Retinal pigment epithelial dystrophy in Briard dogs.

Science.gov (United States)

Lightfoot, R M; Cabral, L; Gooch, L; Bedford, P G; Boulton, M E

1996-01-01

The eyes of normal Briard dogs, Briards affected with inherited retinal pigment epithelial dystrophy (RPED) and a range of normal crossbred and beagle dogs were examined and the histopathology of RPED in the Briard was compared with the histopathological features of ageing in the normal canine retina. RPED was characterised by the accumulation of auto-fluorescent lipofuscin-like inclusions in the retinal pigment epithelium (RPE), which initially involved only non-pigmented RPE cells overlying the tapetum but subsequently spread to all pigmented RPE cells. Secondary neuro-retinal degeneration was characterised by a gradual loss of the outer nuclear layer and the subsequent atrophy and degeneration of the inner retina. The loss of primary photoreceptors in the peripheral retina was accompanied by the migration of photoreceptor nuclei and appeared to resemble severe changes due to ageing. Intra-vitreal radiolabelled leucine was used to examine the rate of turnover of the outer segments of the rods in some Briards, but no significant variations were found. The activity of acid phosphatase in RPE was assayed in vitro and showed comparable regional variations in Briard and crossbred dogs. The results suggest that RPED in the Briard is unlikely to be due either to an increased rate of turnover of rod outer segments (and thus an increased phagocytic load) or to a primary insufficiency of lysosomal enzyme.

Natural history of drusenoid pigment epithelial detachment in age-related macular degeneration: Age-Related Eye Disease Study Report No. 28.

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Cukras, Catherine; Agrón, Elvira; Klein, Michael L; Ferris, Frederick L; Chew, Emily Y; Gensler, Gary; Wong, Wai T

2010-03-01

To describe the natural history of eyes with drusenoid pigment epithelial detachments (DPEDs) associated with age-related macular degeneration (AMD). Multicenter, clinic-based, prospective cohort study. Among 4757 participants enrolled in the Age-Related Eye Disease Study (AREDS), 255 were identified as having DPED in at least 1 eye and having 5 or more years of follow-up after the initial detection of the DPED. Baseline and annual fundus photographs were evaluated for the evolution of the fundus features and the development of advanced AMD in the forms of central geographic atrophy (CGA) or neovascular (NV) AMD. Kaplan-Meier analyses of progression to advanced AMD and of moderate vision loss (> or =15 letters compared with baseline) were performed. Rate of progression to advanced AMD and change in visual acuity from baseline (in terms of mean letters lost and proportion losing > or =15 letters). A total of 311 eyes (from 255 participants) with DPED were followed for a median follow-up time of 8 years subsequent to the initial detection of a DPED. Of the 282 eyes that did not have advanced AMD at baseline, advanced AMD developed within 5 years in 119 eyes (42%) (19% progressing to CGA and 23% progressing to NV-AMD). In the remaining eyes that did not develop advanced AMD (n=163), progressive fundus changes, typified by the development of calcified drusen and pigmentary changes, were detected. Visual decline was prominent among study eyes, with approximately 40% of all eyes decreasing in visual acuity by > or =15 letters at 5 years follow-up. Mean visual acuity decreased from 76 letters ( approximately 20/30) at baseline to 61 letters ( approximately 20/60) at 5 years. Five-year decreases in mean visual acuity averaged 26 letters for eyes progressing to advanced AMD and 8 letters for non-progressing eyes. The natural history of eyes containing DPED is characterized by a high rate of progression to both CGA and NV-AMD. Among eyes not progressing to advanced AMD

Overexpression of Snail in retinal pigment epithelial triggered epithelial–mesenchymal transition

International Nuclear Information System (INIS)

Li, Hui; Li, Min; Xu, Ding; Zhao, Chun; Liu, Guodong; Wang, Fang

2014-01-01

Highlights: • First reported overexpression of Snail in RPE cells could directly trigger EMT. • Further confirmed the regulator role of Snail in RPE cells EMT in vitro. • Snail may be a potential therapeutic target to prevent the fibrosis of PVR. - Abstract: Snail transcription factor has been implicated as an important regulator in epithelial–mesenchymal transition (EMT) during tumourigenesis and fibrogenesis. Our previous work showed that Snail transcription factor was activated in transforming growth factor β1 (TGF-β1) induced EMT in retinal pigment epithelial (RPE) cells and may contribute to the development of retinal fibrotic disease such as proliferative vitreoretinopathy (PVR). However, whether Snail alone has a direct role on retinal pigment epithelial–mesenchymal transition has not been investigated. Here, we analyzed the capacity of Snail to drive EMT in human RPE cells. A vector encoding Snail gene or an empty vector were transfected into human RPE cell lines ARPE-19 respectively. Snail overexpression in ARPE-19 cells resulted in EMT, which was characterized by the expected phenotypic transition from a typical epithelial morphology to mesenchymal spindle-shaped. The expression of epithelial markers E-cadherin and Zona occludin-1 (ZO-1) were down-regulated, whereas mesenchymal markers a-smooth muscle actin (a-SMA) and fibronectin were up-regulated in Snail expression vector transfected cells. In addition, ectopic expression of Snail significantly enhanced ARPE-19 cell motility and migration. The present data suggest that overexpression of Snail in ARPE-19 cells could directly trigger EMT. These results may provide novel insight into understanding the regulator role of Snail in the development of retinal pigment epithelial–mesenchymal transition

Combined Laser Treatment in a Patient with Pigment Dispersion Secondary to a Large Iris Pigment Epithelial Cyst

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Özlem Yıldırım

2012-09-01

Full Text Available We reported a case of bilateral extensive iris pigment epithelial cysts masquerading as pigment dispersion. A-30-year-old male patient presented with a dull pain in both eyes and a decreased visual acuity OD. He underwent a complete ophthalmic examination. OD was injected and the cells were graded as +3 and pigmented a +2, in the OS. Intraocular pressures (IOP were measured as 42 (OD and 22 (OS mmHg. Gonioscopy revealed a confluent accumulation of dense pigment in both eyes. Visual fields, peripapillary retinal nerve fiber layer thickness (Spectral OCT/SLO OTI-OPKO Health. Inc, Miami, FL and optic nerve head tomography (HRT-II Heidelberg Engineering, Heidelberg, Germany results were within normal limits. On ultrasound biomicroscopy (UBM, bilateral extensive cysts were identified in the midzonal portion of the iris and in the ciliary body. An, antiglaucomatous treatment was started. Then, we decided to perform both Nd:YAG laser iridocystotomyc and selective laser trabeculoplasty. Fourteen months after the combined therapy, the cysts had not recurred, and still apposed and the IOPs were under control without medication.

Combined laser treatment in a patient with pigment dispersion secondary to a large iris pigment epithelial cyst.

Science.gov (United States)

Aykan, Umit; Yıldırım, Ozlem

2012-09-01

We reported a case of bilateral extensive iris pigment epithelial cysts masquerading as pigment dispersion. A-30-year-old male patient presented with a dull pain in both eyes and a decreased visual acuity OD. He underwent a complete ophthalmic examination. OD was injected and the cells were graded as +3 and pigmented a +2, in the OS. Intraocular pressures (IOP) were measured as 42 (OD) and 22 (OS) mmHg. Gonioscopy revealed a confluent accumulation of dense pigment in both eyes. Visual fields, peripapillary retinal nerve fiber layer thickness (Spectral OCT/SLO OTI-OPKO Health. Inc, Miami, FL) and optic nerve head tomography (HRT-II Heidelberg Engineering, Heidelberg, Germany) results were within normal limits. On ultrasound biomicroscopy (UBM), bilateral extensive cysts were identified in the midzonal portion of the iris and in the ciliary body. An, antiglaucomatous treatment was started. Then, we decided to perform both Nd:YAG laser iridocystotomyc and selective laser trabeculoplasty. Fourteen months after the combined therapy, the cysts had not recurred, and still apposed and the IOPs were under control without medication.

Differentiation of Pluripotent Stem Cells to Retinal Pigment Epithelial Cells: An Approach Toward Retinal Degenerative Diseases Treatment

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Maryam Parvini

2013-10-01

Full Text Available Pluripotent stem cells as the cells with a capacity for self-renewal and differentiation into various specificcell types have been highly regarded in regenerative medicine studies. To repair the eye disease damages, thedifferentiation into retinal pigment epithelial cells of pluripotent stem cells has gained great importance inrecent decades because the inappropriate function of these cells is the main cause of degenerative diseases suchas the age-related macular degeneration. Millions of people in the world suffer this disease.To restore the damaged cells and, finally, to improve the vision, numerous studies have been conducted on usingpluripotent stem cells, their differentiation into retinal pigment epithelial cells, and finally, their applicationin cell therapy. Based on this, many researchers have attempted to produce highly efficient retinal pigmentepithelial cells, such that they show a proper function after transplant, along with the host cells. In this reviewarticle, the importance and the role of pigment epithelial cells, as well as, the studies on the in vitro productionof these cells were examined

Retinal Pigment Epithelial Tears in the Era of Intravitreal Pharmacotherapy: Risk Factors, Pathogenesis, Prognosis and Treatment (An American Ophthalmological Society Thesis)

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Sarraf, David; Joseph, Anthony; Rahimy, Ehsan

2014-01-01

Purpose: To describe the risk factors, pathogenesis, and prognosis of retinal pigment epithelial (RPE) tears and to demonstrate our hypothesis that continued anti–vascular endothelial growth factor (VEGF) therapy after an RPE tear has occurred correlates with improved long-term visual and anatomical outcomes. Methods: We searched a database of 10,089 patients and retrospectively identified a large case series of 56 eyes with neovascular age-related macular degeneration (AMD) complicated by an RPE tear over an 8-year period. Baseline visual acuity (VA) was tabulated and analysis of the RPE tear was performed with multimodal imaging. Follow-up VA, progression of the tear, and severity of fibrosis were evaluated, and each was correlated with number of anti-VEGF injections. Results: Average follow-up for the 56 eyes was 42 months, and mean logMAR VA at baseline was 0.88 (Snellen VA 20/150) with minimal decline over 3 years. LogMAR VA plotted against number of anti-VEGF injections demonstrated that more frequent and cumulative injections correlated with better VA (Ptear, reduced fibrosis, and lower risk of a large, end-stage exudative disciform scar. Conclusions: Fifteen to 20% of vascularized pigment epithelial detachments (PEDs) may develop RPE tears after anti-VEGF therapy due to progressive contraction of the type 1 choroidal neovascular membrane in a PED at risk. Continued monitoring of RPE tears for exudative changes warranting anti-VEGF therapy may stabilize VA, improve anatomical outcomes, reduce fibrosis, and decrease the risk of developing a large blinding end-stage exudative disciform scar. PMID:25646033

Resveratrol inhibits transforming growth factor-β2-induced epithelial-to-mesenchymal transition in human retinal pigment epithelial cells by suppressing the Smad pathway

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Chen CL

2017-01-01

Full Text Available Ching-Long Chen,1,2 Yi-Hao Chen,1,2 Ming-Cheng Tai,2 Chang-Min Liang,2 Da-Wen Lu,1,2 Jiann-Torng Chen1,2 1Graduate Institute of Medical Science, National Defense Medical Center, Taipei, Taiwan; 2Department of Ophthalmology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan Abstract: Proliferative vitreoretinopathy (PVR is the main cause of failure following retinal detachment surgery. Transforming growth factor (TGF-β2-induced epithelial-to-mesenchymal transition (EMT plays an important role in the development of PVR, and EMT inhibition decreases collagen gel contraction and fibrotic membrane formation, resulting in prevention of PVR. Resveratrol is naturally found in red wine and has inhibitory effects on EMT. Resveratrol is widely used in cardioprotection, neuroprotection, chemotherapy, and antiaging therapy. The purpose of this study was to investigate the effects of resveratrol on TGF-β2-induced EMT in ARPE-19 cells in vitro. We found that resveratrol suppressed the decrease of zona occludens-1 (ZO-1 and caused an increase of alpha-smooth muscle actin expression in TGF-β2-treated ARPE-19 cells, assessed using Western blots; moreover, it also suppressed the decrease in ZO-1 and the increase of vimentin expression, observed using immunocytochemistry. Resveratrol attenuated TGF-β2-induced wound closure and cell migration in ARPE-19 cells in a scratch wound test and modified Boyden chamber assay, respectively. We also found that resveratrol reduced collagen gel contraction – assessed by collagen matrix contraction assay – and suppressed the phosphorylation of Smad2 and Smad3 in TGF-β2-treated ARPE-19 cells. These results suggest that resveratrol mediates anti-EMT effects, which could be used in the prevention of PVR. Keywords: resveratrol, epithelial-to-mesenchymal transition, proliferative vitreoretinopathy, transforming growth factor-β2, retinal pigment epithelial cells

Ultrastructural analysis of the pigment dispersion syndrome in DBA/2J mice.

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Schraermeyer, Mareike; Schnichels, Sven; Julien, Sylvie; Heiduschka, Peter; Bartz-Schmidt, Karl-Ulrich; Schraermeyer, Ulrich

2009-11-01

To characterise ocular pigment abnormalities associated with iris atrophy in DBA/2J mice as a model for human pigment dispersion syndrome. Immunohistochemistry, electron and light microscopy were performed to examine the eyes of DBA/2J mice ranging in age from 2.5 to 18 months old. The focus of our study was the description of the ultrastructural modifications in the irides of DBA/2J mice. The DBA/2J mice presented modifications in the melanosomes in all the pigmented parts of the eye, including the retinal pigment epithelial cells and choroidal melanocytes of the ciliary pigment epithelium. The extracellular matrix of the iris stroma disappeared with ageing. Pigmented cells detached from the iris and migrated into the trabecular meshwork exclusively on the anterior iris surface. These cells were identified as macrophages by immunohistochemistry and electron microscopy. There was no evidence that melanocytes or iris pigment epithelial cells migrated into the trabecular meshwork, but they became more and more depigmented. The aqueous outflow was blocked by pigment-laden cells, but not by cellular debris or melanosomes. No substantial amount of extracellular melanosomes was observed. The morphology of melanosomes is aberrant in all pigment cells in the eyes of DBA/2J mice. We conclude that the disease process begins with the transfer of both immature melanosomes from the iris pigment epithelium (IPE) and melanocytes to macrophages, which subsequently migrate into the trabecular meshwork. Accumulating macrophages cause a blockade of the chamber angle. As the disease progresses, the IPE, melanocytes and iris stroma, including blood vessels, disappear, leading to iris atrophy. It is speculated that the loss of these pigment cells is partly caused by reduction of the iris stroma.

Guanine nucleotide-binding regulatory proteins in retinal pigment epithelial cells.

OpenAIRE

Jiang, M; Pandey, S; Tran, V T; Fong, H K

1991-01-01

The expression of GTP-binding regulatory proteins (G proteins) in retinal pigment epithelial (RPE) cells was analyzed by RNA blot hybridization and cDNA amplification. Both adult and fetal human RPE cells contain mRNA for multiple G protein alpha subunits (G alpha) including Gs alpha, Gi-1 alpha, Gi-2 alpha, Gi-3 alpha, and Gz alpha (or Gx alpha), where Gs and Gi are proteins that stimulate or inhibit adenylyl cyclase, respectively, and Gz is a protein that may mediate pertussis toxin-insensi...

Spontaneous or secondary to intravitreal injections of anti-angiogenic agents retinal pigment epithelial tears in age-related macular degeneration

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Pia E. Leon

2014-08-01

Full Text Available AIM:To evaluate the visual function evolution of retinal pigment epithelial (RPE tears in patients with age-related macular degeneration (AMD according to type of occurrence [spontaneous or secondary to anti-vascular endothelial growth factor (anti-VEGF injection] and the topographic location of the tear after a two-year follow-up period.METHODS:A total of 15 eyes of 14 patients with RPE tears in exudative AMD were analyzed retrospectively at the University Eye Clinic of Trieste. Inclusion criteria were:patient age of 50 or older with AMD and RPE tears both spontaneous occurring or post anti-VEGF treatment. Screening included:careful medical history, complete ophthalmological examination, fluorescein angiography (FA, indocyanine green angiography (ICG, autofluorescence and infrared imaging and optical coherence tomography (OCT. Patients were evaluated every month for visual acuity (VA, fundus examination and OCT. Other data reported were:presence of PED, number of injections before the tear, location of the lesion.RESULTS: Mean follow-up was 24wk (SD±4wk. A total of 15 eyes were studied for RPE tear. In 6 cases (40%, the RPE tears occurred within two years of anti-VEGF injections the others occurred spontaneously. In 13 cases (86.6%, the RPE tear was associated with pigment epithelial detachment (PED. In 7 cases (46.6%, the RPE tear occurred in the central area of the retina and involved the fovea. Two lesions were found in the parafoveal region, six in the extra-macular area. In all cases visual acuity decreased at the end of the follow-up period (P<0.01 independently of the type or the topographical location of the lesion.CONCLUSION:RPE tear occurs in exudative AMD as a spontaneous complication or in relation to anti-VEGF injections. Visual acuity decreased significantly and gradually in the follow-up period in all cases. No correlation was found between visual loss and the type of onset or the topographic location of the tears.

Differential behavioral outcomes following neonatal versus fetal human retinal pigment epithelial cell striatal implants in parkinsonian rats

DEFF Research Database (Denmark)

Russ, Kaspar; Flores, Joseph; Brudek, Tomasz

2017-01-01

Following the failure of a Phase II clinical study evaluating human retinal pigment epithelial (hRPE) cell implants as a potential treatment option for Parkinson's disease, speculation has centered on implant function and survival as possible contributors to the therapeutic outcomes. We recently ...

Repair mechanism of retinal pigment epithelial tears in age-related macular degeneration.

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Mukai, Ryo; Sato, Taku; Kishi, Shoji

2015-03-01

To investigate repair mechanisms of retinal pigment epithelial (RPE) tears in age-related macular degeneration. The authors retrospectively studied 10 eyes with age-related macular degeneration that developed RPE tears during follow-up or after treatment with an anti-vascular endothelial growth factor drug or photodynamic therapy combined with ranibizumab. After development of the RPE tears, all follow-ups exceeded 13 months. Spectral domain or swept-source optical coherence tomography have been used to examine consecutive retinal changes where the RPE tears developed and attempted to determine the repair mechanisms. Retinal pigment epithelial tears developed during the natural course (n = 4) after ranibizumab treatment (n = 2) and after photodynamic therapy and ranibizumab (n = 4). Subretinal fluid persisted for more than 6 months after the RPE tears developed (n = 4), with the area where the RPE was lost found to be covered with thickened proliferative tissue. In 6 eyes where the subretinal fluid was absorbed within 2 months, optical coherence tomography showed the outer retina appeared to be directly attached to Bruch membrane, and there was attenuation of the normal hyperreflective band attributable to normal RPE during follow-up. Results suggest that two repair processes may be present in the area where RPE tears developed. Persistent subretinal fluid may lead to repair with thick proliferative tissue, while the outer retina appears to attach to Bruch membrane when there is early subretinal fluid resolution after RPE tear development.

Culture of Iris Pigment Epithelial Cells on Expanded-Polytetrafluroethylene (ePTFE Substrates for the Treatment of Age-Related Macular Degeneration

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S Nian

2011-05-01

Full Text Available Introduction: Transplantation of an intact differentiated retinal pigment epithelial (RPE cell layer may provide a means to treat Age-Related Macular Degeneration (AMD. However, harvesting RPE cells can be a technically complicated procedure. Our current work aimed to prepare intact differentiated iris pigment epithelial (IPE cell layers, which are easy to obtain and have the same embryonic origin and similar properties as RPE cells, on ePTFE substrates for transplantation purposes to rescue deteriorated photoreceptors in AMD. Methods: IPE cells isolated from rat eyes were seeded on different substrates, including fibronectin n-heptylamine (HA ePTFE substrates, HA ePTFE substrates, ePTFE substrates and fibronectin tissue culture polystyrene (TCPS as control. Cell number and morphology were assessed at each time interval. The formation of tight junction was examined by immunostaining of junction proteins. Results: An obvious increasing trend of cell number was observed in IPE cells on fibronectin n-heptylamine (HA ePTFE substrate, exhibiting heavy pigmentation and epithelial morphology. At Day 28, tight junction formation was indicated by cell-cell junctional proteins along cell borders. Conclusion: Harvested IPE cells cultured on fibronectin HA-ePTFE substrates can differentiate and form a cell monolayer that may be suitable for transplantation.

Retinal pigment epithelial cells upregulate expression of complement factors after co-culture with activated T cells

DEFF Research Database (Denmark)

Juel, Helene Bæk; Kaestel, Charlotte; Folkersen, Lasse

2011-01-01

In this study we examined the effect of T cell-derived cytokines on retinal pigment epithelial (RPE) cells with respect to expression of complement components. We used an in vitro co-culture system in which CD3/CD28-activated human T cells were separated from the human RPE cell line (ARPE-19...

Two-Year Outcome of Aflibercept in Patients with Pigment Epithelial Detachment due to Neovascular Age-Related Macular Degeneration (nAMD) Refractory to Ranibizumab

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Dumas, Stéphane; Coscas, Florence

2017-01-01

Purpose To evaluate the response of intravitreal aflibercept injection (IAI) in eyes with detachment of retinal pigment epithelium (DEP) secondary to nAMD refractory to monthly ranibizumab. Patients and Methods This is a retrospective, multicenter study. All patients received 3 IAI then treated as needed every 4 weeks for 12 months. During the second year, the eyes were treated with a treat- and-extend regimen. Results Forty-four eyes were included. Best-corrected visual acuity improved significantly after the loading phase (3.1 ± 6.4 letters) and at 6 months (2.8 ± 6.4 letters), but change was not significant at 1 year and 2 years. The height of the DEP was significantly decreased at 3 months and 6 months, but the difference did not reach statistical difference at 1 and 2 years. Rate of eyes with complete resolution of exudation was 59% after the loading phase and 34.3% at 2 years. Mean interval of anti-VEGF injection was extended from 31 ± 2.6 days to 61 ± 5 days after conversion. Conclusions Aflibercept intravitreal injection in patients with fibrovascular DEP due to nAMD who respond poorly to monthly ranibizumab led to short-term functional and anatomical improvement. Reduction of intravitreal injection frequency was obtained until 2 years of follow-up. PMID:29093970

Acute Retinal Pigment Epitheliitis: Spectral Domain Optical Coherence Tomography, Fluorescein Angiography, and Autofluorescence Findings

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Tuğba Aydoğan

2015-01-01

Full Text Available A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes’ best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF was slightly increased. Spectral domain optical coherence tomography (SD-OCT showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL. One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease.

Melanin targeting for intracellular drug delivery: Quantification of bound and free drug in retinal pigment epithelial cells.

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Rimpelä, Anna-Kaisa; Hagström, Marja; Kidron, Heidi; Urtti, Arto

2018-05-31

Melanin binding affects drug distribution and retention in pigmented ocular tissues, thereby affecting drug response, duration of activity and toxicity. Therefore, it is a promising possibility for drug targeting and controlled release in the pigmented cells and tissues. Intracellular unbound drug concentrations determine pharmacological and toxicological actions, but analyses of unbound vs. total drug concentrations in pigmented cells are lacking. We studied intracellular binding and cellular drug uptake in pigmented retinal pigment epithelial cells and in non-pigmented ARPE-19 cells with five model drugs (chloroquine, propranolol, timolol, diclofenac, methotrexate). The unbound drug fractions in pigmented cells were 0.00016-0.73 and in non-pigmented cells 0.017-1.0. Cellular uptake (i.e. distribution ratio Kp), ranged from 1.3 to 6300 in pigmented cells and from 1.0 to 25 in non-pigmented cells. Values for intracellular bioavailability, F ic , were similar in both cells types (although larger variation in pigmented cells). In vitro melanin binding parameters were used to predict intracellular unbound drug fraction and cell uptake. Comparison of predictions with experimental data indicates that other factors (e.g. ion-trapping, lipophilicity-related binding to other cell components) also play a role. Melanin binding is a major factor that leads to cellular uptake and unbound drug fractions of a range of 3-4 orders of magnitude indicating that large reservoirs of melanin bound drug can be generated in the cells. Understanding melanin binding has important implications on retinal drug targeting, efficacy and toxicity. Copyright © 2017. Published by Elsevier B.V.

Annular and central heavy pigment deposition on the posterior lens capsule in the pigment dispersion syndrome: pigment deposition on the posterior lens capsule in the pigment dispersion syndrome.

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Turgut, Burak; Türkçüoğlu, Peykan; Deniz, Nurettin; Catak, Onur

2008-12-01

To report annular and central heavy pigment deposition on the posterior lens capsule in a case of pigment dispersion syndrome. Case report. A 36-year-old female with bilateral pigment dispersion syndrome presented with progressive decrease in visual acuity in the right eye over the past 1-2 years. Clinical examination revealed the typical findings of pigment dispersion syndrome including bilateral Krunkenberg spindles, iris transillumination defects, and dense trabecular meshwork pigmentation. Remarkably, annular and central dense pigmentation of the posterior lens capsule was noted in the right eye. Annular pigment deposition on the posterior lens capsule may be a rare finding associated with pigment dispersion syndrome. Such a finding suggests that there may be aqueous flow into the retrolental space in some patients with this condition. The way of central pigmentation is the entrance of aqueous to Berger's space. In our case, it is probable that spontaneous detachment of the anterior hyaloid membrane aided this entrance.

Poly(trimethylene carbonate) as an elastic biodegradable film for human embryonic stem cell-derived retinal pigment epithelial cells

NARCIS (Netherlands)

Sorkio, Anni; Haimi, Suvi; Verdoold, Vincent; Juuti-Uusitalo, Kati; Grijpma, Dirk; Skottman, Heli

2017-01-01

Human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cell therapies show tremendous potential for the treatment of retinal degenerative diseases. A tissue engineering approach, where cells are delivered to the subretinal space on a biodegradable carrier as a sheet, shows great

Poly(trimethylene carbonate) as an elastic biodegradable film for human embryonic stem cell-derived retinal pigment epithelial cells

NARCIS (Netherlands)

Sorkio, Anni; Haimi, Suvi; Verdoold, Vincent; Juuti-Uusitalo, Kati; Grijpma, Dirk; Skottman, Heli

Human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cell therapies show tremendous potential for the treatment of retinal degenerative diseases. A tissue engineering approach, where cells are delivered to the subretinal space on a biodegradable carrier as a sheet, shows great

[Bilateral spontaneously reattached rhegmatogenous retinal detachment. Case report and differential diagnosis with pigmentary retinopathies].

Science.gov (United States)

García-Guzmán, Jorge Guillermo; Franco-Yáñez, Yasmín; Lima-Gómez, Virgilio

2014-01-01

A dark pigmentation of the ocular fundus presents in degenerative diseases such as retinitis pigmentosa; this disease must be distinguished from others whose evolution is not progressive, in order to estimate the functional prognosis of the patient. To analyze the features which distinguish spontaneously reattached retinal detachment from other causes of ocular fundus pigmentation, in order to be able to identify it even in bilateral cases. A case of a female with chronic visual loss is presented, who was referred for evaluation with the diagnosis of a pigmented retinopathy. Clinical exploration discarded causes as retinitis pigmentosa, retinal inflammatory diseases or trauma. Based on the clinical features, on the topography of pigmentation and in the information provided by electroretinography, a bilateral spontaneous reattachment of rhegmatogenous retinal detachment was diagnosed made. Clinical features of this entity are discussed, as well as the diagnostic approach to distinguish it from other pigment retinopathies. Clinical features of spontaneously reattached retinal detachment allow the explorer to distinguish it from other causes of bilateral pigmentation, despite presenting bilaterally. Since the prognosis of the attached retina is better than that of a degenerative disease, the correct diagnosis makes rehabilitation easier.

Lattice degeneration of the retina and the pigment dispersion syndrome.

Science.gov (United States)

Weseley, P; Liebmann, J; Walsh, J B; Ritch, R

1992-11-15

Retinal detachment occurs more frequently in patients with pigment dispersion syndrome. We evaluated the incidence of peripheral retinal abnormalities known to predispose to rhegmatogenous retinal detachment in a consecutive series of 60 patients with pigment dispersion syndrome with or without glaucoma. Lattice degeneration was present in at least one eye of 12 patients (20%). Seven patients had bilateral lesions. Full-thickness retinal breaks were found in seven patients (11.7%) and two patients (3.3%) had asymptomatic rhegmatogenous retinal detachments that required scleral buckle procedures. The incidence of lattice degeneration and full-thickness retinal breaks appears to be increased in this group of patients, and may be responsible for the increased risk of rhegmatogenous detachment.

Structure and barrier properties of human embryonic stem cell-derived retinal pigment epithelial cells are affected by extracellular matrix protein coating.

Science.gov (United States)

Sorkio, Anni; Hongisto, Heidi; Kaarniranta, Kai; Uusitalo, Hannu; Juuti-Uusitalo, Kati; Skottman, Heli

2014-02-01

Extracellular matrix (ECM) interactions play a vital role in cell morphology, migration, proliferation, and differentiation of cells. We investigated the role of ECM proteins on the structure and function of human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells during their differentiation and maturation from hESCs into RPE cells in adherent differentiation cultures on several human ECM proteins found in native human Bruch's membrane, namely, collagen I, collagen IV, laminin, fibronectin, and vitronectin, as well as on commercial substrates of xeno-free CELLstart™ and Matrigel™. Cell pigmentation, expression of RPE-specific proteins, fine structure, as well as the production of basal lamina by hESC-RPE on different protein coatings were evaluated after 140 days of differentiation. The integrity of hESC-RPE epithelium and barrier properties on different coatings were investigated by measuring transepithelial resistance. All coatings supported the differentiation of hESC-RPE cells as demonstrated by early onset of cell pigmentation and further maturation to RPE monolayers after enrichment. Mature RPE phenotype was verified by RPE-specific gene and protein expression, correct epithelial polarization, and phagocytic activity. Significant differences were found in the degree of RPE cell pigmentation and tightness of epithelial barrier between different coatings. Further, the thickness of self-assembled basal lamina and secretion of the key ECM proteins found in the basement membrane of the native RPE varied between hESC-RPE cultured on compared protein coatings. In conclusion, this study shows that the cell culture substrate has a major effect on the structure and basal lamina production during the differentiation and maturation of hESC-RPE potentially influencing the success of cell integrations and survival after cell transplantation.

Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin

OpenAIRE

Johnson, Adam S; Garc?a, Dana M

2007-01-01

Abstract Background Inside bluegill (Lepomis macrochirus) retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog) is one example. Previous research indicates that the ca...

Toxicity and detoxification of lipid-derived aldehydes in cultured retinal pigmented epithelial cells

International Nuclear Information System (INIS)

Choudhary, S.; Xiao, T.; Srivastava, S.; Zhang, W.; Chan, L.L.; Vergara, L.A.; Van Kuijk, F.J.G.M.; Ansari, N.H.

2005-01-01

Age-related macular degeneration (ARMD) is the leading cause of blindness in the developed world and yet its pathogenesis remains poorly understood. Retina has high levels of polyunsaturated fatty acids (PUFAs) and functions under conditions of oxidative stress. To investigate whether peroxidative products of PUFAs induce apoptosis in retinal pigmented epithelial (RPE) cells and possibly contribute to ARMD, human retinal pigmented epithelial cells (ARPE-19) were exposed to micromolar concentrations of H 2 O 2 , 4-hydroxynonenal (HNE) and 4-hydroxyhexenal (HHE). A concentration- and time-dependent increase in H 2 O 2 -, HNE-, and HHE-induced apoptosis was observed when monitored by quantifying DNA fragmentation as determined by ELISA, flow cytometry, and Hoechst staining. The broad-spectrum inhibitor of apoptosis Z-VAD inhibited apoptosis. Treatment of RPE cells with a thionein peptide prior to exposure to H 2 O 2 or HNE reduced the formation of protein-HNE adducts as well as alteration in mitochondrial membrane potential and apoptosis. Using 3 H-HNE, various metabolic pathways to detoxify HNE by ARPE-19 cells were studied. The metabolites were separated by HPLC and characterized by ElectroSpray Ionization-Mass Spectrometry (ESI-MS) and gas chromatography-MS. Three main metabolic routes of HNE detoxification were detected: (1) conjugation with glutathione (GSH) to form GS-HNE, catalyzed by glutathione-S-transferase (GST) (2) reduction of GS-HNE catalyzed by aldose reductase, and (3) oxidation of HNE catalyzed by aldehyde dehydrogenase (ALDH). Preventing HNE formation by a combined strategy of antioxidants, scavenging HNE by thionein peptide, and inhibiting apoptosis by caspase inhibitors may offer a potential therapy to limit retinal degeneration in ARMD

Adenovirus-Mediated Delivery of Catalase to Retinal Pigment Epithelial Cells Protects Neighboring Photoreceptors from Photo-Oxidative Stress

OpenAIRE

Rex, T.S.; Tsui, I.; Hahn, P.; Maguire, A.M.; Duan, D.; Bennett, J.; Dunaief, J.L.

2004-01-01

Oxidative stress is involved in the pathogenesis of many diseases. Overexpression of antioxidant enzymes by gene therapy may protect tissues from oxidative damage. Because the reactive oxygen species hydrogen peroxide can diffuse across cell membranes, we hypothesized that overexpression of the antioxidant catalase within certain cells might protect neighboring cells. To test this hypothesis, we transduced retinal pigment epithelial (RPE) cells in vitro and in vivo with adenovirus carrying th...

Two-photon excited autofluorescence imaging of human retinal pigment epithelial cells

Science.gov (United States)

Han, Meng; Blindewald-Wittich, Almut; Holz, Frank G.; Giese, Günter; Niemz, Markolf H.; Snyder, Sarah; Sun, Hui; Yu, Jiayi; Agopov, Michael; La Schiazza, Olivier; Bille, Josef F.

2006-01-01

Degeneration of retinal pigment epithelial (RPE) cells severely impairs the visual function of retina photoreceptors. However, little is known about the events that trigger the death of RPE cells at the subcellular level. Two-photon excited autofluorescence (TPEF) imaging of RPE cells proves to be well suited to investigate both the morphological and the spectral characteristics of the human RPE cells. The dominant fluorophores of autofluorescence derive from lipofuscin (LF) granules that accumulate in the cytoplasm of the RPE cells with increasing age. Spectral TPEF imaging reveals the existence of abnormal LF granules with blue shifted autofluorescence in RPE cells of aging patients and brings new insights into the complicated composition of the LF granules. Based on a proposed two-photon laser scanning ophthalmoscope, TPEF imaging of the living retina may be valuable for diagnostic and pathological studies of age related eye diseases.

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...

Rapid, Directed Differentiation of Retinal Pigment Epithelial Cells from Human Embryonic or Induced Pluripotent Stem Cells

OpenAIRE

Foltz, LP; Clegg, DO

2017-01-01

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing a detailed and thorough protocol is to clearly demonstrate each step and to make this readily available to researchers in the field. This protocol results in a homogenous layer of RPE with minimal or no manual dissection needed. The method presented here has been shown to be effective for induced pluripotent stem cells (iPSC) and human embry...

Retinal pigment epithelial cell multinucleation in the aging eye - a mechanism to repair damage and maintain homoeostasis.

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Chen, Mei; Rajapakse, Dinusha; Fraczek, Monika; Luo, Chang; Forrester, John V; Xu, Heping

2016-06-01

Retinal pigment epithelial (RPE) cells are central to retinal health and homoeostasis. Dysfunction or death of RPE cells underlies many age-related retinal degenerative disorders particularly age-related macular degeneration. During aging RPE cells decline in number, suggesting an age-dependent cell loss. RPE cells are considered to be postmitotic, and how they repair damage during aging remains poorly defined. We show that RPE cells increase in size and become multinucleate during aging in C57BL/6J mice. Multinucleation appeared not to be due to cell fusion, but to incomplete cell division, that is failure of cytokinesis. Interestingly, the phagocytic activity of multinucleate RPE cells was not different from that of mononuclear RPE cells. Furthermore, exposure of RPE cells in vitro to photoreceptor outer segment (POS), particularly oxidized POS, dose-dependently promoted multinucleation and suppressed cell proliferation. Both failure of cytokinesis and suppression of proliferation required contact with POS. Exposure to POS also induced reactive oxygen species and DNA oxidation in RPE cells. We propose that RPE cells have the potential to proliferate in vivo and to repair defects in the monolayer. We further propose that the conventionally accepted 'postmitotic' status of RPE cells is due to a modified form of contact inhibition mediated by POS and that RPE cells are released from this state when contact with POS is lost. This is seen in long-standing rhegmatogenous retinal detachment as overtly proliferating RPE cells (proliferative vitreoretinopathy) and more subtly as multinucleation during normal aging. Age-related oxidative stress may promote failure of cytokinesis and multinucleation in RPE cells. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

[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.

High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

Energy Technology Data Exchange (ETDEWEB)

Lengyel,I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

2007-01-01

One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.

High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

International Nuclear Information System (INIS)

Lengyel, I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

2007-01-01

One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD

Suppressive effect of AMP-activated protein kinase on the epithelial-mesenchymal transition in retinal pigment epithelial cells.

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Ryo Matoba

Full Text Available The epithelial-mesenchymal transition (EMT in retinal pigment epithelial (RPE cells plays a central role in the development of proliferative vitreoretinopathy (PVR. The purpose of this study was to investigate the effect of AMP-activated protein kinase (AMPK, a key regulator of energy homeostasis, on the EMT in RPE cells. In this study, EMT-associated formation of cellular aggregates was induced by co-stimulation of cultured ARPE-19 cells with tumor necrosis factor (TNF-α (10 ng/ml and transforming growth factor (TGF-β2 (5 ng/ml. 5-Aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR, a potent activator of AMPK, significantly suppressed TNF-α and TGF-β2-induced cellular aggregate formation (p < 0.01. Dipyridamole almost completely reversed the suppressive effect of AICAR, whereas 5'-amino-5'-deoxyadenosine restored aggregate formation by approximately 50%. AICAR suppressed the downregulation of E-cadherin and the upregulation of fibronectin and α-smooth muscle actin by TNF-α and TGF-β2. The levels of matrix metalloproteinase (MMP-2, MMP-9, interleukin-6, and vascular endothelial growth factor were significantly decreased by AICAR. Activation of the mitogen-activated protein kinase and mammalian target of rapamycin pathways, but not the Smad pathway, was inhibited by AICAR. These findings indicate that AICAR suppresses the EMT in RPE cells at least partially via activation of AMPK. AMPK is a potential target molecule for the prevention and treatment of PVR, so AICAR may be a promising candidate for PVR therapy.

Thrombin induces epithelial-mesenchymal transition and collagen production by retinal pigment epithelial cells via autocrine PDGF-receptor signaling.

Science.gov (United States)

Bastiaans, Jeroen; van Meurs, Jan C; van Holten-Neelen, Conny; Nagtzaam, Nicole M A; van Hagen, P Martin; Chambers, Rachel C; Hooijkaas, Herbert; Dik, Willem A

2013-12-19

De-differentiation of RPE cells into mesenchymal cells (epithelial-mesenchymal transition; EMT) and associated collagen production contributes to development of proliferative vitreoretinopathy (PVR). In patients with PVR, intraocular coagulation cascade activation occurs and may play an important initiating role. Therefore, we examined the effect of the coagulation proteins factor Xa and thrombin on EMT and collagen production by RPE cells. Retinal pigment epithelial cells were stimulated with factor Xa or thrombin and the effect on zonula occludens (ZO)-1, α-smooth muscle actin (α-SMA), collagen, and platelet-derived growth factor (PDGF)-B were determined by real-time quantitative-polymerase chain reaction (RQ-PCR), immunofluorescence microscopy, and HPLC and ELISA for collagen and PDGF-BB in culture supernatants, respectively. PDGF-receptor activation was determined by phosphorylation analysis and inhibition studies using the PDGF-receptor tyrosine kinase inhibitor AG1296. Thrombin reduced ZO-1 gene expression (P production of α-SMA and collagen increased. In contrast to thrombin, factor Xa hardly stimulated EMT by RPE. Thrombin clearly induced PDGF-BB production and PDGF-Rβ chain phosphorylation in RPE. Moreover, AG1296 significantly blocked the effect of thrombin on EMT and collagen production. Our findings demonstrate that thrombin is a potent inducer of EMT by RPE via autocrine activation of PDGF-receptor signaling. Coagulation cascade-induced EMT of RPE may thus contribute to the formation of fibrotic retinal membranes in PVR and should be considered as treatment target in PVR.

Lack of FasL expression in cultured human retinal pigment epithelial cells

DEFF Research Database (Denmark)

Kaestel, C G; Madsen, H O; Prause, J U

2001-01-01

Retinal pigment epithelial (RPE) cells have been proposed to play a part in maintaining the eye as an immune privileged organ. However, our knowledge of the implicated mechanism is still sparse. Fas ligand (FasL) expression of RPE cells is generally recognized to be essential for the immune...... privilege of the eye, but due to contradictory published results, it is unclear whether RPE cells express this molecule. The purpose of this study was to investigate the expression of FasL in RPE cells in vitro and in vivo. Cultured human fetal and adult RPE cells were examined by flow cytometry, Western...... blotting, RT-PCR and RNase Protection assay for FasL expression. Additionally, sections of ocular tissue were stained for FasL by immunohistochemistry. None of the used methods indicated FasL expression in cultured fetal or adult RPE cells of various passages. However, RPE cells in vivo, as judged from...

Long-term results of repeated anti-vascular endothelial growth factor therapy in eyes with retinal pigment epithelial tears.

Science.gov (United States)

Moreira, Carlos A; Arana, Luis A; Zago, Rommel J

2013-02-01

To evaluate the long-term results of retinal pigment epithelium tears in eyes treated with repeated anti-vascular endothelial growth factor (VEGF) therapy. Five patients with retinal pigment epithelial tears (without foveal center involvement) after anti-VEGF injection were studied retrospectively. Mean follow-up time was 52 months, with measurements of visual acuity and evaluation of macular findings by angiography and optical coherence tomography during this period. All eyes had a persistent submacular neovascular membrane 30 days after the tear. An anti-VEGF drug was reinjected until the membranes stopped leaking. The mean initial visual acuity immediately after the tear was 20/160, and the mean final visual acuity was 20/60. The number of anti-VEGF reinjections varied from two to eight during the follow-up period. Long-term optical coherence tomography analysis showed reduced fluid and remodeling of the torn retinal pigment epithelium. Long-term visual results with repeated anti-VEGF therapy are not as devastating as suggested previously. Visual acuity and metamorphopsia improve with time as long as the neovascular membrane is inactive. Optical coherence tomography changes in the macular area reflect the visual acuity improvement.

Round atrophic holes in lattice degeneration--an important cause of phakic retinal detachment.

Science.gov (United States)

Tillery, W V; Lucier, A C

1976-01-01

Round atrophic holes in lattice degeneration are an important cause of phakic retinal detachment. Detachments due solely to round holes in lattice accounted for almost 2.8% of all retinal detachments treated at Wills Eye Hospital from January 1970 to August 1973. These detachments had the following important characteristics: 1. One of the patients were under the age of 30 years. 2. Over 75% of the patients had refractive errors more myopic than -3 D spherical equivalent. 3. Inferior detachments were slightly more common than superior detachments. When located inferiorly, there was a tendency for slow progression as indicated by the frequent presence of pigmented demarcation lines. 4. Surgical repair with standard scleral buckling techniques was successful in 98% of these detachments. Young, moderate to highly myopic patients with round holes in areas of lattice degeneration seem to have a greater risk of developing this type of detachment. Patients with the triad of youth, myopia, and round holes in lattice degeneration deserve close observation.

Lecithin-Bound Iodine Prevents Disruption of Tight Junctions of Retinal Pigment Epithelial Cells under Hypoxic Stress

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Masahiko Sugimoto

2016-01-01

Full Text Available Aim. We investigated whether lecithin-bound iodine (LBI can protect the integrity of tight junctions of retinal pigment epithelial cells from hypoxia. Method. Cultured human retinal pigment epithelial (ARPE-19 cells were pretreated with LBI. To mimic hypoxic conditions, cells were incubated with CoCl2. We compared the integrity of the tight junctions (TJs of control to cells with either LBI alone, CoCl2 alone, or LBI + CoCl2. The levels of cytokines in the conditioned media were also determined. Results. Significant decrease in the zonula occludens-1 (ZO-1 intensity in the CoCl2 group compared to the control (5787.7 ± 4126.4 in CoCl2 group versus 29244.6 ± 2981.2 in control; average ± standard deviation. But the decrease was not significant in the LBI + CoCl2 (27189.0 ± 11231.1. The levels of monocyte chemoattractant protein-1 (MCP-1 and Chemokine (C-C Motif Ligand 11 (CCL-11 were significantly higher in the CoCl2 than in the control (340.8 ± 43.3 versus 279.7 ± 68.3 pg/mL for MCP-1, and 15.2 ± 12.9 versus 12.5 ± 6.1 pg/mL for CCL-11. With LBI pretreatment, the levels of both cytokines were decreased to 182.6 ± 23.8 (MCP-1 and 5.46 ± 1.9 pg/mL for CCL-11. Blockade of MCP-1 or CCL-11 also shows similar result representing TJ protection from hypoxic stress. Conclusions. LBI results in a protective action from hypoxia.

Blue-light filtering alters angiogenic signaling in human retinal pigmented epithelial cells culture model.

Science.gov (United States)

Vila, Natalia; Siblini, Aya; Esposito, Evangelina; Bravo-Filho, Vasco; Zoroquiain, Pablo; Aldrees, Sultan; Logan, Patrick; Arias, Lluis; Burnier, Miguel N

2017-11-02

Light exposure and more specifically the spectrum of blue light contribute to the oxidative stress in Age-related macular degeneration (AMD). The purpose of the study was to establish whether blue light filtering could modify proangiogenic signaling produced by retinal pigmented epithelial (RPE) cells under different conditions simulating risk factors for AMD. Three experiments were carried out in order to expose ARPE-19 cells to white light for 48 h with and without blue light-blocking filters (BLF) in different conditions. In each experiment one group was exposed to light with no BLF protection, a second group was exposed to light with BLF protection, and a control group was not exposed to light. The ARPE-19 cells used in each experiment prior to light exposure were cultured for 24 h as follows: Experiment 1) Normoxia, Experiment 2) Hypoxia, and Experiment 3) Lutein supplemented media in normoxia. The media of all groups was harvested after light exposure for sandwich ELISA-based assays to quantify 10 pro-angiogenic cytokines. A significant decrease in angiogenin secretion levels and a significant increase in bFGF were observed following light exposure, compared to dark conditions, in both normoxia and hypoxia conditions. With the addition of a blue light-blocking filter in normoxia, a significant increase in angiogenin levels was observed. Although statistical significance was not achieved, blue light filters reduce light-induced secretion of bFGF and VEGF to near normal levels. This trend is also observed when ARPE-19 cells are grown under hypoxic conditions and when pre-treated with lutein prior to exposure to experimental conditions. Following light exposure, there is a decrease in angiogenin secretion by ARPE-19 cells, which was abrogated with a blue light - blocking filter. Our findings support the position that blue light filtering affects the secretion of angiogenic factors by retinal pigmented epithelial cells under normoxic, hypoxic, and lutein

Phototoxicity and cytotoxicity of fullerol in human retinal pigment epithelial cells

International Nuclear Information System (INIS)

Wielgus, Albert R.; Zhao, Baozhong; Chignell, Colin F.; Hu, Dan-Ning; Roberts, Joan E.

2010-01-01

The water-soluble nanoparticle hydroxylated fullerene [fullerol, nano-C 60 (OH) 22-26 ] has several clinical applications including use as a drug carrier to bypass the blood ocular barriers. We have previously found that fullerol is both cytotoxic and phototoxic to human lens epithelial cells (HLE B-3) and that the endogenous antioxidant lutein blocked some of this phototoxicity. In the present study we have found that fullerol induces cytotoxic and phototoxic damage to human retinal pigment epithelial cells. Accumulation of nano-C 60 (OH) 22-26 in the cells was confirmed spectrophotometrically at 405 nm, and cell viability, cell metabolism and membrane permeability were estimated using trypan blue, MTS and LDH assays, respectively. Fullerol was cytotoxic toward hRPE cells maintained in the dark at concentrations higher than 10 μM. Exposure to an 8.5 J.cm -2 dose of visible light in the presence of > 5 μM fullerol induced TBARS formation and early apoptosis, indicating phototoxic damage in the form of lipid peroxidation. Pretreatment with 10 and 20 μM lutein offered some protection against fullerol photodamage. Using time resolved photophysical techniques, we have now confirmed that fullerol produces singlet oxygen with a quantum yield of Φ = 0.05 in D 2 O and with a range of 0.002-0.139 in various solvents. As our previous studies have shown that fullerol also produces superoxide in the presence of light, retinal phototoxic damage may occur through both type I (free radical) and type II (singlet oxygen) mechanisms. In conclusion, ocular exposure to fullerol, particularly in the presence of sunlight, may lead to retinal damage.

Role of macrophage migration inhibitory factor (MIF) in the effects of oxidative stress on human retinal pigment epithelial cells.

Science.gov (United States)

Ko, Ji-Ae; Sotani, Yasuyuki; Ibrahim, Diah Gemala; Kiuchi, Yoshiaki

2017-10-01

Proliferative vitreoretinopathy (PVR) is the major cause of treatment failure in individuals who undergo surgery for retinal detachment. The epithelial-mesenchymal transition (EMT) in retinal pigment epithelium (RPE) cells contributes to the pathogenesis of PVR. Oxidative stress is thought to play a role in the progression of retinal diseases including PVR. We have now examined the effects of oxidative stress on the EMT and related processes in the human RPE cell line. We found that H 2 O 2 induced the contraction of RPE cells in a three-dimensional collagen gel. Analysis of a cytokine array revealed that H 2 O 2 specifically increased the release of macrophage migration inhibitory factor (MIF) from RPE cells. Reverse transcription-polymerase chain reaction and immunoblot analyses showed that H 2 O 2 increased the expression of MIF in RPE cells. Immunoblot and immunofluorescence analyses revealed that H 2 O 2 upregulated the expression of α-SMA and vimentin and downregulated that of ZO-1 and N-cadherin. Consistent with these observations, the transepithelial electrical resistance of cell was reduced by exposure to H 2 O 2 . The effects of oxidative stress on EMT-related and junctional protein expression as well as on transepithelial electrical resistance were inhibited by antibodies to MIF, but they were not mimicked by treatment with recombinant MIF. Finally, analysis with a profiling array for mitogen-activated protein kinase signalling revealed that H 2 O 2 specifically induced the phosphorylation of p38 mitogen-activated protein kinase. Our results thus suggest that MIF may play a role in induction of the EMT and related processes by oxidative stress in RPE cells and that it might thereby contribute to the pathogenesis of PVR. Proliferative vitreoretinopathy is a major complication of rhegmatogenous retinal detachment, and both oxidative stress and induction of the EMT in RPE cells are thought to contribute to the pathogenesis of this condition. We have now

Effects of the Macular Carotenoid Lutein in Human Retinal Pigment Epithelial Cells

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Xiaoming Gong

2017-12-01

Full Text Available Retinal pigment epithelial (RPE cells are central to retinal health and homoeostasis. Oxidative stress-induced damage to the RPE occurs as part of the pathogenesis of age-related macular degeneration and neovascular retinopathies (e.g., retinopathy of prematurity, diabetic retinopathy. The xanthophyll carotenoids, lutein and zeaxanthin, are selectively taken up by the RPE, preferentially accumulated in the human macula, and transferred to photoreceptors. These macular xanthophylls protect the macula (and the broader retina via their antioxidant and photo-protective activities. This study was designed to investigate effects of various carotenoids (β-carotene, lycopene, and lutein on RPE cells subjected to either hypoxia or oxidative stress, in order to determine if there is effect specificity for macular pigment carotenoids. Using human RPE-derived ARPE-19 cells as an in vitro model, we exposed RPE cells to various concentrations of the specific carotenoids, followed by either graded hypoxia or oxidative stress using tert-butyl hydroperoxide (tBHP. The results indicate that lutein and lycopene, but not β-carotene, inhibit cell growth in undifferentiated ARPE-19 cells. Moreover, cell viability was decreased under hypoxic conditions. Pre-incubation of ARPE-19 cells with lutein or lycopene protected against tBHP-induced cell loss and cell co-exposure of lutein or lycopene with tBHP essentially neutralized tBHP-dependent cell death at tBHP concentrations up to 500 μM. Our findings indicate that lutein and lycopene inhibit the growth of human RPE cells and protect the RPE against oxidative stress-induced cell loss. These findings contribute to the understanding of the protective mechanisms attributable to retinal xanthophylls in eye health and retinopathies.

Proteomic analysis of the vitreous following experimental retinal detachment in rabbits

DEFF Research Database (Denmark)

Mandal, Nakul; Lewis, Geoffrey P.; Fisher, Steven K.

2015-01-01

of the vitreous following experimental retinal detachment using a comparative proteomic based approach. Materials and Methods. Retinal detachment was created in the right eyes of six New Zealand red pigmented rabbits. Sham surgery was undertaken in five other rabbits that were used as controls. After seven days......Purpose. The pathogenesis of rhegmatogenous retinal detachment (RRD) remains incompletely understood, with no clinically effective treatment for potentially severe complications such as photoreceptor cell death and proliferative vitreoretinopathy. Here we investigate the protein profile...... the eyes were enucleated and the vitreous was removed. The vitreous samples were evaluated with two-dimensional polyacrylamide gel electrophoresis and the differentially expressed proteins were identified with tandem mass spectrometry. Results. Ten protein spots were found to be at least twofold...

Cytoplasmic and nuclear anti-apoptotic roles of αB-crystallin in retinal pigment epithelial cells.

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Woo Jin Jeong

Full Text Available In addition to its well-characterized role in the lens, αB-crystallin performs other functions. Methylglyoxal (MGO can alter the function of the basement membrane of retinal pigment epithelial (RPE cells. Thus, if MGO is not efficiently detoxified, it can induce adverse reactions in RPE cells. In this study, we examined the mechanisms underlying the anti-apoptotic activity of αB-crystallin in the human retinal pigment epithelial cell line ARPE-19 following MGO treatment using various assays, including nuclear staining, flow cytometry, DNA electrophoresis, pulse field gel electrophoresis, western blot analysis, confocal microscopy and co-immunoprecipitation assays. To directly assess the role of phosphorylation of αB-crystallin, we used site-directed mutagenesis to convert relevant serine residues to alanine residues. Using these techniques, we demonstrated that MGO induces apoptosis in ARPE-19 cells. Silencing αB-crystallin sensitized ARPE-19 cells to MGO-induced apoptosis, indicating that αB-crystallin protects ARPE-19 cells from MGO-induced apoptosis. Furthermore, we found that αB-crystallin interacts with the caspase subtypes, caspase-2L, -2S, -3, -4, -7, -8, -9 and -12 in untreated control ARPE-19 cells and that MGO treatment caused the dissociation of these caspase subtypes from αB-crystallin; transfection of S19A, S45A or S59A mutants caused the depletion of αB-crystallin from the nuclei of untreated control RPE cells leading to the release of caspase subtypes. Additionally, transfection of these mutants enhanced MGO-induced apoptosis in ARPE-19 cells, indicating that phosphorylation of nuclear αB-crystallin on serine residues 19, 45 and 59 plays a pivotal role in preventing apoptosis in ARPE-19 cells. Taken together, these results suggest that αB-crystallin prevents caspase activation by physically interacting with caspase subtypes in the cytoplasm and nucleus, thereby protecting RPE cells from MGO-induced apoptosis.

Guanine nucleotide-binding regulatory proteins in retinal pigment epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Jiang, Meisheng; Tran, V.T.; Fong, H.K.W. (Univ. of Southern California, Los Angeles (United States)); Pandey, S. (Doheny Eye Inst., Los Angeles, CA (United States))

1991-05-01

The expression of GTP-binding regulatory proteins (G proteins) in retinal pigment epithelial (RPE) cells was analyzed by RNA blot hybridization and cDNA amplification. Both adult and fetal human RPE cells contain mRNA for multiple G protein {alpha} subunits (G{alpha}) including G{sub s}{alpha}, G{sub i-1}{alpha}, G{sub i-2}{alpha}, G{sub i-3}{alpha}, and G{sub z}{alpha} (or G{sub x}{alpha}), where G{sub s} and G{sub i} are proteins that stimulate or inhibit adenylyl cyclase, respectively, and G{sub z} is a protein that may mediate pertussis toxin-insensitive events. Other G{alpha}-related mRNA transcripts were detected in fetal RPE cells by low-stringency hybridization to G{sub i-2}{alpha} and G{sub s}{alpha} protein-coding cDNA probes. The diversity of G proteins in RPE cells was further studied by cDNA amplification with reverse transcriptase and the polymerase chain reaction. This approach revealed that, besides the above mentioned members of the G{alpha} gene family, at least two other G{alpha} subunits are expressed in RPE cells. Human retinal cDNA clones that encode one of the additional G{alpha} subunits were isolated and characterized. The results indicate that this G{alpha} subunit belongs to a separate subfamily of G proteins that may be insensitive to inhibition by pertussis toxin.

Automatic segmentation in three-dimensional analysis of fibrovascular pigmentepithelial detachment using high-definition optical coherence tomography.

Science.gov (United States)

Ahlers, C; Simader, C; Geitzenauer, W; Stock, G; Stetson, P; Dastmalchi, S; Schmidt-Erfurth, U

2008-02-01

A limited number of scans compromise conventional optical coherence tomography (OCT) to track chorioretinal disease in its full extension. Failures in edge-detection algorithms falsify the results of retinal mapping even further. High-definition-OCT (HD-OCT) is based on raster scanning and was used to visualise the localisation and volume of intra- and sub-pigment-epithelial (RPE) changes in fibrovascular pigment epithelial detachments (fPED). Two different scanning patterns were evaluated. 22 eyes with fPED were imaged using a frequency-domain, high-speed prototype of the Cirrus HD-OCT. The axial resolution was 6 mum, and the scanning speed was 25 kA scans/s. Two different scanning patterns covering an area of 6 x 6 mm in the macular retina were compared. Three-dimensional topographic reconstructions and volume calculations were performed using MATLAB-based automatic segmentation software. Detailed information about layer-specific distribution of fluid accumulation and volumetric measurements can be obtained for retinal- and sub-RPE volumes. Both raster scans show a high correlation (p0.89) of measured values, that is PED volume/area, retinal volume and mean retinal thickness. Quality control of the automatic segmentation revealed reasonable results in over 90% of the examinations. Automatic segmentation allows for detailed quantitative and topographic analysis of the RPE and the overlying retina. In fPED, the 128 x 512 scanning-pattern shows mild advantages when compared with the 256 x 256 scan. Together with the ability for automatic segmentation, HD-OCT clearly improves the clinical monitoring of chorioretinal disease by adding relevant new parameters. HD-OCT is likely capable of enhancing the understanding of pathophysiology and benefits of treatment for current anti-CNV strategies in future.

Distributions of elements in the human retinal pigment epithelium

International Nuclear Information System (INIS)

Ulshafer, R.J.; Allen, C.B.; Rubin, M.L.

1990-01-01

Distributions of elements above the atomic number of sodium were mapped in the retinal pigment epithelia of eight human eyes. X-ray energy spectra and maps were collected from cryofixed, freeze-dried, and epoxy-embedded tissues using energy-dispersive x-ray microanalysis. All eyes had high concentrations of phosphorus in the nuclei of retinal pigment epithelial cells. Melanosomes were rich in sulfur, zinc, calcium, and iron. Lipofuscin and cytoplasm contained only phosphorus and sulfur in detectable amounts. Drusen, when present, contained phosphorus and calcium. Six eyes had a prominent aluminum peak recorded from melanosomes, nuclei, and Bruch's membrane. In one pair of 90-year-old eyes, small, electron-dense deposits surrounded many melanosomes and contained mercury and selenium. Retinal pigment epithelial melanosomes may bind and accumulate metals and other potentially toxic ions over time, preventing them from reaching the neural retina

Long Non-Coding RNA MALAT1 Mediates Transforming Growth Factor Beta1-Induced Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells.

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Shuai Yang

Full Text Available To study the role of long non-coding RNA (lncRNA MALAT1 in transforming growth factor beta 1 (TGF-β1-induced epithelial-mesenchymal transition (EMT of retinal pigment epithelial (RPE cells.ARPE-19 cells were cultured and exposed to TGF-β1. The EMT of APRE-19 cells is confirmed by morphological change, as well as the increased expression of alpha-smooth muscle actin (αSMA and fibronectin, and the down-regulation of E-cadherin and Zona occludin-1(ZO-1 at both mRNA and protein levels. The expression of lncRNA MALAT1 in RPE cells were detected by quantitative real-time PCR. Knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA. The effect of inhibition of MALAT1 on EMT, migration, proliferation, and TGFβ signalings were observed. MALAT1 expression was also detected in primary RPE cells incubated with proliferative vitreoretinopathy (PVR vitreous samples.The expression of MALAT1 is significantly increased in RPE cells incubated with TGFβ1. MALAT1 silencing attenuates TGFβ1-induced EMT, migration, and proliferation of RPE cells, at least partially through activating Smad2/3 signaling. MALAT1 is also significantly increased in primary RPE cells incubated with PVR vitreous samples.LncRNA MALAT1 is involved in TGFβ1-induced EMT of human RPE cells and provides new understandings for the pathogenesis of PVR.

Lattice degeneration of the retina and retinal detachment.

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Semes, L P

1992-01-01

Lattice retinal degeneration is considered the most significant peripheral retinal disorder potentially predisposing to retinal breaks and retinal detachment. Lattice degeneration affects the vitreous and inner retinal layers with secondary changes as deep as the retinal pigment epithelium and perhaps the choriocapillaris. Variations in clinical appearance are the rule; geographically, lattice lesions favor the vertical meridians between the equator and the ora serrata. Lattice degeneration begins early in life and has been reported in sequential generations of the same family. Along with its customary bilateral occurrence, lattice shares other characteristics of a dystrophy. The association between the vitreous and retina in lattice lesions may be responsible for the majority of lattice-induced retinal detachments. The tumultuous event of posterior vitreous separation in the presence of abnormally strong vitreoretinal adherence is the trigger for a retinal tear that, in turn, may lead to retinal detachment. Although retinal holes in young patients with lattice degeneration may play a role in the evolution of retinal detachment, the clinical course of lattice degeneration seems to be one of dormancy rather than of progressive change. This discussion outlines the pathophysiology of lattice retinal degeneration and the relationship of pathophysiology to clinical presentation. The epidemiology of lattice degeneration is summarized, as are the possible precursors to retinal detachment. A clinical characterization of the natural history of lattice degeneration is offered, and interventions for complications are described. To conclude, management strategies from a primary-care standpoint are reviewed.

Regression of Some High-risk Features of Age-related Macular Degeneration (AMD in Patients Receiving Intensive Statin Treatment

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Demetrios G. Vavvas

2016-03-01

Conclusions: High-dose statins may result in resolution of drusenoid pigment epithelial detachments (PEDs and improvement in VA, without atrophy or neovascularization in a high-risk subgroup of AMD patients. Confirmation from larger studies is warranted.

Human amniotic fluid promotes retinal pigmented epithelial cells' trans-differentiation into rod photoreceptors and retinal ganglion cells.

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Ghaderi, Shima; Soheili, Zahra-Soheila; Ahmadieh, Hamid; Davari, Maliheh; Jahromi, Fatemeh Sanie; Samie, Shahram; Rezaie-Kanavi, Mozhgan; Pakravesh, Jalil; Deezagi, Abdolkhalegh

2011-09-01

To evaluate the effect of human amniotic fluid (HAF) on retinal pigmented epithelial cells growth and trans-differentiation into retinal neurons, retinal pigmented epithelium (RPE) cells were isolated from neonatal human cadaver eye globes and cultured in Dulbecco's modified Eagle's medium-F12 supplemented with 10% fetal bovine serum (FBS). Confluent monolayer cultures were trypsinized and passaged using FBS-containing or HAF-containing media. Amniotic fluid samples were received from pregnant women in the first trimester of gestation. Cell proliferation and death enzyme-linked immunosorbent assays were performed to assess the effect of HAF on RPE cell growth. Trans-differentiation into rod photoreceptors and retinal ganglion cells was also studied using immunocytochemistry and real-time polymerase chain reaction techniques. Primary cultures of RPE cells were successfully established under FBS-containing or HAF-containing media leading to rapid cell growth and proliferation. When RPE cells were moved to in vitro culture system, they began to lose their differentiation markers such as pigmentation and RPE65 marker and trans-differentiated neural-like cells followed by spheroid colonies pertaining to stem/progenitor cells were morphologically detected. Immunocytochemistry (ICC) analysis of HAF-treated cultures showed a considerable expression of Rhodopsin gene (30% Rhodopsin-positive cells) indicating trans-differentiation of RPE cells to rod photoreceptors. Real-time polymerase chain reaction revealed an HAF-dose-dependant expression of Thy-1 gene (RGC marker) and significant promoting effect of HAF on RGCs generation. The data presented here suggest that HAF possesses invaluable stimulatory effect on RPE cells growth and trans-differentiation into retinal neurons. It can be regarded as a newly introduced enriched supplement in serum-free kinds of media used in neuro-retinal regeneration studies.

