A phthalic indicator dye that appears yellow-green in normal tear film and bright green in a more alkaline medium such as the aqueous humor.
A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.
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.
Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.
Measurement of light given off by fluorescein in order to assess the integrity of various ocular barriers. The method is used to investigate the blood-aqueous barrier, blood-retinal barrier, aqueous flow measurements, corneal endothelial permeability, and tear flow dynamics.
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)
Organic derivatives of thiocyanic acid which contain the general formula R-SCN.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
The blood vessels which supply and drain the RETINA.
A pathological process consisting of the formation of new blood vessels in the CHOROID.
The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.
The fluid secreted by the lacrimal glands. This fluid moistens the CONJUNCTIVA and CORNEA.
A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.
Corneal and conjunctival dryness due to deficient tear production, predominantly in menopausal and post-menopausal women. Filamentary keratitis or erosion of the conjunctival and corneal epithelium may be caused by these disorders. Sensation of the presence of a foreign body in the eye and burning of the eyes may occur.
Retinal diseases refer to a diverse group of vision-threatening disorders that affect the retina's structure and function, including age-related macular degeneration, diabetic retinopathy, retinal detachment, retinitis pigmentosa, and macular edema, among others.
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.
A tricarbocyanine dye that is used diagnostically in liver function tests and to determine blood volume and cardiac output.
The use of green light-producing LASERS to stop bleeding. The green light is selectively absorbed by HEMOGLOBIN, thus triggering BLOOD COAGULATION.
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 bright bluish pink compound that has been used as a dye, biological stain, and diagnostic aid.
Measurement of the intensity and quality of fluorescence.
A family of 3,6-di(substituted-amino)-9-benzoate derivatives of xanthene that are used as dyes and as indicators for various metals; also used as fluorescent tracers in histochemistry.
The property of blood capillary ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-NERVE BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement.
Disorders of the choroid including hereditary choroidal diseases, neoplasms, and other abnormalities of the vascular layer of the uvea.
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.
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.
Examination of the interior of the eye with an ophthalmoscope.
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)
An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.
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.
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.
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.
A tetraiodofluorescein used as a red coloring in some foods (cherries, fish), as a disclosure of DENTAL PLAQUE, and as a stain of some cell types. It has structural similarity to THYROXINE.
Fluid accumulation in the outer layer of the MACULA LUTEA that results from intraocular or systemic insults. It may develop in a diffuse pattern where the macula appears thickened or it may acquire the characteristic petaloid appearance referred to as cystoid macular edema. Although macular edema may be associated with various underlying conditions, it is most commonly seen following intraocular surgery, venous occlusive disease, DIABETIC RETINOPATHY, and posterior segment inflammatory disease. (From Survey of Ophthalmology 2004; 49(5) 470-90)
Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.
A red fluorescein dye used as a histologic stain. It may be cytotoxic, mutagenic, and inhibit certain mitochondrial functions.
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.
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.
Central retinal artery and its branches. It arises from the ophthalmic artery, pierces the optic nerve and runs through its center, enters the eye through the porus opticus and branches to supply the retina.
Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.
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.
Blockage of the RETINAL VEIN. Those at high risk for this condition include patients with HYPERTENSION; DIABETES MELLITUS; ATHEROSCLEROSIS; and other CARDIOVASCULAR DISEASES.
The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. (Cline et al., Dictionary of Visual Science, 4th ed, p109)
Diseases of the uvea.
The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.
The photography of images produced on a fluorescent screen by X-rays.
Method of making images on a sensitized surface by exposure to light or other radiant energy.
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 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.
Central retinal vein and its tributaries. It runs a short course within the optic nerve and then leaves and empties into the superior ophthalmic vein or cavernous sinus.
Sudden ISCHEMIA in the RETINA due to blocked blood flow through the CENTRAL RETINAL ARTERY or its branches leading to sudden complete or partial loss of vision, respectively, in the eye.
Bleeding from the vessels of the retina.
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)
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.
Organic compounds which contain mercury as an integral part of the molecule.
Formation of new blood vessels originating from the retinal veins and extending along the inner (vitreal) surface of the retina.
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)
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)
The administration of substances into the VITREOUS BODY of the eye with a hypodermic syringe.
The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)
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).
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.
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.
Green dyes containing ammonium and aryl sulfonate moieties that facilitate the visualization of tissues, if given intravenously. They have mostly been used in the study of kidney physiology.
The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball.
The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
The rate dynamics in chemical or physical systems.
Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.
Therapy using oral or topical photosensitizing agents with subsequent exposure to light.
Swelling of the OPTIC DISK, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause OPTIC ATROPHY and visual loss. (Miller et al., Clinical Neuro-Ophthalmology, 4th ed, p175)
Stratified squamous epithelium that covers the outer surface of the CORNEA. It is smooth and contains many free nerve endings.
The administration of substances into the eye with a hypodermic syringe.
Recording of electric potentials in the retina after stimulation by light.
Introduction of substances into the body using a needle and syringe.
The selectively permeable barrier, in the EYE, formed by the nonpigmented layer of the EPITHELIUM of the CILIARY BODY, and the ENDOTHELIUM of the BLOOD VESSELS of the IRIS. TIGHT JUNCTIONS joining adjacent cells keep the barrier between cells continuous.
A visual impairment characterized by the accumulation of fluid under the retina through a defect in the retinal pigment epithelium.
Inflammation of the choroid.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Devices for examining the interior of the eye, permitting the clear visualization of the structures of the eye at any depth. (UMDNS, 1999)
Drying and inflammation of the conjunctiva as a result of insufficient lacrimal secretion. When found in association with XEROSTOMIA and polyarthritis, it is called SJOGREN'S SYNDROME.
Inflammation of the retinal vasculature with various causes including infectious disease; LUPUS ERYTHEMATOSUS, SYSTEMIC; MULTIPLE SCLEROSIS; BEHCET SYNDROME; and CHORIORETINITIS.
The prototypical uricosuric agent. It inhibits the renal excretion of organic anions and reduces tubular reabsorption of urate. Probenecid has also been used to treat patients with renal impairment, and, because it reduces the renal tubular excretion of other drugs, has been used as an adjunct to antibacterial therapy.
Microscopy in which the image is formed by ultraviolet radiation and is displayed and recorded by means of photographic film.
Small breaks in the elastin-filled tissue of the retina.
The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.
Discharge of cerebrospinal fluid through the nose. Common etiologies include trauma, neoplasms, and prior surgery, although the condition may occur spontaneously. (Otolaryngol Head Neck Surg 1997 Apr;116(4):442-9)
The escape of diagnostic or therapeutic material from the vessel into which it is introduced into the surrounding tissue or body cavity.
The minute vessels that connect the arterioles and venules.
The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.
Measurement of the various properties of light.
The sebaceous glands situated on the inner surface of the eyelids between the tarsal plates and CONJUNCTIVA.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
Elements of limited time intervals, contributing to particular results or situations.
Permanent dilation of preexisting blood vessels (CAPILLARIES; ARTERIOLES; VENULES) creating small focal red lesions, most commonly in the skin or mucous membranes. It is characterized by the prominence of skin blood vessels, such as vascular spiders.
Diseases affecting the eye.
Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.
Eyelid diseases refer to various medical conditions that affect the function, structure, or appearance of the eyelids, including inflammatory, infectious, neoplastic, congenital, and traumatic disorders, which can impact vision, comfort, and overall ocular health.
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.
The metal-free red phycobilin pigment in a conjugated chromoprotein of red algae. It functions as a light-absorbing substance together with chlorophylls.
Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.
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.
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.
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).
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.
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.
The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.
Single layer of large flattened cells covering the surface of the cornea.
Diseases, dysfunctions, or disorders of or located in the iris.
The tear-forming and tear-conducting system which includes the lacrimal glands, eyelid margins, conjunctival sac, and the tear drainage system.
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.
Small antigenic determinants capable of eliciting an immune response only when coupled to a carrier. Haptens bind to antibodies but by themselves cannot elicit an antibody response.
A mixture of alkylbenzyldimethylammonium compounds. It is a bactericidal quaternary ammonium detergent used topically in medicaments, deodorants, mouthwashes, as a surgical antiseptic, and as a as preservative and emulsifier in drugs and cosmetics.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Antibodies produced by a single clone of cells.
Damage or trauma inflicted to the eye by external means. The concept includes both surface injuries and intraocular injuries.

Relocating the active site of activated protein C eliminates the need for its protein S cofactor. A fluorescence resonance energy transfer study. (1/850)

The effect of replacing the gamma-carboxyglutamic acid domain of activated protein C (APC) with that of prothrombin on the topography of the membrane-bound enzyme was examined using fluorescence resonance energy transfer. The average distance of closest approach (assuming kappa2 = 2/3) between a fluorescein in the active site of the chimera and octadecylrhodamine at the membrane surface was 89 A, compared with 94 A for wild-type APC. The gamma-carboxyglutamic acid domain substitution therefore lowered and/or reoriented the active site, repositioning it close to the 84 A observed for the APC. protein S complex. Protein S enhances wild-type APC cleavage of factor Va at Arg306, but the inactivation rate of factor Va Leiden by the chimera alone is essentially equal to that by wild-type APC plus protein S. These data suggest that the activities of the chimera and of the APC.protein S complex are equivalent because the active site of the chimeric protein is already positioned near the optimal location above the membrane surface to cleave Arg306. Thus, one mechanism by which protein S regulates APC activity is by relocating its active site to the proper position above the membrane surface to optimize factor Va cleavage.  (+info)

Estimation of corneal endothelial pump function in long-term contact lens wearers. (2/850)

PURPOSE: To study the effects of long-term contact lens wear on morphologic and physiologic properties of corneal endothelial cells. METHODS: The endothelial permeability to fluorescein and the rate of corneal deswelling from hypoxia-induced edema were measured in 20 long-term (mean, 17+/-9 years; range, 5-33 years) contact lens wearers and 20 age-matched control subjects. From these data, the relative endothelial pump rate in each subject was estimated, based on the pump-leak hypothesis of corneal hydration control. Corneal autofluorescence and the aqueous humor flow rate were determined by fluorescein fluorophotometry. Images of corneal endothelial cells were recorded by using specular microscopy, and morphologic indices (cell density, coefficient of variation of cell area, percentage of hexagonal cells, and skewness) were determined. RESULTS: No statistically significant differences were found between the contact lens and control groups in endothelial permeability, corneal deswelling, relative endothelial pump rate ([mean +/- SD] 1.07+/-0.33 relative pump units versus 1.01+/-0.25 relative pump units; contact lens versus control; P = 0.57), and endothelial cell density. Contact lens wearers had a significantly higher aqueous humor flow rate (3.57+/-1.03 microl/min versus 2.77+/-0.51 microl/min; P = 0.005), coefficient of variation of cell area (0.35+/-0.09 versus 0.28+/-0.04; P = 0.006), and corneal autofluorescence (3.1+/-0.6 ng/ml versus 2.3+/-0.3 ng/ml fluorescein equivalents; P < 0.001) than did non-contact lens wearers. CONCLUSIONS: Despite the known effects of long-term contact lens wear on corneal endothelial morphometry, no effect on endothelial function was found.  (+info)

Enhancement of endocytosis due to aminophospholipid transport across the plasma membrane of living cells. (3/850)

Formation of intracellular vesicles is initiated by membrane budding. Here we test the hypothesis that the plasma membrane surface area asymmetry could be a driving force for vesicle formation during endocytosis. The inner layer phospholipid number was therefore increased by adding exogenous aminophospholipids to living cells, which were then translocated from the outer to the inner layer of the membrane by the ubiquitous flippase. Addition of either phosphatidylserine or phosphatidylethanolamine led to an enhancement of endocytosis, showing that the observed acceleration does not depend on the lipid polar head group. Conversely, a closely related aminophospholipid that is not recognized by the flippase, lyso-alpha-phosphatidylserine, inhibited endocytosis, and similar results were obtained with a cholesterol derivative that also remains in the plasma membrane outer layer. Thus an increase of lipid concentration in the inner layer enhanced internalization, whereas an increase of the lipid concentration in the outer layer inhibited internalization. These experiments suggest that transient asymmetries in lipid concentration might contribute to the formation of endocytic vesicles.  (+info)

Renin inhibition by substituted piperidines: a novel paradigm for the inhibition of monomeric aspartic proteinases? (4/850)

BACKGROUND: The aspartic proteinase renin catalyses the first and rate-limiting step in the conversion of angiotensinogen to the hormone angiotensin II, and therefore plays an important physiological role in the regulation of blood pressure. Numerous potent peptidomimetic inhibitors of this important drug target have been developed, but none of these compounds have progressed past clinical phase II trials. Limited oral bioavailability or excessive production costs have prevented these inhibitors from becoming new antihypertensive drugs. We were interested in developing new nonpeptidomimetic renin inhibitors. RESULTS: High-throughput screening of the Roche compound library identified a simple 3, 4-disubstituted piperidine lead compound. We determined the crystal structures of recombinant human renin complexed with two representatives of this new class. Binding of these substituted piperidine derivatives is accompanied by major induced-fit adaptations around the enzyme's active site. CONCLUSIONS: The efficient optimisation of the piperidine inhibitors was facilitated by structural analysis of the renin active site in two renin-inhibitor complexes (some of the piperidine derivatives have picomolar affinities for renin). These structural changes provide the basis for a novel paradigm for inhibition of monomeric aspartic proteinases.  (+info)

Molecular forceps from combinatorial libraries prevent the farnesylation of Ras by binding to its carboxyl terminus. (5/850)

INTRODUCTION: Ras is one of the major oncogenes. In order to function properly it has to undergo post-translational processing at its carboxyl terminus. It has been shown that inhibitors of farnesyl transferase, the first enzyme in the processing chain, can suppress the transforming activity of oncogenic Ras. RESULTS: We have identified molecular forceps, branched peptidic molecules, from combinatorial libraries that bind to the carboxyl terminus of Ras and interfere with its farnesylation without inhibiting the farnesyl transferase. The active molecules were selected by a screening against the carboxy-terminal octapeptide of Ras. CONCLUSIONS: The implications of our findings are twofold. First, we demonstrate that it is possible to prevent enzymatic transformations by blocking the enzyme's access to its substrate using a synthetic small molecule to mask the substrate. Second, we show that it is feasible to derive molecules from combinatorial libraries that bind a specific epitope on a protein by selecting these molecules with the isolated peptide epitope.  (+info)

Receptor-mediated targeting of fluorescent probes in living cells. (6/850)

A strategy was developed to label specified sites in living cells with a wide selection of fluorescent or other probes and applied to study pH regulation in Golgi. cDNA transfection was used to target a single-chain antibody to a specified site such as an organelle lumen. The targeted antibody functioned as a high affinity receptor to trap cell-permeable hapten-fluorophore conjugates. Synthesized conjugates of a hapten (4-ethoxymethylene-2-phenyl-2-oxazolin-5-one, phOx) and fluorescent probes (Bodipy Fl, tetramethylrhodamine, fluorescein) were bound with high affinity (approximately 5 nM) and specific localization to the single-chain antibody expressed in the endoplasmic reticulum, Golgi, and plasma membrane of living Chinese hamster ovary cells. Using the pH-sensitive phOx-fluorescein conjugate and ratio imaging microscopy, pH was measured in the lumen of Golgi (pH 6.25 +/- 0.06). Measurements of pH-dependent vacuolar H+/ATPase pump activity and H+ leak in Golgi provided direct evidence that resting Golgi pH is determined by balanced leak-pump kinetics rather than the inability of the H+/ATPase to pump against an electrochemical gradient. Like expression of the green fluorescent protein, the receptor-mediated fluorophore targeting approach permits specific intracellular fluorescence labeling. A significant advantage of the new approach is the ability to target chemical probes with custom-designed spectral and indicator properties.  (+info)

Scanning near-field fluorescence resonance energy transfer microscopy. (7/850)

A new microscopic technique is demonstrated that combines attributes from both near-field scanning optical microscopy (NSOM) and fluorescence resonance energy transfer (FRET). The method relies on attaching the acceptor dye of a FRET pair to the end of a near-field fiber optic probe. Light exiting the NSOM probe, which is nonresonant with the acceptor dye, excites the donor dye introduced into a sample. As the tip approaches the sample containing the donor dye, energy transfer from the excited donor to the tip-bound acceptor produces a red-shifted fluorescence. By monitoring this red-shifted acceptor emission, a dramatic reduction in the sample volume probed by the uncoated NSOM tip is observed. This technique is demonstrated by imaging the fluorescence from a multilayer film created using the Langmuir-Blodgett (LB) technique. The film consists of L-alpha-dipalmitoylphosphatidylcholine (DPPC) monolayers containing the donor dye, fluorescein, separated by a spacer group of three arachidic acid layers. A DPPC monolayer containing the acceptor dye, rhodamine, was also transferred onto an NSOM tip using the LB technique. Using this modified probe, fluorescence images of the multilayer film reveal distinct differences between images collected monitoring either the donor or acceptor emission. The latter results from energy transfer from the sample to the NSOM probe. This method is shown to provide enhanced depth sensitivity in fluorescence measurements, which may be particularly informative in studies on thick specimens such as cells. The technique also provides a mechanism for obtaining high spatial resolution without the need for a metal coating around the NSOM probe and should work equally well with nonwaveguide probes such as atomic force microscopy tips. This may lead to dramatically improved spatial resolution in fluorescence imaging.  (+info)

Inhibitory effects of catecholamines and anti-oxidants on the fluorescence reaction of 4,5-diaminofluorescein, DAF-2, a novel indicator of nitric oxide. (8/850)

4,5-Diaminofluorescein (DAF-2) is a newly developed indicator of nitric oxide (NO). Two amino groups of DAF-2 are oxidized by NO. We investigated the effects of reducers on the NO-induced oxidation of DAF-2. NOC-5 (0.1-10 microM), a NO-donor, concentration-dependently elicited fluorescence with 10 microM DAF-2. The rate of the fluorescence reaction was dependent on the width of the excitation band path. The presence of catecholamines (1 microM), but not tyrosine or phenylephrine, attenuated the fluorescence induced by NOC-5. Ascorbate and other reducers like dithiothreitol, 2-mercaptoethanol, or glutathione (all 1 mM) abolished the fluorescence. These results suggest that reducers attenuate the NO-induced fluorescence of DAF-2 mainly through an anti-oxidative action.  (+info)

Fluorescein is not a medical condition or term, but rather a diagnostic dye used in various medical tests and procedures. Medically, it is referred to as Fluorescein Sodium, a fluorescent compound that absorbs light at one wavelength and emits light at another longer wavelength when excited.

