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.
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.
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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"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 ...
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 ... AMD-like pathology begins with small yellow deposits (drusen) in the macula, between the retinal pigment epithelium and the ... Intermediate AMD is diagnosed by large drusen and/or any retinal pigment abnormalities. Intermediate AMD may cause some vision ...
... - 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 ...
"Entrez Gene: RPE65 retinal pigment epithelium-specific protein 65kDa". Wolf G (Mar 2005). "Function of the protein RPE65 in the ... Retinal pigment epithelium-specific 65 kDa protein, also known as retinoid isomerohydrolase, is an enzyme of the vertebrate ... RPE65 is a critical enzyme in the vertebrate visual cycle found in the retinal pigmented epithelium. It is also found in rods ... Jin M, Li S, Moghrabi WN, Sun H, Travis GH (Aug 2005). "Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium". ...
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. doi:10.1098 ... 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 ... 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. ...
In view of their location between the retinal pigment epithelium (RPE) and its vascular supply, the choriocapillaris, it is ... April 2007). "High concentration of zinc in sub-retinal pigment epithelial deposits". Exp. Eye Res. 84 (4): 772-80. doi:10.1016 ... are tiny yellow or white accumulations of extracellular material that build up between Bruch's membrane and the retinal pigment ...
Jiang M, Pandey S, Tran VT, Fong HK (May 1991). "Guanine nucleotide-binding regulatory proteins in retinal pigment epithelial ...
The photosensitive retinal ganglion cells contain a pigment called melanopsin. This photopigment is depolarized in the presence ...
Limaye SR, Mahmood MA (October 1987). "Retinal microangiopathy in pigmented paravenous chorioretinal atrophy". The British ...
"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): ...
... of the blood supply to the retinal pigment epithelium. They went on to use fundus autoflorescence to image the retinal pigment ... Since the choriocapillaris is the main blood supply of the retinal pigment epithelium, it is leading some to believe that ... It is likely multifactorial and triggered by intrinsic and extrinsic stressors of the poorly regenerative retinal pigment ... Bonilha, Vera L (2008). "Age and disease-related structural changes in the retinal pigment epithelium". Clinical Ophthalmology ...
... 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 ( ...
Its eyes, however, are insensitive to this wavelength; it has an additional retinal pigment which fluoresces blue-green when ... The additional pigment is thought to be assimilated from chlorophyll derivatives found in the copepods which form part of its ... This adaptation allows the fish to see red-pigmented prey, which are normally absent from the deep ocean environment where red ... If selection were to favor a mutation in the oxygenase enzyme required for the breakdown of pigment molecules (molecules often ...
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. ...
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". Porter ML, Blasic JR, Bok MJ, Cameron EG, Pringle T, ... Rivolta C, Berson EL, Dryja TP (2007). "Mutation screening of the peropsin gene, a retinal pigment epithelium specific ... Peropsin, a visual pigment-like receptor, is a protein that in humans is encoded by the RRH gene. Peropsin is an opsin and so ...
The pupil can be adjusted in size and a retinal pigment screens incident light in bright conditions.[22] ... Chromatophores contain yellow, orange, red, brown, or black pigments; most species have three of these colours, while some have ... The lens is suspended behind the pupil and photoreceptive retinal cells cover the back of the eye. ... The main pigment in the ink is melanin, which gives it its black colour.[52] Cirrate octopuses lack the ink sac.[31] ...
The membranous photoreceptor protein opsin contains a pigment molecule called retinal. In rod cells, these together are called ... When light hits a photoreceptive pigment within the photoreceptor cell, the pigment changes shape. The pigment, called iodopsin ... an organic molecule called retinal (a derivative of vitamin A). The retinal exists in the 11-cis-retinal form when in the dark ... In cone cells, there are different types of opsins that combine with retinal to form pigments called photopsins. Three ...
Bridges, C.D. and Alvarez, R.A. (1987). "The visual cycle operates via an isomerase acting on all-trans retinol in the pigment ... trans-retinyl palmitate by homogenates of human retinal epithelial cells". J. Biol. Chem. 262: 53-58. PMID 3793734. ...
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 ... Each of the three types of cones in the retina of the eye contains a different type of photosensitive pigment, which is ...
This protein is associated with the primary cilia of the retinal pigment epithelial cells, fibroblasts and kidney tubular cells ...
Retinal pigment epithelium. Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine ...
Ovaj gen kodira pigment iz familije opsina koji apsorbuje svetlost. On se naziva crveni fotopigment kupastih ćelija, ili opsin ... trp-281 is essential for proper folding and protein-retinal interactions.". Biochemistry. 37 (50): 17487-94. PMID 9860863. doi: ... Applebury ML, Hargrave PA (1987). „Molecular biology of the visual pigments.". Vision Res. 26 (12): 1881-95. PMID 3303660. doi: ... Entrez Gene: OPN1LW opsin 1 (cone pigments), long-wave-sensitive (color blindness, protan)".. ...
2001). Immunocytochemical demonstration of visual pigments in the degenerate retinal and pineal photoreceptors of the blind ... Istenic L. in Ziegler I. (1974). Riboflavin as "pigment" in the skin of Proteus anguinus L. Naturwissenschaften 12: 686-687. ... Koža je tanka, v njej v naravnih pogojih ni pigmenta melanina, ampak bolj ali manj izrazit rumeni "pigment" riboflavin [4], ... Tudi pinealni organ človeške ribice ima pokrnele fotoreceptorne celice in vsebujejo vidni pigment kot pokrnele celice v ...
The major source of retinoids from the diet are plant pigments such as carotenes and retinyl esters derived from animal sources ... First generation include retinol, retinal, tretinoin (retinoic acid), isotretinoin, and alitretinoin. *Second generation ...
Opsins are proteins and the retinal-binding visual pigments found in the photoreceptor cells in the retinas of eyes. An opsin ... retinal + O2 + H2O → retinoic acid + H2O2 (catalyzed by retinal oxidase). catalyzed by retinal dehydrogenases[11] also known as ... Retinal is a conjugated chromophore. In the human eye, retinal begins in an 11-cis-retinal configuration, which, upon capturing ... An opsin protein surrounds a molecule of retinal, awaiting detection of a photon. Once retinal captures a photon, retinal's ...
Large cultures of Micrococcus luteus growing on pyridine (left) and succinic acid (right). The yellow pigment being produced in ... FAD is required to convert retinol (vitamin A) to retinoic acid via cytosolic retinal dehydrogenase ...
"Pigmented Conjunctival Tumors - The Eye Cancer Network". Retrieved 2010-03-10.. *^ "Pingueculum - The Eye Cancer Network". ... eventual vision loss and if they continue to grow the tumor can break past the retina causing retinal detachment. Sometimes the ...
Gerlach W, Rohrschneider W (1934). "Besteht das Pigment des Kayser-Fleischerschen Hornhautringes aus Silber?". Klin Wochenschr ... Ocular ischemic syndrome / Central retinal vein occlusion. *Central retinal artery occlusion. *Branch retinal artery occlusion ...
