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https://www.readbyqxmd.com/read/29782826/sheets-of-human-retinal-progenitor-transplants-improve-vision-in-rats-with-severe-retinal-degeneration
#1
Bin Lin, Bryce T McLelland, Anuradha Mathur, Robert B Aramant, Magdalene J Seiler
Loss of photoreceptors and other retinal cells is a common endpoint in retinal degenerate (RD) diseases that cause blindness. Retinal transplantation is a potential therapy to replace damaged retinal cells and improve vision. In this study, we examined the development of human fetal retinal sheets with or without their retinal pigment epithelium (RPE) transplanted to immunodeficient retinal degenerate rho S334ter-3 rats. Sheets were dissected from fetal human eyes (11-15.7 weeks gestation) and then transplanted to the subretinal space of 24-31 d old RD nude rats...
May 18, 2018: Experimental Eye Research
https://www.readbyqxmd.com/read/29770464/chemically-characterised-extract-of-saraca-asoca-improves-the-sexual-function-in-male-wistar-rats
#2
M Gill, A Rai, M Kinra, S Sumalatha, C M Rao, S P Cheruku, R Devkar, N Kumar
In this study, methanolic extract of Saraca asoca bark was evaluated for its aphrodisiac potential using male and female Wistar albino rats. Male rats were dosed daily for 54 days at a dose of 100 mg/kg p.o. Sexual activity of male rats was assessed after 14, 28, 42 and 54 days of the study. Male rats were placed in a glass chamber lit with a dim red light (10W) followed by the introduction of sexually receptive female rats in a ratio of 1:1. Improvement in sexual behaviour of male rats was characterised by an increase in both mount frequency and intromission frequency and decrease or reduction in mount latency and intromission latency compared to normal control...
May 16, 2018: Andrologia
https://www.readbyqxmd.com/read/29764618/investigating-daily-fatigue-scores-during-two-week-offshore-day-shifts
#3
Vanessa Riethmeister, Ute Bültmann, Marijke Gordijn, Sandra Brouwer, Michiel de Boer
OBJECTIVES: This study examined daily scores of fatigue and circadian rhythm markers over two-week offshore day shift periods. METHODS: A prospective cohort study among N = 60 offshore day-shift workers working two-week offshore shifts was conducted. Offshore day shifts lasted from 07:00 - 19:00 h. Fatigue was measured objectively with pre- and post-shift scores of the 3-minute psychomotor vigilance tasks (PVT-B) parameters (reaction times, number of lapses, errors and false starts) and subjectively with pre- and post-shift Karolinska Sleepiness Scale (KSS) ratings...
September 2018: Applied Ergonomics
https://www.readbyqxmd.com/read/29763583/m%C3%A3-ller-glial-cells-contribute-to-dim-light-vision-in-the-spectacled-caiman-caiman-crocodilus-fuscus-analysis-of-retinal-light-transmission
#4
Silke Agte, Alexey Savvinov, Anett Karl, Astrid Zayas-Santiago, Elke Ulbricht, Vladimir I Makarov, Andreas Reichenbach, Andreas Bringmann, Serguei N Skatchkov
In this study, we show the capability of Müller glial cells to transport light through the inverted retina of reptiles, specifically the retina of the spectacled caimans. Thus, confirming that Müller cells of lower vertebrates also improve retinal light transmission. Confocal imaging of freshly isolated retinal wholemounts, that preserved the refractive index landscape of the tissue, indicated that the retina of the spectacled caiman is adapted for vision under dim light conditions. For light transmission experiments, we used a setup with two axially aligned objectives imaging the retina from both sides to project the light onto the inner (vitreal) surface and to detect the transmitted light behind the retina at the receptor layer...
May 12, 2018: Experimental Eye Research
https://www.readbyqxmd.com/read/29753728/retinal-adaptation-to-dim-light-vision-in-spectacled-caimans-caiman-crocodilus-fuscus-analysis-of-retinal-ultrastructure
#5
Anett Karl, Silke Agte, Astrid Zayas-Santiago, Felix N Makarov, Yomarie Rivera, Jan Benedikt, Mike Francke, Andreas Reichenbach, Serguei N Skatchkov, Andreas Bringmann
It has been shown that mammalian retinal glial (Müller) cells act as living optical fibers that guide the light through the retinal tissue to the photoreceptor cells (Agte et al., 2011; Franze et al., 2007). However, for nonmammalian species it is unclear whether Müller cells also improve the transretinal light transmission. Furthermore, for nonmammalian species there is a lack of ultrastructural data of the retinal cells, which, in general, delivers fundamental information of the retinal function, i.e. the vision of the species...
