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Sample records for purified rat retinal

  1. Comparison of two methods used to culture and purify rat retinal Müller cells.

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    Song, Wei-Tao; Zhang, Xue-Yong; Xiong, Si-Qi; Wen, Dan; Jiang, Jian; Xia, Xiao-Bo

    2013-01-01

    To study two methods for culturing and purifying Sprague-Dawley (SD) rat retinal Müller cells and determine which one is better. The passage culture method of Müller cells was respectively carried out by complete pancreatic enzyme digestion method and repeated incomplete pancreatic enzyme digestion method. After culturing retinal cells for one month through these two methods, fluorescence-activated cell sorter (FACS), RT-PCR, and immunohistochemistry technology were performed to examine the enrichment and purity of Müller glial cells, and carried out two-sample approximate t test using SSPS 13.0 to further compare the Müller cell positive rate in both methods. The statistical results showed that the purity of Müller cells was 83.2%±5.16% in group A, and the purity was 98.5%±1.08% in group B. The two-sample approximate t test analysis demonstrated that the difference between group A and group B was statistically significant (t=-9.178, Pcells cultured by the complete pancreatic enzyme digestion method (group A) and the repeated incomplete pancreatic enzyme digestion method (group B). Compared with the complete pancreatic enzyme digestion method, this novel method was more efficient and a higher purity of Müller cells could be obtained using this approach.

  2. Effect of Purified Murine NGF on Isolated Photoreceptors of a Rodent Developing Retinitis Pigmentosa

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    Rocco, Maria Luisa; Balzamino, Bijorn Omar; Petrocchi Passeri, Pamela; Micera, Alessandra; Aloe, Luigi

    2015-01-01

    A number of different studies have shown that neurotrophins, including nerve growth factor (NGF) support the survival of retinal ganglion neurons during a variety if insults. Recently, we have reported that that eye NGF administration can protect also photoreceptor degeneration in a mice and rat with inherited retinitis pigmentosa. However, the evidence that NGF acts directly on photoreceptors and that other retinal cells mediate the NGF effect could not be excluded. In the present study we have isolated retinal cells from rats with inherited retinitis pigmentosa (RP) during the post-natal stage of photoreceptor degenerative. In presence of NGF, these cells are characterized by enhanced expression of NGF-receptors and rhodopsin, the specific marker of photoreceptor and better cell survival, as well as neuritis outgrowth. Together these observations support the hypothesis that NGF that NGF acts directly on photoreceptors survival and prevents photoreceptor degeneration as previously suggested by in vivo studies. PMID:25897972

  3. Glucose metabolism in rat retinal pigment epithelium.

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    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2006-01-01

    The retinal pigment epithelium (RPE) is the major transport pathway for exchange of metabolites and ions between choroidal blood supply and the neural retina. To gain insight into the mechanisms controlling glucose metabolism in RPE and its possible relationship to retinopathy, we studied the influence of different glucose concentrations on glycogen and lactate levels and CO(2) production in RPE from normal and streptozotocin-treated diabetic rats. Incubation of normal RPE in the absence of glucose caused a decrease in lactate production and glycogen content. In normal RPE, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO(2) yield, as well as reduction in lactate and glycogen production. In RPE from diabetic rats glucose accumulation did not increase in the presence of high glucose substrate, but it showed a four- and a seven-fold increase in CO(2) production through the mitochondrial and pentose phosphate pathways, respectively. We found high glycogen levels in RPE which can be used as an energy reserve for RPE itself and/or neural retina. Findings further show that the RPE possesses a high oxidative capacity. The large increase in glucose shunting to the pentose phosphate pathway in diabetic retina exposed to high glucose suggests a need for reducing capacity, consistent with increased oxidative stress.

  4. Rat retinal vasomotion assessed by laser speckle imaging

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    Neganova, Anastasiia Y; Postnov, Dmitry D; Sosnovtseva, Olga

    2017-01-01

    that can address the role and dynamical properties of vasomotion in vivo. We apply laser speckle imaging to study spontaneous and drug induced vasomotion in retinal network of anesthetized rats. The results reveal a wide variety of dynamical patterns. Wavelet-based analysis shows that (i) spontaneous...... can track the dynamical changes they cause....

  5. 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.

  6. Protection by dimethylthiourea against retinal light damage in rats.

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    Organisciak, D T; Darrow, R M; Jiang, Y I; Marak, G E; Blanks, J C

    1992-04-01

    The protective effect of dimethylthiourea (DMTU) against retinal light damage was determined in albino rats reared in darkness or in weak cyclic light. Rats maintained under these conditions were treated with DMTU at different concentrations and dosing schedules and then exposed for various times to intense visible light, either intermittently (1 hr light and 2 hr dark) or continuously. The extent of retinal light damage was determined 2 weeks after light exposure by comparing rhodopsin levels in experimental rats with those in unexposed control animals. To determine the effect of DMTU on rod outer segment (ROS) membrane fatty acids, ROS were isolated immediately after intermittent light exposure, and fatty acid compositions were measured. The time course for DMTU uptake and its distribution in serum, retina, and the retinal pigment epithelium (RPE)/choroid complex was determined in other rats not exposed to intense light. After intraperitoneal injection of the drug (500 mg/kg body weight), DMTU appeared rapidly in the serum, retina, and the RPE and choroid. In the ocular tissues, it was distributed 70-80% in the retina and 20-30% in the RPE and choroid. This antioxidant appears to have a long half-life because it was present in these same tissues 72 hr after a second intraperitoneal injection. For rats reared in the weak cyclic light environment, DMTU (two injections) provided complete protection against rhodopsin loss after intense light exposures of up to 16 hr. Only 15% rhodopsin loss was found in cyclic-light DMTU-treated rats after 24 hr of intermittent or continuous light. For rats reared in darkness, DMTU treatment resulted in a rhodopsin loss of less than 20% after 8-16 hr of continuous light and approximately 40% after similar exposure to intermittent light. Irrespective of the type of light exposure, rhodopsin loss in the dark-reared DMTU-treated rats was nearly identical to that found in uninjected cyclic light-reared animals. In rats from both light

  7. Postconditioning with inhaled hydrogen promotes survival of retinal ganglion cells in a rat model of retinal ischemia/reperfusion injury.

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    Wang, Ruobing; Wu, Jiangchun; Chen, Zeli; Xia, Fangzhou; Sun, Qinglei; Liu, Lin

    2016-02-01

    Retinal ischemia/reperfusion (I/R) injury plays a crucial role in the pathophysiology of various ocular diseases. Intraperitoneal injection or ocular instillation with hydrogen (H2)-rich saline was recently shown to be neuroprotective in the retina due to its anti-oxidative and anti-inflammatory effects. Our study aims to explore whether postconditioning with inhaled H2 can protect retinal ganglion cells (RGCs) in a rat model of retinal I/R injury. Retinal I/R injury was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining and retrograde labeling with cholera toxin beta (CTB). Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). Potential biomarkers of retinal oxidative stress and inflammatory responses were measured, including the expression of 4-Hydroxynonenalv (4-HNE), interleukin-1 beta (IL1-β) and tumor necrosis factor alpha (TNF-α). HE and CTB tracing showed that the survival rate of RGCs in the H2-treated group was significantly higher than the rate in the I/R group. Rats with H2 inhalation showed better visual function in assessments of FVEP and PLR. Moreover, H2 treatment significantly decreased the number of 4-HNE-stained cells in the ganglion cell layer and inhibited the retinal overexpression of IL1-β and TNF-α that was induced by retinal I/R injury. Our results demonstrate that postconditioning with inhaled high-dose H2 appears to confer neuroprotection against retinal I/R injury via anti-oxidative, anti-inflammatory and anti-apoptosis pathways.

  8. Differences in expression of retinal proteins between diabetic and normal rats

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    Shang-Qing Liu; Jian Kang; Cheng-Jun Li; En-Jie Tang; Bin Wen; Rong Cai; Hui-Jun Yang

    2007-01-01

    AIM: To compare and identify the differences in expression of retinal proteins between normal and diabetic rats, and to analyze the molecular pathogenetic mechanisms of retinal diseases caused by diabetes.METHODS: Changes in protein expression of retinal tissues from diabetic and normal rats were observed using 2-dimensional polyacrylamide gel electrophoresis (2-DE). Some protein spots exhibiting statistically significant variations (P < 0.05) were selected randomly and identified by tandem mass spectrometry and analyzed by bioinformatics.RESULTS: 2-DE showed that the expression was upregulated in 5 retinal proteins, down-regulated in 23retinal proteins, and disappeared in 8 retinal proteins.Eight spots were identified from the 36 spots by tandem mass spectrometry (MS/MS) and analyzed by bioinformatics. Guanylate kinase 1, triosephosphate isomerase 1, ATP synthase subunit d, albumin and dimethylarginine dimethylaminohydrolase 2 played an important role in signal transduction. Triosephosphate isomerase 1, crystallin alpha B, ATP synthase subunit d and peroxiredoxin 6 were involved in energy metabolism of retinal tissues. Guanylate kinase 1 played an important role in photoexcitation of retinal rod photoreceptor cells.Whether crystallin beta A1 plays a role in diabetic retinas is unknown so far.CONCLUSION: There are differences in expression of retinal proteins between diabetic and normal rats.These proteins may be involved in the mechanisms and prognosis of retinal diseases caused by diabetes.

  9. Effect of lidocaine on retinal aquaporin-4 expression after ischemia/reperfusion injury in the rat

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    Liying He; Li Li

    2008-01-01

    BACKGROUND: Several studies have demonstrated that high doses of lidocaine can reduce edema in rats with brain injury by down-regulating aquaporin-4 (AQP4) expression. The hypothesis for the present study is that lidocaine could retinal edema that is associated with AQP4 expression.OBJECTIVE: This study was designed to investigate the interventional effects of lidocaine on retinal AQP4 expression and retinal edema following ischemia/reperfusion injury in the rat.DESIGN, TIME AND SETTING: This study, a randomized, controlled, animal experiment, was performed at the Basic Research Institute, Chongqing Medical University from September 2006 to May 2007.MATERIALS: Seventy-five, healthy, adult, female, Sprague-Dawley rats were included. A total of 50 rats were used to establish a retinal ischemia/reperfusion injury model using an anterior chamber enhancing perfusion unit. Rabbit anti-rat AQP4 antibody was purchased from Santa Cruz Biotechnology, USA.METHODS: All 75 rats were randomly divided into three groups, with 25 rats in each: control, model, and lidocaine. At each time point (1, 6, 12, 24, and 48 hours after modeling, five rats for each time point), each rat in the lidocaine group was intraperitoneally administered lidocaine with an initial dose of 30 mg/kg, followed by subsequent doses of 15 mg/kg every six hours. The entire treatment process lasted three days for each rat. At each above-mentioned time point, rats in the model group were modeled, but not administered any substances. Rats in the control group received the same treatments as in the lidocaine group except that lidocaine was replaceld by physiological saline.MAIN OUTCOME MEASURES: Following hematoxylin-eosin staining, rat retinal tissue was observed to investigate retinal edema degree through the use of an optical microscope and transmission electron microscope. Retinal AQP4 expression was determined by immunohistochemistry.RESULTS: At each above-mentioned time point, AQP4 expression was

  10. Vasodilator effects of adenosine on retinal arterioles in streptozotocin-induced diabetic rats.

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    Nakazawa, Taisuke; Mori, Asami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2008-02-01

    Adenosine is a potent vasodilator of retinal blood vessels and is implicated to be a major regulator of retinal blood flow during metabolic stress, but little is known about the impact of diabetes on the role of adenosine in regulation of retinal hemodynamics. Therefore, we examined how diabetes affects adenosine-induced vasodilation of retinal arterioles. Male Wistar rats were treated with streptozotocin (80 mg/kg, intraperitoneally), and experiments were performed 6-8 weeks later. Rats were treated with tetrodotoxin (50 microg/kg, intravenously [i.v.]) to eliminate any nerve activity and prevent movement of the eye and infused with methoxamine continuously to maintain adequate systemic circulation. Fundus images were captured with a digital camera that was equipped with a special objective lens, and diameters of retinal arterioles were measured. Adenosine increased diameters of retinal arterioles and decreased systemic blood pressure. These responses were significantly attenuated by the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (30 mg/kg, i.v.) and the adenosine triphosphate-dependent K+ (K(ATP)) channel blocker glibenclamide (20 mg/kg, i.v.). The depressor responses to adenosine were reduced in diabetic rats, whereas diabetes did not alter vasodilation of retinal arterioles to adenosine. In contrast, both depressor response and vasodilation of retinal arteriole to acetylcholine were reduced in diabetic rats. The retinal vasodilator responses to adenosine and acetylcholine observed in diabetic rats were diminished by N(G)-nitro-L-arginine methyl ester. There were no differences in the responses to pinacidil, a K(ATP) channel opener, between the diabetic and nondiabetic rats. These results suggest that both the activation of nitric oxide synthase and opening of K(ATP) channels contribute to the vasodilator effects of adenosine in rats in vivo. However, diabetes has no significant impact on the vasodilation mediated by these mechanisms in

  11. Safranal, a saffron constituent, attenuates retinal degeneration in P23H rats.

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    Fernández-Sánchez, Laura; Lax, Pedro; Esquiva, Gema; Martín-Nieto, José; Pinilla, Isabel; Cuenca, Nicolás

    2012-01-01

    Saffron, an extract from Crocus sativus, has been largely used in traditional medicine for its antiapoptotic and anticarcinogenic properties. In this work, we investigate the effects of safranal, a component of saffron stigmas, in attenuating retinal degeneration in the P23H rat model of autosomal dominant retinitis pigmentosa. We demonstrate that administration of safranal to homozygous P23H line-3 rats preserves both photoreceptor morphology and number. Electroretinographic recordings showed higher a- and b-wave amplitudes under both photopic and scotopic conditions in safranal-treated versus non-treated animals. Furthermore, the capillary network in safranal-treated animals was preserved, unlike that found in untreated animals. Our findings indicate that dietary supplementation with safranal slows photoreceptor cell degeneration and ameliorates the loss of retinal function and vascular network disruption in P23H rats. This work also suggests that safranal could be potentially useful to retard retinal degeneration in patients with retinitis pigmentosa.

  12. Safranal, a saffron constituent, attenuates retinal degeneration in P23H rats.

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    Laura Fernández-Sánchez

    Full Text Available Saffron, an extract from Crocus sativus, has been largely used in traditional medicine for its antiapoptotic and anticarcinogenic properties. In this work, we investigate the effects of safranal, a component of saffron stigmas, in attenuating retinal degeneration in the P23H rat model of autosomal dominant retinitis pigmentosa. We demonstrate that administration of safranal to homozygous P23H line-3 rats preserves both photoreceptor morphology and number. Electroretinographic recordings showed higher a- and b-wave amplitudes under both photopic and scotopic conditions in safranal-treated versus non-treated animals. Furthermore, the capillary network in safranal-treated animals was preserved, unlike that found in untreated animals. Our findings indicate that dietary supplementation with safranal slows photoreceptor cell degeneration and ameliorates the loss of retinal function and vascular network disruption in P23H rats. This work also suggests that safranal could be potentially useful to retard retinal degeneration in patients with retinitis pigmentosa.

  13. Establishing an experimental rat model of photodynamically-induced retinal vein occlusion using erythrosin B

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    Chen, Wei; Wu, Ying; Zheng, Mi; Gu, Qing; Zheng, Zhi; Xia, Xin

    2014-01-01

    AIM To develop a reliable, reproducible rat model of retinal vein occlusion (RVO) with a novel photosensitizer (erythrosin B) and study the cellular responses in the retina. METHODS Central and branch RVOs were created in adult male rats via photochemically-induced ischemia. Retinal changes were monitored via color fundus photography and fluorescein angiography at 1 and 3h, and 1, 4, 7, 14, and 21d after irradiation. Tissue slices were evaluated histopathologically. Retinal ganglion cell survival at different times after RVO induction was quantified by nuclear density count. Retinal thickness was also observed. RESULTS For all rats in both the central and branch RVO groups, blood flow ceased immediately after laser irradiation and retinal edema was evident at one hour. The retinal detachment rate was 100% at 3h and developed into bullous retinal detachment within 24h. Retinal hemorrhages were not observed until 24h. Clearance of the occluded veins at 7d was observed by fluorescein angiography. Disease manifestation in the central RVO eyes was more severe than in the branch RVO group. A remarkable reduction in the ganglion cell count and retinal thickness was observed in the central RVO group by 21d, whereas moderate changes occurred in the branch RVO group. CONCLUSION Rat RVO created by photochemically-induced ischemia using erythrosin B is a reproducible and reliable animal model for mimicking the key features of human RVO. However, considering the 100% rate of retinal detachment, this animal model is more suitable for studying RVO with chronic retinal detachment. PMID:24790863

  14. Establishing an experimental rat model of photodynamically-induced retinal vein occlusion using erythrosin B

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    Wei Chen

    2014-04-01

    Full Text Available AIM:To develop a reliable, reproducible rat model of retinal vein occlusion (RVO with a novel photosensitizer (erythrosin B and study the cellular responses in the retina.METHODS:Central and branch RVOs were created in adult male rats via photochemically-induced ischemia. Retinal changes were monitored via color fundus photography and fluorescein angiography at 1 and 3h, and 1, 4, 7, 14, and 21d after irradiation. Tissue slices were evaluated histopathologically. Retinal ganglion cell survival at different times after RVO induction was quantified by nuclear density count. Retinal thickness was also observed.RESULTS:For all rats in both the central and branch RVO groups, blood flow ceased immediately after laser irradiation and retinal edema was evident at one hour. The retinal detachment rate was 100% at 3h and developed into bullous retinal detachment within 24h. Retinal hemorrhages were not observed until 24h. Clearance of the occluded veins at 7d was observed by fluorescein angiography. Disease manifestation in the central RVO eyes was more severe than in the branch RVO group. A remarkable reduction in the ganglion cell count and retinal thickness was observed in the central RVO group by 21d, whereas moderate changes occurred in the branch RVO group.CONCLUSION: Rat RVO created by photochemically-induced ischemia using erythrosin B is a reproducible and reliable animal model for mimicking the key features of human RVO. However, considering the 100% rate of retinal detachment, this animal model is more suitable for studying RVO with chronic retinal detachment.

  15. Effects of Lead on Temporal Response Properties of Retinal Ganglion Cells in Developing Rats

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    阮迪云; 汤立新; 赵晨; 郭宇静

    1994-01-01

    Neonatal rats have taken in lead, during the period from their parturition to their weaning, from the milk of dams fed with water containing 0.2% lead acetate solutions. The alterations in the temporal response properties of retinal ganglion cells in adult rats (90 days) following the lead exposure at their developing stage have been studied. The results of this investigation demonstrate that the lead exposure in neonatal rats causes decreases in the optimal temporal frequency, bandwidth at half amplitude, temporal resolution and response phase of the retinal ganglion cells in adult rats. Compared with the sustained cells, the transient cells have a much greater alteration in temporal response properties.

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

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    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.

  17. Beta-adrenoceptor-mediated vasodilation of retinal blood vessels is reduced in streptozotocin-induced diabetic rats.

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    Nakazawa, Taisuke; Sato, Ayumi; Mori, Asami; Saito, Maki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2008-01-01

    We investigated the effects of epinephrine and dopamine on retinal blood vessels in streptozotocin (STZ, 80 mg/kg, i.p.)-treated rats and age-matched control rats to determine whether diabetes mellitus alters the retinal vascular responses to circulating catecholamines. Experiments were performed 6-8 weeks after treatment with STZ or the vehicle. The fundus images were captured with the digital fundus camera system for small animals we developed and diameters of retinal blood vessels contained in the digital images were measured. Epinephrine increased the diameters of retinal blood vessels, but the vasodilator responses were reduced in diabetic rats. Dopamine produced a biphasic retinal vascular response with an initial vasoconstriction followed by a vasodilation. The vasoconstrictor effects of dopamine on retinal arterioles were enhanced in diabetic rats, whereas the difference between the two groups was abolished by treatment with propranolol. The vasodilator effect of isoproterenol, but not of the activator of adenylyl cyclase colforsin, on retinal blood vessels was reduced in diabetic rats. No difference in vasoconstriction of retinal blood vessels to phenylephrine between non-diabetic and diabetic rats was observed. The vasodilator responses of retinal blood vessels to 1,1-dimethyl-4-phenylpiperazinium, a ganglionic nicotinic receptor agonist, were also attenuated in diabetic rats. These results suggest that diabetes mellitus alters the retinal vascular responses to circulating catecholamines and the impairment of vasodilator responses mediated by beta-adrenoceptors contributes to the alteration.

  18. Neuroprotective Effect of Melatonin on Retinal Ganglion Cells in Rats

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    TANG Qiongyan; HU Yizhen; CAO Yang

    2006-01-01

    To investigate the neuroprotective effect of melatonin (MT) on retinal ganglion cells (RGCs) in rats with ischemia reperfusion injury (RIR), 24 healthy SD rats were randomly divided into two groups:group A and group B. RIR model was induced in the left eyes by increasing the pressure of the anterior chamber. Group A was treated with 10 % alcohol- normal saline (1 mL/kg/d, ip), while group B was treated with 0.5 % MT (1 mL/kg/d, ip). On the basis of the time interval between the left eyes RIR and the sacrifice, rats in both group A and group B were further divided into 3 subgroups: groups A1 and B1 (days 7), groups A2 and B2 (days 14), groups A3 and B3 (days 30), with4 rats in each subgroup. 7 day before the sacrifice, 3 % fluorogold was bilaterally injected into superior colliculi and geniculate body. The eyes were enucleated after being sacrificed, and mounting of the retina from both eyes was performed on a slide and observed under a fluorescence microscope. Four photos were taken from each of the four quadrants of the retina.The labeled-RGCs were counted by using a computerized image analyzer. The rate of the labeledRGCs was used for statistical analysis. Our results showed that, in group A, the rate of the labeled-RGCs was (77. 16±6.35) %, (65.53±7.01) %, (53.85±4.38) % on day 7, 14 and 30.In group B, the rate of the labeled-RGCs was (81.33±9.27) %, (79.80±8.36) %, (80.34±11.05) % on day 7, 14 and 30. In group B, which was treated with MT after RIR, the rate of labeled-RGCs was significantly higher than that of group A on day 14 and day 30 (P<0.05). It is concluded that, in the RIR rats, MT therapy could increase the survival rate of the RGCs and could rescue and restore the injured RGCs.

  19. [Effect of premature birth on retinal vascular development in the neonatal rat].

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    Yang, Xiang-min; Li, Rong; Wang, Yu-sheng; Chu, Zhao-jie; Gao, Xiang

    2013-08-01

    To study the effects of premature birth on the development of rat retinal vasculature. Experimental study. Sixty pregnant Sprague-Dawley rats were divided into four groups: bacterial lipopolysaccharide-induced preterm group (LPS group), RU-486 induced preterm group (RP group), cesarean section induced preterm group (CP group), and the normal delivery rats as the control group. The weight of rats from each group was recorded until postnatal day 21. On postnatal day 4, 7, 10 and 14 (P4, P7, P10 and P14), the retina of right eye was dissected and whole-mounted. Each premature group was divided into two subgroups based on the number of rats in each litter, the small subgroup (6-8 rats per litter, group 1) and the large subgroup (14-18 rats per litter, group 2). The development of retinal vascularization process was observed on P4, P7 and P10 (n = 6).Independent t test, one-way ANOVA and LSD-t test were used to analyzed the results. The weight of premature rats in LPS, CP and RP groups was significantly lower than that in the normal group within postnatal 21 days (LSD-t test: all P premature rats have lower weight and much slower rate of early retinal vascularization, as compared with the normal rats. Furthermore, in the premature rats, the proportion of retinal vascularization in larger litters is less than that in smaller litters. These results indicate that premature birth and larger litter size have effects on the development of rat retinal vasculature.

  20. Optimization of a filter-lysis protocol to purify rat testicular homogenates for automated spermatid counting.

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    Pacheco, Sara E; Anderson, Linnea M; Boekelheide, Kim

    2012-01-01

    Quantifying testicular homogenization-resistant spermatid heads (HRSH) is a powerful indicator of spermatogenesis. These counts have traditionally been performed manually using a hemocytometer, but this method can be time consuming and biased. We aimed to develop a protocol to reduce debris for the application of automated counting, which would allow for efficient and unbiased quantification of rat HRSH. We developed a filter-lysis protocol that effectively removes debris from rat testicular homogenates. After filtering and lysing the homogenates, we found no statistical differences between manual (classic and filter-lysis) and automated (filter-lysis) counts using 1-way analysis of variance with Bonferroni's multiple comparison test. In addition, Pearson's correlation coefficients were calculated to compare the counting methods, and there was a strong correlation between the classic manual counts and the filter-lysis manual (r = 0.85, P = .002) and the filter-lysis automated (r = 0.89, P = .0005) counts. We also tested the utility of the automated method in a low-dose exposure model known to decrease HRSH. Adult Fischer 344 rats exposed to 0.33% 2,5-hexanedione in the drinking water for 12 weeks demonstrated decreased body (P = .02) and testes (P = .002) weights. In addition, there was a significant reduction in the number of HRSH per testis (P = .002) when compared to controls. A filterlysis protocol was optimized to purify rat testicular homogenates for automated HRSH counts. Automated counting systems yield unbiased data and can be applied to detect changes in the testis after low-dose toxicant exposure.

  1. Retinal ganglion cells of high cytochrome oxidase activity in the rat

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    JENLS; CHAURMW

    1990-01-01

    Retinal ganglion cells in the rat were studied using the heavy metal intensified cytochrome oxidase and horseradish peroxidase histochemical methods.The results show that a population of large retinal ganglion cells was consistently observed with the cytochrome oxidase staining method in retinas of normal rats or rats which received unilateral thalamotomy at birth.These cytochrome oxidase rich ganglion cells appeared to have large somata,3-6 primary dendrites and extensive dendritic arbors,and are comparable to ganglion cells labeled by the wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP).However,the morphological details of some of the cells revealed by the cytochrome oxidase staining method are frequently better than those shown by the HRP histochemical method.These results suggest that the mitochondrial enzyme cytochrome oxidase can be used as a simple but reliable marker for identifying and studying a population of retinal genglion cells with high metabolic rate in the rat.

  2. Cultured rat and purified human Pneumocystis carinii stimulate intra- but not extracellular free radical production in human neutrophils

    DEFF Research Database (Denmark)

    Jensen, T; Aliouat, E M; Lundgren, B

    1998-01-01

    The production of free radicals in human neutrophils was studied in both Pneumocystis carinii derived from cultures of L2 rat lung epithelial-like cells and Pneumocystis carinii purified from human lung. Using the cytochrome C technique, which selectively measured extracellular superoxide....... It was established that 1) P. carinii stimulated intra- but not extracellular free radical production in human neutrophils, 2) opsonized cultured rat-derived P. carinii stimulated human neutrophils to a strong intracellular response of superoxide production, and 3) opsonized P. carinii, purified from human lung also...

  3. Chitosan oligosaccharides attenuates oxidative-stress related retinal degeneration in rats.

    Directory of Open Access Journals (Sweden)

    I-Mo Fang

    Full Text Available This study investigated the therapeutic potential and mechanisms of chitosan oligosaccharides (COS for oxidative stress-induced retinal diseases. Retinal oxidative damage was induced in Sprague-Dawley rats by intravitreal injection of paraquat (PQ. Low-dose (5 mg/kg or high-dose (10 mg/kg COS or PBS was intragastrically given for 14 days after PQ injection. Electroretinograms were performed to determine the functionality of the retinas. The surviving neurons in the retinal ganglion cell layer and retinal apoptosis were determined by counting Neu N-positive cells in whole-mounted retinas and TUNEL staining, respectively. The generation of reactive oxygen species (ROS was determined by lucigenin- and luminol-enhanced chemiluminescence. Retinal oxidative damages were assessed by staining with nitrotyrosine, acrolein, and 8-hydroxy-2'-deoxyguanosine (8-OHdG. Immunohistochemical studies were used to demonstrate the expression of nuclear factor-kappa B (NF-κB p65 in retinas. An in vitro study using RGC-5 cells was performed to verify the results. We demonstrated COS significantly enhanced the recovery of retinal function, preserved inner retinal thickness, and decreased retinal neurons loss in a dose-dependent manner. COS administration demonstrated anti-oxidative effects by reducing luminol- and lucigenin-dependent chemiluminenscense levels and activating superoxide dismutase and catalase, leading to decreased retinal apoptosis. COS markedly reduced retinal NF-κB p65. An in vitro study demonstrated COS increased IκB expression, attenuated the increase of p65 and thus decreased NF-κB/DNA binding activity in PQ-stimulated RGC-5 cells. In conclusion, COS attenuates oxidative stress-induced retinal damages, probably by decreasing free radicals, maintaining the activities of anti-oxidative enzymes, and inhibiting the activation of NF-κB.

  4. The 73 kilodalton heat shock cognate protein purified from rat brain contains nonesterified palmitic and stearic acids.

    Science.gov (United States)

    Guidon, P T; Hightower, L E

    1986-08-01

    A protein related to the 71 kilodalton inducible rat heat shock protein was purified to electrophoretic homogeneity in milligram amounts from brain tissue of nonheat-stressed rats. The protein has been designated as a stress cognate protein based on previous studies and data presented herein that this protein cross-reacted with a monoclonal antibody originally raised against the Drosophila 70 kilodalton heat shock protein. The purified protein had an apparent molecular mass of 73 kilodaltons when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and an apparent mass of 150 kilodaltons as determined by nondissociative gel chromatography, suggesting that the purified protein is a homodimer. The purified protein had isoelectric points of 5.0 under nondissociative conditions and 5.6 when exposed to protein denaturants, suggesting loss of bound anionic molecules and/or net exposure of basic residues upon denaturation. Chloroform/methanol extraction of the purified protein and subsequent analyses by thin layer and gas-liquid chromatography resulted in the identification of palmitic and stearic acids noncovalently bound to the protein. Approximately four molecules of fatty acids were bound per dimer with palmitic and stearic acids present in a one-to-one ratio. The purified protein did not bind exogenously added radioactive palmitate, indicating that the fatty acid-binding sites of the cognate protein were fully occupied and that the associated fatty acids were too tightly bound to exchange readily. The possible significance of the fatty acids associated with the 73 kilodalton stress cognate protein is discussed.

  5. Activation of Neuropeptide Y Receptors Modulates Retinal Ganglion Cell Physiology and Exerts Neuroprotective Actions In Vitro

    DEFF Research Database (Denmark)

    Martins, João; Elvas, Filipe; Brudzewsky, Dan

    2015-01-01

    Neuropeptide Y (NPY) is expressed in mammalian retina but the location and potential modulatory effects of NPY receptor activation remain largely unknown. Retinal ganglion cell (RGC) death is a hallmark of several retinal degenerative diseases, particularly glaucoma. Using purified RGCs and ex vivo...... receptor activation, at the level of inner or outer plexiform layers, leads to modulation of RGC receptive field properties. Using in vitro cultures of rat retinal explants exposed to NMDA, we found that NPY pretreatment prevented NMDA-induced cell death. However, in an animal model of retinal ischemia...... actions detected in retinal explants can be translated into animal models of retinal degenerative diseases....

  6. 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

    Branch retinal vein occlusion (BRVO) is the second most frequent retinal vascular disorder. Currently the first-line therapies for BRVO include anti-VEGF and dexamethasone implant treatment, however, with direct or indirect damage on retinal neurons, it has limited effect in improving patients visual acuity. Therefore, novel treatments with neuroprotective effect for BRVO retina were expected. Minocycline is a semisynthetic, broad spectrum tetracycline antibiotic with high penetration through the blood brain barrier. The neuroprotective effects of minocycline have been shown in various central nervous system (CNS) disease. Since both CNS and retina were composed of neurons and glials, it is reasonable to expect a neuroprotective effect by minocycline for BRVO retina. Therefore, the aim of the present study was to study whether minocycline has neuroprotective effect in branch retinal vein occlusion (BRVO) and the possible underlying molecular basis. We created BRVO in rats using laser photocoagulation. The animals were then randomly divided into 4 groups to evaluate the effect of minocycline: group A: minocycline 45 mg/kg intraperitoneal injection (i.p.), group B: minocycline 90 mg/kg i.p., group C: normal saline i.p., group D: sham injection. Fundus photography and fluorescein angiography (FA) were conducted. The changes in thickness of retinal layers were measured with optical coherence tomography (OCT) in vivo. We found that retinal edema occurred predominantly in the inner retinal layers. Intraperitoneal administration of minocycline significantly ameliorated retinal edema in the early stage of BRVO. We performed Full field Electroretinography (ffERG) to evaluate retinal function and found that the reduction of b wave amplitude decreased in the combined maximal response. The expressional levels of apoptosis related genes (Bax, Bcl-2) and inflammation related genes (IL-1 β, TNF α, MCP-1 and CCR2) were measured by real-time PCR, the results showed that

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

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    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.

  8. PROPERTIES OF PROLIFERATION AND DIFFERENTIATION OF NEONATAL RAT RETINAL PROGENITOR CELLS IN VITRO

    Institute of Scientific and Technical Information of China (English)

    Kang Qianyan; Liu Yong; Zhao Jianjun; Qiu Fen; Chen Xinlin; Tian Yumei; Hu Ming

    2006-01-01

    Objective To investigate the properties of proliferation and differentiation of neonatal rat retinal progenitor cells (RPCs) in vitro. Methods RPCs were isolated from neonatal SD rats neural retina and cultured in DMEM/F12+N2 with EGF and bFGF (suspension medium )or 10%FBS without EGF and bFGF (differentiation medium). The cells grew as suspended spheres or adherent monolayers, depending on different culture conditions. The neural stem cells or retinal progenitors, neurons, astrocytes, retinal ganglion cells, rod photoreceptors and the proliferating cells were evaluated with immunofluorescence analysis by Nestin or Pax6, Map2, GFAP, Thy-1, Rhodopsin and BrdU antibodies respectively. Results RPCs could propagate and differentiate in suspension or differentiation medium and express the markers of Nestin (92.86%) or Pax6 (86.75%), Map2 (38.54%), GFAP (20.93%), Thy-1 (27.66%) and Rhodopsin(13.33%)in suspension medium; however, Nestin (60.27%), Pax6 (52%), Map2 (34.94%), GFAP (38.17%), Thy-1(30.84%) and Rhodopsin (34.67%) in differentiation medium. 96.4% of the population in the neurospheres was BrdU-positive cells. The cells could spontaneously adherent forming some subspheres and retinal specific cell types. Conclusion Neonatal rat RPCs possess the high degree of proliferation and can differentiate into neurons, astrocytes, retinal ganglion cells and rod photoreceptors in vitro. There are different proportions for RPCs to differentiate into specific cell types.

  9. Caspase-dependent retinal ganglion cell apoptosis in the rat model of acute diabetes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background Neural apoptosis is generally believed to be mediated by two distinct pathways, caspase-dependant and caspase-independent pathways. This study investigated the apoptotic pathways involved in retinal ganglion ceils in acute diabetes in rats. Methods Diabetes was induced in male Wistar rats by a peritoneal injection of streptozotocin (STZ). Expression and localization of caspase-3 and apoptosis-inducing factor (AIF) proteins in the retina of diabetic rats was examined by Western blotting and immunohistochemistry analyses. Terminal transferase dUTP nick end labeling (TUNEL) assay and immunofluorescent staining specific for caspase-3 and AIF were applied to analyze for apoptosis of retinal ganglion cells. In addition, a caspase-3 inhibitor DEVD-CHO was injected intravitreally to further determine the apoptotic pathways of retinal ganglion cells triggered in acute diabetes. Results Two weeks after induction of diabetes, a significant increase in caspase-3 protein expression and localization occurred in the nerve fiber layer, ganglion cell layer, and inner plexiform layer of the retina. Four weeks after the onset of diabetes, the increase in caspase-3 expression was profound eight weeks postinduction of diabetes (P<0.05). Meanwhile, no AIF protein expression was detected in this study. In addition, intravitreal administration of the caspase-3 inhibitor DEVD-CHO reduced apoptosis of retinal ganglion cells by its direct inhibitory action on caspase-3. Conclusion Caspase-dependent apoptotic pathways may be the main stimulant of STZ-induced retinal ganglion cell apoptosis in acute diabetes.

  10. Effects of intravitreal injection of netrin-1 in retinal neovascularization of streptozotocin-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Yu Y

    2015-12-01

    Full Text Available Yao Yu,1,2,* Jing Zou,3,* Yun Han,4 Luowa Quyang,4 Hui He,4 Peihong Hu,2 Yi Shao,2 Ping Tu11Nanchang Key Laboratory of Diabetes, Department of Endocrinology and Metabolism, The Third Hospital of Nanchang, Jiangxi, People’s Republic of China; 2Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, Jiangxi, People’s Republic of China; 3Department of Ophthalmology, Xiangya Hospital, Central South University, Hunan, People’s Republic of China; 4Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute of Xiamen University, Fujian, People’s Republic of China*These authors have contributed equally to this workBackground: In a previous study, we confirmed that netrin-1 acts as an antiangiogenic factor by inhibiting alkali burn-induced corneal neovascularization in rats. Here, we continue working on the role of netrin-1 in retinal neovascularization.Methods: Using an in vitro angiogenesis assay, we detected the effects of netrin-1 on human umbilical vein endothelial cell tube formation, viability and proliferation, migration, and invasion at concentrations of 0.1 µg/mL or 5 µg/mL. We intravitreally injected 0.1 µg/mL or 5 µg/mL netrin-1 into streptozotocin-induced rats to assess retinal neovascularization using retinal electrophysiology and electroretinography, enzyme-linked immunosorbent assay, fundus fluoresce in angiography, measurement of inner blood retinal barrier, retinal hematoxylin-eosin staining, and retinal flat-mount fluorescence assays.Results: Human umbilical vein endothelial cell tube formation, viability and proliferation, migration, and invasion were upregulated by netrin-1 at a concentration of 0.1 µg/mL (P<0.05, while 5 µg/mL netrin-1 had an opposite effect (P<0.05 in our in vitro angiogenesis assay. Retinal electrophysiology testing revealed that intravitreal injection of netrin-1 affected the amplitude of a- and b

  11. Protective effects of human iPS-derived retinal pigment epithelium cell transplantation in the retinal dystrophic rat.

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    Amanda-Jayne Carr

    Full Text Available Transformation of somatic cells with a set of embryonic transcription factors produces cells with the pluripotent properties of embryonic stem cells (ESCs. These induced pluripotent stem (iPS cells have the potential to differentiate into any cell type, making them a potential source from which to produce cells as a therapeutic platform for the treatment of a wide range of diseases. In many forms of human retinal disease, including age-related macular degeneration (AMD, the underlying pathogenesis resides within the support cells of the retina, the retinal pigment epithelium (RPE. As a monolayer of cells critical to photoreceptor function and survival, the RPE is an ideally accessible target for cellular therapy. Here we report the differentiation of human iPS cells into RPE. We found that differentiated iPS-RPE cells were morphologically similar to, and expressed numerous markers of developing and mature RPE cells. iPS-RPE are capable of phagocytosing photoreceptor material, in vitro and in vivo following transplantation into the Royal College of Surgeons (RCS dystrophic rat. Our results demonstrate that iPS cells can be differentiated into functional iPS-RPE and that transplantation of these cells can facilitate the short-term maintenance of photoreceptors through phagocytosis of photoreceptor outer segments. Long-term visual function is maintained in this model of retinal disease even though the xenografted cells are eventually lost, suggesting a secondary protective host cellular response. These findings have identified an alternative source of replacement tissue for use in human retinal cellular therapies, and provide a new in vitro cellular model system in which to study RPE diseases affecting human patients.

  12. 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.

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

    Science.gov (United States)

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

    2016-06-01

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

  14. A method for the isolation and culture of adult rat retinal pigment epithelial (RPE cells to study retinal diseases

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    Janosch Peter Heller

    2015-11-01

    Full Text Available Diseases such as age-related macular degeneration (AMD affect the retinal pigment epithelium (RPE and lead to the death of the epithelial cells and ultimately blindness. RPE transplantation is currently a major focus of eye research and clinical trials using human stem cell-derived RPE cells are ongoing. However, it remains to be established to which extent the source of RPE cells for transplantation affects their therapeutic efficacy and this needs to be explored in animal models. Autotransplantation of RPE cells has attractions as a therapy, but existing protocols to isolate adult RPE cells from rodents are technically difficult, time-consuming, have a low yield and are not optimized for long-term cell culturing. Here, we report a newly devised protocol which facilitates reliable and simple isolation and culture of RPE cells from adult rats. Incubation of a whole rat eyeball in 20 U/ml papain solution for 50 minutes yielded 4 x 104 viable RPE cells. These cells were hexagonal and pigmented upon culture. Using immunostaining, we demonstrated that the cells expressed RPE cell-specific marker proteins including cytokeratin 18 and RPE65, similar to RPE cells in vivo. Additionally, the cells were able to produce and secrete Bruch’s membrane matrix components similar to in vivo situation. Similarly, the cultured RPE cells adhered to isolated Bruch’s membrane as has previously been reported. Therefore, the protocol described in this article provides an efficient method for the rapid and easy isolation of high quantities of adult rat RPE cells. This provides a reliable platform for studying the therapeutic targets, testing the effects of drugs in a preclinical setup and to perform in vitro and in vivo transplantation experiments to study retinal diseases.

  15. A rat retinal damage model predicts for potential clinical visual disturbances induced by Hsp90 inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Dan, E-mail: DZhou@syntapharma.com [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Liu, Yuan; Ye, Josephine; Ying, Weiwen; Ogawa, Luisa Shin; Inoue, Takayo; Tatsuta, Noriaki; Wada, Yumiko; Koya, Keizo [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States); Huang, Qin [Department of Pathology and Laboratory Medicine, Veterans Affairs Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132 (United States); Bates, Richard C.; Sonderfan, Andrew J. [Synta Pharmaceuticals Corp., 45 Hartwell Avenue, Lexington, MA 02421 (United States)

    2013-12-01

    In human trials certain heat shock protein 90 (Hsp90) inhibitors, including 17-DMAG and NVP-AUY922, have caused visual disorders indicative of retinal dysfunction; others such as 17-AAG and ganetespib have not. To understand these safety profile differences we evaluated histopathological changes and exposure profiles of four Hsp90 inhibitors, with or without clinical reports of adverse ocular effects, using a rat retinal model. Retinal morphology, Hsp70 expression (a surrogate marker of Hsp90 inhibition), apoptotic induction and pharmacokinetic drug exposure analysis were examined in rats treated with the ansamycins 17-DMAG and 17-AAG, or with the second-generation compounds NVP-AUY922 and ganetespib. Both 17-DMAG and NVP-AUY922 induced strong yet restricted retinal Hsp70 up-regulation and promoted marked photoreceptor cell death 24 h after the final dose. In contrast, neither 17-AAG nor ganetespib elicited photoreceptor injury. When the relationship between drug distribution and photoreceptor degeneration was examined, 17-DMAG and NVP-AUY922 showed substantial retinal accumulation, with high retina/plasma (R/P) ratios and slow elimination rates, such that 51% of 17-DMAG and 65% of NVP-AUY922 present at 30 min post-injection were retained in the retina 6 h post-dose. For 17-AAG and ganetespib, retinal elimination was rapid (90% and 70% of drugs eliminated from the retina at 6 h, respectively) which correlated with lower R/P ratios. These findings indicate that prolonged inhibition of Hsp90 activity in the eye results in photoreceptor cell death. Moreover, the results suggest that the retina/plasma exposure ratio and retinal elimination rate profiles of Hsp90 inhibitors, irrespective of their chemical class, may predict for ocular toxicity potential. - Highlights: • In human trials some Hsp90 inhibitors cause visual disorders, others do not. • Prolonged inhibition of Hsp90 in the rat eye results in photoreceptor cell death. • Retina/plasma ratio and retinal

  16. Regulation of retinal proteome by topical antiglaucomatous eye drops in an inherited glaucoma rat model.

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    Maurice Schallenberg

    Full Text Available Examination of the response of the retinal proteome to elevated intraocular pressure (IOP and to the pharmacological normalization of IOP is crucial, in order to develop drugs with neuroptorective potential. We used a hereditary rat model of ocular hypertension to lower IOP with travaprost and dorzolamide applied topically on the eye surface, and examine changes of the retinal proteome. Our data demonstrate that elevated IOP causes alterations in the retinal protein profile, in particular in high-mobility-group-protein B1 (HMGB1, calmodulin, heat-shock-protein (HSP 70 and carbonic anhydrase II expression. The changes of the retinal proteome by dorzolamide or travoprost are different and independent of the IOP lowering effect. This fact suggests that the eye drops exert a direct IOP-independent effect on retinal metabolism. Further investigations are required to elucidate the potential neuroprotective mechanisms signaled through changes of HMGB1, calmodulin, HSP70 and carbonic anhydrase II expression in glaucoma. The data may facilitate development of eye drops that exert neuroprotection through direct pharmacological effect.

  17. 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

  18. Measurement of retinal blood flow in the rat by combining Doppler Fourier-domain optical coherence tomography with fundus imaging

    Science.gov (United States)

    Werkmeister, René M.; Vietauer, Martin; Knopf, Corinna; Fürnsinn, Clemens; Leitgeb, Rainer A.; Reitsamer, Herbert; Gröschl, Martin; Garhöfer, Gerhard; Vilser, Walthard; Schmetterer, Leopold

    2014-10-01

    A wide variety of ocular diseases are associated with abnormalities in ocular circulation. As such, there is considerable interest in techniques for quantifying retinal blood flow, among which Doppler optical coherence tomography (OCT) may be the most promising. We present an approach to measure retinal blood flow in the rat using a new optical system that combines the measurement of blood flow velocities via Doppler Fourier-domain optical coherence tomography and the measurement of vessel diameters using a fundus camera-based technique. Relying on fundus images for extraction of retinal vessel diameters instead of OCT images improves the reliability of the technique. The system was operated with an 841-nm superluminescent diode and a charge-coupled device camera that could be operated at a line rate of 20 kHz. We show that the system is capable of quantifying the response of 100% oxygen breathing on the retinal blood flow. In six rats, we observed a decrease in retinal vessel diameters of 13.2% and a decrease in retinal blood velocity of 42.6%, leading to a decrease in retinal blood flow of 56.7%. Furthermore, in four rats, the response of retinal blood flow during stimulation with diffuse flicker light was assessed. Retinal vessel diameter and blood velocity increased by 3.4% and 28.1%, respectively, leading to a relative increase in blood flow of 36.2%;. The presented technique shows much promise to quantify early changes in retinal blood flow during provocation with various stimuli in rodent models of ocular diseases in rats.

  19. Epiretinal transplantation of human bone marrow mesenchymal stem cells rescues retinal and vision function in a rat model of retinal degeneration

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    Adi Tzameret

    2015-09-01

    Our findings suggest that transplantation of hBM-MSCs as a thin epiretinal layer is effective for treatment of retinal degeneration in RCS rats, and that transplanting the cells in close proximity to the retina enhances hBM-MSC therapeutic effect compared with intravitreal injection.

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

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    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.

  1. Effects of Combined Ketamine/Xylazine Anesthesia on Light Induced Retinal Degeneration in Rats

    Science.gov (United States)

    Bolz, Sylvia; Eslava-Schmalbach, Javier; Willmann, Gabriel; Zhour, Ahmad; Zrenner, Eberhart; Fischer, M. Dominik; Gekeler, Florian

    2012-01-01

    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. PMID:22558200

  2. Chemical stimulation of rat retinal neurons: feasibility of an epiretinal neurotransmitter-based prosthesis

    Science.gov (United States)

    Inayat, Samsoon; Rountree, Corey M.; Troy, John B.; Saggere, Laxman

    2015-02-01

    Objective. No cure currently exists for photoreceptor degenerative diseases, which cause partial or total blindness in millions of people worldwide. Electrical retinal prostheses have been developed by several groups with the goal of restoring vision lost to these diseases, but electrical stimulation has limitations. It excites both somas and axons, activating retinal pathways nonphysiologically, and limits spatial resolution because of current spread. Chemical stimulation of retinal ganglion cells (RGCs) using the neurotransmitter glutamate has been suggested as an alternative to electrical stimulation with some significant advantages. However, sufficient scientific data to support developing a chemical-based retinal prosthesis is lacking. The goal of this study was to investigate the feasibility of a neurotransmitter-based retinal prosthesis and determine therapeutic stimulation parameters. Approach. We injected controlled amounts of glutamate into rat retinas from the epiretinal side ex vivo via micropipettes using a pressure injection system and recorded RGC responses with a multielectrode array. Responsive units were identified using a spike rate threshold of 3 Hz. Main results. We recorded both somal and axonal units and demonstrated successful glutamatergic stimulation across different RGC subtypes. Analyses show that exogenous glutamate acts on RGC synapses similar to endogenous glutamate and, unlike electrical prostheses, stimulates only RGC somata. The spatial spread of glutamate stimulation was ˜ 290 μm from the injection site, comparable to current electrical prostheses. Further, the glutamate injections produced spatially differential responses in OFF, ON, and ON-OFF RGC subtypes, suggesting that differential stimulation of the OFF and ON systems may be possible. A temporal resolution of 3.2 Hz was obtained, which is a rate suitable for spatial vision. Significance. We provide strong support for the feasibility of an epiretinal neurotransmitter

  3. Astaxanthin Inhibits Expression of Retinal Oxidative Stress and Inflammatory Mediators in Streptozotocin-Induced Diabetic Rats.

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    Po-Ting Yeh

    Full Text Available We evaluated whether orally administered astaxanthin (AST protects against oxidative damage in the ocular tissues of streptozotocin (STZ-induced diabetic rats.Fifty 6-week-old female Wistar rats were randomly assigned to receive an injection of STZ to induce diabetes (n = 40 or to remain uninduced (n = 10. The diabetic rats were randomly selected into four groups and they were separately administered normal saline, 0.6 mg/kg AST, 3 mg/kg AST, or 0.5 mg/kg lutein daily for eight weeks. Retinal functions of each group were evaluated by electroretinography. The expression of oxidative stress and inflammatory mediators in the ocular tissues was then assessed by immunohistochemistry, western blot analysis, ELISA, RT-PCR, and electrophoretic mobility shift assay (EMSA. Retinal functions were preserved by AST and lutein in different levels. Ocular tissues from AST- and lutein-treated rats had significantly reduced levels of oxidative stress mediators (8-hydroxy-2'-deoxyguanosine, nitrotyrosine, and acrolein and inflammatory mediators (intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and fractalkine, increased levels of antioxidant enzymes (heme oxygenase-1 and peroxiredoxin, and reduced activity of the transcription factor nuclear factor-kappaB (NF-κB.The xanthophyll carotenoids AST and lutein have neuroprotective effects and reduce ocular oxidative stress, and inflammation in the STZ diabetic rat model, which may be mediated by downregulation of NF-κB activity.

  4. In Vivo CRISPR/Cas9 Gene Editing Corrects Retinal Dystrophy in the S334ter-3 Rat Model of Autosomal Dominant Retinitis Pigmentosa.

    Science.gov (United States)

    Bakondi, Benjamin; Lv, Wenjian; Lu, Bin; Jones, Melissa K; Tsai, Yuchun; Kim, Kevin J; Levy, Rachelle; Akhtar, Aslam Abbasi; Breunig, Joshua J; Svendsen, Clive N; Wang, Shaomei

    2016-03-01

    Reliable genome editing via Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas9 may provide a means to correct inherited diseases in patients. As proof of principle, we show that CRISPR/Cas9 can be used in vivo to selectively ablate the rhodopsin gene carrying the dominant S334ter mutation (Rho(S334)) in rats that model severe autosomal dominant retinitis pigmentosa. A single subretinal injection of guide RNA/Cas9 plasmid in combination with electroporation generated allele-specific disruption of Rho(S334), which prevented retinal degeneration and improved visual function.

  5. Lycium barbarum polysaccharides promotes in vivo proliferation of adult rat retinal progenitor cells

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    Hua Wang

    2015-01-01

    Full Text Available Lycium barbarum is a widely used Chinese herbal medicine prescription for protection of optic nerve. However, it remains unclear regarding the effects of Lycium barbarum polysaccharides, the main component of Lycium barbarum, on in vivo proliferation of adult ciliary body cells. In this study, adult rats were intragastrically administered low- and high-dose Lycium barbarum polysaccharides (1 and 10 mg/kg for 35 days and those intragastrically administered phosphate buffered saline served as controls. The number of Ki-67-positive cells in rat ciliary body in the Lycium barbarum polysaccharides groups, in particular low-dose Lycium barbarum polysaccharides group, was significantly greater than that in the phosphate buffered saline group. Ki-67-positive rat ciliary body cells expressed nestin but they did not express glial fibrillary acidic protein. These findings suggest that Lycium barbarum polysaccharides can promote the proliferation of adult rat retinal progenitor cells and the proliferated cells present with neuronal phenotype.