... cDNA sequence and retinal localization of the UV-sensitive visual pigment of the budgerigar (Melopsittacus undulatus)". ...
Collin, S. P. (2010). "Evolution and Ecology of Retinal Photoreception in Early Vertebrates". Brain, Behavior and Evolution. 75 ... "Visual pigments in a living fossil, the Australian lungfish Neoceratodus forsteri" (PDF). BMC Evolutionary Biology. 7: 200-207 ... "Evolution of colour vision: The story of lost visual pigments". Perception. 35. Archived from the original on 2014-10-06 ...
... retinal pigment epithelium, hepatocytes, mesangial cells in the kidney, endometrial cells, cervical cells and vaginal ... When the porphyrin ring is broken up, the fragments are normally secreted as a yellow pigment called bilirubin, which is ... Urobilinogen leaves the body in faeces, in a pigment called stercobilin. Globulin is metabolised into amino acids that are then ... lacking the red hemoglobin pigment) and microcytic (smaller than normal). Other anemias are rarer. In hemolysis (accelerated ...
"MicroRNA expression in human retinal pigment epithelial (ARPE-19) cells: increased expression of microRNA-9 by N-(4- ...
The term retinal detachment is used to describe a separation of the neurosensory retina from the retinal pigment epithelium.[57 ... Retinal diseases in dogs include retinal dysplasia, progressive retinal atrophy, and sudden acquired retinal degeneration. ... When light strikes 11-cis-retinal (in the disks in the rods and cones), 11-cis-retinal changes to all-trans-retinal which then ... "The retinal pigment epithelium". Webvision. Retrieved 1 January 2018.. *^ Photobiology of the retina "Light-Induced Damage to ...
... is a light-harvesting apocarotenoid, a pigment associated with chlorophyll and found in the peridinin-chlorophyll- ... Peridinin is an apocarotenoid pigment that some organisms use in photosynthesis. Many photosynthetic dinoflagellates use ... wrapped around a pigment-filled central cavity. Each eight-helix segment binds one chlorophyll molecule (green, with central ...
Light is absorbed by a retinal pigment covalently linked to the protein, that result in a conformational change of the molecule ...
Hemorrhagic smallpox can cause subconjunctival and retinal hemorrhages. In 2 to 5 percent of young children with smallpox, ...
Some descriptions of carbon monoxide poisoning include retinal hemorrhages, and an abnormal cherry-red blood hue.[32] In most ... The carbon monoxide combines with myoglobin to form carboxymyoglobin, a bright-cherry-red pigment. Carboxymyoglobin is more ... stable than the oxygenated form of myoglobin, oxymyoglobin, which can become oxidized to the brown pigment metmyoglobin. This ...
망막색소상피세포(Retinal Pigment Epithelium cells, RPE cells)는 망막 감각신경 부분의 바깥에 존재하며, 색소가 있는 세포들을 지칭한다. [1] ... Bok D. The retinal pigment epithelium: a versatile partner in vision. J Cell Sci Suppl 17: 189-195, 1993. ... Strauss, O (2005). "The Retinal Pigment Epithelium in Visual Function". 》Physiological review》 85 (3): 845-881. PMID 15987797. ... Rizzolo, lj (2014). "Barrier properties of cultured retinal pigment epithelium". 》Experimental Eye Research》 126: 16-26. PMID ...
Light/dark information reaches the suprachiasmatic nuclei from retinal photosensitive ganglion cells of the eyes[81][82] rather ... Pigment Cell Res. 17 (5): 454-60. doi:10.1111/j.1600-0749.2004.00185.x. PMID 15357831.. ...
... pigment. The short-wavelength pigment is shifted towards the green area of the spectrum. This is the rarest form of anomalous ... Since cone monochromacy is the lack of/damage of more than one cone in retinal environment, having two types of dichromacy ... pigment. The medium-wavelength pigment is shifted towards the red end of the spectrum resulting in a reduction in sensitivity ... each containing a different pigment, which are activated when the pigments absorb light. The spectral sensitivities of the ...
... and change the pigments of the lashes.[9] ... Central retinal artery occlusion. *Branch retinal artery ... Ocular ischemic syndrome / Central retinal vein occlusion. * ...
3.A.1.204 The Eye Pigment Precursor Transporter (EPP) Family (ABCG) 3.A.1.205 The Pleiotropic Drug Resistance (PDR) Family ( ... ABCG) 3.A.1.211 The Cholesterol/Phospholipid/Retinal (CPR) Flippase Family (ABCA) 9.B.74 The Phage Infection Protein (PIP) ...
Retinal pigment epithelium. Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine ... "Melanopsin-Expressing Retinal Ganglion-Cell Photoreceptors: Cellular Diversity and Role in Pattern Vision". Neuron. 67 (1): 49 ...
A 6-year-old boy presents with lesions of the retinal pigment epithelium in one eye. Is this a benign finding or does it ... thicker than normal surrounding retinal pigment epithelium.[5] Lesions differ by the quality of the margins (smooth vs ... and the lesions are surrounded by characteristic pigmented or nonpigmented halos.[4,6] Common pigment variations include ... First described by Buettner in 1974, CHRPE appears as a flat, pigmented, well-demarcated lesion located at level of the RPE.[1, ...
Tight Junction Retinal Pigment Epithelium Retinal Pigment Epithelium Cell Transepithelial Electrical Resistance Neural Retina ... The retinal pigment epithelium induces fenestration of endothelial cells in vivo. Curr Eye Res 1992;11:863-873.PubMedCrossRef ... Development and role of tight junctions in the retinal pigment epithelium. Int Rev Cytol 2006;258:195-234.CrossRefGoogle ... Retinal pigment epithelial transport mechanisms and their contributions to the electroretinogram. Prog Retin Eye Res 1997;16: ...
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 ... Gardner syndrome is characterized by FAP (familial adenomatous polyps), osseous and soft tissue tumors, retinal pigment ... "Relative contributions of the neurosensory retina and retinal pigment epithelium to macular hypofluorescence." Arch Ophthalmol ...
Phagocytosis by retinal pigment epithelium explants in culture.. Philp NJ, Bernstein MH. ...
Purpose: To report the unusual association of vitreomacular traction syndrome (VMT) with retinal pigment epithelium (RPE) ... Conclusion: Retinal pigment epithelium detachment could be associated with VMT. Although the incidence is rare, it may ... Retinal pigment epithelium detachment associated with vitreomacular traction syndrome - Case report. *Georgalas I ... Purpose: To report the unusual association of vitreomacular traction syndrome (VMT) with retinal pigment epithelium (RPE) ...
Retinal Pigmented Epithelial Cells * hTERT RPE-1 (ATCC® CRL-4000™) ATCC® Number: CRL-4000™ Organism: Homo sapiens, human ...
