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Sample records for chloride protects retinal

  1. Chloride channel protein 2 prevents glutamate-induced apoptosis in retinal ganglion cells

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    Bi, Miao-Miao; Hong, Sen; Ma, Ling-Jun; Zhou, Hong-Yan; Lu, Jia; Zhao, Jing; Zheng, Ya-Juan

    2016-01-01

    Objective(s): The purpose of this study was to investigate the role of chloride channel protein 2 (ClC-2) in glutamate-induced apoptosis in the retinal ganglion cell line (RGC-5). Materials and Methods: RGC-5 cells were treated with 1 mM glutamate for 24 hr. The expression of ClC-2, Bax, and Bcl-2 was detected by western blot analysis. Cell survival and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Caspase-3 and -9 activities were determined by a colorimetric assay. The roles of ClC-2 in glutamate-induced apoptosis were examined by using ClC-2 complementary deoxyribonucleic acid (cDNA) and small inference ribonucleic acid (RNA) transfection technology. Results: Overexpression of ClC-2 in RGC-5 cells significantly decreased glutamate-induced apoptosis and increased cell viability, whereas silencing of ClC-2 with short hairpin (sh) RNA produced opposite effects. ClC-2 overexpression increased the expression of Bcl-2, decreased the expression of Bax, and decreased caspase-3 and -9 activation in RGC-5 cells treated with glutamate, but silencing of ClC-2 produced opposite effects. Conclusion: Our data suggest that ClC-2 chloride channels might play a protective role in glutamate-induced apoptosis in retinal ganglion cells via the mitochondria-dependent apoptosis pathway. PMID:27635193

  2. Neuroprotective effects of ClC-3 chloride channel in glutamate-induced retinal ganglion cell RGC-5 apoptosis

    Institute of Scientific and Technical Information of China (English)

    Li Yu; Ning Han; Ligang Jiang; Yajuan Zheng; Lifeng Liu

    2011-01-01

    Transforming growth factor β plays a role in regulation of apoptosis in ClC-3 and the Smads signaling pathway, although the underlying mechanisms remain unclear. The present study determined possible signal transduction mechanisms based on CIC-3 expression, which accordingly affected apoptosis of retinal ganglion cells in a glutamate-induced retinal ganglion cell RGC-5 apoptosis model. Results revealed significantly increased cell survival rate and significantly decreased apoptosis rate following apoptosis of ClC-3 cDNA-transfected glutamate-induced retinal ganglion cells. Following inhibition of the ClC-3 chloride channel using RNAi technology, cell survival and apoptosis rates were reversed. In addition, expression of transforming growth factor β2, Smads2, Smads3, Smads4, and Smads7 increased to varying degrees. These results suggest that ClC-3 chloride channel plays a protective role in glutamate-induced apoptosis of retinal ganglion cells, and transforming growth factor β/Smads signal transduction pathways are involved in this process.

  3. Molecular pharmacodynamics of emixustat in protection against retinal degeneration.

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    Zhang, Jianye; Kiser, Philip D; Badiee, Mohsen; Palczewska, Grazyna; Dong, Zhiqian; Golczak, Marcin; Tochtrop, Gregory P; Palczewski, Krzysztof

    2015-07-01

    Emixustat is a visual cycle modulator that has entered clinical trials as a treatment for age-related macular degeneration (AMD). This molecule has been proposed to inhibit the visual cycle isomerase RPE65, thereby slowing regeneration of 11-cis-retinal and reducing production of retinaldehyde condensation byproducts that may be involved in AMD pathology. Previously, we reported that all-trans-retinal (atRAL) is directly cytotoxic and that certain primary amine compounds that transiently sequester atRAL via Schiff base formation ameliorate retinal degeneration. Here, we have shown that emixustat stereoselectively inhibits RPE65 by direct active site binding. However, we detected the presence of emixustat-atRAL Schiff base conjugates, indicating that emixustat also acts as a retinal scavenger, which may contribute to its therapeutic effects. Using agents that lack either RPE65 inhibitory activity or the capacity to sequester atRAL, we assessed the relative importance of these 2 modes of action in protection against retinal phototoxicity in mice. The atRAL sequestrant QEA-B-001-NH2 conferred protection against phototoxicity without inhibiting RPE65, whereas an emixustat derivative incapable of atRAL sequestration was minimally protective, despite direct inhibition of RPE65. These data indicate that atRAL sequestration is an essential mechanism underlying the protective effects of emixustat and related compounds against retinal phototoxicity. Moreover, atRAL sequestration should be considered in the design of next-generation visual cycle modulators.

  4. Aerobic exercise protects retinal function and structure from light-induced retinal degeneration.

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    Lawson, Eric C; Han, Moon K; Sellers, Jana T; Chrenek, Micah A; Hanif, Adam; Gogniat, Marissa A; Boatright, Jeffrey H; Pardue, Machelle T

    2014-02-12

    Aerobic exercise is a common intervention for rehabilitation of motor, and more recently, cognitive function (Intlekofer and Cotman, 2013; Wood et al., 2012). While the underlying mechanisms are complex, BDNF may mediate much of the beneficial effects of exercise to these neurons (Ploughman et al., 2007; Griffin et al., 2011; Real et al., 2013). We studied the effects of aerobic exercise on retinal neurons undergoing degeneration. We exercised wild-type BALB/c mice on a treadmill (10 m/min for 1 h) for 5 d/week or placed control mice on static treadmills. After 2 weeks of exercise, mice were exposed to either toxic bright light (10,000 lux) for 4 h to induce photoreceptor degeneration or maintenance dim light (25 lux). Bright light caused 75% loss of both retinal function and photoreceptor numbers. However, exercised mice exposed to bright light had 2 times greater retinal function and photoreceptor nuclei than inactive mice exposed to bright light. In addition, exercise increased retinal BDNF protein levels by 20% compared with inactive mice. Systemic injections of a BDNF tropomyosin-receptor-kinase (TrkB) receptor antagonist reduced retinal function and photoreceptor nuclei counts in exercised mice to inactive levels, effectively blocking the protective effects seen with aerobic exercise. The data suggest that aerobic exercise is neuroprotective for retinal degeneration and that this effect is mediated by BDNF signaling. PMID:24523530

  5. Hydrophobic treatment of concrete as protection against chloride penetration

    NARCIS (Netherlands)

    Vries, J. de; Polder, R.B.; Borsje, H.

    1996-01-01

    Hydrophobic treatment makes a concrete surface absorb less water and less chloride. Hydrophobic treatment was studied as a protection agninst chloride penetration from deicing salts. Test methods were designed. Nine hydrophobic products were tested, of which three complied to the requirements on fin

  6. SiC protective coating for photovoltaic retinal prosthesis

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    Lei, Xin; Kane, Sheryl; Cogan, Stuart; Lorach, Henri; Galambos, Ludwig; Huie, Philip; Mathieson, Keith; Kamins, Theodore; Harris, James; Palanker, Daniel

    2016-08-01

    Objective. To evaluate plasma-enhanced, chemically vapor deposited (PECVD) amorphous silicon carbide (α-SiC:H) as a protective coating for retinal prostheses and other implantable devices, and to study their failure mechanisms in vivo. Approach. Retinal prostheses were implanted in rats sub-retinally for up to 1 year. Degradation of implants was characterized by optical and scanning electron microscopy. Dissolution rates of SiC, SiN x and thermal SiO2 were measured in accelerated soaking tests in saline at 87 °C. Defects in SiC films were revealed and analyzed by selectively removing the materials underneath those defects. Main results. At 87 °C SiN x dissolved at 18.3 ± 0.3 nm d‑1, while SiO2 grown at high temperature (1000 °C) dissolved at 0.104 ± 0.008 nm d‑1. SiC films demonstrated the best stability, with no quantifiable change after 112 d. Defects in thin SiC films appeared primarily over complicated topography and rough surfaces. Significance. SiC coatings demonstrating no erosion in accelerated aging test for 112 d at 87 °C, equivalent to about 10 years in vivo, can offer effective protection of the implants. Photovoltaic retinal prostheses with PECVD SiC coatings exhibited effective protection from erosion during the 4 month follow-up in vivo. The optimal thickness of SiC layers is about 560 nm, as defined by anti-reflective properties and by sufficient coverage to eliminate defects.

  7. Bimatoprost protects retinal neuronal damage via Akt pathway.

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    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.

  8. Protective Effects of Radix Pseudostellariae Extract Against Retinal Laser Injury

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    Guo Rui

    2014-05-01

    Full Text Available Background: This study aimed to analyze the protective effects of a saponin extract from Radix Pseudostellariae (RP on retinal laser injury based on a retinal photocoagulation model. Methods: Fifty-eight rabbits were randomly divided into three groups: Group A (saponin extract orally, Group B (physiological saline, and Group C (control. The animals were sacrificed 1 day, 7 days, 14 days, and 30 days after photocoagulation and lesions were evaluated with fundus photography, light microscopy, and electron microscopy. Superoxide dismutase (SOD and malondialdehyde (MDA levels were measured, and expression levels of c-fos and Bax genes were also determined. Results: The lesion sizes in Group A were smaller than in Group B. The levels of SOD in Group B were significantly lower than in groups A and C (PConclusion: The saponin extract of RP can inhibit oxidative stress, downregulate the levels of c-fos and Bax gene expression, and inhibit apoptosis in the retina after photocoagulation.

  9. 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.

  10. Pericytes derived from adipose-derived stem cells protect against retinal vasculopathy.

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    Thomas A Mendel

    Full Text Available BACKGROUND: Retinal vasculopathies, including diabetic retinopathy (DR, threaten the vision of over 100 million people. Retinal pericytes are critical for microvascular control, supporting retinal endothelial cells via direct contact and paracrine mechanisms. With pericyte death or loss, endothelial dysfunction ensues, resulting in hypoxic insult, pathologic angiogenesis, and ultimately blindness. Adipose-derived stem cells (ASCs differentiate into pericytes, suggesting they may be useful as a protective and regenerative cellular therapy for retinal vascular disease. In this study, we examine the ability of ASCs to differentiate into pericytes that can stabilize retinal vessels in multiple pre-clinical models of retinal vasculopathy. METHODOLOGY/PRINCIPAL FINDINGS: We found that ASCs express pericyte-specific markers in vitro. When injected intravitreally into the murine eye subjected to oxygen-induced retinopathy (OIR, ASCs were capable of migrating to and integrating with the retinal vasculature. Integrated ASCs maintained marker expression and pericyte-like morphology in vivo for at least 2 months. ASCs injected after OIR vessel destabilization and ablation enhanced vessel regrowth (16% reduction in avascular area. ASCs injected intravitreally before OIR vessel destabilization prevented retinal capillary dropout (53% reduction. Treatment of ASCs with transforming growth factor beta (TGF-β1 enhanced hASC pericyte function, in a manner similar to native retinal pericytes, with increased marker expression of smooth muscle actin, cellular contractility, endothelial stabilization, and microvascular protection in OIR. Finally, injected ASCs prevented capillary loss in the diabetic retinopathic Akimba mouse (79% reduction 2 months after injection. CONCLUSIONS/SIGNIFICANCE: ASC-derived pericytes can integrate with retinal vasculature, adopting both pericyte morphology and marker expression, and provide functional vascular protection in multiple

  11. Protection against methanol-induced retinal toxicity by LED photostimulation

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    Whelan, Harry T.; Wong-Riley, Margaret T. T.; Eells, Janis T.

    2002-06-01

    We have initiated experiments designed to test the hypothesis that 670-nm Light-Emitting Diode (LED) exposure will attenuate formate-induced retinal dysfunction in a rodent model of methanol toxicity. Methanol intoxication produces toxic injury to the retina. The toxic metabolite formed in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit cytochrome oxidase activity. 670-nm LED light has been hypothesized to act by stimulating cytochrome oxidase activity. To test this hypothesis, one group of animals was intoxicated with methanol, a second group was intoxicated with methanol and LED-treated and a third group was untreated. LED treatment (670 nm for 1 min 45 seconds equals 50 mW/cm2, 4 joules/cm2) was administered at 5, 25, and 50 hours after the initial dose of methanol. At 72 hours of methanol intoxication, retinal function was assessed by measurement of ERG responses and retinas were prepared for histologic analysis. ERG responses recorded in methanol-intoxicated animals revealed profound attenuation of both rod-dominated and UV-cone mediated responses. In contrast, methanol- intoxicated animals exposed to LED treatment exhibited a nearly complete recovery of rod-dominated ERG responses and a slight improvement of UV-cone mediated ERG responses. LED treatment also protected the retina against the histopathologic changes produced by formate in methanol intoxication. These data provide evidence that LED phototherapy protects the retina against the cytotoxic actions of formate and are consistent with the hypothesis that LED photostimulation improves mitochondrial respiratory chain function.

  12. Mitochondrial Protection by Exogenous Otx2 in Mouse Retinal Neurons

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    Hyoung-Tai Kim

    2015-11-01

    Full Text Available OTX2 (orthodenticle homeobox 2 haplodeficiency causes diverse defects in mammalian visual systems ranging from retinal dysfunction to anophthalmia. We find that the retinal dystrophy of Otx2+/GFP heterozygous knockin mice is mainly due to the loss of bipolar cells and consequent deficits in retinal activity. Among bipolar cell types, OFF-cone bipolar subsets, which lack autonomous Otx2 gene expression but receive Otx2 proteins from photoreceptors, degenerate most rapidly in Otx2+/GFP mouse retinas, suggesting a neuroprotective effect of the imported Otx2 protein. In support of this hypothesis, retinal dystrophy in Otx2+/GFP mice is prevented by intraocular injection of Otx2 protein, which localizes to the mitochondria of bipolar cells and facilitates ATP synthesis as a part of mitochondrial ATP synthase complex. Taken together, our findings demonstrate a mitochondrial function for Otx2 and suggest a potential therapeutic application of OTX2 protein delivery in human retinal dystrophy.

  13. The Protective Effects of Lycium Barbarum Polysaccharides on Transient Retinal Ischemia

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    Di Yang

    2011-05-01

    Full Text Available Retinal ischemia/reperfusion (I/R injury leads to irreversible neuronal death, glial activation, retinal swelling and oxidative stress. It is a common feature in various ocular diseases, such as glaucoma, diabetic retinopathy and amaurosis fugax. In the present study, we aimed to evaluate the effects of Lycium Barbarum Polysaccharides (LBP in a murine retinal I/R model. Mice were orally treated with either vehicle (PBS or LBP (1mg/kg daily for 1 week before induction of retinal ischemia. Retinae were collected after 2 hours ischemia and 22 hours reperfusion. Paraffin-embedded sections were prepared for immunohistochemical analyses. Significantly fewer viable cells were found in vehicle-treated retinae comparing to LBP group. This finding was further confirmed by TUNEL assay where significantly fewer apoptotic cells were identified in LBP-treated retinae. Additionally, retinal swelling induced by retinal I/R injury in the vehicle-treated group was not observed in LBP-treated group. Moreover, intense GFAP immunoreactivity and IgG extravasation were observed in vehicle-treated group but not in LBP treated group. The results showed that pre-treatment with LBP was protective in retinal I/R injury via reducing neuronal death, apoptosis, retinal swelling, GFAP activation and blood vessel leakage. LBP may be used as a preventive agent for retinal ischemia diseases.

  14. Protective responses to sublytic complement in the retinal pigment epithelium.

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    Tan, Li Xuan; Toops, Kimberly A; Lakkaraju, Aparna

    2016-08-01

    The retinal pigment epithelium (RPE) is a key site of injury in inherited and age-related macular degenerations. Abnormal activation of the complement system is a feature of these blinding diseases, yet how the RPE combats complement attack is poorly understood. The complement cascade terminates in the cell-surface assembly of membrane attack complexes (MACs), which promote inflammation by causing aberrant signal transduction. Here, we investigated mechanisms crucial for limiting MAC assembly and preserving cellular integrity in the RPE and asked how these are compromised in models of macular degeneration. Using polarized primary RPE and the pigmented Abca4(-/-) Stargardt disease mouse model, we provide evidence for two protective responses occurring within minutes of complement attack, which are essential for maintaining mitochondrial health in the RPE. First, accelerated recycling of the membrane-bound complement regulator CD59 to the RPE cell surface inhibits MAC formation. Second, fusion of lysosomes with the RPE plasma membrane immediately after complement attack limits sustained elevations in intracellular calcium and prevents mitochondrial injury. Cholesterol accumulation in the RPE, induced by vitamin A dimers or oxidized LDL, inhibits these defense mechanisms by activating acid sphingomyelinase (ASMase), which increases tubulin acetylation and derails organelle traffic. Defective CD59 recycling and lysosome exocytosis after complement attack lead to mitochondrial fragmentation and oxidative stress in the RPE. Drugs that stimulate cholesterol efflux or inhibit ASMase restore both these critical safeguards in the RPE and avert complement-induced mitochondrial injury in vitro and in Abca4(-/-) mice, indicating that they could be effective therapeutic approaches for macular degenerations. PMID:27432952

  15. Agmatine protects retinal ganglion cells from hypoxia-induced apoptosis in transformed rat retinal ganglion cell line

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    Kim Chan

    2007-10-01

    Full Text Available Abstract Background Agmatine is an endogenous polyamine formed by the decarboxylation of L-arginine. We investigated the protective effects of agmatine against hypoxia-induced apoptosis of immortalized rat retinal ganglion cells (RGC-5. RGC-5 cells were cultured in a closed hypoxic chamber (5% O2 with or without agmatine. Cell viability was determined by lactate dehydrogenase (LDH assay and apoptosis was examined by annexin V and caspase-3 assays. Expression and phosphorylation of mitogen-activated protein kinases (MAPKs; JNK, ERK p44/42, and p38 and nuclear factor-kappa B (NF-κB were investigated by Western immunoblot analysis. The effects of agmatine were compared to those of brain-derived neurotrophic factor (BDNF, a well-known protective neurotrophin for retinal ganglion cells. Results After 48 hours of hypoxic culture, the LDH assay showed 52.3% cell loss, which was reduced to 25.6% and 30.1% when agmatine and BDNF were administered, respectively. This observed cell loss was due to apoptotic cell death, as established by annexin V and caspase-3 assays. Although total expression of MAPKs and NF-κB was not influenced by hypoxic injury, phosphorylation of these two proteins was increased. Agmatine reduced phosphorylation of JNK and NF-κB, while BDNF suppressed phosphorylation of ERK and p38. Conclusion Our results show that agmatine has neuroprotective effects against hypoxia-induced retinal ganglion cell damage in RGC-5 cells and that its effects may act through the JNK and NF-κB signaling pathways. Our data suggest that agmatine may lead to a novel therapeutic strategy to reduce retinal ganglion cell injury related to hypoxia.

  16. Aerobic Exercise Protects Retinal Function and Structure from Light-Induced Retinal Degeneration

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    Lawson, Eric C.; Han, Moon K.; Sellers, Jana T.; Chrenek, Micah A; Hanif, Adam; Gogniat, Marissa A.; Boatright, Jeffrey H.; Pardue, Machelle T.

    2014-01-01

    Aerobic exercise is a common intervention for rehabilitation of motor, and more recently, cognitive function (Intlekofer and Cotman, 2013; Wood et al., 2012). While the underlying mechanisms are complex, BDNF may mediate much of the beneficial effects of exercise to these neurons (Ploughman et al., 2007; Griffin et al., 2011; Real et al., 2013). We studied the effects of aerobic exercise on retinal neurons undergoing degeneration. We exercised wild-type BALB/c mice on a treadmill (10 m/min fo...

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

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    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.

  18. Edaravone protect against retinal damage in streptozotocin-induced diabetic mice.

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    Dongqing Yuan

    Full Text Available Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one, a free radical scavenger, is used for the clinical treatment of retinal injury. In this study, we investigated the protective effects of edaravone against diabetic retinal damage in the mouse. Diabetic retinopathy in the mouse was induced by injection of streptozotocin. Edaravone was given once-daily and was intraperitoneally (i.p. treated at a dose of 3 mg/kg from streptozotocin injection to 4 weeks after onset of diabetes. Retinal ganglion cells (RGCs damage was evaluated by recording the pattern electroretinogram (ERG. RGCs damage was also detected by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining, and the levels of reactive oxygen species (ROS were determined fluorometrically. The expressions of phosporylated-ERK1/2, BDNF, and caspase-3 were determined by Western blot analysis. Retinal levels of ROS, phosphorylated ERK1/2, and cleaved caspase-3 were significantly increased, whereas the expression of BDNF was significantly decreased in the retinas of diabetic mice, compared to nondiabetic mice. Administration of edaravone significantly attenuated diabetes induced RGCs death, upregulation of ROS, ERK1/2 phosphorylation, and cleaved caspase-3 and downregulation of BDNF. These findings suggest that oxidative stress plays a pivotal role in diabetic retinal damage and that systemic administration of edaravone may slow the progression of retinal neuropathy induced by diabetes.

  19. Protective effects of resveratrol in experimental retinal detachment.

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    Wei Huang

    Full Text Available BACKGROUND: Oxidative stress is one of the major factors that trigger photoreceptor apoptosis. To investigate whether resveratrol, a potent antioxidant and small molecule activator of the FoxO pathway, would be neuroprotective against photoreceptor cell death in a rodent model of retinal detachment. METHODS: Retinal detachment was created in adult Brown Norway rats by subretinal injection of sodium hyaluronate. The animals were treated daily with vehicle or resveratrol (20 mg/kg intraperitoneal injection. Photoreceptor death was assessed by counting the number of apoptotic cells with TdT-dUTP terminal nick-end labeling (TUNEL and measurement of the outer nuclear layer (ONL thickness 3 days after RD. Changes in expression of FoxO1a, FoxO3a, and FoxO4 were analyzed by western blot. The activity of caspase 3, caspase 8, caspase 9, spectrin and their cleavage forms were studied. RESULTS: Three days after retinal detachment, caspase 3, caspase 8 and caspase 9 were significantly activated in the detached retina. Spectrin cleavage products at 120 and 145 kDa were also detected. Both caspase and calpain activation are involved in apoptotic photoreceptor cell death in detached retinas. Treatment with resveratrol increases FoxO1a, FoxO3a, and FoxO4 protein expression in detached retinas only. Resveratrol treatment decreases activation of intrinsic and extrinsic caspase apoptotic pathways triggered by RD. The number of TUNEL-positive cells decreases from 1301±51 cells/mm(2 in control groups to 430±35 cells/mm(2 in treatment groups (p<0.05. Resveratrol treatment also demonstrates 59% less ONL thickness loss compared to controls. CONCLUSIONS: Resveratrol treatment up-regulates the FoxO family and blocks Caspase3, 8, and 9 activation. Resveratrol has the potential to be used as a novel therapeutic agent for preventing vision loss in diseases characterized by photoreceptor detachment.

  20. Selenium Protects Retinal Cells from Cisplatin-Induced Alterations in Carbohydrate Residues

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    Akşit, Dilek; Yazıcı, Alper; Akşit, Hasan; Sarı, Esin S.; Yay, Arzu; Yıldız, Onur; Kılıç, Adil; Ermiş, Sıtkı S.; Seyrek, Kamil

    2016-01-01

    Background: Investigate alterations in the expression and localization of carbohydrate units in rat retinal cells exposed to cisplatin toxicity. Aims: The aim of the study was to evaluate putative protective effects of selenium on retinal cells subjected to cisplatin. Study Design: Animal experiment. Methods: Eighteen healthy Wistar rats were divided into three equal groups: 1. Control, 2. Cisplatin and 3. Cisplatin+selenium groups. After anesthesia, the right eye of each rat was enucleated. Results: Histochemically, retinal cells of control groups reacted with α-2,3-bound sialic acid-specific Maackia amurensis lectin (MAA) strongly, while cisplatin reduced the staining intensity for MAA. However, selenium administration alleviated the reducing effect of cisplatin on the binding sites for MAA in retinal cells. The staining intensity for N-acetylgalactosamine (GalNAc residues) specific Griffonia simplicifolia-1 (GSL–1) was relatively slight in control animals and cisplatin reduced this slight staining for GSL-1 further. Selenium administration mitigated the reducing effect of cisplatin on the binding sites for GSL-1. A diffuse staining for N-acetylglucosamine (GlcNAc) specific wheat germ agglutinin (WGA) was observed throughout the retina of the control animals. In particular, cells localized in the inner plexiform and photoreceptor layers are reacted strongly with WGA. Compared to the control animals, binding sites for WGA in the retina of rats given cisplatin were remarkably decreased. However, the retinal cells of rats given selenium reacted strongly with WGA. Conclusion: Cisplatin reduces α-2,3-bound sialic acid, GlcNAc and GalNAc residues in certain retinal cells. However, selenium alleviates the reducing effect of cisplatin on carbohydrate residues in retinal cells. PMID:27606141

  1. Consumption of Polyphenol-Rich Zingiber Zerumbet Rhizome Extracts Protects against the Breakdown of the Blood-Retinal Barrier and Retinal Inflammation Induced by Diabetes

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    Thing-Fong Tzeng

    2015-09-01

    Full Text Available The present study investigates the amelioration of diabetic retinopathy (DR by Zingiber zerumbet rhizome ethanol extracts (ZZRext in streptozotocin-induced diabetic rats (STZ-diabetic rats. ZZRext contains high phenolic and flavonoid contents. STZ-diabetic rats were treated orally with ZZRext (200, 300 mg/kg per day for three months. Blood-retinal barrier (BRB breakdown and increased vascular permeability were found in diabetic rats, with downregulation of occludin, and claudin-5. ZZRext treatment effectively preserved the expression of occludin, and claudin-5, leading to less BRB breakdown and less vascular permeability. Retinal histopathological observation showed that the disarrangement and reduction in thickness of retinal layers were reversed in ZZRext-treated diabetic rats. Retinal gene expression of tumor necrosis factor-α, interleukin (IL-1β, IL-6, vascular endothelial growth factor, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were all decreased in ZZRext-treated diabetic rats. Moreover, ZZRext treatment not only inhibited the nuclear factor κB (NF-κB activation, but also downregulated the protein expression of p38 mitogen-activated protein kinase (MAPK in diabetic retina. In conclusion, the results suggest that the retinal protective effects of ZZRext occur through improved retinal structural change and inhibiting retinal inflammation. The antiretinopathy property of ZZRext might be related to the downregulation of p38 MAPK and NF-κB signal transduction induced by diabetes.

  2. Brazilian Green Propolis Protects against Retinal Damage In Vitro and In Vivo

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    Yuta Inokuchi

    2006-01-01

    Full Text Available Propolis, a honeybee product, has gained popularity as a food and alternative medicine. Its constituents have been shown to exert pharmacological (anticancer, antimicrobial and anti-inflammatory effects. We investigated whether Brazilian green propolis exerts neuroprotective effects in the retina in vitro and/or in vivo. In vitro, retinal damage was induced by 24 h hydrogen peroxide (H2O2 exposure, and cell viability was measured by Hoechst 33342 and YO-PRO-1 staining or by a resazurin–reduction assay. Propolis inhibited the neurotoxicity and apoptosis induced in cultured retinal ganglion cells (RGC-5, a rat ganglion cell line transformed using E1A virus by 24 h H2O2 exposure. Propolis also inhibited the neurotoxicity induced in RGC-5 cultures by staurosporine. Regarding the possible underlying mechanism, in pig retina homogenates propolis protected against oxidative stress (lipid peroxidation, as also did trolox (water-soluble vitamin E. In mice in vivo, propolis (100 mg kg−1; intraperitoneally administered four times reduced the retinal damage (decrease in retinal ganglion cells and in thickness of inner plexiform layer induced by intravitreal in vivo N-methyl-d-aspartate injection. These findings indicate that Brazilian green propolis has neuroprotective effects against retinal damage both in vitro and in vivo, and that a propolis-induced inhibition of oxidative stress may be partly responsible for these neuroprotective effects.

  3. A compensatory mechanism protects retinal mitochondria from initial insult in diabetic retinopathy

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    Santos, Julia M.; Tewari, Shikha; Kowluru, Renu A.

    2012-01-01

    In the pathogenesis of diabetic retinopathy, an increase in retinal oxidative stress precedes mitochondrial dysfunction and capillary cell apoptosis. This study is designed to understand the mechanism responsible for the protection of mitochondria damage in the early stages of diabetic retinopathy. After 15 days–12 months of streptozotocin-induced diabetes in rats, retina was analyzed for mitochondria DNA (mtDNA) damage by extended length PCR. DNA repair enzyme and replication machinery were ...

  4. Protective effect and mechanism of lithium chloride pretreatment on myocardial ischemia-reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Fang-Jiang Li; Tao Hsu; Hui-Xian Li; Jin-Zheng Shi; Mei-Ling Du; Xiao-Yuan Wang; Wen-Ting Zhang

    2014-01-01

    Objective:To investigate the protective effect and mechanism of lithium chloride pretreatment on myocardial ischemia-reperfusion injury(I-RI) in rats.Methods:A total of60SD rats were randomly divided into control group, model group, lithium chloride intervention group and L-arginine methyl ester+ lithium chloride intervention group with15 in each.TheI-RI model was established in model group, the lithium chloride intervention group andL-arginine methyl ester+ lithium chloride intervention group by method of seaming along left anterior descending coronary artery myocardial, control group was only opened the chest without seaming,ST-elevation within2 min was regarded as modeling success.Model group did not adopted any intervention, lithium chloride intervention group was treated with lithium chloride injection 15 mg/kg by jugular venipuncture preoperatively,L-arginine methyl ester+ lithium chloride intervention group was treated with intraperitoneal injection of30 mg•kg-1•d-1L-arginine methyl ester7 d before the test, and intravenous catheter of15 mg/kg lithium chloride preoperatively. The hydroxybutyric acid dehydrogenase(HBDH), creatine kinase isoenzyme(CK-MB), superoxide dismutase(SOD), malondialdehyde(MDA) level and nitric oxide synthase(NOS) activites were tested.Each large area of myocardial ischemia tissue was extracted for determination of the MDA content,SOD activity in tissue and serum, and morphological changes of myocardial tissue.Results:SOD activity was highest in lithium chloride intervention group, followed by L-arginine methyl ester+ lithium chloride intervention group, control group and model group (P0.05);HBDH andCK-MB of plasma were highest in model group, followed byL-arginine methyl ester+ lithium chloride intervention group, lithium chloride intervention group and control group(P<0.05).A significantly lighter myocardial damage was observed microscopically in lithium chloride intervention group than that inL-arginine methyl ester+ lithium

  5. Protection of visual functions by human neural progenitors in a rat model of retinal disease.

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    David M Gamm

    Full Text Available BACKGROUND: A promising clinical application for stem and progenitor cell transplantation is in rescue therapy for degenerative diseases. This strategy seeks to preserve rather than restore host tissue function by taking advantage of unique properties often displayed by these versatile cells. In studies using different neurodegenerative disease models, transplanted human neural progenitor cells (hNPC protected dying host neurons within both the brain and spinal cord. Based on these reports, we explored the potential of hNPC transplantation to rescue visual function in an animal model of retinal degeneration, the Royal College of Surgeons rat. METHODOLOGY/PRINCIPAL FINDINGS: Animals received unilateral subretinal injections of hNPC or medium alone at an age preceding major photoreceptor loss. Principal outcomes were quantified using electroretinography, visual acuity measurements and luminance threshold recordings from the superior colliculus. At 90-100 days postnatal, a time point when untreated rats exhibit little or no retinal or visual function, hNPC-treated eyes retained substantial retinal electrical activity and visual field with near-normal visual acuity. Functional efficacy was further enhanced when hNPC were genetically engineered to secrete glial cell line-derived neurotrophic factor. Histological examination at 150 days postnatal showed hNPC had formed a nearly continuous pigmented layer between the neural retina and retinal pigment epithelium, as well as distributed within the inner retina. A concomitant preservation of host cone photoreceptors was also observed. CONCLUSIONS/SIGNIFICANCE: Wild type and genetically modified human neural progenitor cells survive for prolonged periods, migrate extensively, secrete growth factors and rescue visual functions following subretinal transplantation in the Royal College of Surgeons rat. These results underscore the potential therapeutic utility of hNPC in the treatment of retinal degenerative

  6. Beneficial protective effect of pramipexole on light-induced retinal damage in mice.

    Science.gov (United States)

    Shibagaki, Keiichi; Okamoto, Kazuyoshi; Katsuta, Osamu; Nakamura, Masatsugu

    2015-10-01

    We investigated the effects of pramipexole, a potent dopamine receptor D2/D3 agonist, on light-induced retinal damage in mice, H2O2-induced retinal pigment epithelium ARPE-19 cell injury in humans, and hydroxyl radical scavenging activity in a cell-free system. Pramipexole (0.1 and 1 mg/kg body weight) was orally administered to mice 1 h before light exposure (5000 lux, 2 h). Electrophysiological and morphologic studies were performed to evaluate the effects of the pramipexole on light-induced retinal damage in mice. Pramipexole significantly prevented the reduction of the a- and b-wave electroretinogram (ERG) amplitudes caused by light exposure in a dose-dependent manner. In parallel, damage to the inner and outer segments (IS/OS) of the photoreceptors, loss of photoreceptor nuclei, and the number of Tdt-mediated dUTP nick-end labeling (TUNEL)-positive cells in the outer nuclear layer (ONL) caused by light exposure were notably ameliorated by pramipexole. Additionally, pramipexole suppressed H2O2-induced ARPE-19 cell death in vitro in a concentration-dependent manner. The effect of pramipexole was significant at concentrations of 10(-6) M or higher. Pramipexole also significantly prevented H2O2-induced activation of caspases-3/7 and the intracellular accumulation of reactive oxygen species (ROS) in a concentration-dependent manner ranging from 10(-5) to 10(-3) M. Furthermore, pramipexole increased the scavenging activity toward a hydroxyl radical generated from H2O2 in a Fenton reaction. Our results suggest that pramipexole protects against light-induced retinal damage as an antioxidant and that it may be a novel and effective therapy for retinal degenerative disorders, such as dry age-related macular degeneration. PMID:26213307

  7. Modeling of Multi-Layered Protection Systems for Chloride Penetration in Concrete Bridge Decks

    Science.gov (United States)

    Harajli, Ali A.

    Modeling of Multi-Layered Protection Systems for Chloride Penetration in Concrete Bridge Decks. This paper covers the development of a new methodology for predicting the chloride concentration and corrosion initiation times for a multi-layer protection overlay system. The first topic will be presenting an innovative method to predict the chloride concentrations using different diffusion coefficients for each protective layer. The new method covers the cases where the applied surface chloride concentrations are either a constant or linear functions with time. The second topic will implement the results from field data about the chloride variations due to the presence of applied topical layers for comparison with the theoretical models. This section will also apply damage factors that are time-dependent to simulate external factors such as traffic loading or vibrations. The third topic will investigate the sensitivity of the single and multi-layer systems due to diffusivity parameter changes. The fourth topic will analyze the random variation of the diffusivity values to predict the mean and standard deviation of chloride concentrations. The diffusivity values are selected from published values by NIST and are based on certain water cement (w/c) ratios.

  8. Dietary supplement enriched in antioxidants and omega-3 protects from progressive light-induced retinal degeneration.

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    Khaoula Ramchani-Ben Othman

    Full Text Available In the present study, we have evaluated one of the dietary supplements enriched with antioxidants and fish oil used in clinical care for patient with age-related macular degeneration. Rats were orally fed by a gastric canula daily with 0.2 ml of water or dietary supplement until they were sacrificed. After one week of treatment, animals were either sacrificed for lipid analysis in plasma and retina, or used for evaluation of rod-response recovery by electroretinography (ERG followed by their sacrifice to measure rhodopsin content, or used for progressive light-induced retinal degeneration (PLIRD. For PLIRD, animals were transferred to bright cyclic light for one week. Retinal damage was quantified by ERG, histology and detection of apoptotic nuclei. Animals kept in dim-cyclic-light were processed in parallel. PLIRD induced a thinning of the outer nuclear layer and a reduction of the b-wave amplitude of the ERG in the water group. Retinal structure and function were preserved in supplemented animals. Supplement induced a significant increase in omega-3 fatty acids in plasma by 168% for eicosapentaenoic acid (EPA, 142% for docosapentaenoic acid (DPA and 19% for docosahexaenoic acid (DHA and a decrease in the omega-6 fatty acids, DPA by 28%. In the retina, supplement induced significant reduction of linolenic acid by 67% and an increase in EPA and DPA by 80% and 72%, respectively, associated with significant decrease in omega-6 DPA by 42%. Supplement did not affect rhodopsin content or rod-response recovery. The present data indicate that supplement rapidly modified the fatty acid content and induced an accumulation of EPA in the retina without affecting rhodopsin content or recovery. In addition, it protected the retina from oxidative stress induced by light. Therefore, this supplement might be beneficial to slow down progression of certain retinal degeneration.

  9. Protective Role of Sodium Selenite on Mercuric Chloride Induced Oxidative and Renal Stress in Rats

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    Necib, Youcef

    2013-04-01

    Full Text Available Backgroud: Reactive oxygen species are known to play a major role in mercuric chloride induced oxidative and renal stress. Sodium selenite as an exogenous source of selenium is used for endogenous selenoprotein synthesis to scavenge the free radicals. The study was designed to investigate the possible protective role of sodium selenite in mercuric chloride induced renal stress, by using biochemical approaches. Adult male Albinos Wistar rats were randomly divided into four groups. The first group was served as the control, the second group was given sodium selenite (0.25 mg/kg b.w, while the third group was given mercuric chloride (0.25 mg/kg, finally, the fourth group was given combined treatment of sodium selenite and mercuric chloride for 3 weeks.Results: The effects of sodium selenite on mercuric chloride induced oxidative and renal stress were evaluated by serum creatinine, urea, uric acid, billirubin levels and LDH activity, kidney tissue lipid peroxidation, GSH levels, GSH-Px, GST and catalase activities and hematological parameters. Administration of mercuric chloride induced significant increase in serum: creatinine, urea, uric acid and billirubin concentration showing renal stress. Mercuric chloride also induced oxidative stress, as indicate by decreased kidney tissue of GSH level, GSH-Px, GST, and catalase activities along with increase the level of lipid peroxidation. Furthermore, treatment with mercuric chloride caused a marked elevation of kidney weight and decreased body weight and erythrocytes, hemoglobin, hematocrit levels. Sodium selenite treatment markedly reduced elevated serum: creatinine, urea, uric acid and billirubin levels, and LDH activity and conteracted the deterious effects of mercuric chloride on oxidative stress markers and hematological parameters and atteneuated histopathological changes caused by HgCl2 in kidney.Conclusion: Our results indicate that sodium selenite could have a beneficial role against mercuric

  10. Applicability of certain materials and protective coatings in fused chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Migai, L.L.; Verizhnikova, G.N.

    1976-09-01

    The corrosion resistance of a number of metals, alloys, ceramic materials, and enamel coatings was investigated in mixtures of fused freshly prepared chlorides at 500 to 550/sup 0/C in air. The chlorides NaCl, KCl, and CaCl/sub 2/ of cp and ar grade were dried in air at 200 to 250/sup 0/C for 6 h, remelted at 800/sup 0/C, and fused in given ratios for 3 h; anhydrous commercial MgCl/sub 2/, AlCl/sub 3/, and FeCl/sub 3/, until a homogeneous melt was obtained. The corrosion resistances of the metals and ceramic materials were assessed from the change in weight. The chemical resistance of the enamel coating were determined from the loss of continuity of the coating by means of an IDS flaw detector. The corrosion rate of W, Mo, Ni, Ta, Cr, Zr, NMZhMts (28-1.5-2), KhN4510, N50Kh40Yu10, N60KH40, OKh15N65M16G3, OKh15N65M16V, N65M20V15, N65M19V16, N70M27F, and stainless steels Kh28Yu5, Kh28S2, Kh18N10T, Kh20N18Yu3, Kh25N20S2, and OKh23N28M3D3T in melts of these compositions exceeded 100g/m/sup 2/h. Ceramic of pure oxides, silicon carbide with a nitride binder, and silicified graphite are strongly impregnated by the melt, and may therefore crack with a sudden change in temperature. Cermet coating M1 disintegrated in places. Of the cermic materials tested the most stable are basalt ceramic and fluorphlogopite. Enamel coating 6S-12 has a low resistance, the surface became rough; enamel coating 15, Kh19-6, N-14-15, and N14-10 became porous.Enamels 8/2-72, 81A/sub 8/, and 81 are quite unstable in these melts at 500 to 550/sup 0/C. Enamel coatings 143/54-15, 143/54-50, 54, and 122 are the most stable in fused chlorides. These studies showed that none of the metallic materials tested can be used as a structural material in the chloride melts (%) KCl 39, NaCl 7 CaCl/sub 2/ 3.5, MgCl/sub 2/ 2.5, AlCl/sub 3/ 20, and FeCl/sub 3/ 28 and KCL 58-FeCl/sub 3/ 42 at 500 to 550/sup 0/C. Fluorphlogopite, basalt ceramic, and enamels 143/54-15, 143/54-50, 54, and 122 are recommended for pilot

  11. Lycium barbarum polysaccharides protected human retinal pigment epithelial cells against oxidative stressinduced apoptosis

    Institute of Scientific and Technical Information of China (English)

    Lian; Liu; Wei; Lao; Qing-Shan; Ji; Zhi-Hao; Yang; Guo-Cheng; Yu; Jing-Xiang; Zhong

    2015-01-01

    AIM: To investigate the protective effect and its mechanism of lycium barbarum polysaccharides(LBP)against oxidative stress-induced apoptosis in human retinal pigment epithelial cells.METHODS: ARPE-19 cells, a human retinal pigment epithelial cell lines, were exposed to different concentrations of H2O2 for 24h, then cell viability was measured by Cell Counting Kit-8(CCK-8) assay to get the properly concentration of H2O2 which can induce half apoptosis of APRE-19. With different concentrations of LBP pretreatment, the ARPE-19 cells were then exposed to appropriate concentration of H2O2, cell apoptosis was detected by flow cytometric analysis. Expression levels of Bcl-2 and Bax were measured by real time quantitative polymerase chain reaction(RT-PCR) technique.RSULTS: LBP significantly reduced the H2O2-induced ARPE-19 cells’ apoptosis. LBP inhibited the H2O2-induced down-regulation of Bcl-2 and up-regulation of Bax.CONCLUSION: LBP could protect ARPE-19 cells from H2O2-induced apoptosis. The Bcl-2 family had relationship with the protective effects of LBP.

  12. Protective Effect of Proanthocyanidins from Sea Buckthorn (Hippophae Rhamnoides L. Seed against Visible Light-Induced Retinal Degeneration in Vivo

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    Yong Wang

    2016-05-01

    Full Text Available Dietary proanthocyanidins (PACs as health-protective agents have become an important area of human nutrition research because of their potent bioactivities. We investigated the retinoprotective effects of PACs from sea buckthorn (Hippophae rhamnoides L. seed against visible light-induced retinal degeneration in vivo. Pigmented rabbits were orally administered sea buckthorn seed PACs (50 and 100 mg/kg/day for 14 consecutive days of pre-illumination and seven consecutive days of post-illumination. Retinal function was quantified via electroretinography 7 days after light exposure. Retinal damage was evaluated by measuring the thickness of the full-thickness retina and outer nuclear layer 7 days after light exposure. Sea buckthorn seed PACs significantly attenuated the destruction of electroretinograms and maintained the retinal structure. Increased retinal photooxidative damage was expressed by the depletion of glutathione peroxidase and catalase activities, the decrease of total antioxidant capacity level and the increase of malondialdehyde level. Light exposure induced a significant increase of inflammatory cytokines (IL-1β, TNF-α and IL-6 and angiogenesis (VEGF levels in retina. Light exposure upregulated the expression of pro-apoptotic proteins Bax and caspase-3 and downregulated the expression of anti-apoptotic protein Bcl-2. However, sea buckthorn seed PACs ameliorated these changes induced by light exposure. Sea buckthorn seed PACs mediated the protective effect against light-induced retinal degeneration via antioxidant, anti-inflammatory and antiapoptotic mechanisms.

  13. Idebenone protects against retinal damage and loss of vision in a mouse model of Leber's hereditary optic neuropathy.

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    Fabrice D Heitz

    Full Text Available Leber's hereditary optic neuropathy (LHON is an inherited disease caused by mutations in complex I of the mitochondrial respiratory chain. The disease is characterized by loss of central vision due to retinal ganglion cell (RGC dysfunction and optic nerve atrophy. Despite progress towards a better understanding of the disease, no therapeutic treatment is currently approved for this devastating disease. Idebenone, a short-chain benzoquinone, has shown promising evidence of efficacy in protecting vision loss and in accelerating recovery of visual acuity in patients with LHON. It was therefore of interest to study suitable LHON models in vitro and in vivo to identify anatomical correlates for this protective activity. At nanomolar concentrations, idebenone protected the rodent RGC cell line RGC-5 against complex I dysfunction in vitro. Consistent with the reported dosing and observed effects in LHON patients, we describe that in mice, idebenone penetrated into the eye at concentrations equivalent to those which protected RGC-5 cells from complex I dysfunction in vitro. Consequently, we next investigated the protective effect of idebenone in a mouse model of LHON, whereby mitochondrial complex I dysfunction was caused by exposure to rotenone. In this model, idebenone protected against the loss of retinal ganglion cells, reduction in retinal thickness and gliosis. Furthermore, consistent with this protection of retinal integrity, idebenone restored the functional loss of vision in this disease model. These results support the pharmacological activity of idebenone and indicate that idebenone holds potential as an effective treatment for vision loss in LHON patients.

  14. Idebenone protects against retinal damage and loss of vision in a mouse model of Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Heitz, Fabrice D; Erb, Michael; Anklin, Corinne; Robay, Dimitri; Pernet, Vincent; Gueven, Nuri

    2012-01-01

    Leber's hereditary optic neuropathy (LHON) is an inherited disease caused by mutations in complex I of the mitochondrial respiratory chain. The disease is characterized by loss of central vision due to retinal ganglion cell (RGC) dysfunction and optic nerve atrophy. Despite progress towards a better understanding of the disease, no therapeutic treatment is currently approved for this devastating disease. Idebenone, a short-chain benzoquinone, has shown promising evidence of efficacy in protecting vision loss and in accelerating recovery of visual acuity in patients with LHON. It was therefore of interest to study suitable LHON models in vitro and in vivo to identify anatomical correlates for this protective activity. At nanomolar concentrations, idebenone protected the rodent RGC cell line RGC-5 against complex I dysfunction in vitro. Consistent with the reported dosing and observed effects in LHON patients, we describe that in mice, idebenone penetrated into the eye at concentrations equivalent to those which protected RGC-5 cells from complex I dysfunction in vitro. Consequently, we next investigated the protective effect of idebenone in a mouse model of LHON, whereby mitochondrial complex I dysfunction was caused by exposure to rotenone. In this model, idebenone protected against the loss of retinal ganglion cells, reduction in retinal thickness and gliosis. Furthermore, consistent with this protection of retinal integrity, idebenone restored the functional loss of vision in this disease model. These results support the pharmacological activity of idebenone and indicate that idebenone holds potential as an effective treatment for vision loss in LHON patients.

  15. Protection of cadmium chloride induced DNA damage by Lamiaceae plants

    Institute of Scientific and Technical Information of China (English)

    Ramaraj Thirugnanasampandan; Rajarajeswaran Jayakumar

    2011-01-01

    Objective: To analyze the total phenolic content, DNA protecting and radical scavenging activity of ethanolic leaf extracts of three Lamiaceae plants, i.e. Anisomelos malabarica (A. malabarica), Leucas aspera (L. aspera) and Ocimum basilicum (O. basilicum). Methods: The total polyphenols and flavonoids were analyzed in the ethanolic leaf extracts of the lamiaceae plants. To determine the DNA protecting activity, various concentrations of the plant extracts were prepared and treated on cultured HepG2 human lung cancer cells. The pretreated cells were exposed to H2O2 to induce DNA damage through oxidative stress. Comet assay was done and the tail length of individual comets was measured. Nitric oxide and superoxide anion scavenging activities of lamiaceae plants were analyzed. Results: Among the three plant extracts, the highest amount of total phenolic content was found in O. basilicum (189.33 mg/g), whereas A. malabarica showed high levels of flavonoids (10.66 mg/g). O. basilicum also showed high levels of DNA protecting (85%) and radical scavenging activity. Conclusions: The results of this study shows that bioactive phenols present in lamiaceae plants may prevent carcinogenesis through scavenging free radicals and inhibiting DNA damage.

  16. Investigation of the Protective Effects of Taurine against Alloxan-Induced Diabetic Retinal Changes via Electroretinogram and Retinal Histology with New Zealand White Rabbits

    Directory of Open Access Journals (Sweden)

    Samuel Tung-Hsing Chiang

    2014-01-01

    Full Text Available The purpose of this study was to investigate the protective role of orally administered taurine against diabetic retinal changes via electroretinogram (ERG and retinal histology on rabbits. Rabbits were randomly assigned into groups: Group I (vehicle administration only; Group II (diabetes: induced by 100 mg/kg alloxan injection; Group III (diabetes and fed with 200 mg/kg taurine; and Group IV (diabetes and fed with 400 mg/kg taurine. The body weight and blood glucose levels of the rabbits were monitored weekly. The ERG was measured on weeks 5 and 15. Retinal histology was analyzed in the end of the experiment. Results revealed that a taurine supplement significantly ameliorates the alloxan-induced hyperglycemia and protects the retina from electrophysiological changes. Group II showed a significant (P0.05 between all groups and when compared with those of Group I. Our study provides solid evidences that taurine possesses an antidiabetic activity, reduced loss of body weight, and less electrophysiological changes of the diabetic retina.

  17. Apelin Protects Primary Rat Retinal Pericytes from Chemical Hypoxia-Induced Apoptosis

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    Li Chen

    2015-01-01

    Full Text Available Pericytes are a population of cells that participate in normal vessel architecture and regulate permeability. Apelin, as the endogenous ligand of G protein-coupled receptor APJ, participates in a number of physiological and pathological processes. To date, the effect of apelin on pericyte is not clear. Our study aimed to investigate the potential protection mechanisms of apelin, with regard to primary rat retinal pericytes under hypoxia. Immunofluorescence staining revealed that pericytes colocalized with APJ in the fibrovascular membranes dissected from proliferative diabetic retinopathy patients. In the in vitro studies, we first demonstrated that the expression of apelin/APJ was upregulated in pericytes under hypoxia, and apelin increased pericytes proliferation and migration. Moreover, knockdown of apelin in pericyte was achieved via lentivirus-mediated RNA interference. After the inhibition of apelin, pericytes proliferation was inhibited significantly in hypoxia culture condition. Furthermore, exogenous recombinant apelin effectively prevented hypoxia-induced apoptosis through downregulating active-caspase 3 expression and increasing the ratio of B cell lymphoma-2 (Bcl-2/Bcl-2 associated X protein (Bax in pericytes. These results suggest that apelin suppressed hypoxia-induced pericytes injury, which indicated that apelin could be a potential therapeutic target for retinal angiogenic diseases.

  18. Imipramine protects retinal ganglion cells from oxidative stress through the tyrosine kinase receptor B signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Ming-lei Han; Guo-hua Liu; Jin Guo; Shu-juan Yu; Jing Huang

    2016-01-01

    Retinal ganglion cell (RGC) degeneration is irreversible in glaucoma and tyrosine kinase receptor B (TrkB)-associated signaling pathways have been implicated in the process. In this study, we attempted to examine whether imipramine, a tricyclic antidepressant, may protect hydrogen peroxide (H2O2)-induced RGC degeneration through the activation of the TrkB pathway in RGC-5 cell lines. RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H2O2. Western blot assay showed that in H2O2-damaged RGC-5 cells, imipramine activated TrkB pathways through extracellular signal-regulated protein kinase/TrkB phosphorylation. TUNEL staining assay also demonstrated that imipramine ameliorated H2O2-induced apoptosis in RGC-5 cells. Finally, TrkB-IgG intervention was able to reverse the protective effect of imipramine on H2O2-induced RGC-5 apoptosis. Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the TrkB signaling pathway.

  19. Losartan Treatment Protects Retinal Ganglion Cells and Alters Scleral Remodeling in Experimental Glaucoma.

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    Harry A Quigley

    Full Text Available To determine if oral losartan treatment decreases the retinal ganglion cell (RGC death caused by experimental intraocular pressure (IOP elevation in mice.We produced IOP increase in CD1 mice and performed unilateral optic nerve crush. Mice received oral losartan, spironolactone, enalapril, or no drug to test effects of inhibiting angiotensin receptors. IOP was monitored by Tonolab, and blood pressure was monitored by tail cuff device. RGC loss was measured in masked axon counts and RGC bodies by β-tubulin labeling. Scleral changes that could modulate RGC injury were measured including axial length, scleral thickness, and retinal layer thicknesses, pressure-strain behavior in inflation testing, and study of angiotensin receptors and pathways by reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry.Losartan treatment prevented significant RGC loss (median loss = 2.5%, p = 0.13, while median loss with water, spironolactone, and enalapril treatments were 26%, 28% and 43%; p < 0.0001. The lower RGC loss with losartan was significantly less than the loss with spironolactone or enalapril (regression model p = 0.001; drug treatment group term p = 0.01. Both losartan and enalapril significantly lowered blood pressure (p< 0.001, but losartan was protective, while enalapril led to worse than water-treated RGC loss. RGC loss after crush injury was unaffected by losartan treatment (difference from control p = 0.9. Survival of RGC in cell culture was not prolonged by sartan treatment. Axonal transport blockade after 3 day IOP elevations was less in losartan-treated than in control glaucoma eyes (p = 0.007. Losartan inhibited effects of glaucoma, including reduction in extracellular signal-related kinase activity and modification of glaucoma-related changes in scleral thickness and creep under controlled IOP.The neuroprotective effect of losartan in mouse glaucoma is associated with adaptive changes in the sclera expressed at

  20. Synergistic protective effects of escin and low‑dose glucocorticoids on blood‑retinal barrier breakdown in a rat model of retinal ischemia.

    Science.gov (United States)

    Zhang, Fenglan; Li, Yuanbin; Zhang, Leiming; Mu, Guoying

    2013-05-01

    Escin, a natural mixture of triterpenoid saponins isolated from the seed of the horse chestnut (Aesculus hippocastanum), has been demonstrated to possess glucocorticoid (GC)‑like anti‑edematous and anti‑inflammatory effects. The aim of the present study was to investigate whether escin exhibits synergistic protective effects on blood‑retinal barrier (BRB) breakdown when combined with GCs in a rat model of retinal ischemia. Low concentrations of escin and triamcinolone acetonide (TA) alone did not affect BRB permeability. However, when administered together, low‑dose escin and TA significantly reduced BRB permeability following ischemia. Furthermore, low‑dose escin and TA alone did not affect the expression of occludin in the ischemic retina; however, when administered together, they significantly increased occludin expression in the ganglion cell layer of the ischemic retina. This indicates that escin and GCs have synergistic protective effects on BRB breakdown and the molecular mechanisms may be correlated with the upregulation of occludin. Therefore, the administration of escin may allow a reduction in the dose of GCs for the treatment of macular edema. The combination of escin with GCs is potentially a beneficial treatment method for BRB breakdown and warrants further investigation. PMID:23525122

  1. Protective effect of alpha-mangostin against oxidative stress induced-retinal cell death

    Science.gov (United States)

    Fang, Yuan; Su, Tu; Qiu, Xiaorong; Mao, Pingan; Xu, Yidan; Hu, Zizhong; Zhang, Yi; Zheng, Xinhua; Xie, Ping; Liu, Qinghuai

    2016-01-01

    It is known that oxidative stress plays a pivotal role in age-related macular degeneration (AMD) pathogenesis. Alpha-mangostin is the main xanthone purified from mangosteen known as anti-oxidative properties. The aim of the study was to test the protective effect of alpha-mangostin against oxidative stress both in retina of light-damaged mice model and in hydrogen peroxide (H2O2)-stressed RPE cells. We observed that alpha-mangostin significantly inhibited light-induced degeneration of photoreceptors and 200 μM H2O2-induced apoptosis of RPE cells. 200 μM H2O2-induced generation of reactive oxygen species (ROS) and light-induced generation of malondialdehyde (MDA) were suppressed by alpha-mangostin. Alpha-mangostin stimulation resulted in an increase of superoxide dismutase (SOD) activity, glutathione peroxidase (GPX) activity and glutathione (GSH) content both in vivo and vitro. Furthermore, the mechanism of retinal protection against oxidative stress by alpha-mangostin involves accumulation and the nuclear translocation of the NF-E2-related factor (Nrf2) along with up-regulation the expression of heme oxygenas-1 (HO-1). Meanwhile, alpha-mangostin can activate the expression of PKC-δ and down-regulate the expression of mitogen-activated protein kinases (MAPKs), including ERK1/2, JNK, P38. The results suggest that alpha-mangostin could be a new approach to suspend the onset and development of AMD. PMID:26888416

  2. Protective effects of the compounds isolated from the seed of Psoralea corylifolia on oxidative stress-induced retinal damage

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung-A [Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Shim, Sang Hee [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Ahn, Hong Ryul [Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Jung, Sang Hoon, E-mail: shjung507@gmail.com [Functional Food Center, Korea Institute of Science and Technology (KIST) Gangneung Institute, Gangneung 210-340 (Korea, Republic of)

    2013-06-01

    The mechanism underlying glaucoma remains controversial, but apoptosis caused by increased levels of reactive oxygen species (ROS) is thought to play a role in its pathogenesis. We investigated the effects of compounds isolated from Psoralea corylifolia on oxidative stress-induced cell death in vitro and in vivo. Transformed retinal ganglion cells (RGC-5) were treated with L-buthione-(S,R)-sulfoximine (BSO) and glutamate in the presence or with pre-treatment with compound 6, bakuchiol isolated from P. corylifolia. We observed reduced cell death in cells pre-treated with bakuchiol. Moreover, bakuchiol inhibited the oxidative stress-induced decrease of mitochondrial membrane potential (MMP, ΔΨm). Furthermore, while intracellular Ca{sup 2+} was high in RGC-5 cells after exposure to oxidative stress, bakuchiol reduced these levels. In an in vivo study, in which rat retinal damage was induced by intravitreal injection of N-methyl-D-aspartate (NMDA), bakuchiol markedly reduced translocation of AIF and release of cytochrome c, and inhibited up-regulation of cleaved caspase-3, cleaved caspase-9, and cleaved PARP. The survival rate of retinal ganglion cells (RGCs) 7 days after optic nerve crush (ONC) in mice was significantly decreased; however, bakuchiol attenuated the loss of RGCs. Moreover, bakuchiol attenuated ONC-induced up-regulation of apoptotic proteins, including cleaved PARP, cleaved caspase-3, and cleaved caspase-9. Bakuchiol also significantly inhibited translocation of mitochondrial AIF into the nuclear fraction and release of mitochondrial cytochrome c into the cytosol. These results demonstrate that bakuchiol isolated from P. corylifolia has protective effects against oxidative stress-induced retinal damage, and may be considered as an agent for treating or preventing retinal degeneration. - Highlights: • Psoralea corylifolia have neuroprotective effects in vitro and in vivo. • Bakuchiol attenuated the increase of apoptotic proteins induced by oxidative

  3. Protection of retinal pigment epithelium by OT-551 and its metabolite TEMPOL-H against light-induced damage in rats

    OpenAIRE

    Tanito, Masaki; Li, Feng; Anderson, Robert E.