Pigment dispersion syndrome: a clinical study.

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Scheie, H G; Cameron, J D

1981-01-01

This study involved a group of 407 patients (799 eyes) with pigment dispersion syndrome gathered from a glaucoma population of 9200 patients. The sex distribution was equal. The majority (65%) of patients were myopic. The incidence of retinal detachment was 6.4%. No patients were black, but 5 were mulatto. Approximately one-quarter of the patients wih pigment dispersion syndrome (31% of the men, 19% of the women) had glaucoma. The average age of onset of glaucoma was 15 years less than in control patients with chronic simple glaucoma. When both eyes were affected by glaucoma, the glaucoma was consistently more severe in the eye with the more heavily pigmented angle. The degree of iris transillumination was found to be of no importance in predicting the presence of glaucoma or the severity of trabecular pigmentation. The pressure in 66% of the eyes with pigmentary glaucoma was controlled medically. A higher percentage of patients with pigmentary glaucoma required surgery than patients in the control group with chronic simple glaucoma. Men with pigmentary glaucoma required surgery at a much earlier age than women with pigmentary glaucoma. PMID:7236571

Effects of mechanical stress and vitreous samples in retinal pigment epithelial cells

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Takahashi, Eri, E-mail: eritakahashi@fc.kuh.kumamoto-u.ac.jp; Fukushima, Ayako; Haga, Akira; Inomata, Yasuya; Ito, Yasuhiro; Fukushima, Mikiko; Tanihara, Hidenobu

2016-02-12

In rhegmatogenous retinal detachment (RRD), scattered RPE cells from the basement membrane into the vitreous cavity undergo an epithelial mesenchymal transition (EMT) and form the intraocular fibrous membrane in response to vitreous fluid. We investigated whether exposure to vitreous samples was associated with EMT-associated signals and mesenchymal characters. Human vitreous samples were collected from patients with RRD, epiretinal membrane (ERM), or macular hole (MH). We evaluated the effects of vitreous on ARPE-19 cells in suspension cultures using poly 2-hydroxyethyl methacrylate-coated dishes and three-dimensional (3D) Matrigel cultures. We found that exposure to vitreous samples did not induce morphological changes or accelerate wound closure in monolayers. Several samples showed increased phosphorylation of Smad2 and nuclear translocation of nuclear factor-κB. Mechanical stress triggered an elevation of phosphorylation levels in Smad2. In addition, exposure to vitreous fluid increased the phosphorylation of p38 mitogen-activated protein kinase in cell suspension cultures after mechanical stress. Moreover, ARPE-19 cells showed a stellate invasive phenotype in 3D Matrigel cultures with vitreous samples. In this study, we demonstrated that mechanical stress and vitreous were associated with EMT-associated signals and invasive phenotypes in 3D cultures but not in monolayers. These results have important implications for the role of vitreous humor in the induction of EMT and intraocular fibrosis.

Construction of a cDNA library from human retinal pigment epithelial cells challenged with rod outer segments.

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Cavaney, D M; Rakoczy, P E; Constable, I J

1995-05-01

To study genes expressed by retinal pigment epithelial (RPE) cells during phagocytosis and digestion of rod outer segments (ROS), a complementary (c)DNA library was produced using an in-vitro model. The cDNA library can be used to study molecular changes which contribute to the development of diseases due to a failure in outer segment phagocytosis and digestion by RPE cells. Here we demonstrate a way to study genes and their functions using a molecular biological approach and describing the first step involved in this process, the construction of a cDNA library. Human RPE cells obtained from the eyes of a seven-year-old donor were cultured and challenged with bovine ROS. The culture was harvested and total RNA was extracted. Complementary DNA was transcribed from the messenger (m)RNA and was directionally cloned into the LambdaGEM-4 bacteriophage vector successfully. Some clones were picked and the DNA extracted, to determine the size of the inserts as a measure of the quality of the library. Molecular biology and cell culture are important tools to be used in eye research, especially in areas where tissue is limiting and animal models are not available. We now have a ROS challenged RPE cDNA library which will be used to identify genes responsible for degrading phagocytosed debris within the retinal pigment epithelium.

Fasudil, a Clinically Used ROCK Inhibitor, Stabilizes Rod Photoreceptor Synapses after Retinal Detachment.

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Townes-Anderson, Ellen; Wang, Jianfeng; Halász, Éva; Sugino, Ilene; Pitler, Amy; Whitehead, Ian; Zarbin, Marco

2017-06-01

Retinal detachment disrupts the rod-bipolar synapse in the outer plexiform layer by retraction of rod axons. We showed that breakage is due to RhoA activation whereas inhibition of Rho kinase (ROCK), using Y27632, reduces synaptic damage. We test whether the ROCK inhibitor fasudil, used for other clinical applications, can prevent synaptic injury after detachment. Detachments were made in pigs by subretinal injection of balanced salt solution (BSS) or fasudil (1, 10 mM). In some animals, fasudil was injected intravitreally after BSS-induced detachment. After 2 to 4 hours, retinae were fixed for immunocytochemistry and confocal microscopy. Axon retraction was quantified by imaging synaptic vesicle label in the outer nuclear layer. Apoptosis was analyzed using propidium iodide staining. For biochemical analysis by Western blotting, retinal explants, detached from retinal pigmented epithelium, were cultured for 2 hours. Subretinal injection of fasudil (10 mM) reduced retraction of rod spherules by 51.3% compared to control detachments ( n = 3 pigs, P = 0.002). Intravitreal injection of 10 mM fasudil, a more clinically feasible route of administration, also reduced retraction (28.7%, n = 5, P ROCK, was decreased with 30 μM fasudil ( n = 8-10 explants, P ROCK signaling with fasudil reduced photoreceptor degeneration and preserved the rod-bipolar synapse after retinal detachment. These results support the possibility, previously tested with Y27632, that ROCK inhibition may attenuate synaptic damage in iatrogenic detachments.

Differential Gene Expression in Explanted Human Retinal Pigment Epithelial Cells 24-Hours Post-Exposure to 532 nm, 3.0 ns Pulsed Laser Light and 1064 nm, 170 ps Pulsed Laser Light 12-Hours Post-Exposure: Results Compendium

National Research Council Canada - National Science Library

Obringer, John

2004-01-01

.... We assessed the sublethal insult to human retinal pigment epithelial cells using a cadaver organ donor explant system for genes differentially expressed 12 and 24 hours post- exposure using gene...

Xeno-Free and Defined Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells Functionally Integrate in a Large-Eyed Preclinical Model

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Alvaro Plaza Reyes

2016-01-01

Full Text Available Human embryonic stem cell (hESC-derived retinal pigment epithelial (RPE cells could replace lost tissue in geographic atrophy (GA but efficacy has yet to be demonstrated in a large-eyed model. Also, production of hESC-RPE has not yet been achieved in a xeno-free and defined manner, which is critical for clinical compliance and reduced immunogenicity. Here we describe an effective differentiation methodology using human laminin-521 matrix with xeno-free and defined medium. Differentiated cells exhibited characteristics of native RPE including morphology, pigmentation, marker expression, monolayer integrity, and polarization together with phagocytic activity. Furthermore, we established a large-eyed GA model that allowed in vivo imaging of hESC-RPE and host retina. Cells transplanted in suspension showed long-term integration and formed polarized monolayers exhibiting phagocytic and photoreceptor rescue capacity. We have developed a xeno-free and defined hESC-RPE differentiation method and present evidence of functional integration of clinically compliant hESC-RPE in a large-eyed disease model.

Rhegmatogenous Retinal Detachment Associated with Choroidal Detachment

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L. Sh. Bilandarli

2017-01-01

Full Text Available Review describes the theme of rhegmatogenous retinal dеtаchment associated with choroidal separation. It is rare, but quite severe eye pathology. In most cases it has a very poor prognosis. Most authors consider the retinal detachment as a primary pathogenetic part, which decompensates the production of aqueous humor by increasing the absorptive surface of the retinal pigment epithelium. Dilatation of choroidal arterioles occurs in hypotension, it leads to extravasation of protein-rich fluid in the choroidal and the suprachoroidal space. This helps to further swelling and separation of the ciliary body and the choroid with reduced production of aqueous humor and progressive hypotension. There is a high risk of developing “retino-choroidal” separation in patients with macular rupture due to localization of retinal separation and rupture rear hyaloid membrane. The protein level in aqueous humor can be increased to 70 times. It may be a result of reflux of suprachoroidal proteins through uveoscleral route and / or venous proteins through the trabecular network. In addition, the diffusion of proteins from the posterior camera and vitreous cavity is possible. This creates favorable conditions for cell proliferation that can lead to postoperative proliferative vitreoretinopathy. Typically patients have a pronounced signs of inflammation, pain, and “red eye”, which is accompanied with vision decrement. Rhegmatogenous retinal reparationcan be associated with such clinical symptoms as severe panuveit, deepening of the anterior camera and the inflammatory response in the moisture, concentric wrinkles and sagging back of the iris, posterior synechia, iridofakodenez, blurred vitreous detachment of the ciliary body, hypotension, and choroidal and retinal detachment in addition. Debatableness of etiopathogenesis and a clinical picture, which is similar to other eye diseases create significant difficulties in early diagnosis and proper treatment of

Autologous transplantation of genetically modified iris pigment epithelial cells: A promising concept for the treatment of age-related macular degeneration and other disorders of the eye

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Semkova, Irina; Kreppel, Florian; Welsandt, Gerhard; Luther, Thomas; Kozlowski, Jolanta; Janicki, Hanna; Kochanek, Stefan; Schraermeyer, Ulrich

2002-10-01

Age-related macular degeneration (ARMD) is the leading cause for visual impairment and blindness in the elder population. Laser photocoagulation, photodynamic therapy and excision of neovascular membranes have met with limited success. Submacular transplantation of autologous iris pigment epithelial (IPE) cells has been proposed to replace the damaged retinal pigment epithelium following surgical removal of the membranes. We tested our hypothesis that the subretinal transplantation of genetically modified autologous IPE cells expressing biological therapeutics might be a promising strategy for the treatment of ARMD and other retinal disorders. Pigment epithelium-derived factor (PEDF) has strong antiangiogenic and neuroprotective activities in the eye. Subretinal transplantation of PEDF expressing IPE cells inhibited pathological choroidal neovascularization in rat models of laser-induced rupture of Bruch's membrane and of oxygen induced ischemic retinopathy. PEDF expressing IPE transplants also increased the survival and preserved rhodopsin expression of photoreceptor cells in the RCS rat, a model of retinal degeneration. These findings suggest a promising concept for the treatment of ARMD and other retinal disorders.

JNK Promotes Epithelial Cell Anoikis by Transcriptional and Post-translational Regulation of BH3-Only Proteins

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Nomeda Girnius

2017-11-01

Full Text Available Summary: Developmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis. While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here, we tested the role of the cJUN NH2-terminal kinase (JNK signaling pathway using murine models with compound JNK deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that JNK acts through a BAK/BAX-dependent apoptotic pathway by increasing BIM expression and phosphorylating BMF, leading to death of detached epithelial cells. : Developmental morphogenesis, tissue injury, and oncogenic transformation can cause epithelial cell detachment. These cells are eliminated by a specialized form of apoptosis termed anoikis. Girnius and Davis show that anoikis is mediated by the cJUN NH2-terminal kinase (JNK, which increases BIM expression and phosphorylates BMF to engage BAK/BAX-dependent apoptosis. Keywords: apoptosis, anoikis, epithelial cell, mammary gland, JNK, BAX, BAK, BH3-only protein, BIM, BMF

Collectin-11 Is an Important Modulator of Retinal Pigment Epithelial Cell Phagocytosis and Cytokine Production.

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Dong, Xia; Wu, Weiju; Ma, Liang; Liu, Chengfei; Bhuckory, Mohajeet B; Wang, Liping; Nandrot, Emeline F; Xu, Heping; Li, Ke; Liu, Yizhi; Zhou, Wuding

2017-01-01

In this paper, we report previously unknown roles for collectin-11 (CL-11, a soluble C-type lectin) in modulating the retinal pigment epithelial (RPE) cell functions of phagocytosis and cytokine production. We found that CL-11 and its carbohydrate ligand are expressed in both the murine and human neural retina; these resemble each other in terms of RPE and photoreceptor cells. Functional analysis of murine RPE cells showed that CL-11 facilitates the opsonophagocytosis of photoreceptor outer segments and apoptotic cells, and also upregulates IL-10 production. Mechanistic analysis revealed that calreticulin on the RPE cells is required for CL-11-mediated opsonophagocytosis whereas signal-regulatory protein α and mannosyl residues on the cells are involved in the CL-11-mediated upregulation of IL-10 production. This study is the first to demonstrate the role of CL-11 and the molecular mechanisms involved in modulating RPE cell phagocytosis and cytokine production. It provides a new insight into retinal health and disease and has implications for other phagocytic cells. © 2017 S. Karger AG, Basel.

Atypical retinal pigment epithelial defects with retained photoreceptor layers

DEFF Research Database (Denmark)

Giannakaki-Zimmermann, Helena; Querques, Giuseppe; Munch, Inger Christine

2017-01-01

BACKGROUND: To report patients with age-related macular degeneration and atypical central retinal pigment epithelium (RPE) defects not attributable to geographic atrophy (GA) or RPE-tears with overlying preserved photoreceptor layers. METHODS: Multimodal imaging case-series evaluating the course...

Transcriptional regulation of epithelial-mesenchymal transition in melanoma

International Nuclear Information System (INIS)

Wels, C.

2010-01-01

The downregulation of epithelial markers followed by upregulation of mesenchymal characteristics is an important step in melanoma development. This process goes along with gains in cell proliferation and motility, depolarization and detachment from neighbouring cells, finally enabling melanoma cells to leave the primary site of tumor growth and to circulate through the blood or lymphatic system. The entirety of these events is referred to as epithelial-mesenchymal transition (EMT). Changes during EMT are accomplished by a set of transcription factors which share the same DNA binding site called E-box. These E-box binding transcription factors are subsumed as epithelial-mesenchymal transitions regulators (EMTRs). In this thesis, I studied the interplay of the zinc-finger transcription factors Slug and ZEB1 and the basic helix-loop-helix transcription factor Twist during melanoma progression. I demonstrate for the first time the direct and specific transcriptional upregulation of one EMTR, ZEB1, by another, Slug, using gene silencing and overexpression studies together with mobility shift and luciferase assays. The two transcription factors cooperate in repressing the epithelial adhesion molecule E-cadherin which is supposed to be a crucial step during early EMT. Further, they show additive effects in promoting detachment from neighbouring cells and cell migration. Conceptually, Slug and ZEB1 are supported by Twist, a transcription factor that might be less pivotal for E-cadherin repression but rather for inducing the expression of the mesenchymal marker N-cadherin, enabling adhesion to mesenchymal cells, thereby promoting migration and invasion of melanoma cells.Taken together, I provide a model of a hierarchical organization of EMT transcription factors, with Slug as a transcriptional activator of ZEB1, leading to cooperative effects on detachment and migration and, together with Twist, leading to EMT in melanoma. (author) [de

In vivo imaging of the retinal pigment epithelial cells

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Morgan, Jessica Ijams Wolfing

The retinal pigment epithelial (RPE) cells form an important layer of the retina because they are responsible for providing metabolic support to the photoreceptors. Techniques to image the RPE layer include autofluorescence imaging with a scanning laser ophthalmoscope (SLO). However, previous studies were unable to resolve single RPE cells in vivo. This thesis describes the technique of combining autofluorescence, SLO, adaptive optics (AO), and dual-wavelength simultaneous imaging and registration to visualize the individual cells in the RPE mosaic in human and primate retina for the first time in vivo. After imaging the RPE mosaic non-invasively, the cell layer's structure and regularity were characterized using quantitative metrics of cell density, spacing, and nearest neighbor distances. The RPE mosaic was compared to the cone mosaic, and RPE imaging methods were confirmed using histology. The ability to image the RPE mosaic led to the discovery of a novel retinal change following light exposure; 568 nm exposures caused an immediate reduction in autofluorescence followed by either full recovery or permanent damage in the RPE layer. A safety study was conducted to determine the range of exposure irradiances that caused permanent damage or transient autofluorescence reductions. Additionally, the threshold exposure causing autofluorescence reduction was determined and reciprocity of radiant exposure was confirmed. Light exposures delivered by the AOSLO were not significantly different than those delivered by a uniform source. As all exposures tested were near or below the permissible light levels of safety standards, this thesis provides evidence that the current light safety standards need to be revised. Finally, with the retinal damage and autofluorescence reduction thresholds identified, the methods of RPE imaging were modified to allow successful imaging of the individual cells in the RPE mosaic while still ensuring retinal safety. This thesis has provided a

Gingival pigmentation beneath a metallic crown

International Nuclear Information System (INIS)

Sakai, T.; Hirayasu, R.; Sakai, H.; Hashimoto, N.

1988-01-01

Light and electron microscopic studies and energy dispersive X-ray analysis disclosed that the essential cause of gingival discoloration following the placement of a metallic crown, was marked deposition of melanin pigment. Deposition of melanin pigment was observed in epithelial cells, on basement membranes, and in fibroblasts, macrophages and among intercellular ground substance of the proprial layer. Brown or dark brown colored granules were observed in the deep portion of the proprial layer. Some metallic elements as silver and sulfur were detected. It was presumed that these materials were dental metals accidentally implanted in gingival tissues during the therapeutic procedure. The deposition of melanin pigment closely corresponded with mucosal tissue where these materials were present in the deep portion of the proprial layer. These findings suggested that these materials influenced the physiological metabolism of melanin and induced its pathological deposition in the proprial tissue. (author)

Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin.

Science.gov (United States)

Johnson, Adam S; García, Dana M

2007-12-19

Inside bluegill (Lepomis macrochirus) retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog) is one example. Previous research indicates that the carbachol-receptor interaction activates a Gq-mediated pathway which is commonly linked to Ca2+ mobilization. The purpose of the present study was to test for involvement of calcium and to probe calcium-dependent mediators to reveal their role in carbachol-mediated dispersion. Carbachol-induced pigment granule dispersion was blocked by the calcium chelator BAPTA. In contrast, the calcium channel antagonist verapamil, and incubation in Ca2+-free medium failed to block carbachol-induced dispersion. The calcineurin inhibitor cypermethrin blocked carbachol-induced dispersion; whereas, two protein kinase C inhibitors (staurosporine and bisindolylmaleimide II) failed to block carbachol-induced dispersion, and the protein kinase C activator phorbol 12-myristate 13-acetate failed to elicit dispersion. A rise in intracellular calcium is necessary for carbachol-induced dispersion; however, the Ca2+ requirement is not dependent on extracellular sources, implying that intracellular stores are sufficient to enable pigment granule dispersion to occur. Calcineurin is a likely Ca2+-dependent mediator involved in the signal cascade. Although the pathway leads to the generation of diacylglycerol and calcium (both required for the activation of certain PKC isoforms), our evidence does not support a significant role for PKC.

Biological effects of cigarette smoke in cultured human retinal pigment epithelial cells.

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Alice L Yu

Full Text Available The goal of the present study was to determine whether treatment with cigarette smoke extract (CSE induces cell loss, cellular senescence, and extracellular matrix (ECM synthesis in primary human retinal pigment epithelial (RPE cells. Primary cultured human RPE cells were exposed to 2, 4, 8, and 12% of CSE concentration for 24 hours. Cell loss was detected by cell viability assay. Lipid peroxidation was assessed by loss of cis-parinaric acid (PNA fluorescence. Senescence-associated ß-galactosidase (SA-ß-Gal activity was detected by histochemical staining. Expression of apolipoprotein J (Apo J, connective tissue growth factor (CTGF, fibronectin, and laminin were examined by real-time PCR, western blot, or ELISA experiments. The results showed that exposure of cells to 12% of CSE concentration induced cell death, while treatment of cells with 2, 4, and 8% CSE increased lipid peroxidation. Exposure to 8% of CSE markedly increased the number of SA-ß-Gal positive cells to up to 82%, and the mRNA expression of Apo J, CTGF, and fibronectin by approximately 3-4 fold. Treatment with 8% of CSE also increased the protein expression of Apo J and CTGF and the secretion of fibronectin and laminin. Thus, treatment with CSE can induce cell loss, senescent changes, and ECM synthesis in primary human RPE cells. It may be speculated that cigarette smoke could be involved in cellular events in RPE cells as seen in age-related macular degeneration.

Retrobulbar optic neuritis and rhegmatogenous retinal detachment in a fourteen-year-old girl with retinitis pigmentosa sine pigmento.

Science.gov (United States)

Hatta, M; Hayasaka, S; Kato, T; Kadoi, C

2000-01-01

A 14-year-old girl complained of a sudden decrease in right visual acuity. The patient had night blindness, a mottled retina but no pigments, extinguished scotopic electroretinographic response, central scotoma in the right eye and rhegmatogenous retinal detachment. She had initially received laser photocoagulation around the retinal tear and then corticosteroid therapy, cryoretinopexy and segmental buckling. Her right visual acuity increased to 1.0. The association of retinitis pigmentosa sine pigmento, retrobulbar optic neuritis and rhegmatogenous retinal detachment, as demonstrated in our patient, may be uncommon. Copyright 2000 S. Karger AG, Basel

Transport of protons and lactate in cultured human fetal retinal pigment epithelial cells

DEFF Research Database (Denmark)

Hamann, Steffen; Cour, Morten la; Ming Lui, Ge

2000-01-01

Electron microscopy, intracellular pH, monocarboxylate transport, pigment epithelium of eye, proton-lactate cotransport, retinal metabolism, sodium/proton exchange......Electron microscopy, intracellular pH, monocarboxylate transport, pigment epithelium of eye, proton-lactate cotransport, retinal metabolism, sodium/proton exchange...

The immune privilege of the eye: human retinal pigment epithelial cells selectively modulate T-cell activation in vitro

DEFF Research Database (Denmark)

Kaestel, Charlotte G; Lovato, Paola; Ødum, Niels

2005-01-01

PURPOSE: To examine the effect of human retinal pigment epithelial (RPE) cells on phytohemagglutinin (PHA) activation of T cells. METHODS: Resting peripheral blood lymphocytes (PBLs) were stimulated with PHA with or without the presence of gamma-irradiated RPE cells. Proliferation and the cell...... in cell culture supernatant was measured by ELISA. RESULTS: Human RPE cells were found to suppress PHA-induced proliferation, cyclin A, IL-2R-alpha and -gamma, and CD71 expression and decrease the production of IL-2; but RPE cells do not inhibit the PHA-induced expression of early activation markers CD69......, MHC class I and II, and of cyclin D of the PBLs. CONCLUSIONS: These results are the first to indicate that RPE cells impede generation of activated T cells by interfering with the induction of high-affinity IL-2R-alphabetagamma, IL-2 production, and the expression of CD71 and cyclin A....

Divertor detachment

Science.gov (United States)

Krasheninnikov, Sergei

2015-11-01

The heat exhaust is one of the main conceptual issues of magnetic fusion reactor. In a standard operational regime the large heat flux onto divertor target reaches unacceptable level in any foreseeable reactor design. However, about two decades ago so-called ``detached divertor'' regimes were found. They are characterized by reduced power and plasma flux on divertor targets and look as a promising solution for heat exhaust in future reactors. In particular, it is envisioned that ITER will operate in a partly detached divertor regime. However, even though divertor detachment was studied extensively for two decades, still there are some issues requiring a new look. Among them is the compatibility of detached divertor regime with a good core confinement. For example, ELMy H-mode exhibits a very good core confinement, but large ELMs can ``burn through'' detached divertor and release large amounts of energy on the targets. In addition, detached divertor regimes can be subject to thermal instabilities resulting in the MARFE formation, which, potentially, can cause disruption of the discharge. Finally, often inner and outer divertors detach at different plasma conditions, which can lead to core confinement degradation. Here we discuss basic physics of divertor detachment including different mechanisms of power and momentum loss (ionization, impurity and hydrogen radiation loss, ion-neutral collisions, recombination, and their synergistic effects) and evaluate the roles of different plasma processes in the reduction of the plasma flux; detachment stability; and an impact of ELMs on detachment. We also evaluate an impact of different magnetic and divertor geometries on detachment onset, stability, in- out- asymmetry, and tolerance to the ELMs. Supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-DE-FG02-04ER54739 at UCSD.

Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin

Directory of Open Access Journals (Sweden)

García Dana M

2007-12-01

Full Text Available Abstract Background Inside bluegill (Lepomis macrochirus retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog is one example. Previous research indicates that the carbachol-receptor interaction activates a Gq-mediated pathway which is commonly linked to Ca2+ mobilization. The purpose of the present study was to test for involvement of calcium and to probe calcium-dependent mediators to reveal their role in carbachol-mediated dispersion. Results Carbachol-induced pigment granule dispersion was blocked by the calcium chelator BAPTA. In contrast, the calcium channel antagonist verapamil, and incubation in Ca2+-free medium failed to block carbachol-induced dispersion. The calcineurin inhibitor cypermethrin blocked carbachol-induced dispersion; whereas, two protein kinase C inhibitors (staurosporine and bisindolylmaleimide II failed to block carbachol-induced dispersion, and the protein kinase C activator phorbol 12-myristate 13-acetate failed to elicit dispersion. Conclusion A rise in intracellular calcium is necessary for carbachol-induced dispersion; however, the Ca2+ requirement is not dependent on extracellular sources, implying that intracellular stores are sufficient to enable pigment granule dispersion to occur. Calcineurin is a likely Ca2+-dependent mediator involved in the signal cascade. Although the pathway leads to the generation of diacylglycerol and calcium (both required for the activation of certain PKC isoforms, our evidence does not support a significant role for PKC.

Protective Effects of Blueberry Anthocyanins against H2O2-Induced Oxidative Injuries in Human Retinal Pigment Epithelial Cells.

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Huang, Wu-Yang; Wu, Han; Li, Da-Jing; Song, Jiang-Feng; Xiao, Ya-Dong; Liu, Chun-Quan; Zhou, Jian-Zhong; Sui, Zhong-Quan

2018-02-21

Blueberry anthocyanins are considered protective of eye health because of their recognized antioxidant properties. In this study, blueberry anthocyanin extract (BAE), malvidin (Mv), malvidin-3-glucoside (Mv-3-glc), and malvidin-3-galactoside (Mv-3-gal) all reduced H 2 O 2 -induced oxidative stress by decreasing the levels of reactive oxygen species and malondialdehyde and increasing the levels of superoxide dismutase, catalase, and glutathione peroxidase in human retinal pigment epithelial cells. BAE and the anthocyanin standards enhanced cell viability from 63.69 ± 3.36 to 86.57 ± 6.92% (BAE), 115.72 ± 23.41% (Mv), 98.15 ± 9.39% (Mv-3-glc), and 127.97 ± 20.09% (Mv-3-gal) and significantly inhibited cell apoptosis (P blueberry anthocyanins could inhibit the induction and progression of age-related macular degeneration (AMD) through antioxidant mechanisms.

A2E induces IL-1ß production in retinal pigment epithelial cells via the NLRP3 inflammasome.

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Anderson, Owen A; Finkelstein, Arthur; Shima, David T

2013-01-01

With ageing extracellular material is deposited in Bruch's membrane, as drusen. Lipofuscin is deposited in retinal pigment epithelial cells. Both of these changes are associated with age related macular degeneration, a disease now believed to involve chronic inflammation at the retinal-choroidal interface. We hypothesise that these molecules may act as danger signals, causing the production of inflammatory chemokines and cytokines by the retinal pigment epithelium, via activation of pattern recognition receptors. ARPE-19 cells were stimulated in vitro with the following reported components of drusen: amyloid-ß (1-42), Carboxyethylpyrrole (CEP) modified proteins (CEP-HSA), Nε-(Carboxymethyl)lysine (CML) modified proteins and aggregated vitronectin. The cells were also stimulated with the major fluorophore of lipofuscin: N-retinylidene-N-retinylethanolamine (A2E). Inflammatory chemokine and cytokine production was assessed using Multiplex assays and ELISA. The mechanistic evaluation of the NLRP3 inflammasome pathway was assessed in a stepwise fashion. Of all the molecules tested only A2E induced inflammatory chemokine and cytokine production. 25 µM A2E induced the production of significantly increased levels of the chemokines IL-8, MCP-1, MCG and MIP-1α, the cytokines IL-1ß, IL-2, IL-6, and TNF-α, and the protein VEGF-A. The release of IL-1ß was studied further, and was determined to be due to NLRP3 inflammasome activation. The pathway of activation involved endocytosis of A2E, and the three inflammasome components NLRP3, ASC and activated caspase-1. Immunohistochemical staining of ABCA4 knockout mice, which show progressive accumulation of A2E levels with age, showed increased amounts of IL-1ß proximal to the retinal pigment epithelium. A2E has the ability to stimulate inflammatory chemokine and cytokine production by RPE cells. The pattern recognition receptor NLRP3 is involved in this process. This provides further evidence for the link between A2E

Possible role of HIWI2 in modulating tight junction proteins in retinal pigment epithelial cells through Akt signaling pathway.

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Sivagurunathan, Suganya; Palanisamy, Karthikka; Arunachalam, Jayamuruga Pandian; Chidambaram, Subbulakshmi

2017-03-01

PIWI subfamily of proteins is shown to be primarily expressed in germline cells. They maintain the genomic integrity by silencing the transposable elements. Although the role of PIWI proteins in germ cells has been documented, their presence and function in somatic cells remains unclear. Intriguingly, we detected all four members of PIWI-like proteins in human ocular tissues and somatic cell lines. When HIWI2 was knocked down in retinal pigment epithelial cells, the typical honeycomb morphology was affected. Further analysis showed that the expression of tight junction (TJ) proteins, CLDN1, and TJP1 were altered in HIWI2 knockdown. Moreover, confocal imaging revealed disrupted TJP1 assembly at the TJ. Previous studies report the role of GSK3β in regulating TJ proteins. Accordingly, phospho-kinase proteome profiler array indicated increased phosphorylation of Akt and GSK3α/β in HIWI2 knockdown, suggesting that HIWI2 might affect TJ proteins through Akt-GSK3α/β signaling axis. Moreover, treating the HIWI2 knockdown cells with wortmannin increased the levels of TJP1 and CLDN1. Taken together, our study demonstrates the presence of PIWI-like proteins in somatic cells and the possible role of HIWI2 in preserving the functional integrity of epithelial cells probably by modulating the phosphorylation status of Akt.

Anatomical and visual outcomes of ranibizumab injections in retinal pigment epithelium tears

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Muhammet Kazım Erol

2015-06-01

Full Text Available ABSTRACT Purpose: To report the anatomical and visual results in patients diagnosed as having retinal pigment epithelium (RPE tears after receiving ranibizumab injections. Methods: Eyes diagnosed as having RPE tears with a minimum 6-month follow-up were retrospectively evaluated. Each eye was treated with at least three doses of ranibizumab at monthly intervals. Best-corrected visual acuity (BCVA, anterior segment findings, intraocular pressure, and fundus examination results were evaluated during control visits. Color fundus photography, fundus fluorescein angiographies, fundus autofluorescence, and spectral domain optical coherence tomography (SD-OCT images were obtained. The height of pigment epithelial detachment (PED was measured by SD-OCT. Results: Twelve eyes with RPE tears were studied. Nine eyes (75% developed RPE tears during ranibizumab injections for choroidal neovascularization (eight eyes with vascularized PED and one eye with choroidal osteoma, and tears occurred in three eyes before any injections. The median number of ranibizumab injections after diagnosis of RPE tears was 3 (min 2, max 5. In the most recent follow-up visit, there was no statistically significant correlation between the grade of RPE and logMAR of BCVA (p>0.05, r=0.112. Eight of twelve eyes had PED, and seven of these had irregular PED contours before injection therapy. The mean PED height was 447 ± 122 µm. Conclusions: In this series, RPE tears developed mostly after intravitreal anti-VEGF injections for vascularized PED. Increased vertical height and irregular contours of the PEDs can be risk factors for the formation of RPE tears. The continuation of anti-VEGF therapy after tear formation is beneficial for vision improvement in eyes with RPE tears.

Efflux protein expression in human stem cell-derived retinal pigment epithelial cells.

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Kati Juuti-Uusitalo

Full Text Available Retinal pigment epithelial (RPE cells in the back of the eye nourish photoreceptor cells and form a selective barrier that influences drug transport from the blood to the photoreceptor cells. At the molecular level, ATP-dependent efflux transporters have a major role in drug delivery in human RPE. In this study, we assessed the relative expression of several ATP-dependent efflux transporter genes (MRP1, -2, -3, -4, -5, -6, p-gp, and BCRP, the protein expression and localization of MRP1, MRP4, and MRP5, and the functionality of MRP1 efflux pumps at different maturation stages of undifferentiated human embryonic stem cells (hESC and RPE derived from the hESC (hESC-RPE. Our findings revealed that the gene expression of ATP-dependent efflux transporters MRP1, -3, -4, -5, and p-gp fluctuated during hESC-RPE maturation from undifferentiated hESC to fusiform, epithelioid, and finally to cobblestone hESC-RPE. Epithelioid hESC-RPE had the highest expression of MRP1, -3, -4, and P-gp, whereas the most mature cobblestone hESC-RPE had the highest expression of MRP5 and MRP6. These findings indicate that a similar efflux protein profile is shared between hESC-RPE and the human RPE cell line, ARPE-19, and suggest that hESC-RPE cells are suitable in vitro RPE models for drug transport studies. Embryonic stem cell model might provide a novel tool to study retinal cell differentiation, mechanisms of RPE-derived diseases, drug testing and targeted drug therapy.

Patterning bacterial communities on epithelial cells.

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Mohammed Dwidar

Full Text Available Micropatterning of bacteria using aqueous two phase system (ATPS enables the localized culture and formation of physically separated bacterial communities on human epithelial cell sheets. This method was used to compare the effects of Escherichia coli strain MG1655 and an isogenic invasive counterpart that expresses the invasin (inv gene from Yersinia pseudotuberculosis on the underlying epithelial cell layer. Large portions of the cell layer beneath the invasive strain were killed or detached while the non-invasive E. coli had no apparent effect on the epithelial cell layer over a 24 h observation period. In addition, simultaneous testing of the localized effects of three different bacterial species; E. coli MG1655, Shigella boydii KACC 10792 and Pseudomonas sp DSM 50906 on an epithelial cell layer is also demonstrated. The paper further shows the ability to use a bacterial predator, Bdellovibriobacteriovorus HD 100, to selectively remove the E. coli, S. boydii and P. sp communities from this bacteria-patterned epithelial cell layer. Importantly, predation and removal of the P. Sp was critical for maintaining viability of the underlying epithelial cells. Although this paper focuses on a few specific cell types, the technique should be broadly applicable to understand a variety of bacteria-epithelial cell interactions.

[Photosynthetic characteristics of Cuscuta japonica and its hosts during parasitization and after detachment].

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Wang, Dong; Hu, Fei; Chen, Yu-Fen; Yang, Jun; Kong, Chui-Hua

2007-08-01

The study on the photosynthetic characteristics of Cuscuta japonica and its hosts showed that there was a negative correlation between the photosynthetic pigment content (PPC) of C. japonica and its hosts. The PPC increased in the C. japonica-preferred hosts' parasitized and neighboring leaves, but decreased in its less preferred hosts' parasitized and neighboring leaves. The leaves parasitized by C. japonica and their neighboring far from the parasitized ones had a lowered net photosynthesis rate P(n), and the decreasing order accorded with that of parasitization. The decrease of P(n) for C. japonica-less preferred hosts was mainly due to the stomatal factors, but that for the preferred hosts was regulated by multi-factors. Under light, the PPC of C. japonica detached from preferred hosts increased faster than that of C. japonica detached from less preferred hosts, but the dry matter decrease was in adverse. In dark, however, the changes in PPC and dry matter content of C. japonica were not significant, whatever hosts it was detached from.

Influence of ultraviolet A radiation on osmolytes transport in human retinal pigment epithelial cells

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Da-Yang Wu

2014-04-01

Full Text Available AIM: To demonstrate that ultraviolet A(UVAinduces osmolytes accumulation in retinal pigment epithelial(RPEcells.METHODS: Under different experimental conditions such as UVA exposure, hyperosmotic stress condition and hypoosmotic stress condition, RPE cells were cultured for different time periods. The betaine /γ-amino- n-butyric acid(GABAtransporter, the sodium-dependent myoinositol transporter and the taurine transporter(TAUTmRNA were measured by quantitative PCR. The radioactive labeled osmolytes were measured to evaluate the level of osmolytes transportation. RESULTS: This study demonstrated that RPE expressed mRNA specific for the betaine/GABA transporter, for the sodium-dependent myoinositol transporter and for the TAUT. In comparison to norm osmotic(300mosmol/Lcontrols, a 3-5-fold induction of mRNA expression for the betaine/GABA transporter, the sodium-dependent myoinositol transporter and the TAUT was observed within 6-24h after hyperosmotic exposure(400mosmol/L. Expression of osmolyte transporters was associated with an increased uptake of radioactive labeled osmolytes. Conversely, hypoosmotic(200mosmol/Lstimulation induced significant efflux of these osmolytes. UVA significantly stimulated osmolyte uptake. Increased osmolyte uptake was associated with upregulation of mRNA steady-state levels for osmolyte transporters in irradiated cells.CONCLUSION: UVA induces osmolyte uptake in RPE. It is similar reaction to hyperosmotic stress. This suggests that osmolyte uptake response by UVA may be important to maintain homeostasis.

Some physiological and biochemical responses to copper of detached cucumber (cucumis sativus l.) cotyledons pre-floated in salicylic acid

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Gulengul, S.C.; Yildiz, T.; Deveci, D.

2017-01-01

Salicylic acid (SA) is a growth regulator that promotes growth of plants under stress and non-stress conditions. In the present investigation we studied the role of salicylic acid in copper induced physiological and biochemical changes and the possible induction of oxidative stress in detached cucumber cotyledons. Detached cotyledons of young cucumber seedlings were floated in 150 ppm SA. Then, the responses of these cotyledons to different concentrations (0, 10, 20 ve 50 mM) of copper (CuCl2. H2O) were investigated. In detached cucumber cotyledons exposed to increasing Cu concentrations, the fresh weight accumulation and the photosynthetic pigment content were decreased. Furthermore, the levels of some important parameters regarding oxidative stress in the cotyledons, namely lipid peroxidation (MDA), glutathione (GSH) and proline were increased. In the detached cucumber cotyledons pre-floation process with SA alleviated the negative effect of Cu ( 20 mM and 50 mM Cu) on growth parameters. (author)

Chronic Central Serous Chorioretinopathy in a Patient with Pigment Dispersion Syndrome: A Possible Correlation.

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Kourkoutas, Dimitrios; Tsakonas, George; Karamaounas, Aristotelis; Karamaounas, Nikolaos

2017-01-01

Chronic central serous chorioretinopathy (CSCR) is a progressive chorioretinopathy with widespread atrophic RPE abnormalities and serous retinal detachments (SRDs) present for 6 months or longer. We report a case of CSCR in a 38-year-old patient with Pigment Dispersion Syndrome (PDS). In the presented case of CSCR, the chronic course of the disease may in part be associated with an underlying generalized degenerative dysfunction of the pigmented cells of the eye on grounds of PDS. We suggest that a chronic course of disease may be suspected in the setting of CSCR with concurrent RPE pathology, such as what is found in PDS.

RBP-Jκ-dependent Notch signaling enhances retinal pigment epithelial cell proliferation in transgenic mice.

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Schouwey, K; Aydin, I T; Radtke, F; Beermann, F

2011-01-20

The Notch signaling pathway is an ubiquitous cell-cell interaction mechanism, which is essential in controlling processes like cell proliferation, cell fate decision, differentiation or stem cell maintenance. Recent data have shown that Notch signaling is RBP-Jκ-dependent in melanocytes, being required for survival of these pigment cells that are responsible for coloration of the skin and hairs in mammals. In addition, Notch is believed to function as an oncogene in melanoma, whereas it is a tumor suppressor in mouse epidermis. In this study, we addressed the implication of the Notch signaling in the development of another population of pigment cells forming the retinal pigment epithelium (RPE) in mammalian eyes. The constitutive activity of Notch in Tyrp1::NotchIC/° transgenic mice enhanced RPE cell proliferation, and the resulting RPE-derived pigmented tumor severely affected the overall eye structure. This RPE cell proliferation is dependent on the presence of the transcription factor RBP-Jκ, as it is rescued in mice lacking RBP-Jκ in the RPE. In conclusion, Notch signaling in the RPE uses the canonical pathway, which is dependent on the transcription factor RBP-Jκ. In addition, it is of importance for RPE development, and constitutive Notch activity leads to hyperproliferation and benign tumors of these pigment cells.

Pupal development and pigmentation process of a polka-dotted fruit fly, Drosophila guttifera (Insecta, Diptera).

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Fukutomi, Yuichi; Matsumoto, Keiji; Agata, Kiyokazu; Funayama, Noriko; Koshikawa, Shigeyuki

2017-06-01

Various organisms have color patterns on their body surfaces, and these color patterns are thought to contribute to physiological regulation, communication with conspecifics, and signaling with the environment. An adult fly of Drosophila guttifera (Insecta: Diptera: Drosophilidae) has melanin pigmentation patterns on its body and wings. Though D. guttifera has been used for research into color pattern formation, how its pupal development proceeds and when the pigmentation starts have not been well studied. In this study, we defined the pupal stages of D. guttifera and measured the pigment content of wing spots from the pupal period to the period after eclosion. Using a transgenic line which carries eGFP connected with an enhancer of yellow, a gene necessary for melanin synthesis, we analyzed the timing at which the yellow enhancer starts to drive eGFP. We also analyzed the distribution of Yellow-producing cells, as indicated by the expression of eGFP during pupal and young adult periods. The results suggested that Yellow-producing cells were removed from wings within 3 h after eclosion, and wing pigmentation continued without epithelial cells. Furthermore, the results of vein cutting experiments showed that the transport of melanin precursors through veins was necessary for wing pigmentation. These results showed the importance of melanin precursors transported through veins and of extracellular factors which were secreted from epithelial cells and left in the cuticle.

The Effects of Curcuma Longa on the Functionality of Pigmentation for Thin Film Coating

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Marsi, N.; Rus, A. Z. M.; Tan, N. A. M. S.

2017-08-01

This project presents the effects of turmeric (Curcuma Longa) on the functionality of pigmentation was carried out to improve the sustainability, environment impact and reduction of potential cost saving without sacrificing the performance of thin film coating. The Curcuma Longa pigment was extracted by grating the turmeric into small particles at different percentages which is 20%, 40%, 60% and 80% of Curcuma Longa pigment with 3, 6 and 9 layers of coating. The different percentages of Curcuma Longa pigment was formulated and synthesized with polyols by crosslinking agent of glycerol and calcium carbonate into temperature at 140 °C for 2 hours. The results of water droplet test (ASTM D5964) showed the water contact angle was achieved the optimum superhydrophobic characteristic up to 60% of Curcuma Longa at 153°. The formulation of 60% Curcuma Longa was revealed the optimum adhesion resistance test with no flaking and detachment when the coating applied at 9 layers in the classification grading of adhesion test at 5B. It is indicated that the adhesion resistance of thin film coating on metal substrate was obviously increased as the layer of coating as well as the Curcuma Longa pigment percentage up to 60% at 9 layers. This project also highlighted the potential of Curcuma Longa pigment to produce quality in the natural pigmentation as a replacement synthetic pigment which is long-term health hazards.

Chronic Central Serous Chorioretinopathy in a Patient with Pigment Dispersion Syndrome: A Possible Correlation

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Dimitrios Kourkoutas

2017-01-01

Full Text Available Chronic central serous chorioretinopathy (CSCR is a progressive chorioretinopathy with widespread atrophic RPE abnormalities and serous retinal detachments (SRDs present for 6 months or longer. We report a case of CSCR in a 38-year-old patient with Pigment Dispersion Syndrome (PDS. In the presented case of CSCR, the chronic course of the disease may in part be associated with an underlying generalized degenerative dysfunction of the pigmented cells of the eye on grounds of PDS. We suggest that a chronic course of disease may be suspected in the setting of CSCR with concurrent RPE pathology, such as what is found in PDS.

Treatment of gingival pigmentation : A case series

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Prasad Deepak

2005-01-01

Full Text Available A smile expresses a feeling of joy, success, sensuality, affection and courtesy, and reveals self confidence and kindness. The harmony of the smile is determined not only by the shape, the position and the color of the teeth but also by the gingival tissues. Gingival health and appearance are essential components of an attractive smile. Gingival pigmentation results from melanin granules, which are produced by melanoblasts. The degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of ′black gums′ are common particularly in patients having a very high smile line (gummy smile. For depigmentation of gingiva different treatment modalities have been reported like- Bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery and laser. In the present case series bur abrasion, scraping, partial thickness flap (epithelial excision cryotherapy and electrosurgery have been tried for depigmentation, which are simple, effective and yield good results, along with good patient satisfaction. The problems encountered with some of these techniques have also been discussed.

Noninvasive near infrared autofluorescence imaging of retinal pigment epithelial cells in the human retina using adaptive optics.

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Liu, Tao; Jung, HaeWon; Liu, Jianfei; Droettboom, Michael; Tam, Johnny

2017-10-01

The retinal pigment epithelial (RPE) cells contain intrinsic fluorophores that can be visualized using infrared autofluorescence (IRAF). Although IRAF is routinely utilized in the clinic for visualizing retinal health and disease, currently, it is not possible to discern cellular details using IRAF due to limits in resolution. We demonstrate that the combination of adaptive optics (AO) with IRAF (AO-IRAF) enables higher-resolution imaging of the IRAF signal, revealing the RPE mosaic in the living human eye. Quantitative analysis of visualized RPE cells in 10 healthy subjects across various eccentricities demonstrates the possibility for in vivo density measurements of RPE cells, which range from 6505 to 5388 cells/mm 2 for the areas measured (peaking at the fovea). We also identified cone photoreceptors in relation to underlying RPE cells, and found that RPE cells support on average up to 18.74 cone photoreceptors in the fovea down to an average of 1.03 cone photoreceptors per RPE cell at an eccentricity of 6 mm. Clinical application of AO-IRAF to a patient with retinitis pigmentosa illustrates the potential for AO-IRAF imaging to become a valuable complementary approach to the current landscape of high resolution imaging modalities.

The Role of Bloom Index of Gelatin on the Interaction with Retinal Pigment Epithelial Cells

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Jui Yang Lai

2009-08-01

Full Text Available Biocompatible materials are of considerable interest in the development of cell/drug delivery carriers for therapeutic applications. This paper investigates the effects of the Bloom index of gelatin on its interaction with retinal pigment epithelial (RPE cells. Following two days of culture of ARPE-19 cells with gelatin samples G75-100, G175, and G300, the in vitro biocompatibility was determined by cell proliferation and viability assays, and glutamate uptake measurements, as well as cytokine expression analyses. The mitochondrial dehydrogenase activity in the G300 groups was significantly lower than that of G75-100 and G175 groups. The Live/Dead assays also showed that the gelatin samples G300 induced mild cytotoxicity. In comparison with the treatment of gelatins with low Bloom index, the exposure to high Bloom strength gelatins markedly reduced the glutamate uptake capacity of ARPE-19 cells. One possible explanation for these observations is that the presence of gelatin samples G300 with high viscosity in the medium may affect the nutrient availability to cultured cells. The analyses of pro-inflammatory cytokine IL-6 expression at both mRNA and protein levels showed that the gelatins with low Bloom index caused less cellular inflammatory reaction and had more acceptable biocompatibility than their high Bloom strength counterparts. These findings suggest that the Bloom index gives influence on cellular responses to gelatin materials.

Contacting co-culture of human retinal microvascular endothelial cells alters barrier function of human embryonic stem cell derived retinal pigment epithelial cells.

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Skottman, H; Muranen, J; Lähdekorpi, H; Pajula, E; Mäkelä, K; Koivusalo, L; Koistinen, A; Uusitalo, H; Kaarniranta, K; Juuti-Uusitalo, K

2017-10-01

Here we evaluated the effects of human retinal microvascular endothelial cells (hREC) on mature human embryonic stem cell (hESC) derived retinal pigment epithelial (RPE) cells. The hESC-RPE cells (Regea08/017, Regea08/023 or Regea11/013) and hREC (ACBRI 181) were co-cultured on opposite sides of transparent membranes for up to six weeks. Thereafter barrier function, small molecule permeability, localization of RPE and endothelial cell marker proteins, cellular fine structure, and growth factor secretion of were evaluated. After co-culture, the RPE specific CRALBP and endothelial cell specific von Willebrand factor were appropriately localized. In addition, the general morphology, pigmentation, and fine structure of hESC-RPE cells were unaffected. Co-culture increased the barrier function of hESC-RPE cells, detected both with TEER measurements and cumulative permeability of FD4 - although the differences varied among the cell lines. Co-culturing significantly altered VEGF and PEDF secretion, but again the differences were cell line specific. The results of this study showed that co-culture with hREC affects hESC-RPE functionality. In addition, co-culture revealed drastic cell line specific differences, most notably in growth factor secretion. This model has the potential to be used as an in vitro outer blood-retinal barrier model for drug permeability testing. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

PRESENTATION OF CENTRAL SEROUS CHORIORETINOPATHY IN TWO HUSBAND AND WIFE COUPLES.

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Kanesa-Thasan, Aditya; Fawzi, Amani A; Gill, Manjot K

2018-01-01

Central serous chorioretinopathy (CSC) is a disease in which serous detachment of the neurosensory retina occurs over an area of leakage from the choriocapillaris through the retinal pigment epithelium. Associations have been drawn between high-stress personality types and steroid exposure. This article aims to describe a unique case series of two husband and wife couples with CSC. All methods were approved by the authors' institution's institutional review board. History, physical examination, and imaging data were obtained from the electronic medical records of the patients in question and from the providers who cared for these patients. Couple 1: A 35-year-old man presented with "dark spots" in his right eye. He reported no recent steroid use. Visual acuity at presentation was 20/30 in the right eye and 20/20 in the left eye. On fundus examination, there was subretinal fluid in the right eye. His wife presented on the same day with a "wavy section" in the right eye for 6 weeks. She also had no recent steroid use. Visual acuity at presentation was 20/20 in both eyes with blunting of the foveal reflex in the right eye. Optical coherence tomography showed a thick choroid with a pigment epithelial detachment in the right eye. Couple 2: A 34-year-old man presented with "blurry vision" in his right eye for one month. He was taking oral and nasal steroids for chronic sinusitis. Visual acuity was 20/30 in the right eye and 20/20 in the left eye. Fluorescein angiography and indocyanine green confirmed the diagnosis of CSC. After 3 months of persistent subretinal fluid, he received photodynamic therapy in the right eye. Three days after his photodynamic therapy, his 38-year-old wife presented with subjective blurring in both eyes. Visual acuity was 20/20 in both eyes, but optical coherence tomography showed thick choroid in both eyes, a large central pigment epithelial detachment in the right eye, and 3 small pigment epithelial detachments in the left eye. She had no

Monomethylfumarate induces γ-globin expression and fetal hemoglobin production in cultured human retinal pigment epithelial (RPE) and erythroid cells, and in intact retina.

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Promsote, Wanwisa; Makala, Levi; Li, Biaoru; Smith, Sylvia B; Singh, Nagendra; Ganapathy, Vadivel; Pace, Betty S; Martin, Pamela M

2014-05-13

Sickle retinopathy (SR) is a major cause of vision loss in sickle cell disease (SCD). There are no strategies to prevent SR and treatments are extremely limited. The present study evaluated (1) the retinal pigment epithelial (RPE) cell as a hemoglobin producer and novel cellular target for fetal hemoglobin (HbF) induction, and (2) monomethylfumarate (MMF) as an HbF-inducing therapy and abrogator of oxidative stress and inflammation in SCD retina. Human globin gene expression was evaluated by RT-quantitative (q)PCR in the human RPE cell line ARPE-19 and in primary RPE cells isolated from Townes humanized SCD mice. γ-Globin promoter activity was monitored in KU812 stable dual luciferase reporter expressing cells treated with 0 to 1000 μM dimethylfumarate, MMF, or hydroxyurea (HU; positive control) by dual luciferase assay. Reverse transcriptase-qPCR, fluorescence-activated cell sorting (FACS), immunofluorescence, and Western blot techniques were used to evaluate γ-globin expression and HbF production in primary human erythroid progenitors, ARPE-19, and normal hemoglobin producing (HbAA) and homozygous β(s) mutation (HbSS) RPE that were treated similarly, and in MMF-injected (1000 μM) HbAA and HbSS retinas. Dihydroethidium labeling and nuclear factor (erythroid-derived 2)-like 2 (Nrf2), IL-1β, and VEGF expression were also analyzed. Retinal pigment epithelial cells express globin genes and synthesize adult and fetal hemoglobin MMF stimulated γ-globin expression and HbF production in cultured RPE and erythroid cells, and in HbSS mouse retina where it also reduced oxidative stress and inflammation. The production of hemoglobin by RPE suggests the potential involvement of this cell type in the etiology of SR. Monomethylfumarate influences multiple parameters consistent with improved retinal health in SCD and may therefore be of therapeutic potential in SR treatment. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Myo-inositol uptake by cultured calf retinal pigment epithelial cells: regulation by glucose

International Nuclear Information System (INIS)

Khatami, M.; Rockey, J.H.

1986-01-01

Confluent primary (P-1) or subcultured passage 2 or 3 (P-2, P-3) calf retinal pigment epithelial cells (RPE) were incubated with [ 3 H]-myo-inositol (MI, 100-200 μM) in balanced salt solution (BSS), for 5 to 60 min at 37 0 C. MI uptake into RPE (P-2, 5 days old) was saturable with K/sub m/ of 147 μM and V/sub max/ of 5.5 pmole/min/μg DNA. P-1 or P-2 incubated with 10 μM MI for 40 min accumulated MI against a concentration gradient ([MI]in/[MI]out > 20). Replacement of 150 mM NaCl in BSS by 150 mM choline-Cl reduced the uptake of MI by 87%. MI uptake was inhibited (39%) when cells were incubated in BSS in the absence of Ca Cl 2 . Transport of MI into RPE incubated in the presence of phloridzin, ouabain or 2,4-dinitrophenol (1 mM each) for 10 min was inhibited by 65, 37 and 21%, respectively. α-D-Glucose (20 mM) in the incubation media inhibited MI uptake into primary (or P-2) cultured RPE by 30 or 43% when cells were incubated for 10 or 60 min, respectively. The ability of RPE cells, grown in the presence of 50 mM glucose for 15-25 days, to concentrate MI (40 μM) was reduced up to 41%. Cultured RPE cells accumulated myo-inositol by an active transport system, sensitive to ouabain, DNP and phloridzin. High glucose in the incubation media or in the growth media inhibited the uptake of MI into calf RPE cells

Serous retinal detachment accompanied by MEWDS in a myopic patient with dome-shaped macula.

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Shin, Min Kyu; Byon, Ik Soo; Park, Sung Who; Lee, Ji Eun

2014-01-01

Macular serous retinal detachment (MSRD) is a rare complication in highly myopic patients with an inferior staphyloma, tilted disc, or dome-shaped macula. Multiple evanescent white dot syndrome (MEWDS) presents with sudden visual loss and multiple yellowish dots that resolve spontaneously within several weeks. The authors report the development and spontaneous resolution of subretinal fluid accompanied by MEWDS in a myopic patient with a dome-shaped macula. Dysfunction of the retinal pigment epithelium due to MEWDS likely induced temporary MSRD in this patient. Copyright 2014, SLACK Incorporated.

Rhegmatogenous retinal detachment and conventional surgical treatment.

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Golubovic, M

2013-01-01

The aim of the paper was to present the efficacy and indications for application of conventional surgical treatment of retinal detachment by using external implants, that is,application of encircling band and buckle. This study comprised patients from the University Eye Clinic in Skopje. A total of 33 patients were diagnosed and surgically treated in the period between May 2010 and August 2011. Conventional surgery was applied in smaller number of patients whose changes of the vitreous body were manifested by detachment of posterior hyaloid membrane, syneresis, with appearance of a small number of pigment cells in the vitreous body and synchysis, and the very retina was with fresh detachment without folds or epiretinal changes (that is, PVR A grade). There were a larger number of patients with more distinct proliferative changes of the vitreous body and of the retina, grades PVR B to C1-C2, and who also underwent the same surgical approach. Routine ophthalmologic examinations were performed, including: determination of visual acuity by Snellen's optotypes, determination of eye pressure with Schiotz's tonometer, examination of anterior segment on biomicroscopy, indirect biomicroscopy of posterior eye segment (vitreous body and retina) and examination on biomicroscopy with Goldmann prism, B scan echography of the eyes before and after surgical treatment. Conventional treatment was used by external application of buckle or application of buckle and encircling band. In case of one break, radial buckle was applied and in case of multiple breaks in one quadrant limbus parallel buckle was applied. Besides buckle, encircling band was applied in patients with total or subtotal retinal detachment with already present distinct changes in the vitreous body (PVR B or C1-C2) and degenerative changes in the vitreous body. Breaks were closed with cryopexy. The results obtained have shown that male gender was predominant and that the disease was manifested in younger male adults

HIV-1 impairs human retinal pigment epithelial barrier function: possible association with the pathogenesis of HIV-associated retinopathy.

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Tan, Suiyi; Duan, Heng; Xun, Tianrong; Ci, Wei; Qiu, Jiayin; Yu, Fei; Zhao, Xuyan; Wu, Linxuan; Li, Lin; Lu, Lu; Jiang, Shibo; Liu, Shuwen

2014-07-01

The breakdown of human retinal pigment epithelial (HRPE) barrier is considered as the etiology of retinopathy, which affects the quality of life of HIV/AIDS patients. Here we demonstrate that HIV-1 could directly impair HRPE barrier function, which leads to the translocation of HIV-1 and bacteria. HRPE cells (D407) were grown to form polarized, confluent monolayers and treated with different HIV-1 infectious clones. A significant increase of monolayer permeability, as measured by trans-epithelial electrical resistance (TEER) and apical-basolateral movements of sodium fluorescein, was observed. Disrupted tightness of HRPE barrier was associated with the downregulation of several tight junction proteins in D407 cells, including ZO-1, Occludin, Claudin-1, Claudin-2, Claudin-3, Claudin-4, and Claudin-5, after exposure to HIV-1, without affecting the viability of cells. HIV-1 gp120 was shown to participate in the alteration of barrier properties, as evidenced by decreased TEER and weakened expression of tight junction proteins in D407 monolayers after exposure to pseudotyped HIV-1, UV-inactivated HIV-1, and free gp120, but not to an envelope (Env)-defective mutant of HIV. Furthermore, exposure to HIV-1 particles could induce the release of pro-inflammatory cytokines in D407, including IL-6 and MCP-1, both of which downregulated the expression of ZO-1 in the HRPE barrier. Disrupted HRPE monolayer allowed translocation of HIV-1 and bacteria across the epithelium. Overall, these findings suggest that HIV-1 may exploit its Env glycoprotein to induce an inflammatory state in HRPE cells, which could result in impairment of HRPE monolayer integrity, allowing virus and bacteria existing in ocular fluids to cross the epithelium and penetrate the HRPE barrier. Our study highlights the role of HIV-1 in the pathogenesis of HIV/AIDS-related retinopathy and suggests potential therapeutic targets for this ocular complication.

Efficient gene delivery to primary human retinal pigment epithelial cells: The innate and acquired properties of vectors.

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Tasharrofi, Nooshin; Kouhkan, Fatemeh; Soleimani, Masoud; Soheili, Zahra-Soheila; Atyabi, Fatemeh; Akbari Javar, Hamid; Abedin Dorkoosh, Farid

2017-02-25

The purpose of this study is designing non-viral gene delivery vectors for transfection of the primary human retinal pigment epithelial cells (RPE). In the design process of gene delivery vectors, considering physicochemical properties of vectors alone does not seem to be enough since they interact with constituents of the surrounding environment and hence gain new characteristics. Moreover, due to these interactions, their cargo can be released untimely or undergo degradation before reaching to the target cells. Further, the characteristics of cells itself can also influence the transfection efficacy. For example, the non-dividing property of RPE cells can impede the transfection efficiency which in most studies was ignored by using immortal cell lines. In this study, vectors with different characteristics differing in mixing orders of pDNA, PEI polymer, and PLGA/PEI or PLGA nanoparticles were prepared and characterized. Then, their characteristics and efficacy in gene delivery to RPE cells in the presence of vitreous or fetal bovine serum (FBS) were evaluated. All formulations showed no cytotoxicity and were able to protect pDNA from premature release and degradation in extracellular media. Also, the adsorption of vitreous or serum proteins onto the surface of vectors changed their properties and hence cellular uptake and transfection efficacy. Copyright © 2016 Elsevier B.V. All rights reserved.

2-ethylpyridine, a cigarette smoke component, causes mitochondrial damage in human retinal pigment epithelial cells in vitro

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S Mansoor

2014-01-01

Full Text Available Purpose: Our goal was to identify the cellular and molecular effects of 2-ethylpyridine (2-EP, a component of cigarette smoke on human retinal pigment epithelial cells (ARPE-19 in vitro. Materials and Methods: ARPE-19 cells were exposed to varying concentrations of 2-EP. Cell viability (CV was measured by a trypan blue dye exclusion assay. Caspase-3/7 and caspase-9 activities were measured by fluorochrome assays. The production of reactive oxygen/nitrogen species (ROS/RNS was detected with a 2′,7′-dichlorodihydrofluorescein diacetate dye assay. The JC-1 assay was used to measure mitochondrial membrane potential (ΔΨm. Mitochondrial redox potential was measured using a RedoxSensor Red kit and mitochondria were evaluated with Mitotracker dye. Results: After 2-EP exposure, ARPE-19 cells showed significantly decreased CV, increased caspase-3/7 and caspase-9 activities, elevated ROS/RNS levels, decreased ΔΨm value and decreased redox fluorescence when compared with control samples. Conclusions: These results show that 2-EP treatment induced cell death by caspase-dependent apoptosis associated with an oxidative stress and mitochondrial dysfunction. These data represent a possible mechanism by which smoking contributes to age-related macular degeneration and other retinal diseases and identify mitochondria as a target for future therapeutic interventions.

Gremlin promotes retinal pigmentation epithelial (RPE) cell proliferation, migration and VEGF production via activating VEGFR2-Akt-mTORC2 signaling.

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Liu, Yuan; Chen, Zhijun; Cheng, Haixia; Chen, Juan; Qian, Jing

2017-01-03

Retinopathy of prematurity (ROP) is characterized by late-phase pathologic retinal vasoproliferation. Gremlin is a novel vascular endothelial growth factors (VEGF) receptor 2 (VEGFR2) agonist and promotes angiogenic response. We demonstrated that gremlin expression was significantly increased in retinas of ROP model mice, which was correlated with VEGF upregulation. In retinal pigmentation epithelial (RPE) cells, gremlin activated VEGFR2-Akt-mTORC2 (mammalian target of rapamycin complex 2) signaling, and promoted cell proliferation, migration and VEGF production. VEGFR inhibition (by SU5416) or shRNA knockdown almost abolished gremlin-mediated pleiotropic functions in RPE cells. Further, pharmacological inhibition of Akt-mTOR, or shRNA knockdown of key mTORC2 component (Rictor or Sin1) also attenuated gremlin-exerted activities in RPE cells. We conclude that gremlin promotes RPE cell proliferation, migration and VEGF production possibly via activating VEGFR2-Akt-mTORC2 signaling. Gremlin could be a novel therapeutic target of ROP or other retinal vasoproliferation diseases.

Intraocular osseous metaplasia. A clinico-pathological study

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Vemuganti Geeta; Honavar Santosh; Jalali Subhadra

2002-01-01

Purpose: To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Methods: Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membra...

