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Medical Dictionary


υ, upper case Υ
  • upsilon, 20th letter of the Greek alphabet
  • kinematic viscosity
  • internal energy
  • kilurane
  • unit
  • uracil
  • uranium
  • uridine in polymers
  • uracil
  • urinary concentration, followed by subscripts indicating location and chemical species
U wave
a positive wave following the T wave on an electrocardiogram

ubihydroquinone (u′bi-hi-dro-qui′non)

ubiquinol (QH2, H2Q) (u′bi-kwi′nol, u-bik′wi-nol)
The reduction product of a ubiquinone. SYN: ubihydroquinone.

ubiquinone (u′bi-kwi′non, u-bik′wi-non)
A 2,3-dimethoxy-5-methyl-1,4-benzoquinone with a multiprenyl side chain; a mobile component of electron transport. SEE ALSO: coenzyme Q.

ubiquinone-6 (-Q6)
Ubiquinone-30; coenzyme Q6;2,3-dimethoxy-5-methyl-6-hexaprenyl-1,4 benzoquinone.

ubiquinone-10 (-Q10)
Ubiquinone-50; coenzyme Q10;2,3-dimethoxy-5-methyl-6-decaprenyl-1,4-benzoquinone.

ubiquitin (oo-bik′kwi-tin)
A small (76 amino acyl residues) protein found in all cells of higher organisms and one whose structure has changed minimally during evolutionary history; involved in at least two processes; histone modification and intracellular protein breakdown.

Abbreviation for uridine 5′-diphosphate.

UDP-N-acetylglucosamine:lysosomal enzyme N-acetylglucosaminyl-1-phosphotransferase
An enzyme that participates in the posttranslational modification of a number of lysosomal proteins; a deficiency or defect in this enzyme results in two forms of mucolipidoses, I-cell disease, and pseudo-Hurler polydystrophy.

Abbreviation for uridine diphosphoglucose.

Abbreviation for uridine diphosphogalactose.

Uridine diphosphogalactose.

UDPgalactose 4-epimerase
SYN: UDPglucose 4-epimerase.

Abbreviation for uridine diphosphoglucose.

Abbreviation for uridine diphosphoglucuronic acid.

SYN: uridine diphosphoglucose.

UDPglucose 4-epimerase
An enzyme that catalyzes the reversible Walden inversion of UDPglucose to UDPgalactose; a deficiency of this enzyme is associated with one type of galactosemia. SYN: UDPgalactose 4-epimerase, uridine diphosphoglucose 4-epimerase.

UDPglucose-hexose-1-phosphate uridylyltransferase
An enzyme that catalyzes the reversible reaction of α-d-glucose 1-phosphate UDPgalactose to produce UDPglucose and α-d-galactose 1-phosphate. SEE ALSO: UDPglucose 4-epimerase. SYN: hexose-1-phosphate uridylyltransferase, phosphogalactoisomerase.

UDPglucuronate-bilirubinglucuronoside glucuronosyltransferase
SYN: UDPglucuronate-bilirubin glucuronosyltransferase.

UDPglucuronate-bilirubin glucuronosyltransferase
Hepatic transferases that catalyze the transfer of the glucuronic moiety of UDP-glucuronic acid to bilirubin or bilirubin glucuronide, thus producing UDP and either bilirubin-glucoronoside or bilirubin bisglucuronoside, respectively; these bile conjugates are then secreted into the bile. SYN: UDPglucuronate-bilirubinglucuronoside glucuronosyltransferase.

A sugar derivative in which a pyrophosphate group links the 5′ position of uridine and the 1-position of d-xylose; formed by the decarboxylation of UDPglucuronic acid; required for the synthesis of proteoglycans; inhibits UDPglucose dehydrogenase.

E., Swiss pathologist, *1899. See Meyenburg-Altherr-U. syndrome.

Abbreviation for unesterified free fatty acid.

