the Retinal Internal Nuclear Layer Associated with Optic Atrophy: A Prospective Study

    Directory of Open Access Journals (Sweden)

    Benjamin Wolff

    2014-01-01

    Full Text Available Purpose. This study aimed at assessing the prevalence of pathologies presenting retinal inner nuclear layer (RINL microcystic perimacular changes associated with optic nerve atrophy (OA. The charts of patients presenting a significant defect of the Retinal Nerve Fiber Layer (RNFL were included prospectively in this study. Patients were classified according to the etiology of the RNFL defect. Two hundred and one eyes of 138 patients were enrolled in this analysis. Retinal images obtained showed the typical hyporeflective perifoveal crescent-shaped lesion composed of small round hyporeflective microcysts confined to the RINL in 35.3% of the eyes. Those findings were found in 75% of eyes presenting hereditary OA, 50% of eyes presenting ischemic optic neuritis, 50% of eyes with drusen of the optic nerve (ON, 44.4% of eyes presenting a compressive OA, 32% of eyes presenting inflammatory optic neuropathy from multiple sclerosis, 18.5% of eyes presenting OA from undetermined origin, and 17.6% of eyes having primary open-angle glaucoma. This study demonstrates that microcystic changes in RINL are not specific to a disease but are found in OA of various etiologies. Moreover, their incidence was found to be dependent upon the cause of OA, with the highest incidence occurring in genetic OA.

  8. Argus II retinal prosthesis system: An update.

    Science.gov (United States)

    Rachitskaya, Aleksandra V; Yuan, Alex

    2016-09-01

    This review focuses on a description of the Argus II retinal prosthesis system (Argus II; Second Sight Medical Products, Sylmar, CA) that was approved for humanitarian use by the FDA in 2013 in patients with retinitis pigmentosa with bare or no light perception vision. The article describes the components of Argus II, the studies on the implant, and future directions.

  9. Fundus autofluorescence applications in retinal imaging

    Directory of Open Access Journals (Sweden)

    Andrea Gabai

    2015-01-01

    Full Text Available Fundus autofluorescence (FAF is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications.

  10. RETINAL VEIN OCCLUSIONS - A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Ramadevi

    2015-11-01

    Full Text Available Retinal vein occlusion is the most common retinal occlusive disorder encountered by opthalmologists and is usually associated with a variable amount of visual loss.The study was conducted over a period of 22 months, we performed a combined analysis of risk factors, clinical presentation, management and complication of these 51 patients

  11. Anatomy of the retinal nerve fiber layer.

    Science.gov (United States)

    Radius, R L; de Bruin, J

    1981-11-01

    Anatomy of the retinal nerve fiber layer in rabbit eyes is studied by light microscopy, transmission electron microscopy, and scanning electron microscopy. It is demonstrated that retinal striations noted ophthalmoscopically in these eyes represent individual fiber bundles, Axon bundles are compartmentalized within tissue tunnels comprised of elongated processes of glial cell origin.

  12. Retinal ischemia and embolism. Causes and outcomes

    NARCIS (Netherlands)

    Wijman, C.A.C.

    2007-01-01

    The ocular fundus allows direct visualization of the retinal vasculature, blood vessels that are part of the cerebral circulation. Unraveling the causes of retinal ischemia may provide further insight in the pathophysiological processes that underlie cerebral ischemia. The primary aim of the studies

  13. Retinal vein occlusion: pathophysiology and treatment options

    OpenAIRE

    Niral Karia

    2010-01-01

    Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss

  14. Basic Fibroblast Growth Factor Contributes to a Shift in the Angioregulatory Activity of Retinal Glial (Müller) Cells

    Science.gov (United States)

    Yafai, Yousef; Iandiev, Ianors; Lange, Johannes; Yang, Xiu Mei; Wiedemann, Peter; Bringmann, Andreas; Eichler, Wolfram

    2013-01-01

    Basic fibroblast growth factor (bFGF) is a pleiotropic cytokine with pro-angiogenic and neurotrophic effects. The angioregulatory role of this molecule may become especially significant in retinal neovascularization, which is a hallmark of a number of ischemic eye diseases. This study was undertaken to reveal expression characteristics of bFGF, produced by retinal glial (Müller) cells, and to determine conditions under which glial bFGF may stimulate the proliferation of retinal microvascular endothelial cells. Immunofluorescence labeling detected bFGF in Müller cells of the rat retina and in acutely isolated Müller cells with bFGF levels, which increased after ischemia-reperfusion in postischemic retinas. In patients with proliferative diabetic retinopathy or myopia, the immunoreactivity of bFGF co-localized to glial fibrillary acidic protein (GFAP)-positive cells in surgically excised retinal tissues. RT-PCR and ELISA analyses indicated that cultured Müller cells produce bFGF, which is elevated under hypoxia or oxidative stress, as well as under stimulation with various growth factors and cytokines, including pro-inflammatory factors. When retinal endothelial cells were cultured in the presence of media from hypoxia (0.2%)-conditioned Müller cells, a distinct picture of endothelial cell proliferation emerged. Media from 24-h cultured Müller cells inhibited proliferation, whereas 72-h conditioned media elicited a stimulatory effect. BFGF-neutralizing antibodies suppressed the enhanced endothelial cell proliferation to a similar extent as anti-VEGF antibodies. Furthermore, phosphorylation of extracellular signal-regulated kinases (ERK−1/−2) in retinal endothelial cells was increased when the cells were cultured in 72-h conditioned media, while neutralizing bFGF attenuated the activation of this signaling pathway. These data provide evidence that retinal (glial) Müller cells are major sources of bFGF in the ischemic retina. Müller cells under

  15. Basic fibroblast growth factor contributes to a shift in the angioregulatory activity of retinal glial (Muller cells.

    Directory of Open Access Journals (Sweden)

    Yousef Yafai

    Full Text Available Basic fibroblast growth factor (bFGF is a pleiotropic cytokine with pro-angiogenic and neurotrophic effects. The angioregulatory role of this molecule may become especially significant in retinal neovascularization, which is a hallmark of a number of ischemic eye diseases. This study was undertaken to reveal expression characteristics of bFGF, produced by retinal glial (Müller cells, and to determine conditions under which glial bFGF may stimulate the proliferation of retinal microvascular endothelial cells. Immunofluorescence labeling detected bFGF in Müller cells of the rat retina and in acutely isolated Müller cells with bFGF levels, which increased after ischemia-reperfusion in postischemic retinas. In patients with proliferative diabetic retinopathy or myopia, the immunoreactivity of bFGF co-localized to glial fibrillary acidic protein (GFAP-positive cells in surgically excised retinal tissues. RT-PCR and ELISA analyses indicated that cultured Müller cells produce bFGF, which is elevated under hypoxia or oxidative stress, as well as under stimulation with various growth factors and cytokines, including pro-inflammatory factors. When retinal endothelial cells were cultured in the presence of media from hypoxia (0.2%-conditioned Müller cells, a distinct picture of endothelial cell proliferation emerged. Media from 24-h cultured Müller cells inhibited proliferation, whereas 72-h conditioned media elicited a stimulatory effect. BFGF-neutralizing antibodies suppressed the enhanced endothelial cell proliferation to a similar extent as anti-VEGF antibodies. Furthermore, phosphorylation of extracellular signal-regulated kinases (ERK-1/-2 in retinal endothelial cells was increased when the cells were cultured in 72-h conditioned media, while neutralizing bFGF attenuated the activation of this signaling pathway. These data provide evidence that retinal (glial Müller cells are major sources of bFGF in the ischemic retina. Müller cells under

  16. Anterior ischemic optic neuropathy in association with optic nervehead drusen

    Directory of Open Access Journals (Sweden)

    Bharathi Megur

    2014-01-01

    Full Text Available Optic nerve head drusen (ONHD are incidental ophthalmologic finding in the optic nerve. Patients with ONHD are often asymptomatic, but sometimes present with transient visual obscuration′s (TVO, the reported incidence of which is 8.6%. Optic nerve head drusen are of two types: Superficial; visible and deep. The deep-buried drusen mimic papilledema. Because of the varied presentation deep-buried drusen pose a diagnostic challenge to the ophthalmologists. In young patients, they are mistaken for papilledema as it is clinically difficult to detect a buried drusen in the optic nerve head, but are seen on the surface with aging as the retinal nerve fiber layer thins out. They are observed as pale yellow lesions more often located towards the poles. Clinical examination aided with diagnostic tests like computed tomography (CT orbits and ultrasound B scan can help establish the diagnosis. Herein, we report a rare case of optic nerve head drusen in a young lady, who presented with loss of vision and clinical evaluation and investigations suggested ONHD with anterior ischemic optic neuropathy.

  17. Ischemic preconditioning reduces ischemic brain injury by suppressing nuclear factor kappa B expression and neuronal apoptosis

    Institute of Scientific and Technical Information of China (English)

    Songsheng Shi; Weizhong Yang; Xiankun Tu; Chunmei Chen; Chunhua Wang

    2013-01-01

    Ischemic stroke induces a series of complex pathophysiological events including blood-brain barrier disruption, inflammatory response and neuronal apoptosis. Previous studies demonstrate that ischemic preconditioning attenuates ischemic brain damage via inhibiting blood-brain barrier disruption and the inflammatory response. Rats underwent transient (15 minutes) occlusion of the bilateral common carotid artery with 48 hours of reperfusion, and were subjected to permanent middle cerebral artery occlusion. This study explored whether ischemic preconditioning could reduce ischemic brain injury and relevant molecular mechanisms by inhibiting neuronal apoptosis. Results found that at 72 hours following cerebral ischemia, myeloperoxidase activity was enhanced, malondialdehyde levels increased, and neurological function was obviously damaged. Simultaneously, neuronal apoptosis increased, and nuclear factor-κB and cleaved caspase-3 expression was significantly increased in ischemic brain tissues. Ischemic preconditioning reduced the cerebral ischemia-induced inflammatory response, lipid peroxidation, and neurological function injury. In addition, ischemic preconditioning decreased nuclear factor-κB p65 and cleaved caspase-3 expression. These results suggested that ischemic preconditioning plays a protective effect against ischemic brain injury by suppressing the inflammatory response, reducing lipid peroxidation, and neuronal apoptosis via inhibition of nuclear factor-κB and cleaved caspase-3 expression.

  18. Retinal artery occlusions in children.

    Science.gov (United States)

    Dharmasena, Aruna; Wallis, Simon

    2014-01-01

    The purpose of this study is to present a case of RAO in a 13 year old girl with a preceding history of hyperextension of the neck at her hairdressers for a long duration and use of her mobile phone handset resting it against the side of her neck presumably exerting some pressure on carotids during the same time. Materials and methods of this study was reported as case report and review of literature. A 13 year-old girl presented with the left supero-nasal scotoma due to an inferior temporal branch retinal artery occlusion (BRAO). She underwent extensive investigations and no underlying cause was discovered. She gave a history of cervical extension over a long period of time while having the hair coloured twice in the preceding week. She also mentioned that she was using her mobile phone more or less continuously during both these occasions keeping it against her neck. Given the above history it is possible that the pressure on the ipsilateral carotid arteries or the prolong neck extension may have been responsible for the formation of a platelet embolus resulting in the BRAO. In conclusion, although cerebro-vascular accidents due to 'beauty parlor stroke syndrome' (JAMA 269:2085-2086, 1993) have been reported previously it has not been reported in children to our knowledge. On the other hand, 'beauty parlor stroke syndrome' occurs due to a dissection of the vertebral arteries or due to mechanical compression of the vertebral arteries during the prolonged hyperextension of the neck. The central retinal artery originates from the internal carotid circulation and it is highly unlikely for an embolus to enter the retinal circulation from the vertebral arteries. Therefore, the authors favour the possibility that the compulsive use of a mobile phone exerting pressure on the carotid arteries for a long time may have led to the formation of an embolus and subsequent RAO in this case.

  19. Does soccer ball heading cause retinal bleeding?

    Science.gov (United States)

    Reed, William F; Feldman, Kenneth W; Weiss, Avery H; Tencer, Alan F

    2002-04-01

    To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage. Regional Children's Hospital, youth soccer camp. Male and female soccer players, 13 to 16 years old, who regularly head soccer balls. Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball. Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7 +/- 1.3g. Rotational accelerations were negligible. Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.

  20. The cell stress machinery and retinal degeneration.

    Science.gov (United States)

    Athanasiou, Dimitra; Aguilà, Monica; Bevilacqua, Dalila; Novoselov, Sergey S; Parfitt, David A; Cheetham, Michael E

    2013-06-27

    Retinal degenerations are a group of clinically and genetically heterogeneous disorders characterised by progressive loss of vision due to neurodegeneration. The retina is a highly specialised tissue with a unique architecture and maintaining homeostasis in all the different retinal cell types is crucial for healthy vision. The retina can be exposed to a variety of environmental insults and stress, including light-induced damage, oxidative stress and inherited mutations that can lead to protein misfolding. Within retinal cells there are different mechanisms to cope with disturbances in proteostasis, such as the heat shock response, the unfolded protein response and autophagy. In this review, we discuss the multiple responses of the retina to different types of stress involved in retinal degenerations, such as retinitis pigmentosa, age-related macular degeneration and glaucoma. Understanding the mechanisms that maintain and re-establish proteostasis in the retina is important for developing new therapeutic approaches to fight blindness.

  1. Prevalence of generalized retinal dystrophy in Denmark

    DEFF Research Database (Denmark)

    Bertelsen, Mette; Jensen, Hanne; Bregnhøj, Jesper F;

    2014-01-01

    of this study was to examine the prevalence and diagnostic spectrum of generalized retinal dystrophy in the Danish population. METHODS: A population-based cross-sectional study with data from the Danish Retinitis Pigmentosa Registry that comprises all patients in Denmark with generalized retinal....... RESULTS: Of the 5,602,628 Danish citizens on January 1, 2013, 1622 patients were registered as having a generalized retinal dystrophy and were alive and living in Denmark, corresponding to a prevalence of 1:3,454. In 28% of cases the eye condition was part of a syndrome, while the remaining 72% had eye...... disease only. Aside from simplex cases (45%), the most common hereditary pattern was autosomal recessive (23%). CONCLUSION: This epidemiological survey demonstrates that the prevalence of generalized retinal dystrophy in the Danish population is 1:3454. Many of the dystrophies are the subjects of clinical...

  2. Bimatoprost protects retinal neuronal damage via Akt pathway.

    Science.gov (United States)

    Takano, Norihito; Tsuruma, Kazuhiro; Ohno, Yuta; Shimazawa, Masamitsu; Hara, Hideaki

    2013-02-28

    Worldwide, prostaglandin analogs, such as bimatoprost, have become the major therapeutic class for medical treatment of glaucoma because of their efficacy and generally well tolerated systemic safety profile. However, the detailed mechanism of the direct action of bimatoprost on retinal ganglion cells (RGC) has rarely been understood. Thus, in this study, we elucidated the mechanism of the protective effects of bimatoprost on RGC against oxidative stress. To examine the protective effects of bimatoprost, cultured RGC with various concentrations of bimatoprost (in both free acid and amide form) were exposed to l-buthionin-(S,R)-sulfoximine (BSO) plus glutamate or serum depletion in vitro and intravitreal injection of N-methyl-D-aspartate (NMDA) was used to induce retinal damage in vivo. To elucidate the protective mechanism of bimatoprost, we used western blot analysis to investigate the phosphorylation of Akt and extracellular signal-regulated kinase (ERK). Bimatoprost significantly reduced BSO plus glutamate- and serum deprivation-induced death in concentration-dependent manners. Bimatoprost induced activation of Akt and ERK, and a phosphatidylinositol 3-kinase inhibitor, LY294002, attenuated the protective effect of bimatoprost. On the other hand, a mitogen-activated protein kinase kinase inhibitor, U0126, exhibited protective effect unexpectedly. Moreover, ERK was more phosphorylated by attenuation of Akt activity in cultured RGC. In an in vivo study, bimatoprost reduced NMDA-induced RGC death. Taken together, these findings indicate that bimatoprost has protective effects on in vitro and in vivo retinal damage, suggesting that the mechanism underlying may be via the Akt pathway, which may modulate the ERK pathway.

  3. Retinal oxygen saturation evaluation by multi-spectral fundus imaging

    Science.gov (United States)

    Khoobehi, Bahram; Ning, Jinfeng; Puissegur, Elise; Bordeaux, Kimberly; Balasubramanian, Madhusudhanan; Beach, James

    2007-03-01

    Purpose: To develop a multi-spectral method to measure oxygen saturation of the retina in the human eye. Methods: Five Cynomolgus monkeys with normal eyes were anesthetized with intramuscular ketamine/xylazine and intravenous pentobarbital. Multi-spectral fundus imaging was performed in five monkeys with a commercial fundus camera equipped with a liquid crystal tuned filter in the illumination light path and a 16-bit digital camera. Recording parameters were controlled with software written specifically for the application. Seven images at successively longer oxygen-sensing wavelengths were recorded within 4 seconds. Individual images for each wavelength were captured in less than 100 msec of flash illumination. Slightly misaligned images of separate wavelengths due to slight eye motion were registered and corrected by translational and rotational image registration prior to analysis. Numerical values of relative oxygen saturation of retinal arteries and veins and the underlying tissue in between the artery/vein pairs were evaluated by an algorithm previously described, but which is now corrected for blood volume from averaged pixels (n > 1000). Color saturation maps were constructed by applying the algorithm at each image pixel using a Matlab script. Results: Both the numerical values of relative oxygen saturation and the saturation maps correspond to the physiological condition, that is, in a normal retina, the artery is more saturated than the tissue and the tissue is more saturated than the vein. With the multi-spectral fundus camera and proper registration of the multi-wavelength images, we were able to determine oxygen saturation in the primate retinal structures on a tolerable time scale which is applicable to human subjects. Conclusions: Seven wavelength multi-spectral imagery can be used to measure oxygen saturation in retinal artery, vein, and tissue (microcirculation). This technique is safe and can be used to monitor oxygen uptake in humans. This work

  4. Bilateral retinitis following typhoid fever

    OpenAIRE

    Prabhushanker, M.; Topiwalla, Tasneem T.; Ganesan, Geetha; Appandaraj, Sripal

    2017-01-01

    Background Post typhoid fever immune related reactions affecting the eye is a rare finding which can have various presentations in which typhoid retinopathy is not a well recognized sequelae. Case presentation Here we present a case of 59?year old male who presented with right eye sudden painless loss of vision 4?weeks after typhoid fever which was diagnosed and treated successfully. His BCVA was 2/60 in right eye and 6/6 in left eye. Fundus examination showed retinitis along with macular ser...

  5. Regenerative Therapy for Retinal Disorders

    Directory of Open Access Journals (Sweden)

    Narsis Daftarian

    2010-01-01

    Full Text Available Major advances in various disciplines of basic sciences including embryology, molecular and cell biology, genetics, and nanotechnology, as well as stem cell biology have opened new horizons for regenerative therapy. The unique characteristics of stem cells prompt a sound understanding for their use in modern regenerative therapies. This review article discusses stem cells, developmental stages of the eye field, eye field transcriptional factors, and endogenous and exogenous sources of stem cells. Recent studies and challenges in the application of stem cells for retinal pigment epithelial degeneration models will be summarized followed by obstacles facing regenerative therapy.

  6. Bilateral Progressive Obliterative Retinal Vasculitis

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    In this paper, 10 cases of a special type of retinal vasculitis are reported, which was characterized by progressive obliteration of vessels in both eyes, developed from the periphery to the posterior ploe, and was complicated by vitreous hemorrhage (5 eyes) and neovascular glaucoma (5 eyes) in later stage. The visual acuity was 0. 05 in 10 eyes (50%). Argon laser pho-tocoagulation seemed to be able to retard the natural course of the disease. Fundus changes, differential diagnosis and treatment etc are...

  7. Adenosine Preconditioning versus Ischemic Preconditioning in Patients undergoing Off-Pump Coronary Artery Bypass (OPCAB

    Directory of Open Access Journals (Sweden)

    SeyedKhalil Forouzannia

    2015-10-01

    Full Text Available Background: During off-pump coronary artery bypass (OPCAB, the heart is subjected to ischemic and reperfusion injury. Preconditioning is a mechanism that permits the heart to tolerate myocardial ischemia. The aim of this study was to compare the effects of Adenosine preconditioning with ischemic preconditioning on the global ejection fraction (EF in patients undergoing OPCAB.Methods: In this single-blind, randomized controlled trial, sixty patients undergoing OPCAB were allocated into three equally-numbered groups through simple randomization: Adenosine group, ischemic group, and control group. The patients in the Adenosine group received an infusion of Adenosine. In the ischemic group, ischemic preconditioning was induced by the temporary occlusion of the left anterior descending coronary artery twice for a 2-minute period, followed by 3-minute reperfusion before bypass grafting of the first coronary vessel. The control group received an intravenous infusion of 0.9% saline. Blood samples at different times were sent for the measurement of creatine kinase isoenzyme MB (CK-MB and cardiac troponin I (cTnI. We also recorded electrocardiographic indices and clinical parameters, including postoperative use of inotropic drugs and preoperative and postoperative EF.Results: History of myocardial infarction, hyperlipidemia, diabetes mellitus, kidney disease, preoperative arrhythmias, and utilization of postoperative inotrope was the same between the three groups. The incidence of postoperative arrhythmias was not significant between the three groups. Also, there were no significant differences in preoperative and postoperative EF and the serum levels of enzymes (cTnI and CK-MB between the groups.Conclusion: Based on the findings of this study, there was no significant difference in the postoperative EF between the groups. Although the incidence of arrhythmias was higher in the ischemic preconditioning group than in the other groups, the difference

  8. Remote ischemic preconditioning in percutaneous coronary revascularization: a double-blind randomized controlled clinical trial.

    Science.gov (United States)

    Ghaemian, Ali; Nouraei, S Mahmoud; Abdollahian, Fatemeh; Naghshvar, Farshad; Giussani, Dino A; Nouraei, S A Reza

    2012-10-01

    To assess the impact of pre-procedural remote ischemic preconditioning on the incidence of myocardial complications following percutaneous coronary intervention. Ischemic preconditioning of a remote vascular territory improves the subsequent ischemic tolerance of distant organs. The Myocardial Event Reduction with Ischemic Preconditioning Therapy (MERIT) trial recruited 80 consecutive patients undergoing elective angioplasty with drug-eluting stents to receive two 5-min lower limb tourniquet occlusions or an un-inflated tourniquet (controls) 1 h before the procedure. The primary outcome was troponin T level at 24 h. Secondary outcomes were intra-procedural chest pain and ST-segment deviation. 6 patients in the control group and 2 in the ischemic preconditioning group had pre-procedural raised troponin T (p = 0.23). This increased to 16 (40%) in the control group and 5 (12.5%) in the study group at 24 h (p = 0.01). Fewer patients in the study group experienced intra-procedural chest pain (1 vs. 7, p = 0.056). Mean ST-segment deviation time was 13 ± 35 s in the study group and 58 ± 118 s in the control group (p = 0.02). At a mean follow-up of 11 months, the major adverse cardiac event rate did not differ significantly between the groups. These data suggest that ischemic preconditioning reduces the absolute risk of post-procedure cardiomyocyte necrosis by 27.5%, and reduces intra-procedural chest pain and ST-segment deviation in patients undergoing percutaneous coronary interventions. We suggest its routine use in percutaneous coronary intervention, although the long-term prognostic impact in this patient group warrants further investigation.

  9. Characteristics of Misclassified CT Perfusion Ischemic Core in Patients with Acute Ischemic Stroke.

    Directory of Open Access Journals (Sweden)

    Ralph R E G Geuskens

    Full Text Available CT perfusion (CTP is used to estimate the extent of ischemic core and penumbra in patients with acute ischemic stroke. CTP reliability, however, is limited. This study aims to identify regions misclassified as ischemic core on CTP, using infarct on follow-up noncontrast CT. We aim to assess differences in volumetric and perfusion characteristics in these regions compared to areas that ended up as infarct on follow-up.This study included 35 patients with >100 mm brain coverage CTP. CTP processing was performed using Philips software (IntelliSpace 7.0. Final infarct was automatically segmented on follow-up noncontrast CT and used as reference. CTP and follow-up noncontrast CT image data were registered. This allowed classification of ischemic lesion agreement (core on CTP: rMTT≥145%, aCBV<2.0 ml/100g and infarct on follow-up noncontrast CT and misclassified ischemic core (core on CTP, not identified on follow-up noncontrast CT regions. False discovery ratio (FDR, defined as misclassified ischemic core volume divided by total CTP ischemic core volume, was calculated. Absolute and relative CTP parameters (CBV, CBF, and MTT were calculated for both misclassified CTP ischemic core and ischemic lesion agreement regions and compared using paired rank-sum tests.Median total CTP ischemic core volume was 49.7ml (IQR:29.9ml-132ml; median misclassified ischemic core volume was 30.4ml (IQR:20.9ml-77.0ml. Median FDR between patients was 62% (IQR:49%-80%. Median relative mean transit time was 243% (IQR:198%-289% and 342% (IQR:249%-432% for misclassified and ischemic lesion agreement regions, respectively. Median absolute cerebral blood volume was 1.59 (IQR:1.43-1.79 ml/100g (P<0.01 and 1.38 (IQR:1.15-1.49 ml/100g (P<0.01 for misclassified ischemic core and ischemic lesion agreement, respectively. All CTP parameter values differed significantly.For all patients a considerable region of the CTP ischemic core is misclassified. CTP parameters significantly

  10. Demarcation laser photocoagulation induced retinal necrosis and rupture resulting in large retinal tear formation.

    Science.gov (United States)

    Quezada, Carlos; Pieramici, Dante J; Matsui, Rodrigo; Rabena, Melvin; Graue, Federico

    2015-06-01

    Retinal tears after laser photocoagulation are a rare complication that occurs after intense laser. It is talked about among retina specialist occurring particularly at the end of a surgical case while applying endophotocoagulation; to the best our knowledge, there are no reports in the literature of a large retinal tear induced after attempted in-office demarcation laser photocoagulation (DLP) that simulated a giant retinal tear. DLP has been employed in the management of selected cases of macula sparring rhegmatogenous retinal detachment (RRD). Even though extension of the retinal detachment through the "laser barrier" is considered a failure of treatment, few complications have been described with the use of this less invasive retinal detachment repair technique. We describe a case of a high myopic woman who initially was treated with demarcation laser photocoagulation for an asymptomatic retinal detachment associated with a single horseshoe tear and a full thickness large retinal tear was created where the laser was placed. Intense laser photocoagulation resulted in abrupt laser induced retinal necrosis and rupture creating this large retinal break. Proper laser technique should reduce the risks associated with this procedure.

