Sign In

Remember Me


A service of the National Library of Medicine.

MerckSource received the 2006 WebAward for Outstanding Website Development from the Web Marketing Association at the annual WebAward competition.

MerckSource was honored at the Healthcare Internet Conference in Atlanta, receiving the 2006 Gold eHealthcare Leadership Award for best health/healthcare content.

MerckSource received the 2006 WWW site Award of Excellence from the Health Improvement Institute.  This award honors excellence in health communications.

More Awards

Resource Library

Powered by Dorland's Illustrated Medical Dictionary

This information is provided by an independent source. Merck & Co., Inc. is not responsible for this content. Please discuss any and all treatment options with your healthcare professional. The manufacturer of a product generally has the most complete information about that product.
Return to Main Index >> How to Use  

Harcourt - Saunders Logo
Previous A-B  | C-D  | E-F  | G-H  | I-J  | K-L  | M-N  | O-P  | Q-R  | S-T  | U-V  | W-X  | Y-Z Next

Leber's congenital amaurosis, etc. - Lenz syndrome

Leber's congenital amaurosis, etc. (Le·ber's congenital amaurosis, etc.) (la´bərz) [Theodor Leber, German ophthalmologist, 1840–1917]  see amaurosis congenita, under amaurosis, Hassall's corpuscles, under corpuscle, and Hovius' plexus, under plexus; and see under neuropathy.

Lebistes (Le·bis·tes) (lə-bis´tēz)  a genus of small fish or minnows. L. reticula′tus is the guppy, a top-feeding species also called “millions,” cultivated in Barbados to eliminate mosquito larvae.

Leboyer method (technique) (Le·boy·er method (technique)) (lə-bwah-ya´) [Frédérick Leboyer, French obstetrician, born 1918]  see under method.

lecanopagus (lec·an·op·a·gus) (lek”ən-op´ə-gəs) [Gr. lekanē basin + -pagus]  ischiodidymus.

leche de higuerón (le·che de hi·gue·rón) (la´cha da e-ga-rōn´) [Sp. “milk of fig”]  the sap or latex of the wild fig tree Ficus anthelmintica, used as a vermifuge.

lechopyra (lech·o·py·ra) (lek”o-pi´rə) [Gr. lechō parturient woman + pyr fever]  puerperal fever.

lechuguilla (le·chu·gui·lla) (la-choo-ge´yə) [Sp. “little lettuce”]  Agave lecheguilla.

lecithal (lec·i·thal) (les´ĭ-thəl) [lecith- + -al1]  vitelline.

-lecithal (-lecithal) [Gr. lekithos yolk]  a word termination denoting yolk, affixed to a word stem descriptive of the state of the yolk substance, as centrolecithal, isolecithal, etc. See also entries under ovum.

lecithid (lec·i·thid) (les´ĭ-thid)  a compound of lecithin with venom hemolysin.

cobra l.  a hemolytic compound formed by cobra toxin and the lecithin of the blood.

lecithin (lec·i·thin) (les´ĭ-thin)  phosphatidylcholine.

lecithin–cholesterol acyltransferase (lec·i·thin–cho·les·ter·ol ac·yl·trans·fer·ase) (LCAT) (les´ĭ-thin kə-les´tər-ol a”səl-trans´fər-ās)  phosphatidylcholine–sterol O-acyltransferase.

lecithin–cholesterol acyltransferase deficiency (le·ci·thin–cho·les·ter·ol ac·yl·trans·fer·ase de·fi·cien·cy)  an autosomal recessive disorder due to failure of LCAT to esterify plasma cholesterol; cholesterol and phosphatidylcholine accumulate in the plasma and tissues, causing corneal opacities, anemia, and often proteinuria. All classes of lipoproteins show abnormalities. See also fish eye disease under disease.

lecithinemia (lec·i·thin·emia) (les”ĭ-thĭ-ne´me-ə)  hyperlecithinemia.

lecith(o)- (lecith(o)-) [Gr. lekithos yolk]  a combining form denoting relationship to the yolk of an egg or ovum.

lecithoblast (lec·i·tho·blast) (les´ĭ-tho-blast”) [lecitho- + -blast]  the primordial endoderm of a two-layered blastodisc.

lecithoprotein (lec·i·tho·pro·tein) (les”ĭ-tho-pro´tēn)  a compound of the protein molecule with a molecule of lecithin; lecithoproteins occur in all cells.

lecithovitellin (lec·i·tho·vi·tel·lin) (les”ĭ-tho-vi-tel´in)  a saline extract of egg yolks used in egg-yolk agar to test for bacterial lecithinase.

lectin (lec·tin) (lek´tin)  any of a group of hemagglutinating proteins found primarily in plant seeds, which bind specifically to the branching sugar molecules of glycoproteins and glycolipids on the surface of cells. Certain lectins selectively cause agglutination of erythrocytes of certain blood groups and of malignant cells but not their normal counterparts; others stimulate the proliferation of lymphocytes.

lectotype (lec·to·type) (lek´to-tīp)  in bacteriology, a culture taken from the original material to serve as a type culture when the original investigator did not designate a type.

Lecythophora (Lec·y·thoph·o·ra) (les”ĭ-thof´ə-rə)  a genus of imperfect fungi of the form-family Dematiaceae, formerly considered part of the genus Phialophora. L. hoffman´nii occasionally causes hyalohyphomycosis and L. muta´bilis has been found in cases of endocarditis, some fatal.

Ledbänder (Led·bän·der) (led´bān-der) [Ger.]  Büngner's bands; see under band.

Le Dentu's suture (Le Den·tu's suture) (lə-dahn-tūz´) [Jean François-Auguste Le Dentu, Paris surgeon, 1841–1926]  see under suture.

Lederberg (Led·er·berg) (led´ər-bərg)  Joshua, born 1925. American biochemist; co-winner, with George W. Beadle and Edward L. Tatum, of the Nobel prize for medicine or physiology in 1958 for discoveries concerning genetic recombination and the organization of the genetic material of bacteria.

LeDuc technique (implantation) (Le·Duc technique (implantation)) (lədōōk´) [A. LeDuc, French urologist, 20th century]  see under technique.

Lee's ganglion (Lee's ganglion) (lēz) [Robert Lee, English obstetrician and gynecologist, 1793–1877]  cervical ganglion of uterus; see under ganglion.

leech (leech) (lēch) [L. hirudo]  1. any of the annelids of the class Hirudinea. Some species are bloodsuckers and may become temporarily parasitic upon animals, including humans. Leeches are sometimes used for drawing blood (see leeching).  2. to apply leeches.

