The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.
The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.
Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.
Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.
A naturally occurring lipid pigment with histochemical characteristics similar to ceroid. It accumulates in various normal tissues and apparently increases in quantity with age.
The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.
The inner layer of CHOROID, also called the lamina basalis choroideae, located adjacent to the RETINAL PIGMENT EPITHELIUM; (RPE) of the EYE. It is a membrane composed of the basement membranes of the choriocapillaris ENDOTHELIUM and that of the RPE. The membrane stops at the OPTIC NERVE, as does the RPE.
Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.
Enzymes that catalyze the rearrangement of geometry about double bonds. EC 5.2.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)
Linear TETRAPYRROLES that give a characteristic color to BILE including: BILIRUBIN; BILIVERDIN; and bilicyanin.
Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.
Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).
Inorganic salts of iodic acid (HIO3).
The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)
Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.
Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.
An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)
A group of tetraterpenes, with four terpene units joined head-to-tail. Biologically active members of this class are used clinically in the treatment of severe cystic ACNE; PSORIASIS; and other disorders of keratinization.
A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
A carotenoid constituent of visual pigments. It is the oxidized form of retinol which functions as the active component of the visual cycle. It is bound to the protein opsin forming the complex rhodopsin. When stimulated by visible light, the retinal component of the rhodopsin complex undergoes isomerization at the 11-position of the double bond to the cis-form; this is reversed in "dark" reactions to return to the native trans-configuration.
A pathological process consisting of the formation of new blood vessels in the CHOROID.
Vitreoretinal membrane shrinkage or contraction secondary to the proliferation of primarily retinal pigment epithelial cells and glial cells, particularly fibrous astrocytes, followed by membrane formation. The formation of fibrillar collagen and cellular proliferation appear to be the basis for the contractile properties of the epiretinal and vitreous membranes.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Recording of electric potentials in the retina after stimulation by light.
Coloration or discoloration of a part by a pigment.
Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.
The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
Melanin-containing organelles found in melanocytes and melanophores.
Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.
A specialized transport barrier, in the EYE, formed by the retinal pigment EPITHELIUM, and the ENDOTHELIUM of the BLOOD VESSELS of the RETINA. TIGHT JUNCTIONS joining adjacent cells keep the barrier between cells continuous.
The transparent, semigelatinous substance that fills the cavity behind the CRYSTALLINE LENS of the EYE and in front of the RETINA. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Rats bearing mutant genes which are phenotypically expressed in the animals.
Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.
Disorders of the choroid including hereditary choroidal diseases, neoplasms, and other abnormalities of the vascular layer of the uvea.
An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.
Colloid or hyaline bodies lying beneath the retinal pigment epithelium. They may occur either secondary to changes in the choroid that affect the pigment epithelium or as an autosomal dominant disorder of the retinal pigment epithelium.
Chromatophores (large pigment cells of fish, amphibia, reptiles and many invertebrates) which contain melanin. Short term color changes are brought about by an active redistribution of the melanophores pigment containing organelles (MELANOSOMES). Mammals do not have melanophores; however they have retained smaller pigment cells known as MELANOCYTES.
A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. This family includes alpha 1-antitrypsin, angiotensinogen, ovalbumin, antiplasmin, alpha 1-antichymotrypsin, thyroxine-binding protein, complement 1 inactivators, antithrombin III, heparin cofactor II, plasminogen inactivators, gene Y protein, placental plasminogen activator inhibitor, and barley Z protein. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES, and some serpins occur in plants where their function is not known.
The large pigment cells of fish, amphibia, reptiles and many invertebrates which actively disperse and aggregate their pigment granules. These cells include MELANOPHORES, erythrophores, xanthophores, leucophores and iridiophores. (In algae, chromatophores refer to CHLOROPLASTS. In phototrophic bacteria chromatophores refer to membranous organelles (BACTERIAL CHROMATOPHORES).)
Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.
The light sensitive outer portion of a retinal rod or a cone photoreceptor cell. The outer segment contains a stack of disk membranes laden with photoreceptive pigments (RETINAL PIGMENTS). The outer segment is connected to the inner segment by a PHOTORECEPTOR CONNECTING CILIUM.
Examination of the interior of the eye with an ophthalmoscope.
A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). Rhodopsin exhibits peak absorption wavelength at about 500 nm.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
General term for a number of inherited defects of amino acid metabolism in which there is a deficiency or absence of pigment in the eyes, skin, or hair.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Perforations through the whole thickness of the retina including the macula as the result of inflammation, trauma, degeneration, etc. The concept includes retinal breaks, tears, dialyses, and holes.
Established cell cultures that have the potential to propagate indefinitely.
A diazo-naphthalene sulfonate that is widely used as a stain.
The use of green light-producing LASERS to stop bleeding. The green light is selectively absorbed by HEMOGLOBIN, thus triggering BLOOD COAGULATION.
The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
Oxygenated forms of carotenoids. They are usually derived from alpha and beta carotene.
The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.
A form of MACULAR DEGENERATION also known as dry macular degeneration marked by occurrence of a well-defined progressive lesion or atrophy in the central part of the RETINA called the MACULA LUTEA. It is distinguishable from WET MACULAR DEGENERATION in that the latter involves neovascular exudates.
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
A xanthophyll found in the major LIGHT-HARVESTING PROTEIN COMPLEXES of plants. Dietary lutein accumulates in the MACULA LUTEA.
Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a non-covalently-bound ligand.
A basic helix-loop-helix leucine zipper transcription factor that regulates the CELL DIFFERENTIATION and development of a variety of cell types including MELANOCYTES; OSTEOCLASTS; and RETINAL PIGMENT EPITHELIUM. Mutations in MITF protein have been associated with OSTEOPETROSIS and WAARDENBURG SYNDROME.
Mammalian pigment cells that produce MELANINS, pigments found mainly in the EPIDERMIS, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called MELANOSOMES. The large non-mammalian melanin-containing cells are called MELANOPHORES.
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.
Photosensitive afferent neurons located in the peripheral retina, with their density increases radially away from the FOVEA CENTRALIS. Being much more sensitive to light than the RETINAL CONE CELLS, the rod cells are responsible for twilight vision (at scotopic intensities) as well as peripheral vision, but provide no color discrimination.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
An X chromosome-linked abnormality characterized by atrophy of the choroid and degeneration of the retinal pigment epithelium causing night blindness.
The blood vessels which supply and drain the RETINA.
The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.
A direct-acting oxidative stress-inducing agent used to examine the effects of oxidant stress on Ca(2+)-dependent signal transduction in vascular endothelial cells. It is also used as a catalyst in polymerization reactions and to introduce peroxy groups into organic molecules.
The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
Introduction of substances into the body using a needle and syringe.
Transference of cells within an individual, between individuals of the same species, or between individuals of different species.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A tricarbocyanine dye that is used diagnostically in liver function tests and to determine blood volume and cardiac output.
Diseases affecting the eye.
Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.
Nerve cells of the RETINA in the pathway of transmitting light signals to the CENTRAL NERVOUS SYSTEM. They include the outer layer of PHOTORECEPTOR CELLS, the intermediate layer of RETINAL BIPOLAR CELLS and AMACRINE CELLS, and the internal layer of RETINAL GANGLION CELLS.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
The original member of the family of endothelial cell growth factors referred to as VASCULAR ENDOTHELIAL GROWTH FACTORS. Vascular endothelial growth factor-A was originally isolated from tumor cells and referred to as "tumor angiogenesis factor" and "vascular permeability factor". Although expressed at high levels in certain tumor-derived cells it is produced by a wide variety of cell types. In addition to stimulating vascular growth and vascular permeability it may play a role in stimulating VASODILATION via NITRIC OXIDE-dependent pathways. Alternative splicing of the mRNA for vascular endothelial growth factor A results in several isoforms of the protein being produced.
A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.
Congenital or developmental anomaly in which the eyeballs are abnormally small.
Color of the iris.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Photosensitive proteins expressed in the CONE PHOTORECEPTOR CELLS. They are the protein components of cone photopigments. Cone opsins are classified by their peak absorption wavelengths.
Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
A form of RETINAL DEGENERATION in which abnormal CHOROIDAL NEOVASCULARIZATION occurs under the RETINA and MACULA LUTEA, causing bleeding and leaking of fluid. This leads to bulging and or lifting of the macula and the distortion or destruction of central vision.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
A 195-kDa zonula occludens protein that is distinguished by the presence of a ZU5 domain at the C-terminal of the molecule.
An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.
A group of disorders involving predominantly the posterior portion of the ocular fundus, due to degeneration in the sensory layer of the RETINA; RETINAL PIGMENT EPITHELIUM; BRUCH MEMBRANE; CHOROID; or a combination of these tissues.
Transport proteins that carry specific substances in the blood or across cell membranes.
Tumors of the choroid; most common intraocular tumors are malignant melanomas of the choroid. These usually occur after puberty and increase in incidence with advancing age. Most malignant melanomas of the uveal tract develop from benign melanomas (nevi).
Devices for examining the interior of the eye, permitting the clear visualization of the structures of the eye at any depth. (UMDNS, 1999)
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
Optic disk bodies composed primarily of acid mucopolysaccharides that may produce pseudopapilledema (elevation of the optic disk without associated INTRACRANIAL HYPERTENSION) and visual field deficits. Drusen may also occur in the retina (see RETINAL DRUSEN). (Miller et al., Clinical Neuro-Ophthalmology, 4th ed, p355)
A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.
Inflammation of the RETINA. It is rarely limited to the retina, but is commonly associated with diseases of the choroid (CHORIORETINITIS) and of the OPTIC DISK (neuroretinitis).
An esterified form of TRIAMCINOLONE. It is an anti-inflammatory glucocorticoid used topically in the treatment of various skin disorders. Intralesional, intramuscular, and intra-articular injections are also administered under certain conditions.
The pigmented vascular coat of the eyeball, consisting of the CHOROID; CILIARY BODY; and IRIS, which are continuous with each other. (Cline et al., Dictionary of Visual Science, 4th ed)
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
Granulomatous uveitis which follows in one eye after a penetrating injury to the other eye; the secondarily affected eye is called the sympathizing eye, and the injured eye is called the exciting or activating eye.
Methods for maintaining or growing CELLS in vitro.
The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
An intracellular proteinase found in a variety of tissue. It has specificity similar to but narrower than that of pepsin A. The enzyme is involved in catabolism of cartilage and connective tissue. EC (Formerly EC
A TGF-beta subtype that was originally identified as a GLIOBLASTOMA-derived factor which inhibits the antigen-dependent growth of both helper and CYTOTOXIC T LYMPHOCYTES. It is synthesized as a precursor molecule that is cleaved to form mature TGF-beta2 and TGF-beta2 latency-associated peptide. The association of the cleavage products results in the formation a latent protein which must be activated to bind its receptor.
The coagulation of tissue by an intense beam of light, including laser (LASER COAGULATION). In the eye it is used in the treatment of retinal detachments, retinal holes, aneurysms, hemorrhages, and malignant and benign neoplasms. (Dictionary of Visual Science, 3d ed)
Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Cell-cell junctions that seal adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. (Alberts et al., Molecular Biology of the Cell, 2nd ed, p22)
A membrane on the vitreal surface of the retina resulting from the proliferation of one or more of three retinal elements: (1) fibrous astrocytes; (2) fibrocytes; and (3) retinal pigment epithelial cells. Localized epiretinal membranes may occur at the posterior pole of the eye without clinical signs or may cause marked loss of vision as a result of covering, distorting, or detaching the fovea centralis. Epiretinal membranes may cause vascular leakage and secondary retinal edema. In younger individuals some membranes appear to be developmental in origin and occur in otherwise normal eyes. The majority occur in association with retinal holes, ocular concussions, retinal inflammation, or after ocular surgery. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p291)
The process by which chemical compounds provide protection to cells against harmful agents.
The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
A pyridoxal phosphate enzyme that catalyzes the formation of glutamate gamma-semialdehyde and an L-amino acid from L-ornithine and a 2-keto-acid. EC
A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.
The relationship between the dose of an administered drug and the response of the organism to the drug.
A form of interference microscopy in which variations of the refracting index in the object are converted into variations of intensity in the image. This is achieved by the action of a phase plate.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Tumors or cancer of the EYE.
Coloration of the skin.
Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.
The most diversified of all fish orders and the largest vertebrate order. It includes many of the commonly known fish such as porgies, croakers, sunfishes, dolphin fish, mackerels, TUNA, etc.
Transference of fetal tissue between individuals of the same species or between individuals of different species.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Measurement of the various properties of light.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Elements of limited time intervals, contributing to particular results or situations.
A conditionally essential nutrient, important during mammalian development. It is present in milk but is isolated mostly from ox bile and strongly conjugates bile acids.
The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
A family of VERTEBRATE homeodomain proteins that share homology with orthodenticle protein, Drosophila. They regulate GENETIC TRANSCRIPTION and play an important role in EMBRYONIC DEVELOPMENT of the BRAIN.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.
Albinism affecting the eye in which pigment of the hair and skin is normal or only slightly diluted. The classic type is X-linked (Nettleship-Falls), but an autosomal recessive form also exists. Ocular abnormalities may include reduced pigmentation of the iris, nystagmus, photophobia, strabismus, and decreased visual acuity.
A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.
Formation of new blood vessels originating from the retinal veins and extending along the inner (vitreal) surface of the retina.
The administration of substances into the VITREOUS BODY of the eye with a hypodermic syringe.
Disease of the RETINA as a complication of DIABETES MELLITUS. It is characterized by the progressive microvascular complications, such as ANEURYSM, interretinal EDEMA, and intraocular PATHOLOGIC NEOVASCULARIZATION.
An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.
Inflammation of the choroid in which the sensory retina becomes edematous and opaque. The inflammatory cells and exudate may burst through the sensory retina to cloud the vitreous body.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
4-Methoxy-5-((5-methyl-4-pentyl-2H-pyrrol-2-ylidene)methyl)- 2,2'-bi-1H-pyrrole. A toxic, bright red tripyrrole pigment from Serratia marcescens and others. It has antibacterial, anticoccidial, antimalarial, and antifungal activities, but is used mainly as a biochemical tool.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured. Such rupture is supposed to be under metabolic (hormonal) control. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN.
Exudates are fluids, CELLS, or other cellular substances that are slowly discharged from BLOOD VESSELS usually from inflamed tissues. Transudates are fluids that pass through a membrane or squeeze through tissue or into the EXTRACELLULAR SPACE of TISSUES. Transudates are thin and watery and contain few cells or PROTEINS.
Organic compounds containing a carbonyl group in the form -CHO.
Inflammation of part or all of the uvea, the middle (vascular) tunic of the eye, and commonly involving the other tunics (sclera and cornea, and the retina). (Dorland, 27th ed)
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.
Centers for storing various parts of the eye for future use.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
The surgical removal of the eyeball leaving the eye muscles and remaining orbital contents intact.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
The absence of light.
A group of FLAVONOIDS derived from FLAVONOLS, which lack the ketone oxygen at the 4-position. They are glycosylated versions of cyanidin, pelargonidin or delphinidin. The conjugated bonds result in blue, red, and purple colors in flowers of plants.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
The quality of surface form or outline of ORGANELLES.
Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.
Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.
Devices used in a technique by which cells or tissues are grown in vitro or, by implantation, in vivo within chambers permeable to diffusion of solutes across the chamber walls. The chambers are used for studies of drug effects, osmotic responses, cytogenic and immunologic phenomena, metabolism, etc., and include tissue cages.
A disorder consisting of areas of macular depigmentation, commonly on extensor aspects of extremities, on the face or neck, and in skin folds. Age of onset is often in young adulthood and the condition tends to progress gradually with lesions enlarging and extending until a quiescent state is reached.
An inhibitor of anion conductance including band 3-mediated anion transport.
Mice bearing mutant genes which are phenotypically expressed in the animals.
A member of the family of tissue inhibitor of metalloproteinases. Mutations of the gene for TIMP3 PROTEIN causes Sorsby fundus dystrophy.
The administration of substances into the eye with a hypodermic syringe.
A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.