Jules A.C., German physician, 1837–1894. See U. reagent.

Abbreviation for upper gastrointestinal series.

Henry S.M., U.S. internist, *1921. See U. anomaly.

Wilhelm, German ophthalmologist, 1853–1927. See U. sign, U. symptom.

Abbreviation for usual interstitial pneumonia of Liebow.

ukambin (oo-kam′bin)
An African arrow poison from plants of the family Apocynaceae; a heart poison resembling digitalis or strophanthus in its action.

ulcer (ul′ser)
A lesion through the skin or a mucous membrane resulting from loss of tissue, usually with inflammation. See erosion. SYN: ulcus. [L. ulcus (u.-), a sore, u.] acute decubitus u. a severe form of bedsore, of neurotrophic origin, occurring in hemiplegia or paraplegia. anastomotic u. an u. of jejunum, after gastroenterostomy. Buruli u. an u. of the skin, with widespread necrosis of subcutaneous fat, due to infection with Mycobacterium ulcerans; occurs in Uganda in persons living on the Nile river banks. [Buruli, district in Uganda] chrome u. an u. of the extremities or nasal septum produced by exposure to chromium compounds. SYN: tanner's u.. chronic u. a longstanding u. with fibrous scar tissue in the floor of the u.. stress u. an u. of the duodenum in a patient with extensive superficial burns, intracranial lesions, or severe bodily injury. SYN: Curling u.. decubitus u. a chronic u. that appears in pressure areas of skin overlying a bony prominence in debilitated patients confined to bed or otherwise immobilized, due to a circulatory defect. SYN: bedsore, decubital gangrene, hospital gangrene, pressure gangrene, pressure sore, pressure u.. dendritic corneal u. keratitis caused by herpes simplex virus. dental u. an u. on the oral mucuous membrane caused by biting or by rubbing against the edge of a broken tooth. diphtheritic u. an u. covered with a gray adherent membrane, caused by Corynebacterium diphtheriae. distention u. an u. of the intestine in the dilated part above a stricture. elusive u. SYN: Hunner u.. fascicular u. a localized vascularization of the cornea to the site of a corneal u.. Fenwick-Hunner u. SYN: Hunner u.. Gaboon u. a form of tropical u. affecting the residents of this region; it resembles a syphilitic u., especially in the appearance of its scar. [Gaboon, a region in Africa] gastric u. an u. of the stomach. gravitational u. a chronic u. of the leg with impaired healing because of the dependent position of the extremity and the incompetence of the valves in the deep venous system of the leg and thigh; the venous return stagnates and creates hypoxemia. SEE ALSO: varicose u.. gummatous u. lesion of the skin occurring in late syphilis. hard u. SYN: chancre. healed u. an u. covered by epithelial regeneration, beneath which there may be scarring and absence of glands or appendages. herpetic u. u. caused by herpes simplex virus. Hunner u. a focal and often multiple lesion involving all layers of the bladder wall in chronic interstitial cystitis; the surface epithelium is destroyed by inflammation and the initially pale lesion cracks and bleeds with distention of the bladder. SYN: elusive u., Fenwick-Hunner u.. hypopyon u. 1. an advancing central suppurative u. of the cornea; SEE ALSO: hypopyon. 