Serous Macular Detachments

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Hakan Özdemir

2012-03-01

Full Text Available Serous macular detachment has only recently been recognized to occur in a significant number of eyes with macular pathology including diabetic retinopathy, retinal vein occlusion, Behçet disease, Irvine-Gass syndrome and pars planitis. These serous retinal detachments associated with retinal vascular leakage are not suspected clinically or angiographically but can be diagnosed with optical coherence tomography (OCT beneath the edematous neurosensory retina. The detection of shallow foveal detachment may be helpful in better understanding the pathogenesis of these disorders. In addition, the detection of serous macular detachment may also help to better guide and assess the results of therapy in the future. (Turk J Oph thal mol 2012; 42: 146-9

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.

Retinal pigment epithelium culture;a potential source of retinal stem cells.

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Akrami, Hassan; Soheili, Zahra-Soheila; Khalooghi, Keynoush; Ahmadieh, Hamid; Rezaie-Kanavi, Mojgan; Samiei, Shahram; Davari, Malihe; Ghaderi, Shima; Sanie-Jahromi, Fatemeh

2009-07-01

To establish human retinal pigment epithelial (RPE) cell culture as a source for cell replacement therapy in ocular diseases. Human cadaver globes were used to isolate RPE cells. Each globe was cut into several pieces of a few millimeters in size. After removing the sclera and choroid, remaining tissues were washed in phosphate buffer saline and RPE cells were isolated using dispase enzyme solution and cultured in Dulbecco's Modified Eagle's Medium: Nutrient Mixture F-12 supplemented with 10% fetal calf serum. Primary cultures of RPE cells were established and spheroid colonies related to progenitor/stem cells developed in a number of cultures. The colonies included purely pigmented or mixed pigmented and non-pigmented cells. After multiple cellular passages, several types of photoreceptors and neural-like cells were detected morphologically. Cellular plasticity in RPE cell cultures revealed promising results in terms of generation of stem/progenitor cells from human RPE cells. Whether the spheroids and neural-like retinal cells were directly derived from retinal stem cells or offspring of trans-differentiating or de-differentiating RPE cells remains to be answered.

Multi-level communication of human retinal pigment epithelial cells via tunneling nanotubes.

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Dierk Wittig

Full Text Available BACKGROUND: Tunneling nanotubes (TNTs may offer a very specific and effective way of intercellular communication. Here we investigated TNTs in the human retinal pigment epithelial (RPE cell line ARPE-19. Morphology of TNTs was examined by immunostaining and scanning electron microscopy. To determine the function of TNTs between cells, we studied the TNT-dependent intercellular communication at different levels including electrical and calcium signalling, small molecular diffusion as well as mitochondrial re-localization. Further, intercellular organelles transfer was assayed by FACS analysis. METHODOLOGY AND PRINCIPAL FINDINGS: Microscopy showed that cultured ARPE-19 cells are frequently connected by TNTs, which are not attached to the substratum. The TNTs were straight connections between cells, had a typical diameter of 50 to 300 nm and a length of up to 120 µm. We observed de novo formation of TNTs by diverging from migrating cells after a short time of interaction. Scanning electron microscopy confirmed characteristic features of TNTs. Fluorescence microscopy revealed that TNTs between ARPE-19 cells contain F-actin but no microtubules. Depolymerisation of F-actin, induced by addition of latrunculin-B, led to disappearance of TNTs. Importantly, these TNTs could function as channels for the diffusion of small molecules such as Lucifer Yellow, but not for large molecules like Dextran Red. Further, organelle exchange between cells via TNTs was observed by microscopy. Using Ca²⁺ imaging we show the intercellular transmission of calcium signals through TNTs. Mechanical stimulation led to membrane depolarisation, which expand through TNT connections between ARPE-19 cells. We further demonstrate that TNTs can mediate electrical coupling between distant cells. Immunolabelling for Cx43 showed that this gap junction protein is interposed at one end of 44% of TNTs between ARPE-19 cells. CONCLUSIONS AND SIGNIFICANCE: Our observations indicate that

Lycopene inhibits PDGF-BB-induced retinal pigment epithelial cell migration by suppression of PI3K/Akt and MAPK pathways

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Chan, Chi-Ming [School of Medicine, Fu Jen Catholic University, Taipei Hsien, Taiwan, ROC (China); Department of Ophthalmology, Cardinal Tien Hospital, Taipei Hsien, Taiwan, ROC (China); Fang, Jia-You [Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan, ROC (China); Lin, Hsin-Huang [School of Medicine, Fu Jen Catholic University, Taipei Hsien, Taiwan, ROC (China); Yang, Chi-Yea [Department of Biotechnology, Vanung University, Taoyuan, Taiwan, ROC (China); Hung, Chi-Feng, E-mail: 054317@mail.fju.edu.tw [School of Medicine, Fu Jen Catholic University, Taipei Hsien, Taiwan, ROC (China)

2009-10-09

Retinal pigment epithelial (RPE) cells play a dominant role in the development of proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal reattachment surgery. Several studies have shown that platelet-derived growth factor (PDGF) exhibits chemotaxis and proliferation effects on RPE cells in PVR. In this study, the inhibitory effect of lycopene on PDGF-BB-induced ARPE19 cell migration is examined. In electric cell-substrate impedance sensing (ECIS) and Transwell migration assays, significant suppression of PDGF-BB-induced ARPE19 cell migration by lycopene is observed. Cell viability assays show no cytotoxicity of lycopene on RPE cells. Lycopene shows no effect on ARPE19 cell adhesion and is found to inhibit PDGF-BB-induced tyrosine phosphorylation and the underlying signaling pathways of PI3K, Akt, ERK and p38 activation. However, PDGF-BB and lycopene show no effects on JNK activation. Taken together, our results demonstrate that lycopene inhibits PDGF-BB-induced ARPE19 cell migration through inhibition of PI3K/Akt, ERK and p38 activation.

Lycopene inhibits PDGF-BB-induced retinal pigment epithelial cell migration by suppression of PI3K/Akt and MAPK pathways

International Nuclear Information System (INIS)

Chan, Chi-Ming; Fang, Jia-You; Lin, Hsin-Huang; Yang, Chi-Yea; Hung, Chi-Feng

2009-01-01

Retinal pigment epithelial (RPE) cells play a dominant role in the development of proliferative vitreoretinopathy (PVR), which is the leading cause of failure in retinal reattachment surgery. Several studies have shown that platelet-derived growth factor (PDGF) exhibits chemotaxis and proliferation effects on RPE cells in PVR. In this study, the inhibitory effect of lycopene on PDGF-BB-induced ARPE19 cell migration is examined. In electric cell-substrate impedance sensing (ECIS) and Transwell migration assays, significant suppression of PDGF-BB-induced ARPE19 cell migration by lycopene is observed. Cell viability assays show no cytotoxicity of lycopene on RPE cells. Lycopene shows no effect on ARPE19 cell adhesion and is found to inhibit PDGF-BB-induced tyrosine phosphorylation and the underlying signaling pathways of PI3K, Akt, ERK and p38 activation. However, PDGF-BB and lycopene show no effects on JNK activation. Taken together, our results demonstrate that lycopene inhibits PDGF-BB-induced ARPE19 cell migration through inhibition of PI3K/Akt, ERK and p38 activation.

Ocular toxicity of beta-blockers and benzalkonium chloride in pigmented rabbits: electrophysiological and morphological studies.

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Chou, A; Hori, S; Takase, M

1985-01-01

Subconjunctival injection of 0.2 ml of the following solutions was carried out once a day for two weeks in the albino and pigmented rabbit: commercial 0.5% timolol or 1% befunolol ophthalmic solutions, both containing benzalkonium chloride, and also these drug solutions containing no preservative, ophthalmic base solutions containing benzalkonium chloride, physiological saline solution or phosphate buffer solution. One week after daily injections of the commercial drug solutions or base solutions with benzalkonium chloride, the electroretinogram (ERG) showed a marked reduction in the a- and b-wave amplitudes in the pigmented rabbit, but the ERG changes were slight in the albino rabbit. After two weeks of injections, histological studies of the pigmented rabbit eyes revealed retinal detachment, visual cell loss and atrophy of the retinal pigment epithelium and choroid; the changes in the albino rabbit eyes were minimal. Injections of the beta-blockers containing no benzalkonium resulted in no significant changes in the ERG or in the tissue structures of all rabbits. Injections of only physiological saline or phosphate buffer had no deleterious effects. Therefore, the ocular toxicity of the beta-blockers was thought to be minor and the toxic effects seen in this study were thought to be due to benzalkonium chloride, which possibly accumulates in the ocular pigments.

Modulation of the Proteasome Pathway by Nano-Curcumin and Curcumin in Retinal Pigment Epithelial Cells.

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Ramos de Carvalho, J Emanuel; Verwoert, Milan T; Vogels, Ilse M C; Schipper-Krom, Sabine; Van Noorden, Cornelis J F; Reits, Eric A; Klaassen, Ingeborg; Schlingemann, Reinier O

2018-01-01

Curcumin has multiple biological effects including the modulation of protein homeostasis by the ubiquitin-proteasome system. The purpose of this study was to assess the in vitro cytotoxic and oxidative effects of nano-curcumin and standard curcumin and characterize their effects on proteasome regulation in retinal pigment epithelial (RPE) cells. Viability, cell cycle progression, and reactive oxygen species (ROS) production were determined after treatment with nano-curcumin or curcumin. Subsequently, the effects of nano-curcumin and curcumin on proteasome activity and the gene and protein expression of proteasome subunits PA28α, α7, β5, and β5i were assessed. Nano-curcumin (5-100 μM) did not show significant cytotoxicity or anti-oxidative effects against H2O2-induced oxidative stress, whereas curcumin (≥10 μM) was cytotoxic and a potent inducer of ROS production. Both nano-curcumin and curcumin induced changes in proteasome-mediated proteolytic activity characterized by increased activity of the proteasome subunits β2 and β5i/β1 and reduced activity of β5/β1i. Likewise, nano-curcumin and curcumin affected mRNA and protein levels of household and immunoproteasome subunits. Nano-curcumin is less toxic to RPE cells and less prone to induce ROS production than curcumin. Both nano-curcumin and curcumin increase proteasome-mediated proteolytic activity. These results suggest that nano-curcumin may be regarded as a proteasome-modulating agent of limited cytotoxicity for RPE cells. The Author(s). Published by S. Karger AG, Basel.

Fisetin and luteolin protect human retinal pigment epithelial cells from oxidative stress-induced cell death and regulate inflammation

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Hytti, Maria; Piippo, Niina; Korhonen, Eveliina; Honkakoski, Paavo; Kaarniranta, Kai; Kauppinen, Anu

2015-01-01

Degeneration of retinal pigment epithelial (RPE) cells is a clinical hallmark of age-related macular degeneration (AMD), the leading cause of blindness among aged people in the Western world. Both inflammation and oxidative stress are known to play vital roles in the development of this disease. Here, we assess the ability of fisetin and luteolin, to protect ARPE-19 cells from oxidative stress-induced cell death and to decrease intracellular inflammation. We also compare the growth and reactivity of human ARPE-19 cells in serum-free and serum-containing conditions. The absence of serum in the culture medium did not prevent ARPE-19 cells from reaching full confluency but caused an increased sensitivity to oxidative stress-induced cell death. Both fisetin and luteolin protected ARPE-19 cells from oxidative stress-induced cell death. They also significantly decreased the release of pro-inflammatory cytokines into the culture medium. The decrease in inflammation was associated with reduced activation of MAPKs and CREB, but was not linked to NF- κB or SIRT1. The ability of fisetin and luteolin to protect and repair stressed RPE cells even after the oxidative insult make them attractive in the search for treatments for AMD. PMID:26619957

Retinal Pigment Epithelial Cell Culture and Cooperation of L-carnitine in Reducing Stress Induced Cellular Damage

International Nuclear Information System (INIS)

Shamsi, Farrukh A.; Al-Rajhi, Ali A.; Athmanathan, S.; Boulton, M.; Chaudhry, Imtiaz A.

2006-01-01

Purpose was to show that L-carnitine (LC) is capable of reducing non-oxidative stress in the retinal pigment epithelial cells (RPE) of the human eye. The RPE cells were cultured from donor eyes, obtained immediately after post-mortem. The interaction between bovine serum albumin (BSA) and non-oxidative (sodium hydroxide and methyl methane sulphonate) stress-inducers was observed by recording the change in the absorption profiles of the interacting molecules after incubation in light for 5 hours and after treatment with LC. The isolated and cultured RPE cells from the human eyes were treated with sodium hydroxide or methyl methane sulphonate and/or LC for 5 hours under light, and the qualitative effect on cell morphology after treatment was analyzed by staining cells with Giemsa and visualization by light microscopy. The cell morphology was also qualitatively analyzed by scanning electron microscopy (SEM). L-carnitine and stress-inducers interact with BSA and bring about changes in the spectral profile of the interacted molecules. Light microscopy as well as SEM show that the changes in the cellular morphology, induced by 100 uM concentrations of non-oxidative stress-inducers, are considerably reduced in the presence of 100 uM LC. However, L-carnitine alone does not cause any qualitative damage to the cell morphology during incubation under similar conditions. The results give a preliminary indication that LC has ability to reduce the changes brought about by the non-oxidative stress-inducers in the RPF cells in culture. (author)

Neutrophils Compromise Retinal Pigment Epithelial Barrier Integrity

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Jiehao Zhou

2010-01-01

Full Text Available We hypothesized that neutrophils and their secreted factors mediate breakdown of the integrity of the outer blood-retina-barrier by degrading the apical tight junctions of the retinal pigment epithelium (RPE. The effect of activated neutrophils or neutrophil cell lysate on apparent permeability of bovine RPE-Choroid explants was evaluated by measuring [H] mannitol flux in a modified Ussing chamber. The expression of matrix metalloproteinase- (MMP- 9 in murine peritoneal neutrophils, and the effects of neutrophils on RPE tight-junction protein expression were assessed by confocal microscopy and western blot. Our results revealed that basolateral incubation of explants with neutrophils decreased occludin and ZO-1 expression at 1 and 3 hours and increased the permeability of bovine RPE-Choroid explants by >3-fold (P<.05. Similarly, basolateral incubation of explants with neutrophil lysate decreased ZO-1 expression at 1 and 3 hours (P<.05 and increased permeability of explants by 75%. Further, we found that neutrophils prominently express MMP-9 and that incubation of explants with neutrophils in the presence of anti-MMP-9 antibody inhibited the increase in permeability. These data suggest that neutrophil-derived MMP-9 may play an important role in disrupting the integrity of the outer blood-retina barrier.

Intraocular osseous metaplasia. A clinico-pathological study.

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Vemuganti, Geeta K; Honavar, Santosh G; Jalali, Subhadra

2002-09-01

To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membrane, fibrovascular proliferation and inflammation. Immunohistochemistry using monoclonal antibody against glial fibrillary acidic protein was performed to assess the glial component within the membranes and the proliferative vitreoretinal mass. Clinical records were reviewed and correlated with histopathologic findings. Osseous metaplasiaS was noted in 8 of 151 (5.2%) eyes examined. Clinical diagnosis in these was phthisis bulbi, staphyloma, absolute glaucoma and microphthalmos. Enucleation was performed for relief of symptoms (in painful blind eyes) or for cosmesis, and in an eye inciting sympathetic ophthalmia. Retinal detachment, gliosis and retinal pigment epithelial hyperplasia were noted in all the cases. Drusen with calcification or ossification (5 of 8), fibrovascular proliferation in the vitreous (5 of 8) and active inflammation (4 of 8) were the other associated histologic features. Location of ossification was subretinal in 3 cases, preretinal (ora serrata) in 1 case and in both locations in 4 cases. The eyes with subretinal osseous metaplasia had associated calcified drusen, while preretinal ossification was seen within the fibrovascular membranes. Chronic retinal detachment, hyperplasia and transdifferentiation of retinal pigment epithelium appear to be a few of the prerequisites for intraocular osseous metaplasia. Ossification can occur at isolated subretinal and preretinal locations or can involve both. Though a larger study is required to postulate the chronology of events, in

Intraocular osseous metaplasia. A clinico-pathological study

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Vemuganti Geeta

2002-01-01

Full Text Available Purpose: To evaluate the clinico-pathologic features of intraocular osseous metaplasia. Methods: Pathology specimens of enucleated eyes submitted to the ophthalmic pathology service at a tertiary eye-care referral center between January 1995 and June 1999 were studied for intraocular osseous metaplasia. Specific histopathologic features noted in specimens with osseous metaplasia were the presence of retinal detachment, gliosis, retinal pigment epithelial hyperplasia, drusen, epiretinal membrane, fibrovascular proliferation and inflammation. Immunohistochemistry using monoclonal antibody against glial fibrillary acidic protein was performed to assess the glial component within the membranes and the proliferative vitreoretinal mass. Clinical records were reviewed and correlated with histopathologic findings. Results: Osseous metaplasiaS was noted in 8 of 151 (5.2% eyes examined. Clinical diagnosis in these was phthisis bulbi, staphyloma, absolute glaucoma and microphthalmos. Enucleation was performed for relief of symptoms (in painful blind eyes or for cosmesis, and in an eye inciting sympathetic ophthalmia. Retinal detachment, gliosis and retinal pigment epithelial hyperplasia were noted in all the cases. Drusen with calcification or ossification (5 of 8, fibrovascular proliferation in the vitreous (5 of 8 and active inflammation (4 of 8 were the other associated histologic features. Location of ossification was subretinal in 3 cases, preretinal (ora serrata in 1 case and in both locations in 4 cases. The eyes with subretinal osseous metaplasia had associated calcified drusen, while preretinal ossification was seen within the fibrovascular membranes. Conclusion: Chronic retinal detachment, hyperplasia and transdifferentiation of retinal pigment epithelium appear to be a few of the prerequisites for intraocular osseous metaplasia. Ossification can occur at isolated subretinal and preretinal locations or can involve both. Though a larger study is

Raised intraocular pressure and recurrence of retinal detachment as complications of external retinal detachment surgery

International Nuclear Information System (INIS)

Jawwad, M.; Khan, B.; Shah, M.A.; Qayyum, I.; Aftab, M.; Qayyum, I.

2015-01-01

Patients with Rhegmatogenous retinal detachment may develop raised intraocular pressure and recurrence of retinal detachment when they undergo external retinal detachment surgery. The present study was conducted to determine the postoperative rise in intraocular pressure (IOP) and recurrence of retinal detachment. Methods: The present descriptive study was conducted at Eye department of Lady Reading Hospital, Peshawar on 25 patients of both genders from August 2012 to July 2014. Results: Of the 25 patients, 18 (72%) developed raised IOP in the immediate postoperative period; this figure decreased to 12 (48%) at one week. Following medical or surgical intervention in these 12 cases, there was only 1 (4%) case with mildly raised IOP at two weeks postoperative. Five (20%) cases developed recurrent retinal detachment which later resolved with treatment. There were no significant differences by age or gender. Conclusion: External Retinal Detachment Surgery raised intraocular pressure postoperatively and caused recurrence of retinal detachment. These complications were treated medically and surgically with resolution within two weeks. (author)

Quantitative Fundus Autofluorescence in Best Vitelliform Macular Dystrophy: RPE Lipofuscin is not Increased in Non-Lesion Areas of Retina.

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Sparrow, Janet R; Duncker, Tobias; Woods, Russell; Delori, François C

2016-01-01

Since the lipofuscin of retinal pigment epithelial (RPE) cells has been implicated in the pathogenesis of Best vitelliform macular dystrophy, we quantified fundus autofluorescence (quantitative fundus autofluorescence, qAF) as an indirect measure of RPE lipofuscin levels. Mean non-lesion qAF was found to be within normal limits for age. By spectral domain optical coherence tomography (SD-OCT) vitelliform lesions presented as fluid-filled subretinal detachments containing reflective material. We discuss photoreceptor outer segment debris as the source of the intense fluorescence of these lesions and loss of anion channel functioning as an explanation for the bullous photoreceptor-RPE detachment. Unexplained is the propensity of the disease for central retina.

The effects of platelet gel on cultured human retinal pigment epithelial (hRPE cells

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Sahar Balagholi

2017-11-01

Full Text Available The positive role of platelet gel (PG in tissue regeneration is well known, however, other characteristics of PG still remain to be determined. We investigated cellular and molecular changes in cultured human retinal pigment epithelial (hRPE cells when treated with different concentrations of PG named PG1, PG2, and PG3. hRPE cells were isolated from donor eyes of two newborn children, within 24 hours after their death. The cells were treated with three concentrations of PG for 7 days: 3 × 104/ml (PG1, 6 × 104/ml (PG2, and 9 × 104/ml (PG3. Fetal bovine serum was used as a control. Immunocytochemistry was performed with anti-RPE65 (H-85, anti-Cytokeratin 8/18 (NCL-5D3, and anti-PAX6 antibody. We used MTT assay to determine cell viability. Gene expressions of PAX6, MMP2, RPE65, ACTA2, MKI67, MMP9, and KDR were analyzed using real-time PCR. A significant increase in viability was observed for PG3-treated cells compared to control (p = 0.044 and compared to PG1 group (p = 0.027, on day 7. Cellular elongation together with dendritiform extensions were observed in PG-treated cells on days 1 and 3, while epithelioid morphology was observed on day 7. All cells were immunoreactive for RPE65, cytokeratin 8/18, and PAX6. No significant change was observed in the expression of MKI67 and PAX6, but the expressions of MMP2, MMP9, ACTA2, and KDR were significantly higher in PG2-treated cells compared to controls (p < 0.05. Our results indicate that increased concentration of PG and extended exposure time have positive effects on viability of hRPE cells. PG may be useful for hRPE cell encapsulation in retinal cell replacement therapy.

Vitreous-induced cytoskeletal rearrangements via the Rac1 GTPase-dependent signaling pathway in human retinal pigment epithelial cells

International Nuclear Information System (INIS)

Huang, Xionggao; Wei, Yantao; Ma, Haizhi; Zhang, Shaochong

2012-01-01

Highlights: ► Vitreous induces morphological changes and cytoskeletal rearrangements in RPE cells. ► Rac1 is activated in vitreous-transformed RPE cells. ► Rac inhibition prevents morphological changes in vitreous-transformed RPE cells. ► Rac inhibition suppresses cytoskeletal rearrangements in vitreous-transformed RPE cells. ► The vitreous-induced effects are mediated by a Rac1 GTPase/LIMK1/cofilin pathway. -- Abstract: Proliferative vitreoretinopathy (PVR) is mainly caused by retinal pigment epithelial (RPE) cell migration, invasion, proliferation and transformation into fibroblast-like cells that produce the extracellular matrix (ECM). The vitreous humor is known to play an important role in PVR. An epithelial-to-mesenchymal transdifferentiation (EMT) of human RPE cells induced by 25% vitreous treatment has been linked to stimulation of the mesenchymal phenotype, migration and invasion. Here, we characterized the effects of the vitreous on the cell morphology and cytoskeleton in human RPE cells. The signaling pathway that mediates these effects was investigated. Serum-starved RPE cells were incubated with 25% vitreous, and the morphological changes were examined by phase-contrast microscopy. Filamentous actin (F-actin) was examined by immunofluorescence and confocal microscopy. Protein phosphorylation of AKT, ERK1/2, Smad2/3, LIM kinase (LIMK) 1 and cofilin was analyzed by Western blot analysis. Vitreous treatment induced cytoskeletal rearrangements, activated Rac1 and enhanced the phosphorylation of AKT, ERK1/2 and Smad2/3. When the cells were treated with a Rac activation-specific inhibitor, the cytoskeletal rearrangements were prevented, and the phosphorylation of Smad2/3 was blocked. Vitreous treatment also enhanced the phosphorylation of LIMK1 and cofilin and the Rac inhibitor blocked this effect. We propose that vitreous-transformed human RPE cells undergo cytoskeletal rearrangements via Rac1 GTPase-dependent pathways that modulate LIMK1 and

Vitreous-induced cytoskeletal rearrangements via the Rac1 GTPase-dependent signaling pathway in human retinal pigment epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Huang, Xionggao [State Key Ophthalmic Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou (China); Department of Ophthalmology, Hainan Medical College, Haikou (China); Wei, Yantao; Ma, Haizhi [State Key Ophthalmic Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou (China); Zhang, Shaochong, E-mail: zhshaochong@163.com [State Key Ophthalmic Laboratory, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou (China)

2012-03-09

Highlights: Black-Right-Pointing-Pointer Vitreous induces morphological changes and cytoskeletal rearrangements in RPE cells. Black-Right-Pointing-Pointer Rac1 is activated in vitreous-transformed RPE cells. Black-Right-Pointing-Pointer Rac inhibition prevents morphological changes in vitreous-transformed RPE cells. Black-Right-Pointing-Pointer Rac inhibition suppresses cytoskeletal rearrangements in vitreous-transformed RPE cells. Black-Right-Pointing-Pointer The vitreous-induced effects are mediated by a Rac1 GTPase/LIMK1/cofilin pathway. -- Abstract: Proliferative vitreoretinopathy (PVR) is mainly caused by retinal pigment epithelial (RPE) cell migration, invasion, proliferation and transformation into fibroblast-like cells that produce the extracellular matrix (ECM). The vitreous humor is known to play an important role in PVR. An epithelial-to-mesenchymal transdifferentiation (EMT) of human RPE cells induced by 25% vitreous treatment has been linked to stimulation of the mesenchymal phenotype, migration and invasion. Here, we characterized the effects of the vitreous on the cell morphology and cytoskeleton in human RPE cells. The signaling pathway that mediates these effects was investigated. Serum-starved RPE cells were incubated with 25% vitreous, and the morphological changes were examined by phase-contrast microscopy. Filamentous actin (F-actin) was examined by immunofluorescence and confocal microscopy. Protein phosphorylation of AKT, ERK1/2, Smad2/3, LIM kinase (LIMK) 1 and cofilin was analyzed by Western blot analysis. Vitreous treatment induced cytoskeletal rearrangements, activated Rac1 and enhanced the phosphorylation of AKT, ERK1/2 and Smad2/3. When the cells were treated with a Rac activation-specific inhibitor, the cytoskeletal rearrangements were prevented, and the phosphorylation of Smad2/3 was blocked. Vitreous treatment also enhanced the phosphorylation of LIMK1 and cofilin and the Rac inhibitor blocked this effect. We propose that vitreous

Tonic Pupil and Corneal Anesthesia after Vitrectomy and Encircling Band for Retinal Detachment in an Ex-Premature Child

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Xavier Valldeperas

2010-09-01

Full Text Available An 11-year-old boy presented with a total retinal detachment in his right eye. He had a bilateral 360° argon laser treatment for an active retinopathy of prematurity performed after his birth. He underwent an uneventful pars plana vitrectomy, encircling band, 810-nm diode endolaser and heavy silicone oil (Densiron® endotamponade. A tonic pupil and abolition of corneal sensitivity, with a large epithelial defect, were observed during the postoperative period. We discuss the possible etiopathogenic mechanisms of the long and short ciliary nerves damage, and the role that retinopathy of prematurity and retinal detachment laser treatment and the encircling band placement might have played in the development of the tonic pupil and the corneal anesthesia.

Retinal detachment following endophthalmitis.

Science.gov (United States)

Nelsen, P T; Marcus, D A; Bovino, J A

1985-08-01

Fifty-five consecutive patients with a clinical diagnosis of bacterial endophthalmitis were reviewed. All patients were treated with systemic, periocular, topical, and intravitreal antibiotics. In addition, 33 of the patients underwent a pars plana vitrectomy. Nine retinal detachments occurred within six months of initial diagnosis. The higher frequency of retinal detachment in the vitrectomy group (21%) as compared to those patients managed without vitrectomy (9%) may be explained by a combination of surgical complications and the increased severity of endophthalmitis in the vitrectomy group. The two patients who developed retinal detachment during vitrectomy surgery rapidly progressed to no light perception. Conversely, the repair of retinal detachments diagnosed postoperatively had a good prognosis.

Water permeability of Na+-K+-2Cl- cotransporters in mammalian epithelial cells

DEFF Research Database (Denmark)

Hamann, Steffen; Herrera-Perez, José Jaime; Bundgaard, Magnus

2005-01-01

Water transport properties of the Na+-K+-2Cl- cotransporter (NKCC) were studied in cultures of pigmented epithelial cells (PE) from the ciliary body of the eye. Here, the membrane that faces upwards contains NKCCs and can be subjected to rapid changes in bathing solution composition and osmolarity...

PlGF gene knockdown in human retinal pigment epithelial cells.

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Akrami, Hassan; Soheili, Zahra-Soheila; Sadeghizadeh, Majid; Ahmadieh, Hamid; Rezaeikanavi, Mozhgan; Samiei, Shahram; Khalooghi, Keynoush

2011-04-01

To evaluate the knockdown of placental growth factor (PlGF) gene expression in human retinal pigment epithelium (RPE) cells and its effect on cell proliferation, apoptosis and angiogenic potential of RPE cells. Human RPE cells were isolated by dispase I solution and cultured in DMEM/F12 supplemented with 10% fetal calf serum (FCS). A small interfering RNA (siRNA) corresponding to PlGF mRNA and a scrambled siRNA (scRNA) were introduced into the cells. Cell proliferation and cell death were examined by ELISA. PlGF mRNA and protein were quantified by real-time polymerase chain reaction (PCR) and western blot. The levels of gene expression for human retinal pigment epithelium-specific protein 65 kDa (RPE65), cellular retinaldehyde-binding protein (CRALBP) and tyrosinase were examined by real-time PCR. The angiogenic activity of RPE cell-derived conditioned media was assayed by a tube formation assay using human umbilical vein endothelial cells (HUVECs). At a final siRNA concentration of 20 pmol/ml, the transfection efficiency was about 80%. The amount of PlGF transcripts was reduced to 10% after 36 h of incubation, and the amount of PlGF protein in culture supernatant was significantly decreased. Suppression of PlGF gene had no effect on RPE cell proliferation and survival, and there were no notable changes in the transcript levels of RPE65, CRALBP or tyrosinase for the cultures treated by siRNA cognate to PlGF. Vascular tube formation was efficiently reduced in HUVECs. Our findings present PlGF as a key modulator of angiogenic potential in RPE cells of the human retina.

Interventions for asymptomatic retinal breaks and lattice degeneration for preventing retinal detachment.

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Wilkinson, Charles P

2014-09-05

Asymptomatic retinal breaks and lattice degeneration are visible lesions that are risk factors for later retinal detachment. Retinal detachments occur when fluid in the vitreous cavity passes through tears or holes in the retina and separates the retina from the underlying retinal pigment epithelium. Creation of an adhesion surrounding retinal breaks and lattice degeneration, with laser photocoagulation or cryotherapy, has been recommended as an effective means of preventing retinal detachment. This therapy is of value in the management of retinal tears associated with the symptoms of flashes and floaters and persistent vitreous traction upon the retina in the region of the retinal break, because such symptomatic retinal tears are associated with a high rate of progression to retinal detachment. Retinal tears and holes unassociated with acute symptoms and lattice degeneration are significantly less likely to be the sites of retinal breaks that are responsible for later retinal detachment. Nevertheless, treatment of these lesions frequently is recommended, in spite of the fact that the effectiveness of this therapy is unproven. The objective of this review was to assess the effectiveness and safety of techniques used to treat asymptomatic retinal breaks and lattice degeneration for the prevention of retinal detachment. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 2), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2014), EMBASE (January 1980 to February 2014), PubMed (January 1948 to February 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials

Duration of reappearance of gingival melanin pigmentation after surgical removal - A clinical study

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Kaur Harjit

2010-01-01

Full Text Available Background: In dentistry, esthetics has a special place. Although gingival melanin pigmentation does not present a medical problem, clinicians are often faced with a challenge of achieving gingival esthetics. Materials and Methods: A method of de-epithelialization of the pigmented gingiva using Kirkland′s gingivectomy knife is described. Twenty patients who were conscious about their gingival melanin pigmentation were selected. The gingiva of the whole of the arch was abraded until the entire visible pigmentation was removed. Clinical observations for intensity of pigmentation were recorded at baseline and then after surgery at monthly intervals over a period of 9 months according to Dummett-Gupta Oral Pigmentation Index scoring criteria proposed by Dummett C. O. in 1964. Results: The mean gingival melanin pigmentation score came down to 0.407 after 9 months as compared to preoperative score, which was 2.24. No repigmentation occurred in fair-complexioned persons. In persons with wheatish complexion, repigmentation was seen in 85.71% of the cases, but scores came down to 0.38 postoperatively as compared to 2.27 preoperatively. In dark complexioned persons, repigmentation occurred in all cases, but the mean scores were 0.93 as compared to 2.40 preoperatively. The difference between preoperative and postoperative mean scores for each segment was put to statistical analysis by applying paired t test and was found to be significant. Conclusion: As this method has shown statistically significant results, it can be used in patients who are conscious of pigmented gingiva and want an esthetically satisfactory color.

A protective effect of anthocyanins and xanthophylls on UVB-induced damage in retinal pigment epithelial cells.

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Silván, Jose Manuel; Reguero, Marina; de Pascual-Teresa, Sonia

2016-02-01

Increased exposure to solar ultraviolet B (UVB) radiation causes oxidative damage that may promote age related macular degeneration (AMD) and other ocular pathologies. This study is aimed to demonstrate the protective effects of some anthocyanins and xanthophylls against the UVB-induced oxidative damage to retinal pigment epithelial (RPE) cells. ARPE-19 cells were treated with 5 μM cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, lutein, zeaxanthin or a mixture of cyanidin-3-O-glucoside:zeaxanthin prior to UVB exposure (500 J m(-2)). Cell viability and mitogen-activated protein kinase (MAPK) phosphorylation were determined by MTT assay and western blot analysis, respectively. Oxidative damage was evaluated by measuring the intracellular reactive oxygen species (ROS). The data showed that UVB irradiation reduces the cell viability to 46% with increasing of intracellular ROS levels and phosphorylation of MAPKs. However, pre-treatment (60 min) with 5 μM cyanidin-3-O-glucoside, lutein or zeaxanthin significantly reduced cellular ROS levels and phosphorylation of MAPKs (JNK1/2 and p38) mediated by UVB irradiation and subsequently increased cell viability. Thus, results show that UVB irradiation is able to induce apoptosis in ARPE-19 cells through oxidative stress; however anthocyanins and xanthophylls pre-treatment can attenuate this damage. This suggests that cyanidin-3-O-glucoside, lutein and zeaxanthin are effective in preventing UVB-induced damage in RPE cells and may be suitable as chemoprotective factors for the prevention of ocular damage. The use of natural dietary antioxidants might reduce ocular oxidative damage caused by UVB radiation.

Bioengineered Bruch's-like extracellular matrix promotes retinal pigment epithelial differentiation

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Samuel McLenachan

2017-07-01

Full Text Available In the eye, the retinal pigment epithelium (RPE adheres to a complex protein matrix known as Bruch's membrane (BrM. The aim of this study was to provide enriched conditions for RPE cell culture through the production of a BrM-like matrix. Our hypothesis was that a human RPE cell line would deposit an extracellular matrix (ECM resembling BrM. The composition and structure of ECM deposited by ARPE19 cells (ARPE19-ECM was characterized. To produce ARPE19-ECM, ARPE19 cells were cultured in the presence dextran sulphate. ARPE19-ECM was decellularized using deoxycholate and characterized by immunostaining and western blot analysis. Primary human RPE and induced pluripotent stem cells were seeded onto ARPE19-ECM or geltrex coated surfaces and examined by microscopy or RT-PCR. Culture of ARPE19 cells with dextran sulphate promoted nuclear localization of SOX2, formation of tight junctions and deposition of ECM. ARPE19 cells deposited ECM proteins found in the inner layers of BrM, including fibronectin, vitronectin, collagens IV and V as well as laminin-alpha-5, but not those found in the middle elastic layer (elastin or the outer layers (collagen VI. ARPE19-ECM promoted pigmentation in human RPE and pluripotent stem cell cultures. Expression of RPE65 was significantly increased on ARPE19-ECM compared with geltrex in differentiating pluripotent stem cell cultures. ARPE19 cells deposit ECM with a composition and structure similar to BrM in the retina. Molecular cues present in ARPE19-ECM promote the acquisition and maintenance of the RPE phenotype. Together, these results demonstrate a simple method for generating a BrM-like surface for enriched RPE cell cultures.

Microbiota facilitates dietary heme-induced epithelial hyperproliferation and hyperplasia by breaking the mucus barrier

NARCIS (Netherlands)

IJssennagger, Noortje; Belzer, Clara; Hooiveld, Guido; Dekker, Jan; Muller, Michael; Kleerebezem, Michiel; Meer, van der Roelof

2015-01-01

Colorectal cancer risk is associated with diets high in red meat. Heme, the pigment of red meat, induces cytotoxicity of colonic contents and elicits epithelial damage and compensatory hyperproliferation, leading to hyperplasia. Here we explore the possible causal role of the gut microbiota in

Risk factor profile in retinal detachment

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Azad Raj

1988-01-01

Full Text Available 150 cases of retinal detachment comprising 50 patients each of bilateral retinal detachment, unilateral retinal detachment without any retinal lesions in the fellow eve and unilateral retinal detachment with retinal lesions in the fellow eye were studied and the various associated risk factors were statistically analysed. The findings are discussed in relation to their aetiological and prognostic significance in the different types of retinal detachment. Based on these observations certain guidelines are offered which may be of value in decision making, in prophylactic detachment surgery. Tractional breaks in the superior temporal quadrant especially when symptomatic. mandate prophylactic treatment. Urgency is enhanced it′ the patient is aphakic. Associated myopia adds to the urgency. The higher incidence of initial right e′ e involvement in all groups suggests a vascular original possibly ischaemic.

The oxysterol 27-hydroxycholesterol increases β-amyloid and oxidative stress in retinal pigment epithelial cells

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Dasari Bhanu

2010-09-01

Full Text Available Abstract Background Alzheimer's disease (AD and age-related macular degeneration (AMD share several pathological features including β-amyloid (Aβ peptide accumulation, oxidative damage, and cell death. The causes of AD and AMD are not known but several studies suggest disturbances in cholesterol metabolism as a culprit of these diseases. We have recently shown that the cholesterol oxidation metabolite 27-hydroxycholesterol (27-OHC causes AD-like pathology in human neuroblastoma SH-SY5Y cells and in organotypic hippocampal slices. However, the extent to which and the mechanisms by which 27-OHC may also cause pathological hallmarks related to AMD are ill-defined. In this study, the effects of 27-OHC on AMD-related pathology were determined in ARPE-19 cells. These cells have structural and functional properties relevant to retinal pigmented epithelial cells, a target in the course of AMD. Methods ARPE-19 cells were treated with 0, 10 or 25 μM 27-OHC for 24 hours. Levels of Aβ peptide, mitochondrial and endoplasmic reticulum (ER stress markers, Ca2+ homeostasis, glutathione depletion, reactive oxygen species (ROS generation, inflammation and cell death were assessed using ELISA, Western blot, immunocytochemistry, and specific assays. Results 27-OHC dose-dependently increased Aβ peptide production, increased levels of ER stress specific markers caspase 12 and gadd153 (also called CHOP, reduced mitochondrial membrane potential, triggered Ca2+ dyshomeostasis, increased levels of the nuclear factor κB (NFκB and heme-oxygenase 1 (HO-1, two proteins activated by oxidative stress. Additionally, 27-OHC caused glutathione depletion, ROS generation, inflammation and apoptotic-mediated cell death. Conclusions The cholesterol metabolite 27-OHC is toxic to RPE cells. The deleterious effects of this oxysterol ranged from Aβ accumulation to oxidative cell damage. Our results suggest that high levels of 27-OHC may represent a common pathogenic factor for

Progression of retinal pigment epithelial atrophy in antiangiogenic therapy of neovascular age-related macular degeneration.

Science.gov (United States)

Schütze, Christopher; Wedl, Manuela; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

2015-06-01

To monitor retinal pigment epithelial (RPE) atrophy progression during antiangiogenic therapy of neovascular age-related macular degeneration (AMD) over 2 years using polarization-sensitive optical coherence tomography (OCT). Prospective interventional case series. setting: Clinical practice. Thirty patients (31 eyes) with treatment-naïve neovascular AMD. Standard intravitreal therapy (0.5 mg ranibizumab) was administered monthly during the first year and pro re nata (PRN; as-needed) during the second year. Spectral-domain (SD) OCT and polarization-sensitive OCT (selectively imaging the RPE) examinations were performed at baseline and at 1, 3, 6, 12, and 24 months using a standardized protocol. RPE-related changes were evaluated using a semi-automated polarization-sensitive OCT segmentation algorithm and correlated with SD OCT and fundus autofluorescence (FAF) findings. RPE response, geographic atrophy (GA) progression. Atrophic RPE changes included RPE thinning, RPE porosity, focal RPE atrophy, and development of GA. Early RPE loss (ie, RPE porosity, focal atrophy) increased progressively during initial monthly treatment and remained stable during subsequent PRN-based therapy. GA developed in 61% of eyes at month 24. Mean GA area increased from 0.77 mm(2) at 12 months to 1.10 mm(2) (standard deviation = 1.09 mm(2)) at 24 months. Reactive accumulation of RPE-related material at the lesion borders increased until month 3 and subsequently decreased. Progressive RPE atrophy and GA developed in the majority of eyes. RPE migration signifies certain RPE plasticity. Polarization-sensitive OCT specifically images RPE-related changes in neovascular AMD, contrary to conventional imaging methods. Polarization-sensitive OCT allows for precisely monitoring the sequence of RPE-related morphologic changes. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Mouse Retinal Pigmented Epithelial Cell Lines retain their phenotypic characteristics after transfection with Human Papilloma Virus: A new tool to further the study of RPE biology

Science.gov (United States)

Catanuto, Paola; Espinosa-Heidmann, Diego; Pereira-Simon, Simone; Sanchez, Patricia; Salas, Pedro; Hernandez, Eleut; Cousins, Scott W.; Elliot, Sharon J.

2009-01-01

Development of immortalized mouse retinal pigmented epithelial cell (RPE) lines that retain many of their in vivo phenotypic characteristics, would aid in studies of ocular diseases including age related macular degeneration (AMD). RPE cells were isolated from 16 month old (estrogen receptor knockout) ERKOα and ERKOβ mice and their C57Bl/6 wild type littermates. RPE65 and cellular retinaldehyde binding protein (CRALBP) expression, in vivo markers of RPE cells, were detected by real-time RT-PCR and western analysis. We confirmed the presence of epithelial cell markers, ZO1, cytokeratin 8 and 18 by immunofluorescence staining. In addition, we confirmed the distribution of actin filaments and the expression of ezrin. To develop cell lines, RPE cells were isolated, propagated and immortalized using human papilloma virus (HPV) 16 (E6/E7). RPE-specific markers and morphology were assessed before and after immortalization. In wildtype littermate controls, there was no evidence of any alterations in the parameters that we examined including MMP-2, TIMP-2, collagen type IV, and estrogen receptor (ER) α and ERβ protein expression and ER copy number ratio. Therefore, immortalized mouse RPE cell lines that retain their in vivo phenotype can be isolated from either pharmacologically or genetically manipulated mice, and may be used to study RPE cell biology. PMID:19013153

Neural retina-specific Aldh1a1 controls dorsal choroidal vascular development via Sox9 expression in retinal pigment epithelial cells.

Science.gov (United States)

Goto, So; Onishi, Akishi; Misaki, Kazuyo; Yonemura, Shigenobu; Sugita, Sunao; Ito, Hiromi; Ohigashi, Yoko; Ema, Masatsugu; Sakaguchi, Hirokazu; Nishida, Kohji; Takahashi, Masayo

2018-04-03

VEGF secreted from retinal pigment epithelial (RPE) cells is responsible for the choroidal vascular development; however, the molecular regulatory mechanism is unclear. We found that Aldh1a1 -/- mice showed choroidal hypoplasia with insufficient vascularization in the dorsal region, although Aldh1a1, an enzyme that synthesizes retinoic acids (RAs), is expressed in the dorsal neural retina, not in the RPE/choroid complex. The level of VEGF in the RPE/choroid was significantly decreased in Aldh1a1 -/- mice, and RA-dependent enhancement of VEGF was observed in primary RPE cells. An RA-deficient diet resulted in dorsal choroidal hypoplasia, and simple RA treatment of Aldh1a1 -/- pregnant females suppressed choroid hypoplasia in their offspring. We also found downregulation of Sox9 in the dorsal neural retina and RPE of Aldh1a1 -/- mice and RPE-specific disruption of Sox9 phenocopied Aldh1a1 -/- choroidal development. These results suggest that RAs produced by Aldh1a1 in the neural retina directs dorsal choroidal vascular development via Sox9 upregulation in the dorsal RPE cells to enhance RPE-derived VEGF secretion. © 2018, Goto et al.

[Prophylactic treatment of retinal detachment].

Science.gov (United States)

Binder, S; Riss, B

1981-08-01

The indications for and results of prophylactic treatment of retinal detachment during a period of five years are reported and compared with the results in the literature. Half of the cases (3 out of 6 eyes) which developed a retinal detachment had been horse-shoe tears combined with a vitreous hemorrhage. For this reason a small buckle operation is recommended in these cases, to prevent further traction. Lattice degeneration should rather be observed than treated, except in special cases: This includes eyes where the fellow eye had a detachment from a lattice degeneration, cases in which one eye is blind from an uncured detachment or has no useful visual acuity, and eyes whose fellow eye has giant tears. In aphakic eyes treatment of lattice degeneration is recommended, because the incidence of detachment from these areas is high, especially in young aphakic cases. In one aphakic eye which had been photocoagulated several times the formation of a preretinal membrane was observed.

KRAS Mutation and Epithelial-Macrophage Interplay in Pancreatic Neoplastic Transformation.

Science.gov (United States)

Bishehsari, Faraz; Zhang, Lijuan; Barlass, Usman; Preite, Nailliw; Turturro, Sanja; Najor, Matthew S; Shetuni, Brandon B; Zayas, Janet P; Mahdavinia, Mahboobeh; Abukhdeir, Abde M; Keshavarzian, Ali

2018-05-14

Pancreatic ductal adenocarcinoma (PDA) is characterized by epithelial mutations in KRAS and prominent tumor-associated inflammation, including macrophage infiltration. But knowledge of early interactions between neoplastic epithelium and macrophages in PDA carcinogenesis is limited. Using a pancreatic organoid model, we found that the expression of mutant KRAS in organoids increased i) ductal to acinar gene expression ratios, ii) epithelial cells proliferation, and iii) colony formation capacity in vitro, and endowed pancreatic cells with the ability to generate neoplastic tumors in vivo. KRAS mutations induced a pro-tumorigenic phenotype in macrophages. Altered macrophages decreased epithelial Pigment Epithelial Derived Factor (PEDF) expression and induced a cancerous phenotype. We validated our findings using annotated patient samples from The Cancer Genome Atlas (TCGA) as well as in our human PDA specimens. Epithelium-macrophage cross talk occurs early in pancreatic carcinogenesis where KRAS directly induces cancer-related phenotypes in epithelium, and also promotes a pro-tumorigenic phenotype in macrophages, in turn augmenting neoplastic growth. This article is protected by copyright. All rights reserved. © 2018 UICC.

Gut microbiota facilitates dietary heme-induced epithelial hyperproliferation by opening the mucus barrier in colon

NARCIS (Netherlands)

Ijssennagger, Noortje; Belzer, Clara; Hooiveld, Guido J; Dekker, Jan; van Mil, Saskia W C; Müller, Michael; Kleerebezem, Michiel; van der Meer, Roelof; van Mil, SWC

2015-01-01

Colorectal cancer risk is associated with diets high in red meat. Heme, the pigment of red meat, induces cytotoxicity of colonic contents and elicits epithelial damage and compensatory hyperproliferation, leading to hyperplasia. Here we explore the possible causal role of the gut microbiota in

Intraretinal proliferation induced by retinal detachment

International Nuclear Information System (INIS)

Fisher, S.K.; Erickson, P.A.; Lewis, G.P.; Anderson, D.H.

1991-01-01

Cellular proliferation after retinal detachment was studied by 3 H-thymidine light microscopic autoradiography in cats that had experimental detachments of 0.5-180 days duration. The animals underwent labeling 2 hr before death with an intraocular injection of 200 microCi of 3 H-thymidine. The number of labeled nuclei were counted in 1-micron thick tissue sections in regions of detachment, in regions of the experimental eyes that remained attached, and in control eyes that had no detachments. In the normal eye, in one that had only the lens and vitreous removed, and in the eyes with 0.5- and 1-day detachments, the number of labeled nuclei ranged from 0/mm (0.5-day detachment) to 0.38/mm (lens and vitreous removed only). By 2 days postdetachment, the number of labeled nuclei increased to 2.09/mm. The highest levels of labeling occurred in two animals with detachments of 3 (7.86/mm) and 4 (7.09/mm) days. Thereafter, the numbers declined steadily until near-baseline counts were obtained at 14 days. The number of labeled nuclei was slightly elevated in the attached regions of two animals with 3-day detachments. Labeled cell types included: Mueller cells, astrocytes, pericytes, and endothelial cells of the retinal vasculature, and both resident (microglial cells) and invading macrophages. In an earlier study RPE cells were also shown to proliferate in response to detachment. Thus, these data show that proliferation is a rapid response to detachment, reaching a maximum within 4 days, and that virtually every nonneuronal cell type in the retina can participate in this response. The data suggest that events leading to such clinical manifestations as proliferative vitreoretinopathy and subretinal fibrosis may have their beginnings in this very early proliferative response

An erupted odontoma associated with pigmentation: A histogenetic and histological perspective

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Gurkiran A Kaur

2012-01-01

Full Text Available Odontomas are hamartomatous malformations of odontogenic origin composed of all the structures that form the tooth. Pigmentation associated with odontomas is rare, with only two cases reported in the literature. The genesis of this composite malformation is attributable to the organizational failure of the developing odontogenic apparatus leading to abnormal morphodifferentiation. Although some odontomas erupt into the oral cavity, it defies the existing views of normal physiologic tooth movement thus raising questions over the use of this term. Here, we review a case of large odontoma in a 23-year-old male surfacing into the oral cavity from its intraosseous location. The unusual occurrence of melanotic pigmentation in the odontogenic epithelial rests was demonstrated by Mason Fontana special stain. The histogenesis of this unusual entity and explanation to its possible occurrence is discussed.

Survival Improvement in Human Retinal Pigment Epithelial Cells via Fas Receptor Targeting by miR-374a.

Science.gov (United States)

Tasharrofi, Nooshin; Kouhkan, Fatemeh; Soleimani, Masoud; Soheili, Zahra-Sheila; Kabiri, Mahboubeh; Mahmoudi Saber, Mohaddeseh; Dorkoosh, Farid Abedin

2017-12-01

Oxidative conditions of the eye could contribute to retinal cells loss through activating the Fas-L/Fas pathway. This phenomenon is one of the leading causes of some ocular diseases like age-related macular degeneration (AMD). By targeting proteins at their mRNA level, microRNAs (miRNAs) can regulate gene expression and cell function. The aim of the present study is to investigate Fas targeting by miR-374a and find whether it can inhibit Fas-mediated apoptosis in primary human retinal pigment epithelial (RPE) cells under oxidative stress. So, the primary human RPE cells were transfected with pre-miR-374a pLEX construct using polymeric carrier and were exposed to H 2 O 2 (200 μM) as an oxidant agent for induction of Fas expression. Fas expression at mRNA and protein level was evaluated by quantitative real-time PCR and Western blot analysis, respectively. These results revealed that miR-374a could prevent Fas upregulation under oxidative conditions. Moreover, Luciferase activity assay confirmed that Fas could be a direct target of miR-374a. The cell viability studies demonstrated that caspase-3 activity was negligible in miR-374a treated cells compared to the controls. Our data suggest miR-374a is a negative regulator of Fas death receptor which is able to enhance the cell survival and protect RPE cells against oxidative conditions. J. Cell. Biochem. 118: 4854-4861, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The influences of purple sweet potato anthocyanin on the growth characteristics of human retinal pigment epithelial cells

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Min Sun

2015-06-01

Full Text Available Background: Anthocyanins have been proven to be beneficial to the eyes. However, information is scarce about the effects of purple sweet potato (Ipomoea batatas, L. anthocyanin (PSPA, a class of anthocyanins derived from purple sweet potato roots, on visual health. Objective: The aim of this study was to investigate whether PSPA could have influences on the growth characteristics (cellular morphology, survival, and proliferation of human retinal pigment epithelial (RPE cells, which perform essential functions for the visual process. Methods: The RPE cell line D407 was used in the present study. The cytotoxicity of PSPA was assessed by MTT assay. Then, cellular morphology, viability, cell cycle, Ki67expression, and PI3K/MAPK activation of RPE cells treated with PSPA were determined. Results: PSPA exhibited dose-dependent promotion of RPE cell proliferation at concentrations ranging from 10 to 1,000 µg/ml. RPE cells treated with PSPA demonstrated a predominantly polygonal morphology in a mosaic arrangement, and colony-like cells displayed numerous short apical microvilli and typical ultrastructure. PSPA treatment also resulted in a better platform growing status, statistically higher viability, an increase in the S-phase, and more Ki67+ cells. However, neither pAkt nor pERK were detected in either group. Conclusions: We found that PSPA maintained high cell viability, boosted DNA synthesis, and preserved a high percentage of continuously cycling cells to promote cell survival and division without changing cell morphology. This paper lays the foundation for further research about the damage-protective activities of PSPA on RPE cells or human vision.

RECURRENCE OF CHOROIDAL NEOVASCULARIZATION LESION ACTIVITY AFTER AFLIBERCEPT TREATMENT FOR AGE-RELATED MACULAR DEGENERATION.

Science.gov (United States)

Wakazono, Tomotaka; Yamashiro, Kenji; Oishi, Akio; Ooto, Sotaro; Tamura, Hiroshi; Akagi-Kurashige, Yumiko; Hata, Masayuki; Takahashi, Ayako; Tsujikawa, Akitaka; Yoshimura, Nagahisa

2017-11-01

To examine the recurrence rate of choroidal neovascularization (CNV) lesion activity in age-related macular degeneration (AMD) and associated factors after 1-year aflibercept treatment. Age-related macular degeneration eyes with 1-year aflibercept fixed-regimen treatment and a follow-up period of at least 18 months from the initial aflibercept injection for treatment-naive exudative AMD were retrospectively evaluated. The recurrence rate was examined. Age, gender, visual acuity, AMD subtype, greatest linear dimension, and retinal and choroidal thicknesses at the 12th month examination were compared between eyes with and without recurrence. Presence of remnant polyps and pigment epithelial detachment (PED) morphology were also compared in polypoidal choroidal vasculopathy (PCV) eyes. Of the 98 eyes studied, 69 displayed a dry macula at the 12th month examination; 43.7% exhibited recurrence during the subsequent 12-month period in Kaplan-Meier analysis. Although no factors associated with recurrence were detected in AMD, remnant polyps and pigment epithelial detachment morphology at the 12th month examination were significantly associated with recurrence in polypoidal choroidal vasculopathy (P = 0.018 and 0.048, respectively). Continuous, proactive treatment would be considered overtreatment for more than half of the AMD eyes that achieved a dry macula. Angiography and optical coherence tomography analyses may be useful for predicting recurrence in polypoidal choroidal vasculopathy eyes.

Bevacizumab (Avastin® no tratamento da membrana neovascular coroidal secundária à degeneração macular relacionada à idade: relato de caso Bevacizumab (Avastin® in treatment of choroidal neovascularization secondary to age-related macular degeneration: a case report

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Tiago Eugênio Faria e Arantes

2007-12-01

Full Text Available As drogas anti-angiogênicas foram introduzidas recentemente no arsenal terapêutico das membranas neovasculares coroidais. O objetivo deste relato é descrever um caso de membranas neovasculares coroidais oculta com extenso descolamento do epitélio pigmentado da retina, tratada com bevacizumab (Avastin® intravítrea. A eficácia da medicação foi avaliada por meio da acuidade visual e de exames complementares (angiografia fluoresceínica, videoangiografia com indocianina verde e tomografia de coerência óptica. Após três injeções intravítreas de bevacizumab, obteve-se uma resposta anatômica e visual satisfatória, denotando benefícios da droga, apesar do extenso descolamento do epitélio pigmentado da retina associada a membranas neovasculares coroidais oculta.The antiangiogenic drugs have been recently introduced in the therapeutic armamentarium of choroidal neovascularization. The purpose of this report is to describe a case of occult choroidal neovascularization with extensive retinal pigment epithelial detachment treated with intravitreal bevacizumab (Avastin®. The efficacy of the medication was evaluated by means of visual acuity and complementary exams (fluorescein angiography, indocyanine green video angiography and optical coherence tomography. After three intravitreal injections of bevacizumab a satisfactory anatomic and visual response was achieved, showing benefits of the drug, despite the extensive retinal pigment epithelial detachment associated with occult choroidal neovascularization.

Controlling marginally detached divertor plasmas

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Eldon, D.; Kolemen, E.; Barton, J. L.; Briesemeister, A. R.; Humphreys, D. A.; Leonard, A. W.; Maingi, R.; Makowski, M. A.; McLean, A. G.; Moser, A. L.; Stangeby, P. C.

2017-06-01

A new control system at DIII-D has stabilized the inter-ELM detached divertor plasma state for H-mode in close proximity to the threshold for reattachment, thus demonstrating the ability to maintain detachment with minimal gas puffing. When the same control system was instead ordered to hold the plasma at the threshold (here defined as T e  =  5 eV near the divertor target plate), the resulting T e profiles separated into two groups with one group consistent with marginal detachment, and the other with marginal attachment. The plasma dithers between the attached and detached states when the control system attempts to hold at the threshold. The control system is upgraded from the one described in Kolemen et al (2015 J. Nucl. Mater. 463 1186) and it handles ELMing plasmas by using real time D α measurements to remove during-ELM slices from real time T e measurements derived from divertor Thomson scattering. The difference between measured and requested inter-ELM T e is passed to a PID (proportional-integral-derivative) controller to determine gas puff commands. While some degree of detachment is essential for the health of ITER’s divertor, more deeply detached plasmas have greater radiative losses and, at the extreme, confinement degradation, making it desirable to limit detachment to the minimum level needed to protect the target plate (Kolemen et al 2015 J. Nucl. Mater. 463 1186). However, the observed bifurcation in plasma conditions at the outer strike point with the ion B   ×  \

Pilot study of oral administration of a curcumin-phospholipid formulation for treatment of central serous chorioretinopathy

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Mazzolani F

2012-05-01

Full Text Available Fabio MazzolaniPrivate Practice, Milan, ItalyBackground: The purpose of this open-label study was to investigate the effect of a curcumin-phospholipid (lecithin, Meriva® formulation (Norflo® tablet on visual acuity and retinal thickness in patients with acute or chronic central serous chorioretinopathy.Methods: Visual acuity was assessed by ophthalmologic evaluation, and optical coherence tomography was used to measure retinal thickness. Norflo tablets were administered twice a day to patients affected by central serous chorioretinopathy. The study included 18 eyes from 12 patients who completed a 6-month follow-up period. Visual acuity before and after Norflo treatment was the primary endpoint. The secondary endpoints were neuroretinal or pigment epithelial detachment, as measured by optical coherence tomography.Results: After 6 months of therapy, 0% of eyes showed reduction in visual acuity, 39% showed stabilization, and 61% showed improvement. The improvement was statistically significant (P = 0.08. After 6 months of therapy, 78% of eyes showed reduction of neuroretinal or retinal pigment epithelium detachment, 11% showed stabilization, and 11% showed an increase.Conclusion: Our results, albeit preliminary, show that curcumin administered as Norflo tablets is efficacious for the management of central serous chorioretinopathy, a relapsing eye disease, and suggest that bioavailable curcumin is worth considering as a therapeutic agent for the management of inflammatory and degenerative eye conditions, including those that activate the retinal microglia.Keywords: curcumin, central serous chorioretinopathy, retinal pigment epithelium detachment, Norflo®, Meriva®

Uranium induces oxidative stress in lung epithelial cells

International Nuclear Information System (INIS)

Periyakaruppan, Adaikkappan; Kumar, Felix; Sarkar, Shubhashish; Sharma, Chidananda S.; Ramesh, Govindarajan T.

2007-01-01

Uranium compounds are widely used in the nuclear fuel cycle, antitank weapons, tank armor, and also as a pigment to color ceramics and glass. Effective management of waste uranium compounds is necessary to prevent exposure to avoid adverse health effects on the population. Health risks associated with uranium exposure includes kidney disease and respiratory disorders. In addition, several published results have shown uranium or depleted uranium causes DNA damage, mutagenicity, cancer and neurological defects. In the current study, uranium toxicity was evaluated in rat lung epithelial cells. The study shows uranium induces significant oxidative stress in rat lung epithelial cells followed by concomitant decrease in the antioxidant potential of the cells. Treatment with uranium to rat lung epithelial cells also decreased cell proliferation after 72 h in culture. The decrease in cell proliferation was attributed to loss of total glutathione and superoxide dismutase in the presence of uranium. Thus the results indicate the ineffectiveness of antioxidant system's response to the oxidative stress induced by uranium in the cells. (orig.)

Self-sustained detachment observed in LHD and comparison with detachment and Marfe in W7-AS

International Nuclear Information System (INIS)

Miyazawa, J.; Masuzaki, S.; Yamada, H.; Sakamoto, R.; Peterson, B. J.; Shoji, M.; Ohyabu, N.; Komori, A.; Motojima, O.

2005-01-01

One of the crucial issues for a magnetically confined fusion reactor [1-3] is the reduction of the divertor heat load. Edge plasma cooling by increasing the density or introducing impurities such as neon as radiators is effective for reducing the divertor heat load by detaching the plasma from the divertor plates. In high-density tokamak plasmas, the so-called high-recycling regime is predicted by two-point model [4,5], where the divertor temperature (density) nonlinearly decreases (increases) with the main plasma density. Detachment takes place when the density is increased further. Then, the pressure in the flux tube is no longer conserved due to the increased radiation loss, charge exchange loss, and volume recombination. Eventually, the discharge is terminated by disruption often via rapid formation of a radiation condensation Marfe [5,6]. This scenario well explains the experimental results of tokamaks [5,7]. A similar kind of conventional detachment has been also intensively studied in a stellarator, W7-AS, after modification to the island divertor configuration [8,9]. Detachment in W7-AS is achieved by increasing the density beyond the density threshold for the high-density H-mode (HDH) [10]. As the density is increased further to the operational density limit, complete detachment takes place and, in some cases, the Marfe is formed on (or inside of) the last-closed-flux-surface (LCFS) [11-13]. These are reviewed in Section 4. Recently, a new state of self-sustained detachment has been found in LHD and named the Serpens mode (Self-regulated plasma edge neath the last-closed-flux-surface) [15,16]. In the Serpens mode, the hot plasma boundary is shrinking to equal 90 % of the LCFS radius. Large fluctuations appear in the divertor flux, H alpha and Cm signals, together with a rotating radiation belt named the serpent [17]. Detachment in LHD is observed in a significant decrease in the ion saturation current, Isat, measured on the divertor tiles [18,19]. In this

Canine goniodysgenesis-related glaucoma: a morphologic review of 100 cases looking at inflammation and pigment dispersion.

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Reilly, Christopher M; Morris, Rebecca; Dubielzig, Richard R

2005-01-01

To investigate the role of pigment dispersion and inflammation in the pathogenesis of goniodysgenesis-related glaucoma (GDRG). Cases of GDRG were selected when the duration of the disease was specified and there was not any confounding pathology. Cases were grouped into 7-day (chronic) durations, based on the time required to effect end-stage retinal damage. Acute cases were further divided into pigment dispersion: segmental loss of posterior iris pigment epithelium, clumping of posterior iris pigment epithelium, pigmented cells in the trabecular meshwork or anterior chamber and preferential settling of pigmented cells in the ventral aspect of the iridocorneal angle. Slides were also evaluated for the presence of neutrophils and/or lymphoplasmacytic cells in the trabecular meshwork (TM). Differences between groups were analyzed statistically. Of 100 cases evaluated, 34 were 7-days (chronic) in duration. Of all globes examined, 96% had at least one sign of pigment dispersion, with no significant difference between groups. Two or more signs of pigment dispersion were present in 76% of all globes. The 4-7-day group was significantly more likely than the 7-day groups. Neutrophils were present in the TM of 86% of 7-day cases to have neutrophils in the TM, with 65% and 17% [corrected] positive cases, respectively. Lymphoplasmacytic inflammation was present in 53% of all cases, with no significant difference between groups. Cases in the 7-day cases to have both types of inflammation. Our results indicate that both acute inflammation and pigment dispersion may be key factors in the pathogenesis of GDRG. Pigment dispersion is prevalent at all time points and increases during the first 7 days. The finding of iris pigment epithelial loss supports the theory that pupillary block associated with iris-lens touching may be important in the pathogenesis of GDRG.

Paediatric retinal detachment: aetiology, characteristics and outcomes.