  6. Effects of an acidic phospholipase A2 purified from Ophiophagus hannah (king cobra) venom on rat heart.

    Science.gov (United States)

    Huang, M Z; Wang, Q C; Liu, G F

    1993-05-01

    An acidic phospholipase A2 (OHV A-PLA2) purified from Ophiophagus hannah venom had a cardiotoxic action on rat heart. In rats OHV A-PLA2 (2-4 mg/kg) caused ECG abnormalities including decreased heart rate, prolonged P-R interval, widened QRS complex and complete A-V block. When tested on isolated rat right atria, OHV A-PLA2 (10-20 micrograms/ml) produced a positive chronotropic effect. When tested on isolated rat left atria or papillary muscle preparations, OHV A-PLA2 (2.5-20 micrograms/ml) caused positive inotropic effect, followed by contracture. The positive inotropic effects could be abolished by high Ca2+ and enhanced by low Ca2+; both treatments accelerated contracture. The contracture could be inhibited in Mn2+ (5 mM)-containing medium and abolished by Ca(2+)-free bath solution containing 1 mM EDTA. The cardiotoxic action of OHV A-PLA2 was not influenced by verapamil, tetrodotoxin, propranolol, phentolamine, atropine or indomethacin. It is suggested that the cardiotoxic effects of OHV A-PLA2 may result from increasing intracellular levels of Ca2+.

  7. Long-term Characterization of Retinal Degeneration in Royal College of Surgeons Rats Using Spectral-Domain Optical Coherence Tomography

    Science.gov (United States)

    Ryals, Renee C.; Andrews, Michael D.; Datta, Shreya; Coyner, Aaron S.; Fischer, Cody M.; Wen, Yuquan; Pennesi, Mark E.; McGill, Trevor J.

    2017-01-01

    Purpose Prospective treatments for age-related macular degeneration and inherited retinal degenerations are commonly evaluated in the Royal College of Surgeons (RCS) rat before translation into clinical application. Historically, retinal thickness obtained through postmortem anatomic assessments has been a key outcome measure; however, utility of this measurement is limited because it precludes the ability to perform longitudinal studies. To overcome this limitation, the present study was designed to provide a baseline longitudinal quantification of retinal thickness in the RCS rat by using spectral-domain optical coherence tomography (SD-OCT). Methods Horizontal and vertical linear SD-OCT scans centered on the optic nerve were captured from Long-Evans control rats at P30, P60, P90 and from RCS rats between P17 and P90. Total retina (TR), outer nuclear layer+ (ONL+), inner nuclear layer (INL), and retinal pigment epithelium (RPE) thicknesses were quantified. Histologic sections of RCS retina obtained from P21 to P60 were compared to SD-OCT images. Results In RCS rats, TR and ONL+ thickness decreased significantly as compared to Long-Evans controls. Changes in INL and RPE thickness were not significantly different between control and RCS retinas. From P30 to P90 a subretinal hyperreflective layer (HRL) was observed and quantified in RCS rats. After correlation with histology, the HRL was identified as disorganized outer segments and the location of accumulated debris. Conclusions Retinal layer thickness can be quantified longitudinally throughout the course of retinal degeneration in the RCS rat by using SD-OCT. Thickness measurements obtained with SD-OCT were consistent with previous anatomic thickness assessments. This study provides baseline data for future longitudinal assessment of therapeutic agents in the RCS rat. PMID:28253400

  8. Application of Two-Dimensional Electrophoresis in the Research of Retinal Proteins of Diabetic Rat

    Institute of Scientific and Technical Information of China (English)

    Shangqing Liu; Yanyan Zhang; Xianyong Xie; Weiming Hu; Rong Cai; Jian Kang; Huijun Yang

    2007-01-01

    Diabetes mellitus (DM) is a chronic disease which is associated with numerous serious health complications such as diabetic retinopathy, and is the leading cause of new cases of blindness in adults at the age of 20-74 years old. The aim of the study was to establish and optimize a two-dimensional polyacrylamide gel electrophoresis (2-DE) technique for retina proteomics to improve the resolution and reproducibility, and to observe the proteomic changes of retinal tissues in diabetic and normal rats. Proteins were extracted from retinal tissues of normal and 8 weeks diabetic SD rats and used in two-dimensional electrophoresis. Various conditions of retina proteomic 2-DE were adjusted, optimized and protein spots of differential expression were obtained through analysis of 2-DE images with PDQuest software. By choosing appropriate sample amount, using pre-cast IPG dry strips (pH 5-8)and casting 12% equal gel, satisfactory 2-DE images of retina were obtained and a steady 2-DE technique was established. In this way, we found 36 spots in 2-DE gel of diabetic retinas that exhibited statistically significant variations, including up-regulation of 5 proteins in diabetic rat retinas, down-regulation of 23, and disappearance of 8, in comparison with normal tissues. The differences of protein expression were observed in retinas between diabetic and normal rats. Our established 2-DE technique of retina proteins could be effectively applied in proteomics of retina diseases.

  9. [Role of a purified Sertoli cell protein (CMB-21) in the biosynthesis of Leydig cell testosterone in the immature rat].

    Science.gov (United States)

    Boujrad, N; Papadopoulos, V; Drosdowsky, M A; Carreau, S

    1989-09-01

    The existence of Sertoli cell factors which modulate the rat Leydig cell function prompted us to study the biological activity of selected proteins called CMB proteins and produced by immature rat Sertoli cells. Percoll purified Leydig cells (10(5)) from 20 days-old rats have been incubated 5 h at 32 degrees C in 1 ml Ham F12/DME medium with increasing concentrations of partially purified CMB proteins (0-1,000 ng/ml) either in presence or absence of oLH (25 ng/ml). Among the CMB proteins tested, only CMB-21 produces a dose related increase of testosterone production: from 2 to 500 pg/ml of CMB-21, testosterone output is unchanged (51 pg/10(5) cells) but 1 to 1,000 ng/ml of this protein produces a linear increase of testosterone productions (86 to 870 pg). In the presence of oLH which induces a 10-fold increase of testosterone production (499 pg), increasing doses of CMB-21 further stimulate testosterone output (775 to 2.272 pg/10(5) cells). Whatever the concentration of oLH used (0 to 50 ng/ml), CMB-21 (500 ng/ml) leads to a further 2 fold augmentation of testosterone synthesis; similarly, in the presence of dbcAMP (1 mM), CMB 21 increases the testosterone production but no effect is observed when Leydig cells are incubated in the presence of 22R-hydroxycholesterol (30 microM). The cAMP levels which are increased more than 4 fold by oLH, remain unchanged in the presence of CMB-21 either alone or with oLH, as observed when Sertoli cell culture medium is used.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Endothelin B receptors contribute to retinal ganglion cell loss in a rat model of glaucoma.

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    Alena Z Minton

    Full Text Available Glaucoma is an optic neuropathy, commonly associated with elevated intraocular pressure (IOP characterized by optic nerve degeneration, cupping of the optic disc, and loss of retinal ganglion cells which could lead to loss of vision. Endothelin-1 (ET-1 is a 21-amino acid vasoactive peptide that plays a key role in the pathogenesis of glaucoma; however, the receptors mediating these effects have not been defined. In the current study, endothelin B (ET(B receptor expression was assessed in vivo, in the Morrison's ocular hypertension model of glaucoma in rats. Elevation of IOP in Brown Norway rats produced increased expression of ET(B receptors in the retina, mainly in retinal ganglion cells (RGCs, nerve fiber layer (NFL, and also in the inner plexiform layer (IPL and inner nuclear layer (INL. To determine the role of ET(B receptors in neurodegeneration, Wistar-Kyoto wild type (WT and ET(B receptor-deficient (KO rats were subjected to retrograde labeling with Fluoro-Gold (FG, following which IOP was elevated in one eye while the contralateral eye served as control. IOP elevation for 4 weeks in WT rats caused an appreciable loss of RGCs, which was significantly attenuated in KO rats. In addition, degenerative changes in the optic nerve were greatly reduced in KO rats compared to those in WT rats. Taken together, elevated intraocular pressure mediated increase in ET(B receptor expression and its activation may contribute to a decrease in RGC survival as seen in glaucoma. These findings raise the possibility of using endothelin receptor antagonists as neuroprotective agents for the treatment of glaucoma.

  11. Functional ectopic neuritogenesis by retinal rod bipolar cells is regulated by miR-125b-5p during retinal remodeling in RCS rats.

    Science.gov (United States)

    Fu, Yan; Hou, Baoke; Weng, Chuanhuang; Liu, Weiping; Dai, Jiaman; Zhao, Congjian; Yin, Zheng Qin

    2017-04-21

    Following retinal degeneration, retinal remodeling can cause neuronal microcircuits to undergo structural alterations, which particularly affect the dendrites of bipolar cells. However, the mechanisms and functional consequences of such changes remain unclear. Here, we used Royal College of Surgeon (RCS) rats as a model of retinal degeneration, to study structural changes in rod bipolar cells (RBCs) and the underlying mechanisms of these changes. We found that, with retinal degeneration, RBC dendrites extended into the outer nuclear layer (ONL) of the retina, and the ectopic dendrites formed synapses with the remaining photoreceptors. This ectopic neuritogenesis was associated with brain-derived neurotrophic factor (BDNF) - expression of which was negatively regulated by miR-125b-5p. Overexpression of miR-125b-5p in the retinae of RCS rats diminished RBC ectopic dendrites, and compromised the b-wave of the flash electroretinogram (ERG). In contrast, down-regulation of miR-125b-5p (or exogenous BDNF treatment) increased RBC ectopic dendrites, and improved b-wave. Furthermore, we showed that the regulation of ectopic neuritogenesis by BDNF occurred via the downstream modulation of the TrkB-CREB signaling pathway. Based on these findings, we conclude that ectopic dendrites are likely to be providing functional benefits and that, in RCS rats, miR-125b-5p regulates ectopic neuritogenesis by RBCs through modulation of the BDNF-TrkB-CREB pathway. This suggests that therapies that reduce miR-125b-5p expression could be beneficial in human retinal degenerative disease.

  12. Evidence that beta-hydroxyacyl-CoA dehydrase purified from rat liver microsomes is of peroxisomal origin.

    Science.gov (United States)

    Cook, L; Nagi, M N; Suneja, S K; Hand, A R; Cinti, D L

    1992-01-01

    The present study provides strong evidence that the previously isolated hepatic microsomal beta-hydroxyacyl-CoA dehydrase (EC 4.2.1.17), believed to be a component of the fatty acid chain-elongation system, is derived, not from the endoplasmic reticulum, but rather from the peroxisomes. The isolated dehydrase was purified over 3000-fold and showed optimal enzymic activity toward beta-hydroxyacyl-CoAs or trans-2-enoyl-CoAs with carbon chain lengths of 8-10. The purified preparation (VDH) displayed a pH optimum at 7.5 with beta-hydroxydecanoyl-CoA, and at 6.0 with beta-hydroxystearoyl-CoA. Competitive-inhibition studies suggested that VDH contained dehydrase isoforms, and SDS/PAGE showed three major bands at 47, 71 and 78 kDa, all of which reacted to antibody raised to the purified preparation. Immunocytochemical studies with anti-rabbit IgG to VDH unequivocally demonstrated gold particles randomly distributed throughout the peroxisomal matrix of liver sections from both untreated and di-(2-ethylhexyl) phthalate-treated rats. No labelling was associated with endoplasmic reticulum or with the microsomal fraction. Substrate-specificity studies and the use of antibodies to VDH and to the peroxisomal trifunctional protein indicated that VDH and the latter are separate enzymes. On the other hand, the VDH possesses biochemical characteristics similar to those of the D-beta-hydroxyacyl-CoA dehydrase recently isolated from rat liver peroxisomes [Li, Smeland & Schulz (1990) J. Biol. Chem. 265, 13629-13634; Hiltunen, Palosaari & Kunau (1989) J. Biol. Chem. 264, 13536-13540]. Neither enzyme utilizes crotonoyl-CoA or cis-2-enoyl-CoA as substrates, but both enzymes convert trans-2-enoyl substrates into the D-isomer only. In addition, the VDH also contained beta-oxoacyl-CoA reductase (beta-hydroxyacyl-CoA dehydrogenase) activity, which co-purified with the dehydrase. Images Fig. 4. Fig. 7. Fig. 8. PMID:1417796

  13. Effects of 3,4-methylenedioxymethamphetamine administration on retinal physiology in the rat.

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    João Martins

    Full Text Available 3,4-Methylenedioxymethamphetamine (MDMA; ecstasy is known to produce euphoric states, but may also cause adverse consequences in humans, such as hyperthermia and neurocognitive deficits. Although MDMA consumption has been associated with visual problems, the effects of this recreational drug in retinal physiology have not been addressed hitherto. In this work, we evaluated the effect of a single MDMA administration in the rat electroretinogram (ERG. Wistar rats were administered MDMA (15 mg/kg or saline and ERGs were recorded before (Baseline ERG, and 3 h, 24 h, and 7 days after treatment. A high temperature (HT saline-treated control group was also included. Overall, significantly augmented and shorter latency ERG responses were found in MDMA and HT groups 3 h after treatment when compared to Baseline. Twenty-four hours after treatment some of the alterations found at 3 h, mainly characterized by shorter latency, tended to return to Baseline values. However, MDMA-treated animals still presented increased scotopic a-wave and b-wave amplitudes compared to Baseline ERGs, which were independent of temperature elevation though the latter might underlie the acute ERG alterations observed 3 h after MDMA administration. Seven days after MDMA administration recovery from these effects had occurred. The effects seem to stem from specific changes observed at the a-wave level, which indicates that MDMA affects subacutely (at 24 h retinal physiology at the outer retinal (photoreceptor/bipolar layers. In conclusion, we have found direct evidence that MDMA causes subacute enhancement of the outer retinal responses (most prominent in the a-wave, though ERG alterations resume within one week. These changes in photoreceptor/bipolar cell physiology may have implications for the understanding of the subacute visual manifestations induced by MDMA in humans.

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

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    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

  15. Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model.

    Science.gov (United States)

    Danias, John; Shen, Fran; Kavalarakis, Manolis; Chen, Bin; Goldblum, David; Lee, Kevin; Zamora, Maria-Florencia; Su, YanLing; Brodie, Scott E; Podos, Steven M; Mittag, Thom

    2006-02-01

    Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains. IOP was raised in one eye of Wistar (N = 5) and Brown-Norway(B-N)(N = 7) rats by EVC and monitored monthly until IOP in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats (N = 7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined. Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. The group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but 1 of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs than contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared to contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (> 30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones. The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP

  16. In vivo quantitative evaluation of the rat retinal nerve fiber layer with optical coherence tomography.

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    Nagata, Atsushi; Higashide, Tomomi; Ohkubo, Shinji; Takeda, Hisashi; Sugiyama, Kazuhisa

    2009-06-01

    To determine whether optical coherence tomography (OCT) is useful for quantitative evaluation of the thickness of the rat retinal nerve fiber layer (RNFL) in an optic nerve crush model. An OCT system was developed with a modified commercial time-domain OCT and a superluminescent diode with a bandwidth of 150 nm. Optical components were optimized to acquire rat retinal images. The right optic nerve was crushed intraorbitally with a clip. The left eye served as the untreated control. Circumpapillary OCT scans with a circle diameter of 500 microm centered on the optic disc were performed before and 1, 2, and 4 weeks after the crush. Repeatability and reproducibility of RNFL thickness measurements were evaluated. The RNFL thicknesses at 400, 500, and 600 microm from the center of the optic disc determined by linear vertical OCT scans were compared with thicknesses in retinal sections. The mean RNFL thicknesses in circumpapillary OCT scans were 27.9 +/- 1.8, 29.2 +/- 2.4, 19.9 +/- 2.3, and 4.5 +/- 3.6 microm before and 1, 2, and 4 weeks after the crush, respectively. RNFL thickness was unchanged 1 week after the crush, but then decreased significantly and progressively after the second week (P < 0.01). Coefficients of repeatability and reproducibility were less than 10% except for the crushed eyes at 4 weeks. RNFL thicknesses in OCT images correlated significantly with thicknesses determined histologically (r = 0.90, P < 0.001). OCT is a useful and valuable tool for quantitative evaluation of rat RNFL thickness.

  17. Epiretinal transplantation of human bone marrow mesenchymal stem cells rescues retinal and vision function in a rat model of retinal degeneration.

    Science.gov (United States)

    Tzameret, Adi; Sher, Ifat; Belkin, Michael; Treves, Avraham J; Meir, Amilia; Nagler, Arnon; Levkovitch-Verbin, Hani; Rotenstreich, Ygal; Solomon, Arieh S

    2015-09-01

    Vision incapacitation and blindness associated with incurable retinal degeneration affect millions of people worldwide. In this study, 0.25×10(6) human bone marrow stem cells (hBM-MSCs) were transplanted epiretinally in the right eye of Royal College Surgeons (RCS) rats at the age of 28 days. Epiretinally transplanted cells were identified as a thin layer of cells along vitreous cavity, in close proximity to the retina or attached to the lens capsule, up to 6 weeks following transplantation. Epiretinal transplantation delayed photoreceptor degeneration and rescued retinal function up to 20 weeks following cell transplantation. Visual functions remained close to normal levels in epiretinal transplantation rats. No inflammation or any other adverse effects were observed in transplanted eyes. Our findings suggest that transplantation of hBM-MSCs as a thin epiretinal layer is effective for treatment of retinal degeneration in RCS rats, and that transplanting the cells in close proximity to the retina enhances hBM-MSC therapeutic effect compared with intravitreal injection.

  18. Electrophysiological properties of rat retinal Müller (glial) cells in postnatally developing and in pathologically altered retinae.

    Science.gov (United States)

    Felmy, F; Pannicke, T; Richt, J A; Reichenbach, A; Guenther, E

    2001-05-01

    Retinal glial Müller cells are characterized by dominant K(+) conductances. The cells may undergo changes of their membrane currents during ontogeny and gliosis as described in rabbit and man. Although the rat retina is often used in physiological experiments, the electrophysiology of rat Müller cells is less well studied. The aim of the present study was to characterize their membrane currents in postnatal development and in two models of retinal degeneration. Freshly isolated cells were subjected to whole-cell patch clamp recordings. During the first 4 weeks after birth of rats, their Müller cells displayed an increase in all membrane currents, particularly in the inward currents elicited at hyperpolarizing potentials. The decrease of the membrane resistance from more than 760 MOmega to less than 50 MOmega was accompanied by a shift of the zero current potential from about -20 mV to -80 mV, similar as earlier observed in developing rabbit Müller cells. These developmental changes were found in pigmented Brown Norway rats as well as in rats with inherited retinal dystrophy (RCS rats). Moreover, an infection of Lewis rats with the Borna disease virus caused substantial neuroretinal degeneration but did not result in a strong reduction of inward currents and of the zero current potential of the Müller cells. Thus, rat Müller cells fail to change their basic membrane properties in two different models of retinal pathology. This is in contrast to human and rabbit Müller cells, which have been shown to undergo dramatic changes of their membrane physiology in response to retinal diseases and injuries.

  19. Effect of Chinese medicine Qidengmingmu capsule on the STZ induced hyperglycemia rat's blood-retinal barrier

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    Fu-Wen Zhang

    2013-06-01

    Full Text Available AIM: To observe retinal vessel leakage of streptozotocin(STZinduced diabetic rat, and the effect of traditional Chinese medicine on it. METHODS: We induced diabetic rat model by peritoneal injection of STZ, after the blood glucose raised, we used Evans blue to trace the leakage of blood-retina barrier(BRBevery month. After blood glucose rose three months later, we treated the Chinese medicine group diabetic rat with Qidengmingmu capsule. There were three groups of different dose, low dose group of 125mg/kg, middle dose group of 250mg/kg, high dose group of 500mg/kg. The control group was treated with calcium dobesilate(200mg/kg. After three months treated by medicine, the leakage of rat blood-retina barrier was evaluated. RESULTS: The damage of BRB and visual function occurred at two week after the blood glucose rose, and the damage aggravated with the continuing of high diabetic. But after the Chinese medicine treated three months, the rat's retina vessel leakage was reduced. CONCLUSION: BRB break down and visual acuity damage appears in early phase of STZ diabetic rat and get worse as the hyperglycemia keep on. The Chinese medicine Qidengmingmu capsule can prevent the vessel leakage by damage of BRB.

  20. 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

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    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.

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

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

    2015-01-01

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

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

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    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

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

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

    2013-01-01

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

  4. Postnatal visual deprivation in rats regulates several retinal genes and proteins, including differentiation-associated fibroblast growth factor-2.

    Science.gov (United States)

    Prokosch-Willing, Verena; Meyer zu Hoerste, Melissa; Mertsch, Sonja; Stupp, Tobias; Thanos, Solon

    2015-01-01

    Little is known about the retinal cellular basis of amblyopia, which is a developmental disease characterized by impaired visual acuity. This study examined the retinal transcripts associated with experimentally induced unilateral amblyopia in rats. Surgical tarsorrhaphy of the eyelids on one side was performed in pups prior to eye opening at postnatal day 14, thereby preventing any visual experience. This condition was maintained for over 2 months, after which electroretinograms (ERGs) were recorded, the retinal ganglion cell (RGC) arrangement and number were determined using neuroanatomical tracing, the retinal transcripts were studied using microarray analysis, regulated mRNAs were confirmed with quantitative reverse-transcriptase PCR, and proteins were stained using Western blotting and immunohistochemistry. An attenuated ERG was found in eyes that were deprived of visual experience. Retrograde neuroanatomical staining disclosed a larger number of RGCs within the retina on the visually deprived side compared to the non-deprived, control side, and a multilayered distribution of RGCs. At the retinomic level, several transcripts associated with retinal differentiation, such as fibroblast growth factor 2 (FGF-2), were either up- or downregulated. Most of the transcripts could be verified at the mRNA level. To unravel the role of a differentiation-associated protein, we tested FGF-2 in dissociated postnatal retinal cell cultures and found that FGF-2 is a potent factor triggering ganglion cell differentiation. The data suggest that visual experience shapes the postnatal retinal differentiation, whereas visual deprivation induces changes at the functional, cellular and molecular levels within the retina.

  5. In the Early Stages of Diabetes, Rat Retinal Mitochondria Undergo Mild Uncoupling due to UCP2 Activity

    Science.gov (United States)

    Osorio-Paz, Ixchel; Uribe-Carvajal, Salvador; Salceda, Rocío

    2015-01-01

    In order to maintain high transmembrane ionic gradients, retinal tissues require a large amount of energy probably provided by a high rate of both, glycolysis and oxidative phosphorylation. However, little information exists on retinal mitochondrial efficiency. We analyzed the retinal mitochondrial activity in ex vivo retinas and in isolated mitochondria from normal rat retina and from short-term streptozotocin-diabetic rats. In normal ex vivo retinas, increasing glucose concentrations from 5.6mM to 30mM caused a four-fold increase in glucose accumulation and CO2 production. Retina from diabetic rats accumulated similar amounts of glucose. However, CO2 production was not as high. Isolated mitochondria from normal rat retina exhibited a resting rate of oxygen consumption of 14.6 ± 1.1 natgO (min.mg prot)-1 and a respiratory control of 4.0. Mitochondria from 7, 20 and 45 days diabetic rats increased the resting rate of oxygen consumption and the activity of the electron transport complexes; under these conditions the mitochondrial transmembrane potential decreased. In spite of this, the ATP synthesis was not modified. GDP, an UCP2 inhibitor, increased mitochondrial membrane potential and superoxide production in controls and at 45 days of diabetes. The role of UCP2 is discussed. The results suggest that at the early stage of diabetes we studied, retinal mitochondria undergo adaptations leading to maintain energetic requirements and prevent oxidative stress. PMID:25951172

  6. In the Early Stages of Diabetes, Rat Retinal Mitochondria Undergo Mild Uncoupling due to UCP2 Activity.

    Science.gov (United States)

    Osorio-Paz, Ixchel; Uribe-Carvajal, Salvador; Salceda, Rocío

    2015-01-01

    In order to maintain high transmembrane ionic gradients, retinal tissues require a large amount of energy probably provided by a high rate of both, glycolysis and oxidative phosphorylation. However, little information exists on retinal mitochondrial efficiency. We analyzed the retinal mitochondrial activity in ex vivo retinas and in isolated mitochondria from normal rat retina and from short-term streptozotocin-diabetic rats. In normal ex vivo retinas, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO2 production. Retina from diabetic rats accumulated similar amounts of glucose. However, CO2 production was not as high. Isolated mitochondria from normal rat retina exhibited a resting rate of oxygen consumption of 14.6 ± 1.1 natgO (min.mg prot)(-1) and a respiratory control of 4.0. Mitochondria from 7, 20 and 45 days diabetic rats increased the resting rate of oxygen consumption and the activity of the electron transport complexes; under these conditions the mitochondrial transmembrane potential decreased. In spite of this, the ATP synthesis was not modified. GDP, an UCP2 inhibitor, increased mitochondrial membrane potential and superoxide production in controls and at 45 days of diabetes. The role of UCP2 is discussed. The results suggest that at the early stage of diabetes we studied, retinal mitochondria undergo adaptations leading to maintain energetic requirements and prevent oxidative stress.

  7. In the Early Stages of Diabetes, Rat Retinal Mitochondria Undergo Mild Uncoupling due to UCP2 Activity.

    Directory of Open Access Journals (Sweden)

    Ixchel Osorio-Paz

    Full Text Available In order to maintain high transmembrane ionic gradients, retinal tissues require a large amount of energy probably provided by a high rate of both, glycolysis and oxidative phosphorylation. However, little information exists on retinal mitochondrial efficiency. We analyzed the retinal mitochondrial activity in ex vivo retinas and in isolated mitochondria from normal rat retina and from short-term streptozotocin-diabetic rats. In normal ex vivo retinas, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO2 production. Retina from diabetic rats accumulated similar amounts of glucose. However, CO2 production was not as high. Isolated mitochondria from normal rat retina exhibited a resting rate of oxygen consumption of 14.6 ± 1.1 natgO (min.mg prot(-1 and a respiratory control of 4.0. Mitochondria from 7, 20 and 45 days diabetic rats increased the resting rate of oxygen consumption and the activity of the electron transport complexes; under these conditions the mitochondrial transmembrane potential decreased. In spite of this, the ATP synthesis was not modified. GDP, an UCP2 inhibitor, increased mitochondrial membrane potential and superoxide production in controls and at 45 days of diabetes. The role of UCP2 is discussed. The results suggest that at the early stage of diabetes we studied, retinal mitochondria undergo adaptations leading to maintain energetic requirements and prevent oxidative stress.

  8. Purifying Nanomaterials

    Science.gov (United States)

    Hung, Ching-Cheh (Inventor); Hurst, Janet (Inventor)

    2014-01-01

    A method of purifying a nanomaterial and the resultant purified nanomaterial in which a salt, such as ferric chloride, at or near its liquid phase temperature, is used to penetrate and wet the internal surfaces of a nanomaterial to dissolve impurities that may be present, for example, from processes used in the manufacture of the nanomaterial.

  9. Retrograde Labeling of Adult Rat Retinal Ganglion Cells with the Flurogold

    Institute of Scientific and Technical Information of China (English)

    Wei Huang; Yannian Hui; Miaoli Zhang

    2000-01-01

    Purpose: To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely.Methods: FG was injected to the superior colliculi(SC) and dorsal lateral geniculate nuclei (dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time.Results: FG-labelled RGC were observed in the retina as early as 3 days after application of FG. The labelled cells gradually increased in density, reached 95% of the maximal number on days 7 and the maximal number on days 30. The density of labelled cells was higher in the posterior pole than in the peripheral area. The fluorescence intensity in labelled cells maintained up to 60 days.Conclusion: The FG retrograde labeling method is reliable and effective for quantity of RGC. Eye Science 2000; 16:29 ~ 33.

  10. Retrograde Labeling of Adult Rat Retinal Ganglion Cells with the Flurogold

    Institute of Scientific and Technical Information of China (English)

    WeiHuang; YannianHui; 等

    2002-01-01

    Purpose:To study the densities and distribution of retinal ganglion cells(RGC) in adult rat retinae with flurogold(FG) labeling retogradely.Methods:FG was injected to the superior colliculid(SC) and dorsal lateral geniculate nuclei(dLGN) in adult rats and the retinae were examined by fluorescence microscopy at various periods of time.Results:FG-labelled RGC were observed in the retina as early as 3 days after application of FG.The labeled cells gradually increased in density,reached 95% of the maximal number on days 7 and the maximal nuber on days 30.The density of labeled cells was higher in the posterior pole than in the peripheral area.The fluorescence intensity in labeled cells maintained up to 60 days.Conclusion:The FG retrograde labeling method is reliable and effective for quantity of RGC.Eye Science 2000;46:29-33.

  11. Zinc deficiency leads to lipofuscin accumulation in the retinal pigment epithelium of pigmented rats.

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    Sylvie Julien

    Full Text Available BACKGROUND: Age-related macular degeneration (AMD is associated with lipofuscin accumulation whereas the content of melanosomes decreases. Melanosomes are the main storage of zinc in the pigmented tissues. Since the elderly population, as the most affected group for AMD, is prone to zinc deficit, we investigated the chemical and ultrastructural effects of zinc deficiency in pigmented rat eyes after a six-month zinc penury diet. METHODOLOGY/PRINCIPAL FINDINGS: Adult Long Evans (LE rats were investigated. The control animals were fed with a normal alimentation whereas the zinc-deficiency rats (ZD-LE were fed with a zinc deficient diet for six months. Quantitative Energy Dispersive X-ray (EDX microanalysis yielded the zinc mole fractions of melanosomes in the retinal pigment epithelium (RPE. The lateral resolution of the analysis was 100 nm. The zinc mole fractions of melanosomes were significantly smaller in the RPE of ZD-LE rats as compared to the LE control rats. Light, fluorescence and electron microscopy, as well as immunohistochemistry were performed. The numbers of lipofuscin granules in the RPE and of infiltrated cells (Ø>3 µm found in the choroid were quantified. The number of lipofuscin granules significantly increased in ZD-LE as compared to control rats. Infiltrated cells bigger than 3 µm were only detected in the choroid of ZD-LE animals. Moreover, the thickness of the Bruch's membrane of ZD-LE rats varied between 0.4-3 µm and thin, rangy ED1 positive macrophages were found attached at these sites of Bruch's membrane or even inside it. CONCLUSIONS/SIGNIFICANCE: In pigmented rats, zinc deficiency yielded an accumulation of lipofuscin in the RPE and of large pigmented macrophages in the choroids as well as the appearance of thin, rangy macrophages at Bruch's membrane. Moreover, we showed that a zinc diet reduced the zinc mole fraction of melanosomes in the RPE and modulated the thickness of the Bruch's membrane.

  12. Increased vascular density and vitreo-retinal membranes accompany vascularization of the pigment epithelium in the dystrophic rat retina.

    Science.gov (United States)

    Caldwell, R B; Roque, R S; Solomon, S W

    1989-09-01

    Observations of vascularization of the retinal pigment epithelium (RPE) and formation of vitreo-retinal membranes (VRMs) in Royal College of Surgeons (RCS) rats with inherited retinal dystrophy suggest that vascular proliferation occurs in this model. To test this hypothesis, we studied the progression of vascular changes in RCS and age-matched control rats using quantitative light microscope morphometry and electron microscopy. At 2 weeks, prior to photoreceptor degeneration, the dystrophic retina is comparable with the control. By 2 months, extensive degeneration of photoreceptor cells results in significant thinning of the dystrophic retina as compared with the control. Signs of vascular degeneration are evident at the electron microscope level--"ghost" vessels consisting of acellular basal lamina surrounded by amorphous electron-dense material; degenerating endothelial cells and pericytes; and abnormal deposits of extracellular matrix (ECM) material around blood vessels. Vascular degeneration is accompanied by glial changes in the form of necrotic perivascular glial processes and abnormal ECM deposits among the altered Muller cell processes. At 2-4 months in the dystrophic retina, numbers of vessel profiles in dystrophic retinas are decreased as compared with controls. However, vascular degeneration is overshadowed by the formation of numerous capillary tufts within the RPE layer, which together with retinal thinning results in increased vessel density. Between 4-12 months, the retinal thickness diminishes further, vascularization of the RPE increases, vitreo-retinal membranes are formed, and vascular density increases. In summary, following an initial period of vascular degeneration, vascularization of the RPE is accompanied by an increase in retinal vessel density and by the formation of vitreo-retinal membranes.

  13. 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.

  14. Recognition of mannose 6-phosphate ligands by dystrophic rat retinal pigment epithelium

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    Tarnowski, B.; Shepherd, V.; McLaughlin, B.

    1986-05-01

    Retinal pigment epithelium (RPE) phagocytize discarded rod outer segments (ROS) during normal eye function. In the dystrophic rat, an animal model for retinitis pigmentosa in humans, ROS phagocytosis is defective. Dystrophic RPE can phagocytize particles other than ROS, suggesting that the defect may be in the RPE phagocytic recognition. They are currently investigating the recognition markers on RPE in dystrophic rats. In studies using ligand-coated latex beads, no uptake of mannose-coated beads was found in dystrophic rat RPE. They found that dystrophic RPE could specifically phagocytize phosphomannan-coated beads. Studies were begun to examine the presence and function of a phosphomannan receptor (PMR) on dystrophic RPE. ..cap alpha..-Mannosidase, isolated from D. discoideum has been shown to be an efficient ligand for the PMR in fibroblasts and macrophages. It is also recognized by the macrophage mannose receptor. Dystrophic rat RPE and retina explants were placed in culture dishes (5-7/well). /sup 125/I-Labelled ..cap alpha..-mannosidase was added to each well in the presence or absence of 10 mM mannose 6-phosphate (M6P) or yeast mannan (lmg/ml). Explants were incubated at 37/sup 0/ for 2 hr., washed and bound /sup 125/I-mannosidase quantitated. Approximately 2-3% of total counts added were bound to the RPE via a M6P-inhibitable recognition process. The binding to RPE was not blocked by mannan. No mannan or M6P-specific binding was found in retina explants. These results support the findings of specific uptake of phosphomannan-coated beads and demonstrate the presence of a specific PMR on dystrophic RPE phagocytic membranes.

  15. Interferon-gamma and tumour necrosis factor induce expression of major histocompatibility complex antigen on rat retinal astrocytes.

    OpenAIRE

    el-Asrar, A M; Maimone, D.; Morse, P H; Lascola, C; Reder, A T

    1991-01-01

    Cultured rat retinal astrocytes were tested by indirect immunofluorescence staining for their ability to express class I and II major histocompatibility complex (MHC) antigens under basal culture conditions and after three days of stimulation with two recombinant cytokines, rat interferon-gamma (IFN-gamma) and human tumour necrosis factor alpha (TNF alpha). Under basal culture conditions low levels of class I antigens were detected on a small percentage of cells, but there was no visible clas...

  16. Prenatal hypoxia is associated with long-term retinal dysfunction in rats.

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    Stephane L Bourque

    Full Text Available BACKGROUND: Intra-uterine growth restriction (IUGR has been associated with increased predisposition to age-related complications. We tested the hypothesis that rat offspring models of IUGR would exhibit exacerbated, age-related retinal dysfunction. METHODS: Female Sprague-Dawley rats (maintained at 11.5% O2 from gestational day 15 to 21 to induce IUGR and control offspring (maintained at 21% O2 throughout pregnancy had retinal function assessed at 2 months (young and 14 months of age (aged with electroretinogram (ERG recordings. Retinal anatomy was assessed by immunofluorescence. RESULTS: Deficits in rod-driven retina function were observed in aged IUGR offspring, as evidenced by reduced amplitudes of dark-adapted mixed a-wave V(max (by 49.3%, P < 0.01, b-wave V(max (by 42.1%, P < 0.001 and dark-adapted peak oscillatory potentials (by 42.3%, P < 0.01. In contrast to the rod-driven defects specific to aged IUGR offspring, light adapted ERG recordings revealed cone defects in young animals, that were stationary until old age. At 2 months, IUGR offspring had amplitude reductions for both b-wave (V(max by 46%, P < 0.01 and peak oscillatory potential (V(max by 38%, P < 0.05. Finally, defects in cone-driven responses were further confirmed by reduced maximal photopic flicker amplitudes at 2 (by 42%, P < 0.001 and 14 months (by 34%, P  =  0.06 and critical flicker fusion frequencies at 14 months ( CONTROL: 42 ± 1 Hz, IUGR: 35 ± 2 Hz, P < 0.05. These functional changes were not paralleled by anatomical losses in IUGR offspring retinas. CONCLUSIONS: These data support that the developing retina is sensitive to stressors, and that pathways governing cone- and rod-driven function differ in their susceptibilities. In the case of prenatal hypoxia, cone- and rod-driven dysfunction manifest at young and old ages, respectively. We must, therefore, take into account the specific impact that fetal programming might exert on age-related retinal dystrophies

  17. Zerumbone, a Phytochemical of Subtropical Ginger, Protects against Hyperglycemia-Induced Retinal Damage in Experimental Diabetic Rats.

    Science.gov (United States)

    Tzeng, Thing-Fong; Liou, Shorong-Shii; Tzeng, Yu-Cheng; Liu, I-Min

    2016-07-25

    Diabetic retinopathy (DR), the most ordinary and specific microvascular complication of diabetes, is a disease of the retina. Zerumbone (ZER) is a monocyclic sesquiterpene compound, and based on reports, it is the predominant bioactive compound from the rhizomes of Zingiber zerumbet. The aim of the current study is to evaluate the protective effect of zerumbone against DR in streptozotocin (STZ)-induced diabetic rats. STZ-diabetic rats were treated with ZER (40 mg/kg) once a day orally for 8 weeks. ZER administration significantly (p diabetic rats. Retinal histopathological observations indicated that disarrangement and reduction in thickness of retinal layers were reversed in ZER-treated diabetic rats. ZER downregulated both the elevated levels of advanced glycosylated end products (AGEs) and the higher levels of the receptors for AGEs (RAGE) in retinas of diabetic rats. What's more, ZER significantly (p diabetes-induced upregulation of tumor necrosis factor-α, interleukin (IL)-1 and IL-6. ZER also attenuated overexpression of vascular endothelial growth factor and intercellular adhesion molecule-1, and suppressed activation of nuclear factor (NF)-κB and apoptosis in the retinas of STZ-diabetic rats. Our results suggest ZER possesses retinal protective effects, which might be associated with the blockade of the AGEs/RAGE/NF-κB pathway and its anti-inflammatory activity.

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

    Science.gov (United States)

    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.

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

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    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

  20. 17β-estradiol ameliorates light-induced retinal damage in Sprague-Dawley rats by reducing oxidative stress.

    Science.gov (United States)

    Wang, Shaolan; Wang, Baoying; Feng, Yan; Mo, Mingshu; Du, Fangying; Li, Hongbo; Yu, Xiaorui

    2015-01-01

    Oxidative stress is considered as a major cause of light-induced retinal neurodegeneration. The protective role of 17β-estradiol (βE2) in neurodegenerative disorders is well known, but its underlying mechanism remains unclear. Here, we utilized a light-induced retinal damage model to explore the mechanism by which βE2 exerts its neuroprotective effect. Adult male and female ovariectomized (OVX) rats were exposed to 8,000 lx white light for 12 h to induce retinal light damage. Electroretinogram (ERG) assays and hematoxylin and eosin (H&E) staining revealed that exposure to light for 12 h resulted in functional damage to the rat retina, histological changes, and retinal neuron loss. However, intravitreal injection (IVI) of βE2 significantly rescued this impaired retinal function in both female and male rats. Based on the level of malondialdehyde (MDA) production (a biomarker of oxidative stress), an increase in retinal oxidative stress followed light exposure, and βE2 administration reduced this light-induced oxidative stress. Quantitative reverse-transcriptase (qRT)-PCR indicated that the messenger RNA (mRNA) levels of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (Gpx) were downregulated in female OVX rats but were upregulated in male rats after light exposure, suggesting a gender difference in the regulation of these antioxidant enzyme genes in response to light. However, βE2 administration restored or enhanced the SOD and Gpx expression levels following light exposure. Although the catalase (CAT) expression level was insensitive to light stimulation, βE2 also increased the CAT gene expression level in both female OVX and male rats. Further examination indicated that the antioxidant proteins thioredoxin (Trx) and nuclear factor erythroid 2-related factor 2 (Nrf2) are also involved in βE2-mediated antioxidation and that the cytoprotective protein heme oxygenase-1 (HO-1) plays a key role in the endogenous defense mechanism

  1. In vitro Culture of Bone Marrow Mesenchymal Stem Cells in Rats and Differentiation into Retinal Neural-like Cells

    Institute of Scientific and Technical Information of China (English)

    SUN Xufang; JIANG Huanrong; YANG Hong

    2007-01-01

    In order to study the in vitro culture and expansion of bone marrow mesenchymal stem cells in rats (rMSCs) and the possibility of rMSCs differentiation into retinal neural cells, the bone marrow-derived cells in SD rats were isolated and cultured in vitro. The retinal neural cells in SD rats were cultured and the supernatants were collected to prepare conditioned medium. The cultured rMSCs were induced to differentiate by two steps. Imrnunofluorescence method and anti-nestin, anti-NeuN, anti-GFAP and anti-Thy1.1 antibodies were used to identify the cells derived from the rMSCs. The results showed that the in vitro cultured rMSCs grew well and expanded quickly. After induction with two conditioned media, rMSCs was induced to differentiate into neural progenitor cells, then into retinal neural-like cells which were positive for nestin, NeuN, GFAP and Thy1.1 de-tected by fluorescence method. The findings suggested that rMSCs could be culture and expanded in vitro, and induced to differentiate into retinal neural-like cells.

  2. 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.

  3. Early retinal blood vessel growth in normal and growth restricted rat pups raised in oxygen and room air.

    Science.gov (United States)

    Dhaliwal, C A; Wade, J; Gillespie, T; Aspinall, P; McIntosh, N; Fleck, B W

    2011-11-01

    Premature infants are born with incompletely vascularised retinas and are at a risk of developing retinopathy of prematurity (ROP). Rate of prenatal and postnatal body growth is important in the pathogenesis of ROP. The aim of this study was to develop a physiology-based rat model in order to study the effect of growth restriction and oxygen on early retinal vascular development. Rat mothers were fed either a normal (18% casein) or low (9% casein) protein diet (to cause pup growth restriction) from the last week of gestation. After birth, mother and pups were placed in either room air or a specialised oxygen chamber that delivered a rapidly fluctuating hyperoxic oxygen profile. The oxygen profile was based on that from a premature infant who developed severe ROP. On day 14, retinas were dissected, flat-mounted and stained using biotinylated lectin. Images were captured by confocal microscopy. The avascular areas of the retinas were measured and compared. Growth restricted rat pups had significantly larger retinal avascular areas than 'normally grown' rat pups (Mann-Whitney U test, pair (Mann-Whitney U test, p=0.001). The authors have developed a novel model for ROP that involves inducing both intrauterine and postnatal growth restriction and also exposes neonatal rat pups to fluctuating oxygen. This physiology-based model can be used to study the effects of growth, nutrition and oxygen on early retinal vascular development.

  4. Effects of nuclear factor κB expression on retinal neovascularization and apoptosis in a diabetic retinopathy rat model

    Institute of Scientific and Technical Information of China (English)

    Ning; Jiang; Xiao-Long; Chen; Hong-Wei; Yang; Yu-Ru; Ma

    2015-01-01

    AIM: To investigate the expression and role of nuclear factor κB(NF-κB) in diabetic retinopathy(DR) and its relationship with neovascularization and retinal cell apoptosis. METHODS: A total of 80 male Wistar rats were randomly assigned to control(4, 8, 12 and 16 wk, n =10 in each group) and diabetes mellitus(DM) groups(4, 8, 12 and 16wk, n =10 in each group). A diabetic rat model was established by intraperitoneal injection of streptozotocin(60 mg/kg). After 4, 8, 12 and 16 wk, rats were sacrificed.Retinal layers and retinal neovascularization growth were stained with hematoxylin-eosin and examined under light microscopy. Cell apoptosis in the retina was detected by Td T-mediated d UTP nick end labeling, and NF-κB distribution and expression in the retina was determined using immunohistochemistry. RESULTS: DM model success rate up to 100%.Diabetes model at each time point after the experimental groupcompared with the control group, the blood glucose was significantly increased, decreased body weight, each time point showed significant differences compared with the control group(P <0.01). After 12 wk other pathological changes in the retina of diabetic rats were observed; after 16 wk, neovascularization were observed. After 1mo, retinal cell apoptosis was observed.Compared with the control group, NF-κB expression in the DM group significantly increased with disease duration.CONCLUSION: With the prolonging of DM progression,the expression NF-κB increases. NF-κB may be related to retinal cell apoptosis and neovascularization.

  5. ER stress in retinal degeneration in S334ter Rho rats.

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    Vishal M Shinde

    Full Text Available The S334ter rhodopsin (Rho rat (line 4 bears the rhodopsin gene with an early termination codon at residue 334 that is a model for several such mutations found in human patients with autosomal dominant retinitis pigmentosa (ADRP. The Unfolded Protein Response (UPR is implicated in the pathophysiology of several retinal disorders including ADRP in P23H Rho rats. The aim of this study was to examine the onset of UPR gene expression in S334ter Rho retinas to determine if UPR is activated in ADRP animal models and to investigate how the activation of UPR molecules leads to the final demise of S334ter Rho photoreceptors. RT-PCR was performed to evaluate the gene expression profiles for the P10, P12, P15, and P21 stages of the development and progression of ADRP in S334ter Rho photoreceptors. We determined that during the P12-P15 period, ER stress-related genes are strongly upregulated in transgenic retinas, resulting in the activation of the UPR that was confirmed using western blot analysis and RT-PCR. The activation of UPR was associated with the increased expression of JNK, Bik, Bim, Bid, Noxa, and Puma genes and cleavage of caspase-12 that together with activated calpains presumably compromise the integrity of the mitochondrial MPTP, leading to the release of pro-apoptotic AIF1 into the cytosol of S334ter Rho photoreceptor cells. Therefore, two major cross-talking pathways, the UPR and mitochondrial MPTP occur in S334ter-4 Rho retina concomitantly and eventually promote the death of the photoreceptor cells.

  6. Alpha B-crystallin improved survival of retinal ganglion cells in a rat model of acute ocular hypertension

    Institute of Scientific and Technical Information of China (English)

    Zhihong Wu; Layi Wang; Shike Hou

    2012-01-01

    Increased endogenous αB-crystallin protein levels have been shown to reduce cell apoptosis,although the effects of exogenous αB-crystallin protein remain poorly understood.The present study established an acute ocular hypertension model in the right eye of Sprague-Dawley rats.Fluorogold retrograde tracing and immunofluorescence methods showed that the number of retinal ganglion cells decreased in the right eyes and caspase-3 expression increased following acute ocular hypertension.Intravitreal injection of αB-crystallin in the right eye increased the number of retinal ganglion cells and reduced caspase-3 expression.Results demonstrated that exogenous αB-crystallin protein inhibited caspase-3 expression and improved retinal ganglion cell survival following acute ocular hypertension.

  7. Retinal glutamate transporter changes in experimental glaucoma and after optic nerve transection in the rat.

    Science.gov (United States)

    Martin, Keith R G; Levkovitch-Verbin, Hana; Valenta, Danielle; Baumrind, Lisa; Pease, Mary Ellen; Quigley, Harry A

    2002-07-01

    High levels of glutamate can be toxic to retinal ganglion cells. Effective buffering of extracellular glutamate by retinal glutamate transporters is therefore important. This study was conducted to investigate whether glutamate transporter changes occur with two models of optic nerve injury in the rat. Glaucoma was induced in one eye of 35 adult Wistar rats by translimbal diode laser treatment to the trabecular meshwork. Twenty-five more rats underwent unilateral optic nerve transection. Two glutamate transporters, GLAST (EAAT-1) and GLT-1 (EAAT-2), were studied by immunohistochemistry and quantitative Western blot analysis. Treated and control eyes were compared 3 days and 1, 4, and 6 weeks after injury. Optic nerve damage was assessed semiquantitatively in epoxy-embedded optic nerve cross sections. Trabecular laser treatment resulted in moderate intraocular pressure (IOP) elevation in all animals. After 1 to 6 weeks of experimental glaucoma, all treated eyes had significant optic nerve damage. Glutamate transporter changes were not detected by immunohistochemistry. Western blot analysis demonstrated significantly reduced GLT-1 in glaucomatous eyes compared with control eyes at 3 days (29.3% +/- 6.7%, P = 0.01), 1 week (55.5% +/- 13.6%, P = 0.02), 4 weeks (27.2% +/- 10.1%, P = 0.05), and 6 weeks (38.1% +/- 7.9%, P = 0.01; mean reduction +/- SEM, paired t-tests, n = 5 animals per group, four duplicate Western blot analyses per eye). The magnitude of the reduction in GLT-1 correlated significantly with mean IOP in the glaucomatous eye (r(2) = 0.31, P = 0.01, linear regression). GLAST was significantly reduced (33.8% +/- 8.1%, mean +/- SEM) after 4 weeks of elevated IOP (P = 0.01, paired t-test, n = 5 animals per group). In contrast to glaucoma, optic nerve transection resulted in an increase in GLT-1 compared with the control eye (P = 0.01, paired t-test, n = 15 animals). There was no significant change in GLAST after transection. GLT-1 and GLAST were significantly

  8. Effect of SIRT1 regulating cholesterol synthesis in repairing retinal ganglion cells after optic nerve injury in rats

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    Yan Zhang

    2014-10-01

    Full Text Available AIM: To investigate the repair mechanism associated with cholesterol synthesis regulated by silent information regulator 1(SIRT1in rat model of optic nerve damage. METHODS: Preparation of optic nerve damage in 70 rats was randomly divided into normal group(10 rats, resveratrol treatment group(experimental group 30 ratsand PBS buffer control group(30 rats. The experimental group and control group was further divided into 3 subgroups(each group 10 rats, respectively. After 7, 14, 21d injected resveratrol or PBS, optic nerve injury were observed, then the rats were sacrificed. Retina was segregated; the surviving retinal ganglion cell(RGCswas counted. Dissection of optic nerve, cholesterol content of them were tested; RT-PCR was used to detect mRNA expression of SIRT1, SREBP2 and HMGCR; Western blot assay was used to test the protein expression levels of SIRT1, cholesterol regulatory element binding protein 2(SREBP2and HMGCR. RESULTS: The numbers of RGCs and cholesterol levels of rat model with optic nerve injury decreased significantly(PPPPCONCLUSION: Up-regulating the expression of SIRT1, SREBP2 and down-regulating HMGCR by resveratrol could repair the injury of optic nerve through promoting the synthesis of cholesterol in neurons and retinal ganglion cells in the repair process. SIRT1 may be as a promising new target for treatment on optic nerve damage.

  9. 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

  10. Adenosine A(2A receptor up-regulates retinal wave frequency via starburst amacrine cells in the developing rat retina.

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    Pin-Chien Huang

    Full Text Available BACKGROUND: Developing retinas display retinal waves, the patterned spontaneous activity essential for circuit refinement. During the first postnatal week in rodents, retinal waves are mediated by synaptic transmission between starburst amacrine cells (SACs and retinal ganglion cells (RGCs. The neuromodulator adenosine is essential for the generation of retinal waves. However, the cellular basis underlying adenosine's regulation of retinal waves remains elusive. Here, we investigated whether and how the adenosine A(2A receptor (A(2AR regulates retinal waves and whether A(2AR regulation of retinal waves acts via presynaptic SACs. METHODOLOGY/PRINCIPAL FINDINGS: We showed that A(2AR was expressed in the inner plexiform layer and ganglion cell layer of the developing rat retina. Knockdown of A(2AR decreased the frequency of spontaneous Ca²⁺ transients, suggesting that endogenous A(2AR may up-regulate wave frequency. To investigate whether A(2AR acts via presynaptic SACs, we targeted gene expression to SACs by the metabotropic glutamate receptor type II promoter. Ca²⁺ transient frequency was increased by expressing wild-type A(2AR (A2AR-WT in SACs, suggesting that A(2AR may up-regulate retinal waves via presynaptic SACs. Subsequent patch-clamp recordings on RGCs revealed that presynaptic A(2AR-WT increased the frequency of wave-associated postsynaptic currents (PSCs or depolarizations compared to the control, without changing the RGC's excitability, membrane potentials, or PSC charge. These findings suggest that presynaptic A(2AR may not affect the membrane properties of postsynaptic RGCs. In contrast, by expressing the C-terminal truncated A(2AR mutant (A(2AR-ΔC in SACs, the wave frequency was reduced compared to the A(2AR-WT, but was similar to the control, suggesting that the full-length A(2AR in SACs is required for A(2AR up-regulation of retinal waves. CONCLUSIONS/SIGNIFICANCE: A(2AR up-regulates the frequency of retinal waves via

  11. Retinal ganglion cell neuroprotection in a rat model of glaucoma following brimonidine, latanoprost or combined treatments.