American l.  Macrobdella decora.

artificial l.  an apparatus for drawing blood by artificial suction.

horse l.  see Limnatis and Haemopis.

land l.  Haemadipsa.

medicinal l.  Hirudo medicinalis.

leeches (leeches) (lēch´əz) [pl. of leech, from the appearance of the lesions]  pythiosis.

leeching (leech·ing) (lēch´ing)  the application of a leech for the withdrawal of blood; formerly used extensively in the treatment of various disorders and still used occasionally to reduce postsurgical venous congestion, as in tissue flaps, grafts, or transplants; called also hirudinization.

Leeuwenhoekia (Leeu·wen·hoe·kia) (la”wen-hoo´ke-ə) [Anton (Anthony, Antony) van Leeuwenhoek, Dutch microscopist, 1632–1723]  a genus of mites. L. australien´sis is a species found in Australia that causes great irritation by burrowing in the skin.

leflunomide (le·flu·no·mide) (lə-floo´no-mīd)  an immunomodulator that inhibits pyrimidine synthesis, used as a disease-modifying antirheumatic drug in treatment of rheumatoid arthritis; administered orally.

Le Fort fracture, etc. (Le Fort fracture, etc.) (lə-for´) [Léon-Clément Le Fort, French surgeon, 1829–1893]  see under amputation, fracture, operation, sound, and suture.

left-handed (left-hand·ed) (left-hand´əd)  using the left hand preferentially, or more skillfully than the right, in voluntary motor acts. See also handedness and laterality.

leg (leg) (leg)  1. that section of the lower limb between the knee and ankle; called also crus and shank.  2. in common usage, the entire lower limb (in which case, the part below the knee is called the lower leg).  3. any of the four limbs of a quadruped.

badger l.  inequality in the length of the lower limbs.

baker l.  genu valgum.

bandy l.  genu varum.

bayonet l.  uncorrected backward displacement of the bones of the lower limb at the knee, followed by ankylosis at the joint.

black l.  blackleg.

bow l.  genu varum.

hind l.  the back leg (pelvic limb) of a quadruped. Cf. foreleg.

milk l.  phlegmasia alba dolens.

red l.  a fatal septicemia in frogs caused by Aeromonas hydrophila.

restless l.’s  see under syndrome.

rider's l.  strain of the adductor muscles of the thigh in horseback riders.

scaly l.  a type of mange in fowls in which the legs become enlarged and encrusted due to infestation by species of Knemidokoptes.

scissor l.  deformity with crossing of the legs in walking, due to spasticity of adductor muscles of the thighs.

splay l.’s ,  spraddle l.s  myofibrillar hypoplasia.

tennis l.  a sudden tear at the musculotendinous junction of the medial belly of the gastrocnemius muscle, usually seen in older persons participating in tennis and other sports.

white l.  phlegmasia alba dolens.

Legg's disease (Legg's disease) (legz) [Arthur Thornton Legg, American surgeon, 1874–1939]  Legg-Calvé-Perthes disease; see under disease.

Legg-Calvé-Perthes disease (Legg-Cal·vé-Per·thes disease) (leg kahl-va´ per´təz) [A.T. Legg; Jacques Calvé, French orthopedist, 1875–1954; Georg Clemens Perthes, German surgeon, 1869–1927]  see under disease.

Legg-Calvé-Perthes-Waldenström disease (Legg-Cal·vé-Per·thes-Wal·den·ström disease) (leg kahl-va´ per´təz vahl´den-strermz) [A.T. Legg; J. Calvé; G.C. Perthes; Johan Henning Waldenström, Swedish orthopedic surgeon, 1877–1972]  Legg-Calvé-Perthes disease; see under disease.

Legionella (Le·gion·el·la) (le”jə-nel´ə) [from legionnaires' disease]  a genus of gram-negative, aerobic, rod-shaped bacteria of the family Legionellaceae, made up of motile, pleomorphic organisms that require cysteine and iron for growth. Their normal habitat is lakes, streams, and moist soil, but they have also been found as contaminants in human habitations. Human infection causes legionellosis, a pneumonialike disease; the mode of spread is the airborne route. The type species is L. pneumo´phila.

L. bozema´nii  a species isolated from human lung tissue that has been associated with pneumonia.

L. dumof´fii  a species isolated from human lung tissue and from cooling-tower water that has been associated with pneumonia.

L. fee´leii  a species isolated from coolant-system waters that has been associated with Pontiac fever.

L. gorma´nii  a species isolated from riparian soil that has been associated with pneumonia.

L. jorda´nis  a species isolated from riparian soil and treated sewage.

L. long-beach´ae  a species isolated from human lung tissue and respiratory secretions that has been associated with pneumonia.

L. micda´dei  a species isolated from human lung tissue, respiratory secretions, and pleural fluid and from cooling-tower water, shower heads, tap water, and nebulizers of respiratory therapy equipment. It is the causative agent of Pittsburgh pneumonia. Called also L. pittsburgensis and Pittsburgh pneumonia agent.

L. pittsburgen´sis  L. micdadei.

L. pneumo´phila  the causative agent of legionnaires' disease and Pontiac fever. It was the first species of the genus isolated and characterized, and it has been found in human lung tissue, respiratory secretions, pleural fluid, and blood and in numerous environmental sites such as riparian and other soil, and in cooling-tower water, tap water, shower heads, construction and excavation sites, and aerosolized droplets from heat-exchange systems.

L. wadswor´thii  a species isolated from pleural tissue, a cause of human pneumonia.

legionella (le·gion·el·la) (le”jə-nel´ə)  pl. legionel´lae  Any microorganism of the genus Legionella.

Legionellaceae (Le·gion·el·la·ceae) (le”jə-nel-a´se-e)  a family of bacteria that contains the single genus Legionella.

legionellae (le·gion·el·lae) (le”jə-nel´e)  plural of legionella.

legionellosis (le·gion·el·lo·sis) (le”jə-nel-o´sis)  any of several illnesses caused by infection with species of Legionella; see legionnaires' disease, Pittsburgh pneumonia, and Pontiac fever. Called also Legionella pneumonia.

legionnaires' disease (le·gion·naires' disease) (le-jən-ārz´) [legionnaires, members of the American Legion, whose convention in Philadelphia in 1976 was the scene of a highly publicized epidemic]  see under disease.

legume (le·gume) (leg´ūm, lə-gūm´)  1. the pod, seed, or fruit of a plant of the family Leguminosae, such as a pea or bean.  2. any plant of the family Leguminosae.

legumelin (leg·u·me·lin) (leg”u-me´lin)  an albumin from lentils, beans, and other leguminous seeds.

legumin (le·gu·min) (lə-gu´min) [L. legumen pulse]  a globulin from the seeds of various plants, chiefly of the legumes.

leguminivorous (le·gu·mi·niv·o·rous) (lə-gu”mĭ-niv´ə-rəs)  feeding on legumes (beans and peas).