    2010-01-01

    OT-551 (1-hydroxy-4-cyclopropanecarbonyloxy-2,2,6,6-tetramethylpiperidine hydrochloride), is a novel small molecule with antioxidant and anti-inflammatory effects. Protective efficacy of OT-551 and its metabolite TEMPOL-H (TP-H) against light-induced degeneration of retinal pigment epithelium (RPE) was tested. Albino rats were intraperitoneally injected with OT-551, TP-H, or water approximately 30 min prior to a 6 h exposure to 2700 lux white fluorescent light. Retinal protection was evaluate...

  4. Protective effects of Achyranthes bidentata polypeptides on retinal ganglion cells post-optic nerve crush in rats

    Institute of Scientific and Technical Information of China (English)

    Nan Hu; Qi Zhao; Fangling Zhang; Junfang Zhang; Xiaosong Gu

    2011-01-01

    Achyranthes bidentata polypeptides (ABPP) have been reported to inhibit apoptosis of retinal ganglion cells (RGCs).The present study investigated the protective effects of ABPP on RGCs in a rat model of optic nerve injury.With prolonged injury time,RGC densities were gradually decreased.ABPP (5 μg) significantly increased RGC densities and upregulated growth associated protein 43 expression in rats with optic nerve injury.Results demonstrate that ABPP can protect RGCs and promote axonal growth after optic nerve crush.

  5. Protective role of grape seed extract against the effect of electromagnetic radiation on retinal rhodopsin

    International Nuclear Information System (INIS)

    In recent time, people exposure to blue light has increased. Much of the world of commercial display and industry is lit with cool white fluorescent tubes which emit a strong spike of light in the blue and ultraviolet ranges. Indeed many homes and offices are lit with cool white fluorescent tubes. No doubts, more people are spending more time in front of Video Display Terminals which produce blue light. This study aimed to investigate the effect of blue light and the combined effect of blue light and gamma radiation on retinal rhodopsin. Also, the possible protective role of grape seed extract (GSE) to retinal rhodopsin was tested. New zealand albino rabbits were used in this study. The rabbits were classified into five groups I, II, III, IV and V according to the following: Group I: used as control group. Group II: subdivided into four subgroups subgroups were exposed to blue light of intensity 3.9 lux and decapitated after 48 hours, one week, two weeks and 3 weeks respectively. Group III: subdivided into four subgroups. All rabbits were supplemented with 10 mg/Kg body weight Grape seed extract (GSE) two weeks before exposure to 3.9 lux blue light. GSE supplementation was continued till decapitation. Rabbits were decapitated after 48 hours, one week, two weeks and 3 weeks of exposure to blue light respectively. Group IV: subdivided into two subgroups. The two subgroups were exposed to blue light of 3.9 lux for one week and two weeks, then irradiated with 5 Gy gamma rays and decapitated. Group V: subdivided into two subgroups. The rabbits were supplemented with 10 mg/Kg body weight Grape seed extract (GSE) two weeks before exposure to 3.9 lux blue light for one week and two weeks respectively. After these periods, the rabbits were irradiated with 5 Gy gamma rays then decapitated. GSE supplementation was continued till decapitation. At the end of each period, the electroretinogram (ERG) was recorded. After the decapitation, the rhodopsin was extracted and the

  6. Protection of copper surface with phytic acid against corrosion in chloride solution.

    Science.gov (United States)

    Peca, Dunja; Pihlar, Boris; Ingrid, Milošev

    2014-01-01

    Phytic acid (inositol hexaphosphate) was tested as a corrosion inhibitor for copper in 3% sodium chloride. Phytic acid is a natural compound derived from plants, it is not toxic and can be considered as a green inhibitor. Electrochemical methods of linear polarization and potentiodynamic polarization were used to study the electrochemical behaviour and evaluate the inhibition effectiveness. To obtain the optimal corrosion protection the following experimental conditions were investigated: effect of surface pre-treatment (abrasion and three procedures of surface roughening), pre-formation of the layer of phytic acid, time of immersion and concentration of phytic acid. To evaluate the surface pre-treatment procedures the surface roughness and contact angle were measured. Optimal conditions for formation of phytic layer were selected resulting in the inhibition effectiveness of nearly 80%. Morphology and composition of the layer were further studied by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The layer of phytic acid with thickness in the nanometer range homogeneously covers the copper surface. The obtained results show that this natural compound can be used as a mildly effective corrosion inhibitor for copper in chloride solution. PMID:25286201

  7. PROTECTIVE EFFECTS OF CALCIUM ANTAGONIST ON VASCULAR SYSTEM AGAINST TOXICITY INDUCED BY MERCURIC CHLORIDE

    Institute of Scientific and Technical Information of China (English)

    马欣; 厉英倩; 白宇飞; 刘明

    2004-01-01

    Objective To explore the toxic effects of mercuric chloride (HgCl2) on vascular smooth muscle as well as its relationship to calcium antagonist. Methods By using isolated vascular tension methods, we studied the effect of HgCl2 on isolated rabbit aortic rings. Results HgCl2 (1-100μmol*L-1) caused a concentration-dependent contraction of rabbit aortic rings, which did not change with phentolamin or without endothelium. In KH solution with Ca2+ , the maximum contraction amplitude reduced by(61.2±3.3)%. Nifedipine produced a concentration-dependent decrease of the maximum contraction amplitude. Conclusion Calcium antagonist has protective effects on vascular smooth muscle against damage induced by HgCl2.

  8. Vaccination for protection of retinal ganglion cells against death from glutamate cytotoxicity and ocular hypertension: Implications for glaucoma

    Science.gov (United States)

    Schori, Hadas; Kipnis, Jonathan; Yoles, Eti; Woldemussie, Elizabeth; Ruiz, Guadalupe; Wheeler, Larry A.; Schwartz, Michal

    2001-03-01

    Our group recently demonstrated that autoimmune T cells directed against central nervous system-associated myelin antigens protect neurons from secondary degeneration. We further showed that the synthetic peptide copolymer 1 (Cop-1), known to suppress experimental autoimmune encephalomyelitis, can be safely substituted for the natural myelin antigen in both passive and active immunization for neuroprotection of the injured optic nerve. Here we attempted to determine whether similar immunizations are protective from retinal ganglion cell loss resulting from a direct biochemical insult caused, for example, by glutamate (a major mediator of degeneration in acute and chronic optic nerve insults) and in a rat model of ocular hypertension. Passive immunization with T cells reactive to myelin basic protein or active immunization with myelin oligodendrocyte glycoprotein-derived peptide, although neuroprotective after optic nerve injury, was ineffective against glutamate toxicity in mice and rats. In contrast, the number of surviving retinal ganglion cells per square millimeter in glutamate-injected retinas was significantly larger in mice immunized 10 days previously with Cop-1 emulsified in complete Freund's adjuvant than in mice injected with PBS in the same adjuvant (2,133 ± 270 and 1,329 ± 121, respectively, mean ± SEM; P myelin. The use of Cop-1 apparently circumvents this antigen specificity barrier. In the rat ocular hypertension model, which simulates glaucoma, immunization with Cop-1 significantly reduced the retinal ganglion cell loss from 27.8%±6.8% to 4.3%±1.6%, without affecting the intraocular pressure. This study may point the way to a therapy for glaucoma, a neurodegenerative disease of the optic nerve often associated with increased intraocular pressure, as well as for acute and chronic degenerative disorders in which glutamate is a prominent participant.

  9. Lactobacillus plantarum L67 glycoprotein protects against cadmium chloride toxicity in RAW 264.7 cells.

    Science.gov (United States)

    Song, Sooyeon; Oh, Sejong; Lim, Kye-Taek

    2016-03-01

    The food and water we consume may be contaminated with a range of chemicals and heavy metals, such as lead, cadmium, arsenic, chromium, and mercury by accumulation through the food chain. Cadmium is known to be one of the major components in cigarette smoke and can cause lesions in many organs. Some lactobacilli can bind and remove heavy metals such as cadmium, lead, and copper. However, the mechanisms of cadmium toxicity and inhibition by probiotics are not clear. In this study, we demonstrated that glycoprotein (18 kDa) isolated from Lactobacillus plantarum L67 protected RAW 264.7 cells from expression of inflammation-related factors stimulated by cadmium chloride (100 µM). Furthermore, we evaluated the cytotoxicity of cadmium using the MTT assay and intracellular Ca(2+) using fluorescence, and assessed activities of activator protein kinase C (PKC-α), inducible nitric oxide synthase, activator protein (AP)-1, and mitogen-activated protein kinases using immunoblot. Our results indicated that glycoprotein isolated from L. plantarum L67 inhibited intracellular Ca(2+) mobilization. It also significantly suppressed inflammatory factors such as AP-1 (c-Jun and c-Fos), mitogen-activated protein kinases (ERK, JNK, and p38), and inducible nitric oxide synthase. Our findings suggest that the 24-kDa glycoprotein isolated from L. plantarum L67 might be used as a food component for protection of inflammation caused by cadmium ion.

  10. Melanin precursor 5,6-dihydroxyindol: protective effects and cytotoxicity on retinal cells in vitro and in vivo.

    Science.gov (United States)

    Heiduschka, Peter; Blitgen-Heinecke, Petra; Tura, Aysegül; Kokkinou, Despina; Julien, Sylvie; Hofmeister, Sabine; Bartz-Schmidt, Karl Ulrich; Schraermeyer, Ulrich

    2007-12-01

    5,6-dihydroxyindole (DHI) is a melanin pigment precursor with antioxidant properties. In the light of a report about cytotoxicity of DHI, the aim of this study was to assess possible toxic effects of DHI on cells related to the eye, such as human ARPE-19 cells and mouse retinal explants. Moreover, DHI was tested on its effects on retinal function in vivo using electroretinography. We found cytotoxicity of DHI against ARPE-19 cells at 100 microM, but not at 10 microM. 10 microM DHI exhibited a slight, though not significant protective activity against UV-A damage in ARPE-19 cells. We found cytoprotection in cultured mouse retinas by 50 microM DHI or its diacetylated derivative 5,6-diacetoxyindole (DAI), respectively. In ERG measurements in vivo, amplitudes were decreased only slightly by 100 microM DHI compared to saline, whereas a better preservation of amplitudes was visible at 10 microM DHI, in particular with respect to cones. In histological sections, more cones were found at 10 microM DHI than at 100 microM DHI. As a conclusion, DHI shows a slight protective effect at 10 microM both in vitro and in vivo. At 100 microM, it shows a strong cytotoxicity in vitro, which is strongly reduced in vivo.

  11. Erythropoietin protects adult retinal ganglion cells against NMDA-, trophic factor withdrawal-, and TNF-α-induced damage.

    Directory of Open Access Journals (Sweden)

    Zhi-Yang Chang

    Full Text Available PURPOSE: This study aimed to evaluate the neuroprotective effect of EPO in the presence of N-methyl-d-aspartate (NMDA-, trophic factor withdrawal (TFW-, and tumor necrosis factor-alpha (TNF-α-induced toxicity on total, small, and large retinal ganglion cells (RGCs. METHODS: Retinal cells from adult rats were cultured in a medium containing brain-derived neurotrophic factor (BDNF, ciliary neurotrophic factor (CNTF, basic fibroblast growth factor (bFGF, and forskolin. Expression of RGC markers and EPOR was examined using immunocytochemistry. RGCs were classified according to their morphological properties. Cytotoxicity was induced by NMDA, TFW, or TNF-α. RGC survival was assessed by counting thy-1 and neurofilament-l double-positive cells. RESULTS: EPO offered dose-dependent (EC₅₀ = 5.7 ng/mL protection against NMDA toxicity for small RGCs; protection was not significant for large RGCs. Time-course analysis showed that the presence of EPO either before or after NMDA exposure gave effective protection. For both small and large RGCs undergoing trophic factor withdrawal, EPO at concentrations of 1, 10, or 100 ng/mL improved survival. However, EPO had to be administered soon after the onset of injury to provide effective protection. For TNF-α-induced toxicity, survival of small RGCs was seen only for the highest examined concentration (100 ng/mL of EPO, whereas large RGCs were protected at concentrations of 1, 10, or 100 ng/mL of EPO. Time-course analysis showed that pretreatment with EPO provided protection only for large RGCs; early post-treatment with EPO protected both small and large RGCs. Inhibitors of signal transduction and activators of transcription such as (STAT-5, mitogen-activated protein kinases (MAPK/extracellular-regulated kinase (ERK, and phosphatidyl inositol-3 kinase (PI3K/Akt impaired the protective effect of EPO on RGCs exposed to different insults. CONCLUSION: EPO provided neuroprotection to cultured adult rat RGCs

  12. Protection by an oral disubstituted hydroxylamine derivative against loss of retinal ganglion cell differentiation following optic nerve crush.

    Directory of Open Access Journals (Sweden)

    James D Lindsey

    Full Text Available Thy-1 is a cell surface protein that is expressed during the differentiation of retinal ganglion cells (RGCs. Optic nerve injury induces progressive loss in the number of RGCs expressing Thy-1. The rate of this loss is fastest during the first week after optic nerve injury and slower in subsequent weeks. This study was undertaken to determine whether oral treatment with a water-soluble N-hydroxy-2,2,6,6-tetramethylpiperidine derivative (OT-440 protects against loss of Thy-1 promoter activation following optic nerve crush and whether this effect targets the earlier quick phase or the later slow phase. The retina of mice expressing cyan fluorescent protein under control of the Thy-1 promoter (Thy1-CFP mice was imaged using a blue-light confocal scanning laser ophthalmoscope (bCSLO. These mice then received oral OT-440 prepared in cream cheese or dissolved in water, or plain vehicle, for two weeks and were imaged again prior to unilateral optic nerve crush. Treatments and weekly imaging continued for four more weeks. Fluorescent neurons were counted in the same defined retinal areas imaged at each time point in a masked fashion. When the counts at each time point were directly compared, the numbers of fluorescent cells at each time point were greater in the animals that received OT-440 in cream cheese by 8%, 27%, 52% and 60% than in corresponding control animals at 1, 2, 3 and 4 weeks after optic nerve crush. Similar results were obtained when the vehicle was water. Rate analysis indicated the protective effect of OT-440 was greatest during the first two weeks and was maintained in the second two weeks after crush for both the cream cheese vehicle study and water vehicle study. Because most of the fluorescent cells detected by bCSLO are RGCs, these findings suggest that oral OT-440 can either protect against or delay early degenerative responses occurring in RGCs following optic nerve injury.

  13. Protective effect of lithium chloride against hypoglycemia-induced apoptosis in neuronal PC12 cell.

    Science.gov (United States)

    Xu, Yuzhen; Wang, Qian; Li, Dongsheng; Wu, Zhenghua; Li, Dawei; Lu, Kaili; Zhao, Yuwu; Sun, Yongning

    2016-08-25

    Hypoglycemia is defined by an arbitrary plasma glucose level lower than 3.9mmol/L and is a most common and feared adverse effect of treatment of diabetes mellitus. Emerging evidences demonstrated that hypoglycemia could induce enhanced apoptosis. Lithium chloride (LiCl), a FDA approved drug clinically used for treatment of bipolar disorders, is recently proven having neuroprotection against various stresses in the cellular and animal models of neural disorders. Here, we have established a hypoglycemia model in vitro and assessed the neuroprotective efficacy of LiCl against hypoglycemia-induced apoptosis and the underlying cellular and molecular mechanisms. Our studies showed that LiCl protects against hypoglycemia-induced neurotoxicity in vitro. Exposure to hypoglycemia results in enhanced apoptosis and the underlying cellular and molecular mechanisms involved inhibition of the canonical Wnt signaling pathway by decreasing wnt3a levels, β-catenin levels and increasing GSK-3β levels, which was confirmed by the use of Wnt-specific activator LiCl. Hypoglycemia-induced apoptosis were significantly reversed by LiCl, leading to increased cell survival. LiCl also alters the expression/levels of the Wnt pathway genes/proteins, which were reduced due to exposed to hypoglycemia. Overall, our results conclude that LiCl provides neuroprotection against hypoglycemia-induced apoptosis via activation of the canonical Wnt signaling pathway. PMID:27241942

  14. Protection of blood retinal barrier and systemic vasculature by insulin-like growth factor binding protein-3.

    Directory of Open Access Journals (Sweden)

    Yagna P R Jarajapu

    Full Text Available Previously, we showed that insulin growth factor (IGF-1 binding protein-3 (IGFBP-3, independent of IGF-1, reduces pathological angiogenesis in a mouse model of the oxygen-induced retinopathy (OIR. The current study evaluates novel endothelium-dependent functions of IGFBP-3 including blood retinal barrier (BRB integrity and vasorelaxation. To evaluate vascular barrier function, either plasmid expressing IGFBP-3 under the regulation of an endothelial-specific promoter or a control plasmid was injected into the vitreous humor of mouse pups (P1 and compared to the non-injected eyes of the same pups undergoing standard OIR protocol. Prior to sacrifice, the mice were given an injection of horseradish peroxidase (HRP. IGFBP-3 plasmid-injected eyes displayed near-normal vessel morphology and enhanced vascular barrier function. Further, in vitro IGFBP-3 protects retinal endothelial cells from VEGF-induced loss of junctional integrity by antagonizing the dissociation of the junctional complexes. To assess the vasodilatory effects of IGFBP-3, rat posterior cerebral arteries were examined in vitro. Intraluminal IGFBP-3 decreased both pressure- and serotonin-induced constrictions by stimulating nitric oxide (NO release that were blocked by L-NAME or scavenger receptor-B1 neutralizing antibody (SRB1-Ab. Both wild-type and IGF-1-nonbinding mutant IGFBP-3 (IGFBP-3NB stimulated eNOS activity/NO release to a similar extent in human microvascular endothelial cells (HMVECs. NO release was neither associated with an increase in intracellular calcium nor decreased by Ca(2+/calmodulin-dependent protein kinase II (CamKII blockade; however, dephosphorylation of eNOS-Thr(495 was observed. Phosphatidylinositol 3-kinase (PI3K activity and Akt-Ser(473 phosphorylation were both increased by IGFBP-3 and selectively blocked by the SRB1-Ab or PI3K blocker LY294002. In conclusion, IGFBP-3 mediates protective effects on BRB integrity and mediates robust NO release to stimulate

  15. Protective effects of Purendan superfine powder on retinal neuron apoptosis in a rat model of type 2 diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Zhijun Dong; Xiangyi Tao; Xiaoxiao Fu; Haibin Wang; Donghua Wang; Tiemin Zhang

    2012-01-01

    This study sought to investigate the effects of Purendan superfine powder comprised of Momordica charantia, Radix Ginseng, and Radix Salviae Miltiorrhiae on neuronal apoptosis and expression of bcl-2, bax, and caspase-3, which are retinal apoptosis-associated factors in rats with diabetes mellitus induced by continuous intraperitoneal injection of streptozotocin. The results showed that Purendan superfine powder could upregulate the expression of bcl-2 protein and mRNA, and downregulate the expression of bax and caspase-3 in the retina of diabetes mellitus rats. In addition, Purendan superfine powder was shown to reduce the number of apoptotic neurons. Our experimental findings indicate that Purendan superfine powder can inhibit neuronal apoptosis in the retina of diabetes mellitus rats and has protective effects on diabetic retinopathy.

  16. Protective effects of triptolide on retinal ganglion cells in a rat model of chronic glaucoma

    Directory of Open Access Journals (Sweden)

    Yang F

    2015-11-01

    Full Text Available Fan Yang, Dongmei Wang, Lingling Wu, Ying Li Ophthalmology Department, Peking University Third Hospital, Beijing, People’s Republic of China Purpose: To study the effects of triptolide, a Chinese herb extract, on retinal ganglion cells (RGCs in a rat model of chronic glaucoma.Methods: Eighty Wistar rats were randomly divided into triptolide group (n=40 and normal saline (NS group (n=40. Angle photocoagulation was used to establish the model of glaucoma, with right eye as laser treated eye and left eye as control eye. Triptolide group received triptolide intraperitoneally daily, while NS group received NS. Intraocular pressure (IOP, anti-CD11b immunofluorescent stain in retina and optic nerve, RGCs count with Nissel stain and microglia count with anti-CD11b immunofluorescence stain in retina flat mounts, retinal tumor necrosis factor (TNF-α mRNA detection by reverse transcription–polymerase chain reaction, and double immunofluorescent labeling with anti-TNF-α and anti-CD11b in retinal frozen section were performed.Results: Mean IOP of the laser treated eyes significantly increased 3 weeks after photocoagulation (P<0.05, with no statistical difference between the two groups (P>0.05. RGCs survival in the laser treated eyes was significantly improved in the triptolide group than the NS group (P<0.05. Microglia count in superficial retina of the laser treated eyes was significantly less in the triptolide group (30.40±4.90 than the NS group (35.06±7.59 (P<0.05. TNF-α mRNA expression in the retina of the laser treated eyes in the triptolide group decreased by 60% compared with that in the NS group (P<0.01. The double immunofluorescent labeling showed that TNF-α was mainly distributed around the microglia.Conclusion: Triptolide improved RGCs survival in this rat model of chronic glaucoma, which did not depend on IOP decrease but might be exerted by inhibiting microglia activities and reducing TNF-α secretion. Keywords: glaucoma, triptolide

  17. The Protective Effects of Gadolinum Chloride on Pneumotoxic Effects of Styrene in Rat

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Arab

    2015-07-01

    Full Text Available Objective: The aim of the present study was to evaluate the protective effects of gadolinum on pneumotoxic effects of styrene in rats as an experimental model. Materials and Methods: In this experimental study a total number of 40 adult male Sprague Dawley rats that weighed 200 ± 13 g were randomly divided into five groups: i. styrene (St, N=10, ii. styrene+gadolinium chloride (GdCl3, N=10, iii. control (N=10, iv. GdCl3 (N=5 and v. normal saline (Nor.Sal, as a solvent of GdCl3, N=5. Normal saline, as a sham control group, was otherwise treated identically. Rats from the experimental groups were exposed to St in an exposure chamber for 6 days/week, 4 hours/day for up to 3 weeks. At the end of the experiment, rats from all groups were killed by deep anesthesia. Their lungs were removed, then fixed in formalin and weighed. Tissue samples were processed routinely and sections stained by the hematoxylin and eosin (H&E and periodic acid Schiff (PAS methods. We measured the thicknesses of the respiratory epithelia and interalveolar septa. Obtained data were analyzed by ANOVA, the Tukey test and the paired t test. Results: Shedding of apical cytoplasm in the bronchiole was a prominent feature of the St group. PAS staining revealed histochemical changes in goblet cells in the epithelium of the St group. While there were no significant changes in lung weights and respiratory epithelial thicknesses between all studied groups, statistical analysis showed a significant alteration in the thickness of interalveolar septa in the St and St+GdCl3 group compared to the control groups (P<0.001. Conclusion: Styrene induced structural and histochemical changes in bronchiole, interalveolar septa and alveolar organization in the rats’ lungs. Gadolinium appeared to partially reduce the toxic effects of styrene on the lungs.

  18. Prolactin protects retinal pigment epithelium by inhibiting sirtuin 2-dependent cell death

    Directory of Open Access Journals (Sweden)

    Rodrigo Meléndez García

    2016-05-01

    Full Text Available The identification of pathways necessary for retinal pigment epithelium (RPE function is fundamental to uncover therapies for blindness. Prolactin (PRL receptors are expressed in the retina, but nothing is known about the role of PRL in RPE. Using the adult RPE 19 (ARPE-19 human cell line and mouse RPE, we identified the presence of PRL receptors and demonstrated that PRL is necessary for RPE cell survival via anti-apoptotic and antioxidant actions. PRL promotes the antioxidant capacity of ARPE-19 cells by reducing glutathione. It also blocks the hydrogen peroxide-induced increase in deacetylase sirtuin 2 (SIRT2 expression, which inhibits the TRPM2-mediated intracellular Ca2+ rise associated with reduced survival under oxidant conditions. RPE from PRL receptor-null (prlr−/− mice showed increased levels of oxidative stress, Sirt2 expression and apoptosis, effects that were exacerbated in animals with advancing age. These observations identify PRL as a regulator of RPE homeostasis.

  19. Inflammatory cytokines protect retinal pigment epithelial cells from oxidative stress-induced death

    DEFF Research Database (Denmark)

    Juel, Helene B; Faber, Carsten; Svendsen, Signe Goul;

    2013-01-01

    -cultured with activated T cells, or treated with cytokines showed increased expression of anti-oxidative genes, with upregulation of superoxide dismutase 2 protein following PCM treatment. CONCLUSION: Oxidative stress-induced cell death was reduced by concomitant inflammatory stress. This is likely due to the cytokine......PURPOSE: To investigate the effects of inflammatory factors and oxidative stress on cell survival of the human retinal pigment epithelial (RPE) cell line, ARPE-19. METHODS: Confluent RPE cells were treated with peripheral blood mononuclear cells-conditioned medium (PCM), H2O2, NaIO3, interferon...... expression of anti-oxidative enzymes, and protein expression was validated by immunoblotting. RESULTS: Viability of RPE cells was reduced by exposure to inflammatory agents (PCM, IFNγ+/-TNFα) or to oxidative agents (H2O2 or NaIO3). Unexpectedly, cells treated with either H2O2 or NaIO3 were partially...

  20. Prolactin protects retinal pigment epithelium by inhibiting sirtuin 2-dependent cell death.

    Science.gov (United States)

    Meléndez García, Rodrigo; Arredondo Zamarripa, David; Arnold, Edith; Ruiz-Herrera, Xarubet; Noguez Imm, Ramsés; Baeza Cruz, German; Adán, Norma; Binart, Nadine; Riesgo-Escovar, Juan; Goffin, Vincent; Ordaz, Benito; Peña-Ortega, Fernando; Martínez-Torres, Ataúlfo; Clapp, Carmen; Thebault, Stéphanie

    2016-05-01

    The identification of pathways necessary for retinal pigment epithelium (RPE) function is fundamental to uncover therapies for blindness. Prolactin (PRL) receptors are expressed in the retina, but nothing is known about the role of PRL in RPE. Using the adult RPE 19 (ARPE-19) human cell line and mouse RPE, we identified the presence of PRL receptors and demonstrated that PRL is necessary for RPE cell survival via anti-apoptotic and antioxidant actions. PRL promotes the antioxidant capacity of ARPE-19 cells by reducing glutathione. It also blocks the hydrogen peroxide-induced increase in deacetylase sirtuin 2 (SIRT2) expression, which inhibits the TRPM2-mediated intracellular Ca(2+) rise associated with reduced survival under oxidant conditions. RPE from PRL receptor-null (prlr(-/-)) mice showed increased levels of oxidative stress, Sirt2 expression and apoptosis, effects that were exacerbated in animals with advancing age. These observations identify PRL as a regulator of RPE homeostasis.

  1. Bone marrow mesenchymal stem cells protect against retinal ganglion cell loss in aged rats with glaucoma

    Directory of Open Access Journals (Sweden)

    Hu Y

    2013-10-01

    Full Text Available Ying Hu,1,2 Hai Bo Tan,1 Xin Mei Wang,3 Hua Rong,1 Hong Ping Cui,1 Hao Cui2 Departments of Ophthalmology, 1Shanghai East Hospital of Tongji University, Shanghai, 2First Affiliated Hospital, 3Fourth Affiliated Hospital, Harbin Medical University, Harbin, People's Republic of China Abstract: Glaucoma is a common eye disease in the aged population and has severe consequences. The present study examined the therapeutic effects of bone marrow mesenchymal stem cell (BMSC transplantation in preventing loss of visual function in aged rats with glaucoma caused by laser-induced ocular hypertension. We found that BMSCs promoted survival of retinal ganglion cells in the transplanted eye as compared with the control eye. Further, in swimming tests guided by visual cues, the rats with a BMSC transplant performed significantly better. We believe that BMSC transplantation therapy is effective in treating aged rats with glaucoma. Keywords: glaucoma, stem cell, transplantation, cell therapy, aging

  2. Ablation of C/EBP homologous protein does not protect T17M RHO mice from retinal degeneration.

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    Sonali Nashine

    Full Text Available Despite the proposed link between ablation of the CHOP protein and delay of the onset of ER stress-mediated disorders including diabetes, Alzheimer Disease, and cardiac hypertrophy, the role of CHOP protein in photoreceptor cell death associated with Autosomal Dominant Retinitis Pigmentosa (ADRP has not been investigated. T17M RHO transgenic mice carry a mutated human rhodopsin transgene, the expression of which in retina leads to protein misfolding, activation of UPR and progressive retinal degeneration. The purpose of this study is to investigate the role of CHOP protein in T17M RHO retina. Wild-type, CHOP-/-, T17M RHO and T17M RHO CHOP-/-mice were used in the study. Evaluation of the impact of CHOP ablation was performed using electroretinography (ERG, spectral-domain optical coherence tomography (SD-OCT, quantitative Real-Time PCR (qRT-PCR and western blot analysis. Dark-adapted ERG analysis demonstrated that by 1 month, the T17M RHO CHOP-/- mice had a 70% reduction of the a-wave amplitude compared to the T17M RHO mice. The loss of function in T17M RHO CHOP-/- photoreceptors was associated with a 22-24% decline in the thickness of the outer nuclear layer. These mice had significant reduction in the expression of transcription factors, Crx and Nrl, and also in mouse Rho, and human RHO. The reduction was associated with an 8-fold elevation of the UPR marker, p-eIf2α protein and 30% down-regulation of sXbp1 protein. In addition, the histone deacetylase 1 (Hdac1 protein was 2-fold elevated in the T17M RHO CHOP-/- retina. The ablation of CHOP led to a reduction in the expression of photoreceptor-specific transcriptional factors, and both endogenous and exogenous RHO mRNA. Thus, despite its role in promoting apoptosis, CHOP protects rod photoreceptors carrying an ADRP mutation.

  3. Increased production of omega-3 fatty acids protects retinal ganglion cells after optic nerve injury in mice.

    Science.gov (United States)

    Peng, Shanshan; Shi, Zhe; Su, Huanxing; So, Kwok-Fai; Cui, Qi

    2016-07-01

    Injury to the central nervous system causes progressive degeneration of injured axons, leading to loss of the neuronal bodies. Neuronal survival after injury is a prerequisite for successful regeneration of injured axons. In this study, we investigated the effects of increased production of omega-3 fatty acids and elevation of cAMP on retinal ganglion cell (RGC) survival and axonal regeneration after optic nerve (ON) crush injury in adult mice. We found that increased production of omega-3 fatty acids in mice enhanced RGC survival, but not axonal regeneration, over a period of 3 weeks after ON injury. cAMP elevation promoted RGC survival in wild type mice, but no significant difference in cell survival was seen in mice over-producing omega-3 fatty acids and receiving intravitreal injections of CPT-cAMP, suggesting that cAMP elevation protects RGCs after injury but does not potentiate the actions of the omega-3 fatty acids. The observed omega-3 fatty acid-mediated neuroprotection is likely achieved partially through ERK1/2 signaling as inhibition of this pathway by PD98059 hindered, but did not completely block, RGC protection. Our study thus enhances our current understanding of neural repair after CNS injury, including the visual system.

  4. Delayed administration of glial cell line-derived neurotrophic factor (GDNF) protects retinal ganglion cells in a pig model of acute retinal ischemia

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Klassen, Henry; Johansson, Ulrica Englund;

    2009-01-01

    This study investigates whether intravitreal administration of glial cell line-derived neurotrophic factor (GDNF) enhances survival of NeuN positive retinal cells in a porcine model of retinal ischemia. 16 pigs were subjected to an ischemic insult where intraocular pressure was maintained at 5 mm......Hg below mean arterial blood pressure for 2 h. The mean IOP during the ischemic insult was 79.5 mmHg (s.e.m. 2.1 mmHg, n = 15). Three days after the insult the pigs received an intravitreal injection of GDNF microspheres or blank microspheres. The pigs were evaluated by way of multifocal.......04-0.16) in eyes treated with blank microspheres, and 0.24 (95% CI: 0.18-0.32) and 0.23 (95% CI: 0.15-0.33) in eyes treated with GDNF microspheres. These differences were statistically significant (P

  5. The evaluation of organic inhibitors for the protection of grade 5 titanium in chloride media

    International Nuclear Information System (INIS)

    The corrosion failures of titanium and titanium alloys are inevitably associated with the non-observance of environmental limits prescribed in corrosion handbooks, such as its use in solutions chloride. Titanium alloys are often used in the thermal transfer technology especially in the heat exchangers cooled with sea cooled water. However, it is not indicated its use in strong oxidant and any concentrated chloride environments. For the evaluation of grade 5 titanium alloy samples behaviour in solutions containing chloride ions in presence, respectively, absence of some organic inhibitors were performed by potentiodynamic polarization method. On the basis of our experimental results we consider that the most adequate inhibitor for the system Ti-5 alloys/0.083M NaCl solution is the resorcinol. (authors)

  6. Protection of neurons in the retinal ganglion cell layer against excitotoxicity by the N-acylethanolamine, N-linoleoylethanolamine

    Directory of Open Access Journals (Sweden)

    Duncan RS

    2011-04-01

    Full Text Available R. Scott Duncan1,*, Hua Xin1,*, Daryl L Goad1, Kent D Chapman2,3, Peter Koulen1,31Vision Research Center and Departments of Ophthalmology and Basic Medical Science, School of Medicine, University of Missouri, Kansas City, MO, USA; 2Department of Biological Sciences, University of North Texas, Denton, TX, USA; 3Center for Plant Lipid Research, University of North Texas, Denton, TX, USA *Authors contributed equallyAbstract: Retinal ganglion cell (RGC death is a hallmark of neurodegenerative diseases and disease processes of the eye, including glaucoma. The protection of RGCs has been an important strategy for combating glaucoma, but little clinical success has been reported to date. One pathophysiological consequence of glaucoma is excessive extracellular glutamate subsequently leading to excitotoxicity in the retina. Endocannabinoids, such as the N-acylethanolamine (NAE, arachidonylethanolamine (NAE 20:4, exhibit neuroprotective properties in some models of neurodegenerative disease. The majority of NAEs, however, are not cannabinoids, and their physiological function is not clear. Here, we determined whether the noncannabinoid NAE, linoleoylethanolamine (NAE18:2, protects neurons in the RGC layer against glutamate excitotoxicity in ex-vivo retina cultures. Using a terminal deoxynucleotidyl transferase-mediated dUTP (2´-deoxyuridine 5´-triphosphate nick-end labeling (TUNEL assay, we determined that NAE18:2 reduces the number of apoptotic RGC layer neurons in response to glutamate and conclude that NAE18:2 is a neuroprotective compound with potential for treating glaucomatous retinopathy.Keywords: neuroprotection, glutamate, calcium signaling, immunocytochemistry, eye, vision, glaucoma.

  7. Heat Shock Protein 72 Protects Retinal Ganglion Cells in Rat Model of Acute Glaucoma

    Institute of Scientific and Technical Information of China (English)

    Guoping Qing; Xuanchu Duan; Youqin Jiang

    2005-01-01

    Purpose: To investigate whether the induction of heat shock protein (HSP)72 by heat stress (HS) or zinc (Zn2+ ) administration can increase survival of retinal ganglion cells (RGC) in rat model of acute experimental glaucoma.Methods: Acute glaucoma model was made by intracameral irrigation with BSS at 102 mmHg for two hours in right eyes of male Wistar rats. Glaucoma model rats were treated with HS once a week (six rats) or intraperitoneal injection of zinc sulfate (24.6 mg/kg) every two weeks (six rats), and were referred to as HS group and zinc group, respectively. Untreated model rats served as damage group (six rats). In control groups, quercetin (400 mg/kg) was intraperitoneally injected to inhibit the induction of heat shock proteins 6 hours before HS or zinc administration, and were referred to as HS+que group (six rats) and zinc+que group (six rats), respectively. Subsequent to 16 days of IOP elevation, the rats were sacrificed. Eyes were quickly enucleated, and the retinas were dissected. RGC were labeled with Nissl staining and counted under microscope.Results: The average RGC density in normal Wistar rats was (2504±181) cells/mm2. In damage group, it decreased to (2015±111 ) cells/mm2. The RGC densities at 1,2, and 3 mm from the center of the optic nerve head were (2716±215), (2496±168), and (2317±171) cells/mm2, respectively, for normal rats and (2211±133), (1969±154),and (1872±68) cells/mm2, respectively, for damage group. The latter was significantly lower at all locations compared with the former (P=0.027 for each, Mann-Whitney test).The average RGC densities were (2207±200) cells/mm2 for HS group, (2272±155) cells/mm2 for zinc group, (1964±188) cells/mm2 for HS+que group, (2051 ±214) cells/mm2 for zinc+que group and (2015±111 ) cells/mm2 for damage group. There were significant differences in density of labeled RGCs among the five groups (P=0.040,Kruskal-Wallis test). Both HS and zinc group had higher RGC densities than damage group (P

  8. Palladium-catalyzed direct desulfitative C2 arylations of 3-halo-N-protected indoles using (hetero)arenesulfonyl chlorides.

    Science.gov (United States)

    Hfaiedh, Anoir; Ben Ammar, Hamed; Soulé, Jean-François; Doucet, Henri

    2016-06-01

    The direct arylation of N-protected 3-haloindole derivatives with benzenesulfonyl chlorides as coupling partners using 5 mol% of bis(acetonitrile)dichloropalladium(ii) catalyst and lithium carbonate as a base in 1,4-dioxane was investigated. We demonstrated that both iodo and chloro substituents at the indolyl C3 position act as temporary blocking groups allowing the formation of 2-arylindoles through a direct desulfitative arylation, followed by in situ dehalogenation. While, from 3-bromoindole derivatives, 2-aryl-3-bromoindoles were obtained without debromination, and could be converted into 2,3-diarylindoles through a second palladium coupling. This method allows one to prepare in a few steps a very wide variety of indole derivatives, which are of interest in the synthesis of bioactive molecules. PMID:27171489

  9. Corrosion protection of aluminium pretreated by vinyltriethoxysilane in sodium chloride solution

    International Nuclear Information System (INIS)

    The corrosion protection of vinyltriethoxysilane (VTES) films on aluminium during exposure to 3% NaCl was investigated using electrochemical impedance spectroscopy (EIS), potential-time measurements and optical microscopy coupled with image analysis. Composition and thickness of films were analyzed using Auger electron spectroscopy (AES) combined with depth profiling. It was shown that films deposited from 5% solution were significantly thicker and exhibited lower porosity and better corrosion stability, as compared to films deposited from 2 vol.% solution. VTES films deposited from 5 vol.% solutions and cured for 30 min exhibited better protection properties than other investigated films.

  10. Eruca sativa seeds possess antioxidant activity and exert a protective effect on mercuric chloride induced renal toxicity.

    Science.gov (United States)

    Sarwar Alam, M; Kaur, Gurpreet; Jabbar, Zoobi; Javed, Kaleem; Athar, Mohammad

    2007-06-01

    Mercuric chloride (HgCl(2)) is a well-known nephrotoxic agent. Increasing number of evidences suggest the role of oxidative stress in HgCl(2) induced nephrotoxicity. Eruca sativa is widely used in folklore medicines and has a good reputation as a remedy of renal ailments. In the present study, the antioxidant potential of ethanolic extract of E. sativa seeds was determined and its protective effect on HgCl(2) induced renal toxicity was investigated. The extract was found to possess a potent antioxidant effect, with a large amount of polyphenols and a high reducing ability. HPLC analysis of the extract revealed glucoerucin and flavonoids to be the major antioxidants present in it. E. sativa extract significantly scavenged several reactive oxygen species (ROS) and reactive nitrogen species (RNS). Feeding of the extract to rats afforded a significant protection against HgCl(2) induced renal toxicity. Subcutaneous administration of 4 mg/kg body weight HgCl(2) induced renal injury evident as a marked elevation in serum creatinine and blood urea nitrogen levels, and histopathological changes such as necrosis, oedema and congestion of stroma and glomeruli. Oxidative modulation of renal tissues following HgCl(2) exposure was evident from a significant elevation in lipid peroxidation and attenuation in glutathione (GSH) contents and activities of antioxidant enzymes viz., catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD) and glutathione reductase (GR). Oral administration of E. sativa extract to rats at a dose regimen: 50-200 mg/kg body weight for 7 days prior to HgCl(2) treatment significantly and dose dependently protected against alterations in all these diagnostic parameters. The data obtained in the present study suggests E. sativa seeds to possess a potent antioxidant and renal protective activity and preclude oxidative damage inflicted to the kidney.

  11. Corrosion protection of the reinforcing steels in chloride-laden concrete environment through epoxy/polyaniline–camphorsulfonate nanocomposite coating

    International Nuclear Information System (INIS)

    Highlights: • Epoxy/polyaniline–camphorsulfonate nanocomposite coating well protects steel rebar. • Coating performance is evaluated by impedance measurements up to 1 year. • Ultimate bond strength between the coated rebars and concrete is measured. • Self-compacting concrete shows better anticorrosive property compared to normal one. - Abstract: In this study, an epoxy/polyaniline–camphorsulfonate nanocomposite (epoxy/PANI–CSA) is employed to protect reinforcing steels in chloride-laden concrete environment. The synthesized nanocomposite was characterized using Fourier transform infrared spectroscopy and transmission electron microscopy. Bare, epoxy-coated and epoxy/PANI–CSA nanocomposite-coated steel rebars were embedded in normal and self-compacting concretes. To evaluate their corrosion behaviors, open circuit potential and impedance measurements were performed for the duration of 1 year. Ultimate bond strength of concrete with the reinforcement bars were measured in corroded and uncorroded conditions. It was found that epoxy/PANI–CSA coating provides good corrosion resistance and durable bond strength with concrete for steel rebars

  12. A new dioxime corrosion inhibitor for the protection and conservation of copper: synthesis, characterization and evaluation in acidic chloride solution

    Science.gov (United States)

    Abu-Baker, Ahmad N.; Al-Qudah, Mahmoud A.

    2016-08-01

    This study aimed to investigate a new dioxime compound as a corrosion inhibitor for copper. The compound (4,6-dihydroxy benzene-1,3-dicarbaldehyde dioxime) was synthesized and characterized by nuclear magnetic resonance spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were used to compare the dioxime compound with benzotriazole for their effectiveness as corrosion inhibitors for copper in 0.1 M HCl solution. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to investigate the bonding mechanisms and morphological changes of the two inhibitors on the copper surface. The electrochemical techniques showed that the new dioxime compound was more effective than benzotriazole in inhibiting copper corrosion in the acidic chloride medium. The FTIR and SEM results indicated that the dioxime compound was able to coordinate with copper ions and formed a protective film on the copper surface. It was concluded that the new dioxime compound proved effectiveness to be used as a corrosion inhibitor for the protection and conservation of copper.

  13. Retinal cartography.

    Science.gov (United States)

    Mosier, M A

    1982-10-01

    This paper analyses retinal cartography in terms of its reflection of anatomic data and its relation to several forms of geographic methods of map-making. It shows that the distances between anatomic landmarks of the eye are reasonably similar to the relative distances on the retinal drawing chart currently used. Two forms of geographic cartography--azimuth equidistant and orthographic--are described and compared with retinal cartography. The retinal drawing chart currently used most closely approximates an azimuth equidistant projection, which suffers from circumferential distortion, a fact that retinal surgeons must keep in mind. It is therefore recommended that the chart be modified to have equally spaced concentric circles and clearer identification of the ora serrata; the present accurate marking of anatomic landmarks, such as the equator and the posterior border of the ciliary body, should be preserved.

  14. Transgenic inhibition of astroglial NF-κB protects from optic nerve damage and retinal ganglion cell loss in experimental optic neuritis

    Directory of Open Access Journals (Sweden)

    Brambilla Roberta

    2012-09-01

    Full Text Available Abstract Background Optic neuritis is an acute, demyelinating neuropathy of the optic nerve often representing the first appreciable symptom of multiple sclerosis. Wallerian degeneration of irreversibly damaged optic nerve axons leads to death of retinal ganglion cells, which is the cause of permanent visual impairment. Although the specific mechanisms responsible for triggering these events are unknown, it has been suggested that a key pathological factor is the activation of immune-inflammatory processes secondary to leukocyte infiltration. However, to date, there is no conclusive evidence to support such a causal role for infiltrating peripheral immune cells in the etiopathology of optic neuritis. Methods To dissect the contribution of the peripheral immune-inflammatory response versus the CNS-specific inflammatory response in the development of optic neuritis, we analyzed optic nerve and retinal ganglion cells pathology in wild-type and GFAP-IκBα-dn transgenic mice, where NF-κB is selectively inactivated in astrocytes, following induction of EAE. Results We found that, in wild-type mice, axonal demyelination in the optic nerve occurred as early as 8 days post induction of EAE, prior to the earliest signs of leukocyte infiltration (20 days post induction. On the contrary, GFAP-IκBα-dn mice were significantly protected and showed a nearly complete prevention of axonal demyelination, as well as a drastic attenuation in retinal ganglion cell death. This correlated with a decrease in the expression of pro-inflammatory cytokines, chemokines, adhesion molecules, as well as a prevention of NAD(PH oxidase subunit upregulation. Conclusions Our results provide evidence that astrocytes, not infiltrating immune cells, play a key role in the development of optic neuritis and that astrocyte-mediated neurotoxicity is dependent on activation of a transcriptional program regulated by NF-κB. Hence, interventions targeting the NF-κB transcription

  15. 40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride, vinyl chloride, and/or polyvinyl chloride plant shall comply with the requirements of this section....

  16. Protective effect of butylated hydroxytoluene (BHT against the clastogenic acitivity of cadmium chloride and potassium dichromate in hamster ovary cells

    Directory of Open Access Journals (Sweden)

    Grillo Claudia A.

    1999-01-01

    Full Text Available The effect of butylated hydroxytoluene (BHT, a widely used food additive, on chromosomal alterations induced by cadmium chloride (CC and potassium dichromate (PD in Chinese hamster ovary (CHO cells was studied both at metaphase and anaphase-telophase. CHO cells were cultured for 15-16 h in the presence of PD (6.0, 9.0 or 12.0 mM, BHT (1.0 mg/ml, or PD plus BHT as well as CC (0.5, 1.0 and 2.0 mM, BHT or CC plus BHT for the analysis of chromosomal aberrations. To perform the anaphase-telophase test, cells were cultured in cover glasses and treated 8 h before fixation with the same chemicals. An extra dose of CC (4 mM was used in this test. Both metal salts significantly increased chromosomal aberration frequencies in relation to untreated controls, and to DMSO- and BHT-treated cells. Post-treatment with BHT decreased the yield of chromosomal damage in relation to treatments performed with CC and PD. However, chromosomal aberration frequencies were significantly higher than those of the controls. In the anaphase-telophase test, CC significantly increased the yield of lagging chromosomes with the four doses employed and the frequency of lagging fragments with the highest dose. In combined treatments of CC and BHT, frequencies of the two types of alterations decreased significantly in relation to the cells treated with CC alone. No significant variation was found in the frequencies of chromatin bridges. Significant increases of numbers of chromatin bridges, lagging chromosomes and lagging fragments were found in cells treated with PD. The protective effect of BHT in combined treatments was evidenced by the significant decrease of chromatid bridges and lagging chromosomes in relation to PD-treated cells. Whereas BHT is able to induce chromosomal damage, it can also protect against oxidative damage induced by other genotoxicants.

  17. Protective effects of pomegranate peel against hematotoxicity, chromosomal aberrations, and genotoxicity induced by barium chloride in adult rats.

    Science.gov (United States)

    Elwej, Awatef; Ben Salah, Ghada; Kallel, Choumous; Fakhfakh, Faiza; Zeghal, Najiba; Ben Amara, Ibtissem

    2016-06-01

    Context Pomegranate peel (PP) has health benefits including antibacterial, antioxidant, anti-inflammatory, and antimutagenic properties. Objective This study investigated the biochemical composition and protective effects of PP against hematotoxicity and genotoxicity induced by barium chloride (BaCl2) in adult rats. Materials and methods Adult Wistar rats were divided into four groups of six each: control, barium (67 ppm via drinking water), PP (5% via diet), and their combination during 21 d. Oxidative stress was determined by MDA, AOPP, and antioxidant status: CAT, GPx, GSH, Vit C. Osmotic fragility (OF), chromosomal aberrations (CAs), and micronucleus (MN) assays were also studied. Results PP showed a rich composition of antioxidant compounds. DPPH test found IC50 value= 5.3 μg/mL and a high polysaccharides content (315 ± 5 mg/g of extract). In vivo study showed a decrease in red blood cells (70%) and platelet counts (46%), hemoglobin content (8%), hematocrit percent (7%), and an 80% increase of white blood cells in Ba-treated rats. A reduction in antioxidant status: catalase, glutathione peroxidase activities, glutathione, and vitamin C levels by 31, 21, 28, and 29%, respectively, and an increase in MDA (46%) and AOPP levels (72%) were also observed compared with controls. BaCl2-treatment showed a significant increase in the frequencies of total chromosomal aberrations with abnormal metaphases and micronucleus in bone-marrow cells. Oxidative stress induced by BaCl2 might be the major cause for chromosomal abnormalities leading to DNA damage. Discussion and conclusion A decrease in hematotoxic and genotoxic effects induced by PP is due to its powerful antioxidant capacity. PMID:26971618

  18. Camel's Milk Protects against Aluminum Chloride-Induced Toxicity in the Liver and Kidney of White Albino Rats

    Directory of Open Access Journals (Sweden)

    Fahaid Al-Hashem

    2009-01-01

    Full Text Available Problem statement: Aluminum chloride (AlCl3 is commonly used in daily life but it can be potentially toxic. Therefore, the present study was carried out to investigate the protective effects of camel' milk against aluminum-induced biochemical alterations and oxidative stress in the liver and kidney of white albino rats. Approach: White albino male rats (230-250 g were divided into three groups of 10 rats: a control group treated with normal saline, the AlCl3-treated group and the camel's milk-AlCl3-treated group. The AlCl3 treated group received 0.5 mg kg-1 of AlCl3 orally. The camel's milk-AlCl3-treated group was fed 1 mL of fresh camel's milk 10 minutes prior to the administration of oral AlCl3. All rats were treated every day for 30 days. Liver and kidney biochemical serum parameters were analyzed. Lipid peroxidation, as determined by the tissue concentrations of thiobarbituric acid reactive substances (TBARS and hydrogen peroxide (HP, and the oxidative stress status, as measured by glutathione (GSH, superoxide dismutase (SOD and catalase (CAT activity, were evaluated in the kidney and liver of treated rats. Results: Data showed that the oral administration of AlCl3 resulted in statistically significant increases in the serum levels of urea, creatinine, bilirubin, aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, lactate dehydrogenase (LDH, cholesterol and triglycerides; the total amount of protein and albumin were also significantly decreased. However, these parameters were within normal levels in the rats given camel's milk prior to AlCl3. Additionally, oral administration of AlCl3 induced lipid peroxidation in the liver and kidney, which was indicated by a significant increase in lipid peroxidation biomarkers (TBARS and HP and a significant decrease in the activities of GSH, SOD and CAT. In all rats treated with camel's milk before being given AlCl3, lipid peroxidation and oxidative stress

  19. Protective Effect of Virgin Olive Oil (Olea europea L. Against Oxidative Damage Induced by Mercuric Chloride in Rat Albinos Wistar

    Directory of Open Access Journals (Sweden)

    Youcef Necib

    2014-03-01

    Full Text Available Olive oil is beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil on mercuric chloride induced oxidative damage in the liver of rats. Adult male Albinos Wistar rats randomly divided into four groups, were the first was served as a control, whereas the remaining groups respectively treated with: virgin olive oil (2ml/ kg b.w; by gavage, mercuric chloride (0.5 mg/kg body weight i.p and combination of virgin olive oil and HgCl2. Change in liver enzyme activities, thiobarbituric acid reactive substances (TBARS level, antioxidants and reduced glutathione (GSH contents were determined after 2 weeks of experimental period. Exposure of rats to mercuric chloride caused a significant increase the lipid peroxidation level along with corresponding decrease in the reduced glutathione and various antioxidant enzymes in liver. And increase in serum: glucose level, APL and transaminases activities and decreased in total protein and albumin levels. Furthermore, treatment with mercuric chloride caused a marked elevation of liver weight and decreased body weight. Supplementation of virgin olive oil resulted in decreased of lipid peroxidation level and in the serum: AST, ALT and APL activities were decreased along with increase in total protein, albumin and liver GSH levels. The activities of antioxidants enzymes: glutathione peroxidase (GSH-Px and glutathione –S-transferase (GST were also concomitantly restored to near normal level by virgin olive oil supplementation to mercuric chloride intoxicated rats. Liver histological studies have confirmed the changes observed in biochemical parameters and proved the beneficial role of virgin olive oil. The results clearly demonstrate that virgin olive oil treatment augments the antioxidants defense mechanism in mercuric chloride induced toxicity and provides evidence that it may have a

  20. PROTECTIVE EFFECT OF VIRGIN OLIVE OIL ( OLEA EUROPEA L.) AGAINST OXIDATIVE DAMAGE INDUCED BY MERCURIC CHLORIDE IN RAT ALBINOS WISTAR

    OpenAIRE

    Necib, Youcef; Bahi, Ahlem; Zerizer, Sakina; Abdennour, Cherif; Boulakoud, Mohamed

    2014-01-01

    Olive oil is beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil on mercuric chloride induced oxidative damage in the liver of rats. Adult male Albinos Wistar rats randomly divided into four groups, were the first was served as a control, whereas the remaining groups respectively treated with: virgin olive oil (2ml/ kg b.w; by gavage), mercuric chloride (0....

  1. Protective Effect of Virgin Olive Oil (Olea europea L.) Against Oxidative Damage Induced by Mercuric Chloride in Rat Albinos Wistar

    OpenAIRE

    Youcef Necib; Ahlem Bahi; Sakina Zerizer; Cherif Abdennour; Mohamed Salah Boulakoud

    2014-01-01

    Olive oil is beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil on mercuric chloride induced oxidative damage in the liver of rats. Adult male Albinos Wistar rats randomly divided into four groups, were the first was served as a control, whereas the remaining groups respectively treated with: virgin olive oil (2ml/ kg b.w; by gavage), mercuric chloride (0....