2. a corneal u. with pus in the anterior chamber; indolent u. a chronic u., with hard elevated edges and few or no granulations, and showing no tendency to heal. inflamed u. an u. with a purulent discharge and inflamed borders. Mann-Williamson u. Mann-Williamson operation. marginal ring u. of cornea a slowly advancing intermittent u. involving the circumference of the corneal margin. Marjolin u. well-differentiated but aggressive squamous cell carcinoma occurring in cicatricial tissue at the epidermal edge of a sinus draining underlying osteomyelitis. Meleney u. undermining u. of the skin and subcutaneous tissues caused by a synergistic infection by microaerophilic nonhemolytic streptococci and aerobic hemolytic staphylococci. SYN: Meleney gangrene, progressive bacterial synergistic gangrene. Mooren u. chronic inflammation of the peripheral cornea that slowly progresses centrally with corneal thinning and sometimes perforation. Oriental u. the lesion occurring in cutaneous leishmaniasis. penetrating u. an u. extending into deeper tissues of an organ. peptic u. an u. of the alimentary mucosa, usually in the stomach or duodenum, exposed to acid gastric secretion. perforated u. an u. extending through the wall of an organ. perforating u. of foot a round, deep, trophic u. of the sole of the foot, following disease or injury, in any part of its course from the center to the periphery of the nerve supplying the part. phagedenic u. a rapidly spreading u. attended by the formation of extensive sloughing. SYN: sloughing u.. phlegmonous u. a u. accompanied by inflammation of the neighboring tissues. pressure u. SYN: decubitus u.. recurrent aphthous ulcers SYN: aphtha (2) . ring u. of cornea inflammation of the greater part or the whole of the corneal periphery. rodent u. historic term for a slowly enlarging ulcerated basal cell carcinoma, usually on the face. Saemisch u. a form of serpiginous keratitis, frequently accompanied by hypopyon. serpent u. of cornea SYN: serpiginous keratitis. serpiginous u. an u. extending on one side while healing at the opposite edge, forming an undulating margin. serpiginous corneal u. serpentine ulceration of the cornea, due to infection, most often with Streptococcus pneumoniae. simple u. a local, not constitutional, u. not accompanied by marked pain or inflammation. sloughing u. SYN: phagedenic u.. soft u. SYN: chancroid. stasis u. SYN: varicose u.. stercoral u. an u. of the colon due to pressure and irritation of retained fecal masses. stomal u. an intestinal u. occurring after gastrojejunostomy in the jejunal mucosa near the opening (stoma) between the stomach and the jejunum. Curling u. SYN: stress u.. Sutton u. a solitary, deep, painful u. of the buccal or genital mucous membrane. syphilitic u. 1. SYN: chancre. 2. any ulceration caused by a syphilitic infection. Syriac u., Syrian u. old names for diphtheria. tanner's u. SYN: chrome u.. trophic u. u. resulting from cutaneous sensory denervation. SEE ALSO: perforating u. of foot. SYN: trophic gangrene. tropical u. 1. the lesion occurring in cutaneous leishmaniasis; SYN: tropical sore. SEE ALSO: cutaneous leishmaniasis. 2. tropical phagedenic ulceration caused by a variety of microorganisms, including mycobacteria; common in northern Nigeria. undermining u. a chronic cutaneous u. with overhanging margins; due to hemolytic streptococci, tubercle bacilli, or other bacteria. varicose u. the loss of skin surface in the drainage area of a varicose vein, usually in the leg, resulting from stasis and infection. SEE ALSO: gravitational u.. SYN: stasis u., venous u.. venereal u. SYN: chancroid. venous u. SYN: varicose u.. Zambesi u. an u., usually single, about 3 cm in diameter, on the foot or leg, occurring in laborers in the Zambesi Delta; it has a sloughing surface, but does not spread and produces no constitutional symptoms or glandular enlargement; it is associated with the presence of a spirillum and a large fusiform bacillus; one attack seems to confer a partial immunity.