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McElnea, Elizabeth; Stephenson, Kirk; Gilmore, Sarah; O'Keefe, Michael; Keegan, David

2018-01-01

To provide contemporary data on the aetiology, clinical features and outcomes of paediatric retinal detachment. A retrospective review of all those under 16y who underwent surgical repair for retinal detachment at a single centre between the years 2008 and 2015 inclusive was performed. In each case the cause of retinal detachment, the type of detachment, the presence or absence of macular involvement, the number and form of reparative surgeries undertaken, and the surgical outcome achieved was recorded. Twenty-eight eyes of 24 patients, 15 (62.5%) of whom were male and 9 (37.5%) of whom were female, their mean age being 11.6y and range 2-16y developed retinal detachment over the eight year period studied. Trauma featured in the development of retinal detachment in 14 (50.0%) cases. Retinal detachment was associated with other ocular and/or systemic conditions in 11 (39.3%) cases. A mean of 3.0 procedures with a range of 1-9 procedures per patient were undertaken in the management of retinal detachment. Complex vitrectomy combined with scleral buckling or complex vitrectomy alone were those most frequently performed. Mean postoperative visual acuity was 1.2 logMAR with range 0.0-3.0 logMAR. In 22 of 26 (84.6%) cases which underwent surgical repair the retina was attached at last follow-up. Aggressive management of paediatric retinal detachment including re-operation increases the likelihood of anatomical success. In cases where the retinal detachment can be repaired by an external approach alone there is a more favourable visual outcome.

Resveratrol Protects Against Ultraviolet A-Mediated Inhibition of the Phagocytic Function of Human Retinal Pigment Epithelial Cells Via Large-Conductance Calcium-Activated Potassium Channels

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Shwu-Jiuan Sheu

2009-07-01

Full Text Available This study was undertaken to examine the protective effect of resveratrol on human retinal pigment epithelial (RPE cell phagocytosis against ultraviolet irradiation damage. Cultured RPE cells were exposed to ultraviolet A (UVA, 20 minutes irradiation, and treated with meclofenamic acid (30μM, 20 minutes, paxilline (100 μM, 20 minutes or resveratrol (10μM, 20 minutes. Meclofenamic acid and resveratrol were given after exposure to UVA. Pretreatment with meclofenamic acid, resveratrol or paxilline before UVA irradiation was also performed. Fluorescent latex beads were then fed for 4 hours and the phagocytotic function was assessed by flow cytometry. UVA irradiation inhibited the phagocytic function of human RPE cells. The large-conductance calcium-activated potassium channel activator meclofenamic acid ameliorated the damage caused by UVA irradiation. Pretreatment with resveratrol acid also provided protection against damage caused by UVA. Posttreatment with meclofenamic acid offered mild protection, whereas resveratrol did not. In conclusion, the red wine flavonoid resveratrol ameliorated UVA-mediated inhibition of human RPE phagocytosis. The underlying mechanism might involve the large-conductance calcium-activated potassium channels.

Transconjunctival drainage of serous and hemorrhagic choroidal detachment.

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Rezende, Flávio A; Kickinger, Mônica C; Li, Gisèle; Prado, Renata F; Regis, Luiz Gustavo T

2012-02-01

To describe a novel surgical technique for drainage of bullous serous and hemorrhagic choroidal detachments. A prospective, consecutive case series of 6 eyes with serous and/or hemorrhagic choroidal detachments secondary to intraocular surgery was documented to evaluate the feasibility of using the 25-gauge and 20-gauge transconjunctival trocar/cannula systems to drain choroidal detachments. Two eyes had expulsive hemorrhagic choroidal detachments and 4 eyes had serous choroidal detachments after glaucoma surgeries. A 25-gauge infusion line was placed in the anterior chamber. A 20-gauge (in eyes with hemorrhagic choroidal detachments) or a 25-gauge (in eyes with serous detachments) trocar/cannula system was inserted into the suprachoroidal space 7.0 mm from limbus. After drainage, the cannulas were removed and no sutures were placed. Pars plana vitrectomy was performed only in eyes with concomitant pathology that demanded the additional procedure. The primary outcome measure was presence of choroidal detachment at 1 week, 2 weeks, and 1 month postoperatively. Secondary outcome measures were visual acuity at 6 months and intraocular pressure at 1 week and 1, 3, and 6 months postoperatively. Drainage of hemorrhagic choroidal detachments resulted in resolution of the detachments by 1 month postoperatively. In eyes with serous detachments, resolution was achieved by 1 week postdrainage. In both groups, intraocular pressure increased to at least 10 mmHg by postoperative Week 1. The visual acuity improved in all eyes. No complications related to the transconjunctival technique were noted. Transconjunctival drainage of serous and hemorrhagic choroidal detachments seems to be a feasible and simple surgical option with minimal scleral and conjunctival damage. Pars plana vitrectomy may not be necessary when draining choroidal detachments in this manner.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus

OpenAIRE

Jing Zhang; Yujuan Suo; Daofeng Zhang; Fangning Jin; Hang Zhao; Chunlei Shi

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus, is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to...

Paediatric retinal detachment: aetiology, characteristics and outcomes

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Elizabeth McElnea

2018-02-01

Full Text Available AIM: To provide contemporary data on the aetiology, clinical features and outcomes of paediatric retinal detachment. METHODS: A retrospective review of all those under 16y who underwent surgical repair for retinal detachment at a single centre between the years 2008 and 2015 inclusive was performed. In each case the cause of retinal detachment, the type of detachment, the presence or absence of macular involvement, the number and form of reparative surgeries undertaken, and the surgical outcome achieved was recorded. RESULTS: Twenty-eight eyes of 24 patients, 15 (62.5% of whom were male and 9 (37.5% of whom were female, their mean age being 11.6y and range 2-16y developed retinal detachment over the eight year period studied. Trauma featured in the development of retinal detachment in 14 (50.0% cases. Retinal detachment was associated with other ocular and/or systemic conditions in 11 (39.3% cases. A mean of 3.0 procedures with a range of 1-9 procedures per patient were undertaken in the management of retinal detachment. Complex vitrectomy combined with scleral buckling or complex vitrectomy alone were those most frequently performed. Mean postoperative visual acuity was 1.2 logMAR with range 0.0-3.0 logMAR. In 22 of 26 (84.6% cases which underwent surgical repair the retina was attached at last follow-up. CONCLUSION: Aggressive management of paediatric retinal detachment including re-operation increases the likelihood of anatomical success. In cases where the retinal detachment can be repaired by an external approach alone there is a more favourable visual outcome.

Study on imaging diagnosis of the ciliochoroidal detachment

International Nuclear Information System (INIS)

Shi Dapeng; Feng Gansheng; Li Shuyin

2008-01-01

Objective: To investigate the characteristics of imaging appearances and diagnostic value of ciliochoroidal detachment. Methods: Ultrasound, MRI and CT appearances of 19 eases of ciliochoroidal detachment were reviewed, which included 9 cases of serous ciliochoroidal detachment, 7 cases of choroid hematoma, and 3 cases of ciliary, body detachment. All cases were examined by both B ultrasound and MRI at the same time, 11 of them were examined by CT. Results: Ultrasound showed membrane bulge of the eyeball wall with different extent in 9 cases of serous ciliochoroidal detachment. Its postzone connected the equator or close to optic disc and its prozone could not been detected by ultrasound. There was echofree fluid darkspace under detached membrane. MRI showed membrane detachment at both nasal side and temporal side of ocular annelation in 9 cases of ciliochoroidal detachment. The detached membrane was approximately symmetry, its anterior margin did not exceed ciliary body adhesion of ocular annelation and its posterior margin stopped at posterior part of ocular annelation. There was long T 1 and long T 2 signal under detached membrane. CT showed slight thickening of ocular annelation and slightly increased density of eyeball in 5 eases of serous ciliochoroidal detachment. Ultrasound showed hemispheroid or curve bulge of eyeball wall, projected toward the vitreous cavity in 7 cases of choroid hematoma, and there was an amount of low echo light spot under the detached membrane. Both MRI (7 cases) and CT (5 cases) showed hemispheroid, fusiform or curve bulge on the nasal side, temporal side and posterior part of ocular annelation. They appeared as isodensity or slight high density on CT, iso- or high signal on T 1 WI and T 2 WI. Stratification was seen on T 2 WI in 1 case of choroid hematoma. Ciliary body detachment could not been detected by either MRI (3 cases) or CT (1 case) except ultrasound. Conclusion: Imaging examination may provide reliable diagnostic evidence

Effects of glaucoma medications and preservatives on cultured human trabecular meshwork and non-pigmented ciliary epithelial cell lines.

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Ammar, David A; Kahook, Malik Y

2011-10-01

We investigated the potential cytotoxicity of various topical ophthalmic glaucoma formulations containing different preservatives in cultured human trabecular meshwork (TM) and non-pigmented ciliary epithelial (NPCE) cell lines. We tested 0.004% travoprost preserved with either 0.015% benzalkonium chloride (BAK), sofZia or 0.001% Polyquad (PQ); and 0.005% latanoprost preserved with 0.020% BAK. We also tested a range of BAK concentrations in balanced salt solution (BSS). TM cells were treated for 10 min at 37°C with solutions diluted 1:10 to mimic the reduced penetration of topical preparations to the anterior chamber. Viability was determined by the uptake of the fluorescent vital dye calcein-AM (n = 6). BAK solutions (diluted 1:10) demonstrated a dose-dependent reduction in cell viability in both cell types (TM and NPCE). With a 1:10 dilution of 0.020% BAK, there were significantly more living NPCE cells (89 ± 6%) than TM cells (57 ± 6%; p < 0.001). In TM cells, travoprost + BAK had statistically fewer live cells (83 ± 5%) than both travoprost + sofZia (97 ± 5%) and travoprost + PQ (97 ± 6%; p < 0.05). Compared with BSS-treated NPCE cells, travoprost had statistically fewer live cells (p < 0.05) when preserved with BAK (85 ± 16%), sofZia (91 ± 6%) or PQ (94 ± 2%). These results demonstrate that substitution of BAK from topical ophthalmic drugs results in greater viability of cultured TM cells, the cells involved in the conventional outflow pathway. Cultured NPCE, responsible for aqueous inflow, appear more resilient to BAK.

Role for nectin-1 in herpes simplex virus 1 entry and spread in human retinal pigment epithelial cells

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Tiwari, Vaibhav; Oh, Myung-Jin; Kovacs, Maria; Shukla, Shripaad Y.; Valyi-Nagy, Tibor; Shukla, Deepak

2009-01-01

Herpes simplex virus 1 (HSV-1) demonstrates a unique ability to infect a variety of host cell types. Retinal pigment epithelial (RPE) cells form the outermost layer of the retina and provide a potential target for viral invasion and permanent vision impairment. Here we examine the initial cellular and molecular mechanisms that facilitate HSV-1 invasion of human RPE cells. High-resolution confocal microscopy demonstrated initial interaction of green fluorescent protein (GFP)-tagged virions with filopodia-like structures present on cell surfaces. Unidirectional movement of the virions on filopodia to the cell body was detected by live cell imaging of RPE cells, which demonstrated susceptibility to pH-dependent HSV-1 entry and replication. Use of RT-PCR indicated expression of nectin-1, herpes virus entry mediator (HVEM) and 3-O-sulfotransferase-3 (as a surrogate marker for 3-O-sulfated heparan sulfate). HVEM and nectin-1 expression was subsequently verified by flow cytometry. Nectin-1 expression in murine retinal tissue was also demonstrated by immunohistochemistry. Antibodies against nectin-1, but not HVEM, were able to block HSV-1 infection. Similar blocking effects were seen with a small interfering RNA construct specifically directed against nectin-1, which also blocked RPE cell fusion with HSV-1 glycoprotein-expressing Chinese hamster ovary (CHO-K1) cells. Anti-nectin-1 antibodies and F-actin depolymerizers were also successful in blocking the cytoskeletal changes that occur upon HSV-1 entry into cells. Our findings shed new light on the cellular and molecular mechanisms that help the virus to enter the cells of the inner eye. PMID:18803666

Ostracism of an albino individual by a group of pigmented catfish.

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Ondřej Slavík

Full Text Available Physiological and behavioural constraints hinder albino individuals. Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness. The social aspect of albinism is reported only for human beings, and the effect is distinguishable in time and space when social benefits, are used to a limited the extent. Thus far, the social consequences of albinism for animals remain unknown. We used socially established groups of the pigmented catfish, (Silurus glanis, to observe space and temporal distance detachment of albino specimens in laboratory conditions. The albino fish were separated at larger distances from the group than pigmented individuals with the same social status determined by familiarity, and this asymmetry also varied in time. Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk. The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group. Our findings indicate a role for albinism in behavioural processes related to sociality in a group of conspecifics.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus.

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Zhang, Jing; Suo, Yujuan; Zhang, Daofeng; Jin, Fangning; Zhao, Hang; Shi, Chunlei

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus , is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD 450 ) of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST), and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM . Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs) and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59%) and ST25 (13%). Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus , non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus .

Retinal Detachment

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... to your brain. It provides the sharp, central vision needed for reading, driving, and seeing fine detail. A retinal detachment lifts or pulls the retina from its normal position. It can occur at ...

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Jing Zhang

2018-04-01

Full Text Available Staphyloxanthin (STX, a golden carotenoid pigment produced by Staphylococcus aureus, is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD450 of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST, and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM. Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59% and ST25 (13%. Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus, non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus.

A history of detachable coils: 1987-2012.

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Hui, Ferdinand K; Fiorella, David; Masaryk, Thomas J; Rasmussen, Peter A; Dion, Jacques E

2014-03-01

The development of detachable coils is one of the most pivotal developments in neurointervention, providing a tool that could be used to treat a wide variety of hemorrhagic stroke. From the original Guglielmi detachable coil, a number of different coil designs and delivery designs have evolved. This article reviews the history of commercially available detachable coils. A timeline of detachable coils was constructed and coil design philosophies were reviewed. A complete list of commercially available coils is presented in a timeline format. Detachable coil technology continues to evolve. Advances in construction and design have yielded products which may benefit patients in terms of safety, radiation dose reduction and cost of treatment. Continued evolution is expected, irrespective of competing disruptive technologies.

Cotransport of water by the Na+-K+-2Cl(-) cotransporter NKCC1 in mammalian epithelial cells

DEFF Research Database (Denmark)

Hamann, Steffen; Herrera-Perez, José J; Zeuthen, Thomas

2010-01-01

Water transport by the Na+-K+-2Cl(-) cotransporter (NKCC1) was studied in confluent cultures of pigmented epithelial (PE) cells from the ciliary body of the fetal human eye. Interdependence among water, Na+ and Cl(-) fluxes mediated by NKCC1 was inferred from changes in cell water volume, monitored...

SPECIFIC ROLE OF LYMPHATIC MARKER PODOPLANIN IN RETINAL PIGMENT EPITHELIAL CELLS

Science.gov (United States)

Grimaldo, S.; Garcia, M.; Zhang, H.; Chen, L.

2015-01-01

Podoplanin is a small transmembrane glycoprotein widely known to be a marker for lymphatic endothelial cells. In this study, we identify a novel localization of podoplanin in the retinal pigment epithelium (RPE), a cellular monolayer critically involved in the visual process. Using a small interfering RNA (siRNA)-mediated gene silencing approach, we have also demonstrated, for the first time, that podoplanin depletion in human RPE cells leads to a marked reduction of cell aggregates and tight junctions. Additionally, the podoplanin-depleted cells also exhibit a significantly lower rate of proliferation. These data together indicate that podoplanin plays a crucial role in RPE cell functions. Further investigation on this factor may reveal novel mechanisms and therapeutic strategies for RPE-related eye diseases, such as proliferative retinopathy and age-related macular degeneration. PMID:21226415

Suppression of experimental tractional retinal detachment by low-dose radiation therapy

International Nuclear Information System (INIS)

Meredith, T.A.; Ficker, L.; Stevens, R.; Olkowski, Z.; Anderson, M.; Hartmann, J.; Crocker, I.

1988-01-01

We used a standardized model of traction retinal detachment (TRD) created by cellular membranes in the rabbit to test the effects of low-dose radiation therapy in suppressing TRD. The vitreous and lens were removed from pigmented rabbits, and homologous conjunctival fibroblasts were grown in cell culture. After resolution of postoperative inflammation, 50,000 fibroblasts in 0.1 mL of culture fluid were injected into the vitreous cavity. Ten eyes were maintained as controls. Nineteen eyes received 6 Gy (600 rad) of x-ray irradiation one to three hours after cellular injection. Eyes were monitored weekly for three weeks with indirect ophthalmoscopy. Seven (70%) of ten control eyes developed TRD at one week; no additional TRDs were noted at weeks 2 and 3. Significantly smaller numbers of irradiated eyes developed TRD: at week 1, two (11%) of 19; at week 2, five (28%) of 18; and at week 3, five (29%) of 17

Risk of retinal detachment in patients with lattice degeneration.

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Sasaki, K; Ideta, H; Yonemoto, J; Tanaka, S; Hirose, A; Oka, C

1998-01-01

To determine the risk of retinal detachment in patients with lattice degeneration of the retina, we statistically analyzed the incidence of retinal detachment in these patients. The data of hospital patients with retinal detachment associated with lattice degeneration in Kumamoto Prefecture, Japan, in 1990 were collected. The prevalence of lattice degeneration in Kumamoto was reported to be 9.5% in 1980. Based on population data from the 1990 census, the cumulative incidence of retinal detachment associated with lattice degeneration was calculated in this study. Among 1,840,000 residents in Kumamoto, there were 110 patients with retinal detachment associated with lattice degeneration; 72 with detachment resulting from tractional tears (tears), and 38 with detachment from atrophic holes. The cumulative incidence of retinal detachment from atrophic holes was 1.5% at the age of 40 years; from tears it was 3.6% at the age of 80 years. The cumulative incidence of detachment from both atrophic holes and tears was 5.3% at the age of 80 years. The results of this study are useful for clarifying the natural course of lattice degeneration.

Iris phenotypes and pigment dispersion caused by genes influencing pigmentation.

Science.gov (United States)

Anderson, Michael G; Hawes, Norman L; Trantow, Colleen M; Chang, Bo; John, Simon W M

2008-10-01

Spontaneous mutations altering mouse coat colors have been a classic resource for discovery of numerous molecular pathways. Although often overlooked, the mouse iris is also densely pigmented and easily observed, thus representing a similarly powerful opportunity for studying pigment cell biology. Here, we present an analysis of iris phenotypes among 16 mouse strains with mutations influencing melanosomes. Many of these strains exhibit biologically and medically relevant phenotypes, including pigment dispersion, a common feature of several human ocular diseases. Pigment dispersion was identified in several strains with mutant alleles known to influence melanosomes, including beige, light, and vitiligo. Pigment dispersion was also detected in the recently arising spontaneous coat color variant, nm2798. We have identified the nm2798 mutation as a missense mutation in the Dct gene, an identical re-occurrence of the slaty light mutation. These results suggest that dysregulated events of melanosomes can be potent contributors to the pigment dispersion phenotype. Combined, these findings illustrate the utility of studying iris phenotypes as a means of discovering new pathways, and re-linking old ones, to processes of pigmented cells in health and disease.

Skin Pigmentation Disorders

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Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

Frictional and elastic energy in gecko adhesive detachment.

Science.gov (United States)

Gravish, Nick; Wilkinson, Matt; Autumn, Kellar

2008-03-06

Geckos use millions of adhesive setae on their toes to climb vertical surfaces at speeds of over 1 m s(-1). Climbing presents a significant challenge for an adhesive since it requires both strong attachment and easy, rapid removal. Conventional pressure-sensitive adhesives are either strong and difficult to remove (e.g. duct tape) or weak and easy to remove (e.g. sticky notes). We discovered that the energy required to detach adhering tokay gecko setae (W(d)) is modulated by the angle (theta) of a linear path of detachment. Gecko setae resist detachment when dragged towards the animal during detachment (theta = 30 degrees ) requiring W(d) = 5.0+/-0.86(s.e.) J m(-2) to detach, largely due to frictional losses. This external frictional loss is analogous to viscous internal frictional losses during detachment of pressure-sensitive adhesives. We found that, remarkably, setae possess a built-in release mechanism. Setae acted as springs when loaded in tension during attachment and returned elastic energy when detached along the optimal path (theta=130 degrees ), resulting in W(d) = -0.8+/-0.12 J m(-2). The release of elastic energy from the setal shaft probably causes spontaneous release, suggesting that curved shafts may enable easy detachment in natural, and synthetic, gecko adhesives.

Ectopic AP4 expression induces cellular senescence via activation of p53 in long-term confluent retinal pigment epithelial cells.

Science.gov (United States)

Wang, Yiping; Wong, Matthew Man-Kin; Zhang, Xiaojian; Chiu, Sung-Kay

2015-11-15

When cells are grown to confluence, cell-cell contact inhibition occurs and drives the cells to enter reversible quiescence rather than senescence. Confluent retinal pigment epithelial (RPE) cells exhibiting contact inhibition was used as a model in this study to examine the role of overexpression of transcription factor AP4, a highly expressed transcription factor in many types of cancer, in these cells during long-term culture. We generated stable inducible RPE cell clones expressing AP4 or AP4 without the DNA binding domain (DN-AP4) and observed that, when cultured for 24 days, RPE cells with a high level of AP4 exhibit a large, flattened morphology and even cease proliferating; these changes were not observed in DN-AP4-expressing cells or non-induced cells. In addition, AP4-expressing cells exhibited senescence-associated β-galactosidase activity and the senescence-associated secretory phenotype. We demonstrated that the induced cellular senescence was mediated by enhanced p53 expression and that AP4 regulates the p53 gene by binding directly to two of the three E-boxes present on the promoter of the p53 gene. Moreover, we showed that serum is essential for AP4 in inducing p53-associated cellular senescence. Collectively, we showed that overexpression of AP4 mediates cellular senescence involving in activation of p53 in long-term post-confluent RPE cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Risk of Retinal Detachment After Pediatric Cataract Surgery

DEFF Research Database (Denmark)

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

2014-01-01

PURPOSE: To determine the long-term risk of retinal detachment following pediatric cataract surgery and to identify risk factors for retinal detachment. METHODS: We included all children (aged 0 to 17 years) who during the time period of 1977 to 2005 underwent pediatric cataract surgery in Denmark...... was based on medical chart review. RESULTS: Among 1043 eyes of 656 children undergoing surgery for pediatric cataract, 25 eyes (23 children) developed retinal detachment at a median time of 9.1 years after surgery. The overall 20-year risk of retinal detachment was 7% (95% confidence interval [CI]: 3...... (16% [95% CI: 6%-24%]). CONCLUSIONS: The estimated overall risk of retinal detachment 20 years after pediatric cataract surgery was 7%, but only 3% for isolated cataract. Particularly high risks of retinal detachment after cataract surgery were associated with mental retardation and having other...

Retinal Detachment

Directory of Open Access Journals (Sweden)

Adnan Riaz, MD

2018-04-01

Full Text Available History of present illness: A 58-year-old female presented to the emergency department reporting six days of progressive, atraumatic left eye vision loss. Her symptoms started with the appearance of dark spots and “spider webs,” and then progressed to darkening of vision in her left eye. She reports mild pain since yesterday. Her review of symptoms was otherwise negative. Ocular physical examination revealed normal external appearance, intact extraocular movements, and visual acuities of 20/25 OD and light/dark sensitivity OS. Fluorescein uptake was negative and slit lamp exam was unremarkable. Significant findings: Bedside ocular ultrasound revealed a serpentine, hyperechoic membrane that appeared tethered to the optic disc posteriorly with hyperechoic material underneath. These findings are consistent with retinal detachment (RD and associated retinal hemorrhage. Discussion: The retina is a layer of organized neurons that line the posterior portion of the posterior chamber of the eye. RD occurs when this layer separates from the underlying epithelium, resulting in ischemia and progressive photoreceptor degeneration, with potentially rapid and permanent vision loss if left untreated.1 Risk factors include advanced age, male sex (60%, race (Asians and Jews, and myopia and lattice degeneration.2 Bedside ultrasound (US performed by emergency physicians provides a valuable tool that has been used by ophthalmologists for decades to evaluate intraocular disease.1,3 Findings on bedside ultrasound consistent with RD include a hyperechoic membrane floating in the posterior chamber. RD usuallyremain tethered to the optic disc posteriorly and do not cross midline, a feature distinguishing them from posterior vitreous detachments. Associated retinal hemorrhage, seen as hyperechoic material under the retinal flap, can often be seen.1,2 US can also distinguish between “mac-on” and “mac-off” detachments. If the retina is still attached to the

Epithelial ingrowth under a laser in situ keratomileusis flap after phacoemulsification.

Science.gov (United States)

Braunstein, Richard E; Airiani, Suzanna; Chang, Stanley

2003-11-01

A 47-year-old man was referred to us for management of a cataract in the left eye. The patient had an ocular history of high myopia with anisometropia, amblyopia in the left eye, and stable myopic lattice degeneration in both eyes. The patient had successful bilateral laser in situ keratomileusis 3 years before and multiple retinal surgeries for treatment of a rhegmatogenous retinal detachment associated with a giant retinal tear in the temporal region of the retina with subsequent proliferative vitreoretinopathy. Phacoemulsification was performed uneventfully. A single interrupted 10-0 nylon suture was placed in the temporal clear corneal wound and removed 7 weeks postoperatively. One month later, slitlamp examination revealed a 1.5 mm tongue-like area of epithelial ingrowth under the corneal flap. The epithelial cells seemed to enter the flap-stroma interface through the previously placed suture tract and advanced centrally.

Human Ocular Epithelial Cells Endogenously Expressing SOX2 and OCT4 Yield High Efficiency of Pluripotency Reprogramming.

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Ming-Wai Poon

Full Text Available A variety of pluripotency reprogramming frequencies from different somatic cells has been observed, indicating cell origin is a critical contributor for efficiency of pluripotency reprogramming. Identifying the cell sources for efficient induced pluripotent stem cells (iPSCs generation, and defining its advantages or disadvantages on reprogramming, is therefore important. Human ocular tissue-derived conjunctival epithelial cells (OECs exhibited endogenous expression of reprogramming factors OCT4A (the specific OCT 4 isoform on pluripotency reprogramming and SOX2. We therefore determined whether OECs could be used for high efficiency of iPSCs generation. We compared the endogenous expression levels of four pluripotency factors and the pluripotency reprograming efficiency of human OECs with that of ocular stromal cells (OSCs. Real-time PCR, microarray analysis, Western blotting and immunostaining assays were employed to compare OECiPSCs with OSCiPSCs on molecular bases of reprogramming efficiency and preferred lineage-differentiation potential. Using the traditional KMOS (KLF4, C-MYC, OCT4 and SOX2 reprogramming protocol, we confirmed that OECs, endogenously expressing reprogramming factors OCT4A and SOX2, yield very high efficiency of iPSCs generation (~1.5%. Furthermore, higher efficiency of retinal pigmented epithelial differentiation (RPE cells was observed in OECiPSCs compared to OSCiPSCs or skin fibroblast iMR90iPSCs. The findings in this study suggest that conjunctival-derived epithelial (OECs cells can be easier converted to iPSCs than conjunctival-derived stromal cells (OSCs. This cell type may also have advantages in retinal pigmented epithelial differentiation.

Human Ocular Epithelial Cells Endogenously Expressing SOX2 and OCT4 Yield High Efficiency of Pluripotency Reprogramming.

Science.gov (United States)

Poon, Ming-Wai; He, Jia; Fang, Xiaowei; Zhang, Zhao; Wang, Weixin; Wang, Junwen; Qiu, Fangfang; Tse, Hung-Fat; Li, Wei; Liu, Zuguo; Lian, Qizhou

2015-01-01

A variety of pluripotency reprogramming frequencies from different somatic cells has been observed, indicating cell origin is a critical contributor for efficiency of pluripotency reprogramming. Identifying the cell sources for efficient induced pluripotent stem cells (iPSCs) generation, and defining its advantages or disadvantages on reprogramming, is therefore important. Human ocular tissue-derived conjunctival epithelial cells (OECs) exhibited endogenous expression of reprogramming factors OCT4A (the specific OCT 4 isoform on pluripotency reprogramming) and SOX2. We therefore determined whether OECs could be used for high efficiency of iPSCs generation. We compared the endogenous expression levels of four pluripotency factors and the pluripotency reprograming efficiency of human OECs with that of ocular stromal cells (OSCs). Real-time PCR, microarray analysis, Western blotting and immunostaining assays were employed to compare OECiPSCs with OSCiPSCs on molecular bases of reprogramming efficiency and preferred lineage-differentiation potential. Using the traditional KMOS (KLF4, C-MYC, OCT4 and SOX2) reprogramming protocol, we confirmed that OECs, endogenously expressing reprogramming factors OCT4A and SOX2, yield very high efficiency of iPSCs generation (~1.5%). Furthermore, higher efficiency of retinal pigmented epithelial differentiation (RPE cells) was observed in OECiPSCs compared to OSCiPSCs or skin fibroblast iMR90iPSCs. The findings in this study suggest that conjunctival-derived epithelial (OECs) cells can be easier converted to iPSCs than conjunctival-derived stromal cells (OSCs). This cell type may also have advantages in retinal pigmented epithelial differentiation.

Dense pigmentation of the posterior lens capsule associated with the pigment dispersion syndrome.

Science.gov (United States)

Lin, Danny Y; Volpicelli, Mark; Singh, Kuldev

2003-12-01

To report an unusual case of pigment dispersion syndrome associated with unilateral dense pigmentation of the posterior lens capsule. Case report. A 59-year-old male with bilateral pigment dispersion syndrome presented with progressive decrease in visual acuity in the left eye over the past 10 to 20 years. Clinical examination revealed the typical findings of pigment dispersion syndrome including the presence of bilateral Krunkenberg spindles, iris transillumination defects, and heavy trabecular meshwork pigmentation. Of note, there was remarkably dense pigmentation of the posterior lens capsule in the eye with decreased visual acuity. Pigmentation of the posterior lens capsule may be a rare finding associated with pigment dispersion syndrome. Such a finding suggests that there may be aqueous flow into the retrolental space in some patients with this condition. The optimal treatment of this unusual condition remains undetermined.

Pyridine-pyrimidine amides that prevent HGF-induced epithelial scattering by two distinct mechanisms.

Science.gov (United States)

Siddiqui-Jain, Adam; Hoj, Jacob P; Hargiss, J Blade; Hoj, Taylor H; Payne, Carter J; Ritchie, Collin A; Herron, Steven R; Quinn, Colette; Schuler, Jeffrey T; Hansen, Marc D H

2017-09-01

Stimulation of cultured epithelial cells with scatter factor/hepatocyte growth factor (HGF) results in individual cells detaching and assuming a migratory and invasive phenotype. Epithelial scattering recapitulates cancer progression and studies have implicated HGF signaling as a driver of cancer metastasis. Inhibitors of HGF signaling have been proposed to act as anti-cancer agents. We previously screened a small molecule library for compounds that block HGF-induced epithelial scattering. Most hits identified in this screen exhibit anti-mitotic properties. Here we assess the biological mechanism of a compound that blocks HGF-induced scattering with limited anti-mitotic activity. Analogs of this compound have one of two distinct activities: inhibiting either cell migration or cell proliferation with cell cycle arrest in G2/M. Each activity bears unique structure-activity relationships. The mechanism of action of anti-mitotic compounds is by inhibition of microtubule polymerization; these compounds entropically and enthalpically bind tubulin in the colchicine binding site, generating a conformational change in the tubulin dimer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultrastructure of photo-sensory cells and pigment epithelium in the retina of the Antarctic fish Notothenia neglecta Nybelin (Nototheniidae

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Lucelia Donatti

2002-03-01

Full Text Available The Antarctic nototheniid Notothenia neglecta is the dominant fish in its habitat in Admiralty Bay, King George Island. They are predators, often ambush feeders, with accurate visual behaviour. For that reason, the ultrastructure of retinal photoreceptive cells and the pigment epithelium was analysed through electron microscopy. Their retina has a pigment epithelium, five different photoreceptors : rods, short single, long single, double, and triple cones, and neurones and support cells. The pigment epithelium is characterised by infoldings of the basal membrane, basal mitochondria, smooth reticule, large amount of microtubules, melanin granules, phagosomes and detached membranes of photoreceptors. Cones show bimembranous discs in the outer segment, an accessory outer segment, a connecting cilium, calycal processes, microtubules in the inferior ellipsoid and myoid, centrioles in the ellipsoid, interdigitating myoid fins and apical microvilli of Muller cells in the myoid and elliposid region. All these features allow all sorts of adaptations to the environmental photic variations, and situate N. neglecta among fish with a complex retina, with cells that are arranged in ten layers, allowing horizontal and vertical integration among them. This allows optimal visual behaviour and perception of food and environment in every Antarctic season.

Melanin dependent survival of Apergillus fumigatus conidia in lung epithelial cells.

Science.gov (United States)

Amin, Shayista; Thywissen, Andreas; Heinekamp, Thorsten; Saluz, Hans Peter; Brakhage, Axel A

2014-07-01

Aspergillus fumigatus is the most important air-borne pathogenic fungus of humans. Upon inhalation of conidia, the fungus makes close contact with lung epithelial cells, which only possess low phagocytic activity. These cells are in particular interesting to address the question whether there is some form of persistence of conidia of A. fumigatus in the human host. Therefore, by also using uracil-auxotrophic mutant strains, we were able to investigate the interaction of A549 lung epithelial cells and A. fumigatus conidia in detail for long periods. Interestingly, unlike professional phagocytes, our study showed that the presence of conidial dihydroxynaphthalene (DHN) melanin enhanced the uptake of A. fumigatus conidia by epithelial cells when compared with non-pigmented pksP mutant conidia. Furthermore, conidia of A. fumigatus were able to survive within epithelial cells. This was due to the presence of DHN melanin in the cell wall of conidia, because melanised wild-type conidia showed a higher survival rate inside epithelial cells and led to inhibition of acidification of phagolysosomes. Both effects were not observed for white (non-melanised) conidia of the pksP mutant strain. Moreover, in contrast to pksP mutant conidia, melanised wild-type conidia were able to inhibit the extrinsic apoptotic pathway in A549 lung epithelial cells even for longer periods. The anti-apoptotic effect was not restricted to conidia, because both conidia-derived melanin ghosts (cell-free DHN melanin) and a different type of melanin, dihydroxyphenylalanine (DOPA) melanin, acted anti-apoptotically. Taken together, these data indicate the possibility of melanin-dependent persistence of conidia in lung epithelial cells. Copyright © 2014 Elsevier GmbH. All rights reserved.

Retinal detachment repair

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... medicines Problems breathing You may not recover full vision. ... detachments can be repaired. Failure to repair the retina always results in loss of vision to some degree. After surgery, the quality of ...

Retinal detachment in paediatric patients

International Nuclear Information System (INIS)

Zafar, S. N.; Qureshi, N.; Azad, N.; Khan, A.

2013-01-01

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

The prognosis of retinal detachment due to lattice degeneration.

Science.gov (United States)

Benson, W E; Morse, P H

1978-09-01

In a series of 553 consecutive retinal detachments, 29% (120) were due to lattice degeneration. Forty-five percent of these were due to atrophic holes in the lattice degeneration and 55% were due to tears caused by traction posterior to or at the end of a patch of lattice. In phakic patients, retinal detachments due to atrophic holes were most common in young myopes. Detachments due to traction tears were seen in older, less myopic patients. The incidence of massive periretinal proliferation was less (5%) in detachments due to lattice degeneration than in detachments not due to lattice degeneration (6.5%).

Extensile posterior approach to the ankle with detachment of the achilles tendon for oncologic indications.

Science.gov (United States)

Maheshwari, Aditya V; Walters, Jason A; Henshaw, Robert M

2012-05-01

We describe an extensile posterior approach to the ankle with detachment of the Achilles tendon for resection of extensive tumors involving the posterior ankle. To the best of our knowledge, this approach and its results have not been reported for oncologic indications. The surgical technique involved detachment of the Achilles tendon, tumor resection and reconstruction of the Achilles tendon with anchor sutures, and was used in six patients. The diagnosis was pigmented villonodular synovitis (5) and chondroblastoma (1). At a mean of 6 (range, 2 to 10) years followup, all patients were free from tumor. All patients could walk an unlimited amount without any support. There were no problems with Achilles incompetence. The mean Musculoskeletal Tumor Society score was 97 ± 4.2% (range, 90 to 100) and the mean Achilles Tendon Total Rupture Score was 95 ± 5.7 (range, 87 to 100). One patient with screwed suture anchors had backing out of two anchors along with deep infection, requiring surgical debridement and anchor removal. One other patient had a post-traumatic small wound dehiscence which responded to local wound care. Excellent exposure, tumor control and patient function were achieved by this approach in a select group of patients. The surgical technique described in this report offers another alternative for an extensile posterior approach to the ankle and/or subtalar joints.

Fluctuation characteristics in detached recombining plasmas

International Nuclear Information System (INIS)

Ohno, Noriyasu; Tanaka, Naoyuki; Takamura, Shuichi; Budaev, Viatcheslav

2002-01-01

Fluctuation in detached recombining plasmas has been investigated experimentally in the linear divertor plasma simulator, NAGDIS-II. As increasing neutral gas pressure, floating potential fluctuation of the target plate installed at the end of the NADIS-II device becomes larger and bursty negative spikes are observed in the signal associated with a transition from attached to detached a plasmas. The fluctuation property has been analyzed by using Fast Fourier Transform (FFT), probability distribution function (PDF) and wavelet transform. The PDF of the floating potential fluctuation in the attached plasma condition obeys the Gaussian distribution function, on the other hand, the PDF in detached plasma shows a strong deviation from the Gaussian distribution function, which can be characterized by flatness and skewness. Comparison of the fluctuation properties between the floating potential and the optical emission from the detached plasma has been done based on the wavelet transform to show that a strong correlation between them, which could indicate bursty transport of energetic electrons from upstream to downstream region along the magnetic field. (author)

Retinal pigment epithelial changes in chronic Vogt-Koyanagi-Harada disease: fundus autofluorescence and spectral domain-optical coherence tomography findings.

Science.gov (United States)

Vasconcelos-Santos, Daniel V; Sohn, Elliott H; Sadda, Srinivas; Rao, Narsing A

2010-01-01

The purpose of this study was to determine whether fundus autofluorescence (FAF) and spectral domain-optical coherence tomography (SD-OCT) imaging allow better assessment of retinal pigment epithelium and the outer retina in subjects with chronic Vogt-Koyanagi-Harada disease compared with examination and angiography alone. A cross-sectional analysis of a series of seven consecutive patients with chronic Vogt-Koyanagi-Harada disease undergoing FAF and SD-OCT was conducted. Chronic disease was defined as duration of intraocular inflammation >3 months. Color fundus photographs were correlated to FAF and SD-OCT images. The images were later correlated to fluorescein angiography and indocyanine green angiography. All patients had sunset glow fundus, which resulted in no apparent corresponding abnormality on FAF or SD-OCT. Lesions with decreased autofluorescence signal were observed in 11 eyes (85%), being associated with loss of the retinal pigment epithelium and involvement of the outer retina on SD-OCT. In 5 eyes (38%), some of these lesions were very subtle on clinical examination but easily detected by FAF. Lesions with increased autofluorescence signal were seen in 8 eyes (61.5%), showing variable involvement of the outer retina on SD-OCT and corresponding clinically to areas of retinal pigment epithelium proliferation and cystoid macular edema. Combined use of FAF and SD-OCT imaging allowed noninvasive delineation of retinal pigment epithelium/outer retina changes in patients with chronic Vogt-Koyanagi-Harada disease, which were consistent with previous histopathologic reports. Some of these changes were not apparent on clinical examination.

Safety study of 38 503 intravitreal ranibizumab injections performed mainly by physicians in training and nurses in a hospital setting

DEFF Research Database (Denmark)

Hasler, Pascal W; Bloch, Sara Brandi; Villumsen, Jørgen

2015-01-01

detachment from 2007 to 2012. RESULTS: Overall, 38,503 intravitreal ranibizumab injections were performed in 4623 eyes. Injections were performed by nurses (32.5%), ophthalmology residents (61.3%) and vitreoretinal surgeons (6.2%). Severe complications to treatment were observed in 17 eyes: Endophthalmitis...... (14 eyes, 0.36 ‰ of injections whereof seven cases were culture-positive), anterior uveitis (one eye, 0.026 ‰), traumatic cataract (one eye, 0.026 ‰) and rhegmatogenous retinal detachment (one eye, 0.026 ‰). Retinal pigment epithelial tears were registered in 14 eyes in 14 subjects within the first...... year of treatment with ranibizumab. Of the 14 cases of endophthalmitis, seven occurred within a period of 5 weeks in 2010 when occasionally abnormal needle outflow resistance prompted the needle replacement in the operating room. No drug-related adverse events were recorded. CONCLUSIONS: Intravitreal...

Ocular hemodynamics in patients with rhegmatogenous retinal detachment

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N. H. Zavgorodnya

2014-10-01

Full Text Available Aim. In case of retinal detachment atrophic processes lead to irreversible loss of functions within 4–6 days, it happens on underlying low ocular blood flow. In order to evaluate the degree of violation of regional hemodynamics in patients with retinal detachment two groups of patients were examined: the main group (52 patients with rhegmatogenous retinal detachment and the control group (24 myopic patients with lattice form of peripheral chorioretinal dystrophy. Methods and results. Doppler and reography results had been compared, significant decrease of blood flow in patients with retinal detachment was found. No differences between affected and fellow eye in these patients, close negative correlation between the level of ocular blood flow and the degree of myopia in the control group. Conclusion. This demonstrates the feasibility of actions to improve regional blood flow in patients operated on for retinal detachment.

Characterization of active ion transport across primary rabbit corneal epithelial cell layers (RCrECL) cultured at an air-interface.

Science.gov (United States)

Chang-Lin, Joan-En; Kim, Kwang-Jin; Lee, Vincent H L

2005-06-01

Previously, we reported the development of a primary culture model of tight rabbit corneal epithelial cell layers (RCrECL) characterizing bioelectric parameters, morphology, cytokeratin, and passive permeability. In the present study, we specifically evaluated the active ion transport processes of RCrECL cultured from either pigmented or albino rabbits. Primary cultured RCrECL were grown at an air-interface on Clear-Snapwells precoated with collagen/fibronectin/laminin and mounted in a modified Ussing-type chamber for the evaluation of their active ion transport processes under short-circuited conditions. Contribution of active Na(+) and Cl(-) transport to overall short-circuit current (I(sc)) was evaluated by removing Na(+) and Cl(-), respectively, from bathing fluids of RCrECL and measurements of net fluxes of Na(+) and Cl(-) using (22)Na and (36)Cl, respectively. Amiloride and benzamil were used to determine the role of apical Na(+)-channel activities to net Na(+) fluxes. N-phenylanthranilic acid (NPAA), ouabain, BaCl(2) and bumetanide were used to determine the role of basolateral Na,K-ATPase, apical Cl(-)-channel, and basolateral K(+)-channel and Na(+)(K(+))2Cl(-)-cotransporter activities, respectively, in active ion transport across RCrECL. I(sc) of RCrECL derived from pigmented rabbits was comprised of 64+/-2% and 44+/-5% for active Na(+) and Cl(-) transport, respectively, consistent with net Na(+) absorption and Cl(-) secretion of 0.062+/-0.006 and 0.046+/-0.008 muEq/cm(2)/hr estimated from radionuclide fluxes. Apical amiloride and benzamil inhibited I(sc) by up to approximately 50% with an IC(50) of 1 and 0.1 microm, respectively, consistent with participation of apical epithelial Na(+)-channels to net Na(+) absorption across RCrECL cultured from pigmented rabbits. Addition of ouabain to the basolateral, NPAA to the apical, BaCl(2) to the basolateral and bumetanide to basolateral fluid decreased I(sc) by 86+/-1.5%, 53+/-3%, 18+/-1.8% and 13+/-1.9% in RCr

Risk of progression in macula-on rhegmatogenous retinal detachment.

Science.gov (United States)

Callizo, Josep; Pfeiffer, Sebastian; Lahme, Eva; van Oterendorp, Christian; Khattab, Mohammed; Bemme, Sebastian; Kulanga, Miroslav; Hoerauf, Hans; Feltgen, Nicolas

2017-08-01

To identify factors that may lead to a rapid progression in macula-on rhegmatogenous retinal detachment (RRD), in particular, those that may lead to macular involvement. Observational, prospective, single-center study. Patients referred for surgery due to primary rhegmatogenous retinal detachment with the macula on between 2009 and 2013 were included. Relevant factors analyzed included age, time delay until surgery, lens status, myopia, the detachment's location and configuration as well as number, size and type of retinal breaks. Eyes underwent optical coherence tomography to detect macular detachment. A multivariate analysis was performed to investigate the effect of several factors in the progression of retinal detachment. A total of 116 eyes of 116 patients were included. Mean time delay between admission and surgery was 1.8 ± 1.4 days. Progression was observed in 19.8% of the eyes. Of those, 47.8% presented macular detachment. Ten of the 11 (90.9%) eyes presenting progression involving the macula also exhibited a bullous configuration, which was the only parameter that correlated significantly with detachment progression in patients with (p = 0.0036) and without (p = 0.0014) macular involvement. For the first time in a prospective trial, a bullous configuration was found to be a highly significant predictor for progression in macula-on detachments. Our data support prompt surgery in patients diagnosed with bullous macula-on RRD.

Evidence from a mouse model that epithelial cell migration and mesenchymal-epithelial transition contribute to rapid restoration of uterine tissue integrity during menstruation.

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Fiona L Cousins

Full Text Available BACKGROUND: In women dynamic changes in uterine tissue architecture occur during each menstrual cycle. Menses, characterised by the shedding of the upper functional layer of the endometrium, is the culmination of a cascade of irreversible changes in tissue function including stromal decidualisation, inflammation and production of degradative enzymes. The molecular mechanisms that contribute to the rapid restoration of tissue homeostasis at time of menses are poorly understood. METHODOLOGY: A modified mouse model of menses was developed to focus on the events occurring within the uterine lining during endometrial shedding/repair. Decidualisation, vaginal bleeding, tissue architecture and cell proliferation were evaluated at 4, 8, 12, and 24 hours after progesterone (P4 withdrawal; mice received a single injection of bromodeoxyuridine (BrdU 90 mins before culling. Expression of genes implicated in the regulation of mesenchymal to epithelial transition (MET was determined using a RT2 PCR profiler array, qRTPCR and bioinformatic analysis. PRINCIPAL FINDINGS: Mice exhibited vaginal bleeding between 4 and 12 hours after P4 withdrawal, concomitant with detachment of the decidualised cell mass from the basal portion of the endometrial lining. Immunostaining for BrdU and pan cytokeratin revealed evidence of epithelial cell proliferation and migration. Cells that appeared to be in transition from a mesenchymal to an epithelial cell identity were identified within the stromal compartment. Analysis of mRNAs encoding genes expressed exclusively in the epithelial or stromal compartments, or implicated in MET, revealed dynamic changes in expression, consistent with a role for reprogramming of mesenchymal cells so that they could contribute to re-epithelialisation. CONCLUSIONS/SIGNIFICANCE: These studies have provided novel insights into the cellular processes that contribute to re-epithelialisation post-menses implicating both epithelial cell migration and

Evidence from a mouse model that epithelial cell migration and mesenchymal-epithelial transition contribute to rapid restoration of uterine tissue integrity during menstruation.

Science.gov (United States)

Cousins, Fiona L; Murray, Alison; Esnal, Arantza; Gibson, Douglas A; Critchley, Hilary O D; Saunders, Philippa T K

2014-01-01

In women dynamic changes in uterine tissue architecture occur during each menstrual cycle. Menses, characterised by the shedding of the upper functional layer of the endometrium, is the culmination of a cascade of irreversible changes in tissue function including stromal decidualisation, inflammation and production of degradative enzymes. The molecular mechanisms that contribute to the rapid restoration of tissue homeostasis at time of menses are poorly understood. A modified mouse model of menses was developed to focus on the events occurring within the uterine lining during endometrial shedding/repair. Decidualisation, vaginal bleeding, tissue architecture and cell proliferation were evaluated at 4, 8, 12, and 24 hours after progesterone (P4) withdrawal; mice received a single injection of bromodeoxyuridine (BrdU) 90 mins before culling. Expression of genes implicated in the regulation of mesenchymal to epithelial transition (MET) was determined using a RT2 PCR profiler array, qRTPCR and bioinformatic analysis. Mice exhibited vaginal bleeding between 4 and 12 hours after P4 withdrawal, concomitant with detachment of the decidualised cell mass from the basal portion of the endometrial lining. Immunostaining for BrdU and pan cytokeratin revealed evidence of epithelial cell proliferation and migration. Cells that appeared to be in transition from a mesenchymal to an epithelial cell identity were identified within the stromal compartment. Analysis of mRNAs encoding genes expressed exclusively in the epithelial or stromal compartments, or implicated in MET, revealed dynamic changes in expression, consistent with a role for reprogramming of mesenchymal cells so that they could contribute to re-epithelialisation. These studies have provided novel insights into the cellular processes that contribute to re-epithelialisation post-menses implicating both epithelial cell migration and mesenchymal cell differentiation in restoration of an intact epithelial cell layer. These

Posterior vitreous detachment and retinal detachment after cataract surgery.

Science.gov (United States)

Ripandelli, Guido; Coppé, Andrea Maria; Parisi, Vincenzo; Olzi, Diego; Scassa, Cecilia; Chiaravalloti, Adele; Stirpe, Mario

2007-04-01

To evaluate possible changes of vitreous status in emmetropic eyes after uneventful phacoemulsification surgery, and possible related complications such as the onset of retinal detachment (RD). Retrospective case series. Four hundred fifty-three emmetropic eyes from 453 patients (mean age, 62.03+/-5.57 years) subjected to uneventful phacoemulsification with intraocular lens implantation in the capsular bag were considered in the study. They had a refractive error within +/-0.5 diopters (mean, -0.21+/-0.08). Eyes with peripheral retinal lattice degeneration were included only if asymptomatic and only if the degeneration involved one retinal quadrant. After cataract surgery, the 453 eyes were evaluated preoperatively at days 1, 15, and 30 and months 3, 6, 12, 18, 24, 36, 48, and 60. The whole period of follow-up was 5 years. Evaluation of vitreous status by biomicroscopic examination, indirect binocular ophthalmoscopy, and B-scan ultrasonography. Postoperative onset of posterior vitreous detachment (PVD) and RD. After cataract surgery, a PVD occurred in 107 of 141 (75.88%) eyes without preoperative PVD or lattice degeneration. Posterior vitreous detachment occurred in 41 of 47 eyes (87.23%) with preoperative lattice degeneration and no PVD. Eyes with preoperative lattice degeneration and postoperative PVD showed a higher incidence of RD after cataract surgery (21.27%) than eyes without preoperative PVD or lattice degeneration (0.70%). In all patients with lattice degeneration, RD originated from horseshoe retinal tears on lattice areas located on the superior quadrants. No correlation was observed between the development of RD and age. Our results suggest that the onset of postoperative PVD should be considered an important risk factor for the development of RD after cataract surgery, particularly in eyes with lattice areas.

The potential and need for energy saving in standard family detached and semi-detached wooden houses in arctic Greenland

DEFF Research Database (Denmark)

Bjarløv, Søren Peter; Vladyková, Petra

2011-01-01

The paper gives an account of the potential and need for energy saving in standard family detached and semi-detached wooden houses in Greenland. It is based on studies of house construction compared with Building Regulation requirements and the spread of buildings over time. In the climatic...... conditions of Greenland, there is considerable potential for energy saving in houses due to their construction, shape and condition. To estimate the total potential for energy saving and thus reducing CO2 emissions, we carried out a detailed investigation of three typical standard semi-detached family houses...

A review of direct experimental measurements of detachment

Science.gov (United States)

Boedo, J.; McLean, A. G.; Rudakov, D. L.; Watkins, J. G.

2018-04-01

Detached divertor plasmas feature strong radial and parallel gradients of density, temperature, electric fields and flow over the divertor volume and therefore, sampling the divertor plasma directly provides crucial knowledge to the interpretation and modeling efforts. We review the contribution of diagnostics that directly sample the plasma to the advancement of knowledge of the physics of detachment and detached divertors, such as the characteristics of the various regimes, discovery and quantification of drifts and identification of convection of heat and particles. We focus on wall probes, scanning probes, retarding field analyzers and Thomson scattering in the divertor region and also include the contribution of measurements away from the divertor that provide insight on how divertor detachment affects core, edge or pedestal conditions. Wall probes are critical as they can be installed in closed volumes of difficult access to other diagnostics and measure plasma parameters at the divertor structures, which define the plasma boundary conditions and where detachment effects are more likely to be strongest.

Ecological-friendly pigments from fungi.

Science.gov (United States)

Durán, Nelson; Teixeira, Maria F S; De Conti, Roseli; Esposito, Elisa

2002-01-01

The dyestuff industry is suffering from the increases in costs of feedstock and energy for dye synthesis, and they are under increasing pressure to minimize the damage to the environment. The industries are continuously looking for cheaper, more environmentally friendly routes to existing dyes. The aim of this minireview is to discuss the most important advances in the fungal pigment area and its interest in biotechnological applications. Characteristic pigments are produced by a wide variety of fungi and the chemical composition of natural dyes are described. These pigments exhibit several biological activities besides cytotoxicity. The synthetic pigments authorized by the EC and in USA and the natural pigments available in the world market are discussed. The obstacle to the exploitation of new natural pigments sources is the food legislation, requesting costly toxicological research, manufacturing costs, and acceptance by consumers. The dislike for novel ingredients is likely to be the biggest impediment for expansion of the pigment list in the near future. If the necessary toxicological testing and the comparison with accepted pigments are made, the fungal pigments, could be acceptable by the current consumer. The potentiality of pigment production in Brazil is possible due to tremendous Amazonian region biodiversity.

PRMT1 and PRMT4 Regulate Oxidative Stress-Induced Retinal Pigment Epithelial Cell Damage in SIRT1-Dependent and SIRT1-Independent Manners

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Dong-Il Kim

2015-01-01

Full Text Available Oxidative stress-induced retinal pigment epithelial (RPE cell damage is involved in the progression of diabetic retinopathy. Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs has emerged as an important histone modification involved in diverse diseases. Sirtuin (SIRT1 is a protein deacetylase implicated in the onset of metabolic diseases. Therefore, we examined the roles of type I PRMTs and their relationship with SIRT1 in human RPE cells under H2O2-induced oxidative stress. H2O2 treatment increased PRMT1 and PRMT4 expression but decreased SIRT1 expression. Similar to H2O2 treatment, PRMT1 or PRMT4 overexpression increased RPE cell damage. Moreover, the H2O2-induced RPE cell damage was attenuated by PRMT1 or PRMT4 knockdown and SIRT1 overexpression. In this study, we revealed that SIRT1 expression was regulated by PRMT1 but not by PRMT4. Finally, we found that PRMT1 and PRMT4 expression is increased in the RPE layer of streptozotocin-treated rats. Taken together, we demonstrated that oxidative stress induces apoptosis both via PRMT1 in a SIRT1-dependent manner and via PRMT4 in a SIRT1-independent manner. The inhibition of the expression of type I PRMTs, especially PRMT1 and PRMT4, and increased SIRT1 could be therapeutic approaches for diabetic retinopathy.

Tractional retinal detachment in Usher syndrome type II.

Science.gov (United States)

Rani, Alka; Pal, Nikhil; Azad, Raj Vardhan; Sharma, Yog Raj; Chandra, Parijat; Vikram Singh, Deependra

2005-08-01

Retinal detachment is a rare complication in patients with retinitis pigmentosa. A case is reported of tractional retinal detachment in a patient with retinitis pigmentosa and sensorineural hearing loss, which was diagnosed as Usher syndrome type II. Because of the poor visual prognosis, the patient refused surgery in that eye. Tractional retinal detachment should be added to the differential diagnoses of visual loss in patients with retinitis pigmentosa.

Transition in plasma fluctuation between attached and detached plasmas

International Nuclear Information System (INIS)

Okazaki, Katsuya; Ohno, Noriyasu; Kajita, Shin; Tanaka, Hirohiko

2012-01-01

The static and dynamic behaviors of detached plasmas have received considerable attention because the use of a detached divertor is thought to provide a promising method for reducing the heat flux to plasma-facing components. In this study, fluctuations were measured with an electrostatic probe as the plasma was changed from attached to detached states by increasing the neutral gas pressure. The transition from an attached plasma to a detached plasma was found to change the phase relation between the density and the potential. (author)

A computer investigation of chemically mediated detachment in bacterial biofilms.

Science.gov (United States)

Hunt, Stephen M; Hamilton, Martin A; Sears, John T; Harkin, Gary; Reno, Jason

2003-05-01

A three-dimensional computer model was used to evaluate the effect of chemically mediated detachment on biofilm development in a negligible-shear environment. The model, BacLAB, combines conventional diffusion-reaction equations for chemicals with a cellular automata algorithm to simulate bacterial growth, movement and detachment. BacLAB simulates the life cycle of a bacterial biofilm from its initial colonization of a surface to the development of a mature biofilm with cell areal densities comparable to those in the laboratory. A base model founded on well established transport equations that are easily adaptable to investigate conjectures at the biological level has been created. In this study, the conjecture of a detachment mechanism involving a bacterially produced chemical detachment factor in which high local concentrations of this detachment factor cause the bacteria to detach from the biofilm was examined. The results show that the often observed 'mushroom'-shaped structure can occur if detachment events create voids so that the remaining attached cells look like mushrooms.

Detached Bridgman Growth of Germanium and Germanium-Silicon Alloy Crystals

Science.gov (United States)

Szofran, F. R.; Volz, M. P.; Schweizer, M.; Cobb, S. D.; Motakef, S.; Croell, A.; Dold, P.; Curreri, Peter A. (Technical Monitor)

2002-01-01

Earth based experiments on the science of detached crystal growth are being conducted on germanium and germanium-silicon alloys (2 at% Si average composition) in preparation for a series of experiments aboard the International Space Station (ISS). The purpose of the microgravity experiments includes differentiating among proposed mechanisms contributing to detachment, and confirming or refining our understanding of the detachment mechanism. Because large contact angle are critical to detachment, sessile drop measurements were used to determine the contact angles as a function of temperature and composition for a large number of substrates made of potential ampoule materials. Growth experiments have used pyrolytic boron nitride (pBN) and fused silica ampoules with the majority of the detached results occurring predictably in the pBN. The contact angles were 173 deg (Ge) and 165 deg (GeSi) for pBN. For fused silica, the contact angle decreases from 150 deg to an equilibrium value of 117 deg (Ge) or from 129 deg to an equilibrium value of 100 deg (GeSi) over the duration of the experiment. The nature and extent of detachment is determined by using profilometry in conjunction with optical and electron microscopy. The stability of detachment has been analyzed, and an empirical model for the conditions necessary to achieve sufficient stability to maintain detached growth for extended periods has been developed. Results in this presentation will show that we have established the effects on detachment of ampoule material, pressure difference above and below the melt, and silicon concentration; samples that are nearly completely detached can be grown repeatedly in pBN.

7,8-Dihydroxyflavone ameliorates high-glucose induced diabetic apoptosis in human retinal pigment epithelial cells by activating TrkB.

Science.gov (United States)

Yu, Xiaoyi; Liu, Qiuhong; Wang, Xiaochuan; Liu, Hong; Wang, Yan

2018-01-01

In diabetic retinopathy, prolonged high-level blood glucose induced significant impairments among various retinal tissues, including retinal pigment epithelial (RPE) cells. In an in vitro model of human RPE cells, we evaluated whether 7,8-Dihydroxyflavone (DHF) may effectively prevent high glucose-induced diabetic apoptosis among human RPE cells. ARPE-19 cells, a Human RPE cell line, were treated with d-glucose (50 mM) to induce apoptosis in vitro. Prior to glucose, ARPE-19 cells were pre-incubated with various concentrations of DHF. The effect of DHF on d-glucose-induced apoptosis was examined by TUNEL assay, in a concentration-dependent manner. The biological effects of DHF on Caspase-9 (Casp-9) and TrkB signaling pathways in d-glucose-injured ARPE-19 cells were evaluated by qRT-PCR and western blot (WB) assays. A TrkB antagonist, K252a, was also applied in DHF and d-glucose treated ARPE-19 cells. Possible effect of K252a blocking TrkB signaling pathway, thus reversing DHF-modulated apoptosis prevention was also examined by TUNEL and WB assays. DHF ameliorated d-glucose-induced diabetic apoptosis in ARPE-19 cells. Apoptotic factor Casp-9, at both mRNA and protein levels, were drastically inhibited by DHF in d-glucose-injured ARPE-19 cells. Also, DHF activated TrkB signaling pathway through phosphorylation. K252a dramatically reversed the preventive effect of DHF on d-glucose-induced apoptosis in ARPE-19 cells. Further investigation showed that K252a functioned through de-activating or de-phosphorylating TrkB signaling pathway. This work demonstrates that DHF, through activation of TrkB signaling pathway, has a preventive function in d-glucose-induced apoptosis in PRE cells in diabetic retinopathy. Copyright © 2017. Published by Elsevier Inc.

Response of vascular pigment epithelium detachment due to age-related macular degeneration to monthly treatment with ranibizumab: the prospective, multicentre RECOVER study.

Science.gov (United States)

Clemens, Christoph R; Wolf, Armin; Alten, Florian; Milojcic, Carolin; Heiduschka, Peter; Eter, Nicole

2017-11-01

To assess the effects of monthly intravitreal ranibizumab injections in patients with vascularized pigment epithelium detachment (vPED) secondary to age-related macular degeneration (AMD). A total of 40 patients were prospectively observed and treated monthly with 0.5 mg ranibizumab injections (ClinicalTrials.gov Ident. NCT00976222). Inclusion criterion was a treatment-naïve vPED lesion with a minimum height of ≥200 μm. Best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) were evaluated at all visits. Fluorescein angiography and indocyanine green angiography were performed at baseline and quarterly. Lesions were differentiated between serous vascular PED (svPED, group A, 29 patients) and fibrovascular PED (fPED, group B, 11 patients). Primary outcome was the effectivity of continuous monthly treatment during a 12-month period as measured in change in BCVA. Secondary outcomes were change in PED height and PED greatest linear diameter (GLD). Further secondary outcomes were the presence of subretinal fluid and prognostic markers of an impending retinal pigment epithelium (RPE) tear: PED lesion height and diameter, ratio of choroidal neovascularization (CNV) size to PED size, hyperreflective lines in near-infrared images, microrips and subretinal cleft. Mean BCVA was 56.9 ± 11.5 letters (A: 55.4 ± 10.8; B: 59.1 ± 13.4) at baseline and 55.1 ± 15.9 (A: 53.7 ± 17.0; B: 58.9 ± 12.7) at 12-month follow-up. Excluding the RPE tear patients, the svPED group showed an increase in BCVA from 56.1 ± 10.3 at baseline to 62.4 ± 10.2 at 12-month follow-up (p = 0.048). Best-corrected visual acuity in patient who developed a RPE tear was 55.8 ± 12.5 at baseline and 37.1 ± 14.9 at 12-month follow-up. The mean change in PED height was -242.1 μm ± 285.5 (A: -427.3 μm ± 299.7; B: -51.6 μm ± 99.5). The mean decrease in PED GLD was -471.8 μm ± 727.6 (A: -738.9 μm ± 788.2; B: -10.4�

Experimental results from detached plasmas in TFTR

International Nuclear Information System (INIS)

Strachan, J.D.; Boody, F.P.; Bush, C.E.