Leguminosae (Le·gu·mi·no·sae) (lə-gu”mĭ-noəse)  the pea or legume family, a large family of plants that includes trees, shrubs, and vines; many genera either produce edible seeds or are of medical importance.

leguminous (le·gu·mi·nous) (lə-gu´mĭ-nəs)  pertaining to a legume.

leiasthenia (lei·as·the·nia) (li”əs-the´ne-ə) [leio- + asthenia]  asthenia of smooth muscle.

Leichtenstern's encephalitis, sign (phenomenon) (Leich·ten·stern's encephalitis, sign (phenomenon)) (līk´tən-shternz) [Otto Michael Leichtenstern, German physician, 1845–1900]  see hemorrhagic encephalitis, under encephalitis, and see under sign.

Leigh disease (Leigh disease) (le) [Archibald Denis Leigh, British neuropathologist, born 1915]  subacute necrotizing encephalomyelopathy.

Leiner's disease (Lei·ner's disease) (li´nərz) [Karl Leiner, Austrian pediatrician, 1871–1930]  see under disease.

leio- (leio-) [Gr. leios smooth]  a combining form meaning smooth.

leiodermia (leio·der·mia) (li”o-dər´me-ə) [leio- + derm- + -ia]  abnormal glossiness and smoothness of the skin.

leiodystonia (leio·dys·to·nia) (li”o-dis-to´ne-ə) [leio- + dystonia]  dystonia of smooth muscle.

Leiognathus bacoti (Lei·og·na·thus ba·co·ti) (li-og´nə-thəs bə-ko´te)  Ornithonyssus bacoti.

leiomyoblastoma (leio·myo·blas·to·ma) (li”o-mi”o-blas-to´mə)  epithelioid leiomyoma.

leiomyofibroma (leio·myo·fi·bro·ma) (li”o-mi”o-fi-bro´mə)  leiomyoma.

leiomyoma (leio·myo·ma) (li”o-mi-o´mə)  pl. leiomyomas, leiomyo´mata [leio- + myoma]  a benign tumor derived from smooth muscle, most commonly of the uterus; called also fibroid and fibroid tumor.

bizarre l.  epithelioid l.

l. cu´tis  one arising from cutaneous or subcutaneous smooth muscle fibers, occurring singly or multiply, usually in the form of lesions arising from arrectores pilorum muscles (piloleiomyoma); it may also occur as a solitary genital lesion arising from dartoic, vulvar, or mammillary muscle or as a solitary angioleiomyoma (q.v.) arising from the muscle of veins. Lesions present as smooth, firm, painful, often translucent or waxy nodules and are characterized by interlacing bundles of elongated rod- or spindle-shaped cells with finely fibrillar cytoplasm.

epithelioid l.  a relatively rare smooth muscle tumor, usually of the stomach, in which the cells are polygonal rather than spindle-shaped; called also bizarre l. and leiomyoblastoma.

intraligamentous l.  a uterine leiomyoma with lateral growth that extends outward between the folds of the broad ligament.

intramural l.  a uterine leiomyoma located within the substance of the myometrium in the uterine corpus.

parasitic l.  a pedunculated leiomyoma that has partially or completely detached from its site of origin and is attached to the omentum, which now has extended blood vessels into it.

pedunculated l.  a submucosal leiomyoma that protrudes into the uterine cavity, forming a bulbous polyp with a firm, round head.

submucosal l.  a uterine leiomyoma located next to the endometrium in the corpus of the uterus; this type frequently protrudes into the endometrial cavity, forming a pedunculated leiomyoma.

subserosal l.  a uterine leiomyoma located just beneath the tunica serosa of the corpus of the uterus.

l. u´teri ,  uterine l.  a leiomyoma of the uterus, usually occurring in the third and fourth decades, characterized by the development of multiple, sharply circumscribed, unencapsulated, gray-white tumors, which are firm, usually round, and show a whorled pattern on cut section. The majority are within the myometrium of the corpus of the uterus, but they may also occur in the cervix, usually in its posterior wall. Those in the corpus are distinguished by location as either intramural, submucosal, or subserosal leiomyomas. Called also fibromyoma uteri, uterine myoma, and, colloquially, fibroids.

vascular l.  angioleiomyoma.

leiomyomatosis (leio·my·o·ma·to·sis) (li”o-mi”o-mə-to´sis)  a condition in which multiple leiomyomas occur throughout the body.

l. peritonea´lis dissemina´ta  abdominal smooth muscle tumors arising as small nodules scattered throughout the peritoneal surfaces, occurring exclusively in women of reproductive age and appearing very similar to low-grade leiomyosarcoma or metastatic carcinoma but usually regressing spontaneously following menopause.

leiomyosarcoma (leio·myo·sar·co·ma) (li”o-mi”o-sahr-ko´mə) [leio- + myosarcoma]  a sarcoma containing large spindle cells of smooth muscle, most commonly of the uterus, retroperitoneal region, or extremities.

renal l.  a rare leiomyosarcoma in the kidney, usually in the capsule; it occurs more often in women.

leip(o)- (leip(o)-)  for words beginning thus, see those beginning lip(o)-.

Leishman's cells, stain (Leish·man's cells, stain) (lēsh´mənz) [Sir William Boog Leishman, English army surgeon and bacteriologist, 1865–1926]  see under cell and see Stains and Staining Methods, under stain.

Leishman-Donovan body (Leish·man-Don·o·van body) (lēsh´mən don´ə-vən) [Sir W.B. Leishman; Charles Donovan, Irish physician in India, 1863–1951]  amastigote.

Leishmania (Leish·ma·nia) (lēsh-ma´ne-ə) [Sir William B. Leishman]  a genus of flagellate protozoa (suborder Trypanosomatina, order Kinetoplastida) comprising parasites of worldwide distribution, several species of which are pathogenic for humans. The organisms have two morphologic stages in their life cycle: amastigote (Leishman-Donovan body), found intracellularly in the vertebrate (i.e., human) host; and promastigote (leptomonad), found in the digestive tract of the invertebrate host (i.e., phlebotomine sandfly) and in cultures. Because all species are morphologically indistinguishable, the organisms have usually been assigned to species and subspecies according to their geographic origin, the clinical syndrome they produce, and their ecologic characteristics, or they have been separated on the basis of their tendency to cause visceral, cutaneous, or mucocutaneous leishmaniasis. In some classifications, leishmanias are placed in four complexes comprising species and subspecies: L. donovani, L. tropica, L. mexicana, and L. viannia (formerly L. brasiliensis).

