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Medical Dictionary


lucent (loo′sent)
Bright; clear; translucent. [L. luceo, to shine]

lucid (loo′sid)
Clear, not obscured or confused, as in a l. moment or l. spoken expression. [L. lucidus, clear]

lucidification (loo-sid′i-fi-ka′shun)
SYN: clarification. [L. lucidus, clear, + facio, to make]

lucidity (loo-sid′i-te)
The quality or state of being lucid.

luciferases (loo-sif′er-as-ez)
Enzymes present in certain luminous organisms that act to bring about the oxidation of luciferins; energy produced in the process is liberated as bioluminescence; such enzymes can be used to detect very low concentrations of metabolites.

luciferins (loo-sif′er-inz)
Chemical substances present in certain luminous organisms that, when acted upon by luciferases, produce bioluminescence. [L. lux, light + fero. to bear]

lucifugal (loo-sif′u-gal)
Avoiding light. [L. lux, light, + fugio, to flee from]

Lucilia (loo-sil′e-a)
A genus of scavenging blowflies (family Calliphoridae), commonly called bluebottle or greenbottle flies, whose larvae feed on carrion or excrement; they occasionally cause wound infestation or myiasis. L. caesar a species whose larvae formerly were used in the treatment of septic wounds. SEE ALSO: Phormia regina. L. illustris a metallic blue-green blowfly widely distributed in North America; the eggs are deposited chiefly on animal carcasses. L. sericata SYN: Phaenicia sericata.

lucimycin (loo-si-mi′sin)
SYN: lucensomycin.

R., Mexican physician, 1819–1866. See L. leprosy, L. leprosy phenomenon.

lucipetal (loo-sip′i-tal)
Seeking light. [L. lux, light, + peto, to seek]

Balduin, U.S. pathologist, 1889–1954. See Lucké virus.

George A., German surgeon, 1829–1894. See L. test.

lückenschädel (luk-en-sha′dl)
Craniolacunia with meningocele or encephalocele. [Ger. Lücke, gap + Schädel, skull]

Daniel, German anatomist, 1625–1680. See L. angle.

Karl F.W., German anatomist and physiologist, 1816–1895. See depressor nerve of L., L. ganglion, L. labyrinth, L. nerve, L. stromuhr.

Kurt, German anatomist, *1922. See Klinger-L. acid-thionin stain for sex chromatin.

Wilhelm Friedrich von, German surgeon, 1790–1865. See L. angina.

J. See Rapoport-L. shunt.

German instrument maker, &dag;1883. See L. syringe, L.-Lok syringe.

lues (loo′ez)
A plague or pestilence; specifically, syphilis. [L. pestilence] l. venerea SYN: syphilis.

luetic (loo-et′ik)
SYN: syphilitic.

John H., U.S. histologist, *1927. See L. potassium permanganate fixative.

Rolf, Swedish endocrinologist, *1914. See L. disease.

Jean G.A., French physician, 1786–1851. See L. iodine solution.

L.J., 20th century U.S. pathologist. See L.-Collins classification.

Lukes-Collins classification
See under classification.

Abbreviation for left upper lobe (of lung).

luliberin (loo-lib′er-in)
A decapeptide hormone from the hypothalamus that stimulates the anterior pituitary to release both follicle-stimulating hormone and luteinizing hormone; gonadotropin-releasing hormone. SYN: luteinizing hormone-releasing hormone. [luteinizing hormone + L. libero, to free, + -in]

lumbago (lum-ba′go)
Pain in mid and lower back; a descriptive term not specifying cause. [L. fr. lumbus, loin] ischemic l. an ischemic form of backache characterized by a painful cramp of the muscles in the lumbar region incited by the exertion of walking or standing and promptly relieved by rest.

lumbar (lum′bar)
Relating to the loins, or the part of the back and sides between the ribs and the pelvis. [L. lumbus, a loin]

lumbarization (lum′bar-i-za′shun)
A congenital anomaly of the lumbosacral junction characterized by development of the first sacral vertebra as a lumbar vertebra, resulting in six lumbar vertebrae instead of five.

lumbi (lum′bi)
Plural of lumbus. [L.]

lumboabdominal (lum′bo-ab-dom′i-nal)
Relating to the sides and front of the abdomen.

lumbocostal (lum′bo-kos′tal)
1. Relating to the lumbar and the hypochondriac regions. 2. Relating to the lumbar vertebrae and the ribs; denoting a ligament connecting the first lumbar vertebra with the neck of the twelfth rib. [L. lumbus, loin, + costa, rib]

lumboiliac (lum-bo-il′e-ak)
SYN: lumboinguinal.

lumboinguinal (lum′bo-ing′gwi-nal)
Relating to the lumbar and the inguinal regions. SYN: lumboiliac. [L. lumbus, loin, + inguen (inguin-), groin]

lumbo-ovarian (lum-bo-o-va′re-an)
Relating to the ovary and the lumbar regions.