    Science.gov (United States)

    Hernández, María; Urcola, J Haritz; Vecino, Elena

    2008-05-01

    The aim of the present study is to evaluate the neuroprotective effect of two antiglaucomatous substances, regardless of their hypotensive effect in the eye. Brimonidine, which does not reduce IOP when administered intraperitoneally, and latanoprost, which has a renowned hypotensive effect topically. We examined rat retinal ganglion cell (RGC) survival and size distribution in experimental glaucoma in response to different glaucomatous agents. IOP was elevated by episcleral vein cauterization (EVC) prior to the application of different treatments: (I) PBS application (control group), (II) intraperitoneal administration of brimonidine (a general hypotensive agent), (III) topical application of latanoprost (an ocular hypotensive agent), and (IV) latanoprost combined with brimonidine. After 12 weeks, RGCs were retrogradely labeled with fluorogold and RGC density was analyzed. EVC caused a significant increase (42%) in IOP in each group before drug treatment. After 12weeks of EVC, RGC survival in control vs. EVC rats was 78.9+/-3.2%. No IOP reduction was observed in brimonidine injected rats, but RGC survival at 12 weeks was total (103.7+/-2.7%). In latanoprost treated rats, IOP dropped by around 22% and 94.7+/-3.7% of the RGC population survived. Finally in the latanoprost+brimonidine combined group, IOP was significantly reduced by 25% and 94.4+/-2.2% of RGCs survived. Surprisingly, whereas EVC led to a 6% increase in RGC soma size, brimonidine treatment was associated with a 9% reduction in the soma size of RGCs at 12 weeks. We conclude that brimonidine exerts a neuroprotective effect via a mechanism which is independent of IOP reduction. These findings indicate that cell survival in glaucoma may be enhanced by neuroprotective strategies which are independent of IOP reduction. No synergistic neuroprotective effect was observed when both treatments were applied simultaneously.

  12. Interferon-gamma and tumour necrosis factor induce expression of major histocompatibility complex antigen on rat retinal astrocytes.

    Science.gov (United States)

    el-Asrar, A M; Maimone, D; Morse, P H; Lascola, C; Reder, A T

    1991-08-01

    Cultured rat retinal astrocytes were tested by indirect immunofluorescence staining for their ability to express class I and II major histocompatibility complex (MHC) antigens under basal culture conditions and after three days of stimulation with two recombinant cytokines, rat interferon-gamma (IFN-gamma) and human tumour necrosis factor alpha (TNF alpha). Under basal culture conditions low levels of class I antigens were detected on a small percentage of cells, but there was no visible class II. IFN-gamma and TNF alpha stimulation enhanced class I expression. TNF alpha had no effect on class II expression, whereas IFN-gamma induced the expression of class II in a dose dependent manner. These findings suggest that retinal astrocytes might play a part in immunological events occurring in the retina.

  13. Transplantation of human bone marrow mesenchymal stem cells as a thin subretinal layer ameliorates retinal degeneration in a rat model of retinal dystrophy.

    Science.gov (United States)

    Tzameret, Adi; Sher, Ifat; Belkin, Michael; Treves, Avraham J; Meir, Amilia; Nagler, Arnon; Levkovitch-Verbin, Hani; Barshack, Iris; Rosner, Mordechai; Rotenstreich, Ygal

    2014-01-01

    Vision incapacitation and blindness associated with retinal degeneration affect millions of people worldwide. Cell based therapy and specifically transplantation of human adult bone marrow-derived stem cells (hBM-MSCs) present possible treatment strategy. Subretinal transplantation of human or rat BM-MSCs was shown previously to improve retinal function in Royal College Surgeons (RCS) rats. In those studies cells were transplanted via a transscleral-transchoroidal approach, creating a localized subretinal bleb. Limited number of cells could be injected and photoreceptor rescue was restricted to areas in proximity to the injection site. Here we describe a new surgical method for subretinal transplantation that facilitates uniform distribution of transplanted cells as a thin layer along most of the subretinal space. We assessed the therapeutic effect of hBM-MSCs on RCS rats when transplanted either subretinally or intravitreally. We also examined whether a second transplantation can prolong the therapeutic effect. A cell suspension of 2.5 × 10(6) cells in 5 μl was injected subretinally or intravitreally in RCS rats at 28 days postnatal. In the subretinal group, hBM-MSCs were transplanted posterior to the limbus in the superotemporal part of the eye through a longitudinal triangular scleral tunnel reaching the choroid. In the intravitreal group, the cells were injected into the superotemporal part of the vitreous cavity. In cross sections of subretinally transplanted eyes, removed 2 h following transplantation, hBM-MSCs were distributed as a near-homogenous thin layer along most of the subretinal space. In some animals the cells were also detected in the choroid. In the intravitreal injection group, hBM-MSCs were clustered in the vitreous cavity. Transplanted cells could be detected up to 2 weeks after transplantation but not at later time points. Retinal function and structure were assessed by electroretinogram (ERG) and histology analysis, respectively. Six

  14. Compound 49b Restores Retinal Thickness and Reduces Degenerate Capillaries in the Rat Retina following Ischemia/Reperfusion.

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    Li Liu

    Full Text Available We have recently reported that Compound 49b, a novel β-adrenergic receptor agonist, can significantly reduce VEGF levels in retinal endothelial cells (REC grown in diabetic-like conditions. In this study, we investigated whether Compound 49b could protect the retina under hypoxic conditions using the ischemia-reperfusion (I/R-induced model in rats, as well REC cultured in hypoxic conditions. Some rats received 1mM topical Compound 49b for the 2 (5 rats each group or 10 (4 rats in each group days post-I/R. Analyses for retinal thickness and cell loss in the ganglion cell layer was done at 2 days post-I/R, while numbers of degenerate capillaries and pericyte ghosts were measured at 10 days post-I/R. Additionally, REC were cultured in normal oxygen or hypoxia (5% O2 only or treated with 50 nM Compound 49b for 12 hours. Twelve hours after Compound 49b exposure, cells were collected and analyzed for protein levels of insulin-like growth factor binding protein 3 (IGFBP-3, vascular endothelial cell growth factor (VEGF and its receptor (KDR, angiopoietin 1 and its receptor Tie2 for Western blotting. Data indicate that exposure to I/R significantly decreased retinal thickness, with increasing numbers of degenerate capillaries and pericyte ghosts. Compound 49b treatment inhibited these retinal changes. In REC cultured in hypoxia, levels of IGFBP-3 were reduced, which were significantly increased by Compound 49b. Hypoxia significantly increased protein levels of VEGF, KDR, Angiopoiein 1, and Tie2, which were reduced following Compound 49b treatment. These data strongly suggested that Compound 49b protected the retina against I/R-induced injury. This provides additional support for a role of β-adrenergic receptor actions in the retina.

  15. CNTF induces regeneration of cone outer segments in a rat model of retinal degeneration.

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    Yiwen Li

    Full Text Available BACKGROUND: Cone photoreceptors are responsible for color and central vision. In the late stage of retinitis pigmentosa and in geographic atrophy associated with age-related macular degeneration, cone degeneration eventually causes loss of central vision. In the present work, we investigated cone degeneration secondary to rod loss in the S334ter-3 transgenic rats carrying the rhodopsin mutation S334ter. METHODOLOGY/PRINCIPAL FINDINGS: Recombinant human ciliary neurotrophic factor (CNTF was delivered by intravitreal injection to the left eye of an animal, and vehicle to the right eye. Eyes were harvested 10 days after injection. Cone outer segments (COS, and cell bodies were identified by staining with peanut agglutinin and cone arrestin antibodies in whole-mount retinas. For long-term treatment with CNTF, CNTF secreting microdevices were implanted into the left eyes at postnatal day (PD 20 and control devices into the right eyes. Cone ERG was recorded at PD 160 from implanted animals. Our results demonstrate that an early sign of cone degeneration is the loss of COS, which concentrated in many small areas throughout the retina and is progressive with age. Treatment with CNTF induces regeneration of COS and thus reverses the degeneration process in early stages of cone degeneration. Sustained delivery of CNTF prevents cones from degeneration and helps them to maintain COS and light-sensing function. CONCLUSIONS/SIGNIFICANCE: Loss of COS is an early sign of secondary cone degeneration whereas cell death occurs much later. At early stages, degenerating cones are capable of regenerating outer segments, indicating the reversal of the degenerative process. Sustained delivery of CNTF preserves cone cells and their function. Long-term treatment with CNTF starting at early stages of degeneration could be a viable strategy for preservation of central vision for patients with retinal degenerations.

  16. Protective effect of light emitting diode phototherapy on fluorescent light induced retinal damage in Wistar strain albino rats.

    Science.gov (United States)

    Ahamed Basha, A; Mathangi, D C; Shyamala, R; Ramesh Rao, K

    2014-09-01

    Artificial light at night alters retinal physiology. Several studies have shown that light emitting diode phototherapy protects the retina from the damaging effects of acute light exposure. The aim of this study has been to elucidate the protective effects of 670 nm LED light on retinal damage induced by chronic fluorescent light in Wistar rats. Male Wistar albino rats were divided into four groups: group 1 were control (CL), group 2, 3 and 4 were exposed to fluorescent light (FL), LED preexposure+fluorescent light exposure (LL) and only LED light exposure (OL) respectively. All animals were maintained in their specific exposure regime for 30 days. Fluorescent light of 1800 lx was exposed between 8 pm to 8 am. Rats were exposed to therapeutic LED light of 670 nm of 9 J/cm2 at 25 mW/cm2 for 6 min duration. Histopathological changes in the retina were studied. Animals of the FL group showed a significant reduction in the outer nuclear layer thickness and cell count in addition to the total thickness of the retina. LL group which were exposed to 670 nm LED prior to exposure to fluorescent light showed a significant decrease in the degree of damage. 670 nm LED light preexposure is protective to retinal cells against fluorescent light-induced damage. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. Zerumbone, a Phytochemical of Subtropical Ginger, Protects against Hyperglycemia-Induced Retinal Damage in Experimental Diabetic Rats

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    Thing-Fong Tzeng

    2016-07-01

    Full Text Available Diabetic retinopathy (DR, the most ordinary and specific microvascular complication of diabetes, is a disease of the retina. Zerumbone (ZER is a monocyclic sesquiterpene compound, and based on reports, it is the predominant bioactive compound from the rhizomes of Zingiber zerumbet. The aim of the current study is to evaluate the protective effect of zerumbone against DR in streptozotocin (STZ-induced diabetic rats. STZ-diabetic rats were treated with ZER (40 mg/kg once a day orally for 8 weeks. ZER administration significantly (p < 0.05 lowered the levels of plasma glucose (32.5% ± 5.7% lower and glycosylated hemoglobin (29.2% ± 3.4% lower in STZ-diabetic rats. Retinal histopathological observations indicated that disarrangement and reduction in thickness of retinal layers were reversed in ZER-treated diabetic rats. ZER downregulated both the elevated levels of advanced glycosylated end products (AGEs and the higher levels of the receptors for AGEs (RAGE in retinas of diabetic rats. What’s more, ZER significantly (p < 0.05 ameliorated diabetes-induced upregulation of tumor necrosis factor-α, interleukin (IL-1 and IL-6. ZER also attenuated overexpression of vascular endothelial growth factor and intercellular adhesion molecule-1, and suppressed activation of nuclear factor (NF-κB and apoptosis in the retinas of STZ-diabetic rats. Our results suggest ZER possesses retinal protective effects, which might be associated with the blockade of the AGEs/RAGE/NF-κB pathway and its anti-inflammatory activity.

  18. Purified Humanism

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2016-01-01

    Abstract. The aim of the Leicester Conference is to help managers by way of experiential learning to acquire the prerequisites to influence effectively organizational change. For some time there has been an ongoing debate on the innovative potential of social psychological experiments...... and techniques. This article discusses the analytical possibilities of the notion “purified humanism” as part of an alternative analysis of the effective mechanisms of a widely used social psychological experiment. The article unfolds a number of ideas in relation to the socio-material provocations and maneuvers...

  19. White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model.

    Science.gov (United States)

    Shang, Yu-Man; Wang, Gen-Shuh; Sliney, David; Yang, Chang-Hao; Lee, Li-Ling

    2014-03-01

    Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic light sources. Chronic exposure to high-intensity light (2,000-10,000 lux) has previously been found to result in light-induced retinal injury, but chronic exposure to relatively low-intensity (750 lux) light has not been previously assessed with LEDs in a rodent model. We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat using functional, histological, and biochemical measurements. We used blue LEDs (460 nm) and full-spectrum white LEDs, coupled with matching compact fluorescent lights, for exposures. Pathological examinations included electroretinogram, hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and transmission electron microscopy (TEM). We also measured free radical production in the retina to determine the oxidative stress level. H&E staining and TEM revealed apoptosis and necrosis of photoreceptors, which indicated blue-light induced photochemical injury of the retina. Free radical production in the retina was increased in LED-exposed groups. IHC staining demonstrated that oxidative stress was associated with retinal injury. Although we found serious retinal light injury in LED groups, the compact fluorescent lamp (CFL) groups showed moderate to mild injury. Our results raise questions about adverse effects on the retina from chronic exposure to LED light compared with other light sources that have less blue light. Thus, we suggest a precautionary approach with regard to the use of blue-rich "white" LEDs for general lighting. Shang YM, Wang GS, Sliney D, Yang CH, Lee LL. 2014. White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model. Environ Health Perspect 122:269-276; http://dx.doi.org/10.1289/ehp.1307294.

  20. High-mobility group Box-1 is involved in NMDA-induced retinal injury the in rat retina.

    Science.gov (United States)

    Sakamoto, Kenji; Mizuta, Aya; Fujimura, Kyosuke; Kurauchi, Yuki; Mori, Asami; Nakahara, Tsutomu; Ishii, Kunio

    2015-08-01

    High-mobility group Box-1 (HMGB1) is known to be released from injured cells and to induce an inflammatory response. Although HMGB1 was reported to mediate ischemia-reperfusion injury of the brain, its role in glutamate excitotoxicity of the retina remains controversial. Here, the authors demonstrated the evidence that HMGB1 is involved in the retinal damage induced by NMDA. Under ketamine/xylazine anesthesia, male Sprague-Dawley rats were subjected to intravitreal injection of NMDA (200 nmol/eye) or HMGB1 protein derived from bovines (5-15 μg/eye). Intravitreal anti-HMGB1 IgY (5 μg/eye) was simultaneously administered with NMDA or HMGB1. Seven days later, animals were killed and 5-μm retinal sections through the optic nerve head were obtained. These specimens were subjected to morphometry. Intravitreal NMDA and HMGB1 protein evoked cell loss in the ganglion cell layer 7 days later. Intravitreal anti-HMGB1 IgY reduced these damages. Anti-HMGB1 IgY reduced the number of 8-hydroxy-deoxyguanosine (8-OHdG)-positive cells induced by intravitreal NMDA. Toll-like receptor 2/4 antagonist peptide, receptor for advanced glycation end-products (RAGE) antagonist peptide, and FPS-ZM1 significantly reduced the retinal damage induced by HMGB1 protein. The results in the present study suggest that HMGB1 is at least in part involved in NMDA-induced retinal injury, and probably induces cell death of retinal ganglion cells with increase of oxidative stress, via activation of toll-like receptor 2/4 and RAGE in the rat retina.

  1. Endothelins Inhibit Osmotic Swelling of Rat Retinal Glial and Bipolar Cells by Activation of Growth Factor Signaling.

    Science.gov (United States)

    Vogler, Stefanie; Grosche, Antje; Pannicke, Thomas; Wiedemann, Peter; Reichenbach, Andreas; Bringmann, Andreas

    2016-10-01

    Water accumulation in retinal glial (Müller) and neuronal cells resulting in cellular swelling contributes to the development of retinal edema and neurodegeneration. Here, we show that endothelin-1 (ET-1) dose-dependently inhibits the hypoosmotic swelling of Müller cells in freshly isolated retinal slices of control and diabetic rats, with a maximal inhibition at 100 nM. Osmotic Müller cell swelling was also inhibited by ET-2. The effect of ET-1 was mediated by activation of ETA and ETB receptors resulting in transactivation of metabotropic glutamate receptors, purinergic P2Y1, and adenosine A1 receptors. ET-1 (but not ET-2) also inhibited the osmotic swelling of bipolar cells in retinal slices, but failed to inhibit the swelling of freshly isolated bipolar cells. The inhibitory effect of ET-1 on the bipolar cell swelling in retinal slices was abrogated by inhibitors of the FGF receptor kinase (PD173074) and of TGF-β1 superfamily activin receptor-like kinase receptors (SB431542), respectively. Both Müller and bipolar cells displayed immunoreactivities of ETA and ETB receptor proteins. The data may suggest that neuroprotective effects of ETs in the retina are in part mediated by prevention of the cytotoxic swelling of retinal glial and bipolar cells. ET-1 acts directly on Müller cells, while the inhibitory effect of ET-1 on bipolar cell swelling is indirectly mediated, via stimulation of the release of growth factors like bFGF and TGF-β1 from Müller cells.

  2. Gene expression changes under cyclic mechanical stretching in rat retinal glial (Muller cells.

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    Xin Wang

    Full Text Available OBJECTIVE: The retina is subjected to tractional forces in various conditions. As the predominant glial element in the retina, Müller cells are active players in all forms of retinal injury and disease. In this study, we aim to identify patterns of gene expression changes induced by cyclic mechanical stretching in Müller cells. METHODS: Rat Müller cells were seeded onto flexible bottom culture plates and subjected to a cyclic stretching regimen of 15% equibiaxial stretching for 1 and 24 h. RNA was extracted and amplified, labeled, and hybridized to rat genome microarrays. The expression profiles were analyzed using GeneSpring software, and gene ontology analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG were used to select, annotate, and visualize genes by function and pathway. The selected genes of interest were further validated by Quantitative Real-time PCR (qPCR. RESULTS: Microarray data analysis showed that at 1 and 24 h, the expression of 532 and 991 genes in the Müller cells significantly (t-test, p<0.05 differed between the mechanically stretched and unstretched groups. Of these genes, 56 genes at 1 h and 62 genes at 24 h showed more than a twofold change in expression. Several genes related to response to stimulus (e.g., Egr2, IL6, cell proliferation (e.g., Areg, Atf3, tissue remodeling (e.g., PVR, Loxl2, and vasculogenesis (e.g., Epha2, Nrn1 were selected and validated by qPCR. KEGG pathway analysis showed significant changes in MAPK signaling at both time points. CONCLUSIONS: Cyclic mechanical strain induces extensive changes in the gene expression in Müller cells through multiple molecular pathways. These results indicate the complex mechanoresponsive nature of Müller cells, and they provide novel insights into possible molecular mechanisms that would account for many retinal diseases in which the retina is often subjected to mechanical forces, such as pathological myopia and proliferative vitreoretinopathy.

  3. Orexin-A potentiates L-type calcium/barium currents in rat retinal ganglion cells.

    Science.gov (United States)

    Liu, F; Weng, S-J; Yang, X-L; Zhong, Y-M

    2015-10-01

    Two neuropeptides, orexin-A and orexin-B (also called hypocretin-1 and -2), have been implicated in sleep/wake regulation, feeding behaviors via the activation of two subtypes of G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). While the expression of orexins and orexin receptors is immunohistochemically revealed in retinal neurons, the function of these peptides in the retina is largely unknown. Using whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that orexin-A increased L-type-like barium currents (IBa,L) in ganglion cells (GCs), and the effect was blocked by the selective OX1R antagonist SB334867, but not by the OX2R antagonist TCS OX2 29. The orexin-A effect was abolished by intracellular dialysis of GDP-β-S/GPAnt-2A, a Gq protein inhibitor, suggesting the mediation of Gq. Additionally, during internal dialysis of the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor U73122, orexin-A did not change the IBa,L of GCs, whereas the orexin-A effect persisted in the presence of the phosphatidylcholine (PC)-PLC inhibitor D609. The orexin-A-induced potentiation was not seen with internal infusion of Ca(2+)-free solution or when inositol 1,4,5-trisphosphate (IP3)-sensitive Ca(2+) release from intracellular stores was blocked by heparin/xestospongins-C. Moreover, the orexin-A effect was mimicked by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, but was eliminated when PKC was inhibited by bisindolylmaleimide IV (Bis-IV)/Gö6976. Neither adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) nor guanosine 3',5'-cyclic monophosphate (cGMP)-protein kinase G (PKG) signaling pathway was likely involved, as orexin-A persisted to potentiate the IBa,L of GCs no matter these two pathways were activated or inhibited. These results suggest that, by activating OX1R, orexin-A potentiates the IBa,L of rat GCs through a distinct Gq/PI-PLC/IP3/Ca(2+)/PKC signaling pathway.

  4. Therapeutic efficacy of melatonin in reducing retinal damage in an experimental model of early type 2 diabetes in rats.

    Science.gov (United States)

    Salido, Ezequiel M; Bordone, Melina; De Laurentiis, Andrea; Chianelli, Mónica; Keller Sarmiento, María Inés; Dorfman, Damián; Rosenstein, Ruth E

    2013-03-01

    Diabetic retinopathy (DR) is a leading cause of acquired blindness in adults, mostly affected by type 2 diabetes mellitus (T2DM). We have developed an experimental model of early T2DM in adult rats which mimics some features of human T2DM at its initial stages and provokes significant retinal alterations. The aim of this work was to analyze the effect of melatonin on retinal changes induced by the moderate metabolic derangement. For this purpose, adult male Wistar rats received a control diet or 30% sucrose in the drinking water. Three weeks after this treatment, animals were injected with vehicle or streptozotocin (STZ, 25 mg/kg). One day or 3 wk after vehicle or STZ injection, animals were subcutaneously implanted with a pellet of melatonin. Fasting and postprandial glycemia, and glucose, and insulin tolerance tests were analyzed. At 12 wk of treatment, animals which received a sucrose-enriched diet and STZ showed significant differences in metabolic tests, as compared with control groups. Melatonin, which did not affect glucose metabolism in control or diabetic rats, prevented the decrease in the electroretinogram a-wave, b-wave, and oscillatory potential amplitude, and the increase in retinal lipid peroxidation, NOS activity, TNFα, Müller cells glial fibrillary acidic protein, and vascular endothelial growth factor levels. In addition, melatonin prevented the decrease in retinal catalase activity. These results indicate that melatonin protected the retina from the alterations observed in an experimental model of DR associated with type 2 diabetes.

  5. Purified humanism

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2016-01-01

    Abstract. The aim of the Leicester Conference is to help managers by way of experiential learning to acquire the prerequisites to influence effectively organizational change. For some time there has been an ongoing debate on the innovative potential of social psychological experiments...... and culturally specific attitudes in relation to leadership and the question of authority among participants. Keywords: The Leicester Conference, experiential learning, authority, socio-materiality, social techniques...... and techniques. This article discusses the analytical possibilities of the notion “purified humanism” as part of an alternative analysis of the effective mechanisms of a widely used social psychological experiment. The article unfolds a number of ideas in relation to the socio-material provocations and maneuvers...

  6. The Application of a Highly Purified Rat Leydig Cell Assay as a Complement to the H295R Steroidogenesis Assay for the Evaluation of Toxicant Induced Alterations in Testosterone Production

    Data.gov (United States)

    U.S. Environmental Protection Agency — The greater dynamic range of testosterone production in a highly purified rat Leydig cell assay permitted the detection of chemical induced inhibition that was not...

  7. Both electrical stimulation thresholds and SMI-32-immunoreactive retinal ganglion cell density correlate with age in S334ter line 3 rat retina.

    Science.gov (United States)

    Chan, Leanne L H; Lee, Eun-Jin; Humayun, Mark S; Weiland, James D

    2011-06-01

    Electrical stimulation threshold and retinal ganglion cell density were measured in a rat model of retinal degeneration. We performed in vivo electrophysiology and morphometric analysis on normal and S334ter line 3 (RD) rats (ages 84-782 days). We stimulated the retina in anesthetized animals and recorded evoked responses in the superior colliculus. Current pulses were delivered with a platinum-iridium (Pt-Ir) electrode of 75-μm diameter positioned on the epiretinal surface. In the same animals used for electrophysiology, SMI-32 immunolabeling of the retina enabled ganglion cell counting. An increase in threshold currents positively correlated with age of RD rats. SMI-32-labeled retinal ganglion cell density negatively correlated with age of RD rats. ANOVA shows that RD postnatal day (P)100 and P300 rats have threshold and density similar to normal rats, but RD P500 and P700 rats have threshold and density statistically different from normal rats (P < 0.05). Threshold charge densities were within the safety limits of Pt for all groups and pulse configurations, except at RD P600 and RD P700, where pulses were only safe up to 1- and 0.2-ms duration, respectively. Preservation of ganglion cells may enhance the efficiency and safety of electronic retinal implants.

  8. Retinal Electrophysiological Effects of Intravitreal Bone Marrow Derived Mesenchymal Stem Cells in Streptozotocin Induced Diabetic Rats.

    Directory of Open Access Journals (Sweden)

    Eren Çerman

    Full Text Available Diabetic retinopathy is the most common cause of legal blindness in developed countries at middle age adults. In this study diabetes was induced by streptozotocin (STZ in male Wistar albino rats. After 3 months of diabetes, rights eye were injected intravitreally with green fluorescein protein (GFP labelled bone marrow derived stem cells (BMSC and left eyes with balanced salt solution (Sham. Animals were grouped as Baseline (n = 51, Diabetic (n = 45, Diabetic+BMSC (n = 45 eyes, Diabetic+Sham (n = 45 eyes, Healthy+BMSC (n = 6 eyes, Healthy+Sham (n = 6 eyes. Immunohistology analysis showed an increased retinal gliosis in the Diabetic group, compared to Baseline group, which was assessed with GFAP and vimentin expression. In the immunofluorescence analysis BMSC were observed to integrate mostly into the inner retina and expressing GFP. Diabetic group had prominently lower oscillatory potential wave amplitudes than the Baseline group. Three weeks after intravitreal injection Diabetic+BMSC group had significantly better amplitudes than the Diabetic+Sham group. Taken together intravitreal BMSC were thought to improve visual function.

  9. The role of NgR-Rhoa-Rock signal pathway in retinal ganglion cell apoptosis of early diabetic rats

    Directory of Open Access Journals (Sweden)

    Yun-Jie Fu

    2014-09-01

    Full Text Available AIM: To study the function and mechanism of the NgR-Rhoa-Rock signal pathways which exists in the retinal ganglion cells apoptosis in diabetes mellitus(DMrats. METHODS: Some healthy SD rats were operated by means of single intraperitoneal injection of 1% streptozotocin based on the standard of 50mg/kg wight, after that the blood sugar value was greater than 16.7mmol/L as DM model, then randomly divided into 3 groups, each group was 10 rats. In addition to take 10 healthy SD rats as control group. Four groups of rats were bilaterally eyeball intravitreal injection in turn with NgR-siRNA virus 10μL(siRNA group, NgR-siRNA virus diluted 10μL(DM group, NgR-siRNA virus-negative-control solution 10μL(siRNA blank group, NgR-siRNA virus diluted 10μL(normal control group, and fed normally. During that time, some life indexes like blood glucose, body mass, etc. were measured and recorded. After 12wk, the expression of NgR and Rhoa, HE staining, and TUNNEL staining were detected by Western blot analysis. RESULTS: Western blot analysis: compared with normal control group, the expression of NgR and Rhoa in DM group and siRNA blank group increased significantly(PP>0.05; compared with DM group and siRNA blank group, the expression of those proteins significantly lowered in siRNA group. HE staining: compared with normal control group, some extent ganglion cells arranged disorder, irregular shape, spacing not consistent were all found in three groups of model rats; compared with DM group and siRNA blank group, there was some improvement in siRNA group of ganglion cells about the order and shape size. TUNEL staining: compared with normal control group, there were retinal ganglion cells apoptosis in all of three groups of model rats. Compared with DM group and siRNA blank group, the number of retinal ganglion cells apoptotic cells was less, and the shape of cells had improved significantly in siRNA group. CONCLUSION: In the DM phase, the expression of NgR and

  10. Modulation of Type-1 and Type-2 Cannabinoid Receptors by Saffron in a Rat Model of Retinal Neurodegeneration

    Science.gov (United States)

    Maccarone, Rita; Rapino, Cinzia; Zerti, Darin; di Tommaso, Monia; Battista, Natalia; Di Marco, Stefano; Bisti, Silvia; Maccarrone, Mauro

    2016-01-01

    Experimental studies demonstrated that saffron (Crocus sativus) given as a dietary supplement counteracts the effects of bright continuous light (BCL) exposure in the albino rat retina, preserving both morphology and function and probably acting as a regulator of programmed cell death [1]. The purpose of this study was to ascertain whether the neuroprotective effect of saffron on rat retina exposed to BCL is associated with a modulation of the endocannabinoid system (ECS). To this aim, we used eight experimental groups of Sprague-Dawley rats, of which six were exposed to BCL for 24 hours. Following retinal function evaluation, retinas were quickly removed for biochemical and morphological analyses. Rats were either saffron-prefed or intravitreally injected with selective type-1 (CB1) or type-2 (CB2) cannabinoid receptor antagonists before BCL. Prefeeding and intravitreally injections were combined in two experimental groups before BCL. BCL exposure led to enhanced gene and protein expression of retinal CB1 and CB2 without affecting the other ECS elements. This effect of BCL on CB1 and CB2 was reversed by saffron treatment. Selective CB1 and CB2 antagonists reduced photoreceptor death, preserved morphology and visual function of retina, and mitigated the outer nuclear layer (ONL) damage due to BCL. Of interest, CB2-dependent neuroprotection was more pronounced than that conferred by CB1. These data suggest that BCL modulates only distinct ECS elements like CB1 and CB2, and that saffron and cannabinoid receptors could share the same mechanism in order to afford retinal protection. PMID:27861558

  11. Vasoinhibins prevent retinal vasopermeability associated with diabetic retinopathy in rats via protein phosphatase 2A-dependent eNOS inactivation.

    Science.gov (United States)

    García, Celina; Aranda, Jorge; Arnold, Edith; Thébault, Stéphanie; Macotela, Yazmín; López-Casillas, Fernando; Mendoza, Valentín; Quiroz-Mercado, Hugo; Hernández-Montiel, Hebert Luis; Lin, Sue-Hwa; de la Escalera, Gonzalo Martínez; Clapp, Carmen

    2008-06-01

    Increased retinal vasopermeability contributes to diabetic retinopathy, the leading cause of blindness in working-age adults. Despite clinical progress, effective therapy remains a major need. Vasoinhibins, a family of peptides derived from the protein hormone prolactin (and inclusive of the 16-kDa fragment of prolactin), antagonize the proangiogenic effects of VEGF, a primary mediator of retinal vasopermeability. Here, we demonstrate what we believe to be a novel function of vasoinhibins as inhibitors of the increased retinal vasopermeability associated with diabetic retinopathy. Vasoinhibins inhibited VEGF-induced vasopermeability in bovine aortic and rat retinal capillary endothelial cells in vitro. In vivo, vasoinhibins blocked retinal vasopermeability in diabetic rats and in response to intravitreous injection of VEGF or of vitreous from patients with diabetic retinopathy. Inhibition by vasoinhibins was similar to that achieved following immunodepletion of VEGF from human diabetic retinopathy vitreous or blockage of NO synthesis, suggesting that vasoinhibins inhibit VEGF-induced NOS activation. We further showed that vasoinhibins activate protein phosphatase 2A (PP2A), leading to eNOS dephosphorylation at Ser1179 and, thereby, eNOS inactivation. Moreover, intravitreous injection of okadaic acid, a PP2A inhibitor, blocked the vasoinhibin effect on endothelial cell permeability and retinal vasopermeability. These results suggest that vasoinhibins have the potential to be developed as new therapeutic agents to control the excessive retinal vasopermeability observed in diabetic retinopathy and other vasoproliferative retinopathies.

  12. Vasoinhibins prevent retinal vasopermeability associated with diabetic retinopathy in rats via protein phosphatase 2A–dependent eNOS inactivation

    Science.gov (United States)

    García, Celina; Aranda, Jorge; Arnold, Edith; Thébault, Stéphanie; Macotela, Yazmín; López-Casillas, Fernando; Mendoza, Valentín; Quiroz-Mercado, Hugo; Hernández-Montiel, Hebert Luis; Lin, Sue-Hwa; de la Escalera, Gonzalo Martínez; Clapp, Carmen

    2008-01-01

    Increased retinal vasopermeability contributes to diabetic retinopathy, the leading cause of blindness in working-age adults. Despite clinical progress, effective therapy remains a major need. Vasoinhibins, a family of peptides derived from the protein hormone prolactin (and inclusive of the 16-kDa fragment of prolactin), antagonize the proangiogenic effects of VEGF, a primary mediator of retinal vasopermeability. Here, we demonstrate what we believe to be a novel function of vasoinhibins as inhibitors of the increased retinal vasopermeability associated with diabetic retinopathy. Vasoinhibins inhibited VEGF-induced vasopermeability in bovine aortic and rat retinal capillary endothelial cells in vitro. In vivo, vasoinhibins blocked retinal vasopermeability in diabetic rats and in response to intravitreous injection of VEGF or of vitreous from patients with diabetic retinopathy. Inhibition by vasoinhibins was similar to that achieved following immunodepletion of VEGF from human diabetic retinopathy vitreous or blockage of NO synthesis, suggesting that vasoinhibins inhibit VEGF-induced NOS activation. We further showed that vasoinhibins activate protein phosphatase 2A (PP2A), leading to eNOS dephosphorylation at Ser1179 and, thereby, eNOS inactivation. Moreover, intravitreous injection of okadaic acid, a PP2A inhibitor, blocked the vasoinhibin effect on endothelial cell permeability and retinal vasopermeability. These results suggest that vasoinhibins have the potential to be developed as new therapeutic agents to control the excessive retinal vasopermeability observed in diabetic retinopathy and other vasoproliferative retinopathies. PMID:18497878

  13. The Study of Influencing Factors on the Growth Characters of Sprague—Dawley Rat Retinal Neurons in Vitro

    Institute of Scientific and Technical Information of China (English)

    LiuHQ; GeJ

    1999-01-01

    Purpose:To investigate the influencing factors in culturing Srague-Dawley(S-D) rats retinal neurons in order to lay foundation for further experimental research.Materials and Methods:Retinal cells were plated on plastic plates and coverslips coated with poly-lysine or ethylene imine polymer for primary culture.The cultured cells were divided into following groups:1.Culture medium changed every 2 tp 3 days vs changed only once;2.Cytosine arabinoside(Ara-C)added to the culture medium vs not added.The cells were observed and pictured under inverted phase contrast microscope.The cells were identified through immunocytochemistry.Results:The immunofluorescence showed that most of the cultured cells were neurons,among them were a few retinal ganglion cells.In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c,the neurons intended to aggregate into clusters with relatively straight neurites.In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c,the neurons grew dispersively with bent neurites.Both of them survived for 2 to 3 weeks.The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks.In the group of which medium changed several times,the survival time of neurons was shorter than that in the medium changed only once.Conclusions:The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth.It is not favorable for the growth of the neurons by changing culture medium many times.Ara-c may possibly have side effect on the growth of retinal neurons.

  14. 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.

  15. Application of Purified Botulinum Type A Neurotoxin to Treat Experimental Trigeminal Neuropathy in Rats and Patients with Urinary Incontinence and Prostatic Hyperplasia

    Directory of Open Access Journals (Sweden)

    Yoshizo Matsuka

    2012-01-01

    Full Text Available Type A neurotoxin (NTX of Clostridium botulinum was purified by a simple procedure using a lactose gel column. The toxicity of this purified toxin preparation was retained for at least 1 year at −30°C by supplementation with either 0.1% albumin or 0.05% albumin plus 1% trehalose. When purified NTX was used to treat 49 patients with urinary incontinence caused by either refractory idiopathic or neurogenic detrusor overactivity, 36 patients showed significant improvement in symptoms. These beneficial effects were also observed in cases of prostatic hyperplasia. The results obtained with NTX were similar to that of Botox. The effects of NTX on trigeminal neuralgia induced by infraorbital nerve constriction (IoNC in rats were also studied. Trigeminal ganglion neurons from ipsilateral to IoNC exhibited significantly faster onset of FM4-64 release than sham-operated contralateral neurons. Intradermal injection of NTX in the area of IoNC alleviated IoNC-induced pain behavior and reduced the exaggerated FM4-64 release in trigeminal ganglion neurons.

  16. Direct binding of autoimmune disease related T cell epitopes to purified Lewis rat MHC class II molecules

    DEFF Research Database (Denmark)

    Joosten, I; Wauben, M H; Holewijn, M C

    1994-01-01

    must be able to assess peptide-MHC interactions. Several well described autoimmune disease models exist in the Lewis rat and thus this particular rat strain provides a good model system to study the effect of competitor peptides. So far no information has been available on the peptide binding...... characteristics of the Lewis rat MHC class II RT1.B1 molecule. We have now developed a biochemical binding assay which enables competition studies in which the relative MHC binding affinity of a set of non-labelled peptides can be assessed while employing detection of biotinylated marker peptides...... by chemiluminescence. The assay is sensitive and specific. We have used this assay to determine the binding characteristics of several disease associated T cell determinants and their sequence analogues in the Lewis rat. Notably, most of the autoimmune disease associated peptide sequences tested were found...

  17. Protective effect of Aster tataricus extract on retinal damage on the virtue of its antioxidant and anti-inflammatory effect in diabetic rat.

    Science.gov (United States)

    Du, Hao; Zhang, Meng; Yao, Kejun; Hu, Zhitao

    2017-03-02

    Effect of Aster tataricus (AT) was estimated on the retinal injury in diabetic rats by its antioxidant and anti-inflammatory activity. Streptozotocin (STZ) was used to induce diabetes at a dose of 60mg/kg, i.p. and blood glucose was estimated to confirm the diabetic rats. All the animals were separated in to 5 different groups (n=10) such as control, diabetic retinopathy (DR) receives saline solution, and AT treated group receives AT (100, 200 and 400mg/kg) for the duration of 8 week. After treatment protocol period blood glucose and HbA1c% was estimated in the blood sample of diabetic rats. Retinal tissue was isolated for the fundus photography and retinal vessel diameter, retinal vascular permeability and leukocytosis were estimated. Moreover in the retinal tissue homogenate oxidative stress parameters such as superoxide dismutase (SOD), glutathione peroxidase (GSH) and catalase (CAT) and concentration of cytokines (TNFα, IL10) was estimated. Result of the study suggested that root extract of AT contain rich amount of polyphenol in it which significantly reduces the body weight and concentration of glucose in blood in diabetic rats. Fundus photography suggested that AT extract attenuates the structure and functional abnormalities that develops due to diabetes. Retinal leukocytosis and vascular permeability was significantly decreases in AT treated group than DR group. There was significant increase in the activity of GSH, CAT and SOD in AT treated group than DR group. Moreover AT also attenuates the altered concentration of TNFα, IL10 and NF-κB in the retina of STZ induced diabetic rat. Thus present study concludes that root extract of AT effectively manages the diabetic retinopathy by controlling the blood glucose and also by attenuating the altered oxidative stresss and inflammatory mediators such as TNFα, IL10 and NF-κB in the retina of STZ induced diabetic rat.

  18. Protective effects of PF-4708671 against N-methyl-d-aspartic acid-induced retinal damage in rats.

    Science.gov (United States)

    Hayashi, Ikumi; Aoki, Yuto; Ushikubo, Hiroko; Asano, Daiki; Mori, Asami; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

    2016-12-01

    We previously demonstrated that rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), protects against N-methyl-d-aspartic acid (NMDA)-induced retinal damage in rats. Rapamycin inhibits mTOR activity, thereby preventing the phosphorylation of ribosomal protein S6, which is a downstream target of S6 kinase. Therefore, we aimed to determine whether PF-4708671, an inhibitor of S6 kinase, protects against NMDA-induced retinal injury. Intravitreal injection of NMDA (200 nmol/eye) caused cell loss in the ganglion cell layer and neuroinflammatory responses, such as an increase in the number of CD45-positive leukocytes and Iba1-positive microglia. Surprisingly, simultaneous injection of PF-4708671 (50 nmol/eye) with NMDA significantly attenuated these responses without affecting phosphorylated S6 levels. These results suggest that PF-4708671 and rapamycin likely protect against NMDA-induced retinal damage via distinct pathways. The neuroprotective effect of PF-4708671 is unlikely to be associated with inhibition of the S6 kinase, even though PF-4708671 is reported to be a S6 kinase inhibitor.

  19. Co-expression of two subtypes of melatonin receptor on rat M1-type intrinsically photosensitive retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Wen-Long Sheng

    Full Text Available Intrinsically photosensitive retinal ganglion cells (ipRGCs are involved in circadian and other non-image forming visual responses. An open question is whether the activity of these neurons may also be under the regulation mediated by the neurohormone melatonin. In the present work, by double-staining immunohistochemical technique, we studied the expression of MT1 and MT2, two known subtypes of mammalian melatonin receptors, in rat ipRGCs. A single subset of retinal ganglion cells labeled by the specific antibody against melanopsin exhibited the morphology typical of M1-type ipRGCs. Immunoreactivity for both MT1 and MT2 receptors was clearly seen in the cytoplasm of all labeled ipRGCs, indicating that these two receptors were co-expressed in each of these neurons. Furthermore, labeling for both the receptors were found in neonatal M1 cells as early as the day of birth. It is therefore highly plausible that retinal melatonin may directly modulate the activity of ipRGCs, thus regulating non-image forming visual functions.

  20. Multi-modal proteomic analysis of retinal protein expression alterations in a rat model of diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Heather D VanGuilder

    Full Text Available BACKGROUND: As a leading cause of adult blindness, diabetic retinopathy is a prevalent and profound complication of diabetes. We have previously reported duration-dependent changes in retinal vascular permeability, apoptosis, and mRNA expression with diabetes in a rat model system. The aim of this study was to identify retinal proteomic alterations associated with functional dysregulation of the diabetic retina to better understand diabetic retinopathy pathogenesis and that could be used as surrogate endpoints in preclinical drug testing studies. METHODOLOGY/PRINCIPAL FINDINGS: A multi-modal proteomic approach of antibody (Luminex-, electrophoresis (DIGE-, and LC-MS (iTRAQ-based quantitation methods was used to maximize coverage of the retinal proteome. Transcriptomic profiling through microarray analysis was included to identify additional targets and assess potential regulation of protein expression changes at the mRNA level. The proteomic approaches proved complementary, with limited overlap in proteomic coverage. Alterations in pro-inflammatory, signaling and crystallin family proteins were confirmed by orthogonal methods in multiple independent animal cohorts. In an independent experiment, insulin replacement therapy normalized the expression of some proteins (Dbi, Anxa5 while other proteins (Cp, Cryba3, Lgals3, Stat3 were only partially normalized and Fgf2 and Crybb2 expression remained elevated. CONCLUSIONS/SIGNIFICANCE: These results expand the understanding of the changes in retinal protein expression occurring with diabetes and their responsiveness to normalization of blood glucose through insulin therapy. These proteins, especially those not normalized by insulin therapy, may also be useful in preclinical drug development studies.

  1. PROPERTIES OF PROLIFERATION AND DIFFERENTIATION OF NEONATAL RAT RETINAL PROGENITOR CELLS IN VITRO

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Neural stem or progenitor cells are i mmature,multipotent cells that have the capacityto differenti-ate into the three CNSlineages(neurons,astrocytesand oligodendrocytes)[1].Neuronal degeneration isthe cause of visual i mpair ment associated with prev-alent ocular diseases such as retinitis pigmentosa,age-related macular degeneration,retinal detach-ment and glaucoma[2].Transplantation of culturedneural stemcells/progenitors may helprestore visionby repopulating the damaged retina and replacingthe degenerati...

  2. Laser speckle imaging of rat retinal blood flow with hybrid temporal and spatial analysis method

    Science.gov (United States)

    Cheng, Haiying; Yan, Yumei; Duong, Timothy Q.

    2009-02-01

    Noninvasive monitoring of blood flow in retinal circulation will reveal the progression and treatment of ocular disorders, such as diabetic retinopathy, age-related macular degeneration and glaucoma. A non-invasive and direct BF measurement technique with high spatial-temporal resolution is needed for retinal imaging. Laser speckle imaging (LSI) is such a method. Currently, there are two analysis methods for LSI: spatial statistics LSI (SS-LSI) and temporal statistical LSI (TS-LSI). Comparing these two analysis methods, SS-LSI has higher signal to noise ratio (SNR) and TSLSI is less susceptible to artifacts from stationary speckle. We proposed a hybrid temporal and spatial analysis method (HTS-LSI) to measure the retinal blood flow. Gas challenge experiment was performed and images were analyzed by HTS-LSI. Results showed that HTS-LSI can not only remove the stationary speckle but also increase the SNR. Under 100% O2, retinal BF decreased by 20-30%. This was consistent with the results observed with laser Doppler technique. As retinal blood flow is a critical physiological parameter and its perturbation has been implicated in the early stages of many retinal diseases, HTS-LSI will be an efficient method in early detection of retina diseases.

  3. The Effects of a Chactoid Scorpion Venom and Its Purified Toxins on Rat Blood Pressure and Mast Cells Histamine Release

    OpenAIRE

    2013-01-01

    The effect of the venom of the Chactoid family of scorpions on blood pressure was scantly investigated and was addressed in the present study using the venom of the Israeli scorpion, Scorpio maurus palmatus. Blood pressure in rats was monitored via cannulated femoral artery, while venom and toxins were introduced into femoral vein. Venom injection elicited a biphasic effect, expressed first by a fast and transient hypotensive response, which lasted up to 10 min, followed by a hypertensive res...

  4. Light-Emitting Diodes and Cool White Fluorescent Light Similarly Suppress Pineal Gland Melatonin and Maintain Retinal Function and Morphology in the Rat. Part 1

    Science.gov (United States)

    Holley, Daniel C.; Heeke, D.; Mele, G.

    1999-01-01

    Currently, the light sources most commonly used in animal habitat lighting are cool white fluorescent or incandescent lamps. We evaluated a novel light-emitting diode (LED) light source for use in animal habitat lighting by comparing its effectiveness to cool white fluorescent light (CWF) in suppressing pineal gland melatonin and maintaining normal retinal physiology and morphology in the rat. Results of pineal melatonin suppression experiments showed equal suppression of pineal melatonin concentrations for LED light and CWF light at five different light illuminances (100, 40, 10, 1 and 0.1 lux). There were no significant differences in melatonin suppression between LED and CWF light when compared to unexposed controls. Retinal physiology was evaluated using electroretinography. Results show no differences in a-wave implicit times and amplitudes or b-wave implicit times and amplitudes between 100-lux LED-exposed rats and 100-lux CWF-exposed rats. Results of retinal histology assessment show no differences in retinal thickness rod outer segment length and number of rod nuclei between rats exposed to 100-lux LED and 100-lux CWF for days. Furthermore, the retinal pigmented epithelium and rod outer segments of all eyes observed were in good condition and of normal thickness. This study indicates that LED light does not cause retinal damage and can suppress pineal melatonin at similar intensities as a conventional CWF light source. These data suggest that LED light sources may be suitable replacements for conventional light sources used in the lighting of rodent vivariums while providing many mechanical and economical advantages.

  5. Histological and electrophysiological changes in the retinal pigment epithelium after injection of sodium iodate in the orbital venus plexus of pigmented rats

    Directory of Open Access Journals (Sweden)

    Hamid Aboutaleb Kadkhodaeian

    2016-01-01

    Conclusion: NaIO3injection into the retrobulbar venous plexus of pigmented rats can result in significant and progressive damage to the RPE and subsequently to the neuroretina of the injected eye, and may serve as a model of retinal degeneration.

  6. Acute and subchronic toxicity study of Tamra bhasma (incinerated copper prepared from Ashodhita (unpurified and Shodhita (purified tamra in rats

    Directory of Open Access Journals (Sweden)

    C Y Jagtap

    2013-01-01

    Full Text Available The use of metals in traditional medicines is very often seen as matter of concern these days, especially the Bhasma preparations which are always under stringent observations for containing highly reactive inorganic elements such as lead, mercury, arsenic and others. One of the Bhasma extensively used in routine Ayurvedic practice is Tamra (copper bhasma. If it is not prepared properly or Shodhana procedure is not done properly, it acts as a poison. To indicate its toxic potential, Ashtamahadoshas (eight major ill effects have been quoted in classics and due emphasis have been given to its Shodhana procedure. In the present study, Tamra bhasma prepared from Shodhita and Ashodhita Tamra was subjected to oral toxicity study to ascertain the role of Shodhana process on safety profile of Tamra bhasma on subchronic administration to albino rats. Both the samples were administered to rats for 45 consecutive days at the doses of 5.5, 27.5, and 55 mg/kg. Animals were sacrificed on 46 th day and parameters like hematological, serum biochemical, and histopathology of various organs were studied. Results showed that Tamra bhasma prepared from Ashodhita Tamra has pathological implications on different hematological, serum biochemical and cytoarchitecture of different organs even at therapeutic dose level (5.5 mg/kg. Whereas, Tamra bhasma prepared from Shodhita Tamra is safe even at five-fold to therapeutic equivalent doses (27.5 mg/kg. These observations emphasize the role of Shodhana and importance of dose in expression of toxicity of the medicinal preparations.

  7. Baclofen Protects Primary Rat Retinal Ganglion Cells from Chemical Hypoxia-Induced Apoptosis through the Akt and PERK Pathways

    Directory of Open Access Journals (Sweden)

    Pingping Fu

    2016-11-01

    Full Text Available Retinal ganglion cells (RGCs consume large quantities of energy to convert light information into a neuronal signal, which makes them highly susceptible to hypoxic injury. This study aimed to investigate the potential protection by baclofen, a GABAB receptor agonist, of retinal ganglion cells against hypoxia-induced apoptosis. CoCl2 was applied to mimic hypoxia. Primary rat retinal ganglion cells (RGCs were subjected to CoCl2 with or without baclofen treatment, and RNA interference techniques were used to knock down the GABAB2 gene in the primary RGCs. The viability and apoptosis of RGCs were assessed using cell viability and TUNEL assays, Hoechst staining, and flow cytometry. The expression of cleaved caspase-3, bcl-2, bax, Akt, phospho-Akt, PERK, phospho-PERK, eIF2α, phospho-eIF2α, ATF-4, and CHOP were measured using western blotting. GABAB2 mRNA expression was determined using quantitative real-time polymerase chain reaction (qRT-PCR analysis. Our study revealed that CoCl2 significantly induced RGC apoptosis and that baclofen reversed these effects. CoCl2-induced reduction of Akt activity was also reversed by baclofen. Baclofen prevented the activation of the PERK pathway and the increase in CHOP expression induced by CoCl2. Knockdown of GABAB2 and the inactivation of the Akt pathway by inhibitors reduced the protective effect of baclofen on CoCl2-treated RGCs. Taken together, these results demonstrate that baclofen protects RGCs from CoCl2-induced apoptosis by increasing Akt activity and by suppressing the PERK pathway and CHOP activation.

  8. The Effects of a Chactoid Scorpion Venom and Its Purified Toxins on Rat Blood Pressure and Mast Cells Histamine Release

    Directory of Open Access Journals (Sweden)

    Philip Lazarovici

    2013-07-01

    Full Text Available The effect of the venom of the Chactoid family of scorpions on blood pressure was scantly investigated and was addressed in the present study using the venom of the Israeli scorpion, Scorpio maurus palmatus. Blood pressure in rats was monitored via cannulated femoral artery, while venom and toxins were introduced into femoral vein. Venom injection elicited a biphasic effect, expressed first by a fast and transient hypotensive response, which lasted up to 10 min, followed by a hypertensive response, which lasted up to one hour. It was found that these effects resulted from different venom components. Phospholipase A2 produced the hypotensive effect, while a non-enzymatic neurotoxic polypeptide fraction produced the hypertensive effect. Surprisingly, the main neurotoxic polypeptide to mice had no effect on blood pressure. In vitro experiments indicated that the hypertensive factors caused histamine release from the peritoneal mast cells, but this effect is assumed to be not relevant to their in vivo effect. In spite of the cytotoxic activity of phospholipase A2, it did not release histamine. These findings suggest that the effects of venom and isolated fractions on blood pressure parameters are mediated by different mechanisms, which deserve further pharmacological investigation.

