M

M M mega-; methionine; molar¹; molar²; myopia.

M. M. [L.] misce (mix); mistura (a mixture).

M M molar.

M_r M_r relative molecular mass; see molecular weight, under weight.

m m median; meter; milli-.

m. m. [L.] musculus (muscle).

m m mass; molal.

m- m- meta- (2).

μ μ (mu, the twelfth letter of the Greek alphabet) micro-; the heavy chain of IgM (see immunoglobulin).

MA MA Master of Arts; mental age.

mA mA milliampere; one thousandth (10^{− 3}) of an ampere.

MAC MAC membrane attack complex; Mycobacterium avium complex (see under disease).

macerate macérer to soften by wetting or soaking.

machine machine a mechanical contrivance for doing work or generating energy. heart-lung m. cœur-poumon artificiel a combination blood pump (artificial heart) and blood oxygenator (artificial lung) used in open-heart surgery.

Macracanthorhynchus Macracanthorhynchus a genus of parasitic worms (phylum Acanthocephala), including M. hirudinaceus, found in swine.

macrencephaly mégalencéphalie hypertrophy of the brain.

macr(o)- macr(o)- word element [Gr.], large; abnormal size.

macroadenoma macroadénome a pituitary adenoma over 10 mm in diameter.

macroamylase macroamylase a complex in which normal serum amylase is bound to a variety of specific binding proteins, forming a complex too large for renal excretion.

macrobiota macrobiote the macroscopic living organisms of a region. Adj.: macrobiotic.

macroblast macroblaste an abnormally large immature erythrocyte; a large young erythroblast with megaloblastic features.

macroblepharia macroblépharie abnormal largeness of the eyelid.

macrocephaly macrocéphalie megalocephaly; unusually large size of the head. Adj.: macrocephalic.

macrocheilia macrochéilie excessive size of the lip.

macrocheiria macrochéirie megalocheiria.

macrocolon macrocôlon megacolon.

macrocrania macrocrânie abnormal increase in the size of the skull, the face appearing small in comparison.

macrocyte macrocyte an abnormally large erythrocyte.

macrocythemia macrocythémie the presence of macrocytes in the blood.

macrocytic macrocytique pertaining to or characterized by macrocytes.

macrocytosis macrocytose macrocythemia.

macrodactyly macrodactylie megalodactyly.

macroelement macroélément any of the macronutrients that are chemical elements.

macrofauna macrofaune the macroscopic animal organisms of a region.

macroflora macroflore the macroscopic vegetable organisms of a region.

macrofollicular macrofolliculaire pertaining to or characterized by large follicles.

macrogamete macrogamète 1. the larger, less active female anisogamete. 2. the larger of two types of malarial parasites; see gamete (2).

macrogametocyte macrogamétocyte 1. a cell that produces macrogametes. 2. the female gametocyte of certain Sporozoa, such as malarial plasmodia, which matures into a macrogamete.

macrogenitosomia macrogénitosomie excessive bodily development, with unusual enlargement of the genital organs. m. praecox m. précoce, macrogenitosomia praecox macrogenitosomia occurring at an early age.

macroglia macroglie neuroglial cells of ectodermal origin, i.e., the astrocytes and oligodendrocytes considered together.

macroglobulin macroglobuline a globulin of unusually high molecular weight, in the range of 1,000,000. α₂-m. a₂-macroglobuline a plasma protein that inhibits a wide variety of proteolytic enzymes, including trypsin, plasmin, thrombin, kallikrein, and chymotrypsin, by entrapping and reducing the accessibility of their functional sites to large molecules.

macroglobulinemia macroglobulinémie increased levels of macroglobulins in the blood. Waldenström m. m. de Waldenström a plasma cell dyscrasia resembling leukemia, with cells of lymphocytic, plasmacytic, or intermediate morphology that secrete an IgM M component, diffuse infiltration of bone marrow, weakness, fatigue, bleeding disorders, and visual disturbances.

macrognathia macrognathie enlargement of the jaw. Adj.: macrognathic.

macrogyria macrogyrie moderate reduction in the number of sulci of the cerebrum, sometimes with increase in the brain substance, resulting in excessive size of the gyri.