Inhibition of lysosomal degradative functions in RPE cells by a retinoid component of lipofuscin. (1/958)

PURPOSE: To investigate the effect of the lipofuscin component N-retinylidene-N-retinylethanolamine (A2-E) on degradative functions of lysosomes in human retinal pigment epithelial (RPE) cells and to evaluate its mechanism of action. METHODS: A2-E was coupled to low-density lipoprotein (LDL). Human RPE cell cultures were loaded with the A2-E/LDL complex, and controls were run with medium containing LDL alone. To determine whether A2-E accumulated in lysosomes, cells were fractionated in a Percoll gradient, and protein degradation was determined by metabolic labeling and measurement of the release of low-molecular-weight radioactivity. Lysosomal degradation was distinguished from nonlysosomal degradation by inclusion of NH4Cl in the medium. The metabolism of sulfated glycosaminoglycans was studied by radiosulfate incorporation in pulse-chase experiments. Intralysosomal pH was determined using a fluorescent lysosomotropic pH indicator. RESULTS: A2-E accumulated almost exclusively in the lysosomal compartment. Lysosomal protein degradation was reduced in a dose-dependent fashion in A2-E-treated cells. The selectivity of A2-E on lysosomal function was demonstrated by its lack of effect on degradation of extralysosomal protein. Lysosomal glycosaminoglycan catabolism of RPE cells was also strongly inhibited by A2-E. Lysosomal pH was increased by A2-E. CONCLUSIONS: The findings indicate that accumulation of A2-E in RPE cells interferes with lysosomal functions as exemplified by its inhibitory effect on protein and glycosaminoglycan catabolic pathways. The quaternary amine character of the A2-E apparently causes a perturbation of the acidic intralysosomal milieu, resulting in diminished hydrolase action and consequent accumulation of undegraded material. Such mechanism could be operative in retinal diseases associated with excessive lipofuscin accumulation including age-related macular degeneration.  (+info)

Human cone pigment expressed in transgenic mice yields altered vision. (2/958)

Genetically driven alterations in the complement of retinal photopigments are fundamental steps in the evolution of vision. We sought to determine how a newly added photopigment might impact vision by studying a transgenic mouse that expresses a human cone photopigment. Electroretinogram (ERG) measurements indicate that the added pigment works well, significantly changing spectral sensitivity without deleteriously affecting the operation of the native cone pigments. Visual capacities of the transgenic mice were established in behavioral tests. The new pigment was found to provide a significant expansion of the spectral range over which mice can perceive light, thus underlining the immediate utility of acquiring a new photopigment. The transgenic mouse also has the receptor basis for a novel color vision capacity, but tests show that potential was not realized. This failure likely reflects limitations in the organizational arrangement of the mouse retina.  (+info)

Regulation of mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors. (3/958)

Circadian rhythms of mammals are entrained by light to follow the daily solar cycle (photoentrainment). To determine whether retinal rods and cones are required for this response, the effects of light on the regulation of circadian wheel-running behavior were examined in mice lacking these photoreceptors. Mice without cones (cl) or without both rods and cones (rdta/cl) showed unattenuated phase-shifting responses to light. Removal of the eyes abolishes this behavior. Thus, neither rods nor cones are required for photoentrainment, and the murine eye contains additional photoreceptors that regulate the circadian clock.  (+info)

Regulation of the mammalian pineal by non-rod, non-cone, ocular photoreceptors. (4/958)

In mammals, ocular photoreceptors mediate an acute inhibition of pineal melatonin by light. The effect of rod and cone loss on this response was assessed by combining the rd mutation with a transgenic ablation of cones (cl) to produce mice lacking both photoreceptor classes. Despite the loss of all known retinal photoreceptors, rd/rd cl mice showed normal suppression of pineal melatonin in response to monochromatic light of wavelength 509 nanometers. These data indicate that mammals have additional ocular photoreceptors that they use in the regulation of temporal physiology.  (+info)

Mutually exclusive expression of human red and green visual pigment-reporter transgenes occurs at high frequency in murine cone photoreceptors. (5/958)

This study examines the mechanism of mutually exclusive expression of the human X-linked red and green visual pigment genes in their respective cone photoreceptors by asking whether this expression pattern can be produced in a mammal that normally carries only a single X-linked visual pigment gene. To address this question, we generated transgenic mice that carry a single copy of a minimal human X chromosome visual pigment gene array in which the red and green pigment gene transcription units were replaced, respectively, by alkaline phosphatase and beta-galactosidase reporters. As determined by histochemical staining, the reporters are expressed exclusively in cone photoreceptor cells. In 20 transgenic mice carrying any one of three independent transgene insertion events, an average of 63% of expressing cones have alkaline phosphatase activity, 10% have beta-galactosidase activity, and 27% have activity for both reporters. Thus, mutually exclusive expression of red and green pigment transgenes can be achieved in a large fraction of cones in a dichromat mammal, suggesting a facile evolutionary path for the development of trichromacy after visual pigment gene duplication. These observations are consistent with a model of visual pigment expression in which stochastic pairing occurs between a locus control region and either the red or the green pigment gene promotor.  (+info)

Structural specializations of the eye in the vizcacha (Lagostomus maximus maximus). (6/958)

Vizcachas (Lagostomus maximus maximus, Chinchillidae) are nocturnal rodents living in burrows in many regions of Argentina, Bolivia, and Chile. We have studied the eye of the vizcacha using several light and electron microscopic procedures, with the purpose of understanding the role of vision in the behavior of this species. Our observations demonstrated an avascular, rod-rich retina, with a specialized region spanning through most of the equator of the eye. In this central band, all neural retinal layers exhibited a high cell density, whereas the photoreceptor layer was characterized by the presence of very long rods. In addition, the central region was associated with a distinct pigmentation pattern, including scarce granulation of the pigment epithelium, low pigmentation of the choroid, and the selective attachment of suprachoroidal cells to the inner scleral surface. These central modifications probably form the structural basis of a reflecting tapetum. The eye of the vizcacha received both long and short ciliary vessels, and a specialized cilio-sclero-choroidal vascular network appeared at the equatorial region. Our findings suggest that the equatorial region of the eye of the vizcacha could be a highly sensitive light detector related to foraging behaviors during crepuscular or nocturnal hours.  (+info)

Identification and distribution of dietary precursors of the Drosophila visual pigment chromophore: analysis of carotenoids in wild type and ninaD mutants by HPLC. (7/958)

A dietary source of retinoid or carotenoid has been shown to be necessary for the biosynthesis of functional visual pigment in flies. In the present study, the larvae or adults of Drosophila melanogaster were administered specific carotenoid-containing diets and high performance liquid chromatography was used to identify and quantify the carotenoids in extracts of wild type and ninaD visual mutant flies. When beta-carotene was fed to larvae, wild type flies were shown to hydroxylate this molecule and to accumulate zeaxanthin and a small amount of beta-cryptoxanthin. Zeaxanthin content was found to increase throughout development and was a major carotenoid peak detected in the adult fly. Carotenoids were twice as effective at mediating zeaxanthin accumulation when provided to larvae versus adults. In the ninaD mutant, zeaxanthin content was shown to be specifically and significantly altered compared to wild type, and was ineffective at mediating visual pigment synthesis when provided to both larval and adult mutant flies. It is proposed that zeaxanthin is the larval storage form for subsequent visual pigment chromophore biosynthesis during pupation, that zeaxanthin or beta-crytoxanthin is the immediate precursor for light-independent chromophore synthesis in the adult, and that the ninaD mutant is defective in this pathway.  (+info)

How vertebrate and invertebrate visual pigments differ in their mechanism of photoactivation. (8/958)

In vertebrate visual pigments, a glutamic acid serves as a negative counterion to the positively charged chromophore, a protonated Schiff base of retinal. When photoisomerization leads to the Schiff base deprotonating, the anionic glutamic acid becomes protonated, forming a neutral species that activates the visual cascade. We show that in octopus rhodopsin, the glutamic acid has no anionic counterpart. Thus, the "counterion" is already neutral, so no protonated form of an initially anionic group needs to be created to activate. This helps to explain another observation-that the active photoproduct of octopus rhodopsin can be formed without its Schiff base deprotonating. In this sense, the mechanism of light activation of octopus rhodopsin is simpler than for vertebrates, because it eliminates one of the steps required for vertebrate rhodopsins to achieve their activating state.  (+info)