L. aethio´pica  a species of the L. tropica complex causing Ethiopian cutaneous leishmaniasis; animal reservoirs are rock and tree hyraxes in the highlands of Ethiopia and Kenya; the vector in Ethiopia is Phlebotomus longipes and in Kenya it is P. pedifer. Called also L. tropica aethiopica.

L. brasilien´sis  1. L. viannia.  2. L. viannia braziliensis.

L. brazilien´sis  1. L. viannia.  2. L. viannia braziliensis.

L. brazilien´sis brazilien´sis  L. viannia braziliensis.

L. brazilien´sis guyanen´sis  L. viannia guyanensis.

L. brazilien´sis panamen´sis  L. viannia panamensis.

L. donova´ni  1. a taxonomic complex comprising the subspecies causing varieties of visceral leishmaniasis: L. d. donova´ni, L. d. infan´tum, and L. d. chaga´si, all of which multiply in the reticuloendothelial cells and spread to the lymph nodes and then hematogenously throughout the body. The subspecies can be distinguished only by differences in the epidemiology, clinical features, and response to treatment.  2. L. d. donovani.

L. donova´ni chaga´si  a subspecies of the L. donovani complex causing American visceral leishmaniasis, usually transmitted by the sandfly Lutzomyia longipalpis.

L. donova´ni donova´ni  a subspecies of the L. donovani complex causing Indian visceral leishmaniasis. It is transmitted by the sandfly Phlebotomus argentipes, with humans being the only major reservoir hosts. Called also L. donovani.

L. donova´ni infan´tum  a subspecies of the L. donovani complex causing infantile visceral leishmaniasis in the Mediterranean littoral (usual vectors Phlebotomus perniciosus and P. major), Middle East (usual vectors P. papatasi and P. caucasicus), sub-Saharan and East Africa (usual vectors P. orientalis and P. martini), and China (usual vectors P. chinensis and P. sergenti). Called also L. infantum.

L. garnha´mi  a species similar to (or identical with) L. mexicana amazonensis isolated from cases of cutaneous leishmaniasis in the region of the Venezuelan Andes.

L. infan´tum  L. donovani infantum.

L. ma´jor  a species of the L. tropica complex, transmitted by Phlebotomus papatasi, usually causing rural cutaneous leishmaniasis and sometimes causing viscerotropic cutaneous leishmaniasis. Called also L. tropica major.

L. mexica´na  a taxonomic complex comprising the species and subspecies causing New World cutaneous leishmaniasis in humans: L. m. mexicana, L. m. amazonensis, and L. pifanoi, which infect chiefly forest rodents and opossums. They develop only in the midgut and foregut of their sandfly vectors.

L. mexica´na amazonen´sis  a subspecies of the L. mexicana complex, transmitted by Lutzomyia flaviscutellata, and causing a form of New World cutaneous leishmaniasis in the Amazon region of Brazil and neighboring countries and in Trinidad. A single lesion is usually present but a few cases of diffuse cutaneous leishmaniasis caused by L. m. mexicana have been reported.

L. mexica´na mexica´na  a subspecies of the L. mexicana complex transmitted by Lutzomyia olmeca and causing chiclero ulcer.

L. mexica´na pi´fanoi  L. pifanoi.

L. nilo´tica  L. tropica (def. 2).

L. peruvia´na  L. viannia peruviana.

L. pi´fanoi  a species of the L. mexicana complex causing diffuse cutaneous leishmaniasis in Venezuela and certain areas of Brazil. Called also L. mexicana pifanoi.

L. tro´pica  1. a taxonomic complex comprising the species causing Old World cutaneous leishmaniasis: L. tropica, L. major, and L. aethiopica. The species can be differentiated on ecologic, biochemical, and serologic grounds.  2. a species of the L. tropica complex causing dry cutaneous leishmaniasis. It is found in Iran, Iraq, and India, transmitted by Phlebotomus sergenti; and in southern France, Italy, and certain Mediterranean islands, transmitted by P. papatasi. Human to human transmission may also occur. Called also L. nilotica, L. tropica minor, and L. tropica tropica.

L. tro´pica aethio´pica  L. aethiopica.

L. tro´pica ma´jor  L. major.

L. tro´pica mi´nor  L. tropica (def. 2).

L. tro´pica tro´pica  L. tropica (def. 2).

L. vian´nia  a taxonomic complex comprising the subspecies that cause mucocutaneous leishmaniasis in its various forms; all of the subspecies develop in the midgut, foregut, and hindgut of their sandfly vectors. Formerly called L. brasiliensis or L. braziliensis.

L. vian´nia brazilien´sis  a subspecies of the L. viannia complex, transmitted by species of Lutzomyia and Psychodopygus, and causing cutaneous and mucocutaneous leishmaniasis in Brazil, Peru, Ecuador, Bolivia, Venezuela, Paraguay, and Columbia. Called also L. braziliensis.

L. vian´nia guyanen´sis  a subspecies of the L. viannia complex, transmitted chiefly by Lutzomyia umbratilis and causing pian bois (forest yaws).

L. vian´nia panamen´sis  a subspecies of the L. viannia complex, transmitted chiefly by Lutzomyia trapidoi and causing New World cutaneous leishmaniasis in Panama and adjacent areas of Central America and Colombia.

L. vian´nia peruvia´na  a subspecies of the L. viannia complex, found in the Peruvian Andes only at altitudes of 900 to 3000 meters, probably transmitted by Lutzomyia verrucarum and L. peruensis and causing uta in humans. Called also L. peruviana.

leishmania (leish·ma·nia) (lēsh-ma´ne-ə)  1. any protozoan of the genus Leishmania.  2. see amastigote.

leishmanial (leish·ma·ni·al) (lēsh-ma´ne-əl)  1. pertaining to or caused by leishmanias.  2. denoting a morphologic stage in the life cycle of trypanosomatid protozoa; see amastigote.

leishmaniasis (leish·ma·ni·a·sis) (lēsh”mə-ni´ə-sis)  infection caused by Leishmania; the principal classification is into cutaneous, mucocutaneous, and visceral types.

American l.  see New World cutaneous l. and American visceral l.

American cutaneous l.  New World cutaneous l..