  2. Studies on the genotoxic effect of beryllium chloride and the possible protective role of selenium/vitamins A, C and E.

    Science.gov (United States)

    Fahmy, Maha A; Hassan, Nagwa H A; Farghaly, Ayman A; Hassan, Entesar E S

    2008-04-30

    The genotoxic potential of beryllium chloride (BeCl2) was evaluated in vivo in mice using different endpoints. Chromosomal aberrations in bone marrow cells and in spermatocytes as well as sperm abnormalities were determined in the tested mice. The protective role of an orally administered drug consisting of selenium and vitamins A, C and E (selenium-ACE) was also studied. For analysis of chromosomal aberrations, both single and repeated oral treatments for a period of 3 weeks were performed. The doses used were 93.75, 187.50, 375, and 750 mg BeCl2/kg bw, which corresponds to 1/16, 1/8, 1/4, and 1/2 of the experimental LD50. BeCl2 induced a statistically significant increase in the percentage of chromosomal aberrations in both somatic and germ cells, with a dose- and time-response. The percentage of induced chromosomal aberrations was significantly reduced in all BeCl2-treated groups after oral administration of selenium-ACE. Beryllium chloride also induced a significant increase in the percentage of abnormal sperm. This percentage reached values of 9.62 +/- 0.32 and 5.56 +/- 0.31 in mice treated with the highest test dose of BeCl2 and with BeCl2+selenium-ACE, respectively, compared with 1.96 +/- 0.14 for the control. In conclusion, the results demonstrate the genotoxic effect of beryllium chloride and confirm the protective role of selenium-ACE against the genotoxicity of beryllium chloride.

  3. Synthetic and endogenous cannabinoids protect retinal neurons from AMPA excitotoxicity in vivo, via activation of CB1 receptors: Involvement of PI3K/Akt and MEK/ERK signaling pathways.

    Science.gov (United States)

    Kokona, Despina; Thermos, Kyriaki

    2015-07-01

    Cannabinoids have been suggested to protect retinal ganglion cells in different models of toxicity, but their effects on other retinal neurons are poorly known. We investigated the neuroprotective actions of the endocannabinoid N-arachidonoyl ethanolamine (Anandamide/AEA) and the synthetic cannabinoids R1-Methanandamide (MethAEA) and HU-210, in an in vivo retinal model of AMPA excitotoxicity, and the mechanisms involved in the neuroprotection. Sprague-Dawley rats were intravitreally injected with PBS or AMPA in the absence or presence of the cannabinoid agonists. Brain nitric oxide synthase (bNOS) and choline acetyltransferase (ChAT) immunoreactivity (IR), as well as TUNEL staining, assessed the AMPA-induced retinal amacrine cell loss and the dose-dependent neuroprotection afforded by cannabinoids. The CB1 receptor selective antagonist AM251 and the PI3K/Akt inhibitor wortmannin reversed the cannabinoid-induced neuroprotection, suggesting the involvement of CB1 receptors and the PI3K/Akt pathway in cannabinoids' actions. Experiments with the CB2 agonist JWH015 and [(3)H]CP55940 radioligand binding suggested that the CB2 receptor is not involved in the neuroprotection. AEA and HU-210 induced phosphorylation of Akt but only AEA induced phosphorylation of ERK1/2 kinases, as revealed by western blot analysis. To investigate the role of caspase-3 in the AMPA-induced cell death, the caspase-3 inhibitor Z-DEVD-FMK was co-injected with AMPA. Z-DEVD-FMK had no effect on AMPA excitotoxicity. Moreover, no difference was observed in the phosphorylation of SAPK/JNK kinases between PBS- and AMPA-treated retinas. These results suggest that endogenous and synthetic cannabinoids protect retinal amacrine neurons from AMPA excitotoxicity in vivo via a mechanism involving the CB1 receptors, and the PI3K/Akt and/or MEK/ERK1/2 signaling pathways.

  4. Protective effect of butylated hydroxytoluene (BHT) against the clastogenic acitivity of cadmium chloride and potassium dichromate in hamster ovary cells

    OpenAIRE

    Grillo Claudia A.; Seoane Analía I.; Dulout Fernando N.

    1999-01-01

    The effect of butylated hydroxytoluene (BHT), a widely used food additive, on chromosomal alterations induced by cadmium chloride (CC) and potassium dichromate (PD) in Chinese hamster ovary (CHO) cells was studied both at metaphase and anaphase-telophase. CHO cells were cultured for 15-16 h in the presence of PD (6.0, 9.0 or 12.0 mM), BHT (1.0 mg/ml), or PD plus BHT as well as CC (0.5, 1.0 and 2.0 mM), BHT or CC plus BHT for the analysis of chromosomal aberrations. To perform the anaphase-tel...

  5. 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.

  6. 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.

  7. 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

    2015-01-01

    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. PMID:26314276

  8. Protective effect of autophagy on human retinal pigment epithelial cells against lipofuscin fluorophore A2E: implications for age-related macular degeneration.

    Science.gov (United States)

    Zhang, J; Bai, Y; Huang, L; Qi, Y; Zhang, Q; Li, S; Wu, Y; Li, X

    2015-11-12

    Age-related macular degeneration (AMD) is the leading cause of central vision loss in the elderly. Degeneration of retinal pigment epithelial (RPE) cells is a crucial causative factor responsible for the onset and progression of AMD. A2E, a major component of toxic lipofuscin implicated in AMD, is deposited in RPE cells with age. However, the mechanism whereby A2E may contribute to the pathogenesis of AMD remains unclear. We demonstrated that A2E was a danger signal of RPE cells, which induced autophagy and decreased cell viability in a concentration- and time-dependent manner. Within 15 min after the treatment of RPE with 25 μM A2E, the induction of autophagosome was detected by transmission electron microscopy. After continuous incubating RPE cells with A2E, intense punctate staining of LC3 and increased expression of LC3-II and Beclin-1 were identified. Meanwhile, the levels of intercellular adhesion molecule (ICAM), interleukin (IL)1β, IL2, IL-6, IL-8, IL-17A, IL-22, macrophage cationic peptide (MCP)-1, stromal cell-derived factor (SDF)-1, and vascular endothelial growth factor A (VEGFA) were elevated. The autophagic inhibitor 3-methyladenine (3-MA) and activator rapamycin were also used to verify the effect of autophagy on RPE cells against A2E. Our results revealed that 3-MA decreased the autophagosomes and LC3 puncta induced by A2E, increased inflammation-associated protein expression including ICAM, IL1β, IL2, IL-6, IL-8, IL-17A, IL-22, and SDF-1, and upregulated VEGFA expression. Whereas rapamycin augmented the A2E-mediated autophagy, attenuated protein expression of inflammation-associated and angiogenic factors, and blocked the Akt/mTOR pathway. Taken together, A2E induces autophagy in RPE cells at the early stage of incubation, and this autophagic response can be inhibited by 3-MA or augmented by rapamycin via the mTOR pathway. The enhancement of autophagy has a protective role in RPE cells against the adverse effects of A2E by reducing the

  9. Protective effect of an aqueous extract of Harpagophytum procumbens upon Escherichia coli strains submitted to the lethal action of stannous chloride.

    Science.gov (United States)

    Almeida, M C; Soares, S F; Abreu, P R C; Jesus, L M; Brito, L C; Bernardo-Filho, M

    2007-01-01

    Regardless of its lethal effects upon Escherichia coli (E. coli) cultures trough the production of free radicals (FR), stannous chloride (SnCl2) remains to be the most used reducing agent on the production of technetium-99m radiopharmaceuticals, to obtain images on nuclear medicine. Moreover, authors have reported that vegetal extracts are able to protect Escherichia coli cultures against the cytotoxicity of this agent. Harpagophytum procumbens, also known as Devil's Claw, is a plant used in folk medicine, as an analgesic and anti-inflammatory in cases of joint and back pain, on the treatment of degenerative rheumatoid arthritis, osteoarthritis, kidney inflammation and heart diseases. The presence of this extract reduced the lesive effects of SnCl2 upon E. coli AB1157 (proficient in DNA repair), BW9091 (deficient in the xthA gene) and BH110 (deficient in the xthA, nfo and fpg genes) cultures, and the deficient strains (BW9091 e BH110) were more sensible to this SnCl2 action than the proficient one. The substances in the extract could be acting as: (i) chelator of the stannous ions, avoiding the generation of FR, (ii) FR scavenger, protecting the cells against the oxidation, and/or (iii) an oxidant compound acting upon the stannous ions, reducing the SnCl2 cytotoxicity. PMID:17531166

  10. KIOM-79 protects AGE-induced retinal pericyte apoptosis via inhibition of NF-kappaB activation in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Junghyun Kim

    Full Text Available KIOM-79 is an herbal mixture of parched Puerariae radix, gingered Magnoliae cortex, Glycyrrhizae radix and Euphorbiae radix. In the present study, we determined the efficacy and possible mechanism of KIOM-79 on the advanced glycation end product (AGE-modified bovine serum albumin (BSA-induced apoptosis of cultured bovine retinal pericytes and rat retinal pericytes in Zucker diabetic fatty (ZDF rats. Seven-week-old male ZDF rats were treated with KIOM-79 (50 mg/kg body weight once a day orally for 13 weeks. KIOM-79 significantly inhibited pericyte apoptosis which were induced by the AGE-BSA treatment. The KIOM-79 treatment markedly suppressed the activation of nuclear factor-kappaB (NF-κB through the inhibition of inhibitory κB kinase complex. In addition, the oral administration of KIOM-79 inhibited the changes in retinal vasculature (vascular hyperpermeability, acellular capillary. KIOM-79 strongly inhibited pericyte apoptosis, NF-κB activation and the expression of pro-apoptotic Bax and tumor necrosis factor-α. Our results suggest that KIOM-79 may exert inhibitory effects on AGE-induced pericyte apoptosis by blocking NF-κB activation, thereby ameliorating retinal microvascular dysfunction.

  11. 17β-Estradiol eye drops protect the retinal ganglion cell layer and preserve visual function in an in vivo model of glaucoma

    OpenAIRE

    Tatrai, Katalin Prokai; Xin, Hua; Nguyen, Vien; Szarka, Szabolcs; Blazics, Balazs; Prokai, Laszlo; Koulen, Peter

    2013-01-01

    Neuroprotection in glaucoma as a curative strategy complementary to current therapies to lower intraocular pressure (IOP) is highly desirable. This study was designed to investigate neuroprotection by 17β-estradiol (E2) to prevent retinal ganglion cell (RGC) death in a glaucoma model of surgically elevated IOP in rats. We found that daily treatment with E2 containing eye drops resulted in significant E2 concentration in the retina with concomitant profound neuroprotective therapeutic benefits...

  12. Protective effect ofα-mangostin on retinal light damage in mice%α-倒捻子素对小鼠视网膜光损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    方圆; 苏途; 谢平; 袁松涛; 范雯; 许译丹; 胡仔仲; 刘庆淮

    2015-01-01

    AlM:To discuss the protective effect ofα-mangostin on retinal light damage in mice.METHODS:Totally 30 Balb/c mice, aged 6~8wk, were randomly divided into the control group, light-exposure group and α-mangostin group. Every group contained 10 mice. Mice of α-mangostin group were treated with alpha-mangostin at the dose of 30mg/( kg · d ) body weight by intragastric administration daily for 7d, and then exposed to white light at the 5th d. The light-exposure group and α-mangostin group were exposed to 5 000 ± 200lx white light-emmiting diodes (LEDs) for continuously 1h to establish the mice model of retinal light damage. Flash -electroretinograme was recorded 72h after light exposure. The changes in retinal morphology of mice were observed by light microscopy. Retinas were extracted to detect the malondialdhyde ( MDA ) content change of the retinal homogenate.RESULTS: Flash-electroretinogram ( F-ERG ) showed that retinal dysfunction was less severe in α-mangostin group than in light-exposure group ( P<0. 05 ). Light microscopy test showed that retina structural damage was less severe in α-mangostin group than in light-exposure group (P<0. 05). The level of MDA in retinal tissue of α-mangostin group was significantly lower when compared with light-exposure group (P<0. 05).CONCLUSlON: α-mangostin inhibits lipid peroxidation induced by light damage and protect retina against light damage.%目的::探讨α-倒捻子素对小鼠视网膜光损伤的保护作用。方法:取健康6~8 wk Balb/c小鼠30只,随机分成正常对照组、光照组、α-倒捻子素组,每组10只。α-倒捻子素组小鼠每天接受α-倒捻子素30mg/(kg·d)灌胃7d,于灌胃给药第5d进行光损伤造模。对光照组和α-倒捻子素组小鼠采用5000±200 lx白色LED光连续照射1 h。模型完成后72 h记录各组小鼠闪光视网膜电图;应用光镜观察各组小鼠视网膜形态学变化;剥离视网膜,检测各组小鼠视

  13. Fructose-1,6-diphosphate protects against epileptogenesis by modifying cation-chloride co-transporters in a model of amygdaloid-kindling temporal epilepticus.

    Science.gov (United States)

    Ding, Yao; Wang, Shan; Jiang, Yan; Yang, Yi; Zhang, Manman; Guo, Yi; Wang, Shuang; Ding, Mei-ping

    2013-11-20

    Fructose-1,6-diphosphate (FDP) shifts the metabolism of glucose from glycolysis to the pentose phosphate pathway and has anticonvulsant activity in several acute seizure animal models. In the present study, we investigated the anti-epileptogenic effects of FDP in an amygdaloid-kindling seizure model, which is an animal model of the most common form of human temporal lobe epilepsy. We found that 1.0 g/kg FDP slowed seizure progression and shortened the corresponding after-discharge duration (ADD). FDP increased the number of stimulations needed to reach seizure stages 2-5 and prolonged the cumulative ADD prior to reaching stages 3-5. It also shortened staying days and cumulative ADD in stages 4-5. However, it demonstrated no significant protective effect when administered after the animals were fully kindled. In hippocampal neurons, cation-chloride co-transporters (CCCs) are suggested to play interesting roles in epilepsy by modulating γ-aminobutyric acid (GABA)ergic activity through controlling GABAA receptor-mediated reversal potential. We examined the potential link between FDP and the hippocampal expression of two main members of the CCCs: the neuron-specific K(+)-Cl(-)co-transporter 2 (KCC2) and Na(+)-K(+)-Cl(-)co-transporter 1 (NKCC1). FDP inhibited the kindling-induced downregulation of KCC2 expression and decreased NKCC1 expression during the kindling session. Taken together, our data reveal that FDP may have protective activity against epileptogenesis, from partial to generalized tonic-clonic seizures. Furthermore, our findings suggest that the FDP-induced imbalance between KCC2 and NKCC1 expression may be involved in the neuroprotective effect.

  14. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  15. 盐湖氯化物资源开发与环保%Development of Salt Lake Chloride Resoures and Environment Protection

    Institute of Scientific and Technical Information of China (English)

    乌志明; 温现明

    2000-01-01

    简述了盐湖氯化物资源综合开发势在必行;探讨开展氯化学研究的必要;并对与氯平衡相关的环保问题和水制约问题做了分析。%This paper breifs the necessity of comprehensive development of salt lake chloride resources and study on chloride chemistry,analyze the issues coneerning chloride related environment proteetion and water shortage.

  16. Modern retinal laser therapy

    OpenAIRE

    Kozak, Igor; Luttrull, Jeffrey K.

    2014-01-01

    Medicinal lasers are a standard source of light to produce retinal tissue photocoagulation to treat retinovascular disease. The Diabetic Retinopathy Study and the Early Treatment Diabetic Retinopathy Study were large randomized clinical trials that have shown beneficial effect of retinal laser photocoagulation in diabetic retinopathy and have dictated the standard of care for decades. However, current treatment protocols undergo modifications. Types of lasers used in treatment of retinal dise...

  17. The retinal ciliopathies.

    Science.gov (United States)

    Adams, N A; Awadein, Ahmed; Toma, Hassanain S

    2007-09-01

    While the functions of many of the proteins located in or associated with the photoreceptor cilia are poorly understood, disruption of the function of these proteins may result in a wide variety of phenotypes ranging from isolated retinal degeneration to more pleiotropic phenotypes. Systemic findings include neurosensory hearing loss, developmental delay, situs-inversus, infertility, disorders of limb and digit development, obesity, kidney disease, liver disease, and respiratory disease. The concept of "retinal ciliopathies" brings to attention the importance of further molecular analysis of this organelle as well as provides a potential common target for therapies for these disorders. The retinal ciliopathies include retinitis pigmentosa, macular degeneration, cone-dystrophy, cone-rod dystrophy, Leber congenital amaurosis, as well as retinal degenerations associated with Usher syndrome, primary ciliary dyskinesia, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, Laurence-Moon syndrome, McKusick-Kaufman syndrome, and Biemond syndrome. Mutations for these disorders have been found in retinitis pigmentosa-1 (RP1), retinitis pigmentosa GTPase regulator (RPGR), retinitis pigmentosa GTPase regulator interacting protein (RPGR-IP), as well as the Usher, Bardet-Biedl, and nephronophthisis genes. Other systemic disorders associated with retinal degenerations that may also involve ciliary abnormalities include: Alstrom, Edwards-Sethi, Ellis-van Creveld, Jeune, Meckel-Gruber, Orofaciodigital Type 9, and Gurrieri syndromes. Understanding these conditions as ciliopathies may help the ophthalmologist to recognize associations between seemingly unrelated diseases and have a high degree of suspicion that a systemic finding may be present. PMID:17896309

  18. Minocycline protects retinal ganglion cells after optic nerve crush injury in mice by delaying autophagy and upregulating nuclear factor-κB2

    Institute of Scientific and Technical Information of China (English)

    Jiao Xiaoling; Peng Yuan; Yang Liu

    2014-01-01

    Background Currently,no medicine is available that can prevent or treat neural damage associated with optic nerve injury.Minocycline is recently reported to have a neuroprotective function.The aims of this study were to exarmine the neuroprotective effect of minocycline on retinal ganglion cells (RGCs) and determine its underlying mechanisms,using a mouse model of optic nerve crush (ONC).Methods ONC was performed in the left eye of adult male mice,and the mice were randomly divided into minocycline-treated group and saline-treated control group.The mice without receiving ONC injury were used as positive controls.RGC densities were assessed in retinal whole mounts with immunofluorescence labeling of βⅢ-tubulin.Transmission electron microscopy was used to detect RGC morphologies,and Western blotting and real-time PCR were applied to investigate the expression of autophagy markers LC3-Ⅰ,LC3-Ⅱ,and transcriptional factors nuclear factor-κB1 (NF-κB1),NF-κB2.Results In the early stage after ONC (at Days 4 and 7),the density of RGCs in the minocycline-treated group was higher than that of the saline-treated group.Electron micrographs showed that minocycline prevented nuclei and mitochondria injuries at Day 4.Western blotting analysis demonstrated that the conversion of LC3-Ⅰ to LC3-Ⅱ was reduced in the minocycline-treated group at Days 4 and 7,which meant autophagy process was inhibited by minocycline.In addition,the gene expression of NF-κB2 was upregulated by minocycline at Day 4.Conclusion The neuroprotective effect of minocycline is generated in the early stage after ONC in mice,partly through delaying autophagy process and regulating NF-κB2 pathway.

  19. Cholecystokinin octapeptide antagonizes apoptosis in human retinal pigment epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Yuan Liu; Yueling Zhang; Zhaohui Gu; Lina Hao; Juan Du; Qian Yang; Suping Li; Liying Wang; Shilei Gong

    2014-01-01

    Although cholecystokinin octapeptide-8 is important for neurological function, its neuropro-tective properties remain unclear. We speculated that cholecystokinin octapeptide-8 can protect human retinal pigment epithelial cells against oxidative injury. In this study, retinal pigment epithelial cells were treated with peroxynitrite to induce oxidative stress. Peroxynitrite triggered apoptosis in these cells, and increased the expression of Fas-associated death domain, Bax, caspa-se-8 and Bcl-2. These changes were suppressed by treatment with cholecystokinin octapeptide-8. These results suggest that cholecystokinin octapeptide-8 can protect human retinal pigment epi-thelial cells against apoptosis induced by peroxynitrite.

  20. Crocin "saffron" protects against beryllium chloride toxicity in rats through diminution of oxidative stress and enhancing gene expression of antioxidant enzymes.

    Science.gov (United States)

    El-Beshbishy, Hesham A; Hassan, Memy H; Aly, Hamdy A A; Doghish, Ahmed S; Alghaithy, Abdulaziz A A

    2012-09-01

    Beryllium chloride (BeCl(2)) is a highly toxic substance that accumulates in different tissues after absorption. The purpose of this study was to investigate protective role of crocin against BeCl(2)-intoxication in rats. Male Wistar rats were used in this study and categorised into four groups (n=8). Group I served as normal control rats. Group II treated orally with BeCl(2) 86 mg/kg b.w. for five consecutive days. This dose was equivalent to experimental LD(50). Group III treated intraperitoneally with crocin 200 mg/kg b.w. for seven consecutive days. Group IV received crocin for seven consecutive days before BeCl(2) administration. Blood samples and liver and brain homogenates were obtained for haematological, biochemical and RT-PCR examinations. The haematocrit value, RBCs count and haemoglobin concentration were significantly decreased in BeCl(2)-treated rats. A significant increase was observed in rat liver and brain malondialdehyde level and protein carbonyls content in BeCl(2) exposed group compared to the control group, and these values were significantly declined upon administration of crocin. Lactate dehydrogenase levels in rat liver and brain significantly increased compared to the control group and was associated with significant decrease in catalase and superoxide dismutase activities. Reduced glutathione hepatic contents of BeCl(2)-treated rats were significantly decreased. There was significant decline in mRNA expression of catalase and superoxide dismutase genes in BeCl(2)-intoxicated rats compared to the normal rats. Crocin treatment prior to BeCl(2) intake resulted in significant increase in mRNA expressions of catalase and superoxide dismutase genes near to normalcy. The haematological and biochemical parameters were restored near to normal levels. Our results suggested that, BeCl(2) induced oxidation of cellular lipids and proteins and that administration of crocin reduced BeCl(2)-induced oxidative stress combined with initiation of m

  1. Retinal oximetry in patients with ischaemic retinal diseases

    DEFF Research Database (Denmark)

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

    2016-01-01

    The retinal oximeter is a new tool for non-invasive measurement of retinal oxygen saturation in humans. Several studies have investigated the associations between retinal oxygen saturation and retinal diseases. In the present systematic review, we examine whether there are associations between...

  2. 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....

  3. Polycystic Ovary Syndrome: Aggressive or Protective Factor for the Retina? Evaluation of Macular Thickness and Retinal Nerve Fiber Layers Using High-Definition Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    José Edvan de Souza-Júnior

    2015-01-01

    Full Text Available Objective. To compare macular thickness (MT and retinal nerve fiber layers (RNFL between women with polycystic ovary syndrome (PCOS and healthy women. Materials and Methods. The study included 45 women with PCOS and 47 ovulatory women undergoing clinical-gynecological and ophthalmic evaluations, including measurement of MT, RNFL, and optic disc parameters using optical coherence tomography. Results. The superior RNFL around the optic nerve was significantly thicker in PCOS than in healthy volunteers (P=0.036. After stratification according to insulin resistance, the temporal inner macula (TIM, the inferior inner macula (IIM, the nasal inner macula (NIM, and the nasal outer macula (NOM were significantly thicker in PCOS group than in control group (P<0.05. Both the presence of obesity associated with insulin resistance (P=0.037 and glucose intolerance (P=0.001 were associated with significant increase in the PC1 mean score, relative to MT. A significant increase in the PC2 mean score occurred when considering the presence of metabolic syndrome (P<0.0001. There was a significant interaction between obesity and inflammation in a decreasing mean PC2 score relative to macular RNFL thickness (P=0.034. Conclusion. Decreased macular RNFL thickness and increased total MT are associated with metabolic abnormalities, while increased RNFL thickness around the optic nerve is associated with hormonal changes inherent in PCOS.

  4. The novel triterpenoid RTA 408 protects human retinal pigment epithelial cells against H2O2-induced cell injury via NF-E2-related factor 2 (Nrf2) activation.

    Science.gov (United States)

    Liu, Xiaobin; Ward, Keith; Xavier, Christy; Jann, Jamieson; Clark, Abbot F; Pang, Iok-Hou; Wu, Hongli

    2016-08-01

    Oxidative stress-induced retinal pigment epithelial (RPE) cell damage is an important factor in the pathogenesis of age-related macular degeneration (AMD). Previous studies have shown that RTA 408, a synthetic triterpenoid compound, potently activates Nrf2. This study aimed to investigate the protective effects of RTA 408 in cultured RPE cells during oxidative stress and to determine the effects of RTA 408 on Nrf2 and its downstream target genes. Primary human RPE cells were pretreated with RTA 408 and then incubated in 200μM H2O2 for 6h. Cell viability was measured with the WST-8 assay. Apoptosis was quantitatively measured by annexin V/propidium iodide (PI) double staining and Hoechst 33342 fluorescent staining. Reduced (GSH) and oxidized glutathione (GSSG) were measured using colorimetric assays. Nrf2 activation and its downstream effects on phase II enzymes were examined by Western blot. Treatment of RPE cells with nanomolar ranges (10 and 100nM) of RTA 408 markedly attenuated H2O2-induced viability loss and apoptosis. RTA 408 pretreatment significantly protected cells from oxidative stress-induced GSH loss, GSSG formation and decreased ROS production. RTA 408 activated Nrf2 and increased the expression of its downstream genes, such as HO-1, NQO1, SOD2, catalase, Grx1, and Trx1. Consequently, the enzyme activities of NQO1, Grx1, and Trx1 were fully protected by RTA 408 pretreatment under oxidative stress. Moreover, knockdown of Nrf2 by siRNA significantly reduced the cytoprotective effects of RTA 408. In conclusion, our data suggest that RTA 408 protect primary human RPE cells from oxidative stress-induced damage by activating Nrf2 and its downstream genes. PMID:26773873

  5. The novel triterpenoid RTA 408 protects human retinal pigment epithelial cells against H2O2-induced cell injury via NF-E2-related factor 2 (Nrf2 activation

    Directory of Open Access Journals (Sweden)

    Xiaobin Liu

    2016-08-01

    Full Text Available Oxidative stress-induced retinal pigment epithelial (RPE cell damage is an important factor in the pathogenesis of age-related macular degeneration (AMD. Previous studies have shown that RTA 408, a synthetic triterpenoid compound, potently activates Nrf2. This study aimed to investigate the protective effects of RTA 408 in cultured RPE cells during oxidative stress and to determine the effects of RTA 408 on Nrf2 and its downstream target genes. Primary human RPE cells were pretreated with RTA 408 and then incubated in 200 μM H2O2 for 6 h. Cell viability was measured with the WST-8 assay. Apoptosis was quantitatively measured by annexin V/propidium iodide (PI double staining and Hoechst 33342 fluorescent staining. Reduced (GSH and oxidized glutathione (GSSG were measured using colorimetric assays. Nrf2 activation and its downstream effects on phase II enzymes were examined by Western blot. Treatment of RPE cells with nanomolar ranges (10 and 100 nM of RTA 408 markedly attenuated H2O2-induced viability loss and apoptosis. RTA 408 pretreatment significantly protected cells from oxidative stress-induced GSH loss, GSSG formation and decreased ROS production. RTA 408 activated Nrf2 and increased the expression of its downstream genes, such as HO-1, NQO1, SOD2, catalase, Grx1, and Trx1. Consequently, the enzyme activities of NQO1, Grx1, and Trx1 were fully protected by RTA 408 pretreatment under oxidative stress. Moreover, knockdown of Nrf2 by siRNA significantly reduced the cytoprotective effects of RTA 408. In conclusion, our data suggest that RTA 408 protect primary human RPE cells from oxidative stress-induced damage by activating Nrf2 and its downstream genes.

  6. Differential Diagnosis of Retinal Vasculitis

    Science.gov (United States)

    Abu El-Asrar, Ahmed M.; Herbort, Carl P.; Tabbara, Khalid F.

    2009-01-01

    Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings. PMID:20404987

  7. Differential Diagnosis of Retinal Vasculitis

    OpenAIRE

    Abu El-Asrar Ahmed; Herbort Carl; Tabbara Khalid

    2009-01-01

    Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein a...

  8. Differential diagnosis of retinal vasculitis

    Directory of Open Access Journals (Sweden)

    Abu El-Asrar Ahmed

    2009-01-01

    Full Text Available Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings.

  9. Intraocular retinal prosthesis.

    OpenAIRE

    Humayun, M. S.

    2001-01-01

    PURPOSE: An electronic implant that can bypass the damaged photoreceptors and electrically stimulate the remaining retinal neurons to restore useful vision has been proposed. A number of key questions remain to make this approach feasible. The goal of this thesis is to address the following 2 specific null hypotheses: (1) Stimulus parameters make no difference in the electrically elicited retinal responses. (2) Just as we have millions of photoreceptors, so it will take a device that can gene...

  10. The influence of retinal preprocessing in visual cortex oscillations in humans

    OpenAIRE

    Morgenroth, Michael

    2013-01-01

    The present report addresses the reliability of non-invasive retinal recordings in humans using two different recording techniques for retinal activity – skin and DTL electrodes. As skin refers to a common disc electrode on the skin surface and DTL to a contact-electrode with a silver-silver chloride coated fibre. Although the literature suggests that the DTL electrode provides stronger signal amplitudes, in this study, it is demonstrated that the two electrode types are similar in terms of s...

  11. 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.

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27511757

  13. Protective Effect of Meso-Tetrakis-(3,5-di-tert-butyl-4-hydroxyphenylporphyrin on the In Vivo Impact of Trimethyltin Chloride on the Antioxidative Defense System

    Directory of Open Access Journals (Sweden)

    Victor N. Chernyshev

    2006-12-01

    Full Text Available The in vivo effect of trimethyltin chloride (Me3SnCl, free base meso-tetrakis(3,5-di-tert-butyl-4-hydroxyphenylporphyrin (R′4PH2 and their equimolar mixture, on the enzymatic activity of catalase (CAT, superoxide dismutase (SOD, and on the total content of free sulfhydryl groups has been studied in rat liver and kidney. It was demonstrated that the simultaneous treatment of tested animals with the combination of Me3SnCl and R′4PH2 reduced the toxic impact of Me3SnCl.

  14. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

    Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

  15. Protection of zinc against pig retinal ganglion cells' damage induced by microwave%锌对微波致猪视网膜神经节细胞损伤的防护作用

    Institute of Scientific and Technical Information of China (English)

    杨瑞华; 陈景元; 邓中荣; 刘秀红; 郑刚; 赵瑞刚

    2001-01-01

    目的 探讨微波对体外培养的猪视网膜神经节细胞的脂质过氧化损伤作用及耐受剂量,为进一步研究微波的眼底损伤机制及其防护提供一定的实验依据. 方法 体外培养猪视网膜神经节细胞,按微波辐照强度分为对照组,30 mW*cm-2组,60 mW*cm-2组及各辐照剂量加锌组,微波理疗机于微波屏蔽室内辐照1 h,辐照后立即于光镜及电镜观察细胞形态变化,测定超氧化物歧化酶(SOD)和丙二醛(MDA)活性. 结果 微波辐照后,细胞有聚集现象,部分细胞轴突消失,电镜可见线粒体及内质网肿胀,细胞MDA活性明显增高,SOD降低,加锌各组光镜下细胞形态变化不明显,电镜显示线粒体轻度肿胀,嵴完整,MDA活性有所恢复,SOD活性增高. 结论 微波可引起视网膜神经节细胞脂质过氧化损伤,锌可提高细胞的抗氧化能力,在一定程度上减轻微波对视网膜神经节细胞的过氧化损伤.%AIM To determine the lipid peroxidation damage in the primary cultured pig retinal ganglion cells induced by microwave and cells' tolerance to microwave in order to provide some experiment foundation for study of mechanism of microwave damage and its protection. METHODS Pig retinal ganglion cells were cultured in vitro and divided into 3 groups of different radiation intensities (control group, 30 mW*cm-2 group, 60 mW*cm-2 group) and 2 more radiated groups with zinc added. The activity of intracellular superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were assayed after they had been radiated for 1h in a shielded room by 2450 MHz continuous wave physiotherapy machine. The morphological variation of cells was observed immediately after radiation by optics microscope and transmission electronic microscope. RESULTS After radiation, some cells congregated and their axon disappeared. Mitochondria and endoplasmic reticulum were detected swelling by transmission

  16. Stability of succinylcholine chloride injection.

    Science.gov (United States)

    Schmutz, C W; Mühlebach, S F

    1991-03-01

    The stability of succinylcholine chloride injection prepared by a hospital pharmacy was studied under a wide variety of conditions. Batches of succinylcholine chloride injection 10 mg/mL containing sodium chloride, methyl-4-hydroxybenzoate, hydrochloric acid, and water were prepared. Samples were tested for the effect of initial pH (3.0 and 4.2) and sterilization (steam treatment at 100 degrees C for 30 minutes and 121 degrees C for 20 minutes) on stability after three weeks; long-term stability under refrigeration (12, 17, and 23 months of storage at 4 degrees C); and the effect of storage temperature (4-6 degrees C, 20-26 degrees C, 35 degrees C, and 70 degrees C) and light exposure at various intervals up to 12 months. Samples were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Unlike heating at 121 degrees C, heating at 100 degrees C produced no significant loss of succinylcholine chloride, independent of the initial pH. Succinylcholine chloride was hydrolyzed only minimally over 23 months if the solution was stored at 4-6 degrees C. A 10% loss of drug content occurred if solutions were kept at 20-26 degrees C for five months, at 35 degrees C for one month, or at 70 degrees C for one day. Initial degradation was slowed if the solution was protected from light. The assessments by TLC proved to be more sensitive than the HPLC measurements. Succinylcholine chloride injection sterilized at 100 degrees C for 30 minutes can be stored for up to five months at room temperature if protected from light. The preparation is stable for at least two years under refrigeration. PMID:2028996

  17. 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.

  18. 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.

  19. CERKL Knockdown Causes Retinal Degeneration in Zebrafish

    Science.gov (United States)

    Riera, Marina; Burguera, Demian; Garcia-Fernàndez, Jordi; Gonzàlez-Duarte, Roser

    2013-01-01

    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. PMID:23671706

  20. CERKL knockdown causes retinal degeneration in zebrafish.

    Directory of Open Access Journals (Sweden)

    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.

  1. 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 ...

  2. Retinal artery occlusion

    Science.gov (United States)

    ... artery occlusion; Branch retinal artery occlusion; CRAO; BRAO Images Retina References Sanborn GE, Magargal LE. Arterial obstructive disease ... A.M. Editorial team. Related MedlinePlus Health Topics ... audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among ...

  3. 40 CFR 61.63 - Emission standard for vinyl chloride plants.

    Science.gov (United States)

    2010-07-01

    ... formation and purification: The concentration of vinyl chloride in each exhaust gas stream from any... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Emission standard for vinyl chloride... for Vinyl Chloride § 61.63 Emission standard for vinyl chloride plants. An owner or operator of...

  4. Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157:H7 cells protected by a biofilm.

    Science.gov (United States)

    Kim, Nam Hee; Rhee, Min Suk

    2016-06-16

    The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22°C for 6days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p6.5logCFU/cm(2) reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7logCFU/cm(2) reduction; NaCl, <0.5logCFU/cm(2) reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments. PMID:27043385

  5. Observation and management of retinal changes related to diving in professional divers

    Institute of Scientific and Technical Information of China (English)

    Zhou Dan; Wei Wenbin; Tian Bei; Wang Cong; Shi Xuehui; Jiao Xuan

    2014-01-01

    Background It is very common for professional divers to have damage on the retinas.Severe retinal lesions can profoundly affect athletes' training efficacy and their daily lives.At present,it is not clear if there is effective preventive action.Thus,in our study,we continuously tracked the ocular changes in athletes and closely monitored the risk factors associated with retinal detachment.Also,we analyzed possible interventions,their associated factors,and efficacies for timely preventions to protect the retina from damage in professional divers.Methods Between 2009 and 2012,a total of 39 professional divers enrolled in follow-up management.The conducted examinations included ocular examination,record screening on retinal lesion,monitoring best-corrected visual acuity,and checking intraocular pressure (lOP) and the scope of retinal lesion.The management included optimizing training methods,taking customized follow-up based on different retinal lesions,laser treatments for definite cases of retinal tear,retinal degeneration caused by retinal layer thinning or vitreous traction,and observing the changes in the scope of retinopathy.Results Every year,the percentage of divers who have various degrees of retinal lesions is between 43.3% and 56.2%.During the 4 years,there were no statistically significant differences in divers' best-corrected visual acuity and retinal lesions.There were also no statistically significant differences between male and female athletes.However,there were statistically significant differences in lOP during these years.Moreover there were statistically significant differences in IOP and the scope of retinal lesions between platform divers and springboard divers.Conclusions Our management of retinal lesions could be effective to prevent severe retinopathy in professional divers.At the same time,platform divers are more likely to have retinal lesions than springboard divers.

  6. Morphological and migratory alterations in retinal Müller cells during early stages of hypoxia and oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Xiaohui Zhang; Zhaohui Feng; Chunhua Li; Yuping Zheng

    2012-01-01

    In the present study, retinal Müller cells were cultured in vitro and treated with hydrogen peroxide (oxidative stressor) and cobalt chloride (hypoxic injury). Following 24 hours of culture, compensatory hypertrophy was observed and cellular apoptosis increased. Hypoxia enhanced the migration ability of retinal Müller cells and induced the expression of α-smooth muscle actin. Oxidative stress altered the morphology of Müller cells when compared with hypoxia treatment.

  7. Evaluation of the protection behaviour of reinforcement steel against corrosion induced by chlorides in reinforced mortar specimens; Avaliacao do comportamento frente a corrosao pelo ataque de cloreto de argamassa armada apos varios tratamentos protetores

    Energy Technology Data Exchange (ETDEWEB)

    Crivelaro, Marcos

    2002-07-01

    In this work various treatments for protecting reinforcing steels against corrosion induced by chlorides have been evaluated. Additives to mortars and surface treatments given to reinforcing steels were evaluated as corrosion protection measures. In the preliminary tests the corrosion resistance of a CA 50 steel treated by immersion in nearly 50 different solutions, was determined. The solutions were prepared with tannins (from various sources) and/or benzotriazole, and during immersion, a surface film formed on the steel. The corrosion resistance of the coated steels was evaluated in a saturated Ca(OH){sub 2} solution with 5% (wt) NaCl. Preliminary tests were also carried out with mortars reinforced with uncoated steel to which tannin or lignin was added. Two organic coatings, a monocomponent and a bicomponent type, formulated specially for this investigation, with both tannin and benzotriazole, were also tested in the preliminary tests to select the coating with better corrosion protection property. The bicomponent type (epoxy coating) showed better performance than the monocomponent type coating, and the former was therefore chosen to investigate the corrosion performance on CA 50 steel inside mortar specimens. From the preliminary tests, two solutions with tannin from two sources, Black Wattle (Acacia mearnsii) and Brazilian tea (Ilex paraguariensis St. Hill), to which benzotriazole and phosphoric acid were added, were chosen. Mortar specimens reinforced with CA50 steel treated by immersion in these two solutions were prepared. Also, epoxy coated CA50 steel was tested as reinforcement inside mortar specimens. Mortars reinforced with uncoated CA50 steel were also prepared and corrosion tested for comparison. The effect of tannin and lignin as separate additives to the mortar on the corrosion resistance of uncoated steel was also studied. The reinforced mortar specimens were tested with various cycles of immersion for 2 days in 3.5% (wt) NaCl followed by with air

  8. Small Animal Retinal Imaging

    Science.gov (United States)

    Choi, WooJhon; Drexler, Wolfgang; Fujimoto, James G.

    Developing and validating new techniques and methods for small animal imaging is an important research area because there are many small animal models of retinal diseases such as diabetic retinopathy, age-related macular degeneration, and glaucoma [1-6]. Because the retina is a multilayered structure with distinct abnormalities occurring in different intraretinal layers at different stages of disease progression, there is a need for imaging techniques that enable visualization of these layers individually at different time points. Although postmortem histology and ultrastructural analysis can be performed for investigating microscopic changes in the retina in small animal models, this requires sacrificing animals, which makes repeated assessment of the same animal at different time points impossible and increases the number of animals required. Furthermore, some retinal processes such as neurovascular coupling cannot be fully characterized postmortem.

  9. Inhibition of nitrite-induced toxicity in channel catfish by calcium chloride and sodium chloride

    Science.gov (United States)

    Tommasso J.R., Wright; Simco, B.A.; Davis, K.B.

    1980-01-01

    Environmental chloride has been shown to inhibit methemoglobin formation in fish, thereby offering a protective effect against nitrite toxicity. Channel catfish (Ictalurus punctatus) were simultaneously exposed to various environmental nitrite and chloride levels (as either CaCl2 or NaCl) in dechlorinated tap water (40 mg/L total hardness, 47 mg/L alkalinity, 4 mg/L chloride, pH = 6.9-7.1, and temperature 21-24°C). Methemoglobin levels in fish simultaneously exposed to 2.5 mg/L nitrite and up to 30 mg/L chloride as either CaCl2 or NaCl were similar but significantly lower than in unprotected fish. Exposure to 10 mg/L nitrite and 60 mg/L chloride resulted in methemoglobin levels similar to those of the controls; most unprotected fish died. Fish exposed to 10 mg/L nitrite had significantly lower methemoglobin levels when protected with 15.0 mg/L chloride as CaCl2 than with NaCl. Fish exposed to nitrite in the presence of 60 mg/L chloride (as either CaCl2 or NaCl) had similar 24-h LC50 values that were significantly elevated above those obtained in the absence of chloride. Calcium had little effect on tolerance to nitrite toxicity in channel catfish in contrast to its large effect reported in steelhead trout (Salmo gairdneri).

  10. Nrf2 Is an Attractive Therapeutic Target for Retinal Diseases

    Science.gov (United States)

    2016-01-01

    Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that binds to antioxidant response elements located in the promoter region of genes encoding many antioxidant enzymes and phase II detoxifying enzymes. Activation of Nrf2 functions is one of the critical defensive mechanisms against oxidative stress in many species. The retina is constantly exposed to reactive oxygen species, and oxidative stress is a major contributor to age-related macular diseases. Moreover, the resulting inflammation and neuronal degeneration are also related to other retinal diseases. The well-known Nrf2 activators, bardoxolone methyl and its derivatives, have been the subject of a number of clinical trials, including those aimed at treating chronic kidney disease, pulmonary arterial hypertension, and mitochondrial myopathies. Recent studies suggest that Nrf2 activation protects the retina from retinal diseases. In particular, this is supported by the finding that Nrf2 knockout mice display age-related retinal degeneration. Moreover, the concept has been validated by the efficacy of Nrf2 activators in a number of retinal pathological models. We have also recently succeeded in generating a novel Nrf2 activator, RS9, using a biotransformation technique. This review discusses current links between retinal diseases and Nrf2 and the possibility of treating retinal diseases by activating the Nrf2 signaling pathway.

  11. Protective effects of estrogen on chronic ocular hypertension-related rabbit retinal damages%雌激素对慢性高眼压兔视网膜损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    韩瑶; 刘振通; 苗慧鹏; 韩立坡; 苏锐锋

    2010-01-01

    目的 探讨雌激素对慢性高眼压兔视网膜损伤的保护作用.方法 18只成年健康新西兰雌性大白兔随机分为去势组和假去势组.去势组切除两侧卵巢,假去势组仅切除卵巢周围部分脂肪组织.利用前房注射复方卡波姆建立兔慢性高眼压模型.采用末端脱氧核酸转移酶介导的脱氧三磷酸尿苷缺口末端标记法(TUNEL)检测视网膜组织中凋亡细胞的表达;免疫组织化学方法检测B细胞淋巴瘤/白血病(bcl)-2、bax蛋白的表达情况;应用计算机图像分析系统对检测结果进行分析.结果 造模后4、6、8周,去势组较假去势组视网膜神经节细胞数目明显减少,视神经纤维层和内核层变薄;TUNEL阳性细胞表达均较假去势组高(t=3.285,4.012,3.624;P值均<0.01);视网膜bcl-2表达均较假去势组低(t=4.256,3.867,3.459;P值均<0.01);bax阳性细胞表达情况均较假去势组高(t=3.211,3.625,3.253;P值均<0.01).bcl-2的表达与TUNEL的表达呈负相关,凋亡细胞随着bcl-2的表达增多而减少,bcl-2抑制了凋亡的发生.bax的表达与TUNEL的表达呈正相关,凋亡细胞随着bax的表达增多而增多,bax诱导了凋亡的发生.结论 雌激素对慢性高眼压兔视网膜损伤有神经保护作用,这一保护作用主要是通过减少视网膜组织中的凋亡细胞而实现的.%Objective To investigate the protective effects of estrogen on rabbit retinal damages induced by chronic ocular hypertension. Methods A total of 18 white New Zealand female rabbits were randomly divided into ovariectomized (OV) group and sham OV (SOV) group. Bilateral ovaries were remove in OV group while only the adipose tissue around ovarian were remove in SOV group. Chronic ocular hypertension was induced by anterior chamber injection of carbomer. Retinal cell apoptosis was measured by terminal deoxynucteotidyl transferase-mediated dUTP nick end labeling (TUNEL), the expression of bcl-2,bax were detected by immunohistochemistry

  12. 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

  13. Effects of sciatic-conditioned medium on neonatal rat retinal cells in vitro

    Directory of Open Access Journals (Sweden)

    Torres P.M.M.

    1998-01-01

    Full Text Available Schwann cells produce and release trophic factors that induce the regeneration and survival of neurons following lesions in the peripheral nerves. In the present study we examined the in vitro ability of developing rat retinal cells to respond to factors released from fragments of sciatic nerve. Treatment of neonatal rat retinal cells with sciatic-conditioned medium (SCM for 48 h induced an increase of 92.5 ± 8.8% (N = 7 for each group in the amount of total protein. SCM increased cell adhesion, neuronal survival and glial cell proliferation as evaluated by morphological criteria. This effect was completely blocked by 2.5 µM chelerythrine chloride, an inhibitor of protein kinase C (PKC. These data indicate that PKC activation is involved in the effect of SCM on retinal cells and demonstrate that fragments of sciatic nerve release trophic factors having a remarkable effect on neonatal rat retinal cells in culture.

  14. 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.

  15. 银杏叶提取物对培养的人眼视网膜神经节细胞的保护作用%The protective effects of ginkgo biloba extract on cultured human retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    王云松; 徐亮; 马科; 王津津

    2011-01-01

    目的 探讨银杏叶提取物(EGb761)对培养的人眼视网膜神经节细胞(RGC)的保护作用。方法 对照实验研究。将培养的人眼视网膜细胞分为对照组、谷氨酸组、EGb761组及谷氨酸+EGb761组,用Thy-1作为RGC特异性荧光抗体,以免疫流式细胞技术评价EGb761对人眼RGC的保护作用。多组间细胞存活率比较采用重复测量的方差分析,组间两两比较采用LSD t检验。结果 在不同干预因素作用下,RGC存活率呈现不同变化,对照组为(61.94±7.75)%,谷氨酸组为(44.59 +4.19)%,EGb761组为(75.05 +3.90)%,EGb761+谷氨酸组为(63.19±9.44)%;各组间RGC存活率比较差异有统计学意义(F=13.329,P<0.01)。各组与对照组RGC存活率两两比较,显示谷氨酸组RGC存活率降低(P =0.010),EGb761组RGC存活率升高(P=0.019),EGb761+谷氨酸组与对照组RGC存活率差异无统计学意义(P =0.801);与谷氨酸组相比EGb761组和EGb761+谷氨酸组RGC存活率明显升高(P=0.000,0.020)。死亡RGC中大RGC所占百分比,EGb761组为(24.63+7.21)%,EGb761+谷氨酸组为(25.99±5.05)%,与对照组(36.69±2.92)%比较,两组死亡RGC中大RGC所占百分比均降低(P=0.001,0.002);与谷氨酸组(40.78±3.34)%相比,两组大RGC死亡百分比亦降低(P =0.000,0.000)。结论 EGb761可对抗谷氨酸兴奋性毒性造成的RGC损伤,对体外培养的人眼RGC具有明显的保护作用。%Objective This study was designed to investigate the protective effects of ginkgo biloba extract (EGb)761 on human retinal ganglion cells(RGC). Methods It was an experimental study.Cultured human retinal cells were separated for four groups: control group, glutamate group, EGb761 group and EGb761 + glutamate group. RGC survival rate was determined by immune Flow cytometry using Thy-1 as a special fluorescent antibody of RGC. RGC survival rate in Multi groups were analysed by repetitive measure analysis of variance

  16. [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.

  17. C-Phycocyanin protects against acute tributyltin chloride neurotoxicity by modulating glial cell activity along with its anti-oxidant and anti-inflammatory property: A comparative efficacy evaluation with N-acetyl cysteine in adult rat brain.

    Science.gov (United States)

    Mitra, Sumonto; Siddiqui, Waseem A; Khandelwal, Shashi

    2015-08-01

    Spirulina is a widely used health supplement and is a dietary source of C-Phycocyanin (CPC), a potent anti-oxidant. We have previously reported the neurotoxic potential of tributyltin chloride (TBTC), an environmental pollutant and potent biocide. In this study, we have evaluated the protective efficacy of CPC against TBTC induced neurotoxicity. To evaluate the extent of neuroprotection offered by CPC, its efficacy was compared with the degree of protection offered by N-acetylcysteine (NAC) (a well known neuroprotective drug, taken as a positive control). Male Wistar rats (28 day old) were administered with 20mg/kg TBTC (oral) and 50mg/kg CPC or 50mg/kg NAC (i.p.), alone or in combination, and various parameters were evaluated. These include blood-brain barrier (BBB) damage; redox parameters (ROS, GSH, redox pathway associated enzymes, oxidative stress markers); inflammatory, cellular, and stress markers; apoptotic proteins and in situ cell death assay (TUNEL). We observed increased CPC availability in cortical tissue following its administration. Although BBB associated proteins like claudin-5, p-glycoprotein and ZO-1 were restored, CPC/NAC failed to protect against TBTC induced overall BBB permeability (Evans blue extravasation). Both CPC and NAC remarkably reduced oxidative stress and inflammation. NAC effectively modulated redox pathway associated enzymes whereas CPC countered ROS levels efficiently. Interestingly, CPC and NAC were equivalently capable of reducing apoptotic markers, astroglial activation and cell death. This study illustrates the various pathways involved in CPC mediated neuroprotection against this environmental neurotoxicant and highlights its capability to modulate glial cell activity. PMID:26079211

  18. Effect of Ginkgo biloba on the lesions induced by retinal argon laser photocoagulation in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Clairambault, P.; Pairault, C.; Droy-Lefaix, M.T.; Magnier, B.; Magnier, M.

    1986-01-09

    In rabbits, retinal argon laser photocoagulation disrupts the arrangement of cell layers and produces interstitial edema. Photochemical and thermal energy is released with production of free oxygenated radicals that are responsible for destruction of cell membranes. Retinal argon laser photocoagulation in rabbits was used as a pharmacologic model to evaluate the protective effect of EGB 761 against membrane lesions and edema. As a strong free radicals scavengers, EGB 761 confirms its protective action on cells membranes and its anti-edema effect.

  19. Effect of Ginkgo biloba on the lesions induced by retinal argon laser photocoagulation in rabbits

    International Nuclear Information System (INIS)

    In rabbits, retinal argon laser photocoagulation disrupts the arrangement of cell layers and produces interstitial edema. Photochemical and thermal energy is released with production of free oxygenated radicals that are responsible for destruction of cell membranes. Retinal argon laser photocoagulation in rabbits was used as a pharmacologic model to evaluate the protective effect of EGB 761 against membrane lesions and edema. As a strong free radicals scavengers, EGB 761 confirms its protective action on cells membranes and its anti-edema effect

  20. Genetics Home Reference: retinitis pigmentosa

    Science.gov (United States)

    ... by the combination of vision loss and hearing loss beginning early in life. Retinitis pigmentosa is also a feature of several other genetic syndromes, including Bardet-Biedl syndrome ; Refsum disease ; and neuropathy, ... for retinitis pigmentosa lead to a gradual loss of rods and cones in the retina. The ...

  1. New Wrinkles in Retinal Densitometry

    OpenAIRE

    Masella, Benjamin D.; Hunter, Jennifer J.; Williams, David R.

    2014-01-01

    Retinal densitometry has the potential to provide objective information about the function of the retina. However, a number of factors complicate the interpretation of retinal reflectance. We have discovered additional sources of reflectance change and have defined a method to minimize their impact.

  2. Functional link between ferroxidase activity of ceruloplasmin and protective effect of apo-lactoferrin: studying rats kept on a silver chloride diet.

    Science.gov (United States)

    Kostevich, Valeria A; Sokolov, Alexey V; Kozlov, Stanislav O; Vlasenko, Anna Yu; Kolmakov, Nikolay N; Zakharova, Elena T; Vasilyev, Vadim B

    2016-08-01

    Strongly pronounced argyrosis caused by adding AgCl to the feed of laboratory rats efficiently mimics the deficiency of ceruloplasmin (CP) ferroxidase activity. Bringing the concentration of AgCl in the feedstuff of lactating rats to 250 mg % and keeping their progeny (Ag-rats) for 3 months on the same silver-containing feed provided the serum iron content 1.4 times lower than that in the control group. Besides, the ferroxidase activity of CP dropped to zero. In CP purified from sera of Ag-rats two copper ions were substituted with two silver ions. Using rat models of both post-hemorrhagic and hemolytic anemia we showed that the deficiency of CP ferroxidase activity in Ag-rats affects the iron content in serum, though does not prevent the recovery of hemoglobin level accompanied by exhaustion of iron caches in liver and spleen. When apo-lactoferrin (apo-LF) was administered to Ag-rats suffering from either post-hemorrhagic or hemolytic anemia, both hemoglobin and serum iron were restored more rapidly than in the control animals. In independent experiments Ag-rats were compared with those fed on regular diet and the former displayed a prolonged 3-day stabilization of hypoxia-inducible factors 1 and 2 alpha (HIF-1a and HIF-2a) along with an increased serum concentration of erythropoietin. Introduction to Ag-rats of active CP separately or together with apo-LF reduced that effect to 1 day only. It is concluded that saturation of apo-LF with iron, provided by active CP, can strongly affect its protective capacity. PMID:27377930

  3. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash in...

  4. 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.

  5. Ethyl Pyruvate Prevents Methyglyoxal-Induced Retinal Vascular Injury in Rats

    Directory of Open Access Journals (Sweden)

    Junghyun Kim

    2013-01-01

    Full Text Available Pyruvate is an endogenous antioxidant substance. The aim of this study was to investigate the protective effects of ethyl pyruvate (EP on retinal vascular injury in diabetic retinopathy. To investigate the protective effect of EP on vascular cell apoptosis and blood-retinal barrier (BRB breakage, we have used intravitreally methylglyoxal-(MGO- injected rat eyes. Apoptosis of the retinal vascular cell that was stimulated by the intravitreal injection of MGO was evidently attenuated by the EP treatment. EP exerts inhibitory effect on MGO-induced vascular cell apoptosis by blocking oxidative injury. In addition, EP treatment prevented MGO-induced BRB breakage and the degradation of occludin, an important tight junction protein. These observations suggest that EP acts through an antioxidant mechanism to protect against oxidative stress-induced apoptosis in retinal vessels.

  6. Retinal synaptic regeneration via microfluidic guiding channels

    OpenAIRE

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

    2015-01-01

    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 demon...

  7. Retinal Image Preprocessing: Background and Noise Segmentation

    OpenAIRE

    Usman Akram

    2012-01-01

    Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse ...

  8. Lycium barbarum polysaccharides reduce neuronal damage, blood-retinal barrier disruption and oxidative stress in retinal ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Suk-Yee Li

    Full Text Available Neuronal cell death, glial cell activation, retinal swelling and oxidative injury are complications in retinal ischemia/reperfusion (I/R injuries. Lycium barbarum polysaccharides (LBP, extracts from the wolfberries, are good for "eye health" according to Chinese medicine. The aim of our present study is to explore the use of LBP in retinal I/R injury. Retinal I/R injury was induced by surgical occlusion of the internal carotid artery. Prior to induction of ischemia, mice were treated orally with either vehicle (PBS or LBP (1 mg/kg once a day for 1 week. Paraffin-embedded retinal sections were prepared. Viable cells were counted; apoptosis was assessed using TUNEL assay. Expression levels of glial fibrillary acidic protein (GFAP, aquaporin-4 (AQP4, poly(ADP-ribose (PAR and nitrotyrosine (NT were investigated by immunohistochemistry. The integrity of blood-retinal barrier (BRB was examined by IgG extravasations. Apoptosis and decreased viable cell count were found in the ganglion cell layer (GCL and the inner nuclear layer (INL of the vehicle-treated I/R retina. Additionally, increased retinal thickness, GFAP activation, AQP4 up-regulation, IgG extravasations and PAR expression levels were observed in the vehicle-treated I/R retina. Many of these changes were diminished or abolished in the LBP-treated I/R retina. Pre-treatment with LBP for 1 week effectively protected the retina from neuronal death, apoptosis, glial cell activation, aquaporin water channel up-regulation, disruption of BRB and oxidative stress. The present study suggests that LBP may have a neuroprotective role to play in ocular diseases for which I/R is a feature.