In an earlier issue the relationship between macular pigment density, dietary carotenoids, and age-related macular degeneration (AMD) was explored. The studies summarized in that issue demonstrated the following relationships: 1) increased pigment density with increased dietary intake of lutein and zeaxanthin; 2) reduced risk of AMD with higher serum levels of the retinal carotenoids lutein and zeaxanthin; and 3) reduced risk of AMD with increased dietary intake of these carotenoids. There is evidence that increasing macular pigment MP density may help prevent AMD. There is wide inter-patient variation in macular pigment density. However, not much research has been carried out describing the variation among different groups. In a study by Hammond and colleagues (1), results indicated a higher macular pigment density among males compared with females (38% higher density) despite similar plasma levels and dietary intake of carotenoids. This is consistent with epidemiological findings that women ...
A new model for thermal activation is proposed, with a consequent dependence of the activation rate on λmax. The crucial point is that the statistics of thermal activation is determined by the presence of internal energy in a large number of vibrational modes of the visual pigment molecule. The great discrepancy between photoactivation energies and thermal activation energies as estimated in earlier work then disappears as an analytical artifact. The main conclusion is that thermal and photic activation of visual pigments may follow the same molecular route from a very early stage (isomerization of the chromophore in the native conformation of rhodopsin). Furthermore, the model accurately predicts the correlation between the wavelength of maximum absorbance and the rate of thermal activation observed in the whole set of visual pigments studied ...
MPOD was measured with a 1° test stimulus. Test stimuli were presented in natural view and near the center of a 6°, 10.5-cd/m2, 470-nm circular background. The test stimulus was alternately composed of a 458-nm measuring field (peak MP absorbance) and a 570-nm, 16.7-cd/m2 reference field (minimal MP absorbance). Light for the measuring and reference fields and the background was produced by 40-nm band-pass LEDs with peak energy at 458, 570, and 470 nm (Nichia Corp., Mountville, PA). This measurement was obtained in the fovea (where MP is the most dense) and 4° in the parafovea (where light absorption by MP is negligible). A tiny (5-minute) opaque fixation point was located on the left edge of the background, and subjects fixated this point when making the parafoveal measurement. The measuring and reference fields were superposed and presented out of phase at an alternation rate of 11 to 12 Hz in the foveal condition and 6 to 7 Hz in the parafoveal condition. Subjects adjusted the radiance of ...
Alpern, M. & Pugh, E.N. (1974). The density and photosensitivity of human rhodopsin in the living retina. Journal of Physiology, London, 237, 341-370.. Alpern, M. (1967). Lack of uniformity in colour matching. Journal of Physiology, London, 288, 85-105.. Bowmaker, J.K. & Dartnall, H.J.A. (1980). Visual pigments of rods and cones in a human retina. Journal of Physiology, London, 298, 501-511.. Brindley, G.S. (1953). The effects on colour vision of adaptation to very bright lights. Journal of Physiology, London, 122, 332-350.. Brindley, G.S. (1955). A photochemical reaction in the human retina. Proceedings of the physical Society 68B, 862-870. Burns, S.A. & Elsner, A.E. (1993). Color matching at high luminances: photopigment optical density and pupil entry. Journal of the Optical Society of America A 10, 221-230.. Dobelle, W.H., Marks, W.B. & MacNichol, E.F. (1969). Visual pigment densities in single primate foveal cones. Science 166, 1508-1510.. Elsner, A. E., Burns, S.A. & Webb, R.H. (1993). ...
Purpose: : Neither the etiology nor the natural history of age-related maculopathy (ARM) and age-related macular degeneration (ARMD) is clearly known. Epidemiologic studies suggest that the number of risk factors may be associated with ARM. Possibly associated with ARM are personal characteristics e.g. race, age, smoking, and cardiovascular diseases. In addition recent studies indicate that the density of macular pigment (MP) may play a central role in development and progression of ARM. In this study we investigate central MP density and the different pattern of MP distribution in ARM patients with normal versus with high blood cholesterol. Methods: : All Patients underwent MP density measurements (MPD) with a modified confocal scanning laser ophthalmoscope (HRA, Heidelberg Engineering, Germany) following a standard protocol. Inclusion criteria included age above 50 years, the presence of drusen in at least one eye, no evidence of advanced ARMD in the study eye, and no other concomitant eye ...
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The cDNA probes were labeled with [α-32P]dCTP using the random primer method. Plaque hybridization was carried out at 65° in the solution consisting of 6× SSC, 5× Denhardts solution, 0.5% SDS, and 5 μg/ml Escherichia coli DNA. The hybridized membranes were washed in 1× SSC/0.1% SDS at 65° four times (20 min each), which allows ∼20% mismatch (Sambrook and Russel 2001). Three overlapping clones, λzf-B31, λzf-B26, and λzf-B29, encompassing a SWS2 gene (SWS2) and two LWS/MWS genes (LWS-1 and LWS-2) were isolated (Figure 1). Seven overlapping clones, λzf-C6, λzf-C2, λzf-C7, λzf-C13, λzf-C1, λzf-C3, and λzf-C16, were isolated encompassing four RH2 genes (RH2-1, RH2-2, RH2-3, and RH2-4). Two overlapping clones, λzf-A34 and λzf-A7, encompassing a SWS1 gene (SWS1) were isolated. After restriction mapping of these clones, the restriction fragments hybridized to the screening probes were subcloned into the pBluescript II (SK-) plasmid vector (Stratagene, La Jolla, CA). Sequencing of ...
elial cells turned upside down with their tips immersed in the pigmented layer of the retina. Going from the pigmented layer into the neural layer, rods and cones have an outer segment joined to an inner segment by a stalk containing a cilium. The inner segment connects to the cell body, or nuclear region, which is continuous with an inner fibre tipped with synaptic endings.. Image showing the position of the retina in the eye. Taken from chapter3/medialib/summary/1.html, without permission.. The light absorbing visual pigments are packaged in membrane bound discs within the outer segments. The coupling of the photoreceptor pigments to cellular membranes magnifies the surface area available for light trapping. In rods the discs are discontinuous and stacked like hollow pennies within the plasma membrane. In cones the discs become increasingly smaller towards the end of the cell and their membranes are continuous with the plasma membrane. ...
Estimates of the peaks of the absorption spectra of the pigments manufactured by the normal and hybrid pigment genes have been determined by Merbs & Nathans (1992a,b), who constructed hybrid genes from cDNA clones for the normal red and green photopigments and expressed them in cultured mammalian kidney cells. The gene products -- the artificial opsins -- were then combined with 11-cis-retinal and the cell membranes were solubilized in detergent. The absorption spectra of the resulting pigments were estimated by subtracting the absorption at each wavelength before and after bleaching (i.e., by means of photobleaching difference absorption spectroscopy). The absorption spectra of these recombinant human cone pigments, given in Table 1, indicate that the spectral sensitivity of each hybrid pigment is intermediate between the parental green and red pigment sensitivities. The amount of spectral shift depends upon the exons involved in the cross-over or fusion. Amino acids encoded by exons 2, 3, 4 ...
MacuHealth offers eye vitamins for macular degeneration to help anyone with the condition rebuild and maximize macular pigment over his or her lifetime.
I would present improved visual performance benefits of MacuHealth as follows. A formulation containing macular pigments constituent carotenoids, (L, Z, and MZ; MacuHealth;) is required to maximally increase macular pigment and improve visual performance in a way that its competitors do not do (and this has been demonstrated in a randomized, placebo-controlled trial).. It is likely, from an evolutionary perspective, that macular pigment is there to maximize visual performance and result in visual excellence, and this intuitive reason for accumulation of these unique compounds in the central retina is borne out in the recent randomized controlled trial, which showed that supplementation with MacuHealth did indeed result in improved visual performance by maximizing vision under conditions of glare (under twilight and daytime conditions) and by maximizing contrast sensitivity (the ability to discriminate the foreground from the background). In fact, a recent publication has shown this is also true ...
standard colorimetric observer performed poorly compared to the CIEPO06 model for all three subgroups. Finally, a constrained nonlinear optimization on the CIEPO06 model outputs showed that a peak wavelength shift of photopigment density alone could not improve the model prediction errors at higher wavelengths. As an alternative, two optimized weighting functions for each of the LWS and MWS cone photopigment densities led to significant improvement in the prediction of intra-age-group average data for both the 22-23 year and 49-50 year age groups. We hypothesize that the assumption in the CIEPO06 model that the peak optical density of visual pigments does not vary with age is false and is the source of these prediction errors at higher wavelengths. Correcting these errors in the model can lead to an improved age-dependent observer and can also help update the current CIE ...
An in situ spectral absorption and attenuation meter has been developed that measures the absorption coefficient at multiple wavelengths at a rate of several Hz. This instrument is based on the reflective tube absorption meter principle. A collimated beam of light is transmitted through a reflecting tube. Both the directly transmitted light and most of the scattered light are collected using a diffuser and photodiode at the end of the tube. Since most of the scattering in the ocean is near-forward only a small amount of light is lost. The instrument uses precisely the same principle as a spectrophotometer and is perhaps best thought of as an in situ spectrophotometer. Wavelengths are selected by means of a wheel containing interference filters in the light source housing. The device contains a beam splitter and a reference detector to correct for drift in lamp output. The device uses nine wavelengths. Figures 1-3 show profiles and absorption spectra obtained in East Sound, Washington. The ...
Cathepsins Part Three: Natural pain killers from our immune system In the autist the substances released back into the body when the macrophage engulfs and removes the pigment can be epoxides, carboxylase and potentially mu opioids. References ...
TY - JOUR. T1 - Macular pigment density in relation to serum and adipose tissue concentrations of lutein and serum concentrations of zeaxanthin. AU - Broekmans, W.. AU - Berendschot, T.T.J.M.. AU - Klopping-Ketelaars, I.A.A.. AU - de Vries, A.J.. AU - Goldbohm, R.A.. AU - Tijburg, L.B.M.. AU - Kardinaal, A.F.M.. AU - van Poppel, G.. N1 - 000177586600018. PY - 2002. Y1 - 2002. N2 - Background: Macular pigment (MP), concentrated in the central area of the retina, contains the carotenoids lutein and zeaxanthin. A low MP density could be a risk factor for age-related macular degeneration. Little information is available regarding MP density in relation to serum lutein and zeaxanthin and adipose lutein concentrations in a general population. Objective: The objective was to investigate the associations between MP density and serum lutein, serum zeaxanthin, and adipose lutein, taking into account potential confounders in a population. Design: Volunteers (n = 376) aged 18¿75 y were recruited. In a ...
Comparison of macular pigment optical density between phakic and pseudophakic eyes, Burcu Polat Gultekin, Ayten Bulut, Neslihan Bilen, Defne Kalayci
It is believed that different populations have different distributions of macular pigments [11]. Studies to determine MPOD in certain populations have been performed in many locations, including China [14], Australia [16], Central Europe [12], and South Asia [17]. Mean MPOD values have varied substantially from one study to the other. Mean MPOD obtained from a sample from Central Europe (0.126 d.u. ± 0.004) is very close to this Brazilian sample (0.14 d.u. ± 0.05). The remaining studies found higher values: mean MPOD in Australia was 0.41 d.u. ± 0.20; mean MPOD in South Asia was 0.43 d.u. ± 0.14; and mean MPOD in China was 0.303 d.u. ± 0.097. A possibility for this difference could be the technique used to determine MPOD. This study and the one performed in Central Europe were the only ones to use the Visucam 500 (Carl Zeiss Meditec, Jena, Germany). The studies performed in South Asia and Australia used the subjective HFP method. However, the literature shows a strong correlation between ...
1. Showed a 30% reduced macular pigment density in eyes with AMD.. 2. Found a correlation between reduced macular pigment density and increased lens density (cataracts) in seniors; and. 3. Demonstrated that macular pigment density can be increased with dietary and/or supplemental Lutein. Maintaining sufficient levels of Lutein & Zeaxanthin (the only Carotenoid antioxidants active in the retina) can prevent ARMD and Cataracts and preserve youthful visual sensitivity.. Most individuals supplementing with sublingual Lutein and Zeaxanthin report reduced glare and visual fatigue; improved contrast sensitivity. Vinpocetine (vin-po-seh-teen) an extract from periwinkle seeds (vinca major) has been well researched and available in Europe for the past twenty years. Recently, it became available as a dietary supplement. Vinpocetine has been included in this formula for safer and more effective circulatory benefits to the entire retina. There are no known negative interactions with other dietary ...
Visual system homeobox 1 is a protein that in humans is encoded by the VSX1 gene. The protein encoded by this gene contains a paired-like homeodomain and binds to the core of the locus control region of the red/green visual pigment gene cluster. The encoded protein may regulate expression of the cone opsin genes early in development. Mutations in this gene can cause posterior polymorphous corneal dystrophy (PPCD) and keratoconus. Two transcript variants encoding different isoforms have been found for this gene. GRCh38: Ensembl release 89: ENSG00000100987 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000033080 - Ensembl, May 2017 Human PubMed Reference:. Mouse PubMed Reference:. Semina EV, Mintz-Hittner HA, Murray JC (Apr 2000). Isolation and characterization of a novel human paired-like homeodomain-containing transcription factor gene, VSX1, expressed in ocular tissues. Genomics. 63 (2): 289-93. doi:10.1006/geno.1999.6093. PMID 10673340. Entrez Gene: VSX1 visual system homeobox ...