  11. Presumed toxoplasmic central retinal artery occlusion and multifocal retinitis with perivascular sheathing

    Directory of Open Access Journals (Sweden)

    Arai H

    2014-04-01

    Full Text Available Haruka Arai,1 Tsutomu Sakai,1 Kiichiro Okano,1 Ranko Aoyagi,1 Ayano Imai,2 Hiroshi Takase,2 Manabu Mochizuki,2 Hiroshi Tsuneoka11Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; 2Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, JapanAbstract: Central retinal artery occlusion (CRAO and multifocal retinitis with perivascular sheathing are rare in ocular toxoplasmosis. We report a case of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. A healthy 83-year-old male developed left panuveitis. Funduscopic examination of the left eye showed a swollen optic disc and sheathing of the retinal artery with a dense vitreous haze and a white retinal lesion. Serum anti-toxoplasma antibodies were positive in a latex agglutination assay. Vitrectomy was performed to improve visualization of the retinal lesions and for examination of causative microorganisms. A postoperative fundus examination revealed CRAO with optic disc involvement and multifocal retinitis with perivascular sheathing. Qualitative multiplex polymerase chain reaction detected the Toxoplasma gondii B1 gene in ocular fluid from both the aqueous and vitreous humor. The presumed diagnosis of ocular toxoplasmosis was made and treatment was started with prednisone and acetylspiramycin with subsequent improvement. Two months later, the patient developed active retinochoroiditis in the left eye. After 6 weeks of anti-toxoplasma therapy, the disease involuted. Retinal vascular occlusions and multifocal retinitis with perivascular sheathing are rare in toxoplasmosis. This is the first case report of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. The diagnosis of ocular toxoplasmosis should be considered in patients with retinal artery occlusions and multifocal retinitis with perivascular sheathing associated with inflammation.Keywords: ocular toxoplasmosis, toxoplasma retinochoroiditis

  12. Ischemic heart disease in women

    Directory of Open Access Journals (Sweden)

    Stella Iraklianou

    2009-10-01

    Full Text Available Coronary heart disease has long been recognized as the leading cause of death among middle-aged men and an equally important cause of death and disability among older women. Women with acute ischemic syndromes tend to be older than men with such syndromes. This is considered to be attributed to the protective effects of female ovarian sex hormones. Estrogen express an antiatherogenic profile via mechanisms that cause favorable modifications of lipoprotein levels, coagulation and fibrolytic system and alterations in the wall of vessels that cause vasodilation. Women are susceptible to coronary heart disease because of differences in the anatomy and physiology of their vessels. Women's coronary arteries are smaller and have more diffuse disease than men's. Ischemia can be induced in women without flow limiting stenosis because of endothelial dysfunction or coronary spasm. Usually, the way of manifestation of the disease and ECG abnormalities are not typical in women. Female patients usually delay to seek treatment for their symptoms .The way of evaluation and treatment is usually conservative in women than male counterparts. The diagnosis of the disease is overestimated in men and the treatment is more often invasive, even in the category of low risk. Reversely, women of high risk are less likely to undergo a full assessment and invasive diagnostic and therapeutic interventions are seldom. Recommendations of the American Heart Association for ischemic heart disease in women are in accordance to alterations in the way of life interventions in major risk factors such as arterial hypertension, dyslipidemia and diabetes mellitus, preventive use of medications and drugs that are not recommended. In this category of medications belong hormone replacement therapy (HRT.The last is not recommended for primary and secondary prevention of coronary heart disease in women.

  13. Quantitative Measurement of Physical Activity in Acute Ischemic Stroke and Transient Ischemic Attack

    DEFF Research Database (Denmark)

    Strømmen, Anna Maria; Christensen, Thomas; Jensen, Kai

    2014-01-01

    BACKGROUND AND PURPOSE: The purpose of this study was to quantitatively measure and describe the amount and pattern of physical activity in patients within the first week after acute ischemic stroke and transient ischemic attack using accelerometers. METHODS: A total of 100 patients with acute is...... ischemic stroke. The method offers a low cost and noninvasive tool for future clinical interventional physiotherapeutic and early mobilization studies. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01560520....

  14. MicroRNA signature and function in retinal neovascularization

    Institute of Scientific and Technical Information of China (English)

    Saloni; Agrawal; Brahim; Chaqour

    2014-01-01

    Ischemic retinopathies are clinically well-defined chronic microvascular complications characterized by gradually progressive alterations in the retinal microvasculature and a compensatory aberrant neovascularization of the eye. The subsequent metabolic deficiencies result in structural and functional alterations in the retina which is highly susceptible to injurious stimuli such as diabe-tes, trauma, hyperoxia, inflammation, aging and dys-plipidemia. Emerging evidence indicates that an effec-tive therapy may require targeting multiple components of the angiogenic pathway. Conceptually, mircoRNA(miRNA)-based therapy provides the rationale basis for an effective antiangiogenic treatment. miRNAs are an evolutionarily conserved family of short RNAs, each regulating the expression of multiple protein-coding genes. The activity of specific miRNAs is important for vascular cell signaling and blood vessel formation and function. Recently, important progress has been made in mapping the miRNA-gene target network andmiRNA-mediated gene expression control. Here wehighlight the latest findings on angiogenic and antian-giogenic miRNAs and their targets as well as potentiaimplications in ocular neovascular diseases. Emphasis isplaced on how specific vascular-enriched miRNAs regu-late cell responses to various cues by targeting severafactors, receptors and/or signaling molecules in orderto maintain either vascular function or dysfunction. Fur-ther improvement of our knowledge in not only miRNAspecificity, turnover, and transport but also how miRNAsequences and functions can be altered will enhancethe therapeutic utility of such molecules.

  15. Optical coherence tomography angiography in retinal diseases

    Directory of Open Access Journals (Sweden)

    K V Chalam

    2016-01-01

    Full Text Available Optical coherence tomography angiography (OCTA is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA algorithm (a vital component of OCTA software helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD, retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA. Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  16. Genomic analysis of mouse retinal development.

    Directory of Open Access Journals (Sweden)

    Seth Blackshaw

    2004-09-01

    Full Text Available The vertebrate retina is comprised of seven major cell types that are generated in overlapping but well-defined intervals. To identify genes that might regulate retinal development, gene expression in the developing retina was profiled at multiple time points using serial analysis of gene expression (SAGE. The expression patterns of 1,051 genes that showed developmentally dynamic expression by SAGE were investigated using in situ hybridization. A molecular atlas of gene expression in the developing and mature retina was thereby constructed, along with a taxonomic classification of developmental gene expression patterns. Genes were identified that label both temporal and spatial subsets of mitotic progenitor cells. For each developing and mature major retinal cell type, genes selectively expressed in that cell type were identified. The gene expression profiles of retinal Müller glia and mitotic progenitor cells were found to be highly similar, suggesting that Müller glia might serve to produce multiple retinal cell types under the right conditions. In addition, multiple transcripts that were evolutionarily conserved that did not appear to encode open reading frames of more than 100 amino acids in length ("noncoding RNAs" were found to be dynamically and specifically expressed in developing and mature retinal cell types. Finally, many photoreceptor-enriched genes that mapped to chromosomal intervals containing retinal disease genes were identified. These data serve as a starting point for functional investigations of the roles of these genes in retinal development and physiology.

  17. Optical Coherence Tomography Angiography in Retinal Diseases.

    Science.gov (United States)

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  18. Bilateral acute retinal necrosis after herpetic meningitis

    Directory of Open Access Journals (Sweden)

    Katsura T

    2012-04-01

    Full Text Available Keisho Hirota1,2, Masayuki Akimoto1,3, Toshiaki Katsura21Department of Ophthalmology, Kyoto Medical Center, National Hospital Organization, 2Internal Medicine, Kyoto Medical Center, 3Clinical Research Center, Kyoto Medical Center, Kyoto, JapanPurpose: The report of a case of bilateral acute retinal necrosis after herpetic meningitis.Case report: A 47-year-old man was admitted with the chief complaint of persistent high fever and transient loss of consciousness. Although his general condition improved after intravenous acyclovir administration, the patient presented with visual loss in both eyes 4 days after admission. Visual acuity in his right eye was 20/200 and his left eye had light perception alone. Both eyes showed panretinal arteritis diagnosed as acute retinal necrosis. Panretinal photocoagulation was performed for both eyes. Progression of retinal detachment was prevented in both eyes; however, visual acuity of the left eye was totally lost because of neovascular glaucoma. Visual acuity of the right eye recovered to 20/20.Conclusion: Although cases of bilateral acute retinal necrosis have been reported after herpetic encephalitis, this condition is rare after herpetic meningitis. Prophylactic acyclovir therapy and early panretinal photocoagulation may prevent retinal detachment and improve the prognosis. Neurologists and ophthalmologists should be aware that not only herpetic encephalitis but also herpetic meningitis can lead to acute retinal necrosis within a very short interval.Keywords: acute retinal necrosis, herpetic meningitis, herpes simplex, varicella zoster virus

  19. Automatic diagnosis of retinal diseases from color retinal images

    CERN Document Server

    Jayanthi, D; SwarnaParvathi, S

    2010-01-01

    Teleophthalmology holds a great potential to improve the quality, access, and affordability in health care. For patients, it can reduce the need for travel and provide the access to a superspecialist. Ophthalmology lends itself easily to telemedicine as it is a largely image based diagnosis. The main goal of the proposed system is to diagnose the type of disease in the retina and to automatically detect and segment retinal diseases without human supervision or interaction. The proposed system will diagnose the disease present in the retina using a neural network based classifier.The extent of the disease spread in the retina can be identified by extracting the textural features of the retina. This system will diagnose the following type of diseases: Diabetic Retinopathy and Drusen.

  20. 25-Hydroxyvitamin D and symptomatic ischemic stroke

    DEFF Research Database (Denmark)

    Brøndum-Jacobsen, Peter; Nordestgaard, Børge G; Schnohr, Peter

    2013-01-01

    OBJECTIVE: We tested the hypothesis that low plasma concentrations of 25-hydroxyvitamin D are associated with increased risk of symptomatic ischemic stroke in the general population. METHODS: We measured plasma 25-hydroxyvitamin D in 10,170 individuals from the general population, the Copenhagen...... City Heart Study. During 21 years of follow-up, 1,256 and 164 persons developed ischemic and hemorrhagic stroke, respectively. In a meta-analysis of ischemic stroke, we included 10 studies, 58,384 participants, and 2,644 events. RESULTS: Stepwise decreasing plasma 25-hydroxyvitamin D concentrations...... were associated with stepwise increasing risk of ischemic stroke both as a function of seasonally adjusted percentile categories and as a function of clinical categories of 25-hydroxyvitamin D (p for trend ≤ 2 × 10(-3) ). In a Cox regression model comparing individuals with plasma 25-hydroxyvitamin D...

  1. Bacterial pneumonia following acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Li-Fu Chen

    2013-02-01

    Conclusion: Pneumonia after acute ischemic stroke is a severe complication. Once stroke-related pneumonia develops, neurologic assessment, CURB-65 score, and shock can be used to predict the ultimate prognosis.

  2. ischemic brain injury in neonatal rats

    African Journals Online (AJOL)

    Keywords: Hypoxic–ischemic brain injury, α-Lipoic acid, Cerebral infarct area, Edema, Antioxidants,. Inflammatory markers .... were then moved back to their respective dams and immediately ..... various pro-inflammatory cytokines is stimulated.

  3. Ischemic preconditioning decreases intracellular zinc accumulation induced by oxygen-glucose deprivation in gerbil hippocampal CA1 neurons.

    Science.gov (United States)

    Miyawaki, Takahiro; Yokota, Hidenori; Oguro, Keiji; Kato, Kengo; Shimazaki, Kuniko

    2004-05-27

    In normal gerbils, intracellular zinc ions ([Zn2+]i) and calcium ions ([Ca2+]i) accumulate in hippocampal CA1 neurons after global ischemia. We examined whether ischemic preconditioning modifies these changes in gerbil hippocampal slices. In normal slices, large increases in [Zn2+]i and [Ca2+]i were observed in the stratum radiatum of the CA1 area after oxygen-glucose deprivation. In preconditioned slices, there were significantly decreased peak levels of [Zn2+]i and [Ca2+]i in CA1. However, there were no differences in the peak levels of these ions in CA3 and dentate gyrus. These results suggest that modified [Zn2+]i and [Ca2+]i accumulation after an ischemic insult might be important for the mechanisms of ischemic tolerance induced by preconditioning.

  4. Modifiable risk factors for ischemic stroke

    Directory of Open Access Journals (Sweden)

    Alexandros Gianoulakis

    2010-07-01

    Full Text Available Ischemic stroke is the third leading cause of death after cardiac disease and cancer in the developed countries. In patients older than 65 years old, ischemic stroke is one of the main causes of disability. They are also responsible for approximately 4.5 million deaths each year globally.The aim of the present study was to review the literature about the modifiable risk factors related to the development of ischemic stroke.The method οf this study included bibliographic research from both reviews and researches from literature, mainly of the last 8 years. The words used in pub med data base, referred to the modifiable risk factors related to the development of ischemic stroke.Results: In the majority of research studies, responsible risk factors for ischemic stroke are classified according to their ability of modification, in modifiable and non–modifiable risk factors. Some of the modifiable risk factors have been fully documented whereas some others need further research. The main modifiable risk factor is hypertension because on the one hand it promotes atherosclerosis and, on the other hand, leads to deteriorative changes and constrictions of small brain vessels. Atrial fibrillation is the most significant risk factor for ischemic stroke, since it is responsible for more than 50% of thromboembolic cases. Also, patients with diabetes mellitus are in higher risk for developing ischemic stroke compared to healthy population, whereas the danger is increasing in insuline-depented individuals. Increase of lipids in blood and disorders of cholesterol are responsible for atherosclerosis in coronary vessels and carotid. More in detail, carotid stenosis >50% in individuals over than 65 years old consist a significant risk factor for ischemic stroke. Though, the relation of smoking to ischemic stroke is still not fully understood, however smokers are in high risk for developing ischemic stroke for the reason that smoking is significantly related to

  5. [Cilioretinal artery occlusion and central retinal vein occlusion complicating hyperhomocysteinemia: a case report].

    Science.gov (United States)

    Berkani, Z; Kitouni, Y; Belhadj, A; Sifi, K; Abbadi, N; Bellatrache, C; Hartani, D; Kherroubi, R

    2013-09-01

    Hyperhomocysteinemia is known to be a risk factor in both retinal artery and retinal vein occlusions. We report the case of a young patient with combined occlusion of the cilioretinal artery and the central retinal vein due to hyperhomocysteinemia. A 23-year-old patient without significant medical history, presented for sudden, painless visual loss in the right eye. Ophthalmologic examination revealed best-corrected visual acuity of the right eye 8/10 P2, and 10/10 P2 on the left. Anterior segment exam was normal in both eyes, while the right fundus revealed white, ischemic edema, centered around a cilioretinal artery, sparing the fovea, with some hemorrhagic spots and disc edema. Fluorescein angiography confirmed delayed filling of the right cilioretinal artery and revealed a normal disc on the left. Two weeks later, the clinical picture had evolved into a right ischemic CRVO, confirmed by a second angiogram, with a decrease in visual acuity to 3/10. A work-up was performed, including: a full lipid profile, serum electrolytes, ESR, CRP, a complete blood count (leukocytes, platelets, hemoglobin were normal), a coagulation work-up (PT, PTT, protein C, protein S, antithrombin III, factor V Leiden were normal), ANCA, antiphospholipid antibodies and antinuclear antibodies were negative, and finally cardiology studies (cardiac echo, carotid Doppler) and neurology (brain MRI) were ordered and came back normal. Otherwise, plasma homocysteine was moderately high on two samples, at 18.3 μmol/L and 17.78 μmol/L. Thyroid and renal work-ups were ordered. Urgent PRP was performed, and vitamin therapy (vitB12, vitB6, folic acid) was instituted. The subsequent course was remarkable for recovery of visual acuity to 10/10, P2 with persistence of an inferior altitudinal central scotoma. MTHFR C677T polymorphism was negative. Retinal vascular occlusions (RVO) are serious events, which require investigation for underlying systemic disease, which can be life-threatening. The clinical

  6. Roller coaster-associated retinal detachments.

    Science.gov (United States)

    Shaikh, Saad

    2011-01-01

    The purpose of this study was to report two cases of rhegmatogenous retinal detachment noted immediately after roller coaster riding in an at-risk population. In separate incidents, a 35-year-old woman and a 45-year-old woman, both significantly myopic, presented with visual symptoms after riding roller coasters. Both patients were found to have acute rhegmatogenous retinal detachments associated with myopic degenerative changes. The pathology supported an acute, traumatic etiology for the detachments. Roller coaster riding should be considered an adjunct risk factor for retinal detachment in predisposed patients.

  7. Photostress Testing Device for Diagnosing Retinal Disease

    Directory of Open Access Journals (Sweden)

    Elizabeth Swan

    2014-08-01

    Full Text Available Retinal diseases such as Age-Related Macular Degeneration (ARMD affect nearly one in three elderly patients. ARMD damages the central vision photoreceptors in the fovea. The Photostress Test is a simple technique for testing for the early effects of ARMD. Here, the illumination sources in a novel self-administered Photostress Testing device were modeled for safety and distribution in illumination software. After satisfying the design constraints in the model, a prototype of the illumination system was fabricated and tested to confirm the modeling results. The resultant prototype can be used to aid in the diagnosis of retinal disease and is well within retinal safety levels.

  8. Fluid vitreous substitutes in vitreo retinal surgery.

    Science.gov (United States)

    Saxena, S; Gopal, L

    1996-12-01

    Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil), as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membranes adherent to the retina, manipulate retinal detachments and mechanically flatten detached retina. Over the longer term, silicone oil maintains intraocular tamponade. One should be cognizant of the potential uses, benefits and risks of each of these vitreous substitutes.

  9. Fluid vitreous substitutes in vitreo retinal surgery

    Directory of Open Access Journals (Sweden)

    Saxena Sandeep

    1996-01-01

    Full Text Available Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil, as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membranes adherent to the retina, manipulate retinal detachments and mechanically flatten detached retina. Over the longer term, silicone oil maintains intraocular tamponade. One should be cognizant of the potential uses, benefits and risks of each of these vitreous substitutes.

  10. [New drug therapy for retinal degeneration].

    Science.gov (United States)

    Ohguro, Hiroshi

    2008-01-01

    Retinitis pigmentosa (RP) is an inherited retinal degeneration characterized by nyctalopia, ring scotoma, and bone-spicule pigmentation of the retina. So far, no effective therapy has been found for RP. As a possible molecular etiology of RP, retina-specific gene deficits are most likely involved, but little has been identified in terms of intracellular mechanisms leading to retinal photoreceptor cell death at post-translational levels. In order to find an effective therapy for RP, we must look for underlying common mechanisms that are responsible for the development of RP, instead of designing a specific therapy for each of the RP types with different causes. Therefore, in the present study, several animal models with different causes of RP were studied, including (1)Royal College of Surgeons (RCS) rats with a deficit of retinal pigment epithelium (RPE) function caused by rhodopsin mutation; (2) P23H rats, (3) S334ter rats, (4) photo stress rats, (5) retinal degeneration (rd) mice with a deficit of phosphodiesterase(PDE) function; and (6) cancer-associated retinopathy (CAR) model rats with a deficit of recoverin-dependent photoreceptor adaptation function. In each of these models, the following assessments were made in order to elucidate common pathological mechanisms among the models: (1) retinal function assessed by electroretinogram (ERG), (2) retinal morphology, (3) retinoid analysis, (4) rhodopsin regeneration, (5) rhodopsin phosphorylation and dephosphorylation, and (6) cytosolic cGMP levels. We found that unregulated photoreceptor adaptation processes caused by an imbalance of rhodopsin phosphorylation and dephosphorylation caused retinal dysfunction leading to photoreceptor cell death. As possible candidate drugs for normalizing these retinal dysfunctions and stopping further retinal degeneration, nilvadipine, a Ca channel blocker, retinoid derivatives, and anthocyanine were chosen and tested to determine their effect on the above animal models with

  11. Impaired glucose regulation predicted 1-year mortality of Chinese patients with ischemic stroke: data from abnormal glucose regulation in patients with acute stroke across China.

    Science.gov (United States)

    Jia, Qian; Liu, Gaifen; Zheng, Huaguang; Zhao, Xingquan; Wang, Chunxue; Wang, Yilong; Liu, Liping; Wang, Yongjun

    2014-05-01

    It remains uncertain if impaired glucose regulation (IGR) as a predictor for stroke outcomes. This study aimed at observing the effect of IGR on the 1-year outcomes in Chinese patients with ischemic stroke. Patients with acute ischemic stroke were recruited consecutively in multihospitals across China. Oral glucose tolerance test was performed to identify IGR. Cox proportion hazard model was performed to investigate the effect of IGR on 1-year mortality or stroke recurrence in patients with ischemic stroke. The study recruited 2639 patients with ischemic stroke. IGR was shown as an independent risk factor for the mortality of patients with ischemic stroke (hazard ratio [95% confidence interval], 3.088 [1.386-6.884]; P=0.006). However, IGR showed no significant effects on the dependency or stroke recurrence of patients (P=0.540 and 0.618, respectively). IGR was an independent predictor for the mortality of patients with ischemic stroke. IGR should be highlighted and intervened actively in the patients with ischemic stroke.

  12. Neural Stem Cells and Ischemic Brain

    OpenAIRE

    Zhang, ZhengGang; Chopp, Michael

    2016-01-01

    Stroke activates neural stem cells in the ventricular-subventricular zone (V/SVZ) of the lateral ventricle, which increases neuroblasts and oligodendrocyte progenitor cells (OPCs). Within the ischemic brain, neural stem cells, neuroblasts and OPCs appear to actively communicate with cerebral endothelial cells and other brain parenchymal cells to mediate ischemic brain repair; however, stroke-induced neurogenesis unlikely plays any significant roles in neuronal replacement. In this mini-review...

  13. The cost-effectiveness of the Argus II retinal prosthesis in Retinitis Pigmentosa patients

    OpenAIRE

    2014-01-01

    Background Retinitis Pigmentosa (RP) is a hereditary genetic disease causing bilateral retinal degeneration. RP is a leading cause of blindness resulting in incurable visual impairment and drastic reduction in the Quality of life of the patients. Second Sight Medical Products Inc. developed Argus II, a retinal prosthesis system for treating RP. Argus II is the world’s first ever-commercial implant intended to restore some vision in the blind patients. The objective of this study was to assess...

  14. Long-term outcomes in patients undergoing vitrectomy for retinal detachment due to viral retinitis

    Directory of Open Access Journals (Sweden)

    Almeida DRP

    2015-07-01

    Full Text Available David RP Almeida,1 Eric K Chin,1 Ryan M Tarantola,1 Elizabeth O Tegins,1 Christopher A Lopez,1 Herbert Culver Boldt,1 Karen M Gehrs,1 Elliott H Sohn,1 Stephen R Russell,1 James C Folk,1 Vinit B Mahajan1,2 1Department of Ophthalmology and Visual Sciences, 2Omics Laboratory, University of Iowa Hospitals and Clinics, Iowa City, IA, USA Purpose: To determine the outcomes in patients with rhegmatogenous retinal detachment (RRD secondary to viral retinitis. Patients and methods: This was a retrospective, consecutive, noncomparative, interventional case series of 12 eyes in ten patients with RRD secondary to viral retinitis. Results of vitreous or aqueous biopsy, effect of antiviral therapeutics, time to retinal detachment, course of visual acuity, and anatomic and surgical outcomes were investigated. Results: There were 1,259 cases of RRD during the study period, with 12 cases of RRD secondary to viral retinitis (prevalence of 0.95%. Follow-up was available for a mean period of 4.4 years. Varicella zoster virus was detected in six eyes, herpes simplex virus in two eyes, and cytomegalovirus in two eyes. Eight patients were treated with oral valacyclovir and two patients with intravenous acyclovir. Lack of optic nerve involvement correlated with improved final visual acuity of 20/100 or greater. Pars plana vitrectomy (n=12, silicone-oil tamponade (n=11, and scleral buckling (n=10 provided successful anatomic retinal reattachment in all cases, with no recurrent retinal detachment and no cases of hypotony during the follow-up period. Conclusion: Varicella zoster virus was the most frequent cause of viral retinitis, and lack of optic nerve involvement was predictive of a favorable visual acuity prognosis. Vitrectomy with silicone-oil tamponade and scleral buckle placement provided stable anatomical outcomes. Keywords: viral retinitis, acute retinal necrosis, herpetic retinitis, vitrectomy, retinal detachment 

  15. Concurrent central retinal artery occlusion and branch retinal vein occlusion in giant cell arteritis

    OpenAIRE

    Chu, Edward R.; Chen, Celia S

    2010-01-01

    Edward R Chu, Celia S ChenDepartment of Ophthalmology, Flinders Medical Centre and Flinders University, Bedford Park, SA, AustraliaAbstract: Ophthalmic involvement in giant cell arteritis can manifest in a number of ways. Central retinal artery occlusion is one of the common causes of visual loss in giant cell arteritis. On the contrary, branch retinal vein occlusion is rarely associated with the latter. We report an 89-year-old lady with acute left central retinal artery occlusion on a backg...

  16. Challenges with nitrate therapy and nitrate tolerance: prevalence, prevention, and clinical relevance.

    Science.gov (United States)

    Thadani, Udho

    2014-08-01

    Nitrate therapy has been an effective treatment for ischemic heart disease for over 100 years. The anti-ischemic and exercise-promoting benefits of sublingually administered nitrates are well established. Nitroglycerin is indicated for the relief of an established attack of angina and for prophylactic use, but its effects are short lived. In an effort to increase the duration of beneficial effects, long-acting orally administered and topical applications of nitrates have been developed; however, following their continued or frequent daily use, patients soon develop tolerance to these long-acting nitrate preparations. Once tolerance develops, patients begin losing the protective effects of the long-acting nitrate therapy. By providing a nitrate-free interval, or declining nitrate levels at night, one can overcome or reduce the development of tolerance, but cannot provide 24-h anti-anginal and anti-ischemic protection. In addition, patients may be vulnerable to occurrence of rebound angina and myocardial ischemia during periods of absent nitrate levels at night and early hours of the morning, and worsening of exercise capacity prior to the morning dose of the medication. This has been a concern with nitroglycerin patches but not with oral formulations of isosorbide-5 mononitrates, and has not been adequately studied with isosorbide dinitrate. This paper describes problems associated with nitrate tolerance, reviews mechanisms by which nitrate tolerance and loss of efficacy develop, and presents strategies to avoid nitrate tolerance and maintain efficacy when using long-acting nitrate formulations.

