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https://www.readbyqxmd.com/read/28817571/automated-segmentation-of-mouse-oct-volumes-asimov-validation-clinical-study-of-a-light-damage-model
#1
Bhavna Josephine Antony, Byung-Jin Kim, Andrew Lang, Aaron Carass, Jerry L Prince, Donald J Zack
The use of spectral-domain optical coherence tomography (SD-OCT) is becoming commonplace for the in vivo longitudinal study of murine models of ophthalmic disease. Longitudinal studies, however, generate large quantities of data, the manual analysis of which is very challenging due to the time-consuming nature of generating delineations. Thus, it is of importance that automated algorithms be developed to facilitate accurate and timely analysis of these large datasets. Furthermore, as the models target a variety of diseases, the associated structural changes can also be extremely disparate...
2017: PloS One
https://www.readbyqxmd.com/read/28816864/increased-photoreceptor-outer-segment-volume-following-systemic-treatment-of-birdshot-chorioretinopathy
#2
Gavin Docherty, Rosanna Martens, Farzin Forooghian
PURPOSE: Retinal degeneration in birdshot chorioretinopathy can be quantified using spectral domain optical coherence tomography by measuring the photoreceptor outer segment (PROS) volume. The purpose of this study was to determine if the PROS volume in BSCR responds to systemic immunomodulatory therapy (IMT). METHODS: Retrospective chart review with analysis of PROS volume derived from spectral domain optical coherence tomography. RESULTS: We identified a total of three patients who met our inclusion criteria...
August 14, 2017: Retinal Cases & Brief Reports
https://www.readbyqxmd.com/read/28815590/juxtanodin-in-retinal-pigment-epithelial-cells-expression-and-biological-activities-in-regulating-cell-morphology-and-actin-cytoskeleton-organization
#3
Fengyi Liang, Ji Hyun Hwang, Nicholas Weiwei Tang, Walter Hunziker
Juxtanodin (also known as ermin) was initially identified as an actin cytoskeleton-related oligodendroglial protein in the rat central nervous system. It was subsequently also found in the rat olfactory neuroepithelium, especially at the apical junctional belt of the sustentacular cells. We further examined juxtanodin expression and functional roles in the retina using fluorescence histochemistry, confocal microscopy, immuno-electron microscopy, molecular biology and cell culture. Prominent juxtanodin expression was found in the photoreceptor-supporting retinal pigment epithelium (RPE), especially in a zone corresponding to the apices of RPE cells, at the roots of the RPE microvilli, and at the base of RPE cells next to the Bruch's membrane...
August 17, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/28814779/the-beach-protein-lrba-promotes-the-localization-of-the-heterotrimeric-g-protein-golf-to-olfactory-cilia
#4
Stefan Kurtenbach, Andreas Gießl, Siv Strömberg, Jan Kremers, Jenny Atorf, Sebastian Rasche, Eva M Neuhaus, Denis Hervé, Johann Helmut Brandstätter, Esther Asan, Hanns Hatt, Manfred W Kilimann
BEACH domain proteins are involved in membrane protein traffic and human diseases, but their molecular mechanisms are not understood. The BEACH protein LRBA has been implicated in immune response and cell proliferation, and human LRBA mutations cause severe immune deficiency. Here, we report a first functional and molecular phenotype outside the immune system of LRBA-knockout mice: compromised olfaction, manifesting in reduced electro-olfactogram response amplitude, impaired food-finding efficiency, and smaller olfactory bulbs...
August 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28814713/gelsolin-dysfunction-causes-photoreceptor-loss-in-induced-pluripotent-cell-and-animal-retinitis-pigmentosa-models
#5
Roly Megaw, Hashem Abu-Arafeh, Melissa Jungnickel, Carla Mellough, Christine Gurniak, Walter Witke, Wei Zhang, Hemant Khanna, Pleasantine Mill, Baljean Dhillon, Alan F Wright, Majlinda Lako, Charles Ffrench-Constant
Mutations in the Retinitis Pigmentosa GTPase Regulator (RPGR) cause X-linked RP (XLRP), an untreatable, inherited retinal dystrophy that leads to premature blindness. RPGR localises to the photoreceptor connecting cilium where its function remains unknown. Here we show, using murine and human induced pluripotent stem cell models, that RPGR interacts with and activates the actin-severing protein gelsolin, and that gelsolin regulates actin disassembly in the connecting cilium, thus facilitating rhodopsin transport to photoreceptor outer segments...