macrolide macrolide 1. a compound characterized by a large lactone ring with multiple keto and hydroxyl groups. 2. any of a group of antibiotics containing this ring linked to one or more sugars, produced by certain species of Streptomyces.

macromastia macromastie excessive size of the breasts.

macromelia macromélie abnormal largeness of one or more limbs.

macromere macromère one of the large blastomeres formed by unequal cleavage of a zygote as a result of asymmetric positioning of the mitotic spindle.

macromethod macrométhode a chemical method using customary (not minute) quantities of the substance being analyzed.

macromineral macrominéral macroelement.

macromolecule macromolécule a very large molecule having a polymeric chain structure, as in proteins, polysaccharides, etc. Adj.: macromolecular.

macromonocyte macromonocyte an abnormally large monocyte.

macromyeloblast macromyéloblaste an abnormally large myeloblast.

macronodular macronodulaire characterized by large nodules.

macronormoblast macronormoblaste macroblast.

macronucleus macronucléus the larger of two types of nuclei when more than one is present in a cell.

macronutrient élément minéral an essential nutrient required in relatively large amounts, such as carbohydrates, fats, proteins, or water; sometimes certain minerals are included, such as calcium, chloride, or sodium.

macronychia macronychie abnormal largeness of the nails.

macro-ovalocyte macro-ovalocyte an enlarged, oval erythrocyte seen in megaloblastic anemia.

macropenis macropénis excessive size of the penis.

macrophage macrophage any of the large, mononuclear, highly phagocytic cells derived from monocytes that occur in the walls of blood vessels (adventitial cells) and in loose connective tissue (histiocytes, phagocytic reticular cells). They are components of the reticuloendothelial system. Macrophages are usually immobile but become actively mobile when stimulated by inflammation; they also interact with lymphocytes to facilitate antibody production. alveolar m. m. alvéolaire one of the rounded granular, mononuclear phagocytes within the alveoli of the lungs that ingest inhaled particulate matter. armed m ’s m. tueurs those capable of inducing cytotoxicity as a consequence of antigen-binding by cytophilic antibodies on their surfaces or by factors derived from T lymphocytes.

macrophthalmia macrophthalmie megalophthalmos; enlargement of the eyeball.

macropinocytosis macropinocytose [macro- + pinocytosis] pinocytosis in which large amounts of extracellular fluid are taken up by extension of the plasma membrane, with the formation of large vesicles.

macropolycyte macropolycyte a hypersegmented polymorphonuclear leukocyte of greater than normal size.

macroprolactinoma macroprolactinome a prolactinoma more than 10 mm in diameter, usually associated with serum prolactin levels above 500 ng per mL.

macropsia macropsie a disorder of visual perception in which objects appear larger than their actual size.

macroscopic macroscopique gross (2).

macroshock macrochoc in cardiology, a moderate to high level of electric current passing over two areas of intact skin, which can cause ventricular fibrillation.

macrosomatia macrosomatie great bodily size.

macrostomia macrostomie greatly exaggerated width of the mouth.

macrotia macrotie abnormal enlargement of the pinna of the ear.

macula macula pl. maculae [L.] 1. a stain, spot, or thickening; in anatomy, an area distinguishable by color or otherwise from its surroundings. Often used alone to refer to the macula retinae. 2. m. lutea. 3. macule. 4. a corneal scar, appreciated as a gray spot. Adj.: macular, maculate. acoustic maculae taches acoustiques maculae acusticae. maculae acusticae maculae acusticae the macula sacculi and macula utriculi considered together. m. adherens m. adherens desmosome. maculae atrophicae maculae atrophicae white scarlike patches formed on the skin by atrophy. maculae ceruleae maculae ceruleae taches bleues, taches ombrées faint grayish blue spots sometimes found peripheral to the axilla or groin in pediculosis. cerebral m. m. cérébrale tache cérébrale. maculae cribrosae taches criblées three perforated areas (inferior, medial, and superior) on the vestibular wall through which branches of the vestibulocochlear nerve pass to the saccule, utricle, and semicircular canals. m. densa m. densa a zone of heavily nucleated cells in the distal renal tubule. m. flava laryngis m. flava laryngis a yellow nodule at one end of a vocal cord. m. lutea m. lutea retinaem. retinae m. lutea an irregular yellowish depression on the retina, lateral to and slightly below the optic disk. m. sacculi m. auditive du saccule a thickening on the wall of the saccule where the epithelium contains hair cells that are stimulated by linear acceleration and deceleration and by gravity. m. utriculi m. auditive de l ’utricule a thickening in the wall of the utricle where the epithelium contains hair cells that are stimulated by linear acceleration and deceleration and by gravity.