One of the greatest challenges facing the early land vertebrates was the need to effectively interpret a terrestrial environment. Interpretation was based on ocular adaptations evolved for an aquatic environment millions of years earlier. The Australian lungfish Neoceratodus forsteri is thought to be the closest living relative to the first terrestrial vertebrate, and yet nothing is known about the visual pigments present in lungfish or the early tetrapods. Here we identify and characterise five visual pigments (rh1, rh2, lws, sws1 and sws2) expressed in the retina of N. forsteri. Phylogenetic analysis of the molecular evolution of lungfish and other vertebrate visual pigment genes indicates a closer relationship between lungfish and amphibian pigments than to pigments in teleost fishes. However, the relationship between lungfish, the coelacanth and tetrapods could not be absolutely determined from opsin phylogeny, supporting an unresolved trichotomy between the three groups. The presence of four cone
This chapter describes the three visual pigments and their distribution in the retina of Watasenia scintillans. These have absorbance maxima at 471 nm, 484 nm, and 501 nm. The 484 nm pigment is based on retinal, the 501 nm pigment on 3-dehydroretinal, and the 471 nm pigment on the novel chromophore 4-hydroxyretinal. In the dorsal retina, the rhabdomes are 200 μm thick and consist of photoreceptor outer segments containing the visual pigment with retinal (A1 pigment). In the specific region of the ventral retina receiving downwelling light, the rhabdomes, the photoreceptor outer segments are 600 μm thick. The distal outer segment layer, 400 μm thick from the retinal surface, contains the yellowish visual pigment based on 4-hydroxyretinal (A4 pigment) and the proximal outer segment layer contains the pinkish visual pigment based on 3-dehydroretinal (A2 pigment). It was observed that while one type of photoreceptor had rhabdomes only in the proximal outer segment layer, the other types had rhabdomes
Visual pigments are photopigments in the retinal photoreceptors that absorb light and mediate vision. The absorbance spectra of visual pigments that fish has are closely re-lated to the environmental light in its natural habitats. In order to understand the visual spectral sensitivity of juvenile sutchi catfish (Pangasianodon hypophthalmus), the ab-sorbance spectra of visual pigments were measured in this study. Sutchi catfish juve-niles were dark-adapted overnight and then anaesthetized. In the dark room, both eyes of the juveniles were enucleated and retinae were isolated under a dissecting micro-scope with the aid of a night vision goggles. The retinae were cut into small pieces (~ 9 mm2) in a petri dish filled with buffered saline. Each retina sample was placed on a co-verslip with a drop of saline. Second smaller coverslip was then placed on the sample and sealed with Vaseline to prevent dryness. Absorbance measurement was conducted by means of spectrophotometrically using a portable ...
Looking for online definition of pigment genes in the Medical Dictionary? pigment genes explanation free. What is pigment genes? Meaning of pigment genes medical term. What does pigment genes mean?
TY - JOUR. T1 - Absorption spectra of the hybrid pigments responsible for anomalous color vision. AU - Merbs, Shannath L.. AU - Nathans, Jeremy. PY - 1992/1/1. Y1 - 1992/1/1. N2 - Unequal homologous recombination events between green and red cone pigment genes produce the red-green or green-red hybrid pigment genes found in many individuals with variant color vision. Photobleaching difference absorption spectroscopy of hybrid pigments produced in cultured cells shows that the spectral sensitivity of each hybrid pigment is intermediate between the parental green and red pigment sensitivities. Amino acids encoded by exons 2, 3, 4, and 5 produce spectral shifts at the wavelength of maximal absorbance of 0 to 4, 0 to 4, 3 to 4, and 15 to 21 nanometers, respectively, the exact value depending on the identities of amino acids elsewhere in the hybrid.. AB - Unequal homologous recombination events between green and red cone pigment genes produce the red-green or green-red hybrid pigment genes found in ...
The hypothesis that dichromatic behavior on a clinical anomaloscope can be explained by the complement and arrangement of the long- (L) and middle-wavelength (M) pigment genes was tested. It was predicted that dichromacy is associated with an X-chromosome pigment gene array capable of producing only a single functional pigment type. The simplest case of this is when deletion has left only a single X-chromosome pigment gene. The production of a single L or M pigment type can also result from rearrangements in which multiple genes remain. Often, only the two genes at the 5′ end of the array are expressed; thus, dichromacy is also predicted to occur if one of these is defective or encodes a defective pigment, or if both of them encode pigments with identical spectral sensitivities. Subjects were 128 males who accepted the full range of admixtures of the two primary lights as matching the comparison light on a Neitz or Nagel anomaloscope. Strikingly, examination of the L and M pigment genes ...
Results to be showcased internationally in the Journal of Alzheimers Disease.. Ongoing European Research Council-funded research at Waterford Institute of Technologys (WIT) Macular Pigment Research Group (MPRG) is investigating the potential link between cognitive function and levels of a vital eye pigment linked to diet. The study suggests that measuring macular pigment offers potential as a biomarker of cognitive health. The results of this study are highlighted to a global audience through the prestigious international medical journal, the Journal of Alzheimers Disease.. The Waterford clinical trial research, conducted by a team of 10 researchers and healthcare professionals, investigated two patient groups - those free of retinal disease but with low macular pigment and those with early age-related macular degeneration.. A series of tests were carried out on the volunteer trial patients at the analytical and vision laboratories in Carriganore House on WITs West Campus where the MPRG is ...
Shabaan et al. (1998) were the first to examine how a newly added human cone photopigment could affect vision in genetically modified mice. They established that the human transgene for human long wavelength sensitive (L) photopigment was expressed in mouse cones, and that the pigment was efficient at transducing light. Following earlier modeling approaches (Webster & MacLeod, 1988; Peterzell, 1991), we factor-analyzed individual differences in the spectral sensitivity data of Shabaan et al. to (1) measure independent expression of M and L photopigments, and (2) extract estimates of their absorption spectra. Flicker-electroretinogram (ERG) responses from five wild-type controls and five transgenic mice were recorded at 15 and 19 wavelengths (460 to 640 nm). Visual inspection of spectral sensitivity functions revealed one factor for wild-type mice, and two for transgenic mice. Pearson correlations (r) revealed the same. Principal component analyses of covariance matrices confirmed that one- ...
Lutien has been found to play a role in eye care and helping to prevent eye disease. In a presentation given at the American Academy of Ophthalmologys annual meeting in October 2000, Lutien was shown to help reduce the risk of macular degeneration by helping maintain the macular pigment density in the eye. The
Metagenics Vision Care support relief of eye strain & visual fatigue. Metagenics Vision Care support an increase in macular pigment density in the elderly
Three major classes of photosynthetic pigments occur among the algae: chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins. The pigments are characteristic of certain algal groups as indicated below.
February 6, 2013: According to photometry provided by Don Collins (CDK, Swannanoa, NC), the eclipse in the b Per system (HD 26961), predicted for around 2013 January 25, is underway now and began February 4-5. Photometry - multicolor if possible - is urgently needed now to cover the rest of this eclipse, which may last for up to four days altogether, and see post-eclipse behavior of the system.. The campaign to detect and monitor this eclipse in this bright (4.52 V) triple system is described in AAVSO Alert Notice 476 ( Dr. Bob Zavala (U.S. Naval Observatory, Flagstaff) requested AAVSO assistance in obtaining multicolor photometry in order to prepare for and detect a possible eclipse of the AB components by the C component. The eclipse is taking place about a week later than he had predicted it might occur.. Photometry is needed at the level of 0.02-0.03 magnitude or better. Instructions, comparison and check star identifications, etc., are given in ...
Fluctuations in market availability of natural and synthetic pigments have generated a need for new strategies to optimise the use of available pigments and maintain colouration levels of demanded products. Yellow pigments can partially be replaced by red pigments to obtain the same desired result.
Get an answer for what photosynthetic pigments are present in euglenophyta? and find homework help for other Photosynthesis questions at eNotes
Color fading and dulling of foundation pigments can be avoided by new coating materials and application techniques, as this article demonstrates in the case of a pearl protein extract applied by a fluid air bed coating technology. This technology also treats pigments and fillers to give them optical properties to improve skin radiance.
Absorption spectra of AgHal emulsions Influence of crystal size Processing fixed layer in a standard fixing solution: 3 min (-.-), 1 h (-..-), 4 h (-…-), 12 h (-….-). The dependence connecting a starting position of spectral absorption maxima (an X axis) with a maximum of the strip which have arisen after full dissolution AgBr of an initial irradiated layer (an Y axis).
Lumega-Z is a Medical will need a DAC (Doctor Authorization Code) number in order to process your order. If you dont have a DAC number, please call us at (888) 512-5550 so that we may assist you. ...
An apparatus is described for the fully automatic measurement of the relative spectral sensitivity distributions of photoelectric receivers. A substitution method is used in which, after calibration of an auxiliary photomultiplier against a reference thermopile, the sample receiver is mounted in the position formerly occupied by the thermopile. Precision and accuracy of the measurements are discussed.. © 1971 Optical Society of America. Full Article , PDF Article ...
Thank you James for your reply.. I would also be pleased if you or some one else verifies my complete process which I had followed in doing Photometry.. I have taken photos using DSLR Canon 1100D using a tripod. The images taken were stacked using Deep Sky Stacker taking the dark frames and light frames which I had ensured were correct from the histogram of flat frame. Then I had used that image in Astroart to do aperture photometry. I had used a comparison star which was bright enough and should have a constant magnitude ideally. This was done to take the atmospherical conditions into account for the main variable star. For example, beta-lyras comparison star was Vega. We have plotted the points using matlabs polyfit function.. Is this complete process is scientifically correct?. Thanking you. Regards. Aayush Sultania. ...
(2015) Soubias et al. Biophysical Journal. Abstract Lipid composition of the membrane and rhodopsin packing density strongly modulate the early steps of the visual response of photoreceptor membranes. In this study, lipid-order and bovine rhodopsin function in proteoliposomes composed of the sn-1...
Sennelier keeps a watchful eye on the pigments selected for its lines of extra-fine oils, oil sticks, watercolors, soft pastels, and oil pastels. These same pure pigments are now available to artists wishing to master the preparation of their own colors.
PIGMENT METABOLISM PRESENTER - Dr SHREYA PRABHU MODERATOR - Dr ANISHA T S 1 INTRODUCTION  PIGMENTS are colored substances, some of which are normal constituents of cell,…
 Nylon 6/6 (PA 6/6) PTFE 2%, PTFE 2% Comments: PTFE Lubricated Unless otherwise specified, all data listed is for natural or black colored materials. Pigments can affect properties. Information provided by RTP Company.
Question - Photometry test done. What is the analysis and treatment? . Ask a Doctor about diagnosis, treatment and medication for Alcoholism, Ask a General & Family Physician
represents a panel which shows the summary of photometry, and which has a button to apply the result to the XML report document ...
Shop Simple Designs Incandescent Table Lamp Set, Red (LT2013-RED-2PK) at Staples. Choose from our wide selection of Simple Designs Incandescent Table Lamp Set, Red (LT2013-RED-2PK) and get fast & free shipping on select orders.
A color-change material has a reversibly thermochromic layer and a porous layer containing a low-refractive-index pigment. The color-change material changes its color in response to heat or water. The reversibly thermochromic layer and the porous layer are superposed on each other, or the reversibly thermochromic layer and the porous layer are formed side by side. Alternatively, a color-change material has a substrate and formed thereon a color-changing porous layer including a reversibly thermochromic material, a low-refractive-index pigment, and a binder. The reversibly thermochromic material and the pigment are dispersed in the binder and tenaciously adherent thereto.
Easily dispersible (called ED) version of Hostaperm Red D3G 70 for solvent-borne coating systems. These pigments are surface modified with a highly efficient and widely compatible dispersing additive; hence they can also be dispersed with a dissolver, provided that their mill bases have been suitably formulated. The dispersion of ED pigments does not require additional dispersant as they already contain the optimal amount of additive for the modification of their surfaces. The coloristic properties of Hostaperm Red D3G 70-EDS VP 3680 can differ from those of the conventional pigment as a result of their improved ease-of-dispersion.
Dedicated to handmade integrity, Williamsburg Handmade Oils are crafted by skilled American artisans using top-quality pigments from around the world. Each of the more than 140 Colours are made in small batches no larger than five gallons at a time to ensure the highest level of control. Pigments are carefully ground t
Combine phase A under Silverson (Rotor/Stator) mixer until pigments are full dispersed. Combine phase B and mix well. Under a dispersing blade, slowly add phase B to phase A and mix for ~10 minutes under moderate shear. Reduce speed and add phase C mixing until uniform. Add phase D and mix until uniform. Add phase E and mix until uniform ...
A Leading Global Manufacturer of IR Reflective Pigments, Ferro offers Cool Colors® PG 17 Chrome Oxide Green pigments with high NIR Reflectance.
Gem made in 1993-1994. A brief photometric analysis for the new light curves is carried out using the Wilson-Devinney method with spot approximation based on the Roche model. The result suggests the probable presence of two cool spots on the K1 III primary around the phases of ...
