Read by QxMD icon Read


Tianwei E Zhou, José C Rivera, Vikrant K Bhosle, Isabelle Lahaie, Zhuo Shao, Houda Tahiri, Tang Zhu, Anna Polosa, Allison Dorfman, Alexandra Beaudry-Richard, Santiago Costantino, Gregory A Lodygensky, Pierre Lachapelle, Sylvain Chemtob
Retinopathy of prematurity (ROP), the most common cause of blindness in premature infants, has long been associated with inner retinal alterations. However, recent studies reveal outer retinal dysfunctions in patients formerly afflicted with ROP. We have recently demonstrated that choroidal involution occurs early in retinopathy. Herein, we investigated the mechanisms underlying the choroidal involution and its long-term impact on retinal function. An oxygen-induced retinopathy (OIR) model was used. In vitro and ex vivo assays were applied to evaluate cytotoxic effects of IL-1β on choroidal endothelium...
October 18, 2016: American Journal of Pathology
Xin Zhong, Bogale Aredo, Yi Ding, Kaiyan Zhang, Cynthia X Zhao, Rafael L Ufret-Vincenty
Purpose: Oxidative stress, partly due to light, has an important role in many retinal diseases, including macular degeneration and retinal dystrophies. The Leu450Met variant of RPE65 is expressed in C57BL/6 and in many genetically modified mice. It confers significant resistance to light induced retinal degeneration (LIRD). Our goal was to develop an effective and efficient method to induce LIRD in resistant mice that would recapitulate mechanisms seen in known models of LIRD. Methods: The retinas of C57BL/6J mice were exposed to light using a murine fundus camera...
October 1, 2016: Investigative Ophthalmology & Visual Science
Jingyi Zhu, Tilo Mathes, Yusaku Hontani, Maxime T A Alexandre, Kee Chua Toh, Peter Hegemann, John T M Kennis
The two Light, Oxygen, and Voltage domains of phototropin are blue-light photoreceptor domains which control various functions in plants and green algae. The key step of the light-driven reaction is the formation of a photoadduct between its FMN chromophore and a conserved cysteine, where the canonical reaction proceeds through the FMN triplet state. Here, complete photoreaction mapping of CrLOV2 from Chlamydomonas reinhardtii phototropin and AsLOV2 from Avena sativa phototropin-1 was realized by ultrafast broadband spectroscopy from femtoseconds to microseconds...
October 21, 2016: Journal of Physical Chemistry Letters
María da Fonseca, Inés Samengo
The accuracy with which humans detect chromatic differences varies throughout color space. For example, we are far more precise when discriminating two similar orange stimuli than two similar green stimuli. In order for two colors to be perceived as different, the neurons representing chromatic information must respond differently, and the difference must be larger than the trial-to-trial variability of the response to each separate color. Photoreceptors constitute the first stage in the processing of color information; many more stages are required before humans can consciously report whether two stimuli are perceived as chromatically distinguishable...
October 20, 2016: Neural Computation
Vasilios P Papastefanou, Clara Vázquez-Alfageme, Pearse A Keane, Mandeep S Sagoo
PURPOSE: Multimodality image analysis of two cases of torpedo maculopathy. METHODS: Imaging with fundus photography, autofluorescence (AF), swept-source optical coherence tomography (OCT), en face OCT, and OCT angiography. RESULTS: The basal diameter of the torpedo lesions was 1 mm × 2 mm. One case had a satellite lesion. Autofluorescence indicated variable loss of signal. Swept-source OCT and en face OCT demonstrated fundus excavation, attenuation of nuclear layers and disruption of the outer plexiform layer, loss of photoreceptors and a subretinal cleft...
