Medical Dictionary

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unmyelinated (un-mi′e-li-na-ted)
Denoting nerve fibers (axons) lacking a myelin sheath. SYN: amyelinated, amyelinic, nonmedullated, nonmyelinated, unmedullated.

Unna
Paul G., German dermatologist and staining expert, 1850–1929. See U. disease, U. nevus, U. stain, U.-Pappenheim stain, U.-Taenzer stain, U.-Thost syndrome.

unofficial (un-o-fish′al)
Denoting a drug that is not listed in the United States Pharmacopeia or the National Formulary.

unphysiologic (un-fis′e-o-loj′ik)
Pertaining to conditions in the organism which are abnormal; can be used to refer to subjecting the body to abnormal amounts of substances normally present.

unsanitary (un-san′i-tar-e)
SYN: insanitary.

unsaturated (un-sach′ur-at-ed)
1. Not saturated; denoting a solution in which the solvent is capable of dissolving more of the solute. 2. Denoting a chemical compound in which all the affinities are not satisfied, so that still other atoms or radicals may be added to it. 3. In organic chemistry, denoting compounds containing double and/or triple bonds or a ring structure.

unsex (un′seks)
To castrate; to deprive of the gonads.

unstriated (un-stri′at-ed)
Without striations; not striped; denoting the structure of the smooth or involuntary muscles.

unthrifty (un-thrif′te)
In animals, denoting a failure to grow or develop normally as a result of disease.

Unverricht
Heinrich, German physician, 1853–1912. See U. disease.

UPJ
Abbreviation for ureteropelvic junction.

up-regulation
Opposite of down-regulation.

upsiloid (up′si-loyd)
SYN: hypsiloid.

upsilon (up′si-lon)
The 20th letter of the Greek alphabet, Ψ.

upstream (up′strem)
Refers to nucleic acid base sequences proceeding the opposite direction from expression.

uptake (up′tak)
The absorption by a tissue of some substance, food material, mineral, etc., and its permanent or temporary retention.

Ura
Abbreviation for uracil.

urachal (ur′a-kal)
Relating to the urachus.

urachus (ur′a-kus)
That portion of the reduced allantoic stalk between the apex of the bladder and the umbilicus; postnatally, the u. is normally merely a fibrous cord, the median umbilical ligament, but occasionally the old allantoic lumen may persist as a vesicoumbilical fistula. [G. ourachos, the urinary canal of a fetus]

uracil (Ura, U) (ur′a-sil)
2,4-Dioxopyrimidine;a pyrimidine (base) present in ribonucleic acid. u. dehydrogenase an oxidoreductase catalyzing oxidation of u. to barbituric acid; also oxidizes thymine. SYN: u. oxidase. u. mustard an alkylating antineoplastic agent. SYN: uramustine. u. oxidase SYN: u. dehydrogenase. u. phosphoribosyltransferase phosphoribosyltransferase.

uracil-6-carboxylic acid
SYN: orotic acid.

Uragoga (ur′a-go-ga)
A genus of tropical plants (family Rubiaceae). U. ipecacuanha (Cephaelis ipecacuanha) is the source of Rio or Brazilian ipecac; U. acuminata (C. acuminata) is the source of Cartagena, Nicaragua, or Panama ipecac. SYN: Cephaelis.

uramustine (ur-a-mus′ten)
SYN: uracil mustard.

uranin (u′ra-nin)
SYN: fluorescein sodium.

uraninite (u-ran′i-nit)
SYN: pitchblende.

uranisco-
See urano-.

uraniscochasm (u-ra-nis′ko-kazm)
SYN: uranoschisis. [uranisco- + G. chasma, cleft]

uranisconitis (u′ra-nis-ko-ni′tis)
SYN: palatitis.

uraniscoplasty (u′ra-nis′ko-plas-te)
SYN: palatoplasty. [uranisco- + G. plasso, to form]

uraniscorrhaphy (u′ra-nis-kor′a-fe)
SYN: palatorrhaphy. [uranisco- + G. rhaphe, suture]

uraniscus (u′ra-nis′kus)
SYN: palate. [G. ouraniskos, roof of the mouth, dim. of ouranos, sky]

uranium (U) (u-ra′ne-um)
A radioactive metallic element, atomic no. 92, atomic wt. 238.0289, occurring mainly in pitchblende and notable for its two isotopes: 238U and 235U (99.2745% and 0.720%, respectively, the rest being made up by 234U), 235U being the first substance ever shown capable of supporting a self-sustaining chain reaction. [G. myth. character, Uranus]

urano-, uranisco-
The hard palate. [G. ouranos, sky vault, ouraniskos, roof of mouth (palate)]

uranoplasty (u′ra-no-plas-te)
SYN: palatoplasty.

uranorrhaphy (u′ra-nor′a-fe)
SYN: palatorrhaphy. [urano- + G. rhaphe, suture]

uranoschisis (u′ra-nos′ki-sis)
Cleft of the hard palate. SYN: uraniscochasm. [urano- + G. schisis, fissure]

uranostaphyloplasty (u′ra-no-staf′i-lo-plas-te)
Repair of a cleft of both hard and soft palates. SYN: uranostaphylorrhaphy. [urano- + G. staphyle, uvula, + plasso, to form]

uranostaphylorrhaphy (u′ra-no-staf-i-lor′a-fe)
SYN: uranostaphyloplasty.

uranostaphyloschisis (u′ra-no-staf′i-los′ki-sis)
Cleft of the soft and hard palates. SYN: uranoveloschisis. [urano- + G. staphyle, uvula, + schisis, fissure]

uranoveloschisis (u′ra-no-ve-los′ki-sis)
SYN: uranostaphyloschisis.