macule macule a discolored spot on the skin that is not raised above the surface.

maculocerebral maculocérébral cerebromacular.

maculopathy maculopathie any pathological condition of the macula retinae. bull ’s eye m. m. en « œil de bœuf » increase of pigment of a circular area of the macula retinae accompanying degeneration, occurring in various toxic states and diseases.

madarosis madarose loss of eyelashes or eyebrows.

Madurella Madurella a genus of imperfect fungi. M. grisea and M. mycetomi are etiologic agents of maduromycosis.

maduromycosis maduromycose mycetoma.

mafenide mafénide an antibacterial, used topically as the monoacetate salt in superficial infections.

magaldrate magaldrate a chemical combination of aluminum and magnesium hydroxides and sulfate; an antacid.

magenta magenta fuchsin or other salt of rosaniline.

maggot asticot the soft-bodied larva of an insect, especially a form living in decaying flesh.

magma magma 1. a thick, viscous, aqueous suspension of finely divided, insoluble, inorganic material. 2. a thin, pastelike substance composed of organic material.

magnesium (Mg) magnésium chemical element (see Table of Elements), at. no. 12; its salts are essential in nutrition, being required for the activity of many enzymes, especially those concerned with oxidative phosphorylation. Various salts, including m. chloride, m. gluceptate, m. gluconate, and m. lactate are used as electrolyte replenishers. m. carbonate carbonate de m. an antacid. m. chloride chlorure de m. an electrolyte replenisher and a pharmaceutic necessity for hemodialysis and peritoneal dialysis fluids. m. citrate citrate de m. a saline laxative used for bowel evacuation before diagnostic procedures or surgery of the colon. m. hydroxide hydroxyde de m. an antacid and laxative. m. oxide oxyde de m. an antacid and laxative; also used as a preventative for hypomagnesemia and as a sorbent in pharmaceutical preparations. m. salicylate salicylate de m. see salicylate. m. silicate silicate de m. MgSiO₃, a silicate salt of magnesium; the most common hydrated forms found in nature are asbestos and talc. m. sulfate sulfate de m. Epsom salt; an anticonvulsant and electrolyte replenisher, also used as a laxative and local antiinflammatory. m. trisilicate trisilicate de m. a compound of magnesium oxide and silicon dioxide with varying proportions of water; an antacid.

magnet aimant an object having polarity and capable of attracting iron. Adj.: magnetic.

magnetropism magnétropisme a growth response in a nonmotile organism under the influence of a magnet.

magnification grossissement 1. apparent increase in size, as under the microscope. 2. the process of making something appear larger, as by use of lenses. 3. the ratio of apparent (image) size to real size.

ma huang ma huang [Chinese] any of various species of Ephedra used as herbs in Chinese medicine.

maintenance préservation providing a stable state over a long period, or the stable state so produced.

major majeur large; significant; great or greatest in scope, effect, number, size, extent, or importance.

mal mal [Fr.] disease. grand m. grand m. see under epilepsy. m. de mer m. de mer seasickness. petit m. petit m. absence epilepsy.

mala mala [L.] 1. cheek. 2. zygomatic bone.

mala mala [Sanskrit] in ayurveda, waste products of the body formed during metabolism, including urine, feces, mucus, and sweat.

malabsorption malabsorption impaired intestinal absorption of nutrients.

malacia malacie morbid softening or softness of a part or tissue.