  17. The Ischemic Stroke Genetics Study (ISGS Protocol

    Directory of Open Access Journals (Sweden)

    Rich Stephen S

    2003-07-01

    Full Text Available Abstract Background The molecular basis for the genetic risk of ischemic stroke is likely to be multigenic and influenced by environmental factors. Several small case-control studies have suggested associations between ischemic stroke and polymorphisms of genes that code for coagulation cascade proteins and platelet receptors. Our aim is to investigate potential associations between hemostatic gene polymorphisms and ischemic stroke, with particular emphasis on detailed characterization of the phenotype. Methods/Design The Ischemic Stroke Genetic Study is a prospective, multicenter genetic association study in adults with recent first-ever ischemic stroke confirmed with computed tomography or magnetic resonance imaging. Patients are evaluated at academic medical centers in the United States and compared with sex- and age-matched controls. Stroke subtypes are determined by central blinded adjudication using standardized, validated mechanistic and syndromic classification systems. The panel of genes to be tested for polymorphisms includes β-fibrinogen and platelet glycoprotein Ia, Iba, and IIb/IIIa. Immortalized cell lines are created to allow for time- and cost-efficient testing of additional candidate genes in the future. Discussion The study is designed to minimize survival bias and to allow for exploring associations between specific polymorphisms and individual subtypes of ischemic stroke. The data set will also permit the study of genetic determinants of stroke outcome. Having cell lines will permit testing of future candidate risk factor genes.

  18. Thrombolytic therapy for acute ischemic stroke after recent transient ischemic attack.

    Science.gov (United States)

    Alonso de Leciñana, María; Fuentes, Blanca; Masjuan, Jaime; Simal, Patricia; Díaz-Otero, Fernando; Reig, Gemma; Díez-Tejedor, Exuperio; Gil-Nuñez, Antonio; Vivancos, Jose; Egido, Jose-Antonio

    2012-04-01

    Safety and efficacy of intravenous thrombolysis in stroke patients with recent transient ischemic attack are hotly debated. Patients suffering transient ischemic attack may present with diffusion-weighted imaging lesions, and although normal computed tomography would not preclude thrombolysis, the concern is that they may be at higher risk for hemorrhage post-thrombolysis treatment. Prior ipsilateral transient ischemic attack might provide protection due to ischemic preconditioning. We assessed post-thrombolysis outcomes in stroke patients who had prior transient ischemic attack. Multicentered prospective study of consecutive acute stroke patients treated with intravenous tissue plasminogen activator (tPA). Ipsilateral transient ischemic attack, baseline characteristics, risk factors, etiology, and time-lapse to treatment were recorded. National Institutes of Health Stroke Scale at seven-days and modified Rankin Scale at three-months, symptomatic intracranial hemorrhage, and mortality were compared in patients with and without transient ischemic attack. There were 877 patients included, 60 (6·84%) had previous ipsilateral transient ischemic attack within one-month prior to the current stroke (65% in the previous 24 h). Transient ischemic attack patients were more frequently men (70% vs. 53%; P = 0·011), younger (63 vs. 71 years of age; P = 0·011), smokers (37% vs. 25%; P = 0·043), and with large vessel disease (40% vs. 25%; P = 0·011). Severity of stroke at onset was similar to those with and without prior transient ischemic attack (median National Institutes of Health Stroke Scale score 12 vs. 14 P = 0·134). Those with previous transient ischemic attack were treated earlier (117 ± 52 vs. 144 ± 38 mins; P ischemic attack was not associated with differences in stroke outcome such as independence (modified Rankin Scale 0-2) (odds ratios: 1·035 (0·57-1·93) P = 0·91), mortality (odds ratios: 0·99 (0·37-2·67) P = 0

  19. Retinal vascular oximetry during ranibizumab treatment of central retinal vein occlusion.

    Science.gov (United States)

    Traustason, Sindri; la Cour, Morten; Larsen, Michael

    2014-09-01

    To investigate the effect of intravitreal injections of the vascular endothelial growth factor inhibitor ranibizumab on retinal oxygenation in patients with central retinal vein occlusion (CRVO). Retinal oxygen saturation in patients with CRVO was analysed using the Oxymap Retinal Oximeter P3, before and during 6 months of treatment with intravitreal injections of ranibizumab. At presentation, retinal venous oxygen saturation was lower in eyes with CRVO than in the healthy fellow eyes (32±13% vs 59±10%, respectively, p=0.001) whereas retinal arterial saturation was higher in eyes with CRVO than in the fellow eyes (95%±8% and 91%±3%, p=0.04). Mean visual acuity increased from 51±24 letters ETDRS at baseline to 66±24 and 69±20 letters ETRDS, respectively, at 3 months and 6 months treatment (mean±SD, pcentral retinal thickness was reduced from 697±139 µm to 368±113 µm and 340±96 µm, respectively, from baseline to 3 months and 6 months treatment (pRetinal venous oxygen saturation was markedly reduced in untreated CRVO and was roughly halfway normalised during intravitreal ranibizumab treatment. Retinal artery oxygen saturation was not reduced in CRVO. NCT01360385. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Idiopathic pediatric retinal artery occlusion

    Directory of Open Access Journals (Sweden)

    Manayath George

    2010-01-01

    Full Text Available We report a case of branch retinal artery occlusion (BRAO in a healthy young girl. An eight-year-old girl presented with sudden loss of vision in her left eye. She had a pale retina with macular edema consistent with extensive BRAO. A thorough workup was performed to determine any etiologic factor. All test results were within normal limits. Her visual acuity improved from finger counting to 20/40 over two weeks, on immediate treatment with intravenous steroids (methyl prednisolone. This case suggests that BRAO can occur in healthy children without any detectable systemic or ocular disorders and a dramatic improvement may be achieved with prompt treatment with intravenous steroids.

  1. Nanoparticles for retinal gene therapy.

    Science.gov (United States)

    Conley, Shannon M; Naash, Muna I

    2010-09-01

    Ocular gene therapy is becoming a well-established field. Viral gene therapies for the treatment of Leber's congentinal amaurosis (LCA) are in clinical trials, and many other gene therapy approaches are being rapidly developed for application to diverse ophthalmic pathologies. Of late, development of non-viral gene therapies has been an area of intense focus and one technology, polymer-compacted DNA nanoparticles, is especially promising. However, development of pharmaceutically and clinically viable therapeutics depends not only on having an effective and safe vector but also on a practical treatment strategy. Inherited retinal pathologies are caused by mutations in over 220 genes, some of which contain over 200 individual disease-causing mutations, which are individually very rare. This review will focus on both the progress and future of nanoparticles and also on what will be required to make them relevant ocular pharmaceutics. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. Laminins and retinal vascular development.

    Science.gov (United States)

    Edwards, Malia M; Lefebvre, Olivier

    2013-01-01

    The mechanisms controlling vascular development, both normal and pathological, are not yet fully understood. Many diseases, including cancer and diabetic retinopathy, involve abnormal blood vessel formation. Therefore, increasing knowledge of these mechanisms may help develop novel therapeutic targets. The identification of novel proteins or cells involved in this process would be particularly useful. The retina is an ideal model for studying vascular development because it is easy to access, particularly in rodents where this process occurs post-natally. Recent studies have suggested potential roles for laminin chains in vascular development of the retina. This review will provide an overview of these studies, demonstrating the importance of further research into the involvement of laminins in retinal blood vessel formation.

  3. Oral Levosimendan Increases Cerebral Blood Flow Velocities in Patients with a History of Stroke or Transient Ischemic Attack: A Pilot Safety Study

    Directory of Open Access Journals (Sweden)

    Matti Kivikko, MD, PhD

    2015-12-01

    Conclusions: Oral levosimendan increases cerebral blood flow velocities and diminishes NT-pro-BNP levels in patients with earlier ischemic cerebrovascular event. Daily doses up to 1.0 mg were well tolerated, whereas the 2.0 mg dose level induced an increase in ventricular extrasystoles. ClinicalTrials.gov identifier: NCT00698763.

  4. Genetically elevated C-reactive protein and ischemic vascular disease

    DEFF Research Database (Denmark)

    Zacho, J.; Tybjaerg-Hansen, A.; Jensen, J.S.

    2008-01-01

    Background: Elevated levels of C-reactive protein (CRP) are associated with increased risks of ischemic heart disease and ischemic cerebrovascular disease. We tested whether this is a causal association. Methods: We studied 10,276 persons from a general population cohort, including 1786 in whom...... ischemic heart disease developed and 741 in whom ischemic cerebrovascular disease developed. We examined another 31,992 persons from a cross-sectional general population study, of whom 2521 had ischemic heart disease and 1483 had ischemic cerebrovascular disease. Finally, we compared 2238 patients...... with ischemic heart disease with 4474 control subjects and 612 patients with ischemic cerebrovascular disease with 1224 control subjects. We measured levels of high-sensitivity CRP and conducted genotyping for four CRP polymorphisms and two apolipoprotein E polymorphisms. Results: The risk of ischemic heart...

  5. Integration of retinal image sequences

    Science.gov (United States)

    Ballerini, Lucia

    1998-10-01

    In this paper a method for noise reduction in ocular fundus image sequences is described. The eye is the only part of the human body where the capillary network can be observed along with the arterial and venous circulation using a non invasive technique. The study of the retinal vessels is very important both for the study of the local pathology (retinal disease) and for the large amount of information it offers on systematic haemodynamics, such as hypertension, arteriosclerosis, and diabetes. In this paper a method for image integration of ocular fundus image sequences is described. The procedure can be divided in two step: registration and fusion. First we describe an automatic alignment algorithm for registration of ocular fundus images. In order to enhance vessel structures, we used a spatially oriented bank of filters designed to match the properties of the objects of interest. To evaluate interframe misalignment we adopted a fast cross-correlation algorithm. The performances of the alignment method have been estimated by simulating shifts between image pairs and by using a cross-validation approach. Then we propose a temporal integration technique of image sequences so as to compute enhanced pictures of the overall capillary network. Image registration is combined with image enhancement by fusing subsequent frames of a same region. To evaluate the attainable results, the signal-to-noise ratio was estimated before and after integration. Experimental results on synthetic images of vessel-like structures with different kind of Gaussian additive noise as well as on real fundus images are reported.

  6. Photodiode circuits for retinal prostheses.

    Science.gov (United States)

    Loudin, J D; Cogan, S F; Mathieson, K; Sher, A; Palanker, D V

    2011-10-01

    Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.

  7. [Intraocular hypertension after retinal detachment surgery].

    Science.gov (United States)

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachment, 3 days ago operated (posterior vitrectomy, internal tamponament with silicon oil 1000) who developed increased ocular pressure following silicon oil output in the anterior chamber.

  8. [Retinal vein occlusion in a young patient].

    Science.gov (United States)

    Zemba, Mihail; Ochinciuc, Uliana; Sarbu, Laura; Avram, Corina; Camburu, Raluca; Stamate, Alina

    2013-01-01

    We present a case report of a 27 years old pacient with central retinal vein occlussion and macular edema. The pacient has a significant reduction of the macular aedema with complete recovery of vision after the treatment.

  9. The treatment of bullous rhegmatogenous retinal detachment.

    Science.gov (United States)

    Wong, D; Chignell, A H; Inglesby, D V; Little, B C; Franks, W

    1992-01-01

    We describe the results of a consecutive series of 97 cases of bullous superior retinal detachment treated by conventional surgery. The retinal detachments were characterized by either a single retinal break or multiple retinal breaks confined within 1 clock hour and no proliferative vitreoretinopathy. The surgery involved sequential drainage of subretinal fluid, injection of air, cryotherapy and the application of local explant. All cases would otherwise be suitable for pneumatic retinopexy. The anatomical success rate was 85.5% with a single operation and 97% with further procedures. We report on the complications encountered and appraise the advantages and disadvantages of this operation. Forty-five of the 97 cases had detachment of the macula for less than 2 weeks, and 35 of the 45 (80%) achieved a visual acuity of 6/18 or better. These visual results challenge the assertion that better visual outcome might be attained with pneumatic retinopexy.

  10. [Ocular hypertension after surgery for retinal detachment].

    Science.gov (United States)

    Muşat, O; Cristescu, R; Coman, Corina; Asandi, R

    2012-01-01

    This papers presents a case of a patient with retinal detachement, 3 days ago operated (posterior vitrectomy internal tamponament with silicon oil 1000) who develop increased ocular pressure following silicon oil output in the anterior chamber.

  11. Imaging retinal mosaics in the living eye.

    Science.gov (United States)

    Rossi, E A; Chung, M; Dubra, A; Hunter, J J; Merigan, W H; Williams, D R

    2011-03-01

    Adaptive optics imaging of cone photoreceptors has provided unique insight into the structure and function of the human visual system and has become an important tool for both basic scientists and clinicians. Recent advances in adaptive optics retinal imaging instrumentation and methodology have allowed us to expand beyond cone imaging. Multi-wavelength and fluorescence imaging methods with adaptive optics have allowed multiple retinal cell types to be imaged simultaneously. These new methods have recently revealed rod photoreceptors, retinal pigment epithelium (RPE) cells, and the smallest retinal blood vessels. Fluorescence imaging coupled with adaptive optics has been used to examine ganglion cells in living primates. Two-photon imaging combined with adaptive optics can evaluate photoreceptor function non-invasively in the living primate retina.

  12. Regulatory and Economic Considerations of Retinal Drugs.

    Science.gov (United States)

    Shah, Ankoor R; Williams, George A

    2016-01-01

    The advent of anti-VEGF therapy for neovascular age-related macular degeneration and macular edema secondary to retinal vein occlusion and diabetes mellitus has prevented blindness in tens of thousands of people. However, the costs of these drugs are without precedent in ophthalmic drug therapeutics. An analysis of the financial implications of retinal drugs and the impact of the Food and Drug Administration on treatment of retinal disease must include not only an evaluation of the direct costs of the drugs and the costs associated with their administration, but also the cost savings which accrue from their clinical benefit. This chapter will discuss the financial and regulatory issues associated with retinal drugs.

  13. Toleration, Groups, and Multiculturalism

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2014-01-01

    to the political and social relationship between the subject and the objects of toleration. Finally, toleration is often argued to be a normative requirement on the basis of the way it affects the object or receiver of toleration, e.g. on the basis of the good of or right to freedom from non-interference which......The chapter considers how groups might be relevant as objects of policies of toleration and the different senses 'group' might have in relation to questions of toleration. The chapter argues that groups can be relevant to toleration in several different ways as objects of toleration. Toleration...... is routinely defined as involving an objection component, a power requirement and an acceptance component. The objection and acceptance components refer to reasons or dispositions of the subjects of toleration, e.g. public authorities deciding how to act in relation to groups. The power condition refers...

  14. [Application of peloidotherapy at the early stage of rehabilitation after cerebral ischemic stroke].

    Science.gov (United States)

    Gorbunov, F E; Penionzhkevich, D Iu; Kotenko, E P

    2010-01-01

    The objective of the present study was to evaluate clinical efficiency of peloidotherapy in the early reconvalescence period following cerebral ischemic stroke. A rationale for the application of peloidotherapy is presented based on the results of follow-up of 60 patients (26 men and 34 women) aged from 43 to 70 years at the early stage of recovery (within 10 weeks and more after stroke). Special attention was given to clinical dynamics of the post-stroke condition and the influence of peloidotherapy on the mechanisms underlying formation of cerebral hemodynamic effects, adaptive changes in the functional systems of hemostasis and microcirculation, and development of pathophysiological cascade of metabolic processes in the brain. All therapeutic procedures were fairly well tolerated by the patients. Neither allergic reactions nor other adverse effects of the treatment were documented which testifies to the safety of peloidotherapy at the early stage of rehabilitation after cerebral ischemic stroke.

  15. The ischemic preconditioning effect of adenosine in patients with ischemic heart disease

    Directory of Open Access Journals (Sweden)

    Berglund Margareta

    2009-11-01

    Full Text Available Abstract Introduction In vivo and in vitro evidence suggests that adenosine and its agonists play key roles in the process of ischemic preconditioning. The effects of low-dose adenosine infusion on ischemic preconditioning have not been thoroughly studied in humans. Aims We hypothesised that a low-dose adenosine infusion could reduce the ischemic burden evoked by physical exercise and improve the regional left ventricular (LV systolic function. Materials and methods We studied nine severely symptomatic male patients with severe coronary artery disease. Myocardial ischemia was induced by exercise on two separate occasions and quantified by Tissue Doppler Echocardiography. Prior to the exercise test, intravenous low-dose adenosine or placebo was infused over ten minutes according to a randomized, double blind, cross-over protocol. The LV walls were defined as ischemic if a reduction, no increment, or an increment of Results PSV increased from baseline to maximal exercise in non-ischemic walls both during placebo (P = 0.0001 and low-dose adenosine infusion (P = 0.0009. However, in the ischemic walls, PSV increased only during low-dose adenosine infusion (P = 0.001, while no changes in PSV occurred during placebo infusion (P = NS. Conclusion Low-dose adenosine infusion reduced the ischemic burden and improved LV regional systolic function in the ischemic walls of patients with exercise-induced myocardial ischemia, confirming that adenosine is a potential preconditioning agent in humans.

  16. [Treatment of retinal detachment with macular hole].

    Science.gov (United States)

    Pikulski, Z; Nawrocki, J; Dziegielewski, K

    1993-01-01

    The methods and results of surgery in 6 cases of retinal detachment with macular hole are presented. In all 6 cases pars plana vitrectomy was performed, in 4 with subsequent SF6 and in 2 with silicone oil tamponade. Retinal attachment was achieved in 4 eyes. Visual acuity 1/50-2/50 was found after surgery in 5 cases. The follow-up ranged from 6 to 9 months.

  17. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

    Gerald Liew; Jie Jin Wang; Elena Rochtchina; Tien Yin Wong; Paul Mitchell

    2014-01-01

    OBJECTIVE: The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. METHODS: Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken ...

  18. Branch retinal artery occlusion in Susac's syndrome

    Directory of Open Access Journals (Sweden)

    Ricardo Evangelista Marrocos de Aragão

    2015-02-01

    Full Text Available Susac's syndrome is a rare disease attribuited to a microangiopathy involving the arterioles of the cochlea, retina and brain. Encefalopathy, hearing loss, and visual deficits are the hallmarks of the disease. Visual loss is due to multiple, recurrent branch arterial retinal occlusions. We report a case of a 20-year-old women with Susac syndrome presented with peripheral vestibular syndrome, hearing loss, ataxia, vertigo, and vision loss due occlusion of the retinal branch artery.

  19. Programming Retinal Stem Cells into Cone Photoreceptors

    Science.gov (United States)

    2015-12-01

    this grant, we sought to investigate the mechanisms that regulate the earliest events in cone photoreceptor development and to exploit this knowledge...the mRNA for three transcription factors promoted cone photoreceptor formation in retinal stem cells derived from human embryonic stem cells. These...reverse vision loss. 15. SUBJECT TERMS Cone photoreceptor, retina, retinal stem cell, Otx2, Onecut1, Blimp1, RNA-seq., transcription factors, and

  20. Current surgery of retinal detachment recurrence. Review

    Directory of Open Access Journals (Sweden)

    V. D. Zakharov

    2012-01-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  1. Current surgery of retinal detachment recurrence. Review

    Directory of Open Access Journals (Sweden)

    V. D. Zakharov

    2014-07-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  2. Fluid vitreous substitutes in vitreo retinal surgery

    OpenAIRE

    Saxena Sandeep; Gopal Lingam

    1996-01-01

    Advances in the surgical instrumentation and vitreoretinal techniques have allowed intraoperative reapproximation of retina to a more normal position. The use of intravitreally injected liquid materials (viscoelastic liquids, liquid perfluorocarbons and silicone oil), as adjunctive agents to vitreo-retinal surgery play an important role in facilitating retinal reattachment. These materials are used as intraoperative instruments to re-establish intraocular volume, assist in separating membrane...

  3. Safety of iPhone retinal photography.

    Science.gov (United States)

    Hong, Sheng Chiong; Wynn-Williams, Giles; Wilson, Graham

    2017-04-01

    With the advancement in mobile technology, smartphone retinal photography is becoming a popular practice. However, there is limited information about the safety of the latest smartphones used for retinal photography. This study aims to determine the photobiological risk of iPhone 6 and iPhone 6 plus when used in conjunction with a 20Diopter condensing lens for retinal photography. iPhone 6 and iPhone 6 plus (Apple, Cupertino, CA) were used in this study. The geometrical setup of the study was similar to the indirect ophthalmoscopy technique. The phone was set up at one end of the bench with its flash turned on at maximal brightness; a 20 Dioptre lens was placed 15 cm away from the phone. The light that passes through the lens was measured with a spectroradiometer and an illuminance probe at the other end to determine the spectral profile, spatial irradiance, radiant power emitted by the phone's flash. Trigonometric and lens formula were applied to determine the field of view and retinal surface in order to determine the weighted retinal irradiance and weighted retinal radiant exposure. Taking ocular transmission and the distribution of the beam's spatial irradiance into account, the weighted retinal irradiance is 1.40 mW/cm(2) and the weighted retinal radiant exposure is 56.25 mJ/cm(2). The peak weighted foveal irradiance is 1.61 mW/cm(2). Our study concluded that the photobiological risk posed by iPhone 6 indirect ophthalmoscopy was at least 1 order of magnitude below the safety limits set by the ISO15004-2.2.

  4. The effects of taurine on vigabatrin, high light intensity and mydriasis induced retinal toxicity in the pigmented rat.

    Science.gov (United States)

    Rasmussen, Allan D; Truchot, Nathalie; Pickersgill, Nigel; Thale, Zia Irene; Rosolen, Serge G; Botteron, Catherine

    2015-01-01

    The overall purpose of this study was to establish a model that may be used for examining the effect of Vigabatrin-induced retinal toxicity in pigmented rats, and subsequently examine the possible effects of taurine on the retinal toxicity. In the first part of the study, pigmented Long Evans rats were subjected to combinations of induced mydriasis, low/high light intensities (40/2000 lx) and oral administration of near-MTD (Maximum Tolerated Dose) doses (200 mg/kg/day) of Vigabatrin for up to 6 weeks. The combination of mydriasis and high light intensity applied to Long Evans rats resulted in retinal damage that was increased by the administration of Vigabatrin. In the second part of the study Long Evans rats were subjected to combinations of induced mydriasis and high/low light intensity (40/2000 lx) while being orally administered low (30 mg/kg/day) or high (200 mg/kg/day) doses of Vigabatrin for up to 6 weeks. In addition, selected groups of animals were administered taurine via the drinking water (20 mg/ml), resulting in systemic taurine concentrations of approximately threefold the endogenous concentration. The combined results of the studies demonstrate that retinal damage can be induced in pigmented animals when combining mydriasis and high light intensity. Retinal damage was functionally evaluated by electroretinography (ERG), then confirmed by histopathology. While depending on mydriasis and high light intensity, administration of Vigabatrin increased the retinal toxicity and resulted in the formation of rosette-like structures in the retina in a dose-related manner. Administration of taurine did not alleviate the Vigabatrin-induced retinal toxicity, as demonstrated either functionally by ERG or morphologically, although systemic concentrations of 3-fold the endogenous levels were reached, and it was thus not possible to demonstrate a protective effect of taurine in these pigmented animals. Copyright © 2014 Elsevier GmbH. All rights reserved.

  5. Evaluation of the effectiveness and safety of glucocorticoids intravitreal implant therapy in macular edema due to retinal vein occlusion.

    Science.gov (United States)

    Michalska-Małecka, Katarzyna; Gaborek, Aneta; Nowak, Mariusz; Halat, Tomasz; Pawłowska, Mariola; Śpiewak, Dorota

    2016-01-01

    The purpose of this study was to evaluate the impact of intravitreal dexamethasone implant (Ozurdex) on macular morphology and functions in eyes with macular edema (ME) secondary to retinal vein occlusion. Efficacy outcomes of the treatment were best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Safety outcomes were intraocular pressure and cornea endothelial cell density. The study was conducted by the prospective analysis on 36 patients (17 women and 19 men) aged 28-77 years (the average age was 58±15 years) treated with the injection of dexamethasone implant because of the persistent ME at the Department of Ophthalmology and Ophthalmology Outpatient Clinic of the University Centre of Ophthalmology and Oncology in Katowice. The studied group included 16 patients with central retinal vein occlusion (16 eyes), and 20 patients with branch retinal vein occlusion (20 eyes). We found a significant increase of BCVA after first, second, and third month of treatment. Six months after the treatment, BCVA decreased, although not significantly compared with the value obtained in the third month. Two months after the intravitreal implantation of dexamethasone delivery system, CRT was 338±163 μm and was significantly lower compared with pretreatment value. Between third and sixth month after the treatment, we found insignificant increase of CRT compared with thickness observed in second month. Two months after the treatment, we found an increase in intraocular pressure in 36% of cases and a further decrease during the final visit 6 months after the treatment. During the treatment, there were no significant differences in endothelial cell density in branch retinal vein occlusion and central retinal vein occlusion. We found the intravitreal dexamethasone implant to be safe, well tolerated, and likely to lead to fast morphological and functional improvement of the macula and visual rehabilitation in patients with ME due to retinal vein occlusion.

  6. Diagnostic imaging in patients with retinitis pigmentosa.

    Science.gov (United States)

    Mitamura, Yoshinori; Mitamura-Aizawa, Sayaka; Nagasawa, Toshihiko; Katome, Takashi; Eguchi, Hiroshi; Naito, Takeshi

    2012-01-01

    Retinitis pigmentosa (RP) is a progressive inherited retinal disease, and patients with RP have reduced visual function caused by a degeneration of the photoreceptors and retinal pigment epithelium (RPE). At the end stage of RP, the degeneration of the photoreceptors in the fovea reduces central vision, and RP is one of the main causes of acquired blindness in developed countries. Therefore, morphological and functional assessments of the photoreceptors in the macula area can be useful in estimating the residual retinal function in RP patients. Optical coherence tomography (OCT) is a well-established method of examining the retinal architecture in situ. The photoreceptor inner/outer segment (IS/OS) junction is observed as a distinct, highly reflective line by OCT. The presence of the IS/OS junction in the OCT images is essential for normal visual function. Fundus autofluorescence (FAF) results from the accumulation of lipofuscin in the RPE cells and has been used to investigate RPE and retinal function. More than one-half of RP patients have an abnormally high density parafoveal FAF ring (AF ring). The AF ring represents the border between functional and dysfunctional retina. In this review, we shall summarize recent progress on diagnostic imaging in eyes with RP.