lumbosacral (lum′bo-sa′kral)
Relating to the lumbar vertebrae and the sacrum. SYN: sacrolumbar.

lumbrical (lum′bri-kal)
SYN: lumbricoid (1) . [L. lumbricus, earthworm]

See lumbricals (lumbrical muscles) of hand, under muscle, lumbricals (lumbrical muscles) of foot, under muscle.

lumbricidal (lum-bri-si′dal)
Destructive to lumbricoid (intestinal) worms.

lumbricide (lum′bri-sid)
An agent that kills lumbricoid (intestinal) worms. [L. lumbricus, worm, + caedo, to kill]

lumbricoid (lum′bri-koyd)
1. Denoting or resembling a roundworm, especially Ascaris lumbricoides. SYN: lumbrical, lumbricus (1) . SEE ALSO: scolecoid (2) , vermiform. 2. Obsolete common name for Ascaris lumbricoides. [L. lumbricus, earthworm, + G. eidos, resemblance]

lumbricosis (lum′bri-ko′sis)
Infection with round intestinal worms.

lumbricus (lum′bri-kus)
1. SYN: lumbricoid (1) . 2. Obsolete name for Ascaris lumbricoides. [L. earthworm]

lumbus, gen. and pl. lumbi (lum′bus, -bi)
SYN: loin. [L.]

lumen, pl .luminalumens (loo′men, -min-a, -menz)
1. The space in the interior of a tubular structure, such as an artery or the intestine. 2. (lm) The unit of luminous flux; the luminous flux emitted in a unit solid angle of 1 steradian by a uniform point source of light having a luminous intensity of 1 candela. 3. The volume enclosed within the membranes of a mitochondrion or of the endoplasmic reticulum. 4. The bore of a catheter or hollow needle. [L. light, window] false l. in a dissecting aneurysm, the abnormal channel within the wall of the involved artery. residual l. SYN: residual cleft. true l. in a dissecting aneurysm, the channel representing the actual intima-lined artery.

lumichrome (loo′mi-krom)
7,8-Dimethylalloxazine;riboflavin minus its ribityl side chain; produced by ultraviolet irradiation of riboflavin in acid solution.

lumiflavin (loo′mi-fla-vin)
7,8,10-Trimethylisoalloxazine;a yellow photoderivative of riboflavin, bearing a methyl group in place of the ribityl; produced by ultraviolet irradiation of riboflavin in alkaline solution.

lumina (loo′mi-na)
Plural of lumen. [L.]

luminal (loo′mi-nal) [TA]
Relating to the lumen of a blood vessel or other tubular structure. SYN: luminalis [TA] .

luminalis [TA]
SYN: luminal.

luminance (loo′mi-nans)
The brightness of an object, expressed as the luminous flux per unit solid angle per unit projected area, measured in lamberts or in candelas per square meter. [L. lumino, to light up, fr. lumen, light]

luminescence (loo-mi-nes′ens)
Emission of light from a body as a result of a chemical reaction. See bioluminescence. [L. lumen, light]

luminiferous (loo-mi-nif′er-us)
Producing or conveying light. [L. lumen, light, + fero, to carry]

luminophore (loo′mi-no-for)
An atom or atomic grouping in an organic compound that increases its ability to emit light. [L. lumen, light, + G. phoros, bearing]

luminous (loo′mi-nus)
Emitting light, with or without accompanying heat. [L. lumen, light]

lumirhodopsin (loo′mi-ro-dop′sin)
An intermediate between rhodopsin and all-trans-retinal plus opsin during bleaching of rhodopsin by light; formed from bathorhodopsin and converted to metarhodopsin I with a half-life of about 20 μs. [L. lumen, light, + G. rhodon, rose, + opsis, vision]

lumisterol (loom-e-ster′ol)
1. A by-product in ergocalciferol biosynthesis. 2. A phosphorylated derivative of ribulose that is an intermediate in the pentose monophosphate shunt.

lumpectomy (lum-pek′to-me)
Removal of either a benign or malignant lesion from the breast with preservation of essential anatomy of the breast; tylectomy involving breast tissue. [lump + G. ektome, excision]

Lee G., 20th century U.S. medical technologist. See L.-Ishak stain.

lunacy (loo′na-se)
1. An obsolete term for a form of insanity characterized by alternating lucid and insane periods, believed to be influenced by phases of the moon. 2. Any form of insanity. 3. Insanity as defined variously by law. [L. luna, moon]

lunar (loo′ner)
1. Relating to the moon or to a month. 2. Resembling the moon in shape, especially a half moon. SYN: lunate (1) [TA] , semilunar. SEE ALSO: crescentic. 3. Relating to silver (the moon was the symbol of silver in alchemy). [L. luna, moon]

lunar caustic
SYN: toughened silver nitrate.

lunare (loo-na′re)
SYN: lunate (bone).

lunate (loo′nat) [TA]
1. SYN: lunar (2) . 2. Relating to the l. bone.

lunatic (loo′na-tik)
Obsolete term for a mentally ill person. [see lunacy]

lunatomalacia (loo-na′to-ma-la′she-a)
SYN: Kienböck disease.