-malacia -malacie word element [Gr.], morbid softness.

malacoplakia malacoplasie the formation of soft patches of the mucous membrane of a hollow organ. m. vesicae m. vésicale a soft, yellowish, fungus-like growth on the mucosa of the bladder and ureters.

malacosis malacose malacia.

malacosteon malacostéon, os mou osteomalacia.

maladjustment échec de l ’adaptation in psychiatry, defective adaptation to the environment.

malady maladie disease.

malaise malaise a vague feeling of discomfort.

malalignment malalignement displacement, especially of teeth from their normal relation to the line of the dental arch.

malar malaire 1. buccal; pertaining to the cheek. 2. zygomatic.

malaria paludisme an infectious febrile disease endemic in many warm regions of the world, caused by protozoa of the genus Plasmodium, which are parasitic in red blood cells; it is transmitted by Anopheles mosquitoes and marked by attacks of chills, fever, and sweating occurring at intervals that depend on the time required for development of a new generation of parasites in the body. Adj.: malarial. falciparum m. p. à falciparum the most serious form, due to Plasmodium falciparum, with severe constitutional symptoms and sometimes causing death. ovale m. p. à ovale a mild form due to Plasmodium ovale, with recurring tertian febrile paroxysms and a tendency to end in spontaneous recovery. quartan m. fièvre quarte that in which the febrile paroxysms occur every 72 hours, or every fourth day counting the day of occurrence as the first day of each cycle; due to Plasmodium malariae. quotidian m. p. quotidien vivax malaria in which the febrile paroxysms occur daily. tertian m. fièvre tierce vivax malaria in which the febrile paroxysms occur every 42 to 47 hours, or every third day counting the day of occurrence as the first day of the cycle. vivax m. p. à vivax that due to Plasmodium vivax, in which the febrile paroxysms commonly occur every other day (tertian m.), but may occur daily (quotidian m.), if there are two broods of parasites segmenting on alternate days.

Malassezia Malassezia a genus of fungi of the form-class Hyphomycetes, including M. furfur, which causes tinea versicolor in susceptible individuals, and M. pachydermatis.

malassimilation malassimilation 1. imperfect, or disordered, assimilation. 2. the inability of the gastrointestinal tract to take up ingested nutrients, due to faulty digestion (maldigestion) or to impaired intestinal mucosal transport (malabsorption).

malate malate any salt of malic acid.

malathion malathion an organophosphorus insecticide used as a topical pediculicide.

malaxation malaxage an act of kneading.

maldevelopment malformation, développement anormal abnormal growth or development.

male mâle 1. the sex that produces spermatozoa. 2. masculine.

maleate maléate any salt or ester of maleic acid.

maleic acid acide maléique an unsaturated dibasic acid, the cis-isomer of fumaric acid.

maleruption éruption dentaire ectopique eruption of a tooth out of its normal position.

malformation malformation 1. a type of anomaly. 2. a morphologic defect of an organ or larger region of the body, resulting from an intrinsically abnormal developmental process.

malic acid acide malique a crystalline acid from the juices of many fruits and plants and an intermediate in the tricarboxylic acid cycle.

malignancy malignité 1. a tendency to progress in virulence. 2. the quality of being malignant. 3. a cancer, especially one with the potential to cause death.

malignant malin 1. tending to become worse and end in death. 2. having the properties of anaplasia, invasiveness, and metastasis; said of tumors.

malingering simulation willful, fraudulent feigning or exaggeration of the symptoms of illness or injury to attain a consciously desired end.

malleable malléable susceptible of being beaten out into a thin plate.

malleoincudal qui se rapporte au marteau et à l ’enclume pertaining to the malleus and incus.

malleolus malléole pl. malleoli [L.] a rounded process, such as the protuberance on either side of the ankle joint at the lower end of the fibula and the tibia. Adj.: malleolar.

malleotomy malléotomie 1. operative division of the malleus. 2. operative separation of the malleoli.

malleus marteau [L.] hammer; the outermost of the auditory ossicles, and the one attached to the tympanic membrane; its club-shaped head articulates with the incus. See Plate 29.

malnutrition malnutrition any disorder of nutrition.

malocclusion malocclusion improper relations of apposing teeth when the jaws are in contact.

malposition malposition abnormal or anomalous placement.

malpractice faute professionnelle improper or injurious practice; unskillful and faulty medical or surgical treatment.

malpresentation présentation vicieuse, malprésentation faulty fetal presentation.

malrotation malrotation 1. abnormal or pathologic rotation, as of the vertebral column. 2. failure of normal rotation of an organ, as of the gut, during embryonic development.

maltase maltase 1. α-glucosidase. 2. any enzyme with similar glycolytic activity, cleaving α-1,4 and sometimes α-1,6 linked glucose residues from nonreducing termini; in humans there are considered to be four such enzymes; two are the heat-stable enzymes, usually called maltases, constituting the glucoamylase complex; the other two are the heat-labile enzymes, usually called sucrase and isomaltase.