1986-10-01

Detached plasmas are formed in TFTR which have the principal property of the boundary to the high temperature plasma core being defined by a radiating layer. This paper documents the properties of TFTR ohmic-detached plasmas with a range of plasma densities at two different plasma currents

Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

International Nuclear Information System (INIS)

Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin; Yan, Biao

2013-01-01

Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy

Retinal Pigmented Epithelial Cells Obtained from Human Induced Pluripotent Stem Cells Possess Functional Visual Cycle Enzymes in Vitro and in Vivo*

Science.gov (United States)

Maeda, Tadao; Lee, Mee Jee; Palczewska, Grazyna; Marsili, Stefania; Tesar, Paul J.; Palczewski, Krzysztof; Takahashi, Masayo; Maeda, Akiko

2013-01-01

Differentiated retinal pigmented epithelial (RPE) cells have been obtained from human induced pluripotent stem (hiPS) cells. However, the visual (retinoid) cycle in hiPS-RPE cells has not been adequately examined. Here we determined the expression of functional visual cycle enzymes in hiPS-RPE cells compared with that of isolated wild-type mouse primary RPE (mpRPE) cells in vitro and in vivo. hiPS-RPE cells appeared morphologically similar to mpRPE cells. Notably, expression of certain visual cycle proteins was maintained during cell culture of hiPS-RPE cells, whereas expression of these same molecules rapidly decreased in mpRPE cells. Production of the visual chromophore, 11-cis-retinal, and retinosome formation also were documented in hiPS-RPE cells in vitro. When mpRPE cells with luciferase activity were transplanted into the subretinal space of mice, bioluminance intensity was preserved for >3 months. Additionally, transplantation of mpRPE into blind Lrat−/− and Rpe65−/− mice resulted in the recovery of visual function, including increased electrographic signaling and endogenous 11-cis-retinal production. Finally, when hiPS-RPE cells were transplanted into the subretinal space of Lrat−/− and Rpe65−/− mice, their vision improved as well. Moreover, histological analyses of these eyes displayed replacement of dysfunctional RPE cells by hiPS-RPE cells. Together, our results show that hiPS-RPE cells can exhibit a functional visual cycle in vitro and in vivo. These cells could provide potential treatment options for certain blinding retinal degenerative diseases. PMID:24129572

Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

Energy Technology Data Exchange (ETDEWEB)

Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin, E-mail: jqin710@vip.sina.com; Yan, Biao, E-mail: yanbiao1982@hotmail.com

2013-09-06

Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy.

Characterisation of detached plasmas on the MAST tokamak

Energy Technology Data Exchange (ETDEWEB)

Harrison, J.R., E-mail: james.harrison@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Department of Physics, University of York, Heslington, York, YO10 5DD (United Kingdom); Lisgo, S.W. [ITER Organization, Route de Vinon-sur-Verdon, St.Paul-lez-Durance, Cedex (France); Gibson, K.J. [Department of Physics, University of York, Heslington, York, YO10 5DD (United Kingdom); Tamain, P. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Dowling, J. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom)

2011-08-01

Divertor detachment is an attractive operating regime for the next generation of tokamak devices, as it offers a means of mitigating the steady-state heat flux to plasma facing components. In order to clarify the dominant physical mechanisms that govern detachment, high quality data from several diagnostics are required to constrain theoretical models. To that end, high spatial ({approx}3 mm) and temporal (5 kHz) resolution measurements have been made of the intensity of deuterium Balmer and carbon emission lines during the onset and evolution of detachment of the lower inner strike point in MAST L-mode discharges. Furthermore, spatially-resolved measurements of the shapes and intensities of high-n Balmer lines have been recorded to infer plasma conditions during the detached phase.

Subretinal Implantation of Retinal Pigment Epithelial Cells Derived From Human Embryonic Stem Cells: Improved Survival When Implanted as a Monolayer

Science.gov (United States)

Diniz, Bruno; Thomas, Padmaja; Thomas, Biju; Ribeiro, Ramiro; Hu, Yuntao; Brant, Rodrigo; Ahuja, Ashish; Zhu, Danhong; Liu, Laura; Koss, Michael; Maia, Mauricio; Chader, Gerald; Hinton, David R.; Humayun, Mark S.

2013-01-01

Purpose. To evaluate cell survival and tumorigenicity of human embryonic stem cell–derived retinal pigment epithelium (hESC-RPE) transplantation in immunocompromised nude rats. Cells were transplanted as a cell suspension (CS) or as a polarized monolayer plated on a parylene membrane (PM). Methods. Sixty-nine rats (38 male, 31 female) were surgically implanted with CS (n = 33) or PM (n = 36). Cohort subsets were killed at 1, 6, and 12 months after surgery. Both ocular tissues and systemic organs (brain, liver, kidneys, spleen, heart, and lungs) were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned. Every fifth section was stained with hematoxylin and eosin and analyzed histologically. Adjacent sections were processed for immunohistochemical analysis (as needed) using the following antibodies: anti-RPE65 (RPE-specific marker), anti-TRA-1-85 (human cell marker), anti-Ki67 (proliferation marker), anti-CD68 (macrophage), and anti-cytokeratin (epithelial marker). Results. The implanted cells were immunopositive for the RPE65 and TRA-1-85. Cell survival (P = 0.006) and the presence of a monolayer (P < 0.001) of hESC-RPE were significantly higher in eyes that received the PM. Gross morphological and histological analysis of the eye and the systemic organs after the surgery revealed no evidence of tumor or ectopic tissue formation in either group. Conclusions. hESC-RPE can survive for at least 12 months in an immunocompromised animal model. Polarized monolayers of hESC-RPE show improved survival compared to cell suspensions. The lack of teratoma or any ectopic tissue formation in the implanted rats bodes well for similar results with respect to safety in human subjects. PMID:23833067

Rescue of compromised lysosomes enhances degradation of photoreceptor outer segments and reduces lipofuscin-like autofluorescence in retinal pigmented epithelial cells.

Science.gov (United States)

Guha, Sonia; Liu, Ji; Baltazar, Gabe; Laties, Alan M; Mitchell, Claire H

2014-01-01

Healthful cell maintenance requires the efficient degradative processing and removal of waste material. Retinal pigmented epithelial (RPE) cells have the onerous task of degrading both internal cellular debris generated through autophagy as well as phagocytosed photoreceptor outer segments. We propose that the inadequate processing material with the resulting accumulation of cellular waste contributes to the downstream pathologies characterized as age-related macular degeneration (AMD). The lysosomal enzymes responsible for clearance function optimally over a narrow range of acidic pH values; elevation of lysosomal pH by compounds like chloroquine or A2E can impair degradative enzyme activity and lead to a lipofuscin-like autofluorescence. Restoring acidity to the lysosomes of RPE cells can enhance activity of multiple degradative enzymes and is therefore a logical target in early AMD. We have identified several approaches to reacidify lysosomes of compromised RPE cells; stimulation of beta-adrenergic, A2A adenosine and D5 dopamine receptors each lowers lysosomal pH and improves degradation of outer segments. Activation of the CFTR chloride channel also reacidifies lysosomes and increases degradation. These approaches also restore the lysosomal pH of RPE cells from aged ABCA4(-/-) mice with chronically high levels of A2E, suggesting that functional signaling pathways to reacidify lysosomes are retained in aged cells like those in patients with AMD. Acidic nanoparticles transported to RPE lysosomes also lower pH and improve degradation of outer segments. In summary, the ability of diverse approaches to lower lysosomal pH and enhance outer segment degradation support the proposal that lysosomal acidification can prevent the accumulation of lipofuscin-like material in RPE cells.

Development of an automated chip culture system with integrated on-line monitoring for maturation culture of retinal pigment epithelial cells

Directory of Open Access Journals (Sweden)

Mee-Hae Kim

2017-10-01

Full Text Available In cell manufacturing, the establishment of a fully automated, microfluidic, cell culture system that can be used for long-term cell cultures, as well as for process optimization is highly desirable. This study reports the development of a novel chip bioreactor system that can be used for automated long-term maturation cultures of retinal pigment epithelial (RPE cells. The system consists of an incubation unit, a medium supply unit, a culture observation unit, and a control unit. In the incubation unit, the chip contains a closed culture vessel (2.5 mm diameter, working volume 9.1 μL, which can be set to 37 °C and 5% CO2, and uses a gas-permeable resin (poly- dimethylsiloxane as the vessel wall. RPE cells were seeded at 5.0 × 104 cells/cm2 and the medium was changed every day by introducing fresh medium using the medium supply unit. Culture solutions were stored either in the refrigerator or the freezer, and fresh medium was prepared before any medium change by warming to 37 °C and mixing. Automated culture was allowed to continue for 30 days to allow maturation of the RPE cells. This chip culture system allows for the long-term, bubble-free, culture of RPE cells, while also being able to observe cells in order to elucidate their cell morphology or show the presence of tight junctions. This culture system, along with an integrated on-line monitoring system, can therefore be applied to long-term cultures of RPE cells, and should contribute to process control in RPE cell manufacturing.

UV-B affects the immune system and promotes nuclear abnormalities in pigmented and non-pigmented bullfrog tadpoles.

Science.gov (United States)

Franco-Belussi, Lilian; Fanali, Lara Zácari; De Oliveira, Classius

2018-03-01

Ultra-Violet (UV) radiation is a stressor of the immune system and causes DNA damage. Leukocytes can change in response to environmental changes in anurans, making them an important biomarker of stressful situations. The initial barrier against UV in ectothermic animals is melanin-containing cells in skin and in their internal organs. Here, we tested the effects of UV exposure on immune cells and DNA integrity in pigmented and non-pigmented tadpoles of Lithobates catesbeianus. We used an inflammation model with lipopolysaccharide (LPS) of Escherichia coli to test synergic effects of UV and LPS. We tested the following hypotheses: 1) DNA damage caused by UV will be more pronounced in non-pigmented than in pigmented animals; 2) LPS increases leukocytes in both pigmented and non-pigmented animals by systemic inflammation; 3) The combined LPS and UV exposure will decrease the number of leukocytes. We found that the frequency of immune cells differed between pigmented and non-pigmented tadpoles. UV exposure increased mast cells and DNA damage in erythrocytes in both pigmented and non-pigmented tadpoles, while leukocytes decreased after UV exposure. Non-pigmented tadpoles experienced DNA damage and a lower lymphocyte count earlier than pigmented tadpoles. UV altered immune cells likely as a consequence of local and systemic inflammation. These alterations were less severe in pigmented than in non-pigmented animals. UV and LPS increased internal melanin in pigmented tadpoles, which were correlated with DNA damage and leukocytes. Here, we described for the first time the effects of UV and LPS in immune cells of pigmented and non-pigmented tadpoles. In addition, we demonstrated that internal melanin in tadpoles help in these defenses, since leukocyte responses were faster in non-pigmented animals, supporting the hypothesis that melanin is involved in the initial innate immune response. Copyright © 2018 Elsevier B.V. All rights reserved.

[Preventive treatment of retinal detachment in aphakic eyes].

Science.gov (United States)

Regnault, F; Bregeat, P

1977-01-01

We have examined 243 cases with retinal detachment occurring within 6 months following cataract surgery. In 92 of them retinal tear was due to lattice degeneration, in 66 to snail track degeneration and in 17 to equatorial degeneration. 290 other patients had preventive treatments. In this group, there were only 10 cases of retinal detachment. 9 out of 22 patients who had no preventive treatment suffered retinal detachments. There are two reasons for the occurrence of this retinal detachment in the 6 months following cataract surgery in eyes where retinal degenerations are found: (1) surgical trauma even with cryoextraction is responsible for traction of the vitreous base, (2) rapid disappearance of the hyaluronic acid in the aphakic vitreous is responsible for the degradation of the vitreous with formation of large zones of liquid vitreous. When adhesion between the vitreous and the retinal degeneration area remains, the traction is responsible for retinal tear or retinal detachment. The importance of the preventive treatment of retinal lesions prior to cataract surgery should be stressed.

The fellow eye of patients with phakic rhegmatogenous retinal detachment from atrophic holes of lattice degeneration without posterior vitreous detachment.

Science.gov (United States)

Gonzales, C R; Gupta, A; Schwartz, S D; Kreiger, A E

2004-11-01

Primary phakic rhegmatogenous retinal detachment (RRD) without posterior vitreous detachment (PVD) represents a unique clinical entity that behaves differently from RRD associated with PVD. While previous studies have reported the long term findings in the fellow eye of patients with RRD and PVD, the outcome of the fellow eye of patients with RRD without PVD is not known. Consecutive patients with RRD not associated with PVD were studied retrospectively. The authors evaluated the fellow eye for retinal detachment or other vision threatening pathology. 27 patients (mean age 32 years) were studied with follow up of between 9 and 326 months (mean 111 months). 24 (89%) were myopic. Bilateral retinal detachment occurred in eight patients (30%). On initial examination, 17 patients (63%) had retinal findings (including lattice degeneration, atrophic holes, and/or cystic retinal tufts) in the fellow eye that might predispose them to retinal detachment. 14 vision threatening events or diagnoses occurred (nine of which were rhegmatogenous in nature) in the fellow eye including eight retinal detachments, one traumatic PVD without retinal tears, one retinal tear after PVD, one diagnosis of pigmentary glaucoma needing trabeculectomy, two visually significant cataracts, and one diagnosis of chorioretinitis. 23 patients (85%) maintained visual acuity better than 20/50, with most retaining 20/20 vision in the fellow eye. Patients who experience RRD without PVD are at risk of developing vision threatening events in the contralateral eye and, as such, the fellow eye should be followed carefully.

[Prevention of retinal detachment and treatment of retinoschisis].

Science.gov (United States)

Messmer, E P

1990-01-01

The necessity for prophylactic treatment for degenerative disease in the peripheral retina cannot be evaluated merely on the basis of the ophthalmoscopic findings. Factors such as the patient's history, refraction, the status of the vitreous, and prospective future cataract extraction all have a major impact on the risk of developing retinal detachment. The latter condition can be classified in to three groups: (1) low risk (patients with no history of retinal detachment, intraocular surgery or posterior vitreous detachment, myopia less than three diopters): treatment of atrophic holes and lattice degeneration is not justified, treatment of flap tears according to the circumstances; (2) medium risk (patients with no history of retinal or posterior vitreous detachment; however, myopia of more than three diopters and/or aphakia): the treatment of lattice degeneration is not justified; treatment of breaks according to the circumstances; (3) high risk: (patients with symptoms of posterior vitreous detachment): the treatment of lattice degeneration and atrophic holes is not justified: treatment of tears is necessary; fellow eyes: the treatment of retinal breaks is necessary; treatment of lattice degeneration seems advisable in cases with bilateral symmetric findings or prior to cataract extraction. Treatment of senile retinoschisis is only justified in cases with large and centrally located holes in the outer wall or in the presence of symptomatic schisis detachment.

Kinematic evidence for downdip movement on the Mormon Peak detachment

Science.gov (United States)

Walker, Christopher D.; Anders, Mark H.; Christie-Blick, Nicholas

2007-03-01

The Mormon Peak detachment is considered to be one of the best examples of a rooted upper crustal detachment fault that propagated through the brittle crust at a low angle. The hanging wall of the detachment today consists of a number of isolated blocks that have been interpreted as remnants of a once-contiguous extensional allochthon. Here we present the results of a new study of directional indicators from the basal surfaces beneath these blocks. These measurements do not agree with the long-standing interpretation of a S75°W movement direction for the detachment hanging wall. Instead, the most recent movement on each section of the detachment took place approximately parallel to the present downdip direction. We conclude that the Mormon Peak detachment is best explained as the basal surfaces to a series of rootless gravity slides.

A hemolytic pigment of Group B Streptococcus allows bacterial penetration of human placenta

Science.gov (United States)

Whidbey, Christopher; Harrell, Maria Isabel; Burnside, Kellie; Ngo, Lisa; Becraft, Alexis K.; Iyer, Lakshminarayan M.; Aravind, L.; Hitti, Jane

2013-01-01

Microbial infection of the amniotic fluid is a significant cause of fetal injury, preterm birth, and newborn infections. Group B Streptococcus (GBS) is an important human bacterial pathogen associated with preterm birth, fetal injury, and neonatal mortality. Although GBS has been isolated from amniotic fluid of women in preterm labor, mechanisms of in utero infection remain unknown. Previous studies indicated that GBS are unable to invade human amniotic epithelial cells (hAECs), which represent the last barrier to the amniotic cavity and fetus. We show that GBS invades hAECs and strains lacking the hemolysin repressor CovR/S accelerate amniotic barrier failure and penetrate chorioamniotic membranes in a hemolysin-dependent manner. Clinical GBS isolates obtained from women in preterm labor are hyperhemolytic and some are associated with covR/S mutations. We demonstrate for the first time that hemolytic and cytolytic activity of GBS is due to the ornithine rhamnolipid pigment and not due to a pore-forming protein toxin. Our studies emphasize the importance of the hemolytic GBS pigment in ascending infection and fetal injury. PMID:23712433

Method of detaching adherent cells for flow cytometry

KAUST Repository

Kaur, Mandeep

2015-12-24

In one aspect, a method for detaching adherent cells can include adding a cell lifting solution to the media including a sample of adherent cells and incubating the sample of adherent cells with the cell lifting solution. No scraping or pipetting is needed to facilitate cell detachment. The method do not require inactivation of cell lifting solution and no washing of detaching cells is required to remove cell lifting solution. Detached cells can be stained with dye in the presence of cell lifting solution and are further analyzed using flow cytometer. The method has been tested using 6 different cell lines, 4 different assays, two different plate formats (96 and 384 well plates) and two different flow cytometry instruments. The method is simple to perform, less time consuming, with no cell loss and makes high throughput flow cytometry on adherent cells a reality.

Femtosecond laser cutting of endothelial grafts: comparison of endothelial and epithelial applanation.

Science.gov (United States)

Bernard, Aurélien; He, Zhiguo; Gauthier, Anne Sophie; Trone, Marie Caroline; Baubeau, Emmanuel; Forest, Fabien; Dumollard, Jean Marc; Peocʼh, Michel; Thuret, Gilles; Gain, Philippe

2015-02-01

Stromal surface quality of endothelial lamellae cut for endothelial keratoplasty with a femtosecond laser (FSL) with epithelial applanation remains disappointing. Applanation of the endothelial side of the cornea, mounted inverted on an artificial chamber, has therefore been proposed to improve cut quality. We compared lamellar quality after FSL cutting using epithelial versus endothelial applanation. Lamellae were cut with an FSL from organ-cultured corneas. After randomization, 7 were cut with epithelial applanation and 7 with endothelial applanation. Lamellae of 50-, 75-, and 100-μm thickness were targeted. Thickness was measured by optical coherence tomography before and immediately after cutting. Viable endothelial cell density was quantified immediately after cutting using triple labeling with Hoechst/ethidium/calcein-AM coupled with image analysis with ImageJ. The stromal surface was evaluated by 9 masked observers using semiquantitative scoring of scanning electronic microscopy images. Histology of 2 samples was also analyzed before lamellar detachment. Precision (difference in target/actual thickness) and thickness regularity [coefficient of variation (CV) of 10 measurements] were significantly better with endothelial applanation (precision: 18 μm; range, 10-30; CV: 11%; range, 8-12) than with epithelial applanation (precision: 84 μm; range, 54-107; P = 0.002; CV: 24%; range, 13-47; P = 0.001). Endothelial applanation provided thinner lamellae. However, viable endothelial cell density was significantly lower after endothelial applanation (1183 cells/mm2; range, 787-1725 versus 1688 cells/mm2; range, 1288-2025; P = 0.018). FSL cutting of endothelial lamellae using endothelial applanation provides thinner more regular grafts with more predictable thickness than with conventional epithelial applanation but strongly reduces the pool of viable endothelial cells.

Long anterior zonules and pigment dispersion.

Science.gov (United States)

Moroi, Sayoko E; Lark, Kurt K; Sieving, Paul A; Nouri-Mahdavi, Kouros; Schlötzer-Schrehardt, Ursula; Katz, Gregory J; Ritch, Robert

2003-12-01

To describe pigment dispersion associated with long anterior zonules. Multicenter observational case series. Fifteen patients, seven of whom were treated for glaucoma or ocular hypertension, were identified with long anterior zonules and pigment dispersion. Transmission electron microscopy was performed on one anterior capsule specimen. All patients had anterior zonules that inserted centrally on the lens capsule. Signs of pigment dispersion included corneal endothelial pigmentation, loss of the pupillary ruff, and variable trabecular meshwork pigmentation. Ultrasound biomicroscopy verified the lack of posterior iris insertion and concavity. There was no exfoliation material. Transmission electron microscopy showed zonular lamellae with adherent pigment granules, and no exfoliation material. Long anterior zonules inserted onto the central lens capsule may cause mechanical disruption of the pigment epithelium at the pupillary ruff and central iris leading to pigment dispersion.

HAMLET binding to α-actinin facilitates tumor cell detachment.

Science.gov (United States)

Trulsson, Maria; Yu, Hao; Gisselsson, Lennart; Chao, Yinxia; Urbano, Alexander; Aits, Sonja; Mossberg, Ann-Kristin; Svanborg, Catharina

2011-03-08

Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of α-actinin-4. By co-immunoprecipitation of extracts from HAMLET-treated cancer cells, an interaction with α-actinin-1 and -4 was observed. Inhibition of α-actinin-1 and α-actinin-4 expression by siRNA transfection increased detachment, while α-actinin-4-GFP over-expression significantly delayed rounding up and detachment of tumor cells in response to HAMLET. In response to HAMLET, adherent tumor cells rounded up and detached, suggesting a loss of the actin cytoskeletal organization. These changes were accompanied by a reduction in β1 integrin staining and a decrease in FAK and ERK1/2 phosphorylation, consistent with a disruption of integrin-dependent cell adhesion signaling. Detachment per se did not increase cell death during the 22 hour experimental period, regardless of α-actinin-4 and α-actinin-1 expression levels but adherent cells with low α-actinin levels showed increased death in response to HAMLET. The results suggest that the interaction between HAMLET and α-actinins promotes tumor cell detachment. As α-actinins also associate with signaling molecules, cytoplasmic domains of transmembrane receptors and ion channels, additional α-actinin-dependent mechanisms are discussed.

Structural recovery of the detached macula after retinal detachment repair as assessed by optical coherence tomography.

Science.gov (United States)

Joe, Soo Geun; Kim, Yoon Jeon; Chae, Ju Byung; Yang, Sung Jae; Lee, Joo Yong; Kim, June-Gone; Yoon, Young Hee

2013-06-01

To investigate correlations between preoperative and postoperative foveal microstructures in patients with macula-off rhegmatogenous retinal detachment (RRD). We reviewed the records of 31 eyes from 31 patients with macula-off RRD who had undergone successful re-attachment surgery. We analyzed data obtained from complete ophthalmologic examinations and optical coherence tomography (OCT) before and 9 to 12 months after surgery. All postoperative OCT measurements were taken with spectral-domain OCT, but a subset of preoperative OCT measurements were taken with time-domain OCT. The mean duration of macular detachment was 15.5 ± 15.2 days, and mean preoperative best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution) was 1.03 ± 0.68. Preoperative visual acuity was correlated with retinal detachment height (p macula-off duration. The final BCVA was significantly correlated with integrity of the junction between the photoreceptor inner and outer segments (IS/OS) combined with the continuity of external limiting membrane (ELM) (p = 0.025). The presence of IRS and OLU on a detached macula were highly correlated with the final postoperative integrity of the IS/OS junction and the ELM (p = 0.017). Eyes preoperatively exhibiting IRS and OLU showed a higher incidence of disruption to the photoreceptor IS/OS junction and the ELM at final follow-up. Such a close correlation between preoperative and postoperative structural changes may explain why ultimate visual recovery in such eyes is poor.

Anti-apoptotic effects of Curcuma longa L. extract and its curcuminoids against blue light-induced cytotoxicity in A2E-laden human retinal pigment epithelial cells.

Science.gov (United States)

Park, Sang-Il; Lee, Eun Hye; Kim, So Ra; Jang, Young Pyo

2017-03-01

The purpose of the study was to investigate the protective effect of the Curcuma longa L. extract (CLE) and its curcuminoids against blue light-induced cytotoxicity in human retinal pigment epithelial (RPE) cells laded with A2E. A2E has been concerned in age-related macular degeneration (AMD). To perform this study, A2E-accumulated ARPE-19 cells were exposed to blue light to induce cytotoxicity. The cytotoxicity and apoptotic gene expression levels were evaluated using a lactate dehydrogenase (LDH) assay and real-time PCR analysis, respectively. Curcuma longa L. extract was found to exert a protective effect in a dose-dependent manner. At a concentration of 15 μm, curcumin, demethoxycurcumin and bisdemethoxycurcumin exerted significant protective effects against blue light-induced cytotoxicity. Treatment with CLE and curcuminoids meaningfully reduced the mRNA levels of c-Abl and p53, which was known to be augmented in apoptotic RPE cells. Demethoxycurcumin and bisdemethoxycurcumin were found to inhibit p38 expression, which is increased in blue light-irradiated A2E-accumulated RPE cells. Curcuma longa L. extract and its curcuminoids provided significant protection against photooxidative damage and apoptosis in the RPE cells. Our results suggest that curcuminoids may show potential in the treatment of AMD. © 2017 Royal Pharmaceutical Society.

Negative ion detachment processes

International Nuclear Information System (INIS)

Champion, R.L.; Doverspike, L.D.

1990-10-01

This paper discusses the following topics: H - and D - collisions with atomic hydrogen; collisional decomposition of SF 6 - ; two-electron loss processes in negative ion collisions; associative electron detachment; and negative ion desorption from surfaces

Photosynthetic Pigments in Diatoms.

Science.gov (United States)

Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2015-09-16

Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

Photosynthetic Pigments in Diatoms

Directory of Open Access Journals (Sweden)

Paulina Kuczynska

2015-09-01

Full Text Available Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

Exudative Retinal Detachment Treatment in a Patient with Thrombotic Thrombocytopenic Purpura

Directory of Open Access Journals (Sweden)

Magali Sampo

2016-02-01

Full Text Available Purpose: We report a case of unilateral exudative retinal detachment in a patient with thrombotic thrombocytopenic purpura (TTP, without associated hypertension, successfully treated with plasmapheresis. Case Report: A 46-year-old woman with a medical history of TTP presented with unilateral exudative retinal detachment. Biological and radiological assessment eliminated other causes of exudative retinal detachment, including hypertension. Plasma exchange was performed, followed by a rapid improvement in visual acuity and total disappearance of serous detachment. Conclusion: Exudative unilateral retinal detachment is a rare complication of TTP and can be successfully treated by plasma exchange.

[Stickler's syndrome (dystrophia vitreoretinalis hereditaria). Results of surgery for retinal detachment].

Science.gov (United States)

Karel, I; Dolezalová, J; Oudová, P

2001-05-01

Stickler's syndrome (SS) is an autosomal dominant hereditary disease of the collagenous connective tissue where impaired development of the vitreous body gel and peripheral retina and detachment of the retina are associated with general manifestations. The objective of the retrospective study was to evaluate the long-term results of surgery of retinal detachment in SS. The group of patients comprised 7 patients, 6 men and 1 woman aged 4 to 45 years, average age 16.8 years. Autosomal dominant heredity was obvious in 6 members (85.7%) of two families. General manifestations of SS included abnormalities of the facial skeleton (6 patients), cleft palate (4 patients), impaired hearing (2 patients), marfanoid habitus (2 patients) and hyperextensibility of the joints (4 patients). In the eyes with SS was manifested by myopia from -1 to -9 D and a liquid vitreous body. Multiple foci of lattice degeneration supplemented the finding in 6 patients (85.7%). Detachment of the retina was a manifestation of SS in 12 of 14 eyes (85.7%). It was manifested in 5 of 7 patients concurrently or within 12 years in both eyes. The causes of retinal detachment were multiple equatorial and postequatorial tears due to lattice degeneration in 8 eyes (66.7%) or a giant tear in 4 eyes (33.3%). Advanced proliferative vitreoretinopathy (PVR) was associated with retinal detachment in 8 eyes (66.7%) and in 6 eyes (50%) it was not possible to assess the beginning of retinal detachment. In 3 of 5 patients with bilateral retinal detachment the adverse course of retinal detachment on the first eye was followed 8 to 12 years previously in another department: two retinal detachments with giant tears were evaluated as inoperable and one inveterated detachment with advanced PVR was operated unsuccessfully. Retinal detachment was operated in 9 eyes of 7 patients, in two patients both eyes were operated simultaneously. The patients were followed up after surgery for 11 months to 15 years, on average for 65

DETACHMENT OF HUMAN FIBROBLASTS FROM FEP-TEFLON SURFACES

NARCIS (Netherlands)

VANKOOTEN, TG; SCHAKENRAAD, JM; VANDERMEI, HC; BUSSCHER, HJ

1991-01-01

In this study a comparison is made between the detachment behavior of human fibroblasts adhered to hydrophobic FEP-Teflon (water contact angle 109 degrees) and to hydrophilic glass (water contact angle smaller than 15 degrees) during exposure to a laminar, incrementally loaded flow. Detachment from

Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill.

Science.gov (United States)

González, Alfredo; Crittenden, Elizabeth L; García, Dana M

2004-07-13

In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl) carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

Directory of Open Access Journals (Sweden)

Crittenden Elizabeth L

2004-07-01

Full Text Available Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and muscarinic. Muscarinic receptors are in the G-protein coupled receptor superfamily, and five different muscarinic receptors have been molecularly cloned in human. These receptors are coupled to adenylyl cyclase, calcium mobilization and ion channel activation. To determine the receptor pathway involved in eliciting pigment granule migration, we isolated retinal pigment epithelium from bluegill and subjected it to a battery of cholinergic agents. Results The general cholinergic agonist carbachol induces pigment granule dispersion in isolated retinal pigment epithelium. Carbachol-induced pigment granule dispersion is blocked by the muscarinic antagonist atropine, by the M1 antagonist pirenzepine, and by the M3 antagonist 4-DAMP. Pigment granule dispersion was also induced by the M1 agonist 4-[N-(4-chlorophenyl carbamoyloxy]-4-pent-2-ammonium iodide. In contrast the M2 antagonist AF-DX 116 and the M4 antagonist tropicamide failed to block carbachol-induced dispersion, and the M2 agonist arecaidine but-2-ynyl ester tosylate failed to elicit dispersion. Conclusions Our results suggest that carbachol-mediated pigment granule dispersion occurs through the activation of Modd muscarinic receptors, which in other systems couple to phosphoinositide hydrolysis and elevation of intracellular calcium. This conclusion must be corroborated by molecular studies, but suggests Ca2+-dependent pathways may be involved in light-adaptive pigment dispersion.

Natural pigments and sacred art

Science.gov (United States)

Kelekian, Lena, ,, Lady

2010-05-01

Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

Detachments in Shale: Controlling Characteristics on Fold-Thrust Belt Style

Science.gov (United States)

Hansberry, Rowan; King, Ros; Collins, Alan; Morley, Chris

2013-04-01

Fold-thrust belts occur across multiple tectonic settings where thin-skinned deformation is accommodated by one or more detachment zones, both basal and within the fold-thrust belt. These fold-thrust belts exhibit considerable variation in structural style and vergence depending on the characteristics (e.g. strength, thickness, and lithology) and number of detachment zones. Shale as a detachment lithology is intrinsically weaker than more competent silts and sands; however, it can be further weakened by high pore pressures, reducing resistance to sliding and; high temperatures, altering the rheology of the detachment. Despite the implications for petroleum exploration and natural hazard assessment the precise nature by which detachments in shale control and are involved in deformation in fold-thrust belts is poorly understood. Present-day active basal detachment zones are usually located in inaccessible submarine regions. Therefore, this project employs field observations and sample analysis of ancient, exhumed analogues to document the nature of shale detachments (e.g. thickness, lithology, dip and dip direction, deformational temperature and thrust propagation rates) at field sites in Thailand, Norway and New Zealand. X-ray diffraction analysis of illite crystallinity and oxygen stable isotopes analysis are used as a proxy for deformational temperature whilst electron-backscatter diffraction analysis is used to constrain microstructural deformational patterns. K-Ar dating of synkinematic clay fault gouges is being applied to date the final stages of activity on individual faults with a view to constraining thrust activation sequences. It is not possible to directly measure palaeo-data for some key detachment parameters, such as pore pressure and coefficients of friction. However, the use of critical taper wedge theory has been used to successfully infer internal and basal coefficients of friction and depth-normalized pore pressure within a wedge and at its base

Phototrophic pigment production with microalgae

NARCIS (Netherlands)

Mulders, K.J.M.

2014-01-01

Abstract

Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary

Progranulin increases phagocytosis by retinal pigment epithelial cells in culture.

Science.gov (United States)

Murase, Hiromi; Tsuruma, Kazuhiro; Kuse, Yoshiki; Shimazawa, Masamitsu; Hara, Hideaki

2017-12-01

Retinal pigment epithelium (RPE) cells take part in retinal preservation, such as phagocytizing the shed photoreceptor outer segments (POS), every day. The incomplete phagocytic function accelerates RPE degeneration and formation of the toxic by-product lipofuscin. Excessive lipofuscin accumulation is characteristic of various blinding diseases in the human eye. Progranulin is a cysteine-rich protein that has multiple biological activities, and it has a high presence in the retina. Progranulin has been recognized to be involved in macrophage phagocytosis in the brain. The purpose of this study is to determine whether progranulin influences phagocytosis by RPE cells. All experiments were performed on primary human RPE (hRPE) cells in culture. pHrodo was used to label the isolated porcine POS, and quantification of pHrodo fluorescence was used to determine the degree of phagocytosis. Western blotting and immunohistochemistry of key proteins involved in phagocytosis were used to clarify the mechanism of progranulin. Progranulin increased RPE phagocytosis in hydrogen peroxide-treated and nontreated RPE cells. The phosphorylated form of Mer tyrosine kinase, which is important for POS internalization, was significantly increased in the progranulin-exposed cells. This increase was attenuated by SU11274, an inhibitor of hepatic growth factor receptor. Under the oxidative stress condition, exposure to progranulin led to an approximately twofold increase in integrin alpha-v, which is associated with the first step in recognition of POS by RPE cells. These results suggest that progranulin could be an effective stimulator for RPE phagocytosis and could repair RPE function. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Diversity and functional properties of bistable pigments.

Science.gov (United States)

Tsukamoto, Hisao; Terakita, Akihisa

2010-11-01

Rhodopsin and related opsin-based pigments, which are photosensitive membrane proteins, have been extensively studied using a wide variety of techniques, with rhodopsin being the most understood G protein-coupled receptor (GPCR). Animals use various opsin-based pigments for vision and a wide variety of non-visual functions. Many functionally varied pigments are roughly divided into two kinds, based on their photoreaction: bistable and monostable pigments. Bistable pigments are thermally stable before and after photo-activation, but monostable pigments are stable only before activation. Here, we review the diversity of bistable pigments and their molecular characteristics. We also discuss the mechanisms underlying different molecular characteristics of bistable and monostable pigments. In addition, the potential of bistable pigments as a GPCR model is proposed.

[Paediatric retinal detachment and hereditary vitreoretinal disorders].

Science.gov (United States)

Meier, P

2013-09-01

The number of retinal detachments in children is very low in comparison to the number in adults. One predisposing factor for development of paediatric retinal detachment is suffering from hereditary vitreoretinal degeneration (e.g., Stickler syndrome, Wagner syndrome, Kniest dysplasia, familial exudative vitreoretinopathy, congenital X-linked retinoschisis, Knobloch syndrome, incontinentia pigmenti, Norrie disease). Hereditary vitreoretinopathies are characterised by an abnormal-appearing vitreous gel with associated retinal changes. In most of these eyes further ocular abnormalities can be diagnosed. A group of hereditary disorders is associated with characteristic systemic abnormalities. Allied conditions should be considered in the clinical diagnosis. Vitreoretinopathies are the most common cause of inherited retinal detachment. In most eyes primary vitrectomy is necessary, and disease-specific surgical treatment is discussed. Georg Thieme Verlag KG Stuttgart · New York.

Cell detachment method using shock wave induced cavitation

NARCIS (Netherlands)

Junge, L.; Junge, L.; Ohl, C.D.; Wolfrum, B.; Arora, M.; Ikink, R.

2003-01-01

The detachment of adherent HeLa cells from a substrate after the interaction with a shock wave is analyzed. Cavitation bubbles are formed in the trailing, negative pressure cycle following the shock front. We find that the regions of cell detachment are strongly correlated with spatial presence of

Cup detachment during vacuum-assisted vaginal delivery and birth outcome.

Science.gov (United States)

Krispin, Eyal; Aviram, Amir; Salman, Lina; Chen, Rony; Wiznitzer, Arnon; Gabbay-Benziv, Rinat

2017-11-01

To determine the perinatal outcome associated with cup detachment during vacuum-assisted vaginal delivery (VAVD). A retrospective cohort study of all women attempting VAVD in a tertiary hospital (2012-2014). Singleton-term pregnancies were included. Antepartum fetal death and major fetal structural or chromosomal abnormalities were excluded. Primary outcome was neonatal birth trauma (subgaleal hematoma, subarachnoid hematoma, subdural hematoma, skull fracture, and/or erb's palsy). Secondary outcomes were maternal complications or other neonatal morbidities. Outcomes were compared between women after ≥1 cup detachment (study group) and the rest (control group). Logistic regression analysis was utilized to adjust results to potential confounders. Overall, 1779 women attempted VAVD during study period. Of them, in 146 (8.2%), the cup detached prior to delivery; 130/146 (89%) had a single detachment. After detachment, 4 (2.7%) delivered by cesarean section, 77 (52.7%) delivered after cup reapplication, and 65 (44.6%) delivered spontaneously. Women in the study group were more likely to undergo VAVD due to prolonged second stage, and were characterized by lower rates of metal cup use. Neonates in the detachment group had higher rates of subarachnoid hematoma and composite neonatal birth trauma (2.7 vs. 0.1% and 4.8 vs. 1.8%, respectively, p Cup detachment is associated with a higher rate of adverse neonatal outcome. Cup reapplication should be considered carefully.

Skin pigmentation kinetics after UVB exposure

DEFF Research Database (Denmark)

Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

2008-01-01

There have been few previous studies of the kinetics of pigmentation following ultraviolet B (UVB) exposure, and these have included only fair-skinned persons. The current study investigated pigmentation increase to steady state and fading in 12 Scandinavians and 12 Indians/Pakistanis. Over...... a period of 3 weeks the subjects were UV-irradiated 6 times on the right side of the back and 12 times on the left side using a Solar Simulator and narrowband UVB with equal sub-Minimal Melanogenesis Doses (individually predetermined). Pigmentation was measured from skin remittance at 555 urn and 660 nm...... (allowing correction for erythema). The absolute pigmentation increase was independent of pre-exposure pigmentation, therefore the percentage pigmentation increase was higher in fair-skinned volunteers. The UV dose to minimal pigmentation was higher in darker-skinned persons for single and multiple UV...

Numerical analysis of the bubble detachment diameter in nucleate boiling

International Nuclear Information System (INIS)

Lamas, M I; Sáiz Jabardo, J M; Arce, A; Fariñas, P

2012-01-01

The present paper presents a tri-dimensional CFD (Computational Fluid Dynamics) model to investigate the fluid flow around bubbles attached to heated walls. Transient solutions of the governing field equations in a domain containing the bubbles and the surrounding liquid have been obtained. The nucleation, growing and detachment processes have been analyzed. Concerning the software, the open source OpenFOAM has been used. Special attention has been given to the bubble detachment diameter. Two mechanisms have been considered as physically related to the detachment: surface tension and buoyancy. As expected, it has been verified that the bubble detachment diameter depends on the contact angle, operating pressure and properties of the fluid. Several fluids have been considered (water, R134a, ammonia and R123), as well as several operating pressures (between 0.1 and 10 bar) and contact angles (between 10 and 80°). It has been concluded that the detachment diameter depends strongly on the contact angle and fluid properties and slightly on the pressure. A correlation for the bubble detachment diameter has been developed based on the obtained numerical results. Data from this expression compare reasonably well with those from other correlations from the literature.

Design of the Detachable Extension Shaft Assembly for KJRR

International Nuclear Information System (INIS)

Lee, Jin Haeng; Yoo, Yeon-Sik; Cho, Yeong-Garp; Ryou, Myoung-Han; Ryu, Jeong-Soo

2015-01-01

In this study, we designed the ESA and basket which can increase the connecting force between the ES adapter and the ES, and can be easily attachable and detachable with the basket. Because the upper part of the ESA can be placed near the reactor core for a long time and directly connected to the FFA, the deterioration of its mechanical properties is expected to be relatively quicker than the lower part of the ESA. The ESA is therefore composed of an Extension Shaft (ES) and an ES adapter, and the ES adapter can be detachable from the ES and replaceable by new one. In the previous design concept, the ES adapter had four latches which can be detached from the ES in the reactor core by external pulling force, and the detached CAR or SSR, FFA and ES adapter are individually disconnected in some baskets when it is needed to replace CAR/SSR/FFA or shuffle them. When the force is too small, the bundle of CAR/SSR/FFA and ES adapter can be unexpectedly detached from the ES. To solve the problem, we have studied another design concept which can increase the connecting force and can be easily detachable when it is needed. The forces needed to be connected and disconnected were calculated from FE analysis, and the force to be disconnected can be guessed without FE contact analysis. The prototypes of the designed components were fabricated, and they were suitable to be used

Production of Monascus-like pigments

DEFF Research Database (Denmark)

2012-01-01

the cultivation medium with an inoculum of Penicillium to form a cultivation composition; d) cultivating the inoculated cultivation composition of (c); e) separating the one or more produced pigment compositions. The method of the invention may be used for producing Monascus-like pigment compositions for use......The present invention relates to a method for producing one or more Monascus-like pigment composition from Penicillium species comprising: a) providing a cultivation medium comprising a high concentration of C-and N-sources and a high C/N molar ratio, b) adjusting pH to about 5 to 8, c) inoculating...... as colouring agents in food items or non food items. The inventions further relates to Monascus-like pigment composition obtainable by a method of the inventions as well as use of the pigments....

Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy

Directory of Open Access Journals (Sweden)

Takako Hidaka

2016-06-01

Full Text Available Herein, we report a case of nontraumatic bilateral rhegmatogenous retinal detachment (RRD during external beam radiotherapy for nonocular tumor, presented as an observational case study in conjunction with a review of the relevant literature. A 65-year-old male was referred to our hospital due to bilateral RRD. He underwent a biopsy for a tumor of the left frontal lobe 4 months prior to presentation, and the tumor had been diagnosed as primary central nerve system B-cell type lymphoma. He received chemotherapy and external beam radiotherapy for 1 month. There were no traumatic episodes. Bilateral retinal detachment occurred during a series of radiotherapies. Simultaneous nontraumatic bilateral retinal detachment is rare. The effects of radiotherapy on ocular functionality, particularly in cases involving retinal adhesion and vitreous contraction, may include RRD. Thus, it is necessary to closely monitor the eyes of patients undergoing radiotherapy, particularly those undergoing surgery for retinal detachment and those with a history of photocoagulation for retinal tears, a relevant family history, or risk factors known to be associated with RRD.

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work.

Science.gov (United States)

Wendsche, Johannes; Lohmann-Haislah, Andrea

2016-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes.

Cellular volume regulation and substrate stiffness modulate the detachment dynamics of adherent cells

Science.gov (United States)

Yang, Yuehua; Jiang, Hongyuan

2018-03-01

Quantitative characterizations of cell detachment are vital for understanding the fundamental mechanisms of cell adhesion. Experiments have found that cell detachment shows strong rate dependence, which is mostly attributed to the binding-unbinding kinetics of receptor-ligand bond. However, our recent study showed that the cellular volume regulation can significantly regulate the dynamics of adherent cell and cell detachment. How this cellular volume regulation contributes to the rate dependence of cell detachment remains elusive. Here, we systematically study the role of cellular volume regulation in the rate dependence of cell detachment by investigating the cell detachments of nonspecific adhesion and specific adhesion. We find that the cellular volume regulation and the bond kinetics dominate the rate dependence of cell detachment at different time scales. We further test the validity of the traditional Johnson-Kendall-Roberts (JKR) contact model and the detachment model developed by Wyart and Gennes et al (W-G model). When the cell volume is changeable, the JKR model is not appropriate for both the detachments of convex cells and concave cells. The W-G model is valid for the detachment of convex cells but is no longer applicable for the detachment of concave cells. Finally, we show that the rupture force of adherent cells is also highly sensitive to substrate stiffness, since an increase in substrate stiffness will lead to more associated bonds. These findings can provide insight into the critical role of cell volume in cell detachment and might have profound implications for other adhesion-related physiological processes.

Activation of muscarinic acetylcholine receptors elicits pigment granule dispersion in retinal pigment epithelium isolated from bluegill

OpenAIRE

González, Alfredo; Crittenden, Elizabeth L; García, Dana M

2004-01-01

Abstract Background In fish, melanin pigment granules in the retinal pigment epithelium disperse into apical projections as part of the suite of responses the eye makes to bright light conditions. This pigment granule dispersion serves to reduce photobleaching and occurs in response to neurochemicals secreted by the retina. Previous work has shown that acetylcholine may be involved in inducing light-adaptive pigment dispersion. Acetylcholine receptors are of two main types, nicotinic and musc...

LONG-TERM EVOLUTION OF DOME-SHAPED MACULA: Increased Macular Bulge is Associated With Extended Macular Atrophy.

Science.gov (United States)

Soudier, Guillaume; Gaudric, Alain; Gualino, Vincent; Massin, Pascale; Nardin, Mathieu; Tadayoni, Ramin; Speeg-Schatz, Claude; Gaucher, David

2016-05-01

Dome-shaped macula (DSM) may cause impaired vision. This study analyzed the long-term evolution of DSM, most particularly macular changes: serous retinal detachment, retinal pigment epithelium atrophy, and DSM bulge increase. Twenty-nine eyes presenting with DSM were retrospectively studied. Clinical data, color photographs, fluorescein angiographs, and optical coherence tomography examinations were reviewed. Patients were followed up from 6 months to 111 months (mean, 37.89 months). The height of the macular bulge, the size of retinal pigment epithelium macular atrophy, and serous retinal detachment progression were studied. Other macular changes were noted. Mean vision remained stable. Dome-shaped macula height increased significantly from 338.9 μm to 364.3 μm (P = 0.007). Serous retinal detachment was present initially in 15 of 29 eyes; it increased in 4 cases and resolved spontaneously in 7. Macular retinal pigment epithelium atrophy correlated with the bulge height (P = 0.015), and it enlarged during follow-up (1.12 vs. 1.34, P = 0.04). Other macular anomalies were present initially or appeared during follow-up: macular pucker, choroidal neovascularization (CNV), subretinal pigmentary clumps, and flat irregular pigmented epithelium detachment. A few treatments were proven in serous retinal detachment cases but were ineffective in restoring vision. In DSM, vision may be stable for years while macular changes progress: the macular bulge increases as does retinal pigment epithelium atrophy.

Pigment production from a mangrove Penicillium

African Journals Online (AJOL)

SAM

2014-06-25

Jun 25, 2014 ... Key words: Penicillium, 2-(4-acetyl phenyl) acetic acid, bio elements, salts, soluble pigment. .... Table 1. Characteristics of the pigment fractions after solvent extraction. ..... naphthoquinone pigment by Fusarium verticillioides.

Highly sensitive in vitro methods for detection of residual undifferentiated cells in retinal pigment epithelial cells derived from human iPS cells.

Directory of Open Access Journals (Sweden)

Takuya Kuroda

Full Text Available Human induced pluripotent stem cells (hiPSCs possess the capabilities of self-renewal and differentiation into multiple cell types, and they are free of the ethical problems associated with human embryonic stem cells (hESCs. These characteristics make hiPSCs a promising choice for future regenerative medicine research. There are significant obstacles, however, preventing the clinical use of hiPSCs. One of the most obvious safety issues is the presence of residual undifferentiated cells that have tumorigenic potential. To locate residual undifferentiated cells, in vivo teratoma formation assays have been performed with immunodeficient animals, which is both costly and time-consuming. Here, we examined three in vitro assay methods to detect undifferentiated cells (designated an in vitro tumorigenicity assay: soft agar colony formation assay, flow cytometry assay and quantitative real-time polymerase chain reaction assay (qRT-PCR. Although the soft agar colony formation assay was unable to detect hiPSCs even in the presence of a ROCK inhibitor that permits survival of dissociated hiPSCs/hESCs, the flow cytometry assay using anti-TRA-1-60 antibody detected 0.1% undifferentiated hiPSCs that were spiked in primary retinal pigment epithelial (RPE cells. Moreover, qRT-PCR with a specific probe and primers was found to detect a trace amount of Lin28 mRNA, which is equivalent to that present in a mixture of a single hiPSC and 5.0×10⁴ RPE cells. Our findings provide highly sensitive and quantitative in vitro assays essential for facilitating safety profiling of hiPSC-derived products for future regenerative medicine research.

The Apical Localization of Na+, K+-ATPase in Cultured Human Retinal Pigment Epithelial Cells Depends on Expression of the β2 Subunit.

Science.gov (United States)

Lobato-Álvarez, Jorge A; Roldán, María L; López-Murillo, Teresa Del Carmen; González-Ramírez, Ricardo; Bonilla-Delgado, José; Shoshani, Liora

2016-01-01

Na + , K + -ATPase, or the Na + pump, is a key component in the maintenance of the epithelial phenotype. In most epithelia, the pump is located in the basolateral domain. Studies from our laboratory have shown that the β 1 subunit of Na + , K + -ATPase plays an important role in this mechanism because homotypic β 1 -β 1 interactions between neighboring cells stabilize the pump in the lateral membrane. However, in the retinal pigment epithelium (RPE), the Na + pump is located in the apical domain. The mechanism of polarization in this epithelium is unclear. We hypothesized that the apical polarization of the pump in RPE cells depends on the expression of its β 2 subunit. ARPE-19 cells cultured for up to 8 weeks on inserts did not polarize, and Na + , K + -ATPase was expressed in the basolateral membrane. In the presence of insulin, transferrin and selenic acid (ITS), ARPE-19 cells cultured for 4 weeks acquired an RPE phenotype, and the Na + pump was visible in the apical domain. Under these conditions, Western blot analysis was employed to detect the β 2 isoform and immunofluorescence analysis revealed an apparent apical distribution of the β 2 subunit. qPCR results showed a time-dependent increase in the level of β 2 isoform mRNA, suggesting regulation at the transcriptional level. Moreover, silencing the expression of the β 2 isoform in ARPE-19 cells resulted in a decrease in the apical localization of the pump, as assessed by the mislocalization of the α 2 subunit in that domain. Our results demonstrate that the apical polarization of Na + , K + -ATPase in RPE cells depends on the expression of the β 2 subunit.

TGF-β-stimulated aberrant expression of class III β-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

International Nuclear Information System (INIS)

Chung, Eun Jee; Chun, Ji Na; Jung, Sun-Ah; Cho, Jin Won; Lee, Joon H.

2011-01-01

Highlights: ► TGF-β induces aberrant expression of βIII in RPE cells via the ERK pathway. ► TGF-β increases O-GlcNAc modification of βIII in RPE cells. ► Mature RPE cells have the capacity to express a neuron-associated gene by TGF-β. -- Abstract: The class III β-tubulin isotype (β III ) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III β-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-β (TGF-β) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-β on the aberrant expression of class III β-tubulin and the intracellular signaling pathway mediating these changes. TGF-β-induced aberrant expression and O-linked-β-N-acetylglucosamine (O-GlcNac) modification of class III β-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-β also stimulated phosphorylation of ERK. TGF-β-induced aberrant expression of class III β-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-β stimulated aberrant expression of class III β-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-β stimulation and provide useful information towards understanding the pathogenesis of proliferative vitreoretinal diseases.

TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

2011-11-18

Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

From detached to attached buildup complexes

DEFF Research Database (Denmark)

Rafaelsen, B.; Elvebakk, G.; Andreassen, K.

2008-01-01

-like ridges and possibly areas with restricted circulation. Warm-water carbonate buildups, forming ridges and isolated mounds, occur in the Gipsdalen Group (latest Serpukhovian-mid-Sakmarian), where they initially grew in a detached platform setting. The carbonate buildups are several tens of kilometres long...... deposition and buildup growth bridged the detached platform with the attached platform. In the Bjarmeland Group (Lower Permian) 0.35-4.8 km wide, 1.5-27 km long and 60-420 m thick cool-water bryozoan-dominated straight, sinuous and continuous carbonate ridges or atoll-like ridges are located on top...

Outer segment phagocytosis by cultured retinal pigment epithelial cells requires Gas6.

Science.gov (United States)

Hall, M O; Prieto, A L; Obin, M S; Abrams, T A; Burgess, B L; Heeb, M J; Agnew, B J

2001-10-01

The function and viability of vertebrate photoreceptors requires the daily phagocytosis of photoreceptor outer segments (OS) by the adjacent retinal pigment epithelium (RPE). We demonstrate here a critical role in this process for Gas6 and by implication one of its receptor protein tyrosine kinases (RTKs), Mertk (Mer). Gas6 specifically and selectively stimulates the phagocytosis of OS by normal cultured rat RPE cells. The magnitude of the response is dose-dependent and shows an absolute requirement for calcium. By contrast the Royal College of Surgeons (RCS) rat RPE cells, in which a mutation in the gene Mertk results in the expression of a truncated, non-functional receptor, does not respond to Gas6. These data strongly suggest that activation of Mertk by its ligand, Gas6, is the specific signaling pathway responsible for initiating the ingestion of shed OS. Moreover, photoreceptor degeneration in the RCS rat retina, which lacks Mertk, and in humans with a mutation in Mertk, strongly suggests that the Gas6/Mertk signaling pathway is essential for photoreceptor viability. We believe that this is the first demonstration of a specific function for Gas6 in the eye. Copyright 2001 Academic Press.

Detection of detachments and inhomogeneities in frescos by Compton scattering

International Nuclear Information System (INIS)

Castellano, A.; Cesareo, R.; Buccolieri, G.; Donativi, M.; Palama, F.; Quarta, S.; De Nunzio, G.; Brunetti, A.; Marabelli, M.; Santamaria, U.

2005-01-01

A mobile instrument has been developed for the detection and mapping of detachments in frescos by using Compton back scattered photons. The instrument is mainly composed of a high energy X-ray tube, an X-ray detection system and a translation table. The instrument was first applied to samples simulating various detachment situations, and then transferred to the Vatican Museum to detect detachments and inhomogeneities in the stanza di Eliodoro, one of the 'Raphael's stanze'

Long-Term PEDF Release in Rat Iris and Retinal Epithelial Cells after Sleeping Beauty Transposon-Mediated Gene Delivery

Directory of Open Access Journals (Sweden)

Laura Garcia-Garcia

2017-12-01

Full Text Available Pigment epithelium derived factor (PEDF is a potent antiangiogenic, neurotrophic, and neuroprotective molecule that is the endogenous inhibitor of vascular endothelial growth factor (VEGF in the retina. An ex vivo gene therapy approach based on transgenic overexpression of PEDF in the eye is assumed to rebalance the angiogenic-antiangiogenic milieu of the retina, resulting in growth regression of choroidal blood vessels, the hallmark of neovascular age-related macular degeneration. Here, we show that rat pigment epithelial cells can be efficiently transfected with the PEDF-expressing non-viral hyperactive Sleeping Beauty transposon system delivered in a form free of antibiotic resistance marker miniplasmids. The engineered retinal and iris pigment epithelium cells secrete high (141 ± 13 and 222 ± 14 ng PEDF levels in 72 hr in vitro. In vivo studies showed cell survival and insert expression during at least 4 months. Transplantation of the engineered cells to the subretinal space of a rat model of choroidal neovascularization reduces almost 50% of the development of new vessels.

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work

Science.gov (United States)

Wendsche, Johannes; Lohmann-Haislah, Andrea

2017-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes. PMID:28133454

Desquamation takes center stage at the origin of proliferative inflammatory atrophy, epithelial-mesenchymal transition, and stromal growth in benign prostate hyperplasia.

Science.gov (United States)

Ferrucci, Danilo; Biancardi, Manoel F; Nishan, Umar; Rosa-Ribeiro, Rafaela; Carvalho, Hernandes F

2017-11-01

In this commentary, we propose a relationship between desquamation, initially described as the collective detachment and deletion of epithelial cell in the prostate gland after castration, and proliferative inflammatory atrophy (PIA) and stromal growth in benign prostate hyperplasia (BPH). First, in response to diverse stimuli, including inflammatory mediators, epithelial cells desquamate and leave a large surface of the luminal side of the basement membrane (BM) exposed. Basal cells are activated into intermediate-type cells, which change morphology to cover and remodel the exposed BM (simple atrophy) to a new physiological demand (such as in the hypoandrogen environment, simulated by surgical and/or chemical castration) and/or to support re-epithelialization (under normal androgen levels). In the presence of inflammation (that might be the cause of desquamation), the intermediate-type cells proliferate and characterize PIA. Second, in other circumstances, desquamation is an early step of epithelial-to-mesenchymal transition (EMT), which contributes to stromal growth, as suggested by some experimental models of BPH. The proposed associations correlate unexplored cell behaviors and reveal the remarkable plasticity of the prostate epithelium that might be at the origin of prostate diseases. © 2017 International Federation for Cell Biology.

Hairless pigmented guinea pigs: a new model for the study of mammalian pigmentation.

Science.gov (United States)

Bolognia, J L; Murray, M S; Pawelek, J M

1990-09-01

A stock of hairless pigmented guinea pigs was developed to facilitate studies of mammalian pigmentation. This stock combines the convenience of a hairless animal with a pigmentary system that is similar to human skin. In both human and guinea pig skin, active melanocytes are located in the basal layer of the interfollicular epidermis. Hairless albino guinea pigs on an outbred Hartley background (CrI:IAF/HA(hr/hr)BR; designated hr/hr) were mated with red-haired guinea pigs (designated Hr/Hr). Red-haired heterozygotes from the F1 generation (Hr/hr) were then mated with each other or with hairless albino guinea pigs. The F2 generation included hairless pigmented guinea pigs that retained their interfollicular epidermal melanocytes and whose skin was red-brown in color. Following UV irradiation, there was an increase in cutaneous pigmentation as well as an increase in the number of active epidermal melanocytes. An additional strain of black hairless guinea pigs was developed using black Hr/Hr animals and a similar breeding scheme. These two strains should serve as useful models for studies of the mammalian pigment system.

Sensitizing pigment in the fly

International Nuclear Information System (INIS)

Vogt, K.; Kirschfeld, K.

1983-01-01

The sensitizing pigment hypothesis for the high UV sensitivity in fly photoreceptors (R1-6) is further substantiated by measurements of the polarisation sensitivity in the UV. The quantum yield of the energy transfer from sensitizing pigment to rhodopsin was estimated by electrophysiological measurements of the UV sensitivity and the rhabdomeric absorptance (at 490 nm) in individual receptor cells. The transfer efficiency is >=0.75 in receptors with an absorptance in the rhabdomeres of 0.55-0.95. This result suggests that the sensitizing pigment is bound in some way to the rhodopsin. A ratio of two molecules of sensitizing pigment per one rhodopsin is proposed. (orig.)

Raman Spectroscopy of Microbial Pigments

Science.gov (United States)

Edwards, Howell G. M.; Oren, Aharon

2014-01-01

Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions. PMID:24682303

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.

Detection of detachments and inhomogeneities in frescos by Compton scattering

Energy Technology Data Exchange (ETDEWEB)

Castellano, A. [Dipartimento di Scienza dei Materiali, Universita di Lecce, 73100 Lecce (Italy); INFN, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Cesareo, R. [Istituto di Matematica e Fisica, Universita di Sassari, 07100 Sassari (Italy) and INFN, Sezione di Cagliari, Cittadella Universitaria di Monserrato, 09042 Cagliari (Italy)]. E-mail: cesareo@uniss.it; Buccolieri, G. [Dipartimento di Scienza dei Materiali, Universita di Lecce, 73100 Lecce (Italy); INFN, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Donativi, M. [Dipartimento di Scienza dei Materiali, Universita di Lecce, 73100 Lecce (Italy); Palama, F. [Dipartimento di Scienza dei Materiali, Universita di Lecce, 73100 Lecce (Italy); INFN, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Quarta, S. [Dipartimento di Scienza dei Materiali, Universita di Lecce, 73100 Lecce (Italy); INFN, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); De Nunzio, G. [Dipartimento di Scienza dei Materiali, Universita di Lecce, 73100 Lecce (Italy); INFN, Sezione di Lecce, via per Arnesano, 73100 Lecce (Italy); Brunetti, A. [Istituto di Matematica e Fisica, Universita di Sassari, 07100 Sassari (Italy); INFN, Sezione di Cagliari, Cittadella Universitaria di Monserrato, 09042 Cagliari (Italy); Marabelli, M. [Istituto Centrale del Restauro, P.zza S. Francesco di Paola, 00184 Rome (Italy); Santamaria, U. [Laboratori dei Musei Vaticani, Citta del Vaticano, Rome (Italy)

2005-07-01

A mobile instrument has been developed for the detection and mapping of detachments in frescos by using Compton back scattered photons. The instrument is mainly composed of a high energy X-ray tube, an X-ray detection system and a translation table. The instrument was first applied to samples simulating various detachment situations, and then transferred to the Vatican Museum to detect detachments and inhomogeneities in the stanza di Eliodoro, one of the 'Raphael's stanze'.

Disappearance of a detached vapor mass in subcooled water

International Nuclear Information System (INIS)

Inada, Shigeaki; Miyasaka, Yoshiki; Izumi, Ryotaro.

1986-01-01

Experiments on pool transition boiling of water under atmospheric pressure on a heated surface 10 mm in diameter were conducted for subcooling 15 - 50 K. The mass flux of condensation of a detached coalescent vapor bubble was experimentally estimated by a mathematical model based on the mass transfer mechanism of condensation. As a result, it is clarified that the mass flux of condensation of the detached bubble was influenced by the initial growing velocity of a vapor bubble immediately following the detached bubble. The disappearance velocity of the detached bubble defined as a ratio of the bubble diameter at the departure to the time required until the disappearance, is in the range 0.2 to 2.0 m/sec. The disappearance velocity is proportional to the initial growing velocity of the bubble, to the square of the heat flux of the heated surface and to the cube of the wall superheat, separately. (author)

Generation of corneal epithelial cells from induced pluripotent stem cells derived from human dermal fibroblast and corneal limbal epithelium.

Directory of Open Access Journals (Sweden)

Ryuhei Hayashi

Full Text Available Induced pluripotent stem (iPS cells can be established from somatic cells. However, there is currently no established strategy to generate corneal epithelial cells from iPS cells. In this study, we investigated whether corneal epithelial cells could be differentiated from iPS cells. We tested 2 distinct sources: human adult dermal fibroblast (HDF-derived iPS cells (253G1 and human adult corneal limbal epithelial cells (HLEC-derived iPS cells (L1B41. We first established iPS cells from HLEC by introducing the Yamanaka 4 factors. Corneal epithelial cells were successfully induced from the iPS cells by the stromal cell-derived inducing activity (SDIA differentiation method, as Pax6(+/K12(+ corneal epithelial colonies were observed after prolonged differentiation culture (12 weeks or later in both the L1B41 and 253G1 iPS cells following retinal pigment epithelial and lens cell induction. Interestingly, the corneal epithelial differentiation efficiency was higher in L1B41 than in 253G1. DNA methylation analysis revealed that a small proportion of differentially methylated regions still existed between L1B41 and 253G1 iPS cells even though no significant difference in methylation status was detected in the specific corneal epithelium-related genes such as K12, K3, and Pax6. The present study is the first to demonstrate a strategy for corneal epithelial cell differentiation from human iPS cells, and further suggests that the epigenomic status is associated with the propensity of iPS cells to differentiate into corneal epithelial cells.

Effect of pigment concentration on fastness and color values of thermal and UV curable pigment printing

Science.gov (United States)

Baysal, Gulcin; Kalav, Berdan; Karagüzel Kayaoğlu, Burçak

2017-10-01

In the current study, it is aimed to determine the effect of pigment concentration on fastness and colour values of thermal and ultraviolet (UV) curable pigment printing on synthetic leather. For this purpose, thermal curable solvent-based and UV curable water-based formulations were prepared with different pigment concentrations (3, 5 and 7%) separately and applied by screen printing technique using a screen printing machine. Samples printed with solvent-based formulations were thermally cured and samples printed with water-based formulations were cured using a UV curing machine equipped with gallium and mercury (Ga/Hg) lamps at room temperature. The crock fastness values of samples printed with solvent-based formulations showed that increase in pigment concentration was not effective on both dry and wet crock fastness values. On the other hand, in samples printed with UV curable water-based formulations, dry crock fastness was improved and evaluated as very good for all pigment concentrations. However, increasing the pigment concentration affected the wet crock fastness values adversely and lower values were observed. As the energy level increased for each irradiation source, the fastness values were improved. In comparison with samples printed with solvent-based formulations, samples printed with UV curable water-based formulations yielded higher K/S values at all pigment concentrations. The results suggested that, higher K/S values can be obtained in samples printed with UV curable water-based formulations at a lower pigment concentration compared to samples printed with solvent-based formulations.

A chick model of retinal detachment: cone rich and novel.