  7. Retinal Vascular Fractals and Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Yi-Ting Ong

    2014-08-01

    Full Text Available Background: Retinal microvascular network changes have been found in patients with age-related brain diseases such as stroke and dementia including Alzheimer's disease. We examine whether retinal microvascular network changes are also present in preclinical stages of dementia. Methods: This is a cross-sectional study of 300 Chinese participants (age: ≥60 years from the ongoing Epidemiology of Dementia in Singapore study who underwent detailed clinical examinations including retinal photography, brain imaging and neuropsychological testing. Retinal vascular parameters were assessed from optic disc-centered photographs using a semiautomated program. A comprehensive neuropsychological battery was administered, and cognitive function was summarized as composite and domain-specific Z-scores. Cognitive impairment no dementia (CIND and dementia were diagnosed according to standard diagnostic criteria. Results: Among 268 eligible nondemented participants, 78 subjects were categorized as CIND-mild and 69 as CIND-moderate. In multivariable adjusted models, reduced retinal arteriolar and venular fractal dimensions were associated with an increased risk of CIND-mild and CIND-moderate. Reduced fractal dimensions were associated with poorer cognitive performance globally and in the specific domains of verbal memory, visuoconstruction and visuomotor speed. Conclusion: A sparser retinal microvascular network, represented by reduced arteriolar and venular fractal dimensions, was associated with cognitive impairment, suggesting that early microvascular damage may be present in preclinical stages of dementia.

  8. Retinal synaptic regeneration via microfluidic guiding channels.

    Science.gov (United States)

    Su, Ping-Jung; Liu, Zongbin; Zhang, Kai; Han, Xin; Saito, Yuki; Xia, Xiaojun; Yokoi, Kenji; Shen, Haifa; Qin, Lidong

    2015-08-28

    In vitro culture of dissociated retinal neurons is an important model for investigating retinal synaptic regeneration (RSR) and exploring potentials in artificial retina. Here, retinal precursor cells were cultured in a microfluidic chip with multiple arrays of microchannels in order to reconstruct the retinal neuronal synapse. The cultured retinal cells were physically connected through microchannels. Activation of electric signal transduction by the cells through the microchannels was demonstrated by administration of glycinergic factors. In addition, an image-based analytical method was used to quantify the synaptic connections and to assess the kinetics of synaptic regeneration. The rate of RSR decreased significantly below 100 μM of inhibitor glycine and then approached to a relatively constant level at higher concentrations. Furthermore, RSR was enhanced by chemical stimulation with potassium chloride. Collectively, the microfluidic synaptic regeneration chip provides a novel tool for high-throughput investigation of RSR at the cellular level and may be useful in quality control of retinal precursor cell transplantation.

  9. Retinal iron homeostasis in health and disease

    Directory of Open Access Journals (Sweden)

    Delu eSong

    2013-06-01

    Full Text Available Iron is essential for life, but excess iron can be toxic. As a potent free radical creator, iron generates hydroxyl radicals leading to significant oxidative stress. Since iron is not excreted from the body, it accumulates with age in tissues, including the retina, predisposing to age-related oxidative insult. Both hereditary and acquired retinal diseases are associated with increased iron levels. For example, retinal degenerations have been found in hereditary iron overload disorders, like aceruloplasminemia, Friedreich’s ataxia, and pantothenate kinase-associated neurodegeneration. Similarly, mice with targeted mutation of the iron exporter ceruloplasmin and its homolog hephaestin showed age-related retinal iron accumulation and retinal degeneration with features resembling human age-related macular degeneration (AMD. Post mortem AMD eyes have increased levels of iron in retina compared to age-matched healthy donors. Iron accumulation in AMD is likely to result, in part, from inflammation, hypoxia, and oxidative stress, all of which can cause iron dysregulation. Fortunately, it has been demonstrated by in vitro and in vivo studies that iron in the retinal pigment epithelium and retina is chelatable. Iron chelation protects photoreceptors and retinal pigment epithelial cells (RPE in a variety of mouse models. This has therapeutic potential for diminishing iron-induced oxidative damage to prevent or treat AMD.

  10. Intra-Arterial Immunoselected CD34+ Stem Cells for Acute Ischemic Stroke.

    Science.gov (United States)

    Banerjee, Soma; Bentley, Paul; Hamady, Mohammad; Marley, Stephen; Davis, John; Shlebak, Abdul; Nicholls, Joanna; Williamson, Deborah A; Jensen, Steen L; Gordon, Myrtle; Habib, Nagy; Chataway, Jeremy

    2014-11-01

    Treatment with CD34+ hematopoietic stem/progenitor cells has been shown to improve functional recovery in nonhuman models of ischemic stroke via promotion of angiogenesis and neurogenesis. We aimed to determine the safety and feasibility of treatment with CD34+ cells delivered intra-arterially in patients with acute ischemic stroke. This was the first study in human subjects. We performed a prospective, nonrandomized, open-label, phase I study of autologous, immunoselected CD34+ stem/progenitor cell therapy in patients presenting within 7 days of onset with severe anterior circulation ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score≥8). CD34+ cells were collected from the bone marrow of the subjects before being delivered by catheter angiography into the ipsilesional middle cerebral artery. Eighty-two patients with severe anterior circulation ischemic stroke were screened, of whom five proceeded to treatment. The common reasons for exclusion were age>80 years (n=19); medical instability (n=17), and significant carotid stenosis (n=13). The procedure was well tolerated in all patients, and no significant treatment-related adverse effects occurred. All patients showed improvements in clinical functional scores (Modified Rankin Score and NIHSS score) and reductions in lesion volume during a 6-month follow-up period. Autologous CD34+ selected stem/progenitor cell therapy delivered intra-arterially into the infarct territory can be achieved safely in patients with acute ischemic stroke. Future studies that address eligibility criteria, dosage, delivery site, and timing and that use surrogate imaging markers of outcome are desirable before larger scale clinical trials. ©AlphaMed Press.

  11. Retinal Laser Burn Disrupts Immune Privilege in the Eye

    Science.gov (United States)

    Qiao, Hong; Lucas, Kenyatta; Stein-Streilein, Joan

    2009-01-01

    Immune privilege allows for the immune protection of the eye in the absence of inflammation. Very few events are capable of overcoming the immune-privileged mechanisms in the eye. In this study, we report that retinal laser burn (RLB) abrogates immune privilege in both the burned and nonburned eye. As early as 6 hours after RLB, and as late as 56 days after RLB, antigen inoculation into the anterior chamber of the burned eye failed to induce peripheral tolerance. After RLB, aqueous humor samples harvested from nontreated eyes but not from either the burned or the contralateral eye, down-regulated the expression of CD40 and up-regulated interleukin-10 mRNA in peritoneal exudate cells, and converted peritoneal exudate cells into tolerogenic antigen-presenting cells (APCs). Unlike F4/80+ APCs from nontreated mice, F4/80+ APCs from RLB mice were unable to transfer tolerance after anterior chamber inoculation of antigen into naïve mice. The increased use of lasers in both the industrial and medical fields raises the risk of RLB-associated loss of immune regulation and an increased risk of immune inflammation in the eye. PMID:19147817

  12. Intravitreal ranibizumab for macular edema secondary to central retinal vein occlusion.

    Science.gov (United States)

    Risard, Sarah M; Pieramici, Dante J; Rabena, Melvin D; Basefsky, Jessica C; Avery, Robert L; Castellarin, Alessandro A; Nasir, Ma'an A; See, Robert F; Couvillion, Stephen S

    2011-06-01

    To evaluate the safety and efficacy of intravitreal ranibizumab for macular edema secondary to central retinal vein occlusion. Patients with macular edema secondary to perfused central retinal vein occlusion were enrolled in this ongoing, prospective, open-label study. Treatment was initiated with monthly intravitreal ranibizumab for 3 months. In the first year, additional injections were administered for edema in quarterly intervals as needed (PRN) for Cohort 1 (n = 10) and monthly PRN for Cohort 2 (n = 10). In the second year of treatments, all patients received monthly PRN treatment. Early Treatment Diabetic Retinopathy Study best-corrected visual acuity, central retinal thickness, fundus photographs, and fluorescein angiograms were evaluated, and the incidence and severity of adverse events were documented. Mean change in best-corrected visual acuity and central retinal thickness improved during the induction phase in both groups. During the remainder of the first year for Cohort 1, initial gains were lost during quarterly treatment but returned with monthly PRN treatment in the second year. For Cohort 2, improvement in best-corrected visual acuity and central retinal thickness from the induction phase was maintained through Month 24. Nineteen of 20 patients experienced a reduction in intraretinal hemorrhage, optic nerve swelling, and/or venous diameter after treatment. One myocardial infarction, one cerebrovascular accident, and no serious ocular adverse events were reported. Iris neovascularization was developed in none of the eyes. Ranibizumab was well tolerated and associated with a greater reduction in macular edema and improvement in visual acuity in the monthly PRN regimen compared with quarterly treatment. Vision lost during the quarterly PRN injection intervals in the first year of Cohort 1 could be regained by switching to monthly PRN dosing.

  13. Central retinal vessel blood flow after surgical treatment for central retinal vein occlusion.

    Science.gov (United States)

    Crama, Niels; Gualino, Vincent; Restori, Marie; Charteris, David G

    2010-01-01

    The purpose of this study was to determine the effect of radial optic neurotomy and retinal endovascular surgery on retinal blood flow velocity in patients with central retinal vein occlusion. A prospective interventional case series. Six patients with a central retinal vein occlusion of retinal endovascular surgery. Five patients had decreased central venous blood flow velocity compared with the fellow eye, and one patient had similar central venous blood flow in both eyes at baseline. All study eyes had decreased central venous blood flow velocity compared with the fellow eye at 24 weeks after treatment. Two patients had a further decrease in central venous blood flow during the study. Three patients had no minimal change in central venous blood flow, and 1 patient showed a minimal increase from 3 cm/s at baseline to 4 cm/s 24 weeks after surgery. Radial optic neurotomy and retinal endovascular surgery do not alter central retinal blood flow velocity. The place of these therapies in the treatment for central retinal vein occlusion should be questioned.

  14. Lactose tolerance tests

    Science.gov (United States)

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen ...

  15. Critical care in acute ischemic stroke.

    Science.gov (United States)

    McDermott, M; Jacobs, T; Morgenstern, L

    2017-01-01

    Most ischemic strokes are managed on the ward or on designated stroke units. A significant proportion of patients with ischemic stroke require more specialized care. Several studies have shown improved outcomes for patients with acute ischemic stroke when neurocritical care services are available. Features of acute ischemic stroke patients requiring intensive care unit-level care include airway or respiratory compromise; large cerebral or cerebellar hemisphere infarction with swelling; infarction with symptomatic hemorrhagic transformation; infarction complicated by seizures; and a large proportion of patients require close management of blood pressure after thrombolytics. In this chapter, we discuss aspects of acute ischemic stroke care that are of particular relevance to a neurointensivist, covering neuropathology, neurodiagnostics and imaging, blood pressure management, glycemic control, temperature management, and the selection and timing of antithrombotics. We also focus on the care of patients who have received intravenous thrombolysis or mechanical thrombectomy. Complex clinical decision making in decompressive hemicraniectomy for hemispheric infarction and urgent management of basilar artery thrombosis are specifically addressed. © 2017 Elsevier B.V. All rights reserved.

  16. Inflammatory mechanisms in ischemic stroke: therapeutic approaches

    Directory of Open Access Journals (Sweden)

    Kirchgessner Annette

    2009-11-01

    Full Text Available Abstract Acute ischemic stroke is the third leading cause of death in industrialized countries and the most frequent cause of permanent disability in adults worldwide. Despite advances in the understanding of the pathophysiology of cerebral ischemia, therapeutic options remain limited. Only recombinant tissue-plasminogen activator (rt-PA for thrombolysis is currently approved for use in the treatment of this devastating disease. However, its use is limited by its short therapeutic window (three hours, complications derived essentially from the risk of hemorrhage, and the potential damage from reperfusion/ischemic injury. Two important pathophysiological mechanisms involved during ischemic stroke are oxidative stress and inflammation. Brain tissue is not well equipped with antioxidant defenses, so reactive oxygen species and other free radicals/oxidants, released by inflammatory cells, threaten tissue viability in the vicinity of the ischemic core. This review will discuss the molecular aspects of oxidative stress and inflammation in ischemic stroke and potential therapeutic strategies that target neuroinflammation and the innate immune system. Currently, little is known about endogenous counterregulatory immune mechanisms. However, recent studies showing that regulatory T cells are major cerebroprotective immunomodulators after stroke suggest that targeting the endogenous adaptive immune response may offer novel promising neuroprotectant therapies.

  17. Acute antithrombotic treatment of ischemic stroke.

    Science.gov (United States)

    Alderazi, Yazan J; Grotta, James C

    2014-05-01

    Antithrombotic medication is a cornerstone of acute ischemic stroke treatment and secondary prevention. The efficacy of thrombolysis with alteplase in acute stroke has been demonstrated in several clinical trials. This safe and costeffective therapy has transformed the practice of stroke care and has led to subsequent trials of other antithrombotic medications for treatment of ischemic stroke in the acute phase. These antithrombotics include thrombolytic, antiplatelet and anticoagulant agents. While, no other medication has yet demonstrated adequate efficacy, our current and evolving understanding of infarct expansion, ischemic penumbra, collateral circulation and the blood brain barrier is allowing testing of antithrombotic medications tailored to individual patient pathophysiology in clinical trials. This understanding accompanies developments in neuroimaging and organization of stroke care that allow for wide-spread recruitment in these trials. Alteplase remains the mainstay treatment of arterial acute ischemic stroke; however, anticoagulation is the standard therapy for cerebral venous sinus thrombosis. Antithrombotic use in acute stroke, arterial and venous, has demonstrated efficacy but leaves many questions unanswered. This patient population is a fertile ground for novel research, especially as it relates to; combination antithrombotic therapy, combination of pharmacological and mechanical thrombolysis, and the transition to secondary prevention. Here we review the current antithrombotics in the acute phase of ischemic stroke highlighting the evidence-base and areas of uncertainty.

  18. Thrombophilia And Arterial Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    A.A. Abrishamizadeh

    2017-02-01

    Full Text Available Ischemic stroke (IS is a common cause of morbidity and mortality with significant socioeconomic impact especially when it affects young patients. Compared to the older adults, the incidence, risk factors, and etiology are distinctly different in younger IS. Hypercoagulable states are relatively more commonly detected in younger IS patients. Thrombophilic states are disorders of hemostatic mechanisms that result in a predisposition to thrombosis .Thrombophilia is an established cause of venous thrombosis. Therefore, it is tempting to assume that these disorders might have a similar relationship with arterial thrombosis. Despite this fact that 1-4 % of ischemic strokes are attributed to Thrombophillia, this   alone rarely causes arterial occlusions .Even in individuals with a positive thrombophilia screen and arterial thrombosis, the former might not be the primary etiological factor. Thrombophilic   disorders can be broadly divided into inherited or acquired conditions. Inherited thrombophilic states include deficiencies of natural anticoagulants such as protein C, protein S, and antithrombin III (AT III deficiency, polymorphisms causing resistance to activated protein C(Factor V Leiden mutation, and disturbance in the clotting balance (prothrombin gene 20210G/A variant. Of all the inherited  thrombophilic disorders, Factor V Leiden mutation is perhaps the commonest cause. On the contrary, acquired thrombophilic disorders are more common and include conditions such as the antiphospholipid syndrome, associated with lupus anticoagulant and anticardiolipin antibodies. The more useful and practical approach of ordering various diagnostic tests for the uncommon thrombophilic states tests should be determined by a detailed clinical history, physical examination, imaging studies and evaluating whether an underlying hypercoagulable state appears more likely. The laboratory thrombophilia   screening should be comprehensive and avoid missing the

  19. Retinal oxygen saturation in relation to retinal thickness in diabetic macular edema

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Peto, Tunde; Grauslund, Jakob

    to retinal thickness in patients with diabetic macular edema (DME). Methods: We included 18 patients with DME that all had central retinal thickness (CRT) >300 µm and were free of active proliferative diabetic retinopathy. Optical coherence tomography (Topcon 3D OCT-2000 spectral domain OCT) was used...... for paracentral edema, the oxygen saturation in the upper and lower temporal arcade branches were compared to the corresponding upper and lower subfield thickness. Spearman’s rank was used to calculate correlation coefficients between CRT and retinal oximetry. Results: Median age and duration of diabetes was 59....... 92.3%, p=0.52). We found no correlation between CRT and retinal oxygen saturation, even when accounting for paracentral edema (p>0.05). Furthermore, there was no difference in retinal oxygen saturation between the macular hemisphere that was more or less affected by DME (p>0.05). Conclusion: Patients...

  20. Ischemic conditioning-induced endogenous brain protection: Applications pre-, per- or post-stroke.

    Science.gov (United States)

    Wang, Yuechun; Reis, Cesar; Applegate, Richard; Stier, Gary; Martin, Robert; Zhang, John H

    2015-10-01

    In the area of brain injury and neurodegenerative diseases, a plethora of experimental and clinical evidence strongly indicates the promise of therapeutically exploiting the endogenous adaptive system at various levels like triggers, mediators and the end-effectors to stimulate and mobilize intrinsic protective capacities against brain injuries. It is believed that ischemic pre-conditioning and post-conditioning are actually the strongest known interventions to stimulate the innate neuroprotective mechanism to prevent or reverse neurodegenerative diseases including stroke and traumatic brain injury. Recently, studies showed the effectiveness of ischemic per-conditioning in some organs. Therefore the term ischemic conditioning, including all interventions applied pre-, per- and post-ischemia, which spans therapeutic windows in 3 time periods, has recently been broadly accepted by scientific communities. In addition, it is extensively acknowledged that ischemia-mediated protection not only affects the neurons but also all the components of the neurovascular network (consisting of neurons, glial cells, vascular endothelial cells, pericytes, smooth muscle cells, and venule/veins). The concept of cerebroprotection has been widely used in place of neuroprotection. Intensive studies on the cellular signaling pathways involved in ischemic conditioning have improved the mechanistic understanding of tolerance to cerebral ischemia. This has added impetus to exploration for potential pharmacologic mimetics, which could possibly induce and maximize inherent protective capacities. However, most of these studies were performed in rodents, and the efficacy of these mimetics remains to be evaluated in human patients. Several classical signaling pathways involving apoptosis, inflammation, or oxidation have been elaborated in the past decades. Newly characterized mechanisms are emerging with the advances in biotechnology and conceptual renewal. In this review we are going to focus on

  1. Ischemic heart disease: effectiveness and safety of statin treatment ...

    African Journals Online (AJOL)

    Ischemic heart disease: effectiveness and safety of statin treatment in a malaysian tertiary healthcare facility. ... Tropical Journal of Pharmaceutical Research ... and safety of statins in ischemic heart disease (IHD) patients in a Malaysian tertiary ...

  2. Caffeine prevents protection in two human models of ischemic preconditioning.

    NARCIS (Netherlands)

    Riksen, N.P.; Zhou, Z.; Oyen, W.J.G.; Jaspers, R.A.; Ramakers, B.P.; Brouwer, R.M.H.J.; Boerman, O.C.; Steinmetz, N.; Smits, P.; Rongen, G.A.

    2006-01-01

    OBJECTIVES: We studied whether caffeine impairs protection by ischemic preconditioning (IP) in humans. BACKGROUND: Ischemic preconditioning is critically dependent on adenosine receptor stimulation. We hypothesize that the adenosine receptor antagonist caffeine blocks the protective effect of IP.

  3. Caffeine prevents protection in two human models of ischemic preconditioning.

    NARCIS (Netherlands)

    Riksen, N.P.; Zhou, Z.; Oyen, W.J.G.; Jaspers, R.A.; Ramakers, B.P.; Brouwer, R.M.H.J.; Boerman, O.C.; Steinmetz, N.; Smits, P.; Rongen, G.A.

    2006-01-01

    OBJECTIVES: We studied whether caffeine impairs protection by ischemic preconditioning (IP) in humans. BACKGROUND: Ischemic preconditioning is critically dependent on adenosine receptor stimulation. We hypothesize that the adenosine receptor antagonist caffeine blocks the protective effect of IP. ME

  4. Autonomic dysfunction in acute ischemic stroke : An underexplored therapeutic area?

    NARCIS (Netherlands)

    De Raedt, Sylvie; De Vos, Aurelie; De Keyser, Jacques

    2015-01-01

    Impaired autonomic function, characterized by a predominance of sympathetic activity, is common in patients with acute ischemic stroke. This review describes methods to measure autonomic dysfunction in stroke patients. It summarizes a potential relationship between ischemic stroke-associated

  5. Dual antiplatelet therapy after noncardioembolic ischemic stroke or transient ischemic attack: pros and cons.

    Science.gov (United States)

    Hong, Keun-Sik

    2014-07-01

    Dual antiplatelet therapy simultaneously blocks different platelet activation pathways and might thus be more potent at inhibiting platelet activation and more effective at reducing major ischemic vascular events compared to antiplatelet monotherapy. Aspirin plus clopidogrel dual therapy is now the standard therapy for patients with acute coronary syndrome and for those undergoing percutaneous coronary intervention. However, dual antiplatelet therapy carries an increased risk of bleeding. Patients with ischemic stroke or transient ischemic attack (TIA) are generally older and likely to have a fragile cerebrovascular bed, which further increases the risk of systemic major bleeding events and intracranial hemorrhage. Clinical trials and meta-analyses suggest that in comparison to antiplatelet monotherapy, dual antiplatelet therapy initiated early after noncardioembolic ischemic stroke or TIA further reduces the rate of recurrent stroke and major vascular events without significantly increasing the rate of major bleeding events. In contrast, studies of long-term therapy in patients with noncardioembolic ischemic stroke or TIA have yielded inconsistent data regarding the benefit of dual antiplatelet therapy over monotherapy. However, the harm associated with major bleeding events, including intracranial hemorrhage, which is generally more disabling and more fatal than ischemic stroke, is likely to increase with dual antiplatelet therapy. Physicians should carefully assess the benefits and risks of dual antiplatelet therapy versus antiplatelet monotherapy when managing patients with ischemic stroke or TIA.

  6. Ischemic Preconditioning and Placebo Intervention Improves Resistance Exercise Performance.

    Science.gov (United States)

    Marocolo, Moacir; Willardson, Jeffrey M; Marocolo, Isabela C; da Mota, Gustavo Ribeiro; Simão, Roberto; Maior, Alex S

    2016-05-01

    with the IPC condition, it is suggested that ischemic preconditioning might be practiced gradually to assess tolerance and potential enhancements to exercise performance.

  7. Resilience in Patients with Ischemic Heart Disease

    Science.gov (United States)

    de Lemos, Conceição Maria Martins; Moraes, David William; Pellanda, Lucia Campos

    2016-01-01

    Background Resilience is a psychosocial factor associated with clinical outcomes in chronic diseases. The relationship between this protective factor and certain diseases, such heart diseases, is still under-explored. Objective The present study sought to investigate the frequency of resilience in individuals with ischemic heart disease. Method This was a cross-sectional study with 133 patients of both genders, aged between 35 and 65 years, treated at Rio Grande do Sul Cardiology Institute - Cardiology University Foundation, with a diagnosis of ischemic heart disease during the study period. Sixty-seven patients had a history of acute myocardial infarction. The individuals were interviewed and evaluated by the Wagnild & Young resilience scale and a sociodemographic questionnaire. Results Eighty-one percent of patients were classified as resilient according to the scale. Conclusion In the sample studied, resilience was identified in high proportion among patients with ischemic heart disease. PMID:26815312

  8. Short Telomere Length and Ischemic Heart Disease

    DEFF Research Database (Denmark)

    Scheller Madrid, Alexander; Rode, Line; Nordestgaard, Børge Grønne

    2016-01-01

    BACKGROUND: Short telomeres are associated with aging and have been associated with a high risk of ischemic heart disease in observational studies; however, the latter association could be due to residual confounding and/or reverse causation. We wanted to test the hypothesis that short telomeres...... are associated with high risk of ischemic heart disease using a Mendelian randomization approach free of reverse causation and of most confounding. METHODS: We genotyped 3 genetic variants in OBFC1 (oligonucleotide/oligosaccharide binding fold containing 1), TERT (telomerase reverse transcriptase), and TERC...... logistic and instrumental variable analysis for genetic estimates. RESULTS: Observationally, a 200-bp-shorter telomere length was associated with a multivariable adjusted hazard ratio for ischemic heart disease of 1.02 (95% CI, 1.01-1.03). Per allele, telomeres were shorter by 67 bp (73-60). In meta...

  9. Cerebrovascular arteriopathy (arteriosclerosis) and ischemic childhood stroke.

    Science.gov (United States)

    Daniels, S R; Bates, S; Lukin, R R; Benton, C; Third, J; Glueck, C J

    1982-01-01

    The aim of this report is to describe the intracranial cerebrovascular abnormalities and clinical status of 8 children who had familial lipoprotein disorders and evidence of thromboembolic cerebrovascular disease. Six of the 8 children had low levels of plasma high density lipoprotein cholesterol, two had high triglyceride levels, and all came from kindreds characterized by familial lipoprotein abnormalities and premature cardio- and/or cerebrovascular atherosclerosis. Vascular occlusion, irregularities of the arterial lumen, beading, tortuosity, and evidence of collateralization were consistently noted. We speculate that cerebrovascular arteriosclerosis in pediatric ischemic stroke victims who have familial lipoprotein abnormalities may be related to lipoprotein-mediated endothelial damage and thrombosis formation, or to the failure to restore endothelial cells' integrity following damage. The apparent association of lipoproteins and strokes in children and their families merits further exploration, particularly when assessing cerebral angiograms in pediatric ischemic stroke victims. In children with unexplained ischemic cerebrovascular accidents, the diagnostic possibility of occlusive arteriosclerosis with thrombosis must be entertained.