August 16, 2017: Nature Communications
https://www.readbyqxmd.com/read/28813718/transgenic-mice-over-expressing-rbp4-have-rbp4-dependent-and-light-independent-retinal-degeneration
#6
Mei Du, Eric Phelps, Michael J Balangue, Aaron Dockins, Gennadiy Moiseyev, Younghwa Shin, Shelley Kane, Laura Otalora, Jian-Xing Ma, Rafal Farjo, Krysten M Farjo
Purpose: Transgenic mice overexpressing serum retinol-binding protein (RBP4-Tg) develop progressive retinal degeneration, characterized by microglia activation, yet the precise mechanisms underlying retinal degeneration are unclear. Previous studies showed RBP4-Tg mice have normal ocular retinoid levels, suggesting that degeneration is independent of the retinoid visual cycle or light exposure. The present study addresses whether retinal degeneration is light-dependent and RBP4-dependent by testing the effects of dark-rearing and pharmacological lowering of serum RBP4 levels, respectively...
August 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28812418/neurotoxicity-of-cgmp-in-the-vertebrate-retina-from-the-initial-research-on-rd-mutant-mice-to-zebrafish-genetic-approaches
#7
Maria Iribarne, Ichiro Masai
Zebrafish are an excellent animal model for research on vertebrate development and human diseases. Sophisticated genetic tools including large-scale mutagenesis methodology make zebrafish useful for studying neuronal degenerative diseases. Here, we review zebrafish models of inherited ophthalmic diseases, focusing on cGMP metabolism in photoreceptors. cGMP is the second messenger of phototransduction, and abnormal cGMP levels are associated with photoreceptor death. cGMP concentration represents a balance between cGMP phosphodiesterase 6 (PDE6) and guanylate cyclase (GC) activities in photoreceptors...
August 16, 2017: Journal of Neurogenetics
https://www.readbyqxmd.com/read/28810713/co-opted-megasatellite-dna-drives-evolution-of-secondary-night-vision-in-azara-s-owl-monkey
#8
Akihiko Koga, Hideyuki Tanabe, Yuriko Hirai, Hiroo Imai, Masanori Imamura, Takao Oishi, Roscoe Stanyon, Hirohisa Hirai
Owl monkeys (genus Aotus) are the only taxon in simian primates that consists of nocturnal or otherwise cathemeral species. Their night vision is superior to that of other monkeys, apes, and humans but not as good as that of typical nocturnal mammals. This incomplete night vision has been used to conclude that these monkeys only secondarily adapted to a nocturnal lifestyle, or to their cathemeral lifestyle that involves high night-time activity. It is known that the rod cells of many nocturnal mammals possess a unique nuclear architecture in which heterochromatin is centrally located...
July 1, 2017: Genome Biology and Evolution
https://www.readbyqxmd.com/read/28809958/a-cre1-regulated-cluster-is-responsible-for-light-dependent-production-of-dihydrotrichotetronin-in-trichoderma-reesei
#9
Alberto Alonso Monroy, Eva Stappler, Andre Schuster, Michael Sulyok, Monika Schmoll
Changing light conditions, caused by the rotation of earth resulting in day and night or growth on the surface or within a substrate, result in considerably altered physiological processes in fungi. For the biotechnological workhorse Trichoderma reesei, regulation of glycoside hydrolase gene expression, especially cellulase expression was shown to be a target of light dependent gene regulation. Analysis of regulatory targets of the carbon catabolite repressor CRE1 under cellulase inducing conditions revealed a secondary metabolite cluster to be differentially regulated in light and darkness and by photoreceptors...
2017: PloS One
https://www.readbyqxmd.com/read/28809044/shining-new-light-into-the-workings-of-photoreceptors-and-visual-interneurons
#10
EDITORIAL
Zhuoyi Song, Mikko Juusola
No abstract text is available yet for this article.