October 19, 2016: Retinal Cases & Brief Reports
Alice C Wyse-Jackson, Sarah L Roche, Ana M Ruiz-Lopez, Jennifer N Moloney, Ashleigh M Byrne, Thomas G Cotter
Retinitis pigmentosa (RP) is a degenerative retinal disease leading to photoreceptor cell loss. In 2011, our group identified the synthetic progesterone 'Norgestrel' as a potential treatment for RP. Subsequent research showed Norgestrel to work through progesterone receptor membrane component 1 (PGRMC1) activation and upregulation of neuroprotective basic fibroblast growth factor (bFGF). Using trophic factor deprivation of 661W photoreceptor-like cells, we aimed to further elucidate the mechanism leading to Norgestrel-induced neuroprotection...
October 20, 2016: European Journal of Neuroscience
Dierck Hillmann, Hendrik Spahr, Carola Hain, Helge Sudkamp, Gesa Franke, Clara Pfäffle, Christian Winter, Gereon Hüttmann
Certain topics in research and advancements in medical diagnostics may benefit from improved temporal and spatial resolution during non-invasive optical imaging of living tissue. However, so far no imaging technique can generate entirely diffraction-limited tomographic volumes with a single data acquisition, if the target moves or changes rapidly, such as the human retina. Additionally, the presence of aberrations may represent further difficulties. We show that a simple interferometric setup-based on parallelized optical coherence tomography-acquires volumetric data with 10 billion voxels per second, exceeding previous imaging speeds by an order of magnitude...
October 20, 2016: Scientific Reports
Wenzhong Liu, Hao F Zhang
The eye relies on the synergistic cooperation of many different ocular components, including the cornea, crystalline lens, photoreceptors, and retinal neurons, to precisely sense visual information. Complications with a single ocular component can degrade vision and sometimes cause blindness. Immediate treatment and long-term monitoring are paramount to alleviate symptoms, restore vision, and cure ocular diseases. However, successful treatment requires understanding ocular pathological mechanisms, precisely detecting and monitoring the diseases...
September 2016: Photoacoustics
Patricia Müller-Moulé, Kazunari Nozue, Melissa L Pytlak, Christine M Palmer, Michael F Covington, Andreah D Wallace, Stacey L Harmer, Julin N Maloof
Plants respond to neighbor shade by increasing stem and petiole elongation. Shade, sensed by phytochrome photoreceptors, causes stabilization of PHYTOCHROME INTERACTING FACTOR proteins and subsequent induction of YUCCA auxin biosynthetic genes. To investigate the role of YUCCA genes in phytochrome-mediated elongation, we examined auxin signaling kinetics after an end-of-day far-red (EOD-FR) light treatment, and found that an auxin responsive reporter is rapidly induced within 2 hours of far-red exposure. YUCCA2, 5, 8, and 9 are all induced with similar kinetics suggesting that they could act redundantly to control shade-mediated elongation...
2016: PeerJ
Petra Edlund, Heikki Takala, Elin Claesson, Léocadie Henry, Robert Dods, Heli Lehtivuori, Matthijs Panman, Kanupriya Pande, Thomas White, Takanori Nakane, Oskar Berntsson, Emil Gustavsson, Petra Båth, Vaibhav Modi, Shatabdi Roy-Chowdhury, James Zook, Peter Berntsen, Suraj Pandey, Ishwor Poudyal, Jason Tenboer, Christopher Kupitz, Anton Barty, Petra Fromme, Jake D Koralek, Tomoyuki Tanaka, John Spence, Mengning Liang, Mark S Hunter, Sebastien Boutet, Eriko Nango, Keith Moffat, Gerrit Groenhof, Janne Ihalainen, Emina A Stojković, Marius Schmidt, Sebastian Westenhoff
Phytochromes are a family of photoreceptors that control light responses of plants, fungi and bacteria. A sequence of structural changes, which is not yet fully understood, leads to activation of an output domain. Time-resolved serial femtosecond crystallography (SFX) can potentially shine light on these conformational changes. Here we report the room temperature crystal structure of the chromophore-binding domains of the Deinococcus radiodurans phytochrome at 2.1 Å resolution. The structure was obtained by serial femtosecond X-ray crystallography from microcrystals at an X-ray free electron laser...