  10. Spectroscopic Monitoring of Kidney Tissue Ischemic Injury

    Energy Technology Data Exchange (ETDEWEB)

    Demos, S G; Fitzgerald, J T; Michalopoulou, A P; Troppmann, C

    2004-03-11

    Noninvasive evaluation of tissue viability of donor kidneys used for transplantation is an issue that current technology is not able to address. In this work, we explore optical spectroscopy for its potential to assess the degree of ischemic damage in kidney tissue. We hypothesized that ischemic damage to kidney tissue will give rise to changes in its optical properties which in turn may be used to asses the degree of tissue injury. The experimental results demonstrate that the autofluorescence intensity of the injured kidney is decreasing as a function of time exposed to ischemic injury. Changes were also observed in the NIR light scattering intensities most probably arising from changes due to injury and death of the tissue.

  11. Cardiac magnetic resonance determinants of functional mitral regurgitation in ischemic and non ischemic left ventricular dysfunction.

    Science.gov (United States)

    Fernández-Golfín, Covadonga; De Agustin, Alberto; Manzano, M Carmen; Bustos, Ana; Sánchez, Tibisay; Pérez de Isla, Leopoldo; Fuentes, Manuel; Macaya, Carlos; Zamorano, José

    2011-04-01

    Functional mitral regurgitation (FMR) is frequent in left ventricular (LV) dilatation/dysfunction. Echocardiographic predictors of FMR are known. However, cardiac magnetic resonance (CMR) predictors of FMR have not been fully addressed. The aim of the study was to evaluate CMR mitral valve (MV) parameters associated with FMR in ischemic and non ischemic LV dysfunction. 80 patients with LV ejection fraction below 45% and/or left ventricular dilatation of ischemic and non ischemic etiology were included. Cine-MR images (steady state free-precession) were acquired in a short-axis and 4 chambers views where MV evaluation was performed. Delayed enhancement was performed as well. Significant FMR was established as more than mild MR according to the echocardiographic report. Mean age was 59 years, males 79%. FMR was detected in 20 patients (25%) Significant differences were noted in LV functional parameters and in most MV parameters according to the presence of significant FMR. However, differences were noted between ischemic and non ischemic groups. In the first, differences in most MV parameters remained significant while in the non ischemic, only systolic and diastolic interpapillary muscle distance (1.60 vs. 2.19 cm, P = 0.001; 2. 51 vs. 3.04, P = 0.008) were predictors of FMR. FMR is associated with a more severe LV dilatation/dysfunction in the overall population. CMR MV parameters are associated with the presence of significant FMR and are different between ischemic and non ischemic patients. CMR evaluation of these patients may help in risk stratification as well as in surgical candidate selection.

  12. Rhegmatogenous retinal detachment: current opinion

    Directory of Open Access Journals (Sweden)

    T. A. Avanesova

    2015-03-01

    Full Text Available Rhegmatogenous retinal detachment (RRD is a severe ocular disorder which requires prompt treatment to prevent low vision and blindness. It is also a significant socio-economic problem as 84% of RDD patients are able-bodied. RRD grading systems (including current Machemer grading system, risk factors, and pathogenesis are reviewed. The role of proliferative vitreoretinopathy in RDD pathogenesis and recurrence is described. Macula involvement determines RDD outcome. Optical coherence tomography (OCT provides the study of retina anatomy and the analysis of parameters that affect post-op best corrected visual acuity, i.e., defects of the junction between inner segments and outer segments (IS/OS, the integrity of external (ELM and internal limiting membrane (ILM, outer nuclear layer thickness (ONLT etc. Fluorescent angiography allows to understand the reasons for low vision in anatomically successful RDD surgery. Scleral buckling, balloon buckling, pneumatic retinopexy, vitrectomy, cryopexy, and laser coagulation are important tools in surgical armamentarium. In recent years, vitrectomy is growing in popularity for RDD treatment. Criteria for procedure selection and surgical success rate in phakic and pseudophakic eyes are discussed. The outcomes of vitrectomy with air/gas and silicone oil tamponade are compared. Bimanual vitrectomy benefits are discussed. 

  13. Rhegmatogenous retinal detachment: current opinion

    Directory of Open Access Journals (Sweden)

    T. A. Avanesova

    2015-01-01

    Full Text Available Rhegmatogenous retinal detachment (RRD is a severe ocular disorder which requires prompt treatment to prevent low vision and blindness. It is also a significant socio-economic problem as 84% of RDD patients are able-bodied. RRD grading systems (including current Machemer grading system, risk factors, and pathogenesis are reviewed. The role of proliferative vitreoretinopathy in RDD pathogenesis and recurrence is described. Macula involvement determines RDD outcome. Optical coherence tomography (OCT provides the study of retina anatomy and the analysis of parameters that affect post-op best corrected visual acuity, i.e., defects of the junction between inner segments and outer segments (IS/OS, the integrity of external (ELM and internal limiting membrane (ILM, outer nuclear layer thickness (ONLT etc. Fluorescent angiography allows to understand the reasons for low vision in anatomically successful RDD surgery. Scleral buckling, balloon buckling, pneumatic retinopexy, vitrectomy, cryopexy, and laser coagulation are important tools in surgical armamentarium. In recent years, vitrectomy is growing in popularity for RDD treatment. Criteria for procedure selection and surgical success rate in phakic and pseudophakic eyes are discussed. The outcomes of vitrectomy with air/gas and silicone oil tamponade are compared. Bimanual vitrectomy benefits are discussed. 

  14. Polymorphisms in apolipoprotein B and risk of ischemic stroke

    DEFF Research Database (Denmark)

    Benn, Marianne; Nordestgaard, Børge G; Jensen, Jan Skov

    2007-01-01

    Apolipoprotein B levels associate with risk of ischemic stroke. APOB polymorphisms may influence levels of apolipoprotein B and low-density lipoprotein (LDL), but whether they associate with risk of ischemic stroke is unknown.......Apolipoprotein B levels associate with risk of ischemic stroke. APOB polymorphisms may influence levels of apolipoprotein B and low-density lipoprotein (LDL), but whether they associate with risk of ischemic stroke is unknown....

  15. [Nonfasting triglycerides and risk of ischemic stroke--secondary publication

    DEFF Research Database (Denmark)

    Freiberg, J.J.; Tybjaerg-Hansen, A.; Jensen, J.S.

    2009-01-01

    The role of triglycerides in the risk of ischemic stroke remains controversial. We tested the hypothesis that increased levels of nonfasting triglycerides are associated with ischemic stroke in the general population. Men with a nonfasting triglyceride level 5 mmol/l had a multivariable, adjusted...... hazard ratio for ischemic stroke of 2.5 (95% confidence interval: 1.3-4.8) compared with men with a nonfasting triglyceride level triglycerides is associated with risk of ischemic stroke Udgivelsesdato...

  16. [The effect of contrast baths on the hemostatic function of patients with ischemic heart disease].

    Science.gov (United States)

    Sorokina, E I; Ali, O

    1998-01-01

    Contrast baths effects on hemostasis were studied in 72 patients with postinfarction cardiosclerosis and stable angina pectoris. Hemostasis was assessed by recalcification time, blood plasma tolerance to heparin, fibrinolytic activity, functional activity of antithrombin, soluble fibrin-monomeric complex, platelet count and aggregation. The results were compared to those in patients exposed to laser irradiation. Hydrotherapy with contrast baths was hemostatically effective in 70.9% of patients. Blood coagulation and platelet aggregation improved, the risk of intravascular microthrombogenesis diminished. Contrast baths had more pronounced beneficial effects on coagulation in ischemic heart disease of NYHA functional class II.

  17. Anticoagulant Therapy In Ischemic Stroke Or TIA

    Directory of Open Access Journals (Sweden)

    Kaveh Mehrvar

    2017-02-01

    Full Text Available Stroke is the leading cause of disability and the third leading cause of death  . Anticoagulants   have been used to treat patients with acute ischemic stroke for many years. Despite their widespread use, the usefulness of emergency anticoagulation is a subject of debate. Disagreements exist about the best agent to administer, the route of administration, the use of a bolus dose to start treatment, the level of anticoagulation required, and the duration of treatment. There are 2 types of anticoagulants: Parenteral and oral. Heparin is an anticoagulant that used parenteral. Oral anticoagulants are including Warfarin and new anticoagulants such as Dabigatrn,Rivaroxaban ,Apixaban and other newer drugs. In patients with noncardioembolic  ischemic stroke or TIA antiplatelet agents are treatment of choice and preferred to anticoagulants. In cardioembolic  ischemic stroke or TIA with high risk of reembolization  anticoagulants  are considered as preferred treatment.  Warfarin, apixaban10mg/d ,Rivaroxaban20mg/d, and dabigatran 150 mg/d are all indicated for the prevention of recurrent stroke in patients with nonvalvular AF, whether paroxysmal or permanent.Also anticoagulant therapy is recommended for ischemic stroke or TIA patients in the setting of acute MI, atrial or ventricular thrombosis or dilated and restricted cardiomyopathy. Some valvular heart diseases are other indication for anticoagulant therapy in ischemic stroke or TIA patients. Ischemic  Stroke or TIA in patients with Cerebral vein thrombosis and  known hypercoagulable state specially anti phospholipid antibody syndrome are other indications for anticoagulant treatment.

  18. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....

  19. Ischemic Gastropathic Ulcer Mimics Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Saleh Daher

    2016-01-01

    Full Text Available Gastric ulcer due to mesenteric ischemia is a rare clinical finding. As a result, few reports of ischemic gastric ulcers have been reported in the literature. The diagnosis of ischemic gastropathy is seldom considered in patients presenting with abdominal pain and gastric ulcers. In this case report, we describe a patient with increasing abdominal pain, weight loss, and gastric ulcers, who underwent extensive medical evaluation and whose symptoms were resistant to medical interventions. Finally he was diagnosed with chronic mesenteric ischemia, and his clinical and endoscopic abnormalities resolved after surgical revascularization of both the superior mesenteric artery and the celiac trunk.

  20. Flow Augmentation in Acute Ischemic Stroke.

    Science.gov (United States)

    Yadollahikhales, Golnaz; Borhani-Haghighi, Afshin; Torabi-Nami, Mohammad; Edgell, Randall; Cruz-Flores, Salvador

    2016-01-01

    There is an urgent need for additional therapeutic options for acute ischemic stroke considering the major pitfalls of the options available. Herein, we briefly review the role of cerebral blood flow, collaterals, vasoreactivity, and reperfusion injury in acute ischemic stroke. Then, we reviewed pharmacological and interventional measures such as volume expansion and induced hypertension, intra-aortic balloon counterpulsation, partial aortic occlusion, extracranial-intracranial carotid bypass surgery, sphenopalatine ganglion stimulation, and transcranial laser therapy with regard to their effects on flow augmentation and neuroprotection. © The Author(s) 2014.

  1. Retinal Vessel Segmentation Using A New Topological Method

    CERN Document Server

    Brooks, Martin

    2016-01-01

    A novel topological segmentation of retinal images represents blood vessels as connected regions in the continuous image plane, having shape-related analytic and geometric properties. This paper presents topological segmentation results from the DRIVE retinal image database.

  2. Retinal microvascular abnormalities and stroke: a systematic review

    NARCIS (Netherlands)

    Doubal, F.N.; Hokke, P.E.; Wardlaw, J.M.

    2009-01-01

    Background: Lacunar strokes account for 25% of ischaemic strokes, but their precise aetiology is unknown. Similarities between the retinal and cerebral small vessels mean that clarification of the exact relationship between retinal microvascular abnormalities and stroke, and particularly with stroke

  3. Neoplasia versus hyperplasia of the retinal pigment epithelium

    DEFF Research Database (Denmark)

    Heegaard, Steffen; Larsen, J.N.B.; Fledelius, Hans C.

    2001-01-01

    ophthalmology, retinal pigment epithelium, adenoma, tumor-like hyperplasia, histology, immunohistochemistry, tumor, neoplasm, ultrasonography......ophthalmology, retinal pigment epithelium, adenoma, tumor-like hyperplasia, histology, immunohistochemistry, tumor, neoplasm, ultrasonography...

  4. External Approach Microsurgery of Retinal Dialysis

    Institute of Scientific and Technical Information of China (English)

    Ying Zhang; Piqing Hu; Lixin Shun; Xuechun Zhu; Yingwu Yi; Wen Liu

    2005-01-01

    Purpose: To explore the effect of external approach microsurgery in retinal dialysis.Methods: Consecutive 30 eyes of 28 patients with retinal dialysis were enrolled for this study. The progresses of the external approach microsurgery were following. Under the surgical microscopy, the preplacement of mattress sutures for buckling and/or encircling following retrobulbar anesthesia and scleral exposure, draining subretinal fluid, the cryotherapy of retinal breaks, checking the position of breaks on scleral buckle and gases injection were performed in turn.Results: After drainage of subretinal fluid, with scleral depression cryotherapy reaction around breaks could be observed clearly under the microscopy. All breaks were located on anterior slope of the buckle. Intraoperative complications were mild subretinal hemorrhage at drainage site and corneal epithelium exfoliation in 3 eyes, respectively.Postoperative complications were mainly secondary glaucoma and retinal redetachment.The one-operation reattachmentl rate was 96.7% (29 eyes), and the final reattachment rate was 100% after one eye had a second external approach microsurgery. The postoperative vision acuity (VA) was significantly better than the preoperative VA (X2=9.529, P< 0.01).Conclusion: External approach microsurgery has favourable effect on the surgery of retinal dialysis.

  5. Stem Cell Therapies in Retinal Disorders

    Directory of Open Access Journals (Sweden)

    Aakriti Garg

    2017-02-01

    Full Text Available Stem cell therapy has long been considered a promising mode of treatment for retinal conditions. While human embryonic stem cells (ESCs have provided the precedent for regenerative medicine, the development of induced pluripotent stem cells (iPSCs revolutionized this field. iPSCs allow for the development of many types of retinal cells, including those of the retinal pigment epithelium, photoreceptors, and ganglion cells, and can model polygenic diseases such as age-related macular degeneration. Cellular programming and reprogramming technology is especially useful in retinal diseases, as it allows for the study of living cells that have genetic variants that are specific to patients’ diseases. Since iPSCs are a self-renewing resource, scientists can experiment with an unlimited number of pluripotent cells to perfect the process of targeted differentiation, transplantation, and more, for personalized medicine. Challenges in the use of stem cells are present from the scientific, ethical, and political realms. These include transplant complications leading to anatomically incorrect placement, concern for tumorigenesis, and incomplete targeting of differentiation leading to contamination by different types of cells. Despite these limitations, human ESCs and iPSCs specific to individual patients can revolutionize the study of retinal disease and may be effective therapies for conditions currently considered incurable.

  6. Retinal haemorrhages in vacuum extraction deliveries

    Directory of Open Access Journals (Sweden)

    Bahgat Mostafa

    1987-01-01

    Full Text Available Two hundred and thirty eight newly born infants were subjected to fundus examination in the first 5 hours of labour then daily till discharge from the hospital then weekly till complete absorption of retinal haemorrhages The 238 infants were 23 delivered by caesarean section, 90 with spontaneous vaginal delivery,45 babies (over3.5 kgm delivered vaginallyand80 delivered by vacuum extraction. It was found that 37.39% of the newborns had retinal haemorrhages. The incidence, type and severity of retinal haemorrhages were related to the extent of obstetric trauma during birth. They were least with caesarean section. (4.35%, more in babies with spontaneous vaginal delivery (20%, more higher in infants over 3.5 kgm birth weight (33.33% and maximum in vacuum extraction deliveries (68.75%. A good correlation was made between the site and duration of cup application, level and rate of increase of negative pressure, the presence and size of cephalhematoma and the incidence and severity of retinal haemorrhages A good choice of cases as well as good control of the technique of vacuum extraction will minimize the incidence and severity of retinal haemorrhages in the new born.

  7. [Genetic diagnostic testing in inherited retinal dystrophies].

    Science.gov (United States)

    Kohl, S; Biskup, S

    2013-03-01

    Inherited retinal dystrophies are clinically and genetically highly heterogeneous. They can be divided according to the clinical phenotype and course of the disease, as well as the underlying mode of inheritance. Isolated retinal dystrophies (i.e., retinitis pigmentosa, Leber's congenital amaurosis, cone and cone-rod dystrophy, macular dystrophy, achromatopsia, congenital stationary nightblindness) and syndromal forms (i.e., Usher syndrome, Bardet-Biedl syndrome) can be differentiated. To date almost 180 genes and thousands of distinct mutations have been identified that are responsible for the different forms of these blinding illnesses. Until recently, there was no adequate diagnostic genetic testing available. With the development of the next generation sequencing technologies, a comprehensive genetic screening analysis for all known genes for inherited retinal dystrophies has been established at reasonable costs and in appropriate turn-around times. Depending on the primary clinical diagnosis and the presumed mode of inheritance, different diagnostic panels can be chosen for genetic testing. Statistics show that in 55-80 % of the cases the genetic defect of the inherited retinal dystrophy can be identified with this approach, depending on the initial clinical diagnosis. The aim of any genetic diagnostics is to define the genetic cause of a given illness within the affected patient and family and thereby i) confirm the clinical diagnosis, ii) provide targeted genetic testing in family members, iii) enable therapeutic intervention, iv) give a prognosis on disease course and progression and v) in the long run provide the basis for novel therapeutic approaches and personalised medicine.

  8. Mechanical tolerance stackup and analysis

    CERN Document Server

    Fischer, Bryan R

    2004-01-01

    BackgroundDimensioning and TolerancingTolerance Format and Decimal PlacesConverting Plus/Minus Dimensions and Tolerances into Equal Bilaterally Toleranced DimensionsVariation and Sources of VariationTolerance AnalysisWorst-case Tolerance StackupsStatistical Tolerance StackupsGeometric Dimensioning and Tolerancing (GD&T)Converting Plus/Minus Tolerancing to Positional Tolerancing and Projected Tolerance ZonesDiametral and Radial Tolerance StackupsSpecifying Material Condition Modifiers and Their Effect on Tolerance Stackups The Tolerance Stackup SketchThe Tolerance Stackup Report FormTolerance S

  9. Compromise and Toleration

    DEFF Research Database (Denmark)

    Rostbøll, Christian F.

    Political compromise is akin to toleration, since both consist of an "agreement to disagree." Compromise and toleration also share a predicament of being regarded as ambiguous virtues that require of us to accept something we actually regard as wrong. However, we misunderstand the nature......, justification, and limits of compromise if we see it merely as a matter of toleration. While toleration is mainly a matter of accepting citizens' equal right to co-existence as subjects to law, political compromise includes the parties in making law – it makes them co-authors of law. Toleration entails...... respecting the plurality of conceptions of the good in society, whereas political compromise embodies the disagreements in coercive laws. This difference between toleration and compromise has two important consequences. First, political compromise is justified in a different manner than is toleration...

  10. MR detection of retinal hemorrhages: correlation with graded ophthalmologic exam

    Energy Technology Data Exchange (ETDEWEB)

    Beavers, Angela J.; Allbery, Sandra M. [University of Nebraska Medical Center, Department of Radiology, Omaha, NE (United States); Children' s Hospital and Medical Center, Department of Radiology, Omaha, NE (United States); Stagner, Anna M.; Hejkal, Thomas W. [University of Nebraska Medical Center, Department of Ophthalmology, Omaha, NE (United States); Children' s Hospital and Medical Center, Department of Ophthalmology, Omaha, NE (United States); Lyden, Elizabeth R. [University of Nebraska Medical Center, College of Public Health, Omaha, NE (United States); Haney, Suzanne B. [Children' s Hospital and Medical Center, Department of Pediatrics, Omaha, NE (United States); University of Nebraska Medical Center, Department of Pediatrics, Omaha, NE (United States)

    2015-08-15

    Dilated fundoscopic exam is considered the gold standard for detecting retinal hemorrhage, but expertise in obtaining this exam is not always immediately available. MRI can detect retinal hemorrhages, but correlation of the grade or severity of retinal hemorrhage on dilated fundoscopic exam with retinal hemorrhage visibility on MRI has not been described. To determine the value of standard brain protocol MRI in detecting retinal hemorrhage and to determine whether there is any correlation with MR detection of retinal hemorrhage and the dilated fundoscopic exam grade of hemorrhage. We conducted a retrospective chart review of 77 children <2 years old who were seen for head trauma from April 2007 to July 2013 and had both brain MRI and dilated fundoscopic exam or retinal camera images. A staff pediatric radiologist and radiology resident reviewed the MR images. Retinal hemorrhages were graded by a chief ophthalmology resident on a 12-point scale based on the retinal hemorrhage type, size, location and extent as seen on review of retinal camera images and detailed reports by ophthalmologists. Higher scores indicated increased severity of retinal hemorrhages. There was a statistically significant difference in the median grade of retinal hemorrhage examination between children who had retinal hemorrhage detected on MRI and children who did not have retinal hemorrhage detected on MRI (P = 0.02). When examination grade was categorized as low-grade (1-4), moderate-grade (5-8) or high-grade (>8) hemorrhage, there was a statistically significant association between exam grade and diagnosis based on MRI (P = 0.008). For example, only 14% of children with low-grade retinal hemorrhages were identified on MRI compared to 76% of children with high-grade hemorrhages. MR detection of retinal hemorrhage demonstrated a sensitivity of 61%, specificity of 100%, positive predictive value of 100% and negative predictive value of 63%. Retinal hemorrhage was best seen on the gradient

  11. Blood pressure, risk of ischemic cerebrovascular and ischemic heart disease, and longevity in alpha(1)-antitrypsin deficiency

    DEFF Research Database (Denmark)

    Dahl, Morten; Tybjaerg-Hansen, Anne; Sillesen, Henrik

    2003-01-01

    Because elastase in alpha(1)-antitrypsin deficiency may attack elastin in the arterial wall, we tested whether alpha(1)-antitrypsin deficiency is associated with reduced blood pressure, risk of ischemic cerebrovascular (ICVD) and ischemic heart disease (IHD), and longevity.......Because elastase in alpha(1)-antitrypsin deficiency may attack elastin in the arterial wall, we tested whether alpha(1)-antitrypsin deficiency is associated with reduced blood pressure, risk of ischemic cerebrovascular (ICVD) and ischemic heart disease (IHD), and longevity....

  12. Contribution of Microglia-Mediated Neuroinflammation to Retinal Degenerative Diseases

    OpenAIRE

    Madeira, Maria H.; Raquel Boia; Santos, Paulo F.; António F. Ambrósio; Santiago, Ana R.

    2015-01-01

    Retinal degenerative diseases are major causes of vision loss and blindness worldwide and are characterized by chronic and progressive neuronal loss. One common feature of retinal degenerative diseases and brain neurodegenerative diseases is chronic neuroinflammation. There is growing evidence that retinal microglia, as in the brain, become activated in the course of retinal degenerative diseases, having a pivotal role in the initiation and propagation of the neurodegenerative process. A bett...

  13. The porcine retinal vasculature accessed using an endovascular approach

    DEFF Research Database (Denmark)

    Morén, Håkan; Undrén, Per; Gesslein, Bodil;

    2009-01-01

    The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia.......The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia....

  14. Influence of ischemic preconditioning on levels of nerve growth factor, brain-derived neurotrophic factor and their high-affinity receptors in hippocampus following forebrain ischemia.

    Science.gov (United States)

    Lee, Tsong-Hai; Yang, Jen-Tsung; Ko, Yu-Shien; Kato, Hiroyuki; Itoyama, Yasuto; Kogure, Kyuya

    2008-01-02

    Preconditioning of gerbil brain with a sublethal forebrain ischemia is known to protect hippocampal CA1 neurons following a subsequent lethal ischemia (the second ischemia) which usually damages neurons (ischemic tolerance). Present report using a confocal laser scanning microscope demonstrated that the hippocampal cells of sham operation gerbils contained immunofluorescent NGF and BDNF and their high-affinity receptors (TrkA and TrkB). A 2-min ischemia caused little change of these proteins (ANOVA test, PBDNF but not NGF and their high-affinity receptors showed a transient reduction at 4 h (ANOVA test, PBDNF and TrkB decreased transiently from 4 h to 1 day (ANOVA test, PCA3 and dentate gyrus areas, only BDNF decreased significantly at 7 days in the CA3 area without ischemic preconditioning (ANOVA test, PCA3 and dentate gyrus areas with and without ischemic preconditioning. Western blot study showed that in the hippocampal formation with ischemic preconditioning, preconditioning prevented the decline of these protein levels from 1 day to 7 days after the second lethal ischemia (ANOVA test, P>0.05). Results of this study demonstrate that ischemic preconditioning recovers the initial decline in NGF and BDNF and their corresponding receptors in the vulnerable CA1 neurons after the second lethal ischemia, suggesting that growth factors might play a role in the protective mechanism of ischemic preconditioning.

  15. Bilateral and Simultaneous Central Retinal Vein Occlusion in a Patient with Obstructive Sleep Apnea Syndrome

    Directory of Open Access Journals (Sweden)

    Andrea Govetto

    2014-05-01

    Full Text Available Purpose: To describe a case of bilateral and simultaneous central retinal vein occlusion (RVO in a young patient diagnosed with obstructive sleep apnea syndrome (OSAS. Case Report: A 38-year-old man with morbid obesity and daytime sleepiness presented with a history of bilateral vision loss. His visual acuity (VA was hand movements, and fundus examination (FE revealed bilateral central RVO. General medical examination revealed untreated hypertension and type II respiratory failure. Laboratory tests for thrombophilia showed increased hematocrit (59% and high levels of fibrinogen and C-reactive protein. Other causes of congenital and acquired hypercoagulability were ruled out. Pathologic polysomnography led to the diagnosis of OSAS. The patient was treated with antihypertensive drugs and continuous positive air pressure. In addition, he received intravitreal ranibizumab. At 10 months after presentation, his VA was no light perception in the right eye and hand movements in the left eye. FE revealed bilateral retinal and optic nerve atrophy, and the occurrence of a nonarteritic anterior ischemic neuropathy in the right eye was considered.

  16. Central retinal vein occlusion: A review of current Evidence-based treatment options

    Directory of Open Access Journals (Sweden)

    Amy Patel

    2016-01-01

    Full Text Available A central retinal vein occlusion (CRVO can induce an ischemic and hypoxic state with resulting sequelae of macular edema and neovascularization. Many treatment options have been studied. Our review aims to investigate the safety and efficacy of the multiple treatment options of CRVO. A PubMed and Cochrane literature search was performed. Well-controlled randomized clinical trials that demonstrated strong level 1 evidence-based on the rating scale developed by the British Centre for Evidence-Based Medicine were included. Seven clinical trials met inclusion criteria to be included in this review. These included studies that investigated the safety and efficacy of retinal photocoagulation (1 study, intravitreal steroid treatment (2 studies, and antivascular endothelial growth factor treatment (4 studies for the treatment of CRVO. In addition, studies evaluating surgical treatment options for CRVO were also included. Many treatment modalities have been demonstrated to be safe and efficacious in the treatment of CRVO. These treatment options offer therapeutic benefits for patients and clinically superior visual acuity and perhaps the quality of life after suffering from a CRVO.