  9. The effects of a chactoid scorpion venom and its purified toxins on rat blood pressure and mast cells histamine release.

    Science.gov (United States)

    Ettinger, Keren; Cohen, Gadi; Momic, Tatjana; Lazarovici, Philip

    2013-07-29

    The effect of the venom of the Chactoid family of scorpions on blood pressure was scantly investigated and was addressed in the present study using the venom of the Israeli scorpion, Scorpio maurus palmatus. Blood pressure in rats was monitored via cannulated femoral artery, while venom and toxins were introduced into femoral vein. Venom injection elicited a biphasic effect, expressed first by a fast and transient hypotensive response, which lasted up to 10 min, followed by a hypertensive response, which lasted up to one hour. It was found that these effects resulted from different venom components. Phospholipase A₂ produced the hypotensive effect, while a non-enzymatic neurotoxic polypeptide fraction produced the hypertensive effect. Surprisingly, the main neurotoxic polypeptide to mice had no effect on blood pressure. In vitro experiments indicated that the hypertensive factors caused histamine release from the peritoneal mast cells, but this effect is assumed to be not relevant to their in vivo effect. In spite of the cytotoxic activity of phospholipase A₂, it did not release histamine. These findings suggest that the effects of venom and isolated fractions on blood pressure parameters are mediated by different mechanisms, which deserve further pharmacological investigation.

  10. Gene therapy with brain-derived neurotrophic factor as a protection: retinal ganglion cells in a rat glaucoma model.

    Science.gov (United States)

    Martin, Keith R G; Quigley, Harry A; Zack, Donald J; Levkovitch-Verbin, Hana; Kielczewski, Jennifer; Valenta, Danielle; Baumrind, Lisa; Pease, Mary Ellen; Klein, Ronald L; Hauswirth, William W

    2003-10-01

    To develop a modified adenoassociated viral (AAV) vector capable of efficient transfection of retinal ganglion cells (RGCs) and to test the hypothesis that use of this vector to express brain-derived neurotrophic factor (BDNF) could be protective in experimental glaucoma. Ninety-three rats received one unilateral, intravitreal injection of either normal saline (n = 30), AAV-BDNF-woodchuck hepatitis posttranscriptional regulatory element (WPRE; n = 30), or AAV-green fluorescent protein (GFP)-WPRE (n = 33). Two weeks later, experimental glaucoma was induced in the injected eye by laser application to the trabecular meshwork. Survival of RGCs was estimated by counting axons in optic nerve cross sections after 4 weeks of glaucoma. Transgene expression was assessed by immunohistochemistry, Western blot analysis, and direct visualization of GFP. The density of GFP-positive cells in retinal wholemounts was 1,828 +/- 299 cells/mm(2) (72,273 +/- 11,814 cells/retina). Exposure to elevated intraocular pressure was similar in all groups. Four weeks after initial laser treatment, axon loss was 52.3% +/- 27.1% in the saline-treated group (n = 25) and 52.3% +/- 24.2% in the AAV-GFP-WPRE group (n = 30), but only 32.3% +/- 23.0% in the AAV-BDNF-WPRE group (n = 27). Survival in AAV-BDNF-WPRE animals increased markedly and the difference was significant compared with those receiving either AAV-GFP-WPRE (P = 0.002, t-test) or saline (P = 0.006, t-test). Overexpression of the BDNF gene protects RGC as estimated by axon counts in a rat glaucoma model, further supporting the potential feasibility of neurotrophic therapy as a complement to the lowering of IOP in the treatment of glaucoma.

  11. Retinal adaptation to changing glycemic levels in a rat model of type 2 diabetes

    DEFF Research Database (Denmark)

    Johnson, Leif E; Larsen, Michael; Perez, Maria-Thereza

    2013-01-01

    PURPOSE: Glucose concentrations are elevated in retinal cells in undiagnosed and in undertreated diabetes. Studies of diabetic patients suggest that retinal function adapts, to some extent, to this increased supply of glucose. The aim of the present study was to examine such adaptation in a model...... by a reduction in a-wave amplitudes and maximum slopes of about 30%. A direct effect of insulin on the ERG was unlikely since the expression of phosphorylated Akt kinase was not affected by treatment. The electrophysiological differences between untreated ZDFs and controls preceded an activation of Müller cells...... in the ZDFs (up-regulation of glial fibrillary acidic protein), which was attenuated by insulin treatment. There were otherwise no signs of cell death or morphological alterations in any of the experimental groups. These data show that under chronic hyperglycemia, the ZDF retina became abnormally sensitive...

  12. Effects of minocycline on apoptosis and neuronal changes in retinal ganglion cells from experimental optic neuritis rats

    Institute of Scientific and Technical Information of China (English)

    Jing Zhang

    2008-01-01

    BACKGROUND: Minocycline, a tetracycline derivative, is neuroprotective in models of various neurological diseases.OBJECTIVE: To investigate the effects of minocycline on retinal ganglion cells (RGCs) in rats with optic neuritis, and to compare with the effects of methylprednisolone.DESIGN, TIME AND SETTING: This neuropathology controlled study was performed at the First Affiliated Hospital, Chongqing Medical University, China in May 2007.MATERIALS: A total of 22 female Wistar rats were randomly assigned into a normal control group (n = 5) and an experimental group (n = 17). The experimental group was composed of a model subgroup (n = 7), a minocycline subgroup (n = 5), and a methylprednisolone subgroup (n = 5). Minocycline was supplied by Sigma, USA.METHODS: Antigen homogenate made from guinea pig spinal cord and complete Freund adjuvant was used to induce autoimmune encephalomyelitis, which could induce demyelinated optic neuritis models. Rats in the minocycline subgroup were intraperitoneally injected with minocycline (45 mg/kg) daily from day 8 following autoimmunity. Rats in the methylprednisolone subgroup were intraperitoneally injected with methylprednisolone (20 mg/kg) daily from day 8 following autoimmunity.MAIN OUTCOME MEASURES: On day 18 after autoimmunity induction, pathological changes in the optic nerve were observed by hematoxylin-eosin staining. The percentage area of axons in the transverse section of the optic nerve was measured by Bielschowsky staining. Apoptosis of RGCs was detected by TUNEL.RESULTS: Under an optical microscope, the optic nerve in rats with demyelinated optic neuritis showed a vacuole-like structure of fibers, irregular swelling of the axons, and infiltration of a large quantity of inflammatory cells. With an electron microscope, the optic nerve presented with vacuole-like structures in the axons, a small percentage area of axons in the transverse section, loose myelin sheaths, and microtubules and microfilaments disappeared. The

  13. Suppression of outward K⁺ currents by WIN55212-2 in rat retinal ganglion cells is independent of CB1/CB2 receptors.

    Science.gov (United States)

    Zhang, C-Q; Wu, H-J; Wang, S-Y; Yin, S; Lu, X-J; Miao, Y; Wang, X-H; Yang, X-L; Wang, Z

    2013-12-03

    Cannabinoid CB1 receptor (CB1R) signaling system is extensively distributed in the vertebrate retina. Activation of CB1Rs regulates a variety of functions of retinal neurons through modulating different ion channels. In the present work we studied effects of this receptor signaling on K(+) channels in retinal ganglion cells by patch-clamp techniques. The CB1R agonist WIN55212-2 (WIN) suppressed outward K(+) currents in acutely isolated rat retinal ganglion cells in a dose-dependent manner, with an IC50 of 4.7 μM. We further showed that WIN mainly suppressed the tetraethylammonium (TEA)-sensitive K(+) current component. While CB1Rs were expressed in rat retinal ganglion cells, the WIN effect on K(+) currents was not blocked by either AM251/SR141716, specific CB1R antagonists, or AM630, a selective CB2R antagonist. Consistently, cAMP-protein kinase A (PKA) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathways were unlikely involved in the WIN-induced suppression of the K(+) currents because both PKA inhibitors H-89/Rp-cAMP and MAPK/ERK1/2 inhibitor U0126 failed to block the WIN effects. WIN-induced suppression of the K(+) currents was not observed when WIN was intracellularly applied. Furthermore, an endogenous ligand of the cannabinoid receptor anandamide, the specific CB1R agonist ACEA and the selective CB2R agonist CB65 also suppressed the K(+) currents, and the effects were not blocked by AM251/SR141716 or AM630 respectively. All these results suggest that the WIN-induced suppression of the outward K(+) currents in rat retinal ganglion cells, thereby regulating the cell excitability, were not through CB1R/CB2R signaling pathways.

  14. Kv3 channels modulate calcium signals induced by fast firing patterns in the rat retinal ganglion cells.

    Science.gov (United States)

    Kuznetsov, Kirill I; Grygorov, Oleksii O; Maslov, Vitaly Yu; Veselovsky, Nikolay S; Fedulova, Svetlana A

    2012-11-01

    Expression of non-inactivating Kv3.1/Kv3.2 potassium channels determines fast-spiking phenotype of many types of neurones including retinal ganglion cells (RGCs); furthermore Kv3 channels regulate neurotransmitter release from presynaptic terminals. In the present study we investigated how inhibition of Kv3 channel by low TEA concentrations modifies firing properties and Ca2+ influx in the rat RGCs. Experiments were performed on the whole-mount retinal preparations from 4 to 6 weeks old Wistar rats using simultaneous whole cell patch clamp and intracellular Ca2+ measurements in combination with single-cell RT-PCR. In response to 500-ms depolarization step the RGCs demonstrated fast firing tonic behaviour with a mean frequency of spiking 61±5 Hz (n=28). All of the tonic cells tested (n=9) expressed specific mRNA for either Kv3.1 or Kv3.2 or for both channels. Bath applications of TEA (250 μM, 500 μM and 1 mM) modified firing patterns dose-dependently as follows: firing frequency was decreased, mean action potential (AP) half-width increased and mean amplitude of after hyperpolarization was reduced. The amplitude of the Ca2+ signals induced by the cells firing was linearly dependent on number of APs with a mean slope of 7.3±0.9 nM per one AP (n=8). APs widening by TEA increased the slope of the amplitude vs. AP number plots in a dose-dependent manner: 250 μM of TEA increased the mean slope value to 9.5±1.2 nM/AP, 500 μM to 12.4±2.4 nM/AP and 1 mM to 13.2±2.9 nM/AP (n=6). All these parameters, as well as the cells firing properties, were significantly different from controls and from each other except between 500 μM and 1 mM. This is consistent with the pharmacological properties of Kv3.1/Kv3.2 channels: the TEA IC50 is in the range 150-300 μM with almost complete block at 1 mM. This suggests that Kv3.1/Kv3.2 channels underlie the fast firing of the rat RGCs and provide at a given firing frequency 1.8-fold restriction Ca2+ influx, thus protecting the cells

  15. iPSC-Derived Retinal Pigment Epithelium Allografts Do Not Elicit Detrimental Effects in Rats: A Follow-Up Study

    Directory of Open Access Journals (Sweden)

    Peter D. Westenskow

    2016-01-01

    Full Text Available Phototransduction is accomplished in the retina by photoreceptor neurons and retinal pigment epithelium (RPE cells. Photoreceptors rely heavily on the RPE, and death or dysfunction of RPE is characteristic of age-related macular degeneration (AMD, a very common neurodegenerative disease for which no cure exists. RPE replacement is a promising therapeutic intervention for AMD, and large numbers of RPE cells can be generated from pluripotent stem cells. However, questions persist regarding iPSC-derived RPE (iPS-RPE viability, immunogenicity, and tumorigenesis potential. We showed previously that iPS-RPE prevent photoreceptor atrophy in dystrophic rats up until 24 weeks after implantation. In this follow-up study, we longitudinally monitored the same implanted iPS-RPE, in the same animals. We observed no gross abnormalities in the eyes, livers, spleens, brains, and blood in aging rats with iPSC-RPE grafts. iPS-RPE cells that integrated into the subretinal space outlived the photoreceptors and survived for as long as 2 1/2 years while nonintegrating RPE cells were ingested by host macrophages. Both populations could be distinguished using immunohistochemistry and electron microscopy. iPSC-RPE could be isolated from the grafts and maintained in culture; these cells also phagocytosed isolated photoreceptor outer segments. We conclude that iPS-RPE grafts remain viable and do not induce any obvious associated pathological changes.

  16. Aqueous humor enhances the proliferation of rat retinal precursor cells in culture, and this effect is partially reproduced by ascorbic acid

    DEFF Research Database (Denmark)

    Yang, Jing; Klassen, Henry; Pries, Mette

    2006-01-01

    Aqueous humor has been shown to influence the proliferation of various ocular cell types, but the effect on immature retinal cells is not known. Here, the effect of pig aqueous humor on the proliferation of rat retinal precursor cells (RPCs) was investigated. RPCs were prepared from embryonic day...... 19 Sprague-Dawley rats and cultured in the presence or absence of aqueous humor from healthy pigs along with a medium consisting of Dulbecco's modified Eagle's medium:Ham's F-12 medium, N2 supplement, and epidermal growth factor. Proliferation was quantified by [(3)H]thymidine incorporation under...... different treatment conditions, and any associated morphological changes were noted. Potential active components of porcine aqueous humor were partially characterized by gel filtration chromatography, and the effect on RPC proliferation was determined. Results showed that adding 20% aqueous humor increased...

  17. Retinal Ganglion Cell Protection Via Topical and Systemic Alpha-Tocopherol Administration in Optic Nerve Crush Model of Rat

    Directory of Open Access Journals (Sweden)

    Zeynep Aktaş

    2013-06-01

    Full Text Available Pur po se: The aim of our study was to investigate the neuroprotective effects of topical α-tocopherol in optic nerve crush model of rat and to compare its efficacy with that of systemic α -tocopherol. Ma te ri al and Met hod: 50 eyes of 25 Wistar albino rats were included. The eyes were divided into six groups. Optic nerve crush was performed in Groups 1, 3, 5. Additionally, systemic and topical α-tocopherol therapies were given to Groups 1 and 3, respectively. No treatment was applied in Group 5. Groups 2, 4, and 6 were the fellow eyes of the animals comprising Groups 1, 3, and 5. Eyes were enucleated at day 45 of the study. Retinal ganglion cells (RGCs were counted with light microscopy. Re sults: Mean RGC numbers were 14.5±3.7 (10.3-20 and 27.5±2.6 (24-30 in Groups 5 and 6, respectively (p: 0.001 They were measured to be 26.6±7.8 (19-45 and 24.6±3.9 (20-32 in Groups 1 and 2 and 21.1±7.1 (11-34 and 27±7.5 (18-42 in Groups 3 and 4 (p:0.659, p:0.094, respectively. There was no difference in Groups 2 and 4 compared with Group 6 (p:0.210, p:0.299, respectively. Dis cus si on: Topical α-tocopherol has a significant neuroprotective effects in optic nerve crush model of rat and may be used in the future for the treatment of optic neuropathies such as glaucoma. (Turk J Ophthalmol 2013; 43: 161-6

  18. Effects of pyruvate on retinal oxidative damage and retinal ultrastructure in diabetic rats%丙酮酸对糖尿病大鼠视网膜氧化损伤及超微结构的影响

    Institute of Scientific and Technical Information of China (English)

    齐艳秀; 符俊达; 王玉清; 王冬兰

    2014-01-01

    目的:研究糖尿病大鼠视网膜病变过程中视网膜组织学和氧化应激的变化,以及丙酮酸的对抗作用。  方法:将80只Wistar大鼠分成3组:对照组(20只),模型组(30只),治疗组(30只)。模型组和治疗组用STZ诱导糖尿病,治疗组在大鼠饲料和饮水中添加2%丙酮酸。观察大鼠的血糖、体质量变化,并在造模后12 wk观察3组大鼠视网膜组织中GSH-Px、MDA和Na+-K+-ATP酶水平及其超微结构改变。  结果:模型组和对照组相比,体质量显著下降,视网膜中GSH-Px和ATP酶活性显著下降,MDA水平显著升高,视网膜超微结构有显著改变;治疗组和模型组相比,血糖没有显著改变,视网膜组织中 GSH-Px 和 ATP 水平升高, MDA水平下降,视网膜超微结构病变相对较轻。  结论:丙酮酸可以减轻氧化应激反应,改善视网膜的能量代谢,延缓视网膜病变的发展。%AlM:To investigate the changes of retinal histology and oxidative stress in diabetic retinopathy and its reversal by pyruvate in diabetic rats. METHODS: Eighty Wistar rats were divided into 3 groups:control group ( 20 rats ) , model group ( 30 rats ) and treatment group ( 30 rats ) . After streptozotocin ( STZ) induced diabetes mellitus in the model group and the treatment group, the treatment group received 2%pyruvate in diet and drinking. The changes of body weight and blood glucose were observed and the changes of glutathione peroxidase ( GSH-PX ) , malonie dialdehyde ( MDA) , and Na+-K+-ATPase levels of retinal tissue and retinal ultrastructure were investigated in three groups at 12wk after occurrence of diabetes. RESULTS: Compared with control group, the body weight of the model group were significantly decreased, the activities of GSH-PX and ATP in the retina of diabetic rats were significantly lower, the MDA was signigicantly higher and significant changes occurred in retinal ultrastructure. Compared with model group, the blood glucose of

  19. Hearing impairment in the P23H-1 retinal degeneration rat model

    Directory of Open Access Journals (Sweden)

    Jorge V. Sotoca

    2014-09-01

    Full Text Available The transgenic P23H line 1 (P23H-1 rat expresses a variant of rhodopsin with a mutation that leads to loss of visual function. This rat strain is an experimental model usually employed to study photoreceptor degeneration. Although the mutated protein should not interfere with other sensory functions, observing severe loss of auditory reflexes in response to natural sounds led us to study auditory brain response (ABR recording. Animals were separated into different hearing levels following the response to natural stimuli (hand clapping and kissing sounds. Of all the analyzed animals, 25.9% presented auditory loss before 50 days of age (P50 and 45% were totally deaf by P200. ABR recordings showed that all the rats had a higher hearing threshold than the control Sprague-Dawley (SD rats, which was also higher than any other rat strains. The integrity of the central and peripheral auditory pathway was analyzed by histology and immunocytochemistry. In the cochlear nucleus (CN, statistical differences were found between SD and P23H-1 rats in VGluT1 distribution, but none were found when labeling all the CN synapses with anti-Syntaxin. This finding suggests anatomical and/or molecular abnormalities in the auditory downstream pathway. The inner ear of the hypoacusic P23H-1 rats showed several anatomical defects, including loss and disruption of hair cells and spiral ganglion neurons. All these results can explain, at least in part, how hearing impairment can occur in a high percentage of P23H-1 rats. P23H-1 rats may be considered an experimental model with visual and auditory dysfunctions in future research.

  20. Restoration of visual performance by d-serine in models of inner and outer retinal dysfunction assessed using sweep VEP measurements in the conscious rat and rabbit.

    Science.gov (United States)

    Staubli, Ursula; Rangel-Diaz, Natalie; Alcantara, Miguel; Li, Yong-Xin; Yang, Jia-Ying; Zhang, Kai-Ming; Foster, Alan C

    2016-10-01

    The NMDA subtype of glutamate receptor and its co-agonist d-serine play a key role in synaptic function in the central nervous system (CNS), including visual cortex and retina. In retinal diseases such as glaucoma and macular degeneration, a loss of vision arises from malfunction of retinal cells, resulting in a glutamate hypofunctional state along the visual pathway in the affected parts of the visual field. An effective strategy to remedy this loss of function might be to increase extracellular levels of d-serine and thereby boost synaptic NMDA receptor-mediated visual transmission and/or plasticity to compensate for the impairment. We tested this idea in brain slices of visual cortex exhibiting long-term potentiation, and in rodent models of visual dysfunction caused by retinal insults at a time when the injury had stabilized to look for neuroenhancement effects. An essential aspect of the in vivo studies involved adapting sweep VEP technology to conscious rats and rabbits and combining it with intracortical recording while the animals were actively attending to visual information. Using this technology allowed us to establish complete contrast sensitivity function curves. We found that systemic d-serine dose-dependently rescued the contrast sensitivity impairment in rats with blue light-induced visual dysfunction. In rabbits with inner retinal dysfunction, both systemic and intravitreal routes of d-serine provided a rescue of visual function. In sum, we show that co-agonist stimulation of the NMDA receptor via administration of exogenous d-serine might be an effective therapeutic strategy to enhance visual performance and compensate for the loss of vision resulting from retinal disease.

  1. Brain-derived neurotrophic factor inhibits osmotic swelling of rat retinal glial (Müller) and bipolar cells by activation of basic fibroblast growth factor signaling.

    Science.gov (United States)

    Berk, B-A; Vogler, S; Pannicke, T; Kuhrt, H; Garcia, T B; Wiedemann, P; Reichenbach, A; Seeger, J; Bringmann, A

    2015-06-04

    Water accumulation in retinal glial (Müller) and neuronal cells resulting in cellular swelling contributes to the development of retinal edema and neurodegeneration. Intravitreal administration of neurotrophins such as brain-derived neurotrophic factor (BDNF) is known to promote survival of retinal neurons. Here, we show that exogenous BDNF inhibits the osmotic swelling of Müller cell somata induced by superfusion of rat retinal slices or freshly isolated cells with a hypoosmotic solution containing barium ions. BDNF also inhibited the osmotic swelling of bipolar cell somata in retinal slices, but failed to inhibit the osmotic soma swelling of freshly isolated bipolar cells. The inhibitory effect of BDNF on Müller cell swelling was mediated by activation of tropomyosin-related kinase B (TrkB) and transactivation of fibroblast growth factor receptors. Exogenous basic fibroblast growth factor (bFGF) fully inhibited the osmotic swelling of Müller cell somata while it partially inhibited the osmotic swelling of bipolar cell somata. Isolated Müller cells displayed immunoreactivity of truncated TrkB, but not full-length TrkB. Isolated rod bipolar cells displayed immunoreactivities of both TrkB isoforms. Data suggest that the neuroprotective effect of exogenous BDNF in the retina is in part mediated by prevention of the cytotoxic swelling of retinal glial and bipolar cells. While BDNF directly acts on Müller cells by activation of TrkB, BDNF indirectly acts on bipolar cells by inducing glial release of factors like bFGF that inhibit bipolar cell swelling.

  2. Effects of BmKNJX11, a bioactive polypeptide purified from Buthus martensi Karsch, on sodium channels in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Wang, Xi-Jie; An, Shan-Shan; Cheng, Hong; Xu, San-Hua; Cheng, Jie; Lu, Wei; Gao, Rong; Xiao, Hang

    2009-01-01

    A long-chain polypeptide BmKNJX11 was purified from the venom of Asian scorpion Buthus martensi Karsch (BmK) by a combination of gel filtration, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography. The molecular mass was found to be 7036.85 Da by electrospray ionization mass spectrometry. The first 15 N-terminal amino acid sequence of BmKNJX11 was determined to be GRDAY IADSE NCTYT by Edman degradation. With whole cell recording, BmKNJX11 inhibited tetrodotoxin-sensitive voltage-gated sodium channels (TTX-S VGSC) in freshly isolated rat dorsal root ganglion (DRG) neurons in a concentration- and voltage-dependent manner. At a concentration of 40 mug/ml BmKNJX11 lowered the activation threshold and produced negative shifting of TTX-S sodium current (I(Na)) activation curve. In addition, BmKNJX11 induced shifting of the steady-state inactivation curve to the left, delayed the recovery of TTX-S I(Na) from inactivation, and also reduced the fraction of available sodium channels. These results suggested that BmKNJX11 might exert effects on VGSC by binding to a specific site. Considering that TTX-S VGSC expressed in DRG neurons play a critical role in nociceptive transmission, the interaction of BmKNJX11 with TTX-S VGSC might lead to a change in excitability of nociceptive afferent fibers, which may be involved in the observed peripheral pain expression.

  3. Effects of semi-purified dietary fibers isolated from Lagenaria siceraria, Raphanus sativus and Lentinus edodes on fecal steroid excretions in rats.

    Science.gov (United States)

    Sannoumaru, Y; Shimizu, J; Nakamura, K; Hayakawa, T; Takita, T; Innami, S

    1996-04-01

    Rats were fed diets, each of which contained 5% of the semi-purified dietary fiber (DF) preparations from three kinds of foods, continuously for a total of 7 weeks. The fat level was varied, and cholesterol (Chol) was added toward the end of the experimental period. After 7 weeks, decreases of serum and liver Chol concentrations were observed in the Shiitake (Lentinus edodes) group when compared to the cellulose (CP) group. In the absence of Chol, fecal excretions of several secondary bile acids and total bile acids were affected by the type of DF, showing an increase particularly in the Shiitake group. Total neutral steroid excretions were decreased in the test DF groups compared to the CP group at both fat levels, and were increased by Chol supplementation in all of the test DF groups. It was demonstrated that the effects of the three DF preparations on fecal steroid excretions somewhat differed depending on the dietary factors. In the absence of Chol, the lithocholic acid (LCA)/deoxycholic acid (DCA) ratio was significantly lowered in the test DF groups compared to the CP group by the fat level elevation, and was affected by the interaction of fiber with fat. This ratio responded more intensely to the dietary factors than the two other indices (composition ratios of fecal bile acids). However, this response was lost in the presence of Chol. These results suggest that further studies are warranted to examine if the intense response of the LCA/DCA ratio to the tested DF preparations and fat in the present study will also be shown to other DF and what significance it has in evaluating the function of DF.

  4. Apigenin prevents TNF-α induced apoptosis of primary rat retinal ganglion cells.

    Science.gov (United States)

    Fu, M-S; Zhu, B-J; Luo, D-W

    2014-11-25

    TNF-α has recently been identified to be a mediator of retinal ganglion cell (RGC) death, while glial cells are relatively protected against this death stimulus. Exposure of RGCs to TNF-α is thought to contribute to RGC apoptosis. Apigenin is a flavone with powerful anti-inflammatory properties that exists naturally in various plants and Chinese medicine. In our study, MTT assays showed that apigenin significantly inhibited the decrease of RGC viability induced by TNF-α in a dose-dependent manner. Pretreatment with apigenin prevented TNF-α-induced apoptosis in a dose-dependent manner as shown by flow cytometry. The production of ATP and the total oxygen uptake were also promoted after apigenin administration. TNF-α stimulation led to a significant reduction of bcl-2 and enhancement of bax, which was reversed by apigenin treatment. Apigenin treatment also alleviated the increased caspase-3 activity induced by TNF-α. Moreover, luciferase reporter assay indicated that apigenin dose-dependently decreased NF-κB activation induced by TNF-α, but had no significant effect on activation of AP-1. Collectively, these data demonstrated that apigenin alleviated TNF-α-induced apoptosis through inhibition of caspase-dependent apoptotic pathway and activation of nuclear factor-kappaB. Therefore, apigenin may be developed as an anti-apoptotic drug to treat retinopathy.

  5. Beta-amyloid precursor protein cleavage enzyme-1 expression in adult rat retinal neurons in the early period after lead exposure

    Institute of Scientific and Technical Information of China (English)

    Jufang Huang; Kai Huang; Lei Shang; Hui Wang; Xiaoxin Yan; Kun Xiong

    2011-01-01

    Previous studies have reported that non-human primates and rodents exposed to lead during brain development may become dependent on the deposition of pre-determined β-amyloid protein (Aβ), and exhibit upregulation of β-site amyloid precursor protein expression in old age. However, further evidence is required to elucidate the precise relationship and molecular mechanisms underlying the effects of early lead exposure on excessive Aβ production in adult mammals. The present study investigated the effects of lead exposure on expression of β-amyloid precursor protein cleavage enzyme-1 (BACE-1) in the rat retina and the production of Aβ in early development, using the retina as a window for studying Alzheimer's disease. Adult rats were intraocularly injected with different doses of lead acetate (10 μmol/L, 100 μmol/L, 1 mmol/L, 10 mmol/L and 100 mmol/L). The results revealed that retinal lead concentration, BACE-1 and its cleavage products β-C-terminal fragment and retina Aβ1-40 were all significantly increased in almost all of the lead exposure groups 48 hours later in a dose-dependent manner. The only exception was the 10 μmol/L group. The distribution of BACE-1 in the retina did not exhibit obvious changes, and no distinctive increase in the activation of retinal microglia was apparent. Similarly, retinal synaptophysin expression did not exhibit any clear changes. These data suggest that lead exposure can result in the upregulation of retinal neuron BACE-1 expression in the early period of development and further increase the overproduction of Aβ1-40 in the retina. Our results provided novel insight into the molecular mechanisms underlying environmentally-induced Alzheimer's disease.

  6. Proteomic Study of Retinal Proteins Associated with Transcorneal Electric Stimulation in Rats

    Directory of Open Access Journals (Sweden)

    Takashi Kanamoto

    2015-01-01

    Full Text Available Background. To investigate how transcorneal electric stimulation (TES affects the retina, by identifying those proteins up- and downregulated by transcorneal electric stimulation (TES in the retina of rats. Methods. Adult Wistar rats received TES on the left eyes at different electrical currents while the right eyes received no treatment and served as controls. After TES, the eye was enucleated and the retina was isolated. The retinas were analyzed by proteomics. Results. Proteomics showed that twenty-five proteins were upregulated by TES. The identified proteins included cellular signaling proteins, proteins associated with neuronal transmission, metabolic proteins, immunological factors, and structural proteins. Conclusions. TES induced changes in expression of various functional proteins in the retina.

  7. 成年大鼠嗅球嗅鞘细胞的纯化实验%Purifying olfactory ensheathing cells from the olfactory bulb of adult rats

    Institute of Scientific and Technical Information of China (English)

    朱仲庚; 吴小涛; 蒋赞利

    2007-01-01

    BACKGROUND: The diversity of purification procedures resulting in various purities of olfactory ensheathing cells (OECs) used for grafting is considered to be relevant in the effectiveness of OECs transplant. It is important to develop a well-defined method which produces OECs of great purity and is easy to unify for the future standardization of research involving OECs.OBJECTIVE: To establish a method being easy to unify for purifying OECs to acquire highly and uniformly enriched population of OECs for standardized studies on cell transplantation.DESIGN: Randomized and controlled experiment.SETTING: Department of Orthopaedics, Affiliated Zhongda Hospital of Southeast University School of Clinical Medicine;Central Laboratory of Southeast University School of Clinical Medicine; Experimental Animal Center of Southeast University School of Clinical Medicine.MATERIALS: This experiment was carried out in the Central Laboratory of Southeast University School of Clinical Medicine from February to August 2006. Twenty-eight adult female SD rats weighing 200-250 g were selected in this study. The main reagents were detailed as follows: DMEM/F-12 (GIBCO); 2.5 g/L trypsin (GIBCO); poly-L-lysine (SIGMA); bovine pituitary extract (BPE, SIGMA); fetal bovine serum (FBS, Sijiqing Biological Agent Co., Ltd., Hangzhou);rabbit anti-low-affinity nerve growth factor receptor (anti-P75, SIGMA); biotinylated goat anti-rabbit IgG (Boster Bioengineering Co., Ltd., Wuhan); methyl thiazolyl tetrazolium (MTT) kit (SIGMA).METHODS: Primary cultures of OECs were separated from adult SD rats olfactory bulbs. At day 8 in vitro, the primary cultures were divided randomly into 4 groups, namely differential adhesion method group, immunoadsorption method group,the modified method group,and control group.①The cell suspension in the modified method group was seeded into uncoated flasks and incubated at 37 ℃ in 0.05 volume fraction of CO2 for 1 hours. The supematants were seeded into flasks that had

  8. Discovery of a novel class of targeted kinase inhibitors that blocks protein kinase C signaling and ameliorates retinal vascular leakage in a diabetic rat model.

    Science.gov (United States)

    Grant, Stephan; Tran, Phong; Zhang, Qin; Zou, Aihua; Dinh, Dac; Jensen, Jordan; Zhou, Sue; Kang, Xiaolin; Zachwieja, Joseph; Lippincott, John; Liu, Kevin; Johnson, Sarah Ludlum; Scales, Stephanie; Yin, Chunfeng; Nukui, Seiji; Stoner, Chad; Prasanna, Ganesh; Lafontaine, Jennifer; Wells, Peter; Li, Hui

    2010-02-10

    Protein kinase C (PKC) family members such as PKCbetaII may become activated in the hyperglycemic state associated with diabetes. Preclinical and clinical data implicate aberrant PKC activity in the development of diabetic microvasculature abnormalities. Based on this potential etiological role for PKC in diabetic complications, several therapeutic PKC inhibitors have been investigated in clinical trials for the treatment of diabetic patients. In this report, we present the discovery and preclinical evaluation of a novel class of 3-amino-pyrrolo[3,4-c]pyrazole derivatives as inhibitors of PKC that are structurally distinct from the prototypical indolocarbazole and bisindolylmaleimide PKC inhibitors. From this pyrrolo-pyrazole series, several compounds were identified from biochemical assays as potent, ATP-competitive inhibitors of PKC activity with high specificity for PKC over other protein kinases. These compounds were also found to block PKC signaling activity in multiple cellular functional assays. PF-04577806, a representative from this series, inhibited PKC activity in retinal lysates from diabetic rats stimulated with phorbol myristate acetate. When orally administered, PF-04577806 showed good exposure in the retina of diabetic Long-Evans rats and ameliorated retinal vascular leakage in a streptozotocin-induced diabetic rat model. These novel PKC inhibitors represent a promising new class of targeted protein kinase inhibitors with potential as therapeutic agents for the treatment of patients with diabetic microvascular complications.

  9. Expression of novel opsins and intrinsic light responses in the mammalian retinal ganglion cell line RGC-5. Presence of OPN5 in the rat retina.

    Directory of Open Access Journals (Sweden)

    Paula S Nieto

    Full Text Available The vertebrate retina is known to contain three classes of photoreceptor cells: cones and rods responsible for vision, and intrinsically photoresponsive retinal ganglion cells (RGCs involved in diverse non-visual functions such as photic entrainment of daily rhythms and pupillary light responses. In this paper we investigated the potential intrinsic photoresponsiveness of the rat RGC line, RGC-5, by testing for the presence of visual and non-visual opsins and assessing expression of the immediate-early gene protein c-Fos and changes in intracellular Ca(2+ mobilization in response to brief light pulses. Cultured RGC-5 cells express a number of photopigment mRNAs such as retinal G protein coupled receptor (RGR, encephalopsin/panopsin (Opn3, neuropsin (Opn5 and cone opsin (Opn1mw but not melanopsin (Opn4 or rhodopsin. Opn5 immunoreactivity was observed in RGC-5 cells and in the inner retina of rat, mainly localized in the ganglion cell layer (GCL. Furthermore, white light pulses of different intensities and durations elicited changes both in intracellular Ca(2+ levels and in the induction of c-Fos protein in RGC-5 cell cultures. The results demonstrate that RGC-5 cells expressing diverse putative functional photopigments display intrinsic photosensitivity which accounts for the photic induction of c-Fos protein and changes in intracellular Ca(2+ mobilization. The presence of Opn5 in the GCL of the rat retina suggests the existence of a novel type of photoreceptor cell.

  10. Differential calcium signaling mediated by voltage-gated calcium channels in rat retinal ganglion cells and their unmyelinated axons.

    Directory of Open Access Journals (Sweden)

    Allison Sargoy

    Full Text Available Aberrant calcium regulation has been implicated as a causative factor in the degeneration of retinal ganglion cells (RGCs in numerous injury models of optic neuropathy. Since calcium has dual roles in maintaining homeostasis and triggering apoptotic pathways in healthy and injured cells, respectively, investigation of voltage-gated Ca channel (VGCC regulation as a potential strategy to reduce the loss of RGCs is warranted. The accessibility and structure of the retina provide advantages for the investigation of the mechanisms of calcium signalling in both the somata of ganglion cells as well as their unmyelinated axons. The goal of the present study was to determine the distribution of VGCC subtypes in the cell bodies and axons of ganglion cells in the normal retina and to define their contribution to calcium signals in these cellular compartments. We report L-type Ca channel α1C and α1D subunit immunoreactivity in rat RGC somata and axons. The N-type Ca channel α1B subunit was in RGC somata and axons, while the P/Q-type Ca channel α1A subunit was only in the RGC somata. We patch clamped isolated ganglion cells and biophysically identified T-type Ca channels. Calcium imaging studies of RGCs in wholemounted retinas showed that selective Ca channel antagonists reduced depolarization-evoked calcium signals mediated by L-, N-, P/Q- and T-type Ca channels in the cell bodies but only by L-type Ca channels in the axons. This differential contribution of VGCC subtypes to calcium signals in RGC somata and their axons may provide insight into the development of target-specific strategies to spare the loss of RGCs and their axons following injury.

  11. Vesicular glutamate transporter 2 (VGLUT2) is co-stored with PACAP in projections from the rat melanopsin-containing retinal ganglion cells

    DEFF Research Database (Denmark)

    Engelund, Anna Iversen; Fahrenkrug, Jan; Harrison, Adrian Paul

    2010-01-01

    The retinal ganglion cell layer of the eye comprises a subtype of cells characterized by their intrinsic photosensitivity and expression of melanopsin (ipRGCs). These cells regulate a variety of non-image-forming (NIF) functions such as light entrainment of circadian rhythms, acute suppression......-localized in their projections in the suprachiasmatic nucleus, the intergeniculate leaflet, and the olivary pretectal nucleus. We conclude that there is evidence to support the use of glutamate and PACAP as neurotransmitters in NIF photoperception by rat ipRGCs, and that these neurotransmitters are co-stored and probably...

  12. Handbook of purified gases

    CERN Document Server

    Schoen, Helmut

    2015-01-01

    Technical gases are used in almost every field of industry, science and medicine and also as a means of control by government authorities and institutions and are regarded as indispensable means of assistance. In this complete handbook of purified gases the physical foundations of purified gases and mixtures as well as their manufacturing, purification, analysis, storage, handling and transport are presented in a comprehensive way. This important reference work is accompanied with a large number of Data Sheets dedicated to the most important purified gases.  

  13. Effects of GABA receptor antagonists on thresholds of P23H rat retinal ganglion cells to electrical stimulation of the retina

    Science.gov (United States)

    Jensen, Ralph J.; Rizzo, Joseph F., III

    2011-06-01

    An electronic retinal prosthesis may provide useful vision for patients suffering from retinitis pigmentosa (RP). In animal models of RP, the amount of current needed to activate retinal ganglion cells (RGCs) is higher than in normal, healthy retinas. In this study, we sought to reduce the stimulation thresholds of RGCs in a degenerate rat model (P23H-line 1) by blocking GABA receptor mediated inhibition in the retina. We examined the effects of TPMPA, a GABAC receptor antagonist, and SR95531, a GABAA receptor antagonist, on the electrically evoked responses of RGCs to biphasic current pulses delivered to the subretinal surface through a 400 µm diameter electrode. Both TPMPA and SR95531 reduced the stimulation thresholds of ON-center RGCs on average by 15% and 20% respectively. Co-application of the two GABA receptor antagonists had the greatest effect, on average reducing stimulation thresholds by 32%. In addition, co-application of the two GABA receptor antagonists increased the magnitude of the electrically evoked responses on average three-fold. Neither TPMPA nor SR95531, applied alone or in combination, had consistent effects on the stimulation thresholds of OFF-center RGCs. We suggest that the effects of the GABA receptor antagonists on ON-center RGCs may be attributable to blockage of GABA receptors on the axon terminals of ON bipolar cells.

  14. Human dental pulp stem cells respond to cues from the rat retina and differentiate to express the retinal neuronal marker rhodopsin.

    Science.gov (United States)

    Bray, A F; Cevallos, R R; Gazarian, K; Lamas, M

    2014-11-07

    Human adult dental pulp stem cells (DPSCs) are self-renewing stem cells that originate from the neural crest during development and remain within the dental pulp niche through adulthood. Due to their multi-lineage differentiation potential and their relative ease of access they represent an exciting alternative for autologous stem cell-based therapies in neurodegenerative diseases. In animal models, DPSCs transplanted into the brain differentiate into functional neurons or astrocytes in response to local environmental cues that appear to influence the fate of the surviving cells. Here we tested the hypothesis that DPSCs might be able to respond to factors present in the retina enabling the regenerative potential of these cells. We evaluated the response of DPSCs to conditioned media from organotypic explants from control and chemically damaged rat retinas. To evaluate cell differentiation, we analyzed the expression of glial fibrillary acidic protein (GFAP), early neuronal and retinal markers (polysialic acid-neural cell adhesion molecule (PSA-NCAM); Pax6; Ascl1; NeuroD1) and the late photoreceptor marker rhodopsin, by immunofluorescence and reverse transcription polymerase chain reaction (RT-PCR). Exposure of DPSC cultures to conditioned media from control retinas induced a 39% reduction on the number of DPSCs that expressed GFAP; the expression of Pax6, Ascl1, PSA-NCAM or NeuroD1 was undetectable or did not change significantly. Expression of rhodopsin was not detectable in control or after exposure of the cultures with retinal conditioned media. By contrast, 44% of DPSCs exposed to conditioned media from damaged retinas were immunopositive to this protein. This response could not be reproduced when conditioned media from Müller-enriched primary cultures was used. Finally, quantitative RT-PCR was performed to compare the relative expression of glial cell-derived neurotrophic factor (GDNF), nerve growth factor (NGF), ciliary neurotrophic factor (CNTF) and brain

  15. Retinal Vasculitis

    Science.gov (United States)

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

    2016-01-01

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

  16. An AD-related neuroprotector rescues transformed rat retinal ganglion cells from CoCl₂-induced apoptosis.

    Science.gov (United States)

    Men, Jie; Zhang, Xiaohui; Yang, Yang; Gao, Dianwen

    2012-05-01

    Some ocular diseases characterized by apoptotic death of retinal ganglion cells (RGCs) and Alzheimer's disease (AD) are chronic neurodegenerative disorders and have similarities in neuropathology. Humanin (HN) is known for its ability to suppress neuronal death induced by AD-related insults. In present study, we investigated the neuroprotective effects of HN on hypoxia-induced toxicity in RGC-5 cells. Hypoxia mimetic compound cobalt chloride (CoCl₂) could increase the cell viability loss and apoptosis, whereas HN can significantly attenuate these effects. This finding may provide new therapeutics for the retinal neurodegenerative diseases targeting neuroprotection.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  18. The role of highly purified forms of rat liver cytochrome P-450 in the dimethylation of dimethylnitrosamine and its activation to mutagens.

    Science.gov (United States)

    Masson, H A; Ioannides, C; Gibson, G G

    1983-06-01

    Highly purified NADPH-cytochrome P-450 reductase and the major phenobarbital (PB) and beta-naphthoflavone (beta NF) forms of cytochrome P-450 were used in reconstituted systems to study the demethylation and subsequent activation of dimethylnitrosamine (DMN) to mutagenic intermediates. Both forms of cytochrome P-450 were active in the demethylation of DMN, cytochrome P-450 from PB-treated animals being more efficient, generating nearly twice as much formaldehyde per nmol of haemoprotein. Neither form of the cytochrome could activate DMN to mutagens in the Ames test. These findings indicate that DMN demethylation does not lead to its activation to mutagenic products.

  19. The Protective Effect of Cordymin, a Peptide Purified from the Medicinal Mushroom Cordyceps sinensis, on Diabetic Osteopenia in Alloxan-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Wei Qi

    2013-01-01

    Full Text Available The aim of this study was to investigate the protective effect of cordymin on diabetic osteopenia in alloxan-induced diabetic rats and the possible mechanisms involved. The diabetic rats received daily intraperitoneal injection with cordymin (20, 50, and 100 mg/kg/day for 5 weeks. Cordymin could restore the circulating blood glucose, glycosylated hemoglobin (HbA1c, serum alkaline phosphatase (ALP, tartrate resistant acid phosphatase (TRAP, and insulin levels in a dose-dependent manner. Also, the treatment of diabetic rats with cordymin could partially reverse the β cells death and decrease the total antioxidant status (TAOS in the diabetic rats. The results may directly and indirectly account for the possible mechanism of the beneficial effect of cordymin on diabetic osteopenia, which was confirmed with the increased bone mineral content (BMC and bone mineral density (BMD in diabetic rats (P<0.05. All those findings indicate that cordymin may play a protective role in diabetic osteoporosis.

  20. The Protective Effect of Cordymin, a Peptide Purified from the Medicinal Mushroom Cordyceps sinensis, on Diabetic Osteopenia in Alloxan-Induced Diabetic Rats

    Science.gov (United States)

    Qi, Wei; Zhang, Yang; Yan, Ya-bo; Lei, Wei; Wu, Zi-xiang; Liu, Ning; Liu, Shuai; Shi, Lei; Fan, Yong

    2013-01-01

    The aim of this study was to investigate the protective effect of cordymin on diabetic osteopenia in alloxan-induced diabetic rats and the possible mechanisms involved. The diabetic rats received daily intraperitoneal injection with cordymin (20, 50, and 100 mg/kg/day) for 5 weeks. Cordymin could restore the circulating blood glucose, glycosylated hemoglobin (HbA1c), serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), and insulin levels in a dose-dependent manner. Also, the treatment of diabetic rats with cordymin could partially reverse the β cells death and decrease the total antioxidant status (TAOS) in the diabetic rats. The results may directly and indirectly account for the possible mechanism of the beneficial effect of cordymin on diabetic osteopenia, which was confirmed with the increased bone mineral content (BMC) and bone mineral density (BMD) in diabetic rats (P < 0.05). All those findings indicate that cordymin may play a protective role in diabetic osteoporosis. PMID:24174985

  1. Purified water quality study

    Energy Technology Data Exchange (ETDEWEB)

    Spinka, H.; Jackowski, P.

    2000-04-03

    Argonne National Laboratory (HEP) is examining the use of purified water for the detection medium in cosmic ray sensors. These sensors are to be deployed in a remote location in Argentina. The purpose of this study is to provide information and preliminary analysis of available water treatment options and associated costs. This information, along with the technical requirements of the sensors, will allow the project team to determine the required water quality to meet the overall project goals.

  2. Crude extract and purified components isolated from the stems of Tinospora crispa exhibit positive inotropic effects on the isolated left atrium of rats

    DEFF Research Database (Denmark)

    Praman, Siwaporn; Mulvany, Michael J.; Williams, David E.

    2013-01-01

    ETHNOPHARMACOLOGICAL RELEVANCE: Tinospora crispa has been used in folkloric medicine for the control of blood pressure. We previously found that an extract of Tinospora crispa and its constituents effect the heart rate and blood pressure in anesthetized rats. AIM OF THE STUDY: The aim...... was to investigate the effects and mechanisms of the Tinospora crispa extract and bioactive components on the rat isolated left atria. MATERIALS AND METHODS: Air-dried stems of Tinospora crispa were extracted with water, followed by partitioning with chloroform, ethyl acetate, and finally by n-butanol. The n......-butanol soluble material was concentrated and dried under reduced pressure and lyophilized to obtain a crude powder (Tinospora crispa extract). The active components of Tinospora crispa extract were separated by column chromatography and preparative HPLC. The effects and mechanisms of the n-butanol extract...

  3. Therapeutic effects of antigen affinity-purified polyclonal anti-receptor of advanced glycation end-product (RAGE) antibodies on cholestasis-induced liver injury in rats.

    Science.gov (United States)

    Xia, Peng; Deng, Qing; Gao, Jin; Yu, Xiaolan; Zhang, Yang; Li, Jingjing; Guan, Wen; Hu, Jianjun; Tan, Quanhui; Zhou, Liang; Han, Wei; Yuan, Yunsheng; Yu, Yan

    2016-05-15

    Cholestasis leads to acute hepatic injury, fibrosis/cirrhosis, inflammation, and duct proliferation. We investigated whether blocking receptor of advanced glycation end-products (RAGE) with polyclonal anti-RAGE antibodies (anti-RAGE) could regulate acute liver injury and fibrosis in a rat bile duct ligation (BDL) model. Male Wister rats received 0.5mg/kg rabbit anti-RAGE or an equal amount of rabbit IgG by subcutaneous injection twice a week after BDL. Samples of liver tissue and peripheral blood were collected at 14 days after BDL. Serum biochemistry and histology were used to analyze the degree of liver injury. Quantitative real-time PCR (qPCR) and immunohistochemical staining were used to further analyze liver injury. Anti-RAGE improved the gross appearance of the liver and the rat survival rate. Liver tissue histology and relevant serum biochemistry indicated that anti-RAGE attenuated liver necrosis, inflammation, liver fibrosis, and duct proliferation in the BDL model. qPCR and western blotting showed significant reductions in interleukin-1β expression levels in the liver by treatment with anti-RAGE. Anti-RAGE also significantly reduced the mRNA levels of α1(1) collagen (Col1α1) and cholesterol 7α-hydroxylase, and the ratio of tissue inhibitor of matrix metalloproteinase-1 to matrix metalloproteinases (MMPs) in the liver. In addition, anti-RAGE regulated the transcriptional level of Col1α1 and MMP-9 in transforming growth factor-β-induced activated LX-2 cells in vitro. Anti-RAGE was found to inhibit hepatic stellate cell proliferation in vivo and in vitro. Therefore, anti-RAGE can protect the liver from injury induced by BDL in rats. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. 基因转染的虹膜色素上皮细胞移植后RCS鼠视网膜BDNF表达观察%Retinal BDNF expressions in RCS rats after transplantation of gene transfected iris pigment epithelium

    Institute of Scientific and Technical Information of China (English)

    张英瑜; 高朋芬; 杨丽霞

    2011-01-01

    目的 探讨脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)基因转染的虹膜色素上皮细胞(AAV-BDNF-IPE)移植入皇家外科学院(royal college of surgeons,RCS)大鼠视网膜下腔后,不同时期视网膜组织BDNF表达变化.方法 通过外路途径将BDNF基因转染的虹膜色素上皮细胞移植到RCS大鼠视网膜下腔,术后3、5、7、9、11周分别取RCS大鼠手术眼及对照组动物眼视网膜组织,用酶联免疫吸附法(Elisa)检测视网膜组织中BDNF的表达水平,比较分析这些数据.结果 对照组RCS大鼠出生后3周龄时视网膜组织中BDNF仍保持较高水平,其后迅速降低,其中3周龄组与其它周龄组比较,P<0.01;手术组RCS大鼠术时、术后3、5、7、9、11周各组间两两比较,BDNF表达无显著差异(P>0.05);出生后6周龄直到14周龄的不同时期,AAV-BDNF-IPE移植手术组RCS大鼠视网膜BDNF表达水平均明显高于对照组(其中6周龄组P<0.05,其它各周龄组P<0.01).结论 BDNF基因转染的虹膜色素上皮细胞在RCS大鼠视网膜下腔移植后,视网膜组织中BDNF可以持续稳定高水平表达,这为临床开发新的神经营养因子给药方式提供了实验依据.%Objective To investigate the retinal brain derived neurotrophic factor( BDNF) expressions in different phases of royal college of surgeons( RCS) rats after BDNF transfected iris pigment epithelium( AAV-BDNF-IPE) being transplanted into the subretinal space of RCS rat. Methods AAV-BDNF-IPEs were transplanted into the subretinal space of RCS rats. BDNF expressions in retinal tissue of intact RCS rats and surgery RCS rats were detected by enzyme linked immunosorbent assay ( Elisa) at 3 ,5 ,7 ,9and 11 weeks after surgery. Results BDNF expressions in retinal tissue of intact RCS rats were still high at postnatal 3w and were sharply decreased into low level later; retinal BDNF expression of intact RCS rats at postnatal 3w were much higher than those at other

  5. (RS)-glucoraphanin purified from Tuscan black kale and bioactivated with myrosinase enzyme protects against cerebral ischemia/reperfusion injury in rats.