May 10, 2018: Experimental Eye Research
https://www.readbyqxmd.com/read/29743512/daytime-eyeshine-contributes-to-pupil-camouflage-in-a-cryptobenthic-marine-fish
#6
Matteo Santon, Pierre-Paul Bitton, Ulrike K Harant, Nico K Michiels
Ocular reflectors enhance eye sensitivity in dim light, but can produce reflected eyeshine when illuminated. Some fish can occlude their reflectors during the day. The opposite is observed in cryptic sit-and-wait predators such as scorpionfish and toadfish, where reflectors are occluded at night and exposed during the day. This results in daytime eyeshine, proposed to enhance pupil camouflage by reducing the contrast between the otherwise dark pupil and the surrounding tissue. In this study, we test this hypothesis in the scorpionfish Scorpaena porcus and show that eyeshine is the result of two mechanisms: the previously described Stratum Argenteum Reflected (SAR) eyeshine, and Pigment Epithelium Transmitted (PET) eyeshine, a newly described mechanism for this species...
May 9, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29739727/topographic-anatomy-of-the-subthalamic-nucleus-localized-by-high-resolution-human-brain-atlas-superimposing-digital-images-of-cross-sectioned-surfaces-and-histological-images-of-microscopic-sections-from-frozen-cadaveric-brains
#7
Takashi Kawasaki, Masahiro Shin, Yuiko Kimura, Yoshitomo Umitsu, George Matsumura, Fusako Yokochi, Ryoichi Okiyama, Makoto Taniguchi, Nobutaka Arai
Despite the recent advent of neuro-radiographic techniques, creating a 'perfect' human brain atlas providing precise and consistent images with minimal distortion is practically difficult. In this study, we created a new human brain atlas from cadaveric brains with serial sections of 50 μm thickness covering the entire basal ganglia. Human cerebral hemispheres were obtained from 10 donated cadavers and fixed in 10% formalin solution, cut in a block measuring 50 mm × 30 mm × 50 mm around the midpoint of the anterior and posterior commissures and frozen at -40 °C...
May 5, 2018: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/29733537/dim-artificial-light-at-night-affects-mating-reproductive-output-and-reactive-oxygen-species-in-drosophila-melanogaster
#8
Lucy Katherine McLay, Venkatesh Nagarajan-Radha, Mark Philip Green, Therésa Melanie Jones
Humans are lighting the night-time environment with ever increasing extent and intensity, resulting in a variety of negative ecological effects in individuals and populations. Effects of light at night on reproductive fitness traits are demonstrated across taxa however, the mechanisms underlying these effects are largely untested. One possible mechanism is that light at night may result in perturbed reactive oxygen species (ROS) and oxidative stress levels. Here, we reared Drosophila melanogaster under either dim (10 lx) light or no light (0 lx) at night for three generations and then compared mating and lifetime oviposition patterns...
May 7, 2018: Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology
https://www.readbyqxmd.com/read/29727473/can-circadian-dysregulation-exacerbate-migraines
#9
REVIEW
Jason C Ong, Hannah L Taylor, Margaret Park, Helen J Burgess, Rina S Fox, Sarah Snyder, Jeanetta C Rains, Colin A Espie, James K Wyatt
OBJECTIVE: This observational pilot study examined objective circadian phase and sleep timing in chronic migraine (CM) and healthy controls (HC) and the impact of circadian factors on migraine frequency and severity. BACKGROUND: Sleep disturbance has been identified as a risk factor in the development and maintenance of CM but the biological mechanisms linking sleep and migraine remain largely theoretical. METHODS: Twenty women with CM and 20 age-matched HC completed a protocol that included a 7 day sleep assessment at home using wrist actigraphy followed by a circadian phase assessment using salivary melatonin...