  9. 睫状神经营养因子对糖尿病早期大鼠视网膜神经组织的保护作用%Protective effects of ciliary neurotrophic factor on retinal neurons in rats with early diabetes

    Institute of Scientific and Technical Information of China (English)

    梁紫岩; 张卯年

    2012-01-01

    AIM: To evaluate the protective effects of ciliary neurotrophic factor (CNTF) against retinal neurons damage in a rat model of diabetes mellitus(DM).METHODS: Forty Sprague Dawley rats (weighing 250g-280g) received an intraperitoneal injection of streptozotocin (60mg/kg). The rats were then randomly divided into two groups: the treatment (DM+CNTF) or control (DM+BSS) group. The CNTF (0.5μg/μL) or balanced salt solution (2μL) was injected into the vitreus of the rats. Apoptosis of retinal ganglion cells (RGCs) was measured and retinal ultrastructure was assessed 4 and 12 weeks after establishing the model and performing the injections.RESULTS: No difference in blood glucose or body weight was noted between the two groups. There were significantly fewer apoptotic RGCs in DM+CNTF group (8.56±1.22, P0.05).12wk时TUNEL检测DM+CNTF组大鼠神经节细胞凋亡与DM+BSS组相比减少(P<0.05).透射电镜下观察发现从4wk起两组大鼠视网膜神经组织出现细胞凋亡的改变,经CNTF治疗细胞凋亡改变有所减轻,表现为外节膜盘间隙减小,感光细胞水肿减轻及核染色质浓集减轻等.结论:CNTF对DM+CNTF组和DM+BSS组大鼠的体重及血糖无明显影响.CNTF治疗组结果显示对本实验糖尿病大鼠视网膜神经节细胞及感光细胞有一定保护作用.

  10. Chloride ingress prediction

    DEFF Research Database (Denmark)

    Frederiksen, Jens Mejer; Geiker, Mette Rica

    2008-01-01

    makes physical sense for the design engineer, i.e. the achieved chloride diffusion coefficients at 1 year and 100 years, D1 and D100 respectively, and the corresponding achieved chloride concentrations at the exposed concrete surface, C1 and C100. Data from field exposure supports the assumption of time...... dependent surface chloride concentrations and the diffusion coefficients. Model parameters for Portland cement concretes with and without silica fume and fly ash in marine atmospheric and submerged South Scandinavian environment are suggested in a companion paper based on 10 years field exposure data....

  11. Flexible retinal electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  12. Cytomegalovirus retinitis mimicking intraocular lymphoma

    Directory of Open Access Journals (Sweden)

    Patrick Gooi

    2008-12-01

    Full Text Available Patrick Gooi1, James Farmer2, Bernard Hurley3, Elliott Brodbaker41Department of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; 2Department of Pathology and Lab Medicine University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; 3Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada; 4Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CanadaAbstract: We present a case of an unusual retinal infiltrate requiring retinal biopsy for definitive diagnosis. A 62-year-old man with treated lymphoma presented with decreased vision in the right eye associated with a white retinal lesion, which extended inferonasally from an edematous disc. Intraocular lymphoma was considered as a diagnosis; thus, the patient was managed with vitrectomy and retinal biopsy. Cytological analysis of the vitreous aspirate could not rule out a lymphoproliferative disorder. The microbial analysis was negative. Histology of the lesion showed extensive necrosis and large cells with prominent nucleoli. To rule out lymphoma, a battery of immunostains was performed and all were negative. However the limited amount of tissue was exhausted in the process. Subsequently, a hematoxylin and eosin (H/E slide was destained, on which a CMV immunostain was performed. This revealed positivity in the nuclei and intranuclear inclusions within the large atypical cells. A diagnosis of CMV retinitis was made. Retinal biopsy may provide a definitive diagnosis and direct patient care toward intravenous gancyclovir in the case of CMV or toward radiation and chemotherapy for intraocular lymphoma. When faced with a limited amount of tissue, destaining regular H/E slides is a possible avenue to performing additional immunohistochemical studies.Keywords: CMV retinitis, retinal biopsy, immunohistochemistry, destaining

  13. Microsystems Technology for Retinal Implants

    Science.gov (United States)

    Weiland, James

    2005-03-01

    The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

  14. Characterization of a transformed rat retinal ganglion cell line.

    Science.gov (United States)

    Krishnamoorthy, R R; Agarwal, P; Prasanna, G; Vopat, K; Lambert, W; Sheedlo, H J; Pang, I H; Shade, D; Wordinger, R J; Yorio, T; Clark, A F; Agarwal, N

    2001-01-31

    The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the psi2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells. Expression of Thy-1 (a marker for RGC), glial fibrillary acidic protein (GFAP, a positive marker for Muller cells), HPC-1/syntaxin (a marker for amacrine cells), 8A1 (a marker for horizontal and ganglion cells) and neurotrophins was studied using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting and immunocytochemistry. One of the retinal cell clones, designated RGC-5, was positive for Thy-1, Brn-3C, Neuritin, NMDA receptor, GABA-B receptor, and synaptophysin expression and negative for GFAP, HPC-1, and 8A1, suggesting that it represented a putative RGC clone. The results of RT-PCR analysis were confirmed by immunocytochemistry for Thy-1 and GFAP. Upon further characterization by immunoblotting, the RGC-5 clone was positive for Thy-1, negative for GFAP, 8A1 and syntaxin. RGC 5 cells were also positive for the expression of neurotrophins and their cognate receptors. To establish the physiological relevance of RGC-5, the effects of serum/trophic factor deprivation and glutamate toxicity were analyzed to determine if these cells would undergo apoptosis. The protective effects of neurotrophins on RGC-5 after serum deprivation was also investigated. Apoptosis was studied by terminal deoxynucleotidyl transferase-mediated fluoresceinated dUTP nick end labeling (TUNEL). Serum deprivation resulted in apoptosis and supplementation with both BDNF and NT-4 in the growth media, protected the RGC-5 cells from undergoing apoptosis. On differentiation with succinyl concanavalin A (sConA), RGC-5 cells became sensitive to glutamate toxicity, which could be reversed by inclusion of ciplizone (MK801

  15. 77 FR 22847 - National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers...

    Science.gov (United States)

    2012-04-17

    ... Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production; Final Rule #0;#0;Federal Register... Polyvinyl Chloride and Copolymers Production AGENCY: Environmental Protection Agency (EPA). ACTION: Final... Polyvinyl Chloride and Copolymers Production. The final rules establish emission standards that apply at...

  16. 76 FR 30604 - National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers...

    Science.gov (United States)

    2011-05-26

    ... Polyvinyl Chloride and Copolymers Production AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed..., the proposed rule, National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and... Polyvinyl Chloride and Copolymers Production, under Docket ID No. EPA-HQ-OAR-2002-0037 (available at...

  17. 76 FR 42613 - National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers...

    Science.gov (United States)

    2011-07-19

    ... Polyvinyl Chloride and Copolymers Production; Extension of Comment Period AGENCY: Environmental Protection... for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production is being extended for 14... extend the public comment period for the May 20, 2011, Proposed Polyvinyl Chloride and...

  18. Expansion of first-in-class drug candidates that sequester toxic all-trans-retinal and prevent light-induced retinal degeneration.

    Science.gov (United States)

    Zhang, Jianye; Dong, Zhiqian; Mundla, Sreenivasa Reddy; Hu, X Eric; Seibel, William; Papoian, Ruben; Palczewski, Krzysztof; Golczak, Marcin

    2015-01-01

    All-trans-retinal, a retinoid metabolite naturally produced upon photoreceptor light activation, is cytotoxic when present at elevated levels in the retina. To lower its toxicity, two experimentally validated methods have been developed involving inhibition of the retinoid cycle and sequestration of excess of all-trans-retinal by drugs containing a primary amine group. We identified the first-in-class drug candidates that transiently sequester this metabolite or slow down its production by inhibiting regeneration of the visual chromophore, 11-cis-retinal. Two enzymes are critical for retinoid recycling in the eye. Lecithin:retinol acyltransferase (LRAT) is the enzyme that traps vitamin A (all-trans-retinol) from the circulation and photoreceptor cells to produce the esterified substrate for retinoid isomerase (RPE65), which converts all-trans-retinyl ester into 11-cis-retinol. Here we investigated retinylamine and its derivatives to assess their inhibitor/substrate specificities for RPE65 and LRAT, mechanisms of action, potency, retention in the eye, and protection against acute light-induced retinal degeneration in mice. We correlated levels of visual cycle inhibition with retinal protective effects and outlined chemical boundaries for LRAT substrates and RPE65 inhibitors to obtain critical insights into therapeutic properties needed for retinal preservation. PMID:25538117

  19. Retinal detachment in paediatric patients

    International Nuclear Information System (INIS)

    Objective: To assess the causes of retinal detachment in children and the various operative procedures requiring vitreoretinal surgical intervention for the same. Study Design: Case series. Place and Duration of Study: Department of Ophthalmology, Al-Shifa Trust Eye Hospital, Rawalpindi, from January 2006 to May 2009. Methodology: A total of 281 eyes of 258 patients, (aged 0 - 18 years) who underwent vitreo-retinal surgical intervention for retinal detachment were included. Surgical log was searched for the type of retinal detachment and its causes. Frequencies of various interventions done in these patients viz. vitrectomy, scleral buckle, use of tamponading agents, laser photocoagulation and cryotherapy were noted. Results were described as descriptive statistics. Results: Myopia was the cause in 62 (22.1%) and trauma in 51 (18.1%) of the eyes. Total retinal detachment (RD) was treated in 94 (33.5%) eyes, sub total RD in 36 (12.8%), recurrent RD in 32 (11.4%), giant retinal tear in 28 (10%), tractional RD in 15 (5.3%) and exudative RD in 2 (0.7%). Prophylactic laser or cryotherapy was applied in 74 (26.3%) of the eyes. Pars plana vitrectomy (PPV) was carried out in 159 (56.6%) eyes while scleral buckle procedure was done in 129 (45.9%) eyes. Silicon oil was used in 149 (53%), perfluorocarbon liquid in 32 (11.4%) and gas tamponade in 20 (7.1%) eyes. Conclusion: The most common cause of retinal detachment in paediatric patients was myopia, followed by trauma. Total RD was more common as compared to the other types. The most common procedure adopted was pars plana vitrectomy followed by scleral buckle procedure. (author)

  20. Neuroprotective effect of minocycline in a rat model of branch retinal vein occlusion.

    Science.gov (United States)

    Sun, Chuan; Li, Xiao-Xin; He, Xiang-Jun; Zhang, Qi; Tao, Yong

    2013-08-01

    minocycline treatment upregulated Bcl-2 expression and inhibits TNF α expression since early stage of BRVO. We also performed Hematoxylin-Eosin (HE) and immunostaining for Iba 1 (a microgilal marker), active caspase-3, Bax, Bcl-2, IL-1 β, TNF α and found that minocycline inhibits retinal microglial activation, prevents retinal ganglion cell loss, and inhibits retinal caspase-3 activation. Thus, our study indicates that systemic administration of minocycline ameliorates retinal edema and preserves retinal function in the early stage of BRVO possibly via inhibiting microglia activation and protecting RGC from apoptosis. PMID:23748101

  1. Electrical characterization of Calcium Aluminate (CA) in presence of chloride ions

    OpenAIRE

    Torres-Luque, Marcela; Osma, Johann F.; Sánchez-Silva, Mauricio; BASTIDAS-ARTEAGA, Emilio; Schoefs, Franck

    2015-01-01

    International audience Chloride ingress is one of the major causes of reinforced concrete degradation. Chlorides accelerate the breaking of the protective layer of rebars favoring pitting corrosion; furthermore, corrosion products generate cracks in concrete, which further accelerate chloride ingress, increase porosity and reduce the strength. From a chemical perspective, the presence of chlorides and its diffusion into the reinforced concrete matrix is highly influenced by the content and...

  2. ENHANCEMENT OF CHLORIDE RESISTANCE OF PRE-STRESSED CONCRETE SHEET PILE BY BLAST FURNACE SLAG

    OpenAIRE

    Irmawaty, Rita

    2012-01-01

    Chloride-induced corrosion is one of the main mechanisms of deterioration affecting the long-term performance of concrete structures. In Japan, a large majority of structures are built either near the costal or indirect contact with seawater. The durability of reinforced or pre-stressed concrete structure depends on the resistance of concrete to chloride penetration. Naturally concrete provides physical and chemical protection to the reinforcing steel from chloride penetrating. The chloride ...

  3. Crystal structure of Halobacterium salinarum halorhodopsin with a partially depopulated primary chloride-binding site.

    Science.gov (United States)

    Schreiner, Madeleine; Schlesinger, Ramona; Heberle, Joachim; Niemann, Hartmut H

    2016-09-01

    The transmembrane pump halorhodopsin in halophilic archaea translocates chloride ions from the extracellular to the cytoplasmic side upon illumination. In the ground state a tightly bound chloride ion occupies the primary chloride-binding site (CBS I) close to the protonated Schiff base that links the retinal chromophore to the protein. The light-triggered trans-cis isomerization of retinal causes structural changes in the protein associated with movement of the chloride ion. In reverse, chemical depletion of CBS I in Natronomonas pharaonis halorhodopsin (NpHR) through deprotonation of the Schiff base results in conformational changes of the protein: a state thought to mimic late stages of the photocycle. Here, crystals of Halobacterium salinarum halorhodopsin (HsHR) were soaked at high pH to provoke deprotonation of the Schiff base and loss of chloride. The crystals changed colour from purple to yellow and the occupancy of CBS I was reduced from 1 to about 0.5. In contrast to NpHR, this chloride depletion did not cause substantial conformational changes in the protein. Nevertheless, two observations indicate that chloride depletion could eventually result in structural changes similar to those found in NpHR. Firstly, the partially chloride-depleted form of HsHR has increased normalized B factors in the region of helix C that is close to CBS I and changes its conformation in NpHR. Secondly, prolonged soaking of HsHR crystals at high pH resulted in loss of diffraction. In conclusion, the conformation of the chloride-free protein may not be compatible with this crystal form of HsHR despite a packing arrangement that hardly restrains helices E and F that presumably move during ion transport. PMID:27599860

  4. Ischemic Retinal Vasculitis and Its Management

    Directory of Open Access Journals (Sweden)

    Lazha Talat

    2014-01-01

    Full Text Available Ischemic retinal vasculitis is an inflammation of retinal blood vessels associated with vascular occlusion and subsequent retinal hypoperfusion. It can cause visual loss secondary to macular ischemia, macular edema, and neovascularization leading to vitreous hemorrhage, fibrovascular proliferation, and tractional retinal detachment. Ischemic retinal vasculitis can be idiopathic or secondary to systemic disease such as in Behçet’s disease, sarcoidosis, tuberculosis, multiple sclerosis, and systemic lupus erythematosus. Corticosteroids with or without immunosuppressive medication are the mainstay treatment in retinal vasculitis together with laser photocoagulation of retinal ischemic areas. Intravitreal injections of bevacizumab are used to treat neovascularization secondary to systemic lupus erythematosus but should be timed with retinal laser photocoagulation to prevent further progression of retinal ischemia. Antitumor necrosis factor agents have shown promising results in controlling refractory retinal vasculitis excluding multiple sclerosis. Interferon has been useful to control inflammation and induce neovascular regression in retinal vasculitis secondary to Behçet’s disease and multiple sclerosis. The long term effect of these management strategies in preventing the progression of retinal ischemia and preserving vision is not well understood and needs to be further studied.

  5. Chloride removal from vitrification offgas

    International Nuclear Information System (INIS)

    This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations

  6. 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

  7. Induced Pluripotent Stem Cells and Outer Retinal Disease

    Directory of Open Access Journals (Sweden)

    Jin Yang

    2016-01-01

    Full Text Available The retina, which is composed of multiple layers of differing cell types, has been considered the first choice for gene therapy, disease modeling, and stem cell-derived retinal cell transplant therapy. Because of its special characteristics, the retina, located in the posterior part of the eye, can be well observed directly after gene therapy or transplantation. The blood-retinal barrier is part of a specialized ocular microenvironment that is immune privileged. This protects transplanted cells and tissue. Having two eyes makes perfect natural control possible after a single eye receives gene or stem cell therapy. For this reason, research about exploring retinal diseases’ underlying molecular mechanisms and potential therapeutic approach using stem cell technique has been developing rapidly. This review is to present an up-to-date summary of the iPSC’s sources, variations, differentiation methods, and the wide-ranging application of iPSCs-RPCS or iPSCs-RPE on retinal disease modeling, diagnostics, and therapeutics.

  8. Comparative retinal physiology in anthropoids.

    Science.gov (United States)

    Kremers, J; Lee, B B

    1998-11-01

    During the last decade it has become clear that colour vision in platyrrhines (New World monkeys) differs from the uniform trichromatic pattern normally found in catarrhines (Old World monkeys, apes and human). Colour vision in most platyrrhine species is polymorphic, with many dichromatic individuals. The comparison of response properties in retinal ganglion cells and lateral geniculate cells between catarrhines and playrrhines elucidates how the evolution of trichromatic colour vision influenced the post-receptoral processing. We find that spatial and temporal processing is very similar in the platyrrhine and catarrhine retina, strongly suggesting that the retinal structure and function, found in living anthropoids, was already present in their common ancestor. PMID:9893846

  9. 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

  10. Protective effect of antioxidant N-acetylcysteine on the retinal nerve tissue of early diabetic rats%抗氧化剂 N-乙酰半胱氨酸对糖尿病大鼠早期视网膜神经组织的保护作用

    Institute of Scientific and Technical Information of China (English)

    陈玲; 张小玲; 郝扬; 史强; 王静; 张富军; 王宝英

    2016-01-01

    目的:探讨抗氧化剂N‐乙酰半胱氨酸(N‐acetylcysteine ,NAC)对糖尿病大鼠早期视网膜神经组织的保护作用。方法选用健康成年Sprague‐Dawley(SD)雄性大鼠(2月龄)60只,体质量180~220 g。随机分组为正常对照组(CON组,20只)和糖尿病组(DM组,40只)。采用腹腔注射10 g/L的链脲佐菌素(streptozotocin ,STZ)溶液(60 mg/kg)建立糖尿病大鼠模型,血糖≥16.7 mmol/L者视为糖尿病大鼠动物模型成功(32只),CON组注射等量的柠檬酸‐柠檬酸钠缓冲溶液。将糖尿病大鼠模型随机分为糖尿病1月组和糖尿病2月组,每组16只。每只糖尿病模型大鼠左眼设定为糖尿病对照组(D组),右眼设定为NAC治疗组(NAC组)。糖尿病大鼠病程2周时,NAC组玻璃体腔注射4μL (1.6μg/μL)NAC ,其余糖尿病大鼠玻璃体腔注射4μL 0.01 mmol/L的PBS。HE染色观察视网膜外核层厚度变化;透射电镜观察视网膜神经节细胞的超微结构变化;免疫荧光法检测视网膜神经节细胞的数量。结果在不同的时间点上NAC组较D组视网膜外核层厚度增加(P<0.01);而NAC组与CON组视网膜外核层厚度没有明显差异(P>0.05)。透射电镜下NAC组较D组视网膜神经节细胞中细胞器多,细胞质电子密度高,线粒体肿胀较轻;而NAC组与CON组相比视网膜神经节细胞超微结构无明显差异。在不同的时间点上NAC组较D组视网膜神经节细胞数量增加(P<0.01);而NAC组与CON组视网膜神经节细胞数量没有明显差异(P>0.05)。结论抗氧化剂NAC对糖尿病大鼠早期视网膜神经组织有保护作用。%ABSTRACT:Objective To explore the protective effect of the antioxidant N‐acetylcysteine (NAC) on the retinal nerve tissue of early diabetic rats .Methods We randomly divided 60 healthy adult Sprague‐Dawley (SD) rats weighing between 180 g

  11. Electrodeposition of Zinc from Chloride Solution

    OpenAIRE

    NAIK, Yanjerappa Arthoba; VENKATESHA, Thimmappa Venkatarangaiah

    2002-01-01

    The electroplating of zinc is carried out in the presence of 3,4,5-Trimethoxy benzaldehyde from a chloride bath. The bath constituents are optimized through Hull cell experiments. Operating parameters such as pH, temperature, and current density are also optimized. The current efficiency and throwing power are measured at different current densities. Polarization study is carried out under galvanostatic conditions. Corrosion resistance test indicated good protection of steel by the ...

  12. Investigation of factors influencing chloride extraction efficiency during electrochemical chloride extraction from reinforcing concrete

    Science.gov (United States)

    Sharp, Stephen R.

    2005-11-01

    Electrochemical chloride extraction (ECE) is an accelerated bridge restoration method similar to cathodic protection, but operates at higher current densities and utilizes a temporary installation. Both techniques prolong the life of a bridge by reducing the corrosion rate of the reinforcing bar when properly applied. ECE achieves this by moving chlorides away from the reinforcement and out of the concrete while simultaneously increasing the alkalinity of the electrolyte near the reinforcing steel. Despite the proven success, significant use of ECE has not resulted in part due to an incomplete understanding in the following areas: (1) An estimation of the additional service life that can be expected following treatment when the treated member is again subjected to chlorides; (2) The cause of the decrease in current flow and, therefore, chloride removal rate during treatment; (3) Influence of water-to-cement (w/c) ratio and cover depth on the time required for treatment. This dissertation covers the research that is connected to the last two areas listed above. To begin examining these issues, plain carbon steel reinforcing bars (rebar) were embedded in portland cement concrete slabs of varying water-to-cement (w/c) ratios and cover depths, and then exposed to chlorides. A fraction of these slabs had sodium chloride added as an admixture, with all of the slabs subjected to cyclical ponding with a saturated solution of sodium chloride. ECE was then used to remove the chlorides from these slabs while making electrical measurements in the different layers between the rebar (cathode) and the titanium mat (anode) to follow the progress of the ECE process. During this study, it was revealed that the resistance of the outer concrete surface layer increases during ECE, inevitably restricting current flow, while the resistance of the underlying concrete decreases or remains constant. During ECE treatment, a white residue formed on the surface of the concrete. Analyses of the

  13. Saffron reduces ATP-induced retinal cytotoxicity by targeting P2X7 receptors.

    Science.gov (United States)

    Corso, Lucia; Cavallero, Anna; Baroni, Debora; Garbati, Patrizia; Prestipino, Gianfranco; Bisti, Silvia; Nobile, Mario; Picco, Cristiana

    2016-03-01

    P2X7-type purinergic receptors are distributed throughout the nervous system where they contribute to physiological and pathological functions. In the retina, this receptor is found in both inner and outer cells including microglia modulating signaling and health of retinal cells. It is involved in retinal neurodegenerative disorders such as retinitis pigmentosa and age-related macular degeneration (AMD). Experimental studies demonstrated that saffron protects photoreceptors from light-induced damage preserving both retinal morphology and visual function and improves retinal flicker sensitivity in AMD patients. To evaluate a possible interaction between saffron and P2X7 receptors (P2X7Rs), different cellular models and experimental approaches were used. We found that saffron positively influences the viability of mouse primary retinal cells and photoreceptor-derived 661W cells exposed to ATP, and reduced the ATP-induced intracellular calcium increase in 661W cells. Similar results were obtained on HEK cells transfected with recombinant rat P2X7R but not on cells transfected with rat P2X2R. Finally, patch-clamp experiments showed that saffron inhibited cationic currents in HEK-P2X7R cells. These results point out a novel mechanism through which saffron may exert its protective role in neurodegeneration and support the idea that P2X7-mediated calcium signaling may be a crucial therapeutic target in the treatment of neurodegenerative diseases. PMID:26739703

  14. [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.

  15. 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

  16. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  17. Methane attenuates retinal ischemia/reperfusion injury via anti-oxidative and anti-apoptotic pathways.

    Science.gov (United States)

    Liu, Lin; Sun, Qinglei; Wang, Ruobing; Chen, Zeli; Wu, Jiangchun; Xia, Fangzhou; Fan, Xian-Qun

    2016-09-01

    Retinal ischemia/reperfusion injury (IRI) may cause incurable visual impairment due to neural regeneration limits. Methane was shown to exert a protective effect against IRI in many organs. This study aims to explore the possible protective effects of methane-rich saline against retinal IRI in rat. Retinal IRI was performed on the right eyes of male Sprague-Dawley rats, which were immediately injected intraperitoneally with methane-saturated saline (25ml/kg). At one week after surgery, the number of retinal ganglion cells (RGCs), total retinal thickness, visual function were measured by hematoxylin and eosin staining, FluoroGold anterograde labeling and flash visual evoked potentials. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), 4-Hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-9, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in retinas were assessed by immunofluorescence staining, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. As expected, methane treatment significantly improved the retinal IRI-induced RGC loss, total retinal layer thinning and visual dysfunction. Moreover, methane treatment significantly reduced the levels of oxidative stress biomarkers (8-OHdG, 4-HNE, MDA) and increased the antioxidant enzyme activities (SOD, CAT, GPx) in the retinas with IRI. Meanwhile, methane treatment significantly increased the anti-apoptotic gene (Bcl-2) expression and decreased the pro-apoptotic gene (Bax) expression, accompanied by the suppression of caspase-3 and caspase-9 activity. Thus, these data demonstrated that methane can exert a neuroprotective role against retinal IRI through anti-oxidative and anti-apoptotic pathways. PMID:27208496

  18. [Degradation of succinylcholine chloride].

    Science.gov (United States)

    Németh, G; Török, I; Paál, T

    1993-05-01

    Quantitative thin-layer chormatographic method has been developed for the investigation of the degradation of injection formulations containing succinylcholinium chloride. The method is based on the denistometric determination of the main degradation product, choline at 430 nm after visualization with iodine vapour. The stability of the injection was investigated under various storage conditions and it has been stated that considerable decomposition takes place during as short a period as one week. PMID:8362654

  19. The Extract of Aster Koraiensis Prevents Retinal Pericyte Apoptosis in Diabetic Rats and Its Active Compound, Chlorogenic Acid Inhibits AGE Formation and AGE/RAGE Interaction

    Directory of Open Access Journals (Sweden)

    Junghyun Kim

    2016-09-01

    Full Text Available Retinal capillary cell loss is a hallmark of early diabetic retinal changes. Advanced glycation end products (AGEs are believed to contribute to retinal microvascular cell loss in diabetic retinopathy. In this study, the protective effects of Aster koraiensis extract (AKE against damage to retinal vascular cells were investigated in streptozotocin (STZ-induced diabetic rats. To examine this issue further, AGE accumulation, nuclear factor-kappaB (NF-κB and inducible nitric oxide synthase (iNOS were investigated using retinal trypsin digests from streptozotocin-induced diabetic rats. In the diabetic rats, TUNEL (Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling-positive retinal microvascular cells were markedly increased. Immunohistochemical studies revealed that AGEs were accumulated within the retinal microvascular cells, and this accumulation paralleled the activation of NF-κB and the expression of iNOS in the diabetic rats. However, AKE prevented retinal microvascular cell apoptosis through the inhibition of AGE accumulation and NF-κB activation. Moreover, to determine the active compounds of AKE, two major compounds, chlorogenic acid and 3,5-di-O-caffeoylquinic acid, were tested in an in vitro assay. Among these compounds, chlorogenic acid significantly reduced AGE formation as well as AGE/RAGE (receptor for AGEs binding activity. These results suggest that AKE, particularly chlorogenic acid, is useful in inhibiting AGE accumulation in retinal vessels and exerts a preventive effect against the injuries of diabetic retinal vascular cells.

  20. An insight into the passivation of cupronickel alloys in chloride environment

    Indian Academy of Sciences (India)

    J Mathiyarasu; N Palaniswamy; V S Muralidharan

    2001-02-01

    Cupronickels offer enhanced corrosion protection in marine environments by the formation of passive films on the surface. Cyclic voltammetric studies were carried on cupronickels in chloride solutions at H 6.3 to understand the role of chloride ions in passive film formation. Increase in nickel content of the alloy and of chloride ions in solution decreases film resistance. Chloride ions take part in reduction of the passive film to copper. A solid-state model for passive film formation involving chloride ions has been attempted.

  1. Retinal vasculature classification using novel multifractal features

    International Nuclear Information System (INIS)

    Retinal blood vessels have been implicated in a large number of diseases including diabetic retinopathy and cardiovascular diseases, which cause damages to retinal blood vessels. The availability of retinal vessel imaging provides an excellent opportunity for monitoring and diagnosis of retinal diseases, and automatic analysis of retinal vessels will help with the processes. However, state of the art vascular analysis methods such as counting the number of branches or measuring the curvature and diameter of individual vessels are unsuitable for the microvasculature. There has been published research using fractal analysis to calculate fractal dimensions of retinal blood vessels, but so far there has been no systematic research extracting discriminant features from retinal vessels for classifications. This paper introduces new methods for feature extraction from multifractal spectra of retinal vessels for classification. Two publicly available retinal vascular image databases are used for the experiments, and the proposed methods have produced accuracies of 85.5% and 77% for classification of healthy and diabetic retinal vasculatures. Experiments show that classification with multiple fractal features produces better rates compared with methods using a single fractal dimension value. In addition to this, experiments also show that classification accuracy can be affected by the accuracy of vessel segmentation algorithms. (paper)

  2. 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.

  3. Reliability of retinal vessel calibre measurements using a retinal oximeter

    OpenAIRE

    Heitmar, Rebekka; Kalitzeos, Angelos A.

    2015-01-01

    Background Summarised retinal vessel diameters are linked to systemic vascular pathology. Monochromatic images provide best contrast to measure vessel calibres. However, when obtaining images with a dual wavelength oximeter the red-free image can be extracted as the green channel information only which in turn will reduce the number of photographs taken at a given time. This will reduce patient exposure to the camera flash and could provide sufficient quality images to reliably measure vessel...

  4. Automatic diagnosis of retinal diseases from color retinal images

    OpenAIRE

    Jayanthi, D.; N. Devi; 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...

  5. Role of retinal metabolism in methanol-induced retinal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Garner, C.D. [General Motors Corp., Warren, MI (United States)]|[Wayne State Univ., Detroit, MI (United States); Lee, E.W.; Terzo, T.S. [General Motors Corp., Warren, MI (United States); Louis-Ferdinand, R.T. [Wayne State Univ., Detroit, MI (United States)

    1995-08-01

    Methanol is a toxicant that causes systemic and ocular toxicity after acute exposure. The folate-reduced (FR) rat is an excellent animal model that mimics characteristic human methanol toxic responses. The present study examines the role of the methanol metabolites formaldehyde and formate in the initiation of methanol-induced retinal toxicity. After a single oral dose of 3.0 g/kg methanol, blood methanol concentrations were not significantly different in FR rats compared with folate-sufficient (FS) (control) rats. However, FR rats treated with 3.0 g/kg methanol displayed elevated blood (14.6 mM) and vitreous humor (19.5 mM) formate levels and abnormal electroretinograms (loss of b-wave) 48 h postdose. FR rats pretreated with disulfiram (DSF) prior to 3.0 g/kg methanol treatment failed to display these symptoms. Formaldehyde was not detected in blood or vitreous humor with or without DSF treatment, suggesting that formate is the toxic metabolite in methanol-induced retinal toxicity. Additionally, creating a blood formate profile (14.2 mM at 48 h) similar to that observed in methanol-treated rats by iv infusion of pH-buffered formate does not alter the electroretinogram as is observed with methanol treatment. These data suggest that intraretinal metabolism of methanol is necessary for the formate-mediated initiation of methanol-induced retinal toxicity. 31 refs., 5 figs., 2 tabs.

  6. Boldine action against the stannous chloride effect.

    Science.gov (United States)

    Reiniger, I W; Ribeiro da Silva, C; Felzenszwalb, I; de Mattos, J C; de Oliveira, J F; da Silva Dantas, F J; Bezerra, R J; Caldeira-de-Araújo, A; Bernardo-Filho, M

    1999-12-15

    Peumus boldus extract has been used in popular medicine in the treatment of biliar litiase, hepatic insufficiency and liver congestion. Its effects are associated to the substance boldine that is present in its extract. In the present work, we evaluated the influence of boldine both in: (i) the structural conformation of a plasmid pUC 9.1 through gel electrophoresis analysis; and in (ii) the survival of the strain of Escherichia coli AB1157 submitted to reactive oxygen species (ROS), generated by a Fenton like reaction, induced by stannous chloride. Our results show a reduction of the lethal effect induced by stannous chloride on the survival of the E. coli culture in the presence of boldine. The supercoiled form of the plasmid is not modified by stannous chloride in the presence of boldine. We suggest that the protection induced by boldine could be explained by its anti-oxidant mechanism. In this way, the boldine could be reacting with stannous ions, protecting them against the oxidation and, consequently, avoiding the generation of ROS. PMID:10624900

  7. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Science.gov (United States)

    2010-07-01

    ...)-N,N-dimethyl-, N-soya acyl derivs., chlorides. 721.10056 Section 721.10056 Protection of Environment...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses...-dimethyl-, N-soya acyl derivs., chlorides (PMN P-03-47; CAS No. 90194-13-1) is subject to reporting...

  8. 40 CFR Table 4 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits

    Science.gov (United States)

    2010-07-01

    ... Process Heaters With Hydrogen Chloride Emission Limits 4 Table 4 to Subpart DDDDD of Part 63 Protection of... Heaters With Hydrogen Chloride Emission Limits As stated in § 63.7500, you must comply with the following applicable operating limits: If you demonstrate compliance with applicable hydrogen chloride emission...

  9. Retinal Image Preprocessing: Background and Noise Segmentation

    Directory of Open Access Journals (Sweden)

    Usman Akram

    2012-07-01

    Full Text Available Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse segmentation and fine segmentation. Standard retinal images databases Diaretdb0, Diaretdb1, DRIVE and STARE are used to test the validation of our preprocessing technique. The experimental results show the validity of proposed preprocessing technique.

  10. Current perspectives of herpesviral retinitis and choroiditis.

    Science.gov (United States)

    Madhavan, H N; Priya, K; Biswas, J

    2004-10-01

    Vision-threatening viral retinitis are primarily caused by members of the herpesvirus family. The biology and molecular characterization of herpesviruses, clinical presentations of retinopathies, pathology and pathogenesis including the host responses, epidemiology and the laboratory methods of aetiological diagnosis of these diseases are described. Clinical syndromes are acute retinal necrosis (ARN), progressive outer retinal necrosis (PORN), cytomegalovirus (CMV) retinitis, multifocal choroiditis and serpiginous choroiditis besides other viral retinopathies. Herpes simplex virus (HSV) retinitis is more common in immunocompetent persons while varicella zoster virus (VZV) affects both immunocompetent and immunosuppressed patients equally. CMV retinitis is most common among patients with AIDS. The currently employed laboratory methods of antigen detection, virus isolation and antibody detection by enzyme linked immuno-sorbent assay (ELISA) have low sensitivity. Polymerase chain reaction (PCR) has increased the value of diagnosis due to its high clinical sensitivity and absolute specificity in detection of herpesviruses in intraocular specimens. PMID:16295367

  11. Advances in Retinal Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    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.

  12. 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......, 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......-measurements in three pigs. This relationship was approximately linear (R(2) = 0.45, p = 0.04). CONCLUSIONS: Non-invasive spectrophotometric oximetry is sensitive to changes in oxygen saturation in pigs and correlated with intravitreal pO2-measurements and with femoral artery pO2. Pigs present a higher intra...

  13. Retinal vein occlusion: current treatment.

    Science.gov (United States)

    Lattanzio, Rosangela; Torres Gimeno, Ana; Battaglia Parodi, Maurizio; Bandello, Francesco

    2011-01-01

    Retinal vein occlusion (RVO) is a pathology noted for more than 150 years. Although a lot has been written on the matter, it is still a frequent condition with multifactorial etiopathogenesis with many unclear aspects. The RVO pathogenesis has varied systemic and local implications that make it difficult to elaborate treatment guidelines. The management of the patient with RVO is very complex and a multidisciplinary approach is required in order to identify and correct the associated risk factors. Laser therapy remains the gold standard in RVO, but only modest functional improvement has been shown in branch retinal occlusion forms. Multicenter studies of intravitreal drugs present them as an option to combine with laser. Anti-vascular endothelial growth factor, corticosteroids and sustained-release implants are the future weapons to stop disease progression and get a better visual outcome. Consequently, it is useful to clarify some aspects of the pathology that allow a better patient management. PMID:20938213

  14. The protective effect of erythropoietin on cultured retinal Müller cells injured by high glucose%促红细胞生成素对高浓度葡萄糖培养大鼠视网膜 Müller 细胞的保护作用

    Institute of Scientific and Technical Information of China (English)

    曲虹; 厉泉

    2015-01-01

    Objective To investigate the protective effect of erythropoietin on cultured retinal Müller cells injured by high glucose. Methods Neonatal rats’ retinal Müller cells of serial subcultivation were divided into N (normal control group), G (25 mmol/L glucose) group, E1G (1×104 IU/L recombinant human erythropoietin+25 mmol/L glucose) group, E2G (2×104 IU/L recombinant human erythropoietin+25 mmol/L glucose) group and E4G (4×104 IU/L recombinant human erythropoietin+25 mmol/L glucose) group. MTT assay was applied to detect cells viability in five groups. The expression of caspase-3 was detected with enzyme linked immunosorbent assay. Results Cell viability of G group, E1G group, E2G group and E4C group were lower than that of N group. Cell viability of E1G group, E2G group and E4C group were higher than that of G group, E4G group was higher than that of E2G group and E2G group was higher than that of E1G group. The expression of caspase-3 in E1G group, E2G group and E4G group were lower than that in G group which was high compared with N group. The expression of caspase-3 in E1G group, E2G group and E4G group were lower than that in G group which was high compared with N group. With the increase of rhEPO, the expression of caspase-3 was reducing. Conclusion Erythropoietin pretreatment could effectively protect the cultured retinal Müller cells from injuries induced by high glucose.%目的:探讨促红细胞生成素对高浓度葡萄糖培养大鼠视网膜Müller细胞的保护作用。方法体外传代培养大鼠视网膜Müller细胞,分组为N组(正常对照),G组(25 mmol/L葡萄糖), E1G组(1×104 IU/L rhEPO+25 mmol/L葡萄糖),E2G组(2×104 IU/L rhEPO+25 mmol/L葡萄糖), E4G组(4×104 IU/L rhEPO+25 mmol/L葡萄糖),MTT比色法比较五组视网膜Müller细胞活力的改变。酶联免疫吸附试验检测各组细胞caspase-3蛋白表达的情况。结果 G组、E1G组、E2G组、E4G组

  15. Cytomegalovirus retinitis mimicking intraocular lymphoma

    OpenAIRE

    Gooi, Patrick

    2008-01-01

    Patrick Gooi1, James Farmer2, Bernard Hurley3, Elliott Brodbaker41Department of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; 2Department of Pathology and Lab Medicine University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; 3Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada; 4Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CanadaAbstract: We present a case of an unusual retinal infiltra...

  16. Acquired retinal folds in the cat.

    Science.gov (United States)

    MacMillan, A D

    1976-06-01

    Retinal folds were found in 5 cats. The apparent cause of the folding was varied: in 1 cat the folds appeared after a localized retinal detachment; in 2 cats the condition accompanied other intraocular abnormalities associated with feline infectious peritonitis; 1 cat had active keratitis, and the retinal changes were thought to have been injury related; and 1 cat, bilaterally affected, had chronic glomerulonephritis. PMID:945253

  17. Retinal Vascular Fractals and Cognitive Impairment

    OpenAIRE

    Ong, Yi-Ting; Hilal, Saima; Cheung, Carol Yim-Lui; Xu, Xin; Chen, Christopher; Venketasubramanian, Narayanaswamy; Wong, Tien Yin; Ikram, Mohammad Kamran

    2014-01-01

    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...

  18. Retinal Vascular Fractals and Cognitive Impairment

    OpenAIRE

    Yi-Ting Ong; Saima Hilal; Carol Yim-lui Cheung; Xin Xu; Christopher Chen; Narayanaswamy Venketasubramanian; Tien Yin Wong; Mohammad Kamran Ikram

    2014-01-01

    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 photograp...

  19. 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.

  20. Intravitreal injection of erythropoietin sustained-release microspheres protects damaged retinal ganglion cells in rats%促红细胞生成素缓释微球玻璃体腔注射对视网膜神经节细胞的保护作用

    Institute of Scientific and Technical Information of China (English)

    荣先芳; 莫晓芬; 任甜甜; 袁伟恩; 王艳; 王鑫

    2010-01-01

    目的 探讨乳酸/羟基乙酸共聚物(PLGA)装载的促红细胞生成素(EPO)缓释微球(EPO-PLGA微球)经玻璃体腔注射对大鼠视神经挫伤模型中受损视网膜神经节细胞(RGC)的保护作用.方法 选取成年SD大鼠,建立视神经挫伤模型.建模后分别经玻璃体腔内注射含10 IU EPO的PLGA微球(EPO-PLGA组)、10 IU EPO(EPO组)、5 μl空白PLGA(PLGA组)、5 μl PBS(PBS组),另设未治疗组不予玻璃体腔注药.术后5 d和2周,做视网膜切片,对各组RGC凋亡情况行TUNEL检测;术后23 d,DiI上丘逆标RGC,并于术后4周处死大鼠,视网膜铺片观察各组RGC存活情况;每组各个时间点分别处死6只SD大鼠.采用方差分析对结果进行比较.结果 TUNEL检测显示,术后5 d和2周,各组均可见TUNEL阳性细胞,其中EPO-PLGA组和EPO组TUNEL阳性细胞显著减少,其细胞凋亡率明显少于PLGA组、PBS组及未治疗组.术后4周,视网膜铺片RGC计数显示,正常SD大鼠RGC密度为(2387.7±164.9)个/mm2,未治疗组为(748.3±58.8)个/mm2,EPO-PLGA组为(1296.7±157.6)个/mm2,EPO组为(1418.5±154.9)个/mm2,PLGA组为(821.7±52.1)个/mm2,PBS组为(804.4±86.4)个/mm2;可见EPO-PLGA组和EPO组较未治疗组细胞密度显著增高,具有明显的RGC保护作用(P均<0.01),而EPO-PLGA组和EPO组间差异无统计学意义(P=0.065).结论 EPO-PLGA缓释微球与EPO具有等效的RGC保护作用,这为进一步观察EPO-PLGA缓释微球的长效神经保护作用奠定了基础.%Objective To investigate the protective effect of erythropoietin (EPO) encapsulated in poly (L-lactic-co-glycolic acid) (PLGA) microspheres on damaged retinal ganglion cell (RGC) by intravitreal injection after optic nerve crush. Methods Adult SD rats were selected to establish an optic nerve crush model. Immediately after the crush, the animals received intravitreal doses of 10 IU EPO of EPO-PLGA microspheres (EPO-PLGA group), 10 IU EPO (EPO group), blank PLGA microshperes (PLGA group), and PBS (PBS

  1. Protective Effect of Meso-Tetrakis-(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin on the In Vivo Impact of Trimethyltin Chloride on the Antioxidative Defense System

    OpenAIRE

    Victor N. Chernyshev; Pustovalova, Lydia M.; Dodochova, Margarita A.; Yulia A. Gracheva; Vladimir Yu. Tyurin; Milaeva, Elena R.

    2006-01-01

    The in vivo effect of trimethyltin chloride (Me3SnCl), free base meso-tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin (R′4PH2) and their equimolar mixture, on the enzymatic activity of catalase (CAT), superoxide dismutase (SOD), and on the total content of free sulfhydryl groups has been studied in rat liver and kidney. It was demonstrated that the simultaneous treatment of tested animals with the combination of Me3SnCl and R′4PH2 reduced the toxic impact of Me3SnCl....

  2. Protective Effect of Meso-Tetrakis-(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin on the In Vivo Impact of Trimethyltin Chloride on the Antioxidative Defense System

    OpenAIRE

    Milaeva, Elena R.; Tyurin, Vladimir Yu.; Yulia A. Gracheva; Dodochova, Margarita A.; Pustovalova, Lydia M.; Victor N. Chernyshev

    2006-01-01

    The in vivo effect of trimethyltin chloride (Me3SnCl), free base meso-tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin (R′4PH2) and their equimolar mixture, on the enzymatic activity of catalase (CAT), superoxide dismutase (SOD), and on the total content of free sulfhydryl groups has been studied in rat liver and kidney. It was demonstrated that the simultaneous treatment of tested animals with the combination of Me3SnCl and R′4PH2 reduced the toxic impact of Me3SnCl.

  3. Protective Effect of Meso-Tetrakis-(3,5-di-tert- butyl-4-hydroxyphenyl)porphyrin on the In Vivo Impact of Trimethyltin Chloride on the Antioxidative Defense System

    OpenAIRE

    Milaeva, Elena R.; Tyurin, Vladimir Yu.; Yulia A. Gracheva; Dodochova, Margarita A.; Pustovalova, Lydia M.; Victor N. Chernyshev

    2006-01-01

    The in vivo effect of trimethyltin chloride (Me3SnCl), free base meso-tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin (R′4PH2) and their equimolar mixture, on the enzymatic activity of catalase (CAT), superoxide dismutase (SOD), and on the total content of free sulfhydryl groups has been studied in rat liver and kidney. It was demonstrated that the simultaneous treatment of tested animals with the combination of Me3SnCl and R′4PH2 reduced the toxic impact of Me3SnCl.

  4. Applicability of boron-doped diamond electrode to the degradation of chloride-mediated and chloride-free wastewaters

    International Nuclear Information System (INIS)

    The electrochemical degradation of chloride-mediated and chloride-free dye wastewaters was investigated on a boron-doped diamond (BDD) electrode in comparison with that on a dimensionally stable anode (DSA), and the applicability of BDD electrode to the degradation of these two kinds of wastewaters was explored. In chloride-free wastewater, the electrochemical degradation efficiency of dye on BDD electrode was much higher than that on DSA, with a chemical oxygen demand (COD) removal of 100% and 26% for BDD and DSA, respectively. In chloride-mediated dye wastewater, COD removal was faster than that in chloride-free wastewater on both BDD and DSA electrodes with COD removal efficiencies higher than 95%, whereas the rate of COD removal on DSA was faster than that on BDD electrode. The investigation indicates that DSA is more suitable than BDD electrode in degradation of originally chloride contained dye wastewaters for the sake of energy and time saving. However, for chloride-free dye wastewaters, with the aim of environmental protection, BDD electrode is more appropriate to realize complete mineralization. At the same time, the secondary pollution can be avoided

  5. Activation of autophagy in photoreceptor necroptosis after experimental retinal detachment

    Institute of Scientific and Technical Information of China (English)

    Kai; Dong; Zi-Cheng; Zhu; Feng-Hua; Wang; Gen-Jie; Ke; Zhang; Yu; Xun; Xu

    2014-01-01

    AIM:To investigate whether photoreceptor necroptosis induced by z-VAD-FMK(pan caspase inhibitor) was involved the activation of autophagy and whether Necrostatin-1, a specific necroptosis inhibitor, could inhibit this induction of autophagy after experimental retinal detachment.METHODS:Experimental retinal detachment models were created in Sprague-Dawley rats by subretinal injection of sodium hyaluronate and subretinal injections of z-VAD-FMK, vehicle or z-VAD-FMK plus Necrostatin-1.Three days after retinal detachment, morphologic changes were observed by transmission electron microscopy. In other animals, retinas were subjected to immunoprecipitation and Western Blotting, then probed with anti-RIP1, phosphoserine, LC-3II or caspase 8antibody.RESULTS:It was proved by immunoprecipitation and western blotting, that photoreceptor necroptosis was mediated by caspase-8 inhibition and receptor interacting protein kinase(RIP1) phosphorylation activation. Transmission electron microscope and western blotting results indicated that photoreceptornecroptosis was involved the LC-3II and autophagosomes induction. We also discovered Necrostatin-1 could inhibit RIP1 phosphorylation and LC-3II induction.CONCLUSION:These data firstly indicate photoreceptor necroptosis is associated with the activation of autophagy. Necrostatin-1 protects photoreceptors from necroptosis and autophagy by down-regulation of RIP1 phosphorylation and LC-3II.

  6. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

    Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

  7. Retinal damage by optical radiation. An alternative approach to current, ACGIH-inspired guidelines

    NARCIS (Netherlands)

    Vos, J.J.; Norren, D. van

    2005-01-01

    Background: The ACGIH guidelines for protection against retinal damage by optical radiation are often difficult to apply due to their lack of transparency. The less known guidelines by the Netherlands Health Council (HCN), dating from 1978 and updated in 1993, might offer a way out in many cases. Me

  8. 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

  9. 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. PMID:26855177

  10. Prevalence of generalized retinal dystrophy in Denmark

    DEFF Research Database (Denmark)

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

    2014-01-01

    PURPOSE: Generalized retinal dystrophy is a frequent cause of visual impairment and blindness in younger individuals and a subject of new clinical intervention trials. Nonetheless, there are few nation-wide population-based epidemiological data of generalized retinal dystrophy. The purpose of thi...

  11. Caffeine administration prevents retinal neuroinflammation and loss of retinal ganglion cells in an animal model of glaucoma

    Science.gov (United States)

    Madeira, Maria H.; Ortin-Martinez, Arturo; Nadal-Nícolas, Francisco; Ambrósio, António F.; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta; Santiago, Ana Raquel

    2016-01-01

    Glaucoma is the second leading cause of blindness worldwide, being characterized by progressive optic nerve damage and loss of retinal ganglion cells (RGCs), accompanied by increased inflammatory response involving retinal microglial cells. The etiology of glaucoma is still unknown, and despite elevated intraocular pressure (IOP) being a major risk factor, the exact mechanisms responsible for RGC degeneration remain unknown. Caffeine, which is an antagonist of adenosine receptors, is the most widely consumed psychoactive drug in the world. Several evidences suggest that caffeine can attenuate the neuroinflammatory responses and afford protection upon central nervous system (CNS) injury. We took advantage of a well characterized animal model of glaucoma to investigate whether caffeine administration controls neuroinflammation and elicits neuroprotection. Caffeine or water were administered ad libitum and ocular hypertension (OHT) was induced by laser photocoagulation of the limbal veins in Sprague Dawley rats. Herein, we show that caffeine is able to partially decrease the IOP in ocular hypertensive animals. More importantly, we found that drinking caffeine prevented retinal microglia-mediated neuroinflammatory response and attenuated the loss of RGCs in animals with ocular hypertension (OHT). This study opens the possibility that caffeine or adenosine receptor antagonists might be a therapeutic option to manage RGC loss in glaucoma. PMID:27270337

  12. 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.

  13. Retinal Artery Occlusion Treatment with Hyperbaric Oxygen

    Directory of Open Access Journals (Sweden)

    Harun Cakmak

    2016-01-01

    Full Text Available Retinal artery occlusion is one of the vision-threating emergency situations in ophthalmology. In this paper, a case of retinal artery occlusion is presented. Fifty seven year- old female patient presented with a sudden onset visual loss in her left eye. Best corrected visual acuity (BCVA levels were 1.0 and 0.7 in the right and left eye, respectiveley. Dilated fundus examination revealed no pathological finding in the right eye. Whereas calcified plaque was seen in upper arquat artery bifurcation in the left eye. Pallorness with retinal edema was seen in this arterial trace. Retinal artery occlusion was diagnosed and patient was referred for hyperbaric oxygen therapy. After a total of 20 sessions of hyperbaric oxygen therapy, the calcified plaques disappeared and her BCVA increased to 20/20. Hyperbaric oxygen treatment is vision-saving method which should be considered in retinal artery occlusion.

  14. Sildenafil alters retinal function in mouse carriers of retinitis pigmentosa.

    Science.gov (United States)

    Nivison-Smith, Lisa; Zhu, Yuan; Whatham, Andrew; Bui, Bang V; Fletcher, Erica L; Acosta, Monica L; Kalloniatis, Michael

    2014-11-01

    Sildenafil, the active ingredient in Viagra, has been reported to cause transient visual disturbance from inhibition of phosphodiesterase 6 (PDE6), a key enzyme in the visual phototransduction pathway. This study investigated the effects of sildenafil on the rd1(+/-) mouse, a model for carriers of Retinitis Pigmentosa which exhibit normal vision but may have a lower threshold for cellular stress caused by sildenafil due to a heterozygous mutation in PDE6. Sildenafil caused a dose-dependent decrease in electroretinogram (ERG) responses of normal mice which mostly recovered two days post administration. In contrast, rd1(+/-) mice exhibited a significantly reduced photoreceptor and a supernormal bipolar cell response to sildenafil within 1 h of treatment. Carrier mice retinae took two weeks to return to baseline levels suggesting sildenafil has direct effects on both the inner and outer retina and these effects differ significantly between normal and carrier mice. Anatomically, an increase in expression of the early apoptotic marker, cytochrome C in rd1(+/-) mice indicated that the effects of sildenafil on visual function may lead to degeneration. The results of this study are significant considering approximately 1 in 50 people are likely to be carriers of recessive traits leading to retinal degeneration. PMID:25239397

  15. 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.

  16. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride III Appendix III to Part 266 Protection of Environment... to Part 266—Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride...

  17. 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.

  18. 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

  19. Bone marrow-derived cells are differentially involved in pathological and physiological retinal angiogenesis in mice

    International Nuclear Information System (INIS)

    Purpose: Bone marrow-derived cells have been shown to play roles in angiogenesis. Although these cells have been shown to promote angiogenesis, it is not yet clear whether these cells affect all types of angiogenesis. This study investigated the involvement of bone marrow-derived cells in pathological and physiological angiogenesis in the murine retina. Materials and methods: The oxygen-induced retinopathy (OIR) model was used as a retinal angiogenesis model in newborn mice. To block the influence of bone marrow-derived cells, the mice were irradiated with a 4-Gy dose of radiation from a 137Cs source. Irradiation was performed in four different conditions with radio dense 2-cm thick lead disks; (1) H group, the head were covered with these discs to protect the eyes from radiation; (2) A group, all of the body was covered with these discs; (3) N group, mice were completely unshielded; (4) C group, mice were put in the irradiator but were not irradiated. On P17, the retinal areas showing pathological and physiological retinal angiogenesis were measured and compared to the retinas of nonirradiated mice. Results: Although irradiation induced leukocyte depletion, it did not affect the number of other cell types or body weight. Retinal nonperfusion areas were significantly larger in irradiated mice than in control mice (P < 0.05), indicating that physiological angiogenesis was impaired. However, the formation of tuft-like angiogenesis processes was more prominent in the irradiated mice (P < 0.05), indicating that pathological angiogenesis was intact. Conclusions: Bone marrow-derived cells seem to be differentially involved in the formation of physiological and pathological retinal vessels. Pathological angiogenesis in the murine retina does not require functional bone marrow-derived cells, but these cells are important for the formation of physiological vessels. Our results add a new insight into the pathology of retinal angiogenesis and bolster the hypothesis that bone

  20. Sodium chloride, potassium chloride, and virulence in Listeria monocytogenes.

    OpenAIRE

    MYERS, E. R.; Dallmier, A W; Martin, S E

    1993-01-01

    Virulence, as determined in a mouse model, and the virulence factor activities of catalase, superoxide dismutase, and listeriolysin O were examined in a parental strain (10403S) and in a nonhemolytic mutant strain (DP-L224) of Listeria monocytogenes. The cells were propagated in media containing various concentrations of sodium chloride or potassium chloride. Strains 10403S and DP-L224 exhibited significant increases in catalase activity and listeriolysin O activity when grown in medium conta...

  1. Assessment of blood-retinal barrier integrity.

    Science.gov (United States)

    Vinores, S A

    1995-01-01

    The blood-retinal barrier consists of two components which are comprised of the retinal vascular endothelium and the retinal pigment epithelium, respectively. Its functional integrity can be recognized by tight junctions between these cells with a paucity of endocytic vesicles within them and the presence of the molecules that regulate the ionic and metabolic gradients that constitute the barrier. The barrier is compromised in several disease processes and by a variety of agents, but in most cases the location and mechanism for barrier failure is not understood. Perfusion with a variety of radiolabeled tracer molecules, vitreous fluorophotometry, or magnetic resonance imaging can be used to quantitate blood-retinal barrier leakage. Fluorescein angiography or magnetic resonance imaging can localize sites of leakage in vivo with limited resolution. Evans blue dye can be used to visualize blood-retinal barrier failure in gross pathological specimens and immuno-histochemical labeling of serum proteins such as albumin or fibrinogen can be used to localize sites of blood-retinal barrier breakdown by light microscopy. Tracers such as horseradish peroxidase, microperoxidase, or lanthanum, or the immunocytochemical demonstration of albumin can be used to reveal blood-retinal barrier breakdown at the ultrastructural level and provide insights into the mechanisms involved. This review discusses the advantages and limitations of each of these methods to aid in selection of the appropriate techniques to derive the desired information.