    Science.gov (United States)

    Giacoppo, Sabrina; Galuppo, Maria; Iori, Renato; De Nicola, Gina Rosalinda; Bramanti, Placido; Mazzon, Emanuela

    2014-12-01

    Ischemic stroke is the result of a transient or permanent reduction in cerebral blood flow caused by the occlusion of a cerebral artery via an embolus or local thrombosis. Restoration of blood supply to ischemic tissues can cause additional damage known as reperfusion injury that can be more damaging than the initial ischemia. This study was aimed to examine the possible neuroprotective role of (RS)-glucoraphanin, bioactivated with myrosinase enzyme (bioactive RS-GRA), in an experimental rat model of brain ischemia/reperfusion injury (I/R). RS-GRA is a thiosaccharidic compound found in Brassicaceae, notably in Tuscan black kale (Brassica oleracea L. var. acephala sabellica). The mechanism underlying the inhibitory effects of bioactive RS-GRA on inflammatory and apoptotic responses, induced by carotid artery occlusion in rats, was carefully examined. Cerebral I/R was induced by the clamping of carotid artery for 1h, followed by 40 min of reperfusion through the release of clamp. Our results have clearly shown that administration of bioactive RS-GRA (10 mg/kg, i.p.) 15 min after ischemia, significantly reduces proinflammatory parameters, such as inducible nitric oxide synthase expression (iNOS), intercellular adhesion molecule 1 (ICAM-1), nuclear factor (NF)-kB traslocation as well as the triggering of the apoptotic pathway (TUNEL and Caspase 3 expression). Taken together our data have shown that bioactive RS-GRA possesses beneficial neuroprotective effects in counteracting the brain damage associated to I/R. Therefore, bioactive RS-GRA, could be a useful treatment in the cerebral ischemic stroke.

  6. The role of peroxisome proliferator-activated receptor and effects of its agonist, pioglitazone, on a rat model of optic nerve crush: PPARγ in retinal neuroprotection.

    Directory of Open Access Journals (Sweden)

    Juming Zhu

    Full Text Available It has been shown that peroxisome proliferators-activated receptor gamma (PPARγ is beneficial for central nervous system injury. However its role on optic nerve injury remains unknown. In the present study, we examined the change of PPARγ expression in rat retina following optic nerve injury and investigated the effect of pioglitazone (Pio, a PPARγ agonist, on retinal ganglion cells (RGCs neuroprotection using a rat optic nerve crush (ONC model. Our results showed that PPARγ mRNA and protein levels were increased after ONC, and most of PPARγ-immunoreactive cells colocalized with Müller cells. Pio treatment significantly enhanced the number of surviving RGCs and inhibited RGCs apoptosis induced by ONC. However, when PPARγ antagonist GW9662 was used, these neuroprotective effects were abolished. In addition, pio attenuated Müller cell activation after ONC. These results indicate that PPARγ appears to protect RGCs from ONC possibly via the reduction of Müller glial activation. It provides evidence that activation of PPARγ may be a potential alternative treatment for RGCs neuroprotection.

  7. Natural Air Purifier

    Science.gov (United States)

    1993-01-01

    NASA environmental research has led to a plant-based air filtering system. Dr. B.C. Wolverton, a former NASA engineer who developed a biological filtering system for space life support, served as a consultant to Terra Firma Environmental. The company is marketing the BioFilter, a natural air purifier that combines activated carbon and other filter media with living plants and microorganisms. The filter material traps and holds indoor pollutants; plant roots and microorganisms then convert the pollutants into food for the plant. Most non-flowering house plants will work. After pollutants have been removed, the cleansed air is returned to the room through slits in the planter. Terra Firma is currently developing a filter that will also disinfect the air.

  8. 纯化蛆虫分泌物抗菌肽对糖尿病大鼠溃疡创面的抗菌作用%Antibacterial effect of purified maggot secretion antimicrobial peptides on ulcer wound of diabetic rats

    Institute of Scientific and Technical Information of China (English)

    高磊; 尹叶锋; 王寿宇; 王江宁

    2012-01-01

    背景:蛆虫的分泌物对感染创面具有良好的抗菌作用,经课题组研究证实分泌物中有抑制细菌和杀灭细菌的成分抗菌肽,并对该抗菌肽进行了有效纯化.目的:观察纯化蛆虫分泌物抗菌肽对糖尿病大鼠溃疡创面的抗菌和促愈合作用.方法:取3.5月龄雄性SD大鼠20只,体质量330~370 g,制备糖尿病大鼠溃疡创面模型.随机均分为2组,实验组创面涂以纯化的蛆虫分泌物抗菌肽,对照组不予处理.结果与结论:实验组创面清洁,新鲜肉芽生长,无脓性分泌物,愈合情况良好,无金色葡萄球菌感染;对照组创面渗出、糜烂严重,创面不断加大加深,愈合情况不良,金色葡萄球菌感染率为70%.术后7,14,21,28 d,实验组溃疡面积明显小于对照组,差异均有显著性意义(P < 0.05).结果表明纯化的蛆虫分泌物抗菌肽有效促进糖尿病大鼠溃疡创面愈合,预防组织细菌感染.%BACKGROUND: Maggot secretions have a good antibacterial effect on infected wounds. The studies have confirmed that there are antimicrobial peptides that can inhibit and kill the bacteria in the maggot secretions, and we have carried out effective purification of the peptide.OBJECTIVE: To investigate the antibacterial effect and wound healing of purified maggot secretion antimicrobial peptides on ulcer wound of diabetic rats.METHODS: Twenty 3.5-month-old male SD rats weighing 330-370 g was used to prepare diabetic ulcer wound model. The rats were randomly divided into two groups (n=10). In the experimental group, the wounds were coated with purified maggot secretion antimicrobial peptide; the control group was not treated.RESULTS AND CONCLUSION: In the experimental group, the wounds were clean and healed well with fresh granulation, no purulent secretions and no staphylococcus aureus infections. In the control group, wound exudates were found with severe erosion, and the wound was enlarged and deepened that healed poor. The staphylococcus

  9. Effect of crude extract and its semi purified constituents from guaraná seeds [Paullinia cupana var. sorbilis (Mart. lucke] on cognitive performance in Morris water maze in rats

    Directory of Open Access Journals (Sweden)

    Fernanda Jacques Otobone

    2005-09-01

    Full Text Available The effect of crude lyophilized extract (EBPC and the semi-purified constituents (EPA and EPB of Paullinia cupana (guaraná seeds long-term administered in rats by gavage at different doses was studied on cognitive behavior in rats. EBPC (30.0 mg/kg and EPA (2.0 mg/kg, but not EPB (2.0 or 4.0 mg/kg showed a smaller escape latency to find the emerged platform in Morris water maze test (MWMT, showing nootropic-like effect in normal rats, and in scopolamine induced amnesia rats compared to their controls (saline + 0.2% Tween 80 group. These extracts had no significant effect in open field test (OFT. Caffeine did alter escape latency in MWMT only in scopolamine induced amnesia rats and increased the crossings number in OFT, showing significant stimulant effect. Chronic treatment showed the same increase in body weight and average lifespan indicating a low toxicity for the extracts.O efeito do tratamento crônico (gavagem do extrato bruto liofilizado (EBPC das sementes da Paullinia cupana, guaraná, e seus constituintes semi-purificados EPA e EPB, sobre o comportamento cognitivo foi estudado em ratos submetidos ao teste do labirinto aquático de Morris. EBPC (30.0 mg/kg e EPA (2.0 mg/kg, mostraram menor latência para encontrar a plataforma submersa quando comparados ao grupo controle (salina+ tween 80 a 0.2%, em ratos normais ou tratados com escopolamina, o que sugere efeito benéfico sobre a cognição. Estes extratos não alteraram a atividade locomotora no teste do campo aberto. A cafeína, reduziu o tempo de latência para encontrar a plataforma submersa no teste do labirinto aquático de Morris em tratados com escopolamina. Além disso, aumentou o número de cruzamentos no teste do campo aberto, mostrando efeito estimulante. Ratos tratados com EPB não produziram alteração significativa nos testes utilizados. Os animais tratados cronicamente com EBPC, EPA ou EPB tiveram a mesma evolução ponderal e sobrevida o que sugere baixa toxicidade

  10. DHRS3, a retinal reductase, is differentially regulated by retinoic acid and lipopolysaccharide-induced inflammation in THP-1 cells and rat liver.

    Science.gov (United States)

    Zolfaghari, Reza; Chen, Qiuyan; Ross, A Catharine

    2012-09-01

    Both retinoid status and inflammation have been shown to control the level of expression of retinoid homeostatic genes. In the present study, DHRS3, previously shown to possess retinal reductase activity, was identified by microarray analysis of THP-1 monocytes as a possible gene target of all-trans-retinoic acid (RA). In these cells, DHRS3 mRNA increased 30- to 40-fold after treatment with ≤20 nM RA for 24 h, while DHRS3 protein also increased. Of several synthetic retinoids tested, only Am580, a RA receptor-α-selective retinoid, increased DHRS3 mRNA expression. The full-length DHRS3 cDNA was cloned from rat liver and subjected to in vitro transcription-translation. Two major ∼30- and 35-kDa proteins were detected. In adult rat tissues, DHRS3 mRNA was most abundant in the adrenal gland, liver, and ovary. In the liver, DHRS3 is expressed in hepatocytes and possibly in all liver cells. To evaluate whether DHRS3 is regulated in the liver by RA and/or inflammatory stimuli, we treated rats for 6 h with RA or LPS or both. DHRS3 mRNA was doubled by RA but reduced by >90% after treatment with LPS in the absence and presence of RA. On the basis of our results, DHRS3 mRNA expression is regulated by RA in a tissue- or cell-type specific manner; the RA-induced increase in DHRS3 may contribute to retinoid storage; and a reduction of DHRS3 expression in the liver during inflammation may contribute to the perturbation of whole body vitamin A metabolism that has previously been shown to occur in conditions of inflammatory stress.

  11. Retinitis pigmentosa

    NARCIS (Netherlands)

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

    2006-01-01

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

  12. Steroidogenesis in amlodipine treated purified Leydig cells

    Energy Technology Data Exchange (ETDEWEB)

    Latif, Rabia, E-mail: rabialatif08@hotmail.com [Department of Physiology, Army Medical College, National University of Sciences and Technology, Islamabad (Pakistan); Lodhi, Ghulam Mustafa, E-mail: drmustafa786@gmail.com [Department of Physiology, Wah Medical College, Wah (Pakistan); Hameed, Waqas, E-mail: waqham@hotmail.com [Department of Physiology, Rehman Medical College, Peshawar (Pakistan); Aslam, Muhammad, E-mail: professormaslam@yahoo.com [Department of Physiology, Shifa College of Medicine, Islamabad (Pakistan)

    2012-01-01

    Drugs have been shown to adversely affect male fertility and recently anti-hypertensive drugs were added to the list. The anti-fertility effects of amlodipine, a calcium channel blocker, are well-illustrated in in vivo experiments but lack an in vitro proof. The present study was designed to experimentally elucidate the effects of amlodipine on Leydig cell steroidogenesis and intracellular calcium in vitro. Leydig cells of Sprague–Dawley rats were isolated and purified by Percoll. Cells were incubated for 3 h with/without amlodipine in the presence/absence of LH, dbcAMP, Pregnenolone and 25-Hydroxycholesterol. Cytosolic calcium was measured in purified Leydig cells by fluorometric technique. The results showed significantly reduced (P < 0.05) steroidogenesis and intracellular calcium in amlodipine exposed rats. The site of amlodipine induced steroidogenic inhibition seems to be prior to the formation of Pregnenolone at the level of StAR protein. -- Highlights: ► Inhibition of steroidogenesis in isolated and purified Leydig cells by amlodipine. ► Site of inhibition was before Pregnenolone formation, at the level of StAR protein. ► Inhibition of LH stimulated rise in cytosolic calcium by amlodipine.

  13. Chemokine mediated monocyte trafficking into the retina: role of inflammation in alteration of the blood-retinal barrier in diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Sampathkumar Rangasamy

    Full Text Available Inflammation in the diabetic retina is mediated by leukocyte adhesion to the retinal vasculature and alteration of the blood-retinal barrier (BRB. We investigated the role of chemokines in the alteration of the BRB in diabetes. Animals were made diabetic by streptozotocin injection and analyzed for gene expression and monocyte/macrophage infiltration. The expression of CCL2 (chemokine ligand 2 was significantly up-regulated in the retinas of rats with 4 and 8 weeks of diabetes and also in human retinal endothelial cells treated with high glucose and glucose flux. Additionally, diabetes or intraocular injection of recombinant CCL2 resulted in increased expression of the macrophage marker, F4/80. Cell culture impedance sensing studies showed that purified CCL2 was unable to alter the integrity of the human retinal endothelial cell barrier, whereas monocyte conditioned medium resulted in significant reduction in cell resistance, suggesting the relevance of CCL2 in early immune cell recruitment for subsequent barrier alterations. Further, using Cx3cr1-GFP mice, we found that intraocular injection of CCL2 increased retinal GFP+ monocyte/macrophage infiltration. When these mice were made diabetic, increased infiltration of monocytes/macrophages was also present in retinal tissues. Diabetes and CCL2 injection also induced activation of retinal microglia in these animals. Quantification by flow cytometry demonstrated a two-fold increase of CX3CR1+/CD11b+ (monocyte/macrophage and microglia cells in retinas of wildtype diabetic animals in comparison to control non-diabetic ones. Using CCL2 knockout (Ccl2-/- mice, we show a significant reduction in retinal vascular leakage and monocyte infiltration following induction of diabetes indicating the importance of this chemokine in alteration of the BRB. Thus, CCL2 may be an important therapeutic target for the treatment of diabetic macular edema.

  14. Device for purifying drilling mud

    Energy Technology Data Exchange (ETDEWEB)

    Surkov, V.T.; Dorosh, M.M.; Khariv, I.Yu.; Makedonov, N.I.

    1982-01-01

    A device is proposed for purifying drilling mud which includes a dynamic filter made in the form of a spiral-shaped tube with input and output sleeves, and a container for purified solution with outlet sleeve. It is distinguished by the fact that in order to simplify the design, the spiral-shaped tube is perforated from the inside and is installed in the container for the purified solution.

  15. [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

  16. Effect of taurine on GFAP and TauT expressions in rat retinal Müller cells in high glucose culture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-jie; XU Hong-xia; ZENG Kai-hong; MI Man-tian

    2007-01-01

    Objective:To detect the expression of glial fibrillary acid protein (GFAP) and taurine transporter (TauT) in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting, and the possible protective effects of taurine on Müller cells in early diabetic retinopathy. Methods: The Müller cells from the rat retina were cultured in high glucose, and GFAP and TauT expressions were detected in the cells treated with different doses of taurine by immuocytochemical fluorescein staining and Western blotting. Results: High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells. Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucose; 0. 1-10 mmol/L taurine increased the expression of TauT in Müller cells. Conclusion: Taurine can inhibit the changes in Müller cell resulted from high glucose.

  17. Retinitis pigmentosa

    Directory of Open Access Journals (Sweden)

    Hamel Christian

    2006-10-01

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

  18. The hepatic Raldh1 expression is elevated in Zucker fatty rats and its over-expression introduced the retinal-induced Srebp-1c expression in INS-1 cells.

    Directory of Open Access Journals (Sweden)

    Yang Li

    Full Text Available The roles of vitamin A (VA in the development of metabolic diseases remain unanswered. We have reported that retinoids synergized with insulin to induce the expression of sterol-regulatory element-binding protein 1c gene (Srebp-1c expression in primary rat hepatocytes. Additionally, the hepatic Srebp-1c expression is elevated in Zucker fatty (ZF rats, and reduced in those fed a VA deficient diet. VA is metabolized to retinoic acid (RA for regulating gene expression. We hypothesized that the expression of RA production enzymes contributes to the regulation of the hepatic Srebp-1c expression. Therefore, we analyzed their expression levels in Zucker lean (ZL and ZF rats. The mRNA levels of retinaldehyde dehydrogenase family 1 gene (Raldh1 were found to be higher in the isolated and cultured primary hepatocytes from ZF rats than that from ZL rats. The RALDH1 protein level was elevated in the liver of ZF rats. Retinol and retinal dose- and time-dependently induced the expression of RA responsive Cyp26a1 gene in hepatocytes and hepatoma cells. INS-1 cells were identified as an ideal tool to study the effects of RA production on the regulation of gene expression because only RA, but not retinal, induced Srebp-1c mRNA expression in them. Recombinant adenovirus containing rat Raldh1 cDNA was made and used to infect INS-1 cells. The over-expression of RALDH1 introduced the retinal-mediated induction of Srebp-1c expression in INS-1 cells. We conclude that the expression levels of the enzymes for RA production may contribute to the regulation of RA responsive genes, and determine the responses of the cells to retinoid treatments. The elevated hepatic expression of Raldh1 in ZF rats may cause the excessive RA production from retinol, and in turn, result in higher Srebp-1c expression. This excessive RA production may be one of the factors contributing to the elevated lipogenesis in the liver of ZF rats.

  19. AN OVERVIEW ON BLOOD PURIFIER

    Directory of Open Access Journals (Sweden)

    Sabia Chauhan

    2013-09-01

    Full Text Available Blood is a connective tissue which protects us from different problems. Without blood body cannot functions at all and blood doesn’t purify itself. When blood does not purifies itself that times kidney, liver and lymphatic system work together that they help’s to purifiers the blood. Causes which are included in blood impurities are modern life style, junk food, alcohol etc. If the blood becomes impure it causes different problems e.g. acne, rashes, allergic etc. There is not any proper synthetic medication for blood impurities. Only herbal formulations are used for the blood purifier. In this review article we discussed about the market formulations and the different plants which are used in them with their different activities which are helpful in purifies the blood and also protects from other problems.

  20. Involvement of calpain/p35-p25/Cdk5/NMDAR signaling pathway in glutamate-induced neurotoxicity in cultured rat retinal neurons.

    Directory of Open Access Journals (Sweden)

    Yanying Miao

    Full Text Available We investigated possible involvement of a calpain/p35-p25/cyclin-dependent kinase 5 (Cdk5 signaling pathway in modifying NMDA receptors (NMDARs in glutamate-induced injury of cultured rat retinal neurons. Glutamate treatment decreased cell viability and induced cell apoptosis, which was accompanied by an increase in Cdk5 and p-Cdk5(T15 protein levels. The Cdk5 inhibitor roscovitine rescued the cell viability and inhibited the cell apoptosis. In addition, the protein levels of both calpain 2 and calpain-specific alpha-spectrin breakdown products (SBDPs, which are both Ca(2+-dependent, were elevated in glutamate-induced cell injury. The protein levels of Cdk5, p-Cdk5(T15, calpain 2 and SBDPs tended to decline with glutamate treatments of more than 9 h. Furthermore, the elevation of SBDPs was attenuated by either D-APV, a NMDAR antagonist, or CNQX, a non-NMDAR antagonist, but was hardly changed by the inhibitors of intracellular calcium stores dantrolene and xestospongin. Moreover, the Cdk5 co-activator p35 was significantly up-regulated, whereas its cleaved product p25 expression showed a transient increase. Glutamate treatment for less than 9 h also considerably enhanced the ratio of the Cdk5-phosphorylated NMDAR subunit NR2A at Ser1232 site (p-NR2A(S1232 and NR2A (p-NR2A(S1232/NR2A, and caused a translocation of p-NR2A(S1232 from the cytosol to the plasma membrane. The enhanced p-NR2A(S1232 was inhibited by roscovitine, but augmented by over-expression of Cdk5. Calcium imaging experiments further showed that intracellular Ca(2+ concentrations ([Ca(2+](i of retinal cells were steadily increased following glutamate treatments of 2 h, 6 h and 9 h. All these results suggest that the activation of the calpain/p35-p25/Cdk5 signaling pathway may contribute to glutamate neurotoxicity in the retina by up-regulating p-NR2A(S1232 expression.

  1. Metabolic syndrome triggered by high-fructose diet favors choroidal neovascularization and impairs retinal light sensitivity in the rat.

    Science.gov (United States)

    Thierry, Magalie; Pasquis, Bruno; Acar, Niyazi; Grégoire, Stéphane; Febvret, Valérie; Buteau, Bénédicte; Gambert-Nicot, Ségolène; Bron, Alain M; Creuzot-Garcher, Catherine P; Bretillon, Lionel

    2014-01-01

    Diabetic retinopathy and age-related macular degeneration are the leading causes of blindness in Western populations. Although it is a matter of controversy, large-scale population-based studies have reported increased prevalence of age-related macular degeneration in patients with diabetes or diabetic retinopathy. We hypothesized that metabolic syndrome, one of the major risk factors for type 2 diabetes, would represent a favorable environment for the development of choroidal neovascularization, the main complication of age-related macular degeneration. The fructose-fed rat was used as a model for metabolic syndrome in which choroidal neovascularization was induced by laser photocoagulation. Male Brown Norway rats were fed for 1, 3, and 6 months with a standard equilibrated chow diet or a 60%-rich fructose diet (n = 24 per time point). The animals expectedly developed significant body adiposity (+17%), liver steatosis at 3 and 6 months, hyperleptinemia at 1 and 3 months (two-fold increase) and hyperinsulinemia at 3 and 6 months (up to two-fold increase), but remained normoglycemic and normolipemic. The fructose-fed animals exhibited partial loss of rod sensitivity to light stimulus and reduced amplitude of oscillatory potentials at 6 months. Fructose-fed rats developed significantly more choroidal neovascularization at 14 and 21 days post-laser photocoagulation after 1 and 3 months of diet compared to animals fed the control diet. These results were consistent with infiltration/activation of phagocytic cells and up-regulation of pro-angiogenic gene expression such as Vegf and Leptin in the retina. Our data therefore suggested that metabolic syndrome would exacerbate the development of choroidal neovascularization in our experimental model.

  2. Etanercept, a widely used inhibitor of tumor necrosis factor-α (TNF-α, prevents retinal ganglion cell loss in a rat model of glaucoma.

    Directory of Open Access Journals (Sweden)

    Miin Roh

    Full Text Available BACKGROUND: Visual loss in glaucoma is associated with pathological changes in retinal ganglion cell (RGC axons and a slow decline in the RGC population. Age and elevated intraocular pressure (IOP are the main risk factors for glaucomatous loss of vision. Several studies have implicated the proinflammatory cytokine tumor necrosis factor-α (TNF-α as a link between elevated IOP and RGC death, but the cellular source of TNF-α and its causative role in RGC death remain uncertain. Here, using a rat model of glaucoma, we investigated the source of elevated TNF-α and examined whether Etanercept, a TNF-α blocker that is in common clinical use for other indications, is protective against RGC death. METHODOLOGY/PRINCIPAL FINDINGS: Episcleral vein cauterization (EVC caused intraocular pressure (IOP to be elevated for at least 28 days. IOP elevation resulted in a dramatic increase in TNF-α levels within a few days, axonal degeneration, and a 38% loss of RGCs by 4 weeks. Immunostaining coupled with confocal microscopy showed that OHT induced robust induction of TNF-α in Iba-1-positive microglia around the optic nerve head (ONH. Despite persistent elevation of IOP, Etanercept reduced microglial activation, TNF-α levels, axon degeneration in the optic nerve, and the loss of RGCs. CONCLUSIONS/SIGNIFICANCE: Ocular hypertension (OHT triggers an inflammatory response characterized by the appearance of activated microglia around the ONH that express TNF-α. Blocking TNF-α activity with a clinically approved agent inhibits this microglial response and prevents axonal degeneration and loss of RGCs. These findings suggest a new treatment strategy for glaucoma using TNF-α antagonists or suppressors of inflammation.

  3. Effect of A2A receptor antagonist (SCH 442416) on the mRNA expression of glutamate aspartate transporter and glutamine synthetase in rat retinal Müller cells under hypoxic conditions in vitro

    OpenAIRE

    Yu, Jun; Huang, Xin; WU, QIRONG; Wang, Jun; Yu, Xiaoyan; Zhao, Peiquan

    2012-01-01

    The purpose of the present study was to investigate the effect of the A2A receptor antagonist (SCH 442416) on the mRNA expression of glutamate aspartate transporter (GLAST) and glutamine synthetase (GS) in rat retinal Müller cells under hypoxic conditions in vitro. Immunofluorescent staining of GS and GFAP was used for the identification of Müller cells. The GLAST and GS mRNA expression of Müller cells treated with 0.1, 1 and 10 μM SCH 442416 under hypoxic conditions was examined by real-time...

  4. Mechanisms of Retinal Damage from Chronic Laser Radiation.

    Science.gov (United States)

    1981-07-01

    W.K.: The effects of the pineal gland on light-induced retinal photoreceptor damage. Exp. Eye Res. 28:37-44, 1979. 17. Hollyfield, Joe G., Rayborn...co-iI workers in 196612. Noell reported that irreversible retinal damage occurs in normal laboratory rats exposed continuously to an illuminated...light than with either red or blue light. In fact, the action spectrum of the damage paralleled the action spectrum of the ERG. The iris of pigmented rats

  5. Process for purifying geothermal steam

    Science.gov (United States)

    Li, C.T.

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

  6. Conotoxins Are Purified and Cloned

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ A group of CAS scientists have succeeded in purifying many conotoxins and cloning more than 100 new genes from six species of cone snails living in waters off the coast of the South China Sea, paving the way for the development of new drugs to relieve neuropathic pains. The work has been honored with a first prize from the 2005 Awards for S&T Progress in Shanghai.

  7. Neonatal human retinal pigment epithelial cells secrete limited trophic factors in vitro and in vivo following striatal implantation in parkinsonian rats

    DEFF Research Database (Denmark)

    Russ, Kaspar; Flores, Joseph; Brudek, Tomasz

    2015-01-01

    Human retinal pigment epithelial (hRPE) cell implants into the striatum have been investigated as a potential cell-based treatment for Parkinson's disease in a Phase II clinical trial that recently failed. We hypothesize that the trophic factor potential of the hRPE cells could potentially influe...

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

    Science.gov (United States)

    Ebneter, Andreas; Agca, Cavit; Dysli, Chantal; Zinkernagel, Martin S

    2015-01-01

    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 (pretinal 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.

  9. Retinal remodeling in human retinitis pigmentosa.

    Science.gov (United States)

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

    2016-09-01

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

  10. Time-Dependent Nerve Growth Factor Signaling Changes in the Rat Retina During Optic Nerve Crush-Induced Degeneration of Retinal Ganglion Cells

    Directory of Open Access Journals (Sweden)

    Louise A. Mesentier-Louro

    2017-01-01

    Full Text Available Nerve growth factor (NGF is suggested to be neuroprotective after nerve injury; however, retinal ganglion cells (RGC degenerate following optic-nerve crush (ONC, even in the presence of increased levels of endogenous NGF. To further investigate this apparently paradoxical condition, a time-course study was performed to evaluate the effects of unilateral ONC on NGF expression and signaling in the adult retina. Visually evoked potential and immunofluorescence staining were used to assess axonal damage and RGC loss. The levels of NGF, proNGF, p75NTR, TrkA and GFAP and the activation of several intracellular pathways were analyzed at 1, 3, 7 and 14 days after crush (dac by ELISA/Western Blot and PathScan intracellular signaling array. The progressive RGC loss and nerve impairment featured an early and sustained activation of apoptotic pathways; and GFAP and p75NTR enhancement. In contrast, ONC-induced reduction of TrkA, and increased proNGF were observed only at 7 and 14 dac. We propose that proNGF and p75NTR contribute to exacerbate retinal degeneration by further stimulating apoptosis during the second week after injury, and thus hamper the neuroprotective effect of the endogenous NGF. These findings might aid in identifying effective treatment windows for NGF-based strategies to counteract retinal and/or optic-nerve degeneration.

  11. Time-Dependent Nerve Growth Factor Signaling Changes in the Rat Retina During Optic Nerve Crush-Induced Degeneration of Retinal Ganglion Cells

    Science.gov (United States)

    Mesentier-Louro, Louise A.; De Nicolò, Sara; Rosso, Pamela; De Vitis, Luigi A.; Castoldi, Valerio; Leocani, Letizia; Mendez-Otero, Rosalia; Santiago, Marcelo F.; Tirassa, Paola; Rama, Paolo; Lambiase, Alessandro

    2017-01-01

    Nerve growth factor (NGF) is suggested to be neuroprotective after nerve injury; however, retinal ganglion cells (RGC) degenerate following optic-nerve crush (ONC), even in the presence of increased levels of endogenous NGF. To further investigate this apparently paradoxical condition, a time-course study was performed to evaluate the effects of unilateral ONC on NGF expression and signaling in the adult retina. Visually evoked potential and immunofluorescence staining were used to assess axonal damage and RGC loss. The levels of NGF, proNGF, p75NTR, TrkA and GFAP and the activation of several intracellular pathways were analyzed at 1, 3, 7 and 14 days after crush (dac) by ELISA/Western Blot and PathScan intracellular signaling array. The progressive RGC loss and nerve impairment featured an early and sustained activation of apoptotic pathways; and GFAP and p75NTR enhancement. In contrast, ONC-induced reduction of TrkA, and increased proNGF were observed only at 7 and 14 dac. We propose that proNGF and p75NTR contribute to exacerbate retinal degeneration by further stimulating apoptosis during the second week after injury, and thus hamper the neuroprotective effect of the endogenous NGF. These findings might aid in identifying effective treatment windows for NGF-based strategies to counteract retinal and/or optic-nerve degeneration. PMID:28067793

  12. Methods for Purifying Enzymes for Mycoremediation

    Science.gov (United States)

    Cullings, Kenneth W. (Inventor); DeSimone, Julia C. (Inventor); Paavola, Chad D. (Inventor)

    2014-01-01

    A process for purifying laccase from an ectomycorrhizal fruiting body is disclosed. The process includes steps of homogenization, sonication, centrifugation, filtration, affinity chromatography, ion exchange chromatography, and gel filtration. Purified laccase can also be separated into isomers.

  13. Evaluation of a portable air purifier.

    OpenAIRE

    Lawrence, J.C.; Lilly, H. A.; Wilkins, M. D.

    1981-01-01

    A portable air purifier significantly reduced mal odour in a small room. If the atmosphere was deliberately contaminated with Serratia marcescens the unit rapidly removed this organism. However, if incorrectly sited, the purifier could disperse organisms into the atmosphere.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Screening retinal transplants with Fourier-domain OCT

    Science.gov (United States)

    Rao, Bin

    2009-02-01

    Transplant technologies have been studied for the recovery of vision loss from retinitis pigmentosa (RP) and age-related macular degeneration (AMD). In several rodent retinal degeneration models and in patients, retinal progenitor cells transplanted as layers to the subretinal space have been shown to restore or preserve vision. The methods for evaluation of transplants are expensive considering the large amount of animals. Alternatively, time-domain Stratus OCT was previously shown to be able to image the morphological structure of transplants to some extent, but could not clearly identify laminated transplants. The efficacy of screening retinal transplants with Fourier-domain OCT was studied on 37 S334ter line 3 rats with retinal degeneration 6-67 days after transplant surgery. The transplants were morphologically categorized as no transplant, detachment, rosettes, small laminated area and larger laminated area with both Fourier-domain OCT and histology. The efficacy of Fourier-domain OCT in screening retinal transplants was evaluated by comparing the categorization results with OCT and histology. Additionally, 4 rats were randomly selected for multiple OCT examinations (1, 5, 9, 14 and 21days post surgery) in order to determine the earliest image time of OCT examination since the transplanted tissue may need some time to show its tendency of growing. Finally, we demonstrated the efficacy of Fourier-domain OCT in screening retinal transplants in early stages and determined the earliest imaging time for OCT. Fourier-domain OCT makes itself valuable in saving resource spent on animals with unsuccessful transplants.

  16. 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.

  17. 早期糖尿病大鼠视网膜神经节细胞树突形态异常的研究%Study on abnormal dendrite of retinal ganglion cells in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    徐格致; 秦要武; 王文吉

    2008-01-01

    Objective To observe the morphological changes of dendrite and soma in retinal ganglion cells (RGCs) which subsisted in early diabetic rats. Methods The RGCs of 3-months-course diabetic rats and coeval normal rats were marked by gene gun techniques. To collect RGCs photographs by Leica microscope with Z axis and CCD camera;to observe the changes of diameter, variance of structural features in dendritic field and somata after classification which according to the size and morphology. Thy-1 antibody marks on the retinal RGCs, taking a photograph under fluorescent microscope, counting the changes of retinal RGCs density in early diabetic rat. Results In three-month diabetic rats, the density of retinal RGCs was decreased obviously. Morphological changes of RGCs in the dendritic fields were observed with gene gun technique. There was no severe variation in all kinds of the bole of cell dendrite,in which some only showed crispation partially and sparseness also twisting in the dendritic ramus. The mean diameter of dendritic field and soma in class A of diabetic rats was (401±86)μm, the mean diameter of dendritic field in control group was (315±72) μm,compared with each other, there is statistically significant differences (t=21. 249, P0.05); the mean diameter of dendritic field and soma in class B of diabetic rats were (170±36). (14±2) μm respectively, in control group were (165±36), (16±2) μm, the mean diameter of dendritic field and soma in class C of diabetic group were (265±78),(17±5) μm respectively, in control group were (251±57),(17±4) μm , compared with each other,there are on statistically significant differences (t=1.357,0.798,0. 835,1.104 ,P>0.05). ConclusionsIn short-term diabetes, the survived RGCs show good plasticity in adult diabetic rats, especially in class A. The changes of dendrites were more sensitive than the soma, which could be the leading index of themorphologic changes of RGCs in the early stage. The good plasticity showed by

  18. Synaptosomal protein synthesis in P2 and Ficoll purified fractions.

    Science.gov (United States)

    Eyman, Maria; Cefaliello, Carolina; Bruno, Anna Paola; Bruno, Annapaola; Crispino, Marianna; Giuditta, Antonio

    2012-01-30

    Cytoplasmic protein synthesis of brain synaptosomes has generally been determined in the Ficoll purified fraction which contains fewer contaminating mitochondria, microsomes and myelin fragments than the parent P2 fraction. Using a highly selective assay of this activity we have compared the total translation activity and the specific activity of the proteins synthesized by either fraction in control rats and in rats trained for a two-way active avoidance task. In control rats the specific activity remained essentially the same in both fractions but in trained rats the value of the Ficoll fraction was markedly lower (38.5%) than in the P2 fraction. Furthermore, the total translation activity of the Ficoll fraction was 30% lower than in the P2 fraction in control rats and 62% lower in trained rats. These decrements indicate that a large proportion of active synaptosomes present in the P2 fraction is not recovered in the Ficoll fraction, notably in rats undergoing plastic brain changes. We conclude that cytoplasmic protein synthesis of brain synaptosomes is better preserved in the P2 fraction.

  19. Avoiding pitfalls of internal controls: validation of reference genes for analysis by qRT-PCR and Western blot throughout rat retinal development.

    Science.gov (United States)

    Rocha-Martins, Maurício; Njaine, Brian; Silveira, Mariana S

    2012-01-01

    Housekeeping genes have been commonly used as reference to normalize gene expression and protein content data because of its presumed constitutive expression. In this paper, we challenge the consensual idea that housekeeping genes are reliable controls for expression studies in the retina through the investigation of a panel of reference genes potentially suitable for analysis of different stages of retinal development. We applied statistical tools on combinations of retinal developmental stages to assess the most stable internal controls for quantitative RT-PCR (qRT-PCR). The stability of expression of seven putative reference genes (Actb, B2m, Gapdh, Hprt1, Mapk1, Ppia and Rn18s) was analyzed using geNorm, BestKeeper and Normfinder software. In addition, several housekeeping genes were tested as loading controls for Western blot in the same sample panel, using Image J. Overall, for qRT-PCR the combination of Gapdh and Mapk1 showed the highest stability for most experimental sets. Actb was downregulated in more mature stages, while Rn18s and Hprt1 showed the highest variability. We normalized the expression of cyclin D1 using various reference genes and demonstrated that spurious results may result from blind selection of internal controls. For Western blot significant variation could be seen among four putative internal controls (β-actin, cyclophilin b, α-tubulin and lamin A/C), while MAPK1 was stably expressed. Putative housekeeping genes exhibit significant variation in both mRNA and protein content during retinal development. Our results showed that distinct combinations of internal controls fit for each experimental set in the case of qRT-PCR and that MAPK1 is a reliable loading control for Western blot. The results indicate that biased study outcomes may follow the use of reference genes without prior validation for qRT-PCR and Western blot.

  20. Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration

    Science.gov (United States)

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

    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 incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases. PMID:23115615

  1. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Directory of Open Access Journals (Sweden)

    Nicolas Froger

    Full Text Available 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 incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats. After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%, whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases.

  2. Taurine provides neuroprotection against retinal ganglion cell degeneration.

    Science.gov (United States)

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

    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 incriminated in the retinal toxicity of an antiepileptic drug. We demonstrate here that taurine can improve RGC survival in culture or in different animal models of RGC degeneration. Taurine effect on RGC survival was assessed in vitro on primary pure RCG cultures under serum-deprivation conditions, and on NMDA-treated retinal explants from adult rats. In vivo, taurine was administered through the drinking water in two glaucomatous animal models (DBA/2J mice and rats with vein occlusion) and in a model of Retinitis pigmentosa with secondary RGC degeneration (P23H rats). After a 6-day incubation, 1 mM taurine significantly enhanced RGCs survival (+68%), whereas control RGCs were cultured in a taurine-free medium, containing all natural amino-acids. This effect was found to rely on taurine-uptake by RGCs. Furthermore taurine (1 mM) partly prevented NMDA-induced RGC excitotoxicity. Finally, taurine supplementation increased RGC densities both in DBA/2J mice, in rats with vein occlusion and in P23H rats by contrast to controls drinking taurine-free water. This study indicates that enriched taurine nutrition can directly promote RGC survival through RGC intracellular pathways. It provides evidence that taurine can positively interfere with retinal degenerative diseases.

  3. 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....

  4. Applied anatomic study about the central retinal artery in SD rats%SD大鼠视网膜中央动脉的应用解剖学研究

    Institute of Scientific and Technical Information of China (English)

    万炜; 刘政海; 伍校琼; 王晓晟; 罗学港

    2013-01-01

    目的 为建立稳定可靠的视神经损伤动物模型寻求解剖学依据.方法 用红色乳胶灌注技术显示正常SD大鼠视网膜中央动脉的来源、分支、分布及其与视神经的关系,并采用体视显微镜摄片测量;明胶墨汁灌注技术显示距眼球后极2.0mm或6.0 nun处横断视神经后视网膜的血供. 结果 视网膜中央动脉及其分支在视神经鞘内始终与视神经干伴行,视网膜中央动脉起始部到眼球后极的距离为(5.784±0.054)mm;距离眼球后极6.0 mm处鞘内视神经横断组大鼠视网膜单位面积血管数日高于其他部位横断组.结论 在制备视神经损伤SD大鼠模型时,损伤视神经应在鞘内进行,损伤部位距眼球后极6.0 mm最佳.%Objective To provide anatomical basis for establishment of a reliable animal model of optic nerve injury.Method Red latex perfusion technology was used to observe the origin,course,distribution of central retinal artery,and its relationship with the optic nerve in normal SD rats and measurement about several parameters was made on the micrographs recorded using the stereoscopic microscope; Moreover,gelatin-ink perfusion technique was adopted to demonstrate the blood supply of the retina with the optic nerve transected at 2.0 mm and 6.0 mm posterior to the posterior pole of the eye.Result Our study shown the central retinal artery and its branches run with the optic nerve at its course within the optic nerve sheath; the origin of the central retinal artery was located (5.784±0.054) mm posterior to the posterior pole of the eye; the vascular density of the central retinal nerve is highest at the sectional surface of it 6.0 mm posteior to the posterior role of the eye.Conclusion In the preparation of the SD rats model with nerve injury,transection should be made within the sheath,with the best place of the transection being located 6.0 mm posterior to the posterior pole of the eye.

  5. Neuroprotective Effects of Citicoline in in Vitro Models of Retinal Neurodegeneration

    OpenAIRE

    Andrea Matteucci; Monica Varano; Lucia Gaddini; Cinzia Mallozzi; Marika Villa; Flavia Pricci; Fiorella Malchiodi-Albedi

    2014-01-01

    In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM) and analyzed in terms of apoptosis and caspase activation and c...

  6. Dark rearing maintains tyrosine hydroxylase expression in retinal amacrine cells following optic nerve transection

    Institute of Scientific and Technical Information of China (English)

    Wei Wan; Zhenghai Liu; Xiaosheng Wang; Xuegang Luo

    2012-01-01

    The present study examined changes in retinal tyrosine hydroxylase (TH) expression in rats having undergone optic nerve transection and housed under a normal day/night cycle or in the dark. The aim was to investigate the effects of amacrine cells on axonal regeneration in retinal ganglion cells and on the synapses that transmit visual signals. The results revealed that retinal TH expression gradually decreased following optic nerve transection in rats housed under a normal day/night cycle, reaching a minimum at 5 days. In contrast, retinal TH expression decreased to a minimum at 1 day following optic nerve transection in dark reared rats, gradually increasing afterward and reaching a normal level at 5-7 days. The number of TH-positive synaptic particles correlated with the TH levels, indicating that dark rearing can help maintain TH expression during the synaptic degeneration stage (5-7 days after optic nerve injury) in retinal amacrine cells.

  7. Diosmin alleviates retinal edema by protecting the blood-retinal barrier and reducing retinal vascular permeability during ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Nianting Tong

    Full Text Available BACKGROUND AND PURPOSE: Retinal swelling, leading to irreversible visual impairment, is an important early complication in retinal ischemia/reperfusion (I/R injury. Diosmin, a naturally occurring flavonoid glycoside, has been shown to have antioxidative and anti-inflammatory effects against I/R injury. The present study was performed to evaluate the retinal microvascular protective effect of diosmin in a model of I/R injury. METHODS: Unilateral retinal I/R was induced by increasing intraocular pressure to 110 mm Hg for 60 min followed by reperfusion. Diosmin (100 mg/kg or vehicle solution was administered intragastrically 30 min before the onset of ischemia and then daily after I/R injury until the animals were sacrificed. Rats were evaluated for retinal functional injury by electroretinogram (ERG just before sacrifice. Retinas were harvested for HE staining, immunohistochemistry assay, ELISA, and western blotting analysis. Evans blue (EB extravasation was determined to assess blood-retinal barrier (BRB disruption and the structure of tight junctions (TJ was examined by transmission electron microscopy. RESULTS: Diosmin significantly ameliorated the reduction of b-wave, a-wave, and b/a ratio in ERG, alleviated retinal edema, protected the TJ structure, and reduced EB extravasation. All of these effects of diosmin were associated with increased zonular occluden-1 (ZO-1 and occludin protein expression and decreased VEGF/PEDF ratio. CONCLUSIONS: Maintenance of TJ integrity and reduced permeability of capillaries as well as improvements in retinal edema were observed with diosmin treatment, which may contribute to preservation of retinal function. This protective effect of diosmin may be at least partly attributed to its ability to regulate the VEGF/PEDF ratio.

  8. 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.

  9. In vitro differentiation of retinal pigment epithelium from adult retinal stem cells.

    Science.gov (United States)

    Aruta, Claudia; Giordano, Francesca; De Marzo, Anna; Comitato, Antonella; Raposo, Graça; Nandrot, Emeline F; Marigo, Valeria

    2011-02-01

    One of the limitations in molecular and functional studies of the retinal pigment epithelium (RPE) has been the lack of an in vitro system retaining all the features of in vivo RPE cells. Retinal pigment epithelium cell lines do not show characteristics typical of a functional RPE, such as pigmentation and expression of specific markers. The present study was aimed at the development of culture conditions to differentiate, in vitro, retinal stem cells (RSC), derived from the adult ciliary body, into a functional RPE. Retinal stem cells were purified from murine eyes, grown as pigmented neurospheres and induced to differentiate into RPE on an extracellular matrix substrate using specific culture conditions. After 7-15 days of culture, pigmented cells with an epithelial morphology showed a polarized organization and a capacity for phagocytosis. We detected different stages of melanogenesis in cells at 7 days of differentiation, whereas RPE at 15 days contained only mature melanosomes. These data suggest that our protocol to differentiate RPE in vitro can provide a useful model for molecular and functional studies.

  10. Hydrogen purifier module with membrane support

    Science.gov (United States)

    A hydrogen purifier utilizing a hydrogen-permeable membrane to purify hydrogen from mixed gases containing hydrogen is disclosed. Improved mechanical support for the permeable membrane is described, enabling forward or reverse differential pressurization of the membrane, which further stabilizes the membrane from wrinkling upon hydrogen uptake.

    2012-07-24

    A hydrogen purifier utilizing a hydrogen-permeable membrane to purify hydrogen from mixed gases containing hydrogen is disclosed. Improved mechanical support for the permeable membrane is described, enabling forward or reverse differential pressurization of the membrane, which further stabilizes the membrane from wrinkling upon hydrogen uptake.

  11. 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.

  12. Application of a Low-Level Laser Therapy and the Purified Protein from Natural Latex (Hevea brasiliensis in the Controlled Crush Injury of the Sciatic Nerve of Rats: A Morphological, Quantitative, and Ultrastructural Study

    Directory of Open Access Journals (Sweden)

    Fernando José Dias

    2013-01-01

    Full Text Available This study analyzed the effects of a low-level laser therapy (LLLT, 15 J/cm2, 780 nm wavelength and the natural latex protein (P1, 0.1% in sciatic nerve after crush injury (15 Kgf, axonotmesis in rats. Sixty rats (male, 250 g were allocated into the 6 groups (n=10: CG—control group; EG—nerve exposed; IG—injured nerve without treatment; LG—crushed nerve treated with LLLT; PG—injured nerve treated with P1; and LPG—injured nerve treated with LLLT and P1. After 4 or 8 weeks, the nerve samples were processed for morphological, histological quantification and ultrastructural analysis. After 4 weeks, the myelin density and morphological characteristics improved in groups LG, PG, and LPG compared to IG. After 8 weeks, PG, and LPG were similar to CG and the capillary density was higher in the LG, PG, and LPG. In the ultrastructural analysis the PG and LPG had characteristics that were similar to the CG. The application of LLLT and/or P1 improved the recovery from the nerve crush injury, and in the long term, the P1 protein was the better treatment used, since only the application of LLLT has not reached the same results, and these treatments applied together did not potentiate the recovery.

  13. hEPO gene modified Müller cells protects against retinal degeneration of RCS rats%EPO修饰增强Müller细胞对RCS大鼠视网膜变性的干预效果

    Institute of Scientific and Technical Information of China (English)

    李宗义; 李鹏; 高芙蓉; 范氏雪幸; 张敬法; 王方; 吕立夏; 徐国彤

    2014-01-01

    目的:研究人源促红细胞生成素(hEPO)修饰的Müller(hEPO-Müller)细胞对视网膜退行性病变大鼠的干预作用。方法通过质粒转染法构建hEPO和GFP的Müller细胞稳转株(hEPO-Müller和GFP-Müller);以体外共培养和体内细胞移植为研究体系,利用RT-PCR和冰冻切片及免疫荧光染色的方法检测hEPO-Müller对RCS大鼠视网膜退行性病变的干预作用。内核层与外核层厚度比较采用t检验。结果本实验成功构建了hEPO-Müller和GFP-Müller细胞系。将RCS大鼠的视网膜组织剥离并在体外不同条件下培养两周后测定视网膜各核层厚度发现,与对照细胞裂解液共培养组的内核层(15.94±1.77)μm和外核层(24.81±3.03)μm的厚度相比较,两核层的厚度分别在hEPO组为(23.03±3.29)μm,(33.92±7.59)μm(P<0.05);Müller 组为(24.81±2.02)μm,(32.15±3.03)μm(P<0.05);hEPO-Müller组为(32.40±8.35)μm,(40.25±3.29)μm(n=3, P<0.01);以hEPO-Müller组厚度增加最为显著(P<0.05)。提示EPO和Müller细胞对视网膜变性都有干预作用且两者可以叠加。将hEPO-Müller和GFP-Müller分别移植到RCS大鼠的视网膜下腔,四周后取视网膜进行冰冻切片检测,染色结果显示,细胞移植后有更多的外核层细胞存活,且同样也是hEPO-Müller组的外核层细胞更多。此外,Müller移植并不会促进视网膜的胶质化。结论移植Müller细胞可以减缓RCS大鼠视网膜变性,而经hEPO修饰的Müller细胞对视网膜变性有更好的干预作用。因此,Müller细胞可以作为一种供体细胞兼携带hEPO等营养因子的载体用于视网膜变性的治疗。%Objective To study the effects of hEPO gene modified Müller cells (hEPO-Müller) in the rat model of retinal degeneration. Methods The hEPO-Müller and GFP modified Müller cells (GFP-Müller) were established by the transfection of M

  14. Excessive retinal ganglion cell loss after optic nerve crushed with forceps in rats%钳夹法造成大鼠视网膜神经节细胞过量丢失

    Institute of Scientific and Technical Information of China (English)

    廖良; 徐铭谦; 韦企平; 周剑; 孔莹莹; 孙艳红

    2011-01-01

    Objective To evaluate the injury degree of retinal ganglion cells (RGCs) after optic nerve crushed with forceps. Methods A total of 38 male Wistar rats were divided into forceps groups, which was subdivided into group A to group E, with crushing time of 12 seconds,9 seconds,6 seconds,3 seconds and 1 second, the group F was the forceps group at reverse direction,5 rats in each group. The optic nerve at temple side of rat eyeball was exposed. Optic nerves at 2 mm behind the eyeball were crushed with 90 g micro forceps and then with the 40 g forceps at reverse direction. Left eye of each rat was taken operation, and right eye was treated as normal control. Left eyes of rats in shame operation group were taken treatment to expose optic nerve behind the eyeball,but not with crush. Amount and survival rate of RGCs were calculated with fluorogold regressive labeling RGCs and retinal stretched preparation. Results Cell densities of left and right eyes of rats in shame operation group were (2 679 ± 67) mm-2 and(2 689 ±53)mm-2,there was no significant difference(P = 0. 8%) ,and were (220±167)mm-2,(265 ±232)mm-2, (298 ±239)mm-2, (478 ±682)mm -2, (769 ±615) mm-2 and (974 ±476) mm-2 in forceps groups, which were obviously decreased. There was negative correlation between impulse of forceps(force of forceps multiply time) and survival rate of RGCs. Conclusions Crush with forceps can make definite and quantitative optic injury,but the injury is serious and stability is poor. There is still a marked gap between our experiment and the actual pathogenesis of traumatic optic neuropathy.%目的 评估钳夹视神经对视网膜神经节细胞(retinal ganglion cells,RGCs)的损伤程度.方法 取38只雄性Wistar大鼠,夹持组(n=30)按夹持时间12 s、9 s、6 s,3 s、1 s分为A-E组,F为反身夹持组,每组各5只大鼠.沿大鼠眼球颞侧暴露视神经,于球后2 mm处用90 g微型视神经夹夹持视神经,另有40 g反向镊在球后2 mm处夹持视神经,每

  15. 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.

  16. Novel Neuroprotective Strategies in Ischemic Retinal Lesions

    Science.gov (United States)

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

    2010-01-01

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

  17. Quantitative retinal blood flow mapping from fluorescein videoangiography using tracer kinetic modeling.

    Science.gov (United States)

    Tichauer, Kenneth M; Guthrie, Micah; Hones, Logan; Sinha, Lagnojita; St Lawrence, Keith; Kang-Mieler, Jennifer J

    2015-05-15

    Abnormal retinal blood flow (RBF) has been associated with numerous retinal pathologies, yet existing methods for measuring RBF predominantly provide only relative measures of blood flow and are unable to quantify volumetric blood flow, which could allow direct patient to patient comparison. This work presents a methodology based on linear systems theory and an image-based arterial input function to quantitatively map volumetric blood flow from standard fluorescein videoangiography data, and is therefore directly translatable to the clinic. Application of the approach to fluorescein retinal videoangiography in rats (4 control, 4 diabetic) demonstrated significantly higher RBF in 4-5 week diabetic rats as expected from the literature.

  18. Visible-light OCT to quantify retinal oxygen metabolism (Conference Presentation)

    Science.gov (United States)

    Zhang, Hao F.; Yi, Ji; Chen, Siyu; Liu, Wenzhong; Soetikno, Brian T.

    2016-03-01

    We explored, both numerically and experimentally, whether OCT can be a good candidate to accurately measure retinal oxygen metabolism. We first used statistical methods to numerically simulate photon transport in the retina to mimic OCT working under different spectral ranges. Then we analyze accuracy of OCT oximetry subject to parameter variations such as vessel size, pigmentation, and oxygenation. We further developed an experimental OCT system based on the spectral range identified by our simulation work. We applied the newly developed OCT to measure both retinal hemoglobin oxygen saturation (sO2) and retinal retinal flow. After obtaining the retinal sO2 and blood velocity, we further measured retinal vessel diameter and calculated the retinal oxygen metabolism rate (MRO2). To test the capability of our OCT, we imaged wild-type Long-Evans rats ventilated with both normal air and air mixtures with various oxygen concentrations. Our simulation suggested that OCT working within visible spectral range is able to provide accurate measurement of retinal MRO2 using inverse Fourier transform spectral reconstruction. We called this newly developed technology vis-OCT, and showed that vis-OCT was able to measure the sO2 value in every single major retinal vessel around the optical disk as well as in micro retinal vessels. When breathing normal air, the averaged sO2 in arterial and venous blood in Long-Evans rats was measured to be 95% and 72%, respectively. When we challenge the rats using air mixtures with different oxygen concentrations, vis-OCT measurement followed analytical models of retinal oxygen diffusion and pulse oximeter well.