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The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory ... Retinal Pigment Epithelium and Macular Diseases. Springer. ISBN 0-7923-5144-4. Strauss O (2005) "The retinal pigment epithelium ... Yang, Song; Zhou, Jun; Li, Dengwen (28 July 2021). "Functions and Diseases of the Retinal Pigment Epithelium". Frontiers in ... Gardner syndrome is characterized by FAP (familial adenomatous polyps), osseous and soft tissue tumors, retinal pigment ...
"Pfam entry: Retinal pigment epithelial membrane protein". Archived from the original on 2007-09-29. Retrieved 2007-01-25. "Pfam ...
"Light-induced responses of the Retinal pigment epithelium". In: M. F. Marmor and T. J. Wolfensberger, eds. The Retinal Pigment ... "Transport mechanisms in the retinal pigment epithelium". In: The retinal pigment epithelium: function and disease. Marmor MF, ... "Clinical electrophysiology of the retinal pigment epithelium". In: M. F. Marmor and T. J. Wolfensberger, eds. The Retinal ... "Light-evoked modulation of basolateral membrane Cl− conductance in chick retinal-pigment epithelium - the light peak and fast ...
75 Arun D. Singh; Harminder S. Dua (1997). "16 Retinal pigment epitheliopathies". In A. M. Peter Hamilton; Richard Gregson; ... Reddish eyes are due to the lack of pigment in the iris pigment epithelium. When the stroma is unpigmented but the iris pigment ... They also have two layers of pigmented tissue in the eye: the stroma, at the front of the iris, and the iris pigment epithelium ... Pigment cells of the iris pigment epithelium have a separate embryological origin. Piebaldism and amelanism are distinct ...
Fasick, Jeffry I.; Robinson, Phyllis R. (23 June 2016). "Adaptations of Cetacean Retinal Pigments to Aquatic Environments". ... Retinal 1 (11-cis-Retinal) - the common form present in most opsins Retinal 2 (11-cis-3,4-Dehydroretinal) - a rarer form that ... and must bind retinal ⁠- typically 11-cis-retinal ⁠- in order to be photosensitive, since the retinal acts as the chromophore. ... While opsins can only bind retinal, there are two forms of retinal that can act as the chromophore for vertebrate visual opsins ...
Sato S, Lin LR, Reddy VN, Kador PF (August 1993). "Aldose reductase in human retinal pigment epithelial cells". Experimental ...
Strauss O The retinal pigment epithelium in visual function. Physiological Reviews. July 2005; 85(3): 845-881. Quote from p. ... These subjects also have night blindness and retinal dystrophy but few other signs of vitamin A deficiency." ...
There are several functions of the retinal pigment epithelium. One of the main functions of the retinal pigment epithelium is ... As these cells break down and release their pigment, dark clumps of released pigment and later, areas that are less pigmented ... incomplete retinal pigment epithelium and outer retinal atrophy). These 'high-risk' subgroups of intermediate AMD can be used ... The retinal pigment epithelium (RPE) (see diagram) has an essential role in the eye. It secretes a large variety of factors ...
... - Helen Keller Foundation (with video) Machemer R; Laqua H (1975). "Pigment epithelium proliferation in retinal ... He is sometimes called the "father of modern retinal surgery." Helmut Machemer, Robert's father, was an ophthalmologist who ... He established an animal model of retinal detachment and used this model to study proliferative vitreoretinopathy (PVR), which ...
The tapetum lucidum is within the retinal pigment epithelium; in the other three types the tapetum is within the choroid behind ... A classification of anatomical variants of tapeta lucida defines four types: Retinal tapetum, as seen in teleosts, crocodiles, ... adaptive changes in retinal reflections to winter darkness in Arctic reindeer". Proceedings of the Royal Society B. 280 (1773 ... Traditionally it has been difficult to take retinal images of animals with a tapetum lucidum because ophthalmoscopy devices ...
The retinal pigment epithelium also degenerates. Over time, the abnormal accumulation of this substance can damage the cells ... localizes to the basolateral plasma membrane of the retinal pigment epithelium". Proceedings of the National Academy of ... Mutations in the RDS gene disrupt the structures in these cells that contain light-sensing pigments, leading to vision loss. It ... Vitelliform macular dystrophy causes a fatty yellow pigment (lipofuscin) to build up in cells underlying the macula. ...
... is a different disease from PRA involving the retinal pigment epithelium (RPE), and is also known as retinal pigment epithelial ... CPRA is also known as retinal pigment epithelial dystrophy (RPED). The cause of this condition is the loss of the retinal ... It is characterized by accumulation of pigment spots in the retina surrounded by retinal atrophy and a mottled appearance of ... It can also be found in the poodle varieties There is another retinal disease in Briards known as hereditary retinal dysplasia ...
Jiang M, Pandey S, Tran VT, Fong HK (May 1991). "Guanine nucleotide-binding regulatory proteins in retinal pigment epithelial ...
Carotene to Retinal Pigment". Conversion of β-carotene to retinal pigment. Vitamins & Hormones. Vol. 75. pp. 117-30. doi: ... β-carotene content is confirmed in human retinal pigment epithelium. Reviews reported mixed results for observational studies, ... Once taken up by peripheral tissue cells, the major usage of absorbed β-carotene is as a precursor to retinal via symmetric ... β-Carotene (beta-carotene) is an organic, strongly coloured red-orange pigment abundant in fungi, plants, and fruits. It is a ...
"OTX2 regulates expression of DOPAchrome tautomerase in human retinal pigment epithelium". Biochemical and Biophysical Research ... Otx2 also represses specific retinal fates (such as subtypes of retinal ganglion and horizontal cells) of sister cells to ... "Functional and Evolutionary Diversification of Otx2 and Crx in Vertebrate Retinal Photoreceptor and Bipolar Cell Development". ... "The transcription factor Engrailed-2 guides retinal axons". Nature. 438 (7064): 94-8. Bibcode:2005Natur.438...94B. doi:10.1038/ ...
April 2003). "A novel function for Hedgehog signalling in retinal pigment epithelium differentiation". Development. 130 (8): ...
... is caused by bleaching (oversaturation) of the retinal pigment. As the pigment returns to normal, so too does ... If the intensity is great enough, a permanent retinal burn (photic retinopathy) will result." It is unclear whether pain is ...
Pautler EL, Morita M, Beezley D (May 1990). "Hemoprotein(s) mediate blue light damage in the retinal pigment epithelium". ... Photochemically-induced retinal injury is caused by the absorption of light by photoreceptors in the eye. Under normal ... October 2001). "[Retinal hazard from blue light emitting diode]". Nippon Ganka Gakkai Zasshi (in Japanese). 105 (10): 687-95. ... 408 nm and 25 minutes of 430 nm are sufficient to cause irreversible death of photoreceptors and lesions of the retinal pigment ...
Formed by endothelium of retinal vessels and epithelium of retinal pigment. Blood-air barrier - Membrane separating alveolar ... Blood-retinal barrier: non-fenestrated capillaries of the retinal circulation and tight-junctions between retinal epithelial ... ciliary epithelium and retinal pigment epithelium. It is a physical barrier between the local blood vessels and most parts of ... Semipermeable capillary border that allows selective passage of blood constituents into the brain Blood-retinal barrier - Part ...
These parts conduct photosynthetic reactions with retinal pigment rather than chlorophyll. This allows them to create a proton ... This pigment is used to absorb light, which provides energy to create ATP. Halobacteria also possess a second pigment, ... Large blooms appear reddish, from the pigment bacteriorhodopsin. ...
Sato S, Lin LR, Reddy VN, Kador PF (August 1993). "Aldose reductase in human retinal pigment epithelial cells". Experimental ... It has been reported that the action of AR contributes to the activation of retinal microglia, suggesting that inhibition of AR ... Akagi Y, Kador PF, Kuwabara T, Kinoshita JH (November 1983). "Aldose reductase localization in human retinal mural cells". ... "Aldose reductase inhibition prevents endotoxin-induced inflammatory responses in retinal microglia". Investigative ...
Saari JC, Bredberg DL (1989). "Lecithin:retinol acyltransferase in retinal pigment epithelial microsomes". J. Biol. Chem. 264 ( ...
All the retinal molecules in the chromophore of the visual pigment molecule, exist in the 11-trans-retinal state after ... and subsequent conversion to the 11-cis-retinal state in retinal pigment epithelial cells, for both rod and cone cells. The 11- ... retinal Müller and retinal pigment epithelial cells". Experimental Eye Research. 76 (2): 257-60. doi:10.1016/s0014-4835(02) ... CRALBP is not just found in retina and retinal pigment epithelial cells, but also expressed in other cell types. It is majorly ...
... regulates melanosome biogenesis and localization in the retinal pigment epithelium". Development. 133 (20): 4109-18. doi: ... Shroom2 is both necessary and sufficient to govern the localization of pigment granules at the apical surface of epithelial ...
2002). "Apoptosis-mediating receptor-ligand systems in human retinal pigment epithelial cells". Graefes Arch. Clin. Exp. ...
"Membrane receptors for retinol-binding protein in cultured human retinal pigment epithelium". Investigative Ophthalmology & ... "Reductions in serum vitamin A arrest accumulation of toxic retinal fluorophores: a potential therapy for treatment of ... lipofuscin-based retinal diseases". Investigative Ophthalmology & Visual Science. 46 (12): 4393-401. doi:10.1167/iovs.05-0820. ...
Saari JC, Garwin GG, Van Hooser JP, Palczewski K (1998). "Reduction of all-trans-retinal limits regeneration of visual pigment ... All-trans-retinol dehydrogenase (RDH8) is a visual cycle enzyme that reduces all-trans-retinal to all-trans-retinol in the ... 2004). "Retinal dehydrogenase 12 (RDH12) mutations in leber congenital amaurosis". Am. J. Hum. Genet. 75 (4): 639-646. doi: ... It is important in the visual cycle by beginning the rhodopsin regeneration pathway by reducing all-trans-retinal, the product ...
Khanobdee K, Kolberg JB, Dunlevy JR (2005). "Nuclear and plasma membrane localization of SH3BP4 in retinal pigment epithelial ...
... a novel visual pigment-like protein located in the apical microvilli of the retinal pigment epithelium". Proceedings of the ... "Entrez Gene: RRH retinal pigment epithelium-derived rhodopsin homolog". Gühmann M, Porter ML, Bok MJ (August 2022). "The ... In mice, a peropsin is localized to the apical microvilli of the retinal pigment epithelium (RPE). There, it regulates storage ... Since RGR-opsin may be associated with retinitis pigmentosa, which is like peropsin also expressed in the retinal pigment ...
This group was studying human retinal cell development by identifying secreted factors produced by the retinal pigmented ... In humans, pigment epithelium-derived factor is encoded by the SERPINF1 gene. Pigment epithelium-derived factor (PEDF) was ... "Pigment epithelium-derived factor suppresses ischemia-induced retinal neovascularization and VEGF-induced migration and growth ... "Pigment epithelium-derived factor inhibits retinal and choroidal neovascularization". Journal of Cellular Physiology. 188 (2): ...
DasSarma proposed that retinal pigments originally discovered in halophilic Archaea may have predated chlorophyll pigments in ...
Its red color is due primarily to the presence of bacterioruberin, a 50 carbon carotenoid Alcohol (polyol) pigment present ... Upon absorption of a photon, retinal changes its conformation, causing a conformational change in the bacterioopsin protein, as ... It consists of two parts: the 7-transmembrane protein, bacterioopsin, and the light-sensitive cofactor, retinal. ... red or salmon-coloured pigment. H. salinarum is polyploid and highly resistant to ionizing radiation and desiccation, ...
Stereopsis, or retinal (binocular) disparity, or binocular parallax Animals that have their eyes placed frontally can also use ... pigments (red, yellow and orange) to bring features forward towards the viewer, and "cool" ones (blue, violet, and blue-green) ... It may contribute to the depth perception in natural retinal images, because the depth of focus of the human eye is limited. In ... Binocular cues include retinal disparity, which exploits parallax and vergence. Stereopsis is made possible with binocular ...
This mutation results in defective retinal pigment epithelium phagocytosis of photoreceptor outer segments. The shaking rat ... The Royal College of Surgeons rat (or RCS rat) is the first known animal with inherited retinal degeneration. Although the ... "Mutation of the receptor tyrosine kinase gene Mertk in the retinal dystrophic RCS rat". Human Molecular Genetics. 9 (4): 645-51 ...
... steroid-response factors and similarities with retinal pigment epithelium". Molecular Vision. 8: 185-195. PMID 12107412. Pizon ...
DasSarma S, Schwieterman EW (2018). "Early evolution of purple retinal pigments on Earth and implications for exoplanet ... related to the retinal pigment rhodopsin, which it uses to transform light energy into chemical energy by a process unrelated ... Early evolution of retinal proteins has been proposed as the purple Earth hypothesis. Haloarchaea are often considered ... Parts of the membranes of haloarchaea are purplish in color, and large blooms of haloarchaea appear reddish, from the pigment ...
Dry (non-exudative, > 80%)-deposition of yellowish extracellular material in and between Bruch's membrane and retinal pigment ... The retinal mechanism involves the displacement of retinal layers which results in the mislocation of light on the retina. The ... The mechanisms that result in the development of metamorphopsia involve structural changes in the retina of the eye (retinal ... The cortical mechanism was found to work in combination with the retinal mechanism to contribute to metamorphopsia in long- ...
Separation of retinal layers Central serous retinopathy Retinal detachment: Detachment of retinal pigment epithelium (H35.8) ... Other specified retinal disorders (H35.81) Macular edema - distorted central vision, due to a swollen macula (H35.9) Retinal ... Peripheral retinal degeneration (H35.5) Hereditary retinal dystrophy (H35.5) Retinitis pigmentosa - genetic disorder; tunnel ... Retinal detachment - the retina detaches from the choroid, leading to blurred and distorted vision (H33.1) Retinoschisis - the ...
Over time, these pigment cells can accumulate in the anterior chamber and begin to clog the trabecular meshwork. It is a rare ... The retinal nerve fiber layer can be assessed with imaging techniques such as optical coherence tomography, scanning laser ... In glaucoma visual field defects result from damage to the retinal nerve fiber layer. Field defects are seen mainly in primary ... Puyo L, Paques M, Atlan M (2020). "Retinal blood flow reversal in out-of-plane vessels imaged with laser Doppler holography". ...
