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Medical Dictionary


lithomyl (lith′o-mil)
An instrument for pulverizing a stone in the bladder. [litho- + G. myle, mill]

lithonephritis (lith′o-ne-fri′tis)
Interstitial nephritis associated with calculus formation.

lithopedion, lithopedium (lith-o-pe′de-on, -um)
A retained fetus, usually extrauterine, that has become calcified. [litho- + G. paidion, small child]

lithotome (lith′o-tom)
A knife used in lithotomy.

lithotomist (li-thot′o-mist)
A person skilled in lithotomy.

lithotomy (li-thot′o-me)
Cutting for stone; a cutting operation for the removal of a calculus, especially a vesical calculus. SYN: lithectomy. [litho- + G. tome, incision] high l. SYN: suprapubic l.. lateral l. l. in which the perineum is incised to one side of the median line. marian l. SYN: median l.. [L. mas (mar-), male] median l. l. in which the perineal incision is made in the median raphe. SYN: marian l.. perineal l. l. in which the bladder is approached by an incision in the perineum. prerectal l. l. by an incision in the midline of the perineum anterior to anus. suprapubic l. l. in which the bladder is entered by an incision immediately above the symphysis pubis. SYN: high l.. vaginal l. l. in which the bladder or ureter is entered through an incision in the vagina. vesical l. SYN: cystolithotomy.

lithotresis (lith-o-tre′sis)
The boring of holes in a calculus to facilitate its crushing. [litho- + G. tresis, a boring]

lithotripsy (lith′o-trip-se)
The crushing of a stone in the renal pelvis, ureter, or bladder, by mechanical force or focused sound energy. SYN: lithotrity. [litho- + G. tripsis, a rubbing] electrohydraulic shock wave l. (ESWL) destruction of calculi (urinary tract or other) by fragmentation using shock waves sent transcutaneously via ultrasound transducers. extracorporeal shock wave l. (ESWL) (lith′o-trip′se) breaking up of renal or ureteral calculi by focused sound energy. shock wave l. a method of fragmenting calculi. ultrasonic l. the demolition of calculi by high frequency sound waves.

lithotriptic (lith-o-trip′tik)
1. Relating to lithotripsy. 2. An agent that effects the dissolution of a calculus.

lithotriptor (lith-o-trip′tor)
A device used to crush or fragment a calculus in lithotripsy.

lithotriptoscopy (lith′o-trip-tos′ko-pe)
Crushing of a stone in the bladder under direct vision by use of a lithotriptoscope. [litho- + G. tribo, to rub, crush, + skopeo, to view]

lithotrite (lith′o-trit)
A mechanical instrument used to crush a urinary calculus in lithotripsy. SYN: lithoclast. [litho- + L. tero, pp. tritus, to rub]

lithotrity (li-thot′ri-te)
SYN: lithotripsy.

lithotroph (lith′o-trof)
An organism whose carbon needs are satisfied by carbon dioxide. Cf.:chemoautotroph.

lithuresis (lith′u-re′sis)
The passage of gravel in the urine. [litho- + G. ouresis, urination]

lithuria (li-thoo′re-a)
Excretion of uric acid or urates in large amount in the urine. [lithic (acid) + G. ouron, urine]

litmus (lit′mus) [old C.I. 1242]
A blue coloring matter obtained from Roccella tinctoria and other species of lichens, the principal component of which is azolitmin; used as an indicator (reddened by acids and turned blue again by alkalies). [a corruption of lacmus, fr. Dutch lakmoes]

litter (lit′er)
1. A stretcher or portable couch for moving the sick or injured. 2. A group of animals of the same parents, born at the same time. SYN: brood (1) . [Fr. litière; fr. lit, bed]

James, U.S. surgeon, 1836–1885. See L. area.

William J., English surgeon, 1810–1894. See L. disease.

Alexis, French anatomist, 1658–1726. See Littré glands, under gland, Littré hernia.

Karl K.T., German gynecologist, 1815–1890. See L. obliquity.

livebirth, live birth (liv′berth)
The birth of an infant who shows evidence of life after birth. SEE ALSO: liveborn infant.