  17. Cerebro-retinal ischemia after bilateral occlusion of internal carotid artery

    Energy Technology Data Exchange (ETDEWEB)

    Bogousslavsky, J.; Regli, F.

    1985-05-01

    Six patients with occlusion of internal carotid arteries (ICAs) were prospectively followed during a mean period of 14 months. Prior to demonstration of occlusions, four patients suffered a mild stroke, and three isolated transient ischemic attacks (TIAs) or amaurosis fugax. All patients remained alive and with an unchanged functional ability. During follow-up, one patient suffered amaurosis fugax and TIAs followed by a mild stroke, three suffered isolated TIAs or amaurosis fugax, two suffered reversible cerebro-retinal ischemia of more than 24 hours, and one remained symptomfree. In three cases, delayed cerebro-retinal ischemia distal to one of the occluded ICAs was systematically triggered by orthostatic, cardiogenic or iatrogenic hypotension, and resolved after adequate medical treatment or restoration of a functional collateral circulation by endarterectomy of a tightly stenosed ipsilateral external carotid artery (ECA), suggesting hemodynamic phenomena. In three cases, micro-emboli originating from a stump or an ulcerated ipsilateral common carotid artery and migrating through well-developed ECA collateral channels explained delayed episodes of ipsilateral TIAs or amaurosis fugax, which disappeared in two cases after adequate anticoagulant therepy was introduced. Bilateral occlusion of ICA may be a relatively benign condition, if the patients are carefully controlled and treated.

  18. Enhanced generation of retinal progenitor cells from human retinal pigment epithelial cells induced by amniotic fluid

    Directory of Open Access Journals (Sweden)

    Sanie-Jahromi Fatemeh

    2012-04-01

    Full Text Available Abstract Background Retinal progenitor cells are a convenient source of cell replacement therapy in retinal degenerative disorders. The purpose of this study was to evaluate the expression patterns of the homeobox genes PAX6 and CHX10 (retinal progenitor markers during treatment of human retinal pigment epithelium (RPE cells with amniotic fluid (AF, RPE cells harvested from neonatal cadaver globes were cultured in a mixture of DMEM and Ham's F12 supplemented with 10% FBS. At different passages, cells were trypsinized and co-cultured with 30% AF obtained from normal fetuses of 1416 weeks gestational age. Results Compared to FBS-treated controls, AF-treated cultures exhibited special morphological changes in culture, including appearance of spheroid colonies, improved initial cell adhesion and ordered cell alignment. Cell proliferation assays indicated a remarkable increase in the proliferation rate of RPE cells cultivated in 30% AF-supplemented medium, compared with those grown in the absence of AF. Immunocytochemical analyses exhibited nuclear localization of retinal progenitor markers at a ratio of 33% and 27% for CHX10 and PAX6, respectively. This indicated a 3-fold increase in retinal progenitor markers in AF-treated cultures compared to FBS-treated controls. Real-time PCR data of retinal progenitor genes (PAX6, CHX10 and VSX-1 confirmed these results and demonstrated AF's capacity for promoting retinal progenitor cell generation. Conclusion Taken together, the results suggest that AF significantly promotes the rate of retinal progenitor cell generation, indicating that AF can be used as an enriched supplement for serum-free media used for the in vitro propagation of human progenitor cells.

  19. Retinal blood flow velocity in patients with active uveitis using the retinal function imager

    Institute of Scientific and Technical Information of China (English)

    FENG Xing; Kedhar Sanjay; Bhoomibunchoo Chavakij

    2013-01-01

    Background Previous studies suggest a link between macular edema and retinal blood flow velocity (RBFV).The effects of inflammation in the retinal blood vessels are not clearly understood.We want to evaluate the differences in retinal blood flow velocities of patients with active uveitis and healthy controls using the retinal function imager (RFI)and determine the correlation between retinal blood flow veiocity and central macular thickness in uveitis patients.Methods Twenty-eight eyes of 24 patients with active anterior uveitis and 51 eyes of 51 normal control subjects were enrolled.Retinal blood flow velocities evaluated by RFI and central macular thickness evaluated by optical coherence tomography (SLO-OCT) were obtained.Differences among the groups were assessed using Stata statistical software.Results Ten eyes had uveitic cystoid macular edema (CME).Median (first quartile,third quartile) venous velocity for uveitic eyes with CME,uveitic eyes without CME,and controls were 2.09 (1.92,2.44),2.64 (2.32,2.86),and 2.82 (2.39,3.53) mm/s respectively.Median (first and quartile) arterial velocity for uveitic eyes with CME,uveitic eyes without CME,and controls were 3.79 (3.61,4.09),3.46 (2.86,4.12),and 3.93 (3.35,4.65) mm/s.Uveitic eyes with CME had significantly lower venous velocity than controls (P=0.044).There was a strong linear relationship between venous velocity and central retinal thickness (P=-0.007).Conclusions Retinal venous velocities were significantly decreased in eyes with uveitic CME relative to controls.Decreased venous velocity was correlated with increased central retinal thickness in uveitic eyes.

  20. Long-term impact of diabetes in patients hospitalized with ischemic and non-ischemic heart failure

    DEFF Research Database (Denmark)

    Andersson, Charlotte; Weeke, Peter; Pecini, Redi

    2010-01-01

    Abstract Objectives. Diabetes mellitus (DM) in combination with heart failure (HF) is associated with a high risk of death, but it is uncertain whether the prognosis differs in ischemic and non-ischemic HF groups. Design. One thousand, three hundred and six patients with ischemic HF and 1315...

  1. Functional annotation of the human retinal pigment epithelium transcriptome

    NARCIS (Netherlands)

    J.C. Booij (Judith); S. van Soest (Simone); S.M.A. Swagemakers (Sigrid); A.H.W. Essing (Anke); J.H.M. Verkerk (Annemieke); P.J. van der Spek (Peter); T.G.M.F. Gorgels (Theo); A.A.B. Bergen (Arthur)

    2009-01-01

    textabstractBackground: To determine level, variability and functional annotation of gene expression of the human retinal pigment epithelium (RPE), the key tissue involved in retinal diseases like age-related macular degeneration and retinitis pigmentosa. Macular RPE cells from six selected healthy

  2. Functional annotation of the human retinal pigment epithelium transcriptome

    NARCIS (Netherlands)

    Booij, J.C.; van Soest, S.; Swagemakers, S.M.A.; Essing, A.H.W.; Verkerk, A.J.M.H.; van der Spek, P.J.; Gorgels, T.G.M.F.; Bergen, A.A.B.

    2009-01-01

    ABSTRACT: BACKGROUND: To determine level, variability and functional annotation of gene expression of the human retinal pigment epithelium (RPE), the key tissue involved in retinal diseases like age-related macular degeneration and retinitis pigmentosa. Macular RPE cells from six selected healthy hu

  3. THE RESULTS OF RADIAL OPTIC NEUROTOMY FOR TREATMENT OF CENTRAL RETINAL VEIN OCCLUSION

    Directory of Open Access Journals (Sweden)

    S A Tabatabaii

    2008-11-01

    Full Text Available "nCentral retinal vein occlusion (CRVO is the third most common blinding vascular retinal disorder. As there is no proven treatment for CRVO, we performed this study to evaluate the effectiveness of radial optic neurotomy (RON on visual acuity in eyes with CRVO. This study was designed as an interventional case series. Pars plana vitrectomy with RON was performed in 18 eyes of 16 patients with ischemic CRVO with visual acuities of 20/400 or less. Postoperative and preoperative visual acuities were compared using t paired test. Mean preoperative visual acuity was 20/1000 (range, 20/1600 to 20/630. Mean follow-up time was 3.6 months (range, 1 to 9 months. Mean postoperative visual acuity was 20/400 (range, 20/1600 to 20/50 at last follow-up and the difference was significant (P < 0.01; t paired test. Six patients (33% improved to 20/200 postoperatively. There were no major complications intraoperatively. Chorioretinal shunts developed in neurotomy site in 9 cases (50% 4 to 10 weeks after procedure which were associated with faster resolving of hemorrhage and venous dilation. There were no major complications noted with this procedure but vitreous hemorrhage and iris neovascularization was observed in the early postoperative period in 2 (11% of 18 cases. RON may improve visual acuity in eyes with CRVO. It is a technically feasible and fairly safe procedure but postoperatively it may result in some complications such as vitreous hemorrhage, iris neovascularization and retinal detachment.

  4. [Muscular Dystrophies Involving the Retinal Function].

    Science.gov (United States)

    Jägle, H

    2016-03-01

    Muscular dystrophies are rare disorders, with an incidence of approx. 20 in 100 000. Some dystrophies also affect retinal or optic nerve function. In such cases, the ophthalmological findings may be critical for differential diagnosis or patient counseling. For example in Duchenne muscular dystrophy, where the alteration in retinal function seems to reflect cerebral involvement. Other important forms are mitochondrial and metabolic disorders, such as the Kearns-Sayre syndrome and the Refsum syndrome. Molecular genetic analysis has become a major tool for differential diagnosis, but may be complex and demanding. This article gives an overview of major muscular dystrophies involving retinal function and their genetic origin, in order to guide differential diagnosis.

  5. Enhancing retinal images by nonlinear registration

    CERN Document Server

    Molodij, Guillaume; Glanc, Marie; Chenegros, Guillaume

    2014-01-01

    Being able to image the human retina in high resolution opens a new era in many important fields, such as pharmacological research for retinal diseases, researches in human cognition, nervous system, metabolism and blood stream, to name a few. In this paper, we propose to share the knowledge acquired in the fields of optics and imaging in solar astrophysics in order to improve the retinal imaging at very high spatial resolution in the perspective to perform a medical diagnosis. The main purpose would be to assist health care practitioners by enhancing retinal images and detect abnormal features. We apply a nonlinear registration method using local correlation tracking to increase the field of view and follow structure evolutions using correlation techniques borrowed from solar astronomy technique expertise. Another purpose is to define the tracer of movements after analyzing local correlations to follow the proper motions of an image from one moment to another, such as changes in optical flows that would be o...

  6. Marfan Syndrome Presenting with Bilateral Retinal Detachment

    Directory of Open Access Journals (Sweden)

    Subrata Chakrabarti

    2014-02-01

    Full Text Available Marfan syndrome is an autosomal dominant systemic disorder of the connective tissue. Marfan syndrome affects most organs and tissues, especially the skeleton, lungs, eyes, heart, and the large blood vessels. Eye involvement may be in the form of retinal detachment which is a potentially dangerous manifestation for its sight threatening nature .We report a case where a 17 year old male developed sudden blindness due to spontaneous bilateral retinal detachment. Examination revealed features of Marfan syndrome and was stamped as a case of Marfan syndrome by Ghent criteria . The point to stress upon is that a young male developing spontaneous retinal detachment, a diagnosis of underlying Marfan syndrome should be kept in mind if appropriate clinical stigmata are present. [Natl J Med Res 2014; 4(1.000: 104-105

  7. Stem cell therapy for retinal diseases

    Institute of Scientific and Technical Information of China (English)

    Jose Mauricio Garcia,; Luisa Mendon?a; Rodrigo Brant; Murilo Abud; Caio Regatieri; Bruno Diniz

    2015-01-01

    In this review, we discuss about current knowledgeabout stem cell (SC) therapy in the treatment of retinaldegeneration. Both human embryonic stem cell andinduced pluripotent stem cell has been growth inculture for a long time, and started to be explored inthe treatment of blinding conditions. The Food andDrug Administration, recently, has granted clinical trialsusing SC retinal therapy to treat complex disorders, asStargardt's dystrophy, and patients with geographicatrophy, providing good outcomes. This study'sintent is to overview the critical regeneration of thesubretinal anatomy through retinal pigment epitheliumtransplantation, with the goal of reestablish importantpathways from the retina to the occipital cortex of thebrain, as well as the differentiation from pluripotentquiescent SC to adult retina, and its relationshipwith a primary retinal injury, different techniques oftransplantation, management of immune rejection andtumorigenicity, its potential application in improvingpatients' vision, and, finally, approaching future directionsand challenges for the treatment of several conditions.

  8. Prospects for retinal gene replacement therapy.

    Science.gov (United States)

    Smith, Alexander J; Bainbridge, James W; Ali, Robin R

    2009-04-01

    Inherited retinal degeneration, which includes conditions such as retinitis pigmentosa and Leber congenital amaurosis (LCA), affects approximately 1/3000 of the population in the Western world. It is characterized by loss of vision and results from mutations in any one of >100 different genes. There are currently no effective treatments, but many of the genes have now been identified and their functions elucidated, providing a major impetus to develop gene-based treatments. Preliminary results from three clinical trials indicate that the treatment of a form of LCA by gene therapy can be safe and effective. Here, we discuss the potential for treating other forms of retinal degeneration by gene therapy, focusing on the gene defects that are likely to be the most amenable to treatment.

  9. Integrated computer-aided retinal photocoagulation system

    Science.gov (United States)

    Barrett, Steven F.; Wright, Cameron H. G.; Oberg, Erik D.; Rockwell, Benjamin A.; Cain, Clarence P.; Jerath, Maya R.; Rylander, Henry G., III; Welch, Ashley J.

    1996-05-01

    Successful retinal tracking subsystem testing results in vivo on rhesus monkeys using an argon continuous wave laser and an ultra-short pulse laser are presented. Progress on developing an integrated robotic retinal laser surgery system is also presented. Several interesting areas of study have developed: (1) 'doughnut' shaped lesions that occur under certain combinations of laser power, spot size, and irradiation time complicating measurements of central lesion reflectance, (2) the optimal retinal field of view to achieve simultaneous tracking and lesion parameter control, and (3) a fully digital versus a hybrid analog/digital tracker using confocal reflectometry integrated system implementation. These areas are investigated in detail in this paper. The hybrid system warrants a separate presentation and appears in another paper at this conference.

  10. Retinal changes in pregnancy-induced hypertension

    Directory of Open Access Journals (Sweden)

    Akash Pankaj Shah

    2015-01-01

    Full Text Available Aims: The aim was to determine the prevalence of retinal changes in pregnancy-induced hypertension (PIH and any association between the retinal changes and age, parity, blood pressure, proteinuria, and severity of the disease. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: All the patients admitted with a diagnosis of PIH were included in this study. Age, gravida, gestation period, blood pressure, and proteinuria were noted from the case records. Fundus examination was done with a direct ophthalmoscope. The findings were noted and were analyzed using SPSS program. Results: A total of 150 patients of PIH were examined. The mean age of patients was 25.1 years. The gestation period ranged from 27 weeks to 42 weeks; 76 (50.67% were the primi gravida. 92 (61.33% patients had gestational hypertension, 49 (32.67% patients had preeclampsia, and 9 (6% had eclampsia. Retinal changes (hypertensive retinopathy were noted in 18 (12% patients - Grade 1 in 12 (8% and Grade 2 in 6 (4%. Hemorrhages or exudates or retinal detachment were not seen in any patient. There was statistically significant positive association of retinal changes and blood pressure (P = 0.037, proteinuria (P = 0.0005, and severity of the PIH (P = 0.004. Conclusions: Retinal changes were seen in 12% of patients with PIH. Occurrence of hypertensive retinopathy in PIH cases has been decreased due to better antenatal care and early detection and treatment of PIH cases. There is a greater chance of developing retinopathy with increase in blood pressure, severity of PIH, and proteinuria in cases of PIH.

  11. Reading visual braille with a retinal prosthesis.

    Science.gov (United States)

    Lauritzen, Thomas Z; Harris, Jordan; Mohand-Said, Saddek; Sahel, Jose A; Dorn, Jessy D; McClure, Kelly; Greenberg, Robert J

    2012-01-01

    Retinal prostheses, which restore partial vision to patients blinded by outer retinal degeneration, are currently in clinical trial. The Argus II retinal prosthesis system was recently awarded CE approval for commercial use in Europe. While retinal prosthesis users have achieved remarkable visual improvement to the point of reading letters and short sentences, the reading process is still fairly cumbersome. This study investigates the possibility of using an epiretinal prosthesis to stimulate visual braille as a sensory substitution for reading written letters and words. The Argus II retinal prosthesis system, used in this study, includes a 10 × 6 electrode array implanted epiretinally, a tiny video camera mounted on a pair of glasses, and a wearable computer that processes the video and determines the stimulation current of each electrode in real time. In the braille reading system, individual letters are created by a subset of dots from a 3 by 2 array of six dots. For the visual braille experiment, a grid of six electrodes was chosen out of the 10 × 6 Argus II array. Groups of these electrodes were then directly stimulated (bypassing the camera) to create visual percepts of individual braille letters. Experiments were performed in a single subject. Single letters were stimulated in an alternative forced choice (AFC) paradigm, and short 2-4-letter words were stimulated (one letter at a time) in an open-choice reading paradigm. The subject correctly identified 89% of single letters, 80% of 2-letter, 60% of 3-letter, and 70% of 4-letter words. This work suggests that text can successfully be stimulated and read as visual braille in retinal prosthesis patients.

  12. Reading visual Braille with a retinal prosthesis

    Directory of Open Access Journals (Sweden)

    Thomas Zaccarin Lauritzen

    2012-11-01

    Full Text Available Retinal prostheses, which restore partial vision to patients blinded by outer retinal degeneration, are currently in clinical trial. The Argus II retinal prosthesis system was recently awarded CE approval for commercial use in Europe. While retinal prosthesis users have achieved remarkable visual improvement to the point of reading letters and short sentences, the reading process is still fairly cumbersome. This study investigates the possibility of using an epiretinal prosthesis to stimulate visual Braille as a sensory substitution for reading written letters and words. The Argus II retinal prosthesis system, used in this study, includes a 10 x 6 electrode array implanted epiretinally, a tiny video camera mounted on a pair of glasses, and a wearable computer that processes the video and determines the stimulation current of each electrode in real time. In the Braille reading system, individual letters are created by a subset of dots from a 3 by 2 array of six dots. For the visual Braille experiment, a grid of six electrodes was chosen out of the 10 x 6 Argus II array. Groups of these electrodes were then directly stimulated (bypassing the camera to create visual percepts of individual Braille letters. Experiments were performed in a single subject. Single letters were stimulated in an alternative forced choice (AFC paradigm, and short 2-4-letter words were stimulated (one letter at a time in an open-choice reading paradigm. The subject correctly identified 89% of single letters, 80% of 2-letter, 60% of 3-letter, and 70% of 4-letter words. This work suggests that text can successfully be stimulated and read as visual Braille in retinal prosthesis patients.

  13. CT imaging in acute ischemic stroke

    NARCIS (Netherlands)

    Borst, J.

    2016-01-01

    Time is of the essence when treating acute ischemic stroke, to limit the damage caused. One form of intra-arterial treatment (IAT) used in such cases is the mechanical removal of the blood clot using stent-retrievers. It is thought that patient selection for IAT requires improvement and that CT

  14. Hyperglycemia Increases Susceptibility to Ischemic Necrosis

    Directory of Open Access Journals (Sweden)

    D. Lévigne

    2013-01-01

    Full Text Available Diabetic patients are at risk for spontaneous foot ulcers, chronic wounds, infections, and tissue necrosis. Current theories suggest that the development and progression of diabetic foot ulcers are mainly caused by arteriosclerosis and peripheral neuropathy. Tissue necrosis plays a primordial role in the progression of diabetic foot ulcers but the underlying mechanisms are poorly understood. The aim of the present study was to investigate the effects of hyperglycemia per se on the susceptibility of ischemic tissue to necrosis, using a critical ischemic hind limb animal model. We inflicted the same degree of ischemia in both euglycemic and streptozotocin-induced hyperglycemic rats by resecting the external iliac, the femoral, and the saphenous arteries. Postoperative laser Doppler flowmetry of the ischemic feet showed the same degree of reduction in skin perfusion in both hyperglycemic and euglycemic animals. Nevertheless, we found a significantly higher rate of limb necrosis in hyperglycemic rats compared to euglycemic rats (71% versus 29%, resp.. In this study, we revealed that hyperglycemia per se increases the susceptibility to limb necrosis in ischemic conditions. Our results may help to better understand the physiopathology of progressive diabetic wounds and underline the importance of strict glycemic control in patients with critical limb ischemia.

  15. Ischemic Stroke during Pregnancy and Puerperium

    Directory of Open Access Journals (Sweden)

    Elisabetta Del Zotto

    2011-01-01

    Full Text Available Ischemic stroke during pregnancy and puerperium represents a rare occurrence but it could be a serious and stressful event for mothers, infants, and also families. Whenever it does occur, many concerns arise about the safety of the mother and the fetus in relation to common diagnostic tests and therapies leading to a more conservative approach. The physiological adaptations in the cardiovascular system and in the coagulability that accompany the pregnant state, which are more significant around delivery and in the postpartum period, likely contribute to increasing the risk of an ischemic stroke. Most of the causes of an ischemic stroke in the young may also occur in pregnant patients. Despite this, there are specific conditions related to pregnancy which may be considered when assessing this particular group of patients such as pre-eclampsia-eclampsia, choriocarcinoma, peripartum cardiomiopathy, amniotic fluid embolization, and postpartum cerebral angiopathy. This article will consider several questions related to pregnancy-associated ischemic stroke, dwelling on epidemiological and specific etiological aspects, diagnostic issue concerning the use of neuroimaging, and the related potential risks to the embryo and fetus. Therapeutic issues surrounding the use of anticoagulant and antiplatelets agents will be discussed along with the few available reports regarding the use of thrombolytic therapy during pregnancy.

  16. Surgical strategy for mild ischemic mitral insufficiency

    Institute of Scientific and Technical Information of China (English)

    GU Cheng-xiong; WEI Hua; YU Yang

    2010-01-01

    @@ To the Editor: We read with the interest the article by FAN Hong-guang and colleagues~1 having obtained outstanding early and long-term clinical outcomes of left ventricular restoration for the patients with postinfarction ventricular aneurysm and low left ventricular ejection fraction (LVEF) of mean 37.7%. We would like to comment on surgical strategy for mild ischemic mitral insufficiency.

  17. Acute ischemic stroke prognostication, comparison between ...

    African Journals Online (AJOL)

    Ossama Y. Mansour

    2014-11-20

    Nov 20, 2014 ... patients with acute ischemic stroke in comparison with the NIHSS and the GCS. ... comes; In-hospital or 30 days mortality and Modified Rankin Scale (mRS) at 3 ..... 8. Bamford J, Sandercock P, Dennis M, Burn J, Warlow C.

  18. Remnant cholesterol and ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G

    2014-01-01

    PURPOSE OF REVIEW: To review recent advances in the field of remnant cholesterol as a contributor to the development of ischemic heart disease (IHD). RECENT FINDINGS: Epidemiologic, mechanistic, and genetic studies all support a role for elevated remnant cholesterol (=cholesterol in triglyceride...

  19. The diagnosis of transient ischemic attacks

    NARCIS (Netherlands)

    P.J. Koudstaal (Peter Jan)

    1989-01-01

    textabstractThe diagnosis of transient ischemic attack (TIA) is fraught with difficulty, since the diagnosis rests entirely upon the history of the patient's symptoms and the neurologist's skill in questioning the patient. The aim of this thesis is to investigate various measures to improve the reli

  20. Spinal cord stimulation for ischemic heart disease

    NARCIS (Netherlands)

    DeJongste, MJL

    2000-01-01

    An increasing number of patients are suffering from angina pectoris that is chronically refractory to standard anti-ischemic treatment such as pharmacological and surgical strategies. To improve the quality of life of these severely disabled patients, without adversely affecting their prognosis, a n

  1. Rehabilitation Outcomes: Ischemic versus Hemorrhagic Strokes

    Directory of Open Access Journals (Sweden)

    Robert Perna

    2015-01-01

    Full Text Available Background. Ischemic and hemorrhagic strokes have different pathophysiologies and possibly different long-term cerebral and functional implications. Hemorrhagic strokes expose the brain to irritating effects of blood and ischemic strokes reflect localized or diffuse cerebral vascular pathology. Methods. Participants were individuals who suffered either an ischemic (n=172 or hemorrhagic stroke (n=112 within the past six months and were involved in a postacute neurorehabilitation program. Participants completed three months of postacute neurorehabilitation and the Mayo Portland Adaptability Inventory-4 (MPAI-4 at admission and discharge. Admission MPAI-4 scores and level of functioning were comparable. Results. Group ANOVA comparisons show no significant group differences at admission or discharge or difference in change scores. Both groups showed considerably reduced levels of productivity/employment after discharge as compared to preinjury levels. Conclusions. Though the pathophysiology of these types of strokes is different, both ultimately result in ischemic injuries, possibly accounting for lack of findings of differences between groups. In the present study, participants in both groups experienced similar functional levels across all three MPAI-4 domains both at admission and discharge. Limitations of this study include a highly educated sample and few outcome measures.

  2. Molecular Mechanisms of Renal Ischemic Conditioning Strategies

    NARCIS (Netherlands)

    Kierulf-Lassen, Casper; Nieuwenhuijs-Moeke, Gertrude J.; Krogstrup, Nicoline V.; Oltean, Mihai; Jespersen, Bente; Dor, Frank J. M. F.

    2015-01-01

    Ischemia-reperfusion injury is the leading cause of acute kidney injury in a variety of clinical settings such as renal transplantation and hypovolemic and/or septic shock. Strategies to reduce ischemia-reperfusion injury are obviously clinically relevant. Ischemic conditioning is an inherent part o

  3. Treatment of Laser Induced Retinal Injuries.

    Science.gov (United States)

    1986-04-02

    END 1.0 1.18 Yl(-ROCOPY Ri yjTuION If ’,! (HART !. UIH; iLruud @ N TREATMENT OF LASER INDUCED RETINAL INJURIES (ANNUAL REPORT 00 DTIC Michael Belkin...NO. CCESSION NO _______________________________61102A I102BS1O0 CF 1i. 446 TITLE (Indude S*.curny Claifkaion) TREATMENT OF LASER INDUCED RETINAL... INJURIES PERSONAL AUTHOR(S) M. BELKIN N. NAVEH a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Mont. D y) S. PAGE COUNT FROM Xaj& TO l 2Ann

  4. Cytomegalovirus retinitis after initiation of antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Zahra Ahmadinejad

    2013-10-01

    Full Text Available Patients with human immunodeficiency virus (HIV infection receiving antiretroviral therapy (ART, despite a reduced viral load and improved immune responses, may experience clinical deterioration. This so called "immune reconstitution inflammatory syndrome (IRIS" is caused by inflammatory response to both intact subclinical pathogens and residual antigens. Cytomegalovirus retinitis is common in HIV-infected patients on ART with a cluster differentiation 4 (CD4+ counts less than 50 cells/mm3. We reported a patient with blurred vision while receiving ART. She had an unmasking classic CMV retinitis after ART.