MALToma MALTome a form of extranodal marginal zone lymphoma originating in mucosa-associated lymphoid tissue, particularly that of the gastrointestinal tract.

maltitol maltitol a hydrogenated, partially hydrolyzed starch used as a bulk sweetener.

maltose maltose a disaccharide composed of two glucose residues, the fundamental structural unit of glycogen and starch.

malum mal [L.] disease.

malunion consolidation vicieuse d ’une fracture faulty union of the fragments of a fractured bone.

mamba mamba any member of the genus Dendroaspis, extremely venomous elapid snakes. Included are the black mamba (D. polylepis), a large black African tree snake, and the green mamba (D. angusticeps), a large green or black tree snake of eastern and southern Africa.

mamilla mamelon [L.] mammilla.

mamma mamelle pl. mammae [L.] the breast.

mammal mammifère an individual of the class Mammalia. Adj.: mammalian.

mammalgia mammalgie mastalgia.

mammaplasty mammoplastie mammoplasty; plastic reconstruction of the breast, either to augment or reduce its size.

Mammalia Mammalia a class of warm-blooded vertebrate animals, including all that have hair and suckle their young.

mammary mammaire pertaining to the mammary gland, or breast.

mammectomy mammectomie mastectomy.

mammilla pl. mammillae [L.] 1. mamelon nipple (1). 2. mammilla papilla. Adj.: mammillary.

mammillation mammillation a nipple-like elevation or projection. Adj.: mammillated.

mammilliplasty mammiloplastie theleplasty.

mammillitis mammite thelitis.

mammillothalamic mammillothalamique pertaining to or connecting the mammillary body and thalamus.

mammitis mammite mastitis.

mamm(o)- mamm(o)- word element [L.], breast; mammary gland.

mammogram mammograme a radiograph of the breast.

mammography mammographie radiography of the mammary gland.

mammoplasia mammoplasie development of breast tissue.

mammoplasty mammoplastie mammaplasty.

mammose 1. poitrine (à forte) having large breasts. 2. mamelonné mammillated.

mammotomy mammotomie mastotomy.

mammotrophic mammotrophique mammotropic.

mammotropic mammotrope having a stimulating effect on the mammary gland.

mammotropin mammotropine prolactin.

mandible mâchoire inférieure, mandibule the horseshoe-shaped bone forming the lower jaw; the largest and strongest bone of the face, consisting of a body and a pair of rami, which articulate with the skull at the temporomandibular joints. See Plate 1. Adj.: mandibular.

mandibula mandibula pl. mandibulae [L.] mandible.

mandrel mandrin the shaft on which a dental tool is held in the dental handpiece, for rotation by the dental engine.

mandrin mandrin a metal guide for a flexible catheter.

maneuver manœuvre a skillful or dextrous method or procedure. Bracht m. m. de Bracht a method of extraction of the aftercoming head in breech presentation. Brandt-Andrews m. m. de Brandt et Andrews a method of expressing the placenta from the uterus. forward-bending m. m. manoeuvre de Tilliaux a method of detecting retraction signs in neoplastic changes in the mammae; the patient bends forward from the waist with chin held up and arms extended toward the examiner. If retraction is present, an asymmetry in the breast is seen. Heimlich m. m. de Heimlich a method of dislodging food or other material from the throat of a choking victim: wrap one ’s arms around the victim, allowing their upper torso to hang forward; with both hands against the victim ’s abdomen (slightly above the navel and below the rib cage), make a fist with one hand, grasp it with the other, and forcefully press into the abdomen with a quick upward thrust. Repeat several times if necessary. Pajot m. m. de Pajot a method of forceps delivery with traction along the axis of the superior pelvic aperture. Pinard m. m. de Pinard a method of bringing down the foot in breech extraction. Prague m. m. de Prague a method of extracting the aftercoming head in breech presentation. Scanzoni m. m. de Scanzoni double application of forceps blades for delivery of a fetus in the occiput posterior position. Toynbee m. m. de Toynbee pinching the nostrils and swallowing; if the auditory tube is patent, the tympanic membrane will retract medially. Valsalva m. m. de Valsalva 1. increase in intrathoracic pressure by forcible exhalation effort against the closed glottis. 2. increase in the pressure in the eustachian tube and middle ear by forcible exhalation effort against occluded nostrils and closed mouth.