The mutation of Retinal pigment epithelium-specific 65 kDa protein (RPE65) gene which function to produce retinoid ... RPE65 performs a key role in the trans-cis isomerization of retinol in the retinal pigment epithelium of the eye. The ...
"Isomerization of all-trans-retinol to cis-retinols in bovine retinal pigment epithelial cell: dependence on the specificity of ...
... can be attributed to the higher saturation and lighter value of warm pigments in contrast to cool pigments; brown is a dark, ... by defining the CMY primaries as substances that absorbed only one of the retinal primary colors: cyan absorbs only red (−R+G+B ... A pigment that is pure red at high concentrations can behave more like magenta at low concentrations. This allows it to make ... Chromium red pigments can appear orange, and then yellow, as the concentration is reduced. It is even possible to mix very low ...
Her dissertation was titled: Novel roles for the retinal pigment epithelium in expression and turnover of interphotoreceptor ... Cunningham, Lisa Lynn (1999). Novel roles for the retinal pigment epithelium in expression and turnover of interphotoreceptor ...
"Enrichment of Macular Pigment Enhances Contrast Sensitivity in Subjects Free of Retinal Disease: Central Retinal Enrichment ... Bone, RA; Landrum, JT; Cao, Y; Howard, AN; Alvarez-Calderon, F (2007). "Macular pigment response to a supplement containing ... Connolly, EE; Beatty, S; Thurnham, DI; Loughman, J; Howard, AN; Stack, J; Nolan, JM (2010). "Augmentation of macular pigment ... the more normal pigment profile was re-instated, whereas this was not the case when supplemented with a formulation lacking ...
Boon CJ, den Hollander AI, Hoyng CB, Cremers FP, Klevering BJ (March 2008). "The spectrum of retinal dystrophies caused by ... the macular pigment in human eyes". British Journal of Ophthalmology. 82 (8): 907-910. doi:10.1136/bjo.82.8.907. PMC 1722697. ... Progress in Retinal and Eye Research. 28 (3): 187-205. doi:10.1016/j.preteyeres.2009.04.002. PMID 19375515. S2CID 22339729. ... mutations in the peripherin/RDS gene". Progress in Retinal and Eye Research. 27 (2): 213-235. doi:10.1016/j.preteyeres.2008.01. ...
Each different pigment is especially sensitive to a certain wavelength of light (that is, the pigment is most likely to produce ... Calderone, JB; Reese, BE; Jacobs, GH (2003). "Topography of photoreceptors and retinal ganglion cells in the spotted hyena ( ... In fish and birds, for example, four pigments are used for vision. These extra cone receptor visual pigments detect energy of ... Eventually two of these pigments were lost (in placental mammals) and another was gained, resulting in trichromacy among some ...
The conjunction of the two things entirely removes the retinal aspect that I don't like. It was very logical. - Dialogues with ... gathering a thick layer of dust which Duchamp then proceeded to use as a pigment, gluing the dust down with varnish to one part ...
This protein is associated with the primary cilia of the retinal pigment epithelial cells, fibroblasts and kidney tubular cells ...
... became apparent after it was discovered that affected patients showed decreased levels of Dicer in their retinal pigment ... This observation suggested a Dicer specific role in retinal health that was independent of the RNAi pathway and thus not a ...
Common examples include retinal (used in the eye to detect light), various food colorings, fabric dyes (azo compounds), pH ... Visual phototransduction Woodward's rules Chromatophore Pigment Photophore, glandular organ Fluorophore Litmus Biological ... pigment Spectroscopy Kräutler, Bernhard (26 February 2016). "Breakdown of Chlorophyll in Higher Plants-Phyllobilins as Abundant ...
Too much light can enter the eye if it is damaged, such as with corneal abrasion and retinal damage, or if its pupil(s) is ... or congenital glaucoma Iritis Isotretinoin has been associated with photophobia Optic neuritis Pigment dispersion syndrome[ ... citation needed] Pupillary dilation (naturally or chemically induced) Retinal detachment Scarring of the cornea or sclera ... unable to normally constrict (seen with damage to the oculomotor nerve). Due to albinism, the lack of pigment in the colored ...
The uvea consists of the middle layer of pigmented vascular structures of the eye and includes the iris, ciliary body, and ... April 2007). "Limited peripheral T cell anergy predisposes to retinal autoimmunity". Journal of Immunology. 178 (7): 4276-83. ... Uveitis (/ˌjuːvɪaɪtɪs/) is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer ... Old episodes of uveitis are identified by pigment deposits on lens, KPs, and festooned pupil on dilation of pupil. Busacca ...
These neurones produce pigment dispersing factor (PDF), a neuropeptide that acts as a circadian neuromodulator between ... This was shown by Gene Block in isolated mollusk basal retinal neurons (BRNs). At the same time, different cells may ...
The dark stripes are actually chromatophores, tiny sacs of pigment that the cuttlefish can flash. S. lineolata and other ... "Polarization sensitivity and retinal topography of the striped pyjama squid (Sepioloidea lineolata - Quoy/Gaimard 1832)" (PDF ...
"Translational read-through of the RP2 Arg120stop mutation in patient iPSC-derived retinal pigment epithelium cells". Human ... The extent of retinal damage is assessed by fluorescent angiography, retinal scanning and optical coherence tomography; ... The markedly anomalous hair growth should lead to a retinal examination by school entry at the latest, since weak vision will ... "Translational read-through as an alternative approach for ocular gene therapy of retinal dystrophies caused by in-frame ...
Bilirubin, a yellow pigment normally formed in the liver during the breakdown of old red blood cells, cannot always be ... Arden, G. B.; Sivaprasad, S. (2012-02-03). "The pathogenesis of early retinal changes of diabetic retinopathy". Documenta ... Indian medical literature dating to 1500 BCE describes a treatment combining herbs with natural sunlight to treat non-pigmented ... Lazzerini Ospri, Lorenzo; Prusky, Glen; Hattar, Samer (25 July 2017). "Mood, the Circadian System, and Melanopsin Retinal ...
Eye structure retina retinal pigment epithelium (RPE) photoreceptor cell retinal ganglion cell macula capillary lamina of ... The research efforts concentrate on two areas of the eye in particular: the retinal pigment epithelium (RPE), and the ... affecting the retinal pigment epithelium (RPE) and causing progressive loss of vision. On 24 November 2011, Mr. Jonathan Wyatt ... implanting missing or faulty genes to correct retinal dystrophies (inherited conditions). As well as retinal issues, research ...
"Expressed sequence tags and chromosomal localization of cDNA clones from a subtracted retinal pigment epithelium library" (PDF ...
The organ of vision contains a particular substance, retinal purple, on which is imprinted in their exact form these images. ... Inspired by Franz Christian Boll's discovery of rhodopsin (or "visual purple")-a photosensitive pigment present in the rods of ...
... JoVE publishes peer-reviewed scientific video protocols ... Isolation Of Primary Mouse Retinal Pigmented Epithelium Cells - Video. ...
... in which cells acquire neural retina or retinal pigment epithelium (RPE) fates. As these fates arise, the OV assumes a cup ... Stretching of the retinal pigment epithelium contributes to zebrafish optic cup morphogenesis Elife. 2021 Sep 21;10:e63396. doi ... known as the retinal pigmented epithelium (RPE for short), and a thicker inner layer called the neural retina. If this process ... in which cells acquire neural retina or retinal pigment epithelium (RPE) fates. As these fates arise, the OV assumes a cup ...
Therefore, the differentiation of MSCs into retinal pigment epithelial (RPE) cells in vitro and their subsequent ... Direct conversion of human umbilical cord mesenchymal stem cells into retinal pigment epithelial cells for treatment of retinal ... Direct conversion of human umbilical cord mesenchymal stem cells into retinal pigment epithelial cells for treatment of retinal ... Direct conversion of human umbilical cord mesenchymal stem cells into retinal pigment epithelial cells for treatment of retinal ...
Biochemical adaptations of the retina and retinal pigment epithelium support a metabolic ecosystem in the vertebrate eye. Mark ... Photoreceptors then export the lactate as fuel for the retinal pigment epithelium and for neighboring Müller glial cells. A key ... In this model, glucose from the choroidal blood supply passes through the retinal pigment epithelium to the retina where ... That enhances the flow of glucose to the retina by minimizing consumption of glucose within the retinal pigment epithelium. ...
Yap and Taz regulate retinal pigment epithelial cell fate. Development , 142 (17) pp. 3021-3032. 10.1242/dev.119008. ... Yap and Taz regulate retinal pigment epithelial cell fate.pdf Download (12MB) , Preview ... The optic vesicle comprises a pool of bi-potential progenitor cells from which the retinal pigment epithelium (RPE) and neural ... framework for understanding the congenital ocular defects of Sveinssons chorioretinal atrophy and congenital retinal coloboma. ...
OTX2 mutations cause autosomal dominant pattern dystrophy of the retinal pigment epithelium. Posted on October 8, 2014. by hqqu ... Pattern dystrophy (PD) of the retinal pigment epithelium is a slowly progressive genetically heterogeneous autosomal dominant ... Our work is the first to associate OTX2 to cause PD and shows that mutations OTX2 can also lead to progressive retinal diseases ...
A New Method to Visualize the Intact Subretina From Retinal Pigment Epithelium to Retinal Tissue in Whole Mount of Pigmented ... Lipofuscin and A2E in mouse retinal pigment epithelial tissues. Summary mass spectra from retinal pigment epithelial tissues of ... Lipofuscin and A2E in mouse retinal pigment epithelial tissues. Summary mass spectra from retinal pigment epithelial tissues of ... Lipofuscin and A2E in mouse retinal pigment epithelial tissues. Summary mass spectra from retinal pigment epithelial tissues of ...
Retinal pigment epithelium melanin distribution estimated by polarisation entropy and its association with retinal sensitivity ... Retinal pigment epithelium melanin distribution estimated by polarisation entropy and its association with retinal sensitivity ... Retinal pigment epithelium melanin distribution estimated by polarisation entropy and its association with retinal sensitivity ...
The retinal pigment epithelium and choriocapillaris, the blood vessels that provide nutrition to the outer retina, die in age- ... Inflammatory Cells In Choroid During Age-Related Macular Degeneration in Relationship to Retinal Pigmented Epithelium (RPE) ... Inflammatory Cells In Choroid During Age-Related Macular Degeneration in Relationship to Retinal Pigmented Epithelium (RPE) ... retinal macrophages) and tissue macrophages (TM) in choroid during AMD and determine their relationship to RPE atrophy and ...
Wang, AL, Lukas, TJ, Yuan, M, Du, N, Tso, MO & Neufeld, AH 2009, Autophagy and exomoses in the aged retinal pigment epithelium ... Dive into the research topics of Autophagy and exomoses in the aged retinal pigment epithelium: Possible relevance to drusen ... T1 - Autophagy and exomoses in the aged retinal pigment epithelium. T2 - Possible relevance to drusen formation and age-related ... Autophagy and exomoses in the aged retinal pigment epithelium: Possible relevance to drusen formation and age-related macular ...
... are characterized by immunofluorescence with antibodies specific to cytokeratin-18, - ... Porcine Retinal Pigment Epithelial Cells. Cryopreserved Porcine Primary Cells. Catalog number: SCP6540. Unit size: 500 000 cell ... Porcine Retinal Pigment Epithelial Cells (PRPEpiC) are isolated from porcine retina. PRPEpiC are cryopreserved at passage one ... 2] Marmorstein, A. D. (2001) The polarity of the retinal pigment epithelium. Traffic 2:867-872. [3] Araki, M., Takano, T., ...
... oxidative stress H2O2-induced was performed by addition and enzymatic generation using glucose oxidase on human retinal pigment ... impair the physiological functions of Retinal Pigment Epithelial (RPE) cells, which are known as one major cause of age-related ... Kim M-H, Jin C, Yang J-W, Chung S-M, Kwag Yoo J-S. Hydrogen Peroxide-Induced Cell Death in a Human Retinal Pigment Epithelial ... The retinal pigmented epithelium is armed with a robust antioxidant system because of the high ambient oxygen tension required ...
Effects of indocyanine green on the retina and retinal pigment epithelium in a porcine model of retinal hole. ... Effects of indocyanine green on the retina and retinal pigment epithelium in a porcine model of retinal hole. Journal Article ( ... on the retina and retinal pigment epithelium (RPE). METHODS: Yorkshire Cross pigs (n = 23) underwent vitrectomy, separation of ... ICG was applied over the retinal hole. In one additional group (n = 5), 0.5% ICG was injected into the fluid-filled eye. At 4 ...
p,The epigenetic plasticity of amphibian retinal pigment epithelium (RPE) allows them to regenerate the entire retina, a trait ... The epigenetic basis for the impaired ability of adult murine retinal pigment epithelium cells to regenerate retinal tissue.. ... The epigenetic plasticity of amphibian retinal pigment epithelium (RPE) allows them to regenerate the entire retina, a trait ... However, promoters of these genes were demethylated and activated during retinal development. Our data suggest that, ...
... ... Retinal Pigment Epithelial and Outer Retinal Atrophy in Age-Related Macular Degeneration: Correlation with Macular Function, ,, ... Retinal Pigment Epithelial and Outer Retinal Atrophy in Age-Related Macular Degeneration: Correlation with Macular Function, ,, ... The purpose of this study was to investigate the relationship between the retinal pigment epithelium (RPE) and outer retina ...
... ... Natural history of incomplete retinal pigment epithelial and outer retinal atrophy in age-related macular degeneration / G. ... Objective: To assess the time course and risk factors for conversion of incomplete retinal pigment epithelium and outer retina ... Objective: To assess the time course and risk factors for conversion of incomplete retinal pigment epithelium and outer retina ...
Transdifferentiation of retinal pigment epithelial cells into lens in suspension culture. / Tsutsui, Y.; Matsuo, T.; Matsuo, N. ... Tsutsui Y, Matsuo T, Matsuo N. Transdifferentiation of retinal pigment epithelial cells into lens in suspension culture. ... Tsutsui, Y., Matsuo, T., & Matsuo, N. (1997). Transdifferentiation of retinal pigment epithelial cells into lens in suspension ... Tsutsui, Y. ; Matsuo, T. ; Matsuo, N. / Transdifferentiation of retinal pigment epithelial cells into lens in suspension ...
RNA-seq analysis of ageing human retinal pigment epithelium: Unexpected up-regulation of visual cycle gene transcription ... ORCID: 0000-0001-7568-7116 (2021) RNA-seq analysis of ageing human retinal pigment epithelium: Unexpected up-regulation of ... RNA-seq analysis of ageing human retinal pigment epithelium: Unexpected up-regulation of visual cycle gene transcription ... A2E, ageing, LRAT, macular degeneration, retinal pigment epithelium, retinol metabolism, RNA‐, seq, RDH5, RDH10, RDH11, ...