Retinal Pigmented Epithelial Cells Fast STR Profiling Service Authentication of cell lines via STR profile analysis is becoming ...
The retinal pigment epithelium (RPE) interacts with the photoreceptors, which it faces across the subretinal space. In these ... Pigment movement and cellular contractility in the retinal pigment epithelium. In: The retinal pigment epithelium, Marmor MF ... Bok D and Young R (1979) Phagocytic properties of the retinal pigment epithelium. In: The retinal pigment epithelium eds: Zinn ... Steinberg RH and Miller SS (1979) Transport and membrane properties of the retinal pigment epithelium. In: The retinal pigment ...
RRH retinal pigment epithelium-derived rhodopsin homolog [Homo sapiens] RRH retinal pigment epithelium-derived rhodopsin ... Peropsin, a novel visual pigment-like protein located in the apical microvilli of the retinal pigment epithelium. Sun H, et al ... retinal pigment epithelium-derived rhodopsin homologprovided by HGNC. Primary source. HGNC:HGNC:10450 See related. Ensembl: ... RRH retinal pigment epithelium-derived rhodopsin homolog [ Homo sapiens (human) ] Gene ID: 10692, updated on 1-Aug-2020 ...
The retinal pigment epithelium is a single layer of cells in the eye that are primarily responsible for providing nutrition to ... The retinal pigment epithelium, or RPE, is a single layer of cells in the eye, lying between the retina and the choroid, which ... The retinal pigment epithelium is a single layer of cells in the eye, lying between the retina and the choroid.. ... The retinal pigment epithelium serves to transport excess water, along with other waste molecules, from the retina, and out of ...
Human cytomegalovirus uses two distinct pathways to enter retinal pigmented epithelial cells. Dai Wang, Qian-Chun Yu, Jörg ... In this report, we demonstrate by electron microscopy that the virus uses two different routes to enter retinal pigmented ... Human MRC-5 embryonic lung fibroblasts and ARPE-19 retinal pigmented epithelial cells (American Type Culture Collection) at ... Human cytomegalovirus uses two distinct pathways to enter retinal pigmented epithelial cells ...
Light converts 11-cis-retinal (11CR), the visual pigment chromophore, into all-trans-retinal (ATR), which is immediately ... 2010) Comparison of A2E cytotoxicity and phototoxicity with all-trans-retinal in human retinal pigment epithelial cells. ... Accumulation of lipofuscin bisretinoids (LBs) in the retinal pigment epithelium (RPE) is the alleged cause of retinal ... 2010) The retinal pigment epithelium in health and disease. Curr Mol Med 10(9):802-823. ...
Melanosomes of retinal pigment epithelium (RPE) have many vision supporting functions. Melanosome research would benefit from a ... that the isolation method described here can easily be optimized for the isolation of stage IV melanosomes from other pigmented ...
... The purpose of this study is to demonstrate the efficacy of ranibizumab in patients with retinal pigment ... Retinal Pigment Epithelium. The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips ... Retinal Detachment. Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal ... The purpose of this study is to demonstrate the efficacy of ranibizumab in patients with retinal pigment epithelial detachment ...
Intravitreal Ranibizumab in Retinal Pigment Epithelial Detachments. The safety and scientific validity of this study is the ... Change in retinal thickness and height of pigment epithelial detachment [ Time Frame: 12 months ]. *Central visual field and ... The purpose of this study is to demonstrate the efficacy of ranibizumab in patients with retinal pigment epithelial detachment ... To investigate the efficacy of ranibizumab in patients with retinal pigment epithelial detachment secondary to age-related ...
The methodology was validated using clinical-grade induced pluripotent stem cell-derived retinal pigment epithelial cells (iPSC ... Deep learning predicts function of live retinal pigment epithelium from quantitative microscopy. ... Deep learning predicts function of live retinal pigment epithelium from quantitative microscopy. ...
Zinn, K. M., and Benjamin-Henkind, J. V. (1979) Anatomy of the human retinal pigment epithelium, in The Retinal Pigment ... Morphogenesis of the retinal pigment epithelium: Toward understanding retinal degenerative diseases. Ann. N. Y. Acad. Sci. 857 ... Proteomic Characterization of Isolated Retinal Pigment Epithelium Microvilli. Vera L. Bonilha, Sanjoy K. Bhattacharya, Karen A. ... Proteomic Characterization of Isolated Retinal Pigment Epithelium Microvilli. Vera L. Bonilha, Sanjoy K. Bhattacharya, Karen A. ...
... are rare fundus lesions. By combining cases seen by members of ... Combined hamartomas of the retina and retinal pigment epithelium Ophthalmology. 1984 Dec;91(12):1609-15. doi: 10.1016/s0161- ... Combined hamartomas of the retina and retinal pigment epithelium are rare fundus lesions. By combining cases seen by members of ...
Retinal pigment epithelium (RPE) is a monolayer of cuboidal cells that is strategically placed between the rod and cone ... Current understanding on the role of retinal pigment epithelium and its pigmentation Pigment Cell Res. 1999 Aug;12(4):219-36. ... Retinal pigment epithelium (RPE) is a monolayer of cuboidal cells that is strategically placed between the rod and cone ... This short review focuses on the role of the pigment granules in RPE. Although the biology of the pigment granules has been ...
Adenocarcinomas and adenomas arise from a part of the retina called the retinal pigment epithelium (RPE). Benign adenomas are ... Search PubMed for articles on Retinal Pigment Epithelium (RPE) Tumors. *Search Google for information on Retinal Pigment ... Retinal Pigment Epithelium (RPE) Tumors. By Paul T. Finger, MD. Description. Adenocarcinomas and adenomas typically arise from ... Patients with adenomas of the retinal pigment epithelium typically have no symptoms. These tumors are found during routine eye ...
... and pro-IL-18 in AMD lesions of the retinal pigment epithelium (RPE) and photoreceptor. In vitro, a similar increase was evoked ... stimulation in the adult retinal pigment epithelium (ARPE-19) cell line, and the increase was reduced in siRNA transfected ... NLRP3 Upregulation in Retinal Pigment Epithelium in Age-Related Macular Degeneration Yujuan Wang 1,2, Jakub W. Hanus 3, Mones S ... "NLRP3 Upregulation in Retinal Pigment Epithelium in Age-Related Macular Degeneration." Int. J. Mol. Sci. 17, no. 1: 73. ...
Advanced Cell Technology Awarded Broad Patent for Production of Retinal Pigment Epithelial Cells. This broad patent gives ... which is broadly directed to processes developed by ACT scientists for the production of retinal pigment epithelial (RPE) cells ... Our RPE technology is safe, scalable and has tremendous potential for treating many of the 200-plus retinal diseases. This ...