  2. Chickenpox Chorioretinitis with Retinal Exudates and Periphlebitis

    Directory of Open Access Journals (Sweden)

    Hirokuni Kitamei

    2012-05-01

    Full Text Available Background: Chickenpox is rarely associated with posterior segment inflammation. We report on a case of unilateral chickenpox chorioretinitis with retinal exudates and periphlebitis. Case Presentation: A 21-year-old healthy man, who suffered from chickenpox 2 weeks prior to symptom development, exhibited mild anterior chamber cells, vitreous opacity, sheathing of retinal veins, and yellow-white exudates in his right eye. Varicella zoster virus DNA was detected by polymerase chain reaction in the aqueous humor. He was treated with intravenous acyclovir followed by oral prednisolone and valaciclovir. Aqueous cells quickly disappeared and retinal exudates diminished within 1 month, leaving faint retinal scarring. Retinal arteritis had never been observed in this patient. Conclusions: Although the ocular findings in this case were similar to acute retinal necrosis (ARN, the clinical features differed from ARN in the following points: (1 mild anterior chamber inflammation, (2 absence of retinal arteritis, and (3 prompt resolution of inflammatory findings. The distinctive clinical features indicated that chorioretinitis associated with chickenpox may not have the same pathological conditions as ARN.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Edaravone (MCI-186), a free radical scavenger, attenuates retinal ischemia/reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Yi SONG; Yuan-yuan GONG; Zheng-gao XIE; Cai-hong LI; Qing GU; Xing-wei WU

    2008-01-01

    Aim: To investigate the effect of edaravone (MCI-186), a free radical scavenger, against ischemia/reperfusion (I/R) injury in the rat retina. Methods: Retinal is-chemia was induced in male Sprague-Dawley rats by elevating intraocular pres-sure to 110 mmHg for 60 min. The rats were intraperitoneally injected with edaravone at a dose of 3 mg/kg at 30 min before ischemia, and then treated with edaravone (3 mg/kg, ip) twice daffy for 1 or 5 d after I/R. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the retinal tissues were determined on d 1 after I/R injury. The apoptosis of retinal neurons was detected on d 1 after I/R injury by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling staining. The electroretinogram (ERG) was recorded on d 5 after reperfusion. Results: Edaravone lowered MDA levels, raised SOD activity, and attenuated I/R-induced apoptosis of retinal neurons within the inner nuclear, gan-glion cell, and outer nuclear layers of the rat retina. Moreover, edaravone sup-pressed I/R-induced reduction in a- and b-wave amplitudes of ERG. Conclusion: Edaravone can protect the retina from I/R injury in rats through reducing oxidative stress and inhibiting apoptosis of retinal neurons, which suggests that edaravone might be a potential choice for the treatment of I/R-induced eye disorders.

  8. 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.

  9. [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

  10. Retinal isomerization dynamics in dry bacteriorhodopsin films

    Science.gov (United States)

    Colonna, Anne; Groma, Géza I.; Vos, Marten H.

    2005-10-01

    The primary photoprocesses in neutral and acid forms of oriented dried bacteriorhodopsin films were investigated by femtosecond absorption spectroscopy. The excitation energy dependence of the signals was used to distinguish photochemistry from processes involving photophysics of photocycle intermediates. Both the kinetics and the quantum yield of all- trans excited state decay by retinal photoisomerization and subsequent J → K transition were found to be very similar as in hydrated environments. Therefore, unlike slower photocycle phases, communication of the retinal with the environment does not play a role in retinal isomerization. Our results are important for understanding recent nonlinear optical applications of such films.

  11. Zinc might protect oxidative changes in the retina and pancreas at the early stage of diabetic rats

    International Nuclear Information System (INIS)

    It is well documented that oxidative stress is a basic mechanism behind the development of diabetic retinopathy (DR). The current study was undertaken to elucidate the possible role of zinc as an antioxidant and a biological membrane stabilizer in the protection against (DR). Male Wistar rats weighing 250 ± 50 g were made diabetic by injection with a single ip dose of alloxan (100 mg/kg). Another group of rats was simultaneously treated with alloxan (100 mg/kg) and a single ip dose of zinc chloride (ZnCl2) (5 mg/kg). Blood and tissue samples were collected at 24, 48, and 72 h post-treatment in both groups. Diabetic state was confirmed by the determination of plasma glucose levels (significantly elevated at any time of the experiment when compared with controls receiving vehicle). Plasma insulin was significantly increased 24 h after treatment in both alloxan and alloxan plus ZnCl2-treated groups, and then decreased markedly 48 and 72 h post treatment in both groups. Alloxan treatment depleted both retinal and liver glutathione contents. The decrease in retinal and liver GSH in alloxan-treated rats was accompanied with a sustained increase in their thiobarbituric acid (TBA) content. Simultaneous treatment of rats with alloxan and ZnCl2 blunted the sustained increment in plasma glucose induced by alloxan. The combined administration of alloxan and zinc reversed the depleting effect on retinal and hepatic GSH in alloxan-treated rats and reduced the elevations in TBA content of both retinas and livers. At variance with many other antioxidants the current results clearly indicate the beneficial effects of Zn in both controlling hyperglycemia and the protection of the retina against oxidative stress in diabetes which may help set a new direction toward the development of effective treatments of DR

  12. Chloride channels in stroke

    Institute of Scientific and Technical Information of China (English)

    Ya-ping ZHANG; Hao ZHANG; Dayue Darrel DUAN

    2013-01-01

    Vascular remodeling of cerebral arterioles,including proliferation,migration,and apoptosis of vascular smooth muscle cells (VSMCs),is the major cause of changes in the cross-sectional area and diameter of the arteries and sudden interruption of blood flow or hemorrhage in the brain,ie,stroke.Accumulating evidence strongly supports an important role for chloride (Clˉ) channels in vascular remodeling and stroke.At least three Clˉ channel genes are expressed in VSMCs:1) the TMEM16A (or Ano1),which may encode the calcium-activated Clˉ channels (CACCs); 2) the CLC-3 Clˉ channel and Clˉ/H+ antiporter,which is closely related to the volume-regulated Clˉ channels (VRCCs); and 3) the cystic fibrosis transmembrane conductance regulator (CFTR),which encodes the PKA-and PKC-activated Clˉ channels.Activation of the CACCs by agonist-induced increase in intracellular Ca2+ causes membrane depolarization,vasoconstriction,and inhibition of VSMC proliferation.Activation of VRCCs by cell volume increase or membrane stretch promotes the production of reactive oxygen species,induces proliferation and inhibits apoptosis of VSMCs.Activation of CFTR inhibits oxidative stress and may prevent the development of hypertension.In addition,Clˉ current mediated by gammaaminobutyric acid (GABA) receptor has also been implicated a role in ischemic neuron death.This review focuses on the functional roles of Clˉ channels in the development of stroke and provides a perspective on the future directions for research and the potential to develop Clˉ channels as new targets for the prevention and treatment of stroke.

  13. Protective effect of lycium barbarum polysaccharides on methyl mercury chloride-induced hippocampal neural stem cells injury%枸杞多糖对氯化甲基汞诱导海马神经干细胞损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    陈维维; 金国华; 张新化; 聂德康; 李小承; 嵇洪艳; 张夏南; 田建英

    2012-01-01

    Objective To determine the protective roles of lycium barbarum polysaccharide on methyl mercury chloride-induced injury for neuronal differentiation of hippocampal neural stem cells (NSCs). Methods NSCs were collected from the hippocampus of 16-embryonic day Sprague-Dawley rats. The cells were cultivated in neural stem cell-specific medium for 10 days. The neurospheres were dissociated into single cells and cultured in the 24-well plates with poly-L-lysine-coated cover glass. Cells were divided into four groups; a control group in which the cells were cultured in DMEM/F12 medium; a lycium barbarum polysaccharide group-the cells were cultured in DMEM/F12 with lycium barbarum polysaccharide; a methyl mercury chloride group-the ceUs were cultured in DMEM/F12 with methyl mercury chloride; Methyl mercury chloride + lycium barbarum polysaccharide group-the cells were cultured in DMEM/F12 with methyl mercury chloride and lycium barbarum polysaccharide. 1 he cell growth and differentiation were determined by immunostaining against MAP-2 or GFAP antibody. Results The percentage (3.63% ±0.62%) and average perimeter(63. 36(xm±5. 57 |xm) of the differentiated neurons in the methyl mercury chloride group were lower than that in the control group, while the percentage (7. 75% ± 0. 59% ) and average perimeter (253. 3μm ±11. 21 μm) of them in lycium barbarum polys acc haride group were much more than all other groups. Compared with the methyl mercury chloride group, after methyl mercury chloride treatment the lycium barbarum polys ace haride increased the neuronal differentiation (5. 92% ± 0. 98% ) to the level in control group and their average perimeter ( 111. 9(μm ± 6. 07,μm) in this group also showed 2-fold increase. Conclusion Lycium barbarum polys ace haride promotes the NSCs to differentiate into neurons and improves the growth of them. Methyl mercury chloride exertes the damage on NSCs differentiation and growth of neurons that can be rescued by lycium barbarum

  14. Acute Retinal Necrosis in Childhood

    Directory of Open Access Journals (Sweden)

    Yoav Y. Pikkel

    2014-05-01

    Full Text Available Background: Acute retinal necrosis (ARN is a viral syndrome consisting of uveitis/vitritis, occlusive vasculitis and peripheral necrosis. Few incidents are reported in children. The etiology is reactivated herpes simplex virus (HSV or varicella-zoster virus (VZV. Treatment with acyclovir is often used. The administration of oral glucocorticosteroids is of unproven benefit. Prognosis is variable but poor. Methods: Three weeks after contracting mild chickenpox, a healthy 4-year-old girl developed blurred vision in her right eye. Severely reduced visual acuity was noted, together with anterior uveitis, ‘mutton-fat' precipitates and vitral flare. Retinal vasculitis with necrosis was present. Serology for toxoplasma, cytomegalovirus and HIV was negative, while HSV and VZV IgG antibodies were positive. She was treated with 30 mg/kg of intravenous methylprednisolone (3 days, 30 mg of oral prednisone (3 days, and tapering for 8 weeks. Intravenous acyclovir was given for 10 days, followed by oral acyclovir for 4 months. Aspirin (100 mg/day was given for 4 months. Results: At 12 months, the girl felt good. Her right eye acuity was 6/9, with an intraocular pressure of 17 mm Hg. The peripheral retina showed scarring but no detachment. Conclusions: This is the first report of a once-daily high-dose methylprednisolone pulse therapy in one of the youngest known ARN cases. Pulsed steroid therapy was based on its known effectiveness in vasculitis, which is the main pathophysiology in ARN. There was no evidence of steroid-related viral over-replication. Our case achieved an excellent clinical and ophthalmic recovery in spite of the poor prognosis. The positive result of this case report provides a basis for further evaluation of high-dose steroid pulse therapy in ARN.

  15. 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.

  16. [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.

  17. [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.

  18. 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.

  19. 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.

  20. Retinal Macroglial Responses in Health and Disease

    OpenAIRE

    de Hoz, Rosa; Rojas, Blanca; Ramírez, Ana I.; Salazar, Juan J; Gallego, Beatriz I.; Triviño, Alberto; Ramírez, José M.

    2016-01-01

    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 removin...

  1. Marfan Syndrome Presenting with Bilateral Retinal Detachment

    OpenAIRE

    Subrata Chakrabarti; Koushik Pan

    2014-01-01

    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...

  2. Retinal vein occlusion in Benin City, Nigeria

    OpenAIRE

    Uhumwangho, Odarosa M.; Darlingtess Oronsaye

    2016-01-01

    Background: Retinal vein occlusion (RVO) is the most common occlusive retinal vascular disorder and results in varying degrees of visual loss. Aim: To determine the pattern of presentation, risk factors, and treatment outcomes in a group of patients with RVO seen in a tertiary hospital in Nigeria. Materials and Methods: Medical records of patients who presented to the University of Benin Teaching Hospital, Benin City, Nigeria in whom a diagnosis of RVO was made over a 5 years period were revi...

  3. 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.

  4. Retinal Prosthetics, Optogenetics, and Chemical Photoswitches

    OpenAIRE

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-01-01

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral ...

  5. Effects of aging in retinal image quality.

    OpenAIRE

    Artal, Pablo; Ferro, Manuel; Miranda, Ismael; Navarro, Rafael

    1993-01-01

    The retinal image quality characterized by the modulation-transfer function of the eye was measured for two groups of subjects aged in the late twenties and mid sixties, respectively. In both groups, we obtained modulation transfer functions by using a double-pass method under the same experimental conditions: 4-mm artificial pupil, paralyzed accommodation, and objective control of the refractive state and centering. Results showed lower values of modulation in the retinal image for older ...

  6. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

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

    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 at...

  7. Delayed appearance of high altitude retinal hemorrhages.

    Directory of Open Access Journals (Sweden)

    Daniel Barthelmes

    Full Text Available BACKGROUND: Retinal hemorrhages have been described as a component of high altitude retinopathy (HAR in association with altitude illness. In this prospective high altitude study, we aimed to gain new insights into the pathophysiology of HAR and explored whether HAR could be a valid early indicator of altitude illness. METHODOLOGY/PRINCIPAL FINDINGS: 28 mountaineers were randomly assigned to two ascent profiles during a research expedition to Mt. Muztagh Ata (7546 m/24,751 ft. Digital fundus photographs were taken prior to expedition at 490 m (1,607 ft, during expedition at 4497 m (14,750 ft = base camp, 5533 m (18,148 ft, 6265 m (20,549 ft, 6865 m (22,517 ft and 4.5 months thereafter at 490 m. Number, size and time of occurrence of hemorrhages were recorded. Oxygen saturation (SpO₂ and hematocrit were also assessed. 79% of all climbers exhibited retinal hemorrhages during the expedition. Number and area of retinal bleeding increased moderately to medium altitudes (6265 m. Most retinal hemorrhages were detected after return to base camp from a high altitude. No post-expeditional ophthalmic sequelae were detected. Significant negative (SpO₂ Beta: -0.4, p<0.001 and positive (hematocrit Beta: 0.2, p = 0.002, time at altitude Beta: 0.33, p = 0.003 correlations with hemorrhages were found. CONCLUSIONS/SIGNIFICANCE: When closely examined, a very large amount of climbers exhibit retinal hemorrhages during exposure to high altitudes. The incidence of retinal hemorrhages may be greater than previously appreciated as a definite time lag was observed between highest altitude reached and development of retinal bleeding. Retinal hemorrhages should not be considered warning signs of impending severe altitude illness due to their delayed appearance.

  8. Retinal blood flow in diabetic retinopathy.

    OpenAIRE

    Patel, V.; Rassam, S; NEWSOM, R.; Wiek, J; Kohner, E.

    1992-01-01

    OBJECTIVES--(a) To report on the basic parameters of retinal blood flow in a population of diabetic patients with and without retinopathy and non-diabetic controls; (b) to formulate a haemodynamic model for the pathogenesis of diabetic retinopathy from this and other studies. DESIGN--Laser-Doppler velocimetry and computerised image analysis to determine retinal blood flow in a large cross sectional study. SETTING--Diabetic retinopathy outpatient clinic. SUBJECTS--24 non-diabetic controls and ...

  9. 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.

  10. Protection of gastric mucosa against hypertonic sodium chloride by 16,16-dimethyl prostaglandin E2 or sodium thiosulfate in the rat: Evidence for decreased mucosal penetration of damaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Pihan, G.; Szabo, S. (Brigham Women' s Hospital, Boston, MA (USA))

    1989-12-01

    Protection of the gastric mucosa may be the result of either increased cellular resistance to injury (cytoprotection) or, alternatively, decreased exposure of mucosal cells to the damaging agent. To determine whether decreased exposure of mucosal cells to damaging agents plays a role in mucosal protection by 16,16-dm PGE2 or sodium thiosulfate, we estimated the intramucosal concentration of 22NaCl and measured its absorption from the gastric lumen into the systemic circulation 1 and 5 min after intragastric administration of hypertonic (25% w/v) 22NaCl. In an attempt to explain the differences observed, we also measured the net transmucosal water flux in control animals and rats pretreated with the protective agents. Administration of hypertonic NaCl rapidly (within 1 min) induced extensive hemorrhagic mucosal lesions that were significantly reduced by pretreatment with 16,16-dm PGE2 or sodium thiosulfate. Ultra-low temperature autoradiography indicated that luminal hypertonic 22NaCl penetrates the upper layers of the mucosa in relatively high concentrations (12.5% w/v) within 1 min but its concentration decreases rapidly and reached low levels (3.12% w/v) by 5 min. Absorption of NaCl from the gastric lumen into the systemic circulation 1 and 5 min after hypertonic NaCl was lower in both pretreatment groups than in the control. Net gastric transmucosal water flux (from serosa to mucosa) increased (P less than 0.05) from 100 +/- 2 in controls, to 1470 +/- 8 and 715 +/- 9 microliters in rats pretreated with 16,16-dm PGE2 and sodium thiosulfate, respectively. We conclude that 16,16-dm PGE2 and sodium thiosulfate protect the gastric mucosa against hypertonic NaCl, diminish mucosal penetration of NaCl, decrease mucosal absorption of NaCl, and significantly increase serosal to mucosal transmucosal water flux.

  11. Protection of gastric mucosa against hypertonic sodium chloride by 16,16-dimethyl prostaglandin E2 or sodium thiosulfate in the rat: Evidence for decreased mucosal penetration of damaging agent

    International Nuclear Information System (INIS)

    Protection of the gastric mucosa may be the result of either increased cellular resistance to injury (cytoprotection) or, alternatively, decreased exposure of mucosal cells to the damaging agent. To determine whether decreased exposure of mucosal cells to damaging agents plays a role in mucosal protection by 16,16-dm PGE2 or sodium thiosulfate, we estimated the intramucosal concentration of 22NaCl and measured its absorption from the gastric lumen into the systemic circulation 1 and 5 min after intragastric administration of hypertonic (25% w/v) 22NaCl. In an attempt to explain the differences observed, we also measured the net transmucosal water flux in control animals and rats pretreated with the protective agents. Administration of hypertonic NaCl rapidly (within 1 min) induced extensive hemorrhagic mucosal lesions that were significantly reduced by pretreatment with 16,16-dm PGE2 or sodium thiosulfate. Ultra-low temperature autoradiography indicated that luminal hypertonic 22NaCl penetrates the upper layers of the mucosa in relatively high concentrations (12.5% w/v) within 1 min but its concentration decreases rapidly and reached low levels (3.12% w/v) by 5 min. Absorption of NaCl from the gastric lumen into the systemic circulation 1 and 5 min after hypertonic NaCl was lower in both pretreatment groups than in the control. Net gastric transmucosal water flux (from serosa to mucosa) increased (P less than 0.05) from 100 +/- 2 in controls, to 1470 +/- 8 and 715 +/- 9 microliters in rats pretreated with 16,16-dm PGE2 and sodium thiosulfate, respectively. We conclude that 16,16-dm PGE2 and sodium thiosulfate protect the gastric mucosa against hypertonic NaCl, diminish mucosal penetration of NaCl, decrease mucosal absorption of NaCl, and significantly increase serosal to mucosal transmucosal water flux

  12. 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.

  13. Retinal Vascular Fractals and Cognitive Impairment

    Science.gov (United States)

    Ong, Yi-Ting; Hilal, Saima; Cheung, Carol Yim-lui; Xu, Xin; Chen, Christopher; Venketasubramanian, Narayanaswamy; Wong, Tien Yin; Ikram, Mohammad Kamran

    2014-01-01

    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. PMID:25298774

  14. Arginase 2 deficiency prevents oxidative stress and limits hyperoxia-induced retinal vascular degeneration.

    Directory of Open Access Journals (Sweden)

    Jutamas Suwanpradid

    Full Text Available BACKGROUND: Hyperoxia exposure of premature infants causes obliteration of the immature retinal microvessels, leading to a condition of proliferative vitreoretinal neovascularization termed retinopathy of prematurity (ROP. Previous work has demonstrated that the hyperoxia-induced vascular injury is mediated by dysfunction of endothelial nitric oxide synthase resulting in peroxynitrite formation. This study was undertaken to determine the involvement of the ureahydrolase enzyme arginase in this pathology. METHODS AND FINDINGS: Studies were performed using hyperoxia-treated bovine retinal endothelial cells (BRE and mice with oxygen-induced retinopathy (OIR as experimental models of ROP. Treatment with the specific arginase inhibitor 2(S-amino-6-boronohexanoic acid (ABH prevented hyperoxia-induced apoptosis of BRE cells and reduced vaso-obliteration in the OIR model. Furthermore, deletion of the arginase 2 gene protected against hyperoxia-induced vaso-obliteration, enhanced physiological vascular repair, and reduced retinal neovascularization in the OIR model. Additional deletion of one copy of arginase 1 did not improve the vascular pathology. Analyses of peroxynitrite by quantitation of its biomarker nitrotyrosine, superoxide by dihydroethidium imaging and NO formation by diaminofluoroscein imaging showed that the protective actions of arginase 2 deletion were associated with blockade of superoxide and peroxynitrite formation and normalization of NOS activity. CONCLUSIONS: Our data demonstrate the involvement of arginase activity and arginase 2 expression in hyperoxia-induced vascular injury. Arginase 2 deletion prevents hyperoxia-induced retinal vascular injury by preventing NOS uncoupling resulting in decreased reactive oxygen species formation and increased nitric oxide bioavailability.

  15. Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters

    Institute of Scientific and Technical Information of China (English)

    Kwok-Fai So; Mason Chin Pang Leung; Qi Cui

    2014-01-01

    Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the ifrst week with a short period of treatment time (5 minutes) in which 65–66% of retinal ganglion cells survived the optic nerve axotomy whereas 45–47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These ifndings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal gan-glion cells.

  16. 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

    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...

  17. Increased aqueous flare is associated with thickening of inner retinal layers in eyes with retinitis pigmentosa

    Science.gov (United States)

    Nagasaka, Yosuke; Ito, Yasuki; Ueno, Shinji; Terasaki, Hiroko

    2016-01-01

    Retinitis pigmentosa(RP) is a hereditary retinal disease that causes photoreceptor, outer retinal, degeneration. Although the pathogenesis is still unclear, there have been numerous reports regarding inner retinal changes in RP eyes. The aim of this study is to retrospectively evaluate the changes in the thicknesses of different retinal layers of RP eyes, and its association with aqueous flare, which is used for measuring the intensity of intraocular inflammation. A total of 125 eyes of 64 patients with RP and 13 normal eyes were studied. The thicknesses of total neural retina,nerve fiber layer(NFL),ganglion cell layer(GCL),inner plexiform layer(IPL),inner nuclear layer(INL),outer layers and foveal thickness were measured in the optical coherence tomographic images. Aqueous flare was measured with a laser flare-cell meter. The associations between those parameters, visual acuity and visual field were determined in RP eyes using multivariate analysis. The results of this study showed the significant thickening of NFL, GCL and INL, the significant thinning of outer layers and the association of them with increased aqueous flare, whereas NFL and INL thickening associated with outer retinal thinning. These results can suggest the involvement of intraocular inflammation in the pathogenesis of inner retinal thickening as a secondary change following outer retinal degeneration. PMID:27653207

  18. Protein kinase C in porcine retinal arteries and neuroretina following retinal ischemia-reperfusion

    DEFF Research Database (Denmark)

    Gesslein, Bodil; Gustafsson, Lotta; Wackenfors, Angelica;

    2009-01-01

    Identification of the intracellular signal-transduction pathways activated in retinal ischemia may be important in revealing novel pharmacological targets. To date, most studies have focused on identifying neuroprotective agents. The retinal blood vessels are key organs in circulatory failure, an...

  19. Retinal changes detected by wide-field autofluorescence imaging of patients with primary rhegmatogenous retinal detachment

    DEFF Research Database (Denmark)

    Poulsen, Christina Døfler; Grauslund, Jakob; Peto, Tunde

    2014-01-01

    tortuosity, rolled, irregular edge of tear), or C (full thickness retinal starfolds) , peroperative data, complications, Pelli Robson test, Ishihara and multifocal-ERG. Retinal changes in wide-field images were graded using fellow-eye as reference for normal appearance. Twenty-nine patients with major......Titel: “Retinal changes detected by wide-field autofluorescence imaging of patients with primary rhegmatogenous retinal detachment” Purpose: To detect characteristic changes in autofluorescence (AF) images in patients with primary rhegmatogenous retinal detachment (RRD) and to compare...... preoperatively and at a 2-months follow-up. Examinations included best corrected visual acuity (BCVA), slit lamp biomicroscopy, spectral domain optical coherence tomography (SD-OCT) (Topcon 3D-OCT 2000) and wide-field imaging (Optos 200Tx color and AF). Additional data collected included age, gender, previous...

  20. Ustilago maydis accumulates beta-carotene at levels determined by a retinal-forming carotenoid oxygenase.

    Science.gov (United States)

    Estrada, Alejandro F; Brefort, Thomas; Mengel, Carina; Díaz-Sánchez, Violeta; Alder, Adrian; Al-Babili, Salim; Avalos, Javier

    2009-10-01

    The basidiomycete Ustilago maydis, the causative agent of corn smut disease, has emerged as a model organism for dimorphism and fungal phytopathogenicity. In this work, we line out the key conserved enzymes for beta-carotene biosynthesis encoded by the U. maydis genome and show that this biotrophic fungus accumulates beta-carotene. The amount of this pigment depended on culture pH and aeration but was not affected by light and was not increased by oxidative stress. Moreover, we identified the U. maydis gene, cco1, encoding a putative beta-carotene cleavage oxygenase. Heterologous overexpression and in vitro analyses of purified enzyme demonstrated that Cco1 catalyzes the symmetrical cleavage of beta-carotene to yield two molecules of retinal. Analyses of beta-carotene and retinal contents in U. maydiscco1 deletion and over-expression strains confirmed the enzymatic function of Cco1, and revealed that Cco1 determines the beta-carotene content. Our data indicate that carotenoid biosynthesis in U. maydis is carried out to provide retinal rather than to deliver protective pigments. The U. maydis genome also encodes three potential opsins, a family of photoactive proteins that use retinal as chromophore. Two opsin genes showed different light-regulated expression patterns, suggesting specialized roles in photobiology, while no mRNA was detected for the third opsin gene in the same experiments. However, deletion of the cco1 gene, which should abolish function of all the retinal-dependent opsins, did not affect growth, morphology or pathogenicity, suggesting that retinal and opsin proteins play no relevant role in U. maydis under the tested conditions.

  1. Chloride in vesicular trafficking and function.

    Science.gov (United States)

    Stauber, Tobias; Jentsch, Thomas J

    2013-01-01

    Luminal acidification is of pivotal importance for the physiology of the secretory and endocytic pathways and its diverse trafficking events. Acidification by the proton-pumping V-ATPase requires charge compensation by counterion currents that are commonly attributed to chloride. The molecular identification of intracellular chloride transporters and the improvement of methodologies for measuring intraorganellar pH and chloride have facilitated the investigation of the physiology of vesicular chloride transport. New data question the requirement of chloride for pH regulation of various organelles and furthermore ascribe functions to chloride that are beyond merely electrically shunting the proton pump. This review surveys the currently established and proposed intracellular chloride transporters and gives an overview of membrane-trafficking steps that are affected by the perturbation of chloride transport. Finally, potential mechanisms of membrane-trafficking modulation by chloride are discussed and put into the context of organellar ion homeostasis in general. PMID:23092411

  2. Electrochemical Chloride extraction using external electrodes?

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2006-01-01

    Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

  3. Neuoroprotective efficacies by KUS121, a VCP modulator, on animal models of retinal degeneration.

    Science.gov (United States)

    Hasegawa, Tomoko; Muraoka, Yuki; Ikeda, Hanako Ohashi; Tsuruyama, Tatsuaki; Kondo, Mineo; Terasaki, Hiroko; Kakizuka, Akira; Yoshimura, Nagahisa

    2016-01-01

    Retinitis pigmentosa (RP) is one of the leading causes of adult blindness and has no established therapy. We have shown that valosin-containing protein (VCP) modulators, Kyoto University Substances (KUSs), ameliorated abnormally low ATP levels by inhibiting the ATPase of VCP, thereby protected several types of cells, including retinal neurons, from cell death-inducing insults. In this study, we found that KUS121, one of the VCP modulators, effectively protects photoreceptors both morphologically and functionally, in two animal models of retinal degeneration, rd12 mice and RP rabbits with a rhodopsin (Pro347Leu) mutation. In rd12 mice, KUS121 suppressed the loss of photoreceptors, not only rods but also cones, as well as the visual function deterioration. Significant protective effects existed even when the medication was started in later stages of the disease. In RP rabbits, KUS121 suppressed thinning of the outer nuclear layer and maintained visual function. In the retinas treated with KUS121, suppression of endoplasmic reticulum stress, activation of mammalian target of rapamycin and suppression of disease-associated apoptosis were evident. The ability of KUS121 to protect photoreceptors, especially cones, even in later stages of the disease may contribute to the preservation of central vision in RP patients, which is important for quality of vision. PMID:27503804

  4. Chloride binding of cement-based materials subjected to external chloride environment - A review

    OpenAIRE

    Yuan, Q.; Shi, C; Schutter, G. de; Audenaert, K.; Deng, D.

    2009-01-01

    This paper reviews the chloride binding of cement-based materials subjected to external chloride environments. Chloride ion exist either in the pore solution, chemically bound to the hydration products, or physically held to the surface of the hydration products. Chloride binding of cement-based material is very complicated and influenced by many factors, such as chloride concentration, cement composition, hydroxyl concentration, cation of chloride salt, temperature, supplementary cementing m...

  5. Amyloidosis in Retinal Neurodegenerative Diseases

    Science.gov (United States)

    Masuzzo, Ambra; Dinet, Virginie; Cavanagh, Chelsea; Mascarelli, Frederic; Krantic, Slavica

    2016-01-01

    As a part of the central nervous system, the retina may reflect both physiological processes and abnormalities related to pathologies that affect the brain. Amyloidosis due to the accumulation of amyloid-beta (Aβ) was initially regarded as a specific and exclusive characteristic of neurodegenerative alterations seen in the brain of Alzheimer’s disease (AD) patients. More recently, it was discovered that amyloidosis-related alterations, similar to those seen in the brain of Alzheimer’s patients, also occur in the retina. Remarkably, these alterations were identified not only in primary retinal pathologies, such as age-related macular degeneration (AMD) and glaucoma, but also in the retinas of Alzheimer’s patients. In this review, we first briefly discuss the biogenesis of Aβ, a peptide involved in amyloidosis. We then discuss some pathological aspects (synaptic dysfunction, mitochondrial failure, glial activation, and vascular abnormalities) related to the neurotoxic effects of Aβ. We finally highlight common features shared by AD, AMD, and glaucoma in the context of Aβ amyloidosis and further discuss why the retina, due to the transparency of the eye, can be considered as a “window” to the brain. PMID:27551275

  6. 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. 

  7. 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....

  8. 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.

  9. Rod Photopigment Kinetics After Photodisruption of the Retinal Pigment Epithelium

    OpenAIRE

    Masella, Benjamin D.; Hunter, Jennifer J.; Williams, David R.

    2014-01-01

    Advances in retinal imaging have led to the discovery of disruption of the RPE caused by light exposures below published safety limits. To investigate the functional consequences of this RPE disruption, we combined adaptive optics ophthalmoscopy with retinal densitometry.

  10. Genetics Home Reference: neuropathy, ataxia, and retinitis pigmentosa

    Science.gov (United States)

    ... Me Understand Genetics Home Health Conditions NARP neuropathy, ataxia, and retinitis pigmentosa Enable Javascript to view the ... Download PDF Open All Close All Description Neuropathy, ataxia, and retinitis pigmentosa ( NARP ) is a condition that ...

  11. Melanopsin retinal ganglion cell loss in Alzheimer's disease

    DEFF Research Database (Denmark)

    La Morgia, Chiara; Ross-Cisneros, Fred N; Koronyo, Yosef;

    2015-01-01

    OBJECTIVE: Melanopsin retinal ganglion cells (mRGCs) are photoreceptors driving circadian photoentrainment, and circadian dysfunction characterizes Alzheimer's disease (AD). We investigated mRGCs in AD, hypothesizing their contribution to circadian dysfunction. METHODS: We assessed retinal nerve...

  12. 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...

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

    International Nuclear Information System (INIS)

    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

  14. 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

  15. 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.

  16. Automatic Detection of Retinal Exudates using a Support Vector Machine

    OpenAIRE

    Nualsawat HIRANSAKOLWONG; Ekkarat POTHIRUK; Kittipol WISAENG

    2013-01-01

    Retinal exudates are among the preliminary signs of diabetic retinopathy, a major cause of vision loss in diabetic patients. Correct and efficient screening of exudates is very expensive in professional time and may cause human error. Nowadays, the digital retinal image is frequently used to follow-up and diagnoses eye diseases. Therefore, the retinal image is crucial and essential for experts to detect exudates. Unfortunately, it is a normal situation that retinal images in Thailand are poor...

  17. Mouse retinal adaptive response to proton irradiation: Correlation with DNA repair and photoreceptor cell death

    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 study revealed non-linear dose-response relationship for cytotoxicity 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 present study we used the mouse model for MNU-induced retinal degeneration to evaluate adaptive response of retina to proton irradiation and implication in it of glial Muller cells. The data showed that the recovery of retina after genotoxic agents has been associated with increased efficacy of DNA damage repair and lowered death of retinal photoreceptor cells.

  18. Effect of eye NGF administration on two animal models of retinal ganglion cells degeneration

    Directory of Open Access Journals (Sweden)

    Valeria Colafrancesco

    2011-01-01

    Full Text Available The aim of this study was to investigate the effect of nerve growth factor (NGF administration on retinal ganglion cells (RGCs in experimentally induced glaucoma (GL and diabetic retinopathy (DR. GL was induced in adult rats by injection of hypertonic saline into the episcleral vein of the eye and diabetes (DT was induced by administration of streptozoticin. Control and experimental rats were treated daily with either ocular application of NGF or vehicle solution. We found that both animal models present a progressive degeneration of RGCs and changing NGF and VEGF levels in the retina and optic nerve. We then proved that NGF eye drop administration exerts a protective effect on these models of retinal degeneration. In brief, our findings indicate that NGF can play a protective role against RGC degeneration occurring in GL and DR and suggest that ocular NGF administration might be an effective pharmacological approach.

  19. 1,5-Diaminotetrazolium chloride

    Directory of Open Access Journals (Sweden)

    Ling-Qiao Meng

    2010-04-01

    Full Text Available The title compound, CH5N6+·Cl−, crystallized with two indepedent 1,5-diaminotetrazolium cations and two independent chloride anions in the asymmetric unit. In the crystal, there are a number of N—H...Cl hydrogen-bonding interactions, which generate a three-dimensional network.

  20. Chloride : The queen of electrolytes?

    NARCIS (Netherlands)

    Berend, Kenrick; van Hulsteijn, Leonard Hendrik; Gans, Rijk O. B.

    2012-01-01

    Background: Channelopathies, defined as diseases that are caused by mutations in genes encoding ion channels, are associated with a wide variety of symptoms and have been documented extensively over the past decade. In contrast, despite the important role of chloride in serum, textbooks in general d

  1. Differential modulation of retinal degeneration by Ccl2 and Cx3cr1 chemokine signalling.

    Science.gov (United States)

    Luhmann, Ulrich F O; Lange, Clemens A; Robbie, Scott; Munro, Peter M G; Cowing, Jill A; Armer, Hannah E J; Luong, Vy; Carvalho, Livia S; MacLaren, Robert E; Fitzke, Frederick W; Bainbridge, James W B; Ali, Robin R

    2012-01-01

    Microglia and macrophages are recruited to sites of retinal degeneration where local cytokines and chemokines determine protective or neurotoxic microglia responses. Defining the role of Ccl2-Ccr2 and Cx3cl1-Cx3cr1 signalling for retinal pathology is of particular interest because of its potential role in age-related macular degeneration (AMD). Ccl2, Ccr2, and Cx3cr1 signalling defects impair macrophage trafficking, but have, in several conflicting studies, been reported to show different degrees of age-related retinal degeneration. Ccl2/Cx3cr1 double knockout (CCDKO) mice show an early onset retinal degeneration and have been suggested as a model for AMD. In order to understand phenotypic discrepancies in different chemokine knockout lines and to study how defects in Ccl2 and/or Cx3cr1 signalling contribute to the described early onset retinal degeneration, we defined primary and secondary pathological events in CCDKO mice. To control for genetic background variability, we compared the original phenotype with that of single Ccl2, Cx3cr1 and Ccl2/Cx3cr1 double knockout mice obtained from backcrosses of CCDKO with C57Bl/6 mice. We found that the primary pathological event in CCDKO mice develops in the inferior outer nuclear layer independently of light around postnatal day P14. RPE and vascular lesions develop secondarily with increasing penetrance with age and are clinically similar to retinal telangiectasia not to choroidal neovascularisation. Furthermore, we provide evidence that a third autosomal recessive gene causes the degeneration in CCDKO mice and in all affected re-derived lines and subsequently demonstrated co-segregation of the naturally occurring RD8 mutation in the Crb1 gene. By comparing CCDKO mice with re-derived CCl2(-/-)/Crb1(Rd8/RD8), Cx3cr1(-/-)/Crb1(Rd8/RD8) and CCl2(-/-)/Cx3cr1(-/-)/Crb1(Rd8/RD8) mice, we observed a differential modulation of the retinal phenotype by genetic background and both chemokine signalling pathways. These findings

  2. 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.

  3. 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.

  4. 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

  5. Functional annotation of the human retinal pigment epithelium transcriptome

    NARCIS (Netherlands)

    J.C. Booij; S. van Soest; S.M.A. Swagemakers; A.H.W. Essing; A.J.M.H. Verkerk; P.J. van der Spek; T.G.M.F. Gorgels; A.A.B. Bergen

    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

  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. [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.

  8. 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.

  9. 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...

  10. 40 CFR 721.7270 - 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl derivs., chloride.

    Science.gov (United States)

    2010-07-01

    ...-trimethyl-N-soya acyl derivs., chloride. 721.7270 Section 721.7270 Protection of Environment ENVIRONMENTAL...-soya acyl derivs., chloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanaminium, 3-amino-, N,N,N-trimethyl-N-soya acyl...

  11. Preservation of retinotopic map in retinal degeneration.

    Science.gov (United States)

    Xie, John; Wang, Gene-Jack; Yow, Lindy; Humayun, Mark S; Weiland, James D; Cela, Carlos J; Jadvar, Hossein; Lazzi, Gianluca; Dhrami-Gavazi, Elona; Tsang, Stephen H

    2012-05-01

    Retinal degenerations trigger the loss of photoreceptors and cause the remaining de-afferented neural retina to undergo remodeling. Concerns over this potential retinal synaptic reorganization following visual loss have raised questions regarding the usefulness of visual restoration via retinal electrical stimulation. We have used quantitative positron emission tomography (PET) and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) to objectively evaluate the connection between the retina and the primary visual cortex under both light and transcorneal electrical stimulation (TcES) in five subjects with retinal degeneration (RD) who have had more than ten years of light-perception-only best visual acuity and five age-matched normal-sighted controls. All subjects underwent quantitative PET with FDG as the metabolic tracer during stimulation of the right eye under both light stimulation condition and transcorneal electrical stimulation (TcES) using ERG-Jet contact lens electrode. Cortical activation maps from each stimulation condition were obtained using statistical parametric mapping. TcES phosphene threshold current and qualitative visual cortex activation from both stimulation conditions were compared between the two subject groups. Average phosphene threshold current was 0.72 ± 0.18 mA for the five normal-sighted controls and 3.08 ± 2.01 mA for the retinal degenerative subjects. Phosphene threshold current was significantly higher in retinal degenerative subjects compared to normal-sighted controls (p < 0.05). We found both light stimulation and TcES resulted in retinotopically mapped primary visual cortex activation in both groups. In addition, the patterns of early visual area activation between the two subject groups are more similar during TcES than light stimulation. Our findings suggest primary visual cortex continues to maintain its retinotopy in RD subjects despite prolonged visual loss. PMID:22685713

  12. 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.

  13. Aggressive retinal astrocytoma associated with tuberous sclerosis

    Directory of Open Access Journals (Sweden)

    Tomida M

    2012-05-01

    Full Text Available Machiko Tomida,1 Yoshinori Mitamura,1 Takashi Katome,1 Hiroshi Eguchi,1 Takeshi Naito,1 Takayuki Harada21Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, 2Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, JapanAbstract: We report the case of a patient with an aggressive retinal astrocytoma accompanied with macular edema and neovascular vessels, who was initially treated with intravitreal bevacizumab injections. A 24-year-old male presented to our clinic complaining of visual disturbance in his right eye. At 8 years of age, he had been diagnosed as having tuberous sclerosis complex. Fundus examination demonstrated a retinal tumor accompanied with marked neovascular vessels on the surface, retinal hemorrhage, and macular edema. After six monthly intravitreal bevacizumab injections, fundus examination demonstrated marked regression of the macular edema and neovascular vessels. Two months later, a vitreous hemorrhage developed which necessitated pars plana vitrectomy. After additional intravitreal bevacizumab injection for preventing intraoperative bleeding, vitrectomy with endophotocoagulation for the tumor was performed. The vitreous sample was obtained during vitrectomy, and we measured the vascular endothelial growth factor concentration by enzyme-linked immunosorbent assay. The surgically removed epiretinal neovascular membrane and biopsied retinal tumor expressed vascular endothelial growth factor, although several intravitreal bevacizumab injections led to a vitreous vascular endothelial growth factor concentration of undetectable levels. The clinical course and immunohistochemical analyses indicate that intravitreal bevacizumab monotherapy may have been insufficient to treat the aggressive retinal astrocytoma with macular edema and that laser photocoagulation or photodynamic therapy for the tumor should be considered following intravitreal

  14. 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.

  15. Plasmalemma Vesicle-Associated Protein Has a Key Role in Blood-Retinal Barrier Loss.

    Science.gov (United States)

    Wisniewska-Kruk, Joanna; van der Wijk, Anne-Eva; van Veen, Henk A; Gorgels, Theo G M F; Vogels, Ilse M C; Versteeg, Danielle; Van Noorden, Cornelis J F; Schlingemann, Reinier O; Klaassen, Ingeborg

    2016-04-01

    Loss of blood-retinal barrier (BRB) properties induced by vascular endothelial growth factor (VEGF) and other factors is an important cause of diabetic macular edema. Previously, we found that the presence of plasmalemma vesicle-associated protein (PLVAP) in retinal capillaries associates with loss of BRB properties and correlates with increased vascular permeability in diabetic macular edema. In this study, we investigated whether absence of PLVAP protects the BRB from VEGF-induced permeability. We used lentiviral-delivered shRNA or siRNA to inhibit PLVAP expression. The barrier properties of in vitro BRB models were assessed by measuring transendothelial electrical resistance, permeability of differently sized tracers, and the presence of endothelial junction complexes. The effect of VEGF on caveolae formation was studied in human retinal explants. BRB loss in vivo was studied in the mouse oxygen-induced retinopathy model. The inhibition of PLVAP expression resulted in decreased VEGF-induced BRB permeability of fluorescent tracers, both in vivo and in vitro. PLVAP inhibition attenuated transendothelial electrical resistance reduction induced by VEGF in BRB models in vitro and significantly increased transendothelial electrical resistance of the nonbarrier human umbilical vein endothelial cells. Furthermore, PLVAP knockdown prevented VEGF-induced caveolae formation in retinal explants but did not rescue VEGF-induced alterations in endothelial junction complexes. In conclusion, PLVAP is an essential cofactor in VEGF-induced BRB permeability and may become an interesting novel target for diabetic macular edema therapy.

  16. Bone marrow mesenchymal stem cells stimulate proliferation and neuronal differentiation of retinal progenitor cells.

    Directory of Open Access Journals (Sweden)

    Jing Xia

    Full Text Available During retina development, retinal progenitor cell (RPC proliferation and differentiation are regulated by complex inter- and intracellular interactions. Bone marrow mesenchymal stem cells (BMSCs are reported to express a variety of cytokines and neurotrophic factors, which have powerful trophic and protective functions for neural tissue-derived cells. Here, we show that the expanded RPC cultures treated with BMSC-derived conditioned medium (CM which was substantially enriched for bFGF and CNTF, expressed clearly increased levels of nuclear receptor TLX, an essential regulator of neural stem cell (NSC self-renewal, as well as betacellulin (BTC, an EGF-like protein described as supporting NSC expansion. The BMSC CM- or bFGF-treated RPCs also displayed an obviously enhanced proliferation capability, while BMSC CM-derived bFGF knocked down by anti-bFGF, the effect of BMSC CM on enhancing RPC proliferation was partly reversed. Under differentiation conditions, treatment with BMSC CM or CNTF markedly favoured RPC differentiation towards retinal neurons, including Brn3a-positive retinal ganglion cells (RGCs and rhodopsin-positive photoreceptors, and clearly diminished retinal glial cell differentiation. These findings demonstrate that BMSCs supported RPC proliferation and neuronal differentiation which may be partly mediated by BMSC CM-derived bFGF and CNTF, reveal potential limitations of RPC culture systems, and suggest a means for optimizing RPC cell fate determination in vitro.

  17. Neuroprotection, Growth Factors and BDNF-TrkB Signalling in Retinal Degeneration

    Science.gov (United States)

    Kimura, Atsuko; Namekata, Kazuhiko; Guo, Xiaoli; Harada, Chikako; Harada, Takayuki

    2016-01-01

    Neurotrophic factors play key roles in the development and survival of neurons. The potent neuroprotective effects of neurotrophic factors, including brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), glial cell-line derived neurotrophic factor (GDNF) and nerve growth factor (NGF), suggest that they are good therapeutic candidates for neurodegenerative diseases. Glaucoma is a neurodegenerative disease of the eye that causes irreversible blindness. It is characterized by damage to the optic nerve, usually due to high intraocular pressure (IOP), and progressive degeneration of retinal neurons called retinal ganglion cells (RGCs). Current therapy for glaucoma focuses on reduction of IOP, but neuroprotection may also be beneficial. BDNF is a powerful neuroprotective agent especially for RGCs. Exogenous application of BDNF to the retina and increased BDNF expression in retinal neurons using viral vector systems are both effective in protecting RGCs from damage. Furthermore, induction of BDNF expression by agents such as valproic acid has also been beneficial in promoting RGC survival. In this review, we discuss the therapeutic potential of neurotrophic factors in retinal diseases and focus on the differential roles of glial and neuronal TrkB in neuroprotection. We also discuss the role of neurotrophic factors in neuroregeneration. PMID:27657046

  18. Microbial reductive dehalogenation of vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Mannheim, DE; Meshulam-Simon, Galit [Los Angeles, CA; McCarty, Perry L [Stanford, CA

    2014-02-11

    Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

  19. Progress of Carbonation in Chloride Contaminated Concretes

    OpenAIRE

    Wang, Yaocheng; Basheer, P.A.M.; Nanukuttan, S; Bai, Y.

    2016-01-01

    Concretes used in marine environment are generally under the cyclic effect of CO2 and chloride ions (Cl-). To date, the influence of carbonation on ingress of chloride ions in concretes has been widely studied; in comparison, study on the influence of Cl- on the progress of carbonation is limited. During the study, concretes were exposed to independent and combined mechanisms of carbonation and chloride ingress regimes. Profiles of apparent pH and chloride concentration were used to indicate ...

  20. Proliferative diabetic retinopathy in typical retinitis pigmentosa.

    Science.gov (United States)

    Preethi, Srinivasaraghavan; Rajalakshmi, Adithyapuram Ramachandran

    2015-01-01

    A 39-year-old woman with typical retinitis pigmentosa (RP) for 9 years and a positive family history of night blindness was diagnosed with diabetes mellitus (DM). She developed proliferative diabetic retinopathy (PDR) during the course of disease. She was promptly managed with pan retinal photocoagulation (PRP). PDR developing in a case of typical RP is extremely rare and has not been reported in the literature to date. Recognition of this rare, vision threatening complication, points out a definite need to further look deep into the pathogenesis of diabetic retinopathy. PMID:26021380

  1. Metabolic syndrome and central retinal artery occlusion

    OpenAIRE

    Kosanović-Jaković Natalija; Petrović Lidija; Risimić Dijana; Milenković Svetislav; Matić Danica

    2005-01-01

    Background. The accumulation of risk factors for central retinal artery occlusion can be seen in a single person and might be explained by the metabolic syndrome. Case report. We presented the case of a 52-year-old man with no light perception in his right eye. The visual loss was monocular and painless, fundoscopy showed central retinal artery occlusion and the laboratory investigation showed the raised erythrocyte sedimentation rate of 105 mm/h and the raised C-reactive protein of 22 mg/l. ...

  2. Chloride sublimation of gold-arsenic concentrates

    International Nuclear Information System (INIS)

    Present article is devoted to chloride sublimation of gold-arsenic concentrates. The results of studies of chloride sublimation of gold-arsenic comprising concentrates of Chore deposit of Tajikistan are considered. It is found that by application sodium chloride for gold-arsenic comprising concentrates it is possible to extract gold and silver from flotation concentrates.

  3. 21 CFR 172.180 - Stannous chloride.

    Science.gov (United States)

    2010-04-01

    ... Preservatives § 172.180 Stannous chloride. The food additive stannous chloride may be safely used for color... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Stannous chloride. 172.180 Section 172.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  4. 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.

  5. Neuroprotection of Insulin against Oxidative Stress-induced Apoptosis in Cultured Retinal Neurons: Involvement of Phosphoinositide 3-kinase/Akt Signal Pathway

    Institute of Scientific and Technical Information of China (English)

    Xiao-Rui YU; Guo-Rong JIA; Guang-Dao GAO; Shu-Hong WANG; Yan HAN; Wei CAO

    2006-01-01

    In order to investigate the neuroprotection of insulin in retinal neurons, we used retinal neuronal culture as a model system to study the protective effects of insulin against H2O2-induced cytotoxicity and apoptotic death. Primary retinal neuronal cultures were grown from retinas of 0-2-day old Sprague-Dawley rats. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay.Apoptotic cell death was evaluated by the TdT-mediated digoxigenin-dUTP nick-end labeling assay, and by DNA laddering analysis. Phosphoinositide 3-kinase (PI3K) activity was measured using phosphoinositide 4,5-bisphophate and [γ-32p]ATP as substrate. Western blot analysis with anti-phospho-Akt (pS473) antibody was performed to examine the level of phosphorylated Akt. We observed that treatment with 100 μM H2O2 for 24 h significantly decreased cell viability and induced apoptotic death of retinal neurons, and that pretreatment with 10 nM insulin significantly inhibited or attenuated H2O2-induced cytotoxicity and apoptosis. Pretreatment with LY294002, a specific PI3K inhibitor, abolished the cytoprotective effect of insulin. Insulin also strongly activated both PI3K and the downstream effector Akt. These results suggest that insulin protects retinal neurons from oxidative stress-induced apoptosis and that the PI3K/Akt signal pathway is involved in insulinmediated retinal neuroprotection.

  6. HEPATOPROTECTIVE ROLE OF SODIUM SELENITE AGAINST OXIDATIVE DAMAGE INDUCED BY MERCURIC CHLORIDE IN RAT ALBINOS WISTAR

    OpenAIRE

    Youcef Necib; Ahlem Bahi; Sakina Zerizer; Cherif Abdennour; Mohamed Salah Boulakoud

    2013-01-01

    Background: The present study was undertaken, to evaluate the protective effect of sodium selenite against mercuric chloride induced oxidative stress in experimental rats. Female Albinos Wistar rats randomly divided into four groups, were the first was served as a control, whereas the remaining groups respectively treated with: sodium selenite (1mg/ kg b.w; ip), mercuric chloride (1 mg/kg body weight i.p) and combination of sodium selenite and HgCl2. Change in liver enzyme activities, thiobar...

  7. Inferior retinal light exposure is more effective than superior retinal exposure in suppressing melatonin in humans

    Science.gov (United States)

    Glickman, Gena; Hanifin, John P.; Rollag, Mark D.; Wang, Jenny; Cooper, Howard; Brainard, George C.

    2003-01-01

    Illumination of different areas of the human retina elicits differences in acute light-induced suppression of melatonin. The aim of this study was to compare changes in plasma melatonin levels when light exposures of equal illuminance and equal photon dose were administered to superior, inferior, and full retinal fields. Nine healthy subjects participated in the study. Plexiglass eye shields were modified to permit selective exposure of the superior and inferior halves of the retinas of each subject. The Humphrey Visual Field Analyzer was used both to confirm intact full visual fields and to quantify exposure of upper and lower visual fields. On study nights, eyes were dilated, and subjects were exposed to patternless white light for 90 min between 0200 and 0330 under five conditions: (1) full retinal exposure at 200 lux, (2) full retinal exposure at 100 lux, (3) inferior retinal exposure at 200 lux, (4) superior retinal exposure at 200 lux, and (5) a dark-exposed control. Plasma melatonin levels were determined by radioimmunoassay. ANOVA demonstrated a significant effect of exposure condition (F = 5.91, p exposures as well as the inferior retinal exposure; however, superior retinal exposure was significantly less effective in suppressing melatonin. Furthermore, suppression with superior retinal exposure was not significantly different from that of the dark control condition. The results indicate that the inferior retina contributes more to the light-induced suppression of melatonin than the superior retina at the photon dosages tested in this study. Findings suggest a greater sensitivity or denser distribution of photoreceptors in the inferior retina are involved in light detection for the retinohypothalamic tract of humans.

  8. Modifications of retinal neurons in a mouse model of retinitis pigmentosa

    OpenAIRE

    Strettoi, Enrica; Pignatelli, Vincenzo

    2000-01-01

    Animal models of retinitis pigmentosa include the rd mouse, in which a mutation of a rod-specific phosphodiesterase leads to the rapid loss of photoreceptors during the early postnatal life. Very little is known about changes occurring in inner retinal neurons after photoreceptor loss. These changes are important in view of the possibility of restoring vision in retinas with photoreceptor degeneration by means of cell transplantation or direct stimulation of inner ...

  9. 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

  10. Shock compression of polyvinyl chloride

    Science.gov (United States)

    Neogi, Anupam; Mitra, Nilanjan

    2016-04-01

    This study presents shock compression simulation of atactic polyvinyl chloride (PVC) using ab-initio and classical molecular dynamics. The manuscript also identifies the limits of applicability of classical molecular dynamics based shock compression simulation for PVC. The mechanism of bond dissociation under shock loading and its progression is demonstrated in this manuscript using the density functional theory based molecular dynamics simulations. The rate of dissociation of different bonds at different shock velocities is also presented in this manuscript.

