Null mutation in the human 11-cis retinol dehydrogenase gene associated with fundus albipunctatus11The authors have no proprietary interest in any of the materials used in this study.

Ophthalmology ◽  
2001 ◽  
Vol 108 (8) ◽  
pp. 1479-1484 ◽  
Author(s):  
Carola A.G.G Driessen ◽  
Bert P.M Janssen ◽  
Huub J Winkens ◽  
Leonoor D Kuhlmann ◽  
Anke H.M Van Vugt ◽  
...  
Keyword(s):  
Null Mutation ◽  
Retinol Dehydrogenase ◽  
Dehydrogenase Gene ◽  
Materials Used

scholarly journals Targeted disruption of the mouse cis-retinol dehydrogenase gene: visual and nonvisual functions

2002 ◽  
Vol 43 (4) ◽  
pp. 590-597
Author(s):  
Enyuan Shang ◽  
Katherine Lai ◽  
Alan I. Packer ◽  
Jisun Paik ◽  
William S. Blaner ◽  
...  
Keyword(s):  
Retinol Dehydrogenase ◽  
Targeted Disruption ◽  
Dehydrogenase Gene

scholarly journals Rod and cone visual cycle consequences of a null mutation in the 11-cis-retinol dehydrogenase gene in man

2000 ◽  
Vol 17 (5) ◽  
pp. 667-678 ◽  
Author(s):  
ARTUR V. CIDECIYAN ◽  
FRANÇOISE HAESELEER ◽  
ROBERT N. FARISS ◽  
TOMAS S. ALEMAN ◽  
GEENG-FU JANG ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Null Mutation ◽  
Partial Recovery ◽  
Retinol Dehydrogenase ◽  
Rods And Cones ◽  
Key Enzyme ◽  
Kinetics Of

Vertebrate vision starts with photoisomerization of the 11-cis-retinal chromophore to all-trans-retinal. Biosynthesis of 11-cis-retinal is required to maintain vision. A key enzyme catalyzing the oxidation of 11-cis-retinol is 11-cis-retinol dehydrogenase (11-cis-RDH), which is encoded by the RDH5 gene. 11-cis-RDH is expressed in the RPE and not in the neural retina. The consequences of a lack of 11-cis-RDH were studied in a family with fundus albipunctatus. We identified the causative novel RDH5 mutation, Arg157Trp, that replaces an amino acid residue conserved among short-chain alcohol dehydrogenases. Three-dimensional structure modeling and in vitro experiments suggested that this mutation destabilizes proper folding and inactivates the enzyme. Studies using RPE membranes indicated the existence of an alternative oxidizing system for the production of 11-cis-retinal. In vivo visual consequences of this null mutation showed complex kinetics of dark adaptation. Rod and cone resensitization was extremely delayed following full bleaches; unexpectedly, the rate of cone recovery was slower than rods. Cones showed a biphasic recovery with an initial rapid component and an elevated final threshold. Other unanticipated results included normal rod recovery following 0.5% bleach and abnormal recovery following bleaches in the 2–12% range. These intermediate bleaches showed rapid partial recovery of rods with transitory plateaux. Pathways in addition to 11-cis-RDH likely provide 11-cis-retinal for rods and cones and can maintain normal kinetics of visual recovery but only under certain constraints and less efficiently for cone than rod function.

Characterization of a microsomal retinol dehydrogenase gene from amphioxus: retinoid metabolism before vertebrates

2001 ◽  
Vol 130-132 ◽  
pp. 359-370 ◽  
Author(s):  
Diana Dalfó ◽  
Cristian Cañestro ◽  
Ricard Albalat ◽  
Roser Gonzàlez-Duarte
Keyword(s):  
Retinol Dehydrogenase ◽  
Retinoid Metabolism ◽  
Dehydrogenase Gene

scholarly journals Effect of retinol dehydrogenase gene transfer in a novel rat model of Stargardt disease

2021 ◽  
Vol 35 (11) ◽  
Author(s):  
T. Cronin ◽  
M. Croyal ◽  
N. Provost ◽  
J. B. Ducloyer ◽  
A. Mendes‐Madeira ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Rat Model ◽  
Stargardt Disease ◽  
Retinol Dehydrogenase ◽  
Dehydrogenase Gene

scholarly journals Disruption of the 11-cis-Retinol Dehydrogenase Gene Leads to Accumulation of cis-Retinols andcis-Retinyl Esters

2000 ◽  
Vol 20 (12) ◽  
pp. 4275-4287 ◽  
Author(s):  
Carola A. G. G. Driessen ◽  
Huub J. Winkens ◽  
Kirstin Hoffmann ◽  
Leonoor D. Kuhlmann ◽  
Bert P. M. Janssen ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Dehydrogenase Activity ◽  
Knockout Mice ◽  
Dark Adaptation ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinol Dehydrogenase ◽  
Retinyl Ester ◽  
Fundus Albipunctatus ◽  
Dehydrogenase Gene