mangafodipir mangafodipir a contrastenhancing agent used as the trisodium salt in magnetic resonance imaging (MRI) of hepatic lesions.

manganese (Mn) manganèse chemical element (see Table of Elements), at. no. 25; its salts occur in the body tissue in very small amounts and activate liver arginase and other enzymes. Poisoning, usually due to inhalation of manganese dust, is manifested by symptoms including mental disorders accompanying a syndrome resembling parkinsonism, and inflammation of the respiratory system.

mania manie [Gr.] a phase of bipolar disorders characterized by expansiveness, elation, agitation, hyperexcitability, hyperactivity, and increased speed of thought and ideas. Adj.: manic.

-mania -mania word element [Gr.], obsessive preoccupation with something.

manic-depressive maniacodépressif alternating between attacks of mania and depression, as in bipolar disorders.

manikin mannequin a model to illustrate anatomy or on which to practice surgical or other manipulations.

manipulation manipulation skillful or dextrous treatment by the hands.

mannitol mannitol a sugar alcohol formed by reduction of mannose or fructose and widely distributed in plants and fungi; an osmotic diuretic used to prevent and treat acute renal failure, to promote excretion of toxic substances, to reduce cerebral edema or elevated intracranial or intraocular pressure, and to prevent hemolysis during transurethral surgical procedures.

mannose mannose a six-carbon sugar epimeric with glucose and occurring in oligosaccharides of many glycoproteins and glycolipids.

mannosidosis mannosidose a lysosomal storage disease due to a defect in α-mannosidase activity that results in lysosomal accumulation of mannose-rich substrates; it is characterized by coarse facies, upper respiratory problems, mental retardation, hepatosplenomegaly, and cataracts.

manometer manomètre an instrument for measuring the pressure of liquids or gases. Adj.: manometric.

manometry manométrie the measurement of pressure by means of a manometer. anal m. m. anale the measurement of pressure generated by the anal sphincter; used in the evaluation of fecal incontinence.

Mansonella Mansonella a genus of filarial nematodes. M. ozzardi is found in the mesentery and visceral fat of humans in Central and South America.

Mansonia Mansonia a genus of mosquitoes, several species of which transmit Brugia malayi; some may also transmit viruses, such as those of equine encephalomyelitis.

mantle manteau 1. an enveloping cover or layer. 2. cerebral cortex.

manual manuel 1. of or pertaining to the hand; performed by the hand or hands. 2. a small reference book, particularly one giving instructions or guidelines. Diagnostic and Statistical M. of Mental Disorders (DSM) Manuel diagnostique et statistique des troubles mentaux see under D.

manubrium manubrium pl. manubria [L.] a handle-like structure or part, such as the manubrium of the sternum. m. mallei m. of malleus m. du marteau the longest process of the malleus; it is attached to the middle layer of the tympanic membrane and has the tensor tympani muscle attached to it. m. sterni, m. of sternum m. sternal the cranial part of the sternum, articulating with the clavicles and first two pairs of ribs.

manus manus pl. manus [L.] hand.

MAO MAO monoamine oxidase.

MAOI IMAO monoamine oxidase inhibitor.