  11. 黄色晶状体Acrysof Natural对急性视网膜光损伤保护作用的形态学研究%The morphological investigation on AcrySof Natural's protective function from acute retinal light injury

    Institute of Scientific and Technical Information of China (English)

    曲勃; 马立威; 张劲松

    2005-01-01

    AIM: To investigate whether the Acrysof Natural has the protective function for retina from blue light in morphology.METHODS: Fresh porcine eye cups were formed in vitro. Blue light beam between 420-450nm spectrum eradiated the porcine retina and cultured RPE cells in 30J/cm2 and 40J/cm2, respectively. The adjacent region in 3mm diameter was eradiated in various ways: exposed directly to light, through AcrySof one piece IOL, PMMA IOL,AcrySof Natural IOL, and without light. Then the eye cups were cultured for 48h. Lastly, tissue and cell structure were observed with light microscope and transmission electron microscope (TEM).RESULTS: In the retinal region without light, the structure of every layer was clear, cells in neuroepithelial layer arrayed in rule, some bubble presented in external granular layer and internal granular layer, RPE cells were compact, and the color of pigment article was coincident. In the region with direct blue light and that with 30J/cm2+Acrysof one-piece/ pMMlA, cells on photoreceptor and external granular layer were lost partially, bubble increased, RPE cells were with different sizes, and cell edema, cell lost and pigment article cluster could be seen.. In region with 30J/cm2+Natural, a little disorganization could be seen comparing to that without light, but more normal than those with Acrysof and direct eradia tion. When the power was 40J/cm2, the situation was similar to that with 30J/cm2 but more severe.CONCLUSION: ① the blue light intensity in 30J/cm2 and 40J/cm2 could both induce the acute retinal light injury, ② AcrySof one piece IOL and other PMMA IOLhave no obvious effect no retina comparing to direct eradiation, ③AcrySof Natural can weaken the injury of blue light to some extent.%目的:在造成急性视网膜光损伤的光照条件下,通过不同人工晶状体下比较视网膜组织及超微结构的变化,以观察Acrysof№tural对视网膜的保护作用.方法:在无菌条件下将新

  12. Green tea catechins are potent anti-oxidants that ameliorate sodium iodate-induced retinal degeneration in rats.

    Science.gov (United States)

    Yang, Yaping; Qin, Yong Jie; Yip, Yolanda W Y; Chan, Kwok Ping; Chu, Kai On; Chu, Wai Kit; Ng, Tsz Kin; Pang, Chi Pui; Chan, Sun On

    2016-01-01

    Green tea extracts exhibit anti-oxidative and anti-inflammatory actions in different disease conditions. We hypothesized that green tea extract and its catechin constituents ameliorate sodium iodate-induced retinal degeneration in rats by counteracting oxidative stress. In this study, adult Sprague-Dawley rats were intravenously injected with a single dose of sodium iodate. Green tea extract (GTE; Theaphenon-E) or combinations of its catechin constituents, including (-)-epigallocatechin gallate (EGCG), were administered intra-gastrically before injection. Live imaging analysis using confocal scanning laser ophthalmoscopy and spectral-domain optical coherence tomography showed a progressive increase of degenerating profile across the retinal surface and decrease in thickness of outer nuclear layer (ONL) at Day-14 of post-injection. These lesions were significantly ameliorated by Theaphenon-E and catechin combinations with EGCG. Catechins with exclusion of EGCG did not show obvious protective effect. Histological analyses confirmed that Theaphenon-E and catechins containing EGCG protect the retina by reducing ONL disruption. Retinal protective effects were associated with reduced expression of superoxide dismutase, glutathione peroxidase and caspase-3, and suppression of 8-iso-Prostaglandin F2α generation in the retina. In summary, GTE and its catechin constituents are potent anti-oxidants that offer neuroprotection to the outer retinal degeneration after sodium iodate insult, among which EGCG is the most active constituent. PMID:27383468

  13. 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.

  14. 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...... (VEGF) in retinal ischemia. Retinal ischemia was induced in porcine eyes by applying an intraocular pressure, followed by 12 h of reperfusion. HIF-1α mRNA expression was not affected by ischemia, while immunofluorescence staining was higher after ischemia in the neuroretina. HIF-1β immunoreactivity...

  15. Effects of combined ketamine/xylazine anesthesia on light induced retinal degeneration in rats.

    Directory of Open Access Journals (Sweden)

    Blanca Arango-Gonzalez

    Full Text Available OBJECTIVES: To explore the effect of ketamine-xylazine anesthesia on light-induced retinal degeneration in rats. METHODS: Rats were anesthetized with ketamine and xylazine (100 and 5 mg, respectively for 1 h, followed by a recovery phase of 2 h before exposure to 16,000 lux of environmental illumination for 2 h. Functional assessment by electroretinography (ERG and morphological assessment by in vivo imaging (optical coherence tomography, histology (hematoxylin/eosin staining, TUNEL assay and immunohistochemistry (GFAP and rhodopsin staining were performed at baseline (ERG, 36 h, 7 d and 14 d post-treatment. Non-anesthetized animals treated with light damage served as controls. RESULTS: Ketamine-xylazine pre-treatment preserved retinal function and protected against light-induced retinal degeneration. In vivo retinal imaging demonstrated a significant increase of outer nuclear layer (ONL thickness in the non-anesthetized group at 36 h (p0.05, indicating a stabilizing and/or protective effect with regard to phototoxicity. Histology confirmed light-induced photoreceptor cell death and Müller cells gliosis in non-anesthetized rats, especially in the superior hemiretina, while ketamine-xylazine treated rats showed reduced photoreceptor cell death (TUNEL staining: p<0.001 after 7 d, thicker ONL and longer IS/OS. Fourteen days after light damage, a reduction of standard flash induced a-wave amplitudes and a-wave slopes (p = 0.01 and significant alterations in parameters of the scotopic sensitivity function (e.g. Vmax of the Naka Rushton fit p = 0.03 were observed in non-treated vs. ketamine-xylazine treated animals. CONCLUSIONS: Our results suggest that pre-treatment with ketamine-xylazine anesthesia protects retinas against light damage, reducing photoreceptor cell death. These data support the notion that anesthesia with ketamine-xylazine provides neuroprotective effects in light-induced cell damage.

  16. 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.

  17. 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.

  18. a Review of Retinal Prosthesis Approaches

    Science.gov (United States)

    Kien, Tran Trung; Maul, Tomas; Bargiela, Andrzej

    Age-related macular degeneration and retinitis pigmentosa are two of the most common diseases that cause degeneration in the outer retina, which can lead to several visual impairments up to blindness. Vision restoration is an important goal for which several different research approaches are currently being pursued. We are concerned with restoration via retinal prosthetic devices. Prostheses can be implemented intraocularly and extraocularly, which leads to different categories of devices. Cortical Prostheses and Optic Nerve Prostheses are examples of extraocular solutions while Epiretinal Prostheses and Subretinal Prostheses are examples of intraocular solutions. Some of the prostheses that are successfully implanted and tested in animals as well as humans can restore basic visual functions but still have limitations. This paper will give an overview of the current state of art of Retinal Prostheses and compare the advantages and limitations of each type. The purpose of this review is thus to summarize the current technologies and approaches used in developing Retinal Prostheses and therefore to lay a foundation for future designs and research directions.

  19. [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.

  20. 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.

  1. 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.

  2. Intravitreal ranibizumab therapy for retinal arterial macroaneurysm

    OpenAIRE

    Erol, Muhammet Kazim; Dogan, Berna; Coban, Deniz Turgut; Toslak, Devrim; Cengiz, Ayse; Ozel, Deniz

    2015-01-01

    Aim: To evaluate the anatomic and functional results of intravitreal ranibizumab injection for treatment of symptomatic retinal arterial macroaneurysm (RAM). Materials and Methods: A series of seven patients (seven eyes) who had been diagnosed with symptomatic RAM were assessed by comprehensive ophthalmologic examination, fluorescein angiography (FA), optical coherence tomography (OCT), and indocyanine green angiography (ICGA). All patients were treated by intravitreal ranibizumab injection w...

  3. 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.

  4. 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.

  5. Complete blood count and retinal vessel calibers.

    Directory of Open Access Journals (Sweden)

    Gerald Liew

    Full Text Available 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 at baseline examination, 1992-4. Retinal arteriolar and venular calibers were measured from digitized retinal photographs using a validated semi-automated computer program. RESULTS: All analyses adjusted for age, sex, systolic blood pressure, diabetes, smoking and fellow vessel caliber. Higher hematocrit, white cell count and platelet count were associated with narrower arteriolar caliber (p = 0.02, 0.03 and 0.001 respectively, while higher hemoglobin, hematocrit, red cell count, white cell count and platelet count were associated with wider venular caliber (p<0.0001 for all. Each quintile increase in hematocrit, white cell count and platelet count was associated with approximately 0.5 µm narrower arteriolar caliber; whereas each quintile increase in all of the complete blood count components was associated with approximately 1-2 µm wider venular caliber. CONCLUSIONS: These associations show that elevated levels of hematological indices can have adverse effects on the microcirculation.

  6. 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.

  7. 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.

  8. Retinal Imaging Techniques for Diabetic Retinopathy Screening.

    Science.gov (United States)

    Goh, James Kang Hao; Cheung, Carol Y; Sim, Shaun Sebastian; Tan, Pok Chien; Tan, Gavin Siew Wei; Wong, Tien Yin

    2016-03-01

    Due to the increasing prevalence of diabetes mellitus, demand for diabetic retinopathy (DR) screening platforms is steeply increasing. Early detection and treatment of DR are key public health interventions that can greatly reduce the likelihood of vision loss. Current DR screening programs typically employ retinal fundus photography, which relies on skilled readers for manual DR assessment. However, this is labor-intensive and suffers from inconsistency across sites. Hence, there has been a recent proliferation of automated retinal image analysis software that may potentially alleviate this burden cost-effectively. Furthermore, current screening programs based on 2-dimensional fundus photography do not effectively screen for diabetic macular edema (DME). Optical coherence tomography is becoming increasingly recognized as the reference standard for DME assessment and can potentially provide a cost-effective solution for improving DME detection in large-scale DR screening programs. Current screening techniques are also unable to image the peripheral retina and require pharmacological pupil dilation; ultra-widefield imaging and confocal scanning laser ophthalmoscopy, which address these drawbacks, possess great potential. In this review, we summarize the current DR screening methods using various retinal imaging techniques, and also outline future possibilities. Advances in retinal imaging techniques can potentially transform the management of patients with diabetes, providing savings in health care costs and resources. PMID:26830491

  9. 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

  10. Retinal Biochemistry, Physiology and Cell Biology.

    Science.gov (United States)

    Smith, Ricardo Luiz; Sivaprasad, Sobha; Chong, Victor

    2016-01-01

    The vitreous, the vasculature of the retina, macular pigments, phototransduction, retinal pigment epithelium, Bruch's membrane and the extracellular matrix, all play an important role in the normal function of the retina as well as in diseases. Understanding the pathophysiology allows us to target treatment. As ocular angiogenesis, immunity and inflammation are covered elsewhere, those subjects will not be discussed in this chapter.

  11. 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.

  12. 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. 

  13. Hypoxia-dependent retinal toxicity of bioreductive anticancer prodrugs in mice.

    Science.gov (United States)

    Lee, A E; Wilson, W R

    2000-02-15

    The bioreductive anticancer prodrug CI-1010 ((2R)-1-[(2-bromoethyl)amino]-3-(2-nitro-1H-imidazol-1-yl)-2-propanol hydrobromide) is an alkylating nitroimidazole which shows selective toxicity against hypoxic cells in murine tumors, but causes extensive apoptosis in the outer retina in rodents and monkeys. This irreversible retinal toxicity has terminated preclinical development of CI-1010. We have investigated whether such toxicity is due to physiological hypoxia in the retina, and whether it is a general feature of hypoxia-selective bioreductive drugs. Retinal damage was quantified by morphometric analysis of histological sections following treatment of female C57Bl6 mice. Both CI-1010 and tirapazamine (TPZ, 1,2,4-benzotriazin-3-amine 1,4-dioxide), a bioreductive drug in Phase III clinical trial, caused a time and dose-dependent loss of photoreceptor cells of the outer retina following administration of single intraperitoneal doses. The lesion caused by TPZ was qualitatively similar to that with CI-1010, but was less severe at equivalent fractions of the maximum tolerated dose (as defined by lethality). With both bioreductive drugs, lesion severity was increased if animals breathed 10% O(2) for 3 h after drug administration, while breathing 95% O(2)/5% CO(2) was protective. Other hypoxia-selective bioreductive drugs tested (the quinone porfiromycin, the anthraquinone N-oxide AQ4N and the nitrogen mustard prodrugs SN 23816 and SN 25341) did not cause retinal damage at their maximum tolerated doses. This study suggests that the retinal toxicity of bioreductive drugs might be avoided by manipulation of tissue hypoxia using 95% O(2)/5% CO(2), although this intervention could suppress antitumor activity. The finding that not all bioreductive drugs cause retinal toxicity suggests this toxicity can be avoided through appropriate drug design. PMID:10662604

  14. Applying photoacoustics to quantification of melanin concentration in retinal pigment epithelium (Conference Presentation)

    Science.gov (United States)

    Shu, Xiao; Zhang, Hao F.; Liu, Wenzhong

    2016-03-01

    The melanin in the retinal pigment epithelium (RPE) protects retina and other ocular tissues by photo-screening and acting as antioxidant and free radical scavenger. It helps maintain normal visual functions since human eye is subjected to lifelong high oxygen stress and photon exposure. Loss of the RPE melanin weakens the protection mechanism and jeopardizes ocular health. Local decrease in the RPE melanin concentration is believed to be both a cause and a sign of early-stage age-related macular degeneration (AMD), the leading blinding disease in developed world. Current technology cannot quantitatively measure the RPE melanin concentration which might be a promising marker in early AMD screening. Photoacoustic ophthalmoscopy (PAOM), as an emerging optical absorption-based imaging technology, can potentially be applied to measure the RPE melanin concentration if the dependence of the detectable photoacoustic (PA) signal amplitudes on the RPE melanin concentrations is verified. In this study, we tested the feasibility of using PA signal ratio from RPE melanin and the nearby retinal blood vessels as an indicator of the RPE melanin variation. A novel whole eye optical model was designed and Monte Carlo modeling of light (MCML) was employed. We examined the influences on quantification from PAOM axial resolution, the depth and diameter of the retinal blood vessel, and the RPE thickness. The results show that the scheme is robust to individual histological and illumination variations. This study suggests that PAOM is capable of quantitatively measuring the RPE melanin concentration in vivo.

  15. Inner retinal change in a novel rd1-FTL mouse model of retinal degeneration

    Directory of Open Access Journals (Sweden)

    Ursula eGreferath

    2015-07-01

    Full Text Available While photoreceptor loss is the most devastating result of inherited retinal degenerations such as retinitis pigmentosa, inner retinal neurons also undergo significant alteration. Detailing these changes has become important as many vision restorative therapies target the remaining neurons. In this study, the rd1-Fos-Tau-LacZ (rd1-FTL mouse model was used to explore inner retinal change at a late stage of retinal degeneration, after the loss of photoreceptor nuclei. The rd1-FTL model carries a mutation in the phosphodiesterase gene, Pde6b, and an axonally targeted transgenic beta galactosidase reporter system under the control of the c-fos promoter. Retinae of transgenic rd1-FTL mice and control FTL animals aged 2 to 12 months were processed for indirect fluorescence immunocytochemistry. At 2 months of age, a time when the majority of photoreceptor nuclei are lost, there was negligible c-fos reporter (FTL expression, however, from 4 months, reporter expression was observed to increase within subpopulations of amacrine and ganglion cells within the central retina. These areas of inner retinal FTL expression coincided with regions that contained aberrant Müller cells. Specifically, these cells exhibited reduced glutamine synthetase and Kir4.1 immunolabelling, whilst showing evidence of proliferative gliosis (increased cyclinD1 and GFAP expression. These changes were limited to distinct regions where cone photoreceptor terminals were absent. Overall, these results highlight that distinct areas of the rd1-FTL central retina undergo significant glial alterations after cone photoreceptor loss. These areas coincide with up-regulation of the c-fos reporter in the inner retina, which may represent a change in neuronal function/plasticity. The rd1-FTL mouse is a useful model system to probe changes that occur in the inner retina at later stages of retinal degeneration.

  16. Inner retinal change in a novel rd1-FTL mouse model of retinal degeneration.

    Science.gov (United States)

    Greferath, Ursula; Anderson, Emily E; Jobling, Andrew I; Vessey, Kirstan A; Martinez, Gemma; de Iongh, Robb U; Kalloniatis, Michael; Fletcher, Erica L

    2015-01-01

    While photoreceptor loss is the most devastating result of inherited retinal degenerations such as retinitis pigmentosa, inner retinal neurons also undergo significant alteration. Detailing these changes has become important as many vision restorative therapies target the remaining neurons. In this study, the rd1-Fos-Tau-LacZ (rd1-FTL) mouse model was used to explore inner retinal change at a late stage of retinal degeneration, after the loss of photoreceptor nuclei. The rd1-FTL model carries a mutation in the phosphodiesterase gene, Pde6b, and an axonally targeted transgenic beta galactosidase reporter system under the control of the c-fos promoter. Retinae of transgenic rd1-FTL mice and control FTL animals aged 2-12 months were processed for indirect fluorescence immunocytochemistry. At 2 months of age, a time when the majority of photoreceptor nuclei are lost, there was negligible c-fos reporter (FTL) expression, however, from 4 months, reporter expression was observed to increase within subpopulations of amacrine and ganglion cells within the central retina. These areas of inner retinal FTL expression coincided with regions that contained aberrant Müller cells. Specifically, these cells exhibited reduced glutamine synthetase and Kir4.1 immunolabelling, whilst showing evidence of proliferative gliosis (increased cyclinD1 and glial fibrillary acidic protein expression). These changes were limited to distinct regions where cone photoreceptor terminals were absent. Overall, these results highlight that distinct areas of the rd1-FTL central retina undergo significant glial alterations after cone photoreceptor loss. These areas coincide with up-regulation of the c-fos reporter in the inner retina, which may represent a change in neuronal function/plasticity. The rd1-FTL mouse is a useful model system to probe changes that occur in the inner retina at later stages of retinal degeneration. PMID:26283925

  17. Role of endoplasmic reticulum stress in the loss of retinal ganglion cells in diabetic retinopathy

    Institute of Scientific and Technical Information of China (English)

    Liping Yang; Lemeng Wu; Dongmei Wang; Ying Li; Hongliang Dou; Mark OMTso; Zhizhong Ma

    2013-01-01

    Endoplasmic reticulum stress is closely involved in the early stage of diabetic retinopathy. In the present study, a streptozotocin-induced diabetic animal model was given an intraperitoneal injection of tauroursodeoxycholic acid. Results from immunofluorescent co-localization experiments showed that both caspase-12 protein and c-Jun N-terminal kinase 1 phosphorylation levels significantly in-creased, which was associated with retinal ganglion celldeath in diabetic retinas. The C/ERB ho-mologous protein pathway directly contributed to glial reactivity, and was subsequently responsible for neuronal loss and vascular abnormalities in diabetic retinopathy. Our experimental findings in-dicate that endoplasmic reticulum stress plays an important role in diabetes-induced retinal neu-ronal loss and vascular abnormalities, and that inhibiting the activation of the endoplasmic reticulum stress pathway provides effective protection against diabetic retinopathy.

  18. Therapeutic Opportunities for Caffeine and A2A Receptor Antagonists in Retinal Diseases.

    Science.gov (United States)

    Boia, Raquel; Ambrósio, António Francisco; Santiago, Ana Raquel

    2016-01-01

    Caffeine, the major component of coffee, is the most consumed psychostimulant in the world. Caffeine is an adenosine analog and acts as a nonselective adenosine receptor antagonist. The majority of the effects of caffeine are mainly mediated by the blockade of adenosine receptors, and the proved neuroprotective effects of caffeine in brain disorders have been mimicked by the blockade of adenosine A2A receptor (A2AR). A growing body of evidence demonstrates that microglia-mediated neuroinflammation plays a key role in the pathophysiology of brain and retinal diseases. Moreover, the control of microglia reactivity by blocking A2AR has been proposed to be the mechanism underlying the observed protective effects of caffeine. Hence, it is conceivable that caffeine and A2AR antagonists offer therapeutic value for the treatment of retinal diseases, mainly those involving microglia-mediated neuroinflammation.

  19. Simple chloride sensors for continuous groundwater monitoring

    DEFF Research Database (Denmark)

    Thorn, Paul; Mortensen, John

    2012-01-01

    The development of chloride sensors which can be used for continuous, on-line monitoring of groundwater could be very valuable in the management of our coastal water resources. However, sensor stability, drift, and durability all need to be addressed in order for the sensors to be used...... in continuous application. This study looks at the development of a simple, inexpensive chloride electrode, and evaluates its performance under continuous use, both in the laboratory and in a field test in a monitoring well. The results from the study showed a consistent response to changing chloride...... sensor remained responsive even at low chloride concentrations, where the conductivity electrode was no longer responding to changing chloride levels. With the results, it is believed that the simple chloride sensor could be used for continuous monitoring of groundwater quality....

  20. Alterations to retinal architecture prior to photoreceptor loss in a mouse model of retinitis pigmentosa.

    Science.gov (United States)

    Roche, Sarah L; Wyse-Jackson, Alice C; Byrne, Ashleigh M; Ruiz-Lopez, Ana M; Cotter, Thomas G

    2016-01-01

    Mouse models of retinitis pigmentosa (RP) are essential tools in the pursuit to understand fully what cell types and processes underlie the degeneration observed in RP. Knowledge of these processes is required if we are to develop successful therapies to treat this currently incurable disease. We have used the rd10 mouse model of RP to study retinal morphology prior to photoreceptor loss, using immunohistochemistry and confocal microscopy on cryosections, since little is known about how the mutation affects the retina during this period. We report novel findings that the mutation in the rd10 mouse results in retinal abnormalities earlier than was previously thought. Defects in rod and cone outer segments, bipolar cells, amacrine cells and photoreceptor synapses were apparent in the retina during early stages of postnatal retinal development and prior to the loss of photoreceptors. Additionally, we observed a dramatic response of glial cells during this period. Microglia responded as early as postnatal day (P) 5; ?13 days before any photoreceptor loss is detected with Müller glia and astrocytes exhibiting changes from P10 and P15 respectively. Overall, these findings present pathological aspects to the postnatal development of the rd10 retina, contributing significantly to our understanding of disease onset and progression in the rd10 mouse and provide a valuable resource for the study of retinal dystrophies. PMID:27160072

  1. Retinal tears and rhegmatogenous retinal detachment after intravitreal injections: its prevalence and case reports

    Science.gov (United States)

    Karabag, Revan Yildirim; Parlak, Melih; Cetin, Gölgem; Yaman, Aylin; Osman Saatci, A.

    2015-01-01

    Purpose To report the prevalence of postoperative retinal tear or rhegmatogenous retinal detachment secondary to intravitreal injections. Methods Surgical and medical records of patients who received intravitreal injections at the practice of a single retina specialist from January 2004 to May 2013 and who were followed for at least 6 months were investigated retrospectively. Results During the study period, a total of 3,907 intravitreal injections were performed in 1,049 eyes of 784 patients (416 males [47%]). The mean number of injections per eye was 3.72 ± 3.43 (range, 1–22). The mean age of the participants was 67.03 ± 13.56 (range, 5–94 years). The mean follow-up time was 31.98 ± 22.86 months (range, 6–144 months). Retinal break or rhegmatogenous retinal detachment occurred in 3 injections of 3 eyes, yielding an overall prevalence of 0.077% per injection and 0.29% per eye. Conclusions Retinal tear and rhegmatogenous detachment are rare complications of intravitreal injection. Precautions should be taken especially in patients having predisposing conditions, such as high myopia, or any other vitreoretinal disorders. PMID:27330458

  2. Retinal vascular calibres are significantly associated with cardiovascular risk factors

    DEFF Research Database (Denmark)

    von Hanno, T.; Bertelsen, G.; Sjølie, Anne K.;

    2014-01-01

    Purpose: To describe the association between retinal vascular calibres and cardiovascular risk factors. Methods: Population-based cross-sectional study including 6353 participants of the TromsO Eye Study in Norway aged 38-87years. Retinal arteriolar calibre (central retinal artery equivalent....... Association between retinal vessel calibre and the cardiovascular risk factors was assessed by multivariable linear and logistic regression analyses. Results: Retinal arteriolar calibre was independently associated with age, blood pressure, HbA1c and smoking in women and men, and with HDL cholesterol in men...... cardiovascular risk factors were independently associated with retinal vascular calibre, with stronger effect of HDL cholesterol and BMI in men than in women. Blood pressure and smoking contributed most to the explained variance....

  3. Detection and measurement of retinal blood vessel pulsatile motion

    Science.gov (United States)

    Xiao, Di; Frost, Shaun; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. Pulsatile properties caused by cardiac rhythm, such as spontaneous venous pulsation (SVP) and pulsatile motion of small arterioles, can be visualized by dynamic retinal imaging techniques and provide clinical significance. In this paper, we aim at vessel pulsatile motion detection and measurement. We proposed a novel approach for pulsatile motion measurement of retinal blood vessels by applying retinal image registration, blood vessel detection and blood vessel motion detection and measurement on infrared retinal image sequences. The performance of the proposed methods was evaluated on 8 image sequences with 240 images. A preliminary result has demonstrated the good performance of the method for blood vessel pulsatile motion observation and measurement.

  4. The Electroretinogram in Patients with Retinal Vascular Occlusion

    Institute of Scientific and Technical Information of China (English)

    Shizhou Huang; Lezheng Wu; Taiqing Luo; De-Zheng Wu; Futian Jiang; Guangwei Luo; Juanmei Ma

    2001-01-01

    Purpose: to measure and analyze the electroretinogram (ERG) in patients with retinal vascular occlusion. Method: fifty-eight cases (59 eyes) of retinal vascular occlusion and the fellow eyes of 47 cases were tested with Ganzfeld ERG. The scotopic and photopic ERG, and oscillatory potentials were tested according to the ERG standard of ISCEV. Results: The abnormal rates of Ops and b wave were higher in retinal vascular occlusion. The abnormal ERG appeared mostly in CRVO among four types of retinal vascular occlusion. The comparisons of some amplitudes and latencies between the fellow eyes and the affected eyes showed statistically significant difference. Conclusion: The oscillatory potentials and b waves have important roles in evaluating the retinal function of patients with retinal vascular occlusions. There are some clinical significance for comparing ERG between the affected eye and the fellow eye. Eye Science 2001; 17: 50 ~ 53.

  5. Combined branch retinal vein and artery occlusion in toxoplasmosis.

    Science.gov (United States)

    Aggio, Fabio Bom; Novelli, Fernando José de; Rosa, Evandro Luis; Nobrega, Mário Junqueira

    2016-01-01

    A 22-year-old man complained of low visual acuity and pain in his left eye for five days. His ophthalmological examination revealed 2+ anterior chamber reaction and a white, poorly defined retinal lesion at the proximal portion of the inferotemporal vascular arcade. There were retinal hemorrhages in the inferotemporal region extending to the retinal periphery. In addition, venous dilation, increased tortuosity, and ischemic retinal whitening along the inferotemporal vascular arcade were also observed. A proper systemic work-up was performed, and the patient was diagnosed with ocular toxoplasmosis. He was treated with an anti-toxoplasma medication, and his condition slowly improved. Inferior macular inner and middle retinal atrophy could be observed on optical coherence tomography as a sequela of ischemic injury. To our knowledge, this is the first report of combined retinal branch vein and artery occlusion in toxoplasmosis resulting in a striking and unusual macular appearance. PMID:27463632

  6. Polyacrylamide/potassium-chloride mud for drilling water-sensitive shales

    Energy Technology Data Exchange (ETDEWEB)

    Clark, R.K.; Scheuerman, R.F.; Rath, H.; Van Laar, H.G.

    1976-06-01

    A shale-protective, water-base drilling fluid containing a high molecular-weight, partially hydrolyzed polyacrylamide and potassium chloride has been used in many wells around the world. A laboratory test for evaluating the ability of water-base muds to protect stressed shales under dynamic conditions was used in the initial development of the system. Field application of the polyacrylamide/potassium-chloride mud has been successful in stabilizing hard, sloughing shales in Canada and in reducing shale-related hole problems in several offshore areas. Recent use in the Canadian Arctic has extended the application to weighted muds for drilling soft, mud-producing shales.

  7. ENVIRONMENTAL EXPOSURE TO VINYL CHLORIDE

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-09-01

    Full Text Available Vinyl chloride (VC monomer is a wellknown carcinogenic and mutagenic substance causes liver damages, angiosarcoma of the liver, acro – osteolysis, sclerodermalike changes in workers chronically exposed to this gas. There are following VC emitors to the environment: VC production plants, polymerization facilities and planes where polyvinyl products are fabricated. Because of that, the general population is coming into VC contact through polluted air, food and water. VC concentration in all mentioned sites is very low, often not detectable. There was found any health risk for the general population. The VC air concentration in the vicinity to antropogenic emitors is always higher. Such a situation may causes undesirable health effect for residents living in the neighbourhood. Epidemiological studies are performed to detect the adverse VC effect in selected cohorts. Non of the study did not confirmed cases of angiosarcoma among residents living near a vinyl chloride sites. VC production is growing permanently, so VC emission will be higher. Because of that health monitoring of general population and especially of selected groups seems to be necessary in the future.

  8. Psychological and educational recommendations for working with young people with Retinitis Pigmentosa

    NARCIS (Netherlands)

    Chacón López, Elena; Lopez-Justicia, M.D.; Vervloed, M.P.J.

    2014-01-01

    This article reviews the consequences of Retinitis Pigmentosa, a retinal degenerative disease with progressive reduction of the visual field, visual acuity, contrast sensitivity, and night blindness. Retinitis Pigmentosa is addressed from both a psychological and an educational standpoint, focusing

  9. Biophotons Contribute to Retinal Dark Noise.

    Science.gov (United States)

    Li, Zehua; Dai, Jiapei

    2016-06-01

    The discovery of dark noise in retinal photoreceptors resulted in a long-lasting controversy over its origin and the underlying mechanisms. Here, we used a novel ultra-weak biophoton imaging system (UBIS) to detect biophotonic activity (emission) under dark conditions in rat and bullfrog (Rana catesbeiana) retinas in vitro. We found a significant temperature-dependent increase in biophotonic activity that was completely blocked either by removing intracellular and extracellular Ca(2+) together or inhibiting phosphodiesterase 6. These findings suggest that the photon-like component of discrete dark noise may not be caused by a direct contribution of the thermal activation of rhodopsin, but rather by an indirect thermal induction of biophotonic activity, which then activates the retinal chromophore of rhodopsin. Therefore, this study suggests a possible solution regarding the thermal activation energy barrier for discrete dark noise, which has been debated for almost half a century. PMID:27059222

  10. Retinal Image Simulation of Subjective Refraction Techniques.

    Directory of Open Access Journals (Sweden)

    Sara Perches

    Full Text Available Refraction techniques make it possible to determine the most appropriate sphero-cylindrical lens prescription to achieve the best possible visual quality. Among these techniques, subjective refraction (i.e., patient's response-guided refraction is the most commonly used approach. In this context, this paper's main goal is to present a simulation software that implements in a virtual manner various subjective-refraction techniques-including Jackson's Cross-Cylinder test (JCC-relying all on the observation of computer-generated retinal images. This software has also been used to evaluate visual quality when the JCC test is performed in multifocal-contact-lens wearers. The results reveal this software's usefulness to simulate the retinal image quality that a particular visual compensation provides. Moreover, it can help to gain a deeper insight and to improve existing refraction techniques and it can be used for simulated training.

  11. Retinal Image Simulation of Subjective Refraction Techniques.

    Science.gov (United States)

    Perches, Sara; Collados, M Victoria; Ares, Jorge

    2016-01-01

    Refraction techniques make it possible to determine the most appropriate sphero-cylindrical lens prescription to achieve the best possible visual quality. Among these techniques, subjective refraction (i.e., patient's response-guided refraction) is the most commonly used approach. In this context, this paper's main goal is to present a simulation software that implements in a virtual manner various subjective-refraction techniques--including Jackson's Cross-Cylinder test (JCC)--relying all on the observation of computer-generated retinal images. This software has also been used to evaluate visual quality when the JCC test is performed in multifocal-contact-lens wearers. The results reveal this software's usefulness to simulate the retinal image quality that a particular visual compensation provides. Moreover, it can help to gain a deeper insight and to improve existing refraction techniques and it can be used for simulated training. PMID:26938648

  12. Unified detection and tracking in retinal microsurgery.

    Science.gov (United States)

    Sznitman, Raphael; Basu, Anasuya; Richa, Rogerio; Handa, Jim; Gehlbach, Peter; Taylor, Russell H; Jedynak, Bruno; Hager, Gregory D

    2011-01-01

    Traditionally, tool tracking involves two subtasks: (i) detecting the tool in the initial image in which it appears, and (ii) predicting and refining the configuration of the detected tool in subsequent images. With retinal microsurgery in mind, we propose a unified tool detection and tracking framework, removing the need for two separate systems. The basis of our approach is to treat both detection and tracking as a sequential entropy minimization problem, where the goal is to determine the parameters describing a surgical tool in each frame. The resulting framework is capable of both detecting and tracking in situations where the tool enters and leaves the field of view regularly. We demonstrate the benefits of this method in the context of retinal tool tracking. Through extensive experimentation on a phantom eye, we show that this method provides efficient and robust tool tracking and detection. PMID:22003593

  13. Retinal vein occlusion in Benin City, Nigeria

    Directory of Open Access Journals (Sweden)

    Odarosa M Uhumwangho

    2016-01-01

    Full Text Available Background: Retinal vein occlusion (RVO is the most common occlusive retinal vascular disorder and results in varying degrees of visual loss. Aim: To determine the pattern of presentation, risk factors, and treatment outcomes in a group of patients with RVO seen in a tertiary hospital in Nigeria. Materials and Methods: Medical records of patients who presented to the University of Benin Teaching Hospital, Benin City, Nigeria in whom a diagnosis of RVO was made over a 5 years period were reviewed. Data obtained were analyzed with the GraphPad Instat Software, Inc. version V2.05a program, San Diego, Califonia and a P < 0.05 considered significant. Results: There were 20 patients made of 14 (70.0% males and 6 (30.0% females with a mean age of 62.7 ± 10.4 years. There were 15 (68.2% eyes with central RVO, 3 (13.6% eyes with branch RVO, and 4 (18.2% eyes with hemi RVO. Bilateral involvement occurred in 2 (10.0% patients. Risk factors included hypertension 14 (70.0%, diabetes mellitus 9 (45.0%, and glaucoma 5 (22.7%. Multiple risk factors were present in 14 (70.0% patients. Complications included macula edema 15 (68.2%, retinal neovascularization 5 (22.7%, neovascular glaucoma 3 (13.6%, and vitreous hemorrhage 2 (9.1%. Eyes which had definitive treatment with intravitreal antivascular endothelial growth factors and laser photocoagulation for macula edema and retinal neovascularization, respectively, had better visual acuity compared to eyes which did not receive these treatment, P = 0.002. Conclusion: The incidence and visual loss that occurs from RVO can be reduced by modifying known risk factors and early institution of appropriate therapy for complications that occur.

  14. Branch Retinal Vein Occlusion and Its Management

    Institute of Scientific and Technical Information of China (English)

    Desmond; Archer

    1992-01-01

    The natural course of Branch Retinal Vein Occlusion is determined by the site and completeness of the occlusion, the integrity of arterial perfusion to the affected sector and the efficiency of the developing collateral circulation. Most patients with tributary vein occlusion have some capillary fall out and microvascular incompetence in the distribution of the affected retina and vision is significantly compromised in over 50% of patients who have either chronic macular oedema or ischemia involving the...

  15. Objective detection of retinal vessel pulsation.

    Directory of Open Access Journals (Sweden)

    William H Morgan

    Full Text Available PURPOSE: Retinal venous pulsation detection is a subjective sign, which varies in elevated intracranial pressure, venous obstruction and glaucoma. To date no method can objectively measure and identify pulsating regions. METHOD: Using high resolution video-recordings of the optic disk and retina we measured fluctuating light absorption by haemoglobin during pulsation. Pulsation amplitude was calculated from all regions of the retinal image video-frames in a raster pattern. Segmented retinal images were formed by objectively selecting regions with amplitudes above a range of threshold values. These were compared to two observers manually drawing an outline of the pulsating areas while viewing video-clips in order to generate receiver operator characteristics. RESULTS: 216,515 image segments were analysed from 26 eyes in 18 research participants. Using data from each eye, the median area under the receiver operator curve (AU-ROC was 0.95. With all data analysed together the AU-ROC was 0.89. We defined the ideal threshold amplitude for detection of any pulsating segment being that with maximal sensitivity and specificity. This was 5 units (95% confidence interval 4.3 to 6.0 compared to 12 units before any regions were missed. A multivariate model demonstrated that ideal threshold amplitude increased with increased variation in video-sequence illumination (p = 0.0119, but between the two observers (p = 0.0919 or other variables. CONCLUSION: This technique demonstrates accurate identification of retinal vessel pulsating regions with no areas identified manually being missed with the objective technique. The amplitude values are derived objectively and may be a significant advance upon subjective ophthalmodynamometric threshold techniques.

  16. Interconnection between brain and retinal neurodegenerations.

    Science.gov (United States)

    Jindal, Vishal

    2015-01-01

    The eye is a special sensory organ, which is basically an extension of the brain. Both are derived from neural tube and consist of neurons. Therefore, diseases of both the brain and eye should have some similarity. Neurodegenerative disorders like Alzheimer's disease (AD) is the major cause of dementia in the world. Amyloid deposition in the cerebral cortex and hippocampal region is the basic pathology in AD. But along with it, there are various changes that take place in the eye, i.e., abnormal pupillary reaction, decreased vision, decreased contrast sensitivity, visual field changes, loss of retinal ganglionic cells and retinal fiber layer, peripapillary atrophy, increased cup-disk ratio, retinal thinning, tortuosity of blood vessels, and deposition of Aβ-like substance in the retina. And these changes are present in the early part of the disease when only mild cognitive impairment is there. As the brain is covered by a hard bony skull which makes it difficult to directly visualize the changes occurring in the brain at molecular levels, finer details of disease progression are not available with us. But the eye is the window of the brain; with advanced modern techniques, we can directly visualize the changes in the retina at a very fine level. Therefore, by depicting neurodegenerative changes in the eye, we can diagnose and manage AD at very early stages. Along with it, retinal neurodegenerations like glaucoma and age-related macular degeneration (ARMD) are the major cause of loss of vision, and still, there are no effective treatment modalities for these blinding conditions. So if we can understand its pathogenesis and progression by correlating with brain neurodegenerations, we can come up with a better therapy for glaucoma and ARMD.

  17. Histogenesis of retinal dysplasia in trisomy 13

    OpenAIRE

    Gonzalez-Fernandez Federico; Heffner Reid; Lakshminrusimha Satyan; Chan Ada

    2007-01-01

    Abstract Background Although often associated with holoprosencephaly, little detail of the histopathology of cyclopia is available. Here, we describe the ocular findings in a case of trisomy 13 to better understand the histogenesis of the rosettes, or tubules, characteristic of the retinal dysplasia associated with this condition. Methods A full pediatric autopsy was performed of a near term infant who died shortly after birth from multiple congenital anomalies including fused facial-midline ...

  18. Retinal changes associated with neurofibromatosis 2.

    OpenAIRE

    Meyers, S M; Gutman, F A; Kaye, L D; Rothner, A D

    1995-01-01

    INTRODUCTION: Neurofibromatosis (NF) is now known to be more than one disease. NF2, formerly classified as central neurofibromatosis, is characterized by bilateral vestibular schwannomas, previously termed "acoustic neuromas", and is much less common than NF1. Lens opacities at an early age have been described in approximately 85% of NF2 patients. PURPOSE: To determine the frequency of retinal abnormalities in NF2 patients. METHODS: We prospectively examined 15 consecutive patients who met th...

  19. Retinal prosthetics, optogenetics, and chemical photoswitches.

    Science.gov (United States)

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-10-15

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream

  20. Progressive Outer Retinal Necrosis and Immunosuppressive Therapy in Myasthenia Gravis

    Directory of Open Access Journals (Sweden)

    Solène Coisy

    2014-04-01

    Full Text Available Introduction: Progressive outer retinal necrosis (PORN is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV and responsible for severe visual loss. Case Report: A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. Conclusion: VZV PORN is a severe potential ocular complication of immunosuppression, prompting urgent diagnosis and appropriate treatment.

  1. An unusual central retinal dystrophy associated with ichthyosis vulgaris.

    Science.gov (United States)

    Saatci, O A; Ozbek, Z; Köse, S; Durak, I; Kavukçu, S

    2000-06-01

    A number of ichthyosis syndromes may have retinal abnormalities such as the retinitis pigmentosa-like diffuse rod-cone dystrophy in Refsum's syndrome and the maculopathy in Sjögren-Larsson syndrome. We present two sisters who have an unusual, almost identical, bilaterally symmetric central retinal dystrophy associated with ichthyosis vulgaris in the absence of other systemic disorders. We believe that this dystrophy has not been previously described in patients with any of the known varieties of ichthyosis.

  2. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

    OpenAIRE

    Nicolas Froger; Lucia Cadetti; Henri Lorach; Joao Martins; Alexis-Pierre Bemelmans; Elisabeth Dubus; Julie Degardin; Dorothée Pain; Valérie Forster; Laurent Chicaud; Ivana Ivkovic; Manuel Simonutti; Stéphane Fouquet; Firas Jammoul; Thierry Léveillard

    2012-01-01

    Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was inc...

  3. Progressive Outer Retinal Necrosis and Immunosuppressive Therapy in Myasthenia Gravis

    OpenAIRE

    Coisy, Solène; Ebran, Jean-Marc; Milea, Dan

    2014-01-01

    Introduction Progressive outer retinal necrosis (PORN) is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV) and responsible for severe visual loss. Case Report A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. Conclusion VZV PORN is a severe potential ocular complication...

  4. Spontaneous resorption of sub-retinal cortical lens material

    Directory of Open Access Journals (Sweden)

    Salil S Gadkari

    2014-01-01

    Full Text Available We report a rare case of retained sub-retinal cortical material, which underwent spontaneous resorption. Patient presented with a left eye traumatic retinal detachment with a large retinal tear and posteriorly dislocated cataractous lens. Vitrectomy, lensectomy, silicone oil injection, and endolaser were performed. A good visual result was achieved. The report draws attention to this condition and highlights possible technique for minimizing risk of this complication in similar cases.

  5. Retinal Detachment due to CrossFit Training Injury

    OpenAIRE

    Joondeph, Stephanie A.; Joondeph, Brian C.

    2013-01-01

    The purpose of this paper is to describe a traumatic retinal detachment occurring as a result of CrossFit training using an elastic exercise band. The patient sustained an ocular injury from an elastic band during CrossFit training, resulting in a giant retinal dialysis and retinal detachment, which were successfully repaired. Trainers and athletes need to be aware of the potential for ocular injury from elastic exercise bands and take appropriate precautions.

  6. Retinal Detachment due to CrossFit Training Injury.

    Science.gov (United States)

    Joondeph, Stephanie A; Joondeph, Brian C

    2013-01-01

    The purpose of this paper is to describe a traumatic retinal detachment occurring as a result of CrossFit training using an elastic exercise band. The patient sustained an ocular injury from an elastic band during CrossFit training, resulting in a giant retinal dialysis and retinal detachment, which were successfully repaired. Trainers and athletes need to be aware of the potential for ocular injury from elastic exercise bands and take appropriate precautions. PMID:24106626

  7. Retinal Detachment due to CrossFit Training Injury

    Directory of Open Access Journals (Sweden)

    Stephanie A. Joondeph

    2013-01-01

    Full Text Available The purpose of this paper is to describe a traumatic retinal detachment occurring as a result of CrossFit training using an elastic exercise band. The patient sustained an ocular injury from an elastic band during CrossFit training, resulting in a giant retinal dialysis and retinal detachment, which were successfully repaired. Trainers and athletes need to be aware of the potential for ocular injury from elastic exercise bands and take appropriate precautions.

  8. Scleral buckling for retinal detachment in patients with retinoblastoma

    International Nuclear Information System (INIS)

    Three children (two girls and one boy) with bilateral retinoblastoma each developed a presumed rhegmatogenous retinal detachment in one eye. All three eyes had previously received radiation and cryotherapy. In each case the retinal detachment responded promptly to conventional surgical methods via scleral buckling in the area of treated retinoblastoma and presumed retinal break. All three eyes have retained useful vision for follow-up periods of 3.5 to 12 years

  9. Scleral buckling for retinal detachment in patients with retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Buzney, S.M.; Pruett, R.C.; Regan, C.D.; Walton, D.S.; Smith, T.R.

    1984-10-15

    Three children (two girls and one boy) with bilateral retinoblastoma each developed a presumed rhegmatogenous retinal detachment in one eye. All three eyes had previously received radiation and cryotherapy. In each case the retinal detachment responded promptly to conventional surgical methods via scleral buckling in the area of treated retinoblastoma and presumed retinal break. All three eyes have retained useful vision for follow-up periods of 3.5 to 12 years.

  10. Interrelationships between the Retinal Neuroglia and Vasculature in Diabetes

    OpenAIRE

    Kern, Timothy S.

    2014-01-01

    For years, diabetic retinopathy has been defined based on vascular lesions, and neural abnormalities were not regarded as important. This review summarizes evidence that the neural retina has important effects on the retinal vasculature under normal conditions, and the interaction between the retinal neuroglial cells and vascular function is altered in diabetes. Importantly, new evidence raises a possibility that abnormalities within retinal neuroglial cells (notably photoreceptors) might act...

  11. Interrelationships between the Retinal Neuroglia and Vasculature in Diabetes

    Directory of Open Access Journals (Sweden)

    Timothy S. Kern

    2014-06-01

    Full Text Available For years, diabetic retinopathy has been defined based on vascular lesions, and neural abnormalities were not regarded as important. This review summarizes evidence that the neural retina has important effects on the retinal vasculature under normal conditions, and the interaction between the retinal neuroglial cells and vascular function is altered in diabetes. Importantly, new evidence raises a possibility that abnormalities within retinal neuroglial cells (notably photoreceptors might actually be causing or initiating the vascular disease in diabetic retinopathy.

  12. Green process to recover magnesium chloride from residue solution of potassium chloride production plant

    Institute of Scientific and Technical Information of China (English)

    Lin WANG; Yunliang HE; Yanfei WANG; Ying BAO; Jingkang WANG

    2008-01-01

    The green process to recover magnesium chlor-ide from the residue solution of a potassium chloride pro-duction plant, which comes from the leach solution of a potash mine in Laos, is designed and optimized. The res-idue solution contains magnesium chloride above 25 wt-%, potassium chloride and sodium chloride together below 5 wt-% and a few other ions such as Br-, SO2-4and Ca2+. The recovery process contains two steps: the previous impurity removal operation and the two-stage evapora-tion-cooling crystallization procedure to produce magnes-ium chloride. The crystallized impurity carnallite obtained from the first step is recycled to the potassium chloride plant to recover the potassium salt. The developed process is a zero discharge one and thus fulfills the requirements for green chemical industrial production. The produced magnesium chloride is up to industrial criteria.

  13. Non-Coding RNAs in Retinal Development

    Directory of Open Access Journals (Sweden)

    Robert Hindges

    2012-01-01

    Full Text Available Retinal development is dependent on an accurately functioning network of transcriptional and translational regulators. Among the diverse classes of molecules involved, non-coding RNAs (ncRNAs play a significant role. Members of this family are present in the cell as transcripts, but are not translated into proteins. MicroRNAs (miRNAs are small ncRNAs that act as post-transcriptional regulators. During the last decade, they have been implicated in a variety of biological processes, including the development of the nervous system. On the other hand, long-ncRNAs (lncRNAs represent a different class of ncRNAs that act mainly through processes involving chromatin remodeling and epigenetic mechanisms. The visual system is a prominent model to investigate the molecular mechanisms underlying neurogenesis or circuit formation and function, including the differentiation of retinal progenitor cells to generate the seven principal cell classes in the retina, pathfinding decisions of retinal ganglion cell axons in order to establish the correct connectivity from the eye to the brain proper, and activity-dependent mechanisms for the functionality of visual circuits. Recent findings have associated ncRNAs in several of these processes and uncovered a new level of complexity for the existing regulatory mechanisms. This review summarizes and highlights the impact of ncRNAs during the development of the vertebrate visual system, with a specific focus on the role of miRNAs and a synopsis regarding recent findings on lncRNAs in the retina.

  14. Antisense Oligonucleotide Therapy for Inherited Retinal Dystrophies.

    Science.gov (United States)

    Gerard, Xavier; Garanto, Alejandro; Rozet, Jean-Michel; Collin, Rob 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 technical challenges so far prevent a broad clinical application of this approach for other forms of IRD. Many of the mutations leading to these retinal diseases affect pre-mRNA splicing of the mutated genes . Antisense oligonucleotide (AON)-mediated splice modulation appears to be a powerful approach to correct the consequences of such mutations at the pre-mRNA level , as demonstrated by promising results in clinical trials for several inherited disorders like Duchenne muscular dystrophy, hypercholesterolemia and various types of cancer. In this mini-review, we summarize ongoing pre-clinical research on AON-based therapy for a few genetic subtypes of IRD , speculate on other potential therapeutic targets, and discuss the opportunities and challenges that lie ahead to translate splice modulation therapy for retinal disorders to the clinic. PMID:26427454

  15. Subretinal transplantation of mouse retinal progenitor cells

    Institute of Scientific and Technical Information of China (English)

    Caihui Jiang; Maonian Zhang; Henry Klassen; Michael Young

    2011-01-01

    The development of cell replacement techniques is promising as a potential treatment for photoreceptor loss. However, the limited integration ability of donor and recipient cells presents a challenge following transplantation. In the present study, retinal progenitor cells (RPCs) were harvested from the neural retinas of enhanced green fluorescent protein mice on postnatal day 1, and expanded in a neurobasal medium supplemented with fetal bovine serum without endothelial growth factor. Using a confocal microscope, immunohistochemistry demonstrated that expanded RPCs in vitro maintain retinal stem cell properties and can be differentiated into photoreceptor cells. Three weeks after transplantation, subretinal transplanted RPCs were found to have migrated and integrated into the outer nuclear layer of recipient retinas with laser injury, some of the integrated cells had differentiated into photoreceptors, and a subpopulation of these cells expressed photoreceptor specific synaptic protein, appearing to form synaptic connections with bipolar cells. These results suggest that subretinal transplantation of RPCs may provide a feasible therapeutic strategy for the loss of retinal photoreceptor cells.

  16. Retinal image quality assessment using generic features

    Science.gov (United States)

    Fasih, Mahnaz; Langlois, J. M. Pierre; Ben Tahar, Houssem; Cheriet, Farida

    2014-03-01

    Retinal image quality assessment is an important step in automated eye disease diagnosis. Diagnosis accuracy is highly dependent on the quality of retinal images, because poor image quality might prevent the observation of significant eye features and disease manifestations. A robust algorithm is therefore required in order to evaluate the quality of images in a large database. We developed an algorithm for retinal image quality assessment based on generic features that is independent from segmentation methods. It exploits the local sharpness and texture features by applying the cumulative probability of blur detection metric and run-length encoding algorithm, respectively. The quality features are combined to evaluate the image's suitability for diagnosis purposes. Based on the recommendations of medical experts and our experience, we compared a global and a local approach. A support vector machine with radial basis functions was used as a nonlinear classifier in order to classify images to gradable and ungradable groups. We applied our methodology to 65 images of size 2592×1944 pixels that had been graded by a medical expert. The expert evaluated 38 images as gradable and 27 as ungradable. The results indicate very good agreement between the proposed algorithm's predictions and the medical expert's judgment: the sensitivity and specificity for the local approach are respectively 92% and 94%. The algorithm demonstrates sufficient robustness to identify relevant images for automated diagnosis.

  17. Metabolic syndrome and central retinal artery occlusion

    Directory of Open Access Journals (Sweden)

    Kosanović-Jaković Natalija

    2005-01-01

    Full Text Available Background. The accumulation of risk factors for central retinal artery occlusion can be seen in a single person and might be explained by the metabolic syndrome. Case report. We presented the case of a 52-year-old man with no light perception in his right eye. The visual loss was monocular and painless, fundoscopy showed central retinal artery occlusion and the laboratory investigation showed the raised erythrocyte sedimentation rate of 105 mm/h and the raised C-reactive protein of 22 mg/l. Specific laboratory investigations and fluorescein angiography excluded the presence of vasculitis, collagen vascular diseases, hypercoagulable state and antiphospholipid syndrome. Conclusion. The patient met all the five of the National Cholesterol Education Program (NCEP criteria for the metabolic syndrome: hypertension, abnormal lipid profile, abnormal glucose metabolism, obesity and hyperuricemia. Measurement of C-reactive protein is useful for the assessment of therapeutic systemic effect on any abnormality in the metabolic syndrome. Individual therapy for all risk factors in the metabolic syndrome is necessary to prevent complications such as cardiovascular, retinal vascular diseases and stroke.

  18. Idiopathic juxtafoveolar retinal telangiectasis: A current review

    Directory of Open Access Journals (Sweden)

    Nowilaty Sawsan

    2010-01-01

    Full Text Available Idiopathic juxtafoveolar retinal telangiectasis (IJFT, also known as parafoveal telangiectasis or idiopathic macular telangiectasia, refers to a heterogeneous group of well-recognized clinical entities characterized by telangiectatic alterations of the juxtafoveolar capillary network of one or both eyes, but which differ in appearance, presumed pathogenesis, and management strategies. Classically, three groups of IJFT are identified. Group I is unilateral easily visible telangiectasis occurring predominantly in males, and causing visual loss as a result of macular edema. Group II, the most common, is bilateral occurring in both middle-aged men and women, and presenting with telangiectasis that is more difficult to detect on biomicroscopy, but with characteristic and diagnostic angiographic and optical coherence tomography features. Vision loss is due to retinal atrophy, not exudation, and subretinal neovascularization is common. Group III is very rare characterized predominantly by progressive obliteration of the perifoveal capillary network, occurring usually in association with a medical or neurologic disease. This paper presents a current review of juxtafoveolar retinal telangiectasis, reviewing the classification of these entities and focusing primarily on the two most common types encountered in clinical practice, i.e., groups I and II, describing their clinical features, histopathology, natural history, complications, latest results from imaging modalities and functional studies, differential diagnosis, and treatment modalities.

  19. [Optogenetics and prosthetic treatment of retinal degeneration].

    Science.gov (United States)

    Kirpichnikov, M P; Ostrovskiy, M A

    2015-01-01

    This is a review of the current state of optogenetics-based research in the field of ophthalmology and physiology of vision. Optogenetics employs an interdisciplinary approach that amalgamates gene engineering, optics, and physiology. It involves exogenous expression of a light-activated protein in a very particular retinal cell enabling regulation (stimulation vs. inhibition) of its physiological activity. The experience with gene therapy came in very useful for optogenetics. However, unlike gene therapy, which is aimed at repairing damaged genes or replacing them with healthy ones, optogenetics is focused on protein genes delivery for further molecular control of the cell. In retina, the loss of photoreceptors is not necessarily followed by neuronal loss (at least ganglion cells remain intact), which determines the practicability of prosthetic treatment. Clinical trials can now be considered, owing to the first successful conversion of ganglion cells of mouse degenerative retinas into artificial photoreceptive cells with ON and OFF receptive fields, which is crucial for spatial vision. The following issues are reviewed here in detail: 1. Choice of cell targets within the degenerative retina. 2. Strategy of utilizing the existing light-sensitive agents and development of new optogenetic tools. 3. Gene delivery and expression in retinal cells. 4. Methods of evaluating the treatment success. 5. Selection criteria for optogenetic prosthetics. The conclusion discusses currently unsolved problems and prospects for optogenetic approaches to retinal prosthetics.

  20. Optimal retinal cyst segmentation from OCT images

    Science.gov (United States)

    Oguz, Ipek; Zhang, Li; Abramoff, Michael D.; Sonka, Milan

    2016-03-01

    Accurate and reproducible segmentation of cysts and fluid-filled regions from retinal OCT images is an important step allowing quantification of the disease status, longitudinal disease progression, and response to therapy in wet-pathology retinal diseases. However, segmentation of fluid-filled regions from OCT images is a challenging task due to their inhomogeneous appearance, the unpredictability of their number, size and location, as well as the intensity profile similarity between such regions and certain healthy tissue types. While machine learning techniques can be beneficial for this task, they require large training datasets and are often over-fitted to the appearance models of specific scanner vendors. We propose a knowledge-based approach that leverages a carefully designed cost function and graph-based segmentation techniques to provide a vendor-independent solution to this problem. We illustrate the results of this approach on two publicly available datasets with a variety of scanner vendors and retinal disease status. Compared to a previous machine-learning based approach, the volume similarity error was dramatically reduced from 81:3+/-56:4% to 22:2+/-21:3% (paired t-test, p << 0:001).

  1. Blood-retinal barrier permeability versus diabetes duration and retinal morphology in insulin dependent diabetic patients

    DEFF Research Database (Denmark)

    Krogsaa, B; Lund-Andersen, H; Mehlsen, J;

    1987-01-01

    The blood-retinal barrier permeability to fluorescein was quantitated in 54 patients (22 females and 32 males) with insulin dependent diabetes mellitus (IDDM) of different duration. Correlation was demonstrated between permeability and diabetes duration. A normal permeability was measured...... the pattern. However, the pathologically increased permeability after ten years duration of the disease could not be demonstrated in diabetics with onset of the disease after the age of 30 years. The permeability of the blood-retinal barrier correlated well with changes in retinal morphology as seen...... in patients with up to ten years diabetes duration. A pathologically increased permeability was measured with ten to 15 years diabetes duration and during the next decade the permeability increased rapidly to 5-10 times the normal value. Onset of diabetes in the decade before and after puberty did not change...