American visceral l.  a variety seen in South America, Central America, and Mexico, caused by Leishmania donovani chagasi, and affecting humans of any age. Its major reservoirs is dogs and the usual vector is the sandfly Lutzomyia longipalpis.

anergic l.  diffuse cutaneous l.

anergic cutaneous l.  diffuse cutaneous l.

canine l.  infantile visceral l.

classic visceral l.  a form caused by Leishmania donovani donovani, usually affecting older children or young adults; humans are the only reservoir hosts and it is transmitted by the sandfly Phlebotomus argentipes. It occurs primarily in eastern India and Bangladesh.

cutaneous l.  an endemic disease characterized by the development of a cutaneous papule that evolves into a nodule, breaks down to form an indolent ulcer, and heals, leaving a depressed scar. A distinction is made between varieties found in Asia and Africa that are caused by Leishmania major, L. tropica, or L. aethiopica (see Old World cutaneous l.) and varieties found in Central and South America that are caused by L. mexicana or L. viannia (see New World cutaneous l.).

Cutaneous leishmaniasis.

Cutaneous leishmaniasis.

diffuse cutaneous l.  a rare chronic form of cutaneous leishmaniasis caused by Leishmania aethiopica in Ethiopia and Kenya, by L. pifanoi in Venezuela, and by protozoa of the L. viannia and L. mexicana complexes in South and Central America, respectively. It is characterized by the local and hematogenous spread from a primary lesion to produce generalized nodular lesions resembling those of lepromatous leprosy in the skin and sometimes involving the nasal mucosa and laryngopharynx. Individuals with this form of the disease do not develop an effective immune response to the infection. Called also anergic l. and anergic cutaneous l.

dry cutaneous l.  a type of Old World cutaneous leishmaniasis found mainly in large urban areas in the Middle East, the Mediterranean region, and the Indian subcontinent, caused by Leishmania tropica and transmitted by the vectors Phlebotomus sergenti and P. papatasi. The reservoir may be either human or canine. A slowly developing single lesion that persists for a year or more is typical. Called also urban cutaneous l.

Ethiopian cutaneous l.  a form of Old World cutaneous leishmaniasis seen in the highlands of Kenya and Ethiopia, caused by Leishmania aethiopica; reservoirs are hyraxes of the genera Procavia, Heterohyrax, and the vectors are Phlebotomus pedifer and P. longipes. Lesions are less inflamed and more chronic than those of other Old World forms, and generally last for several years; the condition is usually self-limited but may develop into diffuse cutaneous leishmaniasis.

Indian visceral l.  a form caused by Leishmania donovani donovani, usually affecting older children or young adults; humans are the only reservoir hosts and it is transmitted by the sandfly Phlebotomus argentipes. It occurs primarily in eastern India and Bangladesh. Called also classic visceral l.

infantile visceral l. ,  Mediterranean visceral l.  a form caused by Leishmania donovani infantum, usually affecting children between ages 1 and 4; reservoirs are dogs, foxes, jackals, and rodents, and vectors are species of Phlebotomus sandflies. It occurs in the Mediterranean region, sub-Saharan and East Africa, the Middle East, and China.

mucocutaneous l.  chronic, progressive metastatic spread of the lesions of New World cutaneous leishmaniasis caused by Leishmania viannia braziliensis to the nasal, pharyngeal, and buccal mucosa months to years after the appearance of the initial cutaneous lesion, which has usually healed. It is often associated with mutilating destruction of the nasal septum, palate, lips, pharynx, and larynx. Called also espundia.

New World cutaneous l.  any of the types of cutaneous leishmaniasis occurring in South America, Central America, or Mexico, zoonoses caused by species or subspecies of the Leishmania mexicana or L. viannia groups. Their lesions develop and heal similarly to those of the Old World forms but tend to be less nodular and more ulcerative and destructive. Many varieties exist, differing as to animal reservoir, vector, geographical distribution, and clinical and other characteristics; some common forms are mucocutaneous leishmaniasis, chicle or chiclero ulcer, uta, and pian bois. Called also American cutaneous l.

Old World cutaneous l.  any of the types of cutaneous leishmaniasis occurring in Asia, Africa, or the Mediterranean basin; three separate types are distinguished according to the causative organism: dry or urban cutaneous leishmaniasis is caused by Leishmania tropica; wet or rural cutaneous leishmaniasis is caused by L. major; and Ethiopian cutaneous leishmaniasis is caused by L. aethiopica. It has received many names, often according to the locality of its occurrence (see under boil).

post–kala-azar dermal l.  a condition associated with visceral leishmaniasis, commonly characterized by the appearance of hypopigmented or erythematous macules on the face and sometimes on the extremities and trunk; the facial lesions gradually progress to papules or nodules that resemble those of lepromatous leprosy. It is seen in about 20 per cent of Indian patients, usually occurring years after the treatment of or spontaneous recovery from visceral leishmaniasis, and it may last for as long as 20 years. When the condition affects patients in East Africa (2 per cent) and China (rare), it usually occurs shortly after or during treatment and usually does not persist. Called also dermal leishmanoid, leishmanoid, and post–kala-azar dermal leishmanoid.

l. reci´divans  a relapsing form of either wet or dry cutaneous leishmaniasis, resembling tuberculosis of the skin, in which the ulcer heals incompletely, scarring centrally but spreading peripherally, or heals and recrudesces at the edge of the scar; it may last for many years.

rural l.  wet cutaneous l.

rural cutaneous l.  wet cutaneous l.

urban l.  dry cutaneous l.

urban cutaneous l.  dry cutaneous l.

viscerotropic cutaneous l.  a rare type of infection found in northeastern Saudi Arabia; after infection with Leishmania major, instead of the usual cutaneous symptoms, fever and other systemic symptoms are seen and Leishmania can be detected in internal organs.

visceral l.  a chronic infectious disease, highly fatal if untreated, caused by Leishmania donovani donovani, L. d. infantum, and L. d. chagasi, found in various tropical and subtropical regions of the world; parasites are found in the cells of the reticuloendothelial system throughout the body, especially in the liver, spleen, bone marrow, lymph nodes, and skin. It is commonly characterized by hepatosplenomegaly, irregular fever, chills, vomiting, emaciation, anemia, leukopenia, hypergammaglobulinemia, and an earth-gray color of the skin. It has traditionally been divided into three different forms according to geographical distribution, vector, and other factors. See American visceral l., infantile visceral l., and Indian visceral l. Called also kala-azar, tropical splenomegaly, and black, cachectic, cachexial, or Dumdum fever.

wet cutaneous l.  a type of Old World cutaneous leishmaniasis found mainly in rural areas in parts of the Middle East, central Asia, and the Indian subcontinent, caused by Leishmania major; its reservoirs are desert rodents such as ground squirrels and gerbils (particularly Rhombomys opimus and Meriones species) and it spreads to humans via the vector Phlebotomus papatasi. Infection is acute, rapidly evolving, and characterized by multiple sores with inflammation, ulceration, and crusting. Called also rural cutaneous l.

leishmanicidal (leish·man·i·ci·dal) (lēsh”mən-ĭ-si´dəl)  destructive to Leishmania.

leishmanid (leish·man·id) (lēsh´mən-īd)  the early cutaneous nodule of cutaneous leishmaniasis.

leishmanin (leish·ma·nin) (lēsh´mə-nin)  a suspension of killed leishmania promastigotes; used in a skin test for cutaneous leishmaniasis (see leishmanin test, under tests).

leishmanoid (leish·ma·noid) (lēsh´mə-noid)  1. like or resembling leishmaniasis.  2. a lesion of post–kala-azar dermal leishmaniasis.

dermal l. ,  post–kala-azar dermal l.  post–kala-azar dermal leishmaniasis.