livedo (li-ve′do)
A bluish discoloration of the skin, either in limited patches or general. [L. lividness, fr. liveo, to be black and blue] postmortem l. a purple coloration of dependent parts, except in areas of contact pressure, appearing within one half to two hours after death, as a result of gravitational movement of blood within the vessels. SYN: postmortem hypostasis, postmortem lividity, postmortem suggillation. l. reticularis a persistent purplish network-patterned discoloration of the skin caused by dilation of capillaries and venules due to stasis or changes in underlying blood vessels including hyalinization; rarely appears as a developmental defect. SYN: dermatopathia pigmentosa reticularis. l. reticularis idiopathica an extensive and permanent form of l. reticularis; in rare instances associated with central arterial disease. l. reticularis symptomatica a discoloration or mottling of the skin due to some demonstrable cause, such as seen in erythema ab igne, and in certain tuberculids. SEE ALSO: cutis marmorata. l. telangiectatica a permanent mottling of the skin due to an anomaly, probably congenital, of the cutaneous capillaries; a form of l. reticularis.

livedoid (liv′e-doyd)
Pertaining to or resembling livedo.

liver (liv′er) [TA]
The largest gland of the body, lying beneath the diaphragm in the right hypochondrium and upper part of the epigastric region; it is of irregular shape and weighs from 1–2 kg, or about 140 the weight of the body. As an exocrine gland it secretes bile; it initially receives most absorbed nutrients via the portal vein; it detoxifies and is also of great importance in fat, carbohydrate, and protein metabolism and stores glycogen. SYN: hepar [TA] . [A.S. lifer] cardiac l. SYN: cardiac cirrhosis. desiccated l. a dried undefatted powder prepared from mammalian livers used as human food; contains riboflavin, nicotinic acid, and choline; used in the treatment of macrocytic anemias and as a nutritional supplement. fatty l. yellow discoloration of the l. due to fatty degeneration of l. parenchymal cells. SYN: hepatic steatosis. hobnail l. in Laënnec cirrhosis, the contraction of scar tissue and hepatic cellular regeneration which causes a nodular appearance of the livers surface. lardaceous l. SYN: waxy l.. left l. [TA] portion of the l. receiving blood from the left branches of the hepatic artery and portal vein, and from which bile is drained via the left hepatic duct; the plane of the middle hepatic vein (demarcated externally on the visceral surface by the fossae for the gallbladder and inferior vena cava and on the diaphragmatic surface by a line extrapolated from the gallbladder to the terminal inferior vena cava) separates left from right l.. SYN: pars hepatis sinistra [TA] , left part of l.&star. nutmeg l. chronic passive congestion of the l., causing accentuation of the lobular pattern with red central and yellow or tan periportal zones. pigmented l. a l. that contains pigment, such as occurs in Dubin-Johnson syndrome, hemochromatosis, long-standing malaria. polycystic l. gradual cystic dilation of intralobular bile ducts (Meyenburg complexes) that fail to involute in embryologic development of the l.; frequently associated with bilateral congenital polycystic kidneys and occasionally with cystic involvement of the pancreas, lungs, and other organs. SYN: polycystic l. disease. posterior l. posterior hepatic segment I. right l. [TA] portion of the l. receiving blood from the right branches of the hepatic artery and portal vein, and from which bile is drained via the right hepatic duct; the plane of the middle hepatic vein (demarcated externally on the visceral surface by the fossae for the gallbladder and inferior vena cava and on the diaphragmatic surface by a line extrapolated from the gallbladder to the terminal inferior vena cava) separates right from left l.. SYN: pars hepatis dextra [TA] , right part of l.&star. wandering l. SYN: hepatoptosis. waxy l. amyloid degeneration of the l.. SYN: lardaceous l..

livetin (liv′e-tin)
Any of the three major water-soluble proteins in egg yolk: α-l., serum albumin; β-l., α-glycoprotein; γ-l., serum γ-globulin.

Having a black and blue or a leaden or ashy gray color, as in discoloration from a contusion, congestion, or cyanosis. [L. lividus, being black and blue]

lividity (li-vid′i-te)
The state of being livid. postmortem l. SYN: postmortem livedo.

livor (li′vor)
The livid discoloration of the skin on the dependent parts of a corpse. [L. a black and blue spot]

lixivium (lik-siv′e-um)
SYN: lye. [L. ntr. of lixivius, made into lye]

Abbreviation for lysolecithin-lecithin acyltransferase.

Abbreviation for large loop excision of transformation zone of the cervix of the uterus.

Abbreviation for left lower lobe (of lung).

John Uri, U.S. pharmacist, 1849–1936. Noted for investigational work in plant chemistry and phytochemistry as applied to medicines, alkaloids, and glucosides.

Lloyd reagent
See under reagent.

Abbreviation for left lower quadrant (of abdomen).

Abbreviation for licentiate in midwifery.

Abbreviation for lumen (2) .

Abbreviation for left mentoanterior position.

1. Abbreviation for left mentoposterior position; last menstrual period; latent membrane protein; low molecular weight proteins, under protein. 2. Gene product of Epstein-Barr virus (latent membrane protein).