  5. Laser speckle analysis of retinal vascular dynamics

    DEFF Research Database (Denmark)

    Neganova, Anastasiia Y.; Postnov, Dmitry D.; Jacobsen, Jens Christian B.;

    2016-01-01

    Studies of vascular responses are usually performed on isolated vessels or on single vessels in vivo. This allows for precise measurements of diameter or blood flow. However, dynamical responses of the whole microvascular network are difficult to access experimentally. We suggest to use full......-field laser speckle imaging to evaluate vascular responses of the retinal network. Image segmentation and vessel recognition algorithms together with response mapping allow us to analyze diameter changes and blood flow responses in the intact retinal network upon systemic administration of the vasoconstrictor...

  6. [Binocular vision after treatment of retinal detachment].

    Science.gov (United States)

    Maksymowicz, Małgorzata; Raczyńska, Krystyna; Maksymowicz, Jarosław

    2003-01-01

    The study covered 79 patients after treatment of retinal detachment. Double vision, strabismus and disturbances of eyeballs motility were found. Up to 12 months after intervention, the deterioration of binocular vision was observed in 48.28 to 89.66% of patients, depending on the method used. The majority of disturbances were observed during the first 3 months with tendency to gradual subsidence during consecutive 9 months. A patient, after treatment of retinal detachment, can be qualified to return to work where stereopsis is needed under condition that ophthalmologic examination is done every three months during the first year after operation and than once a year.

  7. Retinal image analysis: preprocessing and feature extraction

    Energy Technology Data Exchange (ETDEWEB)

    Marrugo, Andres G; Millan, Maria S, E-mail: andres.marrugo@upc.edu [Grup d' Optica Aplicada i Processament d' Imatge, Departament d' Optica i Optometria Univesitat Politecnica de Catalunya (Spain)

    2011-01-01

    Image processing, analysis and computer vision techniques are found today in all fields of medical science. These techniques are especially relevant to modern ophthalmology, a field heavily dependent on visual data. Retinal images are widely used for diagnostic purposes by ophthalmologists. However, these images often need visual enhancement prior to apply a digital analysis for pathological risk or damage detection. In this work we propose the use of an image enhancement technique for the compensation of non-uniform contrast and luminosity distribution in retinal images. We also explore optic nerve head segmentation by means of color mathematical morphology and the use of active contours.

  8. Hypoxia-inducible factor and vascular endothelial growth factor in the neuroretina and retinal blood vessels after retinal ischemia

    DEFF Research Database (Denmark)

    Håkansson, Gisela; Gesslein, Bodil; Gustafsson, Lotta

    2010-01-01

    Retinal ischemia arises from circulatory failure. As the retinal blood vessels are key organs in circulatory failure, our aim was to study the retinal vasculature separately from the neuroretina to elucidate the role of hypoxia-inducible factor (HIF) 1α and 1β and vascular endothelial growth factor...

  9. Remote Ischemic Conditioning and Renal Protection.

    Science.gov (United States)

    Giannopoulos, Georgios; Vrachatis, Dimitrios A; Panagopoulou, Vasiliki; Vavuranakis, Manolis; Cleman, Michael W; Deftereos, Spyridon

    2017-07-01

    Over the course of the last 2 decades, the concept of remote ischemic conditioning (RIC) has attracted considerable research interest, because RIC, in most of its embodiments offers an inexpensive way of protecting tissues against ischemic damage inflicted by a number of medical conditions or procedures. Acute kidney injury (AKI) is a common side effect in the context of various medical procedures, and RIC has been suggested as a means of reducing its incidence. Outcomes regarding kidney function have been reported in numerous studies that evaluated the effects of RIC in a variety of settings (eg, cardiac surgery, interventions requiring intravenous administration of contrast media). Although several individual studies have implied a beneficial effect of RIC in preserving kidney function, 3 recently published randomized controlled trials evaluating more than 1000 patients each (Effect of Remote Ischemic Preconditioning in the Cardiac Surgery, Remote Ischaemic Preconditioning for Heart Surgery, and ERICCA) were negative. However, AKI or any other index of renal function was not a stand-alone primary end point in any of these trials. On the other hand, a range of meta-analyses (each including thousands of participants) have reported mixed results, with the most recent among them showing benefit from RIC, pinpointing at the same time a number of shortcomings in published studies, adversely affecting the quality of available data. The present review provides a critical appraisal of the current state of this field of research. It is the opinion of the authors of this review that there is a clear need for a common clinical trial framework for ischemic conditioning studies. If the current babel of definitions, procedures, outcomes, and goals persists, it is most likely that soon ischemic conditioning will be "yesterday's news" with no definitive conclusions having been reached in terms of its real clinical utility.

  10. CT findings in isolated ischemic proctosigmoiditis

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Walter; Mortele, Koenraad J.; Ji, Hoon; Khurana, Bharti; Ros, Pablo R. [Department of Radiology, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Glickman, Jonathan N. [Department of Pathology, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

    2002-07-01

    The purpose of our study was to describe the CT features of ischemic proctosigmoiditis in correlation with clinical, laboratory, endoscopic, and histopathologic findings. Our study included seven patients with isolated ischemic proctosigmoiditis. Patients were identified by a retrospective review of all histopathologic records of colonoscopic biopsies performed during a time period of 4 years. All patients presented with left lower abdominal quadrant pain, bloody stools, and leukocytosis, and four patients had fever at the time of presentation. Four of seven patients suffered from diarrhea, one of seven was constipated and two of seven had normal stool consistency. The CT examinations were reviewed by two authors by consensus and compared with clinical and histopathologic results as well as with the initial CT diagnosis. The CT showed a wall thickening confined to the rectum and sigmoid colon in seven of seven patients, stranding of the pararectal fat in four of seven, and stranding of the perisigmoidal fat in one of seven patients. There were no enlarged lymph nodes, but five of seven patients showed coexistent diverticulosis and in three of these patients CT findings were initially misinterpreted as sigmoid diverticulitis. Endoscopies and histopathologic analyses of endoscopic biopsies confirmed non-transmural ischemic proctosigmoiditis in all patients. Isolated ischemic proctosigmoiditis often presents with unspecific CT features and potentially misleading clinical and laboratory findings. In an elderly patient or a patient with known cardiovascular risk factors the diagnosis of ischemic proctosigmoiditis should be considered when wall thickening confined to the rectum and sigmoid colon is seen that is associated with perirectal fat stranding. (orig.)

  11. Chronic Myeloid Leukaemia Presenting as Bilateral Retinal Haemorrhages with Multiple Retinal Infiltrates.

    Science.gov (United States)

    Rane, Priyanka Ramkrishna; Barot, Rakesh K; Gohel, Devadatta Jayantilal; Bhagat, Nupur

    2016-05-01

    Chronic Myeloid Leukaemia (CML) causes retinopathy manifesting as venous dilation and tortuosity, perivascular sheathing, retinal haemorrhages, microaneurysms, cotton-wool spots and optic nerve infiltration. Retina is the most commonly involved intraocular structure in CML. However, retinal involvement is a rare form of presentation of CML and few cases have been reported. We report a case of CML presenting as unilateral sudden visual loss. Fundus showed multiple white centered retinal haemorrhages in both eyes with unilateral macular oedema. Blood work-up showed raised WBC count, high platelet count and low Haemoglobin. Cytological analysis of bone marrow biopsy confirmed Philadelphia chromosome. After a course of Imatinib, visual acuity improved and haemorrhages resolved with normalization of macular thickness. In our case, patient presented early, leading to early detection producing better visual prognosis. This highlights the importance of detailed hematological work up in patients with retinal involvement to rule out leukaemic retinopathy.

  12. Probing how initial retinal configuration controls photochemical dynamics in retinal proteins

    Directory of Open Access Journals (Sweden)

    Sheves M.

    2013-03-01

    Full Text Available The effects of the initial retinal configuration and the active isomerization coordinate on the photochemistry of retinal proteins (RPs are assessed by comparing photochemical dynamics of two stable retinal ground state configurations (all-trans,15-anti vs. 13-cis,15-syn, within two RPs: Bacteriorhodopsin (BR and Anabaena Sensory Rhodopsin (ASR. Hyperspectral pump-probe spectroscopy shows that photochemistry starting from 13-cis retinal in both proteins is 3-10 times faster than when started in the all-trans state, suggesting that the hastening is ubiquitous to microbial RPs, regardless of their different biological functions and origin. This may also relate to the known disparity of photochemical rates between microbial RPs and visual pigments. Importance and possible underlying mechanisms are discussed as well.

  13. Trade-off between object selectivity and tolerance in monkey inferotemporal cortex.

    Science.gov (United States)

    Zoccolan, Davide; Kouh, Minjoon; Poggio, Tomaso; DiCarlo, James J

    2007-11-07

    Object recognition requires both selectivity among different objects and tolerance to vastly different retinal images of the same object, resulting from natural variation in (e.g.) position, size, illumination, and clutter. Thus, discovering neuronal responses that have object selectivity and tolerance to identity-preserving transformations is fundamental to understanding object recognition. Although selectivity and tolerance are found at the highest level of the primate ventral visual stream [the inferotemporal cortex (IT)], both properties are highly varied and poorly understood. If an IT neuron has very sharp selectivity for a unique combination of object features ("diagnostic features"), this might automatically endow it with high tolerance. However, this relationship cannot be taken as given; although some IT neurons are highly object selective and some are highly tolerant, the empirical connection of these key properties is unknown. In this study, we systematically measured both object selectivity and tolerance to different identity-preserving image transformations in the spiking responses of a population of monkey IT neurons. We found that IT neurons with high object selectivity typically have low tolerance (and vice versa), regardless of how object selectivity was quantified and the type of tolerance examined. The discovery of this trade-off illuminates object selectivity and tolerance in IT and unifies a range of previous, seemingly disparate results. This finding also argues against the idea that diagnostic conjunctions of features guarantee tolerance. Instead, it is naturally explained by object recognition models in which object selectivity is built through AND-like tuning mechanisms.

  14. MERICAN CULTURAL TOLERANCE

    Institute of Scientific and Technical Information of China (English)

    ZHANG RUIXIAO

    2014-01-01

    As an emigrant country, the essential characteristic of America culture is its tolerance. It contributes to the formation the diversity of American culture. By tracing back to American history, this essay shows what caused American cultural tolerance. Through describing briefly the manifestation of American cultural tolerance from certain aspects and analyzing the major factors, it will give us a clue about the reason why America can be always prosperous. At last, the paper shows the limitation as well as advantages about the tolerance from the point of current status.

  15. Retinal changes in an ATP-induced model of retinal degeneration

    Directory of Open Access Journals (Sweden)

    Felix Peter Aplin

    2016-04-01

    Full Text Available In rodents and felines, intravitreal administration of adenosine triphosphate (ATP has been shown to induce photoreceptor death providing a tractable model of retinal degeneration in these species. This study investigated the long term effects of photoreceptor loss in an ATP induced feline model of retinal degeneration. Six normal sighted felines were unilaterally blinded using intravitreal ATP injections and assessed using electroretinography (ERG and optical coherence tomography (OCT. At 30 hours (n = 3 or 12 weeks (n = 3 post-injection, the animals were euthanized and the eyes enucleated. Retinae were sectioned and labelled using immunohistochemistry for markers of cell death, neural remodeling and gliosis. Ongoing cell death and retinal degeneration was observed in the outer retina at both 30 hours and 12 weeks following unilateral ATP injection. Markers of mid to late-stage retinal remodeling such as cell displacement and aberrant neurite growth were observed in the inner retina at 12 weeks post-injection. Ganglion cells appeared to remain intact in ATP injected eyes. Müller cell gliosis was observed throughout the inner and outer retina, in some parts completely enveloping and/or displacing the surviving neural tissue. Our data suggests that the ATP injected feline retina continues to undergo progressive retinal degeneration and exhibits abnormalities consistent with a description of retinal remodeling commonly seen in other models of retinal degeneration. These findings validate the use of intravitreal ATP injection in feline as a large animal model of retinal degeneration which may aid in development of therapies aiming to restore visual function after photoreceptor degeneration.

  16. Cytomegalovirus retinitis after central retinal vein occlusion in a patient on systemic immunosuppression: does venooclusive disease predispose to cytomegalovirus retinitis in patients already at risk?

    Directory of Open Access Journals (Sweden)

    Welling JD

    2012-04-01

    Full Text Available John D Welling, Ahmad B Tarabishy, John ChristoforidisDepartment of Ophthalmology, Havener Eye Institute, Ohio State University, Columbus, OH, USAAbstract: Cytomegalovirus (CMV retinitis remains the most common opportunistic ocular infection in immunocompromised patients. Patients with immunocompromising diseases, such as acquired immunodeficiency syndrome, inherited immunodeficiency states, malignancies, and those on systemic immunosuppressive therapy, are known to be at risk. Recently, it has been suggested that patients undergoing intravitreal injection of immunosuppressive agents may also be predisposed. One previous case report speculated that there may be an additional risk for CMV retinitis in acquired immunodeficiency syndrome patients with venoocclusive disease. This case study presents a case of CMV retinitis following central retinal vein occlusion in a patient on systemic immunosuppressants.Keywords: cytomegalovirus retinitis, central retinal vein occlusion, immunosuppression, solid organ transplant, venous stasis, risk factor

  17. Current Concepts in the Treatment of Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    Maria A. Musarella

    2011-01-01

    Full Text Available Inherited retinal degenerations, including retinitis pigmentosa (RP and Leber congenital amaurosis (LCA, affect 1 in 4000 individuals in the general population. A majority of the genes which are mutated in these conditions are expressed in either photoreceptors or the retinal pigment epithelium (RPE. There is considerable variation in the clinical severity of these conditions; the most severe being autosomal recessive LCA, a heterogeneous retinal degenerative disease and the commonest cause of congenital blindness in children. Here, we discuss all the potential treatments that are now available for retinal degeneration. A number of therapeutic avenues are being explored based on our knowledge of the pathophysiology of retinal degeneration derived from research on animal models, including: gene therapy, antiapoptosis agents, neurotrophic factors, and dietary supplementation. Technological advances in retinal implant devices continue to provide the promise of vision for patients with end-stage disease.

  18. Endovascular cannulation with a microneedle for central retinal vein occlusion.

    Science.gov (United States)

    Kadonosono, Kazuaki; Yamane, Shin; Arakawa, Akira; Inoue, Maiko; Yamakawa, Tadashi; Uchio, Eiichi; Yanagi, Yasuo; Amano, Shiro

    2013-06-01

    We developed a new surgical treatment in which a microneedle is used for retinal endovascular cannulation to treat eyes with central retinal vein occlusion by flushing thrombus out of the central retinal vein as it passes through the lamina cribrosa. The eyes of 12 consecutive patients (12 eyes) with central retinal vein occlusion were successfully treated using this novel treatment. At 24 weeks after surgery, 9 of 12 eyes had gained more than 15 letters in best-corrected visual acuity, and the mean decrease in central foveal thickness was 271.1 μm. Few complications were observed. The microneedle is stiff and sharp enough to facilitate retinal endovascular cannulation in eyes with central retinal vein occlusion. This new technique is a promising treatment of macular edema due to central retinal vein occlusion.

  19. Progressive outer retinal necrosis (PORN) in AIDS patients: a different appearance of varicella-zoster retinitis.

    Science.gov (United States)

    Pavesio, C E; Mitchell, S M; Barton, K; Schwartz, S D; Towler, H M; Lightman, S

    1995-01-01

    Retinal infections caused by the varicella-zoster virus (VZV) have been reported in immunocompetent and immunocompromised individuals. Two cases of a VZV-related retinitis are described with the characteristic features of the recently described progressive outer retinal necrosis (PORN) syndrome. Both patients suffered from the acquired immunodeficiency syndrome (AIDS) with greatly reduced peripheral blood CD4+ T lymphocyte counts, and presented with macular retinitis without vitritis. The disease was bilateral in one case and unilateral in the other. The clinical course was rapidly progressive with widespread retinal involvement and the development of rhegmatogenous retinal detachment with complete loss of vision in the affected eyes despite intensive intravenous antiviral therapy. VZV DNA was identified in vitreous biopsies, by molecular techniques based on the polymerase chain reaction (PCR), in both patients. At present, the use of very high-dose intravenous acyclovir may be the best therapeutic option in these patients for whom the visual prognosis is poor. Intravitreal antiviral drugs could also contribute to the management of these cases.

  20. Ground-state properties of the retinal molecule: from quantum mechanical to classical mechanical computations of retinal proteins

    Energy Technology Data Exchange (ETDEWEB)

    Suhai, Sandor [German Cancer Research Center, Heidelberg

    2011-01-01

    Retinal proteins are excellent systems for understanding essential physiological processes such as signal transduction and ion pumping. Although the conjugated polyene system of the retinal chromophore is best described with quantum mechanics, simulations of the long-timescale dynamics of a retinal protein in its physiological, flexible, lipid-membrane environment can only be performed at the classical mechanical level. Torsional energy barriers are a critical ingredient of the classical force-field parameters. Here we review briefly current retinal force fields and discuss new quantum mechanical computations to assess how the retinal Schiff base model and the approach used to derive the force-field parameters may influence the torsional potentials.

  1. Nonsurgical management of diplopia after retinal surgery.

    Science.gov (United States)

    Hodgetts, David J

    2012-01-01

    For those who manage strabismus in adults, the patient with diplopia following retinal surgery presents a challenge. Mechanical and sensory factors may combine to preclude single binocular vision, and neutralizing the patient's strabismus may not be sufficient to permit resolution of their diplopia. This paper reviews the issues involved and discusses some potential solutions.

  2. Genetic loci for retinal arteriolar microcirculation.

    Science.gov (United States)

    Sim, Xueling; Jensen, Richard A; Ikram, M Kamran; Cotch, Mary Frances; Li, Xiaohui; MacGregor, Stuart; Xie, Jing; Smith, Albert Vernon; Boerwinkle, Eric; Mitchell, Paul; Klein, Ronald; Klein, Barbara E K; Glazer, Nicole L; Lumley, Thomas; McKnight, Barbara; Psaty, Bruce M; de Jong, Paulus T V M; Hofman, Albert; Rivadeneira, Fernando; Uitterlinden, Andre G; van Duijn, Cornelia M; Aspelund, Thor; Eiriksdottir, Gudny; Harris, Tamara B; Jonasson, Fridbert; Launer, Lenore J; Attia, John; Baird, Paul N; Harrap, Stephen; Holliday, Elizabeth G; Inouye, Michael; Rochtchina, Elena; Scott, Rodney J; Viswanathan, Ananth; Li, Guo; Smith, Nicholas L; Wiggins, Kerri L; Kuo, Jane Z; Taylor, Kent D; Hewitt, Alex W; Martin, Nicholas G; Montgomery, Grant W; Sun, Cong; Young, Terri L; Mackey, David A; van Zuydam, Natalie R; Doney, Alex S F; Palmer, Colin N A; Morris, Andrew D; Rotter, Jerome I; Tai, E Shyong; Gudnason, Vilmundur; Vingerling, Johannes R; Siscovick, David S; Wang, Jie Jin; Wong, Tien Y

    2013-01-01

    Narrow arterioles in the retina have been shown to predict hypertension as well as other vascular diseases, likely through an increase in the peripheral resistance of the microcirculatory flow. In this study, we performed a genome-wide association study in 18,722 unrelated individuals of European ancestry from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium and the Blue Mountain Eye Study, to identify genetic determinants associated with variations in retinal arteriolar caliber. Retinal vascular calibers were measured on digitized retinal photographs using a standardized protocol. One variant (rs2194025 on chromosome 5q14 near the myocyte enhancer factor 2C MEF2C gene) was associated with retinal arteriolar caliber in the meta-analysis of the discovery cohorts at genome-wide significance of P-value <5×10(-8). This variant was replicated in an additional 3,939 individuals of European ancestry from the Australian Twins Study and Multi-Ethnic Study of Atherosclerosis (rs2194025, P-value = 2.11×10(-12) in combined meta-analysis of discovery and replication cohorts). In independent studies of modest sample sizes, no significant association was found between this variant and clinical outcomes including coronary artery disease, stroke, myocardial infarction or hypertension. In conclusion, we found one novel loci which underlie genetic variation in microvasculature which may be relevant to vascular disease. The relevance of these findings to clinical outcomes remains to be determined.

  3. Photovoltaic retinal prosthesis with high pixel density

    Science.gov (United States)

    Mathieson, Keith; Loudin, James; Goetz, Georges; Huie, Philip; Wang, Lele; Kamins, Theodore I.; Galambos, Ludwig; Smith, Richard; Harris, James S.; Sher, Alexander; Palanker, Daniel

    2012-06-01

    Retinal degenerative diseases lead to blindness due to loss of the `image capturing' photoreceptors, while neurons in the `image-processing' inner retinal layers are relatively well preserved. Electronic retinal prostheses seek to restore sight by electrically stimulating the surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems that deliver energy to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel receive power and data directly through pulsed near-infrared illumination and electrically stimulate neurons. Stimulation is produced in normal and degenerate rat retinas, with pulse durations of 0.5-4 ms, and threshold peak irradiances of 0.2-10 mW mm-2, two orders of magnitude below the ocular safety limit. Neural responses were elicited by illuminating a single 70 µm bipolar pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high pixel density.

  4. Retinal oscillations carry visual information to cortex

    Directory of Open Access Journals (Sweden)

    Kilian Koepsell

    2009-04-01

    Full Text Available Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs and thalamic outputs (spikes and then analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz, is encoded by average firing rate with respect to the stimulus and carries information about local changes in the visual field over time. The other operates in the gamma frequency band (40-80 Hz and is encoded by spike timing relative to retinal oscillations. At times, the second channel conveyed even more information than the first. Because retinal oscillations involve extensive networks of ganglion cells, it is likely that the second channel transmits information about global features of the visual scene.

  5. Multimodal Imaging in Hereditary Retinal Diseases

    Directory of Open Access Journals (Sweden)

    Francesco Pichi

    2013-01-01

    Full Text Available Introduction. In this retrospective study we evaluated the multimodal visualization of retinal genetic diseases to better understand their natural course. Material and Methods. We reviewed the charts of 70 consecutive patients with different genetic retinal pathologies who had previously undergone multimodal imaging analyses. Genomic DNA was extracted from peripheral blood and genotyped at the known locus for the different diseases. Results. The medical records of 3 families of a 4-generation pedigree affected by North Carolina macular dystrophy were reviewed. A total of 8 patients with Stargardt disease were evaluated for their two main defining clinical characteristics, yellow subretinal flecks and central atrophy. Nine male patients with a previous diagnosis of choroideremia and eleven female carriers were evaluated. Fourteen patients with Best vitelliform macular dystrophy and 6 family members with autosomal recessive bestrophinopathy were included. Seven patients with enhanced s-cone syndrome were ascertained. Lastly, we included 3 unrelated patients with fundus albipunctatus. Conclusions. In hereditary retinal diseases, clinical examination is often not sufficient for evaluating the patient’s condition. Retinal imaging then becomes important in making the diagnosis, in monitoring the progression of disease, and as a surrogate outcome measure of the efficacy of an intervention.

  6. Anterior segment complications of retinal photocoagulation.

    Science.gov (United States)

    Kanski, J J

    1975-03-01

    Seven patients had anterior segment complications following xenon arc retinal photocoagulation. Irreversible keratopathy was induced in two cases; all patients showed evidence of iris injury. The absorption of radiation by the iris was considered the main factor in producing overheating of the anterior segment.

  7. Antisense Oligonucleotide Therapy for Inherited Retinal Dystrophies

    NARCIS (Netherlands)

    Gerard, X.; Garanto Iglesias, A.; Rozet, J.M.; Collin, R.W.J.

    2016-01-01

    Inherited retinal dystrophies (IRDs) are an extremely heterogeneous group of genetic diseases for which currently no effective treatment strategies exist. Over the last decade, significant progress has been made utilizing gene augmentation therapy for a few genetic subtypes of IRD, although several

  8. [Retinal detachment with retinoschisis--case report].

    Science.gov (United States)

    Cristescu, R; Muşat, O; Toma, Oana; Coma, Corina; Gabej, Ioana; Burcea, M

    2013-01-01

    We present the case of a 43 year old patient diagnosed with rhegmatogenous retinal detachment and retinoschizis, a rare case of disease association. Surgery is recommended and we practice 23 gauge vitrectomy, laser retinopexy, criopexy in the periphery and internal heavy oil tamponade. Postoperatory evolution was favorable.

  9. Dynamic eye phantom for retinal oximetry measurements

    Science.gov (United States)

    Lemaillet, Paul; Ramella-Roman, Jessica C.

    2009-11-01

    Measurements of oxygen saturation and flow in the retina can yield information about eye health and the onset of eye pathologies such as diabetic retinopathy. Recently, we developed a multiaperture camera that uses the division of the retinal image into several wavelength-sensitive subimages to compute retinal oxygen saturation. The calibration of such instruments is particularly difficult due to the layered structure of the eye and the lack of alternative measurement techniques. For this purpose, we realize an in vitro model of the human eye composed of a lens, the retina vessel, and three layers: the choroid, the retinal pigmented epithelium, and the sclera. The retinal vessel is modeled with a microtube connected to a micropump and a hemoglobin reservoir in a closed circulatory system. Hemoglobin oxygenation in the vessel could be altered using a reversible fuel cell. The sclera is represented by a Spectralon slab. The optical properties of the other layers are mimicked using titanium dioxide as a scatterer, ink as an absorber, and epoxy as a supporting structure. The optical thickness of each layer of the eye phantom is matched to each respective eye layer.

  10. [Pharmacological concepts to treat hereditary retinal degenerations].