Leksell apparatus, technique (Lek·sell apparatus, technique) (lek´səl) [Lars Leksell, Swedish neurosurgeon, 20th century]  see under apparatus and technique.

Lelaps (Le·laps) (le´laps)  Echinolaelaps.

lema (le·ma) (le´mə) [Gr. lēmē]  sebum palpebrale.

Lembert's suture (Lem·bert's suture) (lahm-bārz´) [Antoine Lembert, French surgeon, 1802–1851]  see under suture.

Lemierre syndrome (Le·mierre syndrome) (lə-myār´) [André Lemierre, French physician, born 1875]  see under syndrome.

Lemieux-Neemeh syndrome (Le·mi·eux-Nee·meh syndrome) (lə-mydbobr´ na´ma) [Guy Lemieux, Canadian physician, 20th century; Jean A. Neemeh, Canadian physician, 20th century]  see under syndrome.

lemma (lem·ma) (lem´ə) [Gr. “rind,” “husk”]  a collective term for the three egg membranes.

-lemma (-lemma)  a word termination denoting a sheath around another structure.

lemmoblast (lem·mo·blast) (lem´o-blast)  a primordial or immature lemmocyte.

lemmoblastic (lem·mo·blas·tic) (lem”o-blas´tik)  forming or developing into neurilemma tissue.

lemmocyte (lem·mo·cyte) (lem´o-sīt) [lemma + -cyte]  a cell derived from the neural crest and developing into a cell of the neurilemma.

lemnisci (lem·nis·ci) (lem-nis´i)  plural of lemniscus.

lemniscus (lem·nis·cus) (lem-nis´kəs) gen. and pl. lemnis´ci [L., from Gr. lēmniskos ribbon]  1. a ribbon or band.  2.  [TA] a band or bundle of sensory fibers in the central nervous system; called also fillet. See also bundle, fasciculus, tract, and tractus.

l. latera´lis  [TA]  lateral lemniscus: a tract of longitudinal fibers extending upward through the lateral part of the tegmental substance of the pons, formed chiefly by fibers arising from the opposite cochlear nuclei and the trapezoid body, and ascending to terminate in the inferior colliculus and medial geniculate body.

l. media´lis  [TA]  medial lemniscus: a tract arising from the internal arcuate fibers of the nuclei gracilis and cuneatus, and crossing to the opposite side in the lower part of medulla oblongata to ascend, first between the two olives, and then through the pars dorsalis pontis just dorsal to the pontine nuclei; it continues through the tegmentum of the midbrain and ends in the ventral posterior part of the thalamus. Each lemniscus carries sensory impulses from the opposite side of the body. Called also sensory l.

sensory l.  l. medialis.

l. spina´lis  [TA]  spinal lemniscus: the part of each spinothalamic tract within the pons and mesencephalon, forming a diffuse bundle between the medial and lateral lemnisci. It carries pain, temperature, and tactile impulses from the opposite side of the body and ends in the ventral posterior part of the thalamus. Called also tractus anterolaterales, anterolateral tracts, and anterolateral system.

l. trigemina´lis  [TA]  trigeminal lemniscus: a group of fibers conveying sensory impulses from the trigeminal nuclei to the ventral posterior part of the opposite thalamus; it ascends intermingled with the spinal lemniscus and adjacent medial lemniscus. Called also tractus trigeminothalamicus [TA alternative] and trigeminothalamic tract.

lemon (lem·on) (lem´ən)  1. Citrus limon.  2. the fruit of C. limon, which contains citric and ascorbic acids, used as an antiscorbutic, and whose peel contains lemon oil.

Lempert's fenestration operation (Lem·pert's fenestration operation) (lem´pərts) [Julius Lempert, American otologist, 1890–1968]  see under operation.

LEMS (LEMS)  Lambert-Eaton myasthenic syndrome; see Eaton-Lambert syndrome, under syndrome.

lemur (lem·ur) (lem´ər)  any member of the family Lemuridae.

Lemuridae (Le·mu·ri·dae) (lĕ-mu´rĭ-de)  the lemurs, a family of small, arboreal, usually nocturnal primates native to Madagascar and nearby islands; they resemble monkeys but have a sharp, foxlike muzzle and a tail that is long, furry, and never prehensile.

Lenègre's disease (Le·nè·gre's disease) (lə-neg´rəz) [Jean Lenègre, French cardiologist, born 1904]  see under disease.

length (length) (l) (length)  an expression of the longest dimension of an object, or of the measurement between the two ends.

arch l.  the length of a line segment within the median plane perpendicular to and extending from the line connecting the first premolars to the most labial point on the anterior arch, usually to the point between the maxillary central incisors. Called also anterior arch l.

basialveolar l.  the distance from the basion to the lower end of the intermaxillary suture.

basinasal l.  the distance from basion to nasion.

crown-heel l. (CHL)  the length of an embryo, fetus, or infant from the crown of the head to the heel; used in estimating the age of the embryos during the eighth week and of fetuses. It is the equivalent of standing height in older individuals.

crown-rump l. (CRL)  the length of an embryo, fetus, or infant from the crown of the head to the breech; used in estimating the age of embryos from the fourth to the eighth week. It is the equivalent of sitting vertex height in older individuals.

focal l.  the distance between a lens and an object from which all rays of light are brought to a focus. Symbol f.

foot l.  a heel-toe measurement useful in estimating the age of fetuses because the foot dimensions are less subject to artifacts of curvature and shrinkage than is the fetus as a whole.

greatest l.  a dimension used to express the size of very young embryos that have not yet developed the structures permitting measurement of crown-rump length, as during the third and early fourth weeks.

sitting l.  the distance from the crown of the head to the coccyx.

stem l.  the distance from the vertex to a line joining the ischial tuberosities.

wave l.  see wavelength.

lenitive (len·i·tive) (len´ĭ-tiv) [L. lenire to soothe]  demulcent.