Abbreviation for left mentotransverse position.

SYN: noscapine.

Abbreviation for lymph node permeability factor.

Lo, Lo
See L. dose.

Abbreviation for left occipitoanterior position.

load (lod)
1. A departure from normal body content, as of water, salt, or heat; positive loads are quantities in excess of the normal; negative loads are quantities in deficit. 2. The quantity of a measurable entity borne by an object or organism. [M.E. lode, fr. A.S. lad,] electronic pacemaker l. the impedance to the output, the standard l. being 500 ohms resistance ± 1%. genetic l. the aggregate of more or less harmful genes that are carried, mostly hidden, in the genome that may be transmitted to descendants and cause morbidity and disease; in classical genetic dynamics, genetic l. may be seen as undischarged genetic debts that result from previous mutations, each of which is supposed to exact an average number of lethal equivalents dependent only on the pattern of inheritance, regardless of how mild or severe the phenotype may be. viral l. the plasma level of viral RNA, as determined by various techniques including target amplification assay by reverse transcriptase polymerase chain reaction and branched DNA technology with signal amplification. Because levels of detection vary with method, results of testing by different methods are not comparable.Serial measurement of HIV viral l. has become a standard procedure in monitoring the course of AIDS. Reported as the number of copies of viral RNA per mL of plasma, assessment of viral l. provides important information about the number of lymphoid cells actively infected with HIV. This laboratory procedure has supplanted the CD4 count as an indicator of prognosis of persons infected with HIV, in determining when to start antiretroviral therapy, and in measuring the response to therapy. Because the CD4 count is regarded as superior in determining the level of immune compromise and the risk of opportunistic infection, both tests are currently used. Antiretroviral therapy is started when plasma HIV RNA concentration exceeds 5000 copies/mL. When, as a result of treatment, the number of copies of viral RNA falls below the level that can be detected by standard methods, replication of HIV is considered to have been suppressed. In no case, however, has AIDS been cured, nor has viral proliferation remained arrested after cessation of antiretroviral therapy.

loading (lod′ing)
Administration of a substance for the purpose of testing metabolic function. carbohydrate l. a procedure, popular with long-distance runners and other athletes, of filling muscles with a large glycogen pool prior to an athletic event; often, the athlete consumes very few carbohydrates for three days, followed by a largely carbohydrate diet for the last three days before the event. salt l. the administration of 2 g of sodium chloride (with a regular diet) 3 times a day for 4 days; a diagnostic test in primary aldosteronism, in which the salt l. produces a typical plasma electrolyte and hormonal pattern. soda l. a procedure adopted by a number of athletes of ingesting sodium bicarbonate in an attempt to buffer the production of protons during exercise.

Loa loa (lo′a lo′a)
The African eye worm, a species of the family Onchocercidae (superfamily Filarioidea) that is indigenous to the western part of equatorial Africa, especially in the region of the Congo River, and is the causal agent of loiasis. Adult worms are white or gray-white, cylindroid, and threadlike, the males averaging 25–35 by 0.3–0.4 mm (with a curved tail) and the females ranging from 50–60 by 0.4–0.6 mm; microfilariae are ensheathed, with nuclei extending to the tip of the tail. The life cycle is somewhat similar to that of Wuchereria species; humans are the only known definitive host, and parasites are transmitted by Chrysops flies (family Tabanidae); infective larvae from the latter require 3 years or more to mature in humans, and the adult forms may persist in a human host for as long as 17 years. SEE ALSO: loiasis.

lobar (lo′bar)
Relating to any lobe. l. nephronia 1. a focal renal mass related to acute infection. 2. acute focal bacterial nephritis. 3. renal phlegmon (not an abscess; no free pus).

lobate (lo′bat)
1. Divided into lobes. 2. Lobe-shaped; denoting a bacterial colony with a deeply undulate margin. SYN: lobose, lobous.