D. Bok, "The retinal pigment epithelium: a versatile partner in vision," Journal of Cell Science, vol. 106, no. 17, pp. 189-195 ... Human retinal pigment epithelial (hRPE) cells have been tested as a cell-based therapy for Parkinsons disease but will require ... D. J. Doudet, M. L. Cornfeldt, C. R. Honey, A. W. Schweikert, and R. C. Allen, "PET imaging of implanted human retinal pigment ... PEDF and VEGF-A Output from Human Retinal Pigment Epithelial Cells Grown on Novel Microcarriers. Torsten Falk,1 Nicole R. ...
Phagocytosed photoreceptor outer segments activate mTORC1 in the retinal pigment epithelium. By Bo Yu, Anuoluwapo Egbejimi, ... Phagocytosed photoreceptor outer segments activate mTORC1 in the retinal pigment epithelium. By Bo Yu, Anuoluwapo Egbejimi, ... Phagocytosed photoreceptor outer segments activate mTORC1 in the retinal pigment epithelium Message Subject. (Your Name) has ... The metabolic regulator mTORC1 is activated every morning in the retinal pigment epithelium. ...
Retinal pigment epithelial cell distribution in central retina of rhesus monkeys. Download Prime PubMed App to iPhone, iPad, or ... Retinal Pigment Epithelial Cell Distribution in Central Retina of Rhesus Monkeys. Invest Ophthalmol Vis Sci. 2002;43(9):2815-8 ... Retinal pigment epithelial cell distribution in central retina of rhesus monkeys. Invest Ophthalmol Vis Sci. 2002;43(9):2815-8. ... Genesis of the retinal pigment epithelium in the macaque monkey.. *Photoreceptor topography of the retina in the adult pigtail ...
These findings contribute to the understanding of the protective mechanisms attributable to retinal xanthophylls in eye health ... in order to determine if there is effect specificity for macular pigment carotenoids. Using human RPE-derived ARPE-19 cells as ... cells are central to retinal health and homoeostasis. Oxidative stress-induced damage to the RPE occurs as part of the ... retinal pigment epithelium; hypoxia; oxidative stress; tBHP xanthophyll; lutein; lycopene; carotenoids; retinal pigment ...
The retinal pigment epithelium (RPE) forms a major component of the blood-retinal barrier. It has two functionally distinct ... 1994) Properties of the inwardly rectifying K+ conductance in the toad retinal pigment epithelium. J Physiol (Lond) 476:41-53. ... 1992) α1-Adrenergic modulation of K and Cl transport in bovine retinal pigment epithelium. J Gen Physiol 99:263-290. ... 1993) Retinal pigment epithelial cells modulate lymphocyte function at the blood-retina barrier by autocrine PGE2 and membrane- ...
... the future RPE hyperproliferates and is respecified as retinal tissue but only in a small portion of the dorsal RPE. Using a ... the transcription factor MITF acts to promote the development of the retinal pigment epithelium (RPE). In embryos with Mitf ...
Repopulation of the retinal pigment epithelium after pigment epithelial rip. Retina. 2006;26(9): 1097-9. [ Links ] ... M= male; F= female; BCVA= best-corrected visual acuity; RPE= retinal pigment epithelium; PED= pigment epithelial detachment. ... Keywords: Macular degeneration; Retinal detachment; Retinal pigment epithelium; Intravitreal injections; Antibodies, monoclonal ... Retinal pigment epithelium tears after intravitreal bevacizumab in pigment epithelium detachment. Am J Ophthalmol. 2007;144(2): ...
Tumours of the retinal pigment epithelium. Message subject: (Your Name) has forwarded a page to you from British Journal of ...
  • 50% thicker than normal surrounding retinal pigment epithelium. (
  • Pigment epithelial detachments (PED) secondary to age-related macular degeneration (AMD) have been excluded from practically all study populations of ranibizumab studies so far. (
  • To assess efficacy of intravitreal ranibizumab in retinal pigment epithelium tears secondary to neovascular age-related macular degeneration. (
  • Natural History of Drusenoid Pigment Epithelial Detachment Associated with Age-Related Macular Degeneration: Age-Related Eye Disease Study 2 Report No. 17. (
  • To investigate the natural history and genetic associations of drusenoid pigment epithelial detachment (DPED) associated with age-related macular degeneration (AMD). (
  • This study was designed to investigate effects of various carotenoids (β-carotene, lycopene, and lutein) on RPE cells subjected to either hypoxia or oxidative stress, in order to determine if there is effect specificity for macular pigment carotenoids. (
  • Loss of RPE differentiation has long been known to play a critical role in numerous retinal diseases, including inherited rod-cone degenerations, inherited macular degeneration, age-related macular degeneration, and proliferative vitreoretinopathy. (
  • Total macular thickness was recorded as the distance between superior border of retinal pigment epithelium and superior border of detached neurosensory retina at the Centre of macula. (
  • She suffered commotioretinae (reduced vision caused by trauma) with damage to the retinal pigment epithelium (a layer of cells in the eye) and macular hole formation (the creation of a hole in the macula, which is part of the retina). (
  • The degeneration of the retinal pigment epithelium (RPE) plays a major role in photoreceptor cell death and vision loss in age-related macular degeneration (AMD). (
  • They suggest that synergy of sub-toxic lysosomal and mitochondrial changes in RPE cells with age may cause RPE dysfunction that is known to contribute to human retinal diseases like age-related macular degeneration. (
  • Vascular endothelial growth factor (VEGF) plays an important role in homeostasis and diseases of the retinal pigment epithelium (RPE), choriocapillaris, and, most notably, age-related macular degeneration (AMD). (
  • Tumour necrosis factor-α (TNF-α) is a key mediator of ocular inflammation and its interaction with the retinal pigment epithelium (RPE) may be a driving force in vitreoretinal disorders such as age-related macular degeneration, proliferative vitreoretinopathy (PVR) and diabetic retinopathy. (
  • The recent development of technologies capable of producing induced pluripotent stem (iPS) cells from adult somatic tissues may permit their use to generate autologous retinal pigment epithelium (RPE) grafts for the treatment of diseases like age-related macular degeneration. (
  • Although RPE function is essential to maintaining a dehydrated neural retinal environment, the regulation of the RPE barrier in macular edema has received relatively limited attention. (
  • Intracellular formation of advanced glycation end products (AGEs) is a crucial pathological process in retinal diseases such as age-related macular degeneration (AMD) or diabetic retinopathy (DR). Glyoxal is a physiological metabolite produced during formation of AGEs and has also been shown to derive from photodegraded bisretinoid fluorophores in aging retinal pigment epithelial (RPE) cells. (
  • Recent work suggested that the activity of extracellular signal-regulated kinase 1/2 (ERK1/2) is increased in the retinal pigment epithelium (RPE) of age-related macular degeneration (ARMD) patients and therefore could be an attractive therapeutic target. (
  • 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. (
  • Clinicopathological correlation of retinal pigment epithelial tears in exudative age related macular degeneration: pretear, tear, and scarred tear. (
  • Adenocarcinomas and adenomas typically arise from a part of the retina called the retinal pigment epithelium or RPE. (
  • Retinal pigment epithelium (RPE) is a monolayer of cuboidal cells that is strategically placed between the rod and cone photoreceptors and the vascular bed of the choriocapillaris. (