Directory of Open Access Journals (Sweden)

Colleen M Cebulla

Full Text Available Development of retinal detachment models in small animals can be difficult and expensive. Here we create and characterize a novel, cone-rich retinal detachment (RD model in the chick.Retinal detachments were created in chicks between postnatal days 7 and 21 by subretinal injections of either saline (SA or hyaluronic acid (HA. Injections were performed through a dilated pupil with observation via surgical microscope, using the fellow eye as a control. Immunohistochemical analyses were performed at days 1, 3, 7, 10 and 14 after retinal detachment to evaluate the cellular responses of photoreceptors, Müller glia, microglia and nonastrocytic inner retinal glia (NIRG. Cell proliferation was detected with bromodeoxyuridine (BrdU-incorporation and by the expression of proliferating cell nuclear antigen (PCNA. Cell death was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL. As in mammalian models of RD, there is shortening of photoreceptor outer segments and mis-trafficking of photoreceptor opsins in areas of RD. Photoreceptor cell death was maximal 1 day after RD, but continued until 14 days after RD. Müller glia up-regulated glial fibriliary acidic protein (GFAP, proliferated, showed interkinetic nuclear migration, and migrated to the subretinal space in areas of detachment. Microglia became reactive; they up-regulated CD45, acquired amoeboid morphology, and migrated toward outer retina in areas of RD. Reactive NIRG cells accumulated in detached areas.Subretinal injections of SA or HA in the chick eye successfully produced retinal detachments and cellular responses similar to those seen in standard mammalian models. Given the relatively large eye size, and considering the low cost, the chick model of RD offers advantages for high-throughput studies.

Central posterior capsule pigmentation in a patient with pigment dispersion and previous ocular trauma: a case report.

Science.gov (United States)

Al-Mezaine, Hani S

2010-01-01

We report a 55-year-old man with unusually dense, unilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including a Krukenberg's spindle and dense trabecular pigmentation in both eyes. A history of an old blunt ocular trauma probably caused separation of the anterior hyaloid from the back of the lens, thereby creating an avenue by which pigment could reach the potential space of Berger's from the posterior chamber.

Happy, healthy, and productive: the role of detachment from work during nonwork time.

Science.gov (United States)

Fritz, Charlotte; Yankelevich, Maya; Zarubin, Anna; Barger, Patricia

2010-09-01

Mentally distancing oneself from work during nonwork time can help restore resources lost because of work demands. In this study, we examined possible outcomes of such psychological detachment from work, specifically well-being and job performance. Although employees may need to mentally detach from work to restore their well-being, high levels of detachment may require a longer time to get back into "working mode," which may be negatively associated with job performance. Our results indicate that higher levels of self-reported detachment were associated with higher levels of significant other-reported life satisfaction as well as lower levels of emotional exhaustion. In addition, we found curvilinear relationships between psychological detachment and coworker reported job performance (task performance and proactive behavior). Thus, although high psychological detachment may enhance employee well-being, it seems that medium levels of detachment are most beneficial for job performance. Copyright 2010 APA, all rights reserved

Mechanisms of redox metabolism and cancer cell survival during extracellular matrix detachment.

Science.gov (United States)

Hawk, Mark A; Schafer, Zachary T

2018-01-16

Non-transformed cells that become detached from the extracellular matrix (ECM) undergo dysregulation of redox homeostasis and cell death. In contrast, cancer cells often acquire the ability to mitigate programmed cell death pathways and recalibrate the redox balance to survive after ECM detachment, facilitating metastatic dissemination. Accordingly, recent studies of the mechanisms by which cancer cells overcome ECM detachment-induced metabolic alterations have focused on mechanisms in redox homeostasis. The insights into these mechanisms may inform the development of therapeutics that manipulate redox homeostasis to eliminate ECM-detached cancer cells. Here, we review how ECM-detached cancer cells balance redox metabolism for survival. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Nonresonant excess photon detachment of negative hydrogen ions

International Nuclear Information System (INIS)

Gulley, M. S.; Zhao, Xin Miao; Bryant, H. C.; Strauss, Charlie E. M.; Funk, David J.; Stintz, A.; Rislove, D. C.; Kyrala, G. A.; Ingalls, W. B.; Miller, W. A.

1999-01-01

One-photon detachment and two-photon nonresonant excess photon detachment of electrons from the H - ion (outer-electron binding energy = 0.7542 eV) are observed with 1.165 eV laser pulses from a Nd:YAG laser (where YAG denotes yttrium aluminum garnet). A Penning ion source produces a pulsed 8 μA, 35 keV H - beam that intersects a laser beam cylindrically focused down to a 17 μm full width at half maximum waist in the ion beam direction, creating a high-intensity interaction region with peak intensities of up to 10 11 W/cm 2 . The interaction time is 7 ps. The detached electrons are detected by a time-of-flight apparatus enabling us to detect a very small two-photon signal in the presence of a very large signal from single photon detachments. By rotating the linear polarization angle, we study the angular distribution of the electrons for both one- and two-photon detachments. The spectra are modeled to determine the asymmetry parameters and one- and two-photon cross sections. We find β 2 to be 2.54+0.44/-0.60 and β 4 to be 2.29+0.07/-0.31, corresponding to a D state of 89+3/-12% of the S wave and D wave detachments for the two-photon results. The relative phase angle between the S and D amplitudes is measured to be less than 59 degree sign . The measured cross sections are found to be consistent with theoretical predictions. The one-photon photodetachment cross section is measured to be (3.6±1.7)x10 -17 cm 2 . The two-photon photodetachment generalized cross section is (1.3±0.5)x10 -48 cm 4 sec, consistent with theoretical calculations of the cross section. The three-photon generalized cross section is less than 4.4x10 -79 cm 6 sec 2 . (c) 1999 The American Physical Society

Rapid purification method for vitamin A-derived aging pigments A2E and iso-A2E using cation exchange resin.

Science.gov (United States)

Jee, Eun Hye; Kim, So Ra; Jang, Young Pyo

2012-08-17

A2E, known to be involved in the pathogenesis of age-related macular degeneration (AMD), is one of the major compounds that accumulate as fluorescent pigments in retinal pigment epithelial (RPE) cells with age and in some retinal disorders. While the biomimetic synthesis of A2E and its cis-isomer, iso-A2E is as simple as 'one-pot' reaction, the purification of these amphiphillic compounds has been a bottleneck for the mass production of these pathophysiologically important eye pigments. In order to provide a new method of rapid purification of A2E and iso-A2E, we employed a cation exchange resin for the separation of these pigments from crude reaction mixture. The reaction mixture was loaded on a weak acid resin and was eluted with 80% methanol with sodium hydroxide (pH 12), 100% methanol, and 100% methanol with 0.1% trifluoroacetic acid (TFA) in sequence. A2E and isoA2E were eluted only with 100% methanol solution containing TFA. Most of unreacted starting materials and intermediates were removed with 80% methanol containing sodium hydroxide. The new method can be used as a relatively simple and economic way to purify A2E and iso-A2E compared to conventional HPLC technique. Copyright © 2012 Elsevier B.V. All rights reserved.

Ohmic discharges in Tore Supra - Marfes and detached plasmas

International Nuclear Information System (INIS)

Vallet, J.C.

1990-01-01

The Tore Supra plasma characteristics are given. The observed discharges are either leaning on the graphite inner first wall or limited by movable pump limiters located outboard and at the bottom of the vacuum chamber. The particular plasma conditions which lead to marfes and detached plasmas in ohmically heated He and D2 discharges limited by the inner wall are investigated. The results show that the ratio of radiated power to ohmic power increase linearly with M.g. As M.g rises, attached plasma, marfe and detached plasma are sequentially observed. Detached plasma with an effective radius as small as. 7 times the limiter radius was observed on Tore Supra

Shape Evolution of Detached Bridgman Crystals Grown in Microgravity

Science.gov (United States)

Volz, M. P.; Mazuruk, K.

2015-01-01

A theory describing the shape evolution of detached Bridgman crystals in microgravity has been developed. A starting crystal of initial radius r0 will evolve to one of the following states: Stable detached gap; Attachment to the crucible wall; Meniscus collapse. Only crystals where alpha plus omega is great than 180 degrees will achieve stable detached growth in microgravity. Results of the crystal shape evolution theory are consistent with predictions of the dynamic stability of crystallization (Tatarchenko, Shaped Crystal Growth, Kluwer, 1993). Tests of transient crystal evolution are planned for ICESAGE, a series of Ge and GeSi crystal growth experiments planned to be conducted on the International Space Station (ISS).

FACTORS ASSOCIATED WITH VISUAL OUTCOME AFTER MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT SURGERY.

Science.gov (United States)

Park, Dae Hyun; Choi, Kyung Seek; Sun, Hae Jung; Lee, Sung Jin

2018-01-01

To evaluate preoperative factors influencing the visual outcome and postoperative factors associated with the changes in visual acuity, after reattachment surgery to treat macula-off rhegmatogenous retinal detachment. A total of 180 eyes of 180 patients who underwent reattachment surgery to treat macula-off rhegmatogenous retinal detachment, and who were followed up for more than 12 months, were reviewed retrospectively. Preoperative and postoperative characteristics, including optical coherence tomography findings, were comprehensively analyzed using univariate and multivariate models to evaluate preoperative factors influencing best-corrected visual acuity 12 months after macula-off rhegmatogenous retinal detachment surgery and postoperative factors associated with changes in best-corrected visual acuity after surgery. Preoperatively, the extent of detachment (P = 0.037), macula-off duration (P macula-off rhegmatogenous retinal detachment surgery were the extent of detachment, macula-off duration, and external limiting membrane integrity. Postoperatively, predictive factors were the outer retinal microstructures, particularly the photoreceptor outer segment layer.

[Clinical Characteristics of Rhegmatogenous Retinal Detachment in Highly Myopic and Phakic Eyes].

Science.gov (United States)

Orihara, Tadashi; Hirota, Kazunari; Yokota, Reiji; Kunita, Daisuke; Itoh, Yuji; Rii, Tosho; Koto, Takashi; Hiraoka, Tomoyuki; Inoue, Makoto; Hirakata, Akito

2016-05-01

To evaluate clinical characteristics of rhegmatogenous retinal detachment in high myopic and phakic eyes. The subjects were 1174 eyes of phakic rhegmatogenous retinal detachment detected in 1199 eyes that underwent initial vitreoretinal surgery between April 2006 and March 2011. Eyes with macular hole retinal detachment or secondary retinal detachment were excluded. The 486 eyes with high myopia (spherical equivalent ≤ -6.0 D or axial length ≥ 26.5 mm) and the 688 eyes with non-high myopia were compared. The mean age was significantly younger in the high myopia group (42.7 ± 14.2 years old, p lattice degeneration were more frequent (16.7%, 20.4%, respectively). The incidences of the retinal detachment in younger age and those caused by retinal holes were higher in the high myopia group. Higher incidence of retinal detachment and lattice degeneration in the fellow eyes of the high myopia group indicated that careful observation also in the fellow eyes was recommended.

Classification of posterior vitreous detachment

Science.gov (United States)

Kakehashi, Akihiro; Takezawa, Mikiko; Akiba, Jun

2014-01-01

Diagnosing a posterior vitreous detachment (PVD) is important for predicting the prognosis and determining the indication for vitreoretinal surgery in many vitreoretinal diseases. This article presents both classifications of a PVD by slit-lamp biomicroscopy and of a shallow PVD by optical coherence tomography (OCT). By biomicroscopy, the vitreous condition is determined based on the presence or absence of a PVD. The PVD then is classified as either a complete posterior vitreous detachment (C-PVD) or a partial posterior vitreous detachment (P-PVD). A C-PVD is further divided into a C-PVD with collapse and a C-PVD without collapse, while a P-PVD is divided into a P-PVD with shrinkage of the posterior hyaloid membrane (P-PVD with shrinkage) and a P-PVD without shrinkage of the posterior hyaloid membrane (P-PVD without shrinkage). A P-PVD without shrinkage has a subtype characterized by vitreous gel attachment through the premacular hole in a posterior hyaloid membrane to the macula (P-PVD without shrinkage [M]). By OCT, a shallow PVD is classified as the absence of a shallow PVD or as a shallow PVD. A shallow PVD is then subclassified as a shallow PVD without shrinkage of the posterior vitreous cortex, a shallow PVD with shrinkage of the posterior vitreous cortex, and a peripheral shallow PVD. A shallow PVD without shrinkage of the posterior vitreous cortex has two subtypes: an age-related shallow PVD and a perifoveal PVD associated with a macular hole. PMID:24376338

The visual pigment cyanide effect.

Science.gov (United States)

Crescitelli, F; Karvaly, B

1989-12-01

The visual pigment of the Tokay gecko (Gekko gekko) with its in situ absorption maximum at 521 nm has its spectral position at 500 to 505 nm when chloride-deficient digitonin is used for the extraction. In this case the addition of chloride or bromide to the extract restores the maximum to 521 nm. This property, characteristic of gecko pigments in general, does not occur with any of the rhodopsins that have been tested. Simple salts of cyanide, a pseudohalogenoid with an ionic radius close to those of chloride and bromide and/or its hydrolysis product attacks both this gecko pigment and rhodopsins in the dark. This is seen as a slow thermal loss of photopigment if (sodium) cyanide is present at concentrations above 40 mM for the gecko pigment and 150 mM for the rhodopsins of the midshipman (Porichthys notatus) and of the frog (Rana pipiens). In all cases the loss of the photopigment is accompanied by the appearance of a spectral product with maximum absorption at about 340 nm. Cyanide addition has no effect on the photosensitivity of the native pigments and neither does it alter, as do chloride, bromide and other anions, the spectral absorbance curve. The spectral product at 340 nm also appears when the visual pigments are photolyzed in the presence of cyanide salts below the threshold concentrations given above. Incubation of digitonin-solubilized all-trans-retinal with (sodium) cyanide leads to a reaction product with absorption spectrum similar to that obtained with visual pigments under comparable conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Detached Statements

Directory of Open Access Journals (Sweden)

Mark McBride

2018-04-01

Full Text Available Joseph Raz has introduced an interesting class of statements —detached statements— into the philosophical lexicon. In brief, such statements are (informa- tive normative statements, yet the speaker does not, in so uttering them, express or convey acceptance of the point of view of the hearer to whom they are addressed (as contrasted with committed statements, where the speaker does express or convey such acceptance. I propose to offer a novel analysis of such statements (and to clear away some confusions about them. In brief, such statements will be analysed as wide-scope normative conditionals.

Kinematic Fitting of Detached Vertices

Energy Technology Data Exchange (ETDEWEB)

Mattione, Paul [Rice Univ., Houston, TX (United States)

2007-05-01

The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

Central posterior capsule pigmentation in a patient with pigment dispersion and previous ocular trauma: A case report

Directory of Open Access Journals (Sweden)

Al-Mezaine Hani

2010-01-01

Full Text Available We report a 55-year-old man with unusually dense, unilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including a Krukenberg′s spindle and dense trabecular pigmentation in both eyes. A history of an old blunt ocular trauma probably caused separation of the anterior hyaloid from the back of the lens, thereby creating an avenue by which pigment could reach the potential space of Berger′s from the posterior chamber.

Retinal pigment epithelial cells secrete neurotrophic factors and synthesize dopamine: possible contribution to therapeutic effects of RPE cell transplantation in Parkinson's disease

Directory of Open Access Journals (Sweden)

Gu Qing

2009-06-01

Full Text Available Abstract Background New strategies for the treatment of Parkinson's disease (PD are shifted from dopamine (DA replacement to regeneration or restoration of the nigro-striatal system. A cell therapy using human retinal pigment epithelial (RPE cells as substitution for degenerated dopaminergic (DAergic neurons has been developed and showed promising prospect in clinical treatment of PD, but the exact mechanism underlying this therapy is not fully elucidated. In the present study, we investigated whether the beneficial effects of this therapy are related to the trophic properties of RPE cells and their ability to synthesize DA. Methods We evaluated the protective effects of conditioned medium (CM from cultured RPE cells on the DAergic cells against 6-hydroxydopamine (6-OHDA- and rotenone-induced neurotoxicity and determined the levels of glial cell derived neurotrophic factor (GDNF and brain derived neurotrophic factor (BDNF released by RPE cells. We also measured the DA synthesis and release. Finally we transplanted microcarriers-RPE cells into 6-OHDA lesioned rats and observed the improvement in apomorphine-induced rotations (AIR. Results We report here: (1 CM from RPE cells can secret trophic factors GDNF and BDNF, and protect DAergic neurons against the 6-OHDA- and rotenone-induced cell injury; (2 cultured RPE cells express L-dopa decarboxylase (DDC and synthesize DA; (3 RPE cells attached to microcarriers can survive in the host striatum and improve the AIR in 6-OHDA-lesioned animal model of PD; (4 GDNF and BDNF levels are found significantly higher in the RPE cell-grafted tissues. Conclusion These findings indicate the RPE cells have the ability to secret GDNF and BDNF, and synthesize DA, which probably contribute to the therapeutic effects of RPE cell transplantation in PD.

On The Detachment of Massive Trans-Neptunian Objects

Science.gov (United States)

Fleisig, Jacob; Madigan, Ann-Marie; Zderic, Alexander

2018-06-01

Our Solar System contains a large population of icy bodies stretching well beyond the orbit of Neptune. These objects, known collectively as the Scattered Disk, are remnants from the early formation of the Solar System that were scattered outward from their birth location by Neptune. But not all fit the bill.Sedna, one particularly massive Trans-Neptunian Object (TNO), does not conform to the scattering pattern. Its orbital eccentricity (e) is much lower than expected for a scattered object. This means its perihelion distance (proportional to 1-e) is much larger than the orbit of Neptune, or that it is “detached” from the main Solar System. Many more TNOs share similarities with Sedna. These observations suggest that there is a large population of detached TNOs that have a dynamical history different than that of the objects scattered by Neptune.The physical mechanism by which these massive minor planets become detached is currently unknown. However, we have discovered a phenomenon, driven by differential precession between TNOs of different masses and mutual secular gravitational torques, that naturally detach massive minor planets. This mechanism could have notable consequences for the outer Solar System and may shed some light on the origin of the detached population of minor planets near the Scattered Disk.

Enzymatic detachment of therapeutic mesenchymal stromal cells grown on glass carriers in a bioreactor.

Science.gov (United States)

Salzig, Denise; Schmiermund, Alexandra; P Grace, Pablo; Elseberg, Christiane; Weber, Christian; Czermak, Peter

2013-01-01

Cell therapies require the in vitro expansion of adherent cells such as mesenchymal stromal cells (hMSCs) in bioreactor systems or other culture environments, followed by cell harvest. As hMSCs are strictly adherent cells, cell harvest requires cell detachment. The use of hMSCs for cell therapy requires GMP production in accordance with the guidelines for advanced therapeutic medical products. Therefore, several GMP-conform available proteolytic enzymes were investigated for their ability to promote hMSC detachment. An allogeneic hMSC cell line (hMSC-TERT) that is used in clinical trials in the form of alginate cell capsules was chosen as a model. This study investigated the influence of several factors on the outcome of proteolytic hMSC-TERT detachment. Therefore, hMSC-TERT detachment was analyzed in different cultivation systems (static, dynamic) and in combination with further cell processing including encapsulation. Only two of the commercially available enzymes (AccutaseTM, TrypZeanTM) that fulfill all process requirements (commercial availability, cost, GMP conditions during manufacturing and non-animal origin) are found to be generally suitable for detaching hMSC-TERT. Combining cell detachment with encapsulation demonstrated a high impact of the experimental set up on cell damage. It was preferable to reduce the temperature during detachment and limit the detachment time to a maximum of 20 minutes. Cell detachment in static systems was not comparable with detachment in dynamic systems. Detachment yields in dynamic systems were lower and cell damage was higher for the same experimental conditions. Finally, only TrypZeanTM seemed to be suitable for the detachment of hMSC-TERT from dynamic reactor systems.

Inhibition of microparticle release triggers endothelial cell apoptosis and detachment

NARCIS (Netherlands)

Abid Hussein, Mohammed N.; Böing, Anita N.; Sturk, Augueste; Hau, Chi M.; Nieuwland, Rienk

2007-01-01

Endothelial cell cultures contain caspase 3-containing microparticles (EMP), which are reported to form during or after cell detachment. We hypothesize that also adherent endothelial cells release EMP, thus protecting these cells from caspase 3 accumulation, detachment and apoptosis. Human umbilical

Nitric oxide-dependent pigment migration induced by ultraviolet radiation in retinal pigment cells of the crab Neohelice granulata.

Science.gov (United States)

Filgueira, Daza de Moraes Vaz Batista; Guterres, Laís Pereira; Votto, Ana Paula de Souza; Vargas, Marcelo Alves; Boyle, Robert Tew; Trindade, Gilma Santos; Nery, Luiz Eduardo Maia

2010-01-01

The purpose of this study was to verify the occurrence of pigment dispersion in retinal pigment cells exposed to UVA and UVB radiation, and to investigate the possible participation of a nitric oxide (NO) pathway. Retinal pigment cells from Neohelice granulata were obtained by cellular dissociation. Cells were analyzed for 30 min in the dark (control) and then exposed to 1.1 and 3.3 J cm(-2) UVA, 0.07 and 0.9 J cm(-2) UVB, 20 nmβ-PDH (pigment dispersing hormone) or 10 μm SIN-1 (NO donor). Histological analyses were performed to verify the UV effect in vivo. Cultured cells were exposed to 250 μm L-NAME (NO synthase blocker) and afterwards were treated with UVA, UVB or β-PDH. The retinal cells in culture displayed significant pigment dispersion in response to UVA, UVB and β-PDH. The same responses to UVA and UVB were observed in vivo. SIN-1 did not induce pigment dispersion in the cell cultures. L-NAME significantly decreased the pigment dispersion induced by UVA and UVB but not by β-PDH. All retinal cells showed an immunopositive reaction against neuronal nitric oxide synthases. Therefore, UVA and UVB radiation are capable of inducing pigment dispersion in retinal pigment cells of Neohelice granulata and this dispersion may be nitric oxide synthase dependent. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

Tracing detached and attached care practices in nursing education

DEFF Research Database (Denmark)

Soffer, Ann Katrine B.

2014-01-01

The implementation of skills labs in Danish nursing education can, in itself, be viewed as a complexity. The students are expected to eventually carry out their work in a situated hospital practice, but they learn their professional skills in a different space altogether, detached and removed from...... of care are not explicated in the curriculum or textbooks; however, they surfaced once this crooked approach to studying care in a simulated practice was applied. The article starts from the assertion that detached engagements are not recognized within the field of nursing education as an equal component...... analytical approach to care work, as involving both attached and detached engagement within Danish nursing education, is advocated....

Retinal Detachment due to CrossFit Training Injury.

Science.gov (United States)

Joondeph, Stephanie A; Joondeph, Brian C

2013-01-01

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

Retinal Detachment due to CrossFit Training Injury

OpenAIRE

Joondeph, Stephanie A.; Joondeph, Brian C.

2013-01-01

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

State of art in research of ceramic pigments

International Nuclear Information System (INIS)

Sulcova, P.; Trojan, M.

2004-01-01

The research of our laboratory is focused on investigation of special inorganic pigments, mainly on ceramic pigments. many pigments used just now are questionable from the hygienic point of view. The fact that the most of the pigments contain problematic elements opens necessity of substitution of pigments containing toxic metals (chromium). Yellow ceramic pigments commonly used such as Pb 2 Sb 2 O 7 , PbCrO 4 and CdS are now being expelled from the market because of their toxicity. For this reason the main attention has been directed to the synthesis of new inorganic compounds mainly with yellow, orange and red colour hues, which can be used as pigments for colouring of glaze, plastics or building materials. In harmony with this postulate the pigments based on CeO 2 represent new special inorganic pigments with high-temperature stability have been synthesized. The commercial significance is in thermal, chemical and light stability, combined with their low toxicity. (author)

Seismic Slip on an Oblique Detachment Fault at Low Angles

Science.gov (United States)

Janecke, S. U.; Steely, A. N.; Evans, J. P.

2008-12-01

Pseudotachylytes are one of the few accepted indicators of seismic slip along ancient faults. Low-angle normal faults have produced few large earthquakes in historic times and low-angle normal faults (detachment faults) are typically severely misoriented relative to a vertical maximum compressive stress. As a result many geoscientists question whether low-angle normal faults produce earthquakes at low angles. Relationships in southern California show that a major low-angle normal-oblique fault slipped at low angles and produced large earthquakes. The exhumed Late Cenozoic West Salton detachment fault preserves spectacular fault- related pseudotachylytes along its fault plane and injected into its hanging wall and footwall. Composite pseudotachylyte zones are up to 1.25 m thick and persists over lateral distances of at least 10's of meters. Pseudotachylyte is common in most thin sections of damaged fault rocks with more than 20% (by volume) of cataclasite. We recognized the presence of original melt using numerous criteria: abundant spherulites in thin sections, injection structures at both the thin-section and outcrop scale, black aphanitic textures, quenched vein margins, variations in microcrystallite textures and/or size with respect to the vein margin, and glassy textures in hand sample. Multiple earthquakes are inferred to produce the layered "stratigraphy" in some exposures of pseudotachylytes. We infer that the West Salton detachment fault formed and slipped at low angles because it nearly perfectly reactivates a Cretaceous ductile thrust system at the half km scale and dips between 10 and 45 degrees. The about 30 degree NNE dip of the detachment fault on the north side of Yaqui Ridge is likely steeper than its dip during detachment slip because there is local steepening on the flanks of the Yaqui Ridge antiform in a contractional stepover of a crosscutting Quaternary San Felipe dextral fault zone. These relationships indicate a low dip on the detachment

The seasonal cycle of Titan's detached haze

Science.gov (United States)

West, Robert A.; Seignovert, Benoît; Rannou, Pascal; Dumont, Philip; Turtle, Elizabeth P.; Perry, Jason; Roy, Mou; Ovanessian, Aida

2018-04-01

Titan's `detached' haze, seen in Voyager images in 1980 and 1981 and monitored by the Cassini Imaging Science Subsystem (ISS) during the period 2004-2017, provides a measure of seasonal activity in Titan's mesosphere with observations over almost half of Saturn's seasonal cycle. Here we report on retrieved haze extinction profiles that reveal a depleted layer (having a diminished aerosol content), visually manifested as a gap between the main haze and a thin, detached upper layer. Our measurements show the disappearance of the feature in 2012 and its reappearance in 2016, as well as details after the reappearance. These observations highlight the dynamical nature of the detached haze. The reappearance seems congruent with earlier descriptions by climate models but more complex than previously described. It occurs in two steps, first as haze reappearing at 450 ± 20 km and one year later at 510 ± 20 km. These observations provide additional tight and valuable constraints about the underlying mechanisms, especially for Titan's mesosphere, that control Titan's haze cycle.

In vivo fluorescence imaging of primate retinal ganglion cells and retinal pigment epithelial cells

Science.gov (United States)

Gray, Daniel C.; Merigan, William; Wolfing, Jessica I.; Gee, Bernard P.; Porter, Jason; Dubra, Alfredo; Twietmeyer, Ted H.; Ahamd, Kamran; Tumbar, Remy; Reinholz, Fred; Williams, David R.

2006-08-01

The ability to resolve single cells noninvasively in the living retina has important applications for the study of normal retina, diseased retina, and the efficacy of therapies for retinal disease. We describe a new instrument for high-resolution, in vivo imaging of the mammalian retina that combines the benefits of confocal detection, adaptive optics, multispectral, and fluorescence imaging. The instrument is capable of imaging single ganglion cells and their axons through retrograde transport in ganglion cells of fluorescent dyes injected into the monkey lateral geniculate nucleus (LGN). In addition, we demonstrate a method involving simultaneous imaging in two spectral bands that allows the integration of very weak signals across many frames despite inter-frame movement of the eye. With this method, we are also able to resolve the smallest retinal capillaries in fluorescein angiography and the mosaic of retinal pigment epithelium (RPE) cells with lipofuscin autofluorescence.

True bursal pigmented villonodular synovitis

International Nuclear Information System (INIS)

Abdelwahab, Ibrahim Fikry; Kenan, Samuel; Steiner, German C.; Abdul-Quader, Mohammed

2002-01-01

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

Synthesis of new environment-friendly yellow pigments

International Nuclear Information System (INIS)

Furukawa, Shinya; Masui, Toshiyuki; Imanaka, Nobuhito

2006-01-01

New inorganic pigments based on amorphous cerium tungstate, Ce 1-x M x W 2 O 8 (M = Zr or Ti, 0 ≤ x ≤ 0.6), were synthesized and their color properties were characterized from the viewpoint of possible ecological inorganic pigments. The Ce 1-x M x W 2 O 8 materials absorb the visible and the ultraviolet light under 500 nm efficiently, which is originated in the O 2p -Ce 4f and the O 2p -W 5d double charge transfer transitions, and, as a result, the pigments can show a brilliant yellow color. The optical absorption edge wavelength of these pigments depends on the Zr or Ti content, and the effective yellow hue was observed at x = 0.2 for both pigments. The color properties of the present pigments suggest that they have a potential to be applied as a satisfactory pigment for paints. Furthermore, these pigments can be prepared by a simple co-precipitation method. They are inert and safe and do not produce side effects in the human body because they are composed of non-toxic and safe elements

Swapping one red pigment for another.

Science.gov (United States)

Davies, Kevin M

2015-01-01

Betalains are bright red and yellow pigments, which are produced in only one order of plants, the Caryophyllales, and replace the more familiar anthocyanin pigments. The evolutionary origin of betalain production is a mystery, but a new study has identified the first regulator of betalain production and discovered a previously unknown link between the two pigment pathways.

Induction of oxidative and nitrosative stresses in human retinal pigment epithelial cells by all-trans-retinal

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xue [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu Province (China); Wang, Ke, E-mail: wangke@jsinm.org [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu Province (China); Zhang, Kai [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu Province (China); Zhou, Fanfan [Faculty of Pharmacy, University of Sydney, New South Wales 2006 (Australia); Zhu, Ling [Save Sight Institute, University of Sydney, New South Wales 2000 (Australia)

2016-10-15

Delayed clearance of free form all-trans-retinal (atRAL) is estimated be the key cause of retinal pigment epithelium (RPE) cells injury during the pathogenesis of retinopathies such as age-related macular degeneration (AMD), however, the underlying molecular mechanisms are far from clear. In this study, we investigated the cytotoxicity effect and underlying molecular mechanism of atRAL on human retinal pigment epithelium ARPE-19 cells. The results indicated that atRAL could cause cell dysfunction by inducing oxidative and nitrosative stresses in ARPE-19 cells. The oxidative stress induced by atRAL was mediated through up-regulation of reactive oxygen species (ROS) generation, activating mitochondrial-dependent and MAPKs signaling pathways, and finally resulting in apoptosis of ARPE-19 cells. The NADPH oxidase inhibitor apocynin could partly attenuated ROS generation, indicating that NADPH oxidase activity was involved in atRAL-induced oxidative stress in ARPE-19 cells. The nitrosative stress induced by atRAL was mainly reflected in increasing nitric oxide (NO) production, enhancing iNOS, ICAM-1 and VCAM-1 expressions, and promoting monocyte adhesion. Furthermore, above effects could be dramatically blocked by using a nuclear factor kappa B (NF-κB) inhibitor SN50, indicated that atRAL-induced oxidative and nitrosative stresses were mediated by NF-κB. The results provide better understanding of atRAL-induced toxicity in human RPE cells. - Highlights: • atRAL induces oxidative stress-mediated apoptosis in ARPE-19 cells. • atRAL induces oxidative stress-mediated inflammation in ARPE-19 cells. • NF-κB is involved in atRAL-induced oxidative and nitrosative stresses.

Induction of oxidative and nitrosative stresses in human retinal pigment epithelial cells by all-trans-retinal

International Nuclear Information System (INIS)

Zhu, Xue; Wang, Ke; Zhang, Kai; Zhou, Fanfan; Zhu, Ling

2016-01-01

Delayed clearance of free form all-trans-retinal (atRAL) is estimated be the key cause of retinal pigment epithelium (RPE) cells injury during the pathogenesis of retinopathies such as age-related macular degeneration (AMD), however, the underlying molecular mechanisms are far from clear. In this study, we investigated the cytotoxicity effect and underlying molecular mechanism of atRAL on human retinal pigment epithelium ARPE-19 cells. The results indicated that atRAL could cause cell dysfunction by inducing oxidative and nitrosative stresses in ARPE-19 cells. The oxidative stress induced by atRAL was mediated through up-regulation of reactive oxygen species (ROS) generation, activating mitochondrial-dependent and MAPKs signaling pathways, and finally resulting in apoptosis of ARPE-19 cells. The NADPH oxidase inhibitor apocynin could partly attenuated ROS generation, indicating that NADPH oxidase activity was involved in atRAL-induced oxidative stress in ARPE-19 cells. The nitrosative stress induced by atRAL was mainly reflected in increasing nitric oxide (NO) production, enhancing iNOS, ICAM-1 and VCAM-1 expressions, and promoting monocyte adhesion. Furthermore, above effects could be dramatically blocked by using a nuclear factor kappa B (NF-κB) inhibitor SN50, indicated that atRAL-induced oxidative and nitrosative stresses were mediated by NF-κB. The results provide better understanding of atRAL-induced toxicity in human RPE cells. - Highlights: • atRAL induces oxidative stress-mediated apoptosis in ARPE-19 cells. • atRAL induces oxidative stress-mediated inflammation in ARPE-19 cells. • NF-κB is involved in atRAL-induced oxidative and nitrosative stresses.

N-Acetylcysteine Amide Protects Against Oxidative Stress–Induced Microparticle Release From Human Retinal Pigment Epithelial Cells

Science.gov (United States)

Carver, Kyle A.; Yang, Dongli

2016-01-01

Purpose Oxidative stress is a major factor involved in retinal pigment epithelium (RPE) apoptosis that underlies AMD. Drusen, extracellular lipid- and protein-containing deposits, are strongly associated with the development of AMD. Cell-derived microparticles (MPs) are small membrane-bound vesicles shed from cells. The purpose of this study was to determine if oxidative stress drives MP release from RPE cells, to assess whether these MPs carry membrane complement regulatory proteins (mCRPs: CD46, CD55, and CD59), and to evaluate the effects of a thiol antioxidant on oxidative stress–induced MP release. Methods Retinal pigment epithelium cells isolated from human donor eyes were cultured and treated with hydrogen peroxide (H2O2) to induce oxidative stress. Isolated MPs were fixed for transmission electron microscopy or processed for component analysis by flow cytometry, Western blot analysis, and confocal microscopy. Results Transmission electron microscopy showed that MPs ranged in diameter from 100 to 1000 nm. H2O2 treatment led to time- and dose-dependent elevations in MPs with externalized phosphatidylserine and phosphatidylethanolamine, known markers of MPs. These increases were strongly correlated to RPE apoptosis. Oxidative stress significantly increased the release of mCRP-positive MPs, which were prevented by a thiol antioxidant, N-acetylcysteine amide (NACA). Conclusions This is the first evidence that oxidative stress induces cultured human RPE cells to release MPs that carry mCRPs on their surface. The levels of released MPs are strongly correlated with RPE apoptosis. N-acetylcysteine amide prevents oxidative stress–induced effects. Our findings indicate that oxidative stress reduces mCRPs on the RPE surface through releasing MPs. PMID:26842754

TNF-α promotes human retinal pigment epithelial (RPE) cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression through activation of Akt/mTORC1 signaling

International Nuclear Information System (INIS)

Wang, Cheng-hu; Cao, Guo-Fan; Jiang, Qin; Yao, Jin

2012-01-01

Highlights: ► TNF-α induces MMP-9 expression and secretion to promote RPE cell migration. ► MAPK activation is not critical for TNF-α-induced MMP-9 expression. ► Akt and mTORC1 signaling mediate TNF-α-induced MMP-9 expression. ► SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-α. -- Abstract: Tumor necrosis factor-alpha (TNF-α) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-α promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-α-induced in vitro RPE cell migration. Reversely, exogenously-added active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-α-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-α promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.

TNF-{alpha} promotes human retinal pigment epithelial (RPE) cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression through activation of Akt/mTORC1 signaling

Energy Technology Data Exchange (ETDEWEB)

Wang, Cheng-hu; Cao, Guo-Fan [The Affiliated Eye Hospital of Nanjing Medical University, Nanjing 210029 (China); Jiang, Qin, E-mail: Jqin710@vip.sina.com [The Affiliated Eye Hospital of Nanjing Medical University, Nanjing 210029 (China); Yao, Jin, E-mail: dryaojin@yahoo.com [The Affiliated Eye Hospital of Nanjing Medical University, Nanjing 210029 (China)

2012-08-17

Highlights: Black-Right-Pointing-Pointer TNF-{alpha} induces MMP-9 expression and secretion to promote RPE cell migration. Black-Right-Pointing-Pointer MAPK activation is not critical for TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer Akt and mTORC1 signaling mediate TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-{alpha}. -- Abstract: Tumor necrosis factor-alpha (TNF-{alpha}) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-{alpha} promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-{alpha}-induced in vitro RPE cell migration. Reversely, exogenously-added active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-{alpha}-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-{alpha} promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.

Modification of cadmium pigments for colouring of polyolefins

International Nuclear Information System (INIS)

Kalinskaya, T.V.; Livshits, I.M.

1976-01-01

Modification conditions are studied of cadmium pigments, obtained by different methods, aliphatic acids(C 5 , C 8 and C 17 ). It is found, that cadmium pigments can adsorb acids with the number of atoms of carbon not less than 8. Stearic acid adsorption on lemon cadmium pigment taken as an example has shown the efficiency of pigment modification influence on its dispersancy in non-polar medium. Modification of yellow cadmium pigments of stearic acid makes possible to obtain pigment output forms ensuring a good particle distribution during polyolefine colouring

The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper

International Nuclear Information System (INIS)

Buelow, K.; Kristiansson, P.; Schueler, B.; Tullander, E.; Oestling, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

2002-01-01

The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission. The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper. The dependence of the penetration depth on the pigment grain size was also studied. To study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used. For the study of the penetration depth dependence of pigment size, specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution. The results show that the calendering of the paper considerably affects the penetration depth of ink

Macular pigment optical density spatial distribution measured in a subject with oculocutaneous albinism.

Science.gov (United States)

Putnam, Christopher M; Bland, Pauline J

2014-01-01

Previous studies of macular pigment optical density (MPOD) distribution in individuals with oculocutaneous albinism (OCA) have primarily used objective measurement techniques including fundus reflectometry and autofluorescence. We report here on a subject with OCA and their corresponding MPOD distribution assessed through heterochromatic flicker photometry (HFP). A subject with a history of OCA presented with an ocular history including strabismus surgery of the LE with persistent amblyopia and mild, latent nystagmus. Best corrected visual acuity was 20/25- RE and 20/40- LE. Spectral domain optical coherence tomography (SD-OCT) and fundus photography were also obtained. Evaluation of MPOD spatial distribution up to 8 degrees eccentricity from the fovea was performed using HFP. SD-OCT indicated a persistence of multiple inner retinal layers within the foveal region in the RE and LE including symmetric foveal thickening consistent with foveal hypoplasia. Fundus photography showed mild retinal pigmented epithelial (RPE) hypopigmentation and a poorly demarcated macula. OriginPro 9 was used to plot MPOD spatial distribution of the subject and a 33-subject sample. The OCA subject demonstrated a foveal MPOD of 0.10 with undetectable levels at 6 degrees eccentricity. The study sample showed a mean foveal MPOD of 0.34 and mean 6 degree eccentricity values of 0.03. Consistent with previous macular pigment (MP) studies of OCA, overall MPOD is reduced in our subject. Mild phenotypic expression of OCA with high functional visual acuity may represent a Henle fiber layer amenable to additional MP deposition. Further study of MP supplementation in OCA patients is warranted. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Retinal Detachment due to CrossFit Training Injury

Directory of Open Access Journals (Sweden)

Stephanie A. Joondeph

2013-01-01

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

Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens.

Science.gov (United States)

de Ondarza, José

2017-01-01

Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia 's virulence genes and defenses is therefore valuable. Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 - 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H 2 O 2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens .

Production of Monascus-like pigments

DEFF Research Database (Denmark)

2012-01-01

The present invention relates to a method for producing one or more Monascus-like pigment composition from Penicillium species comprising: a) providing a cultivation medium comprising a high concentration of C-and N-sources and a high C/N molar ratio, b) adjusting pH to about 5 to 8, c) inoculati...... as colouring agents in food items or non food items. The inventions further relates to Monascus-like pigment composition obtainable by a method of the inventions as well as use of the pigments....

Measuring the force of single protein molecule detachment from surfaces with AFM.

Science.gov (United States)

Tsapikouni, Theodora S; Missirlis, Yannis F

2010-01-01

Atomic force microscopy (AFM) was used to measure the non-specific detachment force of single fibrinogen molecules from glass surfaces. The identification of single unbinding events was based on the characteristics of the parabolic curves, recorded during the stretching of protein molecules. Fibrinogen molecules were covalently bound to Si(3)N(4) AFM tips, previously modified with 3-aminopropyl-dimethyl-ethoxysilane, through a homobifunctional poly(ethylene glycol) linker bearing two hydroxysulfosuccinimide esters. The most probable detachment force was found to be 210 pN, when the tip was retracting with a velocity of 1400 nm/s, while the distribution of the detachment distances indicated that the fibrinogen chain can be elongated beyond the length of the physical conformation before detachment. The dependence of the most probable detachment force on the loading rate was examined and the dynamics of fibrinogen binding to the surface were found amenable to the simple expression of the Bell-Evans theory. The theory's expansion, however, by incorporating the concept of the rupture of parallel residue-surface bonds could only describe the detachment of fibrinogen for a small number of such bonds. Finally, the mathematical expression of the Worm-Like Chain model was used to fit the stretching curves before rupture and two interpretations are suggested for the description of the AFM curves with multiple detachment events.

True bursal pigmented villonodular synovitis

Energy Technology Data Exchange (ETDEWEB)

Abdelwahab, Ibrahim Fikry [Department of Radiology, New York Methodist Hospital, Affiliated with New York Hospital-Cornell Medical Center, Brooklyn, NY (United States); Kenan, Samuel [Department of Orthopedics, New York University Medical Center, NY (United States); Steiner, German C. [Department of Pathology, Hospital for Joint Diseases/Orthopedic Institute, New York, NY (United States); Abdul-Quader, Mohammed [Department of Radiology, New York Presbyterian Hospital, Columbia University, New York, NY (United States)

2002-06-01

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

Metabolism during ECM Detachment: Achilles Heel of Cancer Cells?

Science.gov (United States)

Mason, Joshua A; Hagel, Kimberly R; Hawk, Mark A; Schafer, Zachary T

2017-07-01

Integrin-mediated attachment to the extracellular matrix (ECM) is required to combat the induction of programmed cell death in a variety of distinct cell types. If cells fail to maintain proper ECM attachment, they become subject to elimination via an apoptotic cell death program known as anoikis. However, anoikis inhibition is not sufficient to promote the long-term survival of ECM-detached cells. Several recent studies have unveiled the profound (anoikis-independent) impact of cell metabolism on the viability of ECM-detached cells. Thus, we posit that, during metastatic dissemination (when cancer cells are exposed to periods of ECM detachment), cancer cells must alter their metabolism in a fashion that promotes survival and ultimately contributes to metastatic outgrowth. Copyright © 2017 Elsevier Inc. All rights reserved.

Prevalence of choroidal nevus and retinal pigment epithelial alterations in vitiligo patients.

Science.gov (United States)

Fleissig, Efrat; Pavlovksy, Mor; Loewenstein, Anat; Zur, Dinah; Newman, Hadas; Keren, Shay; Goldenberg, Dafna; Bar-Ilan, Efrat; Goldstein, Michaella

2018-05-01

To investigate ocular manifestations in patients with vitiligo by multimodal imaging, including optical coherence tomography (OCT), color fundus photography, and fundus autofluorescence (FAF). In this prospective, observational clinical study, vitiligo patients underwent ophthalmologic and dermatologic clinical assessment and imaging by spectral-domain OCT, FAF, and color fundus imaging. Ocular echography was performed as indicated. Statistical analysis was performed using paired T test and Pearson correlation. A total of 61 eyes of 31 vitiligo patients were examined. Ocular findings consisted of choroidal nevi (n = 10, 32%), of which four (40%) were bilateral; two patients (6.5%) had a prominent choroidal pattern, two (6.5%) had hypopigmentary retinal pigment epithelium (RPE) lesions, and one (3.2%) had peripapillary atrophy of the RPE. Choroidal nevi were demonstrated only in eyes of patients with generalized vitiligo and were more common with upper body involvement (p = 0.02) and more prevalent in women (p = 0.02). Hypopigmentary lesions were detected in two patients and demonstrated on OCT as RPE atrophy and as photoreceptor/RPE changes. In this case series, vitiligo patients had a higher rate of choroidal nevi than previously reported. The hypopigmentary vitiliginous fundus lesions were depicted on OCT as photoreceptor and RPE atrophy. These findings may suggest the advisability of regular ocular monitoring for vitiligo patients.

Crystalline Organic Pigment-Based Field-Effect Transistors.

Science.gov (United States)

Zhang, Haichang; Deng, Ruonan; Wang, Jing; Li, Xiang; Chen, Yu-Ming; Liu, Kewei; Taubert, Clinton J; Cheng, Stephen Z D; Zhu, Yu

2017-07-05

Three conjugated pigment molecules with fused hydrogen bonds, 3,7-diphenylpyrrolo[2,3-f]indole-2,6(1H,5H)-dione (BDP), (E)-6,6'-dibromo-[3,3'-biindolinylidene]-2,2'-dione (IIDG), and 3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo-[3,4-c]pyrrole-1,4-dione (TDPP), were studied in this work. The insoluble pigment molecules were functionalized with tert-butoxylcarbonyl (t-Boc) groups to form soluble pigment precursors (BDP-Boc, IIDG-Boc, and TDPP-Boc) with latent hydrogen bonding. The single crystals of soluble pigment precursors were obtained. Upon simple thermal annealing, the t-Boc groups were removed and the soluble pigment precursor molecules with latent hydrogen bonding were converted into the original pigment molecules with fused hydrogen bonding. Structural analysis indicated that the highly crystalline soluble precursors were directly converted into highly crystalline insoluble pigments, which are usually only achievable by gas-phase routes like physical vapor transport. The distinct crystal structure after the thermal annealing treatment suggests that fused hydrogen bonding is pivotal for the rearrangement of molecules to form a new crystal in solid state, which leads to over 2 orders of magnitude enhancement in charge mobility in organic field-effect transistor (OFET) devices. This work demonstrated that crystalline OFET devices with insoluble pigment molecules can be fabricated by their soluble precursors. The results indicated that a variety of commercially available conjugated pigments could be potential active materials for high-performance OFETs.

Self-sustained detachment in the Large Helical Device

International Nuclear Information System (INIS)

Miyazawa, J.; Masuzaki, S.; Sakamoto, R.; Arimoto, H.; Kondo, K.; Tamura, N.; Shoji, M.; Nishiura, M.; Murakami, S.; Funaba, H.; Peterson, B.J.; Sakakibara, S.; Kobayashi, M.; Tanaka, K.; Narihara, K.; Yamada, I.; Morita, S.; Goto, M.; Osakabe, M.; Ashikawa, N.; Morisaki, T.; Nishimura, K.; Yamada, H.; Ohyabu, N.; Komori, A.; Motojima, O.

2006-01-01

Self-sustained detachment has been obtained in the Large Helical Device (LHD). Strong hydrogen gas puffing of ∼200 Pa m 3 s -1 after a density feedback phase detaches the plasma from the divertor plates with high reproducibility. High electron density of over 1 x 10 20 m -3 is sustained without gas puffing until the heating beam stops and a high-density flat top for 2 s has been demonstrated. Throughout the self-sustained detachment phase, the minor radius of the hot plasma column shrinks to ∼90% of the last-closed-flux-surface, which corresponds to the ι-bar ι/2π = 1/q =1 rational surface. This new state has been named the 'Serpens mode', for self-regulated plasma edge 'neath the last-closed-flux-surface. Global energy confinement of the Serpens mode is compared with the international stellarator scaling 1995 (ISS95) and the recently established scaling for high-density LHD plasmas (HD scaling), where shrinking confinement volume and shallow penetration of the heating beams are taken into account. Although the energy confinement of the Serpens mode seems deteriorated compared with ISS95, as in the case of high-density attached plasmas, it is consistent with the HD scaling. This suggests that the energy confinement properties of detached plasmas in LHD are similar to those in high-density attached plasmas

Postoperative recovery of visual function after macula-off rhegmatogenous retinal detachment.

Science.gov (United States)

van de Put, Mathijs A J; Croonen, Danna; Nolte, Ilja M; Japing, Wouter J; Hooymans, Johanna M M; Los, Leonoor I

2014-01-01

To determine which factors affect the recovery of visual function in macula off rhegmatogenous retinal detachment (RRD). In a prospective study of forty-five patients with a primary macula-off RRD of 24 hours to 6 weeks duration, the height of the macular detachment was determined by ultrasonography. At 12 months postoperatively, best corrected visual acuity (BCVA), contrast acuity, and color confusion indexes (CCI) were obtained. Macular detachment was present for 2-32 (median 7) days before repair. A shorter duration of macular detachment was correlated with a better CCI saturé (p = 0.0026) and lower LogMAR BCVA (better Snellen visual acuity) (p = 0.012). Also, a smaller height of macular detachment was correlated with a lower LogMAR BCVA (p = 0.0034). A younger age and lower pre-operative LogMAR BCVA at presentation were both correlated with better postoperative contrast acuity in the total group (age: p = 1.7×10(-4) and pre-operative LogMAR BCVA: p = 0.0034). Functional recovery after macula-off RRD is affected by the duration and the height of the macular detachment. Recovery of contrast acuity is also affected by age and BCVA at presentation. ARVO annual meeting 2013, May 7, Seattle, Washington, United States of America. trialregister.nl NTR839.

Celecoxib Down-Regulates the Hypoxia-Induced Expression of HIF-1α and VEGF Through the PI3K/AKT Pathway in Retinal Pigment Epithelial Cells

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Yi-zhou Sun

2017-12-01

Full Text Available Background/Aims: The goal of this study was to detect the expression of hypoxia-inducible factor 1α (HIF-1α and vascular endothelial growth factor (VEGF in human retinal pigmented epithelial (RPE cells treated with celecoxib, a selective cyclooxygenase-2 (COX-2 inhibitor, under hypoxic and normoxic conditions and to explore the signaling mechanism involved in regulating the hypoxia-induced expression of HIF-1α and VEGF in RPE cells. Methods: D407 cells were cultured in normoxic or hypoxic conditions, with or without celecoxib or a PI3K inhibitor (LY294002. The anti-proliferative effect of celecoxib was assessed using the MTT assay. RT-PCR, Western blotting and ELISA were performed to detect the levels of PI3K, phosphorylated AKT (p-AKT, HIF-1α, VEGF and COX-2. Results: Celecoxib inhibited the proliferation of RPE cells in a dose-dependent manner. Celecoxib suppressed the expression of VEGF at both the mRNA and protein levels and decreased HIF-1α protein expression. HIF-1α activation was regulated by the PI3K/AKT pathway. The celecoxib-induced down-regulation of HIF-1α and VEGF required the suppression of the hypoxia-induced PI3K/AKT pathway. However, the down-regulation of COX-2 did not occur in cells treated with celecoxib. Conclusions: The antiangiogenic effects of celecoxib in RPE cells under hypoxic conditions resulted from the inhibition of HIF-1α and VEGF expression, which may be partly mediated by a COX-2-independent, PI3K/AKT-dependent pathway.

Familial occurrence of pigment dispersion syndrome.

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Bovell, A M; Damji, K F; Dohadwala, A A; Hodge, W G; Allingham, R R

2001-02-01

Pigment dispersion syndrome affects up to 4% of the white population. It is characterized by the presence of transillumination defects, Krukenberg's spindle and dense trabecular meshwork pigmentation. Open-angle glaucoma will develop in as many as 50% of affected patients. In this study we describe the familial occurrence of pigment dispersion syndrome in six North American pedigrees and the phenotypic characteristics with respect to pigment dispersion syndrome and glaucoma. Probands with pigment dispersion syndrome were identified in glaucoma clinics at university eye centres in Ottawa and Durham, NC. Families with two or more affected members were evaluated. All willing members in each family underwent a thorough clinical examination and were classified as affected with pigment dispersion syndrome, suspect or unaffected. The previous medical records were reviewed to obtain the past medical and ocular history, including risk factors for glaucoma. All six families are white. Three families show at least two generations of affected members. Of the 43 subjects examined 58% were women. All 14 affected members showed moderate to heavy trabecular meshwork pigmentation and either Krukenberg's spindle or transillumination defects. The affected members were also considerably more myopic (mean spherical equivalent for the right eye -4.72 dioptres) than the suspect group or the unaffected group (mean spherical equivalent -0.79 D and +1.19 D respectively) (p pigment dispersion syndrome. Our ultimate goal is to identify the gene(s) that causes this disorder in order to clarify its molecular etiology and pathophysiology. This may give rise to a molecular classification of the disease as well as provide the foundation for genetic testing and new treatment approaches.

Microphysical Modeling of Titan's Detached Haze Layer in a 3D GCM

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Larson, Erik J.; Toon, Owen B.; West, Robert A.; Friedson, A. James

2015-11-01

We investigate the formation and seasonal cycle of the detached haze layer in Titan’s upper atmosphere using a 3D GCM with coupled aerosol microphysics. The base of the detached haze layer is defined by a local minimum in the vertical extinction profile. The detached haze is seen at all latitudes including the south pole as seen in Cassini images from 2005-2012. The layer merges into the winter polar haze at high latitudes where the Hadley circulation carries the particles downward. The hemisphere in which the haze merges with the polar haze varies with season. We find that the base of the detached haze layer occurs where there is a near balance between vertical winds and particle fall velocities. Generally the vertical variation of particle concentration in the detached haze region is simply controlled by sedimentation, so the concentration and the extinction vary roughly in proportion to air density. This variation explains why the upper part of the main haze layer, and the bulk of the detached haze layer follow exponential profiles. However, the shape of the profile is modified in regions where the vertical wind velocity is comparable to the particle fall velocity. Our simulations closely match the period when the base of the detached layer in the tropics is observed to begin its seasonal drop in altitude, and the total range of the altitude drop. However, the simulations have the base of the detached layer about 100 km lower than observed, and the time for the base to descend is slower in the simulations than observed. These differences may point to the model having somewhat lower vertical winds than occur on Titan, or somewhat too large of particle sizes, or some combination of both. Our model is consistent with a dynamical origin for the detached haze rather than a chemical or microphysical one. This balance between the vertical wind and particle fall velocities occurs throughout the summer hemisphere and tropics. The particle concentration gradients that

A case of traction retinal detachment in a patient with Gaucher disease.

Science.gov (United States)

Watanabe, Akira; Gekka, Tamaki; Arai, Kota; Tsuneoka, Hiroshi

2017-01-01

This is the first report of vitreous surgery for traction retinal detachment in a patient with type III Gaucher disease with multiple vitreous opacities. A 16-year-old boy who was diagnosed with Gaucher disease at age two and was undergoing enzyme replacement therapy presented with numerous white opacities of varying sizes in the vitreous bodies of both eyes. Visual acuity was 20/40 in the right eye and 20/2000 in the left eye. The retina of the left eye was completely detached, and vitreous surgery was performed. Liquefaction of the vitreous body was advanced, and the central part of the vitreous cavity contained almost no vitreous humor. The macular region was successfully aspirated with a vitreous cutter to form a posterior vitreous detachment. From the optic disk to the nasal side, however, posterior vitreous detachment formation was prevented by strong adhesions between the retina and the vitreous body. The traction retinal detachment of the posterior fundus improved after vitreous body resection alone. Traction retinal detachment may occur as a result of severe vitreous liquefaction in cases of Gaucher disease with numerous vitreous opacities.

Carbon distribution during plasma detachment triggered by edge magnetic island formation in LHD

International Nuclear Information System (INIS)

Dong, C.F.; Morita, S.; Kobayashi, M.; Oishi, T.; Goto, M.; Wang, E.H.; Huang, X.L.

2013-01-01

The detached plasma has been successfully achieved by applying the edge 1/1 magnetic island in Large Helical Device (LHD). Carbon, which is uniquely the dominant intrinsic impurity in general LHD discharges, is considered to be the main radiating species in the island-triggered detached plasma. The vertical profile of CIV measured from general discharges of LHD is characterized by a single edge intensity peak. In detached plasmas triggered by the edge magnetic island formation, however, the vertical profile of CIV shows a significant difference. Double edge peaks of CIV are found during the plasma detachment and the CIV radiation is also remarkably enhanced in the vicinity of X-point, whereas the vertical profile of CVI does not show any significant difference in both the attached and detached plasmas. In this proceeding the carbon distribution during the plasma detachment is presented and the results are discussed with edge magnetic field structure. (author)

Injurious effects of wool and grain dusts on alveolar epithelial cells and macrophages in vitro.

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Brown, D M; Donaldson, K

1991-01-01

Epidemiological studies of workers in wool textile mills have shown a direct relation between the concentration of wool dust in the air and respiratory symptoms. Injurious effects of wool dust on the bronchial epithelium could be important in causing inflammation and irritation. A pulmonary epithelial cell line in vitro was therefore used to study the toxic effects of wool dust. Cells of the A549 epithelial cell line were labelled with 51Cr and treated with whole wool dusts and extracts of wool, after which injury was assessed. Also, the effects of grain dust, which also causes a form of airway obstruction, were studied. The epithelial injury was assessed by measuring 51Cr release from cells as an indication of lysis, and by monitoring cells which had detached from the substratum. No significant injury to A549 cells was caused by culture with any of the dusts collected from the air but surface "ledge" dust caused significant lysis at some doses. Quartz, used as a toxic control dust, caused significant lysis at the highest concentration of 100 micrograms/well. To determine whether any injurious material was soluble the dusts were incubated in saline and extracts collected. No extracts caused significant injury to epithelial cells. A similar lack of toxicity was found when 51Cr labelled control alveolar macrophages were targets for injury. Significant release of radiolabel was evident when macrophages were exposed to quartz at concentrations of 10 and 20 micrograms/well, there being no significant injury with either wool or grain dusts. These data suggest that neither wool nor grain dust produce direct injury to epithelial cells, and further studies are necessary to explain inflammation leading to respiratory symptoms in wool and grain workers. PMID:2015211

Pigmented xerodermoid - Report of three cases

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Das Jayanta Kumar

2005-01-01

Full Text Available Pigmented xerodermoid, a rare genodermatosis, presents with clinical features and pathology similar to xeroderma pigmentosum, but at a later age. DNA repair replication is normal, but there is total depression of DNA synthesis after exposure to UV radiation. Two siblings in their teens and a man in his thirties with features of pigmented xerodermoid, e.g. photophobia, freckle-like lesions, keratoses, dryness of skin, and hypo- and hyper-pigmentation, are described. Although classically the onset of pigmented xerodermoid is said to be delayed till third to fourth decade of life, it seems the disease may appear earlier in the tropics. Early diagnosis and management could be life-saving.

Incidence and Pattern of Retinal Detachment in a Tertiary Eye ...

African Journals Online (AJOL)

Objectives: The aim was to determine the hospital incidence, pattern and clinical presentation of retinal detachment at the Guinness Eye Center, Onitsha, Nigeria. Materials and Methods: Case files of all retinal detachment patients seen at the Guinness Eye Center Onitsha between June 1997 and May 2012 were reviewed.

A new scaling for divertor detachment

Science.gov (United States)

Goldston, R. J.; Reinke, M. L.; Schwartz, J. A.

2017-05-01

The ITER design, and future reactor designs, depend on divertor ‘detachment,’ whether partial, pronounced or complete, to limit heat flux to plasma-facing components and to limit surface erosion due to sputtering. It would be valuable to have a measure of the difficulty of achieving detachment as a function of machine parameters, such as input power, magnetic field, major radius, etc. Frequently the parallel heat flux, estimated typically as proportional to P sep/R or P sep B/R, is used as a proxy for this difficulty. Here we argue that impurity cooling is dependent on the upstream density, which itself must be limited by a Greenwald-like scaling. Taking this into account self-consistently, we find the impurity fraction required for detachment scales dominantly as power divided by poloidal magnetic field. The absence of any explicit scaling with machine size is concerning, as P sep surely must increase greatly for an economic fusion system, while increases in the poloidal field strength are limited by coil technology and plasma physics. This result should be challenged by comparison with 2D divertor codes and with measurements on existing experiments. Nonetheless, it suggests that higher magnetic field, stronger shaping, double-null operation, ‘advanced’ divertor configurations, as well as alternate means to handle heat flux such as metallic liquid and/or vapor targets merit greater attention.

Emotional detachment in psychopathy: Involvement of dorsal default-mode connections.

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Sethi, Arjun; Gregory, Sarah; Dell'Acqua, Flavio; Periche Thomas, Eva; Simmons, Andy; Murphy, Declan G M; Hodgins, Sheilagh; Blackwood, Nigel J; Craig, Michael C

2015-01-01

Criminal psychopathy is defined by emotional detachment [Psychopathy Checklist - Revised (PCL-R) factor 1], and antisocial behaviour (PCL-R factor 2). Previous work has associated antisocial behaviour in psychopathy with abnormalities in a ventral temporo-amygdala-orbitofrontal network. However, little is known of the neural correlates of emotional detachment. Imaging studies have indicated that the 'default-mode network' (DMN), and in particular its dorsomedial (medial prefrontal - posterior cingulate) component, contributes to affective and social processing in healthy individuals. Furthermore, recent work suggests that this network may be implicated in psychopathy. However, no research has examined the relationship between psychopathy, emotional detachment, and the white matter underpinning the DMN. We therefore used diffusion tensor imaging (DTI) tractography in 13 offenders with psychopathy and 13 non-offenders to investigate the relationship between emotional detachment and the microstructure of white matter connections within the DMN. These included the dorsal cingulum (containing the medial prefrontal - posterior cingulate connections of the DMN), and the ventral cingulum (containing the posterior cingulate - medial temporal connections of the DMN). We found that fractional anisotropy (FA) was reduced in the left dorsal cingulum in the psychopathy group (p = .024). Moreover, within this group, emotional detachment was negatively correlated with FA in this tract portion bilaterally (left: r = -.61, p = .026; right: r = -.62, p = .023). These results suggest the importance of the dorsal DMN in the emotional detachment observed in individuals with psychopathy. We propose a 'dual-network' model of white matter abnormalities in the disorder, which incorporates these with previous findings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Key factors for UV curable pigment dispersions

International Nuclear Information System (INIS)

Magny, B.; Pezron, E.; Ciceron, P.H.; Askienazy, A.

1999-01-01

UV oligomers with good pigment dispersion are needed to allow good formulation flexibility and possibility to apply thinner films. Pigment dispersion mainly depends on three phenomena: the wetting of agglomerates, the breakage of agglomerates by mechanical stress and the stabilization of smaller agglomerates and primary particles against flocculation. It has been shown that oligomers with low viscosity and low surface tension induce a good pigment wetting. Examples of monomers and oligomers for good pigment dispersion are given

Correlation of visual recovery with macular height in macula-off retinal detachments.

Science.gov (United States)

Mowatt, L; Tarin, S; Nair, R G; Menon, J; Price, N J

2010-02-01

To determine the relationship between the preoperative macular height of a macular detachment and visual outcome of the post retinal reattachment. Prospective case series of 26 patients who presented to the Wolverhampton Eye Infirmary with a primary rhegmatogenous macula-off retinal detachment. Macular detachment height was assessed by B-scan ultrasound (10 Mhz) in the seated and supine postures before surgery. Age, gender, duration of the detachment, type of surgery, preoperative (pre-op) and postoperative (post-op) visual acuities at 3 and 6 months and status of the fellow eye were noted. A total of 26 eyes of 26 patients (mean age: 61.4 years+/-15.56 SD) were recruited. The mean logMAR pre- and post-op visual acuities at 3 and 6 months were 1.5+/-1.1 SD (range: 0.2-3), 0.38+/-0.23 SD (range: 0-0.84), and at 6 months 0.29+/-0.22 SD (range: 0-1.0). The median period of the macular detachment was 4.5 days (95% CI: 2-8 days). There was no significant difference between the mean macular heights while seated 2.42 mm+/-1.2 or supine 2.39 mm+/-1.0 (t-test, P=0.9). Correlation showed that the pre-op macular height is a statistical predictor of post-op visual acuity in our group of patients with macula-off retinal detachments. The shallower the macular detachment the greater the likelihood of a good visual outcome.

Behavior of a Spontaneously Arising Human Retinal Pigment Epithelial Cell Line Cultivated on Thin Alginate Film.