  19. Ceramic materials purified by experimental method

    Science.gov (United States)

    1965-01-01

    Crystalline ceramic materials are purified for use as high-temperature electrical insulators. Any impurities migrate to the cathode when a dc voltage is applied across the material while it is heated in an inert gas atmosphere.

  20. Effect of Chinese medicine Qidengmingmu capsule on the STZ induced hyperglycemia rat's blood-retinal barrier%芪灯明目胶囊对高血糖大鼠血视网膜屏障影响的研究

    Institute of Scientific and Technical Information of China (English)

    张富文; 段俊国; 赵凌; 路雪婧; 李强

    2013-01-01

    目的:观察链脲佐菌素(STZ)诱发糖尿病大鼠在造模后血-视网膜屏障(blood-retina barrier,BRB)变化情况,并以阳性药为对照研究中药芪灯明目胶囊对STZ诱发糖尿病大鼠的视网膜血管渗漏影响.方法:采用STZ腹腔注射制作糖尿病大鼠模型,在造模后6mo内各时点(2wk;1,2,3,4,5,6mo)采用伊文思蓝灌注示踪显示血-视网膜的渗漏情况,在造模后3mo开始用中药芪灯明目胶囊(低中高剂量组分别给予125,250,500mg/kg体质量剂量的胶囊内容物灌胃),对照组用安多明胶囊(200mg/kg体质量剂量,相当于10倍成人剂量),灌胃3mo,观察药物对 BRB的影响.结果:STZ糖尿病大鼠在2wk即可出现BRB的损害,并随着高血糖状态的持续而不断加重.对造模3mo STZ糖尿病模型大鼠连续灌胃中药芪灯治疗3mo,结果提示:中药芪灯对STZ糖尿病BRB有保护作用,可明显减少视网膜血管的渗漏.结论:STZ糖尿病模型大鼠在早期即可出现BRB损害,并随着高血糖的持续而加重,中药芪灯明目胶囊可减少高血糖导致的BRB损害.%AIM: To observe retinal vessel leakage of streptozotocin (STZ) induced diabetic rat, and the effect of traditional Chinese medicine on it.METHODS: We induced diabetic rat model by peritoneal injection of STZ, after the blood glucose raised, we used Evans blue to trace the leakage of blood - retina barrier (BRB) every month. After blood glucose rose three months later, we treated the Chinese medicine group diabetic rat with Qidengmingmu capsule. There were three groups of different dose, low dose group of 125mg/kg, middle dose group of 250mg/kg, high dose group of 500mg/kg. The control group was treated with calcium dobesilate (200mg/kg). After three months treated by medicine, the leakage of rat blood - retina barrier was evaluated.RESULTS: The damage of BRB and visual function occurred at two week after the blood glucose rose, and the damage aggravated with the continuing of high diabetic

  1. Detection of mu opioid receptor (MOPR) and its glycosylation in rat and mouse brains by western blot with anti-μC, an affinity-purified polyclonal anti-MOPR antibody.

    Science.gov (United States)

    Huang, Peng; Chen, Chongguang; Liu-Chen, Lee-Yuan

    2015-01-01

    Our experience demonstrates that it is difficult to identify MOPR in rat and mouse brains by western blot, in part due to low abundance of the receptor and a wide relative molecular mass (Mr) range of the receptor associated with its heterogeneous glycosylation states. Here, we describe generation and purification of anti-μC (a rabbit polyclonal anti-MOPR antibody), characterization of its specificity in immunoblotting of HA-tagged MOPR expressed in a cell line, and ultimately, unequivocal detection of the MOPR in brain tissues by western blot with multiple rigorous controls. In particular, using brain tissues from MOPR knockout (K/O) mice as the negative controls allowed unambiguous identification of the MOPR band, since the anti-MOPR antibody, even after affinity purification, recognizes nonspecific protein bands. The MOPR was resolved as a faint, broad, and diffuse band with a wide Mr range of 58-84 kDa depending on brain regions and species. Upon deglycosylation to remove N-linked glycans by PNGase F (but not Endo H), the MOPR became a dense and sharp band with Mr of ~43 kDa, close to the theoretical Mr of its deduced amino acid sequences. Thus, MOPRs in rodent brains are differentially glycosylated by complex type of N-linked glycans in brain region- and species-specific manners. Furthermore, we characterized the MOPR in an A112G/N38D-MOPR knockin mouse model that possesses the equivalent substitution of the A118G/N40D SNP in the human MOPR gene. The substitution removes one of the four and five N-linked consensus glycosylation sites of the mouse and human MOPR, respectively. We demonstrated that the Mr of the MOPR in A112G mouse brains was lower than that in wild-type mouse brains, and that the difference was due to lower degrees of N-linked glycosylation.

  2. Retinal Detachment in Preeclampsia

    Directory of Open Access Journals (Sweden)

    Prado Renata Silva do

    2002-01-01

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

  3. 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.

  4. 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.

  5. Retinal flow cytometer.

    Science.gov (United States)

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

    2007-12-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Puerarin antagonizes peroxyntrite-induced injury in retinal pigment epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Lina Hao; Xudong Zhang; Tao Yang; Junling Ma

    2012-01-01

    A rat model of diabetes mellitus was established by intraperitoneal injection of streptozotocin. Three days later, the rats were intraperitoneally administered 140 mg puerarin/kg daily, for a total of 60 successive days. DNA ladder results showed increased apoptosis over time in retinal pigment epithelial cells from rats with streptozotocin-induced diabetes mellitus. Western blot analysis, Reverse transcription-PCR, immunohistochemistry, and flow cytometry results showed increased expression of 3-nitrotyrosine, a peroxyntrite marker, as well as inducible nitric synthase and Fas/FasL, in retinal pigment epithelial cells. Puerarin reversed these changes, and results demonstrated that puerarin inhibited Fas/FasL expression and alleviated peroxyntrite injury to retinal pigment epithelial cells. These results suggested that puerarin inhibited production of inducible nitric oxide synthase and directly antagonized peroxyntrite injury in retinal pigment epithelial cells.

  8. Whole number, distribution and co-expression of brn3 transcription factors in retinal ganglion cells of adult albino and pigmented rats.

    Directory of Open Access Journals (Sweden)

    Francisco M Nadal-Nicolás

    Full Text Available The three members of the Pou4f family of transcription factors: Pou4f1, Pou4f2, Pou4f3 (Brn3a, Brn3b and Brn3c, respectively play, during development, essential roles in the differentiation and survival of sensory neurons. The purpose of this work is to study the expression of the three Brn3 factors in the albino and pigmented adult rat. Animals were divided into these groups: i untouched; ii fluorogold (FG tracing from both superior colliculli; iii FG-tracing from one superior colliculus; iv intraorbital optic nerve transection or crush. All retinas were dissected as flat-mounts and subjected to single, double or triple immunohistofluorescence The total number of FG-traced, Brn3a, Brn3b, Brn3c or Brn3 expressing RGCs was automatically quantified and their spatial distribution assessed using specific routines. Brn3 factors were studied in the general RGC population, and in the intrinsically photosensitive (ip-RGCs and ipsilateral RGC sub-populations. Our results show that: i 70% of RGCs co- express two or three Brn3s and the remaining 30% express only Brn3a (26% or Brn3b; ii the most abundant Brn3 member is Brn3a followed by Brn3b and finally Brn3c; iii Brn3 a-, b- or c- expressing RGCs are similarly distributed in the retina; iv The vast majority of ip-RGCs do not express Brn3; v The main difference between both rat strains was found in the population of ipsilateral-RGCs, which accounts for 4.2% and 2.5% of the total RGC population in the pigmented and albino strain, respectively. However, more ipsilateral-RGCs express Brn3 factors in the albino than in the pigmented rat; vi RGCs that express only Brn3b and RGCs that co-express the three Brn3 members have the biggest nuclei; vii After axonal injury the level of Brn3a expression in the surviving RGCs decreases compared to control retinas. Finally, this work strengthens the validity of Brn3a as a marker to identify and quantify rat RGCs.

  9. Retinal locus for scanning text.

    Science.gov (United States)

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

    2006-01-01

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

  10. Learning about Retinitis Pigmentosa

    Science.gov (United States)

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

  11. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

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

  12. 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 ...

  13. Retinal imaging with smartphone.

    Science.gov (United States)

    Ademola-Popoola, D S; Olatunji, V A

    2017-03-01

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

  14. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

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

  15. Retinal Imaging with Smartphone

    African Journals Online (AJOL)

    2017-03-06

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

  16. Range of retinal diseases potentially treatable by AAV-vectored gene therapy.

    Science.gov (United States)

    Hauswirth, William W; Li, Quihong; Raisler, Brian; Timmers, Adrian M; Berns, Kenneth I; Flannery, John G; LaVail, Matthew M; Lewin, Alfred S

    2004-01-01

    Viable strategies for retinal gene therapy must be designed to cope with the genetic nature of the disease and/or the primary pathologic process responsible for retinal malfunction. For dominant gene defects the aim must be to destroy the presumably toxic gene product, for recessive gene defects the direct approach aims to provide a wild-type copy of the gene to the affected retinal cell type, and for diseases of either complex or unknown genetic origin, more general cell survival strategies that deal with preserving affected retinal cells are often the best and only option. Hence examples of each type of therapy will be briefly discussed in several animal models, including ribozyme therapy for autosomal dominant retinitis pigmentosa in the transgenic P23H opsin rat, beta-PDE gene augmentation therapy for autosomal recessive retinitis pigmentosa in the rd mouse, glial cell-derived neurotrophic factor (GDNF) gene therapy for autosomal dominant RP in the transgenic S334ter opsin rat and pigment epithelial cell-derived neurotrophic factor (PEDF) gene therapy for neovascular retinal disease in rodents. Each employs a recombinant AAV vectored passenger gene controlled by one of several promoters supporting either photoreceptor-specific expression or more general retinal cell expression depending on the therapeutic requirements.

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

    Directory of Open Access Journals (Sweden)

    Rose Rose

    2016-02-01

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

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

    Science.gov (United States)

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

    2015-09-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Retinal functional change caused by adenoviral vector-mediated transfection of LacZ gene.

    Science.gov (United States)

    Sakamoto, T; Ueno, H; Goto, Y; Oshima, Y; Yamanaka, I; Ishibashi, T; Inomata, H

    1998-04-10

    We examined the effect of insertion of an exogenous gene on retinal function to assess the rationale of adenoviral vector-mediated gene transfer for future gene therapy. An adenoviral vector expressing bacterial LacZ (AdCALacZ) was injected into the eyes of adult rats either intravitreally (group A) or subretinally (group B), and the gene expression and retinal function were thus examined at different time points after gene transfer for 3 weeks. X-Gal histostaining showed that neural retinal cells were transfected in group A and that retinal pigment epithelial cells were transfected in group B. The gene transfer was more efficient in group B (54.4% of the fixed retinal area was stained) than in group A (10.4%). The electroretinogram (ERG) revealed retinal dysfunction in the AdCALacZ-transfected rats even at the stage in which the histological damage was not apparent by electron microscopy and immunohistochemical studies for cytokeratin, S-100 protein, and glial fibrillary acidic protein. The ERG change was correlated with the intensity of inflammation, and retinal function recovered to the original level by 3 weeks, along with a diminution of inflammation. Functional changes were more evident in eyes treated with AdCALacZ than in those infected with adenoviral vector with no exogenous gene; however, no histological difference was observed between these groups, indicating that the insertion of exogenous gene itself affects retinal function. The results showed that different kinds of retinal cells could be gene-transferred by an adenoviral vector, depending on the application method. The retinal dysfunction caused by each adenoviral transfection method was caused by inflammation and the insertion of exogenous gene, and this retinal dysfunction was recoverable. In future gene therapy, special attention should be given to the method of exogenous gene insertion in the retina.

  1. Peripapillary retinal thermal coagulation following electrical injury

    Directory of Open Access Journals (Sweden)

    Manjari Tandon

    2013-01-01

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

  2. Dendrobium chrysotoxum Lindl. Alleviates Diabetic Retinopathy by Preventing Retinal Inflammation and Tight Junction Protein Decrease

    Directory of Open Access Journals (Sweden)

    Zengyang Yu

    2015-01-01

    Full Text Available Diabetic retinopathy (DR is a serious complication of diabetes mellitus. This study aimed to observe the alleviation of the ethanol extract of Dendrobium chrysotoxum Lindl. (DC, a traditional Chinese herbal medicine, on DR and its engaged mechanism. After DC (30 or 300 mg/kg was orally administrated, the breakdown of blood retinal barrier (BRB in streptozotocin- (STZ- induced diabetic rats was attenuated by DC. Decreased retinal mRNA expression of tight junction proteins (including occludin and claudin-1 in diabetic rats was also reversed by DC. Western blot analysis and retinal immunofluorescence staining results further confirmed that DC reversed the decreased expression of occludin and claudin-1 proteins in diabetic rats. DC reduced the increased retinal mRNA expressions of intercellular adhesion molecule-1 (ICAM-1, tumor necrosis factor α (TNFα, interleukin- (IL- 6, and IL-1β in diabetic rats. In addition, DC alleviated the increased 1 and phosphorylated p65, IκB, and IκB kinase (IKK in diabetic rats. DC also reduced the increased serum levels of TNFα, interferon-γ (IFN-γ, IL-6, IL-1β, IL-8, IL-12, IL-2, IL-3, and IL-10 in diabetic rats. Therefore, DC can alleviate DR by inhibiting retinal inflammation and preventing the decrease of tight junction proteins, such as occludin and claudin-1.

  3. Bacteria that purify sludge; Des bacteries epuratrices

    Energy Technology Data Exchange (ETDEWEB)

    Peignen-Seraline, P.; Manem, J. [Cirsee, Lyonnaise des Eaux, 92 - Nanterre (France)

    1997-03-01

    Inherent in water purification processes, the formation of sludges is intensively studied. Recently, original bacteria have been observed by searchers: some of them purify water making ``tassels``, others separate them and some of them even participate in the elimination of the first. This research study is described into details and will probably be used in the future at the industrial scale. (O.M.)

  4. 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 noninvasive 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 400×400  pixels with a spatial resolution of ∼8 microns and a temporal resolution of ∼6.5  ms.

  5. Retinal flow cytometer

    OpenAIRE

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

    2007-01-01

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

  6. New therapeutic modalities of retinal laser injury. Final report, 1 Mar 89-1 Mar 92

    Energy Technology Data Exchange (ETDEWEB)

    Lam, T.T.; Tso, M.O.

    1992-03-31

    Efficacies of three different regimens of high dose of methylprednisolone (MP) treatment on laser-induced non-hemorrhage retinal injury and tissue plasminogen activator (t-PA) in sub-retinal hemorrhage laser injury were evaluated in a sub-human primate model and a rat model respectively. Clinical, histopathological, and morphometric criteria were employed for evaluating the efficacy of MP. High dose and prolonged treatment (4 days) was the most effective regimen while high dose for 8 hours showed limited effect in non-hemorrhagic retinal injury. Intravitreal t-PA showed no apparent beneficial effect in sub-retinal hemorrhage after laser injury. Hence, patients with laser retinal injury may benefit from high dose MP treatment for an appropriate period of time.

  7. 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

  8. 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.

  9. [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.

  10. Why CLEAN when you can PURIFY?

    CERN Document Server

    Carrillo, Rafael E; Wiaux, Yves

    2013-01-01

    We extend previously proposed radio-interferometric imaging approaches based on convex optimization to handle continuous visibilities and large-scale optimization problems. We propose a general algorithmic framework based on the simultaneous-direction method of multipliers to solve sparse imaging problems. The algorithm offers a parallel implementation structure, thus providing a significant gain in terms of speed and scalability to very high dimensions. We implement various state-of-the-art sparsity regularization priors, including our recent average sparsity approach SARA, in a new imaging software dubbed PURIFY. We evaluate through realistic simulations the performance of the software in terms of reconstruction quality and computational speed. Simulation results confirm both the superiority of SARA for continuous Fourier measurements and the fact that the new algorithmic structure offers a promising path to handle large-scale problems. Code is available at https://github.com/basp-group/purify

  11. Retinal oximetry in patients with ischaemic retinal diseases

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  12. Affinity-purified human interleukin I is cytotoxic to isolated islets of Langerhans

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Bendtzen, K; Nerup, J

    1986-01-01

    . These effects were dose-dependent and reproducible when using three different Interleukin-1 preparations. Highly purified human Interleukin-2, Lymphotoxin, Leucocyte Migration Inhibitory Factor and Macrophage Migration Inhibitory Factor were ineffective. These findings suggest that Interleukin-1 may play......Addition of highly purified human Interleukin-1 to the culture medium of isolated rat islets of Langerhans for 6 days led to 88% inhibition of glucose-induced insulin-release, reduction of islet contents of insulin and glucagon to 31% and 8% respectively, and disintegration of the islets...

  13. Utilization of purified cellulose in fiber studies.

    Science.gov (United States)

    Penner, M H; Liaw, E T

    1990-01-01

    Purified cellulose-type fiber products are widely used in experimental nutrition. Their use in a broad spectrum of studies may potentially lead to the acceptance of the misconception that the various commercially available cellulose products are equivalent. In this paper we have attempted to show that this is not the case. The comparative structural data of Table 2 and the compositional data of Olsen et al provide examples which indicate that purified cellulose preparations should not necessarily be considered equivalent. Unfortunately, our current lack of understanding of how fibers are metabolized and how they may affect specific physiological parameters makes it difficult to determine which, if any, of the measurable structural and chemical properties will be of relevance for a given in vivo study. At present, it appears that researchers utilizing/evaluating the consequences of consuming a purified cellulose-type fiber would be prudent to provide at least a limited amount of data on the properties of the cellulose preparation used in their studies. The characterization of the cellulose product may be done by a variety of methods depending on the expertise of the laboratory. The methods and results discussed in this paper provide an example of the type of information which may be obtained from an in vitro characterization of cellulose products.

  14. Maternal enrichment during pregnancy accelerates retinal development of the fetus.

    Directory of Open Access Journals (Sweden)

    Alessandro Sale

    Full Text Available The influence of maternal environment on fetal development is largely unexplored, the available evidence concerns only the deleterious effects elicited by prenatal stress. Here we investigated the influence of prenatal enrichment on the early development of the visual system in the fetus. We studied the anatomical development of the rat retina, by analyzing the migration of neural progenitors and the process of retinal ganglion cell death, which exerts a key role in sculpturing the developing retinal system at perinatal ages. The number of apoptotic cells in the retinal ganglion cell layer was analyzed using two distinct methods: the presence of pyknotic nuclei stained for cresyl violet and the appearance of DNA fragmentation (Tunel method. We report that environmental enrichment of the mother during pregnancy affects the structural maturation of the retina, accelerating the migration of neural progenitors and the dynamics of natural cell death. These effects seem to be under the control of insulin-like growth factor-I: its levels, higher in enriched pregnant rats and in their milk, are increased also in their offspring, its neutralization abolishes the action of maternal enrichment on retinal development and chronic insulin-like growth factor-I injection to standard-reared females mimics the effects of enrichment in the fetuses. Thus, the development of the visual system is sensitive to environmental stimulation during prenatal life. These findings could have a bearing in orienting clinical research in the field of prenatal therapy.

  15. Some Properties of Purified and Non-purified Rumen Tissue Arginase in Cattle

    OpenAIRE

    ERİŞİR, Mine; OZAN, Sema Temizer

    1998-01-01

    Some biochemical properties of purified and non-purified rumen tissue arginase were compared. Homogenization, heating, treatment with aceton, precipitation with ammonium sulfate, dialysis, several centrifugations, gel filtration on sephadex G-200 processes were utilized in the purification procedure of the enzyme. It was found that pre-incubation temperature (60 °C) of arginase and Km (4mM) to its substrate, L-arginine, did not change before and after purification. While pre-incubation peri...

  16. Identification of genes and pathways involved in retinal neovascularization by microarray analysis of two animal models of retinal angiogenesis.

    Science.gov (United States)

    Recchia, Franco M; Xu, Lili; Penn, John S; Boone, Braden; Dexheimer, Phillip J

    2010-02-01

    Comparative retinal gene expression analysis in two rodent models of oxygen-induced retinopathy (OIR) was performed to identify the genes and pathways involved in retinal neovascularization. Three independent experimental runs were conducted for each species, according to standard protocols for induction of OIR. Total retinal RNA was isolated at two time points, corresponding to the early response to relative hypoxia (P13 in mouse, P15 in rat) and to the later phase of maximum retinal neovascularization (P18 in mouse, P20 in rat) and was used to prepare labeled probes for hybridization. Gene expression was compared between normal and experimental conditions for each species at each time point. Probesets with a false-discovery rate of rat and in 1622 in the mouse, with 13 in common. Four pathways were identified in both models. Genes and pathways known to be involved in angiogenesis, as well as other biologically plausible genes and pathways, were identified. This work serves as a comprehensive resource for the study of retinal neovascularization and identification of potential rational targets for antiangiogenic therapy.

  17. Retinal detachment surgery without cryotherapy.

    OpenAIRE

    Chignell, A H; Markham, R H

    1981-01-01

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

  18. Perceptual Fading without Retinal Adaptation

    Science.gov (United States)

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

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

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

    Science.gov (United States)

    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

  20. Spectrophotometric retinal oximetry in pigs

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  1. Bilateral retinitis following typhoid fever.

    Science.gov (United States)

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

    2017-01-01

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

  2. Air Purifiers Eliminate Pathogens, Preserve Food

    Science.gov (United States)

    2009-01-01

    NASA-funded researchers produced an ethylene reduction device for a plant growth unit. KES Science & Technology Inc., a Kennesaw, Georgia-based company specializing in sustaining perishable foods, licensed the ethylene scrubbing technology. KES partnered with Akida Holdings, of Jacksonville, Florida, which now markets the NASA-developed technology as AiroCide. According to the company, it is the only air purifier that completely destroys airborne bacteria, mold, fungi, mycotoxins, viruses, volatile organic compounds (like ethylene), and odors. What?s more, the devices have no filters that need changing and produce no harmful byproducts, such as the ozone created by some filtration systems.

  3. Retinal incorporation and differentiation of mesenchymal stem cells intravitreally injected in the injured retina of rats Incorporação e diferenciação retiniana de células tronco mesenquimais intravítreas em ratos

    Directory of Open Access Journals (Sweden)

    Paula Castanheira

    2008-10-01

    Full Text Available PURPOSE: To evaluate the pattern of retinal integration and differentiation of mesenchymal stem cells (MSCs injected into the vitreous cavity of rat eyes with retinal injury. METHODS: Adult rat retinas were submitted to laser damage followed by transplantation of DAPI-labeled BM-MSCs grafts. To assess the integration and differentiation of BM-MSCs in laser-injured retina, host retinas were evaluated 2.4 and 8 weeks after injury/transplantation. RESULTS: Our results demonstrated that the grafted cells survived in the retina for at least 8 weeks and almost all BM-MSCs migrated and incorporated into the neural retina, specifically in the outer nuclear layer (ONL, inner nuclear layer (INL and ganglion cell layer (GCL while a subset of grafted cells were found in the subretinal space posttransplantation. At 8 weeks immunohistochemical analysis with several retinal specific markers revealed that the majority of the grafted cells expressed rhodopsin, a rod photoreceptor marker, followed by parvalbumin, a marker for bipolar and amacrine cells. A few subsets of cells were able to express a glial marker, glial fibrillary acidic protein. However, grafted cells failed to express pan-cytokeratin, a retinal pigment epithelium marker. CONCLUSIONS: These results suggest the potential of BM-MSCs to differentiate into retinal neurons. Taken together, these findings might be clinically relevant for future mesenchymal stem cell therapy studies concerning retinal degeneration repair.OBJETIVO: Avaliar o padrão de integração e diferenciação retiniana de células tronco mesenquimais (CTM injetadas na cavidade vítrea de ratos portadores de lesões retinianas. MÉTODOS: Ratos Wistar adultos foram submetidos a múltiplas lesões retinianas utilizando-se YAG laser e injeção intravítrea de células tronco mesenquimais. A fim de se avaliar a integração e diferenciação retiniana, o tecido retiniano lesado pelo YAG laser / tratado pelas células tronco, foi

  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. Local signaling from a retinal prosthetic in a rodent retinitis pigmentosa model in vivo

    Science.gov (United States)

    Fransen, James W.; Pangeni, Gobinda; Pardue, Machelle T.; McCall, Maureen A.

    2014-08-01

    Objective. In clinical trials, retinitis pigmentosa patients implanted with a retinal prosthetic device show enhanced spatial vision, including the ability to read large text and navigate. New prosthetics aim to increase spatial resolution by decreasing pixel/electrode size and limiting current spread. To examine spatial resolution of a new prosthetic design, we characterized and compared two photovoltaic array (PVA) designs and their interaction with the retina after subretinal implantation in transgenic S334ter line 3 rats (Tg S334ter-3). Approach. PVAs were implanted subretinally at two stages of degeneration and assessed in vivo using extracellular recordings in the superior colliculus (SC). Several aspects of this interaction were evaluated by varying duration, irradiance and position of a near infrared laser focused on the PVA. These characteristics included: activation threshold, response linearity, SC signal topography and spatial localization. The major design difference between the two PVA designs is the inclusion of local current returns in the newer design. Main results. When tested in vivo, PVA-evoked response thresholds were independent of pixel/electrode size, but differ between the new and old PVA designs. Response thresholds were independent of implantation age and duration (⩽7.5 months). For both prosthesis designs, threshold intensities were within established safety limits. PVA-evoked responses require inner retina synaptic transmission and do not directly activate retinal ganglion cells. The new PVA design evokes local retinal activation, which is not found with the older PVA design that lacks local current returns. Significance. Our study provides in vivo evidence that prosthetics make functional contacts with the inner nuclear layer at several stages of degeneration. The new PVA design enhances local activation within the retina and SC. Together these results predict that the new design can potentially harness the inherent processing within

  6. Study on soot purifying of molding shop in coking factory

    Institute of Scientific and Technical Information of China (English)

    LI Duo-song; ZHANG Hui; BAI Xiang-yu

    2006-01-01

    Exhaust gas in molding shop was complicated in component and characteristic in Iow thickness asphalt smoke, mass steam-gas and dust. It was difficult to purify the soot with common purifier. So we must consider them roundly and develop new multifunction purifier. PFP multifunction soot purifier was made on the base of design optimization and was installed at Shenhuo Coking Factory in 2004. The combined effects of multi- mechanism in purifier make purifying ratio keep in high level. The remove ratio of smut reaches at 92.8%, and asphalt smoke at 83.7%.

  7. Metabolic Memory Phenomenon and Accumulation of Peroxynitrite in Retinal Capillaries

    Directory of Open Access Journals (Sweden)

    Renu A. Kowluru

    2007-01-01

    Full Text Available Aim. Diabetic retinopathy resists reversal after good glycemic control (GC is reinitiated, and preexisting damage at the time of intervention is considered as the major factor in determining the outcome of the GC. This study is to investigate the role of peroxynitrite accumulation in the retinal capillaries in the failure of retinopathy to reverse after reestablishment of GC, and to determine the effect of this reversal on the activity of the enzyme responsible for scavenging mitochondrial superoxide, MnSOD. Methods. In streptozotocin-diabetic rats, 6 months of poor glycemic control (PC, glycated hemoglobin, GHb>12.0% was followed by 6 additional months of GC (GHb about 6%. The trypsin-digested retinal microvessels were prepared for immunostaining of nitrotyrosine (a measure of peroxynitrite and for counting the number of acellular capillaries (a measure of histopathology. The retina from the other eye was used to quantify nitrotyrosine concentration, MnSOD activity and the total antioxidant capacity. Results. Reversal of hyperglycemia after 6 months of PC had no significant effect on nitrotyrosine concentration in the retina, on the nitrotyrosine-positive retinal capillary cells and on the number of acellular capillaries; the values were similar in PC-GC and PC groups. In the same rats retinal MnSOD activity remained inhibited and the total antioxidant capacity was subnormal 6 months after cessation of PC. Conclusions. Peroxynitrite accumulation in the retinal microvasculature, the site of histopathology, fails to normalize after reversal of hyperglycemia, and superoxide remains inadequately scavenged. This failure of reversal of peroxynitrite accumulation could be, in part, responsible for the resistance of diabetic retinopathy to reverse after termination of PC.

  8. Treatment of Laser-Induced Retinal Injuries

    Science.gov (United States)

    1989-06-29

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

  9. Reconstitution of highly purified saxitoxin-sensitive Na+-channels into planar lipid bilayers.

    OpenAIRE

    Hanke, W.; Boheim, G; Barhanin, J; Pauron, D; Lazdunski, M

    1984-01-01

    Highly purified Na+-channels isolated from rat brain have been reconstituted into virtually solvent-free planar lipid bilayer membranes. Two different types of electrically excitable channels were detected in the absence of any neurotoxins. The activity of both channels was blocked by saxitoxin. The first channel type is highly selective for Na+ over K+ (approximately 10:1), it shows a bursting behavior, a conductance of 25 pS in Na+-Ringer and undergoes continuous opening and closing events ...

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

    Science.gov (United States)

    Makino, Shinji; Endoh, Katsuhisa; Tampo, Hironobu

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Shinji Makino

    2013-01-01

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

  12. Ozone Air Purifiers: Can They Improve Asthma Symptoms?

    Science.gov (United States)

    ... daughter has asthma. Would she benefit from an ozone air purifier in her room? Answers from James ... Li, M.D., Ph.D. Despite manufacturers' claims, ozone air purifiers don't remove asthma triggers from ...

  13. Synthesis and characterization of nano-sized CaCO3 in purified diet

    Science.gov (United States)

    Mulyaningsih, N. N.; Tresnasari, D. R.; Ramahwati, M. R.; Juwono, A. L.; Soejoko, D. S.; Astuti, D. A.

    2017-07-01

    The growth and development of animals depend strongly on the balanced nutrition in the diet. This research aims is to characterize the weight variations of nano-sized calcium carbonate (CaCO3) in purified diet that to be fed to animal model of rat. The nano-sized CaCO3 was prepared by milling the calcium carbonate particles for 20 hours at a rotation speed of 1000 rpm and resulting particle size in a range of 2-50 nm. Nano-sized CaCO3 added to purified diet to the four formulas that were identified as normal diet (N), deficiency calcium (DC), rich in calcium (RC), and poor calcium (PC) with containing in nano-sized CaCO3 much as 0.50 %, 0.00 %, 0.75 % and 0.25 % respectively. The nutritional content of the purified diet was proximate analyzed, it resulted as followed moisture, ash, fat, protein, crude fiber. The quantities of chemical element were analyzed by atomic absorption spectrometry (AAS), it resulted iron, magnesium, potassium and calcium. The results showed that N diet (Ca: 16,914.29 ppm) were suggested for healthy rats and RC diet (Ca: 33,696.13 ppm) for conditioned osteoporosis rats. The crystalline phases of the samples that were examined by X-ray diffraction showed that crystalline phase increased with the increasing concentration of CaCO3.

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

    Science.gov (United States)

    Foster, William J

    2011-07-20

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

  15. Isolating and Purifying Clostridium difficile Spores

    Science.gov (United States)

    Edwards, Adrianne N.; McBride, Shonna M.

    2016-01-01

    Summary The ability for the obligate anaerobe, Clostridium difficile, to form a metabolically dormant spore is critical for the survival of this organism outside of the host. This spore form is resistant to a myriad of environmental stresses, including heat, desiccation and exposure to disinfectants and antimicrobials. These intrinsic properties of spores allow C. difficile to survive long-term in an oxygenated environment, to be easily transmitted from host-to-host and to persist within the host following antibiotic treatment. Because of the importance of the spore form to the C. difficile lifecycle and treatment and prevention of C. difficile infection (CDI), the isolation and purification of spores are necessary to study the mechanisms of sporulation and germination, investigate spore properties and resistances, and for use in animal models of CDI. This chapter provides basic protocols, in vitro growth conditions and additional considerations for purifying C. difficile spores for a variety of downstream applications. PMID:27507337

  16. 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.

  17. AUTOMATIC RETINAL VESSEL TORTUOSITY MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Nidhal Khdhair El Abbadi

    2013-01-01

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

  18. [Retinal vasculitis in lupic disease].

    Science.gov (United States)

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

    1985-01-01

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

  19. 21 CFR 880.6710 - Medical ultraviolet water purifier.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical ultraviolet water purifier. 880.6710... Miscellaneous Devices § 880.6710 Medical ultraviolet water purifier. (a) Identification. A medical ultraviolet water purifier is a device intended for medical purposes that is used to destroy bacteria in water...

  20. Retinal prosthesis for the blind.

    Science.gov (United States)

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

    2002-01-01

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

  1. Retinal implants: a systematic review.

    Science.gov (United States)

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

    2014-07-01

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

  2. Filling in the retinal image

    Science.gov (United States)

    Larimer, James; Piantanida, Thomas

    1990-01-01

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

  3. The mechanics of retinal detachment

    Science.gov (United States)

    Chou, Tom; Siegel, Michael

    2013-03-01

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

  4. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  5. Investigating the influence of chromatic aberration and optical illumination bandwidth on fundus imaging in rats

    Science.gov (United States)

    Li, Hao; Liu, Wenzhong; Zhang, Hao F.

    2015-10-01

    Rodent models are indispensable in studying various retinal diseases. Noninvasive, high-resolution retinal imaging of rodent models is highly desired for longitudinally investigating the pathogenesis and therapeutic strategies. However, due to severe aberrations, the retinal image quality in rodents can be much worse than that in humans. We numerically and experimentally investigated the influence of chromatic aberration and optical illumination bandwidth on retinal imaging. We confirmed that the rat retinal image quality decreased with increasing illumination bandwidth. We achieved the retinal image resolution of 10 μm using a 19 nm illumination bandwidth centered at 580 nm in a home-built fundus camera. Furthermore, we observed higher chromatic aberration in albino rat eyes than in pigmented rat eyes. This study provides a design guide for high-resolution fundus camera for rodents. Our method is also beneficial to dispersion compensation in multiwavelength retinal imaging applications.

  6. Inhibition of α-crystallin on proliferation of rat retinal microglia following optic nerve injury%α晶体蛋白对LPS刺激及视神经损伤后大鼠视网膜小胶质细胞增殖及数量的影响

    Institute of Scientific and Technical Information of China (English)

    吴楠; 王艳华; 王晓芹; 刘东宁; 应希; 张莉; 王一

    2008-01-01

    目的 研究α晶体蛋白对大鼠视网膜小胶质细胞增殖能力及视神经损伤后小胶质细胞数量的影响.方法 脂多糖激活离体培养视网膜小胶质细胞,模拟视神经损伤,采用MTF分析α晶体蛋白对激活的小胶质细胞增殖能力的影响;建立大鼠视神经不全损伤模型,损伤后玻璃体腔注射α晶体蛋白,采用视网膜铺片及免疫荧光标记小胶质细胞并计数,比较不同组小胶质细胞的数量.结果 10-g/L~10-2 g/L浓度的脂多糖均可激活小胶质细胞(P<0.05),10-6g/L和10-4g/L浓度的α晶体蛋白可明显抑制10-6g/L浓度的脂多糖激活的小胶质细胞的增殖;视神经损伤1~3周,α晶体蛋白注射组小胶质细胞的数量明显少于损伤组(P<0.05).结论 α晶体蛋白可抑制视网膜上小胶质细胞的增殖和活化,减轻小胶质细胞对RGCs的过度吞噬和继发性损害,可能是视神经损伤后α晶体蛋白问接保护RGCs存活的另一机制.%Objective To investigate the effect of α-crystallin on the proliferation of rat retinal microglia after optic nerve injury. Methods The effect of α-crystallin on number and proliferation of microglia were analyzed by MTT assay.After the rat model with optic nerve injury was established,α-crystallin was iniected into vitreous cavity and the microglia cell number were counted and compared by retinal fiat counting and immunofluorescence labeling in different groups. Results The proliferation and activation of microglia cells could be stimulated by LPS at 10-6g/L to 10-2g/L.α-crystallin at 10-4g/L and 10-6g/L could inhibit proliferation and activation of microglia cells.Compared to BSA iniection group,α-crystallin could inhibit more significantly the number of microglia cells 1-3 weeks after injury (P<0.05). Conclusions α-crystallin can inhibit proliferation and activation of retinal microglia and alleviate overphagocytosis and secondary damage of retinal microglia to retinal ganglion cells

  7. Persistent inflammatory state after photoreceptor loss in an animal model of retinal degeneration.

    Science.gov (United States)

    Noailles, Agustina; Maneu, Victoria; Campello, Laura; Gómez-Vicente, Violeta; Lax, Pedro; Cuenca, Nicolás

    2016-09-14

    Microglia act as the resident immune cells of the central nervous system, including the retina. In response to damaging stimuli microglia adopt an activated state, which can progress into a phagocytic phenotype and play a potentially harmful role by eliciting the expression and release of pro-inflammatory cytokines. The aim of the present study was to assess longitudinal changes in microglia during retinal degeneration in the homozygous P23H rat, a model of dominant retinitis pigmentosa. Microglial phenotypes, morphology and density were analyzed by immunohistochemistry, flow cytometry, and cytokine antibody array. In addition, we performed electroretinograms to evaluate the retinal response. In the P23H retina, sclera, choroid and ciliary body, inflammatory cells increased in number compared with the control at all ages analyzed. As the rats became older, a higher number of amoeboid MHC-II(+) cells were observed in the P23H retina, which correlated with an increase in the expression of pro-inflammatory cytokines. These findings suggest that, in the P23H model, retinal neuroinflammation persists throughout the rat's life span even after photoreceptor depletion. Therefore, the inclusion of anti-inflammatory drugs at advanced stages of the neurodegenerative process may provide better retinal fitness so the remaining cells could still be used as targets of cellular or gene therapies.

  8. Photobiomodulation reduces photoreceptor death and regulates cytoprotection in early states of P23H retinal dystrophy

    Science.gov (United States)

    Kirk, Diana K.; Gopalakrishnan, Sandeep; Schmitt, Heather; Abroe, Betsy; Stoehr, Michele; Dubis, Adam; Carroll, Joseph; Stone, Jonathan; Valter, Krisztina; Eells, Janis

    2013-03-01

    Irradiation by light in the far-red to near-infrared (NIR) region of the spectrum (photobiomodulation, PBM) has been demonstrated to attenuate the severity of neurodegenerative disease in experimental and clinical studies. The purpose of this study was to test the hypothesis that 670 nm PBM would protect against the loss of retinal function and improve photoreceptor survival in a rodent model of retinitis pigmentosa, the P23H transgenic rat. P23H rat pups were treated once per day with a 670 nm LED array (180 sec treatments at 50 mW/cm2; fluence 9 joules/cm2) (Quantum Devices Inc., Barneveld WI) from postnatal day (p) 16-20 or from p10-20. Sham-treated rats were restrained, but not exposed to NIR light. The status of the retina was determined at p22 by assessment of mitochondrial function, oxidative stress and cell death. In a second series of studies, retinal status was assessed at p30 by measuring photoreceptor function by ERG and retinal morphology by Spectral Domain Optical Coherence Tomography (SD-OCT). 670 nm PBM increased retinal mitochondrial cytochrome oxidase activity and upregulated the retina's production of the key mitochondrial antioxidant enzyme, MnSOD. PBM also attenuated photoreceptor cell loss and improved photoreceptor function. PBM protects photoreceptors in the developing P23H retina, by augmenting mitochondrial function and stimulating antioxidant protective pathways. Photobiomodulation may have therapeutic potential, where mitochondrial damage is a step in the death of photoreceptors.

  9. Phloroglucinol protects retinal pigment epithelium and photoreceptor against all-trans-retinal-induced toxicity and inhibits A2E formation.

    Science.gov (United States)

    Cia, David; Cubizolle, Aurélie; Crauste, Céline; Jacquemot, Nathalie; Guillou, Laurent; Vigor, Claire; Angebault, Claire; Hamel, Christian P; Vercauteren, Joseph; Brabet, Philippe

    2016-09-01

    Among retinal macular diseases, the juvenile recessive Stargardt disease and the age-related degenerative disease arise from carbonyl and oxidative stresses (COS). Both stresses originate from an accumulation of all-trans-retinal (atRAL) and are involved in bisretinoid formation by condensation of atRAL with phosphatidylethanolamine (carbonyl stress) in the photoreceptor and its transformation into lipofuscin bisretinoids (oxidative stress) in the retinal pigment epithelium (RPE). As atRAL and bisretinoid accumulation contribute to RPE and photoreceptor cell death, our goal is to select powerful chemical inhibitors of COS. Here, we describe that phloroglucinol, a natural phenolic compound having anti-COS properties, protects both rat RPE and mouse photoreceptor primary cultures from atRAL-induced cell death and reduces hydrogen peroxide (H2 O2 )-induced damage in RPE in a dose-dependent manner. Mechanistic analyses demonstrate that the protective effect encompasses decrease in atRAL-induced intracellular reactive oxygen species and free atRAL levels. Moreover, we show that phloroglucinol reacts with atRAL to form a chromene adduct which prevents bisretinoid A2E synthesis in vitro. Taken together, these data show that the protective effect of phloroglucinol correlates with its ability to trap atRAL and to prevent its further transformation into deleterious bisretinoids. Phloroglucinol might be a good basis to develop efficient therapeutic derivatives in the treatment of retinal macular diseases.

  10. Determination of retinal surface area.

    Science.gov (United States)

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

    2017-09-01

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

  11. ACUTE RETINAL ARTERIAL OCCLUSIVE DISORDERS

    Science.gov (United States)

    Hayreh, Sohan Singh

    2011-01-01

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

  12. Single molecule DNA compaction by purified histones

    Institute of Scientific and Technical Information of China (English)

    RAN ShiYong; WANG XiaoLing; FU WenBo; WANG WeiChi; LI Ming

    2008-01-01

    The compaction of single DNA molecules by purified histones is studied using magnetic tweezers, The compaction rate increases rapidly when the histone concentration is increased from 0.002 to 0.2 mmol/L, and saturates when the concentration is beyond 0.2 mmol/L, The time course of compaction is exponential at low histone concentrations. It becomes sigmoidal at high concentrations. Cooperativity between the histones bound to DNA is proposed to be responsible for the transition. The histones are loaded onto DNA randomly at low concentrations. They tend to bind DNA cooperatively at high con-centrations because the structural torsions of DNA induced by the bound histones become overlapping so that the binding of one histone facilitates the binding of others. Under very large forces, the com-pacted histone-DNA complex can be disrupted in a discrete manner with a step size of ~60 nm. But the histones cannot be completely stripped off DNA, as is revealed by the lowered B-S transition plateau of the histone-bound DNA.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  14. Blood pressure modifies retinal susceptibility to intraocular pressure elevation.

    Directory of Open Access Journals (Sweden)

    Zheng He

    Full Text Available Primary open angle glaucoma affects more than 67 million people. Elevated intraocular pressure (IOP is a risk factor for glaucoma and may reduce nutrient availability by decreasing ocular perfusion pressure (OPP. An interaction between arterial blood pressure and IOP determines OPP; but the exact contribution that these factors have for retinal function is not fully understood. Here we sought to determine how acute modifications of arterial pressure will affect the susceptibility of neuronal function and blood flow to IOP challenge. Anaesthetized (ketamine:xylazine Long-Evan rats with low (∼60 mmHg, sodium nitroprusside infusion, moderate (∼100 mmHg, saline, or high levels (∼160 mmHg, angiotensin II of mean arterial pressure (MAP, n = 5-10 per group were subjected to IOP challenge (10-120 mmHg, 5 mmHg steps every 3 minutes. Electroretinograms were measured at each IOP step to assess bipolar cell (b-wave and inner retinal function (scotopic threshold response or STR. Ocular blood flow was measured using laser-Doppler flowmetry in groups with similar MAP level and the same IOP challenge protocol. Both b-wave and STR amplitudes decreased with IOP elevation. Retinal function was less susceptible to IOP challenge when MAP was high, whereas the converse was true for low MAP. Consistent with the effects on retinal function, higher IOP was needed to attenuated ocular blood flow in animals with higher MAP. The susceptibility of retinal function to IOP challenge can be ameliorated by acute high BP, and exacerbated by low BP. This is partially mediated by modifications in ocular blood flow.

  15. Dietary n-3 and n-6 PUFA enhance DHA incorporation in retinal phospholipids without affecting PGE(1) and PGE (2) levels.

    Science.gov (United States)

    Schnebelen, Coralie; Grégoire, Stéphane; Pasquis, Bruno; Joffre, Corinne; Creuzot-Garcher, Catherine P; Bron, Alain M; Bretillon, Lionel; Acar, Niyazi

    2009-05-01

    The purpose of this study was to determine whether dietary n-3 and n-6 PUFA may affect retinal PUFA composition and PGE(1) and PGE(2) production. Male Wistar rats were fed for 3 months with diets containing: (1) 10% eicosapentaenoic acid (EPA) and 7% docosahexaenoic acid (DHA), or (2) 10% gamma-linolenic acid (GLA), or (3) 10% EPA, 7% DHA and 10% GLA, or (4) a balanced diet deprived of EPA, DHA, and GLA. The fatty acid composition of retinal phospholipids was determined by gas chromatography. Prostaglandin production was measured by enzyme immunoassay. When compared to rats fed the control diet, the retinal levels of DHA were increased in rats fed both diets enriched with n-3 PUFA (EPA + DHA and EPA + DHA + GLA diets) and decreased in those supplemented with n-6 PUFA only (GLA diet). The diet enriched with both n-6 and n-3 PUFA resulted in the greatest increase in retinal DHA. The levels of PGE(1) and PGE(2) were significantly increased in retinal homogenates of rats fed with the GLA-rich diet when compared with those of animals fed the control diet. These higher PGE(1) and PGE(2) levels were not observed in animals fed with EPA + DHA + GLA. In summary, GLA added to EPA + DHA resulted in the highest retinal DHA content but without increasing retinal PGE(2) as seen in animals supplemented with GLA only.

  16. Comparative proteomic analysis of histone post-translational modifications upon ischemia/reperfusion-induced retinal injury

    DEFF Research Database (Denmark)

    Zhao, Xiaolu; Sidoli, Simone; Wang, Leilei;

    2014-01-01

    We present a detailed quantitative map of single and coexisting histone post-translational modifications (PTMs) in rat retinas affected by ischemia and reperfusion (I/R) injury. Retinal I/R injury contributes to serious ocular diseases, which can lead to vision loss and blindness. We applied linear...

  17. Retinal ganglion cell adaptation to small luminance fluctuations.

    Science.gov (United States)

    Freeman, Daniel K; Graña, Gilberto; Passaglia, Christopher L

    2010-08-01

    To accommodate the wide input range over which the visual system operates within the narrow output range of spiking neurons, the retina adjusts its sensitivity to the mean light level so that retinal ganglion cells can faithfully signal contrast, or relative deviations from the mean luminance. Given the large operating range of the visual system, the majority of work on luminance adaptation has involved logarithmic changes in light level. We report that luminance gain controls are recruited for remarkably small fluctuations in luminance as well. Using spike recordings from the rat optic tract, we show that ganglion cell responses to a brief flash of light are modulated in amplitude by local background fluctuations as little as 15% contrast. The time scale of the gain control is rapid (retinal locus of adaptation precedes the ganglion cell spike generator because response gain changes of on cells were uncorrelated with firing rate. The mechanism seems to reside within the inner retinal network and not in the photoreceptors, because the adaptation profiles of on and off cells differed markedly. The response gain changes follow Weber's law, suggesting that network mechanisms of luminance adaptation described in previous work modulates retinal ganglion cell sensitivity, not just when we move between different lighting environments, but also as our eyes scan a visual scene. Finally, we show that response amplitude is uniformly reduced for flashes on a modulated background that has spatial contrast, indicating that another gain control that integrates luminance signals nonlinearly over space operates within the receptive field center of rat ganglion cells.

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

    Science.gov (United States)

    Munteanu, M

    2005-01-01

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

  19. Trophic factors GDNF and BDNF improve function of retinal sheet transplants.

    Science.gov (United States)

    Yang, Pamela B; Seiler, Magdalene J; Aramant, Robert B; Yan, Fengrong; Mahoney, Melissa J; Kitzes, Leonard M; Keirstead, Hans S

    2010-11-01

    The aim of this study was to compare glial-derived neurotrophic factor (GDNF) treatment with brain-derived neurotrophic factor (BDNF) treatment of retinal transplants on restoration of visual responses in the superior colliculus (SC) of the S334ter line 3 rat model of rapid retinal degeneration (RD). RD rats (age 4-6 weeks) received subretinal transplants of intact sheets of fetal retina expressing the marker human placental alkaline phosphatase (hPAP). Experimental groups included: (1) untreated retinal sheet transplants, (2) GDNF-treated transplants, (3) BDNF-treated transplants, (4) none surgical, age-matched RD rats, (5) sham surgery RD controls, (6) progenitor cortex transplant RD controls, and (7) normal pigmented rat controls. At 2-8 months after transplantation, multi-unit visual responses were recorded from the SC using a 40 ms full-field stimulus (-5.9 to +1 log cd/m(2)) after overnight dark-adaptation. Responses were analyzed for light thresholds, spike counts, response latencies, and location within the SC. Transplants were grouped into laminated or rosetted (more disorganized) transplants based on histological analysis. Visual stimulation of control RD rats evoked no responses. In RD rats with retinal transplants, a small area of the SC corresponding to the position of the transplant in the host retina, responded to light stimulation between -4.5 and -0.08 log cd/m(2), whereas the light threshold of normal rats was at or below -5 log cd/m(2) all over the SC. Overall, responses in the SC in rats with laminated transplants had lower response thresholds and were distributed over a wider area than rats with rosetted transplants. BDNF treatment improved responses (spike counts, light thresholds and responsive areas) of rats with laminated transplants whereas GDNF treatment improved responses from rats with both laminated and rosetted (more disorganized) transplants. In conclusion, treatment of retinal transplants with GDNF and BDNF improved the restoration

  20. SirT1—A Sensor for Monitoring Self-Renewal and Aging Process in Retinal Stem Cells

    Directory of Open Access Journals (Sweden)

    Chi-Hsien Peng

    2010-06-01

    Full Text Available Retinal stem cells bear potency of proliferation, self-renewal, and differentiation into many retinal cells. Utilizing appropriate sensors one can effectively detect the self-renewal and aging process abilities. Silencing information regulator (SirT1, a member of the sirtuin family, is a NAD-dependent histone deacetylase and an essential mediator for longevity in normal cells by calorie restriction. We firstly investigate the SirT1 mRNA expression in retinal stem cells from rats and 19 human eyes of different ages. Results revealed that SirT1 expression was significantly decreased in in vivo aged eyes, associated with poor self-renewal abilities. Additionally, SirT1 mRNA levels were dose-dependently increased in resveratrol- treated retinal stem cells. The expression of SirT1 on oxidative stress-induced damage was significantly decreased, negatively correlated with the level of intracellular reactive oxygen species production. Treatment with resveratrol could effectively further reduce oxidative stress induced by H2O2 treatment in retinal stem cells. Importantly, the anti-oxidant effects of resveratrol in H2O2-treated retinal stem cells were significantly abolished by knockdown of SirT1 expression (sh-SirT1. SirT1 expression provides a feasible sensor in assessing self-renewal and aging process in retinal stem cells. Resveratrol can prevent reactive oxygen species-induced damages via increased retinal SirT1 expression.

  1. Distribution, markers and functions of retinal microglia

    NARCIS (Netherlands)

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

    2002-01-01

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

  2. Choroidal melanoma clinically simulating a retinal angioma

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-01-01

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

  3. Choroidal melanoma clinically simulating a retinal angioma.

    Science.gov (United States)

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

    1978-01-01

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

  4. Noninvasive Retinal Markers in Diabetic Retinopathy

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  5. 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

  6. Retinal Optical Coherence Tomography Imaging

    Science.gov (United States)

    Drexler, Wolfgang; Fujimoto, James G.