lung (lung) [TA]
One of a pair of viscera occupying the pulmonary cavities of the thorax, the organs of respiration in which aeration of the blood takes place. In humans, the right l. is slightly larger than the left and is divided into three lobes (an upper, a middle, and a lower or basal), while the left has but two lobes (an upper and a lower or basal). Each l. is irregularly conical in shape, presenting a blunt upper extremity (the apex), a concave base following the curve of the diaphragm, an outer convex surface (costal surface), a generally concave inner or medial surface (mediastinal surface), a thin and sharp anterior border, and a rounded posterior border. SYN: pulmo [TA] . [A.S. lungen] air-conditioner l. an extrinsic allergic alveolitis caused by forced air contaminated by thermophilic actinomycetes and other organisms. bird-breeder's l., bird-fancier's l. extrinsic allergic alveolitis caused by inhalation of particulate avian emanations; sometimes specified by avian species, e.g., pigeon-breeder's l., budgerigar-breeder's l.. SYN: bird-breeder's disease. black l. a form of pneumoconiosis, common in coal miners, characterized by deposits of carbon particles in the l.. SYN: miner's l. (2) . brown l. obstructive airway disease with asthma produced by exposure to cotton dust, flax, or hemp. SEE ALSO: byssinosis. butterfly l. hemorrhagic markings appearing on an animal's l. after inoculation with Leptospira interrogans (L. icterohaemorrhagiae). cardiac l. disturbance in pulmonary anatomy and physiology secondary to valvular disease of the heart or to other disturbances of circulation incident to cardiac disease. cheese worker's l. extrinsic allergic alveolitis caused by inhalation of spores of Penicillium casei from moldy cheese. collier l. SYN: anthracosis. cystic l. SYN: honeycomb l.. endstage l. severe diffuse interstitial fibrosis and honeycombing. farmer's l. a hypersensitivity pneumonitis characterized by fever and dyspnea, caused by inhalation of organic dust from moldy hay containing spores of thermophilic actinomycetes such as Micromonospora vulgaris, M. faeni, and Thermopolyspora polyspora, which thrive in the elevated temperatures of hay lofts and silos; repeated exposure may result in alveolar sensitization and, ultimately, granulomatous l. disease with severe disability. SYN: thresher's l.. fibroid l. chronic interstitial pneumonia in a l.. honeycomb l. the radiologic and gross appearance of the lungs resulting from interstitial fibrosis and cystic dilation of bronchioles and distal air spaces; of unknown cause or a sequel of any of several diseases, including eosinophilic granuloma, sarcoidosis, and any interstitial l. disease. SYN: cystic l.. hyperlucent l. the radiographic finding that a l. or portion thereof is less dense than normal, as from air trapping by a bronchial foreign body, asymmetric emphysema, or decreasing blood flow. See unilateral hyperlucent l.. iron l. SYN: Drinker respirator. malt-worker's l. extrinsic allergic alveolitis caused by inhalation of spores of Aspergillus clavatus and A. fumigatus from contaminated barley during the manufacture of beer. mason's l. silicosis occurring in stone masons. miner's l. 1. SYN: anthracosis. 2. SYN: black l.. mushroom-worker's l. extrinsic allergic alveolitis caused by inhalation of spores of the mold Thermopolyspora polyspora or Micromonospora vulgaris from contaminated mushrooms under cultivation. postperfusion l. a condition in which abnormal pulmonary function develops in patients who have undergone cardiac surgery involving the use of an extracorporeal circulation; now rare due to advances in perfusion technique and equipment. pump l. SYN: shock l.. quiet l. the collapse of a l. during thoracic operations undertaken to facilitate surgical procedure through absence of l. movement. shock l. in shock, the development of edema, impaired perfusion, and reduction in alveolar space so that the alveoli collapse. SYN: pump l., wet l. (1) , white l.. silo-filler's l. pulmonary edema, usually delayed for 1–4 hours, occurring in an individual exposed to silage, probably due to nitrogen dioxide; can progress to bronchiolitis obliterans. thresher's l. SYN: farmer's l.. unilateral hyperlucent l. chronic bronchiolitis obliterans predominating on one side. See unilateral lobar emphysema. SEE ALSO: Swyer-James syndrome (2) . uremic l. perihilar edema of the l. associated with renal failure and hypertension; the peripheral parts of the l. remain clear. SYN: uremic pneumonia (1) , uremic pneumonitis. vanishing l. vanishing l. syndrome. welder's l. relatively benign form of pneumoconiosis, associated with welding, resulting from deposit of fine metallic particles in the l.. wet l., white l. 1. SYN: shock l.. 2. SYN: adult respiratory distress syndrome.

lungworms (lung′wermz)
Nematodes that inhabit the air passages of animals, chiefly in the family Metastrongylidae (or Protostrongylidae). See Aelurostrongylus, Crenosoma vulpis, Metastrongylus, Muellerius capillaris.


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