Science.gov (United States)

Najafabadi, Hoda Shams; Soheili, Zahra-Soheila; Ganji, Shahla Mohammad

2015-01-01

A cell line spontaneously derived from human retinal pigment epithelium (hRPE) was cultured on alginate film gelatinized with different concentrations of neurobasal cell culture medium (NCCM) to assess its growth and morphological behavior on this naturally occurring polysaccharide. Neonatal human globes were used to isolate hRPE cells. They were cultured in Dulbecco's modified Eagle's-medium-and-Ham's-F12-medium-(DMEM/F12) supplemented with 10% fetal bovine serum (FBS). Cultures were continuously studied using phase contrast microscopy. After the nineth passage, cells were characterized through immunocytochemical analysis for Oct4, Chx10, and Pax6 and Ki67 markers. In each well of a 6-well microplate, 1 and 2% weight/volume (w/v) alginate in deionized water was added and gelatinized using 1× and 10× NCCM. hRPE cells were cultured at a density of 2 × 105 cells/well in alginate-coated microplates. After 5 days, hRPE colonies were harvested and re-plated on polystyrene substrates. Morphology and growth of hRPE cultures were determined during the next 2 weeks. The first few passages of the cultures were purely hRPE cells that revealed typical morphological features of the pigmented epithelium. They made spaces, devoid of cells, between hRPE cell monolayer and fill in the unoccupied spaces. They grew faster than native RPE cells and rapidly overgrew. Immunocytochemical test revealed that the founded cells expressed Chx10, Pax6, Ki67 and Oct4. The hRPE cells survived unlimitedly on alginate film and formed giant adjoining colonies. After re-plating, hRPE colonies adhered quickly on polystyrene and displayed native hRPE morphological features. Alginate film can support the survival and growth of hRPE cells and induce the cells to re-organize in tissue-like structures.

Heat flux management via advanced magnetic divertor configurations and divertor detachment

Energy Technology Data Exchange (ETDEWEB)

Kolemen, E., E-mail: ekolemen@princeton.edu [Princeton University, Princeton, NJ 08544 (United States); Allen, S.L. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Bray, B.D. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Fenstermacher, M.E. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Humphreys, D.A.; Hyatt, A.W. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Lasnier, C.J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Leonard, A.W. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Makowski, M.A.; McLean, A.G. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Maingi, R.; Nazikian, R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Petrie, T.W. [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Soukhanovskii, V.A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Unterberg, E.A. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831 (United States)

2015-08-15

The snowflake divertor (SFD) control and detachment control to manage the heat flux at the divertor are successfully demonstrated at DIII-D. Results of the development and implementation of these two heat flux reduction control methods are presented. The SFD control algorithm calculates the position of the two null-points in real-time and controls shaping coil currents to achieve and stabilize various snowflake configurations. Detachment control stabilizes the detachment front fixed at specified distance between the strike point and the X-point throughout the shot.

Klebsiella pneumoniae triggers a cytotoxic effect on airway epithelial cells

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Llobet-Brossa Enrique

2009-08-01

Full Text Available Abstract Background Klebsiella pneumoniae is a capsulated Gram negative bacterial pathogen and a frequent cause of nosocomial infections. Despite its clinical relevance, little is known about the features of the interaction between K. pneumoniae and lung epithelial cells on a cellular level, neither about the role of capsule polysaccharide, one of its best characterised virulence factors, in this interaction. Results The interaction between Klebsiella pneumoniae and cultured airway epithelial cells was analysed. K. pneumoniae infection triggered cytotoxicity, evident by cell rounding and detachment from the substrate. This effect required the presence of live bacteria and of capsule polysaccharide, since it was observed with isolates expressing different amounts of capsule and/or different serotypes but not with non-capsulated bacteria. Cytotoxicity was analysed by lactate dehydrogenase and formazan measurements, ethidium bromide uptake and analysis of DNA integrity, obtaining consistent and complementary results. Moreover, cytotoxicity of non-capsulated strains was restored by addition of purified capsule during infection. While a non-capsulated strain was avirulent in a mouse infection model, capsulated K. pneumoniae isolates displayed different degrees of virulence. Conclusion Our observations allocate a novel role to K. pneumoniae capsule in promotion of cytotoxicity. Although this effect is likely to be associated with virulence, strains expressing different capsule levels were not equally virulent. This fact suggests the existence of other bacterial requirements for virulence, together with capsule polysaccharide.

The fellow eye of patients with phakic lattice retinal detachment.

Science.gov (United States)

Folk, J C; Arrindell, E L; Klugman, M R

1989-01-01

A retrospective study was performed to determine whether the prophylactic treatment of areas of lattice degeneration, holes, or breaks reduced the risk of subsequent new breaks or detachment in the fellow undetached phakic eyes of patients with a phakic lattice retinal detachment (RD). Three hundred eighty-eight consecutive patients who presented to the University of Iowa between 1959 and 1984 were followed for a mean of 7.9 +/- 5.8 years after the detachment in the first eye. Fellow eyes which received no prophylactic treatment had a 2.5 times greater risk of a new break or RD over 7 years than eyes receiving full prophylactic treatment (19.4 versus 7.5%; P = 0.0002). Fellow eyes receiving no treatment also had a greater risk of a new RD over 7 years than eyes receiving full treatment (5.1 versus 1.8%; P = 0.0125). These results do not allow us to make recommendations concerning which fellow eyes, if any, should be prophylactically treated. On the one hand, prophylactic treatment did significantly reduce the risk of new breaks and detachments. On the other hand, however, prophylactic treatment reduced the risk of new RD alone in the fellow eye only from 5.1 to 1.8% over 7 years. In addition, prophylactic treatment did not reduce the risk of detachment in the higher risk eyes with high myopia or extensive lattice.

The gecko visual pigments. The behavior of opsin.

Science.gov (United States)

Crescitelli, F

1979-05-01

The 521-pigment extracted out of the retina of the Tokay gecko has the typical stereospecificity of the vertebrate visual pigments. This is true for the pigment in the chloride-depleted, "blue-shifted" state as well as for the normal pigment with added chloride. While in the chloride-deficient state, pigment regeneration occurred with both 11-cis- and 9-cis-retinals and the regenerated photopigments were also in the blue-shifted, chloride-depleted state. As with the native pigment, these regenerated pigments were bathochromically shifted to their normal positions by the addition of chloride. Chloride-deficient opsin by itself also responded to chloride for the pigment regenerated with 11-cis-retinal from such chloride-treated opsin was in the normal 521-position. Regeneration was always rapid, reaching completion in less than 5 min, and was significantly faster than for cow rhodopsin regenerating under the same conditions. This rapid rate was found with or without chloride, with both 11-cis- and 9-cis-retinals and in the presence of the sulfhydryl poison, p-hydroxymercuribenzoate (PMB). Like the native chloride-deficient pigment, the regenerated chloride-depleted photopigments responded to PMB by a blue shift beyond the position of the chloride-deficient state. The addition of chloride to these "poisoned" regenerated pigments caused a bathochromic shift of such magnitude as to indicate a repair of both the PMB and chloride-deficient blue shift. In this discussion the possible implications of these results to phylogenetic considerations are considered as well as to some molecular properties of the 521-pigment.

On the use of purchased fuelwood in detached houses in Finland

International Nuclear Information System (INIS)

Tuomi, S.; Mattila, K.

1996-01-01

The study, conducted jointly by the Finnish Forest Research Institute (METLA) and the Work Efficiency Institute (TTS-Institute), looked into the volumes of fuelwood consumed by, the manner of fuel wood procurement employed, and the usage plans of people living in detached houses. The study was conducted during the heating season 1992/93. METLA collected the study material by the means of a nation-wide mail inquiry. The base population for the study was provided by all the 1.4 million detached houses in Finland. The sample comprised 12 273 detached houses. This publication of the Forestry Department of TTS-Institute is a separate report on the use of fuelwood and other issues related to purchased fuelwood. An estimated total of 5.6 million m 3 of fuelwood were consumed in by household living in detached houses throughout Finland during the heating season 1992/93. The consumption of fuelwood on farms was 2.5 million m 3 , in detached houses proper 2.3 million m 3 , in recreational homes 0.6 million m 3 , and other houses 0.2 million m 3 . 3.6 million m 3 of the fuelwood consumed was acquired from the users' own woodlots. The proportion of purchased wood was nearly a million m 3 and another million m 3 of fuelwood were acquired by some other way. Of the purchased fuelwood, 12 % was bought ready- chopped. More than one owner of detached houses considered the use of purchased wood a possibility. Ready-chopped firewood was the most popular form of fuelwood. The owners of nearly 220 000 detached houses planned to increase their fuelwood consumption during the next two years and 27 % of them intended to buy their fuelwood. 11 % of the respondents were of the opinion that there was not enough purchased fuelwood in suitable form available in their locality. (19 refs.)

JNK-associated scattered growth of YD-10B oral squamous carcinoma cells while maintaining the epithelial phenotype

International Nuclear Information System (INIS)

Lee, Gayoung; Kim, Hyun-Man

2017-01-01

Cell scattering of epithelial carcinoma cancer cells is one of the critical event in tumorigenesis. Cells losing epithelial cohesion detach from aggregated epithelial cell masses and may migrate to fatal organs through metastasis. The present study investigated the molecular mechanism by which squamous cell carcinoma cells grow scattered at the early phase of transformation while maintaining the epithelial phenotype. We studied YD-10B cells, which are established from human oral squamous cell carcinoma, because the cells grow scattered without the development of E-cadherin junctions (ECJs) under routine culture conditions despite the high expression of functional E-cadherin. The functionality of their E-cadherin was demonstrated in that YD-10B cells developed ECJs, transiently or persistently, when they were cultured on substrates coated with a low amount of fibronectin or to confluence. The phosphorylation of JNK was up-regulated in YD-10B cells compared with that in human normal oral keratinocyte cells or human squamous cell carcinoma cells, which grew aggregated along with well-organized ECJs. The suppression of JNK activity induced the aggregated growth of YD-10B cells concomitant with the development of ECJs. These results indicate for the first time that inherently up-regulated JNK activity induces the scattered growth of the oral squamous cell carcinoma cells through down-regulating the development of ECJ despite the expression of functional E-cadherin, a hallmark of the epithelial phenotype. - Highlights: • JNK dissociates YD-10B oral squamous cell carcinoma cells. • JNK suppresses the development of E-cadherin junctions of oral carcinoma cells. • Suppression of JNK activity reverses the scattered growth of oral carcinoma cells.

Non-aqueous pigmented inkjet inks

NARCIS (Netherlands)

DEROOVER, GEERT; Bernaerts, Katrien; HOOGMARTENS, IVAN

2009-01-01

A non-aqueous inkjet ink comprises a benzimidazolone pigment and a polymeric dispersant according to Formula (I): wherein, T represents hydrogen or a polymerization terminating group; Z represents theA non-aqueous inkjet ink comprises a benzimidazolone pigment and a polymeric dispersant according to

Microscopic Analysis of Pigments Extracted from Spalting Fungi

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Sarath M. Vega Gutierrez

2017-03-01

Full Text Available Pigments that are currently available in the market usually come from synthetic sources, or, if natural, often need mordants to bind to the target substrate. Recent research on the fungal pigment extracts from Scytalidium cuboideum, Scytalidium ganodermophthorum, Chlorociboria aeruginosa, and Chlorociboria aeruginascens have been shown to successfully dye materials, like wood, bamboo, and textiles, however, there is no information about their binding mechanisms. Due to this, a microscopic study was performed to provide information to future manufacturers interested in these pigments. The results of this study show that S. ganodermophthorum and C. aeruginosa form an amorphous layer on substrates, while S. cuboideum forms crystal-like structures. The attachment and morphology indicate that there might be different chemical and physical interactions between the extracted pigments and the materials. This possibility can explain the high resistance of the pigments to UV light and color fastness that makes them competitive against synthetic pigments. These properties make these pigments a viable option for an industry that demands natural pigments with the properties of the synthetic ones.

Scleral buckling for retinal detachment in patients with retinoblastoma

International Nuclear Information System (INIS)

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

1984-01-01

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

Scleral buckling for retinal detachment in patients with retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

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

1984-10-15

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

Recombination dominated hydrogenic emission from the detached plasmas in W7-AS

International Nuclear Information System (INIS)

Ramasubramanian, N.; Koenig, R.; Wenzel, U.; Thomsen, H.; McCormick, K.; Grigull, P.; Feng, Y.; Klinger, T.; John, A.

2003-01-01

Beyond a certain threshold average density in the High-Density H-Mode the island divertor plasma in the stellarator W7-AS undergoes partial detachment. The tomographic reconstruction of the radiated power density from the detached pulses show that the radiation profile in the triangular plane is also asymmetric. In the detached phase, the spectrometer viewing tangentially to the target tiles in the top divertor region manifests that the impurity radiation layer is close to the X-points. The spectral analysis also demonstrates the presence of a hydrogen radiation zone dominated by recombination emission close to the target tiles. This papers presents the emission from the deeply detached locations including the volume recombination in a stable discharge. (orig.)

Three-dimensional neuroepithelial culture from human embryonic stem cells and its use for quantitative conversion to retinal pigment epithelium.

Directory of Open Access Journals (Sweden)

Yu Zhu

Full Text Available A goal in human embryonic stem cell (hESC research is the faithful differentiation to given cell types such as neural lineages. During embryonic development, a basement membrane surrounds the neural plate that forms a tight, apico-basolaterally polarized epithelium before closing to form a neural tube with a single lumen. Here we show that the three-dimensional epithelial cyst culture of hESCs in Matrigel combined with neural induction results in a quantitative conversion into neuroepithelial cysts containing a single lumen. Cells attain a defined neuroepithelial identity by 5 days. The neuroepithelial cysts naturally generate retinal epithelium, in part due to IGF-1/insulin signaling. We demonstrate the utility of this epithelial culture approach by achieving a quantitative production of retinal pigment epithelial (RPE cells from hESCs within 30 days. Direct transplantation of this RPE into a rat model of retinal degeneration without any selection or expansion of the cells results in the formation of a donor-derived RPE monolayer that rescues photoreceptor cells. The cyst method for neuroepithelial differentiation of pluripotent stem cells is not only of importance for RPE generation but will also be relevant to the production of other neuronal cell types and for reconstituting complex patterning events from three-dimensional neuroepithelia.

Chilling-enhanced photooxidation: evidence for the role of singlet oxygen and superoxide in the breakdown of pigments and endogenous antioxidants

International Nuclear Information System (INIS)

Wise, R.R.; Naylor, A.W.

1987-01-01

Chilling temperatures (5 0 C) and high irradiance (1000 microeinsteins per square meter per second) were used to induce photooxidation in detached leaves of cucumber (Cucumis sativus L.), a chilling-sensitive plant. Chlorophyll a, chlorophyll b, β carotene, and three xanthophylls were degraded in a light-dependent fashion at essentially the same rate. Lipid peroxidation (measured as ethane evolution) showed an O 2 dependency. The levels of three endogenous antioxidants, ascorbate, reduced glutathione, and α tocopherol, all showed an irradiance-dependent decline. α-Tocopherol was the first antioxidant affected and appeared to be the only antioxidant that could be implicated in long-term protection of the photosynthetic pigments. Results from the application of antioxidants having relative selectivity for 1 O 2 , O 2 + , or OH indicated that both 1 O 2 and O 2 - were involved in the chilling- and light-induced lipid peroxidation which accompanied photooxidation. Application of D 2 O (which enhances the lifetime of 1 O 2 ) corroborated these results. Chilling under high light produced no evidence of photooxidative damage in detached leaves of chilling-resistant pea (Pisum sativum L.). Their results suggest a fundamental difference in the ability of pea to reduce the destructive effects of free-radical and 1 O 2 production in chloroplasts during chilling in high light

Gingival Pigmentation Affected by Smoking among Different Age Groups: A Quantitative Analysis of Gingival Pigmentation Using Clinical Oral Photographs.

Science.gov (United States)

Kato, Tomotaka; Mizutani, Shinsuke; Takiuchi, Hiroya; Sugiyama, Seiichi; Hanioka, Takashi; Naito, Toru

2017-08-04

The presence of any age-related differences in gingival pigmentation associated with smoking, particularly in a young population, remains to be fully investigated. The purpose of this study was to determine the age-related differences in smoking gingival pigmentation. Gingival pigmentation was analyzed using the gingival melanosis record (GMR) and Hedin's classification with frontal oral photographs taken at 16 dental offices in Japan. Participants were categorized into 10-year age groups, and their baseline photographs were compared. In addition, to evaluate the effect of smoking cessation on gingival pigmentation, subjects were divided into a former smoker group (stopped smoking) and current smoker group. A total of 259 patients 19 to 79 years of age were analyzed. People in their 30s showed the most widespread gingival pigmentation. In addition, subjects in their 20s showed a weak effect of smoking cessation on gingival pigmentation. These findings suggested that the gingival pigmentation induced by smoking was more remarkable in young people than in middle-aged people. This information may be useful for anti-smoking education, especially among young populations with a high affinity for smoking.

Rhegmatogenous retinal detachment following intravitreal ocriplasmin

NARCIS (Netherlands)

Madi, Haifa A.; Haynes, Richard J.; Depla, Diana; de la Cour, Morten D.; Lesnik-Oberstein, Sarit; Muqit, Mahi M. K.; Patton, Niall; Price, Nick; Steel, David H. W.

2016-01-01

To describe the characteristics and outcomes of patients presenting with rhegmatogenous retinal detachment (RRD) after ocriplasmin (OCP) injection. Retrospective, multi-centre, observational case series with case note review. Eight patients with symptomatic vitreomacular traction (six with

PRODUCTION OF MONASCUS-LIKE AZAPHILONE PIGMENT

DEFF Research Database (Denmark)

2009-01-01

The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

Pigmented xerodermoid - Report of three cases

OpenAIRE

Das Jayanta Kumar; Gangopadhyay Asok Kumar

2005-01-01

Pigmented xerodermoid, a rare genodermatosis, presents with clinical features and pathology similar to xeroderma pigmentosum, but at a later age. DNA repair replication is normal, but there is total depression of DNA synthesis after exposure to UV radiation. Two siblings in their teens and a man in his thirties with features of pigmented xerodermoid, e.g. photophobia, freckle-like lesions, keratoses, dryness of skin, and hypo- and hyper-pigmentation, are described. Although classically the on...

Production of Monascus-like azaphilone Pigment

DEFF Research Database (Denmark)

2009-01-01

The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

Photosynthetic Pigments in Diatoms

OpenAIRE

Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2015-01-01

Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvestin...

Turbulent Simulations of Divertor Detachment Based On BOUT + + Framework

Science.gov (United States)

Chen, Bin; Xu, Xueqiao; Xia, Tianyang; Ye, Minyou

2015-11-01

China Fusion Engineering Testing Reactor is under conceptual design, acting as a bridge between ITER and DEMO. The detached divertor operation offers great promise for a reduction of heat flux onto divertor target plates for acceptable erosion. Therefore, a density scan is performed via an increase of D2 gas puffing rates in the range of 0 . 0 ~ 5 . 0 ×1023s-1 by using the B2-Eirene/SOLPS 5.0 code package to study the heat flux control and impurity screening property. As the density increases, it shows a gradually change of the divertor operation status, from low-recycling regime to high-recycling regime and finally to detachment. Significant radiation loss inside the confined plasma in the divertor region during detachment leads to strong parallel density and temperature gradients. Based on the SOLPS simulations, BOUT + + simulations will be presented to investigate the stability and turbulent transport under divertor plasma detachment, particularly the strong parallel gradient driven instabilities and enhanced plasma turbulence to spread heat flux over larger surface areas. The correlation between outer mid-plane and divertor turbulence and the related transport will be analyzed. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-675075.

Peripheral retinal degenerations and the risk of retinal detachment.

Science.gov (United States)

Lewis, Hilel

2003-07-01

To review the degenerative diseases of the peripheral retina in relationship with the risk to develop a rhegmatogenous retinal detachment and to present recommendations for use in eyes at increased risk of developing a retinal detachment. Focused literature review and author's clinical experience. Retinal degenerations are common lesions involving the peripheral retina, and most of them are clinically insignificant. Lattice degeneration, degenerative retinoschisis, cystic retinal tufts, and, rarely, zonular traction tufts, can result in a rhegmatogenous retinal detachment. Therefore, these lesions have been considered for prophylactic therapy; however, adequate studies have not been performed to date. Well-designed, prospective, randomized clinical studies are necessary to determine the benefit-risk ratio of prophylactic treatment. In the meantime, the evidence available suggests that most of the peripheral retinal degenerations should not be treated except in rare, high-risk situations.

Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity

NARCIS (Netherlands)

Saksens, N.T.; Krebs, M.P.; Schoenmaker, F.E.; Hicks, W.; Yu, M.; Shi, L.; Rowe, L.; Collin, G.B.; Charette, J.R.; Letteboer, S.J.; Neveling, K.; Moorsel, T.W. van; Abu-Ltaif, S.; Baere, E. De; Walraedt, S.; Banfi, S.; Simonelli, F.; Cremers, F.P.; Boon, C.J.; Roepman, R.; Leroy, B.P.; Peachey, N.S.; Hoyng, C.B.; Nishina, P.M.; Hollander, A.I. den

2016-01-01

Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here we report the identification of heterozygous missense mutations in the CTNNA1 gene (encoding alpha-catenin 1) in three families with butterfly-shaped pigment

Protein changes in the retina following experimental retinal detachment in rabbits

DEFF Research Database (Denmark)

Mandal, Nakul; Lewis, Geoffrey P.; Fisher, Steven K.

2011-01-01

Retinal detachment leads to the widespread cellular remodeling of the retina. The purpose of this study was to identify protein changes that accompany these cellular alterations by comparing the proteomic profiles of sham and experimentally detached rabbit retina. Elucidation of the proteins most...

Seperation, identification and analysis of pigment (melanin ...

African Journals Online (AJOL)

Nine strains among 180 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and synthetic tyrosine-agar. They also show the positive reaction to Ltyrosine or L-dopa substrates. The pigment has been referred to be as merely as dark brown watersoluble pigment, as melanoid or ...

Dissecting the roles of ROCK isoforms in stress-induced cell detachment.

Science.gov (United States)

Shi, Jianjian; Surma, Michelle; Zhang, Lumin; Wei, Lei

2013-05-15

The homologous Rho kinases, ROCK1 and ROCK2, are involved in stress fiber assembly and cell adhesion and are assumed to be functionally redundant. Using mouse embryonic fibroblasts (MEFs) derived from ROCK1(-/-) and ROCK2(-/-) mice, we have recently reported that they play different roles in regulating doxorubicin-induced stress fiber disassembly and cell detachment: ROCK1 is involved in destabilizing the actin cytoskeleton and cell detachment, whereas ROCK2 is required for stabilizing the actin cytoskeleton and cell adhesion. Here, we present additional insights into the roles of ROCK1 and ROCK2 in regulating stress-induced impairment of cell-matrix and cell-cell adhesion. In response to doxorubicin, ROCK1(-/-) MEFs showed significant preservation of both focal adhesions and adherens junctions, while ROCK2(-/-) MEFs exhibited impaired focal adhesions but preserved adherens junctions compared with the wild-type MEFs. Additionally, inhibition of focal adhesion or adherens junction formations by chemical inhibitors abolished the anti-detachment effects of ROCK1 deletion. Finally, ROCK1(-/-) MEFs, but not ROCK2(-/-) MEFs, also exhibited preserved central stress fibers and reduced cell detachment in response to serum starvation. These results add new insights into a novel mechanism underlying the anti-detachment effects of ROCK1 deletion mediated by reduced peripheral actomyosin contraction and increased actin stabilization to promote cell-cell and cell-matrix adhesion. Our studies further support the differential roles of ROCK isoforms in regulating stress-induced loss of central stress fibers and focal adhesions as well as cell detachment.

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.

Proton beam modification of lead white pigments

International Nuclear Information System (INIS)

Beck, L.; Gutiérrez, P.C.; Miserque, F.; Thomé, L.

2013-01-01

Pigments and paint materials are known to be sensitive to particle irradiation. Occasionally, the analysis of paintings by PIXE can induce a slight or dark stain depending on the experimental conditions (beam current, dose, particle energy). In order to understand this discoloration, we have irradiated various types of art white pigments – lead white (hydrocerussite and basic lead sulfate), gypsum, calcite, zinc oxide and titanium oxide – with an external 3 MeV proton micro-beam commonly used for PIXE experiments. We have observed various sensitivities depending on the pigment. No visible change occurs for calcite and titanium oxide, whereas lead white pigments are very sensitive. For the majority of the studied compounds, the discoloration is proportional to the beam current and charge. The damage induced by proton beam irradiation in lead white pigments was studied by micro-Raman and XPS spectroscopies. Structural modifications and dehydration were detected. Damage recovery was investigated by thermal treatment and UV-light irradiation. The discoloration disappeared after one week of UV illumination, showing that PIXE experiments could be safely undertaken for pigments and paintings

Candida glabrata tryptophan-based pigment production via the Ehrlich pathway.

Science.gov (United States)

Brunke, Sascha; Seider, Katja; Almeida, Ricardo Sergio; Heyken, Antje; Fleck, Christian Benjamin; Brock, Matthias; Barz, Dagmar; Rupp, Steffen; Hube, Bernhard

2010-04-01

Pigments contribute to the pathogenicity of many fungi, mainly by protecting fungal cells from host defence activities. Here, we have dissected the biosynthetic pathway of a tryptophan-derived pigment of the human pathogen Candida glabrata, identified key genes involved in pigment production and have begun to elucidate the possible biological function of the pigment. Using transcriptional analyses and a transposon insertion library, we have identified genes associated with pigment production. Targeted deletion mutants revealed that the pigment is a by-product of the Ehrlich pathway of tryptophan degradation: a mutant lacking a tryptophan-upregulated aromatic aminotransferase (Aro8) displayed significantly reduced pigmentation and a recombinantly expressed version of this protein was sufficient for pigment production in vitro. Pigment production is tightly regulated as the synthesis is affected by the presence of alternative nitrogen sources, carbon sources, cyclic AMP and oxygen. Growth of C. glabrata on pigment inducing medium leads to an increased resistance to hydrogen peroxide, an effect which was not observed with a mutant defective in pigmentation. Furthermore, pigmented yeast cells had a higher survival rate when exposed to human neutrophils and caused increased damage in a monolayer model of human epithelia, indicating a possible role of pigmentation during interactions with host cells.

Effects of temporal muscle detachment and coronoidotomy on facial growth in young rats

Directory of Open Access Journals (Sweden)

Fernanda Engelberg Fernandes Gomes

2012-08-01

Full Text Available This study analyzed the effects of unilateral detachment of the temporal muscle and coronoidotomy on facial growth in young rats. Thirty one-month-old Wistar rats were distributed into three groups: detachment, coronoidotomy and sham-operated. Under general anesthesia, unilateral detachment of the temporal muscle was performed for the detachment group, unilateral coronoidotomy was performed for the coronoidotomy group, and only surgical access was performed for the sham-operated group. The animals were sacrificed at three months of age. Their soft tissues were removed, and the mandible was disarticulated. Radiographic projections-axial views of the skulls and lateral views of hemimandibles-were taken. Cephalometric evaluations were performed, and the values obtained were submitted to statistical analyses. There was a significant homolateral difference in the length of the premaxilla, height of the mandibular ramus and body, and the length of the mandible in all three groups. However, comparisons among the groups revealed no significant differences between the detachment and coronoidotomy groups for most measurements. It was concluded that both experimental detachment of the temporal muscle and coronoidotomy during the growth period in rats induced asymmetry of the mandible and affected the premaxilla.

DNA damage in isolated rat hepatocytes exposed to C.I. pigment orange 5 and C.I. pigment yellow 12 by the alkaline comet assay

DEFF Research Database (Denmark)

Møller, P; Wallin, Håkan; Grunnet, N

1998-01-01

The induction of DNA damage by commonly used printing ink pigments, C.I. pigment orange 5 (C.I. 12075) and C.I. pigment yellow 12 (C.I. 21090), was investigated in freshly isolated rat hepatocytes with the comet assay. C.I. pigment yellow 12 is a 3,3'-dichlorobenzidine-based diarylide pigment...

Phakic retinal detachment associated with atrophic hole of lattice degeneration of the retina.

Science.gov (United States)

Murakami-Nagasako, F; Ohba, N

1983-01-01

Forty patients with phakic nontraumatic retinal detachment caused by atrophic retinal hole of lattice degeneration were reviewed. The condition was characterized by insidious, slowly developing shallow detachment, with frequent formation of demarcation lines. Often, the patients did not recognize their visual problems until the detachment had extended to the macular region. Young patients under 40 years of age were more common than older patients. Myopic refractive errors were frequently associated. The results of surgical repair were favorable. The risk of retinal detachment in lattice degeneration with atrophic holes was estimated to be about 1 in 90 patients, and prophylactic treatment for this common anomaly is not readily recommended.

A numerical study of plasma detachment conditions in JET divertor plasmas

Energy Technology Data Exchange (ETDEWEB)

Simonini, R; Corrigan, G; Radford, G; Spence, J; Taroni, A; Weber, S [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

Simulation results obtained with the EDGE2D/U code confirm that for a given particle inventory in the SOL (including the divertor), the main parameter determining whether or not particle, momentum and energy detachment occurs, is the residual power P - P{sub lost}, where P is the total power entering the SOL and P{sub lost} is the power lost by transport to walls and by volume losses in the SOL outside the region where detachment takes place. For particle contents leading to reasonable values of the separatrix mid-plane density, detachment is found if the residual power is low enough. Typically the residual power must be inferior to 3 MW for good detachment, with the exact value depending on the geometry of the divertor, the transport assumptions and the neutral recirculation scheme. The results show that divertor plasma conditions relevant for the study of power exhaust and impurity control problems are possible in JET. 9 refs., 2 figs., 1 tab.

Massive Bilateral Serous Retinal Detachment in a Case of Hypertensive Chorioretinopathy

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Luis Villalba-Pinto

2014-07-01

Full Text Available Introduction: Systemic high blood pressure is related to a variety of retinal manifestations. We present an atypical case of hypertensive chorioretinopathy with massive bilateral serous retinal detachment. Case Report: A 26-year-old male with a genitourinary malformation and secondary grade IV chronic kidney failure as well as high blood pressure complained of acute vision loss. Dilated fundus examination evidenced a bilateral serous retinal detachment with macular involvement. The patient was unresponsive to oral antihypertensive therapy and dialysis treatment. The serous retinal detachment progressively decreased after the restoration of dialysis and antihypertensive therapy. The final visual acuity was 0.50 in both eyes. Discussion: In cases of serous macular detachment, it is mandatory to rule out different systemic and ocular diseases. The presence of uncontrolled high blood pressure may produce aggressive bilateral retinal changes, thus hypertension must be under early and strict control in order to improve the visual outcomes.

Massive Bilateral Serous Retinal Detachment in a Case of Hypertensive Chorioretinopathy

Science.gov (United States)

Villalba-Pinto, Luis; Hernández-Ortega, M. Ángeles; de los Mozos, F. Javier Lavid; Pascual-Camps, Isabel; Dolz-Marco, Rosa; Arevalo, J. Fernando; Gallego-Pinazo, Roberto

2014-01-01

Introduction Systemic high blood pressure is related to a variety of retinal manifestations. We present an atypical case of hypertensive chorioretinopathy with massive bilateral serous retinal detachment. Case Report A 26-year-old male with a genitourinary malformation and secondary grade IV chronic kidney failure as well as high blood pressure complained of acute vision loss. Dilated fundus examination evidenced a bilateral serous retinal detachment with macular involvement. The patient was unresponsive to oral antihypertensive therapy and dialysis treatment. The serous retinal detachment progressively decreased after the restoration of dialysis and antihypertensive therapy. The final visual acuity was 0.50 in both eyes. Discussion In cases of serous macular detachment, it is mandatory to rule out different systemic and ocular diseases. The presence of uncontrolled high blood pressure may produce aggressive bilateral retinal changes, thus hypertension must be under early and strict control in order to improve the visual outcomes. PMID:25120474

Impact of Pigments on Self-Compacting Concrete

Directory of Open Access Journals (Sweden)

Ernestas Ivanauskas

2011-04-01

Full Text Available We describe an impact of using iron oxide pigment on self-compacting concrete (SCC properties. We have experimented with adding portions of iron oxide pigment from 3 % to 6 % into cement paste. A few alternative pigments (chromic oxide and iron oxide hydroxide were used for performing the same experiments. The impact of these pigments on a normal cement paste is described in this paper. We demonstrate that iron oxide pigment reduces the need for water in a normal cement paste. However, adding the pigment also reduces the compressive strength of concrete up to 20 %. The concrete specimens were tested in various time spans, i.e. 1 day to 28 days, by keeping them in 20 ± 2 ºC water – normal consolidation regimen. Some of the specimens were processed in steam chamber, at 60 ºC in order to make the process of the cement hydration faster, as well as to estimate an impact of active SiO2 proportion in ash on SCC properties. We show that using iron oxide pigment for SCC mixture increases the slump-flow property of concrete mix up to 5 %. Experiments with solidified concrete have demonstrated that iron oxide diminishes water absorption up to 6 % and decreases open concrete porosity that makes concrete resistant against freezing. Article in Lithuanian

Endovascular therapy of arteriovenous fistulae with electrolytically detachable coils

Energy Technology Data Exchange (ETDEWEB)

Jansen, O.; Doerfler, A.; Forsting, M.; Hartmann, M.; Kummer, R. von; Tronnier, V.; Sartor, K. [Dept. of Neuroradiology, University of Heidelberg Medical School (Germany)

1999-12-01

We report our experience in using Guglielmi electrolytically detachable coils (GDC) alone or in combination with other materials in the treatment of intracranial or cervical high-flow fistulae. We treated 14 patients with arteriovenous fistulae on brain-supplying vessels - three involving the external carotid or the vertebral artery, five the cavernous sinus and six the dural sinuses - by endovascular occlusion using electrolytically detachable platinum coils. The fistula was caused by trauma in six cases. In one case Ehlers-Danlos syndrome was the underlying disease, and in the remaining seven cases no aetiology could be found. Fistulae of the external carotid and vertebral arteries and caroticocavernous fistulae were reached via the transarterial route, while in all dural fistulae a combined transarterial-transvenous approach was chosen. All fistulae were treated using electrolytically detachable coils. While small fistulae could be occluded with electrolytically detachable coils alone, large fistulae were treated by using coils to build a stable basket for other types of coil or balloons. In 11 of the 14 patients, endovascular treatment resulted in complete occlusion of the fistula; in the remaining three occlusion was subtotal. Symptoms and signs were completely abolished by this treatment in 12 patients and reduced in 2. On clinical and neuroradiological follow-up (mean 16 months) no reappearance of symptoms was recorded. (orig.)

Normal morphogenesis of epithelial tissues and progression of epithelial tumors

Science.gov (United States)

Wang, Chun-Chao; Jamal, Leen; Janes, Kevin A.

2011-01-01

Epithelial cells organize into various tissue architectures that largely maintain their structure throughout the life of an organism. For decades, the morphogenesis of epithelial tissues has fascinated scientists at the interface of cell, developmental, and molecular biology. Systems biology offers ways to combine knowledge from these disciplines by building integrative models that are quantitative and predictive. Can such models be useful for gaining a deeper understanding of epithelial morphogenesis? Here, we take inventory of some recurring themes in epithelial morphogenesis that systems approaches could strive to capture. Predictive understanding of morphogenesis at the systems level would prove especially valuable for diseases such as cancer, where epithelial tissue architecture is profoundly disrupted. PMID:21898857

Microbial Production of Food Grade Pigments

Directory of Open Access Journals (Sweden)

Laurent Dufossé

2006-01-01

Full Text Available The controversial topic of synthetic dyes in food has been discussed for many years. The scrutiny and negative assessment of synthetic food dyes by the modern consumer have raised a strong interest in natural colouring alternatives. Nature is rich in colours (minerals, plants, microalgae, etc., and pigment-producing microorganisms (fungi, yeasts, bacteria are quite common. Among the molecules produced by microorganisms are carotenoids, melanins, flavins, quinones, and more specifically monascins, violacein or indigo. The success of any pigment produced by fermentation depends upon its acceptability on the market, regulatory approval, and the size of the capital investment required to bring the product to market. A few years ago, some expressed doubts about the successful commercialization of fermentation-derived food grade pigments because of the high capital investment requirements for fermentation facilities and the extensive and lengthy toxicity studies required by regulatory agencies. Public perception of biotechnology-derived products also had to be taken into account. Nowadays some fermentative food grade pigments are on the market: Monascus pigments, astaxanthin from Xanthophyllomyces dendrorhous, Arpink Red from Penicillium oxalicum, riboflavin from Ashbya gossypii, b-carotene from Blakeslea trispora. The successful marketing of pigments derived from algae or extracted from plants, both as a food colour and a nutritional supplement, reflects the presence and importance of niche markets in which consumers are willing to pay a premium for »all natural ingredients«.

Studies on pigments of the myxomycete Physarum nudum. II. Separation and optical properties of the pigments from plasmodia cultured in darkness

Directory of Open Access Journals (Sweden)

L. Raczkowski

2015-01-01

Full Text Available The paper presents the data on Separation and some optical properties of the pigments obtained from the plasmodium of the myxomycete Physarum nudum grown in the dark. Pigment Separation was performed by means of thin-layer chromatography with celulose MN 300 as adsorbent and with the solvent: tert.-butylalcohol, H2O, 3N NH4OH at the ratio 5:2:1 In these conditions the chromatograms revealed 12 coloured bands from which pigments were eluted and their absorption spectra as well as the spectra of fluorescence emission were determined. The isolated pigments differ from one another by their physical properties (different Rf values, localization of absorption maxima, and behaviour in acid solution. Nevertheless, certain analogies perceptible between particular pigments per-mitted to distinguish 3 families of the studied pigments demonstrating similar properties.

Fish pigmentation and the melanocortin system.

Science.gov (United States)

Cal, Laura; Suarez-Bregua, Paula; Cerdá-Reverter, José Miguel; Braasch, Ingo; Rotllant, Josep

2017-09-01

The melanocortin system is a complex neuroendocrine signaling mechanism involved in numerous physiological processes in vertebrates, including pigmentation, steroidogenesis and metabolic control. This review focuses at one of its most fascinating function in fish, its regulatory role in the control of pigmentation, in which the melanocortin 1 receptor (Mc1r), its agonist α-melanocyte stimulating hormone (α-Msh), and the endogenous antagonist agouti signaling protein (Asip1) are the main players. Functional control of Mc1r, which is highly expressed in fish skin and whose activation stimulates melanin production and melanosome dispersion in fish melanophores, is considered a key mechanism for vertebrate pigment phenotypes. The α-Msh peptide, the most documented Mc1r agonist involved in pigmentation, is produced in the pituitary gland, activating melanin synthesis by binding to Mc1r in fish melanophores. Finally, Asip1 is the putative factor for establishing the evolutionarily conserved dorso-ventral pigment pattern found across vertebrates. However, we are just starting to understand how other melanocortin system components are acting in this complex regulatory network. Copyright © 2017 Elsevier Inc. All rights reserved.

The efficacy of fluid-gas exchange for the treatment of postvitrectomy retinal detachment.

Science.gov (United States)

Jang, Ji Hye; Kim, Yu Cheol; Kim, Kwang Soo

2009-12-01

This study was designed to evaluate the efficacy of fluid-gas exchange for the treatment of postvitrectomy retinal detachment. We retrospectively reviewed the records of 33 consecutive patients (35 eyes) who underwent fluid-gas exchange treatment for postvitrectomy retinal detachment using the two-needle pars plana approach technique. The retinal reattachment rate was 80.0% after complete intravitreal gas disappearance following the fluid-gas exchange; the overall success rate was 65.7%. Visual acuity was improved or stable in 80.0% of cases; a two-line or greater vision improvement or a best-corrected visual acuity of 0.4 or better occurred in 62.9% of cases. The success rates for superior retinal detachments and posterior pole retinal detachments were 76.5% and 85.7%, respectively. Fluid-gas exchange represents a simple and cost-effective alternative outpatient procedure for retinal reattachment without reoperation for the treatment of superior and posterior pole retinal detachments.

The influence of refractive error and lattice degeneration on the incidence of retinal detachment.

Science.gov (United States)

Burton, T C

1989-01-01

This study indicates the feasibility of stratifying the general population into various risk pools for retinal detachment depending on a person's age, refractive status, and the presence of lattice degeneration. At first impression the risks seem at variance with the fine clinical studies of Byer, who has shown a very low detachment rate in the population with lattice degeneration. In all likelihood the vast majority of his patients were emmetropic or mildly myopic, so that very few would be expected to develop detachments during their entire lifetimes, let along during intervals of only 10 to 20 years. This study shows the futility of following, or treating prophylactically, young emmetropic individuals with lattice degeneration. Assuming that prophylaxis is actually effective, one would have to treat 1000 emmetropic lattice patients in the 30 to 39 year age group to prevent a single detachment over a 10-year period. Lattice patients with low to moderate degrees of myopia tend to develop detachments between 40 and 60 years of age caused by premature posterior vitreous separation and tractional tears. Clearly prophylaxis for this group is not warranted, since only 5% to 10% of these individuals will experience detachments in their lifetimes. On the other hand this study has verified the previous suspicions that persons with myopia exceeding -5.0 D accompanied by lattice degeneration have an extraordinarily high risk of detachment during their lifetimes. Detachments in this group tend to cluster in the second, third, and fourth decades, are typically caused by atrophic holes, are slowly progressive, and are often simultaneously bilateral. Enhanced vigilance is certainly appropriate during this time and perhaps consideration should be given to prophylactically treating this group. This would be no small task, since within a population of 1 million persons there would be about 1150 aged 10 to 39 years with myopia exceeding -5.0 D and lattice degeneration. Only 4

Vitrectomy, lensectomy and silicone oil tamponade in the management of retinal detachment associated with choroidal detachment

Directory of Open Access Journals (Sweden)

Jian-Di Liu

2013-06-01

Full Text Available AIM: To report the results of combined vitrectomy, lensectomy and silicone oil (SO tamponade in treating primary rhegmatogenous retinal detachment (RRD associated with choroidal detachment (CD.METHODS: A retrospective, consecutive and case series study of 21 subjects with concurrent RRD associated with CD was conducted. All subjects underwent a standard three-port 20G pars plana vitrectomy (PPV with lensectomy and silicone oil tamponade. Mean follow-up time was 8 months (rang from 4 to 19 months. The primary and final anatomic success rate, visual acuity and final intraocular pressure(IOP were recorded and analyzed.RESULTS: Of 21 subjects, 8 were women and 13 were men. Age at presentation ranged from 22 to 75 years (mean 57.4 years. The presenting vision ranged from light perception to 0.15. The initial IOP ranged from 3mmHg to 12mmHg (mean 6.2mmHg. All eyes were phakic except one pseudophakic. No intraocular lens was implanted during the primary surgical intervention. Fifteen of 21 (71.4% eyes had retina reattached after one operation. Six eyes had recurrent inferior retinal detachment due to proliferation. Five of them were successfully reattached after one or more additional operations. Mean IOP at final follow-up was 15.2mmHg (range from 8mmHg to 20mmHg. One case declined for further operation. The final reattachment rate was 95.2%. Visual acuity improved in 19 (90.5% eyes, was unchanged in 1 (4.8% eye and decreased in 1 (4.8% eye.CONCLUSION: Combination of vitrectomy, lensectomy and silicone tamponade is an effective method in treating RRD associated with CD, reducing the incidence of postoperative hypotony.

Pigment dispersion syndrome masquerading as acute anterior uveitis.

Science.gov (United States)

Gonzalez-Gonzalez, Luis Alonso; Rodríguez-García, Alejandro; Foster, C Stephen

2011-06-01

Signs and symptoms of pigment dispersion may be confused with those of acute anterior uveitis. This case series is intended to aid the ophthalmologist in the clinical differentiation between these two disorders. The authors present a series of 6 patients with pigment dispersion who were initially diagnosed as having acute anterior uveitis and treated with anti-inflammatory medication, including corticosteroids. The patients were referred for a second opinion due to poor or no response to therapy and were found to have pigment dispersion instead of uveitis. Symptoms of pigment dispersion may consist of blurred vision, redness, ocular pain, and photophobia, all of which are also symptoms of acute anterior uveitis. These symptoms, plus the fact that pigment floating in the aqueous humor can be mistaken for inflammation, make diagnosis challenging. Moreover, the possible co-existence of true anterior uveitis and pigment dispersion makes the diagnosis and treatment more difficult.

Light-induced vegetative anthocyanin pigmentation in Petunia

OpenAIRE

Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

2009-01-01

The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins...

Complex descemet′s membrane tears and detachment during phacoemulsification

Directory of Open Access Journals (Sweden)

Faik Orucoglu

2015-01-01

Full Text Available Purpose: To report a case of complex Descemet′s membrane detachment (DMD and tears during phacoemulsification cataract surgery. Case Report: A 64-year-old woman underwent phacoemulsification surgery in her right eye and developed tears and partial loss of Descemet′s membrane (DM while the aspiration port was inserted through the main incision. Massive corneal edema obscured the view and the anterior chamber was barely visible the following day. Scheimpflug imaging was used to complement slit lamp examination in the postoperative period. Frequent topical corticosteroid drops were initiated. After 5 days of treatment, multiple tears and detachment of DM were visible and the anterior chamber was filled with air. After 5 weeks, the cornea regained much of its clarity despite large DM tears and focal loss of DM. Conclusion: Despite partial loss of DM, the corneal edema mostly disappeared after 5 weeks of air bubble injection. Scheimpflug imaging was beneficial in the diagnosis and monitoring of DM tears and detachments.

Screening for anthracnose disease resistance in strawberry using a detached leaf assay

Science.gov (United States)

Inoculation of detached strawberry leaves with Colletotrichum species may provide a rapid, non-destructive method of identifying anthracnose resistant germplasm. The reliability and validity of assessing disease severity is critical to disease management decisions. We inoculated detached strawberr...

Retinal detachment repair and cataract surgery in patients with atopic dermatitis.

Science.gov (United States)

Gnana Jothi, V; McGimpsey, S; Sharkey, J A; Chan, W C

2017-09-01

PurposeThe aim of this study is to report a case series of ocular complications including retinal detachment (RD) and cataract in atopic dermatitis (AD) and surgical management involving a majority of Caucasian patients.Patients and methodsThis study is an observational case series, originally designed as an audit. It involves detailed discussion of history, clinical features, and surgical management of patients presenting with retinal detachment and cataracts secondary to severe AD. Six consecutive patients with diagnosis of severe AD requiring posterior segment and cataract surgery were included in the study.ResultsEight eyes of six patients had retinal detachment. Most of them involved the temporal retina. The retinal breaks were located anteriorly close to the ora serrata in six eyes and Giant tear retinal (GRT) detachment was found in two eyes. Five eyes had proliferative vitreo-retinopathy (PVR) at presentation. All six patients had bilateral cataracts and cataract surgery was performed in eleven eyes. Bilateral simultaneous surgery was essential in two patients. Three eyes had secondary intra-ocular lens (IOL) implantation with pars plana vitrectomy for subluxed lens implant.ConclusionsAnterior retinal breaks and temporal RD are common in retinal detachment secondary to AD. PVR is often present, which makes surgical management difficult. Cataract formation is quite often and late subluxation of IOL may occur.

Effects of low-Z and high-Z impurities on divertor detachment and plasma confinement

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H.Q. Wang

2017-08-01

Full Text Available The impurity-seeded detached divertor is essential for heat exhaust in ITER and other reactor-relevant devices. Dedicated experiments with injection of N2, Ne and Ar have been performed in DIII-D to assess the impact of the different impurities on divertor detachment and confinement. Seeding with N2, Ne and Ar all promote divertor detachment, greatly reducing heat flux near the strike point. The upstream plasma density at the onset of detachment decreases with increasing impurity-puffing flow rates. For all injected impurity species, the confinement and pedestal pressure are correlated with the impurity content and the ratio of separatrix loss power to the l-H transition threshold power. As the divertor plasma approaches detachment, the high-Z impurity seeding tends to degrade the core confinement owing to the increased core radiation. In particular, Ar injection with up to 50% of the injected power radiating in the core cools the pedestal and core plasmas, thus significantly degrading the confinement. As for Ne seeding, medium confinement with H98∼0.8 can be maintained during the detachment phase with the pedestal temperature being reduced by about 50%. In contrast, in the N2 seeded plasmas, radiation is predominately confined in the boundary plasma, which leads to less effect on the confinement and pedestal. In the case of strong N2 gas puffing, the confinement recovers during the detachment, from ∼20% reduction at the onset of the detachment to greater than unity comparable to that before the seeding. The core and pedestal temperatures feature a reduction of 30% from the initial attached phase and remain nearly constant during the detachment phase. The improvement in confinement appears to arise from the increase in pedestal and core density despite the temperature reduction.

Clinical characteristics of pigment dispersion syndrome in Chinese patients.

Science.gov (United States)

Qing, G; Wang, N; Tang, X; Zhang, S; Chen, H

2009-08-01

To report clinical findings and characteristics of pigment dispersion syndrome (PDS) in Chinese patients. PDS suspects with any one of the following signs: corneal endothelial pigmentation, iris transillumination defects (ITDs), pigment granule dusting on anterior iris surface, posterior iris bowing, trabecular meshwork (TM) pigmentation, and lenticular or zonular pigmentation were evaluated for PDS at the glaucoma specialty clinic at Beijing Tongren Eye Centre. Diagnosis of PDS required at least two of the following signs: Krukenberg spindle, moderate-to-heavy TM pigmentation (>or=Scheie II) and any degree of lenticular and/or zonular pigmentation. Eighteen patients (12 males and six females) were identified as having PDS during a 1-year period, with mean age of 35.5+/-7.0 years (range, 22-49). All but two eyes from two patients had myopia of -0.5 D or greater, with mean spherical equivalent power of -5.20+/-5.80 D (range, -24.75+/-0.5). The average IOP at initial diagnosis was 33.7+/-10.5 mm Hg (range, 16-56). Fifteen patients (83.3%) were found to have pigmentary glaucoma at their initial diagnosis. All patients showed homogenous increased TM pigmentation as well as lenticular and/or zonular pigmentation. 61.1% of patients (11 of 18) had Krukenberg spindle. None of the patients exhibited spoke-like midperipheral ITDs except for trace-isolated transillumination in both eyes of the two patients. The most common clinical findings in Chinese PDS patients include homogeneous TM pigmentation and pigment granule dusting on lens zonules and/or posterior peripheral lens surface. ITDs are uncommon in Chinese patients with PDS.

Simulation of experimentally achieved detached plasmas using the UEDGE code

International Nuclear Information System (INIS)

Porter, G.D.; Allen, S.; Fenstermacher, M.

1995-01-01

The introduction of a divertor Thomson scattering system in DIII-D has enabled accurate determination of the plasma properties in the divertor region. We identify two plasma regimes; detached and attached. The electron temperature in the detached regime is about 2 eV, much lower than 5 to 10 eV determined earlier. We show that fluid models of the DIII-D scrape-off layer plasma are able to reproduce many of the features of these two plasma regimes, including the boundaries for transition between them. Detailed comparison between the results obtained from the fluid models and experiment suggest the models underestimate the spatial extent of the low temperature region associated the detached plasma mode. We suggest that atomic physics processes at the low electron temperatures reported here may account for this discrepancy

Pigmented skin disorders: Evaluation and treatment

NARCIS (Netherlands)

Kroon, M.W.

2015-01-01

Pigmentary disorders are disturbances of human skin color. Minor changes in the cellular physiology of the skin can dramatically affect pigment production in positive or negative manner. In this these, associated diseases, therapeutical options and disease parameters for the pigmentation disorder

Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies

Science.gov (United States)

Briscoe, Adriana D.; Bybee, Seth M.; Bernard, Gary D.; Yuan, Furong; Sison-Mangus, Marilou P.; Reed, Robert D.; Warren, Andrew D.; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

2010-01-01

The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)—a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with λmax = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

Surgical Management of Iatrogenic Pigment Dispersion Glaucoma.

Science.gov (United States)

Mierlo, Camille Van; Pinto, Luis Abegão; Stalmans, Ingeborg

2015-01-01

Iatrogenic pigment dispersion syndrome generally originates from a repetitive, mechanical trauma to the pigmented posterior epithelium of the iris. This trauma can arise after intraocular surgery, most commonly due to an abnormal contact between the intraocular lens (IOL) and the iris. Whether surgical removal of this primary insult can lead to a successful intraocular pressure (IOP) control remains unclear. Case-series. Patients with IOP elevation and clinical signs of pigment dispersion were screened for a diagnosis of iatrogenic IOL-related pigment dispersion. Three patients in which the IOL or the IOL-bag complex caused a pigment dispersion through a repetitive iris chafing were selected. In two cases, replacement of a sulcus-based single-piece IOL (patient 1) or a sub-luxated in-the-bag IOL (patient 2) by an anterior-chamber (AC) iris-fixed IOL led to a sustained decrease in IOP. In the third case, extensive iris atrophy and poor anatomical AC parameters for IOL implantation precluded further surgical intervention. IOL-exchange appears to be a useful tool in the management of iatrogenic pigment dispersion glaucoma due to inappropriate IOL implantation. This cause-oriented approach seems to be effective in controlling IOP, but should be offered only if safety criteria are met. How to cite this article: Van Mierlo C, Abegao Pinto L, Stalmans I. Surgical Management of Iatrogenic Pigment Dispersion Glaucoma. J Curr Glaucoma Pract 2015;9(1):28-32.

Interaction between Vaccinium bracteatum Thunb. leaf pigment and rice proteins.

Science.gov (United States)

Wang, Li; Xu, Yuan; Zhou, Sumei; Qian, Haifeng; Zhang, Hui; Qi, Xiguang; Fan, Meihua

2016-03-01

In this study, we investigated the interaction of Vaccinium bracteatum Thunb. leaf (VBTL) pigment and rice proteins. In the presence of rice protein, VBTL pigment antioxidant activity and free polyphenol content decreased by 67.19% and 68.11%, respectively, and L(∗) of the protein-pigment complex decreased significantly over time. L(∗) values of albumin, globulin and glutelin during 60-min pigment exposure decreased by 55.00, 57.14, and 54.30%, respectively, indicating that these proteins had bound to the pigment. A significant difference in protein surface hydrophobicity was observed between rice proteins and pigment-protein complexes, indicating that hydrophobic interaction is a major binding mechanism between VBTL pigment and rice proteins. A significant difference in secondary structures between proteins and protein-pigment complexes was also uncovered, indicating that hydrogen bonding may be another mode of interaction between VBTL pigment and rice proteins. Our results indicate that VBTL pigment can stain rice proteins with hydrophobic and hydrogen interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Skin Pigmentation Kinetics after Exposure to Ultraviolet A

DEFF Research Database (Denmark)

Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

2009-01-01

Multiple exposures to ultraviolet radiation (UVR) are the norm in nature and phototherapy. However, studies of the kinetics of pigmentation following UVA exposure have included only fair-skinned persons. The aim of this study was to investigate steady-state pigmentation and fading in 12 Scandinav......Multiple exposures to ultraviolet radiation (UVR) are the norm in nature and phototherapy. However, studies of the kinetics of pigmentation following UVA exposure have included only fair-skinned persons. The aim of this study was to investigate steady-state pigmentation and fading in 12...... Scandinavians and 12 Indians/Pakistanis after 6 and 12 exposures on the back using broadband UVA and UVA1 with equal sub-minimal melanogenic doses (individually predetermined). Pigmentation was measured by skin reflectance at 555 and 660 urn. The UV dose to minimal pigmentation was higher in dark......-skinned persons after a single broadband UVA exposure, but independent of pigmentation/skin type after single and multiple UVA1 exposures. To elicit minimal melanogenic doses after 6 and 12 exposures, every dose is lowered by a factor of 2 and 3, respectively, but the cumulative dose increases three- and four...

Lowest auto-detachment state of the water anion

International Nuclear Information System (INIS)

Houfek, K.; Cizek, M.

2016-01-01

Because of the abundance of water in living tissue the reactive low-energy electron collisions with the water molecule represent an important step in the radiation damage of cells. In this paper, the potential energy surface of the ground state of the water anion H_2O"- is carefully mapped using multireference configuration interaction (MRCI) calculations for a large range of molecular geometries. Particular attention is paid to a consistent description of both the O"-+H_2 and OH"-+H asymptotes and to a relative position of the anion energy to the ground state energy of the neutral molecule. The auto-detachment region, where the anion state crosses to the electronic continuum is identified. The local minimum in the direction of the O"- + H_2 channel previously reported by Werner et al. [J. Chem. Phys. 87, 2913 (1987)] is found to be slightly off the linear geometry and is separated by a saddle from the auto-detachment region. The auto-detachment region is directly accessible from the OH"-+H asymptote. For the molecular geometries in the auto-detachment region and in its vicinity we also performed fixed-nuclei electron-molecule scattering calculations using the R-matrix method. Tuning of consistency of a description of the correlation energy in both the multireference CI and R-matrix calculations is discussed. Two models of the correlation energy within the R-matrix method that are consistent with the quantum chemistry calculations are found. Both models yield scattering quantities in a close agreement. The results of this work will allow a consistent formulation of the nonlocal resonance model of the water anion in a future publication

Assessment of X-point target divertor configuration for power handling and detachment front control

Directory of Open Access Journals (Sweden)

M.V. Umansky

2017-08-01

Full Text Available A study of long-legged tokamak divertor configurations is performed with the edge transport code UEDGE (Rognlien et al., J. Nucl. Mater. 196, 347, 1992. The model parameters are based on the ADX tokamak concept design (LaBombard et al., Nucl. Fusion 55, 053020, 2015. Several long-legged divertor configurations are considered, in particular the X-point target configuration proposed for ADX, and compared with a standard divertor. For otherwise identical conditions, a scan of the input power from the core plasma is performed. It is found that as the power is reduced to a threshold value, the plasma in the outer leg transitions to a fully detached state which defines the upper limit on the power for detached divertor operation. Reducing the power further results in the detachment front shifting upstream but remaining stable. At low power the detachment front eventually moves to the primary X-point, which is usually associated with degradation of the core plasma, and this defines the lower limit on the power for the detached divertor operation. For the studied parameters, the operation window for a detached divertor in the standard divertor configuration is very small, or even non-existent; under the same conditions for long-legged divertors the detached operation window is quite large, in particular for the X-point target configuration, allowing a factor of 5–10 variation in the input power. These modeling results point to possibility of stable fully detached divertor operation for a tokamak with extended divertor legs.

Visual recovery after surgical repair of chronic macular detachment associated with peripheral retinoschisis

OpenAIRE

Vaidehi S. Dedania; Devon H. Ghodasra; Mark W. Johnson

2018-01-01

Purpose: To report 2 cases of chronic macular detachment associated with peripheral retinoschisis in which surgical repair resulted in significant visual recovery. Observations: A 44-year-old man and 60-year-old woman were evaluated for chronic macular detachment, with a duration of 5 years and 6 months, respectively. In each case, optical coherence tomography was used to establish a diagnosis of full-thickness macular detachment resulting from peripheral retinoschisis and to confirm or ident...

Magnetic Detachment and Plume Control in Escaping Magnetized Plasma

International Nuclear Information System (INIS)

Schmit, P.F.; Fisch, N.J.

2008-01-01

The model of two-fluid, axisymmetric, ambipolar magnetized plasma detachment from thruster guide fields is extended to include plasmas with non-zero injection angular velocity profiles. Certain plasma injection angular velocity profiles are shown to narrow the plasma plume, thereby increasing exhaust efficiency. As an example, we consider a magnetic guide field arising from a simple current ring and demonstrate plasma injection schemes that more than double the fraction of useful exhaust aperture area, more than halve the exhaust plume angle, and enhance magnetized plasma detachment

Pigment Production by the Edible Filamentous Fungus Neurospora Intermedia

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Rebecca Gmoser

2018-02-01

Full Text Available The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2 on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production.

Preparation, characterization and application of some anti- corrosive molybdate pigments

International Nuclear Information System (INIS)

Abd El-Ghaffar, M.A.; El-Sawy, S.M.; Ahmed, N.M.

2005-01-01

Some molybdate pigments of single and mixed metal ions, namely, zinc, calcium and zinc-calcium molybdates were prepared, characterized and evaluated according to international standard methods. The evaluated pigments were incorporated in some paint formulations. The physicomechanical, chemical and corrosion protective properties of the paint films were measured; this was done in comparison with a commercial imported molybdate pigment. It was found that, the prepared pigments under investigation are fine white crystalline powders of suitable pigment properties. They can be successfully used as environmentally acceptable anti corrosive pigments. They can replace satisfactorily the similar commercial imported pigment and possess adequate or superior properties against corrosion

Electron detachment in ion-atom collisions

International Nuclear Information System (INIS)

Vreugd, C. de.

1980-01-01

The electron detachment process that occurs in negative ion-atom collisions is investigated. Differential cross sections were measured for the collisions of F - , Cl - , Br - , I - on He, Ne, Ar, Kr, Xe, Na and K. Electron energy distributions were obtained for some of the systems. (Auth.)

Adenocarcinoma of the lung presenting as retinal detachment

Directory of Open Access Journals (Sweden)

Kaushik Saha

2014-01-01

Full Text Available Retinal detachment is a rare presentation of lung cancer. A young female presented with blurring of vision in her right eye for the last 10 days without any history of trauma. On indirect ophthalmoscopy, there was a presence of right sided retinal detachment which was treated with oral prednisolone (60 mg/day. After 1 month of continuous treatment, she came back with dry cough left sided chest pain and deterioration of her eye symptoms. Chest X-ray showed left lung mass. Computed tomography guided fine needle aspiration cytology and with immunohistochemistry confirmed adenocarcinoma of the lung. She was treated with 6 cycles of chemotherapy with paclitaxel and gemcitabine.

Alternative Carrier Solvents for Pigments Extracted from Spalting Fungi

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Lauren Pittis

2018-05-01

Full Text Available The use of both naturally occurring and synthetic pigmented wood has been prevalent in woodcraft for centuries. Modern manifestations generally involve either woodworkers’ aniline dyes, or pigments derived from a special class of fungi known as spalting fungi. While fungal pigments are more renewable than anilines and pose less of an environmental risk, the carrier required for these pigments—dichloromethane (DCM—is both problematic for humans and tends to only deposit the pigments on the surface of wood instead of evenly within the material. Internal coloration of wood is key to adoption of a pigmenting system by woodworkers. To address this issue, five solvents that had moderate solubility with the pigments extracted from Chlorociboria aeruginosa and Scytalidium cuboideum were identified, in the hopes that a reduction in solubility would result in a greater amount of the pigment deposited inside the wood. Of the tested solvents, acetonitrile was found to produce the highest internal color in ash, Douglas-fir, madrone, mountain hemlock, Port-Orford cedar, Pacific silver fir, red alder and sugar maple. While these carrier solvents are not ideal for extracting the pigments from the fungi, acetonitrile in particular does appear to allow for more pigment to be deposited within wood. The use of acetonitrile over DCM offers new opportunities for possible industrial spalting applications, in which larger pieces of wood could be uniformly pigmented and sold to the end user in larger quantities than are currently available with spalted wood.

Safety detaching hook specification.

CSIR Research Space (South Africa)

Roux, JD

1999-05-01

Full Text Available hydraulic tensioning system The impactor must subject the safety detaching hook to an impact energy of 150 kJ minimum. A high speed digital imaging system, capable of recording at least 2000 full frames per second, shall be used to record video images... document compiled by the Contractor, detailing all major events in the production phase, including but not necessarily limited to inspection requirements, test procedures and acceptance/rejection criteria, sampling plans and equipment to be employed...