  • A brown monolayer of cells of the retina situated next to the choroid composed of cells joined by tight junctions and filled with pigment, mainly melanin and lipofuscin (Fig. R9). (
  • A novel approach for subretinal implantation of ultrathin substrates containing stem cell-derived retinal pigment epithelium monolayer," Ophthalmic Research, vol. (
  • Previous studies have shown that the retinal pigment epithelium (RPE) 4 monolayer functions as an immune-privileged tissue ( 4 ), and that RPE cells are the principal mediators of immune privilege in the subretinal space ( 5 , 6 ). (
  • A layer of extracellular matrix proteins, Bruch's membrane, lies adjacent to the choriocapillaris, and a monolayer of retinal pigment epithelium (RPE) cells divides Bruch's membrane from the photoreceptors. (
  • The retinal pigmented epithelium (RPE) is a monolayer of polarized and highly specialized pigmented cells that are located between the outer segments of the photoreceptors and the choroid layer in the eye. (
  • The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells. (
  • The RPE is composed of a single layer of hexagonal cells that are densely packed with pigment granules. (
  • Bok D (1982) Autoradiograpic studies on the polarity of plasma membrane receptors in retinal pigment epithelial cells. (
  • The retinal pigment epithelium , or RPE, is a single layer of cells in the eye, lying between the retina and the choroid , which is a vascular layer at the back of the eye. (
  • The epithelial cells also supply the retinal cells with molecules of essential nutrients , including amino acids, glucose , and vitamin C. Another essential role played by these cells is the supply of vitamin A, which is vital for sight, to the photoreceptors. (
  • Excessive light entering the eye may damage the sensitive retinal cells. (
  • The pigment of the epithelial cells has a complex composition that enables it to absorb a wide spectrum of different light waves. (
  • In this report, we demonstrate by electron microscopy that the virus uses two different routes to enter retinal pigmented epithelial cells, depending on the cell type in which the infecting virus was produced. (
  • Human cytomegalovirus (HCMV) infects multiple cell types in vivo ( 7 ), and it fuses with the plasma membranes of fibroblasts ( 8 ) but enters retinal pigmented epithelial cells and umbilical vein endothelial cells via endocytosis ( 9 , 10 ). (
  • The methodology was validated using clinical-grade induced pluripotent stem cell-derived retinal pigment epithelial cells (iPSC-RPE). (
  • More dynamic and less organized structures are present in the epithelial cells of the placenta and the retinal pigment epithelium (RPE), 1 which perform endocytosis and phagocytosis, respectively. (
  • These include phagocytosis of photoreceptors' shed outer segments, directional transport of nutrients into and removal of waste products from photoreceptor cells, and visual pigment transport and regeneration. (
  • In vitro , a similar increase was evoked by oxidative stress or lipopolysaccharide (LPS) stimulation in the adult retinal pigment epithelium (ARPE-19) cell line, and the increase was reduced in siRNA transfected cells to knockdown NLRP3. (
  • OTCBB: ACTC), a leader in the field of regenerative medicine, announced today that it has been issued U.S. Patent Number 7736896, which is broadly directed to processes developed by ACT scientists for the production of retinal pigment epithelial (RPE) cells from human embryonic stem cells (hESCs). (
  • Human retinal pigment epithelial (hRPE) cells have been tested as a cell-based therapy for Parkinson's disease but will require additional study before further clinical trials can be planned. (
  • Retinal pigment epithelial (RPE) cells are central to retinal health and homoeostasis. (
  • Blue light has high photochemical energy and induces cell apoptosis in retinal pigment epithelial cells. (
  • However, it has not been studied whether blue light in the displays, emitting low intensity light, such as those used in today's smartphones, monitors, and TVs, also causes apoptosis in retinal pigment epithelial cells. (
  • We attempted to examine the blue light effect on human adult retinal epithelial cells using display devices with different blue light wavelength ranges, the peaks of which specifically appear at 449 nm, 458 nm, and 470 nm. (
  • These results show that even at the low intensity utilized in the display devices, blue light can induce ROS production and apoptosis in retinal cells. (
  • Retinal pigment epithelial (RPE) cells maintain the health and functional integrity of both photoreceptors and the choroidal vasculature. (
  • We have previously shown that short pulse laser irradiation in the nanosecond to picosecond time domain causes transient microbubble formation around melanin granules in pigmented cells. (
  • Hui, S., Yi, L. and Fengling, Q. L. (2009), Effects of Light Exposure and Use of Intraocular Lens on Retinal Pigment Epithelial Cells In Vitro . (
  • Retinal pigment epithelium (RPE) cells are vital for retinal health. (
  • Endogenous regeneration of damaged retinal pigment epithelium following low dose sodium iodate administration: an insight into the role of glial cells in retinal repair," Experimental Eye Research, vol. (
  • With the financing, Advanced Cell will be able to advance its retinal pigment epithelium cells program. (
  • This study demonstrates that minocycline protects retinal pigment epithelial cells in culture from the effects of hypoxia. (
  • The results suggest that careful manipulation of the Pax6 regulatory circuit may facilitate the generation of retinal and pigment epithelium cells from embryonic or induced pluripotent stem cells. (
  • Movie showing motility and morphology of cultured hTERT-RPE1 cells (telomerase immortalized human retinal pigment epithelium) arrested in G1 using 0.08 uM nocodazole (Uetake and Sluder 2010, Curr Biol 20:1666-1671). (
  • We provide a reproducible method for culturing confluent monolayers of human fetal retinal pigment epithelial cells (hfRPE) cells that exhibit morphology, physiology, polarity, and protein and gene expression patterns of adult native tissue. (
  • To evaluate the effects of 7-methylxanthine (7-MX) on the growth of human retinal pigment epithelium (RPE) cells and to observe the changes in the expression of adenosine receptors (ADORs) in RPE cells upon 7-MX treatment. (
  • The age lipid A2E and mitochondrial dysfunction synergistically impair phagocytosis by retinal pigment epithelial cells. (
  • Accumulation of indigestible lipofuscin and decreased mitochondrial energy production are characteristic age-related changes of post-mitotic retinal pigment epithelial (RPE) cells in the human eye. (
  • A human retinal pigment epithelium cell line (ARPE-19), a line of immortalized human RPE cells, was used for all experiments. (
  • This effect explains why cultured human retinal epithelial cells are depleted of their stores of retinoids when maintained in medium supplemented with FBS. (
  • The purpose of this study was to characterize the cell surface proteome of native compared to cultured equine retinal pigment epithelium (RPE) cells. (
  • We are investigating immunopathomechanisms of equine recurrent uveitis, an autoimmune inflammatory disease in horses leading to breakdown of the outer blood-retinal barrier and influx of autoreactive T-cells into affected horses' vitrei. (