August 15, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28808926/foveal-microstructure-analysis-in-eyes-with-diabetic-macular-edema-treated-with-vitrectomy
#11
Jiro Kogo, Akira Shiono, Hiroki Sasaki, Ryo Yomoda, Tatsuya Jujo, Yasushi Kitaoka, Hitoshi Takagi
INTRODUCTION: The purpose of this study was to evaluate baseline and postoperative factors affecting outcomes after vitrectomy for diabetic macular edema (DME) using optical coherence tomography (OCT). METHODS: Vitrectomy combined with inner limiting membrane (ILM) peeling and additional laser photocoagulation therapy was performed on 36 eyes of 30 DME patients. Evaluations included the logarithm of the minimal angle of resolution (logMAR), best-corrected visual acuity (BCVA) and OCT parameters at baseline and 1, 3, 6, and 12 months postoperatively...
August 14, 2017: Advances in Therapy
https://www.readbyqxmd.com/read/28807567/a-new-promoter-allows-optogenetic-vision-restoration-with-enhanced-sensitivity-in-macaque-retina
#12
Antoine Chaffiol, Romain Caplette, Céline Jaillard, Elena Brazhnikova, Mélissa Desrosiers, Elisabeth Dubus, Laëtitia Duhamel, Emilie Macé, Olivier Marre, Patrick Benoit, Philippe Hantraye, Alexis-Pierre Bemelmans, Ernst Bamberg, Jens Duebel, José-Alain Sahel, Serge Picaud, Deniz Dalkara
The majority of inherited retinal degenerations converge on the phenotype of photoreceptor cell death. Second- and third-order neurons are spared in these diseases, making it possible to restore retinal light responses using optogenetics. Viral expression of channelrhodopsin in the third-order neurons under ubiquitous promoters was previously shown to restore visual function, albeit at light intensities above illumination safety thresholds. Here, we report (to our knowledge, for the first time) activation of macaque retinas, up to 6 months post-injection, using channelrhodopsin-Ca(2+)-permeable channelrhodopsin (CatCh) at safe light intensities...
July 20, 2017: Molecular Therapy: the Journal of the American Society of Gene Therapy
https://www.readbyqxmd.com/read/28806446/sema3a-reduces-sprouting-of-adult-rod-photoreceptors-in-vitro
#13
Frank Kung, Weiwei Wang, Tracy S Tran, Ellen Townes-Anderson
Purpose: Rod photoreceptor terminals respond to retinal injury with retraction and sprouting. Since the guidance cue Semaphorin3A (Sema3A) is observed in the retina after injury, we asked whether Sema3A contributes to structural plasticity in rod photoreceptors. Methods: We used Western blots and alkaline phosphatase (AP)-tagged neuropilin-1 (NPN-1) to detect the expression of Sema3A in an organotypic model of porcine retinal detachment. We then examined Sema3A binding to cultured salamander rod photoreceptors using AP-tagged Sema3A...
August 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28806173/the-%C3%AE-alanine-transporter-balat-is-required-for-visual-neurotransmission-in-drosophila
#14
Yongchao Han, Liangyao Xiong, Ying Xu, Tian Tian, Tao Wang
The recycling of neurotransmitters is essential for sustained synaptic transmission. In Drosophila, histamine recycling is required for visual synaptic transmission. Synaptic histamine is rapidly taken up by laminar glia, and is converted to carcinine. After delivered back to photoreceptors, carcinine is hydrolyzed to release histamine and β-alanine. This histamine is repackaged into synaptic vesicles, but it is unclear how the β-alanine is returned to the laminar glial cells. Here, we identified a new β-alanine transporter, which we named BalaT (Beta-alanine Transporter)...