Lennert's classification, lymphoma (Len·nert's classification, lymphoma) (len´ərts) [K. Lennert, German pathologist, 20th century]  see Kiel Classification under classification and see under lymphoma.

Lennhoff's index, sign (Lenn·hoff's index, sign) (len´hofs) [Rudolf Lennhoff, German physician, 1866–1933]  see under index and sign.

Lennox syndrome (Len·nox syndrome) (len´əks) [William Gordon Lennox, American neurologist, 1884–1960]  Lennox-Gastaut syndrome.

Lennox-Gastaut syndrome (Len·nox-Gas·taut syndrome) (len´əks gahs-to´) [W.G. Lennox; Henri Jean Pascal Gastaut, French biologist, born 1915]  see under syndrome.

lens (lens) (lenz) [L. “lentil”]  1. a piece of glass or other transparent substance so shaped as to converge or scatter the rays of light, especially the glass used in appropriate frames or other instruments to increase the visual acuity of the human eye. See also glasses and spectacles.  2.  [TA] the transparent biconvex body of the eye situated between the posterior chamber and the vitreous body, constituting part of the refracting mechanism of the eye. Called also l. crystallina or crystalline l.

Lenses: (A–F), Spherical lenses: (A), biconvex; (B), biconcave; (C), planoconvex; (D), planoconcave; (E), concavoconvex, periscopic convex, converging meniscus; (F), convexoconcave, periscopic concave, diverging meniscus; (G, H), cylindrical lenses, concave and convex.

Lenses: (A–F), Spherical lenses: (A), biconvex; (B), biconcave; (C), planoconvex; (D), planoconcave; (E), concavoconvex, periscopic convex, converging meniscus; (F), convexoconcave, periscopic concave, diverging meniscus; (G, H), cylindrical lenses, concave and convex.

Lens of eye.

Lens of eye.

achromatic l.  one corrected for chromatic aberration.

acrylic l.  a plastic lens used to replace the crystalline lens after cataract surgery.

adherent l.  contact l.

anastigmatic l.  a lens with spherical surfaces only and no cylindrical ones; called also stigmatic l.

aniseikonic l.  iseikonic l.

aplanatic l.  one that serves to correct spherical aberration and coma.

apochromatic l.  one corrected for chromatic and spherical aberration.

astigmatic l.  cylindrical l.

bandage l.  a soft contact lens worn on a diseased or injured cornea to protect or treat it.

biconcave l.  a flat lens that has both surfaces concave; called also concavoconcave l.

biconvex l.  a flat lens that has both surfaces convex.

bicylindrical l.  one that has both surfaces cylindrical or toroidal.

bifocal l.  one having two segments with different refractive powers, ordinarily with the upper for distant and the lower for near vision; used in bifocal glasses.

bispherical l.  one that is spherical on both sides.

Brücke l.  a combination of a double convex and double concave lens so arranged as to give considerable working distance.

cataract l.  a powerful lens for glasses to be used after cataract operation.

compound l.  a lens made up of two or more segments.

concave l.  one with a surface curved like part of the interior of a hollow sphere, so that it diverges rays of light. Called also diverging l. and minus l.

concavoconcave l.  biconcave l.

concavoconvex l.  one that has one concave surface and one convex; the concave surface is of greater curvature than the convex. Called also periscopic convex l., converging meniscus l., and positive meniscus l.

condensing l.  a large, powerful convex spherical lens to focus available light upon the eye for examination.

contact l.  a curved shell of glass or plastic applied directly over the globe or cornea to correct refractive errors; called also adherent l.

contact l., corneal  one that rests on the cornea, not on the sclera, and requires no auxiliary liquid; called also corneal l.

contact l., gas permeable  any contact lens that transmits oxygen and carbon dioxide.

contact l., hard  a contact lens that maintains its shape without support and absorbs little or no water; it may be gas permeable or non–gas permeable. Called also hydrophobic contact l. and rigid contact l.

contact l., hydrophilic  soft contact l.

contact l., hydrophobic ,  contact l., rigid  hard contact l.

contact l., non–gas permeable hard  a contact lens, generally formed of polymethyl methacrylate, that transmits little to no oxygen and carbon dioxide to the cornea. Called also PMMA contact l.

contact l., PMMA  a contact lens made of polymethyl methacrylate; see non–gas permeable hard contact l.

contact l., scleral  a contact lens covering the cornea and resting on the sclera, with or without an auxiliary liquid between the lens and the cornea.

contact l., soft  a contact lens that when worn is soft, flexible, and water absorbent; called also hydrophilic contact l.

converging l. ,  convex l.  one curved like part of the exterior of a hollow sphere, so that it brings light to a focus. Called also plus l.

convexoconcave l.  one that has one convex and one concave surface; the convex surface is of greater curvature than the concave. Called also periscopic concave l., diverging meniscus l., and negative meniscus l.

corneal l.  corneal contact l.

Crookes' l.  one made from glass rendered opaque to ultraviolet and infrared rays but transparent to visible light.

crossed l.  a converging lens with minimal spherical aberration.

l. crystalli´na ,  crystalline l.  lens (def. 2).

cylindrical l.  a lens used to correct astigmatism, having one plane surface and one cylindrical, or one spherical surface and one toroidal. The meridian along the lens axis has no refractive power, but the meridian at right angles to the axis has maximum refractive power; thus the principal focus is a straight line, not a point. Symbol C. Abbreviated cyl. Called also astigmatic l.

decentered l.  one in which the optical axis does not pass through the geometric center.

dispersing l.  an incorrect name for concave l.

diverging l.  concave l.

double concave l.  biconcave l.

double convex l.  biconvex l.

flat l.  a lens with equal curvature on both sides, as opposed to a meniscus lens.