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

  7. CD133+ adult human retinal cells remain undifferentiated in Leukaemia Inhibitory Factor (LIF

    Directory of Open Access Journals (Sweden)

    Mayer Eric J

    2009-02-01

    Full Text Available Abstract Background CD133 is a cell surface marker of haematopoietic stem and progenitor cells. Leukaemia inhibitory factor (LIF, sustains proliferation and not differentiation of embryonic stem cells. We used CD133 to purify adult human retinal cells and aimed to determine what effect LIF had on these cultures and whether they still had the ability to generate neurospheres. Methods Retinal cell suspensions were derived from adult human post-mortem tissue with ethical approval. With magnetic automated cell sorting (MACS CD133+ retinal cells were enriched from post mortem adult human retina. CD133+ retinal cell phenotype was analysed by flow cytometry and cultured cells were observed for proliferative capacity, neuropshere generation and differentiation with or without LIF supplementation. Results We demonstrated purification (to 95% of CD133+ cells from adult human postmortem retina. Proliferating cells were identified through BrdU incorporation and expression of the proliferation markers Ki67 and Cyclin D1. CD133+ retinal cells differentiated whilst forming neurospheres containing appropriate lineage markers including glia, neurons and photoreceptors. LIF maintained CD133+ retinal cells in a proliferative and relatively undifferentiated state (Ki67, Cyclin D1 expression without significant neurosphere generation. Differentiation whilst forming neurospheres was re-established on LIF withdrawal. Conclusion These data support the evidence that CD133 expression characterises a population of cells within the resident adult human retina which have progenitor cell properties and that their turnover and differentiation is influenced by LIF. This may explain differences in retinal responses observed following disease or injury.

  8. [Study on preferred retinal locus].

    Science.gov (United States)

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

    2012-03-01

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

  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. Translocation of the retinal pigment epithelium and choroidal neovascularization induced by injecting Matrigel to subretinal space of rats%大鼠视网膜下注射Matrigel诱导视网膜色素上皮易位和脉络膜新生血管形成

    Institute of Scientific and Technical Information of China (English)

    汪振芳; 万鹏霞; 何丽文; 袁钊辉; 温容

    2007-01-01

    Objective To establish an animal model of sub-retinal pigment epithelium (sub-RPE)deposits,and to explore the pathological process of the transloeation of retinal pigment epithelium, choroidal neovascularization and the pathogenesis of age-related macular degeneration (AMD). Methods Matrigel was injected to the subretinal space of rats to create an amorphous deposit. Translocation of retinal pigment epithelium and choroidal neovascularization were observed. Results The subretinal deposit of Matrigel induced RPE translocation and therefore it became a sub-RPE deposit. The RPE mobilization required the presence of photoreceptors. Bruch's membrane devoid of RPE attachment became vulnerable to the invasion of new blood vessels from the choroid. Conclusions A novel model of sub-RPE deposit formation is established successfully. The presence of sub-RPE deposit is sufficient to induce choroidal neovascularization to penetrate Bruch's membrane and may cause the exudative form of AMD.%目的 制备视网膜色素上皮(RPE)下沉积物形成动物模型,并探讨其诱导视网膜色素上皮易位和脉络膜新牛血管(CNV)形成的病理过程以及年龄相关性黄斑变性(AMD)的发病机制.方法 将Matrigel基质胶注射于大鼠视网膜下形成视网膜下沉积物,观察视网膜色素上皮的迁移和脉络膜新生血管的形成.结果 Matrigel形成视网膜下沉积物后诱导RPE易位,而沉积物换位成为视网膜色素上皮层下沉积物.REP细胞的动员需要光感受器细胞的参与.缺乏色素上皮细胞贴附的Bruch膜易受脉络膜新生血管的侵袭.结论 建立了一个新的视网膜色素上皮层下沉积物形成的AMD动物模型.视网膜色素上皮层下沉积物足以导致CNV穿透Bruch膜,可能导致湿性AMD发生.

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

    Science.gov (United States)

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

    2017-01-01

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

  12. mTORC1-independent reduction of retinal protein synthesis in type 1 diabetes.

    Science.gov (United States)

    Fort, Patrice E; Losiewicz, Mandy K; Pennathur, Subramaniam; Jefferson, Leonard S; Kimball, Scot R; Abcouwer, Steven F; Gardner, Thomas W

    2014-09-01

    Poorly controlled diabetes has long been known as a catabolic disorder with profound loss of muscle and fat body mass resulting from a simultaneous reduction in protein synthesis and enhanced protein degradation. By contrast, retinal structure is largely maintained during diabetes despite reduced Akt activity and increased rate of cell death. Therefore, we hypothesized that retinal protein turnover is regulated differently than in other insulin-sensitive tissues, such as skeletal muscle. Ins2(Akita) diabetic mice and streptozotocin-induced diabetic rats exhibited marked reductions in retinal protein synthesis matched by a concomitant reduction in retinal protein degradation associated with preserved retinal mass and protein content. The reduction in protein synthesis depended on both hyperglycemia and insulin deficiency, but protein degradation was only reversed by normalization of hyperglycemia. The reduction in protein synthesis was associated with diminished protein translation efficiency but, surprisingly, not with reduced activity of the mTORC1/S6K1/4E-BP1 pathway. Instead, diabetes induced a specific reduction of mTORC2 complex activity. These findings reveal distinctive responses of diabetes-induced retinal protein turnover compared with muscle and liver that may provide a new means to ameliorate diabetic retinopathy.

  13. Neuroprotective effects of citicoline in in vitro models of retinal neurodegeneration.

    Science.gov (United States)

    Matteucci, Andrea; Varano, Monica; Gaddini, Lucia; Mallozzi, Cinzia; Villa, Marika; Pricci, Flavia; Malchiodi-Albedi, Fiorella

    2014-04-14

    In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM) and analyzed in terms of apoptosis and caspase activation and characterized by immunocytochemistry to identify neuronal and glial cells. Subsequently, excitotoxic concentration of glutamate or High Glucose-containing cell culture medium (HG) was administered as well-known conditions modeling neurodegeneration. Glutamate or HG treatments were performed in the presence or not of citicoline. Neuronal degeneration was evaluated in terms of apoptosis and loss of synapses. The results showed that citicoline did not cause any damage to the retinal neuroglial population up to 1000 µM. At the concentration of 100 µM, it was able to counteract neuronal cell damage both in glutamate- and HG-treated retinal cultures by decreasing proapoptotic effects and contrasting synapse loss. These data confirm that citicoline can efficiently exert a neuroprotective activity. In addition, the results suggest that primary retinal cultures, under conditions inducing neurodegeneration, may represent a useful system to investigate citicoline neuroprotective mechanisms.

  14. Neuroprotective Effects of Citicoline in in Vitro Models of Retinal Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Andrea Matteucci

    2014-04-01

    Full Text Available In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM and analyzed in terms of apoptosis and caspase activation and characterized by immunocytochemistry to identify neuronal and glial cells. Subsequently, excitotoxic concentration of glutamate or High Glucose-containing cell culture medium (HG was administered as well-known conditions modeling neurodegeneration. Glutamate or HG treatments were performed in the presence or not of citicoline. Neuronal degeneration was evaluated in terms of apoptosis and loss of synapses. The results showed that citicoline did not cause any damage to the retinal neuroglial population up to 1000 µM. At the concentration of 100 µM, it was able to counteract neuronal cell damage both in glutamate- and HG-treated retinal cultures by decreasing proapoptotic effects and contrasting synapse loss. These data confirm that citicoline can efficiently exert a neuroprotective activity. In addition, the results suggest that primary retinal cultures, under conditions inducing neurodegeneration, may represent a useful system to investigate citicoline neuroprotective mechanisms.

  15. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  16. Vasoinhibins regulate the inner and outer blood-retinal barrier and limit retinal oxidative stress

    Directory of Open Access Journals (Sweden)

    David eArredondo Zamarripa

    2014-10-01

    Full Text Available Vasoinhibins are prolactin fragments present in the retina, where they have been shown to prevent the hypervasopermeability associated with diabetes. Enhanced bradykinin (BK production contributes to the increased transport through the blood-retina barrier (BRB in diabetes. Here, we studied if vasoinhibins regulate BRB permeability by targeting the vascular endothelium and retinal pigment epithelium (RPE components of this barrier. Intravitreal injection of BK in male rats increased BRB permeability. Vasoinhibins prevented this effect, as did the B2 receptor antagonist Hoe-140. BK induced a transient decrease in mouse retinal and brain capillary endothelial monolayer resistance that was blocked by vasoinhibins. Both vasoinhibins and the nitric oxide (NO synthase inhibitor L-NAME, but not the antioxidant N-acetyl cysteine (NAC, blocked the transient decrease in bovine umbilical vein endothelial cell (BUVEC monolayer resistance induced by BK; this block was reversed by the NO donor DETANONOate. Vasoinhibins also prevented the BK-induced actin cytoskeleton redistribution, as did L-NAME. BK transiently decreased human RPE (ARPE-19 cell monolayer resistance, and this effect was blocked by vasoinhibins, L-NAME, and NAC. DETANONOate reverted the blocking effect of vasoinhibins. Similar to BK, the radical initiator Luperox induced a reduction in ARPE-19 cell monolayer resistance, which was prevented by vasoinhibins. These effects on RPE resistance coincided with actin cytoskeleton redistribution. Intravitreal injection of vasoinhibins reduced the levels of reactive oxygen species (ROS in retinas of streptozotocin-induced diabetic rats, particularly in the RPE and capillary-containing layers. Thus, vasoinhibins reduce BRB permeability by targeting both its main inner and outer components through NO- and ROS-dependent pathways, offering potential treatment strategies against diabetic retinopathies.

  17. [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.

  18. Membrane purifier prototype for hydrogen purification from towngas

    Energy Technology Data Exchange (ETDEWEB)

    Li, A.; Boyd, T.; Gulamhusein, A.; Grace, J.R.; Lim, C.J. [Membrane Reactor Technologies Ltd., Vancouver, BC (Canada)

    2007-07-01

    A prototype membrane purifier designed to purify hydrogen from towngas was described. The purifier was developed as a result of growing demands for metallic membrane purifiers. This paper provided details of a simulation conducted to observe the membrane's ability to purify towngas. The purifier was comprised of a cast-pressured vessel and a membrane module stack able to accommodate up to 6 palladium-silver (Pd-Ag) alloy membrane modules. Performance of the purifier was tested with both a hydrogen and a hydrogen and nitrogen oxide (N{sub 2}) mixture at 400 degrees C under various operating conditions. Results of the study showed that the purifier remained stable during temperature cycling. The hydrogen permeation rate followed Sievert's law in the tested temperature range. The hydrogen permeation rate increased when towngas flow rates and feeding pressures were increased. Hydrogen diffusion through the alloy membrane determined permeation rates through the membrane modules. No N{sub 2} leaks were detected using the mixtures. 1 ref., 1 tab., 6 figs.

  19. 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

  20. [Surgical managment of retinal detachment].

    Science.gov (United States)

    Haritoglou, C; Wolf, A

    2015-05-01

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

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

    Science.gov (United States)

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

    2007-01-01

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

  2. The protactive effects and mechanisms of cx3cr1 antibody on retinal neuron in rats with ischemia reperfusion injury by intravitreal injection%Cx3cr1抗体玻璃体腔注射对视网膜缺血-再灌注损伤大鼠视网膜神经元的保护作用及机制

    Institute of Scientific and Technical Information of China (English)

    李娟娟; 李燕; 汤志伟

    2016-01-01

    中模型对照组大鼠RGCs数目明显少于正常对照组、单纯cx3cr1抗体注射组和模型cx3cr1抗体注射组,差异均有统计学意义(t=7.492、6.125、-4.607,均P<0.01);免疫组织化学法检测表明模型对照组大鼠视网膜中CD68的表达量(A值)明显高于正常对照组、单纯cx3cr1抗体注射组和模型cx3cr1抗体注射组,差异均有统计学意义(t=-3.397,P=0.008:t=-6.207,P=0.000:t=3.494,P=0.007);模型对照组视网膜中cx3cr1 mRNA、TNF-αmRNA和IL-1 β mRNA相对表达量均明显高于正常对照组、单纯cx3cr1抗体注射组和模型cx3cr1抗体注射组,差异均有统计学意义(均P<0.01).正常对照组与单纯cx3cr1抗体注射组间上述检测指标的差异均无统计学意义(均P>0.05).结论 IRI模型大鼠玻璃体腔注射cx3cr1抗体中和cx3cr1的表达可抑制视网膜小胶质细胞的活化并减少视网膜中炎性因子的释放,减少RGCs凋亡,从而对IRI模型鼠的RGCs起保护作用.玻璃体腔注射cx3cr1抗体是安全可行的.%Background Study confirmed that the active microglia may injure retinal ganglion cells (RGCs) in retinal ischemia reperfusion injury (IRI), and increased cx3cr1 expression is an important factor in microglial activation,and thus blocking the expression of cx3cr1 can inhibit microglial activation, which may be useful in neuronal protection.Objective This study was to analyze the protective effects of cx3cr1 antibody on retinal neuron in rat eyes with IRI.Methods Ninety SD rats were divided into 4 groups according to random number table.IRI models were established by perfusing normal saline solution into the anterior chamber.The cx3cr1 antibody of 1 μl (0.2 μg/μl) was intravitreally injected in the right eyes in the normal rats or model rats as the only cx3cr1 antibody injected group and the model cx3cr1 antibody injected group,respectively,and no any drug was injected in the rats of the normal control group and model control group.Retinal sections

  3. 75 FR 73035 - Purified Carboxymethylcellulose From Finland; Notice of Final Results of Antidumping Duty...

    Science.gov (United States)

    2010-11-29

    ... International Trade Administration Purified Carboxymethylcellulose From Finland; Notice of Final Results of... order on purified carboxymethylcellulose from Finland. See Purified Carboxymethylcellulose from Finland... order covering purified carboxymethylcellulose from Finland. See Preliminary Results. The...

  4. Neuroprotective effects of the cannabinoid agonist HU210 on retinal degeneration.

    Science.gov (United States)

    Lax, Pedro; Esquiva, Gema; Altavilla, Cesare; Cuenca, Nicolás

    2014-03-01

    Cannabinoids have been demonstrated to exert neuroprotective effects on different types of neuronal insults. Here we have addressed the therapeutic potential of the synthetic cannabinoid HU210 on photoreceptor degeneration, synaptic connectivity and functional activity of the retina in the transgenic P23H rat, an animal model for autosomal dominant retinitis pigmentosa (RP). In P23H rats administered with HU210 (100 μg/kg, i.p.) from P24 to P90, ERG recordings showed an amelioration of vision loss, as compared to vehicle-administered animals. Under scotopic conditions, the maximum a-wave amplitudes recorded at P60 and P90 were higher in HU210-treated animals, as compared to the values obtained in untreated animals. The scotopic b-waves were significantly higher in treated animals than in untreated rats at P30, P60 and P90. This attenuation of visual deterioration correlated with a delay in photoreceptor degeneration and the preservation of retinal cytoarchitecture. HU210-treated animals had 40% more photoreceptors than untreated animals. Presynaptic and postsynaptic elements, as well as the synaptic contacts between photoreceptors and bipolar or horizontal cells, were also preserved in HU210-treated P23H rats. These results indicate that HU210 preserves cone and rod structure and function, together with their contacts with postsynaptic neurons, in P23H rats. These data suggest that cannabinoids are potentially useful to delay retinal degeneration in RP patients.

  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. Retinal damage induced by commercial light emitting diodes (LEDs).

    Science.gov (United States)

    Jaadane, Imene; Boulenguez, Pierre; Chahory, Sabine; Carré, Samuel; Savoldelli, Michèle; Jonet, Laurent; Behar-Cohen, Francine; Martinsons, Christophe; Torriglia, Alicia

    2015-07-01

    Spectra of "white LEDs" are characterized by an intense emission in the blue region of the visible spectrum, absent in daylight spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate the role of blue light from LEDs in retinal damage. Commercially available white LEDs and four different blue LEDs (507, 473, 467, and 449nm) were used for exposure experiments on Wistar rats. Immunohistochemical stain, transmission electron microscopy, and Western blot were used to exam the retinas. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways, and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase-independent apoptosis, necroptosis, and necrosis. A wavelength dependence of the effects was observed. Phototoxicity of LEDs on the retina is characterized by a strong damage of photoreceptors and by the induction of necrosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Veratridine increases the survival of retinal ganglion cells in vitro

    Directory of Open Access Journals (Sweden)

    S.P.F. Pereira

    1997-12-01

    Full Text Available Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM, a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker and 30.0 µM flunarizine (a Na+ and Ca2+ channel blocker. These results indicate that electrical activity is also important for the maintenance of retinal ganglion cell survival in vitro

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

    Science.gov (United States)

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

    2017-03-01

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

  9. Safety and Efficacy of Human Wharton's Jelly-Derived Mesenchymal Stem Cells Therapy for Retinal Degeneration.

    Directory of Open Access Journals (Sweden)

    S N Leow

    Full Text Available To investigate the safety and efficacy of subretinal injection of human Wharton's Jelly-derived mesenchymal stem cells (hWJ-MSCs on retinal structure and function in Royal College of Surgeons (RCS rats.RCS rats were divided into 2 groups: hWJ-MSCs treated group (n = 8 and placebo control group (n = 8. In the treatment group, hWJ-MSCs from healthy donors were injected into the subretinal space in one eye of each rat at day 21. Control group received saline injection of the same volume. Additional 3 animals were injected with nanogold-labelled stem cells for in vivo tracking of cells localisation using a micro-computed tomography (microCT. Retinal function was assessed by electroretinography (ERG 3 days before the injection and repeated at days 15, 30 and 70 after the injection. Eyes were collected at day 70 for histology, cellular and molecular studies.No retinal tumor formation was detected by histology during the study period. MicroCT scans showed that hWJ-MSCs stayed localised in the eye with no systemic migration. Transmission electron microscopy showed that nanogold-labelled cells were located within the subretinal space. Histology showed preservation of the outer nuclear layer (ONL in the treated group but not in the control group. However, there were no significant differences in the ERG responses between the groups. Confocal microscopy showed evidence of hWJ-MSCs expressing markers for photoreceptor, Müller cells and bipolar cells.Subretinal injection of hWJ-MSCs delay the loss of the ONL in RCS rats. hWJ-MSCs appears to be safe and has potential to differentiate into retinal-like cells. The potential of this cell-based therapy for the treatment of retinal dystrophies warrants further studies.

  10. Diabetes reduces basal retinal insulin receptor signaling: reversal with systemic and local insulin.

    Science.gov (United States)

    Reiter, Chad E N; Wu, Xiaohua; Sandirasegarane, Lakshman; Nakamura, Makoto; Gilbert, Kirk A; Singh, Ravi S J; Fort, Patrice E; Antonetti, David A; Gardner, Thomas W

    2006-04-01

    Diabetic retinopathy is characterized by early onset of neuronal cell death. We previously showed that insulin mediates a prosurvival pathway in retinal neurons and that normal retina expresses a highly active basal insulin receptor/Akt signaling pathway that is stable throughout feeding and fasting. Using the streptozotocin-induced diabetic rat model, we tested the hypothesis that diabetes diminishes basal retinal insulin receptor signaling concomitantly with increased diabetes-induced retinal apoptosis. The expression, phosphorylation status, and/or kinase activity of the insulin receptor and downstream signaling proteins were investigated in retinas of age-matched control, diabetic, and insulin-treated diabetic rats. Four weeks of diabetes reduced basal insulin receptor kinase, insulin receptor substrate (IRS)-1/2-associated phosphatidylinositol 3-kinase, and Akt kinase activity without altering insulin receptor or IRS-1/2 expression or tyrosine phosphorylation. After 12 weeks of diabetes, constitutive insulin receptor autophosphorylation and IRS-2 expression were reduced, without changes in p42/p44 mitogen-activated protein kinase or IRS-1. Sustained systemic insulin treatment of diabetic rats prevented loss of insulin receptor and Akt kinase activity, and acute intravitreal insulin administration restored insulin receptor kinase activity. Insulin treatment restored insulin receptor-beta autophosphorylation in rat retinas maintained ex vivo, demonstrating functional receptors and suggesting loss of ligand as a cause for reduced retinal insulin receptor/Akt pathway activity. These results demonstrate that diabetes progressively impairs the constitutive retinal insulin receptor signaling pathway through Akt and suggests that loss of this survival pathway may contribute to the initial stages of diabetic retinopathy.

  11. 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.

  12. 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

  13. Evaluation of Platinum-Black Stimulus Electrode Array for Electrical Stimulation of Retinal Cells in Retinal Prosthesis System

    Science.gov (United States)

    Watanabe, Taiichiro; Kobayashi, Risato; Komiya, Ken; Fukushima, Takafumi; Tomita, Hiroshi; Sugano, Eriko; Kurino, Hiroyuki; Tanaka, Tetsu; Tamai, Makoto; Koyanagi, Mitsumasa

    2007-04-01

    A retinal prosthesis system with a three-dimensionally (3D) stacked LSI chip has been proposed. We fabricated a new implantable stimulus electrode array deposited with Platinum-black (Pt-b) on a polyimide-based flexible printed circuit (FPC) for the electrical stimulation of the retinal cells. Impedance measurement of the Pt-b electrode-electrolyte interface in a saline solution was performed and the Pt-b electrode realized a very low impedance. The power consumption at the electrode array when retinal cells were stimulated by a stimulus current was evaluated. The power consumption of the Pt-b stimulus electrode array was 91% lower than that of a previously fabricated Al stimulus electrode array due to a convexo-concave surface. In the cytotoxicity test (CT), we confirmed that Pt implantation induced no cellular degeneration of the rat retina. In the animal experiments, electrically evoked potential (EEP) was successfully recorded using Japanese white rabbits. These results indicate that electrical stimulation using the Pt-b stimulus electrode array can restore visual sensation.

  14. 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

  15. SiC protective coating for photovoltaic retinal prosthesis

    Science.gov (United States)

    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.

  16. Thermal Stability of Rhodopsin and Progression of Retinitis Pigmentosa

    Science.gov (United States)

    Liu, Monica Yun; Liu, Jian; Mehrotra, Devi; Liu, Yuting; Guo, Ying; Baldera-Aguayo, Pedro A.; Mooney, Victoria L.; Nour, Adel M.; Yan, Elsa C. Y.

    2013-01-01

    Over 100 point mutations in the rhodopsin gene have been associated with retinitis pigmentosa (RP), a family of inherited visual disorders. Among these, we focused on characterizing the S186W mutation. We compared the thermal properties of the S186W mutant with another RP-causing mutant, D190N, and with WT rhodopsin. To assess thermal stability, we measured the rate of two thermal reactions contributing to the thermal decay of rhodopsin as follows: thermal isomerization of 11-cis-retinal and hydrolysis of the protonated Schiff base linkage between the 11-cis-retinal chromophore and opsin protein. We used UV-visible spectroscopy and HPLC to examine the kinetics of these reactions at 37 and 55 °C for WT and mutant rhodopsin purified from HEK293 cells. Compared with WT rhodopsin and the D190N mutant, the S186W mutation dramatically increases the rates of both thermal isomerization and dark state hydrolysis of the Schiff base by 1–2 orders of magnitude. The results suggest that the S186W mutant thermally destabilizes rhodopsin by disrupting a hydrogen bond network at the receptor's active site. The decrease in the thermal stability of dark state rhodopsin is likely to be associated with higher levels of dark noise that undermine the sensitivity of rhodopsin, potentially accounting for night blindness in the early stages of RP. Further studies of the thermal stability of additional pathogenic rhodopsin mutations in conjunction with clinical studies are expected to provide insight into the molecular mechanism of RP and test the correlation between rhodopsin's thermal stability and RP progression in patients. PMID:23625926

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

    Science.gov (United States)

    Wang, J Z

    1993-07-01

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

  18. Study of gas purifiers for the CMS RPC detector

    CERN Document Server

    Benussi, L; Colafranceschi, S; Fabbri, F L; Felli, F; Ferrini, M; Giardoni, M; Greci, T; Paolozzi, A; Passamonti, L; Piccolo, D; Pierluigi, D; Russo, A; Saviano, G; Buontempo, S; Cimmino, A; de Gruttola, M; Fabozzi, F; Iorio, A O M; Lista, L; Paolucci, P; Baesso, P; Belli, G; Pagano, D; Ratti, S P; Vicini, A; Vitulo, P; Viviani, C; Guida, R; Sharma, A

    2012-01-01

    The CMS RPC muon detector utilizes a gas recirculation system called closed loop (CL) to cope with large gas mixture volumes and costs. A systematic study of CL gas purifiers has been carried out over 400 days between July 2008 and August 2009 at CERN in a low-radiation test area, with the use of RPC chambers with currents monitoring, and gas analysis sampling points. The study aimed to fully clarify the presence of pollutants, the chemistry of purifiers used in the CL, and the regeneration procedure. Preliminary results on contaminants release and purifier characterization are reported.

  19. 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.

  20. 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.

  1. Automatic Vessel Segmentation on Retinal Images

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

  2. Retinal Cell Degeneration in Animal Models

    OpenAIRE

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

    2016-01-01

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

  3. Immunodiffusion Studies of Purified Equine Infectious Anemia Virus

    Science.gov (United States)

    Nakajima, Hideo; Ushimi, Chuzo

    1971-01-01

    Antigenicity of purified equine infectious anemia (EIA) virus was examined by immunodiffusion against sera obtained from horses experimentally infected with EIA virus. The purified virus reacted with the infected horse serum, and virus-specific precipitating antibody was demonstrated. Furthermore, it was found that purified EIA virus reacted against the serum of horses infected with all strains of EIA virus which were antigenically different from one another. From the result, group-specific components of the virus rather than strain-specific ones were considered to be involved in the reaction. Serological reactivity was lost by adding antiserum from the infected horse to the antigen. The precipitating antibody usually appeared in the serum 1 to 2 weeks after the first febrile attack of EIA and remained for a longer period. Some characteristics of the purified antigen and specificity of the reaction for EIA are described. Images PMID:16557982

  4. 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.

  5. Study of gas purifiers in the CMS RPC detector

    CERN Document Server

    Saviano, Giovanna

    2010-01-01

    The CMS RPC muon detector utilizes a gas recirculation system (Closed Loop) to cope with high gas mixture volumes and costs. A systematic study of Closed Loop gas purifiers has been carried out in 2008 and 2009 at the ISR experimental area of CERN, with the use of RPC chambers with currents monitoring, and gas analysis sampling points. Results on contaminants release and purifier characterization are presented

  6. Mitochondrial dysfunction underlying outer retinal diseases

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  7. RETINAL VASCULITIS ASSOCIATED WITH NEUROMYELITIS OPTICA.

    Science.gov (United States)

    Mikhail, Mikel; Khan, Ayesha

    2017-01-01

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

  8. 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.

  9. Retinal occlusive vasculer disorder and rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Huseyin Ortak

    2013-03-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Towards high-resolution retinal prostheses with direct optical addressing and inductive telemetry

    Science.gov (United States)

    Ha, Sohmyung; Khraiche, Massoud L.; Akinin, Abraham; Jing, Yi; Damle, Samir; Kuang, Yanjin; Bauchner, Sue; Lo, Yu-Hwa; Freeman, William R.; Silva, Gabriel A.; Cauwenberghs, Gert

    2016-10-01

    Objective. Despite considerable advances in retinal prostheses over the last two decades, the resolution of restored vision has remained severely limited, well below the 20/200 acuity threshold of blindness. Towards drastic improvements in spatial resolution, we present a scalable architecture for retinal prostheses in which each stimulation electrode is directly activated by incident light and powered by a common voltage pulse transferred over a single wireless inductive link. Approach. The hybrid optical addressability and electronic powering scheme provides separate spatial and temporal control over stimulation, and further provides optoelectronic gain for substantially lower light intensity thresholds than other optically addressed retinal prostheses using passive microphotodiode arrays. The architecture permits the use of high-density electrode arrays with ultra-high photosensitive silicon nanowires, obviating the need for excessive wiring and high-throughput data telemetry. Instead, the single inductive link drives the entire array of electrodes through two wires and provides external control over waveform parameters for common voltage stimulation. Main results. A complete system comprising inductive telemetry link, stimulation pulse demodulator, charge-balancing series capacitor, and nanowire-based electrode device is integrated and validated ex vivo on rat retina tissue. Significance. Measurements demonstrate control over retinal neural activity both by light and electrical bias, validating the feasibility of the proposed architecture and its system components as an important first step towards a high-resolution optically addressed retinal prosthesis.

  12. Effects of white light-emitting diode (LED) exposure on retinal pigment epithelium in vivo.

    Science.gov (United States)

    Jaadane, Imene; Villalpando Rodriguez, Gloria Elisa; Boulenguez, Pierre; Chahory, Sabine; Carré, Samuel; Savoldelli, Michèle; Jonet, Laurent; Behar-Cohen, Francine; Martinsons, Christophe; Torriglia, Alicia

    2017-06-29

    Ageing and alteration of the functions of the retinal pigment epithelium (RPE) are at the origin of lost of vision seen in age-related macular degeneration (AMD). The RPE is known to be vulnerable to high-energy blue light. The white light-emitting diodes (LED) commercially available have relatively high content of blue light, a feature that suggest that they could be deleterious for this retinal cell layer. The aim of our study was to investigate the effects of "white LED" exposure on RPE. For this, commercially available white LEDs were used for exposure experiments on Wistar rats. Immunohistochemical stain on RPE flat mount, transmission electron microscopy and Western blot were used to exam the RPE. LED-induced RPE damage was evaluated by studying oxidative stress, stress response pathways and cell death pathways as well as the integrity of the outer blood-retinal barrier (BRB). We show that white LED light caused structural alterations leading to the disruption of the outer blood-retinal barrier. We observed an increase in oxidized molecules, disturbance of basal autophagy and cell death by necrosis. We conclude that white LEDs induced strong damages in rat RPE characterized by the breakdown of the BRB and the induction of necrotic cell death. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  13. Calcium influx and calpain activation mediate preclinical retinal neurodegeneration in autoimmune optic neuritis.

    Science.gov (United States)

    Hoffmann, Dorit B; Williams, Sarah K; Bojcevski, Jovana; Müller, Andreas; Stadelmann, Christine; Naidoo, Vinogran; Bahr, Ben A; Diem, Ricarda; Fairless, Richard

    2013-08-01

    Optic neuritis is a common manifestation of multiple sclerosis, an inflammatory demyelinating disease of the CNS. Recently, the neurodegenerative component of multiple sclerosis has come under focus particularly because permanent disability in patients correlates well with neurodegeneration; and observations in both humans and multiple sclerosis animal models highlight neurodegeneration of retinal ganglion cells as an early event. After myelin oligodendrocyte glycoprotein immunization of Brown Norway rats, significant retinal ganglion cell loss precedes the onset of pathologically defined autoimmune optic neuritis. To study the role calcium and calpain activation may play in mediating early degeneration, manganese-enhanced magnetic resonance imaging was used to monitor preclinical calcium elevations in the retina and optic nerve of myelin oligodendrocyte glycoprotein-immunized Brown Norway rats. Calcium elevation correlated with an increase in calpain activation during the induction phase of optic neuritis, as revealed by increased calpain-specific cleavage of spectrin. The relevance of early calpain activation to neurodegeneration during disease induction was addressed by performing treatment studies with the calpain inhibitor calpeptin. Treatment not only reduced calpain activity but also protected retinal ganglion cells from preclinical degeneration. These data indicate that elevation of retinal calcium levels and calpain activation are early events in autoimmune optic neuritis, providing a potential therapeutic target for neuroprotection.

  14. Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration

    Directory of Open Access Journals (Sweden)

    Laura Fernández-Sánchez

    2015-07-01

    Full Text Available All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA, the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.

  15. Compact Laser Doppler Flowmeter (LDF Fundus Camera for the Assessment of Retinal Blood Perfusion in Small Animals.

    Directory of Open Access Journals (Sweden)

    Marielle Mentek

    Full Text Available Noninvasive techniques for ocular blood perfusion assessment are of crucial importance for exploring microvascular alterations related to systemic and ocular diseases. However, few techniques adapted to rodents are available and most are invasive or not specifically focused on the optic nerve head (ONH, choroid or retinal circulation. Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF.A confocal miniature flowmeter was fixed to a specially designed 3D rotating mechanical arm and adjusted on a rodent stereotaxic table in order to accurately point the laser beam at the retinal region of interest. The linearity of the LDF measurements was assessed using a rotating Teflon wheel and a flow of microspheres in a glass capillary. In vivo reproducibility was assessed in Wistar rats with repeated measurements (inter-session and inter-day of retinal arteries and ONH blood velocity in six and ten rats, respectively. These parameters were also recorded during an acute intraocular pressure increase to 150 mmHg and after heart arrest (n = 5 rats.The perfusion measurements showed perfect linearity between LDF velocity and Teflon wheel or microsphere speed. Intraclass correlation coefficients for retinal arteries and ONH velocity (0.82 and 0.86, respectively indicated strong inter-session repeatability and stability. Inter-day reproducibility was good (0.79 and 0.7, respectively. Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering.We have demonstrated that, while not adapted for ONH blood perfusion assessment, this device allows pertinent, stable and repeatable measurements of retinal blood perfusion in rats.

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

    Science.gov (United States)

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

    2014-01-07

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  18. 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.

  19. Fundus autofluorescence applications in retinal imaging

    Directory of Open Access Journals (Sweden)

    Andrea Gabai

    2015-01-01

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

  20. RETINAL VEIN OCCLUSIONS - A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Ramadevi

    2015-11-01

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

  1. Anatomy of the retinal nerve fiber layer.

    Science.gov (United States)

    Radius, R L; de Bruin, J

    1981-11-01

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

  2. 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

  3. Retinal vein occlusion: pathophysiology and treatment options

    OpenAIRE

    Niral Karia

    2010-01-01

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

  4. The Proinflammatory Cytokine High-Mobility Group Box-1 Mediates Retinal Neuropathy Induced by Diabetes

    Directory of Open Access Journals (Sweden)

    Ahmed M. Abu El-Asrar

    2014-01-01

    Full Text Available To test the hypothesis that increased expression of proinflammatory cytokine high-mobility group box-1 (HMGB1 in epiretinal membranes and vitreous fluid from patients with proliferative diabetic retinopathy and in retinas of diabetic rats plays a pathogenetic role in mediating diabetes-induced retinal neuropathy. Retinas of 1-month diabetic rats and HMGB1 intravitreally injected normal rats were studied using Western blot analysis, RT-PCR and glutamate assay. In addition, we studied the effect of the HMGB1 inhibitor glycyrrhizin on diabetes-induced biochemical changes in the retina. Diabetes and intravitreal injection of HMGB1 in normal rats induced significant upregulation of HMGB1 protein and mRNA, activated extracellular signal-regulated kinase 1 and 2 (ERK1/2, cleaved caspase-3 and glutamate; and significant downregulation of synaptophysin, tyrosine hydroxylase, glutamine synthetase, and glyoxalase 1. Constant glycyrrhizin intake from the onset of diabetes did not affect the metabolic status of the diabetic rats, but it significantly attenuated diabetes-induced upregulation of HMGB1 protein and mRNA, activated ERK1/2, cleaved caspase-3, and glutamate. In the glycyrrhizin-fed diabetic rats, the decrease in synaptophysin, tyrosine hydroxylase, and glyoxalase 1 caused by diabetes was significantly attenuated. These findings suggest that early retinal neuropathy of diabetes involves upregulated expression of HMGB1 and can be ameliorated by inhibition of HMGB1.

  5. 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.

  6. 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.

  7. Does soccer ball heading cause retinal bleeding?

    Science.gov (United States)

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

    2002-04-01

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

  8. The cell stress machinery and retinal degeneration.

    Science.gov (United States)

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

    2013-06-27

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

  9. Prevalence of generalized retinal dystrophy in Denmark

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  10. Bilateral retinitis following typhoid fever

    OpenAIRE

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

    2017-01-01

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

  11. 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.

  12. Bilateral Progressive Obliterative Retinal Vasculitis

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

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

  13. 代谢性酸中毒诱导新生大鼠视网膜新生血管缺氧诱导因子-lα的表达及其意义%Expression and significance of hypoxia-inducible factor-1α in retinal neovascularization induced by metabolic acidosis in newborn rats

    Institute of Scientific and Technical Information of China (English)

    张玉真; 王娟; 乔立兴; 蒋犁

    2011-01-01

    Objective To investigate the expression and significance of hypoxia-inducible factor-1α (HIF-1α) in the retinal neovascularization by metabolic acidosis in newborn rats. Methods One hundred and twenty newborn SD rats were randomly divided into acidosis (experiment) and normoxia (control) groups. A total of 60 newborn rats in experiment group underwent tubal feeding day for 6 days and followed by a period of recovery. The rats in the two groups were sacrificed at the 3rd, 5th, 8th, 10th, 13th and 20th day after birth, respectively. The morphologic changes of retinal vessels were estimated by observing the vascular pattern in adenosine diphosphatase stained retina flat mounts. The newborn vessels were quantified by HE staining. Immunohistochemical method was used to detect HIF-1α expression. Results In experiment group, numerous neovascularization and un-perfused area at the periphery of vessels occurred on the 10th day. The result of HE staining showed that in experiment group of 10-day old,the number of neovascular nuclei extending into the vireo was 28.78±7.53, and that of the control group was 1.22±1.48 (t=11.169,P<0.01). The results of immunohistochemistry revealed that the expression of HIF-1α protein were stronger in the experiment group than in the control group on the 8th, 10th and 13th day, and there were significant differences between the two groups (108.87±15.21, 183.68±26.58 and 129.42±9.85 vs 74.98±4.50, 76.38± 3.38 and 74.78±1.86, t=4.625, 9.023 and 9.672,P<0.05). Conclusions HIF-lα might play an important role in retinal neovascularization.%目的 探讨缺氧诱导因子-lα(hypoxia-inducible factor-lα,HIF-lα)在代谢性酸中毒诱导视网膜新生血管中的表达和意义.方法 将120只新生SD大鼠随机分为酸中毒模型组和正常对照组,各60只.酸中毒模型组出生后第2天开始按535 mg/(kg·d)的剂量管饲氯化铵溶液 (质量浓度为50 mg/ml),2次/d,连续6 d,停药进入恢复期.2

  14. Overexpression of Heme Oxygenase-1 in Mesenchymal Stem Cells Augments Their Protection on Retinal Cells In Vitro and Attenuates Retinal Ischemia/Reperfusion Injury In Vivo against Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Li Li

    2017-01-01

    Full Text Available Retinal ischemia/reperfusion (I/R injury, involving several ocular diseases, seriously threatens human ocular health, mainly treated by attenuating I/R-induced oxidative stress. Currently, mesenchymal stem cells (MSCs could restore I/R-injured retina through paracrine secretion. Additionally, heme oxygenase-1 (HO-1 could ameliorate oxidative stress and thus retinal apoptosis, but the expression of HO-1 in MSC is limited. Here, we hypothesized that overexpression of HO-1 in MSC (MSC-HO-1 may significantly improve their retina-protective potentials. The overexpression of HO-1 in MSC was achieved by lentivirus transduction. Then, MSC or MSC-HO-1 was cocultured with retinal ganglion cells (RGC-5 in H2O2-simulated oxidative condition and their protection on RGC-5 was systemically valuated in vitro. Compared with MSC, MSC-HO-1 significantly attenuated H2O2-induced injury of RGC-5, including decrease in cellular ROS level and apoptosis, activation of antiapoptotic proteins p-Akt and Bcl-2, and blockage of proapoptotic proteins cleaved caspase 3 and Bax. In retinal I/R rats model, compared with control MSC, MSC-HO-1-treated retina significantly retrieved its structural thickness, reduced cell apoptosis, markedly attenuated retinal oxidative stress level, and largely regained the activities of typical antioxidant enzymes, SOD and CAT. Therefore, it could be concluded that overexpression of HO-1 provides a promising strategy to enhance the MSC-based therapy for I/R-related retinal injury.

  15. Strong purifying selection at genes escaping X chromosome inactivation.

    Science.gov (United States)

    Park, Chungoo; Carrel, Laura; Makova, Kateryna D

    2010-11-01

    To achieve dosage balance of X-linked genes between mammalian males and females, one female X chromosome becomes inactivated. However, approximately 15% of genes on this inactivated chromosome escape X chromosome inactivation (XCI). Here, using a chromosome-wide analysis of primate X-linked orthologs, we test a hypothesis that such genes evolve under a unique selective pressure. We find that escape genes are subject to stronger purifying selection than inactivated genes and that positive selection does not significantly affect the evolution of these genes. The strength of selection does not differ between escape genes with similar versus different expression levels in males versus females. Intriguingly, escape genes possessing Y homologs evolve under the strongest purifying selection. We also found evidence of stronger conservation in gene expression levels in escape than inactivated genes. We hypothesize that divergence in function and expression between X and Y gametologs is driving such strong purifying selection for escape genes.

  16. FTY720 protects retinal ganglion cells in experimental glaucoma.

    Science.gov (United States)

    You, Yuyi; Gupta, Vivek K; Li, Jonathan C; Al-Adawy, Nadia; Klistorner, Alexander; Graham, Stuart L

    2014-04-17

    To investigate the neuroprotective effects of sphingosine-1-phosphate (S1P) analogue fingolimod (FTY720) in experimental glaucoma in rats. A unilateral chronic ocular hypertensive model was established by injections of microbeads into the anterior eye chamber of adult Sprague-Dawley rats. Fingolimod was administered to one group of rats intraperitoneally every week for 3 months. The scotopic threshold response (STR) was recorded to assess the function of the inner retina. Changes in cell density in the ganglion cell layer (GCL) were evaluated by hematoxylin and eosin staining on retinal sections and axonal count of the optic nerve was performed using Bielschowsky's silver staining. Effects of drug treatment on activation of Akt and Erk1/2 were evaluated using Western blotting by assessing phosphorylation levels of these proteins. The expression of S1P receptors in the optic nerve head region was also evaluated using Western blotting and immunohistochemistry. Administration of FTY720 reduced the loss of STR amplitude in glaucomatous eyes (P < 0.05). Counting and plotting the cell numbers/axonal density showed significant neural preservation in the GCL and the optic nerve (P < 0.05). An increased phosphorylation level of Akt and Erk1/2 following FTY720 administration was observed. Both S1P1 and S1P5 receptors were found to be expressed in the retina and the expression of S1P1R was upregulated in experimentally-induced glaucoma. This study demonstrates, for the first time, that FTY720 could act as a neuroprotective agent to protect retinal ganglion cells in experimental glaucoma. Administration of this drug significantly reduces the structural and functional loss of the inner retina elicited indicating that it may potentially be used to attenuate neuronal loss and optic nerve damage in glaucomatous patients. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  17. Human neural progenitor cells promote photoreceptor survival in retinal explants.

    Science.gov (United States)

    Englund-Johansson, Ulrica; Mohlin, Camilla; Liljekvist-Soltic, Ingela; Ekström, Per; Johansson, Kjell

    2010-02-01

    Different types of progenitor and stem cells have been shown to provide neuroprotection in animal models of photoreceptor degeneration. The present study was conducted to investigate whether human neural progenitor cells (HNPCs) have neuroprotective properties on retinal explants models with calpain- and caspase-3-dependent photoreceptor cell death. In the first experiments, HNPCs in a feeder layer were co-cultured for 6 days either with postnatal rd1 mouse or normal rat retinas. Retinal histological sections were used to determine outer nuclear layer (ONL) thickness, and to detect the number of photoreceptors with labeling for calpain activity, cleaved caspase-3 and TUNEL. The ONL thickness of co-cultured rat and rd1 retinas was found to be almost 10% and 40% thicker, respectively, compared to controls. Cell counts of calpain activity, cleaved caspase-3 and TUNEL labeled photoreceptors in both models revealed a 30-50% decrease when co-cultured with HNPCs. The results represent significant increases of photoreceptor survival in the co-cultured retinas. In the second experiments, for an identification of putative survival factors, or a combination of them, a growth factor profile was performed on conditioned medium. The relative levels of various growth factors were analyzed by densitometric measurements of growth factor array membranes. Following growth factors were identified as most potential survival factors; granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor (GMCSF), insulin-like growth factor II (IGF-II), neurotrophic factor 3 (NT-3), placental growth factor (PIGF), transforming growth factors (TGF-beta1 and TGF-beta2) and vascular endothelial growth factor (VEGF-D). HNPCs protect both against calpain- and caspase-3-dependent photoreceptor cell death in the rd1 mouse and against caspase-3-dependent photoreceptor cell death in normal rat retinas in vitro. The protective effect is possibly achieved by a variety of

  18. 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.

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

    Science.gov (United States)

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

    2015-06-01

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

  20. 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

  1. 76 FR 29194 - Purified Carboxymethylcellulose From Mexico and Sweden: Revocation of Antidumping Duty Orders

    Science.gov (United States)

    2011-05-20

    ... International Trade Administration Purified Carboxymethylcellulose From Mexico and Sweden: Revocation of... duty orders on purified carboxymethylcellulose from Mexico and Sweden. Pursuant to section 751(c) of... of the existing antidumping duty orders on purified carboxymethylcellulose from Mexico and...

  2. 75 FR 57815 - Purified Carboxymethylcellulose From Finland, Mexico, Netherlands, and Sweden

    Science.gov (United States)

    2010-09-22

    ... COMMISSION Purified Carboxymethylcellulose From Finland, Mexico, Netherlands, and Sweden AGENCY: United... antidumping duty orders on purified carboxymethylcellulose from Finland, Mexico, Netherlands, and Sweden... antidumping duty orders on purified carboxymethylcellulose from Finland, Mexico, Netherlands, and Sweden...

  3. 76 FR 29191 - Purified Carboxymethylcellulose From Finland and the Netherlands: Continuation of Antidumping...

    Science.gov (United States)

    2011-05-20

    ... International Trade Administration Purified Carboxymethylcellulose From Finland and the Netherlands... from Finland and the Netherlands would likely lead to continuation or recurrence of dumping and... orders on purified carboxymethylcellulose (purified CMC) from Finland and the Netherlands. See Notice...

  4. 大麻素CB1受体对大鼠视网膜神经节细胞诱发动作电位的作用%Activation of cannabinoid CB1 receptors modulates evoked action potentials in rat retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    蒋淑霞; 李倩; 王霄汉; 李芳; 王中峰

    2013-01-01

    Activation of cannabinoid CB1 receptors (CB 1Rs) regulates a variety of physiological functions in the vertebrate retina through modulating various types of ion channels.The aim of the present study was to investigate the effects of this receptor on cell excitability of rat retinal ganglion cells (RGCs) in retinal slices using whole-cell patch-clamp techniques.The results showed that under current-clamped condition perfusing WIN55212-2 (WIN,5 μmol/L),a CB1R agonist,did not significantly change the spontaneous firing frequency and resting membrane potential of RGCs.In the presence of cocktail synaptic blockers,including excitatory postsynaptic receptor blockers CNQX and D-APV,and inhibitory receptor blockers bicuculline and strychnine,perfusion of WIN (5 μmol/L)hardly changed the frequencies of evoked action potentials by a series of positive current injection (from +10 to +100 pA).Phaseplane plot analysis showed that both average threshold voltage for triggering action potential and delay time to reach threshold voltage were not affected by WIN.However,WIN significantly decreased +dV/dtmax and-dV/dtmax of action potentials,suggestive of reduced rising and descending velocities of action potentials.The effects of WIN were reversed by co-application of SR141716,a CB1R selective antagonist.Moreover,WIN did not influence resting membrane potential of RGCs with synaptic inputs being blocked.These results suggest that activation of CB1Rs may regulate intrinsic excitability of rat RGCs through modulating evoked action potentials.%激活大麻素CB1受体(CB1Rs)通过调控多种离子通道,从而调节脊椎动物视网膜的功能.本文旨在利用膜片钳全细胞记录技术,在大鼠视网膜薄片上研究CB1Rs对神经节细胞兴奋性的作用.结果显示,在电流钳制状态下,灌流CB1R激动剂WIN55212-2 (WIN,5μmol/L)对神经节细胞的自发动作电位发放频率和静息膜电位均没有显著影响.在灌流液中加入CNQX,D-APV,bicuculline

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

    Directory of Open Access Journals (Sweden)

    Dora Werling

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Optical coherence tomography angiography in retinal diseases

    Directory of Open Access Journals (Sweden)

    K V Chalam

    2016-01-01

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

  8. 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.

  9. 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.

  10. 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

  11. Fundus changes in central retinal vein occlusion.

    Science.gov (United States)

    Hayreh, Sohan Singh; Zimmerman, M Bridget

    2015-01-01

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

  12. 视网膜缺血再灌注损伤后视网膜神经节细胞pax6的表达变化与意义%Significance of pax6 expression in retinal ganglion cells after ischemia-reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    李雪颖; 康前雁

    2012-01-01

    Objective To observe the expression of pax6 in retinal ganglion cells (RGC) and its significance after retinal ischemia-reperfusion (RIR) injury. Design Experimental study. Participants Rat model of RIR injury. Methods 30 adult female SD rats were randomly divided into 6 groups: group 1(n=5) normal control; group 2-6 (n=5 for each group) RIR injury groups (post injury 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks respectively). The intraocular pressure (IOP) of right eye was increased to induced RIR model. Pax6 expression was assessed by immunohistochemistry. Main Outcome Measures The expression of pax6. Results The positive rate of pax6 in RGC was (1.28±1.41) % in control group, (0.99±1.23)% in 1w group, (14.45±2.72)% in 2w group, (50.88±4.73)% in 4w group, (71.00±4.72)% in 6w group and (78.80±4.62) % in 8w group. The difference of expression of pax6 in RGC among these groups was significant (F=1.350, P<0.0001). Compared with control group, the expression of pax6 in RGC was significant higher in 2w, 4w, 6w and 8w group (all P<0.0001), but not significant different in lw group (P=0.835). Conclusion Pax6 expression was present in every layer of retina after RIR injury. RIR in rat induced activation of endogenous retinal stem cells.%目的 探索视网膜缺血再灌注损伤后视网膜神经节细胞pax6的表达变化及意义.设计实验研究.研究对象缺血再灌注损伤大鼠视网膜.方法 成年健康雄性Sprague-Dawley大鼠30只,随机选取5只作为空白对照组,其余25只为视网膜缺血再灌注损伤组,采用升高右眼眼压的方法制作视网膜缺血再灌注损伤模型.视网膜缺血再灌注后1、2、4、6、8周分5组,每组5只,不同时间点取右眼行免疫荧光染色,观察视网膜神经节细胞中pax6表达情况.主要指标pax6的表达.结果 视网膜缺血再灌注损伤后随着时间推移视网膜各层逐渐出现pax6表达阳性的细胞,对照组视网膜神经节细胞pax6表达阳性率为(1.28±1

  13. Purified guar galactomannan as an improved pharmaceutical excipient.

    Science.gov (United States)

    Gebert, M S; Friend, D R

    1998-08-01

    The purpose of this study was to assess certain pharmaceutical attributes of guar galactomannan, a hydrocolloid polysaccharide obtained from the endosperm of the leguminous plant Cyamopsis tetragonolobus (L.), following purification using both literature procedures and new processes. Experiments were performed to measure viscosity, hydration rate, tablet hardness, and dissolution profiles of guar galactomannan both before and after purification. The viscosity of an aqueous 1% purified galactomannan solution is typically 40-50% higher than its unpurified guar galactomannan precursor. The hydration rate of an aqueous 1% purified galactomannan solution increases by 100% after purification. These physicochemical changes resulted in improvements in pharmaceutical properties such as better stir speed independence in both tablet and capsule dissolution profiles and improved tablet hardness. For instance, time to 50% dissolution of ranitidine HCl from capsules containing unpurified guar gum was 0.4 and 1.8 hr at 20 and 40 rpm, respectively, using USP Apparatus II. Using the same amount of purified guar gum and the same conditions (20 and 40 rpm), these values were increased to 2.9 and 3.8 hr, respectively. These data demonstrate a reduced effect of changing agitation conditions and the need for less guar gum to sustain the release of a water-soluble drug. Tablet hardness of purified guar gum (particle size < 75 microns) was about 7 kP and the same unpurified guar gum of equal particle size and hydration gave a hardness of less than 1 kP.

  14. Partial characterization of hog renin purified by affinity chromatography.

    Science.gov (United States)

    Devaux, C; Ménard, J; Sicard, P; Corvol, P

    1976-05-01

    A method has been set up to purify renin on a large scale by affinity chromatography using Pepstatin, a potent inhibitor of renin, as a ligand. Pepstatin was covalently coupled to Sepharose via six different spacer 'arms'. The Sepharose-hexamethylenediamino-Pepstatin appeared to be the better derivative for renin purification even at a concentration as low as 160 nmol of Pepstatin/ml of moist gel. Renin was extracted from 100 kg of hog kidneys and semi-purified by ammonium sulfate precipitations and chromatography on DEAE-cellulose. The active fraction (48.5 g of proteins) was applied on a 500-ml affinity column. Renin was eluted in the starting buffer containing 6 M urea. Renin was purified 120-fold by the affinity chromatography step with a 79% recovery. Physico-chemical characterization of highly purified renin was performed. Isoelectrofocusing on a pH gradient from 3 to 6 showed a major peak with an isoelectric point (pI) of 4.95 and a minor peak (pI = 4.70). Polyacrylamide gel electrophoresis, pH 7.8, at different gel concentrations, showed a single peak of renin activity which was found in the major protein band. Molecular size estimated on agarose-acrylamide gel filtration was 40 000. All these physical parameters were similar before and after purification.