lobe (lob) [TA]
1. One of the subdivisions of an organ or other part, bounded by fissures, sulci, connective tissue septa, or other structural demarcations. 2. A rounded projecting part, as the l. of the ear. SEE ALSO: lobule. 3. One of the larger divisions of the crown of a tooth, formed from a distinct point of calcification. SYN: lobus [TA] . [G. lobos, l.] anterior l. of hypophysis adenohypophysis. azygos l. of right lung a small accessory l. sometimes formed above the hilum of the right lung; separated from the rest of the upper l. by a deep groove lodging the azygos vein. SYN: lobus azygos pulmonis dextri. caudate l. posterior hepatic segment I. cerebral lobes SYN: lobi cerebri, under lobus. cuneiform l. SYN: biventer lobule. ear l. SYN: lobule of auricle. falciform l. SYN: cingulate gyrus. flocculonodular l. [TA] the small posterior and inferior subdivision of the cerebellar cortex that borders the line of attachment of the choroid roof of the rhomboid fossa, and consists of the left and right flocculus together with the unpaired nodulus (the most posterior of the folia composing the vermis cerebelli). Its major afferent connections come from the vestibular nuclei and directly from the vestibular nerve; it projects largely to the vestibular nuclei, directly and by way of the fastigial nucleus. SYN: lobus flocculonodularis [TA] . frontal l. [TA] SYN: frontal l. of cerebrum. frontal l. of cerebrum [TA] the portion of each cerebral hemisphere anterior to the central sulcus. SYN: frontal l. [TA] , lobus frontalis [TA] . glandular l. of hypophysis SYN: adenohypophysis. Home l. the enlarged middle l. of the prostate gland. inferior l. of (left / right) lung it is located below and behind the oblique fissure and contains five bronchopulmonary segments: superior (S VI), medial basal (S VII), anterior basal (S VIII), lateral basal (S IX), and posterior basal (S X). SYN: lobus inferior pulmonis dextri et sinistri [TA] , lower l. of lung&star. insular l. lobus insula. kidney lobes [TA] one of the subdivisions of the kidney, consisting of a renal pyramid and the cortical tissue associated with it. SYN: lobus renalis [TA] , renal l.. left l. [TA] the left subdivision of several glands, e.g., prostate, thyroid, thymus. SYN: lobus sinister [TA] . left l. of liver [TA] it is separated from the much larger right l. anterior and superior to the falciform and coronary ligaments, and from the quadrate and caudate lobes by the fissure for the ligamentum teres and the fissure for the ligamentum venosum. The lobes of the liver are not functional units, being defined by external structures; the distribution of the portal vein, hepatic artery, and bile ducts does not correspond to the gross lobar divisions of the liver. SYN: lobus hepatis sinister [TA] , divisio lateralis sinistra&star, lateral division of left liver&star. limbic l. [TA] as originally defined by P. Broca: the nearly closed ring of the brain structures surrounding the hilus, or margin, of the cerebral hemisphere of mammals; it is composed of the fornicate gyrus (cingulate gyrus, fasciolar gyrus, parahippocampal gyrus, and uncus), and the hippocampus. See limbic system. SYN: lobus limbicus [TA] . lingual l. SYN: cingulum of tooth. lower l. of lung inferior l. of (left / right) lung. lobes of mammary gland [TA] the 15–20 separate portions of the mammary gland that radiate from the central area deep to the nipplelike wheel spokes and make up the body of the mammary gland; each is drained by a single lactiferous duct. SYN: lobi glandulae mammariae [TA] . middle l. of prostate [TA] the portion of the prostate lying between the urethra and the ejaculatory ducts; indistinct unless hypertrophied. SYN: lobus medius prostatae [TA] , Morgagni caruncle. middle l. of right lung [TA] it is located anteriorly between the horizontal and oblique fissures and includes lateral (S IV) and medial (S V) bronchopulmonary segments. SYN: lobus medius pulmonis dextri [TA] . nervous l. SYN: neurohypophysis. neural l. of hypophysis the bulbous part of the neurohypophysis attached to the hypothalamus by the infundibulum. It is composed of pituicytes, blood vessels, and terminals of nerve fibers from the supraoptic and paraventricular nuclei. occipital l. [TA] SYN: occipital l. of cerebrum. occipital l. of cerebrum [TA] the posterior, somewhat pyramid-shaped part of each cerebral hemisphere, demarcated by no distinct surface markings on the lateral convexity of the hemisphere from the parietal and temporal lobes, but sharply delineated from the parietal l. by the parieto-occipital sulcus on the medial surface. SYN: lobus occipitalis [TA] , occipital l. [TA] . parietal l. [TA] SYN: parietal l. of cerebrum. parietal l. of cerebrum [TA] the middle portion of each cerebral hemisphere, separated from the frontal l. by the central sulcus, from the temporal l. by the lateral sulcus in front and an imaginary line projected posteriorly, and from the occipital l. only partially by the parieto-occipital sulcus on its medial aspect. SYN: lobus parietalis [TA] , parietal l. [TA] . placental lobes cotyledons of the human placenta, viewed on the maternal surface as irregularly shaped elevations or lobes. polyalveolar l. a type of congenital anomaly where a severalfold increase in the total alveolar number leads to congenital lobar emphysema. posterior l. of hypophysis SYN: neurohypophysis. l. of prostate [TA] one of the lateral lobes (right or left) or the middle l. or isthmus of the prostate; in the adult the lobes are ill-defined. SYN: lobus prostatae [TA] . pyramidal l. of thyroid gland [TA] an inconstant narrow l. of the thyroid gland that arises from the upper border of the isthmus and extends upward, sometimes as far as the hyoid bone; it marks the point of continuity with the thyroglossal duct. SYN: lobus pyramidalis glandulae thyroideae [TA] , Lallouette pyramid, Morgagni appendix, pyramid of thyroid. quadrate l. 1. a l. on the inferior surface of the liver located between the fossa for the gallbladder and the fissure for the ligamentum teres; 2. SYN: quadrangular lobule. 3. SYN: precuneus. renal l. SYN: kidney lobes. Riedel l. an occasional tonguelike process extending downward from the right l. of the liver lateral to the gallbladder; a similar process may, though rarely, extend from the left l.. SYN: lobus appendicularis, lobus linguiformis. right l. [TA] the right subdivision of several glands, e.g., prostate, thyroid, thymus. SYN: lobus dexter [TA] . right l. of liver [TA] the largest l. of the liver, separated from the left l. anteriorly and superiorly by the falciform and coronary ligaments and from the caudate and quadrate lobes by the sulcus for the vena cava and the fossa for the gallbladder. SYN: lobus hepatis dexter [TA] . Spigelius l. SYN: posterior hepatic segment I. superior l. of (right/left) lung the l. of the right lung that lies above the oblique and horizontal fissures and includes the apical (S I), posterior (S II), and anterior (S III) bronchopulmonary segments; in the left lung, the l. lies above the oblique fissure and contains the apicoposterior (S I + II), anterior (S III), superior lingular (S IV), and inferior lingular (S V) segments. SYN: lobus superior pulmonis (dextri et sinistri) [TA] , upper l. of lung&star. supplemental l. in dental anatomy, an extra l.; one that is not included in the typical formation of a tooth. temporal l. [TA] a long l., the lowest of the major subdivisions of the cortical mantle, forming the posterior two-thirds of the ventral surface of the cerebral hemisphere, separated from the frontal and parietal lobes above it by the lateral sulcus arbitrarily delineated by an imaginary plane from the occipital l. with which it is continuous posteriorly. The temporal l. has a heterogeneous composition: in addition to a large neocortical component consisting of the superior, middle, and inferior temporal gyri and the lateral and medial occipitotemporal gyri, it includes the largely juxtallocortical parahippocampal gyrus with its paleocortical (olfactory) uncus and, beneath the latter, the amygdala. SYN: lobus temporalis [TA] , temporal cortex. lobes of thyroid gland [TA] the two major divisions of the gland lying on the right and left side of the trachea and connected by the isthmus. A smaller pyramidal l. is frequently present as an upward extension from the isthmus. SYN: lobi glandulae thyroideae [TA] . upper l. of lung superior l. of (right/left) lung.