October 19, 2016: Scientific Reports
Rogan G Fraser, Rose Tan, Lauren N Ayton, Emily Caruso, Robyn H Guymer, Chi D Luu
Purpose: We determine the feasibility of using a dark-adapted chromatic (DAC) perimeter to obtain dark-adapted static and dynamic rod function at multiple retinal locations, and compare these functional parameters between subjects with intermediate age-related macular degeneration (AMD) and normal controls. Methods: Perimetric dark-adapted retinal sensitivities for the 505 and 620 nm stimuli across 7 retinal locations within the central 12° were repeatedly measured after exposing to a single photobleach in 22 intermediate AMD subjects and 8 controls...
October 1, 2016: Investigative Ophthalmology & Visual Science
Andreas Reichenbach, Andreas Bringmann
Müller glia, the principal macroglia of the retina, express diverse subtypes of adenosine and metabotropic purinergic (P2Y) receptors. Müller cells of several species, including man, also express ionotropic P2X7 receptors. ATP is liberated from Müller cells after activation of metabotropic glutamate receptors and during osmotic and mechanical induction of membrane stretch; adenosine is released through equilibrative nucleoside transporters. Müller cell-derived purines modulate the neuronal activity and have autocrine effects, for example, induction of glial calcium waves and regulation of the cellular volume...
October 2016: Journal of Ocular Pharmacology and Therapeutics
Brian P Hafler
PURPOSE: Inherited retinal dystrophies are a significant cause of vision loss and are characterized by the loss of photoreceptors and the retinal pigment epithelium (RPE). Mutations in approximately 250 genes cause inherited retinal degenerations with a high degree of genetic heterogeneity. New techniques in next-generation sequencing are allowing the comprehensive analysis of all retinal disease genes thus changing the approach to the molecular diagnosis of inherited retinal dystrophies...
October 6, 2016: Retina
Jingyu Yao, Lin Jia, Kecia Feathers, Chengmao Lin, Naheed W Khan, Daniel J Klionsky, Thomas A Ferguson, David N Zacks
Autophagy is a lysosomal degradation pathway critical to preventing the accumulation of cytotoxic proteins. Deletion of the essential autophagy gene Atg5 from the rod photoreceptors of the retina (atg5(Δrod) mouse) results in the accumulation of the phototransduction protein transducin and the degeneration of these neurons. The purpose of this study is to test the hypothesis that autophagic degradation of visual transduction proteins prevents retinal degeneration. Targeted deletion of both Gnat1 (a gene encoding the alpha subunit of the heterotrimeric G-protein transducin) and Atg5 in the rod photoreceptors resulted in a significantly decreased rate of rod cell degeneration as compared to the atg5(Δrod) mouse retina, and considerable preservation of photoreceptors...
October 18, 2016: Autophagy
Nobuhiro Nagai, Satoru Iwata, Hirokazu Kaji, Kaori Sampei, Yuki Katsukura, Hideyuki Onami, Matsuhiko Nishizawa, Toru Nakazawa, Yukihiko Mashima, Toshiaki Abe
It has been suggested that unoprostone isopropyl (UNO) has potent neuroprotective activity in the retina. The effect of sustained transscleral UNO delivery to the posterior segment of the eye on photoreceptor degeneration was evaluated. UNO was loaded into a device made of poly(ethyleneglycol) dimethacrylate by polydimethylsiloxane mold-based UV-curing. The amount of UNO diffusing from these devices was measured using high-performance liquid chromatography. The polymeric devices that released UNO at 1.8 μg/day were implanted on the sclerae of S334ter rats at postnatal 21 days, and electroretinograms (ERGs) were compared with those of topical application and placebo devices...