  2. An effective automated system for grading severity of retinal arteriovenous nicking in colour retinal images.

    Science.gov (United States)

    Roy, Pallab Kanti; Nguyen, Uyen T V; Bhuiyan, Alauddin; Ramamohanarao, Kotagiri

    2014-01-01

    Retinal arteriovenous (AV) nicking is a precursor for hypertension, stroke and other cardiovascular diseases. In this paper, an effective method is proposed for the analysis of retinal venular widths to automatically classify the severity level of AV nicking. We use combination of intensity and edge information of the vein to compute its widths. The widths at various sections of the vein near the crossover point are then utilized to train a random forest classifier to classify the severity of AV nicking. We analyzed 47 color retinal images obtained from two population based studies for quantitative evaluation of the proposed method. We compare the detection accuracy of our method with a recently published four class AV nicking classification method. Our proposed method shows 64.51% classification accuracy in-contrast to the reported classification accuracy of 49.46% by the state of the art method. PMID:25571443

  3. Lack of the sodium-driven chloride bicarbonate exchanger NCBE impairs visual function in the mouse retina.

    Directory of Open Access Journals (Sweden)

    Gerrit Hilgen

    Full Text Available Regulation of ion and pH homeostasis is essential for normal neuronal function. The sodium-driven chloride bicarbonate exchanger NCBE (Slc4a10, a member of the SLC4 family of bicarbonate transporters, uses the transmembrane gradient of sodium to drive cellular net uptake of bicarbonate and to extrude chloride, thereby modulating both intracellular pH (pH(i and chloride concentration ([Cl(-](i in neurons. Here we show that NCBE is strongly expressed in the retina. As GABA(A receptors conduct both chloride and bicarbonate, we hypothesized that NCBE may be relevant for GABAergic transmission in the retina. Importantly, we found a differential expression of NCBE in bipolar cells: whereas NCBE was expressed on ON and OFF bipolar cell axon terminals, it only localized to dendrites of OFF bipolar cells. On these compartments, NCBE colocalized with the main neuronal chloride extruder KCC2, which renders GABA hyperpolarizing. NCBE was also expressed in starburst amacrine cells, but was absent from neurons known to depolarize in response to GABA, like horizontal cells. Mice lacking NCBE showed decreased visual acuity and contrast sensitivity in behavioral experiments and smaller b-wave amplitudes and longer latencies in electroretinograms. Ganglion cells from NCBE-deficient mice also showed altered temporal response properties. In summary, our data suggest that NCBE may serve to maintain intracellular chloride and bicarbonate concentration in retinal neurons. Consequently, lack of NCBE in the retina may result in changes in pH(i regulation and chloride-dependent inhibition, leading to altered signal transmission and impaired visual function.

  4. Immunohistochemical and electrophysiological characterization of the mouse model for Retinitis Pigmentosa, rd10

    OpenAIRE

    Biswas, Sonia

    2014-01-01

    In the human disease retinitis pigmentosa (RP) the photoreceptors degenerate over time but the retinal network, in particular the retinal output neurons, the ganglion cells (RGCs) persist, providing a target for electrical stimulation by retinal prostheses. However, remodelling of the retinal network might interfere with this therapeutic approach. In the widely used mouse model of retinal degeneration, rd1, the loss of photoreceptors leads to rhythmic electrical activity of 10 to 16 Hz in the...

  5. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    OpenAIRE

    Gai-Fei Peng; Nai-Qian Feng; Qi-Ming Song

    2014-01-01

    The influence of a chloride-ion adsorption agent (Cl agent in short), composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage...

  6. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construc...

  7. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this st...

  8. Functional analysis of retinal microglia and their effects on progenitors.

    Science.gov (United States)

    Carter, Debra A; Balasubramaniam, Balini; Dick, Andrew D

    2013-01-01

    The identification of stem/progenitor cells within the retinal neural environment has opened up the possibility of therapy via cellular replacement and/or reprogramming of resident cell populations. Within the neuro-retinal niche, following injury or in disease states (including inflammation and degeneration), cellular responses affect tissue homeostasis, reduce cell density, disrupt tissue architecture, and produce scar formation. Microglia (resident retinal immune cell tissue macrophage) are key to the maintenance of retinal homeostasis and are implicated in responses that may influence the control and behavior of retinal progenitors. Factors to consider in the generation of a transplantable cell resource with good migratory and integrative capacity include their yield, purity, and functional viability. Utilizing human postmortem retina, we have created a research platform to isolate, culture, and characterize adult retinal microglia as well as analyze their effect on retinal progenitors. Here, we describe techniques using magnetic labeled bead cell separation to isolate pure populations of retinal CD133(+) precursor cells and CD11b(+) microglia from primary adult retinal cell suspensions (RCSs), enabling flow cytometric cell phenotypic and qPCR genotypic analysis, as well as functional analysis by real-time ratiometric calcium imaging.

  9. Genetic determinants of hyaloid and retinal vasculature in zebrafish

    Directory of Open Access Journals (Sweden)

    Hyde David R

    2007-10-01

    Full Text Available Abstract Background The retinal vasculature is a capillary network of blood vessels that nourishes the inner retina of most mammals. Developmental abnormalities or microvascular complications in the retinal vasculature result in severe human eye diseases that lead to blindness. To exploit the advantages of zebrafish for genetic, developmental and pharmacological studies of retinal vasculature, we characterised the intraocular vasculature in zebrafish. Results We show a detailed morphological and developmental analysis of the retinal blood supply in zebrafish. Similar to the transient hyaloid vasculature in mammalian embryos, vessels are first found attached to the zebrafish lens at 2.5 days post fertilisation. These vessels progressively lose contact with the lens and by 30 days post fertilisation adhere to the inner limiting membrane of the juvenile retina. Ultrastructure analysis shows these vessels to exhibit distinctive hallmarks of mammalian retinal vasculature. For example, smooth muscle actin-expressing pericytes are ensheathed by the basal lamina of the blood vessel, and vesicle vacuolar organelles (VVO, subcellular mediators of vessel-retinal nourishment, are present. Finally, we identify 9 genes with cell membrane, extracellular matrix and unknown identity that are necessary for zebrafish hyaloid and retinal vasculature development. Conclusion Zebrafish have a retinal blood supply with a characteristic developmental and adult morphology. Abnormalities of these intraocular vessels are easily observed, enabling application of genetic and chemical approaches in zebrafish to identify molecular regulators of hyaloid and retinal vasculature in development and disease.

  10. Retinal detachment secondary to ocular perforation during retrobulbar Anaesthesia

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    1995-01-01

    Full Text Available The clinical characteristics and the retinal breaks associated with rhegmatogenous retinal detachments secondary to accidental globe perforation during local infiltration anaesthesia in five highly myopic eyes are presented. Retinal detachment was total with variable proliferative vitreoretinopathy. The pattern of retinal breaks was rather typical and predictable. Management involved vitreous surgery with internal tamponade by silicone oil in four eyes and perfluoropropane gas in one eye. At the last follow-up, all eyes had attached retina. One eye did not recover useful vision due to possible concurrent optic nerve damage.

  11. Safety with laser during retinal therapy : an electroretinographic study

    OpenAIRE

    El-Sayed, E.; Talaat, M.; Sallam, A

    1994-01-01

    Studies of the retinal sensitivity, as reflected in the ERG records, have been made, before, during, and after exposure of the eye to an argon laser beam ( > = 488 nm ; intensity 1 mW/cm2 ; durations 0.12 and 0.25 sec). The applied retinal load thus was similar as that during retinal treatments. The ERG records were carried out at different temperatures (10 - 30°C) for both light and dark adapted eyes. The aim of this study was to assess the best suitable conditions for retinal laser treatmen...

  12. Digital Retinal Images: Background and Damaged Areas Segmentation

    Directory of Open Access Journals (Sweden)

    Eman A. Gani

    2014-07-01

    Full Text Available Digital retinal images are more appropriate for automatic screening of diabetic retinopathy systems. Unfortunately, a significant percentage of these images are poor quality that hiders further analysis due to many factors (such as patient movement, inadequate or non-uniform illumination, acquisition angle and retinal pigmentation. The retinal images of poor quality need to be enhanced before the extraction of features and abnormalities. So, the segmentation of retinal image is essential for this purpose, the segmentation is employed to smooth and strengthen image by separating the background and damaged areas from the overall image thus resulting in retinal image enhancement and less processing time. In this paper, methods for segmenting colored retinal image are proposed to improve the quality of retinal image diagnosis. The methods generates two segmentation masks; i.e., background segmentation mask for extracting the background area and poor quality mask for removing the noisy areas from retinal image. The standard retinal image databases DIARETDB0, DIARETDB1, STARE, DRIVE and some images obtained from ophthalmologists have been used to test the validation of the proposed segmentation technique. Experimental results indicate the introduced methods are effective and can lead to high segmentation accuracy

  13. Multiple evanescent white dot syndrome associated with retinal vasculitis

    Directory of Open Access Journals (Sweden)

    Takahashi A

    2015-09-01

    Full Text Available Akihiro Takahashi, Wataru Saito, Yuki Hashimoto, Susumu Ishida Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo, Japan Purpose: A recent study revealed thickening of the inner retinal layers in acute stage of multiple evanescent white dot syndrome (MEWDS; however, the pathogenesis is still unknown. We report two cases with MEWDS whose funduscopy showed obvious retinal vasculitis. Methods: Case reports. Results: Healthy myopic 16- and 27-year-old women were the cases under study. In both cases, funduscopic examination revealed multiple, faint, small, subretinal white dots at the posterior pole to the midperiphery and macular granularity oculus dexter. Retinal vascular sheathing was also observed at midperiphery. Late-phase fluorescein angiography revealed leakages corresponding to the vascular sheathing. Enhanced depth imaging optical coherence tomography revealed the discontinuity of the ellipsoid zone corresponding to the white dots and increased macular choroidal thickness. One month later, these white dots and retinal sheathing spontaneously resolved in both cases. Three months later, impairments of the outer retinal morphology and the visual acuity were restored. Conclusion: These results suggest that retinal vasculitis possibly plays a role in the pathogenesis of thickened inner retinal layers in acute stage of MEWDS. Keywords: enhanced depth imaging optical coherence tomography, choroidal thickness, inner retinal layer, retinal vascular sheathing

  14. Microvascular Abnormality in Schizophrenia as Shown by Retinal Imaging

    Science.gov (United States)

    Meier, Madeline H.; Shalev, Idan; Moffitt, Terrie E.; Kapur, Shitij; Keefe, Richard S.E.; Wong, Tien; Belsky, Daniel W.; Harrington, HonaLee; Hogan, Sean; Houts, Renate; Caspi, Avshalom; Poulton, Richie

    2013-01-01

    Objective Retinal and cerebral microvessels are structurally and functionally homologous, but, unlike cerebral microvessels, retinal microvessels can be noninvasively measured in vivo via retinal imaging. Here we test the hypothesis that individuals with schizophrenia show microvascular abnormality and evaluate the utility of retinal imaging as a tool for future schizophrenia research. Methods Participants were members of the Dunedin Study, a population-representative cohort followed from birth with 95% retention. Study members underwent retinal imaging at age 38 years. We assessed retinal arteriolar and venular caliber for all members of the cohort, including individuals who developed schizophrenia. Results Study members who developed schizophrenia were distinguished by wider retinal venules, suggesting microvascular abnormality reflective of insufficient brain oxygen supply. Analyses that controlled for confounding health conditions suggested that wider retinal venules are not simply an artifact of co-occurring health problems in schizophrenia patients. Wider venules were also associated with a dimensional measure of adult psychosis symptoms and with psychosis symptoms reported in childhood. Conclusions Findings provide initial support for the hypothesis that individuals with schizophrenia show microvascular abnormality. Moreover, results suggest that the same vascular mechanisms underlie subthreshold symptoms and clinical disorder and that these associations may begin early in life. These findings highlight the promise of retinal imaging as a tool for understanding the pathogenesis of schizophrenia. PMID:24030514

  15. Surgical management of retinal diseases: proliferative diabetic retinopathy and traction retinal detachment.

    Science.gov (United States)

    Cruz-Iñigo, Yousef J; Acabá, Luis A; Berrocal, Maria H

    2014-01-01

    Current indications for pars plana vitrectomy in patients with proliferative diabetic retinopathy (PDR) include vitreous hemorrhage, tractional retinal detachment (TRD), combined tractional and rhegmatogenous retinal detachment (CTRRD), diabetic macular edema associated with posterior hyaloidal traction, and anterior segment neovascularization with media opacities. This chapter will review the indications, surgical objectives, adjunctive pharmacotherapy, microincision surgical techniques, and outcomes of diabetic vitrectomy for PDR, TRD, and CTRRD. With the availability of new microincision vitrectomy technology, wide-angle microscope viewing systems, and pharmacologic agents, vitrectomy can improve visual acuity and achieve long-term anatomic stability in eyes with severe complications from PDR.

  16. Transplantation of retinal pigment epithelial cells - a possible future treatment for age-related macular degeneration

    DEFF Research Database (Denmark)

    Wiencke, Anne Katrine

    2001-01-01

    ophthalmology, age-related macular degeneration, retinal pigment epithelial cells, transplantation, treatment......ophthalmology, age-related macular degeneration, retinal pigment epithelial cells, transplantation, treatment...

  17. Transplantation of retinal pigment epithelial cells - a possible future treatment for age-related macular degeneration

    DEFF Research Database (Denmark)

    Wiencke, Anne Katrine

    2001-01-01

    ophthalmology, age-related macular degeneration, transplantation, retinal pigment epithelial cells, treatment......ophthalmology, age-related macular degeneration, transplantation, retinal pigment epithelial cells, treatment...

  18. Variable involvement of the perivascular retinal tissue in carbonic anhydrase inhibitor induced relaxation of porcine retinal arterioles in vitro

    DEFF Research Database (Denmark)

    Kehler, Anne Katrine; Holmgaard, Kim; Hessellund, Anders;

    2007-01-01

    PURPOSE: Inhibition of carbonic anhydrase in the eye is an important treatment modality for reducing the intraocular pressure in glaucoma. However, evidence suggests that carbonic anhydrase inhibition also exerts a relaxing effect on the vessels in the optic nerve, and it has been suggested......, and the vasodilating effect of acetazolamide almost disappeared. CONCLUSIONS: A further elucidation of the mechanisms of action of carbonic anhydrase-induced dilation of retinal arterioles may contribute to a better understanding of the regulation of retinal blood flow. The perivascular retinal tissue may play...... a significant role in diameter control of retinal arterioles. Udgivelsesdato: 2007-Oct...

  19. 补肾活血中药血清对缺氧条件下纯化培养视网膜神经节细胞的保护作用及其机制%Protection and mechanism of bushenhuoxue on retinal ganglian cells under the hypoxic condition in vitro

    Institute of Scientific and Technical Information of China (English)

    万李; 谢学军; 马荣

    2014-01-01

    Background The early disorder of diabetic retinopathy (DR) is the damage of retinal neural cells induced by high glucose and lack of oxygen.Previous studies show that bushenhuoxue serum can enhance the activity of glutamine synthetase (GS) in Müller cells under hypoxia,and glutamate-mediated retinal excitotoxicity also can be reduced by bushenhuoxue serum intervention.However,whether the concentration of glycine can be increased by bushenhuoxue serum is not clear.Objective This study was to investigate the protective effects of bushenhuoxue serum on retinal ganglion cells (RGCs) under hypoxia.Methods The Sprague Dawley (SD) rat serum containing bushenhuoxue was prepared.The RGCs of newborn SD rats were purified and identified by a twostep immunopanning procedure.After 72 hours,all RGCs were cultured in 96-well plates and divided into four groups:normal control group (cultured in adult SD rats normal serum),bushenhuoxue group (cultured in bushenhuoxue serum),hypoxia group (cultured in 1 mmol/L sodium dithionite); hypoxia + bushenhuoxue intervention group (cultured in bushenhuoxue serum+sodium dithionite).Glutamate and glycine contents in the extracellular fluid were detected by L-8800 automatic amino acid analyzer,and the content of lactate dehydrogenase (LDH) was assayed using LDH kits in 24,48 and 72 hours after culture.Results Cultured cells showed the green fluorescence under the immnofluorescence microscope.The contents of glutamate,glycine and LDH in the extracellular fluid were (0.0805±0.0010)mg/L,(0.0554±0.001 5)mg/L and (1 626.03 ±122.10)μmol/(min · L) in the normal control group in 24 hours after culture,and those in the hypoxia group were (0.022 5±0.001 1) mg/L,(0.014 6±0.001 1)mg/L and (1 458.68±94.23)μμmol/(min · L),showing significant reducing in the hypoxia group (q =-3.53,P =0.00 ; q =-2.45,P =0.00 ; q =-2.98,P =0.02).Compared with the normal control group,LDH and glycine contents in the extracellular fluid were significant raised in the

  20. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    modelled on Fick's law modified by a term for chloride binding. Inclusion of chloride binding significantly improves the profile shape of the modelled ingress profiles. The presence of fine aggregate and formation of interfacial transition zones at paste-aggregate boundaries does not significantly affect...

  1. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  2. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... Commission found that the domestic interested party group response to its notice of institution (74 FR 31757... COMMISSION Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Notice of... chloride from China. SUMMARY: The Commission hereby gives notice that it will proceed with a full...

  3. Chloride binding site of neurotransmitter sodium symporters

    DEFF Research Database (Denmark)

    Kantcheva, Adriana Krassimirova; Quick, Matthias; Shi, Lei;

    2013-01-01

    Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs...

  4. Chronopotentiometric chloride sensing using transition time measurement

    NARCIS (Netherlands)

    Abbas, Y.; Graaf, de D.B.; Olthuis, W.; Berg, van den A.

    2013-01-01

    Detection of chloride ions is crucial to accurately access the concrete structure durability[1]. The existing electrochemical method of chloride ions detection in concrete, potentiometry[1], is not suitable for in-situ measurement due to the long term stability issue of conventional reference electr

  5. Chemische contaminanten in diervoeder additief Choline Chloride

    NARCIS (Netherlands)

    Traag, W.A.; Hoogenboom, L.A.P.; Jong, de J.; Egmond, van H.J.; Dam, ten G.

    2010-01-01

    Dit briefrapport beschrijft de resultaten van een onderzoek naar chemische contaminanten in Choline Chloride. De doelstellingen waren: 1) Inzicht te verkrijgen in het voorkomen van (gebromeerde) vlamvertragers en broomdioxines in het diervoederadditief Choline Chloride en het, op basis van de result

  6. Crevice Corrosion of 321 Stainless Steel in Sodium Chloride Solutions

    International Nuclear Information System (INIS)

    Electrochemical techniques have been applied to study the crevice corrosion behaviour of stabilized 321 stainless steel in both 0.5, 1 and 2 M sodium chloride solutions at 25 and 80 degree . This type of stainless steel enjoys a good corrosion resistance especially in the heat affected zone (Haz) of welds. In this investigation the crevice corrosion of 321 stainless steel was studied in both bulk solution environments as well as in chloride solutions simulating those formed inside crevices. A metal-to-nonmetal crevice assembly, in which disc type specimens were faced to a PTFE crevice former, is used for bulk solution tests. Crevice-free specimens of solutions formed inside crevices (known as the critical crevice solutions, CCS). Cyclic potentiodynamic technique was used in evaluating the electrochemical corrosion performance of the alloy in bulk (0.5 and 1 M Nacl) environment. This revealed that both chloride ion concentration and temperature have a marked effect on the electrochemical parameters generally used for the evaluation of the crevice corrosion susceptibility. This included the corrosion potential. E corr. The passivity breakdown potential, Eb, and the protection potential, E p

  7. The implication of omega-3 polyunsaturated fatty acids in retinal physiology

    Directory of Open Access Journals (Sweden)

    Acar Niyazi

    2007-05-01

    Full Text Available Neuronal tissues such as the retina and the brain are characterized by their high content in phospholipids. In the retina, phospholipids can account for until 80% of total lipids and are mainly composed by species belonging to phosphatidyl-choline and phosphatidyl-ethanolamine sub-classes. Within fatty acids esterified on retinal phospholipids, omega-3 PUFAs are major components since docosahexaenoic acid (DHA can represent until 50% of total fatty acids in the photoreceptor outer segments. For long time, DHA is known to play a major role in membrane function and subsequently in visual processes by affecting permeability, fluidity, thickness and the activation of membrane-bound proteins. Today, more and more studies show that PUFAs from the omega-3 series may also operate as protective factors in retinal vascular and immuno-regulatory processes, in maintaining the physiologic redox balance and in cell survival. They may operate within complex systems involving eicosanoids, angiogenic factors, inflammatory factors and matrix metalloproteinases. This new and emerging concept based on the interrelationship of omega-3 PUFAs with neural and vascular structure and function appears to be essential when considering retinal diseases of public health significance such as age-related macular degeneration.

  8. Conditioned medium from activated spleen cells supports the survival of rat retinal cells in vitro

    Directory of Open Access Journals (Sweden)

    A. Sholl-Franco

    1997-11-01

    Full Text Available Cytokines are a heterogeneous group of molecules that have been associated with several functions in the nervous system, such as survival and differentiation of neuronal and glial cells. In the present study, we demonstrated that conditioned medium from spleen cells activated with concanavalin A increased neuritogenesis and survival of retinal cells, as measured by biochemical and morphological criteria. Our data showed that conditioned medium induced a five-fold increase in the amount of protein after 120 h in vitro. This effect was not inhibited by the blockade of voltage-dependent L-type calcium channels with 5.0 µM nifedipine. However, the use of an intracellular calcium chelator (15.0 µM BAPTA-AM inhibited this effect. Our results support the idea that factors secreted by activated lymphocytes, such as cytokines, can modulate the maintenance and the differentiation of rat retinal cells in vitro, indicating a possible role of these molecules in the development of retinal cells, as well as in its protection against pathological conditions

  9. Diffusion behavior of chloride ions in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Gjoerv, O.E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Div. of Building Materials

    1996-06-01

    In the present paper, an analysis of the diffusion behavior of chloride ions in concrete is presented. In concentrated electrolytic aqueous solutions such as seawater or that typically used in laboratory experiments, the effect of ionic interaction may significantly reduce the chemical potential and thus the driving force of the diffusing species. Because of different drift velocities of the cations and chloride ions in the solution, the lagging motion of the cations will also retard the drift velocity of the chlorides. In addition, both the electrical double layer forming on the solid surface and the chemical binding may significantly interfere with the transport of the chloride ions. As a result, the diffusion behavior of the chloride ions in concrete is a more complex and complicated transport process than what can be described by Fick`s law of diffusion.

  10. Investigation of retinal morphology alterations using spectral domain optical coherence tomography in a mouse model of retinal branch and central retinal vein occlusion.

    Directory of Open Access Journals (Sweden)

    Andreas Ebneter

    Full Text Available Retinal vein occlusion is a leading cause of visual impairment. Experimental models of this condition based on laser photocoagulation of retinal veins have been described and extensively exploited in mammals and larger rodents such as the rat. However, few reports exist on the use of this paradigm in the mouse. The objective of this study was to investigate a model of branch and central retinal vein occlusion in the mouse and characterize in vivo longitudinal retinal morphology alterations using spectral domain optical coherence tomography. Retinal veins were experimentally occluded using laser photocoagulation after intravenous application of Rose Bengal, a photo-activator dye enhancing thrombus formation. Depending on the number of veins occluded, variable amounts of capillary dropout were seen on fluorescein angiography. Vascular endothelial growth factor levels were markedly elevated early and peaked at day one. Retinal thickness measurements with spectral domain optical coherence tomography showed significant swelling (p<0.001 compared to baseline, followed by gradual thinning plateauing two weeks after the experimental intervention (p<0.001. Histological findings at day seven correlated with spectral domain optical coherence tomography imaging. The inner layers were predominantly affected by degeneration with the outer nuclear layer and the photoreceptor outer segments largely preserved. The application of this retinal vein occlusion model in the mouse carries several advantages over its use in other larger species, such as access to a vast range of genetically modified animals. Retinal changes after experimental retinal vein occlusion in this mouse model can be non-invasively quantified by spectral domain optical coherence tomography, and may be used to monitor effects of potential therapeutic interventions.

  11. Glutathione-Induced Calcium Shifts in Chick Retinal Glial Cells.

    Science.gov (United States)

    Freitas, Hercules R; Ferraz, Gabriel; Ferreira, Gustavo C; Ribeiro-Resende, Victor T; Chiarini, Luciana B; do Nascimento, José Luiz M; Matos Oliveira, Karen Renata H; Pereira, Tiago de Lima; Ferreira, Leonardo G B; Kubrusly, Regina C; Faria, Robson X; Herculano, Anderson Manoel; Reis, Ricardo A de Melo

    2016-01-01

    Neuroglia interactions are essential for the nervous system and in the retina Müller cells interact with most of the neurons in a symbiotic manner. Glutathione (GSH) is a low-molecular weight compound that undertakes major antioxidant roles in neurons and glia, however, whether this compound could act as a signaling molecule in neurons and/or glia is currently unknown. Here we used embryonic avian retina to obtain mixed retinal cells or purified Müller glia cells in culture to evaluate calcium shifts induced by GSH. A dose response curve (0.1-10 mM) showed that 5-10 mM GSH, induced calcium shifts exclusively in glial cells (later labeled and identified as 2M6 positive cells), while neurons responded to 50 mM KCl (labeled as βIII tubulin positive cells). BBG 100 nM, a P2X7 blocker, inhibited the effects of GSH on Müller glia. However, addition of DNQX 70 μM and MK-801 20 μM, non-NMDA and NMDA blockers, had no effect on GSH calcium induced shift. Oxidized glutathione (GSSG) at 5 mM failed to induce calcium mobilization in glia cells, indicating that the antioxidant and/or structural features of GSH are essential to promote elevations in cytoplasmic calcium levels. Indeed, a short GSH pulse (60s) protects Müller glia from oxidative damage after 30 min of incubation with 0.1% H2O2. Finally, GSH induced GABA release from chick embryonic retina, mixed neuron-glia or from Müller cell cultures, which were inhibited by BBG or in the absence of sodium. GSH also induced propidium iodide uptake in Müller cells in culture in a P2X7 receptor dependent manner. Our data suggest that GSH, in addition to antioxidant effects, could act signaling calcium shifts at the millimolar range particularly in Müller glia, and could regulate the release of GABA, with additional protective effects on retinal neuron-glial circuit. PMID:27078878

  12. Possibility of enhanced risk of retinal neovascularization in repeated blood donors: blood donation and retinal alteration

    Directory of Open Access Journals (Sweden)

    Rastmanesh R

    2011-09-01

    Full Text Available Reza RastmaneshDepartment of Clinical Nutrition and Dietetics, Shahid Beheshti University of Medical Sciences, National Nutrition and Food Technology Research Institute, Tehran, IranAbstract: Repeated blood donors manifest clinical, subclinical, and biochemical signs of iron deficiency anemia, have significantly higher erythropoietin and vascular endothelial growth factor (VEGF concentrations, and decreased tissue oxygen saturation, oxygenated tissue hemoglobin, and regional cerebral oxygen saturation. Erythropoietin and VEGF are potent retinal angiogenic factors which may initiate and promote the retinal angiogenesis process independently or simultaneously. Increases in circulating levels of erythropoietin and VEGF are proportionate to the levels of hematocrit, hypoxemia, and tissue hypoxia. It is suggested that higher erythropoietin production following iron deficiency anemia-induced chronic hypoxemia/hypoxia may, hypothetically, enhance the risk of retinal angiogenesis and/or neovascularization, possibly by inducing hypoxia inducible factor-1 alpha, which consequently upregulates genes stimulating angiogenesis, resulting in formation of a new vasculature, possibly by modulation of signal transducer and activator of transcription 3 signaling in the retina. Implications of this hypothesis cover erythropoietin doping, chronic hypoxia, and hypoxemic situations, such as angiogenesis-related cardiac and pulmonary diseases.Keywords: repeated blood donation, erythropoietin, retinal neovascularization, vascular endothelial growth factor, hypoxia

  13. Detection of retinal nerve fiber layer defects in retinal fundus images using Gabor filtering

    Science.gov (United States)

    Hayashi, Yoshinori; Nakagawa, Toshiaki; Hatanaka, Yuji; Aoyama, Akira; Kakogawa, Masakatsu; Hara, Takeshi; Fujita, Hiroshi; Yamamoto, Tetsuya

    2007-03-01

    Retinal nerve fiber layer defect (NFLD) is one of the most important findings for the diagnosis of glaucoma reported by ophthalmologists. However, such changes could be overlooked, especially in mass screenings, because ophthalmologists have limited time to search for a number of different changes for the diagnosis of various diseases such as diabetes, hypertension and glaucoma. Therefore, the use of a computer-aided detection (CAD) system can improve the results of diagnosis. In this work, a technique for the detection of NFLDs in retinal fundus images is proposed. In the preprocessing step, blood vessels are "erased" from the original retinal fundus image by using morphological filtering. The preprocessed image is then transformed into a rectangular array. NFLD regions are observed as vertical dark bands in the transformed image. Gabor filtering is then applied to enhance the vertical dark bands. False positives (FPs) are reduced by a rule-based method which uses the information of the location and the width of each candidate region. The detected regions are back-transformed into the original configuration. In this preliminary study, 71% of NFLD regions are detected with average number of FPs of 3.2 per image. In conclusion, we have developed a technique for the detection of NFLDs in retinal fundus images. Promising results have been obtained in this initial study.

  14. Retinal oximeter for the blue-green oximetry technique

    Science.gov (United States)

    Denninghoff, Kurt R.; Sieluzycka, Katarzyna B.; Hendryx, Jennifer K.; Ririe, Tyson J.; Deluca, Lawrence; Chipman, Russell A.

    2011-10-01

    Retinal oximetry offers potential for noninvasive assessment of central venous oxyhemoglobin saturation (SO2) via the retinal vessels but requires a calibrated accuracy of +/-3% saturation in order to be clinically useful. Prior oximeter designs have been hampered by poor saturation calibration accuracy. We demonstrate that the blue-green oximetry (BGO) technique can provide accuracy within +/-3% in swine when multiply scattered light from blood within a retinal vessel is isolated. A noninvasive on-axis scanning retinal oximeter (ROx-3) is constructed that generates a multiwavelength image in the range required for BGO. A field stop in the detection pathway is used in conjunction with an anticonfocal bisecting wire to remove specular vessel reflections and isolate multiply backscattered light from the blood column within a retinal vessel. This design is tested on an enucleated swine eye vessel and a retinal vein in a human volunteer with retinal SO2 measurements of ~1 and ~65%, respectively. These saturations, calculated using the calibration line from earlier work, are internally consistent with a standard error of the mean of +/-2% SO2. The absolute measures are well within the expected saturation range for the site (-1 and 63%). This is the first demonstration of noninvasive on-axis BGO retinal oximetry.

  15. Quality control for retinal OCT in multiple sclerosis

    DEFF Research Database (Denmark)

    Schippling, S; Balk, Lj; Costello, F;

    2015-01-01

    BACKGROUND: Retinal optical coherence tomography (OCT) permits quantification of retinal layer atrophy relevant to assessment of neurodegeneration in multiple sclerosis (MS). Measurement artefacts may limit the use of OCT to MS research. OBJECTIVE: An expert task force convened with the aim to pr...

  16. Changes in the retinal veins in acute optic neuritis

    DEFF Research Database (Denmark)

    Engell, T; Sellebjerg, F; Jensen, C

    1999-01-01

    retinae (PR) and 2 had venous sheathing (VS). Probable MS was found in 15 patients without prior symptoms of MS. One had PR and VS, and 2 had VS. Twenty patients had mono-symptomatic ON, none had retinal changes. CONCLUSION: Changes of the retinal veins should alert the clinician to a probable diagnosis...

  17. Quantification of retinal tangential movement in epiretinal membranes

    DEFF Research Database (Denmark)

    Kofod, Mads; la Cour, Morten

    2012-01-01

    To describe a technique of quantifying retinal vessel movement in eyes with epiretinal membrane (ERM) and correlate the retinal vessel movement with changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), and patients' subjective reports about experienced symptoms (symptoms)....

  18. Retinal Hemorrhages in 4 Patients with Dengue Fever

    OpenAIRE

    Chlebicki, Maciej Piotr; Ang, Brenda; Barkham, Timothy; Laude, Augustinus

    2005-01-01

    We report 4 patients with retinal hemorrhages that developed during hospitalization for dengue fever. Onset of symptoms coincided with resolution of fever and the nadir of thrombocytopenia. Retinal hemorrhages may reflect the rising incidence of dengue in Singapore or may be caused by changes in the predominant serotype of the dengue virus.

  19. Retinal glia promote dorsal root ganglion axon regeneration.

    Directory of Open Access Journals (Sweden)

    Barbara Lorber

    Full Text Available Axon regeneration in the adult central nervous system (CNS is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response.

  20. Optical coherent tomography in diagnoses of peripheral retinal degenarations

    Directory of Open Access Journals (Sweden)

    O. G. Pozdeyeva

    2013-01-01

    Full Text Available Purpose: Studying the capabilities of optical coherence tomography (RTVue-100, OPTOVUE, USA in evaluation of peripheral retinal degenerations, vitreoretinal adhesions, adjacent vitreous body as well as measurement of morphometric data.Methods: The study included 189 patients (239 eyes with peripheral retinal degeneration. 77 men and 112 women aged 18 to 84 underwent an ophthalmologic examination since November 2012 until October 2013. The peripheral retina was visualized with the help of optical coherence tomography («RTVue-100,» USA. The fundography was carried out using a Nikon NF505‑AF (Japan fundus camera. All patients were examined with a Goldmann lens.Results: Optical coherence tomography was used to evaluate different kinds of peripheral retinal degenerations, such as lattice and snail track degeneration, isolated retinal tears, cystoid retinal degeneration, pathological hyperpigmentation, retinoschisis and cobblestone degeneration. The following morphometric data were studied: dimensions of the lesion (average length, retinal thickness along the edge of the lesion, retinal thickness at the base of the lesion and the vitreoretinal interface.Conclusion: Optical coherence tomography is a promising in vivo visualization method which is useful in evaluation of peripheral retinal degenerations, vitreoretinal adhesions and tractions. It also provides a comprehensive protocolling system and monitoring. It will enable ophthalmologists to better define laser and surgical treatment indications and evaluate therapy effectiveness.

  1. Retinal oxygen saturation in patients with systemic hypoxemia

    DEFF Research Database (Denmark)

    Traustason, Sindri; Jensen, Annette Schophuus; Arvidsson, Henrik Sven;

    2011-01-01

    To assess spectrophotometric oximetry across a broad range of arterial saturation levels and to study the effect of chronic systemic hypoxemia on retinal oxygen extraction.......To assess spectrophotometric oximetry across a broad range of arterial saturation levels and to study the effect of chronic systemic hypoxemia on retinal oxygen extraction....

  2. Growth of cultured porcine retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Wiencke, A.K.; Kiilgaard, Jens Folke; Nicolini, Jair;

    2003-01-01

    To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation.......To establish and characterize cultures of porcine retinal pigment epithelial (pRPE) cells in order to produce confluent monolayers of cells for transplantation....

  3. Relationship between retinal vascular occlusions and incident cerebrovascular diseases

    Science.gov (United States)

    Zhou, Yue; Zhu, Wengen; Wang, Changyun

    2016-01-01

    Abstract Several studies investigating the role of retinal vascular occlusions, on cerebrovascular diseases (CVD) have been reported, but the results are still inconsistent. We therefore sought to evaluate the relationship between retinal vascular occlusions and CVD. We systematically searched the Cochrane Library, PubMed, and ScienceDirect databases through January 31, 2016 for studies evaluating the effect of retinal vascular occlusions on the risk of CVD. Data were abstracted using predefined criteria, and then pooled by RevMan 5.3 software. A total of 9 retrospective studies were included in this meta-analysis. When compared with individuals without retinal vascular occlusions, both individuals with retinal artery occlusion (RAO) (odds ratio [OR] = 2.01, 95% confidence interval [CI]: 1.21–3.34; P = 0.005) and individuals with retinal vein occlusion (RVO) (OR = 1.37, 95% CI: 1.24–1.50; P < 0.00001) had higher risks of developing CVD. Additionally, both individuals with central retinal artery occlusion (CRAO) (OR = 2.00, 95% CI: 1.12–3.56; P = 0.02) and branch retinal artery occlusion (BRAO) (OR = 1.60, 95% CI: 1.03–1.48; P = 0.04) were significantly associated with increased risk of CVD. Published literatures support both RVO and RAO are associated with increased risks of CVD. Further prospective studies are needed to confirm these findings. PMID:27368050

  4. Retinal Remodeling: Concerns, Emerging Remedies, and Future Prospects

    Directory of Open Access Journals (Sweden)

    Vidhyasankar eKrishnamoorthy

    2016-02-01

    Full Text Available Deafferentation results not only in sensory loss, but also in a variety of alterations in the postsynaptic circuitry. These alterations may have detrimental impact on potential treatment strategies. Progressive loss of photoreceptors in retinal degenerative diseases, such as retinitis pigmentosa and age-related macular degeneration, leads to several changes in the remnant retinal circuitry. Müller glial cells undergo hypertrophy and form a glial seal. The second- and third-order retinal neurons undergo morphological, biochemical and physiological alterations. A result of these alterations is that retinal ganglion cells (RGCs, the output neurons of the retina, become hyperactive and exhibit spontaneous, oscillatory bursts of spikes. This aberrant electrical activity degrades the signal-to-noise ratio in RGC responses, and thus the quality of information they transmit to the brain. These changes in the remnant retina, collectively termed retinal remodeling, pose challenges for genetic, cellular and bionic approaches to restore vision. It is therefore crucial to understand the nature of retinal remodeling, how it affects the ability of remnant retina to respond to novel therapeutic strategies, and how to ameliorate its effects. In this article, we discuss these topics, and suggest that the pathological state of the retinal output following photoreceptor loss is reversible, and therefore, amenable to restorative strategies.

  5. Calcium Dobesilate Inhibits the Alterations in Tight Junction Proteins and Leukocyte Adhesion to Retinal Endothelial Cells Induced by Diabetes

    OpenAIRE

    Leal, Ermelindo C.; Martins, João; Voabil, Paula; Liberal, Joana; Chiavaroli, Carlo; Bauer, Jacques; Cunha-Vaz, José; Ambrósio, António F.

    2010-01-01

    OBJECTIVE Calcium dobesilate (CaD) has been used in the treatment of diabetic retinopathy in the last decades, but its mechanisms of action are not elucidated. CaD is able to correct the excessive vascular permeability in the retina of diabetic patients and in experimental diabetes. We investigated the molecular and cellular mechanisms underlying the protective effects of CaD against the increase in blood–retinal barrier (BRB) permeability induced by diabetes. RESEARCH DESIGN AND METHODS Wist...

  6. Latin American Consensus on Retinal Vein Occlusion

    Directory of Open Access Journals (Sweden)

    Francisco J. Rodriguez

    2016-01-01

    Full Text Available The introduction of anti-VEGF agents has allowed unprecedented progress in the management and treatment of ophthalmologic conditions characterized by an increased vascular permeability and intraocular neovascularization. One of these conditions is retinal vein occlusion (RVO.  RVO is one of the most common causes of reduced vision due to retinal vascular disease. Without timely treatment, macular edema, macular ischemia, neovascularization and other potential sequelae of RVO can lead to photoreceptor cell death and consequently to irreversible vision loss.   Treatments for this indication that have been recently approved by several regulatory agencies throughout the world include: the VEGF inhibitor ranibizumab (Lucentis, Genentech, the VEGF and placental growth factor inhibitor aflibercept (Eylea, Regeneron Pharmaceuticals and Bayer HealthCare, and a slow release intravitreal implant of dexamethasone (Ozurdex, Allergan. In addition bevacizumab (Avastin, Genentech has been used extensively in an off-label manner.   These new treatments allow us to preserve vision for many RVO patients who could not have expected such favorable results just 5 or 6 years ago. However, not every treatment is effective for every patient, and whether one option is superior to another or a combination of options is superior to monotherapy, have yet to be definitively determined.   A growing body of literature with strong evidence supports the use of these new treatments. However, in several instances the literature is not conclusive to support unified management of RVO. This document is a summary analysis on RVO assembled by a group of specialists summoned by the Pan-American Vitreo-Retinal Society (SPRV to participate in this Latin American consensus.

  7. Towards real time speckle controlled retinal photocoagulation

    Science.gov (United States)

    Bliedtner, Katharina; Seifert, Eric; Stockmann, Leoni; Effe, Lisa; Brinkmann, Ralf

    2016-03-01

    Photocoagulation is a laser treatment widely used for the therapy of several retinal diseases. Intra- and inter-individual variations of the ocular transmission, light scattering and the retinal absorption makes it impossible to achieve a uniform effective exposure and hence a uniform damage throughout the therapy. A real-time monitoring and control of the induced damage is highly requested. Here, an approach to realize a real time optical feedback using dynamic speckle analysis is presented. A 532 nm continuous wave Nd:YAG laser is used for coagulation. During coagulation, speckle dynamics are monitored by a coherent object illumination using a 633nm HeNe laser and analyzed by a CMOS camera with a frame rate up to 1 kHz. It is obvious that a control system needs to determine whether the desired damage is achieved to shut down the system in a fraction of the exposure time. Here we use a fast and simple adaption of the generalized difference algorithm to analyze the speckle movements. This algorithm runs on a FPGA and is able to calculate a feedback value which is correlated to the thermal and coagulation induced tissue motion and thus the achieved damage. For different spot sizes (50-200 μm) and different exposure times (50-500 ms) the algorithm shows the ability to discriminate between different categories of retinal pigment epithelial damage ex-vivo in enucleated porcine eyes. Furthermore in-vivo experiments in rabbits show the ability of the system to determine tissue changes in living tissue during coagulation.

  8. Retinal Blood Vessel Segmentation with Optic Disc Pixels Exclusion

    Directory of Open Access Journals (Sweden)

    Randy Cahya Wihandika

    2013-06-01

    Full Text Available The morphological changes of retinal blood vessels are important indicators used to diagnose and monitor the progression of various diseases. A number of retinal blood vessel segmentation methods have been introduced, including the line operator based methods, which have shown satisfactory results. However, the basic line operator method cannot discriminate the pixels around the retinal optic disc, resulting in false classification of those pixels. In this paper, we integrate the detection of pixels around the retinal optic disc to the line operator method so that those pixels can be excluded from the vessel pixels. The method is evaluated on the widely used retinal dataset, the DRIVE dataset. The results demonstrate that the proposed method has made improvements over the basic and the multi-scale line detector with accuracy and area under curve of 0.942 and 0.9521, respectively.

  9. Optical Coherence Tomography of Retinal and Choroidal Tumors

    Directory of Open Access Journals (Sweden)

    Emil Anthony T. Say

    2011-01-01

    Full Text Available Optical coherence tomography (OCT has revolutionized the field of ophthalmology since its introduction 20 years ago. Originally intended primarily for retina specialists to image the macula, it has found its role in other subspecialties that include glaucoma, cornea, and ocular oncology. In ocular oncology, OCT provides axial resolution to approximately 7 microns with cross-sectional images of the retina, delivering valuable information on the effects of intraocular tumors on the retinal architecture. Some effects include retinal edema, subretinal fluid, retinal atrophy, photoreceptor loss, outer retinal thinning, and retinal pigment epithelial detachment. With more advanced technology, OCT now provides imaging deeper into the choroid using a technique called enhanced depth imaging. This allows characterization of the thickness and reflective quality of small (<3 mm thick choroidal lesions including choroidal nevus and melanoma. Future improvements in image resolution and depth will allow better understanding of the mechanisms of visual loss, tumor growth, and tumor management.

  10. Automatic Detection of Retinal Exudates using a Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Nualsawat HIRANSAKOLWONG

    2013-02-01

    Full Text Available Retinal exudates are among the preliminary signs of diabetic retinopathy, a major cause of vision loss in diabetic patients. Correct and efficient screening of exudates is very expensive in professional time and may cause human error. Nowadays, the digital retinal image is frequently used to follow-up and diagnoses eye diseases. Therefore, the retinal image is crucial and essential for experts to detect exudates. Unfortunately, it is a normal situation that retinal images in Thailand are poor quality images. In this paper, we present a series of experiments on feature selection and exudates classification using the support vector machine classifiers. The retinal images are segmented following key preprocessing steps, i.e., color normalization, contrast enhancement, noise removal and color space selection. On data sets of poor quality images, sensitivity, specificity and accuracy is 94.46%, 89.52% and 92.14%, respectively.

  11. Risk of Retinal Detachment After Pediatric Cataract Surgery

    DEFF Research Database (Denmark)

    Haargaard, Birgitte; Andersen, Elisabeth W; Oudin, Anna;

    2014-01-01

    , excluding cataract cases caused by trauma, or acquired systemic or acquired ocular pathology, and cases with ocular anomalies associated with the development of retinal detachment. Cases of cataract were ascertained from the mandatory Danish National Patient Register, and information on retinal detachment...... was based on medical chart review. RESULTS: Among 1043 eyes of 656 children undergoing surgery for pediatric cataract, 25 eyes (23 children) developed retinal detachment at a median time of 9.1 years after surgery. The overall 20-year risk of retinal detachment was 7% (95% confidence interval [CI]: 3......%-11%) among cataract patients. In otherwise normal children having isolated cataract, the risk was 3% (95% CI: 0%-7%). A significantly higher risk of developing retinal detachment was found in children with mental retardation (23% [95% CI: 9%-35%]) or in cataract cases with other ocular or systemic anomalies...

  12. Rickettsia retinitis cases in India: a few comments.

    Science.gov (United States)

    Tripathy, Koushik; Chawla, Rohan; Sharma, Yog Raj; Vohra, Rajpal

    2016-12-01

    An important cause of infectious retinitis, not well-described in Indian literature, has been analyzed in detail systematically by Kawali A. and colleagues. However, Rickettsia retinitis (RR) was diagnosed at titres of 1:160 by the Weil-Felix test (WFT). The sensitivity and specificity of WFT at this level are poor compared to the gold standard immunofluorescent antibody assay. However, we understand that financial constraints of the Indian patients limit the availability of more definite tests. In our opinion, the optical coherence tomography features of RR described by the authors may be mimicked by other causes of retinitis, such as toxoplasma retinitis or even cotton wool spots. Infectious retinitis including RR should be treated by an antimicrobial agent with or without oral steroids until larger series or randomized controlled trials prove otherwise. PMID:26920002

  13. Four-year follow-up of retinal status and glycosylated haemoglobin in patients with insulin-dependent diabetes mellitus.

    Science.gov (United States)

    Chantelau, E; Weiss, H; Weber, U; Sonnenberg, G E; Berger, M

    1988-01-01

    Retinal status and glycosylated hemoglobin (GHb) was followed in 32 patients with insulin-dependent diabetes mellitus (18 females; age upon entering the study 26 +/- 8 years; duration of diabetes 10 +/- 6 years; means +/- SD) during a total of 136 patient-years, i.e. during 4.3 +/- 0.6 years per patient. Annual mean GHb (given in percent of the mean normal GHb) was calculated from 7 +/- 3 determinations of GHb per patient-year. Fluorescein angiographs were performed at least once per patient-year, and retinal status was assessed by counting microaneurysms. Upon entering the study, early diabetic (background) retinopathy was present in 14 patients; at the end of the follow-up period, it was present in 20 patients. Retinal status deteriorated in 4/42 patient-years with excellent metabolic control (annual mean GHb less than or equal to 125%), in 13/70 patient-years with good control (annual mean GHb 126-150%) and in 8/24 patient-years with poor control (annual mean GHb greater than 150%). The incidence rate of retinal deterioration differed significantly between years with excellent control and years with poor control (X2 5.7, df = 1, p less than 0.05). It is concluded that excellent metabolic control within 14 +/- 6 years after onset of insulin-dependent diabetes mellitus appears to be a protective factor against the development or progression of early diabetic retinopathy.

  14. Light-induced retinal injury enhanced neurotrophins secretion and neurotrophic effect of mesenchymal stem cells in vitro

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2013-04-01

    Full Text Available PURPOSE: To investigate neurotrophins expression and neurotrophic effect change in mesenchymal stem cells (MSCs under different types of stimulation. METHODS: Rats were exposed in 10,000 lux white light to develop light-induced retinal injury. Supernatants of homogenized retina (SHR, either from normal or light-injured retina, were used to stimulate MSCs. Quantitative real time for polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA were conducted for analysis the expression change in basic fibroblast growth factor (bFGF, brain-derived neurotrophic factor (BDNF and ciliary neurotrophic factor (CNTF in MSCs after stimulation. Conditioned medium from SHR-stimulated MSCs and control MSCs were collected for evaluation their effect on retinal explants. RESULTS: Supernatants of homogenized retina from light-injured rats significantly promoted neurotrophins secretion from MSCs (p<0.01. Conditioned medium from mesenchymal stem cells stimulated by light-injured SHR significantly reduced DNA fragmentation (p<0.01, up-regulated bcl-2 (p<0.01 and down-regulated bax (p<0.01 in retinal explants, displaying enhanced protective effect. CONCLUSIONS: Light-induced retinal injury is able to enhance neurotrophins secretion from mesenchymal stem cells and promote the neurotrophic effect of mesenchymal stem cells.

  15. Retinal Vasculitis in Anti-Synthetase Syndrome.

    Science.gov (United States)

    Donovan, Christopher P; Pecen, Paula E; Baynes, Kimberly; Ehlers, Justis P; Srivastava, Sunil K

    2016-09-01

    A 31-year-old woman with a history of anti-synthetase syndrome-related myositis and interstitial lung disease presented with acute-onset blurry vision and rash on her hands and feet. Visual acuity was hand motion in her right eye and 20/40 in her left eye. Dilated fundus exam showed extensive retinal vasculitis, diffuse intraretinal hemorrhages, and subretinal fluid. Optical coherence tomography revealed significant macular thickening, and fluorescein angiography revealed vascular leakage with peripheral nonperfusion. Aggressive systemic immunosuppression was initiated, with gradual resolution of her disease during 8 months of follow-up. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:874-879.].

  16. Electro-oculogram of Retinal Vein Occlusion

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Twenty five cases, including 26 eyes with retinal vein occlusion (RVO) were examined by means of the electro-oculogram. The results showed that 23 of the 26 eyes suffering from RVO exhibited abnormalities of the electro-oculogram (EOG). The potential difference and Arden ratio in the RVO eyes were lower than those in the normal eyes (P<0.01). The more the visual acuity of ill eyes was decreased, the higher the abnormal rate of EOG in ill eyes was. 14 eyes had the visual acuity less than 0.1, whose EOGs ...

  17. Permanent retinal injury from recreational laser pointer.

    Science.gov (United States)

    Noble, Carl; Blice, Jeffrey

    2015-03-01

    This case report was performed to display the visually significant damage to the retina that can occur with brief exposure to a handheld laser pointer. Laser use in the military is ever increasing in form of target designators, rangefinders, or radar warning systems with powers far greater than used in this case. There is great potential for future cases of retinal damage among active duty members, and the importance of prevention through laser safety programs and recognition through trained medical personnel is paramount. PMID:25735035

  18. Chloride Transport in Undersea Concrete Tunnel

    Directory of Open Access Journals (Sweden)

    Yuanzhu Zhang

    2016-01-01

    Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

  19. Shelf life of unrefrigerated succinylcholine chloride injection.

    Science.gov (United States)

    Boehm, J J; Dutton, D M; Poust, R I

    1984-02-01

    The shelf life of succinylcholine chloride injection at several pH values when stored at room temperature was evaluated. Solutions containing 20 mg/ml of succinylcholine chloride were stored at 25 and 40 degrees C. The reaction was studied at pH values ranging from 3.0 to 4.5. At two-week intervals, the solutions were assayed by high-pressure liquid chromatography. The initial amount of succinylcholine chloride in all samples was 100.1 +/- 2.37% of label claim. Hydrolysis of succinylcholine chloride in unbuffered solutions followed apparent zero-order kinetics. The pH range of maximum stability was found to be from 3.75 to 4.50. Succinylcholine chloride decomposed at a considerably higher rate at 40 degrees C. Allowing for the effects of pH adjustment during manufacture and degradation during shipping, losses of 7.0% and 9.0% potency can be expected after storage at 25 degrees C for four and six weeks, respectively. Succinylcholine Chloride Injection, USP, should be stored in the refrigerator; if unbuffered succinylcholine chloride injection complying with USP pH limits must be stored at room temperature, it should not be kept for longer than four weeks. PMID:6702837

  20. Características químicas de um latossolo adubado com uréia e cloreto de potássio em ambiente protegido Chemical characteristics of an Oxisol after urea and potassium chloride fertilization in a protected environment

    Directory of Open Access Journals (Sweden)

    Maria Anita Gonçalves da Silva

    2001-09-01

    this paper was to evaluate the effects of urea and potassium chloride applications on the chemical characteristics of an Eutrorthox, mainly on its acidity and potassium saturation. The N was applied in rates of 13.3 and 39.9g m-2 and the K in rates 5.5 and 16.6 g m-2, in a fatorial (2X2+1 design, including a control. Pepper plants (Capsicum annuum, Mayata cultivar were grown under protected condition, during 34 weeks. After seedling rooting, the nutrients were applied at the rate of one sixth of the total at ten day intervals, up to 60 days. It was observed that urea did not acidify the soil probabily due to its high buffering capacity. The nitric and ammoniacal forms of N were directly effeted by the N rates applied in relation to the soil. In the treatment with N, the roots showed better development compared to the control. However, the highest K rate, applied as KCl, decreased root growth, probably due to the high soil K concentration and possible salinity effects, resulting in more than 5.0 mmol c dm-3 of K and more than 5.3% of K saturation in the exchange complex.

  1. Effects of progesterone on the expression of MAP-1B in retinal ganglion cells of ar ts with optic nerve injury%黄体酮对视神经损伤大鼠视网膜神经节细胞微管相关蛋白-1B的影响

    Institute of Scientific and Technical Information of China (English)

    白瑜; 杜丽敏; 赵平

    2016-01-01

    Objective To observe the effects of progesterone on the expression of microtubule associated protein-1B ( MAP-1B) in retinal ganglion cells of rats with optic nerve injury in order to provide experimental evidence of progesterone’ s protective effects on optic nerve.Methods Sixty rats were randomly divided into 3 groups,with 20 rats in each group.The rats in control group were not treated,however,the optic nerve injury models in right eye of rats were established in injury group 1, with 0.9%sodium chloride solution intraperitoneal injection,and the animal models were also established in injury group 2, with progesterone intraperitoneal injection.On 3d,7d,14d and 28d after injury, the right eyeballs of rats were excised, and retinal tissues were taken out, the morphological changes of retina were observed by HE staining, and the survival numbers of retinal ganglion cell were calculated, furthermore,the expression levels of MAP-1B in retinal ganglion cell were detected by immunohistochemistry.Results After optic nerve injury, the retinal nerve fiber layer appeared obvious edema, and the numbers of retinal ganglion cells were quickly decreased in injury group 1,however, the retinal morphological changes were alleviated,retinal nerve fiber layer appeared slight edema and the numbers of retinal ganglion cells were decreased slowly after treatment with progesterone in injury group 2.There was a significant difference in the optical density value at different time points between injury group 1 and injury group 2 ( P <0.05).Conclusion Progesterone can relieve the damage of retinal ganglion cells at early period of optic nerve injury through increasing the expression levels of cytoskeleton protein-MAP-1b, thus,which has protective effects on optic nerve and retina.%目的:观察并探讨黄体酮对视神经损伤早期视网膜神经节细胞微管相关蛋白-1B的影响,以期为黄体酮在视神经保护方面的作用提供实验依据。方法60

  2. Mitogen-activated protein kinases in the porcine retinal arteries and neuroretina following retinal ischemia-reperfusion

    DEFF Research Database (Denmark)

    Gesslein, Bodil; Håkansson, Gisela; Carpio, Ronald;

    2010-01-01

    The aim of the present study was to examine changes in the expression of intracellular signal-transduction pathways, specifically mitogen-activated protein kinases, following retinal ischemia-reperfusion.......The aim of the present study was to examine changes in the expression of intracellular signal-transduction pathways, specifically mitogen-activated protein kinases, following retinal ischemia-reperfusion....

  3. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  4. Oral fluoroquinolones and the incidence of rhegmatogenous retinal detachment and symptomatic retinal breaks: a population-based study

    Science.gov (United States)

    Kapoor, Kapil G.; Hodge, David O.; St Sauver, Jennifer L.; Barkmeier, Andrew J.