Fresnel l.  a thin lens made up of a number of stepped setbacks concentrically arranged; it has the optical properties of a much thicker lens.

honeybee l.  a magnifying eyeglass lens designed to resemble the multifaceted eye of the honeybee. It consists of three or six small telescopes mounted in the upper portion of the spectacles and directed toward the center and right and left visual fields. Prisms are included to provide a continuous, unbroken magnified field of view.

immersion l.  see under objective.

iseikonic l.  a lens that magnifies but does not refract; it is used to treat aniseikonia because it changes the sizes of the images on the retinas of the eyes. Called also aniseikonic l. and size l.

meniscus l.  a crescent-shaped lens with one concave surface and one convex; the surfaces have different degrees of curvature. See concavoconvex l. and convexoconcave l.

meniscus l., converging  concavoconvex l.

meniscus l., diverging  convexoconcave l.

meniscus l., negative  convexoconcave l.

meniscus l., positive  concavoconvex l.

meter l.  a converging lens with a focal length of one meter and a refracting power of one diopter.

minus l.  concave l.

omnifocal l.  one whose power increases continuously and regularly in a downward direction, thereby avoiding the discontinuity in field and power of a bifocal or trifocal lens.

orthoscopic l.  one that gives a very flat and undistorted field of vision, especially at the periphery.

periscopic l.  one with a 1.25D base curve.

periscopic concave l.  convexoconcave l.

periscopic convex l.  concavoconvex l.

photochromic l. ,  photosensitive l.  a light-sensitive lens that darkens in full light and clears in reduced light.

plane l. ,  plano l.  a lens with no curve and no refracting power; light rays enter and leave parallel.

planoconcave l.  a lens with one plane and one concave side.

planoconvex l.  a lens with one plane and one convex side.

plus l.  convex l.

punktal l.  a toric lens that is corrected for astigmatism over the entire field of vision.

rigid contact l.  hard contact l.

safety l.  one that protects the eyes from injury, especially from impact. Impact-resistant lenses may be made by tempering or by using plastic or laminated lenses. See also safety glasses.

size l.  iseikonic l.

spherical l. (S, sph)  one that is a segment of a sphere. See illustration.

spherocylindrical l.  a lens with one spherical and one cylindrical surface, and functioning as both a simple spherical lens and a simple cylindrical one.

stigmatic l.  anastigmatic l.

toric l.  a meniscus lens with a cylindrical curve ground on the outer (convex) surface.

trial l.  one used in testing the vision.

trifocal l.  one having three segments with different refractive powers, ordinarily with the upper for distant, the middle for intermediate, and the lower for near vision; used in trifocal glasses.

lensometer (lens·om·e·ter) (lenz-om´ə-tər) [lens + -meter]  a device for measuring the optical characteristics of lenses; called also phacometer.

Lente Iletin (Len·te Il·e·tin) (len´te il´ə-tin)  see under Iletin.

lenticel (len·ti·cel) (len´tĭ-sel)  a lens-shaped gland, especially one of those at the base of the tongue.

lenticonus (len·ti·co·nus) (len”ti-ko´nəs) [lens + conus]  a conical protrusion of the substance of the crystalline lens, covered by capsule or connective tissue, occurring more frequently on the posterior surface, and usually affecting only one eye.

lenticula (len·tic·u·la) (len-tik´u-lə) [L.]  nucleus lentiformis.

lenticular (len·tic·u·lar) (len-tik´u-lər) [L. lenticularis]  1. pertaining to or shaped like a lens.  2. pertaining to the crystalline lens.  3. pertaining to the lenticular nucleus.

lenticulo-optic (len·tic·u·lo-op·tic) (len-tik”u-lo-op´tik)  pertaining to the lenticular nucleus and the optic thalamus.

lenticulostriate (len·tic·u·lo·stri·ate) (len-tik”u-lo-stri´āt)  pertaining to the lenticular nucleus and the corpus striatum.

lenticulothalamic (len·tic·u·lo·tha·lam·ic) (len-tik”u-lo-thə-lam´ik)  relating to the lenticular nucleus and the thalamus.

lentiform (len·ti·form) (len´tĭ-form)  shaped like a lens; see under bone and see nucleus lentiformis.

lentigines (len·tig·i·nes) (len-tij´ĭ-nēz) [L.]  plural of lentigo.

lentiginosis (len·tig·i·no·sis) (len-tij”ĭ-no´sis)  the presence of multiple lentigines.

progressive cardiomyopathic l.  Moynahan's syndrome (def. 1).

lentiginous (len·tig·i·nous) (len-tij´ĭ-nəs)  characterized by multiple lentigines; pertaining to or of the nature of a lentigo.

lentiglobus (len·ti·glo·bus) (len”tĭ-glo´bəs) [lens + globus]  an exaggerated curvation of the crystalline lens, producing a spherical bulging on its anterior surface.

lentigo (len·ti·go) (len-ti´go)  pl. lentig´ines [L. “freckle”]  a small, flat, tan to dark brown or black, macular melanosis on the skin resembling a freckle clinically but histologically distinct because of the presence of an increased number of normal-appearing melanocytes along the dermoepidermal junction. Lentigines do not darken on exposure to sunlight, as do freckles. Called also l. simplex.

l. malig´na  see under melanoma.

nevoid l.  a congenital lentigo involving the mucous membranes as well as the skin, occurring in association with various hereditary disorders, including the LEOPARD syndrome and Moynihan's syndrome, and characterized histologically by elongation of rete pegs, an increase in the number of melanocytes with formation of nests, an increase of melanin in both the melanocytes and basal keratinocytes, and melanophages in the upper dermis. Single or multiple lesions may occur, and size and configuration vary widely. Called also l. simplex.

senile l. ,  l. seni´lis  a benign, discrete, hyperpigmented macule occurring on chronically sun-exposed skin in adults, especially on the back of the hands and on the forehead. Called also liver spot and solar l.

l. sim´plex  1. lentigo.  2. nevoid l.

solar l.  senile l.

Lentivirinae (Len·ti·vi·ri·nae) (len”tĭ-vir-i´ne)  the HIV-like viruses: a former subfamily of viruses of the family Retroviridae, containing the genus Lentivirus.

Lentivirus (Len·ti·vi·rus) (len´tĭ-vi”rəs) [L. lentus slow + virus]  a genus of viruses of the family Retroviridae that cause persistent infection that typically results in chronic, progressive, usually fatal disease. It includes the human immunodeficiency viruses, simian immunodeficiency virus, feline immunodeficiency virus, maedi/visna virus, caprine arthritis-encephalitis virus, and equine infectious anemia virus.

lentivirus (len·ti·vi·rus) (len´tĭ-vi”rəs)  any virus of the subfamily Lentivirinae.

lentula (len·tu·la) (len´chu-lə)  lentulo.

lentulo (len·tu·lo) (len´chu-lo, len-too´lo)  in root canal therapy, a flexible, spiral, rotating instrument made of stainless steel wire attached to a handpiece, used to place cement into the prepared canal. Called also lentula, lentulo paste carrier, and paste carrier.

Lenz syndrome (Lenz syndrome) (lents) [Widukind D. Lenz, German physician, born 1919]  see under syndrome.

Previous A-B  | C-D  | E-F  | G-H  | I-J  | K-L  | M-N  | O-P  | Q-R  | S-T  | U-V  | W-X  | Y-Z Next

Copyright 2004. WB Saunders, an Elsevier imprint. All rights reserved.
Click here for important legal information about Dorland's Medical Dictionary.

    Print This Page   Add To My Folder