May 4, 2018: Headache
https://www.readbyqxmd.com/read/29712749/non-linear-amplification-of-graded-voltage-signals-in-the-first-order-visual-interneurons-of-the-butterfly-papilio-xuthus
#10
Juha Rusanen, Roman Frolov, Matti Weckström, Michiyo Kinoshita, Kentaro Arikawa
Lamina monopolar cells (LMCs) are the first-order visual interneurons of insects and crustacea, primarily involved in achromatic vision. Here we investigated morphological and electrophysiological properties of LMCs in the butterfly Papilio xuthus Using intracellular recording coupled with dye injection, we found two types of LMCs. Cells with roundish terminals near the distal surface of the medulla demonstrating no or small depolarizing spikes were classified as L1/2. LMCs with elongated terminals deep in the medulla that showed prominent spiking were classified as L3/4...
April 30, 2018: Journal of Experimental Biology
https://www.readbyqxmd.com/read/29707782/functional-decoupling-of-melatonin-suppression-and-circadian-phase-resetting-in-humans
#11
Shadab A Rahman, Melissa A St Hilaire, Claude Gronfier, Anne-Marie Chang, Nayantara Santhi, Charles A Czeisler, Elizabeth B Klerman, Steven W Lockley
KEY POINTS: There is assumed to be a monotonic association between melatonin suppression and circadian phase resetting induced by light exposure. We tested the association between melatonin suppression and phase resetting in humans. Sixteen young healthy participants received nocturnal bright light (∼9500 lux) exposure of continuous or intermittent patterns, and different durations ranging from 12 min to 6.5 h. Intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression...
April 29, 2018: Journal of Physiology
https://www.readbyqxmd.com/read/29704048/long-range-interactions-of-chara-chloroplasts-are-sensitive-to-plasma-membrane-h-flows-and-comprise-separate-photo-and-dark-operated-pathways
#12
Alexander A Bulychev, Anna A Rybina
Local illumination of the characean internode with a 30-s pulse of white light was found to induce the delayed transient increase of modulated chlorophyll fluorescence in shaded cell parts, provided the analyzed region is located downstream in the cytoplasmic flow at millimeter distances from the light spot. The fluorescence response to photostimulation of a remote cell region indicates that the metabolites produced by source chloroplasts in an illuminated region are carried downstream with the cytoplasmic flow, thus ensuring long-distance communications between anchored plastids in giant internodal cells...
April 27, 2018: Protoplasma
https://www.readbyqxmd.com/read/29697812/regressed-but-not-gone-patterns-of-vision-gene-loss-and-retention-in-subterranean-mammals
#13
Christopher A Emerling
Regressive evolution involves the degradation of formerly useful traits as organisms invade novel ecological niches. In animals, committing to a strict subterranean habit can lead to regression of the eyes, likely due to a limited exposure to light. Several lineages of subterranean mammals show evidence of such degeneration, which can include decreased organization of the retina, malformation of the lens and subcutaneous positioning of the eye. Advances in DNA sequencing have revealed that this regression co-occurs with a degradation of genomic loci encoding visual functions, including protein-coding genes...
April 25, 2018: Integrative and Comparative Biology
https://www.readbyqxmd.com/read/29689214/vision-rods-see-in-bright-light
#14
Almut Kelber
Rods, usually associated with highly sensitive dim-light vision, contribute to vision even in bright photopic intensities. New results in mice have important implications for vision of animals with rod-dominated or pure rod retinae.
April 23, 2018: Current Biology: CB
https://www.readbyqxmd.com/read/29671707/prediction-of-cognitive-performance-and-subjective-sleepiness-using-a-model-of-arousal-dynamics
#15
Svetlana Postnova, Steven W Lockley, Peter A Robinson
A model of arousal dynamics is applied to predict objective performance and subjective sleepiness measures, including lapses and reaction time on a visual Performance Vigilance Test (vPVT), performance on a mathematical addition task (ADD), and the Karolinska Sleepiness Scale (KSS). The arousal dynamics model is comprised of a physiologically based flip-flop switch between the wake- and sleep-active neuronal populations and a dynamic circadian oscillator, thus allowing prediction of sleep propensity. Published group-level experimental constant routine (CR) and forced desynchrony (FD) data are used to calibrate the model to predict performance and sleepiness...