In the field of ophthalmology (eye care), Fluorescein is commonly used in:

1. Fluorescein angiography: A diagnostic test to examine blood flow in the retina and choroid, often used to diagnose and manage conditions like diabetic retinopathy, age-related macular degeneration, and retinal vessel occlusions.
2. Tear film assessment: Fluorescein dye is used to evaluate the quality of tear film and diagnose dry eye syndrome by observing the staining pattern on the cornea.
3. Corneal abrasions/foreign body detection: Fluorescein dye can help identify corneal injuries, such as abrasions or foreign bodies, under a cobalt blue light.

In other medical fields, fluorescein is also used in procedures like:

1. Urinary tract imaging: To detect urinary tract abnormalities and evaluate kidney function.
2. Lymphangiography: A procedure to visualize the lymphatic system.
3. Surgical navigation: In some surgical procedures, fluorescein is used as a marker for better visualization of specific structures or areas.

Fluorescein is not a medical condition, but rather a diagnostic dye that is used in various medical tests and procedures. It is a fluorescent compound that absorbs light at one wavelength and emits light at another wavelength, which makes it useful for imaging and detecting various conditions.

In ophthalmology, fluorescein is commonly used in eye examinations to evaluate the health of the cornea, conjunctiva, and anterior chamber of the eye. A fluorescein dye is applied to the surface of the eye, and then the eye is examined under a blue light. The dye highlights any damage or abnormalities on the surface of the eye, such as scratches, ulcers, or inflammation.

Fluorescein is also used in angiography, a medical imaging technique used to examine blood vessels in the body. A fluorescein dye is injected into a vein, and then a special camera takes pictures of the dye as it flows through the blood vessels. This can help doctors diagnose and monitor conditions such as cancer, diabetes, and macular degeneration.

Overall, fluorescein is a valuable diagnostic tool that helps medical professionals detect and monitor various conditions in the body.

Fluorescein angiography is a medical diagnostic procedure used in ophthalmology to examine the blood flow in the retina and choroid, which are the inner layers of the eye. This test involves injecting a fluorescent dye, Fluorescein, into a patient's arm vein. As the dye reaches the blood vessels in the eye, a specialized camera takes rapid sequences of photographs to capture the dye's circulation through the retina and choroid.

The images produced by fluorescein angiography can help doctors identify any damage to the blood vessels, leakage, or abnormal growth of new blood vessels. This information is crucial in diagnosing and managing various eye conditions such as age-related macular degeneration, diabetic retinopathy, retinal vein occlusions, and inflammatory eye diseases.

It's important to note that while fluorescein angiography is a valuable diagnostic tool, it does carry some risks, including temporary side effects like nausea, vomiting, or allergic reactions to the dye. In rare cases, severe adverse reactions can occur, so patients should discuss these potential risks with their healthcare provider before undergoing the procedure.

Fluorescein-5-isothiocyanate (FITC) is not a medical term per se, but a chemical compound commonly used in biomedical research and clinical diagnostics. Therefore, I will provide a general definition of this term:

Fluorescein-5-isothiocyanate (FITC) is a fluorescent dye with an absorption maximum at approximately 492-495 nm and an emission maximum at around 518-525 nm. It is widely used as a labeling reagent for various biological molecules, such as antibodies, proteins, and nucleic acids, to study their structure, function, and interactions in techniques like flow cytometry, immunofluorescence microscopy, and western blotting. The isothiocyanate group (-N=C=S) in the FITC molecule reacts with primary amines (-NH2) present in biological molecules to form a stable thiourea bond, enabling specific labeling of target molecules for detection and analysis.

Fluorophotometry is a medical diagnostic technique that measures the concentration of fluorescein dye in various tissues, particularly the eye. This technique utilizes a specialized instrument called a fluorophotometer which emits light at a specific wavelength that causes the fluorescein to emit light at a longer wavelength. The intensity of this emitted light is then measured and used to calculate the concentration of fluorescein in the tissue.

Fluorophotometry is often used in ophthalmology to assess the permeability of the blood-retinal barrier, which can be helpful in diagnosing and monitoring conditions such as diabetic retinopathy, age-related macular degeneration, and uveitis. It may also have applications in other medical fields for measuring the concentration of fluorescent markers in various tissues.

"Fundus Oculi" is a medical term that refers to the back part of the interior of the eye, including the optic disc, macula, fovea, retinal vasculature, and peripheral retina. It is the area where light is focused and then transmitted to the brain via the optic nerve, forming visual images. Examinations of the fundus oculi are crucial for detecting various eye conditions such as diabetic retinopathy, macular degeneration, glaucoma, and other retinal diseases. The examination is typically performed using an ophthalmoscope or a specialized camera called a retinal camera.

Thiocyanates are chemical compounds that contain the thiocyanate ion (SCN-), which consists of a sulfur atom, a carbon atom, and a nitrogen atom. The thiocyanate ion is formed by the removal of a hydrogen ion from thiocyanic acid (HSCN). Thiocyanates are used in various applications, including pharmaceuticals, agrochemicals, and industrial chemicals. In medicine, thiocyanates have been studied for their potential effects on the thyroid gland and their use as a treatment for cyanide poisoning. However, excessive exposure to thiocyanates can be harmful and may cause symptoms such as irritation of the eyes, skin, and respiratory tract, as well as potential impacts on thyroid function.

Fluorescent dyes are substances that emit light upon excitation by absorbing light of a shorter wavelength. In a medical context, these dyes are often used in various diagnostic tests and procedures to highlight or mark certain structures or substances within the body. For example, fluorescent dyes may be used in imaging techniques such as fluorescence microscopy or fluorescence angiography to help visualize cells, tissues, or blood vessels. These dyes can also be used in flow cytometry to identify and sort specific types of cells. The choice of fluorescent dye depends on the specific application and the desired properties, such as excitation and emission spectra, quantum yield, and photostability.

Retinal vessels refer to the blood vessels that are located in the retina, which is the light-sensitive tissue that lines the inner surface of the eye. The retina contains two types of blood vessels: arteries and veins.

The central retinal artery supplies oxygenated blood to the inner layers of the retina, while the central retinal vein drains deoxygenated blood from the retina. These vessels can be visualized during a routine eye examination using an ophthalmoscope, which allows healthcare professionals to assess their health and any potential abnormalities.

Retinal vessels are essential for maintaining the health and function of the retina, and any damage or changes to these vessels can affect vision and lead to various eye conditions such as diabetic retinopathy, retinal vein occlusion, and hypertensive retinopathy.

Choroidal neovascularization (CNV) is a medical term that refers to the growth of new, abnormal blood vessels in the choroid layer of the eye, which is located between the retina and the sclera. This condition typically occurs as a complication of age-related macular degeneration (AMD), although it can also be caused by other eye diseases or injuries.

In CNV, the new blood vessels that grow into the choroid layer are fragile and can leak fluid or blood, which can cause distortion or damage to the retina, leading to vision loss. Symptoms of CNV may include blurred or distorted vision, a blind spot in the center of the visual field, or changes in color perception.

Treatment for CNV typically involves medications that are designed to stop the growth of new blood vessels, such as anti-VEGF drugs, which target a protein called vascular endothelial growth factor (VEGF) that is involved in the development of new blood vessels. Laser surgery or photodynamic therapy may also be used in some cases to destroy the abnormal blood vessels and prevent further vision loss.

The choroid is a layer of the eye that contains blood vessels that supply oxygen and nutrients to the outer layers of the retina. It lies between the sclera (the white, protective coat of the eye) and the retina (the light-sensitive tissue at the back of the eye). The choroid is essential for maintaining the health and function of the retina, particularly the photoreceptor cells that detect light and transmit visual signals to the brain. Damage to the choroid can lead to vision loss or impairment.

In medical terms, "tears" are a clear, salty liquid that is produced by the tear glands (lacrimal glands) in our eyes. They serve to keep the eyes moist, protect against dust and other foreign particles, and help to provide clear vision by maintaining a smooth surface on the front of the eye. Tears consist of water, oil, and mucus, which help to prevent evaporation and ensure that the tears spread evenly across the surface of the eye. Emotional or reflexive responses, such as crying or yawning, can also stimulate the production of tears.

Dextrans are a type of complex glucose polymers that are formed by the action of certain bacteria on sucrose. They are branched polysaccharides consisting of linear chains of α-1,6 linked D-glucopyranosyl units with occasional α-1,3 branches.

Dextrans have a wide range of applications in medicine and industry. In medicine, dextrans are used as plasma substitutes, volume expanders, and anticoagulants. They are also used as carriers for drugs and diagnostic agents, and in the manufacture of immunoadsorbents for the removal of toxins and pathogens from blood.

Dextrans can be derived from various bacterial sources, but the most common commercial source is Leuconostoc mesenteroides B-512(F) or L. dextranicum. The molecular weight of dextrans can vary widely, ranging from a few thousand to several million Daltons, depending on the method of preparation and purification.

Dextrans are generally biocompatible and non-toxic, but they can cause allergic reactions in some individuals. Therefore, their use as medical products requires careful monitoring and testing for safety and efficacy.

Dry eye syndrome, also known as keratoconjunctivitis sicca, is a condition characterized by insufficient lubrication and moisture of the eyes. This occurs when the tears produced by the eyes are not sufficient in quantity or quality to keep the eyes moist and comfortable. The medical definition of dry eye syndromes includes the following symptoms:

1. A gritty or sandy sensation in the eyes
2. Burning or stinging sensations
3. Redness and irritation
4. Blurred vision that improves with blinking
5. Light sensitivity
6. A feeling of something foreign in the eye
7. Stringy mucus in or around the eyes
8. Difficulty wearing contact lenses
9. Watery eyes, which may seem contradictory but can be a response to dryness
10. Eye fatigue and discomfort after prolonged screen time or reading

The causes of dry eye syndromes can include aging, hormonal changes, certain medical conditions (such as diabetes, rheumatoid arthritis, lupus, Sjogren's syndrome), medications (antihistamines, decongestants, antidepressants, birth control pills), environmental factors (dry air, wind, smoke, dust), and prolonged screen time or reading.

Treatment for dry eye syndromes depends on the severity of the condition and its underlying causes. It may include artificial tears, lifestyle changes, prescription medications, and in some cases, surgical procedures to improve tear production or drainage.

Retinal diseases refer to a group of conditions that affect the retina, which is the light-sensitive tissue located at the back of the eye. The retina is responsible for converting light into electrical signals that are sent to the brain and interpreted as visual images. Retinal diseases can cause vision loss or even blindness, depending on their severity and location in the retina.

Some common retinal diseases include:

1. Age-related macular degeneration (AMD): A progressive disease that affects the central part of the retina called the macula, causing blurred or distorted vision.
2. Diabetic retinopathy: A complication of diabetes that can damage the blood vessels in the retina, leading to vision loss.
3. Retinal detachment: A serious condition where the retina becomes separated from its underlying tissue, requiring immediate medical attention.
4. Macular edema: Swelling or thickening of the macula due to fluid accumulation, which can cause blurred vision.
5. Retinitis pigmentosa: A group of inherited eye disorders that affect the retina's ability to respond to light, causing progressive vision loss.
6. Macular hole: A small break in the macula that can cause distorted or blurry vision.
7. Retinal vein occlusion: Blockage of the retinal veins that can lead to bleeding, swelling, and potential vision loss.

Treatment for retinal diseases varies depending on the specific condition and its severity. Some treatments include medication, laser therapy, surgery, or a combination of these options. Regular eye exams are essential for early detection and treatment of retinal diseases.

The vitreous body, also known simply as the vitreous, is the clear, gel-like substance that fills the space between the lens and the retina in the eye. It is composed mainly of water, but also contains collagen fibers, hyaluronic acid, and other proteins. The vitreous helps to maintain the shape of the eye and provides a transparent medium for light to pass through to reach the retina. With age, the vitreous can become more liquefied and may eventually separate from the retina, leading to symptoms such as floaters or flashes of light.

Indocyanine green (ICG) is a sterile, water-soluble, tricarbocyanine dye that is used as a diagnostic agent in medical imaging. It is primarily used in ophthalmology for fluorescein angiography to examine blood flow in the retina and choroid, and in cardiac surgery to assess cardiac output and perfusion. When injected into the body, ICG binds to plasma proteins and fluoresces when exposed to near-infrared light, allowing for visualization of various tissues and structures. It is excreted primarily by the liver and has a half-life of approximately 3-4 minutes in the bloodstream.

Laser coagulation, also known as laser photocoagulation, is a medical procedure that uses a laser to seal or destroy abnormal blood vessels or tissue. The laser produces a concentrated beam of light that can be precisely focused on the target area. When the laser energy is absorbed by the tissue, it causes the temperature to rise, which leads to coagulation (the formation of a clot) or destruction of the tissue.

In ophthalmology, laser coagulation is commonly used to treat conditions such as diabetic retinopathy, age-related macular degeneration, and retinal tears or holes. The procedure can help to seal leaking blood vessels, reduce fluid leakage, and prevent further vision loss. It is usually performed as an outpatient procedure and may be repeated if necessary.

In other medical specialties, laser coagulation may be used to control bleeding, destroy tumors, or remove unwanted tissue. The specific technique and parameters of the laser treatment will depend on the individual patient's needs and the condition being treated.

Visual acuity is a measure of the sharpness or clarity of vision. It is usually tested by reading an eye chart from a specific distance, such as 20 feet (6 meters). The standard eye chart used for this purpose is called the Snellen chart, which contains rows of letters that decrease in size as you read down the chart.

Visual acuity is typically expressed as a fraction, with the numerator representing the testing distance and the denominator indicating the smallest line of type that can be read clearly. For example, if a person can read the line on the eye chart that corresponds to a visual acuity of 20/20, it means they have normal vision at 20 feet. If their visual acuity is 20/40, it means they must be as close as 20 feet to see what someone with normal vision can see at 40 feet.

It's important to note that visual acuity is just one aspect of overall vision and does not necessarily reflect other important factors such as peripheral vision, depth perception, color vision, or contrast sensitivity.

Rose Bengal is not a medical term per se, but a chemical compound that is used in various medical applications. It's a dye that is primarily used as a diagnostic stain to test for damaged or denatured cells, particularly in the eye and mouth. In ophthalmology, a Rose Bengal stain is used to identify damage to the cornea's surface, while in dentistry, it can help detect injured oral mucosa or lesions.

The dye works by staining dead or damaged cells more intensely than healthy ones, allowing healthcare professionals to visualize and assess any abnormalities or injuries. However, it is important to note that Rose Bengal itself is not a treatment for these conditions; rather, it is a diagnostic tool used to inform appropriate medical interventions.

Fluorescence spectrometry is a type of analytical technique used to investigate the fluorescent properties of a sample. It involves the measurement of the intensity of light emitted by a substance when it absorbs light at a specific wavelength and then re-emits it at a longer wavelength. This process, known as fluorescence, occurs because the absorbed energy excites electrons in the molecules of the substance to higher energy states, and when these electrons return to their ground state, they release the excess energy as light.

Fluorescence spectrometry typically measures the emission spectrum of a sample, which is a plot of the intensity of emitted light versus the wavelength of emission. This technique can be used to identify and quantify the presence of specific fluorescent molecules in a sample, as well as to study their photophysical properties.

Fluorescence spectrometry has many applications in fields such as biochemistry, environmental science, and materials science. For example, it can be used to detect and measure the concentration of pollutants in water samples, to analyze the composition of complex biological mixtures, or to study the properties of fluorescent nanomaterials.

Rhodamines are not a medical term, but rather a class of chemical compounds that are commonly used as dyes and fluorescent tracers in various fields, including biology, chemistry, and material science. They absorb light at one wavelength and emit it at another, longer wavelength, which makes them useful for tracking and visualizing processes in living cells and tissues.

In a medical context, rhodamines may be used as part of diagnostic tests or procedures, such as in fluorescence microscopy or flow cytometry, to label and detect specific cells or molecules of interest. However, they are not typically used as therapeutic agents themselves.

Capillary permeability refers to the ability of substances to pass through the walls of capillaries, which are the smallest blood vessels in the body. These tiny vessels connect the arterioles and venules, allowing for the exchange of nutrients, waste products, and gases between the blood and the surrounding tissues.

The capillary wall is composed of a single layer of endothelial cells that are held together by tight junctions. The permeability of these walls varies depending on the size and charge of the molecules attempting to pass through. Small, uncharged molecules such as water, oxygen, and carbon dioxide can easily diffuse through the capillary wall, while larger or charged molecules such as proteins and large ions have more difficulty passing through.

Increased capillary permeability can occur in response to inflammation, infection, or injury, allowing larger molecules and immune cells to enter the surrounding tissues. This can lead to swelling (edema) and tissue damage if not controlled. Decreased capillary permeability, on the other hand, can lead to impaired nutrient exchange and tissue hypoxia.

Overall, the permeability of capillaries is a critical factor in maintaining the health and function of tissues throughout the body.

The choroid is a part of the eye located between the retina and the sclera, which contains a large number of blood vessels that supply oxygen and nutrients to the outer layers of the retina. Choroid diseases refer to various medical conditions that affect the health and function of the choroid. Here are some examples:

1. Choroidal neovascularization (CNV): This is a condition where new blood vessels grow from the choroid into the retina, leading to fluid accumulation, bleeding, and scarring. CNV can cause vision loss and is often associated with age-related macular degeneration, myopia, and inflammatory eye diseases.
2. Chorioretinitis: This is an infection or inflammation of the choroid and retina, which can be caused by various microorganisms such as bacteria, viruses, fungi, or parasites. Symptoms may include blurred vision, floaters, light sensitivity, and eye pain.
3. Choroidal hemorrhage: This is a rare but serious condition where there is bleeding into the choroid, often caused by trauma, high blood pressure, or blood clotting disorders. It can lead to sudden vision loss and requires urgent medical attention.
4. Choroideremia: This is a genetic disorder that affects the choroid, retina, and optic nerve, leading to progressive vision loss. It is caused by mutations in the CHM gene and primarily affects males.
5. Central serous retinopathy (CSR): This is a condition where fluid accumulates under the retina, often in the macula, causing distortion or blurring of vision. While the exact cause is unknown, CSR is thought to be related to stress, steroid use, and other factors that affect the choroid's ability to regulate fluid.
6. Polypoidal choroidal vasculopathy (PCV): This is a condition where abnormal blood vessels form in the choroid, leading to serous or hemorrhagic detachment of the retina. PCV is often associated with age-related macular degeneration and can cause vision loss if left untreated.

These are just a few examples of choroidal disorders that can affect vision. If you experience any sudden changes in your vision, it's important to seek medical attention promptly.

Macular degeneration, also known as age-related macular degeneration (AMD), is a medical condition that affects the central part of the retina, called the macula. The macula is responsible for sharp, detailed vision, which is necessary for activities such as reading, driving, and recognizing faces.

In AMD, there is a breakdown or deterioration of the macula, leading to gradual loss of central vision. There are two main types of AMD: dry (atrophic) and wet (exudative). Dry AMD is more common and progresses more slowly, while wet AMD is less common but can cause rapid and severe vision loss if left untreated.

The exact causes of AMD are not fully understood, but risk factors include age, smoking, family history, high blood pressure, obesity, and exposure to sunlight. While there is no cure for AMD, treatments such as vitamin supplements, laser therapy, and medication injections can help slow its progression and reduce the risk of vision loss.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Ophthalmoscopy is a medical examination technique used by healthcare professionals to observe the interior structures of the eye, including the retina, optic disc, and vitreous humor. This procedure typically involves using an ophthalmoscope, a handheld device that consists of a light and magnifying lenses. The healthcare provider looks through the ophthalmoscope and directly observes the internal structures of the eye by illuminating them.

There are several types of ophthalmoscopy, including direct ophthalmoscopy, indirect ophthalmoscopy, and slit-lamp biomicroscopy. Each type has its own advantages and disadvantages, and they may be used in different situations depending on the specific clinical situation and the information needed.

Ophthalmoscopy is an important diagnostic tool for detecting and monitoring a wide range of eye conditions, including diabetic retinopathy, glaucoma, age-related macular degeneration, and other retinal disorders. It can also provide valuable information about the overall health of the individual, as changes in the appearance of the retina or optic nerve may indicate the presence of systemic diseases such as hypertension or diabetes.

The macula lutea, often simply referred to as the macula or fovea centralis, is a part of the eye that is responsible for central vision and color perception. It's located in the center of the retina, the light-sensitive tissue at the back of the eye. The macula contains a high concentration of pigments called xanthophylls, which give it a yellowish color and protect the photoreceptor cells in this area from damage by blue light.

The central part of the macula is called the fovea, which is a small depression that contains only cones, the photoreceptor cells responsible for color vision and high visual acuity. The fovea is surrounded by the parafovea and the perifovea, which contain both cones and rods, the photoreceptor cells responsible for low-light vision and peripheral vision.

Damage to the macula can result in a loss of central vision and color perception, a condition known as age-related macular degeneration (AMD), which is a leading cause of blindness in older adults. Other conditions that can affect the macula include macular edema, macular holes, and macular pucker.

Fluorometry is not a medical term per se, but it is a scientific technique that has applications in the medical field. Fluorometry refers to the measurement of the intensity of fluorescence emitted by a substance when it absorbs light at a specific wavelength. This technique is widely used in various fields such as biochemistry, molecular biology, and clinical chemistry.

In the medical context, fluorometry is often used in diagnostic tests to detect and measure the concentration of certain substances in biological samples such as blood, urine, or tissues. For example, fluorometric assays are commonly used to measure the levels of enzymes, hormones, vitamins, and other biomolecules that exhibit fluorescence.

Fluorometry is also used in research and clinical settings to study various biological processes at the cellular and molecular level. For instance, fluorescent probes can be used to label specific proteins or organelles within cells, allowing researchers to track their movement, localization, and interactions in real-time.

Overall, fluorometry is a valuable tool in medical research and diagnostics, providing sensitive and specific measurements of various biological molecules and processes.

Optical coherence tomography (OCT) is a non-invasive imaging technique that uses low-coherence light to capture high-resolution cross-sectional images of biological tissues, particularly the retina and other ocular structures. OCT works by measuring the echo time delay of light scattered back from different depths within the tissue, creating a detailed map of the tissue's structure. This technique is widely used in ophthalmology to diagnose and monitor various eye conditions such as macular degeneration, diabetic retinopathy, and glaucoma.

The cornea is the clear, dome-shaped surface at the front of the eye. It plays a crucial role in focusing vision. The cornea protects the eye from harmful particles and microorganisms, and it also serves as a barrier against UV light. Its transparency allows light to pass through and get focused onto the retina. The cornea does not contain blood vessels, so it relies on tears and the fluid inside the eye (aqueous humor) for nutrition and oxygen. Any damage or disease that affects its clarity and shape can significantly impact vision and potentially lead to blindness if left untreated.

Ophthalmic solutions are sterile, single-use or multi-dose preparations in a liquid form that are intended for topical administration to the eye. These solutions can contain various types of medications, such as antibiotics, anti-inflammatory agents, antihistamines, or lubricants, which are used to treat or prevent ocular diseases and conditions.

The pH and osmolarity of ophthalmic solutions are carefully controlled to match the physiological environment of the eye and minimize any potential discomfort or irritation. The solutions may be packaged in various forms, including drops, sprays, or irrigations, depending on the intended use and administration route.

It is important to follow the instructions for use provided by a healthcare professional when administering ophthalmic solutions, as improper use can lead to eye injury or reduced effectiveness of the medication.

The blood-retinal barrier (BRB) is a specialized physiological barrier in the eye that helps regulate the movement of molecules between the retina and the bloodstream. It is made up of tight junctions between the endothelial cells of retinal blood vessels and between the pigment epithelium cells of the retina, which restrict the paracellular diffusion of solutes.

The BRB plays a crucial role in maintaining the health and function of the retina by preventing harmful substances from entering the retina while allowing essential nutrients and oxygen to reach the retinal tissues. Disruption of the BRB has been implicated in various retinal diseases, including diabetic retinopathy, age-related macular degeneration, and retinal vein occlusion.

Erythrosine is a type of food dye that is classified as a synthetic organic chemical compound. Its chemical formula is C~20~H~6~Br~4~O~5~. Erythrosine is a form of red food coloring that is commonly used in a variety of foods and beverages, such as candies, popsicles, and maraschino cherries. It is also used in some medications and cosmetics to provide a reddish or pinkish color.

Erythrosine belongs to a class of compounds called xanthenes, which are known for their ability to fluoresce when exposed to light. This property has led to the use of erythrosine as a marker in biological research and as a forensic tool for identifying fingerprints.

Like other food dyes, erythrosine is subject to regulation by government agencies such as the U.S. Food and Drug Administration (FDA) to ensure its safe use in food products. However, some studies have suggested that certain food dyes, including erythrosine, may be associated with adverse health effects such as hyperactivity in children. As a result, some organizations have called for further research on the safety of these substances and for greater restrictions on their use in food.

Macular edema is a medical condition characterized by the accumulation of fluid in the macula, a small area in the center of the retina responsible for sharp, detailed vision. This buildup of fluid causes the macula to thicken and swell, which can distort central vision and lead to vision loss if not treated promptly. Macular edema is often a complication of other eye conditions such as diabetic retinopathy, age-related macular degeneration, retinal vein occlusion, or uveitis. It's important to note that while macular edema can affect anyone, it is more common in people with certain medical conditions like diabetes.

In the context of medicine and physiology, permeability refers to the ability of a tissue or membrane to allow the passage of fluids, solutes, or gases. It is often used to describe the property of the capillary walls, which control the exchange of substances between the blood and the surrounding tissues.

The permeability of a membrane can be influenced by various factors, including its molecular structure, charge, and the size of the molecules attempting to pass through it. A more permeable membrane allows for easier passage of substances, while a less permeable membrane restricts the movement of substances.

In some cases, changes in permeability can have significant consequences for health. For example, increased permeability of the blood-brain barrier (a specialized type of capillary that regulates the passage of substances into the brain) has been implicated in a number of neurological conditions, including multiple sclerosis, Alzheimer's disease, and traumatic brain injury.

I'm sorry for any confusion, but "Eosine I Bluish" is not a medical term or definition. Eosin is a type of stain that is used in histology (the study of the microscopic structure of tissues) and comes in different forms, such as Eosin Y and Eosin B. These stains are used to highlight various structures within tissue samples.

The term "Bluish" might refer to a color observed during a microscopic examination, but without more context, it's difficult to provide an accurate medical definition or interpretation. If you could provide more information about where you encountered this term and in what context, I might be able to give a more precise explanation.

Diabetic retinopathy is a diabetes complication that affects the eyes. It's caused by damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina).

At first, diabetic retinopathy may cause no symptoms or only mild vision problems. Eventually, it can cause blindness. The condition usually affects both eyes.

There are two main stages of diabetic retinopathy:

1. Early diabetic retinopathy. This is when the blood vessels in the eye start to leak fluid or bleed. You might not notice any changes in your vision at this stage, but it's still important to get treatment because it can prevent the condition from getting worse.
2. Advanced diabetic retinopathy. This is when new, abnormal blood vessels grow on the surface of the retina. These vessels can leak fluid and cause severe vision problems, including blindness.

Diabetic retinopathy can be treated with laser surgery, injections of medication into the eye, or a vitrectomy (a surgical procedure to remove the gel-like substance that fills the center of the eye). It's important to get regular eye exams to detect diabetic retinopathy early and get treatment before it causes serious vision problems.

The retina is the innermost, light-sensitive layer of tissue in the eye of many vertebrates and some cephalopods. It receives light that has been focused by the cornea and lens, converts it into neural signals, and sends these to the brain via the optic nerve. The retina contains several types of photoreceptor cells including rods (which handle vision in low light) and cones (which are active in bright light and are capable of color vision).

In medical terms, any pathological changes or diseases affecting the retinal structure and function can lead to visual impairment or blindness. Examples include age-related macular degeneration, diabetic retinopathy, retinal detachment, and retinitis pigmentosa among others.

A retinal artery is a small branch of the ophthalmic artery that supplies oxygenated blood to the inner layers of the retina, which is the light-sensitive tissue located at the back of the eye. There are two main retinal arteries - the central retinal artery and the cilioretinal artery. The central retinal artery enters the eye through the optic nerve and divides into smaller branches to supply blood to the entire retina, while the cilioretinal artery is a smaller artery that supplies blood to a small portion of the retina near the optic nerve. Any damage or blockage to these arteries can lead to serious vision problems, such as retinal artery occlusion or retinal artery embolism.

Coloring agents, also known as food dyes or color additives, are substances that are added to foods, medications, and cosmetics to improve their appearance by giving them a specific color. These agents can be made from both synthetic and natural sources. They must be approved by regulatory agencies such as the U.S. Food and Drug Administration (FDA) before they can be used in products intended for human consumption.

Coloring agents are used for various reasons, including:

* To replace color lost during food processing or preparation
* To make foods more visually appealing
* To help consumers easily identify certain types of food
* To indicate the flavor of a product (e.g., fruit-flavored candies)

It's important to note that while coloring agents can enhance the appearance of products, they do not affect their taste or nutritional value. Some people may have allergic reactions to certain coloring agents, so it's essential to check product labels if you have any known allergies. Additionally, excessive consumption of some synthetic coloring agents has been linked to health concerns, so moderation is key.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Retinal vein occlusion (RVO) is a medical condition that occurs when one of the retinal veins, which drains blood from the retina, becomes blocked by a blood clot or atherosclerotic plaque. This blockage can cause hemorrhages, fluid accumulation, and damage to the retinal tissue, leading to vision loss.

There are two types of RVO: branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). BRVO affects a smaller branch retinal vein, while CRVO affects the main retinal vein. CRVO is generally associated with more severe vision loss than BRVO.

Risk factors for RVO include hypertension, diabetes, high cholesterol levels, smoking, and glaucoma. Age is also a significant risk factor, as RVO becomes more common with increasing age. Treatment options for RVO may include controlling underlying medical conditions, laser therapy, intravitreal injections of anti-VEGF agents or steroids, and surgery in some cases.

The anterior chamber is the front portion of the eye, located between the cornea (the clear front "window" of the eye) and the iris (the colored part of the eye). It is filled with a clear fluid called aqueous humor that provides nutrients to the structures inside the eye and helps maintain its shape. The anterior chamber plays an important role in maintaining the overall health and function of the eye.

Uveal diseases refer to a group of medical conditions that affect the uvea, which is the middle layer of the eye located between the sclera (the white of the eye) and the retina (the light-sensitive tissue at the back of the eye). The uvea consists of the iris (the colored part of the eye), the ciliary body (which controls the lens), and the choroid (a layer of blood vessels that provides nutrients to the retina).

Uveal diseases can cause inflammation, damage, or tumors in the uvea, leading to symptoms such as eye pain, redness, light sensitivity, blurred vision, and floaters. Some common uveal diseases include uveitis (inflammation of the uvea), choroidal melanoma (a type of eye cancer that affects the choroid), and iris nevus (a benign growth on the iris). Treatment for uveal diseases depends on the specific condition and may include medications, surgery, or radiation therapy.

'Staining and labeling' are techniques commonly used in pathology, histology, cytology, and molecular biology to highlight or identify specific components or structures within tissues, cells, or molecules. These methods enable researchers and medical professionals to visualize and analyze the distribution, localization, and interaction of biological entities, contributing to a better understanding of diseases, cellular processes, and potential therapeutic targets.

Medical definitions for 'staining' and 'labeling' are as follows:

1. Staining: A process that involves applying dyes or stains to tissues, cells, or molecules to enhance their contrast and reveal specific structures or components. Stains can be categorized into basic stains (which highlight acidic structures) and acidic stains (which highlight basic structures). Common staining techniques include Hematoxylin and Eosin (H&E), which differentiates cell nuclei from the surrounding cytoplasm and extracellular matrix; special stains, such as PAS (Periodic Acid-Schiff) for carbohydrates or Masson's trichrome for collagen fibers; and immunostains, which use antibodies to target specific proteins.
2. Labeling: A process that involves attaching a detectable marker or tag to a molecule of interest, allowing its identification, quantification, or tracking within a biological system. Labels can be direct, where the marker is directly conjugated to the targeting molecule, or indirect, where an intermediate linker molecule is used to attach the label to the target. Common labeling techniques include fluorescent labels (such as FITC, TRITC, or Alexa Fluor), enzymatic labels (such as horseradish peroxidase or alkaline phosphatase), and radioactive labels (such as ³²P or ¹⁴C). Labeling is often used in conjunction with staining techniques to enhance the specificity and sensitivity of detection.

Together, staining and labeling provide valuable tools for medical research, diagnostics, and therapeutic development, offering insights into cellular and molecular processes that underlie health and disease.

Photofluorography is not a widely used medical term, but it generally refers to a radiographic technique that uses fluorescent screens to produce images. It was historically used for mass screening of pulmonary diseases such as tuberculosis. The patient would be exposed to a low-dose X-ray, and the resulting image would be captured on a special film or sensor that is sensitive to light emitted by the fluorescent screen.

However, it's worth noting that photofluorography has largely been replaced by digital radiography and other modern imaging techniques in clinical practice.

I'm sorry for any confusion, but "photography" is not a term typically used in medical definitions. Photography refers to the art, application, or process of creating images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film.

If you're looking for a medical term related to imaging, there are several terms that might be relevant, such as:

1. Radiography: This is a technique using X-rays to visualize the internal structures of the body.
2. Ultrasonography: Also known as ultrasound, this is a diagnostic imaging technique using high-frequency sound waves to create images of the inside of the body.
3. Computed Tomography (CT): A type of imaging that uses X-rays to create detailed cross-sectional images of the body.
4. Magnetic Resonance Imaging (MRI): A type of imaging that uses magnetic fields and radio waves to create detailed images of the organs and tissues within the body.
5. Nuclear Medicine: This is a branch of medical imaging that uses small amounts of radioactive material to diagnose and treat diseases.

If you have any questions related to medical definitions or topics, feel free to ask!

Confocal microscopy is a powerful imaging technique used in medical and biological research to obtain high-resolution, contrast-rich images of thick samples. This super-resolution technology provides detailed visualization of cellular structures and processes at various depths within a specimen.

In confocal microscopy, a laser beam focused through a pinhole illuminates a small spot within the sample. The emitted fluorescence or reflected light from this spot is then collected by a detector, passing through a second pinhole that ensures only light from the focal plane reaches the detector. This process eliminates out-of-focus light, resulting in sharp images with improved contrast compared to conventional widefield microscopy.

By scanning the laser beam across the sample in a raster pattern and collecting fluorescence at each point, confocal microscopy generates optical sections of the specimen. These sections can be combined to create three-dimensional reconstructions, allowing researchers to study cellular architecture and interactions within complex tissues.

Confocal microscopy has numerous applications in medical research, including studying protein localization, tracking intracellular dynamics, analyzing cell morphology, and investigating disease mechanisms at the cellular level. Additionally, it is widely used in clinical settings for diagnostic purposes, such as analyzing skin lesions or detecting pathogens in patient samples.

Fluorescence is not a medical term per se, but it is widely used in the medical field, particularly in diagnostic tests, medical devices, and research. Fluorescence is a physical phenomenon where a substance absorbs light at a specific wavelength and then emits light at a longer wavelength. This process, often referred to as fluorescing, results in the emission of visible light that can be detected and measured.

In medical terms, fluorescence is used in various applications such as:

1. In-vivo imaging: Fluorescent dyes or probes are introduced into the body to highlight specific structures, cells, or molecules during imaging procedures. This technique can help doctors detect and diagnose diseases such as cancer, inflammation, or infection.
2. Microscopy: Fluorescence microscopy is a powerful tool for visualizing biological samples at the cellular and molecular level. By labeling specific proteins, nucleic acids, or other molecules with fluorescent dyes, researchers can observe their distribution, interactions, and dynamics within cells and tissues.
3. Surgical guidance: Fluorescence-guided surgery is a technique where surgeons use fluorescent markers to identify critical structures such as blood vessels, nerves, or tumors during surgical procedures. This helps ensure precise and safe surgical interventions.
4. Diagnostic tests: Fluorescence-based assays are used in various diagnostic tests to detect and quantify specific biomarkers or analytes. These assays can be performed using techniques such as enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), or flow cytometry.

In summary, fluorescence is a physical process where a substance absorbs and emits light at different wavelengths. In the medical field, this phenomenon is harnessed for various applications such as in-vivo imaging, microscopy, surgical guidance, and diagnostic tests.

A Retinal Vein is a vessel that carries oxygen-depleted blood away from the retina, a light-sensitive layer at the back of the eye. The retinal veins originate from a network of smaller vessels called venules and ultimately merge to form the central retinal vein, which exits the eye through the optic nerve.

Retinal veins are crucial for maintaining the health and function of the retina, as they facilitate the removal of waste products and help regulate the ocular environment. However, they can also be susceptible to various pathological conditions such as retinal vein occlusions, which can lead to vision loss or damage to the eye.

Retinal artery occlusion (RAO) is a medical condition characterized by the blockage or obstruction of the retinal artery, which supplies oxygenated blood to the retina. This blockage typically occurs due to embolism (a small clot or debris that travels to the retinal artery), thrombosis (blood clot formation in the artery), or vasculitis (inflammation of the blood vessels).

There are two types of retinal artery occlusions:

1. Central Retinal Artery Occlusion (CRAO): This type occurs when the main retinal artery is obstructed, affecting the entire inner layer of the retina. It can lead to severe and sudden vision loss in the affected eye.
2. Branch Retinal Artery Occlusion (BRAO): This type affects a branch of the retinal artery, causing visual field loss in the corresponding area. Although it is less severe than CRAO, it can still result in noticeable vision impairment.

Immediate medical attention is crucial for both types of RAO to improve the chances of recovery and minimize potential damage to the eye and vision. Treatment options may include medications, laser therapy, or surgery, depending on the underlying cause and the severity of the condition.

A retinal hemorrhage is a type of bleeding that occurs in the blood vessels of the retina, which is the light-sensitive tissue located at the back of the eye. This condition can result from various underlying causes, including diabetes, high blood pressure, age-related macular degeneration, or trauma to the eye. Retinal hemorrhages can be categorized into different types based on their location and appearance, such as dot and blot hemorrhages, flame-shaped hemorrhages, or subhyaloid hemorrhages. Depending on the severity and cause of the hemorrhage, treatment options may vary from monitoring to laser therapy, medication, or even surgery. It is essential to consult an ophthalmologist for a proper evaluation and management plan if you suspect a retinal hemorrhage.

"Light coagulation," also known as "laser coagulation," is a medical term that refers to the use of laser technology to cauterize (seal or close) tissue. This procedure uses heat generated by a laser to cut, coagulate, or destroy tissue. In light coagulation, the laser beam is focused on the blood vessels in question, causing the blood within them to clot and the vessels to seal. This can be used for various medical purposes, such as stopping bleeding during surgery, destroying abnormal tissues (like tumors), or treating eye conditions like diabetic retinopathy and age-related macular degeneration.

It's important to note that this is a general definition, and the specific use of light coagulation may vary depending on the medical specialty and the individual patient's needs. As always, it's best to consult with a healthcare professional for more detailed information about any medical procedure or treatment.

The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.

The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.

Organomercury compounds are organic chemical compounds that contain at least one mercury atom bonded to carbon. These compounds can be divided into two main categories: those with a covalent bond between carbon and mercury (carbon-mercury bonds), and those with a coordination bond where mercury acts as a ligand to a metal center.

The carbon-mercury bonds are typically found in organometallic compounds, which contain at least one direct bond between a carbon atom and a metal. Examples of organomercury compounds include methylmercury (CH3Hg+) and phenylmercury (C6H5Hg+). These types of organomercury compounds are often used in industry as catalysts, fungicides, and disinfectants. However, they can be highly toxic to humans and the environment, particularly methylmercury which is a potent neurotoxin that can accumulate in the food chain.

The coordination compounds of mercury are those where mercury acts as a ligand, binding to a metal center through a coordinate covalent bond. These types of organomercury compounds are less common and tend to be less toxic than those with carbon-mercury bonds. They may be used in some chemical reactions or as reagents in laboratory settings.

It is important to note that exposure to organomercury compounds should be avoided, as they can have serious health effects even at low levels of exposure.

Retinal neovascularization is a medical condition characterized by the growth of new, abnormal blood vessels on the surface of the retina, which is the light-sensitive tissue located at the back of the eye. This condition typically occurs in response to an insufficient supply of oxygen and nutrients to the retina, often due to damage or disease, such as diabetic retinopathy or retinal vein occlusion.

The new blood vessels that form during neovascularization are fragile and prone to leakage, which can cause fluid and protein to accumulate in the retina, leading to distorted vision, hemorrhages, and potentially blindness if left untreated. Retinal neovascularization is a serious eye condition that requires prompt medical attention and management to prevent further vision loss.

The fovea centralis, also known as the macula lutea, is a small pit or depression located in the center of the retina, an light-sensitive tissue at the back of the eye. It is responsible for sharp, detailed vision (central vision) and color perception. The fovea contains only cones, the photoreceptor cells that are responsible for color vision and high visual acuity. It has a higher concentration of cones than any other area in the retina, allowing it to provide the greatest detail and color discrimination. The center of the fovea is called the foveola, which contains the highest density of cones and is avascular, meaning it lacks blood vessels to avoid interfering with the light passing through to the photoreceptor cells.

The sclera is the tough, white, fibrous outer coating of the eye in humans and other vertebrates, covering about five sixths of the eyeball's surface. It provides protection for the delicate inner structures of the eye and maintains its shape. The sclera is composed mainly of collagen and elastic fiber, making it strong and resilient. Its name comes from the Greek word "skleros," which means hard.

An intravitreal injection is a medical procedure in which medication is delivered directly into the vitreous cavity of the eye, which is the clear, gel-like substance that fills the space between the lens and the retina. This type of injection is typically used to treat various eye conditions such as age-related macular degeneration, diabetic retinopathy, retinal vein occlusion, and uveitis. The medication administered in intravitreal injections can help to reduce inflammation, inhibit the growth of new blood vessels, or prevent the formation of abnormal blood vessels in the eye.

Intravitreal injections are usually performed in an outpatient setting, and the procedure typically takes only a few minutes. Before the injection, the eye is numbed with anesthetic drops to minimize discomfort. The medication is then injected into the vitreous cavity using a small needle. After the injection, patients may experience some mild discomfort or a scratchy sensation in the eye, but this usually resolves within a few hours.

While intravitreal injections are generally safe, there are some potential risks and complications associated with the procedure, including infection, bleeding, retinal detachment, and increased intraocular pressure. Patients who undergo intravitreal injections should be closely monitored by their eye care provider to ensure that any complications are promptly identified and treated.

Aqueous humor is a clear, watery fluid that fills the anterior and posterior chambers of the eye. It is produced by the ciliary processes in the posterior chamber and circulates through the pupil into the anterior chamber, where it provides nutrients to the cornea and lens, maintains intraocular pressure, and helps to shape the eye. The aqueous humor then drains out of the eye through the trabecular meshwork and into the canal of Schlemm, eventually reaching the venous system.

Retinal detachment is a serious eye condition that occurs when the retina, a thin layer of tissue at the back of the eye responsible for processing light and sending visual signals to the brain, pulls away from its normal position. This can lead to significant vision loss or even blindness if not promptly treated. Retinal detachment can be caused by various factors such as aging, trauma, eye disease, or an inflammatory condition. Symptoms of retinal detachment may include sudden flashes of light, floaters, a shadow in the peripheral vision, or a curtain-like covering over part of the visual field. Immediate medical attention is necessary to prevent further damage and preserve vision.

A laser is not a medical term per se, but a physical concept that has important applications in medicine. The term "LASER" stands for "Light Amplification by Stimulated Emission of Radiation." It refers to a device that produces and amplifies light with specific characteristics, such as monochromaticity (single wavelength), coherence (all waves moving in the same direction), and high intensity.

In medicine, lasers are used for various therapeutic and diagnostic purposes, including surgery, dermatology, ophthalmology, and dentistry. They can be used to cut, coagulate, or vaporize tissues with great precision, minimizing damage to surrounding structures. Additionally, lasers can be used to detect and measure physiological parameters, such as blood flow and oxygen saturation.

It's important to note that while lasers are powerful tools in medicine, they must be used by trained professionals to ensure safe and effective treatment.

In medical terms, the iris refers to the colored portion of the eye that surrounds the pupil. It is a circular structure composed of thin, contractile muscle fibers (radial and circumferential) arranged in a regular pattern. These muscles are controlled by the autonomic nervous system and can adjust the size of the pupil in response to changes in light intensity or emotional arousal. By constricting or dilating the iris, the amount of light entering the eye can be regulated, which helps maintain optimal visual acuity under various lighting conditions.

The color of the iris is determined by the concentration and distribution of melanin pigments within the iris stroma. The iris also contains blood vessels, nerves, and connective tissue that support its structure and function. Anatomically, the iris is continuous with the ciliary body and the choroid, forming part of the uveal tract in the eye.

Lissamine Green Dyes are a type of diagnostic dye used in ophthalmology to assess the health and integrity of the tear film and the corneal surface. These dyes have a green color and are often used in conjunction with other dyes like fluorescein. When applied to the eye, Lissamine Green Dyes selectively stain areas of the eye that have been damaged or disrupted, such as areas of dryness, irritation, or inflammation.

The dye binds to denatured proteins and cellular debris on the surface of the eye, highlighting any abnormalities in the tear film or corneal epithelium. Lissamine Green Dyes can help diagnose conditions such as dry eye syndrome, exposure keratopathy, and corneal abrasions. The dye is generally considered safe for use in diagnostic procedures, but it should be used with caution and according to proper protocols to minimize any potential risks or discomfort to the patient.

The conjunctiva is the mucous membrane that lines the inner surface of the eyelids and covers the front part of the eye, also known as the sclera. It helps to keep the eye moist and protected from irritants. The conjunctiva can become inflamed or infected, leading to conditions such as conjunctivitis (pink eye).

The pigment epithelium of the eye, also known as the retinal pigment epithelium (RPE), is a layer of cells located between the photoreceptor cells of the retina and the choroid, which is the vascular layer of the eye. The RPE plays a crucial role in maintaining the health and function of the photoreceptors by providing them with nutrients, removing waste products, and helping to regulate the light that enters the eye.

The RPE cells contain pigment granules that absorb excess light, preventing it from scattering within the eye and improving visual acuity. They also help to create a barrier between the retina and the choroid, which is important for maintaining the proper functioning of the photoreceptors. Additionally, the RPE plays a role in the regeneration of visual pigments in the photoreceptor cells, allowing us to see in different light conditions.

Damage to the RPE can lead to various eye diseases and conditions, including age-related macular degeneration (AMD), which is a leading cause of vision loss in older adults.

Flow cytometry is a medical and research technique used to measure physical and chemical characteristics of cells or particles, one cell at a time, as they flow in a fluid stream through a beam of light. The properties measured include:

* Cell size (light scatter)
* Cell internal complexity (granularity, also light scatter)
* Presence or absence of specific proteins or other molecules on the cell surface or inside the cell (using fluorescent antibodies or other fluorescent probes)

The technique is widely used in cell counting, cell sorting, protein engineering, biomarker discovery and monitoring disease progression, particularly in hematology, immunology, and cancer research.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

Fluorescence Polarization (FP) is not a medical term per se, but a technique used in medical research and diagnostics. Here's a general definition:

Fluorescence Polarization is a biophysical technique used to measure the rotational movement of molecules in solution after they have been excited by polarized light. When a fluorophore (a fluorescent molecule) absorbs light, its electrons become excited and then return to their ground state, releasing energy in the form of light. This emitted light often has different properties than the incident light, one of which can be its polarization. If the fluorophore is large or bound to a large structure, it may not rotate significantly during the time between absorption and emission, resulting in emitted light that maintains the same polarization as the excitation light. Conversely, if the fluorophore is small or unbound, it will rotate rapidly during this period, and the emitted light will be depolarized. By measuring the degree of polarization of the emitted light, researchers can gain information about the size, shape, and mobility of the fluorophore and the molecules to which it is attached. This technique is widely used in various fields including life sciences, biochemistry, and diagnostics.

Photochemotherapy is a medical treatment that combines the use of drugs and light to treat various skin conditions. The most common type of photochemotherapy is PUVA (Psoralen + UVA), where the patient takes a photosensitizing medication called psoralen, followed by exposure to ultraviolet A (UVA) light.

The psoralen makes the skin more sensitive to the UVA light, which helps to reduce inflammation and suppress the overactive immune response that contributes to many skin conditions. This therapy is often used to treat severe cases of psoriasis, eczema, and mycosis fungoides (a type of cutaneous T-cell lymphoma). It's important to note that photochemotherapy can increase the risk of skin cancer and cataracts, so it should only be administered under the close supervision of a healthcare professional.

Papilledema is a medical term that refers to swelling of the optic nerve head, also known as the disc, which is the point where the optic nerve enters the back of the eye (the retina). This swelling can be caused by increased pressure within the skull, such as from brain tumors, meningitis, or idiopathic intracranial hypertension. Papilledema is usually detected through a routine eye examination and may be accompanied by symptoms such as headaches, visual disturbances, and nausea. If left untreated, papilledema can lead to permanent vision loss.

The corneal epithelium is the outermost layer of the cornea, which is the clear, dome-shaped surface at the front of the eye. It is a stratified squamous epithelium, consisting of several layers of flat, scale-like cells that are tightly packed together. The corneal epithelium serves as a barrier to protect the eye from microorganisms, dust, and other foreign particles. It also provides a smooth surface for the refraction of light, contributes to the maintenance of corneal transparency, and plays a role in the eye's sensitivity to touch and pain. The corneal epithelium is constantly being renewed through the process of cell division and shedding, with new cells produced by stem cells located at the limbus, the border between the cornea and the conjunctiva.

Intraocular injections are a type of medical procedure where medication is administered directly into the eye. This technique is often used to deliver drugs that treat various eye conditions, such as age-related macular degeneration, diabetic retinopathy, and endophthalmitis. The most common type of intraocular injection is an intravitreal injection, which involves injecting medication into the vitreous cavity, the space inside the eye filled with a clear gel-like substance called the vitreous humor. This procedure is typically performed by an ophthalmologist in a clinical setting and may be repeated at regular intervals depending on the condition being treated.

Electroretinography (ERG) is a medical test used to evaluate the functioning of the retina, which is the light-sensitive tissue located at the back of the eye. The test measures the electrical responses of the retina to light stimulation.

During the procedure, a special contact lens or electrode is placed on the surface of the eye to record the electrical activity generated by the retina's light-sensitive cells (rods and cones) and other cells in the retina. The test typically involves presenting different levels of flashes of light to the eye while the electrical responses are recorded.

The resulting ERG waveform provides information about the overall health and function of the retina, including the condition of the photoreceptors, the integrity of the inner retinal layers, and the health of the retinal ganglion cells. This test is often used to diagnose and monitor various retinal disorders, such as retinitis pigmentosa, macular degeneration, and diabetic retinopathy.

An injection is a medical procedure in which a medication, vaccine, or other substance is introduced into the body using a needle and syringe. The substance can be delivered into various parts of the body, including into a vein (intravenous), muscle (intramuscular), under the skin (subcutaneous), or into the spinal canal (intrathecal or spinal).

Injections are commonly used to administer medications that cannot be taken orally, have poor oral bioavailability, need to reach the site of action quickly, or require direct delivery to a specific organ or tissue. They can also be used for diagnostic purposes, such as drawing blood samples (venipuncture) or injecting contrast agents for imaging studies.

Proper technique and sterile conditions are essential when administering injections to prevent infection, pain, and other complications. The choice of injection site depends on the type and volume of the substance being administered, as well as the patient's age, health status, and personal preferences.

The blood-aqueous barrier (BAB) is a specialized structure in the eye that helps regulate the exchange of nutrients, oxygen, and waste products between the bloodstream and the anterior chamber of the eye. It is composed of two main components: the nonpigmented epithelial cells of the ciliary body and the endothelial cells of the iris vasculature.

The nonpigmented epithelial cells of the ciliary body form a tight junction that separates the anterior chamber from the ciliary blood vessels, while the endothelial cells lining the iris blood vessels also have tight junctions that restrict the movement of molecules between the blood and the anterior chamber.

The BAB helps maintain the homeostasis of the anterior chamber by controlling the entry of immune cells and preventing the passage of large molecules, toxins, and pathogens from the bloodstream into the eye. Dysfunction of the BAB can lead to various ocular diseases such as uveitis, glaucoma, and age-related macular degeneration.

Central serous chorioretinopathy (CSC) is a medical condition that affects the eye, specifically the retina and the choroid. The choroid is the layer of blood vessels that supplies oxygen and nutrients to the retina. In CSC, there is a buildup of fluid under the retina, leading to distortion or loss of vision.

The term "central" in CSC refers to the fact that the fluid accumulation occurs in the central part of the retina, called the macula, which is responsible for sharp, detailed vision. The term "serous" indicates that the fluid accumulation is made up of serum, the clear portion of blood.

CSC is more common in middle-aged men and can be associated with stress, corticosteroid use, and certain medical conditions such as hypertension and sleep apnea. In many cases, CSC resolves on its own within a few months without treatment. However, some people may experience recurrent episodes or develop chronic CSC, which can lead to permanent vision loss if left untreated. Treatment options for CSC include laser therapy, photodynamic therapy, and medication.

Choroiditis is an inflammatory condition that affects the choroid, a layer of blood vessels in the eye located between the retina (the light-sensitive tissue at the back of the eye) and the sclera (the white outer coat of the eye). The choroid provides oxygen and nutrients to the outer layers of the retina.

Choroiditis is characterized by spots or patches of inflammation in the choroid, which can lead to damage and scarring of the tissue. This can result in vision loss if it affects the macula (the central part of the retina responsible for sharp, detailed vision). Symptoms of choroiditis may include blurred vision, floaters, sensitivity to light, and decreased color perception.

There are several types of choroiditis, including:

1. Multifocal choroiditis: This type is characterized by multiple, small areas of inflammation in the choroid, often accompanied by scarring. It can affect both eyes and may cause vision loss if it involves the macula.
2. Serpiginous choroiditis: This is a chronic, relapsing form of choroiditis that affects the outer layers of the retina and the choroid. It typically causes well-defined, wavy or serpentine-shaped lesions in the posterior pole (the back part) of the eye.
3. Birdshot chorioretinopathy: This is a rare form of choroiditis that primarily affects the peripheral retina and choroid. It is characterized by multiple, cream-colored or yellowish spots throughout the fundus (the interior surface of the eye).
4. Sympathetic ophthalmia: This is a rare condition that occurs when one eye is injured, leading to inflammation in both eyes. The choroid and other structures in the uninjured eye become inflamed due to an autoimmune response.
5. Vogt-Koyanagi-Harada (VKH) disease: This is a multisystemic autoimmune disorder that affects the eyes, skin, hair, and inner ear. In the eye, it causes choroiditis, retinal inflammation, and sometimes optic nerve swelling.

Treatment for choroiditis depends on the underlying cause and may include corticosteroids, immunosuppressive medications, or biologic agents to control inflammation. In some cases, laser therapy or surgery might be necessary to address complications such as retinal detachment or cataracts.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

An ophthalmoscope is a medical device used by healthcare professionals to examine the interior structures of the eye, including the retina, optic disc, and vitreous humor. It consists of a handle with a battery-powered light source and a head that contains lenses for focusing. When placed in contact with the patient's dilated pupil, the ophthalmoscope allows the examiner to visualize the internal structures of the eye and assess their health. Ophthalmoscopes are commonly used in routine eye examinations, as well as in the diagnosis and management of various eye conditions and diseases.

Keratoconjunctivitis Sicca, also known as dry eye syndrome, is a condition characterized by decreased quality and/or quantity of tears to lubricate and nourish the eye. This can result in discomfort, visual disturbance, and potentially damage to the ocular surface. It is often associated with inflammation of the conjunctiva and the cornea. The symptoms may include dryness, scratchiness, burning, foreign body sensation, pain, redness, blurred vision, and light sensitivity.

Retinal vasculitis is a medical condition characterized by inflammation of the blood vessels in the retina, which is the light-sensitive tissue located at the back of the eye. This condition can cause damage to the retina and may lead to vision loss if not treated promptly. The inflammation can affect both the small and large blood vessels in the retina and can occur as a result of various systemic diseases or infections, including autoimmune disorders, tuberculosis, syphilis, and toxoplasmosis. In some cases, retinal vasculitis may also be associated with uveitis, which is inflammation of the middle layer of the eye. Treatment typically involves addressing the underlying cause of the inflammation and may include corticosteroids or other immunosuppressive therapies to reduce inflammation and prevent further damage to the retina.

Probenecid is a medication that is primarily used to treat gout and hyperuricemia (high levels of uric acid in the blood). It works by decreasing the production of uric acid in the body and increasing its excretion through the kidneys.

In medical terms, probenecid is a uricosuric agent, which means it increases the urinary excretion of urate, the salt form of uric acid. It does this by inhibiting the reabsorption of urate in the proximal tubules of the kidneys, thereby promoting its elimination in the urine.

Probenecid is also used in conjunction with certain antibiotics, such as penicillin and cephalosporins, to increase their concentration in the body by reducing their excretion by the kidneys. This is known as probenecid-antibiotic interaction.

It's important to note that probenecid should be used under the supervision of a healthcare provider, and its use may be contraindicated in certain medical conditions or in combination with specific medications.

Ultraviolet microscopy (UV microscopy) is a type of microscopy that uses ultraviolet light to visualize specimens. In this technique, ultraviolet radiation is used as the illumination source, and a special objective lens and filter are used to detect the resulting fluorescence emitted by the specimen.

The sample is usually stained with a fluorescent dye that absorbs the ultraviolet light and re-emits it at a longer wavelength, which can then be detected by the microscope's detector system. This technique allows for the visualization of structures or components within the specimen that may not be visible using traditional brightfield microscopy.

UV microscopy is commonly used in biological research to study the structure and function of cells, tissues, and proteins. It can also be used in forensic science to analyze evidence such as fingerprints, fibers, and other trace materials. However, it's important to note that UV radiation can be harmful to living tissue, so special precautions must be taken when using this technique.

Angioid streaks are abnormal, jagged lines or cracks in the delicate tissue at the back of the eye called the retina. These streaks typically occur near the optic nerve and radiate outward toward the edges of the retina. They are caused by degeneration of the underlying tissue, called Bruch's membrane, which separates the retina from the choroid, a layer of blood vessels that provides nutrients to the retina.

Angioid streaks are often associated with various medical conditions, including pseudoxanthoma elasticum, Paget's disease of bone, Ehlers-Danlos syndrome, and sickle cell anemia. They can also be a complication of cataract surgery or other eye trauma.

While angioid streaks themselves do not cause vision loss, they can lead to serious complications such as retinal hemorrhage, scarring, and detachment, which can result in significant vision loss if left untreated. Regular eye examinations are recommended for individuals with angioid streaks to monitor for any changes or complications that may require treatment.

"Energy transfer" is a general term used in the field of physics and physiology, including medical sciences, to describe the process by which energy is passed from one system, entity, or location to another. In the context of medicine, energy transfer often refers to the ways in which cells and organ systems exchange and utilize various forms of energy for proper functioning and maintenance of life.

In a more specific sense, "energy transfer" may refer to:

1. Bioenergetics: This is the study of energy flow through living organisms, including the conversion, storage, and utilization of energy in biological systems. Key processes include cellular respiration, photosynthesis, and metabolic pathways that transform energy into forms useful for growth, maintenance, and reproduction.
2. Electron transfer: In biochemistry, electrons are transferred between molecules during redox reactions, which play a crucial role in energy production and consumption within cells. Examples include the electron transport chain (ETC) in mitochondria, where high-energy electrons from NADH and FADH2 are passed along a series of protein complexes to generate an electrochemical gradient that drives ATP synthesis.
3. Heat transfer: This is the exchange of thermal energy between systems or objects due to temperature differences. In medicine, heat transfer can be relevant in understanding how body temperature is regulated and maintained, as well as in therapeutic interventions such as hyperthermia or cryotherapy.
4. Mechanical energy transfer: This refers to the transmission of mechanical force or motion from one part of the body to another. For instance, muscle contractions generate forces that are transmitted through tendons and bones to produce movement and maintain posture.
5. Radiation therapy: In oncology, ionizing radiation is used to treat cancer by transferring energy to malignant cells, causing damage to their DNA and leading to cell death or impaired function.
6. Magnetic resonance imaging (MRI): This non-invasive diagnostic technique uses magnetic fields and radio waves to excite hydrogen nuclei in the body, which then release energy as they return to their ground state. The resulting signals are used to generate detailed images of internal structures and tissues.

In summary, "energy transfer" is a broad term that encompasses various processes by which different forms of energy (thermal, mechanical, electromagnetic, etc.) are exchanged or transmitted between systems or objects in the context of medicine and healthcare.

Cerebrospinal fluid (CSF) rhinorrhea is a condition where the cerebrospinal fluid, which surrounds and protects the brain and spinal cord, leaks through the nasal cavity. This occurs due to a defect or opening in the skull base or the thin bone that separates the brain from the nasal cavity, known as the cribriform plate.

CSF rhinorrhea can result from trauma, surgery, or spontaneously due to increased pressure in the brain. It is important to diagnose and treat this condition promptly because it increases the risk of meningitis, an infection of the membranes covering the brain and spinal cord. Treatment options include bed rest, hydration, stool softeners, and sometimes surgical repair of the defect.

Extravasation of diagnostic and therapeutic materials refers to the unintended leakage or escape of these substances from the intended vasculature into the surrounding tissues. This can occur during the administration of various medical treatments, such as chemotherapy, contrast agents for imaging studies, or other injectable medications.

The extravasation can result in a range of complications, depending on the type and volume of the material that has leaked, as well as the location and sensitivity of the surrounding tissues. Possible consequences include local tissue damage, inflammation, pain, and potential long-term effects such as fibrosis or necrosis.

Prompt recognition and management of extravasation are essential to minimize these complications. Treatment may involve local cooling or heating, the use of hyaluronidase or other agents to facilitate dispersion of the extravasated material, or surgical intervention in severe cases.

Capillaries are the smallest blood vessels in the body, with diameters that range from 5 to 10 micrometers. They form a network of tiny tubes that connect the arterioles (small branches of arteries) and venules (small branches of veins), allowing for the exchange of oxygen, carbon dioxide, nutrients, and waste products between the blood and the surrounding tissues.

Capillaries are composed of a single layer of endothelial cells that surround a hollow lumen through which blood flows. The walls of capillaries are extremely thin, allowing for easy diffusion of molecules between the blood and the surrounding tissue. This is essential for maintaining the health and function of all body tissues.

Capillaries can be classified into three types based on their structure and function: continuous, fenestrated, and sinusoidal. Continuous capillaries have a continuous layer of endothelial cells with tight junctions that restrict the passage of large molecules. Fenestrated capillaries have small pores or "fenestrae" in the endothelial cell walls that allow for the passage of larger molecules, such as proteins and lipids. Sinusoidal capillaries are found in organs with high metabolic activity, such as the liver and spleen, and have large, irregular spaces between the endothelial cells that allow for the exchange of even larger molecules.

Overall, capillaries play a critical role in maintaining the health and function of all body tissues by allowing for the exchange of nutrients, oxygen, and waste products between the blood and surrounding tissues.

Diffusion, in the context of medicine and physiology, refers to the process by which molecules move from an area of high concentration to an area of low concentration until they are evenly distributed throughout a space or solution. This passive transport mechanism does not require energy and relies solely on the random motion of particles. Diffusion is a vital process in many biological systems, including the exchange of gases in the lungs, the movement of nutrients and waste products across cell membranes, and the spread of drugs and other substances throughout tissues.

Photometry is the measurement and study of light, specifically its brightness or luminous intensity. In a medical context, photometry is often used in ophthalmology to describe diagnostic tests that measure the amount and type of light that is perceived by the eye. This can help doctors diagnose and monitor various eye conditions and diseases, such as cataracts, glaucoma, and retinal disorders. Photometry may also be used in other medical fields, such as dermatology, to evaluate the effects of different types of light on skin conditions.

Meibomian glands are sebaceous glands located in the eyelids, specifically at the rim of the eyelid near the lashes. They produce an oily substance called meibum that forms the outermost layer of the tear film, helping to prevent evaporation and keep the eye surface lubricated. The Meibomian glands play a crucial role in maintaining the health and comfort of the eyes by providing stability to the tear film and protecting the eye from irritants and dryness.

Cell membrane permeability refers to the ability of various substances, such as molecules and ions, to pass through the cell membrane. The cell membrane, also known as the plasma membrane, is a thin, flexible barrier that surrounds all cells, controlling what enters and leaves the cell. Its primary function is to protect the cell's internal environment and maintain homeostasis.

The permeability of the cell membrane depends on its structure, which consists of a phospholipid bilayer interspersed with proteins. The hydrophilic (water-loving) heads of the phospholipids face outward, while the hydrophobic (water-fearing) tails face inward, creating a barrier that is generally impermeable to large, polar, or charged molecules.

However, specific proteins within the membrane, called channels and transporters, allow certain substances to cross the membrane. Channels are protein structures that span the membrane and provide a pore for ions or small uncharged molecules to pass through. Transporters, on the other hand, are proteins that bind to specific molecules and facilitate their movement across the membrane, often using energy in the form of ATP.

The permeability of the cell membrane can be influenced by various factors, such as temperature, pH, and the presence of certain chemicals or drugs. Changes in permeability can have significant consequences for the cell's function and survival, as they can disrupt ion balances, nutrient uptake, waste removal, and signal transduction.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Telangiectasia is a medical term that refers to the dilation and widening of small blood vessels called capillaries, leading to their visibility under the skin or mucous membranes. These dilated vessels often appear as tiny red lines or patterns, measuring less than 1 millimeter in diameter.

Telangiectasias can occur in various parts of the body, such as the face, nose, cheeks, legs, and fingers. They are typically harmless but may cause cosmetic concerns for some individuals. In certain cases, telangiectasias can be a sign of an underlying medical condition, like rosacea, hereditary hemorrhagic telangiectasia (HHT), or liver disease.

It is essential to consult with a healthcare professional if you notice any unusual changes in your skin or mucous membranes, as they can provide appropriate evaluation and treatment recommendations based on the underlying cause of the telangiectasias.

Eye diseases are a range of conditions that affect the eye or visual system, causing damage to vision and, in some cases, leading to blindness. These diseases can be categorized into various types, including:

1. Refractive errors: These include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia, which affect the way light is focused on the retina and can usually be corrected with glasses or contact lenses.
2. Cataracts: A clouding of the lens inside the eye that leads to blurry vision, glare, and decreased contrast sensitivity. Cataract surgery is the most common treatment for this condition.
3. Glaucoma: A group of diseases characterized by increased pressure in the eye, leading to damage to the optic nerve and potential blindness if left untreated. Treatment includes medications, laser therapy, or surgery.
4. Age-related macular degeneration (AMD): A progressive condition that affects the central part of the retina called the macula, causing blurry vision and, in advanced stages, loss of central vision. Treatment may include anti-VEGF injections, laser therapy, or nutritional supplements.
5. Diabetic retinopathy: A complication of diabetes that affects the blood vessels in the retina, leading to bleeding, leakage, and potential blindness if left untreated. Treatment includes laser therapy, anti-VEGF injections, or surgery.
6. Retinal detachment: A separation of the retina from its underlying tissue, which can lead to vision loss if not treated promptly with surgery.
7. Amblyopia (lazy eye): A condition where one eye does not develop normal vision, often due to a misalignment or refractive error in childhood. Treatment includes correcting the underlying problem and encouraging the use of the weaker eye through patching or other methods.
8. Strabismus (crossed eyes): A misalignment of the eyes that can lead to amblyopia if not treated promptly with surgery, glasses, or other methods.
9. Corneal diseases: Conditions that affect the transparent outer layer of the eye, such as keratoconus, Fuchs' dystrophy, and infectious keratitis, which can lead to vision loss if not treated promptly.
10. Uveitis: Inflammation of the middle layer of the eye, which can cause vision loss if not treated promptly with anti-inflammatory medications or surgery.

Drug delivery systems (DDS) refer to techniques or technologies that are designed to improve the administration of a pharmaceutical compound in terms of its efficiency, safety, and efficacy. A DDS can modify the drug release profile, target the drug to specific cells or tissues, protect the drug from degradation, and reduce side effects.

The goal of a DDS is to optimize the bioavailability of a drug, which is the amount of the drug that reaches the systemic circulation and is available at the site of action. This can be achieved through various approaches, such as encapsulating the drug in a nanoparticle or attaching it to a biomolecule that targets specific cells or tissues.

Some examples of DDS include:

1. Controlled release systems: These systems are designed to release the drug at a controlled rate over an extended period, reducing the frequency of dosing and improving patient compliance.
2. Targeted delivery systems: These systems use biomolecules such as antibodies or ligands to target the drug to specific cells or tissues, increasing its efficacy and reducing side effects.
3. Nanoparticle-based delivery systems: These systems use nanoparticles made of polymers, lipids, or inorganic materials to encapsulate the drug and protect it from degradation, improve its solubility, and target it to specific cells or tissues.
4. Biodegradable implants: These are small devices that can be implanted under the skin or into body cavities to deliver drugs over an extended period. They can be made of biodegradable materials that gradually break down and release the drug.
5. Inhalation delivery systems: These systems use inhalers or nebulizers to deliver drugs directly to the lungs, bypassing the digestive system and improving bioavailability.

Overall, DDS play a critical role in modern pharmaceutical research and development, enabling the creation of new drugs with improved efficacy, safety, and patient compliance.

Eyelid diseases refer to a variety of medical conditions that affect the function and/or appearance of the eyelids. These can include structural abnormalities, such as entropion (inward turning of the eyelid) or ectropion (outward turning of the eyelid), as well as functional issues like ptosis (drooping of the upper eyelid). Other common eyelid diseases include blepharitis (inflammation of the eyelid margin), chalazion (a blocked oil gland in the eyelid), and cancerous or benign growths on the eyelid. Symptoms of eyelid diseases can vary widely, but often include redness, swelling, pain, itching, tearing, and sensitivity to light. Treatment for these conditions depends on the specific diagnosis and may range from self-care measures and medications to surgical intervention.

Retinal drusen are yellow-white, deposits of extracellular material that accumulate beneath the retina, most commonly in the macula. They are a common age-related finding and can also be seen in various other conditions such as inherited retinal diseases. Drusen can vary in size and number, and their presence is often associated with an increased risk of developing age-related macular degeneration (AMD), a leading cause of vision loss in older adults. However, not all individuals with drusen will develop AMD, and the significance of drusen depends on factors such as size, number, and location. It's important to monitor drusen and have regular eye examinations to assess any changes or progression that may indicate a higher risk for developing AMD.

Phycoerythrin is not a medical term, but a term used in biochemistry and cell biology. It refers to a type of protein found in certain algae and cyanobacteria that binds phycobilins, which are linear tetrapyrrole chromophores. Phycoerythrin is a light-harvesting pigment that absorbs light energy and transfers it to the photosynthetic reaction centers. It is often used in research and clinical settings as a fluorescent label for various applications, such as flow cytometry, immunohistochemistry, and microscopy.

Photosensitizing agents are substances that, when exposed to light, particularly ultraviolet or visible light, can cause chemical reactions leading to the production of reactive oxygen species. These reactive oxygen species can interact with biological tissues, leading to damage and a variety of phototoxic or photoallergic adverse effects.

Photosensitizing agents are used in various medical fields, including dermatology and oncology. In dermatology, they are often used in the treatment of conditions such as psoriasis and eczema, where a photosensitizer is applied to the skin and then activated with light to reduce inflammation and slow the growth of skin cells.

In oncology, photosensitizing agents are used in photodynamic therapy (PDT), a type of cancer treatment that involves administering a photosensitizer, allowing it to accumulate in cancer cells, and then exposing the area to light. The light activates the photosensitizer, which produces reactive oxygen species that damage the cancer cells, leading to their death.

Examples of photosensitizing agents include porphyrins, chlorophyll derivatives, and certain antibiotics such as tetracyclines and fluoroquinolones. It is important for healthcare providers to be aware of the potential for photosensitivity when prescribing these medications and to inform patients of the risks associated with exposure to light.

The retinal pigment epithelium (RPE) is a single layer of cells located between the photoreceptor cells of the retina and the choroid, which is a part of the eye containing blood vessels. The RPE plays a crucial role in maintaining the health and function of the photoreceptors by providing them with nutrients, removing waste products, and helping to regulate the light-sensitive visual pigments within the photoreceptors.

The RPE cells contain pigment granules that absorb excess light to prevent scattering within the eye and improve visual acuity. They also help to form the blood-retina barrier, which restricts the movement of certain molecules between the retina and the choroid, providing an important protective function for the retina.

Damage to the RPE can lead to a variety of eye conditions, including age-related macular degeneration (AMD), which is a leading cause of vision loss in older adults.

Biological transport refers to the movement of molecules, ions, or solutes across biological membranes or through cells in living organisms. This process is essential for maintaining homeostasis, regulating cellular functions, and enabling communication between cells. There are two main types of biological transport: passive transport and active transport.

Passive transport does not require the input of energy and includes:

1. Diffusion: The random movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
3. Facilitated diffusion: The assisted passage of polar or charged substances through protein channels or carriers in the cell membrane, which increases the rate of diffusion without consuming energy.

Active transport requires the input of energy (in the form of ATP) and includes:

1. Primary active transport: The direct use of ATP to move molecules against their concentration gradient, often driven by specific transport proteins called pumps.
2. Secondary active transport: The coupling of the movement of one substance down its electrochemical gradient with the uphill transport of another substance, mediated by a shared transport protein. This process is also known as co-transport or counter-transport.

Choroid neoplasms are abnormal growths that develop in the choroid, a layer of blood vessels that lies between the retina and the sclera (the white of the eye). These growths can be benign or malignant (cancerous). Benign choroid neoplasms include choroidal hemangiomas and choroidal osteomas. Malignant choroid neoplasms are typically choroidal melanomas, which are the most common primary eye tumors in adults. Other types of malignant choroid neoplasms include metastatic tumors that have spread to the eye from other parts of the body. Symptoms of choroid neoplasms can vary depending on the size and location of the growth, but may include blurred vision, floaters, or a dark spot in the visual field. Treatment options depend on the type, size, and location of the tumor, as well as the patient's overall health and personal preferences.

Chorioretinitis is a medical term that refers to the inflammation of the choroid and the retina, which are both important structures in the eye. The choroid is a layer of blood vessels that supplies oxygen and nutrients to the retina, while the retina is a light-sensitive tissue that converts light into electrical signals that are sent to the brain and interpreted as visual images.

Chorioretinitis can be caused by various infectious and non-infectious conditions, such as bacterial, viral, fungal, or parasitic infections, autoimmune diseases, or cancer. The symptoms of chorioretinitis may include decreased vision, floaters, blurry vision, sensitivity to light, and eye pain. Treatment for chorioretinitis depends on the underlying cause and may include antibiotics, antiviral medications, corticosteroids, or other immunosuppressive therapies. It is important to seek medical attention promptly if you experience any symptoms of chorioretinitis, as timely diagnosis and treatment can help prevent permanent vision loss.

Exudates and transudates are two types of bodily fluids that can accumulate in various body cavities or tissues as a result of injury, inflammation, or other medical conditions. Here are the medical definitions:

1. Exudates: These are fluids that accumulate due to an active inflammatory process. Exudates contain high levels of protein, white blood cells (such as neutrophils and macrophages), and sometimes other cells like red blood cells or cellular debris. They can be yellow, green, or brown in color and may have a foul odor due to the presence of dead cells and bacteria. Exudates are often seen in conditions such as abscesses, pneumonia, pleurisy, or wound infections.

Examples of exudative fluids include pus, purulent discharge, or inflammatory effusions.

2. Transudates: These are fluids that accumulate due to increased hydrostatic pressure or decreased oncotic pressure within the blood vessels. Transudates contain low levels of protein and cells compared to exudates. They are typically clear and pale yellow in color, with no odor. Transudates can be found in conditions such as congestive heart failure, liver cirrhosis, or nephrotic syndrome.

Examples of transudative fluids include ascites, pleural effusions, or pericardial effusions.

It is essential to differentiate between exudates and transudates because their underlying causes and treatment approaches may differ significantly. Medical professionals often use various tests, such as fluid analysis, to determine whether a fluid sample is an exudate or transudate.

Topical administration refers to a route of administering a medication or treatment directly to a specific area of the body, such as the skin, mucous membranes, or eyes. This method allows the drug to be applied directly to the site where it is needed, which can increase its effectiveness and reduce potential side effects compared to systemic administration (taking the medication by mouth or injecting it into a vein or muscle).

Topical medications come in various forms, including creams, ointments, gels, lotions, solutions, sprays, and patches. They may be used to treat localized conditions such as skin infections, rashes, inflammation, or pain, or to deliver medication to the eyes or mucous membranes for local or systemic effects.

When applying topical medications, it is important to follow the instructions carefully to ensure proper absorption and avoid irritation or other adverse reactions. This may include cleaning the area before application, covering the treated area with a dressing, or avoiding exposure to sunlight or water after application, depending on the specific medication and its intended use.

The endothelium of the cornea is the thin, innermost layer of cells that lines the inner surface of the cornea, which is the clear, dome-shaped structure at the front of the eye. This single layer of specialized cells is essential for maintaining the transparency and proper hydration of the cornea, allowing light to pass through it and focus on the retina.

The endothelial cells are hexagonal in shape and have tight junctions between them, creating a semi-permeable barrier that controls the movement of water and solutes between the corneal stroma (the middle layer of the cornea) and the anterior chamber (the space between the cornea and the iris). The endothelial cells actively pump excess fluid out of the cornea, maintaining a delicate balance of hydration that is critical for corneal clarity.

Damage to or dysfunction of the corneal endothelium can result in corneal edema (swelling), cloudiness, and loss of vision. Factors contributing to endothelial damage include aging, eye trauma, intraocular surgery, and certain diseases such as Fuchs' dystrophy and glaucoma.

Iris diseases refer to a variety of conditions that affect the iris, which is the colored part of the eye that regulates the amount of light reaching the retina by adjusting the size of the pupil. Some common iris diseases include:

1. Iritis: This is an inflammation of the iris and the adjacent tissues in the eye. It can cause pain, redness, photophobia (sensitivity to light), and blurred vision.
2. Aniridia: A congenital condition characterized by the absence or underdevelopment of the iris. This can lead to decreased visual acuity, sensitivity to light, and an increased risk of glaucoma.
3. Iris cysts: These are fluid-filled sacs that form on the iris. They are usually benign but can cause vision problems if they grow too large or interfere with the function of the eye.
4. Iris melanoma: A rare type of eye cancer that develops in the pigmented cells of the iris. It can cause symptoms such as blurred vision, floaters, and changes in the appearance of the iris.
5. Iridocorneal endothelial syndrome (ICE): A group of rare eye conditions that affect the cornea and the iris. They are characterized by the growth of abnormal tissue on the back surface of the cornea and can lead to vision loss.

It is important to seek medical attention if you experience any symptoms of iris diseases, as early diagnosis and treatment can help prevent complications and preserve your vision.

The lacrimal apparatus is a complex system in the eye that produces, stores, and drains tears. It consists of several components including:

1. Lacrimal glands: These are located in the upper outer part of the eyelid and produce tears to keep the eye surface moist and protected from external agents.
2. Tear ducts (lacrimal canaliculi): These are small tubes that drain tears from the surface of the eye into the lacrimal sac.
3. Lacrimal sac: This is a small pouch-like structure located in the inner part of the eyelid, which collects tears from the tear ducts and drains them into the nasolacrimal duct.
4. Nasolacrimal duct: This is a tube that runs from the lacrimal sac to the nose and drains tears into the nasal cavity.

The lacrimal apparatus helps maintain the health and comfort of the eye by keeping it lubricated, protecting it from infection, and removing any foreign particles or debris.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

A hapten is a small molecule that can elicit an immune response only when it is attached to a larger carrier protein. On its own, a hapten is too small to be recognized by the immune system as a foreign substance. However, when it binds to a carrier protein, it creates a new antigenic site that can be detected by the immune system. This process is known as haptenization.

Haptens are important in the study of immunology and allergies because they can cause an allergic response when they bind to proteins in the body. For example, certain chemicals found in cosmetics, drugs, or industrial products can act as haptens and trigger an allergic reaction when they come into contact with the skin or mucous membranes. The resulting immune response can cause symptoms such as rash, itching, or inflammation.

Haptens can also be used in the development of vaccines and diagnostic tests, where they are attached to carrier proteins to stimulate an immune response and produce specific antibodies that can be measured or used for therapy.

Benzalkonium compounds are a group of related chemicals that have antimicrobial properties. They are commonly used as disinfectants and preservatives in various products such as eye drops, nasal sprays, skin creams, and household cleaners. Benzalkonium compounds work by disrupting the cell membranes of bacteria, fungi, and viruses, leading to their death. They are often used in low concentrations and are generally considered safe for topical use, but they can cause irritation and allergic reactions in some people. Prolonged or frequent use of products containing benzalkonium compounds may also lead to the development of bacterial resistance.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Monoclonal antibodies are a type of antibody that are identical because they are produced by a single clone of cells. They are laboratory-produced molecules that act like human antibodies in the immune system. They can be designed to attach to specific proteins found on the surface of cancer cells, making them useful for targeting and treating cancer. Monoclonal antibodies can also be used as a therapy for other diseases, such as autoimmune disorders and inflammatory conditions.

Monoclonal antibodies are produced by fusing a single type of immune cell, called a B cell, with a tumor cell to create a hybrid cell, or hybridoma. This hybrid cell is then able to replicate indefinitely, producing a large number of identical copies of the original antibody. These antibodies can be further modified and engineered to enhance their ability to bind to specific targets, increase their stability, and improve their effectiveness as therapeutic agents.

Monoclonal antibodies have several mechanisms of action in cancer therapy. They can directly kill cancer cells by binding to them and triggering an immune response. They can also block the signals that promote cancer growth and survival. Additionally, monoclonal antibodies can be used to deliver drugs or radiation directly to cancer cells, increasing the effectiveness of these treatments while minimizing their side effects on healthy tissues.

Monoclonal antibodies have become an important tool in modern medicine, with several approved for use in cancer therapy and other diseases. They are continuing to be studied and developed as a promising approach to treating a wide range of medical conditions.

Eye injuries refer to any damage or trauma caused to the eye or its surrounding structures. These injuries can vary in severity and may include:

1. Corneal abrasions: A scratch or scrape on the clear surface of the eye (cornea).
2. Chemical burns: Occurs when chemicals come into contact with the eye, causing damage to the cornea and other structures.
3. Eyelid lacerations: Cuts or tears to the eyelid.
4. Subconjunctival hemorrhage: Bleeding under the conjunctiva, the clear membrane that covers the white part of the eye.
5. Hyphema: Accumulation of blood in the anterior chamber of the eye, which is the space between the cornea and iris.
6. Orbital fractures: Breaks in the bones surrounding the eye.
7. Retinal detachment: Separation of the retina from its underlying tissue, which can lead to vision loss if not treated promptly.
8. Traumatic uveitis: Inflammation of the uvea, the middle layer of the eye, caused by trauma.
9. Optic nerve damage: Damage to the optic nerve, which transmits visual information from the eye to the brain.

Eye injuries can result from a variety of causes, including accidents, sports-related injuries, violence, and chemical exposure. It is important to seek medical attention promptly for any suspected eye injury to prevent further damage and potential vision loss.

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... (FITC) is a derivative of fluorescein used in wide-ranging applications including flow cytometry. ... It is typically available as a mixture of isomers, fluorescein 5-isothiocyanate (5-FITC) and fluorescein 6-isothiocyanate (6- ... A succinimidyl-ester functional group attached to the fluorescein core, creating "NHS-fluorescein", forms another common amine ... Due to the problem of photobleaching, derivatives of fluorescein such as Alexa 488 and DyLight 488 have been tailored for ...
The fluorescein is administered intravenously in intravenous fluorescein angiography (IVFA) and orally in oral fluorescein ... See fluorescein safety in health care applications. Fluorescein angiography does not involve the use of ionizing radiation. ... Fluorescein angiography (FA), fluorescent angiography (FAG), or fundus fluorescein angiography (FFA) is a technique for ... The fluorescein dye also reappears in the patient urine, causing the urine to appear darker, and sometimes orange. It can also ...
Assay for Fluorescein Diacetate Hydrolytic Activity for soil samples Fluorescein Diacetate: A Potential Biological Indicator ... Fluorescein diacetate (FDA) hydrolysis assays can be used to measure the enzyme activity of microbes in a sample. A bright ... "VIABILITY TEST WITH FLUORESCEIN DIACETATE (FDA)". www.cabri.org. Fontvieille, D.A.; Outaguerouine, A.; Thevenot, D.R. (1992). " ... Living cells will actively convert the non-fluorescent FDA into the green fluorescent compound fluorescein, a sign of viability ...
"Fluorescein , Definition of Fluorescein by Oxford Dictionary on Lexico.com also meaning of Fluorescein". Lexico Dictionaries , ... "Fluorescein". Drug Information Portal. U.S. National Library of Medicine. "Fluorescein sodium". Drug Information Portal. U.S. ... Fluorescein is used to help in the diagnosis of a number of eye problems. When applied as a drop or within a strip of paper to ... Fluorescein is a dye which is taken up by damaged cornea such that the area appears green under cobalt blue light. There is ...
... (FLAER) is used in a flow cytometric assay to diagnose paroxysmal nocturnal hemoglobinuria ( ...
"Fluorescein , Biography & History , AllMusic". AllMusic. Retrieved 2016-09-04. "Troy Van Leeuwen , Queens of the Stone Age - ... Van Leeuwen and Scott went on to tour with the band Failure while Rubenstein joined the group Fluorescein. Both of these ...
Fluorescein angiography is a medical procedure in which a fluorescent dye is injected into the bloodstream. The dye highlights ... "Fluorescein Angiography". EMPIRE RETINA CONSULTANTS. Retrieved 22 August 2016. Kashani AH, Chen CL, Gahm JK, Zheng F, Richter ... Cardiac catheterization Computed tomography angiography Contrast medium Echocardiogram Electrocardiogram Fluorescein ...
Fluorescein Conjugate. Biochim. Biophys. Acta, 1427, 33 - 43 (1999) C. Etzlstorfer, I Gutman and H. Falk, Concerning the ...
One study claimed a large difference in observed fluorescein angiography examinations and observed markedly less "progression ... Bennett, Timothy J. (2017). "Fluorescein Fundamentals". Ophthalmic Photographers' Society. Clark, B. a. J. (November 1969). " ...
"Fluorescein Angiography". American Academy of Ophthalmolog. Archived from the original on 27 May 2016. Alander JT, Kaartinen I ... Gass JD, Sever RJ, Sparks D, Goren J (October 1967). "A combined technique of fluorescein funduscopy and angiography of the eye ... Yannuzzi LA, Rohrer KT, Tindel LJ, Sobel RS, Costanza MA, Shields W, Zang E (May 1986). "Fluorescein angiography complication ... Spaide RF, Klancnik JM, Cooney MJ (January 2015). "Retinal vascular layers imaged by fluorescein angiography and optical ...
"Artist/Fluorescein". billboard.com. "Fluorescein Cathy's on Crank!". allmusic.com. "Weezer Poster". wolfgangs.com. "Finally, ... "Fluorescein Revels in the Dark Side". Los Angeles Times. 17 April 1998. Rovner, Michael (13 April 2011). "Bar Crawling From ...
"Fluorescein eye stain". NIH. Archived from the original on 20 May 2012. Retrieved 15 May 2012. Ruggieri S, Frassanito MA, ...
Sato, K. and J. Anzai, Fluorometric determination of sugars using fluorescein-labeled concanavalin A-glycogen conjugates. Anal ... fluorescein (485, 520); NBD (490, 540); NBDE (490, 530); JPW4039 (485, 590); JPW4042 (470, 640); and JPW4045 (470, 640)). Out ...
Fluorescein Fluorescence "C&L Inventory". echa.europa.eu. Retrieved 13 December 2021. "chem industry entry". Archived from the ...
"Expert panel approves fluorescein strips use". Optician Online. 25 September 2013. Retrieved 17 July 2015. "Optical ... The Confederation negotiated a solution to the difficulties posed by the use of fluorescein impregnated paper strips when ...
pioneered the use of fluorescein angiography for the diagnosis of macular and retinal diseases, which led to the accurate ... Norton, EW; Gutman, F (1965). "Diabetic retinopathy studied by fluorescein angiography". Transactions of the American ... a macular degeneration specialist who developed fluorescein angiography as a diagnostic tool, and John T. Flynn, a pediatric ...
Brush, C. K. "Fluorescein Labelled Phosphoramidites". (1996) U.S. Patent 5,583,236. Pitner, J. B.; Linn, C. P. "Synthesis and ... exemplified by 6-FAM amidite 7 for the attachment of fluorescein and dabcyl amidite 8, respectively), hydrophilic and ...
Patz, Arnall; Fine, Stuart L. (1977). Interpretation of the Fundus Fluorescein Angiogram. Boston: Little, Brown. OCLC 3206372. ...
Fluorescein angiography is a helpful adjunct. Findings include delayed venous filling, hypofluorescence caused by hemorrhage ...
Since then, Fluorescein was created as a fluorescent dye by Adolph von Baeyer in 1871 and the method of staining was developed ... Usually fluorescein is used as the fluorophore. Chemical labeling or the use of chemical tags utilizes the interaction between ... Ethidium bromide, fluorescein and green fluorescent protein are common tags. The most commonly labelled molecules are ...
It is produced from fluorescein by bromination. Eosin Y is commonly used as the red dye in red inks. It is commonly used in ...
Fluorescein angiography may demonstrate leakage in areas remote from the retinal infarctions. In a recent analysis (Susac et al ... Both patients underwent fluorescein retinal angiography that demonstrated multifocal retinal artery occlusions without evidence ... Egan, Robert A.; Hills, William L.; Susac, John O. (December 2010). "Gass plaques and fluorescein leakage in Susac Syndrome". ...
A carboxyfluorescein molecule is a fluorescein molecule with a carboxyl group added. They are commonly used as a tracer agents ... Fluorescein Molecular Imaging Products Company (2005-08-26). "5-(and-6)-Carboxyfluorescein (5-(and-6)- FAM,mixed isomer) 100mg ...
Multiple muscular VSDs are a challenge to close, achieving a complete closure can be aided by the use of fluorescein dye. VSDs ... "Use of Fluorescein Dye to Identify Residual Defects". Ann Thorac Surg. 97 (1): e27-8. doi:10.1016/j.athoracsur.2013.10.059. ...
Variability in fluorescein angiography interpretation for photodynamic therapy in age-related macular degeneration. Retina. ... Quantitative image sequence analysis of fundus fluorescein angiography. Ophthalmic Surg Lasers. 1999 Jan;30(1):72-3. Shin DS, ... Quantitative, spatio-temporal image analysis of fluorescein angiography in age-related macular degeneration. Proc SPIE 1998; ... of quantitative retinal imaging with a number of publications on image analysis methods for modalities such as fluorescein ...
Κ-casein labeled with the fluorochrome fluorescein isothiocyanate (FITC) to yield the fluorescein thiocarbamoyl (FTC) ... by κ-casein labeled with the fluorochrome fluorescein isothiocyanate (FITC) to yield the fluorescein thiocarbamoyl (FTC) ... Ageitos, J.M.; Vallejo, J.A.; Poza, M.; Villa, T.G. (2006). "Fluorescein Thiocarbamoyl-Kappa-Casein Assay for the Specific ... InterPro: IPR000117 Kappa casein Fluorescein Thiocarbamoyl-Kappa-Casein Assay for the Specific Testing of Milk-Clotting ...
... Y is a tetrabromo derivative of fluorescein. Eosin B is a dibromo dinitro derivative of fluorescein. Eosin is most often ...
Fluorescein is currently used most as a fluorescent probe. Equipment that can automatically measure and calculate the capacity ... Most of them employ the same principle (i.e. measurement of AAPH-radical mediated damage of fluorescein); however, ORAC-EPR, ... The degeneration (or decomposition) of fluorescein is measured as the presence of the antioxidant slows the fluorescence decay ... The assay measures the oxidative degradation of the fluorescent molecule (either beta-phycoerythrin or fluorescein) after being ...
Fluorescein is also known as a color additive (D&C Yellow no. 7). The disodium salt form of fluorescein is known as uranine or ... 8. Fluorescein is a precursor to the red dye eosin Y by bromination. Oral and intravenous use of fluorescein can cause adverse ... Fluorescein sodium, the sodium salt of fluorescein, is used extensively as a diagnostic tool in the field of ophthalmology and ... Fluorescein has an isosbestic point (equal absorption for all pH values) at 460 nm. Many derivatives of fluorescein are known. ...
Fluorescein injection is used to help certain parts of the eye (eg, retina, iris) become more visible during eye medical ...
Iris fluorescein angiography in diabetic vitrectomy patients. Download Prime PubMed App to iPhone, iPad, or Android ... Iris Fluorescein Angiography in Diabetic Vitrectomy Patients. Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1978 Apr 7;206(1): ... Iris fluorescein angiography in diabetic vitrectomy patients. Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1978;206(1):17-24. ... "Iris Fluorescein Angiography in Diabetic Vitrectomy Patients." Albrecht Von Graefes Archiv Fur Klinische Und Experimentelle ...
The hydrolysis of the fluorescein diacetate (FDA), related to several soil hydrolases, has been utilised to estimate the ... Fluorescein diacetate hydrolysis, respiration and microbial biomass in freshly amended soils. *M. A. Sánchez-Monedero. 1, ... Sánchez-Monedero, M.A., Mondini, C., Cayuela, M.L. et al. Fluorescein diacetate hydrolysis, respiration and microbial biomass ... Schnürer J, Rosswall T (1982) Fluorescein diacetate hydrolysis as a measure of total microbial activity in soil and litter. ...
Fluorescein isothiocyanate-dextran average mol wt 250,000; CAS Number: 60842-46-8; Synonyms: FITC-Dextran; find Sigma-Aldrich- ... Fluorescein Isothiocyanate-Dextran. Dextran is a polymer of anhydroglucose. It is composed of approximately 95% alpha-D-(166) ... Dextran labeled with fluorescein isothiocyanate for possible use in perfusion studies in animals. ...
Fluorescein Angiography. Fluorescein angiography is an invaluable adjunct in the diagnosis and management of diabetic ... Fluorescein angiogram demonstrating foveal dye leakage caused by macular edema. View Media Gallery ... Fluorescein angiogram demonstrating an area of capillary nonperfusion (arrow). View Media Gallery ... An area of neovascularization that leaks fluorescein on angiography. View Media Gallery ...
What is the CPT for a fluorescein dye & wood lamp used to evaluate the entire colon for vascular/ischemic necrosis? Would this ... What is the CPT for a fluorescein dye & wood lamp used to evaluate the entire colon for vascular/ischemic necrosis? Would this ...
Fluorescein dye disappearance test was used to evaluate tear drainage after experimental obstruction of upper, lower, neither ... Fluorescein dye disappearance test was used to evaluate tear drainage after experimental obstruction of upper, lower, neither ... Assessment of tear drainage by fluorescein dye disappearance test after experimental canalicular obstruction Acta Ophthalmol ( ...
Fluorescein labeled Soybean agglutinin has an appropriate number of fluorochromes bound to provide the optimum staining ...
... and supportive government initiatives are the major factors driving the market for fluorescein angiography. ... The global fluorescein angiography market size was valued at USD 498.8 million in 2019. Increasing prevalence of various eye ... Fluorescein Angiography Market Size Report, 2020-2027. Fluorescein Angiography Market Size, Share & Trends Analysis Report By ...
A fluorescein angiogram helps to check the circulation of blood through the eye & suspected diabetic retinopathy. Explore more ... A retinal fluorescein angiography is not a procedure that is completely devoid of risks. The dye called sodium fluorescein is a ... Reasons for Fluorescein Angiography. A fluorescein angiogram is a procedure that is performed to check the circulation of blood ... Medical Health Tests Medical Tests Fluorescein Angiography Reasons, Procedure & Results Interpretation of Fluorescein ...
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Centers RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.. ...
Comprehensive suppliers list with E-mail/RFQ form for Anti-Fluorescein Isothiocyanate (FITC) Polyclonal Antibody ... Anti-Fluorescein Isothiocyanate (FITC) Polyclonal Antibody Suppliers. EMAIL INQUIRY to 2 suppliers ...
Specific Staining of Red Cell Antigens by the Use of Fluorescein-Labelled Antibody Subject Area: Hematology , Oncology ... B.D. Janković; Specific Staining of Red Cell Antigens by the Use of Fluorescein-Labelled Antibody. Acta Haematol 1 May 1959; 22 ...
Bactericidal antibiotics increase hydroxyphenyl fluorescein signal by altering cell morphology. Publikation: Bidrag til ... Bactericidal Antibiotics Increase Hydroxyphenyl Fluorescein Signal by Altering Cell Morphology Forlagets udgivne version, 550 ...
Composites consisting of fluorescein (F) entrapped inside various zeolite structures (i.e. FAU, LTL, MFI, and LTA) were ... Synthesis of fluorescein by a ship-in-a-bottle method in different zeolites M. Łukarska, A. Jankowska, J. Gapiński, S. Valable ... Composites consisting of fluorescein (F) entrapped inside various zeolite structures (i.e. FAU, LTL, MFI, and LTA) were ... Synthesis of fluorescein by a ship-in-a-bottle method in different zeolites† ...
Get up-to-date information on Fluorescein side effects, uses, dosage, overdose, pregnancy, alcohol and more. Learn more about ... Fluorescein is available in the following doses: *Fluorescein 10% Intravenous Solution*Fluorescein 25% Intravenous Solution* ... How was your experience with Fluorescein?. First, a little about yourself. Male Female ... Fluorescein helps the doctor see parts of the eye. Can cause your urine and skin to look bright yellow. It can take 6-12 hours ...
Please be advised that UPSpace will be temporarily unavailable for maintenance starting at 18:00 South African time on Friday, December 8, 2023, until 08:00 on Monday morning, December 11, 2023. We apologise for any inconvenience this may cause.. ...
Due to the established safety profile of fluorescein and the ease of administration, EGF-fluorescein has direct clinical ... Use of EGF-FL in U87 tumors revealed similar tumor specificity as fluorescein (70.9% vs. 68.4%, p=0.71). However, the use of ... However while agents such as fluorescein and aminolevulinic acid have been shown to increase the extent of resection, these ... In this study, we have evaluated the specificity of epidermal growth factor conjugated fluorescein (EGF-FL) and have compared ...
Fluorescein Recombinant monoclonal antibody (4-4-20 enhanced) (Hamster IgGκ) - ENZ-ABS495 ...
50 ml for 5 g of fluorescein). The solution was stirred in at 110 °C for 24 h, after that cooled to the room t... ... fluorescein was incorporated with an equal molar of 1-chloro-4-nitrobenzene and double potassium carbonate (molar ratio), the ... In this work, fluorescein was incorporated with an equal molar of 1-chloro-4-nitrobenzene and double potassium carbonate (molar ... ratio), the solvent of this reaction is dimethylacetamide (50 ml for 5 g of fluorescein). ...
Cellular Accumulation of Cholyl-Glycylamido-Fluorescein in Sandwich-Cultured Rat Hepatocytes: Kinetic Characterization, ... Cellular Accumulation of Cholyl-Glycylamido-Fluorescein in Sandwich-Cultured Rat Hepatocytes: Kinetic Characterization, ... Cellular Accumulation of Cholyl-Glycylamido-Fluorescein in Sandwich-Cultured Rat Hepatocytes: Kinetic Characterization, ... Cellular Accumulation of Cholyl-Glycylamido-Fluorescein in Sandwich-Cultured Rat Hepatocytes: Kinetic Characterization, ...
Since this study is first with use of fluorescein for sentinel node biopsy in breast, we injected fluorescein at decreasing ... Conclusions: Fluorescein can be used as a low cost and effective alternative in sentinel lymph node biopsy for carcinoma breast ... In this study we have investigated the effectiveness and safety of fluorescein in sentinel node biopsy in a cross-sectional ... Abstract P2-01-31: Sentinel node mapping with fluorescein and comparison with methylene blue and technitium sulphur colloid in ...
Launch Diagnostics is a licensed reseller and distributor of POLY-HRP ISH FLUORESCEIN KIT. Launch Diagnostics, part of the ...
Research, Technology, Methods , chemical substances , chemical compounds , sulfur compounds , isothiocyanates , fluorescein-5- ...
CM-Dextran Fluorescein is a carboxymethyl (CM) Dextran labeled with fluorescein (FITC). Ex/Em wavelength 494/518 nm. Purity: , ...
Dextran is labeled with fluorescein (FITC) through conjugation reaction of dextran amine and isothiocyanate of FITC, Ex/Em ...
Conjugation: Fluorescein. Epitope: Heavy and Light Chain. Host: Goat. Isotype: IgG. Reactivity: Mouse. ...
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  • Zakov ZN, Lewis ML. Iris fluorescein angiography in diabetic vitrectomy patients. (unboundmedicine.com)
  • TY - JOUR T1 - Iris fluorescein angiography in diabetic vitrectomy patients. (unboundmedicine.com)
  • Important aspects of workup regarding diabetic retinopathy include fasting glucose and hemoglobin A1c, fluorescein angiography, optical coherence tomography, and B-scan ultrasonography. (medscape.com)
  • Fluorescein angiography is an invaluable adjunct in the diagnosis and management of diabetic retinopathy. (medscape.com)
  • An area of neovascularization that leaks fluorescein on angiography. (medscape.com)
  • A retinal fluorescein angiography is not a procedure that is completely devoid of risks. (medicalhealthtests.com)
  • A fluorescein angiography procedure is performed by an ophthalmologist along with another doctor like a surgeon being close by to monitor for side-effects to the dye. (medicalhealthtests.com)
  • Fluorescein angiography interpretation of results is quite complicated. (medicalhealthtests.com)
  • Fluorescein angiography in the differential diagnosis of sclerokeratitis. (bmj.com)
  • Fluorescein angiography is a photographic test, not involving x-rays, in which a colored vegetable dye is injected into an arm vein. (eyecenters.com)
  • Primarily indicated in diagnostic fluorescein angiography or angioscopy of the fundus and of the iris vasculature. (pharmacycode.com)
  • Fluorescein angiography is a clinical test to look at blood circulation in the retina at the back of the eye. (mcceyeinstitute.com)
  • With the introduction of Optical Coherence Tomography (OCT) testing, fluorescein angiography is being done less often than in the past, but remains an important diagnostic tool for the retina specialist. (mcceyeinstitute.com)
  • After your angiography, your skin and urine may appear discolored for a short time until the Fluorescein is completely out of your system. (mcceyeinstitute.com)
  • There is little risk in having fluorescein angiography, though some people may have mild allergic reactions to the dye that can cause itching, excessive sneezing, flushing of skin and nausea. (mcceyeinstitute.com)
  • Ophthalmic examination and fluorescein angiography showed that occlusions were due to ischaemic events. (who.int)
  • Examples are: fluorescein isothiocyanate 1, often abbreviated as FITC, features an isothiocyanate group (−N=C=S) substituent. (wikipedia.org)
  • Dextran labeled with fluorescein isothiocyanate for possible use in perfusion studies in animals. (sigmaaldrich.com)
  • Dextran is labeled with fluorescein (FITC) through conjugation reaction of dextran amine and isothiocyanate of FITC, Ex/Em wavelength 494/518 nm. (creativepegworks.com)
  • The most widely used fluoresceins include fluorescein isothiocyanate (FITC) for labeling proteins (in particular antibodies) and carboxyfluoresceins (5-FAM and 5(6)-FAM ) for labeling peptides and oligonucleotides. (aatbio.com)
  • Excitation and emission spectra for fluorescein-5-isothiocyanate (5-FITC) *CAS 3326-32-7* (Cat No. 121 ). (aatbio.com)
  • Spectral properties of fluorescein-5-isothiocyanate (5-FITC). (aatbio.com)
  • CM-Dextran Fluorescein is a carboxymethyl (CM) Dextran labeled with fluorescein (FITC). (creativepegworks.com)
  • Comparison of photobleaching rates of iFluor® 488 goat anti-mouse IgG and the conventional fluorescein (FITC) goat anti-mouse IgG. (aatbio.com)
  • Also, the fluorescence lifetimes of the protonated and deprotonated forms of fluorescein are approximately 3 and 4 ns, which allows for pH determination from nonintensity based measurements. (wikipedia.org)
  • However while agents such as fluorescein and aminolevulinic acid have been shown to increase the extent of resection, these fluorophores may result in the fluorescence of the surrounding edematous brain. (cns.org)
  • Cellular fluorescence in U87 cells was highest following treatment with 5ug/mL of EGF-FL, with this fluorescence being significantly greater than that achieved by 15ug/mL of fluorescein (p=0.0014). (cns.org)
  • Evaluation of fluorescein tumor specificity revealed tumor tissue to account for only 68.4% and 59.1% of total fluorescence in low and high EGFR expressing tumors, respectively. (cns.org)
  • Due to the established safety profile of fluorescein and the ease of administration, EGF-fluorescein has direct clinical applicability for use in fluorescence-guided resections and requires further study. (cns.org)
  • While the most investigated agents including fluorescein and aminolevulinic acid have been shown to increase the rates of gross total resection, these fluorophores may result in the fluorescence of the surrounding edematous brain, potentially resulting in the resection of non-tumor brain tissue. (cns.org)
  • To ensure full fluorescence and patient comfort, the Fluorescein Sodium impregnated tip should be moistened before application. (petseyes.cn)
  • Fluorescein-labeled probes can be used for in situ hybridization with direct fluorescence detection and detection by ELISA using Anti-Fluorescein-AP, Fab fragments. (roche.com)
  • Human transferrin fluorescein conjugation has been tested in dot blot and is designed for immunofluorescence microscopy, fluorescence based plate assays (FLISA), fluorescent western blotting, multiplex analysis, including multicolor imaging, utilizing various commercial platforms. (rockland.com)
  • Fluorescein derivatives are one of the most commonly used fluorescent labels for biological detection in flow cytometry and immunofluorescence due to their high absorptivity, excellent fluorescence quantum yields and good water solubility. (aatbio.com)
  • Despite its bright green fluorescence, fluorescein based-dyes and conjugates have a number of caveats that may restrict its use in certain applications, including rapid photobleaching, pH-sensitive fluorescence and susceptibility to quenching. (aatbio.com)
  • Mice were intravenously administered fluorescein sodium or EGF-FL and then sacrificed. (cns.org)
  • The dye called sodium fluorescein is a toxic substance that can immediately alter the pH balance in the blood. (medicalhealthtests.com)
  • Methods: This trial was conducted at two centers : Tata Memorial Centre, Mumbai and All India Institute of Medical Sciences New Delhi in India.We examined 86 patients of early breast cancer with no palpable axillary nodes undergoing SLNB with three tracers (Sulphur colloid /Methylene blue / Sodium Fluorescein). (aacrjournals.org)
  • In this study, we have evaluated the specificity of epidermal growth factor conjugated fluorescein (EGF-FL) and have compared it to conventional fluorescein in vitro and in vivo. (cns.org)
  • EGF-FL is a highly specific fluorophore for the delineation of EGFR-expressing tumors and has comparable efficacy to conventional fluorescein in tumors with low EGFR expression. (cns.org)
  • Additionally, we have compared EGF-FL to conventional fluorescein to evaluate their relative efficacy. (cns.org)
  • Description: Hyaluronic Acid is labeled with both fluorescein and rhodamine. (haworksusa.com)
  • Using this method, saturation curves for Rhodamine B, Rhodamine 560, Fluorescein, and Coumarin 153 were obtained using only one image of the saturated sample and one reference image in each case. (lu.se)
  • The disodium salt form of fluorescein is known as uranine or D&C Yellow no. 8. (wikipedia.org)
  • The hyaluronic acid is labelled with 5-amino-fluorescein. (tdblabs.se)
  • Fluorescein angiogram demonstrating an area of capillary nonperfusion (arrow). (medscape.com)
  • Fluorescein angiogram demonstrating foveal dye leakage caused by macular edema. (medscape.com)
  • A fluorescein angiogram is a procedure that is performed to check the circulation of blood through the eye. (medicalhealthtests.com)
  • Fluorescein-DBCO is a fluorescent dye commonly used in drug research and development to label and track molecules in biological systems. (axispharm.com)
  • We offer a broad selection of fluorescein based-dyes, substrates and conjugates, as well as a series of superior iFluor® fluorescent labeling dyes with improved characteristics optimized for cellular labeling and detection. (aatbio.com)
  • Preoperative iris fluorescein angiograms (IFA) and ophthalmic records of 34 diabetic patients who underwent vitrectomy were reviewed. (unboundmedicine.com)
  • Albrecht von Graefe's archive for clinical and experimental ophthalmology JO - Albrecht Von Graefes Arch Klin Exp Ophthalmol VL - 206 IS - 1 N2 - Preoperative iris fluorescein angiograms (IFA) and ophthalmic records of 34 diabetic patients who underwent vitrectomy were reviewed. (unboundmedicine.com)
  • Many derivatives of fluorescein are known. (wikipedia.org)
  • We can supply derivatives of either of these qualities labelled with fluorescein (F-HA). (tdblabs.se)
  • We offer a broad selection of fluorescein products including reactive fluorescein and fluorescein derivatives for labeling antibodies, nucleic acids and other biomolecules, conjugates, indicators, and substrates for detecting enzymatic activity in cells, homogenates and solution. (aatbio.com)
  • Fluorescein has a pKa of 6.4, and its ionization equilibrium leads to pH-dependent absorption and emission over the range of 5 to 9. (wikipedia.org)
  • Fluorescein has an isosbestic point (equal absorption for all pH values) at 460 nm. (wikipedia.org)
  • Fluorescein injection is used to help certain parts of the eye (eg, retina, iris) become more visible during eye medical procedures. (mayoclinic.org)
  • In oligonucleotide synthesis, several phosphoramidite reagents containing protected fluorescein, e.g. 6-FAM phosphoramidite 2, are used for the preparation of fluorescein-labeled oligonucleotides. (wikipedia.org)
  • How to improve efficiency of the diamine synthesis from fluorescein? (scienceforums.net)
  • Use of EGF-FL in U87 tumors revealed similar tumor specificity as fluorescein (70.9% vs. 68.4%, p=0.71). (cns.org)
  • Fluorescein is a fluorophore commonly used in microscopy, in a type of dye laser as the gain medium, in forensics and serology to detect latent blood stains, and in dye tracing. (wikipedia.org)
  • Phosphoramidite can be used for internally labelling an oligonucleotide with the fluorescein-dT dye moiety. (biosearchtech.com)
  • The hydrolysis of the fluorescein diacetate (FDA), related to several soil hydrolases, has been utilised to estimate the potential microbial activity of soil freshly amended with a wide range of organic amendments and compared to the size and activity of soil microflora, measured by the microbial biomass C ( B C ) and CO 2 evolution, respectively. (springer.com)
  • Adam G, Duncan H (2001) Development of a sensitive and rapid method for the measurement of total microbial activity using fluorescein diacetate (FDA) in a range of soils. (springer.com)
  • Conclusions: Fluorescein can be used as a low cost and effective alternative in sentinel lymph node biopsy for carcinoma breast without the risk of radiation exposure. (aacrjournals.org)
  • This complex then reacts with fluorescein-labeled antibody. (cdc.gov)
  • What is the CPT for a fluorescein dye & wood lamp used to evaluate the entire colon for vascular/ischemic necrosis? (aapc.com)
  • Fluorescein dye disappearance test was used to evaluate tear drainage after experimental obstruction of upper, lower, neither or both canaliculi in 18 subjects by hydroxypropil cellulose rods. (nih.gov)
  • Since this study is first with use of fluorescein for sentinel node biopsy in breast, we injected fluorescein at decreasing time interval from 12 hours to 5 minutes to ascertain the most appropriate time for injection of fluorescein in first 15 patients. (aacrjournals.org)
  • Fluorescein sodium, the sodium salt of fluorescein, is used extensively as a diagnostic tool in the field of ophthalmology and optometry, where topical fluorescein is used in the diagnosis of corneal abrasions, corneal ulcers and herpetic corneal infections. (wikipedia.org)
  • This study has demonstrated targeted EGF-FL to be significantly more specific than fluorescein in EGFR-overexpressing tumors, with comparable efficacy in tumors with low EGFR expression. (cns.org)
  • 25 independent samples (14 tumors, 2 generally reflected in related patterns of fluorescein. (lu.se)
  • The color of its aqueous solutions is green by reflection and orange by transmission (its spectral properties are dependent on pH of the solution), as can be noticed in bubble levels, for example, in which fluorescein is added as a colorant to the alcohol filling the tube in order to increase the visibility of the air bubble contained within. (wikipedia.org)
  • More concentrated solutions of fluorescein can even appear red (because under these conditions nearly all incident emission is re-absorbed by the solution). (wikipedia.org)
  • It is available as sterile single-use sachets containing lint-free paper applicators soaked in fluorescein sodium solution. (wikipedia.org)
  • ProductData": { "ID": "3.6.13.2.1.1", "ProductType": "Others", "BrandName": "Fluorescein-12-dUTP", "ProductNameAddition": "1 mM solution", "RegulatoryDisclaimer1": "For further processing only. (roche.com)
  • The thyroxine ester of fluorescein is used to quantify the thyroxine concentration in blood. (wikipedia.org)
  • This characteristic makes Fluorescein-DBCO a valuable tool for studying biological processes and drug interactions in real-time. (axispharm.com)
  • Oral and intravenous use of fluorescein can cause adverse reactions, including nausea, vomiting, hives, acute hypotension, anaphylaxis and related anaphylactoid reaction, causing cardiac arrest and sudden death due to anaphylactic shock. (wikipedia.org)
  • In this work, fluorescein was incorporated with an equal molar of 1-chloro-4-nitrobenzene and double potassium carbonate (molar ratio), the solvent of this reaction is dimethylacetamide (50 ml for 5 g of fluorescein). (scienceforums.net)
  • Fluorescein-12-dUTP replaces dTTP in the random-primed DNA labeling reaction or in nick translation reactions, as well as in PCR. (roche.com)
  • Fluorescein is also known as a color additive (D&C Yellow no. 7). (wikipedia.org)
  • In this study we have investigated the effectiveness and safety of fluorescein in sentinel node biopsy in a cross-sectional analytical study compared to Methylene Blue and Technitium Sulphar colloid. (aacrjournals.org)
  • Fluorescein helps the doctor see parts of the eye. (rxwiki.com)
  • The contamination rate of the fluorescein eyedrop bottles in this study was 55.5% (5/9 vials). (bvsalud.org)
  • To analyze the presence of microorganisms in fluorescein eyedrops used in a reference eye center in Recife-PE. (bvsalud.org)
  • How well did Fluorescein work for you? (rxwiki.com)