A New Method to Visualize the Intact Subretina From Retinal Pigment Epithelium to Retinal Tissue in Whole Mount of Pigmented ... Early AMD is characterized by retinal pigment epithelium (RPE) alterations with pigment clumping and metabolic deposits in and ... Age-related changes in the retinal pigment epithelium of pigmented rats. Exp Eye Res. 1984; 38: 137-151. ... Roider J, Brinkmann R, Wirbelauer C, Laqua H, Birngruber R. Retinal sparing by selective retinal pigment epithelial ...
Tag Archives: retinal pigment epithelium. New Stem Cell Therapy Trial Approved. Posted on November 23, 2010 by Alan Shazan ... Posted in Technology , Tagged Advanced Cell Technology Inc., retinal pigment epithelium, Robert Lanza, Stargardts Macular ... announced that the Food and Drug Administration has approved the Phase I/II trial of retinal cells for Stargardts Macular ...
retinal pigment epithelium, optical coherence tomography (OCT) Photographer. Tom Steele, CRA. Imaging device. Scanning laser ...
Retinal Pigment. On-line free medical diagnosis assistant. Ranked list of possible diseases from either several symptoms or a ... Retinal pigment epithelium (Epithelium, Retinal Pigment). The single layer of pigment-containing epithelial cells in the retina ... situated closely to the tips (outer segments) of the RETINAL photoreceptor cells. These epithelial cells are macroglia that ...
The differentiation of stem cells to retinal pigment epithelium (RPE) in particular holds promise as a source of cells for ... Project description:Retinal pigment epithelium (RPE) transplantation is a particularly promising treatment of retinal ... Human Amniotic Epithelial Stem Cell-Derived Retinal Pigment Epithelium Cells Repair Retinal Degeneration. ... Features specific to retinal pigment epithelium cells derived from three-dimensional human embryonic stem cell cultures - a new ...
... This deposit contains raw ... Chemical Imaging of Retinal Pigment Epithelium in Frozen Sections of Zebrafish Larvae Using ToF-SIMS. ... Chemical Imaging of Retinal Pigment Epithelium in Frozen Sections of Zebrafish Larvae Using ToF-SIMS. J. Am. Soc. Mass Spectrom ...
Cytokine regulation of RANTES production by human retinal pigment epithelial cells. Isabel J. Crane*, Maria C. Kuppner, Susan ... Cytokine regulation of RANTES production by human retinal pigment epithelial cells. / Crane, Isabel J.; Kuppner, Maria C.; ... Cytokine regulation of RANTES production by human retinal pigment epithelial cells. Cellular Immunology. 1998 Feb 25;184(1):37- ... We have therefore examined the production of RANTES by cultured human retinal pigment epithelial cells (RPE), which form a part ...
Library of Free, Non-Copyrighted Retina Images and ...
Retinal Pigment Epithelium. RW-ROP. Referral-Warranted Retinopathy of Prematurity. SEE. Salisbury Eye Evaluation. ...
Chapter 11: Retina and Retinal Pigment Epithelium. Neoplasia. Combined Hamartoma of the Retina and RPE. A combined hamartoma of ... It is characterized clinically by a slightly elevated, variably pigmented mass that involves the RPE, peripapillary retina, ...
Daily, the retinal pigment epithelium (RPE) ingests a bolus of lipid and protein in the form of phagocytized photoreceptor ... Phagocytosis-dependent ketogenesis in retinal pigment epithelium. Journal of Biological Chemistry. Vol. 292Issue 19p8038-8047 ...
Congenital hypertrophy of retinal pigment epithelium. intraocular tumors. pigmented lesions. retinal pigment epithelium. ... An unusual case of congenital hypertrophy of retinal pigment epithelium with overlying hemorrhages. Indian Journal of ... An unusual case of congenital hypertrophy of retinal pigment epithelium with overlying hemorrhages. ...
  • A key feature of this model is that aerobic glycolysis in photoreceptors produces lactate to suppress glycolysis in the neighboring retinal pigment epithelium. (
  • in affected individuals is blue, and specialized cells in the eye called retinal pigment epithelial cells lack their normal pigment. (
  • 3 Through oxidative stress generated by interaction with blue light, lipofuscin has been implicated in progressive retinal pigment epithelial cytotoxicity 4 and the eventual development of age-related macular degeneration (AMD). (
  • The retinal pigment epithelium and choriocapillaris, the blood vessels that provide nutrition to the outer retina, die in age-related macular degeneration (AMD). (
  • Reactive Oxygen Species (ROS) impair the physiological functions of Retinal Pigment Epithelial (RPE) cells, which are known as one major cause of age-related macular degeneration and retinopathy diseases. (
  • Histologic evaluation demonstrated a statistically significant difference between groups (P = 0.044), with extensive outer retinal degeneration observed in air-filled eyes receiving 1% or 0.5% ICG (66% and 60%, respectively) compared with BSS controls or fluid-filled eyes receiving 0.5% ICG (none of the eyes in either group). (
  • CONCLUSIONS: Retina exposed to ICG concentrations used in human vitreoretinal surgery had greater RPE atrophy and outer retinal degeneration than control eyes undergoing the same surgery without ICG. (
  • The purpose of this study was to investigate the relationship between the retinal pigment epithelium (RPE) and outer retina changes, expressed in terms of sub-RPE illumination (SRI) on optical-coherence tomography (OCT), and central retinal function, measured by visual acuity and focal electroretinogram (fERG), in patients with non-exudative age-related macular degeneration (neAMD). (
  • Objective: To assess the time course and risk factors for conversion of incomplete retinal pigment epithelium and outer retina atrophy (iRORA) to complete retinal pigment epithelium and outer retina atrophy (cRORA) in eyes with non-neovascular intermediate age-related macular degeneration (iAMD), using optical coherence tomography (OCT) analysis. (
  • Natural history of incomplete retinal pigment epithelial and outer retinal atrophy in age-related macular degeneration / G. Corradetti, F. Corvi, M.G. Nittala, M. Nassisi, A.R. Alagorie, J. Scharf, M.Y. Lee, S.R. Sadda, D. Sarraf. (
  • To investigate the effect of selective retina therapy (SRT) on age-related macular degeneration (AMD)-like alterations of retinal pigment epithelium (RPE) and Bruch's membrane (BrM) in AMD mouse models as therapeutic approach for the treatment of dry AMD. (
  • The differentiation of stem cells to retinal pigment epithelium (RPE) in particular holds promise as a source of cells for therapeutic replacement in age-related macular degeneration. (
  • Age-related macular degeneration (AMD) is a highly prevalent form of blindness caused by loss death of cells of the retinal pigment epithelium (RPE). (
  • Age-related macular degeneration (AMD) is a blinding disease characterised by dysfunction of the retinal pigmented epithelium (RPE) which culminates in disruption or loss of the neurosensory retina. (
  • The course of Age-related Macular Degeneration (AMD) is described as the effect of light (400-580 nm) on various molecular targets in photoreceptors and the retinal pigment epithelium (RPE). (
  • photoreceptor degeneration initially leaves the inner retinal circuitry intact and new photoreceptors need only make single, short synaptic connections to contribute to the retinotopic map. (
  • It is shown that host cells are labelled with the donor marker through cytoplasmic transfer, and the occurrence of Cre-Lox recombination between donor and host photoreceptors is detected, which may provide alternate therapeutic strategies at earlier stages of retinal degeneration. (
  • Age-related macular degeneration (AMD), a major cause of blindness in the elderly, is associated with oxidative stress, lipofuscin accumulation and retinal degeneration. (
  • Prognostic Value of Retinal Pigment Epithelium Elevation in Anatomical Success After Loading Phase in Neovascular Age-Related Macular Degeneration Treated with Bevacizumab. (
  • Examination-based Age-related Macular Degeneration as identified in retinal images. (
  • Retinal Degeneration is an inherited condition in Abyssinian cats. (
  • A dietary deficiency of the amino acid Taurine can also occur in cats fed primarily dog food which results in Nutritional Retinal Degeneration. (
  • This condition was first described in 1975 and was called Feline Central Retinal Degeneration (FCRD). (
  • Transcriptome analysis of all major cell types within the human retina showed that TMEM97 is expressed in the RPE, retinal ganglion cells (RGCs) and amacrine cells. (
  • Neovascularization is a multi-step process that involves complex interactions of a variety of mitogenic factors such as VEGF and IGF-I which are produced locally in the human eye by a variety of cells including retinal pigment epithelial (RPE) cells, retinal capillary pericytes, endothelial cells, Mueller cells and ganglion cells. (
  • GDNF/BDNF-MSs) on migration of the human adult retinal pigment epithelial cell-line-19 (ARPE-19) cells, primate choroidal endothelial (RF/6A) cells, and the survival of isolated mouse retinal ganglion cells (RGCs). (
  • Solutions will be evaluated for establishment of a human PSC-derived in vitro retina model system that resembles the morphology of a healthy-native retina and is viable through formation of photoreceptor outer segments and/or long-term survival of retinal ganglion cells with extension of axonal processes. (
  • Off-cone), and Retinal Ganglion Cells (identify at least three subtypes). (
  • Our study thus uncovers a unique role of GSK3 in controlling the production of ganglion cells in the inner nuclear layer, which correspond to dRGCs, a rare and poorly characterized retinal cell type. (
  • Interrestingly, we unexpectedly uncovered a unique role of GSK3s in controlling the genesis of retinal ganglion cells in the inner nuclear layer, which could correspond to a rare and poorly characterized retinal cell type. (
  • Therefore, our mouse models potentially offer a unique and powerful model system to study the visual function of displaced retinal ganglion cells in mammals. (
  • and the blood flow signal could be seen in the CDFI lesion, which could lead to retinal detachment and vitreous opacification. (
  • arthralgia/myalgia, intense headache, lasting up to one headache, arthralgia, Review at 1 y - fatigue, headache , week, occurring approximately left retinal detachment ongoing symptoms shortness of breath, every 2 weeks. (
  • Retinal Detachment Retinal detachment is separation of the neurosensory retina from the underlying retinal pigment epithelium. (
  • The vertebrate eye primordium consists of a pseudostratified neuroepithelium, the optic vesicle (OV), in which cells acquire neural retina or retinal pigment epithelium (RPE) fates. (
  • We show that, in virtual absence of proliferation, RPE cells stretch and flatten, thereby matching the retinal curvature and promoting OV folding. (
  • A single layer of embryonic tissue called the optic vesicle reorganizes itself into a two-layered structure: a thin outer layer of cells, known as the retinal pigmented epithelium (RPE for short), and a thicker inner layer called the neural retina. (
  • Therefore, the differentiation of MSCs into retinal pigment epithelial (RPE) cells in vitro and their subsequent transplantation into the subretinal space is expected to improve the outcome of cell therapy. (
  • It is characterized by visual function damage caused by apoptosis and loss of function of retinal pigment epithelial cells (RPE) and retinal photoreceptor cells [ 2 ]. (
  • Photoreceptors then export the lactate as fuel for the retinal pigment epithelium and for neighboring Müller glial cells. (
  • The optic vesicle comprises a pool of bi-potential progenitor cells from which the retinal pigment epithelium (RPE) and neural retina fates segregate during ocular morphogenesis. (
  • The goal of this study is to document for the first time the number and activation of the inflammatory cells including MC, microglia (retinal macrophages) and tissue macrophages (TM) in choroid during AMD and determine their relationship to RPE atrophy and vascular attenuation. (
  • Porcine Retinal Pigment Epithelial Cells (PRPEpiC) are isolated from porcine retina. (
  • It consists of photoreceptors and retinal pigment epithelial cells (RPEpiC). (
  • A comparative oxidative stress H 2 O 2 -induced was performed by addition and enzymatic generation using glucose oxidase on human retinal pigment epithelial cells line. (
  • The epigenetic basis for the impaired ability of adult murine retinal pigment epithelium cells to regenerate retinal tissue. (
  • To elucidate factors influencing transdifferentiation of retinal pigment epithelial (RPE) cells in suspension culture. (
  • Advanced Cell Technology Inc. announced that the Food and Drug Administration has approved the Phase I/II trial of retinal cells for Stargardt's Macular Dystrophy patients. (
  • The single layer of pigment-containing epithelial cells in the retina , situated closely to the tips (outer segments) of the RETINAL photoreceptor cells . (
  • Efficient differentiation of human embryonic stem cells to retinal pigment epithelium under defined conditions. (
  • The chemokine RANTES has the potential to influence the migration of memory T cells and monocytes across the blood-retinal barrier during inflammatory eye disease. (
  • We have therefore examined the production of RANTES by cultured human retinal pigment epithelial cells (RPE), which form a part of the blood-retinal barrier, in response to cytokines likely to be present in the microenvironment. (
  • Retinoblastoma cells of the Y79 line were co-cultivated with human fibroblasts and bovine iris and retinal pigment epithelium in tissue culture. (
  • The Y79 cells, wich characteristically grow as a suspension culture, were found to attach directly to the fibroblasts and pigment epithelium on the flask surface. (
  • In both the iris and retinal pigment epithelium co-cultures with retinoblastoma cells, there were increased numbers of mitochondria in the tumor cells in areas adjacent to pigment epithelium but no pinocytotic vesicles were seen. (
  • The pigment epithelium attached to Y79 cells showed fewer processes than did the fibroblasts in co-culture. (
  • In summary, both fibroblast and pigment epithelium functioned as an effective carrier cell layer for retinoblastoma cells. (
  • Monomethylfumarate induces γ-globin expression and fetal hemoglobin production in cultured human retinal pigment epithelial (RPE) and erythroid cells, and in intact retina. (
  • 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. (
  • Human retinal pigment epithelial cells in culture were found to release a substance (or substances) that causes the regression of new blood vessels on the chick embryonic yolk sac and inhibits proliferation of fetal bovine aortic endothelial cells in vitro. (
  • Subconfluent and superconfluent cultures of human retinal pigment epithelial cells released higher levels of inhibitor than confluent cultures. (
  • Glaser BM, Campochiaro PA, Davis JL, Sato M. Retinal Pigment Epithelial Cells Release an Inhibitor of Neovascularization. (
  • The MITF protein helps control the development and function of pigment-producing cells called melanocytes . (