uranyl (ur′a-nil)
The ion, UO22+, usually found in such salts as u. nitrate, UO2(NO3)2; u. acetate, UO2(CH3COO)2, is used in electron microscopy.

urapidil (oo-ra′pi-dil)
An antihypertensive agent which acts by influencing serotonin receptors.

uraroma (u′ra-ro′ma)
An obsolete term to describe a spicy, aromatic odor of the urine. [G. ouron, urine, + aroma, spice]

urarthritis (u-rar-thri′tis)
Gouty inflammation of a joint. [urate + arthritis]

urate (ur′at)
A salt of uric acid. u. oxidase a copper-containing, oxygen-requiring oxidoreductase that oxidizes uric acid; used in the clinical diagnosis of increased uric acid levels. SYN: uricase.

uratemia (u-ra-te′me-a)
The presence of urates, especially sodium urate, in the blood. [urate + G. haima, blood]

urateribonucleotide phosphorylase (ur′at-ri-bo-noo′kle-o-tid)
A ribosyltransferase that reacts urate d-ribonucleotide with orthophosphate to produce urate plus d-ribose 1-phosphate.

uratic (u-rat′ik)
Pertaining to a urate or to urates.

uratolysis (u-ra-tol′i-sis)
The decomposition or solution of urates. [urate + G. lysis, solution]

uratolytic (u′ra-to-lit′ik)
Causing the decomposition, or solution and removal of urates, from the tissues.

uratoma (u-ra-to′ma)
SYN: gouty tophus. [urate + G. -oma, tumor]

uratosis (u-ra-to′sis)
Any morbid condition due to the presence of urates in the blood or tissues.

uraturia (u-ra-too′re-a)
The passage of an increased amount of urates in the urine. [urate + G. ouron, urine]

Urbach
Erich, U.S. dermatologist, 1893–1946. See U.-Wiethe disease.

Urban
Jerome A., U.S. surgeon, *1914. See U. operation.

urceiform (ur-se′i-form)
Pitcher-shaped. SYN: urceolate. [L. urceus, pitcher, + forma, form]

urceolate (ur′se-o-lat)
SYN: urceiform. [L. urceolus, dim. of urceus, pitcher]

Urd
Abbreviation for uridine.

ur-defenses (oor′de-fens-ez)
A rarely used term for primitive defenses. [Ger. ur-, primitive, earliest, + defenses]

ure-, urea-, ureo-
Urea; urine. SEE ALSO: urin-, uro-. [G. ouron, urine]

urea (u-re′a)
The chief end product of nitrogen metabolism in mammals, formed in the liver by means of the Krebs-Henseleit cycle and excreted in normal adult human urine in the amount of about 32 g a day (about 67 of the nitrogen excreted from the body). It may be obtained artificially by heating a solution of ammonium cyanate. It occurs as colorless or white prismatic crystals, without odor but with a cooling saline taste, is soluble in water, and forms salts with acids; has been used as a diuretic in kidney function tests, and topically for various dermatitides. [G. ouron, urine] u. peroxide a white crystalline compound used in an aqueous solution as an oxidizing mouthwash. u. stibamine a u. derivative of stibanilic acid, used in the treatment of kala azar and certain other tropical diseases.

ureagenesis (u-re-a-jen′e-sis)
Formation of urea, usually referring to the metabolism of amino acids to urea. SYN: ureapoiesis. [urea + G. genesis, production]

ureal (u-re′al)
Relating to or containing urea. SYN: ureic.

Ureaplasma (u-re′a-plaz′ma)
A genus of microaerophilic to anaerobic, nonmotile bacteria (family Mycoplasmataceae) with no cell walls. Gram-negative, they are predominantly coccoidal to coccobacillary elements, approximately 0.3 μm in diameter, which frequently grow in short filaments; colonies are generally small, 20–30 μm in diameter, and may have no zones of surface growth. U. hydrolyze urea with production of ammonia, and are found in the human genitourinary tract, occasionally in the pharynx and rectum. In males, they are associated with nongonococcal urethritis and prostatitis; in females, with genitourinary tract infections and reproductive failure; in neonates, they may cause pneumonia or meningitis. The type species is U. urealyticum. SYN: T-mycoplasma. U. urealyticum a species that has been isolated from the respiratory tract and central nerve system of newborns. It causes infections of the genitourinary tract, particularly urethritis; thought to be sexually transmitted and transmitted from mother to infant. The laboratory diagnosis is simplified through the use of urea-containng agar, permitting detection of the tiny colonies.

ureapoiesis (u-re′a-poy-e′sis)
SYN: ureagenesis. [urea + G. poiesis, a making]

urease (ur′e-as)
An enzyme that catalyzes the hydrolysis of urea to carbon dioxide and ammonia; used as an antitumor enzyme; it is present in intestinal bacteria and accounts for most of the ammonia generated from urea in mammals.

uredema (u-re-de′ma)
Edema due to infiltration of urine into the subcutaneous tissues. [G. ouron, urine, + oidema, swelling]

ureic (u-re′ik)
SYN: ureal.

ureide (ur′e-id)
Any compound of urea in which one or more of its hydrogen atoms have been substituted by acid radicals.

3-ureidohydantoin (u-re′i-do-hi′dan-to-in)
SYN: allantoin.

3-ureidoisobutyric acid (u-re′i-do-i′so-bu-tir′ik)
An intermediate in thymine catabolism.

3-ureidopropionic acid (u-re′i-do-pro-pi-on′ik)
An intermediate in uracil catabolism.

ureidosuccinic acid (u-re′i-do-suk-sin′ik)
A precursor of the pyrimidines. SYN: N-carbamoylaspartic acid.

urelcosis (u-rel-ko′sis)
Obsolete term for ulceration of any part of the urinary tract. [G. ouron, urine, + helkosis, ulceration]

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