Light-induced vegetative anthocyanin pigmentation in Petunia

Science.gov (United States)

Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

2009-01-01

The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins and flavonols, as well as the activation of the early and late flavonoid biosynthetic genes required for flavonol and anthocyanin production. Pigmentation in Lc petunia only occurred under conditions which normally induce a modest amount of anthocyanin to accumulate in wild-type Mitchell petunia [Petunia axillaris×(Petunia axillaris×Petunia hybrida cv. ‘Rose of Heaven’)]. Anthocyanin pigmentation in Lc petunia leaves appears to screen underlying photosynthetic tissues, increasing light saturation and light compensation points, without reducing the maximal photosynthetic assimilation rate (Amax). In the Lc petunia system, where the bHLH factor Leaf colour is constitutively expressed, expression of the bHLH (Lc) and WD40 (An11) components of the anthocyanin regulatory system were not limited, suggesting that the high-light-induced anthocyanin pigmentation is regulated by endogenous MYB transcription factors. PMID:19380423

Coastal Response, a system of detached breakwaters

Science.gov (United States)

García Ortiz, Isabelo; Negro Valdecantos, Vicente; Santos López, Jose; Esteban, María Dolores

2017-04-01

The coastline's sedimentary response in the form of a tombolo or semi-tombolo (salient) as a result of the construction of detached breakwaters is an aspect that should be known in the design phase so that these marine structures may be properly designed. In achieving an ecological, social and economic value, such areas must also be properly managed. All design methods in existence since Dean (1978) are mainly based on hypotheses formulated from geometric studies on existing formations. No relationship at all is established with climate and littoral dynamics typical of the location (only Suh and Darlymple (1987) and the Japanese Ministry of Construction (1986) present relationships depending on wave variables). Neither has the influence on systems with more than two breakwaters been studied. These methods are not fully adapted to the cases existing on the Spanish Mediterranean littoral. The lines of investigation as proposed by L. Bricio and V. Negro (2010) were continued with for this study. These researchers developed a method for dimensioning isolated, detached breakwaters and their semi-tombolo or tombolo associated formations using all the characteristics of the site (energy, geometric and structural), specific climate and geomorphology and littoral dynamics' characteristics. This methodology is currently acknowledged and accepted in works undertaken on the Spanish Mediterranean littoral. A linear regression was obtained in the investigation undertaken on the 18 detached breakwater systems along the whole of the 1670 km of the Spanish Mediterranean littoral using the proposals made by L. Bricio and V. Negro. The adjustment of R2 ≥ 0.90 was used for the sandy, tombolo formations behind all the detached breakwater systems between several non-dimensional monomials displaying the most representative characteristics of the site. L/H12 + (2ṡB)/G =12,15ṡ(X/Xc)+7,3231 X: Distance of breakwaters from coastline Xc: Distance from coastline where the closure depth

Single- and double-electron detachment in collisions of two negative hydrogen ions

International Nuclear Information System (INIS)

Melchert, F.; Schulze, R.; Kruedener, S.; Meuser, S.; Salzborn, E.

1995-01-01

Employing the crossed-beams technique in conjunction with a beam-pulsing method, we have measured absolute cross sections σ tot for the process H - + H - → H O +... for CM energies between 2.5 and 100 keV. Combining the present results with our previously measured cross sections for double-electron detachment (σ OO ) and triple-electron detachment (σ 0+ ), we obtain cross sections σ 0- for the single electron detachment process from the relation σ 0- = σ tot -σ 00 -σ 0+ . The experimental data of single- and double-electron detachment are well described by theoretical results based on the non-stationary tunnelling approach. Both cross sections are calculated for CM energies between 0.15 and 300 keV. A new two-electron simultaneous transition mechanism is introduced. The importance of this process for the theoretical assessment of the experimental results is discussed. (Author)

Role of Membrane Cholesterol Levels in Activation of Lyn upon Cell Detachment

Directory of Open Access Journals (Sweden)

Takao Morinaga

2018-06-01

Full Text Available Cholesterol, a major component of the plasma membrane, determines the physicalproperties of biological membranes and plays a critical role in the assembly of membranemicrodomains. Enrichment or deprivation of membrane cholesterol affects the activities of manysignaling molecules at the plasma membrane. Cell detachment changes the structure of the plasmamembrane and influences the localizations of lipids, including cholesterol. Recent studies showedthat cell detachment changes the activities of a variety of signaling molecules. We previously reportedthat the localization and the function of the Src-family kinase Lyn are critically regulated by itsmembrane anchorage through lipid modifications. More recently, we found that the localization andthe activity of Lyn were changed upon cell detachment, although the manners of which vary betweencell types. In this review, we highlight the changes in the localization of Lyn and a role of cholesterolin the regulation of Lyn’s activation following cell detachment.

Non-conventional synthesis of ceramic pigments

International Nuclear Information System (INIS)

Dziubak, C.; Rutkowski, R.; Gebel, R.

2003-01-01

A short characterization of traditional methods of homogenization of components, used to produce ceramic pigments, was presented. Efficient and economic methods are searched to prepare raw material sets for ceramic pigments as alternative methods for the traditional way of wet mixing in ball mill or of dry mixing in the mixer of 'Z' type. The results of research of the use of sol-gel method to achieve these aims are presented. At the present stage of research, carried out on the yellow praseodymium and coral-pink iron-zirconium pigments show that traditional methods are better. (author)

A feed-forward regulation of endothelin receptors by c-Jun in human non-pigmented ciliary epithelial cells and retinal ganglion cells.

Directory of Open Access Journals (Sweden)

Junming Wang

Full Text Available c-Jun, c-Jun N-terminal kinase(JNK and endothelin B (ETB receptor have been shown to contribute to the pathogenesis of glaucoma. Previously, we reported that an increase of c-Jun and CCAAT/enhancer binding protein β (C/EBPβ immunohistostaining is associated with upregulation of the ETB receptor within the ganglion cell layer of rats with elevated intraocular pressure (IOP. In addition, both transcription factors regulate the expression of the ETB receptor in human non-pigmented ciliary epithelial cells (HNPE. The current study addressed the mechanisms by which ET-1 produced upregulation of ET receptors in primary rat retinal ganglion cells (RGCs and HNPE cells. Treatment of ET-1 and ET-3 increased the immunocytochemical staining of c-Jun and C/EBPβ in primary rat RGCs and co-localization of both transcription factors was observed. A marked increase in DNA binding activity of AP-1 and C/EBPβ as well as elevated protein levels of c-Jun and c-Jun-N-terminal kinase (JNK were detected following ET-1 treatment in HNPE cells. Overexpression of ETA or ETB receptor promoted the upregulation of c-Jun and also elevated its promoter activity. In addition, upregulation of C/EBPβ augmented DNA binding and mRNA expression of c-Jun, and furthermore, the interaction of c-Jun and C/EBPβ was confirmed using co-immunoprecipitation. Apoptosis of HNPE cells was identified following ET-1 treatment, and overexpression of the ETA or ETB receptor produced enhanced apoptosis. ET-1 mediated upregulation of c-Jun and C/EBPβ and their interaction may represent a novel mechanism contributing to the regulation of endothelin receptor expression. Reciprocally, c-Jun was also found to regulate the ET receptors and C/EBPβ appeared to play a regulatory role in promoting expression of c-Jun. Taken together, the data suggests that ET-1 triggers the upregulation of c-Jun through both ETA and ETB receptors, and conversely c-Jun also upregulates endothelin receptor expression

Retinal detachment secondary to ocular perforation during retrobulbar Anaesthesia

Directory of Open Access Journals (Sweden)

Gopal Lingam

1995-01-01

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

Retinal detachment in black South Africans

African Journals Online (AJOL)

low incidence of retinal detachment in black patients is not known. ... a retinal break. Predisposing factors include peripheral retinal degenerations, myopia, aphakia and trauma. Delay in presentation increases the difficulty in achieving adequate surgical ... On examination, note was taken of the visual acuity in both eyes, the ...

Detached Eddy Simulations of Hypersonic Transition

Science.gov (United States)

Yoon, S.; Barnhardt, M.; Candler, G.

2010-01-01

This slide presentation reviews the use of Detached Eddy Simulation (DES) of hypersonic transistion. The objective of the study was to investigate the feasibility of using CFD in general, DES in particular, for prediction of roughness-induced boundary layer transition to turbulence and the resulting increase in heat transfer.

An Unusual Case of Extensive Lattice Degeneration and Retinal Detachment

OpenAIRE

Mathew, David J.; Sarma, Saurabh Kumar; Basaiawmoit, Jennifer V.

2016-01-01

Lattice degeneration of the retina is not infrequently encountered on a dilated retinal examination and many of them do not need any intervention. We report a case of atypical lattice degeneration variant with peripheral retinal detachment. An asymptomatic 35-year-old lady with minimal refractive error was found to have extensive lattice degeneration, peripheral retinal detachment and fibrotic changes peripherally with elevation of retinal vessels on dilated retinal examination. There were al...

Chilling-enhanced photooxidation: evidence for the role of singlet oxygen and superoxide in the breakdown of pigments and endogenous antioxidants

Energy Technology Data Exchange (ETDEWEB)

Wise, R.R.; Naylor, A.W.

1987-02-01

Chilling temperatures (5/sup 0/C) and high irradiance (1000 microeinsteins per square meter per second) were used to induce photooxidation in detached leaves of cucumber (Cucumis sativus L.), a chilling-sensitive plant. Chlorophyll a, chlorophyll b, ..beta.. carotene, and three xanthophylls were degraded in a light-dependent fashion at essentially the same rate. Lipid peroxidation (measured as ethane evolution) showed an O/sub 2/ dependency. The levels of three endogenous antioxidants, ascorbate, reduced glutathione, and ..cap alpha.. tocopherol, all showed an irradiance-dependent decline. ..cap alpha..-Tocopherol was the first antioxidant affected and appeared to be the only antioxidant that could be implicated in long-term protection of the photosynthetic pigments. Results from the application of antioxidants having relative selectivity for /sup 1/O/sub 2/, O/sub 2//sup +/, or OH indicated that both /sup 1/O/sub 2/ and O/sub 2//sup -/ were involved in the chilling- and light-induced lipid peroxidation which accompanied photooxidation. Application of D/sub 2/O (which enhances the lifetime of /sup 1/O/sub 2/) corroborated these results. Chilling under high light produced no evidence of photooxidative damage in detached leaves of chilling-resistant pea (Pisum sativum L.). Their results suggest a fundamental difference in the ability of pea to reduce the destructive effects of free-radical and /sup 1/O/sub 2/ production in chloroplasts during chilling in high light.

21 CFR 178.3725 - Pigment dispersants.

Science.gov (United States)

2010-04-01

... HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3725 Pigment dispersants. Subject to the provisions of this... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pigment dispersants. 178.3725 Section 178.3725 Food...

Negative ion detachment cross sections

International Nuclear Information System (INIS)

Champion, R.L.; Doverspike, L.D.

1992-10-01

The authors have measured absolute cross sections for electron detachment and charge exchange for collision of O and S with atomic hydrogen, have investigated the sputtering and photodesorption of negative ions from gas covered surfaces, and have begun an investigation of photon-induced field emission of electrons from exotic structures. Brief descriptions of these activities as well as future plans for these projects are given below

Platelet-Rich Plasma Increases Pigmentation.

Science.gov (United States)

Uysal, Cagri A; Ertas, Nilgun Markal

2017-11-01

Platelet-rich plasma (PRP) is an autologous solution of plasma containing 4 to 7 times the baseline concentration of human platelets. Platelet-rich plasma has been widely popular in facial rejuvenation to attenuate wrinkles and has been practically used. The authors have been encountering various patients of increased hiperpigmentation following PRP applications that were performed to attenuate the postinflammatory hiperpigmentation especially after laser treatment. The authors have been using PRP for facial rejuvenation in selected patients and in 1 patient the authors have encountered increased pigmentation over the pigmented skin lesions that were present before the application. The authors recommend that the PRP might increase pigmentation especially in the face region and precautions might be taken before and after the application. Platelet-rich plasma should not be used for the treatment of post inflammatory hiperpigmentation.

Middle Miocene E-W tectonic horst structure of Crete through extensional detachment faults

International Nuclear Information System (INIS)

Papanikolaou, D; Vassilakis, E

2008-01-01

Two east-west trending extensional detachment faults have been recognized in Crete, one with top-to-the-north motion of the hanging wall toward the Cretan Sea and one with top-to-the-south motion of the hanging wall toward the Libyan Sea. The east-west trending zone between these two detachment faults, which forms their common footwall, comprises a tectonic horst formed during Middle Miocene slip on the detachment faults. The detachment faults disrupt the overall tectono-stratigraphic succession of Crete and are localized along pre-existing thrust faults and along particular portions of the stratigraphic sequence, including the transition between the Permo-Triassic Tyros Beds and the base of the Upper Triassic-Eocene carbonate platform of the Tripolis nappe. By recognizing several different tectono-stratigraphic formations within what is generally termed the 'phyllite-quartzite', it is possible to distinguish these extensional detachment faults from thrust faults and minor discontinuities in the sequence. The deformation history of units within Crete can be summarized as: (i) compressional deformation producing arc-parallel east-west trending south-directed thrust faults in Oligocene to Early Miocene time (ii) extensional deformation along arc-parallel, east-west trending detachment faults in Middle Miocene time, with hanging wall motion to the north and south; (iii) Late Miocene-Quaternary extensional deformation along high-angle normal and oblique normal faults that disrupt the older arc-parallel structures

Hyperspectral remote sensing of plant pigments.

Science.gov (United States)

Blackburn, George Alan

2007-01-01

The dynamics of pigment concentrations are diagnostic of a range of plant physiological properties and processes. This paper appraises the developing technologies and analytical methods for quantifying pigments non-destructively and repeatedly across a range of spatial scales using hyperspectral remote sensing. Progress in deriving predictive relationships between various characteristics and transforms of hyperspectral reflectance data are evaluated and the roles of leaf and canopy radiative transfer models are reviewed. Requirements are identified for more extensive intercomparisons of different approaches and for further work on the strategies for interpreting canopy scale data. The paper examines the prospects for extending research to the wider range of pigments in addition to chlorophyll, testing emerging methods of hyperspectral analysis and exploring the fusion of hyperspectral and LIDAR remote sensing. In spite of these opportunities for further development and the refinement of techniques, current evidence of an expanding range of applications in the ecophysiological, environmental, agricultural, and forestry sciences highlights the growing value of hyperspectral remote sensing of plant pigments.

Early rhegmatogenous retinal detachment following laser in situ keratomileusis for high myopia.

Science.gov (United States)

Farah, M E; Höfling-Lima, A L; Nascimento, E

2000-01-01

Four eyes had early rhegmatogenous retinal detachment within 3 months of laser in situ keratomileusis (LASIK) for correction of high myopia using the microkeratome, Clear Corneal Molder. In two eyes, retinal detachment resulted from horseshoe tears, one occurring in an otherwise normal region of the retina and the other at the margin of an area of lattice degeneration detected during preoperative examination. The first eye was treated with retinopexy using a 287 encircling scleral exoplant, drainage of subretinal fluid, and laser photocoagulation by indirect ophthalmoscopy. The other eye was treated with pneumatic retinopexy and cryotherapy. In the other eyes, retinal detachment was the result of giant tears with no evidence of prior retinal degeneration. These eyes were treated with pars plana vitrectomy, fluid-gas exchange with 15% perfluoropropane (C3F8), endolaser photocoagulation, and a 42 encircling scleral exoplant. After treatment, the first two eyes achieved spectacle-corrected visual acuity of 20/40. In the last two eyes, final spectacle-corrected visual acuity was 20/400 in one eye and light perception in the other. Although no cause-effect relationship between LASIK and retinal detachment can be stated, these cases suggest that LASIK may be associated with retinal detachment, particularly in highly myopic eyes. Further studies are necessary to determine high-risk patient characteristics.

Unwanted detachment of the Solitaire device during mechanical thrombectomy in acute ischemic stroke.

Science.gov (United States)

Castaño, C; Dorado, L; Remollo, S; García-Bermejo, P; Gomis, M; Pérez de la Ossa, N; Millán, M; García-Sort, M R; Hidalgo, C; López-Cancio, E; Cubells, C; Dávalos, A

2016-01-27

The use of retrievable stents for endovascular clot retrieval has dramatically improved successful revascularization and clinical outcome in selected patients with acute stroke. To describe the rate and clinical consequences of unwanted spontaneous detachment of these devices during mechanical thrombectomy. We studied 262 consecutive patients treated with the retrievable stent, Solitaire, for acute ischemic stroke between November 2008 and April 2015. Clinical, procedural, and outcome variables were compared between patients with and without unexpected detachment of this device. Detachment was classified as proximal to the stent proximal marker (type A) or distal to the marker (type B). Poor functional outcome was defined as modified Rankin scale score >2 at 90 days. Unwanted detachment occurred in 6/262 (2.3%) cases, four of type A and two of type B. Stent recovery was possible in three patients, all of 'type A', but in none of 'type B'. The number of prior passes was higher in patients with undesired detachment (3 (2-5) vs 2 (1-3), p=0.007). Detachment was associated with higher rate of symptomatic intracranial hemorrhage (SICH) (33.3% vs 4.3%, p=0.001), poorer outcome (100% vs 54.8%, p=0.028), and higher mortality rate at 90 days (50% vs 17%, p=0.038). Unwanted detachment of a Solitaire is an uncommon complication during mechanical thrombectomy in patients with acute ischemic stroke and is associated with the clot retrieval attempts, SICH, poor outcome, and higher mortality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Model of detached plasmas

International Nuclear Information System (INIS)

Yoshikawa, S.; Chance, M.

1986-07-01

Recently a tokamak plasma was observed in TFTR that was not limited by a limiter or a divertor. A model is proposed to explain this equilibrium, which is called a detached plasma. The model consists of (1) the core plasma where ohmic heating power is lost by anomalous heat conduction and (2) the shell plasma where the heat from the core plasma is radiated away by the atomic processes of impurity ions. A simple scaling law is proposed to test the validity of this model

[Primary pigmented breast adenocarcinoma in a male patient].

Science.gov (United States)

Dauendorffer, J-N; Pages, C; Abd Alsamad, I; Bagot, M; Fraitag, S

2013-01-01

Pigmented mammary tumours are rare. Herein, we report the third case of primary pigmented breast adenocarcinoma in a male patient with clinical mimicking of nodular melanoma of the nipple. A male patient presented with a pigmented nodule of the right nipple. Histological examination of the lesion showed dermal and subcutaneous adenocarcinomatous proliferation. The perilesional stroma contained melanin both inside and outside macrophages, leading us to conclude on primary pigmented breast adenocarcinoma clinically mimicking nodular melanoma of the nipple. Local production of melanin by neoplastic cells in the mammary carcinoma was postulated as the cause of hyperpigmentation of the tumour. Other possible causes are transfer of melanin from overlying melanocytes of the pigmented areolar epidermis to the underlying neoplastic cells, or melanin synthesis by intratumoral melanocytes migrating from the epidermis (which strikes us as the most convincing interpretation for the reported case). Breast adenocarcinoma is a rare tumour in men and may present clinically as a pigmented lesion of the nipple, resulting in the problem of differential diagnosis with primary or metastasised nodular melanoma. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Micro-pigmentation: implications for patients and professionals.

Science.gov (United States)

Collingridge, Kim; Calcluth, Julie

In the UK, reconstructive breast surgery is routinely offered to patients undergoing surgery for breast cancer. The results can be excellent, but without a nipple-areola complex the patient can feel incomplete. In response to patient need, an innovative nurse-led micro-pigmentation service has been developed in the authors' NHS trust, which provides women (and men) an opportunity to complete their reconstruction process. With the use of coloured pigments, micro-pigmentation creates a permanent image of a nipple-areola complex, which improves the aesthetic appearance of the surgically-created breast. As with the development of any new nurse-led innovation, the micro-pigmentation service has professional and client implications. Breast cancer can be devastating and may induce many psychological concerns, not least about body image and sexuality. This article addresses these issues, along with professional matters, such as autonomous practice, role expansion and the blurring of clinical boundaries. These factors are considered in relation to the nursing management of the micro-pigmentation service, where patient autonomy is encouraged to promote acceptance of self-image and closure on the breast cancer experience.

Cadherins in the retinal pigment epithelium (RPE revisited: P-cadherin is the highly dominant cadherin expressed in human and mouse RPE in vivo.

Directory of Open Access Journals (Sweden)

Xue Yang

Full Text Available The retinal pigment epithelium (RPE supports the health and function of retinal photoreceptors and is essential for normal vision. RPE cells are post-mitotic, terminally differentiated, and polarized epithelial cells. In pathological conditions, however, they lose their epithelial integrity, become dysfunctional, even dedifferentiate, and ultimately die. The integrity of epithelial cells is maintained, in part, by adherens junctions, which are composed of cadherin homodimers and p120-, β-, and α-catenins linking to actin filaments. While E-cadherin is the major cadherin for forming the epithelial phenotype in most epithelial cell types, it has been reported that cadherin expression in RPE cells is different from other epithelial cells based on results with cultured RPE cells. In this study, we revisited the expression of cadherins in the RPE to clarify their relative contribution by measuring the absolute quantity of cDNAs produced from mRNAs of three classical cadherins (E-, N-, and P-cadherins in the RPE in vivo. We found that P-cadherin (CDH3 is highly dominant in both mouse and human RPE in situ. The degree of dominance of P-cadherin is surprisingly large, with mouse Cdh3 and human CDH3 accounting for 82-85% and 92-93% of the total of the three cadherin mRNAs, respectively. We confirmed the expression of P-cadherin protein at the cell-cell border of mouse RPE in situ by immunofluorescence. Furthermore, we found that oxidative stress induces dissociation of P-cadherin and β-catenin from the cell membrane and subsequent translocation of β-catenin into the nucleus, resulting in activation of the canonical Wnt/β-catenin pathway. This is the first report of absolute comparison of the expression of three cadherins in the RPE, and the results suggest that the physiological role of P-cadherin in the RPE needs to be reevaluated.

Pigment Production from Immobilized Monascus sp. Utilizing Polymeric Resin Adsorption

OpenAIRE

Evans, Patrick J.; Wang, Henry Y.

1984-01-01

Pigment production by the fungus Monascus sp. was studied to determine why Monascus sp. provides more pigment in solid culture than in submerged culture. Adding a sterilized nonionic polymeric adsorbent resin directly to the growing submerged culture did not enhance the pigment production, thus indicating that pigment extraction is probably not a factor. Monascus cells immobilized in hydrogel were studied and exhibited decreased pigment production as a result of immobilization. This result is...

Large-spot subthreshold transpupillary thermotherapy for chronic serous macular detachment

Directory of Open Access Journals (Sweden)

Giuseppe Lo Giudice

2011-03-01

Full Text Available Giuseppe Lo Giudice1, Valentina de Belvis2, Marco Tavolato1, Alessandro Galan11San Paolo Ophthalmic Center, San Antonio Hospital, Padova, Italy; 2Paediatric Low Vision Center, Paediatric Rare Eye Disease Center, Department of Paediatrics, University of Padova, ItalyPurpose: To report the effect of subthreshold transpupillary thermotherapy (TTT in treating serous detachment of the neurosensory retina secondary to chronic central serous chorioretinopathy (CCSC.Methods: Seven eyes from five patients with CCSC, persistent serous detachment of the neurosensory retina and a clinical course of between 12 and 60 months were treated. All eyes received large-spot TTT guided by indocyanine green angiography (ICGA. Subthreshold TTT was performed using an 810 nm diode laser with a spot size of 3.0 mm (power was set at 350 mW. Treatment was applied for 60 seconds to the areas of choroidal hyperfluorescence on ICGA.Results: The mean number of TTT sessions was 1.4 ± 0.5. All eyes were followed up for at least 6 months (mean 9.6 ± 3.2 standard deviation; range 6–12 months. The mean logarithm of the minimum angle of resolution best-corrected visual acuity was significantly better compared with baseline. All TTT-treated eyes had stable or improved vision (P < 0.001. Mean optical coherence tomography (OCT central foveal thickness was significantly lower in all patients (P < 0.001 compared with pretreatment OCT, with a reduction in subretinal fluid and resolution of serous detachment associated with anatomical fovea restoration. No patient had any treatment-related side effects.Conclusion: Modified subthreshold TTT appears to have a beneficial effect in treating patients with CCSC and persistent neurosensory detachment. The encouraging results and lack of visually significant complications suggest that further investigation is warranted.Keywords: central serous chorioretinopathy, indocyanine green angiography, neurosensory detachment, transpupillary

Induced Retro-Differentiation of Human Retinal Pigment Epithelial Cells on PolyHEMA.

Science.gov (United States)

Nazemroaya, Fatemeh; Soheili, Zahra-Soheila; Samiei, Shahram; Deezagi, Abdolkhalegh; Ahmadieh, Hamid; Davari, Malihe; Heidari, Razeih; Bagheri, Abouzar; Darvishalipour-Astaneh, Shamila

2017-10-01

Retinal pigment epithelium (RPE) cells represent a great potential to rescue degenerated cells of the damaged retina. Activation of the virtually plastic properties of RPE cells may aid in recovery of retinal degenerative disorders without the need for entire RPE sheet transplantation. Poly (2-hydroxyethyl methacrylate)(PolyHEMA) is one of the most important hydrogels in the biomaterials world. This hydrophobic polymer does not normally support attachment of mammalian cells. In the current study we investigated the effect of PolyHEMA as a cell culture substrate on the growth, differentiation, and plasticity of hRPE cells. hRPE cells were isolated from neonatal human globes and cultured on PolyHEMA and polystyrene substrates (as controls) in 24-well culture plates. DMEM/F12 was supplemented with 10% fetal bovine serum (FBS) and/or 30% human amniotic fluid (HAF) for cultured cells on polystyrene and PolyHEMA coated vessels. Morphology, rate of cell proliferation and cell death, MTT assay, immunocytochemistry and Real-Time RT-PCR were performed to investigate the effects of PolyHEMA on the growth and differentiation of cultured hRPE cells. Proliferation rate of the cells that had been cultured on PolyHEMA was reduced; PolyHEMA did not induce cell death in the hRPE cultures. hRPE cells cultured on PolyHEMA formed many giant spheroid colonies. The giant colonies were re-cultured and the presence of retinal progenitor markers and markers of hRPE cells were detected in cell cultures on PolyHEMA. PolyHEMA seems to be promising for both maintenance and de-differentiation of hRPE cells and expansion of the retinal progenitor cells from the cultures that are originated from hRPE cells. J. Cell. Biochem. 118: 3080-3089, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Analysis of basidiomycete pigments in situ by Raman spectroscopy.

Science.gov (United States)

Tauber, James P; Matthäus, Christian; Lenz, Claudius; Hoffmeister, Dirk; Popp, Jürgen

2018-02-07

Basidiomycetes, that is, mushroom-type fungi, are known to produce pigments in response to environmental impacts. As antioxidants with a high level of unsaturation, these compounds can neutralize highly oxidative species. In the event of close contact with other microbes, the enzymatically controlled pigment production is triggered and pigment secretion is generated at the interaction zone. The identification and analysis of these pigments is important to understand the defense mechanism of fungi, which is essential to counteract an uncontrolled spread of harmful species. Usually, a detailed analysis of the pigments is time consuming as it depends on laborious sample preparation and isolation procedures. Furthermore, the applied protocols often influence the chemical integrity of the compound of interest. A possibility to noninvasively investigate the pigmentation is Raman microspectroscopy. The methodology has the potential to analyze the chemical composition of the sample spatially resolved at the interaction zone. After the acquisition of a representative spectroscopic library, the pigment production by basidiomycetes was monitored for during response to different fungi and bacteria. The presented results describe a very efficient noninvasive way of pigment analysis which can be applied with minimal sample preparation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of chromium containing pigments from chromium galvanic sludges

International Nuclear Information System (INIS)

Andreola, F.; Barbieri, L.; Bondioli, F.; Cannio, M.; Ferrari, A.M.; Lancellotti, I.

2008-01-01

In this work the screening results of the scientific activity conducted on laboratory scale to valorise chromium(III) contained in the galvanic sludge as chromium precursor for ceramic pigments are reported. The valorisation of this waste as a secondary raw material (SRM) is obtained by achievement of thermal and chemical stable crystal structures able to color ceramic material. Two different pigments pink CaCr 0.04 Sn 0.97 SiO 5 and green Ca 3 Cr 2 (SiO 4 ) 3 were synthesized by solid-state reactions using dried Cr sludge as chromium oxide precursor. The obtained pigments were characterized by X-ray diffraction and SEM analysis. Furthermore the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure Cr 2 O 3 . The characterization carried out corroborates the thermal and chemical stability of the synthesized pigments and, especially for the Cr-Sn pink pigment, the powders develop an intense color that is very similar to the color developed by the pigments obtained starting from pure Cr 2 O 3

[Functional results of cryosurgical procedures in rhegmatogenous retinal detachment including macula region - our experience].

Science.gov (United States)

Chrapek, O; Sín, M; Jirková, B; Jarkovský, J; Rehák, J

2013-10-01

Aim of this study is to evaluate retrospectively functional results of cryosurgical treatment of uncomplicated, idiopathic rhegmatogenous retinal detachment including macula region in phakic patients operated on at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc, Czech Republic, E.U., during the period 2002 -2013, and to evaluate the significance of the macula detachment duration for the final visual acuity. In the study group were included 56 eyes of 56 patients operated in the years 2003 - 2012 at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc. All patients were phakic and in all of them, the retinal detachment including the macula region was diagnosed. The mean follow-up period of the patients was 8,75 months. The initial and final visual acuity testing were performed. Comparing the initial and final visual acuity we rated the level of the visual acuity change. The result was stated as improved, if the visual acuity improved by 1 or more lines on the ETDRS chart. The result was rated as stabilized, if the visual acuity remained the same or it changed by 1 line of the ETDRS chart only. The result was evaluated as worsened, if the visual acuity decreased by 1 or more lines of the ETDRS chart. In the followed-up group, the authors compared visual acuity levels in patients with the macula detachment duration 10 days and 11 days. For the statistical evaluation of achieved results, the Mann - Whitney U test was used. The visual acuity improved in 49 (87 %), did not changed in 5 (9 %) and worsened in 2 (4 %) patients. The patients with macula detachment duration 10 days achieved statistically significant better visual acuity than patients with macula detachment duration 11 days. Patients with macula detachment duration 10 days have better prognosis for functional result than patients with macula detachment duration 11 days.

Chemical characterisation of zircon-cadmium sulfoselenide ceramic pigments

International Nuclear Information System (INIS)

Gazulla Barreda, M. F.; Rodrigo Edo, M.; Blasco Roca, E.; Orduna Cordero, M.

2013-01-01

The present paper addresses the development of a methodology that allows the complete chemical characterisation of zircon cadmium sulfoselenide ceramic pigments including minor and major elements. To develop the methodology, five zircon-cadmium sulfoselenide pigments with different hues were selected, studying the different measurement process steps, from sample preparation to the optimisation of the measurement of the different components of the pigments by spectroscopic techniques (WD-XRF and elemental analysis by combustion and IR detection). The chemical characterisation method developed was validated with synthetic standards prepared from the mixture of certified reference materials and pure oxides because no certified referenced materials of this type of pigments were commercially available. The developed method can be used for a complete chemical characterization of zircon-cadmium sulfoselenide ceramic pigments with a very low uncertainty for all the elements analysed. (Author)

The Assessment of Natural Pigmentation in Archaeological Wool

DEFF Research Database (Denmark)

Scharff, Annemette Bruselius

2018-01-01

Naturally coloured wool contains pigment grains that mainly occur as ellipsoidal organelles (eumelanin) or spher¬ical grains (pheomelanin). Eumelanin is the most commonly occurring pigment, but naturally coloured wool fi¬bres contain both eumelanin and pheomelanin. In black and brown wool....... This can especially be the case if the pigments are degraded. When analysing the textiles from Lønne Hede (a Danish Iron Age inhumation grave), it was difficult to gain exact information about the natural pigmentation in some of the samples. To investigate this further, four samples of red-brown yarns from...... patterned fragments were selected for analyses. Earlier dyestuff analyses of the red-brown yarns gave no results, and it was therefore necessary to test the yarns for natural pigmentation. Three different methods were used for the analy¬ses. Transmitted light microscopy of whole mounts of the fibres...

Classification of posterior vitreous detachment

OpenAIRE

Kakehashi, Akihiro; Takezawa, Mikiko; Akiba, Jun

2013-01-01

Akihiro Kakehashi,1 Mikiko Takezawa,1 Jun Akiba21Department of Ophthalmology, Jichi Medical University, Saitama Medical Center, Saitama, 2Kanjodori Eye Clinic, Asahikawa, JapanAbstract: Diagnosing a posterior vitreous detachment (PVD) is important for predicting the prognosis and determining the indication for vitreoretinal surgery in many vitreoretinal diseases. This article presents both classifications of a PVD by slit-lamp biomicroscopy and of a shallow PVD by optical coherence tomography...

Functional and environmental design of detached, low crest level breakwaters

International Nuclear Information System (INIS)

Bricio Garberi, L.; Negro Valdecantos, V.; Diez Gonzalez, J. J.; Lopez Gutierrez, J. S.

2010-01-01

The research work as presented in this article covers the design of detached breakwaters since they constitute a type of coastal defense work with which to combat many of the erosion problems found on beaches in a stable, sustainable fashion. The main aim of this work is to formulate a functional and environmental (non structural) method of design enabling the fundamental characteristics of a detached breakwater to be defined as a function of the effect it is wished to induce on the coast whilst meeting social demands and preserving or improving the quality of the littoral environment. The general applicability of the method is also sought by means of considering relations between variables od different natures (climatic, geomorphologic and geometric) influencing the changes experienced on the coast after the detached breakwater has been built. The study of the relations between the different variables is carried out on the data from a abase of nineteen actual, existing detached breakwaters on the Spanish Mediterranean coastline and follows a methodology based on the implementation of non-dimensional monomials and on a search for relations of dependency between them. Finally, a discussion on the results obtained lead to a proposal for a design method that uses some of the graphic relations found between the variables studied with which the aforesaid main objective is achieved. (Author) 9 refs.

Neurotized congenital melanocytic nevus resembling a pigmented neurofibroma

Directory of Open Access Journals (Sweden)

Nidhi Singh

2015-01-01

Full Text Available Neurotized congenital melanocytic nevus and pigmented neurofibroma (PNF are close mimics and pose a clinicopathological challenge. We present a case of pigmented hypertrichotic plaque over lumbosacral region and discuss the differential diagnosis and its clinical, histopathological and immunohistochemistry features which may aid in differentiation. We highlight the difficulties faced in differentiating neurotized congenital melanocytic nevus from pigmented neurofibroma.

Efficacy of ophthalmic solutions to detach adhering Pseudomonas aeruginosa from contact lenses

NARCIS (Netherlands)

Landa, AS; van der Mei, HC; van Rij, G; Busscher, HJ

Purpose. To compare the efficacies of two all-in-one contact lens (CL) cleaning solutions and a detergent mixture on the detachment of a pathogenic bacterium adhering to two types of contact lenses in the absence and presence of a tear film. Methods. Bacterial-detachment studies were carried out in

Risk of serous retinal detachment in patients with end-stage renal disease on dialysis.

Directory of Open Access Journals (Sweden)

Yuh-Shin Chang

Full Text Available The aim of this retrospective, nationwide, matched cohort study was to investigate the association of serous retinal detachment with having end-stage renal disease (ESRD while on dialysis. The cohort study included 94,024 patients with ESRD on dialysis registered between January 2000 to December 2009 in the Taiwan National Health Insurance Research Database. An age- and sex-matched control group comprised 94,024 patients selected from the Taiwan Longitudinal Health Insurance Database 2000. Information for each patient was collected from the index date until December 2011. Twenty-seven ESRD patients and 11 controls developed serous retinal detachment (P < 0.001 during follow-up, demonstrating a significantly increased risk of serous retinal detachment in patients with ESRD on dialysis compared with controls (incidence rate ratio = 3.39, 95% confidence interval [CI] = 1.68-6.83. After adjustment for potential confounders, patients were 3.86 times more likely to develop serous retinal detachment than the full cohort (adjusted HR = 3.86, 95% CI = 1.15-12.96. In conclusion, patients with ESRD on dialysis demonstrate an increased risk of serous retinal detachment. Interdisciplinary collaboration between nephrologists and ophthalmologists is important to deal with serous retinal detachment in patients with ESRD on dialysis and prevent impairments of visual acuity.

Macular detachment associated with an optic pit: optical coherence tomography patterns and surgical outcomes.

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Skaat, Alon; Moroz, Iris; Moisseiev, Joseph

2013-01-01

To describe the different optical coherence tomography (OCT) patterns in macular detachment associated with an optic disc pit and their long-term evolution following vitrectomy.
 The data of 5 patients (9-43 years of age) with unilateral macular detachment associated with an optic disc pit, who had at least 1 year of follow-up, were compiled. Pars plana vitrectomy combined with gas tamponade was performed as the primary procedure in all patients. The OCT scans, best-corrected visual acuity (BCVA), and anatomic outcomes were documented.
 Two main OCT patterns were identified: a multilayer schisis pattern and a serous detachment pattern. Patients with multilayer schisis pattern were older and demonstrated worse mean preoperative (20/160) and postoperative (20/50) BCVA compared to serous detachment pattern patients (20/30 and 20/20, respectively). An average of 2.3 procedures per patient was needed in the multilayer schisis pattern compared to just one procedure in the serous detachment pattern. In 3 patients, additional pneumatic retinopexy was performed with full resolution of the subretinal fluid achieved.
 Two distinct OCT patterns were observed in eyes with macular detachments with an optic pit, with different clinical features and prognoses. Excellent final visual acuity was obtained in all eyes, including those that required several surgical procedures.

Influence of Cell Detachment on the Respiration Rate of Tumor and Endothelial Cells

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Danhier, Pierre; Copetti, Tamara; De Preter, Géraldine; Leveque, Philippe; Feron, Olivier; Jordan, Bénédicte F.; Sonveaux, Pierre; Gallez, Bernard

2013-01-01

Cell detachment is a procedure routinely performed in cell culture and a necessary step in many biochemical assays including the determination of oxygen consumption rates (OCR) in vitro. In vivo, cell detachment has been shown to exert profound metabolic influences notably in cancer but also in other pathologies, such as retinal detachment for example. In the present study, we developed and validated a new technique combining electron paramagnetic resonance (EPR) oximetry and the use of cytodex 1 and collagen-coated cytodex 3 dextran microbeads, which allowed the unprecedented comparison of the OCR of adherent and detached cells with high sensitivity. Hence, we demonstrated that both B16F10 melanoma cells and human umbilical vein endothelial cells (HUVEC) experience strong OCR decrease upon trypsin or collagenase treatments. The reduction of cell oxygen consumption was more pronounced with a trypsin compared to a collagenase treatment. Cells remaining in suspension also encounter a marked intracellular ATP depletion and an increase in the lactate production/glucose uptake ratio. These findings highlight the important influence exerted by cell adhesion/detachment on cell respiration, which can be probed with the unprecedented experimental assay that was developed and validated in this study. PMID:23382841

Influence of cell detachment on the respiration rate of tumor and endothelial cells.

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Danhier, Pierre; Copetti, Tamara; De Preter, Géraldine; Leveque, Philippe; Feron, Olivier; Jordan, Bénédicte F; Sonveaux, Pierre; Gallez, Bernard

2013-01-01

Cell detachment is a procedure routinely performed in cell culture and a necessary step in many biochemical assays including the determination of oxygen consumption rates (OCR) in vitro. In vivo, cell detachment has been shown to exert profound metabolic influences notably in cancer but also in other pathologies, such as retinal detachment for example. In the present study, we developed and validated a new technique combining electron paramagnetic resonance (EPR) oximetry and the use of cytodex 1 and collagen-coated cytodex 3 dextran microbeads, which allowed the unprecedented comparison of the OCR of adherent and detached cells with high sensitivity. Hence, we demonstrated that both B16F10 melanoma cells and human umbilical vein endothelial cells (HUVEC) experience strong OCR decrease upon trypsin or collagenase treatments. The reduction of cell oxygen consumption was more pronounced with a trypsin compared to a collagenase treatment. Cells remaining in suspension also encounter a marked intracellular ATP depletion and an increase in the lactate production/glucose uptake ratio. These findings highlight the important influence exerted by cell adhesion/detachment on cell respiration, which can be probed with the unprecedented experimental assay that was developed and validated in this study.

Electron-detachment cross sections of halogen negative-ion projectiles for inertial confinement fusion

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Sant'Anna, M. M.; Zappa, F.; Santos, A. C. F.; de Barros, A. L. F.; Wolff, W.; Coelho, L. F. S.; de Castro Faria, N. V.

2004-07-01

Negative-ion beams have recently been suggested as sources of high-energy heavy atoms to be used as drivers for inertial confinement fusion (ICF). Owing to their electron affinities limited to a few eV, anions can be efficiently photo-detached in the vicinity of the fusion chamber, with the resulting high-velocity neutral projectiles following ballistic trajectories towards the hydrogen pellet target. Electron-detachment cross sections are needed as parameters to estimate the beam attenuation in the path from the ion source to the hydrogen pellet. Halogen anions are possible projectile choices. In this paper we present experimental data for total electron-detachment cross sections for F-, Cl-, Br- and I- ions incident on N2, in the 0.94-74 keV u-1 energy range. Our measurements can benchmark theory on anion electron detachment at intermediate to high velocities. Comparison between different projectiles shows very similar collision velocity dependencies. A simple geometrical scaling is presented, providing an estimate for electron-detachment cross sections at the MeV u-1 energy range. The presented scaling indicates that the vacuum requirements due to the use of halogen anions for ICF are less critical than previously suggested.

Electron-detachment cross sections of halogen negative-ion projectiles for inertial confinement fusion

International Nuclear Information System (INIS)

Sant'Anna, M M; Zappa, F; Santos, A C F; Barros, A L F de; Wolff, W; Coelho, L F S; Faria, N V de Castro

2004-01-01

Negative-ion beams have recently been suggested as sources of high-energy heavy atoms to be used as drivers for inertial confinement fusion (ICF). Owing to their electron affinities limited to a few eV, anions can be efficiently photo-detached in the vicinity of the fusion chamber, with the resulting high-velocity neutral projectiles following ballistic trajectories towards the hydrogen pellet target. Electron-detachment cross sections are needed as parameters to estimate the beam attenuation in the path from the ion source to the hydrogen pellet. Halogen anions are possible projectile choices. In this paper we present experimental data for total electron-detachment cross sections for F - , Cl - , Br - and I - ions incident on N 2 , in the 0.94-74 keV u -1 energy range. Our measurements can benchmark theory on anion electron detachment at intermediate to high velocities. Comparison between different projectiles shows very similar collision velocity dependencies. A simple geometrical scaling is presented, providing an estimate for electron-detachment cross sections at the MeV u -1 energy range. The presented scaling indicates that the vacuum requirements due to the use of halogen anions for ICF are less critical than previously suggested

The P2Y12 Receptor Antagonist Ticagrelor Reduces Lysosomal pH and Autofluorescence in Retinal Pigmented Epithelial Cells From the ABCA4-/- Mouse Model of Retinal Degeneration

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Wennan Lu

2018-04-01

Full Text Available The accumulation of partially degraded lipid waste in lysosomal-related organelles may contribute to pathology in many aging diseases. The presence of these lipofuscin granules is particularly evident in the autofluorescent lysosome-associated organelles of the retinal pigmented epithelial (RPE cells, and may be related to early stages of age-related macular degeneration. While lysosomal enzymes degrade material optimally at acidic pH levels, lysosomal pH is elevated in RPE cells from the ABCA4-/- mouse model of Stargardt’s disease, an early onset retinal degeneration. Lowering lysosomal pH through cAMP-dependent pathways decreases accumulation of autofluorescent material in RPE cells in vitro, but identification of an appropriate receptor is crucial for manipulating this pathway in vivo. As the P2Y12 receptor for ADP is coupled to the inhibitory Gi protein, we asked whether blocking the P2Y12 receptor with ticagrelor could restore lysosomal acidity and reduce autofluorescence in compromised RPE cells from ABCA4-/- mice. Oral delivery of ticagrelor giving rise to clinically relevant exposure lowered lysosomal pH in these RPE cells. Ticagrelor also partially reduced autofluorescence in the RPE cells of ABCA4-/- mice. In vitro studies in ARPE-19 cells using more specific antagonists AR-C69931 and AR-C66096 confirmed the importance of the P2Y12 receptor for lowering lysosomal pH and reducing autofluorescence. These observations identify P2Y12 receptor blockade as a potential target to lower lysosomal pH and clear lysosomal waste in RPE cells.

Phototherapeutic LASEK for a persistent epithelial defect and a recurrent epithelial erosion.

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Hondur, Ahmet; Bilgihan, Kamil; Hasanreisoglu, Berati

2005-01-01

To present two patients, one with persistent epithelial defect and one with recurrent epithelial erosion, unresponsive to conventional therapy treated with phototherapeutic keratectomy (PTK) with the laser subepithelial keratomileusis (LASEK) technique (phototherapeutic LASEK). The epithelial flap was created following 18% ethanol application for 20 seconds. A 10-microm deep ablation was performed in the central 7.0-mm zone. A contact lens was placed and the patient examined daily until epithelial closure. Upon epithelial closure, the contact lens was removed. A mild topical steroid and artificial tears were applied for 2 weeks. The epithelium healed in 4 days in both patients. Patients reported only mild pain until epithelial closure. The manifest refraction and uncorrected visual acuity remained unchanged in both eyes. No haze was noted. The first patient has remained asymptomatic without any recurrence for 12 months, and the second for 9 months. Phototherapeutic LASEK provides a therapeutic option for refractory recurrent erosions and persistent epithelial defects, with the additional benefit of being less painful and less risky for haze development than conventional PTK.

A molecular investigation of adsorption onto mineral pigments

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Ninness, Brian J.

Pigment suspensions are important in several processes such as ceramics, paints, inks, and coatings. In the wet state, pigments are combined with a variety of chemical species such as polymers, surfactants, and polyelectrolytes which produce a complex colloidal system. The adsorption, desorption, and redistribution of these species at the pigment-aqueous solution interface can have an impact on the behavior in both the wet state or its final dried state. The goal of this work is to establish a molecular picture of the adsorption properties of these pigmented systems. A novel in situ infrared technique has been developed which allows the detection of adsorbed surface species on pigment particles in an aqueous environment. The technique involves the use of a polymeric binder to anchor the colloidal pigment particles to the surface of an internal reflection element (IRE). The binder only weakly perturbs about 25% of the reactive surface sites (hydroxyl groups) on silica. The reaction of succinic anhydride with an aminosilanized silica surface has been quantified using this technique. The adsorption dynamics of the cationic surfactant cetyltrimethylammonium bromide (C16TAB) at the TiO2-aqueous solution interface has been investigated using Fourier transform infrared-attenuated total reflection spectroscopy (FTIR-ATR) and electrokinetic analysis. At low bulk concentrations, C16TAB is shown to adsorb as isolated islands with a "defective" bilayer structure. Anionic probe molecules are shown to effectively "tune" the adsorbed surfactant microstructure. The results indicate that the structure of the adsorbed surfactant layer, and not the amount of adsorbed surfactant, dictates the subsequent adsorption behavior of the system. Atomic Layer Deposition is used to deposit a TiO2 layer onto the surfaces of silica and kaolin pigments. The process involves the cyclic reaction sequence of the vapors of TiCl4 and H2O. Three complete deposition cycles are needed before the surfaces

Electron detachment by H- + H- collisions

International Nuclear Information System (INIS)

Chibisov, M.I.; Yavlinskii, Yu.N.

1994-01-01

The autoionization channels for electrons detachment in collisions of two negative hydrogen ions in the energy range 300 - 500 eV and > 500 eV are investigated. In small energy range at large inter-ion distances the asymptotic approximation is used; at high energies - perturbation theory and classical motion are used. 18 refs., 3 figs

Pigment and terracotta analyses of Hellenistic figurines in Crete

International Nuclear Information System (INIS)

Maravelaki-Kalaitzaki, P.; Kallithrakas-Kontos, N.

2003-01-01

The results of the analyses performed on blue, black, brown, orange, white and purple pigments decorating Hellenistic figurines, excavated in a rock-cut tomb in the archaeological zone of Chania, Crete, Greece, are presented. Different spectroscopic techniques, such as Fourier transform infrared spectroscopy and energy dispersive X-ray fluorescence identified the compounds present in the chromatic layers. X-ray diffraction analysis gave complementary information and further support to the spectral assignments. Optical microscopy revealed the nature and sequence of the pigmented layer on the terracotta. Several precious pigments, such as Egyptian blue for the bluish areas, Tyrian purple for the purple ones, and the rare huntite for the white-pigmented areas were identified among the studied pigmented areas. The pigment analysis provides information on the technical aspects related to terracotta manufacture and preservation, and promotes historical indications on cultural and commercial changes among the Mediterranean civilisations

The gecko visual pigment: the anion hypsochromic effect.

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Crescitelli, F; Karvaly, B

1991-01-01

The 521-pigment in the retina of the Tokay gecko (Gekko gekko) readily responds to particular physical and chemical changes in its environment. When solubilized in chloride deficient state the addition of Class I anions (Cl-, Br-) induces a bathochromic shift of the absorption spectrum. Class II anions (NO3-, IO3-, N3-, OCN-, SCN-, SeCN-, N(CN)2-), which exhibit ambidental properties, cause an hypsochromic shift. Class III anions (F-, I-, NO2-, CN-, AsO3-, SO2(4-), S2O2(3-) have no spectral effect on the 521-pigment. Cations appear to have no influence on the pigment absorption and Class I anions prevent or reverse the hypsochromic shift caused by Class II anions. It is suggested that the spectral displacements reflect specific changes in the opsin conformation, which alter the immediate (dipolar) environment of the retinal chromophore. The protein conformation seems to promote excited-state processes most in the native 521-pigment state and least in the presence of Class II anions. This in turn suggests that the photosensitivity of the 521-pigment is controlled by the excited rather than by the ground-state properties of the pigment.

Prophylactic treatment of the fellow eye of patients with retinal detachment: a retrospective study.

Science.gov (United States)

Avitabile, Teresio; Bonfiglio, Vincenza; Reibaldi, Michele; Torrisi, Benedetto; Reibaldi, Alfredo

2004-03-01

Controversy exists over the prophylactic treatment of predisposing lesions to prevent retinal detachment. Seven hundred sixty consecutive phakic fellow eyes with rhegmatogenous retinal detachment in the first eye were examined by the same vitreoretinal surgeon before detachment surgery and for a follow-up period ranging from 1 to 72 months, with a mean of 36 months. During this period, in 305 fellow eyes (40.1%) predisposing retinal lesions were present and prophylactic treatments (photocoagulation, cryotherapy or scleral buckle) were performed independently of vitreous status. The results were then compared with the incidence of bilateral RD without prophylaxis reported in Folk and Burton's study of 1982; the two study's data were well matched and showed no significant difference in regards to age, sex, incidence myopia > or =-2.5 and incidence of lattice degeneration. The objective was to investigate whether or not prophylactic treatment is able to avert retinal detachment in the fellow eye. The age of the patients with peripheral retinal lesions was correlated inversely with the presence of myopia. Nine eyes out of 305 eyes treated (2.9%) developed a retinal detachment, reducing the rate of bilateral retinal detachment to 1.2% (9 eyes out of 760). This incidence of bilaterality (1.2%) was lower than the incidence of retinal detachment in fellow eyes not prophylactically treated as reported in the literature, and there exists a highly statistically significant difference between this study's data of 1.2% after prophylaxis and a 13.4% rate of bilaterality as reported by Folk without prophylaxis (P=0.0000).

iTRAQ Quantitative Proteomic Analysis of Vitreous from Patients with Retinal Detachment

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Fátima Milhano Santos

2018-04-01

Full Text Available Rhegmatogenous retinal detachment (RRD is a potentially blinding condition characterized by a physical separation between neurosensory retina and retinal pigment epithelium. Quantitative proteomics can help to understand the changes that occur at the cellular level during RRD, providing additional information about the molecular mechanisms underlying its pathogenesis. In the present study, iTRAQ labeling was combined with two-dimensional LC-ESI-MS/MS to find expression changes in the proteome of vitreous from patients with RRD when compared to control samples. A total of 150 proteins were found differentially expressed in the vitreous of patients with RRD, including 96 overexpressed and 54 underexpressed. Several overexpressed proteins, several such as glycolytic enzymes (fructose-bisphosphate aldolase A, gamma-enolase, and phosphoglycerate kinase 1, glucose transporters (GLUT-1, growth factors (metalloproteinase inhibitor 1, and serine protease inhibitors (plasminogen activator inhibitor 1 are regulated by HIF-1, which suggests that HIF-1 signaling pathway can be triggered in response to RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Nevertheless, the differentially expressed proteins found in this study suggest that different mechanisms are activated after RRD to promote the survival of retinal cells through complex cellular responses.

Meniscus Shapes in Detached Bridgman Growth

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Volz, M. P.; Mazuruk, K

2010-01-01

In detached Bridgman crystal growth, most of the melt is in contact with the ampoule wall, but the crystal is separated from the wall by a small gap, typically 1-100 micrometers. A liquid free surface, or meniscus, bridges across this gap at the position of the melt-crystal interface. Meniscus shapes have been calculated for the case of detached Bridgman growth in cylindrical ampoules by solving the Young-Laplace equation. Key parameters affecting meniscus shapes are the growth angle, contact angle of the meniscus to the ampoule wall, the pressure differential across the meniscus, and the Bond number, a measure of the ratio of gravitational to capillary forces. In general, for specified values of growth and contact angles, solutions exist only over a finite range of pressure differentials. For intermediate values of the Bond number, there are multiple solutions to the Young-Laplace equations. There are also cases where, as a function of pressure differential, existence intervals alternate with intervals where no solutions exist. The implications of the meniscus shape calculations on meniscus stability are discussed.

Activated Retinal Pigment Epithelium, an Optical Coherence Tomography Biomarker for Progression in Age-Related Macular Degeneration

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Curcio, Christine A.; Zanzottera, Emma C.; Ach, Thomas; Balaratnasingam, Chandrakumar; Freund, K. Bailey

2017-01-01

Purpose To summarize and contextualize recent histology and clinical imaging publications on retinal pigment epithelium (RPE) fate in advanced age-related macular degeneration (AMD); to support RPE activation and migration as important precursors to atrophy, manifest as intraretinal hyperreflective foci in spectral-domain optical coherence tomography (SDOCT). Methods The Project MACULA online resource for AMD histopathology was surveyed systematically to form a catalog of 15 phenotypes of RPE and RPE-derived cells and layer thicknesses in advanced disease. Phenotypes were also sought in correlations with clinical longitudinal eye-tracked SDOCT and with ex vivo imaging–histopathology correlations in geographic atrophy (GA) and pigment epithelium detachments (PED). Results The morphology catalog suggested two main pathways of RPE fate: basolateral shedding of intracellular organelles (apparent apoptosis in situ) and activation with anterior migration. Acquired vitelliform lesions may represent a third pathway. Migrated cells are packed with RPE organelles and confirmed as hyperreflective on SDOCT. RPE layer thickening due to cellular dysmorphia and thick basal laminar deposit is observed near the border of GA. Drusenoid PED show a life cycle of slow growth and rapid collapse preceded by RPE layer disruption and anterior migration. Conclusions RPE activation and migration comprise an important precursor to atrophy that can be observed at the cellular level in vivo via validated SDOCT. Collapse of large drusen and drusenoid PED appears to occur when RPE death and migration prevent continued production of druse components. Data implicate excessive diffusion distance from choriocapillaris in RPE death as well as support a potential benefit in targeting drusen in GA. PMID:28785769

Antimicrobial activity of Micrococcus luteus Cartenoid pigment

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Huda Z. Majeed

2017-11-01

Full Text Available Cartenoids are group of pigments, with enormous types different structurally and functionally, have colors range from red to yellow found in a wide variety of plants, fungi, algae and bacteria. The animals took from food because they cannot make it, on contrary, the plants and microbes produce them due to subjection to environment. The aim of the study is to isolate and characterize the cartenoid pigment from Micrococcus luteus. The pigment extraction was done by acetone, and then was characterized with UltraViolet-Visible spectroscopy (UV–Vis and Fourier Transform Infrared (FTIR spectroscopy. Then, it was tested for antibacterial activity against five different bacterial isolates and antifungal activity tests against six different fungal isolates by well diffusion method. The results found that, the extracted pigment having antibacterial activity and antifungal activity and having the ability to absorb UVA rays within the range of 300-500 nm. There was no significant difference in antimicrobial effect of pigment, even when the extraction and isolation were done by two culture mediums (Nutrient Broth and Luria Bertani Broth. There were considerable inhibition percentages of adhesion after subjection to Cartenoid pigment ranged between (5.71, 23.84 % for Klebsiella spp. and Pseudomonas aeruginosa respectively and all the 11 isolate changed from Biofilm producer to non-producer. The isolated compound can be used against different bacterial and fungal infections. So they had a great future in medicine, cosmetics and as a sun protecting agent.

An Unusual Case of Extensive Lattice Degeneration and Retinal Detachment.

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Mathew, David J; Sarma, Saurabh Kumar; Basaiawmoit, Jennifer V

2016-07-01

Lattice degeneration of the retina is not infrequently encountered on a dilated retinal examination and many of them do not need any intervention. We report a case of atypical lattice degeneration variant with peripheral retinal detachment. An asymptomatic 35-year-old lady with minimal refractive error was found to have extensive lattice degeneration, peripheral retinal detachment and fibrotic changes peripherally with elevation of retinal vessels on dilated retinal examination. There were also areas of white without pressure, chorioretinal scarring and retinal breaks. All the changes were limited to beyond the equator but were found to span 360 degrees. She was treated with barrage laser all around to prevent extension of the retinal detachment posteriorly. She remained stable till her latest follow-up two years after the barrage laser. This case is reported for its rarity with a discussion of the probable differential diagnoses. To the best of our knowledge, this is the first report of such findings in lattice degeneration.

Intraclutch variation in avian eggshell pigmentation: the anaemia hypothesis.

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De Coster, Greet; De Neve, Liesbeth; Lens, Luc

2012-10-01

Many passerine species lay eggs that are speckled with dark protoporphyrin pigmentation. Because protoporphyrin is mainly derived from the blood, we here formulate and test a new hypothesis that links an increase in anaemia along the laying sequence to within-clutch variation in egg pigmentation. More intense pigmentation is expected if pigments accumulate during enhanced red blood cell production in response to anaemia. Reduced pigmentation is expected if pigments are derived from the degradation of red blood cells that circulate in smaller numbers due to blood loss. To test this hypothesis, we manipulated anaemia in great tit (Parus major) females by infesting the nests with hen fleas (Ceratophyllus gallinae) prior to egg laying. Polychromatophil (i.e., immature red blood cells) percentage, as a measure of blood cell production, was positively correlated with parasite load confirming that female great tits experienced stronger anaemia when infested with haematophagous parasites during egg laying. We found a positive relationship between spot darkness and laying order that weakened under high parasite load. This result suggests that anaemia in females due to blood-sucking parasites led to diminished protoporphyrin from disintegrated red blood cells and hence a decreased deposition of protoporphyrin. However, the overall increase in pigment darkness along the laying sequence suggests that pigments also accumulate by enhanced red blood cell production caused by anaemia due to egg production itself.

Psychological detachment from work during non-work time: linear or curvilinear relations with mental health and work engagement?

Science.gov (United States)

Shimazu, Akihito; Matsudaira, Ko; Jonge, Jan DE; Tosaka, Naoya; Watanabe, Kazuhiro; Takahashi, Masaya

2016-06-10

This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental health, and work engagement as well as for job characteristics and demographic variables as potential confounders. The hypothesized model was tested with moderated structural equation modeling techniques among 2,234 respondents working in the tertiary industries with regular employment. Results showed that psychological detachment had curvilinear relations with mental health as well as with work engagement. Mental health improved when psychological detachment increased from a low to higher levels but did not benefit any further from extremely high levels of psychological detachment. Work engagement showed the highest level at an intermediate level of detachment (inverted U-shaped pattern). Although high psychological detachment may enhance employee mental health, moderate levels of psychological detachment are most beneficial for his or her work engagement.

Multiscale Pigment Analysis of Medieval Illuminated Manuscripts

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Sestak, Erica; Manukyan, Khachatur; Wiescher, Michael; Gura, David

2017-09-01

Three medieval illuminated manuscripts (codd. Lat. b. 1; Lat. b. 2; Lat. e. 4), housed at the University of Notre Dame's Hesburgh Library, vary in style, pigments, scribes, and regions, despite all three being Psalters used in the Late Middle Ages. XRF and Raman spectroscopy, which provided the elemental and molecular composition of the pigments, respectively, were used to analyze the pigments' compositions in an attempt to narrow further the manuscripts' possible origins. This experimental investigation emphasizes the importance of understanding the history of the manuscript through their pigments. Codd. Lat. b. 1 and Lat. b. 2 are Latinate German Psalters from the fifteenth century likely used in Katharinenkloster in Nuremberg. While there are visible differences in style within each Psalter, the variations in some of the pigment compositions, such as the inconstant presence of zinc, suggest different admixtures. Cod. Lat. e. 4 is a Latinate English Psalter from the fourteenth century, and it was written by two scribes and illuminated by two distinct painters. It is currently being tested to determine whether there are any correlations between the scribes and painters. These physical analyses will clarify the origins and provenances of the manuscripts.

Corrosion inhibition by lithium zinc phosphate pigment

International Nuclear Information System (INIS)

Alibakhshi, E.; Ghasemi, E.; Mahdavian, M.

2013-01-01

Highlights: •Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method. •Corrosion inhibition activity of pigments compare with zinc phosphate (ZP). •LZP showed superior corrosion inhibition effect in EIS measurements. •Evaluation of adhesion strength and dispersion stability. -- Abstract: Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP

Differences in pigmentation between life cycle stages in Scrippsiella lachrymosa (dinophyceae).

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Persson, Agneta; Smith, Barry C; Cyronak, Tyler; Cooper, Emily; DiTullio, Giacomo R

2016-02-01

Various life cycle stages of cyst-producing dinoflagellates often appear differently colored under the microscope; gametes appear paler while zygotes are darker in comparison to vegetative cells. To compare physiological and photochemical competency, the pigment composition of discrete life cycle stages was determined for the common resting cyst-producing dinoflagellate Scrippsiella lachrymosa. Vegetative cells had the highest cellular pigment content (25.2 ± 0.5 pg · cell(-1) ), whereas gamete pigment content was 22% lower. The pigment content of zygotes was 82% lower than vegetative cells, even though they appeared darker under the microscope. Zygotes of S. lachrymosa contained significantly higher cellular concentrations of β-carotene (0.65 ± 0.15 pg · cell(-1) ) than all other life stages. Photoprotective pigments and the de-epoxidation ratio of xanthophylls-cycle pigments in S. lachrymosa were significantly elevated in zygotes and cysts compared to other stages. This suggests a role for accessory pigments in combating intracellular oxidative stress during sexual reproduction or encystment. Resting cysts contained some pigments even though chloroplasts were not visible, suggesting that the brightly colored accumulation body contained photosynthetic pigments. The differences in pigmentation between life stages have implications for interpretation of pigment data from field samples when sampled during dinoflagellate blooms. © 2015 Phycological Society of America.

Detachment dynamics of colloidal spheres with adhesive interactions

Science.gov (United States)

Bergenholtz, J.

2018-04-01

Escape of colloidal-size particles from various kinds of solids, such as aggregates and surfaces, occurs in a wide variety of settings of both fundamental and applied scientific interest. In this paper an exact solution for the detachment of adhesive spheres from each other by means of diffusion is presented. The solution takes into account repeated detachment and reattachment events in the course of time on the way toward the permanently separated state. For strongly adhesive spheres this state is approached in an exponential manner essentially regardless of how the bound state is specified. The analytical solution is shown to capture semiquantitatively the escape from more realistic potential wells using a mapping procedure whereby equality of second virial coefficients is imposed.

Variations of posterior vitreous detachment

OpenAIRE

Kakehashi, A.; Kado, M.; Akiba, J.; Hirokawa, H.

1997-01-01

AIMS—To identify variations in posterior vitreous detachment (PVD) and establish a clinical classification system for PVD.
METHODS—400 consecutive eyes were examined using biomicroscopy and vitreous photography and classified the PVD variations—complete PVD with collapse, complete PVD without collapse, partial PVD with thickened posterior vitreous cortex (TPVC), or partial PVD without TPVC.
RESULTS—In each PVD type, the most frequently seen ocular pathologies were as follows: in complete PVD ...

Fe K-edge XANES of Maya blue pigment

Science.gov (United States)

Río, M. Sánchez del; Sodo, A.; Eeckhout, S. G.; Neisius, T.; Martinetto, P.; Dooryhée, E.; Reyes-Valerio, C.

2005-08-01

The utilization of techniques used in Materials Science for the characterization of artefacts of interest for cultural heritage is getting more and more attention nowadays. One of the products of the ancient Maya chemistry is the "Maya blue" pigment, made with natural indigo and palygorskite. This pigment is different from any other pigment used in other parts of the world. It is durable and acid-resistant, and still keeps many secrets to scientists even though it has been studied for more than 50 years. Although the pigment is basically made of palygorskite Si8(Mg2Al2)O20(OH)2(OH2)4.4H2O and an organic colourant (indigo: C16H10N2O2), a number of other compounds have been found in previous studies on archaeological samples, like other clays and minerals, iron nanoparticles, iron oxides, impurities of transition metals (Cr, Mn, Ti, V), etc. We measured at the ESRF ID26 beamline the Fe K-edge XANES spectra of the blue pigment in ancient samples. They are compared to XANES spectra of Maya blue samples synthesized under controlled conditions, and iron oxides usually employed as pigments (hematite and goethite). Our results show that the iron found in ancient Maya blue pigment is related to the Fe exchanged in the palygorskite clay. We did not find iron in metallic form or goethite in archaeological Maya blue.