August 14, 2017: ELife
https://www.readbyqxmd.com/read/28805249/a-non-dna-binding-activity-for-the-athb4-transcription-factor-in-the-control-of-vegetation-proximity
#15
Marçal Gallemí, Maria Jose Molina-Contreras, Sandi Paulišić, Mercè Salla-Martret, Céline Sorin, Marta Godoy, Jose Manuel Franco-Zorrilla, Roberto Solano, Jaime F Martínez-García
In plants, perception of vegetation proximity by phytochrome photoreceptors activates a transcriptional network that implements a set of responses to adapt to plant competition, including elongation of stems or hypocotyls. In Arabidopsis thaliana, the homeodomain-leucine zipper (HD-Zip) transcription factor ARABIDOPSIS THALIANA HOMEOBOX 4 (ATHB4) regulates this and other responses, such as leaf polarity. To better understand the shade regulatory transcriptional network, we have carried out structure-function analyses of ATHB4 by overexpressing a series of truncated and mutated forms and analyzing three different responses: hypocotyl response to shade, transcriptional activity and leaf polarity...
August 14, 2017: New Phytologist
https://www.readbyqxmd.com/read/28801634/mapping-physiological-inputs-from-multiple-photoreceptor-systems-to-dopaminergic-amacrine-cells-in-the-mouse-retina
#16
Xiwu Zhao, Kwoon Y Wong, Dao-Qi Zhang
In the vertebrate retina, dopamine is synthesized and released by a specialized type of amacrine cell, the dopaminergic amacrine cell (DAC). DAC activity is stimulated by rods, cones, and melanopsin-expressing intrinsically photosensitive retinal ganglion cells upon illumination. However, the relative contributions of these three photoreceptor systems to the DAC light-induced response are unknown. Here we found that rods excite dark-adapted DACs across a wide range of stimulation intensities, primarily through connexin-36-dependent rod pathways...
August 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28801351/calcium-induced-calpain-mediates-apoptosis-via-caspase-3-in-a-mouse-photoreceptor-cell-line
#17
Ashish K Sharma, Baerbel Rohrer
No abstract text is available yet for this article.
August 11, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28800629/protective-effects-on-the-retina-after-ranibizumab-treatment-in-an-ischemia-model
#18
Stephanie C Joachim, Marina Renner, Jacqueline Reinhard, Carsten Theiss, Caroline May, Stephanie Lohmann, Sabrina Reinehr, Gesa Stute, Andreas Faissner, Katrin Marcus, H Burkhard Dick
Retinal ischemia is common in eye disorders, like diabetic retinopathy or retinal vascular occlusion. The goal of this study was to evaluate the potential protective effects of an intravitreally injected vascular endothelial growth factor (VEGF) inhibitor (ranibizumab) on retinal cells in an ischemia animal model via immunohistochemistry (IF) and quantitative real-time PCR (PCR). A positive binding of ranibizumab to rat VEGF-A was confirmed via dot blot. One eye underwent ischemia and a subgroup received ranibizumab...
2017: PloS One
https://www.readbyqxmd.com/read/28800386/3d-correlative-single-cell-imaging-utilizing-fluorescence-and-refractive-index-tomography
#19
Mirjam Schürmann, Gheorghe Cojoc, Salvatore Girardo, Elke Ulbricht, Jochen Guck, Paul Müller
Cells alter the path of light, a fact that leads to well-known aberrations in single cell or tissue imaging. Optical diffraction tomography (ODT) measures the biophysical property that causes these aberrations, the refractive index (RI). ODT is complementary to fluorescence imaging and does not require any markers. The present study introduces RI and fluorescence tomography with optofluidic rotation (RAFTOR) of suspended cells, facilitating the segmentation of the 3D-correlated RI and fluorescence data for a quantitative interpretation of the nuclear RI...
August 11, 2017: Journal of Biophotonics
https://www.readbyqxmd.com/read/28800019/the-natural-history-of-full-field-stimulus-threshold-decline-in-choroideremia
#20
Ioannis S Dimopoulos, Paul R Freund, Jacob A Knowles, Ian M MacDonald
PURPOSE: To evaluate full-field sensitivity thresholds (FSTs) across a wide range of choroideremia (CHM) disease stages and to determine their applicability as functional endpoints for CHM clinical trials. METHODS: Thirty CHM subjects (60 eyes) and 50 healthy controls (50 eyes) underwent FST testing under dark-adapted conditions to determine rod- and cone-mediated FSTs. Central retinal structure and function were assessed using fundus autofluorescence and microperimetry...
August 9, 2017: Retina
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