  15. Influence of a highly purified senna extract on colonic epithelium

    NARCIS (Netherlands)

    van Gorkom, B A; Karrenbeld, A; van Der Sluis, T; Koudstaal, J; de Vries, E G; Kleibeuker, J H

    2000-01-01

    BACKGROUND: Chronic use of sennoside laxatives often causes pseudomelanosis coli. A recent study suggested that pseudomelanosis coli is associated with an increased colorectal cancer risk. A single high dose of highly purified senna extract increased proliferation rate and reduced crypt length in th

  16. Mechanical Properties, Purifying Techniques and Processing Methods of Metal Yttrium

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mechanical properties of metal yttrium such as strength, plasticity, hardness and elasticity were introduced. The purifying techniques of yttrium were discussed in detail. The processing methods for metal yttrium including extruding, forging, rolling, wiredrawing and welding were also introduced. Finally, the potential use of yttrium and its alloys were prospected.

  17. Strong Purifying Selection in Transmission of Mammalian Mitochondrial DNA

    Science.gov (United States)

    Stewart, James Bruce; Freyer, Christoph; Elson, Joanna L; Wredenberg, Anna; Cansu, Zekiye; Trifunovic, Aleksandra; Larsson, Nils-Göran

    2008-01-01

    There is an intense debate concerning whether selection or demographics has been most important in shaping the sequence variation observed in modern human mitochondrial DNA (mtDNA). Purifying selection is thought to be important in shaping mtDNA sequence evolution, but the strength of this selection has been debated, mainly due to the threshold effect of pathogenic mtDNA mutations and an observed excess of new mtDNA mutations in human population data. We experimentally addressed this issue by studying the maternal transmission of random mtDNA mutations in mtDNA mutator mice expressing a proofreading-deficient mitochondrial DNA polymerase. We report a rapid and strong elimination of nonsynonymous changes in protein-coding genes; the hallmark of purifying selection. There are striking similarities between the mutational patterns in our experimental mouse system and human mtDNA polymorphisms. These data show strong purifying selection against mutations within mtDNA protein-coding genes. To our knowledge, our study presents the first direct experimental observations of the fate of random mtDNA mutations in the mammalian germ line and demonstrates the importance of purifying selection in shaping mitochondrial sequence diversity. PMID:18232733

  18. Highly thermostable xylanase purified from Rhizomucor miehei NRL 3169.

    Science.gov (United States)

    Fawzi, E M

    2011-03-01

    A thermostable xylanase was purified and characterized from the thermophilic fungus Rhizomucor miehei (Cooney & Emerson) Schipper. The enzyme was purified to homogeneity by ammonium sulfate precipitation, sephadex G-100 gel filtration and diethylaminoethyl cellulose anion exchange chromatography with a 29.1-fold. The enzyme was highly active within a range of pH from 5.0 to 6.5. The optimum temperature of the purified enzyme was 75°C. The enzyme showed high thermal stability at 70°C and 75°C and the half-life of the xylanase at 90°C was 30 min. Km and Vmax values at 50°C of the purified enzyme were 0.055 mg/ml and 113.5 μmol min⁻¹ mg⁻¹ respectively. The enzyme was activated by Ca²+, Cu²+, K+ and Na+. On the other hand, Ag²+, Hg²+, Ba²+, and Zn²+ inhibited the enzyme. The molecular weight of the xylanase was estimated to be 27 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The present study is among the first works to examine and describe a secreted highly thermostable endoxylanase from the Rhizomucor miehei fungus. This enzyme displays a number of biochemical properties that make it a potentially strong candidate for industrial and commercial application in pulp bleaching.

  19. Prevention of retinal light damage by zinc oxide combined with rosemary extract

    OpenAIRE

    Organisciak, Daniel T.; Darrow, R. M.; Rapp, C. M.; Smuts, J. P.; Armstrong, D.W.; Lang, J. C.

    2013-01-01

    Purpose Zinc oxide effectively reduces visual cell loss in rats exposed to intense visible light and is known to slow the rate of disease progression in advanced stages of age-related macular degeneration. Our goal was to determine the efficacy of zinc oxide in combination with novel and well-established antioxidants in an animal model of light-induced oxidative retinal damage. Methods One group of male Sprague-Dawley rats was pretreated with zinc oxide with or without a detergent extract of ...

  20. Neuroprotective effects of the cannabinoid agonist HU210 on retinal degeneration

    OpenAIRE

    Lax Zapata, Pedro; Esquiva Sobrino, Gema; Altavilla, Cesare; Cuenca Navarro, Nicolás

    2014-01-01

    Cannabinoids have been demonstrated to exert neuroprotective effects on different types of neuronal insults. Here we have addressed the therapeutic potential of the synthetic cannabinoid HU210 on photoreceptor degeneration, synaptic connectivity and functional activity of the retina in the transgenic P23H rat, an animal model for autosomal dominant retinitis pigmentosa (RP). In P23H rats administered with HU210 (100 μg/kg, i.p.) from P24 to P90, ERG recordings showed an amelioration of vision...

  1. 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.

  2. 体外诱导大鼠骨髓间充质干细胞向视网膜色素上皮细胞分化的可行性研究%Feasibility study of differentiation of invitro induced rat bone marrow-derived mesenchymal stem cells into retinal pigment epithelial cells

    Institute of Scientific and Technical Information of China (English)

    高斐; 董方田

    2009-01-01

    Objective To investigate the feasibility of differentiation of invitro induced rat bone marrow-derived mesenchymal stem cells(rMSCs) into retinal pigment epithelial (RPE) cells.Methods The rMSCs from Brwon-Norway (BN) rats were isolated and cultured by adherent screening method.RPE cells lysate made by repeated freeze-thawing was put into the rMSCs culture system to identify whether the induced cells could express characteristic label cytokeratin(CK)and S-100 simultaneously or not.Results The growth rate of rMSCs induced by RPE cells lysate was slower and protuberant burr surrounded the fusiform cells.The results of immunoblotting and double immunofluorescence showed that partial induced cells expressed CK and S-100 simultaneously.The result of flow cytometry indicated that 14.1% induced cells expressed CK and S-100 simultaneously.Conclusion Induced by RPE cells lysate,rMSCs can differentiate into RPE cells.%目的 探讨体外诱导大鼠骨髓间充质干细胞(rMSCs)向视网膜色素上皮(RPE)细胞分化的可行性.方法 采用贴壁筛选法分离、培养Brown-Norway(BN)rMSCs.将反复冻融制成的BN大鼠RPE细胞裂解液加入到rMSCs培养体系中,鉴定被诱导的细胞是否同时表达RPE细胞的特征性标记物细胞角蛋白(CK)与S-100.结果 经RPE细胞裂解液诱导的rMSCs生长速度减慢,细胞呈长梭形,周边有毛刺样突起.免疫印迹法和双重免疫荧光标记显示部分经诱导的细胞同时表达CK与S-100.流式细胞术显示14.1%的细胞能够同时表达CK与S-100.结论 rMSCs经RPE细胞裂解液诱导后能够向RPE细胞方向分化.

  3. Microbiological stability of homeopathic medicines using purified water as vehicle

    Directory of Open Access Journals (Sweden)

    Virginia Teresa Cegalla

    2011-09-01

    Full Text Available Background: Homeopathic medicines are prepared in homeopathic pharmacies. This leads to freedom of prescription but requires more knowledge of the clinicians to achieve the best results. Preparations made of purified water receive a validity of 24 hours, but there are prescriptions for up to 30 days. This contradiction raises tensions among physicians, pharmacists and patients. Aims: to evaluate the increase in microbiological contamination in homeopathic medicines using purified water as vehicle compared with the microbiological stability of purified water. Contribute to the quality of homeopathic medicine and treatment. Methodology: daily microbiological analysis for one week to assess the growth of heterotrophic bacteria, Pseudomonas, yeasts and molds. The reference used was the USP 32/NF 27 and the Brazilian Pharmacopoeia 5th edition. Results: there was a higher growth of microorganisms on the medicine, compared with purified water. From the 2nd day on, this growth has been beyond the legal limits. Discussion: medicines for oral use are not sterile preparations, but they must remain stable during its shelf life. Our results indicate that contamination occurs from the earliest days of use. This shows the need to change the prescription in relation of the vehicle, to ensure hygiene and avoid potential contamination of the patient. It is necessary to prevent conflict of information between pharmacists and patients, and the contradiction of the doctor's advice, besides the potential risk of responsibility to be attributed to the pharmacy. It is necessary to promote a discussion between pharmacists and clinicians, to spread this information for those that prescribe. Conclusion: there was an increased of microbiological contamination of the medicines dispensed in purified water, which harms the quality of homeopathic medicine and homeopathic treatment.

  4. Roller coaster-associated retinal detachments.

    Science.gov (United States)

    Shaikh, Saad

    2011-01-01

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

  5. 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.

  6. Fluid vitreous substitutes in vitreo retinal surgery.

    Science.gov (United States)

    Saxena, S; Gopal, L

    1996-12-01

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

  7. Fluid vitreous substitutes in vitreo retinal surgery

    Directory of Open Access Journals (Sweden)

    Saxena Sandeep

    1996-01-01

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

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

    OpenAIRE

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Almeida DRP

    2015-07-01

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

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

    OpenAIRE

    Chu, Edward R.; Chen, Celia S

    2010-01-01

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

  11. Strategies to improve stimulation efficiency for retinal prostheses.

    Science.gov (United States)

    Davuluri, Navya S; Nimmagadda, Kiran; Petrossians, Artin; Humayun, Mark S; Weiland, James D

    2016-08-01

    Retinitis Pigmentosa (RP) is a degenerative disease of the retina that leads to vision loss. Retinal prostheses are being developed in order to restore functional vision in patients suffering from RP. We conducted in-vivo experiments in order to identify strategies to efficiently stimulate the retina. We electrically stimulated the retina and measured electrically evoked potentials (EERs) from the superior colliculus of rats. We compared the strength of EERs when voltage-controlled and current-controlled pulses of varying pulse width and charge levels were applied to the retina. In addition to comparing EER strength, we evaluated improvement in power efficiency afforded by a high surface area platinum-iridium material. Voltage-controlled pulses were more efficient than current-controlled pulses when the pulses have a short duration (<; 1 ms) and current-controlled pulses were more efficient than voltage-controlled pulses when the pulse width was greater than 1 ms. The high surface area platinum-iridium stimulation electrode consumed power significantly lower than a standard platinum-iridium electrode.

  12. Reconstitution of highly purified saxitoxin-sensitive Na+-channels into planar lipid bilayers.

    Science.gov (United States)

    Hanke, W; Boheim, G; Barhanin, J; Pauron, D; Lazdunski, M

    1984-03-01

    Highly purified Na+-channels isolated from rat brain have been reconstituted into virtually solvent-free planar lipid bilayer membranes. Two different types of electrically excitable channels were detected in the absence of any neurotoxins. The activity of both channels was blocked by saxitoxin. The first channel type is highly selective for Na+ over K+ (approximately 10:1), it shows a bursting behavior, a conductance of 25 pS in Na+-Ringer and undergoes continuous opening and closing events for periods of minutes within a defined range of negative membranes voltages. The second channel type has a conductance of 150 pS and a lower selectivity for Na+ and K+ (2.2:1); only a few opening and closing events are observed with this channel after one voltage jump. The latter type of channel is also found with highly purified Na+-channel from Electrophorus electricus electroplax. A qualitative analysis of the physicochemical and pharmacological properties of the high conductance channel has been carried out. Channel properties are affected not only by saxitoxin but also by a scorpion (Centruroides suffusus suffusus) toxin and a sea anemone (Anemonia sulcata) toxin both known to be selective for the Na+-channel. The spontaneous transformation of the large conductance channel type into the small one has been considered; the two channel types may represent the expression of activity of different conformational states of the same protein.

  13. Isolation of functionally active and highly purified neuronal mitochondria from human cortex.

    Science.gov (United States)

    Khattar, Nicolas K; Yablonska, Svitlana; Baranov, Sergei V; Baranova, Oxana V; Kretz, Eric S; Larkin, Timothy M; Carlisle, Diane L; Richardson, R Mark; Friedlander, Robert M

    2016-04-01

    Functional and structural properties of mitochondria are highly tissue and cell dependent, but isolation of highly purified human neuronal mitochondria is not currently available. We developed and validated a procedure to isolate purified neuronal mitochondria from brain tissue. The method combines Percoll gradient centrifugation to obtain synaptosomal fraction with nitrogen cavitation mediated synaptosome disruption and extraction of mitochondria using anti mitochondrial outer membrane protein antibodies conjugated to magnetic beads. The final products of isolation are non-synaptosomal mitochondria, which are a mixture of mitochondria isolated from different brain cells (i.e. neurons, astrocytes, oligodendrocytes, microglia) and synaptic mitochondria, which are of neuronal origin. This method is well suited for preparing functional mitochondria from human cortex tissue that is surgically extracted. The procedure produces mitochondria with minimal cytoplasmic contaminations that are functionally active based on measurements of mitochondrial respiration as well as mitochondrial protein import. The procedure requires approximately four hours for the isolation of human neuronal mitochondria and can also be used to isolate mitochondria from mouse/rat/monkey brains. This method will allow researchers to study highly enriched neuronal mitochondria without the confounding effect of cellular and organelle contaminants. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2014-09-01

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

  15. Idiopathic pediatric retinal artery occlusion

    Directory of Open Access Journals (Sweden)

    Manayath George

    2010-01-01

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

  16. Nanoparticles for retinal gene therapy.

    Science.gov (United States)

    Conley, Shannon M; Naash, Muna I

    2010-09-01

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

  17. Laminins and retinal vascular development.

    Science.gov (United States)

    Edwards, Malia M; Lefebvre, Olivier

    2013-01-01

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

  18. The Comparative Protective Effects of Ganoderma Spores Lipid and Fish Oil on N-Methyl-N-Nitrosourea-Induced Photoreceptor Cell Lesion in Rats

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2011-01-01

    Full Text Available Purpose. To compare Ganoderma spores lipid (GSL and fish oil (FO in inhibiting retinal photoreceptor cell lesions induced by N-methyl-N-nitrosourea (MNU in rats. Methods. 120 rats were untreated (normal control, NC group or treated with a single intraperitoneal injection of 40 mg/kg MNU (MNU group then treated with GSL (GSL group or FO (FO group. Eyes were obtained at 1, 3, 5, 7, and 10 days. Results. Light microscopy assay demonstrated that GSL and FO alleviated rat retinal photoreceptor cell damage (GSL and FO versus MNU group P.05. Conclusion. GSL, like FO, alleviates rat retinal photoreceptor cell damage induced by MNU.

  19. 轴突导向因子netrin-1对早期糖尿病大鼠血视网膜屏障的影响%The effect of netrin-1 on the retinal vascular permeability in early diabetic retinopathy rats

    Institute of Scientific and Technical Information of China (English)

    周贤慧; 孟旭霞; 孙运波; 胡迭; 郭庆敏

    2015-01-01

    视网膜IA值与正常对照组比较,差异有统计学意义(t=12.87,P=0.00).EB渗漏试验结果显示,DM+ BSS组、DM+ netrin-1低剂量、DM+ netrin-1高剂量组间大鼠视网膜EB渗漏量比较,差异有统计意义(F=179.69,P=0.00);DM+ netrin-1低剂量组大鼠视网膜EB渗漏量与DM+netrin-1高剂量组比较,差异有统计学意义(t=12.73,P=0.00).结论 玻璃体腔注射外源性netrin-1对早期DM大鼠BRB有保护作用;这种保护作用可能是通过抑制视网膜occludin的减少实现.%Objective To explore the effect and mechanism of netrin-1 on blood-retinal barrier permeability in diabetes mellitus (DM) rats.Methods Eighty Sprague-Dawley rats were randomly divided into the normal control group,DM+balanced salt solution (BSS) group,DM+netrin-1 low dose group and DM+ netrin-1 high dose group,with 20 rats in each group.DM rats were induced by intraperitoneal injection of streptozocin (STZ).These rats were feed with high sugar and fat for 3 months after STZ injection.All rats were sacrificed at 1 month after intravitreal injection.RetinM vascular permeability was measured by Evans blue.The expression level of occludin was determined by immunohistochemistry.Hematoxylin-eosin (HE) staining of retina was used to observe the pathological change of DM and the level of occludin mRNA was analyzed by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR).Five rats of each group.Results HE staining of retina showed that the degree of edema and vascularization in DM+ netrin 1 high dose group was better than DM+BSS group.Staining of occludin in retina was limited to nerve fiber layer,ganglion cells,inner plexiform layer and inner nuclear layer in normal rats,but in DM+BSS group,the color of staining positive of occludin was lighter and more reduced.However,DM+ netrin 1 group oceludin staining was deepen and enlarged.The result of RT-PCR showed that the expression of occludin mRNA in other three groups was less than

  20. Study on the differentiation of retinal ganglion cells from rat Müller cells in vitro%体外诱导大鼠视网膜Müller细胞向神经节细胞定向分化的研究

    Institute of Scientific and Technical Information of China (English)

    曾琦; 夏晓波

    2010-01-01

    Objective To certify the ability of retinal Müller cells for producing neural stem cells in vitro and to find a method that can aquire more retinal ganglion cells from these stem cells. Methods Müller cells were isolated from rat retina, and proliferating cells were expanded in serum-containing medium. The third or fourth passage of cells were identified by RT-PCR and Immunocytochemistry analysis. For dedifferentiation, the cultured cells were transferred to the sphere-culture medium composed of DMEM/F-12 supplemented with N2,bFGF and EGF. After 3-5 days, the culture media were substituted with BDNF,RA and 5% FBS and culture was continued for 7-10 days. At last, cells in this two stages were identified by immunocytochemical analysis. Results Approximately (95. 17 ±2. 68)% of cells in the culture were Miiller cells as revealed by expressing glutamate-spartate transporters (GLAST) and glutamine synthetase ( GS) immunoreactivities. RT-PCR analysis also revealed that the culture was enriched for Müller cells and not contaminated with other retinal cells. After 3-5 days cultured in the the sphere-culture medium, the Mttller cells became round and differentiate to neurospheres. (95. 26 ± 1. 35)% of cells in the neurosphere were positively reacted for Nestin,and (90. 33 ±4. 12)% for BrdU. Neurospheres cultured for 7-10 days with 5% FBS,BDNF and RA can redifferentiate to various new cells. And the expression of Thyl. 1 which is a marker of retinal ganglion cells was observed in (21. 14 ± 1. 49)% of these cells. Conclusions Adult rodent Müller cells can generate clonal neurospheres,which consist of proliferating and multipotent cells,and redifferentiate to ganglion cells. This study may provide a novel tool in the study on stem cells and contribute to therapies for neural regeneration in retina.%目的 研究鼠视网膜Müller细胞经体外条件培养基诱导后去分化为神经干细胞及进一步定向分化成神经节样细胞的特性.方法 实

  1. 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.

  2. Photodiode circuits for retinal prostheses.

    Science.gov (United States)

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

    2011-10-01

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

  3. Allogeneic Transplantation of Müller-Derived Retinal Ganglion Cells Improves Retinal Function in a Feline Model of Ganglion Cell Depletion.

    Science.gov (United States)

    Becker, Silke; Eastlake, Karen; Jayaram, Hari; Jones, Megan F; Brown, Robert A; McLellan, Gillian J; Charteris, David G; Khaw, Peng T; Limb, G Astrid

    2016-02-01

    Human Müller glia with stem cell characteristics (hMGSCs) have been shown to improve retinal function upon transplantation into rat models of retinal ganglion cell (RGC) depletion. However, their translational potential may depend upon successful engraftment and improvement of retinal function in experimental models with anatomical and functional features resembling those of the human eye. We investigated the effect of allogeneic transplantation of feline Müller glia with the ability to differentiate into cells expressing RGC markers, following ablation of RGCs by N-methyl-d-aspartate (NMDA). Unlike previous observations in the rat, transplantation of hMGSC-derived RGCs into the feline vitreous formed aggregates and elicited a severe inflammatory response without improving visual function. In contrast, allogeneic transplantation of feline MGSC (fMGSC)-derived RGCs into the vitrectomized eye improved the scotopic threshold response (STR) of the electroretinogram (ERG). Despite causing functional improvement, the cells did not attach onto the retina and formed aggregates on peripheral vitreous remnants, suggesting that vitreous may constitute a barrier for cell attachment onto the retina. This was confirmed by observations that cellular scaffolds of compressed collagen and enriched preparations of fMGSC-derived RGCs facilitated cell attachment. Although cells did not migrate into the RGC layer or the optic nerve, they significantly improved the STR and the photopic negative response of the ERG, indicative of increased RGC function. These results suggest that MGSCs have a neuroprotective ability that promotes partial recovery of impaired RGC function and indicate that cell attachment onto the retina may be necessary for transplanted cells to confer neuroprotection to the retina. Significance: Müller glia with stem cell characteristics are present in the adult human retina, but they do not have regenerative ability. These cells, however, have potential for

  4. Gestational lead exposure selectively decreases retinal dopamine amacrine cells and dopamine content in adult mice.

    Science.gov (United States)

    Fox, Donald A; Hamilton, W Ryan; Johnson, Jerry E; Xiao, Weimin; Chaney, Shawntay; Mukherjee, Shradha; Miller, Diane B; O'Callaghan, James P

    2011-11-01

    Gestational lead exposure (GLE) produces supernormal scotopic electroretinograms (ERG) in children, monkeys and rats, and a novel retinal phenotype characterized by an increased number of rod photoreceptors and bipolar cells in adult mice and rats. Since the loss of dopaminergic amacrine cells (DA ACs) in GLE monkeys and rats contributes to supernormal ERGs, the retinal DA system was analyzed in mice following GLE. C57BL/6 female mice were exposed to low (27 ppm), moderate (55 ppm) or high (109 ppm) lead throughout gestation and until postnatal day 10 (PN10). Blood [Pb] in control, low-, moderate- and high-dose GLE was ≤ 1, ≤ 10, ~25 and ~40 μg/dL, respectively, on PN10 and by PN30 all were ≤ 1 μg/dL. At PN60, confocal-stereology studies used vertical sections and wholemounts to characterize tyrosine hydroxylase (TH) expression and the number of DA and other ACs. GLE dose-dependently and selectively decreased the number of TH-immunoreactive (IR) DA ACs and their synaptic plexus without affecting GABAergic, glycinergic or cholinergic ACs. Immunoblots and confocal revealed dose-dependent decreases in retinal TH protein expression and content, although monoamine oxidase-A protein and gene expression were unchanged. High-pressure liquid chromatography showed that GLE dose-dependently decreased retinal DA content, its metabolites and DA utilization/release. The mechanism of DA selective vulnerability is unknown. However, a GLE-induced loss/dysfunction of DA ACs during development could increase the number of rods and bipolar cells since DA helps regulate neuronal proliferation, whereas during adulthood it could produce ERG supernormality as well as altered circadian rhythms, dark/light adaptation and spatial contrast sensitivity.

  5. [Intraocular hypertension after retinal detachment surgery].

    Science.gov (United States)

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

    2012-01-01

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

  6. [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.

  7. The treatment of bullous rhegmatogenous retinal detachment.

    Science.gov (United States)

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

    1992-01-01

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

  8. [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.

  9. 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.

  10. 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.

  11. 玻璃体腔移植人脐带间充质干细胞对糖尿病大鼠视网膜形态及胶质细胞原纤维酸性蛋白和视紫红质表达的影响%The influence of human umbilical cord mesenchymal stem cells transplantation into vitreous cavity of diabetic rats on retinal morphology and the expression level of glial fibrillary acidic protein and rhodopsin

    Institute of Scientific and Technical Information of China (English)

    邹媛媛; 汪建涛; 李筱荣

    2016-01-01

    Objective To observe the influence of human umbilical cord mesenchymal stem cells (hUCMSC) transplantation into vitreous cavity of diabetic rats on the retinal morphology,and the expression of glial fibrillary acidic protein (GFAP) and rhodopsin (RHO).Methods 78 male SpragueDawley rats were used.70 rats were injected with streptozotocin by tail vein injection at a dose of 40 mg/kg to establish the diabetes mellitus model,and another 8 rats were injected with 0.1 mol/L pH 4.0 citric acid buffer at the same dose as the normal control group.After 5 weeks of modeling,10 rats were taken as the control group of diabetic model.hUCMSC suspension was injected into the right eye vitreous cavity of the remaining 60 rats,and the same volume of Dulbecco's modified Eagle/F12 medium was injected into the left vitreous cavity as control eyes.1,2 and 4 weeks after transplantation,follow-up experiments were performed.The experimental eyes were labeled as U1,U2,and U4 groups,while the control eyes were recorded as D1,D2,D4,and each group consisted of 20 eyes.After paraffin section and hematoxylin-eosin staining,the structure of the retina was observed by optical microscopy and the thickness of the outer nuclear layer and the inner nuclear layer (INL) were measured.The distribution and migration of hUCMSC in rat retina were observed by frozen section-tissue immunofluorescence assay.The mRNA and protein expression of GFAP and RHO in the retina were detected by real-time quantitative polymerase chain reaction (PCR) and Western blot assays.Results The results of optical microscope observation showed the normal structure of retina in normal control group.The retinal nerve fiber layer (NFL) was thinned and the number of retinal ganglion cells (RGC) in the control group of diabetic rats was decreased.The decreased number and disorder arrangement of RGC were observed as well in U1,D1 rats.The RGC number of U2,U4,D2,D4 rats was gradually decreased.Compared with D4 group,the thickness of INL

  12. Therapeutic effect of the NMDA antagonist MK-801 on low-level laser induced retinal injury

    Science.gov (United States)

    Yan, W.-H.; Wu, J.; Chen, P.; Dou, J.-T.; Pan, C.-Y.; Mu, Y.-M.; Lu, J.-M.

    2009-03-01

    The aim of this article was to explore the mechanism of injury in rat retina after constant low-level helium-neon (He-Ne) laser exposure and therapeutic effects of MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, on laser-induced retinal injury. He-Ne laser lesions were created in the central retina of adult Wistar Kyoto rats and were followed immediately by intraperitoneal injection of MK-801 (2 mg/kg) or saline, macroscopical and microscopical lesion were observed by funduscope and light microscope. Ultrastructural changes of the degenerating cells were examined by electron microscopy. Photoreceptor apoptosis was evaluated by TdT-mediated dUTP nick end-labeling (TUNEL). mRNA levels were measured by in situ hybridization and NMDA receptor expression was determined by immunohistochemistry. Laser induced damage was histologically quantified by image-analysis morphometry. Electroretinograms (ERGs) were recorded at different time point after the cessation of exposure to constant irradiation. There was no visible bleeding, exudation or necrosis under funduscope. TUNEL and electron microscopy showed photoreceptor apoptosis after irradiation. MK-801-treated animals had significantly fewer TUNEL-positive cells in the photoreceptors than saline-treated animals after exposure to laser. In situ hybridization (ISH) showed that the NMDAR mRNA level of MK-801-treated rats decreased in the inner plexiform layer 6 h after the cessation of exposure to constant irradiation when compared with that of saline-treated rats. So did Immunohistochemistry (IHC). Electroretinogram showed that b-wave amplitudes of MK-801-treated group were higher than that of saline-treated group after laser exposure. These findings suggest that Low level laser may cause the retinal pathological changes under given conditions. High expression of NMDAR is one of the possible mechanisms causing experimental retinal laser injury of rats. MK-801 exhibits the therapeutic effect due to promote the

  13. Tetrandrine protects mouse retinal ganglion cells from ischemic injury

    Directory of Open Access Journals (Sweden)

    Li WY

    2014-03-01

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

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

    Science.gov (United States)

    Pikulski, Z; Nawrocki, J; Dziegielewski, K

    1993-01-01

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

  15. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

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

    2014-01-01

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

  16. 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.

  17. Programming Retinal Stem Cells into Cone Photoreceptors

    Science.gov (United States)

    2015-12-01

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

  18. 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.

  19. Current surgery of retinal detachment recurrence. Review

    Directory of Open Access Journals (Sweden)

    V. D. Zakharov

    2014-07-01

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

  20. Fluid vitreous substitutes in vitreo retinal surgery

    OpenAIRE

    Saxena Sandeep; Gopal Lingam

    1996-01-01

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

  1. Safety of iPhone retinal photography.

    Science.gov (United States)

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

    2017-04-01

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

  2. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration.

    Directory of Open Access Journals (Sweden)

    Violeta Gómez-Vicente

    Full Text Available Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss.

  3. Diosmetin protects against retinal injury via reduction of DNA damage and oxidative stress

    Directory of Open Access Journals (Sweden)

    Zeren Shen

    2016-01-01

    Full Text Available Visual impairment is a global public health problem that needs new candidate drugs. Chrysanthemum is a traditional Chinese drug, famous for its eye-protective function, with an unclear mechanism of action. To determine how chrysanthemum contributes to vision, we identified, for the first time, the component of chrysanthemum, diosmetin (DIO, which acts in protecting the injured retina in an adriamycin (ADR improving model. We observed that DIO could attenuate the apoptosis of retinal cells in Sprague–Dawley rats and verified this effect in cultured human retinal pigment epithelium (RPE cells, ARPE-19. Our further study on the mechanism revealed the counteractive effect of DIO on the attenuation of DNA damage and oxidative stress, which occurs in a wide range of retinal disorders. These results collectively promise the potential value of DIO as a retinal-protective agent for disorders that lead to blindness. In addition, we identified, for the first time, the component of chrysanthemum, DIO, which acts in protecting the injured retina.

  4. Gene expression analysis of zebrafish melanocytes, iridophores, and retinal pigmented epithelium reveals indicators of biological function and developmental origin.

    Science.gov (United States)

    Higdon, Charles W; Mitra, Robi D; Johnson, Stephen L

    2013-01-01

    In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology.

  5. Gene expression analysis of zebrafish melanocytes, iridophores, and retinal pigmented epithelium reveals indicators of biological function and developmental origin.

    Directory of Open Access Journals (Sweden)

    Charles W Higdon

    Full Text Available In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology.

  6. Properties of purified recombinant human polyamine oxidase, PAOh1/SMO.

    Science.gov (United States)

    Wang, Yanlin; Murray-Stewart, Tracy; Devereux, Wendy; Hacker, Amy; Frydman, Benjamin; Woster, Patrick M; Casero, Robert A

    2003-05-16

    The discovery of an inducible oxidase whose apparent substrate preference is spermine indicates that polyamine catabolism is more complex than that originally proposed. To facilitate the study of this enzyme, the purification and characterization of the recombinant human PAOh1/SMO polyamine oxidase are reported. Purified PAOh1/SMO oxidizes both spermine (K(m)=1.6 microM) and N(1)-acetylspermine (K(m)=51 microM), but does not oxidize spermidine. The purified human enzyme also does not oxidize eight representative antitumor polyamine analogues; however, specific oligamine analogues were found to be potent inhibitors of the oxidation of spermine by PAOh1/SMO. The results of these studies are consistent with the hypothesis that PAOh1/SMO represents a new addition to the polyamine metabolic pathway that may represent a new target for antineoplastic drug development.

  7. Thermal inactivation kinetics of partially purified mango pectin methylesterase

    Directory of Open Access Journals (Sweden)

    Claudio Alonso DÍAZ-CRUZ

    2016-01-01

    Full Text Available Abstract Kinetic parameters of thermal inactivation of pectin methylesterase (PME in a partially purified mango enzyme extract were determined. The PME of mango partially purified by salting out showed different patterns of thermal inactivation, indicating the presence of a thermostable fraction at 70 °C and a thermolabile fraction at lower temperatures. The inactivation of the thermostable fraction exhibited a linear behavior that yielded a z-value of 9.44 °C and an activation energy (Ea of 245.6 kJ mol-1 K-1 using the Arrhenius model. The thermostable mango PME fraction represented 17% of total crude enzyme extract, which emphasizes the importance of residual enzyme activity after heat treatment.

  8. Diagnostic imaging in patients with retinitis pigmentosa.

    Science.gov (United States)

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

    2012-01-01

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

  9. 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.

  10. 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.

  11. Retinal iron homeostasis in health and disease

    Directory of Open Access Journals (Sweden)

    Delu eSong

    2013-06-01

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

  12. 42 CFR 84.171 - Non-powered air-purifying particulate respirators; required components.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate respirators... PROTECTIVE DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.171 Non-powered air-purifying particulate respirators; required components. (a) Each non-powered air-purifying particulate...

  13. 42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate respirators... DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.170 Non-powered air-purifying particulate respirators; description. (a) Non-powered air-purifying particulate respirators utilize the wearer's...

  14. Isolation of Microorganisms Able To Metabolize Purified Natural Rubber

    OpenAIRE

    Heisey, R. M.; Papadatos, S

    1995-01-01

    Bacteria able to grow on purified natural rubber in the absence of other organic carbon sources were isolated from soil. Ten isolates reduced the weight of vulcanized rubber from latex gloves by >10% in 6 weeks. Scanning electron microscopy clearly revealed the ability of the microorganisms to colonize, penetrate, and dramatically alter the physical structure of the rubber. The rubber-metabolizing bacteria were identified on the basis of fatty acid profiles and cell wall characteristics. Seve...

  15. Survey of Air Purifier Market Acceptance in China

    OpenAIRE

    Yang, Shan

    2016-01-01

    In recent years, air cleaner products have drawn a wide attention due to the extensive concern of air pollution in China. The study aims at research market acceptance of air purifiers. Meanwhile, an outlook of present market and competitive environment were introduced for driving forces of the research as background knowledge. In this thesis, a theoretical framework was designed to express the theory of customer acceptance, which provided theoretical support for the analysis process in th...

  16. Proteomic analysis of purified Newcastle disease virus particles

    Directory of Open Access Journals (Sweden)

    Ren Xiangpeng

    2012-05-01

    Full Text Available Abstract Background Newcastle disease virus (NDV is an enveloped RNA virus, bearing severe economic losses to the poultry industry worldwide. Previous virion proteomic studies have shown that enveloped viruses carry multiple host cellular proteins both internally and externally during their life cycle. To address whether it also occurred during NDV infection, we performed a comprehensive proteomic analysis of highly purified NDV La Sota strain particles. Results In addition to five viral structural proteins, we detected thirty cellular proteins associated with purified NDV La Sota particles. The identified cellular proteins comprised several functional categories, including cytoskeleton proteins, annexins, molecular chaperones, chromatin modifying proteins, enzymes-binding proteins, calcium-binding proteins and signal transduction-associated proteins. Among these, three host proteins have not been previously reported in virions of other virus families, including two signal transduction-associated proteins (syntenin and Ras small GTPase and one tumor-associated protein (tumor protein D52. The presence of five selected cellular proteins (i.e., β-actin, tubulin, annexin A2, heat shock protein Hsp90 and ezrin associated with the purified NDV particles was validated by Western blot or immunogold labeling assays. Conclusions The current study presented the first standard proteomic profile of NDV. The results demonstrated the incorporation of cellular proteins in NDV particles, which provides valuable information for elucidating viral infection and pathogenesis.

  17. Proteomic analysis of purified coronavirus infectious bronchitis virus particles

    Directory of Open Access Journals (Sweden)

    Shu Dingming

    2010-06-01

    Full Text Available Abstract Background Infectious bronchitis virus (IBV is the coronavirus of domestic chickens causing major economic losses to the poultry industry. Because of the complexity of the IBV life cycle and the small number of viral structural proteins, important virus-host relationships likely remain to be discovered. Toward this goal, we performed two-dimensional gel electrophoresis fractionation coupled to mass spectrometry identification approaches to perform a comprehensive proteomic analysis of purified IBV particles. Results Apart from the virus-encoded structural proteins, we detected 60 host proteins in the purified virions which can be grouped into several functional categories including intracellular trafficking proteins (20%, molecular chaperone (18%, macromolcular biosynthesis proteins (17%, cytoskeletal proteins (15%, signal transport proteins (15%, protein degradation (8%, chromosome associated proteins (2%, ribosomal proteins (2%, and other function proteins (3%. Interestingly, 21 of the total host proteins have not been reported to be present in virions of other virus families, such as major vault protein, TENP protein, ovalbumin, and scavenger receptor protein. Following identification of the host proteins by proteomic methods, the presence of 4 proteins in the purified IBV preparation was verified by western blotting and immunogold labeling detection. Conclusions The results present the first standard proteomic profile of IBV and may facilitate the understanding of the pathogenic mechanisms.

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

    Science.gov (United States)

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

    2010-01-01

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

  19. A novel platform for minimally invasive delivery of cellular therapy as a thin layer across the subretina for treatment of retinal degeneration

    Science.gov (United States)

    Rotenstreich, Ygal; Tzameret, Adi; Kalish, Sapir E.; Belkin, Michael; Meir, Amilia; Treves, Avraham J.; Nagler, Arnon; Sher, Ifat

    2015-03-01

    Incurable retinal degenerations affect millions worldwide. Stem cell transplantation rescued visual functions in animal models of retinal degeneration. In those studies cells were transplanted in subretinal "blebs", limited number of cells could be injected and photoreceptor rescue was restricted to areas in proximity to the injection sites. We developed a minimally-invasive surgical platform for drug and cell delivery in a thin layer across the subretina and extravascular spaces of the choroid. The novel system is comprised of a syringe with a blunt-tipped needle and an adjustable separator. Human bone marrow mesenchymal stem cells (hBM-MSCs) were transplanted in eyes of RCS rats and NZW rabbits through a longitudinal triangular scleral incision. No immunosuppressants were used. Retinal function was determined by electroretinogram analysis and retinal structure was determined by histological analysis and OCT. Transplanted cells were identified as a thin layer across the subretina and extravascular spaces of the choroid. In RCS rats, cell transplantation delayed photoreceptor degeneration across the entire retina and significantly enhanced retinal functions. No retinal detachment or choroidal hemorrhages were observed in rabbits following transplantation. This novel platform opens a new avenue for drug and cell delivery, placing the transplanted cells in close proximity to the damaged RPE and retina as a thin layer, across the subretina and thereby slowing down cell death and photoreceptor degeneration, without retinal detachment or choroidal hemorrhage. This new transplantation system may increase the therapeutic effect of other cell-based therapies and therapeutic agents. This study is expected to directly lead to phase I/II clinical trials for autologous hBM-MSCs transplantation in retinal degeneration patients.

  20. Calpain Inhibition Attenuates Apoptosis of Retinal Ganglion Cells in Acute Optic Neuritis

    Science.gov (United States)

    Smith, Amena W.; Das, Arabinda; Guyton, M. Kelly; Ray, Swapan K.; Rohrer, Baerbel

    2011-01-01

    Purpose. Optic neuritis (ON), inflammation of the optic nerve, is strongly associated with the pathogenesis of multiple sclerosis (MS) and is initiated by the attack of autoreactive T cells against self-myelin antigens, resulting in demyelination, degeneration of retinal ganglion cells (RGCs), and cumulative visual impairment. Methods. Experimental autoimmune encephalomyelitis (EAE) was induced in Lewis rats on day 0, and animals received daily intraperitoneal injections of calpain inhibitor (calpeptin) or vehicle from day 1 until killed. Retinal cell death was analyzed by DNA fragmentation, and surviving ganglion cells were quantified after double labeling of retinal tissue with TUNEL and Brn3a. The expression of apoptotic and inflammatory proteins was determined by Western blotting. Results. It was demonstrated that calpain inhibition downregulates expression of proapoptotic proteins and the proinflammatory molecule nuclear factor-kappa B (NF-κB) in the retina of Lewis rats with acute EAE. Immunofluorescent labeling revealed that apoptotic cells in the RGC layer of vehicle-treated EAE animals were Brn3a positive, and a moderate dose of calpeptin dramatically reduced the frequency of apoptotic RGCs. Conclusions. These results suggest that calpain inhibition might be a useful supplement to immunomodulatory therapies such as corticosteroids in ON, due to its neuroprotective effect on RGCs. PMID:21613375

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

    DEFF Research Database (Denmark)

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

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

  2. Acute and Chronic Oral Toxicity of a Partially Purified Plaunotol Extract from Croton stellatopilosus Ohba

    Directory of Open Access Journals (Sweden)

    Chatchai Chaotham

    2013-01-01

    Full Text Available Plaunotol, an acyclic diterpenoid with highly effective antigastric ulcer properties, has been commercially isolated from leaves of Croton stellatopilosus Ohba. This Thai medicinal plant was traditionally used in the form of crude extracts, suggesting that it is possible to administer these plaunotol-containing extracts without toxicity. To confirm its safety, the oral toxicity of a partially purified plaunotol extract (PPE was evaluated in vivo. The PPE was simply prepared by 95% ethanol reflux extraction followed by hexane partition. The obtained extract was analyzed and found to contain 43% w/w of plaunotol and another compound, likely a fatty acid-plaunotol conjugate that is considered a major impurity. Oral administration of PPE to ICR mice and Wistar rats was conducted to evaluate acute and chronic toxicity of the plaunotol extract, respectively. The acute toxicity study demonstrated that PPE was practically nontoxic based on its high median lethal dose value (LD50=10.25 g/kg. The chronic toxicity studies also showed the absence of mortality and clinical symptoms in all rats treated with 11–1,100 mg/kg/day of PPE during a 6-month period. Histopathological and hematological analyses revealed that altered liver and kidney function and increased blood platelet number, but only at the high doses (550–1,100 mg/kg/day. These results suggest that PPE is potentially safe for further development as a therapeutic agent in humans.

  3. Identification of an Alternative Splicing Product of the Otx2 Gene Expressed in the Neural Retina and Retinal Pigmented Epithelial Cells.

    Science.gov (United States)

    Kole, Christo; Berdugo, Naomi; Da Silva, Corinne; Aït-Ali, Najate; Millet-Puel, Géraldine; Pagan, Delphine; Blond, Frédéric; Poidevin, Laetitia; Ripp, Raymond; Fontaine, Valérie; Wincker, Patrick; Zack, Donald J; Sahel, José-Alain; Poch, Olivier; Léveillard, Thierry

    2016-01-01

    To investigate the complexity of alternative splicing in the retina, we sequenced and analyzed a total of 115,706 clones from normalized cDNA libraries from mouse neural retina (66,217) and rat retinal pigmented epithelium (49,489). Based upon clustering the cDNAs and mapping them with their respective genomes, the estimated numbers of genes were 9,134 for the mouse neural retina and 12,050 for the rat retinal pigmented epithelium libraries. This unique collection of retinal of messenger RNAs is maintained and accessible through a web-base server to the whole community of retinal biologists for further functional characterization. The analysis revealed 3,248 and 3,202 alternative splice events for mouse neural retina and rat retinal pigmented epithelium, respectively. We focused on transcription factors involved in vision. Among the six candidates suitable for functional analysis, we selected Otx2S, a novel variant of the Otx2 gene with a deletion within the homeodomain sequence. Otx2S is expressed in both the neural retina and retinal pigmented epithelium, and encodes a protein that is targeted to the nucleus. OTX2S exerts transdominant activity on the tyrosinase promoter when tested in the physiological environment of primary RPE cells. By overexpressing OTX2S in primary RPE cells using an adeno associated viral vector, we identified 10 genes whose expression is positively regulated by OTX2S. We find that OTX2S is able to bind to the chromatin at the promoter of the retinal dehydrogenase 10 (RDH10) gene.

  4. Identification of an Alternative Splicing Product of the Otx2 Gene Expressed in the Neural Retina and Retinal Pigmented Epithelial Cells

    Science.gov (United States)

    Kole, Christo; Berdugo, Naomi; Da Silva, Corinne; Aït-Ali, Najate; Millet-Puel, Géraldine; Pagan, Delphine; Blond, Frédéric; Poidevin, Laetitia; Ripp, Raymond; Fontaine, Valérie; Wincker, Patrick; Zack, Donald J.; Sahel, José-Alain; Poch, Olivier; Léveillard, Thierry

    2016-01-01

    To investigate the complexity of alternative splicing in the retina, we sequenced and analyzed a total of 115,706 clones from normalized cDNA libraries from mouse neural retina (66,217) and rat retinal pigmented epithelium (49,489). Based upon clustering the cDNAs and mapping them with their respective genomes, the estimated numbers of genes were 9,134 for the mouse neural retina and 12,050 for the rat retinal pigmented epithelium libraries. This unique collection of retinal of messenger RNAs is maintained and accessible through a web-base server to the whole community of retinal biologists for further functional characterization. The analysis revealed 3,248 and 3,202 alternative splice events for mouse neural retina and rat retinal pigmented epithelium, respectively. We focused on transcription factors involved in vision. Among the six candidates suitable for functional analysis, we selected Otx2S, a novel variant of the Otx2 gene with a deletion within the homeodomain sequence. Otx2S is expressed in both the neural retina and retinal pigmented epithelium, and encodes a protein that is targeted to the nucleus. OTX2S exerts transdominant activity on the tyrosinase promoter when tested in the physiological environment of primary RPE cells. By overexpressing OTX2S in primary RPE cells using an adeno associated viral vector, we identified 10 genes whose expression is positively regulated by OTX2S. We find that OTX2S is able to bind to the chromatin at the promoter of the retinal dehydrogenase 10 (RDH10) gene. PMID:26985665

  5. Evidence of BrdU-positive retinal neurons after application of an Alpha7 nicotinic acetylcholine receptor agonist.

    Science.gov (United States)

    Webster, Mark K; Cooley-Themm, Cynthia A; Barnett, Joseph D; Bach, Harrison B; Vainner, Jessica M; Webster, Sarah E; Linn, Cindy L

    2017-03-27

    Irreversible vision loss due to disease or age is responsible for a reduced quality of life. The experiments in this study test the hypothesis that the α7 nicotinic acetylcholine receptor agonist, PNU-282987, leads to the generation of retinal neurons in an adult mammalian retina in the absence of retinal injury or exogenous growth factors. Using antibodies against BrdU, retinal ganglion cells, progenitor cells and Müller glia, the results of this study demonstrate that multiple types of retinal cells and neurons are generated after eye drop application of PNU-282987 in adult Long Evans rats in a dose-dependent manner. The results of this study provide evidence that progenitor cells, derived from Müller glia after treatment with PNU-282987, differentiate and migrate to the photoreceptor and retinal ganglion cell layers. If retinas were treated with the alpha7 nAChR antagonist, methyllycaconitine, before agonist treatment, BrdU-positive cells were significantly reduced. As adult mammalian neurons do not typically regenerate or proliferate, these results have implications for reversing vision loss due to neurodegenerative disease or the aging process to improve the quality of life for millions of patients. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Rhegmatogenous retinal detachment: current opinion

    Directory of Open Access Journals (Sweden)

    T. A. Avanesova

    2015-03-01

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

  7. 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. 

  8. Expression of ERK and c-fos and effect of brain derived neurotrophic factor in early retinal neuropathy of streptozotocin-induced diabetes in rat%糖尿病早期大鼠视网膜中细胞外信号调节激酶与c-fos的变化及脑源性神经营养因子的作用

    Institute of Scientific and Technical Information of China (English)

    万超; 刘宁宁; 柳力敏; 才娜; 陈蕾

    2012-01-01

    背景 研究表明糖尿病患者视网膜的神经病变出现在血管并发症之前,严重危害患者的视力,而神经营养因子对其具有保护作用.目的 观察在糖尿病大鼠玻璃体腔内注射脑源性神经营养因子(BDNF)前后大鼠视网膜中BDNF及其受体TrkB、通路蛋白磷酸化细胞外信号调节激酶1/2( p-ERK1/2)、c-fos质量浓度的变化.方法 9周龄雄性健康Wistar大鼠按随机数字表法随机分为BDNF治疗组、糖尿病对照组和正常对照组,每组20只.BDNF治疗组、糖尿病对照组大鼠应用链脲佐菌素(STZ)腹腔注射制成糖尿病模型,BDNF治疗组大鼠于成模后2周开始向玻璃体腔内注射1 g/L BDNF溶液5μl.于成模后4周处死全部大鼠,取出眼球进行BDNF原位杂交,计数视网膜中BDNF阳性细胞数.采用 ELISA抗体夹心法检测视网膜中TrkB、p-ERK1/2以及c-fos蛋白质的质量浓度. 结果 糖尿病对照组大鼠视网膜中BDNF阳性细胞数目明显少于正常对照组及BDNF治疗组,且染色浅,3个组BDNF阳性细胞数及阳性细胞灰度值比较差异均有统计学意义(F=102.36、92.55,P<0.05).3个组TrkB、p-ERK1/2及c-fos表达的比较,差异均有统计学意义( F=92.54、95.46、94.84,P<0.05).糖尿病对照组较正常对照组及BDNF治疗组TrkB质量浓度降低,而通路蛋白p-ERK1/2、c-fos质量浓度升高(P<0.05);正常对照组与BDNF治疗组间上述3个指标比较差异均无统计学意义(P>0.05).结论 在糖尿病早期,大鼠视网膜中BDNF mRNA水平及其受体TrkB蛋白质量浓度降低,其下游通路蛋白p-ERK1/2、c -fos质量浓度升高,玻璃体腔内注射BDNF可逆转上述变化.%Background Recent studies showed that diabetic retinal neuropathy is an earlier and more dangerous complication and neurotrophin has a protective effect on retina. Objective The present study was to observe the changes of brain derived neurotrophic factor (BDNF),its receptor TrkB,signal pathway protein

  9. Suppression of autoimmune retinal inflammation by an antiangiogenic drug.

    Directory of Open Access Journals (Sweden)

    Takeru Yoshimura

    Full Text Available Chronic and recurrent uveitis account for approximately 10% of legal blindness in the western world. Autoimmune uveitis is driven by activated CD4(+ T cells that differentiate into effector T helper cells (Th1, Th2, and Th17 which release proinflammatory cytokines that damage the retina. In this study we investigated the effect of the methionine aminopeptidase 2 (MetAP2 inhibitor, Lodamin, on T cell activation and differentiation. MetAp2 is an enzyme which regulates cellular protein synthesis and is highly expressed in T cells. Lodamin was found to suppress T cell receptor (TCR mediated T cell proliferation and reduced the production of Th1 and Th17 cells. Further, Lodamin suppressed overall inflammation in the mouse model of experimental autoimmune uveitis (EAU by a six fold. This effect was attributed in part to a reduction in retinal proinflammatory cytokines, down regulation of MetAP2 expression in purified lymph node CD4(+ T cells, and a general normalization of the systemic immune reaction.

  10. Potentiating action of propofol at GABAA receptors of retinal bipolar cells

    DEFF Research Database (Denmark)

    Yue, Lan; Xie, An; Bruzik, Karol S

    2011-01-01

    Purpose. Propofol (2,6-diisopropyl phenol), a widely used systemic anesthetic, is known to potentiate GABA(A) receptor activity in a number of CNS neurons and to produce changes in electroretinographically recorded responses of the retina. However, little is known about propofol's effects...... on specific retinal neurons. The authors investigated the action of propofol on GABA-elicited membrane current responses of retinal bipolar cells, which have both GABA(A) and GABA(C) receptors. Methods. Single, enzymatically dissociated bipolar cells obtained from rat retina were treated with propofol...... delivered by brief application in combination with GABA or other pharmacologic agents or as a component of the superfusing medium. Results. When applied with GABA at subsaturating concentrations and with TPMPA (a known GABA(C) antagonist), propofol markedly increased the peak amplitude and altered...

  11. 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.

  12. 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.

  13. Retinal microvascular abnormalities and stroke: a systematic review

    NARCIS (Netherlands)

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

    2009-01-01

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

  14. 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...

  15. Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

    Directory of Open Access Journals (Sweden)

    Renata Angeli

    2009-01-01

    Full Text Available A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A and Cratylia mollis (Cramoll 1 and Cramoll 1,4 did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.

  16. Purification of Bovine Interphotoreceptor Retinoidbinding Protein and Its Uveitogenicity in Lewis Rats

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EA...

  17. 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.

  18. Stem Cell Therapies in Retinal Disorders

    Directory of Open Access Journals (Sweden)

    Aakriti Garg

    2017-02-01

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

  19. Retinal haemorrhages in vacuum extraction deliveries

    Directory of Open Access Journals (Sweden)

    Bahgat Mostafa

    1987-01-01

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

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

    Science.gov (United States)

    Kohl, S; Biskup, S

    2013-03-01

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