lobectomy (lo-bek′to-me)
Excision of a lobe of any organ or gland. [G. lobos, lobe, + ektome, excision]

lobelia (lo-be′le-a)
1. The dried leaves and tops of L. inflata (family Lobeliaceae); it contains several alkaloids: lobeline, lobelamine, lobelanidine, lobelanine, norlobelanine, norlobelanidine, and isolobelanine. The fluid extract and the tincture have been used as an expectorant in asthma and chronic bronchitis. 2. One of a class of alkaloids isolated from l. (1). 3. Any plant of the genus L.. SYN: asthma-weed (1) , wild tobacco.

lobeline, lobelin (lo′be-len, lob′e-len, -lin)
A piperidylacetophenone; an alkaloid of lobelia with the same actions as nicotine, but with less potency. l. sulfate a form of l. occurring in yellow friable masses, soluble in water; used in whooping cough and asthma; it has been suggested as a smoking deterrent.

lobi (lo′bi)
Plural of lobus. [L.]

lobitis (lo-bi′tis)
Inflammation of a lobe.

Jorge, Brazilian physician, 1900–1979. See L. disease.

Loboa loboi (lo-bo′a lo-bo′e)
A species of fungus causing lobomycosis. The organism has not been grown in culture.

lobomycosis (lo-bo-mi-ko′sis)
A chronic localized mycosis of the skin reported from South America resulting in granulomatous nodules or keloids that contain budding, thick-walled cells about 9 μm in diameter, i.e., the tissue form of Loboa loboi, the causative fungus, which has not been cultured. Also occurs in dolphins. SYN: Lobo disease.


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