  • As we believe that initiating events, leading to the breakdown of the outer blood-retinal barrier, take place at the cell surface of RPE cells as a particularly exposed barrier structure, this differential characterization of cell surface proteomes of native and cultured equine RPE cells is a prerequisite for future studies. (
  • The current study tested the hypothesis that CeO2 NP would cause a dose-dependent phototoxic reaction in human-derived retinal pigment epithelial cells (ARPE-19) after UV exposure. (
  • T cells that encounter ocular pigment epithelium in vitro are inhibited from undergoing TCR-triggered activation, and instead acquire the capacity to suppress the activation of bystander T cells. (
  • Because retinal pigment epithelial (RPE) cells suppress T cell activation by releasing soluble inhibitory factors, we studied whether soluble factors also promote the generation of T regulatory (Treg) cells. (
  • In addition, pigment epithelium cells derived from the retina have been shown to secrete soluble factors such as TGFβ ( 6 , 7 ), thrombospondin-1 ( 6 , 7 , 8 ), and PGE 2 ( 7 , 9 ), which can alter the expression of both adaptive and innate immune effector mechanisms in vitro. (
  • We recently reported that T cells stimulated by anti-CD3 Ab in the presence of primary cultured iris pigment epithelium (IPE) from the anterior segment of the eye acquire the capacity to regulate bystander T cells in subsequent cultures ( 10 , 11 , 12 , 13 ). (
  • The retina, and specifically the retinal pigment epithelium (RPE) is the only neural tissue that is exposed directly and frequently to light, which favors the oxidation of lipids that become extremely toxic to the cells of the retina. (
  • The dispersion of retinal pigment epithelial cells (RPE) in the vitreous seems to be fundamental in PVR membrane formation and subsequent retinal detachment. (
  • Human retinal pigmented epithelial (RPE) cells labeled for clathrin-coated pits (green), focal adhesions (red) and nuclei (blue). (
  • Under inflammatory conditions, the ability of RPE cells to maintain the blood-retinal barrier and immune privilege may be lost and proliferation of RPE cells is facilitated. (
  • This study provides insight into the unique responses of RPE cells to TNF-α stimulation and suggests a role for genes involved in apoptosis and retinal epithelial development. (
  • Time lapse series of cell growth and division in cultured hTERT-RPE1 cells (telomerase immortalized human retinal pigment epithelium) using differential interference contrast optics. (
  • Retinal pigment epithelial cells undergoing mitotic catastrophe are vulnerable to autophagy inhibition. (
  • Photoreceptor nuclei rows and microglial cells in the different retinal layers were quantified. (
  • Thus, the retinal degeneration caused by pigment epithelium malfunction is more inflammatory and would probably respond better to interventions by inhibiting microglial cells. (
  • The retinal pigment epithelium (RPE) is constantly exposed to external injuries which lead to degeneration, dysfunction or loss of RPE cells. (
  • In this study, human retinal pigment epithelial cells ARPE19 were exposed to 100 J/m(2) stop of UV-C and MAPK pathways were studied. (
  • Retinal pigment epithelial (RPE) cells, a major cellular component of the fibrotic membrane, is one of the cell types that have been previously reported to associate with PVR pathogenesis. (
  • Retinal pigment epithelial (RPE) cells are one of the major cellular components of the fibrotic membrane. (
  • These very specific cells were made in the laboratory from induced pluripotent stem cells (iPS cells), a technique that could, in the future, enable human retinal cells to be made from another human tissue, for example a skin sample. (
  • The retinal pigment epithelium (RPE) is a layer of cells in the retina behind the photoreceptors that is necessary for vision. (
  • In recent years, several international research groups have been working to replace the damaged retinal pigment epithelium by an implant of new cells differentiated in the laboratory from stem cells or induced pluripotent cells. (
  • It verifies the safety and efficacy of the transplant of this retinal cell layer that has been grown in the laboratory from induced pluripotent cells. (
  • Its gene is expressed in two cell types: melanocytes, derived from migrating neural crest cells, and, in the CNS, retinal pigment epithelium cells, derived from the optic cup. (
  • We find no evidence for tyrosinase gene expression in the CNS outside the retinal pigment epithelium cells. (
  • van Bilsen K, van Hagen PM, Bastiaans J: The neonatal Fc receptor is expressed by human retinal pigment epithelial cells and is downregulated by tumour necrosis factor-alpha. (
  • Their primary nutrient source is the choriocapillaris, and both the choriocapillaris and photoreceptors require trophic and functional support from retinal pigment epithelium (RPE) cells. (
  • The light-sensing cells in the eye, known as photoreceptors, need tremendous amounts of glucose, which they receive from the blood with the help of neighboring cells called retinal pigment epithelium (RPE) cells. (
  • Retinal pigment epithelial (RPE) cells apically polarize proteins that are basolateral in other epithelia. (
  • T he retinal pigment epithelium (RPE) 1 is a highly specialized derivative of the embryonic neural tube that lies with its apical surface in intimate contact with the light-sensitive cells of the retina ( Zinn and Marmor, 1979 ), performing critical transport, barrier, and phagocytic support functions for the neural retina. (
  • Mechanisms of interferon-induced inhibition of Toxoplasma gondii replication in human retinal pigment epithelial cells. (
  • Despite the earlier discoveries, the presence of Na v channel-mediated currents in the cells of retinal pigment epithelium (RPE) has been dismissed as a cell culture artifact. (
  • Photoreceptors then export the lactate as fuel for the retinal pigment epithelium and for neighboring Müller glial cells. (
  • We used human retinal epithelial cells to show that lactate can suppress consumption of glucose by the retinal pigment epithelium. (
  • Drusen, extracellular lesions formed underneath the retinal pigment epithelial (RPE) cells, are a clinical feature of AMD and associated with AMD progression. (
  • A defect in retinal pigment epithelial (RPE) cells may cause dysfunction of the neural retina, so rapid recovery of differentiated RPE cells is required after RPE injury. (
  • The loss of ERK1/2 activity resulted in a significant decrease in the level of RPE65 expression, a decrease in ocular retinoid levels concomitant with low visual function, and a rapid disorganization of RPE cells, ultimately leading to retinal degeneration. (
  • 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. (
  • Histopathological examination indicated that the tumor was contiguous with the normal surrounding RPE and was composed of cords and tubules of mostly non-pigmented spindle-shaped cells with round to oval nuclei and a small amount of cytoplasm containing melanin granules. (
  • Most pigmented cells in the body originate from the neural crest. (
  • The embryonic chick can regenerate its retina by transdifferentiation of the retinal pigmented epithelium (RPE) and by activation of stem/progenitor cells present in the ciliary margin. (
  • Background and aims: The retinal pigment epithelium (RPE) cells are paramount for normal vision. (
  • High lipofuscin levels in the RPE have been associated with retinal degeneration and blindness in Stargardt disease patients and animal models. (
  • Accumulation of lipofuscin bisretinoids (LBs) in the retinal pigment epithelium (RPE) is the alleged cause of retinal degeneration in genetic blinding diseases (e.g. (