November 2016: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
D G A B Oonincx, N Volk, J J E Diehl, J J A van Loon, G Belušič
Mating in the black soldier fly (BSF) is a visually mediated behaviour that under natural conditions occurs in full sunlight. Artificial light conditions promoting mating by BSF were designed based on the spectral characteristics of the compound eye retina. Electrophysiological measurements revealed that BSF ommatidia contained UV-, blue- and green-sensitive photoreceptor cells, allowing trichromatic vision. An illumination system for indoor breeding based on UV, blue and green LEDs was designed and its efficiency was compared with illumination by fluorescent tubes which have been successfully used to sustain a BSF colony for five years...
October 14, 2016: Journal of Insect Physiology
George Taylor-Walker, Savannah A Lynn, Eloise Keeling, Rosie Munday, David A Johnston, Anton Page, Jennifer A Scott, Srini Goverdhan, Andrew J Lotery, J Arjuna Ratnayaka
Age-related Macular Degeneration (AMD) is a common, irreversible blinding condition that leads to the loss of central vision. AMD has a complex aetiology with both genetic as well as environmental risks factors, and share many similarities with Alzheimer's disease. Recent findings have contributed significantly to unravelling its genetic architecture that is yet to be matched by molecular insights. Studies are made more challenging by observations that aged and AMD retinas accumulate the highly pathogenic Alzheimer's-related Amyloid beta (Aβ) group of peptides, for which there appears to be no clear genetic basis...
October 14, 2016: Experimental Eye Research
Pavitra Ramachandran, Vivian Lee, Zhangyong Wei, Ji Yun Song, Giulia Casal, Therese Cronin, Keirnan Willett, Rachel Huckfeldt, Jessica I W Morgan, Tomas S Aleman, Albert M Maguire, Jean Bennett
Within the next decade, we will see many gene therapy clinical trials for eye diseases progress, which may lead to treatments for thousands of visually impaired people around the world. To target retinal diseases that affect specific cell types, several recombinant adeno-associated virus (AAV) serotypes have been generated and used successfully in pre-clinical mouse studies. Because there are numerous anatomic, and physiologic differences between the eyes of mice and 'men' and because surgical delivery approaches and immunologic responses also differ between these species, we evaluated the transduction characteristics of two promising new serotypes AAV7m8 and AAV8BP2, in retinas of animals that are most similar to those of humans: non-human primates (NHPs)...
October 18, 2016: Human Gene Therapy
Tapasi Rana, Pravallika Kotla, Roderick Fullard, Marina Gorbatyuk
Expression of T17M rhodopsin (T17M) in rods activates the Unfolded Protein Response (UPR) and leads to the development of autosomal dominant retinitis pigmentosa (adRP). The rod death occurs in adRP retinas prior to cone photoreceptor death, so the mechanism by which cone photoreceptors die remains unclear. Therefore, the goal of the study was to verify whether UPR in rods induces TNFa-mediated signaling to the cones and to determine whether the TNFa deficit could prevent adRP cone cell death. Primary rod photoreceptors and cone-derived 661W cells transfected with siRNA against TNFa were treated with tunicamycin to mimic activation of UPR in T17M retinas expressing normal and reduced TNFa levels...
October 14, 2016: Biochimica et Biophysica Acta
L Tyler Mix, Julia Kirpich, Masato Kumauchi, Jie Ren, Mikas Vengris, Wouter D Hoff, Delmar S Larsen
We explored the photoisomerization mechanisms in novel homologs of Photoactive Yellow Protein (PYP) from Leptospira biflexa to identify conserved features and functional diversity in the primary photochemistry of this family of photoreceptors. In close agreement with the prototypical PYP from Halorhodospira halophila, we observe excited state absorbance near 375 nm and stimulated emission near 500 nm, with triphasic excited state decay. While the excited state decay for Lbif PYP is the slowest among known PYPs due to the redistribution of the amplitudes of the three decay components, the quantum yield for productive photocycle entry is very similar to that of Hhal PYP...
October 17, 2016: Biochemistry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"