    Science.gov (United States)

    Poloschek, C M; Jägle, H

    2012-02-01

    This article reviews the current pharmacological strategies to treat inherited retinal degeneration. To date there is no causal therapy despite growing knowledge of the particular pathomechanisms. However, treatment is available for complications, such as cystic macular changes and cystoid macular edema. To reduce retinal thickness systemic or topical carboanhydrase inhibitors can be applied and in rare cases combined with steroids when indicated, however reduction of retinal thickness is not always accompanied by improvement of visual acuity. Regular follow-up with optical coherence tomography is required. In some cases, potentially neuroprotective agents (valproic acid, ciliary neurotrophic factor and Ca(2+ ) channel inhibitors) or food supplementation (vitamin A, lutein, synthetic retinoids and decosahexaenoic acid) may have a positive impact on disease progression (e.g. reduction in progression of visual field loss or individual electrophysiological parameters). However, beneficial effects and side effects, e.g. of vitamin A substitution, depend not only on the disease phenotype (such as retinitis pigmentosa) but also on the actual genotype. Furthermore, no data are available regarding the application of pharmaceuticals in the pediatric population.

  11. AUTOMATIC RETINAL VESSEL DETECTION AND TORTUOSITY MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Temitope Mapayi

    2016-07-01

    Full Text Available As retinopathies continue to be major causes of visual loss and blindness worldwide, early detection and management of these diseases will help achieve significant reduction of blindness cases. However, an efficient automatic retinal vessel segmentation approach remains a challenge. Since efficient vessel network detection is a very important step needed in ophthalmology for reliable retinal vessel characterization, this paper presents study on the combination of difference image and K-means clustering for the segmentation of retinal vessels. Stationary points in the vessel center-lines are used to model the detection of twists in the vessel segments. The combination of arc-chord ratio with stationary points is used to compute tortuosity index. Experimental results show that the proposed K-means combined with difference image achieved a robust segmentation of retinal vessels. A maximum average accuracy of 0.9556 and a maximum average sensitivity of 0.7581 were achieved on DRIVE database while a maximum average accuracy of 0.9509 and a maximum average sensitivity of 0.7666 were achieved on STARE database. When compared with the previously proposed techniques on DRIVE and STARE databases, the proposed technique yields higher mean sensitivity and mean accuracy rates in the same range of very good specificity. In a related development, a non-normalized tortuosity index that combined distance metric and the vessel twist frequency proposed in this paper also achieved a strong correlation of 0.80 with the expert ground truth.

  12. Genetic loci for retinal arteriolar microcirculation.

    Directory of Open Access Journals (Sweden)

    Xueling Sim

    Full Text Available Narrow arterioles in the retina have been shown to predict hypertension as well as other vascular diseases, likely through an increase in the peripheral resistance of the microcirculatory flow. In this study, we performed a genome-wide association study in 18,722 unrelated individuals of European ancestry from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium and the Blue Mountain Eye Study, to identify genetic determinants associated with variations in retinal arteriolar caliber. Retinal vascular calibers were measured on digitized retinal photographs using a standardized protocol. One variant (rs2194025 on chromosome 5q14 near the myocyte enhancer factor 2C MEF2C gene was associated with retinal arteriolar caliber in the meta-analysis of the discovery cohorts at genome-wide significance of P-value <5×10(-8. This variant was replicated in an additional 3,939 individuals of European ancestry from the Australian Twins Study and Multi-Ethnic Study of Atherosclerosis (rs2194025, P-value = 2.11×10(-12 in combined meta-analysis of discovery and replication cohorts. In independent studies of modest sample sizes, no significant association was found between this variant and clinical outcomes including coronary artery disease, stroke, myocardial infarction or hypertension. In conclusion, we found one novel loci which underlie genetic variation in microvasculature which may be relevant to vascular disease. The relevance of these findings to clinical outcomes remains to be determined.

  13. Connexin43 in retinal injury and disease.

    Science.gov (United States)

    Danesh-Meyer, Helen V; Zhang, Jie; Acosta, Monica L; Rupenthal, Ilva D; Green, Colin R

    2016-03-01

    Gap junctions are specialized cell-to-cell contacts that allow the direct transfer of small molecules between cells. A single gap junction channel consists of two hemichannels, or connexons, each of which is composed of six connexin protein subunits. Connexin43 is the most ubiquitously expressed isoform of the connexin family and in the retina it is prevalent in astrocytes, Müller cells, microglia, retinal pigment epithelium and endothelial cells. Prior to docking with a neighboring cell, Connexin43 hemichannels have a low open probability as open channels constitute a large, relatively non-specific membrane pore. However, with injury and disease Connexin43 upregulation and hemichannel opening has been implicated in all aspects of secondary damage, especially glial cell activation, edema and loss of vascular integrity, leading to neuronal death. We here review gap junctions and their roles in the retina, and then focus in on Connexin43 gap junction channels in injury and disease. In particular, the effect of pathological opening of gap junction hemichannels is described, and hemichannel mediated loss of vascular integrity explained. This latter phenomenon underlies retinal pigment epithelium loss and is a common feature in several retinal diseases. Finally, Connexin43 channel roles in a number of retinal diseases including macular degeneration, glaucoma and diabetic retinopathy are considered, along with results from related animal models. A final section describes gap junction channel modulation and the ocular delivery of potential therapeutic molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    Directory of Open Access Journals (Sweden)

    Wendeson S Oliveira

    Full Text Available Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  15. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    Science.gov (United States)

    Oliveira, Wendeson S; Teixeira, Joyce Vitor; Ren, Tsang Ing; Cavalcanti, George D C; Sijbers, Jan

    2016-01-01

    Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  16. Red blood cells in retinal vascular disorders.

    Science.gov (United States)

    Agrawal, Rupesh; Sherwood, Joseph; Chhablani, Jay; Ricchariya, Ashutosh; Kim, Sangho; Jones, Philip H; Balabani, Stavroula; Shima, David

    2016-01-01

    Microvascular circulation plays a vital role in regulating physiological functions, such as vascular resistance, and maintaining organ health. Pathologies such as hypertension, diabetes, or hematologic diseases affect the microcirculation posing a significant risk to human health. The retinal vasculature provides a unique window for non-invasive visualisation of the human circulation in vivo and retinal vascular image analysis has been established to predict the development of both clinical and subclinical cardiovascular, metabolic, renal and retinal disease in epidemiologic studies. Blood viscosity which was otherwise thought to play a negligible role in determining blood flow based on Poiseuille's law up to the 1970s has now been shown to play an equally if not a more important role in controlling microcirculation and quantifying blood flow. Understanding the hemodynamics/rheology of the microcirculation and its changes in diseased states remains a challenging task; this is due to the particulate nature of blood, the mechanical properties of the cells (such as deformability and aggregability) and the complex architecture of the microvasculature. In our review, we have tried to postulate a possible role of red blood cell (RBC) biomechanical properties and laid down future framework for research related to hemorrheological aspects of blood in patients with retinal vascular disorders.

  17. Melanopsin expressing human retinal ganglion cells

    DEFF Research Database (Denmark)

    Hannibal, Jens; Christensen, Anders Tolstrup; Heegaard, Steffen

    2017-01-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin belong to a heterogenic population of RGCs which regulate the circadian clock, masking behavior, melatonin suppression, the pupillary light reflex and sleep/wake cycles. The different functions seem...

  18. Retinal breaks due to intravitreal ocriplasmin

    Directory of Open Access Journals (Sweden)

    Silva RA

    2014-08-01

    Full Text Available Ruwan A Silva, Darius M Moshfeghi, Theodore Leng Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, CA, USA Abstract: Ocriplasmin represents a new treatment option for numerous vitreoretinopathies involving an abnormal vitreomacular interface. While the drug may circumvent the traditional risks of surgical treatment, pharmacologic vitreolysis is not devoid of risk itself. This report presents two cases, one of vitreomacular traction syndrome and the other of a full-thickness macular hole, both of which were treated with an intravitreal injection of ocriplasmin. Notably, in both cases, vitreomacular traction of the macula appears to have been alleviated; however, failure to completely relieve vitreoretinal traction from the peripheral retina generated retinal breaks with one patient eventually developing a macula-involving retinal detachment. Thus, even in instances of ‘successful’ pharmacologic treatment of vitreomacular traction, continued follow-up evaluation is essential. Keywords: posterior vitreous detachment, retinal detachment, vitreomacular traction, ocriplasmin, retinal break, macular hole, laser retinopexy

  19. CERKL knockdown causes retinal degeneration in zebrafish.

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    Marina Riera

    Full Text Available The human CERKL gene is responsible for common and severe forms of retinal dystrophies. Despite intense in vitro studies at the molecular and cellular level and in vivo analyses of the retina of murine knockout models, CERKL function remains unknown. In this study, we aimed to approach the developmental and functional features of cerkl in Danio rerio within an Evo-Devo framework. We show that gene expression increases from early developmental stages until the formation of the retina in the optic cup. Unlike the high mRNA-CERKL isoform multiplicity shown in mammals, the moderate transcriptional complexity in fish facilitates phenotypic studies derived from gene silencing. Moreover, of relevance to pathogenicity, teleost CERKL shares the two main human protein isoforms. Morpholino injection has been used to generate a cerkl knockdown zebrafish model. The morphant phenotype results in abnormal eye development with lamination defects, failure to develop photoreceptor outer segments, increased apoptosis of retinal cells and small eyes. Our data support that zebrafish Cerkl does not interfere with proliferation and neural differentiation during early developmental stages but is relevant for survival and protection of the retinal tissue. Overall, we propose that this zebrafish model is a powerful tool to unveil CERKL contribution to human retinal degeneration.

  20. Blood flow mechanics and oxygen transport and delivery in the retinal microcirculation: multiscale mathematical modeling and numerical simulation.

    Science.gov (United States)

    Causin, Paola; Guidoboni, Giovanna; Malgaroli, Francesca; Sacco, Riccardo; Harris, Alon

    2016-06-01

    The scientific community continues to accrue evidence that blood flow alterations and ischemic conditions in the retina play an important role in the pathogenesis of ocular diseases. Many factors influence retinal hemodynamics and tissue oxygenation, including blood pressure, blood rheology, oxygen arterial permeability and tissue metabolic demand. Since the influence of these factors on the retinal circulation is difficult to isolate in vivo, we propose here a novel mathematical and computational model describing the coupling between blood flow mechanics and oxygen ([Formula: see text]) transport in the retina. Albeit in a simplified manner, the model accounts for the three-dimensional anatomical structure of the retina, consisting in a layered tissue nourished by an arteriolar/venular network laying on the surface proximal to the vitreous. Capillary plexi, originating from terminal arterioles and converging into smaller venules, are embedded in two distinct tissue layers. Arteriolar and venular networks are represented by fractal trees, whereas capillary plexi are represented using a simplified lumped description. In the model, [Formula: see text] is transported along the vasculature and delivered to the tissue at a rate that depends on the metabolic demand of the various tissue layers. First, the model is validated against available experimental results to identify baseline conditions. Then, a sensitivity analysis is performed to quantify the influence of blood pressure, blood rheology, oxygen arterial permeability and tissue oxygen demand on the [Formula: see text] distribution within the blood vessels and in the tissue. This analysis shows that: (1) systemic arterial blood pressure has a strong influence on the [Formula: see text] profiles in both blood and tissue; (2) plasma viscosity and metabolic consumption rates have a strong influence on the [Formula: see text] tension at the level of the retinal ganglion cells; and (3) arterial [Formula: see text

  1. Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study

    Directory of Open Access Journals (Sweden)

    Baran Gencer

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline; 10 min after intubation (Supine 1; 10 (Prone 1, 60 (Prone 2, 120 (Prone 3 min after prone position; and just after postoperative supine position (Supine 2. RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p = 0.009 and p = 0.003, respectively. We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery.

  2. Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Xia, D.Y. [Department of Neurology, Navy General Hospital of PLA, Beijing (China); Li, W. [General Hospital of Shenyang Military Command, Department of Neurology, Shenyang, China, Department of Neurology, General Hospital of Shenyang Military Command, Shenyang (China); Qian, H.R.; Yao, S.; Liu, J.G.; Qi, X.K. [Department of Neurology, Navy General Hospital of PLA, Beijing (China)

    2013-08-10

    Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

  3. Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

    Directory of Open Access Journals (Sweden)

    D.Y. Xia

    2013-08-01

    Full Text Available Sublethal ischemic preconditioning (IPC is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration, 5×5 min (5 min duration, 2 episodes, 15-min interval, 5×5×5 min (5 min duration, 3 episodes, 15-min intervals, and 15 min (15 min duration, and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

  4. Optimal management of cytomegalovirus retinitis in patients with AIDS

    Directory of Open Access Journals (Sweden)

    Michael W Stewart

    2010-04-01

    Full Text Available Michael W StewartDepartment of Ophthalmology, Mayo School of Medicine, Jacksonville, FL, USAAbstract: Cytomegalovirus (CMV retinitis is the most common cause of vision loss in patients with acquired immunodeficiency syndrome (AIDS. CMV retinitis afflicted 25% to 42% of AIDS patients in the pre-highly active antiretroviral therapy (HAART era, with most vision loss due to macula-involving retinitis or retinal detachment. The introduction of HAART significantly decreased the incidence and severity of CMV retinitis. Optimal treatment of CMV retinitis requires a thorough evaluation of the patient’s immune status and an accurate classification of the retinal lesions. When retinitis is diagnosed, HAART therapy should be started or improved, and anti-CMV therapy with oral valganciclovir, intravenous ganciclovir, foscarnet, or cidofovir should be administered. Selected patients, especially those with zone 1 retinitis, may receive intravitreal drug injections or surgical implantation of a sustained-release ganciclovir reservoir. Effective anti-CMV therapy coupled with HAART significantly decreases the incidence of vision loss and improves patient survival. Immune recovery uveitis and retinal detachments are important causes of moderate to severe loss of vision. Compared with the early years of the AIDS epidemic, the treatment emphasis in the post-HAART era has changed from short-term control of retinitis to long-term preservation of vision. Developing countries face shortages of health care professionals and inadequate supplies of anti-CMV and anti-HIV medications. Intravitreal ganciclovir injections may be the most cost effective strategy to treat CMV retinitis in these areas.Keywords: cytomegalovirus, AIDS, retinitis, immune recovery uveitis, retinal detachment, treatment

  5. Prospectives for gene therapy of retinal degenerations.

    Science.gov (United States)

    Thumann, Gabriele

    2012-08-01

    Retinal degenerations encompass a large number of diseases in which the retina and associated retinal pigment epithelial (RPE) cells progressively degenerate leading to severe visual disorders or blindness. Retinal degenerations can be divided into two groups, a group in which the defect has been linked to a specific gene and a second group that has a complex etiology that includes environmental and genetic influences. The first group encompasses a number of relatively rare diseases with the most prevalent being Retinitis pigmentosa that affects approximately 1 million individuals worldwide. Attempts have been made to correct the defective gene by transfecting the appropriate cells with the wild-type gene and while these attempts have been successful in animal models, human gene therapy for these inherited retinal degenerations has only begun recently and the results are promising. To the second group belong glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). These retinal degenerations have a genetic component since they occur more often in families with affected probands but they are also linked to environmental factors, specifically elevated intraocular pressure, age and high blood sugar levels respectively. The economic and medical impact of these three diseases can be assessed by the number of individuals affected; AMD affects over 30 million, DR over 40 million and glaucoma over 65 million individuals worldwide. The basic defect in these diseases appears to be the relative lack of a neurogenic environment; the neovascularization that often accompanies these diseases has suggested that a decrease in pigment epithelium-derived factor (PEDF), at least in part, may be responsible for the neurodegeneration since PEDF is not only an effective neurogenic and neuroprotective agent but also a potent inhibitor of neovascularization. In the last few years inhibitors of vascularization, especially antibodies against vascular endothelial cell

  6. Fault tolerant computing systems

    CERN Document Server

    Randell, B

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection, damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (15 refs).

  7. Tolerances in micro manufacturing

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Zhang, Yang; Islam, Aminul

    2017-01-01

    This paper describes a method for analysis of tolerances in micro manufacturing. It proposes a mapping oftolerances to dimensions and compares this with current available international standards. The analysisdocuments that tolerances are not scaled down as the absolute dimension. In practice...

  8. Loss Tolerant Optical Qubits

    CERN Document Server

    Ralph, T C; Gilchrist, A; Gilchrist, Alexei

    2005-01-01

    We present a linear optics quantum computation scheme that employs a new encoding approach that incrementally adds qubits and is tolerant to photon loss errors. The scheme employs a circuit model but uses techniques from cluster state computation and achieves comparable resource usage. To illustrate our techniques we describe a quantum memory which is fault tolerant to photon loss.

  9. Inequality, Tolerance, and Growth

    DEFF Research Database (Denmark)

    Bjørnskov, Christian

    This paper argues for the importance of individuals' tolerance of inequality for economic growth. By using the political ideology of governments as a measure of revealed tolerance of inequality, the paper shows that controlling for ideology improves the accuracy with which the effects of inequality...

  10. Toleration out of respect?

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2014-01-01

    Under conditions of pluralism different cultures, interests or values can come into conflict, which raises the problem of how to secure peaceful co-existence. The idea of toleration historically emerged as an answer to this problem. Recently Rainer Forst has argued that toleration should not just...

  11. A Lesson in Tolerance

    Science.gov (United States)

    Johnt, Marlene

    2004-01-01

    This article describes one classroom's experience integrating a three-part lesson that focused on tolerance. In the lesson, students examined works by American folk-art painter Edward Hicks, researched quotes about tolerance in society, and applied calligraphy skills to an original composition.

  12. Remember Tolerance Differently

    DEFF Research Database (Denmark)

    Tønder, Lars

    2012-01-01

    This essay questions the linear conception of history which often accompanies the way contemporary democratic theory tends to disavow tolerance's discontinuities and remainders. In the spirit of Foucault's genealogy of descent, the idea is to develop a new sense of tolerance's history, not by inv...

  13. Effect of remote ischemic conditioning on atrial fibrillation and outcome after coronary artery bypass grafting (RICO-trial

    Directory of Open Access Journals (Sweden)

    Wouters Patrick

    2011-05-01

    Full Text Available Abstract Background Pre- and postconditioning describe mechanisms whereby short ischemic periods protect an organ against a longer period of ischemia. Interestingly, short ischemic periods of a limb, in itself harmless, may increase the ischemia tolerance of remote organs, e.g. the heart (remote conditioning, RC. Although several studies have shown reduced biomarker release by RC, a reduction of complications and improvement of patient outcome still has to be demonstrated. Atrial fibrillation (AF is one of the most common complications after coronary artery bypass graft surgery (CABG, affecting 27-46% of patients. It is associated with increased mortality, adverse cardiovascular events, and prolonged in-hospital stay. We hypothesize that remote ischemic pre- and/or post-conditioning reduce the incidence of AF following CABG, and improve patient outcome. Methods/design This study is a randomized, controlled, patient and investigator blinded multicenter trial. Elective CABG patients are randomized to one of the following four groups: 1 control, 2 remote ischemic preconditioning, 3 remote ischemic postconditioning, or 4 remote ischemic pre- and postconditioning. Remote conditioning is applied at the arm by 3 cycles of 5 minutes of ischemia and reperfusion. Primary endpoint is the incidence AF in the first 72 hours after surgery, detected using a Holter-monitor. Secondary endpoints include length-of-stay on the intensive care unit and in-hospital, and the occurrence of major adverse cardiovascular events at 30 days, 3 months and 1 year. Based on an expected incidence in the control group of 27%, 195 patients per group are needed to detect with 80% power a reduction by 45% following either pre- or postconditioning, while allowing for a 10% dropout and at an alpha of 0.05. With the combined intervention expected to be stronger, we need 75 patients in this group to detect a reduction in incidence of AF of 60%. Discussion The RICO-trial (the effect of

  14. Evaluation of the effectiveness and safety of glucocorticoids intravitreal implant therapy in macular edema due to retinal vein occlusion

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    Michalska-Małecka K

    2016-05-01

    CRT compared with thickness observed in second month. Two months after the treatment, we found an increase in intraocular pressure in 36% of cases and a further decrease during the final visit 6 months after the treatment. During the treatment, there were no significant differences in endothelial cell density in branch retinal vein occlusion and central retinal vein occlusion. We found the intravitreal dexamethasone implant to be safe, well tolerated, and likely to lead to fast morphological and functional improvement of the macula and visual rehabilitation in patients with ME due to retinal vein occlusion. Keywords: macular edema, retinal vein occlusion, intravitreal implant, dexamethasone, best-corrected visual acuity, intraocular pressure

  15. Retinoic acid from retinal pigment epithelium induces T regulatory cells.

    Science.gov (United States)

    Kawazoe, Yuko; Sugita, Sunao; Keino, Hiroshi; Yamada, Yukiko; Imai, Ayano; Horie, Shintaro; Mochizuki, Manabu

    2012-01-01

    Primary cultured retinal pigment epithelial (RPE) cells can convert T cells into T regulatory cells (Tregs) through inhibitory factor(s) including transforming growth factor β (TGFβ) in vitro. Retinoic acid (RA) enhances induction of CD4(+) Tregs in the presence of TGFβ. We investigated whether RA produced by RPE cells can promote generation of Tregs. We found that in vitro, RA-treated T cells expressed high levels of Foxp3 in the presence of recombinant TGFβ. In GeneChip analysis, cultured RPE cells constitutively expressed RA-associated molecules such as RA-binding proteins, enzymes, and receptors. RPE from normal mice, but not vitamin A-deficient mice, contained significant levels of TGFβ. RPE-induced Tregs from vitamin A-deficient mice failed to suppress activation of target T cells. Only a few Foxp3(+) T cells were found in intraocular cells from vitamin A-deficient experimental autoimmune uveitis (EAU) mice, whereas expression was higher in cells from normal EAU mice. RA receptor antagonist-pretreated or RA-binding protein-siRNA-transfected RPE cells failed to convert CD4(+) T cells into Tregs. Our data support the hypothesis that RPE cells produce RA, thereby enabling bystander T cells to be converted into Tregs through TGFβ promotion, which can then participate in the establishment of immune tolerance in the eye.

  16. Atrial fibrillation in patients with ischemic stroke

    DEFF Research Database (Denmark)

    Thygesen, Sandra Kruchov; Frost, Lars; Eagle, Kim A;

    2009-01-01

    BACKGROUND: Atrial fibrillation is a major risk factor for ischemic stroke. However, the prognostic impact of atrial fibrillation among patients with stroke is not fully clarified. We compared patient characteristics, including severity of stroke and comorbidity, quality of in-hospital care...... and outcomes in a cohort of first-time ischemic stroke patients with and without atrial fibrillation. METHODS: Based on linkage of public medical databases, we did a population-based follow-up study among 3,849 stroke patients from the County of Aarhus, Denmark admitted in the period of 2003......-2007 and prospectively registered in the Danish National Indicator Project. RESULTS: Atrial fibrillation was associated with an adverse prognostic profile but not with an overall poorer quality of in-hospital care. Patients with atrial fibrillation had a longer total length of stay (median: 15 vs 9 days), and were...

  17. [Ischemic cholangiopathy induced by extended burns].

    Science.gov (United States)

    Cohen, Laurence; Angot, Emilie; Goria, Odile; Koning, Edith; François, Arnaud; Sabourin, Jean-Christophe

    2013-04-01

    Ischemic cholangiopathy is a recently described entity occurring mainly after hepatic grafts. Very few cases after intensive care unit (ICU) for extended burn injury were reported. We report the case of a 73-year-old woman consulting in an hepatology unit, for a jaundice appearing during a hospitalisation in an intensive care unit and increasing from her leaving from ICU, where she was treated for an extended burn injury. She had no pre-existing biological features of biliary disease. Biological tests were normal. Magnetic resonance imaging acquisitions of biliary tracts pointed out severe stenosing lesions of diffuse cholangiopathy concerning intrahepatic biliary tract, mainly peri-hilar. Biopsie from the liver confirmed the diagnosis, showing a biliary cirrhosis with bile infarcts. This case is the fourth case of ischemic cholangiopathy after extended burn injury, concerning a patient without a prior history of hepatic or biliary illness and appearing after hospitalisation in intensive care unit.

  18. Cardiac Connexin 43 and Ischemic Cardioprotection

    Institute of Scientific and Technical Information of China (English)

    Jin-yi LI; Guo-qiang ZHONG; Yan HE; Yun LING

    2009-01-01

    The connexin 43 (Cx43) proteins, which is the predominant protein that can form gap junctions and non-junctional hemichannels in ventricular myocardium, are central to the cardioprotection afforded by ischemic precondi-tioning (IP) and maybe ischemic postconditioning (PC) too. Recent studies showed that recruitment of Cx43 to the mitochondria in IP might play a role in the production of reactive oxygen species (ROS) that mediates IP. The localiza-tion of Cx43 at mitochondria appears to be important for the achieved cardioprotection and opens a new door for us to reveal the exact mechanisms of ischemia/reperfusion (I/R) injury and cardioprotection, and it might be new targets of pharmacological modulator to achieved cardioprotection.

  19. Cost and Outcome in Pediatric Ischemic Stroke.

    Science.gov (United States)

    Hamilton, William; Huang, Haijuan; Seiber, Eric; Lo, Warren

    2015-10-01

    The cost of childhood stroke receives little notice. The authors examined potential drivers of cost and outcome to test whether (1) neonatal strokes cost less than childhood strokes, (2) associated diseases influence cost, (3) arterial ischemic stroke is more costly than sinovenous thrombosis, and (4) cost correlates with outcome. The authors reviewed records of 111 children who sustained arterial ischemic stroke or sinovenous thrombosis between 2005 and 2010 to identify costs for the following year. They assessed outcomes in 46 with the Recovery and Recurrence Questionnaire and the Pediatric Quality of Life Inventory. Neonatal strokes cost less than childhood stroke. Strokes associated with congenital heart disease or vasculopathy cost the most, while perinatal or idiopathic strokes cost the least. Higher costs are correlated with worse impairment and poorer quality of life. Stroke etiology significantly influences the cost of pediatric stroke. Future cost-benefit studies must consider etiology when estimating the incremental costs associated with stroke.

  20. Genetics of ischemic stroke: Indian perspective

    Directory of Open Access Journals (Sweden)

    Subhash Kaul

    2012-01-01

    Full Text Available A stroke is still a major cause of long-term disability and the third largest killer in the world after heart attack and cancer. Inherited genetic variation has been shown to play a role in its pathogenesis and therefore, there is a need to identify the culprit genetic variants. They may provide novel targets for preventive therapeutics. The most intensively investigated candidate gene is PDE4D. There are several positive replication studies of PDE4D gene with stroke. The genetic contribution to ischemic stroke risk in India has not been explored adequately. Reports on few candidate genes are available but we are still lagging behind in this aspect. Most of the reports are from Andhra Pradesh, a province in south India and a few parts of north India. PDE4D has been identified as a predisposition gene for ischemic stroke in Southern as well as the Northern population of India.