  • Deficit of melanin pigment is associated with age-related macula degeneration, the leading cause of blindness. (
  • To study the course of photoreceptor cell death and macro and microglial reactivity in two rat models of retinal degeneration with different etiologies. (
  • The etiology of retinal degeneration determines the initiation and pattern of photoreceptor cell death and simultaneously there is microglial activation and migration, while the macroglial response is delayed. (
  • Ultrastructural Changes and Expression of PCNA and RPE65 in Sodium Iodate-Induced Acute Retinal Pigment Epithelium Degeneration Model. (
  • We analyzed the sequential ultrastructure and expression of proliferating cell nuclear antigen (PCNA) and retina-specific RPE65 in NaIO3-induced retinal degeneration model. (
  • NaIO3-induced retinal degeneration was successfully established. (
  • Loss of Extracellular Signal-Regulated Kinase 1/2 in the Retinal Pigment Epithelium Leads to RPE65 Decrease and Retinal Degeneration. (
  • Authors: Kim HL, Nam SM, Chang BJ, Nahm SS, Lee JH Abstract Alteration in retinal pigment epithelium (RPE) results in the visual dysfunction and blindness of retinal degenerative diseases. (
  • The height of pigment epithelial detachment (PED) was measured by SD-OCT. (
  • Feeney L (1978) Lipofuscin and melanin of human retinal pigment epithelium. (
  • Lipofuscin accumulation in the retinal pigment epithelium (RPE) is a hallmark of aging. (
  • Currently, there is no treatment to prevent and/or revert lipofuscin-driven retinal degenerative changes. (
  • In this study, we report that beta cyclodextrins, cyclic sugars composed of seven glucose units, can bind retinal lipofuscin, prevent its oxidation and remove it from RPE. (
  • Barker, Pierrette Dayhaw 1991-08-01 00:00:00 The photophysical properties of purified populations of melanin and lipofuscin granules from human retinal pigment epithelium, and their changes with donor age, have been investigated using high‐sensitivity time‐resolved fluorescence spectroscopy techniques with picosecond gating capabilities. (
  • Furthermore, the ability of this technique to identify and quantify individual fluorophores within granules may provide an important insight into the origin and development of lipofuscin within the retinal pigment epithelium and ultimately into the mechanisms of age‐related retinal diseases. (
  • Epithelial transport: As mentioned above, RPE compose the outer blood-retinal barrier, the epithelia has tight junctions between the lateral surfaces and implies an isolation of the inner retina from the systemic influences. (
  • One region, the outer blood-retinal barrier, has an unusual structure. (
  • The retinal pigment epithelium (RPE) forms a major component of the blood-retinal barrier. (
  • The RPE plays an essential role in visual function and represents the outer blood-retinal barrier. (
  • The RPE is a major component of the blood retinal barrier and it therefore determines the microenvironment of the photoreceptors. (
  • Phagocytosis by retinal pigment epithelium explants in culture. (
  • Each cell has an outer part that is clear, and an inner part that is densely filled with granules of pigment, which gives the epithelium its dark appearance. (
  • This short review focuses on the role of the pigment granules in RPE. (
  • Although the biology of the pigment granules has been neglected in the past, they do seem to be involved in many important functions, such as protection from oxidative stress, detoxification of peroxides, and binding of zinc and drugs, and, therefore, serve as a versatile partner of the RPE cell. (
  • The retinal pigment epithelium (RPE) interacts with the photoreceptors, which it faces across the subretinal space. (
  • Bok D and Filerman B (1979) Localization of Na + , K + ATPase in retinal photoreceptors and RPE with 3 H-ouabain. (
  • To determine the cell density profile of the retinal pigment epithelium (RPE) in the central retina and relate it to the distribution of photoreceptors. (
  • Geography atrophy appears as confluent regions of cell death in photoreceptors and in the retinal pigment epithelium , according to the report in the August 27th online issue of The New England Journal of Medicine. (
  • Metabolic flux, locations of key enzymes, and our finding that glucose enters mouse and zebrafish retinas mostly through photoreceptors support a conceptually new model for retinal metabolism. (
  • In this model, glucose from the choroidal blood passes through the retinal pigment epithelium to the retina where photoreceptors convert it to lactate. (
  • Separation of the inner layers of the retina (neural retina) from the pigment epithelium. (
  • Like the choroid plexus, the RPE plays an important glial-like role in maintaining the health and integrity of the nearby neurons, and the retinal-facing membrane contains an array of metabotropic receptors that enable the RPE to carry out its glial functions. (
  • The internal structures were disorganized with diffuse calcification and bone formation at the level of the retinal pigment epithelium and choroid. (
  • Retinal pigment epithelium (RPE) is located between the retina and choroid. (
  • Tian J, Ishibashi K, Ishibashi K, Reiser K, Grebe R, Biswal S, Gehlbach P, Handa JT (2005) Advanced glycation endproduct-induced aging of the retinal pigment epithelium and choroid: a comprehensive transcriptional response. (
  • Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. (
  • Inherited retinal degenerative diseases are a major cause of blindness in the world. (
  • This first surgical test has shown positive results and constitutes the first step of a preclinical study with the goal to provide therapeutic options for retinal degenerative diseases. (
  • These data indicate the presence of metabotropic P 2Y /P 2U -purinoceptors at the RPE apical membrane and implicate extracellular ATP in vivo as a retinal signaling molecule that could help regulate the hydration and chemical composition of the subretinal space. (
  • It has two functionally distinct membranes that face different extracellular environments: the apical (retinal-facing) membrane directly opposes the photoreceptor outer segments, and the basolateral (serosal-facing) membrane faces the fenestrated choroicapillaris. (
  • It is physiologically characterised by increased cell proliferation, migration and secretion of extracellular matrix (ECM) proteins, which results in the formation of fibrotic membranes in response to retinal detachment. (
  • Drusen are yellowish extracellular deposits beneath retinal pigment epithelium (RPE) found in aging eyes and considered as a biomarker of AMD. (
  • Peropsin, a novel visual pigment-like protein located in the apical microvilli of the retinal pigment epithelium. (
  • The main functions of the RPE are: control of the flow of fluid and nutrients entering the retina (blood-retina barrier), absorption of scattered light, visual pigment metabolism, vitamin A metabolism which contributes to visual pigment regeneration, ingestion and digestion of photoreceptor discs (phagocytosis), retinal adhesion and synthesis of growth factors of adjacent tissues. (
  • The ancestral condition of the visual system of vertebrates, which has been retained in many extant taxa, includes a cone photoreceptor whose visual pigment contains the short-wavelength-sensitive type 1 (SWS1) opsin. (
  • The light sensitivity of a visual pigment is to a large extent determined by the amino-acid sequence of its opsin moiety (e.g. (