April 2018: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/29669178/the-utility-of-multiparametric-flow-cytometry-in-the-detection-of-primary-effusion-lymphoma-pel
#16
Jacobo Galán, Isaac Martin, Itziar Carmona, José María Rodriguez-Barbero, Esperanza Cuadrado, Luis García-Alonso, José Antonio García-Vela
Primary effusion lymphoma (PEL) is a rare B cell lymphoproliferative disorder that arises predominantly in body cavities causing malignant effusions.The incidence of PEL is very low, accounting for approximately 4% of all HIV-associated non-Hodgkin lymphomas. PEL has also been described in elderly patients and after solid-organ transplantation. It is associated in all cases with human herpesvirus 8 (HHV8). We describe a case of PEL in a 88-year-old HIV-negative woman who presented with progressive dyspnea and moderate right-sided pleural effusion without significate lymphadenopathies or other effusions...
April 18, 2018: Cytometry. Part B, Clinical Cytometry
https://www.readbyqxmd.com/read/29627754/long-term-dim-light-during-nighttime-changes-activity-patterns-and-space-use-in-experimental-small-mammal-populations
#17
Julia Hoffmann, Rupert Palme, Jana Anja Eccard
Artificial light at night (ALAN) is spreading worldwide and thereby is increasingly interfering with natural dark-light cycles. Meanwhile, effects of very low intensities of light pollution on animals have rarely been investigated. We explored the effects of low intensity ALAN over seven months in eight experimental bank vole (Myodes glareolus) populations in large grassland enclosures over winter and early breeding season, using LED garden lamps. Initial populations consisted of eight individuals (32 animals per hectare) in enclosures with or without ALAN...
April 5, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29625838/suppression-of-melatonin-secretion-in-totally-visually-blind-people-by-ocular-exposure-to-white-light-clinical-characteristics
#18
Joseph T Hull, Charles A Czeisler, Steven W Lockley
PURPOSE: Although most totally visually blind individuals exhibit nonentrained circadian rhythms due to an inability of light to entrain the circadian pacemaker, a small proportion retain photic circadian entrainment, melatonin suppression, and other nonimage-forming responses to light. It is thought that these responses to light persist because of the survival of melanospin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs), which project primarily to the circadian pacemaker and are functionally distinct from the rod and cone photoreceptors that mediate vision...
April 3, 2018: Ophthalmology
https://www.readbyqxmd.com/read/29622667/multiple-spectral-channels-in-branchiopods-ii-role-in-light-dependent-behavior-and-natural-light-environments
#19
Nicolas Lessios, Ronald L Rutowski, Jonathan H Cohen
Light is a primary environmental factor used by aquatic invertebrates for depth selection behavior. Many branchiopod crustaceans live in ephemeral aquatic habitats. All branchiopod crustaceans studied to date express four or more visual opsins in their compound eyes. We asked whether two branchiopods, Triops longicaudatus , and Streptocephalus mackini , use multiple spectral channels to regulate their position in the water column. At the lowest intensities that elicited photonegative behavior, both species had broad spectral bandwidths, suggesting they use multiple spectral photoreceptor classes...
April 5, 2018: Journal of Experimental Biology
https://www.readbyqxmd.com/read/29622664/multiple-spectral-channels-in-branchiopods-i-vision-in-dim-light-and-neural-correlates
#20
Nicolas Lessios, Ronald L Rutowski, Jonathan H Cohen, Marcel E Sayre, Nicholas J Strausfeld
Animals that have true color vision possess several spectral classes of photoreceptors. Pancrustaceans (Hexapoda + Crustacea) that integrate spectral information about their reconstructed visual world do so from photoreceptor terminals supplying their second optic neuropils, with subsequent participation of the third (lobula) and deeper centers (optic foci). Here we describe experiments and correlative neural arrangements underlying convergent visual pathways in two species of branchiopod crustaceans that have to cope with a broad range of spectral ambience and illuminance in ephemeral pools, yet possess just two optic neuropils, the lamina and optic tectum...
April 5, 2018: Journal of Experimental Biology
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