  • Within these cells, this protein controls production of the pigment melanin, which contributes to hair, eye, and skin color. (
  • However, the expression pattern of TMEM97 in the human retina and its functional role in retinal cells has remained elusive. (
  • We have observed expression of somatostatin receptor protein in retinal pigment epithelial (RPE) cells of the human eye using immunohistochemistry and have confirmed expression of somatostatin receptors in cultured human RPE cells using reverse transcriptase-PCR. (
  • The Retinal Pigment Epithelium: a Convenient Source of New Photoreceptor cells? (
  • The dysfunction of retinal pigment epithelial (RPE) cells is assumed to be a significant factor in the development of AMD. (
  • Adult retinal pigment epithelial (ARPE-19) cells, human embryonic stem cell-derived retinal pigment epithelial cells (hESC-RPE), human embryonic primary RPE cells and endothelial cells (EaHy 926) were used in transfections. (
  • Isolation and characterization of circumferential microfilament bundles from retinal pigmented epithelial cells. (
  • Chicken retinal pigmented epithelial cells have circumferential microfilament bundles (CMBs) at the zonula adherens region. (
  • Autophagy-derived and photoreceptor outer segment (POS)-derived lipofuscin formation was assessed using FACS analysis and confocal microscopy in cultured retinal pigment epithelial (RPE) cells in the presence or absence of the 5-HT1A receptor agonist, 8-OH DPAT. (
  • In order to recapitulate the ocular fundus functions, neural supporting cells such as retinal pigment epithelial (RPE) cells were cultured within a three-dimensional microfluidic device, and cell responses at the tissue level to changes in the microenvironment were analyzed. (
  • BTC exhibits mitogenic activity for retinal pigment epithelial cells and vascular smooth muscle cells. (
  • Immunohistochemical analysis showed DRAM2 localization to photoreceptor inner segments and to the apical surface of retinal pigment epithelial cells where it might be involved in the process of photoreceptor renewal and recycling to preserve visual function. (
  • In addition, two copies of the M allele large enough to produce the merle coat color are thought to cause the death of skin melanocytes, retinal pigment cells, and melanocytes of the inner ear which can result in significant white areas of the coat, eye abnormalities and deafness. (
  • Tumor-induced glaucoma may be produced by obstruction of outflow pathways by pigment cells (pigment dispersion syndrome), melanin-laden macrophages (melanomalytic glaucoma), or tumor cells. (
  • However, we unexpectedly detected a large number of cells in the inner nuclear layer expressing retinal ganglion cell (RGC)-specific markers (called displaced RGCs, dRGCs) when at least one allele of Gsk3α is expressed. (
  • Batten disease refers to a group of conditions that are all caused by an excessive amount of a lipid pigment known as lipofuscin accumulating inside cells. (
  • Lutein, as the main component of macular pigment, Lutein plays a very important role in the development of visual cells in the macular region. (
  • The spots may be single or multiple and are pigmented cells called Melanocytes that have overgrown. (
  • Overall, this study identifies Yap and Taz as key early regulators of RPE genesis and provides a mechanistic framework for understanding the congenital ocular defects of Sveinsson's chorioretinal atrophy and congenital retinal coloboma. (
  • Our results indicate that the severity of retinal pigment epithelium and outer retina atrophy (RORA), indirectly quantified through the detection of SRI areas by commercial OCT algorithms, is correlated with central retinal dysfunction, as determined by visual acuity and fERG, supporting the combined use of structural exams and functional tests as valid tools to detect the extent of RPE and photoreceptors' disruption. (
  • Participants: Tracked structural Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) volume datasets from 2 retinal specialists at the University of California-Los Angeles were retrospectively screened to identify consecutive participants with non-neovascular iAMD without signs of atrophy or macular neovascularization in either eye at baseline. (
  • IMSEAR at SEARO: Progressive atrophy of retinal pigment epithelium after trypan-blue-assisted ILM peeling for macular hole surgery. (
  • We report a case of progressive atrophy of the retinal pigment epithelium (RPE) after trypan-blue-assisted peeling of internal limiting membrane (ILM) for macular hole surgery. (
  • The composition of lipofuscin is best characterized in the RPE, 12 where its accumulation is thought to depend on the availability of all- trans retinal, a potentially highly toxic allelic aldehyde, produced in the photoreceptor outer segments on light exposure. (
  • Photoreceptor loss causes irreversible blindness in many retinal diseases. (
  • Effects of indocyanine green on the retina and retinal pigment epithelium in a porcine model of retinal hole. (
  • PURPOSE: This study was designed to emulate human macular hole surgery and to test the effects of indocyanine green (ICG) on the retina and retinal pigment epithelium (RPE). (
  • Our work is the first to associate OTX2 to cause PD and shows that mutations OTX2 can also lead to progressive retinal diseases. (
  • Grill C, Bergsteinsdottir K, Ogmundsdottir MH, Pogenberg V, Schepsky A, Wilmanns M, Pingault V, Steingrimsson E. MITF mutations associated with pigment deficiency syndromes and melanoma have different effects on protein function. (
  • Mutations in BEST1 cause five distinct retinal degenerative diseases, including adult vitelliform macular dystrophy (AVMD), autosomal recessive bestrophinopathy (ARB), autosomal dominant vitreoretinochoroidopathy (ADVIRC), and retinitis pigmentosa (RP). (
  • In humans WNT2B mutations are associated with coloboma and WNT2B may also assist in retinal progenitor cell differentiation in chicken, yet the potential role of WNT2B in retinal neuronal development is understudied. (
  • Biallelic mutations in the autophagy regulator DRAM2 cause retinal dystrophy with early macular involvement. (
  • Retinal dystrophies are an overlapping group of genetically heterogeneous conditions resulting from mutations in more than 250 genes. (
  • Pattern dystrophy (PD) of the retinal pigment epithelium is a slowly progressive genetically heterogeneous autosomal dominant disorder. (
  • We report the clinical and electrophysiologic findings in three patients with Bietti's crystalline corneal-retinal dystrophy. (
  • Here we describe five families affected by an adult-onset retinal dystrophy with early macular involvement and associated central visual loss in the third or fourth decade of life. (
  • The neuroectoderm of the primitive forebrain is the origin of melanocytes in the retinal pigment epithelium, iris epithelium (anterior and posterior), and ciliary epithelium (outer pigmented and inner nonpigmented). (
  • Metabolic flux, locations of key enzymes and our finding that glucose enters the neural retina almost entirely through photoreceptors support a conceptually new model for retinal metabolism. (
  • In this model, glucose from the choroidal blood supply passes through the retinal pigment epithelium to the retina where photoreceptors convert it to lactate. (
  • The Relationship Between O and Non-O Blood Groups with Retinal Vein Occlusion. (
  • 5-HT1A receptor agonists may have potential as therapeutic agents in the treatment of retinal degenerative disease. (
  • ICG has a peak absorption and fluorescence in the near infrared range, which allows visualization of choroidal pathology through overlying serosanguineous fluid, pigment, or a thin layer of hemorrhage that usually blocks visualization during FA. (
  • 1] Rizzolo, L. J. (1997) Polarity and the development of the outer blood-retinal barrier. (
  • Decreased melanin production (hypopigmentation) accounts for the light skin and hair color and the retinal pigment epithelium changes that are characteristic of Tietz syndrome. (
  • Albinism consists of a group of inherited abnormalities of melanin synthesis and are typically characterized by a congenital reduction or absence of melanin pigment. (
  • Melanin is a photoprotective pigment in the skin that absorbs UV light from the sun, thereby preventing skin damage. (
  • With sun exposure, the skin normally tans as a result of increased melanin pigment in the skin. (
  • In this presentation I present the practical applications of canon wide field OCT-A imaging in retinal vascular disease such as vein occlusions, diabetes and other less common conditions. (
  • This study explored the effects of WNT2B on retinal neuronal and vascular formation using systemic Wnt2b knockout (KO) mice generated by crossing Wnt2bflox/flox (fl/fl) mice with CMV-cre mice. (
  • Racemose hemangioma is an arteriovenous vascular malformation in which the retinal vessels appear abnormally dilated. (
  • [ 1 ] Choroidal neovascularization (CNV) involves the growth of new blood vessels that originate from the choroid through a break in the Bruch membrane into the sub-retinal pigment epithelium (sub-RPE) or subretinal space. (
  • Freund et al have recommended a new classification for CNV based on the anatomical findings on OCT.[1] Choroidal neovascularization (CNV) involves the growth of new blood vessels that originate from the choroid through a break in the Bruch membrane into the sub-retinal pigment epithelium (sub-RPE) or subretinal space. (
  • Lipofuscin, a fluorescent lysosomal pigment made of lipophilic molecules, is associated with age-related pathophysiological processes in the retinal pigment epithelium (RPE). (
  • One of the hallmarks of aging in the eye is the accumulation of autofluorescent degradation material in the lysosomal storage bodies of the retinal pigment epithelium (RPE), termed lipofuscin. (
  • The aim of this study was to determine if a 5-HT1A receptor agonist can reduce lipofuscin accumulation, reduce oxidative damage and prevent retinal cell loss both in vitro and in vivo. (
  • Here we show that the complete loss of GSK3 signaling in mouse retinal progenitors leads to microphthalmia with broad morphologic defects. (
  • Solutions presented should have a sustained, powerful influence on the understanding of retinal diseases and accelerating research toward new therapies. (
  • The solution will have a lasting impact on how retinal diseases and how treatments are studied. (
  • Prior periocular pharmacological or IVT treatment (including anti-VEGF medication) for other retinal diseases. (
  • Microphthalmia-associated transcription factor (MITF) promotes differentiation of human retinal pigment epithelium (RPE) by regulating microRNAs-204/211 expression. (
  • The dry form can turn into the wet form, which results in leakage, bleeding, and lipid and pigment accumulation. (
  • METHODS: Yorkshire Cross pigs (n = 23) underwent vitrectomy, separation of the posterior cortical vitreous, and creation of a single retinal hole. (
  • It is characterized clinically by a slightly elevated, variably pigmented mass that involves the RPE, peripapillary retina, optic nerve, and overlying vitreous (see Chapter 17, Fig 17-14C). (
  • This is the point where the retinal arterioles and optic nerve enter the rear of the eyeball. (
  • Among other extracolonic manifestations, odontomas, pigmented lesions of the fundus, congenital hypertrophy of the retinal pigment epithelium and dental anomalies, such as supernumerary and impacted teeth, are present. (
  • β-Carotene is composed of two retinyl groups, and is broken down in the mucosa of the human small intestine by β-carotene 15‚15'-monooxygenase to retinal, a form of vitamin A. β-Carotene can be stored in the liver and body fat and converted to retinal as needed, thus making it a form of vitamin A for humans and some other mammals. (
  • Components (neurons, retinal pigment epithelium [RPE], glia) may be produced separately or dissociated and recombined (1) if protocol addresses a significant biological or technical hurdle and (2) if in the process of re-assembly, specific functions/roles of cell types are delineated. (
  • 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. (
  • Characterization of retinal cell types, retina organoid structure, and retina organoid function are expected. (
  • However, promoters of these genes were demethylated and activated during retinal development. (
  • This framework for metabolic relationships in retina provides new insights into the underlying causes of retinal disease, age-related vision loss and metabolism-based therapies. (
  • The initial evaluation in one patient demonstrated diffuse disease involving retinal pigment epithelium and choriocapillaris with severe widespread disturbance of retinal function. (
  • Two brothers had regional involvement of the posterior pole with disturbances of retinal function attributable to localized disease, and there was only mild progression in these patients. (
  • UK Inherited Retinal Disease Consortium None. (
  • Sufficiently clear ocular media and adequate pupillary dilatation to allow acquisition of good quality retinal images to confirm diagnosis. (
  • The ocular tissue where these tumors arise, the uvea, is a densely pigmented layer that lies for the most part between the sclera and the retina. (
  • There was anterior segment dysgenesis and retinal non-attachment in all patients. (
  • This delivery strategy could be useful as a potential co-therapy in retinal degenerations and glaucoma, in line with future personalized long-term intravitreal treatment as different amounts (doses) of microparticles can be administered according to patients' needs. (
  • Other features include photophobia, iris transillumination, nystagmus, and pigment deficiency in the peripheral retina. (
  • If the pigmented area on the iris is flat, the lesion is referred to as an Ins Melanosis. (
  • Iris melanoma is the term used if the pigmented area on the iris is raised. (
  • Other retinal neuronal layers showed normal organization in both thickness and lamination, without detectable signs of retinal thinning. (
  • Of the 33 children examined by fundoscopy, 24% had abnormal findings, including rarefaction of the retinal pigment epithelium, atrophic macular lesions, macular scarring and macular reflection juxtafoveal changes. (
  • In this study, we investigated the epigenetic plasticity of adult murine RPE to identify possible mechanisms that prevent mammalian RPE from regenerating retinal tissue. (
  • Additionally, the MITF protein regulates the development of the retinal pigment epithelium. (
  • BEST1 encodes Bestrophin-1 (Best1), a homo-oligomeric, integral membrane protein localized to the basolateral plasma membrane of the retinal pigment epithelium. (
  • Wnt2b KO eyes exhibited relatively normal anterior segments and retinal vasculature. (
  • Early AMD is characterized by retinal pigment epithelium (RPE) alterations with pigment clumping and metabolic deposits in and around Bruch's membrane (BrM) and RPE, 2 , 3 called drusen. (
  • The most common cause is a retinal break (a tear or, less commonly, a hole-rhegmatogenous. (
  • Retinal pigment epithelial tear involving the macula on study Day 1. (