ABSTRACT To elucidate the possible role of 11-cis-retinol dehydrogenase in the visual cycle and/or 9-cis-retinoic acid biosynthesis, we generated mice carrying a targeted disruption of the 11-cis-retinol dehydrogenase gene. Homozygous 11-cis-retinol dehydrogenase mutants developed normally, including their retinas. There was no appreciable loss of photoreceptors. Recently, mutations in the 11-cis-retinol dehydrogenase gene in humans have been associated with fundus albipunctatus. In 11-cis-retinol dehydrogenase knockout mice, the appearance of the fundus was normal and punctata typical of this human hereditary ocular disease were not present. A second typical symptom associated with this disease is delayed dark adaptation. Homozygous 11-cis-retinol dehydrogenase mutants showed normal rod and cone responses. 11-cis-Retinol dehydrogenase knockout mice were capable of dark adaptation. At bleaching levels under which patients suffering from fundus albipunctatus could be detected unequivocally, 11-cis-retinol dehydrogenase knockout animals displayed normal dark adaptation kinetics. However, at high bleaching levels, delayed dark adaptation in 11-cis-retinol dehydrogenase knockout mice was noticed. Reduced 11-cis-retinol oxidation capacity resulted in 11-cis-retinol/13-cis-retinol and 11-cis-retinyl/13-cis-retinyl ester accumulation. Compared with wild-type mice, a large increase in the 11-cis-retinyl ester concentration was noticed in 11-cis-retinol dehydrogenase knockout mice. In the murine retinal pigment epithelium, there has to be an additional mechanism for the biosynthesis of 11-cis-retinal which partially compensates for the loss of the 11-cis-retinol dehydrogenase activity. 11-cis-Retinyl ester formation is an important part of this adaptation process. Functional consequences of the loss of 11-cis-retinol dehydrogenase activity illustrate important differences in the compensation mechanisms between mice and humans. We furthermore demonstrate that upon 11-cis-retinol accumulation, the 13-cis-retinol concentration also increases. This retinoid is inapplicable to the visual processes, and we therefore speculate that it could be an important catabolic metabolite and its biosynthesis could be part of a process involved in regulating 11-cis-retinol concentrations within the retinal pigment epithelium of 11-cis-retinol dehydrogenase knockout mice.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

High Voltage Transmission Microscopy of Surveyor III Camera Shrouds

1971 ◽  
Vol 29 ◽  
pp. 138-139
Author(s):  
W. R. Duff ◽  
L. E. Thomas ◽  
R. M. Fisher ◽  
S. V. Radcliffe
Keyword(s):  
Alloy Sheet ◽  
Transmission Microscopy ◽  
Television Camera ◽  
Window Method ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Lunar Environment ◽  
Successful Retrieval ◽  
Materials Used ◽  
Abrasive Paper

Successful retrieval of the television camera and other components from the Surveyor III spacecraft by the Apollo 12 astronauts has provided a unique opportunity to study the effects of a known and relatively extensive exposure to the lunar environment. Microstructural effects including those produced by micro-meteorite impact, radiation damage (by both the solar wind and cosmic rays) and solar heating might be expected in the materials used to fabricate the spacecraft. Samples received were in the form of 1 cm2 of painted unpainted aluminum alloy sheet from the top of the camera visor (JPL Code 933) and the sides (935,936) and bottom (934) of the lower camera shroud. They were prepared for transmission electron microscopy by first hand-grinding with abrasive paper to a thickness of 0.006". The edges were lacquered and the sample electropolished in 10% perchloric methanol using the “window” method, to a thickness of ~0.001". Final thinning was accomplished by polishing 3 mm punched disks in an acetic-phosphoric-nitric acid solution.

XRF and PIXE Analysis of light and Dark Adapted Ocular Tissue

1982 ◽  
Vol 40 ◽  
pp. 190-191
Author(s):  
B. J. Panessa ◽  
H. W. Kraner ◽  
J. B. Warren ◽  
K. W. Jones
Keyword(s):  
Trace Metals ◽  
Pigment Epithelium ◽  
Nerve Impulse ◽  
Light Response ◽  
Ocular Tissue ◽  
Emission Spectrometry ◽  
Retinol Dehydrogenase ◽  
Pixe Analysis ◽  
X Ray ◽  
Optimal Function

During photoexcitation the retina requires specific electrolytes and trace metals for optimal function (Na, Mg, Cl, K, Ca, S, P, Cu and Zn). According to Hagins (1981), photoexcitation and generation of a nerve impulse involves the movement of Ca from the rhodopsin-ladened membranes of the rod outer segment (ROS) to the plasmalemma, which in turn decreases the in-flow of Na into the photoreceptor, resulting in hyperpolarization. In toad isolated retinas, the presence of Ba has been found to increase the amplitude and prolong the delay of the light response (Brown and Flaming, 1978). Trace metals such as Cu, Zn and Se are essential for the activity of the metalloenzymes of the retina and retina pigment epithelium (RPE) (i.e. carbonic anhydrase, retinol dehydrogenase, tyrosinase, glutathione peroxidase, superoxide dismutase...). Therefore the content and fluctuations of these elements in the retina and choroid are of fundamental importance for the maintenance of vision. This paper presents elemental data from light and dark adapted frog ocular tissues examined by electron beam induced x-ray microanalysis, x-ray fluorescence spectrometry (XRF) and proton induced x-ray emission spectrometry (PIXE).

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