  • RPE cross-section of the retina depicting the layers of the retina including the retinal pigment epithelium. (
  • Bridges CDB, Fong S-L, Liou GI, Alvarez RA and Landers RA (1983) Transport, utilization and metabolism of visual cycle retinoids in the retina and pigment epithelium. (
  • [ 5 ] Histologically, the lesions show pigment granule hypertrophy with hypopigmented RPE at the margins to give the characteristic halo. (
  • Another disorder related to the RPE is retinal pigment epithelial hypertrophy , which occurs when regions of the epithelium become thicker than normal. (
  • Congenital hypertrophy of the retinal pigment epithelium (CHRPE), a benign retinal lesion without visual sequelae, is estimated to be up to 94% sensitive in screening asymptomatic members of familial adenomatous polyposis kindreds exhibiting the CHRPE phenotype (1). (
  • congenital hypertrophy of the retinal pigment epithelium is a topic covered in the Taber's Medical Dictionary . (
  • Taber's Online , (
  • King, "Microarray analysis of gene expression in West Nile virus-infected human retinal pigment epithelium ," Molecular Vision, vol. (
  • Among the latter were two RPE markers with highly specialized RPE functions: cellular retinaldehyde-binding protein (CRALBP) and retinal pigment epithelium-specific protein 65kDa (RPE65). (
  • Retinyl esters are stored in retinosomes in retinal pigment epithelium (RPE) and serve as a substrate for RPE65 to generate 11- cis -retinol which is further oxidized and used to regenerate rhodopsin. (
  • Highly conserved among vertebrate species, RPE65 is a major protein of the retinal pigment epithelium (RPE). (
  • Mutations in RPE65 are responsible for certain forms of autosomal recessive severe retinal dystrophy, including Leber Congenital Amaurosis (LCA). (
  • Proliferative vitreoretinopathy (PVR) is a serious complication that is caused by rhegmatogenous retinal detachment and is the leading cause of retinal detachment surgery failure ( 1 , 2 ). (
  • A regulatory loop involving PAX6, MITF, and WNT signaling controls retinal pigment epithelium development. (
  • Here we show in mice that the transcription factor PAX6, well-known for its retina-promoting activity, also plays a crucial role in early pigment epithelium development. (
  • This gene belongs to the seven-exon subfamily of mammalian opsin genes that includes opsin 5 and retinal G protein coupled receptor. (
  • The latter shows the interactions between GPR143 and the different genes responsible for melanogenesis as well as growth factors such as SERPINF1 and VEGF in melanocytes or the retinal pigment epithelium. (
  • During the differentiation of the RPE, PAX6 regulates the expression of an RPE-specific isoform of Mitf and importantly, at the same time, PAX6 functions together with MITF to directly activate the expression of downstream genes required for pigment biogenesis. (
  • Certain percent of the eyes with proliferative diabetic retinopathymay require pars plana vitrectomy (PPV) due to vitreous haemorrhage, proliferative membrane, and tractional retinal detac. (
  • Persons with HM are predisposed to other eye pathologies such as retinal detachment, myopic retinopathy or glaucomatous optic neuropathy, complications that may at least partly result from the extensive liquefaction of the myopic vitreous gel. (
  • Gremlin is predominantly localised to the outer retina, and high levels of its expression have been demonstrated in bovine retinal pericytes in response to elevated glucose levels compared with control treated pericytes ( 13 ). (
  • Suppression of glucose consumption in the retinal pigment epithelium can increase the amount of glucose that reaches the retina. (
  • We have exploited a method for isolating microvilli from the mouse eye using wheat germ agglutinin (WGA)-agarose beads to begin to understand the specific molecular composition of apical microvilli of the retinal pigment epithelium (RPE) and expand our knowledge of the potential function of this interface. (
  • At this surface, the microvilli interact with the tips of cylindrical photoreceptor outer segments extending from the outer retinal surface. (
  • CHRPE is a benign pigmented lesion that often raises suspicion for malignant choroidal melanoma . (
  • In the rare instance of retinal adenocarcinoma, most patients have been enucleated with a presumed diagnosis of choroidal melanoma. (
  • BACKGROUND: Adenoma of the retinal pigment epithelium (RPE) is a rare intraocular tumor that can simulate other pigmented tumors such as choroidal melanoma. (
  • A 50-year-old man underwent bilateral serous retinal detachments . (
  • CONCLUSION: Adenoma of the retinal pigment epithelium may be associated with incompetent vessels leading to serous retinal detachment and extensive visual loss, and may exhibit clinical characteristics similar to choroidal hemangioma. (
  • This comes not directly from the visual cycle but from several retinal pools of retinal binding proteins which are connected to each other by the transportation and reaction steps of the visual cycle. (
  • The selective damage of the retinal pigment epithelium (RPE) is a new treatment method for several retinal diseases. (
  • In the present study, we used conventional electrophysiological and [Ca 2+ ] in fluorescence imaging techniques to investigate the effects of ATP added to Ringer's solution perfusing the retinal-facing (apical) membrane of freshly isolated monolayers of bovine retinal pigment epithelium (RPE). (
  • Hughes, Bret A. 2017-10-05 00:00:00 The basolateral membrane anion conductance of the retinal pigment epithelium (RPE) is a key component of the transepithelial Cl- transport pathway. (
  • Rizzolo, "Development and role of tight junctions in the retinal pigment epithelium ," International Review of Cytology, vol. (
  • This role is seen, however, only in a background genetically sensitized by mutations in the pigment cell transcription factor MITF. (
  • Transcription physiology" of pigment formation in melanocytes: central role of MITF. (
  • Peropsin gene is not a common cause of retinitis pigmentosa or some related retinal degenerations, at least in the set of patients we analyzed. (
  • The transcription factors Pax2 and Pax6 are co-expressed in the entire optic vesicle (OV) prior and concomitant with the establishment of distinct neuroretinal, retinal, pigmented-epithelial and optic-stalk progenitor domains, suggesting redundant functions during retinal determination. (
  • Here, we directly investigated the involvement of PAX6 in the differentiation of one lineage, the retinal pigmented epithelium (RPE), a neuroectodermal-derived tissue that is essential for retinal development and function. (
  • Construction and delivery of tissue-engineered human retinal pigment epithelial cell sheets, using magnetite nanoparticles and magnetic force. (
  • Transplantation of cultured retinal pigment epithelium (RPE) cell sheet by tissue engineering is a possible approach to the treatment of CNV. (
  • Proliferative Vitreoretinopathy (PVR) is a major cause for visual loss after retinal detachment surgery. (
  • Optical coherence tomography reveals retinal thinning over the area of CHRPE as well as loss of the photoreceptor layer, corresponding to the related visual field defects observed. (
  • The patient underwent vitrectomy and epiretinal component peeling, with improvement in visual acuity, metamorphopsia, and retinal architecture, assessed by optical coherence tomography. (
  • To report the anatomical and visual results in patients diagnosed as having retinal pigment epithelium (RPE) tears after receiving ranibizumab injections. (