    2016-01-01

    Objective To examine whether oral fluoroquinolone antibiotics are associated with an increase in subsequent rhegmatogenous retinal detachment and symptomatic retinal breaks in a large, population-based cohort. Design Population-based cohort study Participants and Controls Adult residents of Olmsted County, Minnesota who were prescribed oral fluoroquinolone medications from 1/01/03 – 6/30/11. Comparison cohorts consisted of patients prescribed oral macrolide and β-lactam antibiotics during the study period. Methods Procedure codes were used to identify retinal detachment repair and prophylaxis procedures occurring within 1 year of prescription dates. Travel clinic, pro re nata, and self-treatment prescriptions were excluded. Patients with tractional retinal detachment, previous retinal detachment repair, endophthalmitis, and necrotizing retinitis were excluded, as were those with intraocular surgery or severe head/eye trauma ≤ 90 days prior to the procedure. Main Outcome Measures Rates of retinal detachment repair and prophylaxis procedures within 7, 30, 90, and 365 days of the first prescription were calculated and compared between antibiotic prescription cohorts using Chi-square tests. Retinal detachment repair rates were also compared to the expected Olmsted County, Minnesota rates using the one-sample log rank test. Results Oral fluoroquinolones were prescribed for 38,046 patients (macrolide n=48,074, β-lactam n=69,079) during the study period. Retinal detachment repair procedures were performed within 365 days of the first prescription in 0.03% (95% confidence interval [CI] 0.01–0.06%) of the fluoroquinolone, 0.02% (95% CI 0.01–0.03%) of the macrolide, and 0.03% (95% CI 0.02–0.05%) of the β-lactam cohorts (p>0.05). Retinal detachment prophylaxis procedures for symptomatic retinal breaks were performed within 365 days of the first prescription in 0.01% (95% CI 0.00–0.03%) of the fluoroquinolone, 0.02% (95% CI 0.01–0.04%) of the macrolide, and 0

  5. Reliability-Based Planning of Chloride Measurements

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Engelund, S.

    1996-01-01

    on measurements of the chloride content obtained from the given structure. In the present paper optimal planning of measurements of the chloride content in reinforced concrete structures is considered. It is shown how optimal experimental plans can be obtained using FORM-analysis. Bayesian statistics are used......In reinforced concrete structures corrosion is initiated when the chloride concentration around the reinforcement exceeds a threshold value. If corrosion starts then expensive repairs can be necessary. The estimation of the probability that corrosion has been initiated in a given structure is based...

  6. Binary Nucleation of Water and Sodium Chloride

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Thomas [Institute of Thermomechanics ASCR, Prague, Czech Republic; Marsik, Frantisek [Institute of Thermomechanics ASCR, Prague, Czech Republic; Palmer, Donald [ORNL

    2005-01-01

    Nucleation processes in the binary water-sodium chloride system are investigated in the sense of the classical nucleation theory (CNT). The CNT is modified to be able to handle the electrolytic nature of the system and is employed to investigate the acceleration of the nucleation process due to the presence of sodium chloride in the steam. This phenomenon, frequently observed in the Wilson zone of steam turbines, is called early condensation. Therefore, the nucleation rates of the water-sodium chloride mixture are of key importance in the power cycle industry.

  7. Protective effect of neuroglobin on retinal ganglion cell in glaucoma mice model%神经球蛋白对慢性高眼压小鼠视网膜神经节细胞损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    魏欣; 刘旭阳; 邓应平; 陈晓明

    2012-01-01

    .05).1周时,Ngb-Tg小鼠微球单次注射组视网膜中DHE含量明显低于WT小鼠微球单次注射组(t=3.212,P=0.008),而ATP的含量则明显高于WT小鼠微球单次注射组(t=2.864,P<0.01). 结论 Ngb可能是青光眼损伤的内源性神经保护因子,对高眼压所致RGCs损伤有保护作用,其机制可能是通过降低氧化应激和改善线粒体功能实现的.%Background Neuroglobin (Ngb) is a newly discovered member of globin superfamily.It is thought to regulate cell survival under hypoxia or oxidative stress condition.Ngb is expressed at a high level in retinal neuron,suggesting that retina may be one of important functional sites of Ngb.Objective The aim of this study was to investigate the protective role of endogenous Ngb on retina ganglion cells (RGCs) following chronic high intraocular pressure(IOP)in mice and the underlying mechanisms.Methods This study included the in vitro and in vivo experiment.RGCs derived from adult C57BL/6J wild type(WT) mice and Ngb-transgenic(Ngb-Tg) mice which cultivated by our laboratory were incubated with 5.0,7.5,10.0 mmol/L glutamic acid for 3 days.RGCs survival rate was calculated for the ration of dead and survival cells using a double labeling kit to evaluate the influence of Ngb on RGCs survival rate in the addition of glutamic acid.Chronic ocular hypertension models were established by injection of fluorescent microballon(MB) (10 μm)into the anterior chamber of WT mice and Ngb-Tg mice,The mice were divided into WT control group(n=18),Ngb-Tg control group(n=30),WT+MB single injection group(n=38),Ngb-Tg+MB single injection group (n =38),WT+MB twice injection group (n =6) and Ngb-Tg + twice injection group (n=6).In addition,WT+PBS injection group (n =6) and Ngb-Tg+ PBS injection group (n =6) were designed as negative controls to identify if it can affect IOP or not.The mice were sacrificed on 0 day(control group),3 days and 1,4,8 weeks followed the MB anterior chamber injection.Real-time PCR

  8. Facilitating facial retinization through barrier improvement.

    Science.gov (United States)

    Draelos, Zoe Diana; Ertel, Keith D; Berge, Cynthia A

    2006-10-01

    The utility of topical tretinoin as a treatment for improving the appearance of photodamaged skin is limited by irritation that occurs during the early phases of facial retinization. The observed side effects are consistent with stratum corneum barrier compromise. This paired double-blinded study was conducted to determine if preconditioning the skin with a barrier-enhancing cosmetic facial moisturizer before beginning tretinoin therapy and continuing moisturizer application during therapy would mitigate these side effects. Women with facial photodamage were recruited and randomly assigned to apply one cosmetic moisturizer to one side of the face and the other cosmetic moisturizer to the other side of the face twice daily for 10 weeks. One moisturizer contained a mixture of vitamins (niacinamide, panthenol, and tocopheryl acetate) to enhance stratum corneum barrier function, and the other moisturizer contained similar moisturizing ingredients but no vitamins. Daily full-face treatment with tretinoin cream 0.025% commenced 2 weeks into the study. Subjects' facial skin condition was monitored via investigator assessments, instrumental measurements, and subject self-assessments. The results show that improving stratum corneum barrier function before beginning topical tretinoin therapy and continuing use of a barrier-enhancing cosmetic moisturizer during therapy facilitates the early phase of facial retinization and augments the treatment response. PMID:17121065

  9. Retinal connectomics: towards complete, accurate networks.

    Science.gov (United States)

    Marc, Robert E; Jones, Bryan W; Watt, Carl B; Anderson, James R; Sigulinsky, Crystal; Lauritzen, Scott

    2013-11-01

    Connectomics is a strategy for mapping complex neural networks based on high-speed automated electron optical imaging, computational assembly of neural data volumes, web-based navigational tools to explore 10(12)-10(15) byte (terabyte to petabyte) image volumes, and annotation and markup tools to convert images into rich networks with cellular metadata. These collections of network data and associated metadata, analyzed using tools from graph theory and classification theory, can be merged with classical systems theory, giving a more completely parameterized view of how biologic information processing systems are implemented in retina and brain. Networks have two separable features: topology and connection attributes. The first findings from connectomics strongly validate the idea that the topologies of complete retinal networks are far more complex than the simple schematics that emerged from classical anatomy. In particular, connectomics has permitted an aggressive refactoring of the retinal inner plexiform layer, demonstrating that network function cannot be simply inferred from stratification; exposing the complex geometric rules for inserting different cells into a shared network; revealing unexpected bidirectional signaling pathways between mammalian rod and cone systems; documenting selective feedforward systems, novel candidate signaling architectures, new coupling motifs, and the highly complex architecture of the mammalian AII amacrine cell. This is but the beginning, as the underlying principles of connectomics are readily transferrable to non-neural cell complexes and provide new contexts for assessing intercellular communication. PMID:24016532

  10. Polymer optoelectronic structures for retinal prosthesis.

    Science.gov (United States)

    Gautam, Vini; Narayan, K S

    2014-01-01

    This commentary highlights the effectiveness of optoelectronic properties of polymer semiconductors based on recent results emerging from our laboratory, where these materials are explored as artificial receptors for interfacing with the visual systems. Organic semiconductors based polymer layers in contact with physiological media exhibit interesting photophysical features, which mimic certain natural photoreceptors, including those in the retina. The availability of such optoelectronic materials opens up a gateway to utilize these structures as neuronal interfaces for stimulating retinal ganglion cells. In a recently reported work entitled "A polymer optoelectronic interface provides visual cues to a blind retina," we utilized a specific configuration of a polymer semiconductor device structure to elicit neuronal activity in a blind retina upon photoexcitation. The elicited neuronal signals were found to have several features that followed the optoelectronic response of the polymer film. More importantly, the polymer-induced retinal response resembled the natural response of the retina to photoexcitation. These observations open up a promising material alternative for artificial retina applications.

  11. Clinical trials in branch retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    Tandava Krishnan Panakanti

    2016-01-01

    Full Text Available Branch retinal vein occlusion (BRVO is the second most common retinal vascular disorder. The management of macular edema has changed considerably over time. The laser is considered the gold standard treatment for over two decades. However, visual recovery with laser is usually slow and incomplete. The advent of intravitreal agents, specifically anti-vascular endothelial growth factors (VEGF have heralded a new era which promises rapid recovery of vision and quality of vision. Randomized clinical trials have reported optimal results with anti-VEGF agents (ranibizumab, bevacizumab, and aflibercept compared to laser therapy or steroids. However, nearly 50% of the patients require repeat intravitreal anti-VEGF therapy up to 4 years after initiating therapy to sustain the visual gains. The adverse events (systemic and ocular of these agents are minimal. Monotherapy with anti-VEGF agents have been found to provide better results than any combination with laser. This review article summarizes evidence from randomized controlled trials evaluating treatment options for the treatment of macular edema secondary to BRVO with a special focus on anti-VEGF therapy.

  12. Neuroprotection by α2-Adrenergic Receptor Stimulation after Excitotoxic Retinal Injury: A Study of the Total Population of Retinal Ganglion Cells and Their Distribution in the Chicken Retina

    Science.gov (United States)

    Galindo-Romero, Caridad; Harun-Or-Rashid, Mohammad; Jiménez-López, Manuel; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta

    2016-01-01

    We have studied the effect of α2-adrenergic receptor stimulation on the total excitotoxically injured chicken retinal ganglion cell population. N-methyl-D-aspartate (NMDA) was intraocularly injected at embryonic day 18 and Brn3a positive retinal ganglion cells (Brn3a+ RGCs) were counted in flat-mounted retinas using automated routines. The number and distribution of the Brn3a+ RGCs were analyzed in series of normal retinas from embryonic day 8 to post-hatch day 11 retinas and in retinas 7 or 14 days post NMDA lesion. The total number of Brn3a+ RGCs in the post-hatch retina was approximately 1.9x106 with a density of approximately 9.2x103 cells/mm2. The isodensity maps of normal retina showed that the density decreased with age as the retinal size increased. In contrast to previous studies, we did not find any specific region with increased RGC density, rather the Brn3a+ RGCs were homogeneously distributed over the central retina with decreasing density in the periphery and in the region of the pecten oculli. Injection of 5–10 μg NMDA caused 30–50% loss of Brn3a+ cells and the loss was more severe in the dorsal than in the ventral retina. Pretreatment with brimonidine reduced the loss of Brn3a+ cells both 7 and 14 days post lesion and the protective effect was higher in the dorsal than in the ventral retina. We conclude that α2-adrenergic receptor stimulation reduced the impact of the excitotoxic injury in chicken similarly to what has been shown in mammals. Furthermore, the data show that the RGCs are evenly distributed over in the retina, which challenges previous results that indicate the presence of specific high RGC-density regions of the chicken retina. PMID:27611432

  13. Surface adsorption in strontium chloride ammines

    DEFF Research Database (Denmark)

    Ammitzbøll, Andreas L.; Lysgaard, Steen; Klukowska, Agata;

    2013-01-01

    An adsorbed state and its implications on the ab- and desorption kinetics of ammonia in strontium chloride ammine is identified using a combination of ammonia absorption measurements, thermogravimetric analysis, and density functional theory calculations. During thermogravimetric analysis, ammoni...

  14. Catastrophic event modeling. [lithium thionyl chloride batteries

    Science.gov (United States)

    Frank, H. A.

    1981-01-01

    A mathematical model for the catastrophic failures (venting or explosion of the cell) in lithium thionyl chloride batteries is presented. The phenomenology of the various processes leading to cell failure is reviewed.

  15. Telomerization of Vinyl Chloride with Chloroform Initiated by Ferrous Chloride-Dimethylacetamide under Ultrasonic Conditions

    Directory of Open Access Journals (Sweden)

    Hua Qian

    2015-01-01

    Full Text Available Telomerization of vinyl chloride with chloroform was investigated using ferrous chloride-dimethylacetamide system, and 42.1% yield, more than four times the one reported before, was achieved. The addition of ultrasound further improved the reaction and yield was raised to 51.9% with trace byproducts at highly reduced reaction time and temperature. Ferrous chloride-dimethylacetamide under ultrasonic irradiation acts as a very efficient catalyst system for the 1 : 1 telomerization.

  16. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; A. S. Kayaalp

    2009-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many...

  17. Estimating the chloride transport in cement paste

    OpenAIRE

    Princigallo, A.

    2012-01-01

    A method was developed to measure the diffusion coefficient of chloride ions in cement paste based on an analytical solution to Fick’s 2nd law in a cylindrical coordinate system. This natural method yielded diffusivity results within as little as a month. Testing time was reduced by exploiting the three-dimensional inward flux in the specimen. In an attempt to determine the saturation concentration, dense portland cement pastes were exposed to a concentrated chloride solution. The method prov...

  18. Subclinical primary retinal pathology in neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Jeong, In Hye; Kim, Ho Jin; Kim, Nam-Hee; Jeong, Kyoung Sook; Park, Choul Yong

    2016-07-01

    Foveal thickness may be a more sensitive indicator of primary retinal pathology than retinal nerve fiber layer thickness since the fovea contains no or sparse retinal nerve fiber layer, which coalesces into axons of the optic nerve. To our knowledge, few quantitative in vivo studies have investigated foveal thickness. By using optical coherence tomography, we measured foveal thickness to evaluate intrinsic retinal pathology. Seventy-two neuromyelitis optica spectrum disorder patients (99 eyes with optic neuritis and 45 eyes without optic neuritis) and 34 age-matched controls were included. Foveal thinning was observed both in eyes with non-optic neuritis (185.1 µm, p optica spectrum disorder, foveal thickness correlated with 2.5 % low contrast visual acuity, while retinal nerve fiber layer thickness correlated with high or low contrast visual acuity, extended disability status scale, and disease duration. In this study, we observed foveal thinning irrespective of optic neuritis; thus, we believe that subclinical primary retinal pathology, prior to retinal nerve fiber layer thinning, may exist in neuromyelitis optica spectrum disorder.

  19. Vitamin A derivatives as treatment options for retinal degenerative diseases.

    Science.gov (United States)

    Perusek, Lindsay; Maeda, Tadao

    2013-07-12

    The visual cycle is a sequential enzymatic reaction for vitamin A, all-trans-retinol, occurring in the outer layer of the human retina and is essential for the maintenance of vision. The central source of retinol is derived from dietary intake of both retinol and pro-vitamin A carotenoids. A series of enzymatic reactions, located in both the photoreceptor outer segment and the retinal pigment epithelium, transform retinol into the visual chromophore 11-cis-retinal, regenerating visual pigments. Retina specific proteins carry out the majority of the visual cycle, and any significant interruption in this sequence of reactions is capable of causing varying degrees of blindness. Among these important proteins are Lecithin:retinol acyltransferase (LRAT) and retinal pigment epithelium-specific 65-kDa protein (RPE65) known to be responsible for esterification of retinol to all-trans-retinyl esters and isomerization of these esters to 11-cis-retinal, respectively. Deleterious mutations in these genes are identified in human retinal diseases that cause blindness, such as Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP). Herein, we discuss the pathology of 11-cis-retinal deficiency caused by these mutations in both animal disease models and human patients. We also review novel therapeutic strategies employing artificial visual chromophore 9-cis-retinoids which have been employed in clinical trials involving LCA patients.

  20. Vitamin A Derivatives as Treatment Options for Retinal Degenerative Diseases

    Directory of Open Access Journals (Sweden)

    Tadao Maeda

    2013-07-01

    Full Text Available The visual cycle is a sequential enzymatic reaction for vitamin A, all-trans-retinol, occurring in the outer layer of the human retina and is essential for the maintenance of vision. The central source of retinol is derived from dietary intake of both retinol and pro-vitamin A carotenoids. A series of enzymatic reactions, located in both the photoreceptor outer segment and the retinal pigment epithelium, transform retinol into the visual chromophore 11-cis-retinal, regenerating visual pigments. Retina specific proteins carry out the majority of the visual cycle, and any significant interruption in this sequence of reactions is capable of causing varying degrees of blindness. Among these important proteins are Lecithin:retinol acyltransferase (LRAT and retinal pigment epithelium-specific 65-kDa protein (RPE65 known to be responsible for esterification of retinol to all-trans-retinyl esters and isomerization of these esters to 11-cis-retinal, respectively. Deleterious mutations in these genes are identified in human retinal diseases that cause blindness, such as Leber congenital amaurosis (LCA and retinitis pigmentosa (RP. Herein, we discuss the pathology of 11-cis-retinal deficiency caused by these mutations in both animal disease models and human patients. We also review novel therapeutic strategies employing artificial visual chromophore 9-cis-retinoids which have been employed in clinical trials involving LCA patients.

  1. EFFECTUAL HUMAN AUTHENTICATION FOR CRITICAL SECURITY APPLICATIONS USING RETINAL IMAGES

    Directory of Open Access Journals (Sweden)

    L. Latha

    2010-11-01

    Full Text Available A robust method of human authentication based on the retinal blood vessel pattern is presented in this paper. This method entails a segmentation process to identify retinal blood vessel pattern, template generation consisting of the bifurcation points in the retina and matching of the intersection points in the template patterns. The number of matched blood vessel intersection points between the two patterns compared is used as a measure of similarity. As Liveness detection is a highly desirable anti-spoofing measure in biometric authentication, it is ensured while acquiring retinal images in realtime. The validity of our approach is verified with experimental results obtained from 603 comparisons made using 303 retinal images from three different publicly available databases, namely DRIVE, VARIA and STARE. We found that the proposed retinal recognition method gives 100%, 96.3% and 91.1% recognition rates respectively for the above databases. To the best of our knowledge, this is the first work that uses a large number of retinal images from different retinal databases for the authentication purpose.

  2. Zapora mrežničnih ven: Retinal vein occlusion:

    OpenAIRE

    Jaki, Polona; Mavri, Alenka; Štalc, Monika

    2011-01-01

    Retinal vein occlusion is a common disease, especially in the elderly, and is associated with significant visual morbidity, as a consequence of persistent macular oedema, macular ischemia, and in the advanced stages of the disease, due to retinal or iris neovascularisation with vitreal haemorrhages or neovascular glaucoma. There are two types of retinal vein occlusion with respect to the site of occlusion: branch retinal vein occlusion and central retinal vein occlusion. The obstruction is ma...

  3. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    Directory of Open Access Journals (Sweden)

    Gai-Fei Peng

    2014-04-01

    Full Text Available The influence of a chloride-ion adsorption agent (Cl agent in short, composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms.

  4. Effect of Chloride Type on Penetration of Chloride Ions in Concrete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of chloride type on the diffusivity of chloride ions in concrete was studied by experiment. The result shows that the glectric resistance of concrete and the chloride diffusion coefficient are influenced by chloride type. For the same water/cement ratio (W/C), the diffusion coefficient D in KCl solution is larger than that in NaCl solution; however, the concrete resistance in KCl solution is smaller than that in NaCl solution. The experimental result is analyzed with theory of diffusion.

  5. Retinal Arterial Macroaneurysm. A Case Report Macroaneurisma arterial retinal. Presentación de un caso.

    Directory of Open Access Journals (Sweden)

    Aimé Broche Hernández

    2011-08-01

    Full Text Available Retinal macroaneurysms are saccular dilatations of the retinal arteries. They commonly appear in temporary arches, which are found in elderly patients with hypertension and / or generalized vascular disease. They are slightly more frequent in women. In this article we present a case with a macroaneurysm rupture that was treated with laser photocoagulation and evolved favorably.Los macroaneurismas retinianos son dilataciones saculares de las arterias retinianas, con mayor frecuencia en arcadas temporales, que se detectan en pacientes de edad avanzada con hipertensión arterial y/o enfermedad vascular generalizada; son ligeramente más frecuentes en mujeres. Se presenta un caso clínico con ruptura de un macroaneurisma, que fue tratado con fotocoagulación con láser y evolucionó favorablemente.

  6. Overexpression of Pax6 results in microphthalmia, retinal dysplasia and defective retinal ganglion cell axon guidance

    Directory of Open Access Journals (Sweden)

    Jeffery Glen

    2008-05-01

    Full Text Available Abstract Background The transcription factor Pax6 is expressed by many cell types in the developing eye. Eyes do not form in homozygous loss-of-function mouse mutants (Pax6Sey/Sey and are abnormally small in Pax6Sey/+ mutants. Eyes are also abnormally small in PAX77 mice expressing multiple copies of human PAX6 in addition to endogenous Pax6; protein sequences are identical in the two species. The developmental events that lead to microphthalmia in PAX77 mice are not well-characterised, so it is not clear whether over- and under-expression of Pax6/PAX6 cause microphthalmia through similar mechanisms. Here, we examined the consequences of over-expression for the eye and its axonal connections. Results Eyes form in PAX77+/+ embryos but subsequently degenerate. At E12.5, we found no abnormalities in ocular morphology, retinal cell cycle parameters and the incidence of retinal cell death. From E14.5 on, we observed malformations of the optic disc. From E16.5 into postnatal life there is progressively more severe retinal dysplasia and microphthalmia. Analyses of patterns of gene expression indicated that PAX77+/+ retinae produce a normal range of cell types, including retinal ganglion cells (RGCs. At E14.5 and E16.5, quantitative RT-PCR with probes for a range of molecules associated with retinal development showed only one significant change: a slight reduction in levels of mRNA encoding the secreted morphogen Shh at E16.5. At E16.5, tract-tracing with carbocyanine dyes in PAX77+/+ embryos revealed errors in intraretinal navigation by RGC axons, a decrease in the number of RGC axons reaching the thalamus and an increase in the proportion of ipsilateral projections among those RGC axons that do reach the thalamus. A survey of embryos with different Pax6/PAX6 gene dosage (Pax6Sey/+, Pax6+/+, PAX77+ and PAX77+/+ showed that (1 the total number of RGC axons projected by the retina and (2 the proportions that are sorted into the ipsilateral and

  7. Retinal Neuroprotective Effects of Flibanserin, an FDA-Approved Dual Serotonin Receptor Agonist-Antagonist.

    Directory of Open Access Journals (Sweden)

    Aaron S Coyner

    Full Text Available To assess the neuroprotective effects of flibanserin (formerly BIMT-17, a dual 5-HT1A agonist and 5-HT2A antagonist, in a light-induced retinopathy model.Albino BALB/c mice were injected intraperitoneally with either vehicle or increasing doses of flibanserin ranging from 0.75 to 15 mg/kg flibanserin. To assess 5-HT1A-mediated effects, BALB/c mice were injected with 10 mg/kg WAY 100635, a 5-HT1A antagonist, prior to 6 mg/kg flibanserin and 5-HT1A knockout mice were injected with 6 mg/kg flibanserin. Injections were administered once immediately prior to light exposure or over the course of five days. Light exposure lasted for one hour at an intensity of 10,000 lux. Retinal structure was assessed using spectral domain optical coherence tomography and retinal function was assessed using electroretinography. To investigate the mechanisms of flibanserin-mediated neuroprotection, gene expression, measured by RT-qPCR, was assessed following five days of daily 15 mg/kg flibanserin injections.A five-day treatment regimen of 3 to 15 mg/kg of flibanserin significantly preserved outer retinal structure and function in a dose-dependent manner. Additionally, a single-day treatment regimen of 6 to 15 mg/kg of flibanserin still provided significant protection. The action of flibanserin was hindered by the 5-HT1A antagonist, WAY 100635, and was not effective in 5-HT1A knockout mice. Creb, c-Jun, c-Fos, Bcl-2, Cast1, Nqo1, Sod1, and Cat were significantly increased in flibanserin-injected mice versus vehicle-injected mice.Intraperitoneal delivery of flibanserin in a light-induced retinopathy mouse model provides retinal neuroprotection. Mechanistic data suggests that this effect is mediated through 5-HT1A receptors and that flibanserin augments the expression of genes capable of reducing mitochondrial dysfunction and oxidative stress. Since flibanserin is already FDA-approved for other indications, the potential to repurpose this drug for treating retinal

  8. Visual Cycle Modulation as an Approach toward Preservation of Retinal Integrity.

    Directory of Open Access Journals (Sweden)

    Claes Bavik

    Full Text Available Increased exposure to blue or visible light, fluctuations in oxygen tension, and the excessive accumulation of toxic retinoid byproducts places a tremendous amount of stress on the retina. Reduction of visual chromophore biosynthesis may be an effective method to reduce the impact of these stressors and preserve retinal integrity. A class of non-retinoid, small molecule compounds that target key proteins of the visual cycle have been developed. The first candidate in this class of compounds, referred to as visual cycle modulators, is emixustat hydrochloride (emixustat. Here, we describe the effects of emixustat, an inhibitor of the visual cycle isomerase (RPE65, on visual cycle function and preservation of retinal integrity in animal models. Emixustat potently inhibited isomerase activity in vitro (IC50 = 4.4 nM and was found to reduce the production of visual chromophore (11-cis retinal in wild-type mice following a single oral dose (ED50 = 0.18 mg/kg. Measure of drug effect on the retina by electroretinography revealed a dose-dependent slowing of rod photoreceptor recovery (ED50 = 0.21 mg/kg that was consistent with the pattern of visual chromophore reduction. In albino mice, emixustat was shown to be effective in preventing photoreceptor cell death caused by intense light exposure. Pre-treatment with a single dose of emixustat (0.3 mg/kg provided a ~50% protective effect against light-induced photoreceptor cell loss, while higher doses (1-3 mg/kg were nearly 100% effective. In Abca4-/- mice, an animal model of excessive lipofuscin and retinoid toxin (A2E accumulation, chronic (3 month emixustat treatment markedly reduced lipofuscin autofluorescence and reduced A2E levels by ~60% (ED50 = 0.47 mg/kg. Finally, in the retinopathy of prematurity rodent model, treatment with emixustat during the period of ischemia and reperfusion injury produced a ~30% reduction in retinal neovascularization (ED50 = 0.46mg/kg. These data demonstrate the ability of

  9. Bilateral Simultaneous Rhegmatogenous Retinal Detachment following Laser in situ Keratomileusis

    Directory of Open Access Journals (Sweden)

    Erhan Yumusak

    2016-06-01

    Full Text Available A 21-year-old woman developed simultaneous rhegmatogenous retinal detachment after laser in situ keratomileusis (LASIK in both eyes. She underwent pars plana vitrectomy surgery combined with endolaser photocoagulation and silicone oil tamponade in the right eye. A week later, pneumatic retinopexy was done in the left eye. As the retinal tear did not seal, 360° scleral buckling surgery was performed and retina was attached. Bilateral simultaneous rhegmatogenous retinal detachment after LASIK for correction of myopia can be a serious complication. Patients should be informed about the possibility of this complication.

  10. Hybrid Deconvolution of Adaptive Optics Retinal Images from Wavefront Sensing

    Institute of Scientific and Technical Information of China (English)

    TIAN Yu; RAO Chang-Hui; RAO Xue-Jun; WANG Cheng; YU Xiang; LIU Qian; XUE Li-Xia; LING Ning; JIANG Wen-Han

    2008-01-01

    Adaptive optics can be used to compensate for the wave aberration of the human eyes to achieve high-resolution imaging in real time.However the correction is partial due to the limitation of hardware.We propose a kind of hybrid image post-processing method.which uses the blind deconvolution combined with the residual data in wavefront sensor to restore the partially adaptive optics corrected retinal image.This method is applied in the image restoration of the vivid human retinal images.The results show that it is effective to improve the retinal image quality.

  11. High speed optical holography of retinal blood flow

    Science.gov (United States)

    Pellizzari, M.; Simonutti, M.; Degardin, J.; Sahel, J.-A.; Fink, M.; Paques, M.; Atlan, M.

    2016-08-01

    We performed non-invasive video imaging of retinal blood flow in a pigmented rat by holographic interferometry of near-infrared laser light backscattered by retinal tissue, beating against an off-axis reference beam sampled at a frame rate of 39 kHz with a high throughput camera. Local Doppler contrasts emerged from the envelopes of short-time Fourier transforms and the phase of autocorrelation functions of holograms rendered by Fresnel transformation. This approach permitted imaging of blood flow in large retinal vessels (30 microns diameter) over 400 by 400 pixels with a spatial resolution of 8 microns and a temporal resolution of 6.5 ms.

  12. High speed optical holography of retinal blood flow

    CERN Document Server

    Pellizzari, Mathilde; Degardin, Julie; Sahel, Jose-Alain; Fink, Mathias; Paques, Michel; Atlan, Michael

    2016-01-01

    We performed non-invasive video imaging of retinal blood flow in a pigmented rat by holographic interferometry of near-infrared laser light backscattered by retinal tissue, beating against an off-axis reference beam sampled at a frame rate of 39 kHz with a high throughput camera. Local Doppler contrasts emerged from the envelopes of short-time Fourier transforms and the phase of autocorrelation functions of holograms rendered by Fresnel transformation. This approach permitted imaging of blood flow in large retinal vessels (30 microns diameter) over 400 by 400 pixels with a spatial resolution of 8 microns and a temporal resolution of 6.5 ms.

  13. Two-photon in vivo imaging of retinal microstructures

    Science.gov (United States)

    Schejter, Adi; Farah, Nairouz; Shoham, Shy

    2014-02-01

    Non-invasive fluorescence retinal imaging in small animals is an important requirement in an array of translational vision applications. Two-photon imaging has the potential for long-term investigation of healthy and diseased retinal function and structure in vivo. Here, we demonstrate that two-photon microscopy through a mouse's pupil can yield high-quality optically sectioned fundus images. By remotely scanning using an electronically tunable lens we acquire highly-resolved 3D fluorescein angiograms. These results provide an important step towards various applications that will benefit from the use of infrared light, including functional imaging of retinal responses to light stimulation.

  14. Hybrid Deconvolution of Adaptive Optics Retinal Images from Wavefront Sensing

    International Nuclear Information System (INIS)

    Adaptive optics can be used to compensate for the wave aberration of the human eyes to achieve high-resolution imaging in real time. However the correction is partial due to the limitation of hardware. We propose a kind of hybrid image post-processing method, which uses the blind deconvolution combined with the residual data in wavefront sensor to restore the partially adaptive optics corrected retinal image. This method is applied in the image restoration of the vivid human retinal images. The results show that it is effective to improve the retinal image quality

  15. Massive retinal gliosis: An unusual case with immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Sanjay D Deshmukh

    2011-01-01

    Full Text Available Massive retinal gliosis (MRG is a rare, benign intraocular condition that results from the proliferation of well-differentiated glial cells. Immunohistochemically, these cells show positivity for glial fibrillary acid protein (GFAP, neuron specific enolase (NSE, and S-100 protein. We encountered a case of a 45-year-old female with loss of vision in the left eye. She had a history of trauma to that eye two years ago. Enucleation was carried out, because malignancy was suspected due to retinal calcification. On the basis of light microscopy and immunohistochemistry (IHC performed on the enucleated eye, it was diagnosed as massive retinal gliosis.

  16. Reactive retinal microglia, neuronal survival and the formation of retinal folds and detachments

    OpenAIRE

    Fischer, Andy J.; Zelinka, Christopher; Milani-Nejad, Nima

    2014-01-01

    Reactive microglia and macrophages are prevalent in damaged retinas. Accordingly, we investigate how the activation or ablation of microglia/macrophages influences the survival of neurons in the chick retina in vivo. We applied intraocular injections of interleukin 6 (IL6) to stimulate the reactivity of microglia/macrophages and clodronate-liposomes to ablate microglia/macrophages. Activation of the microglia/macrophages with IL6 delays the death of retinal neurons from N-methyl-D-aspartate (...

  17. Influence of retinal image shifts and extra-retinal eye movement signals on binocular rivalry alternations

    OpenAIRE

    Kalisvaart, Joke P.; Jeroen Goossens

    2013-01-01

    Previous studies have indicated that saccadic eye movements correlate positively with perceptual alternations in binocular rivalry, presumably because the foveal image changes resulting from saccades, rather than the eye movement themselves, cause switches in awareness. Recently, however, we found evidence that retinal image shifts elicit so-called onset rivalry and not percept switches as such. These findings raise the interesting question whether onset rivalry may account for correlations b...

  18. Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

    DEFF Research Database (Denmark)

    Pedersen, Daniella Bach; Koch Jensen, Peter; la Cour, Morten;

    2005-01-01

    Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension in the...... pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied....

  19. Carbonic anhydrase inhibition increases retinal oxygen tension and dilates retinal vessels

    DEFF Research Database (Denmark)

    Pedersen, Daniella Bach; Koch Jensen, Peter; la Cour, Morten;

    2005-01-01

    Carbonic anhydrase inhibitors (CAIs) increase blood flow in the brain and probably also in the optic nerve and retina. Additionally they elevate the oxygen tension in the optic nerve in the pig. We propose that they also raise the oxygen tension in the retina. We studied the oxygen tension in the...... in the pig retina and optic nerve before and after dorzolamide injection. Also the retinal vessel diameters during carbonic anhydrase inhibition were studied....

  20. 21 CFR 178.3290 - Chromic chloride complexes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chromic chloride complexes. 178.3290 Section 178... SANITIZERS Certain Adjuvants and Production Aids § 178.3290 Chromic chloride complexes. Myristo chromic chloride complex and stearato chromic chloride complex may be safely used as release agents in the...

  1. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17...) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride... on or after March 16, 2009 used for the transportation of hydrogen chloride, refrigerated...

  2. Advantages of diabetic tractional retinal detachment repair

    Directory of Open Access Journals (Sweden)

    Sternfeld A

    2015-10-01

    Full Text Available Amir Sternfeld, Ruth Axer-Siegel, Hadas Stiebel-Kalish, Dov Weinberger, Rita Ehrlich Department of Ophthalmology, Rabin Medical Center, Beilinson Campus, Petach Tikva, Israel Purpose: To evaluate the outcomes and complications of patients with diabetic tractional retinal detachment (TRD treated with pars plana vitrectomy (PPV.Patients and methods: We retrospectively studied a case series of 24 eyes of 21 patients at a single tertiary, university-affiliated medical center. A review was carried out on patients who underwent PPV for the management of TRD due to proliferative diabetic retinopathy from October 2011 to November 2013. Preoperative and final visual outcomes, intraoperative and postoperative complications, and medical background were evaluated.Results: A 23 G instrumentation was used in 23 eyes (95.8%, and a 25 G instrumentation in one (4.2%. Mean postoperative follow-up time was 13.3 months (4–30 months. Visual acuity significantly improved from logarithm of the minimum angle of resolution (LogMAR 1.48 to LogMAR 1.05 (P<0.05. Visual acuity improved by ≥3 lines in 75% of patients. Intraoperative complications included iatrogenic retinal breaks in seven eyes (22.9% and vitreal hemorrhage in nine eyes (37.5%. In two eyes, one sclerotomy was enlarged to 20 G (8.3%. Postoperative complications included reoperation in five eyes (20.8% due to persistent subretinal fluid (n=3, vitreous hemorrhage (n=1, and dislocated intraocular lens (n=1. Thirteen patients (54.2% had postoperative vitreous hemorrhage that cleared spontaneously, five patients (20.8% required antiglaucoma medications for increased intraocular pressure, seven patients (29.2% developed an epiretinal membrane, and two patients (8.3% developed a macular hole.Conclusion: Patients with diabetic TRD can benefit from PPV surgery. Intraoperative and postoperative complications can be attributed to the complexity of this disease. Keywords: diabetic retinopathy, proliferative

  3. Influence of choroidal perfusion on retinal temperature increase during retinal laser treatments

    Science.gov (United States)

    Herrmann, Katharina; Flöhr, Christian; Stalljohann, Jens; Apiou-Sbirlea, Gabriela; Kandulla, Jochen; Birngruber, Reginald; Brinkmann, Ralf

    2007-07-01

    In most retinal laser treatments the therapeutic effect is initiated by a transient temperature increase at and around the retinal pigment epithelium (RPE). Especially in long exposure time treatments like Transpupillary Thermotherapy (TTT) choroidal perfusion has a strong influence on the realized temperature at the fundus. The fundus blood circulation and therefore the heat dissipation is influenced by the intraocular pressure (IOP), which is investigated in the study presented here. In order to reduce the choroidal perfusion, the IOP is increased by injection of physiological saline solution into the eye of anaesthetized rabbits. The fundus is irradiated with 3.64 W/cm2 by means of a TTT-laser (λ = 810 nm) for t = 20 s causing a retinal temperature increase. Realtime temperature determination at the irradiated spot is achieved by a non invasive optoacoustic technique. Perfusion can be reduced by increasing IOP, which leads to different temperature increases when irradiating the retina. This should be considered for long time laser treatments.

  4. Preliminary investigation of multispectral retinal tissue oximetry mapping using a hyperspectral retinal camera.

    Science.gov (United States)

    Desjardins, Michèle; Sylvestre, Jean-Philippe; Jafari, Reza; Kulasekara, Susith; Rose, Kalpana; Trussart, Rachel; Arbour, Jean Daniel; Hudson, Chris; Lesage, Frédéric

    2016-05-01

    Oximetry measurement of principal retinal vessels represents a first step towards understanding retinal metabolism, but the technique could be significantly enhanced by spectral imaging of the fundus outside of main vessels. In this study, a recently developed Hyperspectral Retinal Camera was used to measure relative oximetric (SatO2) and total hemoglobin (HbT) maps of the retina, outside of large vessels, in healthy volunteers at baseline (N = 7) and during systemic hypoxia (N = 11), as well as in patients with glaucoma (N = 2). Images of the retina, on a field of view of ∼30°, were acquired between 500 and 600 nm with 2 and 5 nm steps, in under 3 s. The reflectance spectrum from each pixel was fitted to a model having oxy- and deoxyhemoglobin as the main absorbers and scattering modeled by a power law, yielding estimates of relative SatO2 and HbT over the fundus. Average optic nerve head (ONH) saturation over 8 eyes was 68 ± 5%. During systemic hypoxia, mean ONH saturation decreased by 12.5% on average. Upon further development and validation, the relative SatO2 and HbT maps of microvasculature obtained with this imaging system could ultimately contribute to the diagnostic and management of diseases affecting the ONH and retina. PMID:27060375

  5. Detection of retinal nerve fiber layer defects on retinal fundus images for early diagnosis of glaucoma

    Science.gov (United States)

    Muramatsu, Chisako; Hayashi, Yoshinori; Sawada, Akira; Hatanaka, Yuji; Hara, Takeshi; Yamamoto, Tetsuya; Fujita, Hiroshi

    2010-01-01

    Retinal nerve fiber layer defect (NFLD) is a major sign of glaucoma, which is the second leading cause of blindness in the world. Early detection of NFLDs is critical for improved prognosis of this progressive, blinding disease. We have investigated a computerized scheme for detection of NFLDs on retinal fundus images. In this study, 162 images, including 81 images with 99 NFLDs, were used. After major blood vessels were removed, the images were transformed so that the curved paths of retinal nerves become approximately straight on the basis of ellipses, and the Gabor filters were applied for enhancement of NFLDs. Bandlike regions darker than the surrounding pixels were detected as candidates of NFLDs. For each candidate, image features were determined and the likelihood of a true NFLD was determined by using the linear discriminant analysis and an artificial neural network (ANN). The sensitivity for detecting the NFLDs was 91% at 1.0 false positive per image by using the ANN. The proposed computerized system for the detection of NFLDs can be useful to physicians in the diagnosis of glaucoma in a mass screening.

  6. Bietti crystalline retinal dystrophy with subfoveal neurosensory detachment and congenital tortuosity of retinal vessels: case report.

    Science.gov (United States)

    Padhi, Tapas Ranjan; Kesarwani, Siddharth; Jalali, Subhadra

    2011-06-01

    A 34-year-old man presented with reduction and distortion of vision in both the eyes. The best-corrected vision was 20/20 parts, N6 in either eye. The external and slit lamp examination of both the eyes was unremarkable. The fundus examination showed multiple intraretinal crystalline deposits at the posterior pole, extending up to midperiphery, tortuous retinal blood vessels with S-shaped deflections, and absent foveal reflex in both the eyes. There were no corneal crystals, and the color vision was defective in both the eyes. Fundus autofluorescence and fundus fluorescein angiogram (FFA) were suggestive of geographic areas of retinal pigment epithelium (RPE) and choriocapillary (CC) loss. OCT revealed subfoveal neurosensory detachment. Flash ERG and EOG were normal except for a slight decrease in amplitude and delay in latency of pattern ERG waveforms. The Humphrey's visual field showed paracentral scotoma with reduction in the amplitude of waveforms from the corresponding area in the multifocal ERG in both the eyes. Systemic evaluation for crystalline retinopathy was unremarkable. He was diagnosed to be a case of Bietti crystalline retinopathy (local/regional variant). The subfoveal neurosensory detachment could represent early RPE dysfunction caused by these crystals and could account for the mild visual disturbance in both the eyes. Retinal vascular tortuosity and neurosensory detachment seen in this case is the first time to be reported in literature. PMID:21611771

  7. Astrocytes and Müller cells changes during retinal degeneration in a transgenic rat model of retinitis pigmentosa.

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    Laura eFernández-Sánchez

    2015-12-01

    Full Text Available Purpose: Retinitis pigmentosa includes a group of progressive retinal degenerative diseases that affect the structure and function of photoreceptors. Secondarily to the loss of photoreceptors, there is a reduction in retinal vascularization, which seems to influence the cellular degenerative process. Retinal macroglial cells, astrocytes and Müller cells provide support for retinal neurons and are fundamental for maintaining normal retinal function. The aim of this study was to investigate the evolution of macroglial changes during retinal degeneration in P23H rats. Methods: Homozygous P23H line-3 rats aged from P18 to 18 months were used to study the evolution of the disease, and SD rats were used as controls. Immunolabeling with antibodies against GFAP, vimentin, and transducin were used to visualize macroglial cells and cone photoreceptors. Results: In P23H rats, increased GFAP labeling in Müller cells was observed as an early indicator of retinal gliosis. At 4 and 12 months of age, the apical processes of Müller cells in P23H rats clustered in firework-like structures, which were associated with ring-like shaped areas of cone degeneration in the outer nuclear layer. These structures were not observed at 16 months of age. The number of astrocytes was higher in P23H rats than in the SD matched controls at 4 and 12 months of age, supporting the idea of astrocyte proliferation. As the disease progressed, astrocytes exhibited a deteriorated morphology and marked hypertrophy. The increase in the complexity of the astrocytic processes correlated with greater connexin 43 expression and higher density of connexin 43 immunoreactive puncta within the ganglion cell layer of P23H versus SD rat retinas. Conclusions: In the P23H rat model of retinitis pigmentosa, the loss of photoreceptors triggers major changes in the number and morphology of glial cells affecting the inner retina.

  8. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

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    H. Guan

    2009-09-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many coastal areas of Australia, may have perturbed catchment chloride balance conditions for appropriate use in CMB applications. In order to deal with these issues, a high resolution chloride deposition map in the coastal region is needed. In this study, we examined geographic, orographic, and atmospheric factors influencing chloride deposition in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia, using partial correlation and regression analyses. The results indicate that coastal distance, and terrain aspect and slope are two most significant factors controlling chloride deposition. Coastal distance accounts for 65% spatial variability in chloride deposition, with terrain aspect and slope for 8%. The deposition gradient is about 0.08 gm-2 year-1 km-1 as one progresses inland. The results are incorporated into a published de-trended residual kriging approach (ASOADeK to produce a 1 km×1 km resolution annual chloride deposition map and a bulk precipitation chloride concentration map. The average uncertainty of the deposition map is about 30% in the western MLR, and over 50% in the eastern MLR. The maps will form a very useful basis for examining catchment chloride balances for use in the CMB application in the study area.

  9. Nimodipine rescues N-methyl-N-nitrosourea-induced retinal degeneration in rats

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    Dan Wang

    2013-01-01

    Full Text Available Background: That nimodipine (NMD is potentially useful for ophthalmic treatment. However, the effect of NMD is unknown on retinal degenerative diseases. Objective: The purpose of the present study was to investigate the effect of NMD on N-methyl-N-nitrosourea (MNU-induced retinal degeneration (RD and elucidate its possible mechanisms. Materials and Methods: Morphological observation of NMD on MNU-induced RD was evaluated by light microscopy and electron microscopy. Nonenzymatic antioxidant glutathione (GSH was measured by a colorimetric method. Transforming growth factor-beta (TGF-β was measured by enzyme-linked immunosorbent assay (ELISA. Telomerase was detected by reverse transcriptase polymerase chain reaction (RT-PCR. Results: The significantly protective effect of NMD on MNU-induced RD was demonstrated morphologically. NMD increased the content of GSH and decreased the level of TGF-β in rat retina. RT-PCR analysis demonstrated that NMD treatment significantly decreased mRNA level of telomerase. Conclusion: These data suggest that NMD inhibit MNU-induced RD in rats. The expressions of TGF-β, telomerase and GSH contents might partially contribute to its protective effects on MNU-induced RD.

  10. 白蒺藜皂苷对慢性高眼压兔视网膜神经节细胞的保护作用%Protective effect of gross saponins from tribulus terrestris L on retinal ganglion cells in rabbits with chronic high intraocular pressure

    Institute of Scientific and Technical Information of China (English)

    李诺; 黄丽娜; 曾平; 刘军

    2010-01-01

    目的:观察白蒺藜皂苷(gross saponins from tribulus terrestris L,GSTT)及灯盏细辛注射液\\对慢性高眼压模型兔视网膜神经节细胞(retinal ganglion cells,RGCs)的保护作用. 方法:健康新西兰白兔24只,随机分为对照组、高眼压组、EBHM治疗组和GSTT治疗组,高眼压组和EBHM治疗组及GSTT治疗组的兔眼前房内注射20g/L甲基纤维素制成慢性高眼压模型,EBHM治疗组的兔每日耳缘ivEBHM注射液4.5mg/kg,GSTT治疗组的兔每日耳缘iv GSTT注射液5mg/kg,高眼压持续4wk时,处死实验兔,摘取眼球,做RGCs电镜检查.结果:造模后各组眼压均升高,电镜下高眼压组相对于GSTT治疗组及EBHM注射液治疗组,RGCs超微结构有明显损伤.结论:GSTT及EBHM注射液对慢性高眼压兔RGCs均具有保护作用.

  11. Reducing the artifacts in the identification of outer retinal boundary in the SD-OCT image with inherit retinal dystrophies.

    Science.gov (United States)

    Min Zhang; Sekiguchi, Hiroyuki; Uji, Akihito; Yakami, Masahiro; Togashi, Kaori

    2015-08-01

    This paper presents a new SD-OCT outer retinal boundary identification method based on the improved graph-theoretic approach in SD-OCT retinal image, which is robust to the image quality degradation and the pathological morphology variability. The performance of the proposed method was verified using the SD-OCT image database with inherit retinal dystrophies, which suffer from the artifacts most among different macular degeneration diseases. The experimental results of the subjective evaluation indicated that the identification results using the proposed method was substantially improved compared with the current built-in software in the SD-OCT devices. PMID:26737258

  12. Retinal oximetry with a multiaperture camera

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    Lemaillet, Paul; Lompado, Art; Ibrahim, Mohamed; Nguyen, Quan Dong; Ramella-Roman, Jessica C.

    2010-02-01

    Oxygen saturation measurements in the retina is an essential measurement in monitoring eye health of diabetic patient. In this paper, preliminary result of oxygen saturation measurements for a healthy patient retina is presented. The retinal oximeter used is based on a regular fundus camera to which was added an optimized optical train designed to perform aperture division whereas a filter array help select the requested wavelengths. Hence, nine equivalent wavelength-dependent sub-images are taken in a snapshot which helps minimizing the effects of eye movements. The setup is calibrated by using a set of reflectance calibration phantoms and a lookuptable (LUT) is computed. An inverse model based on the LUT is presented to extract the optical properties of a patient fundus and further estimate the oxygen saturation in a retina vessel.

  13. Retinal Changes Induced by Epiretinal Tangential Forces

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    Mario R. Romano

    2015-01-01

    Full Text Available Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-posterior forces. However, tangential forces are less characterized and classified in literature compared to the anterior-posterior ones. Tangential epiretinal forces are mainly due to anomalous posterior vitreous detachment (PVD, vitreoschisis, vitreopapillary adhesion (VPA, and epiretinal membranes (ERMs. Anomalous PVD plays a key role in the formation of the tangential vectorial forces on the retinal surface as consequence of gel liquefaction (synchysis without sufficient and fast vitreous dehiscence at the vitreoretinal interface. The anomalous and persistent adherence of the posterior hyaloid to the retina can lead to vitreomacular/vitreopapillary adhesion or to a formation of avascular fibrocellular tissue (ERM resulting from the proliferation and transdifferentiation of hyalocytes resident in the cortical vitreous remnants after vitreoschisis. The right interpretation of the forces involved in the epiretinal tangential tractions helps in a better definition of diagnosis, progression, prognosis, and surgical outcomes of vitreomacular interfaces.

  14. Multifractal Analysis of Human Retinal Vessels

    CERN Document Server

    Stosic, T

    2004-01-01

    In this work it is shown that vascular structures of the human retina represent geometrical multifractals, characterized by a hierarchy of exponents rather then a single fractal dimension. A number of retinal images from the STARE database (www.parl.clemson.edu/stare) are analyzed, corresponding to both normal and pathological states of the retina. In all studied cases a clearly multifractal behavior is observed, where capacity dimension is always found to be smaller then the information dimension, which is in turn always smaller then the correlation dimension, all the three being significantly lower then the DLA (Diffusion Limited Aggregation) fractal dimension. We also observe a tendency of images corresponding to the normal state of the retina to have higher generalized dimensions and a wider spectrum range, in comparison with the pathological cases.

  15. Atoh7 promotes the differentiation of retinal stem cells derived from Müller cells into retinal ganglion cells by inhibiting Notch signaling

    OpenAIRE

    Song, Wei-tao; Zhang, Xue-yong; Xia, Xiao-Bo

    2013-01-01

    Introduction Retinal Müller cells exhibit the characteristics of retinal progenitor cells, and differentiate into ganglion cells under certain conditions. However, the number of ganglion cells differentiated from retinal Müller cells falls far short of therapeutic needs. This study aimed to develop a novel protocol to promote the differentiation of retinal Müller cells into ganglion cells and explore the underlying signaling mechanisms. Methods Müller cells were isolated and purified from rat...

  16. Advantages of diabetic tractional retinal detachment repair

    Science.gov (United States)

    Sternfeld, Amir; Axer-Siegel, Ruth; Stiebel-Kalish, Hadas; Weinberger, Dov; Ehrlich, Rita

    2015-01-01

    Purpose To evaluate the outcomes and complications of patients with diabetic tractional retinal detachment (TRD) treated with pars plana vitrectomy (PPV). Patients and methods We retrospectively studied a case series of 24 eyes of 21 patients at a single tertiary, university-affiliated medical center. A review was carried out on patients who underwent PPV for the management of TRD due to proliferative diabetic retinopathy from October 2011 to November 2013. Preoperative and final visual outcomes, intraoperative and postoperative complications, and medical background were evaluated. Results A 23 G instrumentation was used in 23 eyes (95.8%), and a 25 G instrumentation in one (4.2%). Mean postoperative follow-up time was 13.3 months (4–30 months). Visual acuity significantly improved from logarithm of the minimum angle of resolution (LogMAR) 1.48 to LogMAR 1.05 (P<0.05). Visual acuity improved by ≥3 lines in 75% of patients. Intraoperative complications included iatrogenic retinal breaks in seven eyes (22.9%) and vitreal hemorrhage in nine eyes (37.5%). In two eyes, one sclerotomy was enlarged to 20 G (8.3%). Postoperative complications included reoperation in five eyes (20.8%) due to persistent subretinal fluid (n=3), vitreous hemorrhage (n=1), and dislocated intraocular lens (n=1). Thirteen patients (54.2%) had postoperative vitreous hemorrhage that cleared spontaneously, five patients (20.8%) required antiglaucoma medications for increased intraocular pressure, seven patients (29.2%) developed an epiretinal membrane, and two patients (8.3%) developed a macular hole. Conclusion Patients with diabetic TRD can benefit from PPV surgery. Intraoperative and postoperative complications can be attributed to the complexity of this disease. PMID:26604667

  17. Retinal detachment after laser In Situ keratomileusis

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    Saba Al-Rashaed

    2011-01-01

    Full Text Available Purpose : To report characteristics and outcome of rhegmatogenous retinal detachment (RRD after laser in situ keratomileusis (LASIK for myopia. Materials and Methods : A retrospective chart review of patients who presented with RRD after myopic LASIK over a 10-year period. Results : Fourteen eyes were identified with RRD. Of these, two of 6112 LASIK procedures were from our center. The mean age of patients with RRD was 35.43 years. The mean interval of RRD after LASIK was 37.71 months (range, 4 months to 10 years. The macula was involved in eight eyes and spared in six eyes. Retinal breaks included a macular hole in two eyes, and giant tear in two eyes. Multiple breaks (>2 breaks occurred in 6 cases. Pars plana vitrectomy (PPV was performed in 3 (21.4% eyes, a scleral buckle (SB was performed in 4 (28.5% eyes and 7 (50% eyes underwent combined PPV and SB. Mean follow-up was 15.18 months (range, 1 month to 7 years. The retina was successfully attached in all cases. The final visual acuity was 20/40 or better in 7 (50% eyes, 20/40 to 20/60 in 4 (28.5% eyes, and 20/200 or less in 3 (21.4% eyes. Poor visual outcome was secondary to proliferative vitreoretinopathy, epiretinal membrane, macular scar and amblyopia. Conclusion : The prevalence of RRD after LASIK was low at our institute. Anatomical and visual outcomes were acceptable in eyes that were managed promptly. Although there is no cause-effect relationship between LASIK and RRD, a dilated fundus examination is highly recommended before and after LASIK for myopia.

  18. Thrombophilic screening in retinal artery occlusion patients

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    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

  19. Mitigation of chloride and sulfate based corrosion in reinforced concrete via electrokinetic nanoparticle treatment

    Science.gov (United States)

    Kupwade-Patil, Kunal

    Concrete is a porous material which is susceptible to the migration of highly deleterious species such as chlorides and sulfates. Various external sources, including sea salt spray, direct seawater wetting, deicing salts and chlorides can contaminate reinforced concrete. Chlorides diffuse into the capillary pores of concrete and come into contact with the reinforcement. When chloride concentration at the reinforcement exceeds a threshold level it breaks down the passive oxide layer, leading to chloride induced corrosion. The application of electrokinetics using positively charged nanoparticles for corrosion protection in reinforced concrete structures is an emerging technology. This technique involves the principle of electrophoretic migration of nanoparticles to hinder chloride diffusion in the concrete. The return of chlorides is inhibited by the electrodeposited assembly of the nanoparticles at the reinforcement interface. This work examined the nanoparticle treatment impact on chloride and sulfate induced corrosion in concrete. Electrokinetic Nanoparticle (EN) treatments were conducted on reinforced cylindrical concrete, rectangular ASTM G109 specimens that simulate a bridge deck and full scale beam specimens. EN treatment to mitigate external sulfate attack in concrete was performed on cylindrical concrete specimens. Corrosion results indicated lower corrosion potentials and rates as compared to the untreated specimens. Scanning electron microscopy (SEM) showed a dense microstructure within the EN treated specimens. Chemical analysis (Raman spectroscopy, X ray-diffraction, and Fourier transform infrared spectroscopy FTIR) showed the presence of strength enhancing phases such as calcium aluminate hydrate (C-A-H) and increased amounts of calcium silicate hydrate (C-S-H) within the EN treated specimens. Strength and porosity results showed an increase in strength and a reduction in porosity among the EN treated specimens. EN treatment acted as a protective

  20. Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease

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    Despina Kokona

    2016-01-01

    Full Text Available The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago. In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP. This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma. The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss. Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness. The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease.