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Medical Dictionary


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gout (gowt)
A disorder of purine metabolism, occurring especially in men, characterized by a raised but variable blood uric acid level and severe recurrent acute arthritis of sudden onset resulting from deposition of crystals of sodium urate in connective tissues and articular cartilage; most cases are inherited, resulting from a variety of abnormalities of purine metabolism. The familial aggregation is for the most part galtonian with a threshold of expression determined by the solubility of uric acid. However, g. is also a feature of the Lesch-Nyhan syndrome an X-linked disorder [MIM*308000]. [L. gutta, drop] abarticular g. rarely used term for g. involving structures other than the joints. articular g. the usual form of g. attacking one or more of the joints. calcium g. SYN: pseudogout. idiopathic g. acute episodes of crystal-induced synovitis due to abnormality of purine metabolism; lower than normal urinary excretion of urate leading to hyperuricemia and acute episodes of joint inflammation. SYN: primary g.. interval g. an asymptomatic phase between acute attacks of g.. latent g. hyperuricemia without symptoms of g.. Often used synonymously with interval g.. SYN: masked g.. lead g. SYN: saturnine g.. masked g. SYN: latent g.. primary g. SYN: idiopathic g.. retrocedent g. obsolete term for the occurrence of severe gastric, cardiac, or cerebral symptoms during an attack of g., especially when the joint and other symptoms suddenly subside at the same time. saturnine g. g. occurring in a person with lead poisoning. SYN: lead g.. secondary g. g. resulting from increased serum uric acid levels as a result of an antecedent disease, such as a proliferative disease of the blood and bone marrow, lead poisoning, or prolonged chronic renal failure (on dialysis). tophaceous g. g. in which deposits of uric acid and urates occur as gouty tophi.

gouty (gow′te)
Relating to or characteristic of gout.

Gowers
Sir William R., English neurologist, 1845–1915. See G. column, G. contraction, G. disease, G. syndrome, G. tract.

GPI
Abbreviation for Gingival-Periodontal Index.

GPT
Abbreviation for glutamic-pyruvic transaminase.

gr
Abbreviation for grain (3) .

Graaf
Reijnier de, Dutch physiologist and histologist, 1641–1673. See graafian follicle.

graafian
Relating to or described by R. de Graaf.

gracilis (gras′i-lis)
1. Slender; denoting a thin or slender structure. 2. SYN: g. (muscle). [L.]

grad.
Abbreviation for L. gradatim, by degrees, gradually.

grade (grad)
1. A rank, division, or level on the scale of a value system. 2. In cancer pathology, a classification of the degree of malignancy or differentiation of tumor tissue; e.g., well, moderately well, or poorly differentiated, and undifferentiated or anaplastic. 3. In exercise testing, the measurement of a vertical rise or fall as a percent of the horizontal distance traveled. [L. gradus, step] Gleason tumor g. a classification of adenocarcinoma of the prostate by evaluation of the pattern of glandular differentiation; the tumor g., known as Gleason score, is the sum of the dominant and secondary patterns, each numbered on a scale of 1 to 5. Heath-Edwards grades a system that describes the pathology of hypertensive pulmonary vascular disease.

Gradenigo
Giuseppe, Italian otologist, 1859–1926. See G. syndrome.

gradient (gra′de-ent)
Rate of change of temperature, pressure, magnetic field, or other variable as a function of distance, time, etc. atrioventricular g. the diastolic pressure difference between the atrium and ventricle. concentration g. SYN: density g.. density g. a solution in which the concentration (density) of a solute increases in a continuous fashion from top to bottom, or end to end, of a container ( e.g., the centrifuge tube in density-g. centrifugation). SYN: concentration g.. electrochemical g. a measure of the tendency of an ion to move passively from one point to another, taking into consideration the differences in its concentration and in the electrical potentials between the two points; commonly expressed as the additional voltage needed to achieve equilibrium. g. encoding SYN: phase encoding. field g. SYN: magnetic field g.. magnetic field g. in magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow calculation of their spatial position. SYN: field g.. mitral g. the diastolic pressure difference between the left atrium and left ventricle. systolic g. the difference in pressure during systole between two communicating cardiovascular chambers, e.g., between the left ventricle and aorta in aortic stenosis. ventricular g. the algebraic sum of ( i.e., the net electrical difference between) the area enclosed within the QRS complex and that within the T wave in the electrocardiogram.

graduate (grad′u-at)
A vessel, usually of glass and suitably marked, used for measuring the volume of liquids; g. cylinder. [Mediev. L. graduatus, fr. L. gradus, step]

graduated (grad′u-at′ed)
1. Marked by lines or in other ways to denote capacity, degrees, percentages, etc. 2. Divided or arranged in levels, grades, or successive steps.

Graefe
Albrecht von, German ophthalmologist, 1828–1870. See G. forceps, G. knife, G. operation, G. sign, pseudo-G. phenomenon, G. sign, von G. sign.

Graefenberg
Ernst, German gynecologist in America, 1881–1957. See G. ring.

Graffi
Arnold, German pathologist, *1910. See G. virus.

graft (graft)
1. Any tissue or organ for transplantation. 2. To transplant such structures. SEE ALSO: flap, implant, transplant. [A.S. graef] allogeneic g. SYN: allograft. animal g. SYN: zoograft. autogeneic g. SYN: autograft. autologous g. SYN: autograft. autoplastic g. SYN: autograft. bone g. bone transplanted from a donor site to a recipient site, without anastomosis of nutrient vessels; bone can be transplanted within the same individual ( i.e., autogeneic g.) or between different individuals ( i.e., allogeneic g.). SEE ALSO: osteoplasty. chorioallantoic g. transplanting of living material to the chorioallantoic membrane of the embryonic chick. composite g. a g. composed of several tissues, such as skin and cartilage or a full-thickness segment of the ear. corneal g. SYN: keratoplasty. Davis g. “pinch grafts,” i.e., small pieces (2–3 mm) of full-thickness skin grafts. delayed g. delaying application of a skin g. for several days until recipient bed is clean or no longer bleeding. dermal g. a g. of dermis, made from skin by cutting away the epidermis. dermal-fat g. a dermal g. with attached subcutaneous fat. dowel g. in orthopedic surgery, a specific type of bone g. characterized by a circular shape usually obtained with special instruments used as a structural bone g. to obtain fusion between two adjacent vertebrae. SYN: dowel (4) . fascia g. a g. of fibrous tissue, usually the fascia lata. fascicular g. a nerve g. in which each bundle of fibers is approximated and sutured separately. fat g. a free g. of fat. free g. a g. transplanted without its normal attachment (a pedicle) from one site to another. full-thickness g. a g. of the full thickness of mucosa and submucosa or of skin and subcutaneous tissue. funicular g. a nerve g. in which each funiculus (composed of two or more fasciculi) is approximated and sutured separately. H g. SYN: H shunt. heterologous g. SYN: xenograft. heteroplastic g. SYN: xenograft. heterotopic g. transplantation of a tissue or organ into a position it normally does not occupy. homologous g. SYN: allograft. homoplastic g. SYN: allograft. inlay g. a skin g. wrapped (raw side out) around a firm supporting material and inserted into a prepared surgical pocket. SYN: epithelial inlay. isogeneic g. SYN: syngraft. isologous g. SYN: syngraft. isoplastic g. SYN: syngraft. Krause g. a full-thickness skin g.. SYN: Krause-Wolfe g.. Krause-Wolfe g. SYN: Krause g.. mesh g. split-thickness g. incised with multiple staggered vertical cuts to allow expansion; used to cover problematic wounds or when donor skin is lacking. mucosal g. a g. of mucous membrane, usually the full thickness of the lining of the cheek or lower lip. nerve g. a nerve, or part of a nerve, used as a g.. Ollier g. a thin split-thickness g.. SYN: Ollier-Thiersch g.. Ollier-Thiersch g. SYN: Ollier g.. onlay g. a bone g. applied on the outside of the recipient bone(s). orthotopic g. transplantation of a tissue or organ into its normal anatomic position. osteoperiosteal g. a g. of bone with its attached periosteum. partial-thickness g. SYN: split-thickness g.. pedicle g. pedicle flap. periosteal g. a g. of periosteum. pinch g. old technique in which small bits of skin, of partial or full thickness, removed from a healthy area and seeded onto an open wound. SYN: Reverdin g.. porcine g. a split-thickness g. from a pig, applied to a raw area on a human as a temporary dressing. primary skin g. a skin g. transferred immediately after the creation of a raw area. punch grafts small full-thickness grafts of the scalp, removed with a circular punch and transplanted to a bald area to grow hair. Reverdin g. SYN: pinch g.. skin g. a piece of skin transplanted from one part of the body to another to cover a denuded area. sleeve g. a g. for repairing a severed nerve by connecting central and peripheral ends with a sleevelike structure, commonly, a segment of vein. split-skin g. SYN: split-thickness g.. split-thickness g. a g. of the upper portions of the skin, i.e., the epidermis and part of the dermis, or of the mucosa and submucosa. SYN: partial-thickness g., split-skin g.. Stent g. an inlay skin g., or a skin g. held in place by sutures tied over a conforming/immobilizing dressing. syngeneic g. SYN: syngraft. tendon g. a g. of tendon, as in tendon transplantation. Thiersch g. old term for split-thickness g., See Ollier-Thiersch g.. Wolfe g. a full-thickness skin g. without subcutaneous fat. SYN: Wolfe-Krause g.. Wolfe-Krause g. SYN: Wolfe g.. xenogeneic g. SYN: xenograft. zooplastic g. SYN: zoograft.

grafting
The process of applying a graft.

Graham
Evarts Ambrose, U.S. surgeon, 1883–1957. Reported with W. H. Cole the first successful cholecystography in 1924; In 1933, with J. J. Singer, reported first successful removal of a lung for cancer in one stage. See G.-Cole test.

Graham
Thomas, English chemist, 1805–1869. See G. law.

Grahamella (gra-am-el′a)
A former genus of aerobic, nonmotile bacteria that are now reclassified as members of the genus Bartonella. [G. S. Graham-Smith]

Graham Steell
See Steell.

grain (gran)
1. Cereal plants, such as corn, wheat, or rye, or a seed of one of them. 2. A minute, hard particle of any substance, as of sand. 3. (gr) A unit of weight, 160 dram (apoth. or troy), 1437.5 avoirdupois ounce, 1480 troy ounce, 15760 troy pound, 17000 avoirdupois pound; the equivalent of 0.064799 g.. 4. A macroscopically visible cluster of organisms living in tissue of patients with actinomycosis or mycetoma. [L. granum]

grains (granz)
Parakeratotic nuclei within the horny layer of the epidermis, found in keratosis follicularis.

Gram
Hans C.J., Danish bacteriologist, 1853–1938. See G. iodine, G. stain, G.-chromotrope stain, Weigert-G. stain.

gram (g, gm)
A unit of weight in the metric or centesimal system, the equivalent of 15.432358 gr or 0.03527 avoirdupois ounce.

-gram
A recording, usually by an instrument. Cf.:-graph. [G. gramma, character, mark]

gram-centimeter
The energy exerted, or work done, when a mass of 1 g is raised a height of 1 cm; equal to 9.807 × 10−5 J or newton-meters.

gramicidin (gram-i-si′din)
One of a group of polypeptide antibiotics produced by Bacillus brevis that are primarily bacteriostatic in action against Gram-positive cocci and bacilli. Commercial preparations contain several gramicidins known as g. A, B, C, and D; g. S (for Soviet) is cyclic, the others are linear.

gram-ion
The weight in grams of an ion that is equal to the sum of the atomic weights of the atoms making up the ion.

gram-meter
A unit of energy equal to 100 gram-centimeters.

gram-molecule
See under molecule.

Gram-negative
Refers to the inability of a bacterium to resist decolorization with alcohol after being treated with Gram crystal violet. However, following decolorization, these bacteria can be readily counterstained with safranin, imparting a pink or red color to the bacterium when viewed by light microscopy. This reaction is usually an indication that the outer structure of the bacterium consists of a cytoplasmic (inner) membrane surrounded by a relatively thin peptidoglycan layer, which in turn, is surrounded by an outer membrane. See Gram stain.

Gram-positive
Refers to the ability of a bacterium to resist decolorization with alcohol after being treated with Gram crystal violet stain, imparting a violet color to the bacterium when viewed by light microscopy. This reaction is usually an indication that the outer structure of the bacterium consists of a cytoplasmic membrane surrounded by a thick, rigid bacterial cell wall composed of peptidoglycan. See Gram stain.

grana (gra′na)
Bodies within the chloroplasts of plant cells that contain layers composed of chlorophyll and phospholipids. [pl. of L. granum, grain]

granatum (gra-na′tum)
SYN: pomegranate. [L. granatus, having many seeds]

grandiose (gran′de-os)
Pertaining to feelings of great importance, expansiveness, or delusions of grandeur. [It. grandioso, fr. L. grandis, large]

Granger
Amedee, U.S. radiologist, 1879–1939. See G. line.

Granit
Ragnar A., Finnish-Swedish neurophysiologist and Nobel laureate, 1900–1991 See G. loop.

granular (gran′u-lar)
1. Composed of or resembling granules or granulations. 2. Particles with strong affinity for nuclear stains, seen in many bacterial species.

granulatio, pl .granulationes (gran-u-la′she-o, -she-o′nez)
SYN: granulation. [L.] granulationes arachnoideae [TA] SYN: arachnoid granulations, under granulation. SEE ALSO: arachnoid villi, under villus.

granulation (gran′u-la′shun)
1. Formation into grains or granules; the state of being granular. 2. A granular mass in or on the surface of any organ or membrane; or one of the individual granules forming the mass. 3. The formation of minute, rounded, fleshy connective tissue projections on the surface of a wound, ulcer, or inflamed tissue surface in the process of healing; one of the fleshy granules composing this surface. SEE ALSO: g. tissue. 4. In pharmacy, the formation of crystals by constant agitation of a supersaturated solution of a salt; product used in the manufacture of tablets for oral use. SYN: granulatio. [L. granulatio] arachnoid granulations [TA] tufted prolongations of pia-arachnoid, composed of numerous arachnoid villi that penetrate dural venous sinuses and effect transfer of cerebrospinal fluid to the venous system. At advanced age these are more numerous and tend to calcify. SYN: arachnoidal granulations [TA] , granulationes arachnoideae [TA] , pacchionian bodies, pacchionian corpuscles, pacchionian glands, pacchionian granulations. arachnoidal granulations [TA] SYN: arachnoid granulations. pacchionian granulations SYN: arachnoid granulations.

granulationes (gran-u-la-she-o′nez)
Plural of granulatio.

granule (gran′ul)
1. A grainlike particle; a granulation; a minute discrete mass. 2. A very small pill, usually gelatin or sugar coated, containing a drug to be given in a small dose. 3. A colony of the bacterium or fungus causing a disease or simply colonizing the tissues of the patient. In immunocompromised patients the differentiation is difficult. 4. A small particle that can be seen by electron microscopy; contains stored material. [L. granulum, dim. of granum, grain] α granules large, rodlike, or filamentous granules found in several types of cells, especially platelets where they are the most numerous type of g.; contain secretory proteins, including fibrinogen, fibronectin, fibrospondin, von Willebrand factor (collectively known as adhesive proteins) and other proteins (platelet factor 4, platelet-derived growth factor, coagulation factor V, etc.). acidophil g. a g. that stains with an acid dye such as eosin. SYN: oxyphil g.. acrosomal g. the single glycoprotein rich g. within an acrosomal vesicle, which results from the coalescence of proacrosomal granules. alpha g. a g. of an alpha cell that was named as the first of several kinds or because it was acidophilic. Altmann g. 1. SYN: fuchsinophil g.. 2. SYN: mitochondrion. amphophil g. a g. that stains with both acid and basic dyes. argentaffin granules granules that reduce silver ions from an ammoniac silver nitrate staining solution. azurophil g. a g. that stains a reddish purple color with an azure dye; such granules are seen in dry smears of certain mature and developing blood cells, and are membrane-bound primary lysosomes containing enzymes. SYN: kappa g.. basal g. SYN: basal body. basophil g. a g. that stains readily with a basic dye. Bensley specific granules granules in the cells of the islands of Langerhans in the pancreas. beta g. a g. of a beta cell. Birbeck g. SYN: Langerhans g.. Bollinger granules 1. relatively small, but frequently microscopically visible, pale yellow or yellow-white granules observed in the granulomatous lesion, or the exudate, in botryomycosis; the granules consist of irregular aggregates or colonizations of Gram-positive cocci, usually staphylococci; 2. term sometimes incorrectly used synonymously with Bollinger bodies. chromatic g. SYN: chromophil g. (2) . chromophil g. 1. any readily stainable g.; 2. a g. of chromophil (Nissl) substance. SYN: chromatic g.. chromophobe granules granules that do not stain or stain poorly with the ordinary dyes; such granules are present in some cells in the anterior lobe of the pituitary. cone g. nucleus of a retinal cell connecting with one of the cones. Crooke granules lumpy masses of basophilic material in the basophil cells of the anterior lobe of the pituitary, associated with Cushing disease, or following the administration of ACTH. delta g. a g. of a delta cell. elementary g. a particle of blood dust, or hemoconia. eosinophil g. a g. that stains with eosin. Fordyce granules SYN: Fordyce spots, under spot. fuchsinophil g. a g. that has an affinity for fuchsin. SYN: Altmann g. (1) . glycogen g. glycogen occurring in cells as beta granules which average about 300 Å in diameter, or as alpha granules which are aggregates measuring 900 Å of smaller particles. iodophil g. a g. that stains brown with iodine; found in many of the polymorphonuclear leukocytes in pneumonia, erysipelas, scarlet fever, and various other acute diseases. juxtaglomerular granules osmophilic secretory granules present in the juxtaglomerular cells, thought to contain renin. kappa g. SYN: azurophil g.. keratohyalin granules irregularly shaped basophilic granules in the cells of the stratum granulosum of the epidermis. lamellar g. SYN: keratinosome. Langerhans g. a small tennis racket-shaped membrane-bound g. with characteristic cross-striated internal ultrastructure; first reported in Langerhans cells of the epidermis. SYN: Birbeck g.. Langley granules granules in serous secreting cells. membrane-coating g. SYN: keratinosome. metachromatic granules 1. granules that stain a color different from that of the dye used; SEE ALSO: metachromasia. 2. term sometimes used as a synonym for volutin. mucinogen granules granules that produce mucin, as in cells of the salivary glands and in the gastric and intestinal mucosae. Neusser granules tiny basophilic granules sometimes observed in an indistinct zone about the nucleus of a leukocyte. neutrophil g. a g. stainable with the neutral component of stains, e.g., the Romanovsky-type blood stains. Nissl granules SYN: Nissl substance. oxyphil g. SYN: acidophil g.. Palade g. SYN: ribosome. proacrosomal granules small carbohydrate-rich granules appearing in vesicles of the Golgi apparatus of spermatids; they coalesce into a single acrosomal g. contained within an acrosomal vesicle. prosecretion granules granules in the cytoplasm of a cell indicative of a preliminary step in the formation of a secretory product. rod g. the nucleus of a retinal cell connecting with one of the rods. Schüffner granules SYN: Schüffner dots, under dot. secretory g. a membrane-bound particle, usually protein, formed in the granular endoplasmic reticulum and the Golgi complex. seminal g. one of the minute granular bodies present in the semen. specific granules the distinctive granules of basophilic, eosinophilic, and neutrophilic leukocytes, as opposed to their nonspecific azurophilic granules. volutin granules SYN: volutin. Zimmermann g. obsolete term for platelet. zymogen g. secretory g. in pancreatic acinar cells.

granulo-
Granular, granules. [L. granulum, a small grain.]

granuloblast (gran′u-lo-blast)
Rarely used term for an immature hematopoietic cell capable of giving rise to granulocytes. [granulo- + G. blastos, germ]

granulocyte (gran′u-lo-sit)
A mature granular leukocyte, including neutrophilic, acidophilic, and basophilic types of polymorphonuclear leukocytes, i.e., respectively, neutrophils, eosinophils, and basophils. [granulo- + G. kytos, cell] immature g. an immature neutrophil; it may be neutrophilic, acidophilic, or basophilic in character.

granulocytopenia (gran′u-lo-si-to-pe′ne-a)
Less than the normal number of granular leukocytes in the blood. SYN: granulopenia, hypogranulocytosis. [granulocyte + G. penia, poverty]

granulocytopoiesis (gran′u-lo-si′to-poy-e′sis)
SYN: granulopoiesis.

granulocytopoietic (gran′u-lo-si′to-poy-et′ik)
SYN: granulopoietic. [granulocyte + G. poieo, to make]

granulocytosis (gran′u-lo-si-to′sis)
A condition characterized by more than the normal number of granulocytes in the circulating blood or in the tissues.




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