ulcerate (ul′ser-at)
To form an ulcer.

ulcerated (ul′ser-at-ed)
Having undergone ulceration.

ulceration (ul-ser-a′shun)
1. The formation of an ulcer. 2. An ulcer or aggregation of ulcers. tracheal u. erosion of the tracheal mucous membrane with, in some cases, exposure of the cartilaginous rings, at the site at which a cuffed tracheostomy tube has been present for some time.

ulcerative (ul′ser-a-tiv)
Relating to, causing, or marked by an ulcer or ulcers.

ulcerogenic (ul′ser-o-jen′ik)

ulceroglandular (ul′ser-o-gland′u-lar)
Denoting a local ulceration at a site of infection followed by regional or generalized lymphadenopathy.

ulceromembranous (ul′ser-o-mem′bra-nus)
Relating to or characterized by ulceration and the formation of a false membrane.

ulcus, pl .ulcera (ul′kus, ul′ser-a)
SYN: ulcer. [L.]

See ulo-.

ulegyria (u′le-ji′re-a)
A defect of the cerebral cortex characterized by narrow and distorted gyri; may be congenital or the result of scars. [G. oule, scar, + gyros, ring]

ulerythema (oo′ler-i-the′ma)
Scarring with erythema. [G. oule, scar, + erythema, redness of the skin] u. ophryogenes folliculitis of the eyebrows resulting in scarring and alopecia.

ulex europaeus (oo-leks oor′o-pa-us)
A lectin that reacts specifically with α-l-fucose, used as a marker for endothelial cells in paraffin sections.

Emerich, Hungarian surgeon, 1861–1937. See U. line, U. syndrome.

Otto, German physician, 1894–1957. See Morquio-U. disease.

ulna, gen. and pl. ulnae (ul′na, ul′ne) [TA]
The medial and larger of the two bones of the forearm. SYN: cubitus (2) [TA] . [L. elbow, arm, fr. G. olene]

ulnad (ul′nad)
In a direction toward the ulna. [ulna + L. ad, to]

ulnar (ul′nar) [TA]
Relating to the ulna, or to any of the structures ( e.g., artery, nerve) named from it; relating to the u. or medial aspect of the upper limb. SYN: ulnaris [TA] .

ulnaris (ul-na′ris) [TA]
SYN: ulnar. [Mod. L.]

ulnen (ul′nen)
Relating to the ulna independent of other structures. [ulna + G. en, in]

ulnocarpal (ul′no-kar′pal)
Relating to the ulna and the carpus, or to the ulnar side of the wrist.

ulnoradial (ul′no-ra′de-al)
Relating to both ulna and radius; denoting the two articulations, ligaments, etc., between them.

ulo-, ule-
1. Scar, scarring. [G. oule] 2. The gums. SEE ALSO: gingivo-. [G. oulon] 3. Curly. [G. oulo-, ouli-, woolly.]

uloid (u′loyd)
1. Resembling a scar. 2. A scarlike lesion due to a degenerative process in deeper layers of skin. [G. oule, scar + eidos, resemblance]

ulotrichous (u-lot′ri-kus)
Having curly hair. Cf.:leiotrichous. [G. oulotrichos, curly haired, fr. oulos, wooly, + thrix (trich-), hair]

ultimobranchial (ul′ti-mo-brang′ke-al)
In embryology, relating to the caudal-most pharyngeal pouch. [L. ultimus, last, + G. branchia, gills]

ultimum moriens (ul′ti-mum mor′i-enz)
The right atrium of the heart, said to contract after the rest of the heart is still. [L. the last thing dying]

Excess, exaggeration, beyond. [L. beyond]

ultrabrachycephalic (ul-tra-brak-e-se-fal′ik)
Denoting an extremely short skull, one with an index of at least 90.

ultracentrifugation (ul-tra-sen′tri-fu-ga-shun)
The process of subjecting to an ultracentrifuge.

ultracentrifuge (ul′tra-sen′tri-fuj)
A high-speed centrifuge (up to 100,000 rpm) by means of which large molecules, e.g., of protein or nucleic acids, are caused to sediment at practicable rates; used for determinations of molecular weights, separation of large molecules, criteria of homogeneity of large molecules, conformational studies, etc.

ultracytostome (ul-tra-si′to-stom)
Former name for micropore. [ultra- + G. kytos, cell, + stoma, mouth]

ultradian (ul-tra′de-an)
Relating to biologic variations or rhythms occurring in cycles more frequent than every 24 hours. Cf.:circadian, infradian. [ultra- + L. dies, day]


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