MAP PAM mean arterial pressure.

map carte a two-dimensional graphic representation of arrangement in space. chromosome m. c. chromosomique one that shows the position of genetic loci on a chromosome, such as a gene map or cytogenetic map. cytogenetic m. c. cytogénétique one that gives the position of gene loci relative to chromosome bands. gene m. c. des gènes one showing the linear arrangement of genetic loci on a DNA molecule and indicating the distance between them, either in relative or physical units. genetic m., linkage m. c. génétique a gene map giving the positions of known genes and markers relative to each other, based on recombination frequencies, rather than as specific physical points. physical m. c. physique a gene map showing the linear order of genes or markers in the genome, along with the physical distances between them, rather than the frequencies of recombination.

maprotiline maprotiline a tetracyclic antidepressant with actions similar to those of the tricyclic antidepressants; used as the hydrochloride salt.

marasmus marasme a form of protein-energy malnutrition predominantly due to prolonged severe caloric deficit, chiefly occurring in the first year of life, with growth retardation and wasting of subcutaneous fat and muscle. Adj.: marantic, marasmic.

march marche the progression of electrical activity through the motor cortex. jacksonian m. m. jacksonienne the spread of abnormal electrical activity from one area of the cerebral cortex to adjacent areas, characteristic of jacksonian epilepsy.

marfanoid marfanoïde having the characteristic symptoms of Marfan syndrome.

margin marge an edge or border. Adj.: marginal. gingival m., gum m. m. gingivale the border of the gingiva surrounding, but unattached to, the substance of the teeth. m. of safety m. de sécurité a calculation estimating a maximum safe level of exposure for humans, now superseded by the reference dose.

margination margination accumulation and adhesion of leukocytes to the epithelial cells of blood vessel walls at the site of injury in the early stages of inflammation.

marginoplasty marginoplastie surgical restoration of a border, as of the eyelid.

margo margo pl. margines margin.

marihuana marijuana marijuana.

marijuana marijuana a preparation of the leaves and flowering tops of hemp plants (Cannabis sativa), usually smoked in cigarettes for its euphoric properties.

marital marital of or pertaining to marriage.

mark marque a spot, blemish, or other circumscribed area visible on a surface. birth m. nœvus cutané see birthmark. port-wine m. tache de vin nevus flammeus. strawberry m. fraise 1. strawberry hemangioma (1). 2. cavernous hemangioma.

marker marqueur something that identifies or that is used to identify. tumor m. m. tumoral a biochemical substance indicative of neoplasia, ideally specific, sensitive, and proportional to tumor load.

marrow moelle 1. bone m. 2. any of various soft substances resembling bone marrow. bone m. m. osseuse the soft organic material filling the cavities of bones, made up of a fiber-rich meshwork of connective tissue, the meshes being filled with marrow cells, which consist variously of fat cells, large nucleated cells or myelocytes, and megakaryocytes. Yellow bone m. is that in which fat cells predominate; red bone m. is the site of production of erythrocytes and granular leukocytes and occurs in developing bone, as of the ribs and vertebrae. spinal m. m. épinière spinal cord.

Marsupialia Marsupialia an order of mammals characterized by the possession of a marsupium, including opossums, kangaroos, wallabies, koala bears, and wombats.

marshmallow guimauve a perennial Eurasian herb, Althaea officinalis, or preparations of its flowers, leaves, or roots, which are used in the treatment of cough and for irritation of the oral and pharyngeal mucosa; also used in folk medicine.

marsupialization marsupialisation conversion of a closed cavity into an open pouch, by incising it and suturing the edges of its wall to the edges of the wound.

masculine masculin pertaining to or having qualities normally associated with the male sex.

masculinity masculinité virility; the possession of masculine qualities.

masculinization masculinisation 1. normal development of male primary or secondary sex characters in a male. 2. development of male secondary sex characters in a female or prepubescent male. 3. the condition of having such sex characters.

maser maser a device which produces an extremely intense, small and nearly nondivergent beam of monochromatic radiation in the microwave region, with all the waves in phase.

mask 1. masque a covering or appliance for shading, protecting, or medicating the face. 2. masquer to cover or conceal. 3. masquer in audiometry, to obscure or diminish a sound by the presence of another sound of different frequency. 4. masquer in dentistry, to camouflage metal parts of a prosthesis by covering with opaque material.

masked masqué 1. concealed from view; hidden. 2. masqué, caché not presenting or producing the usual symptoms. 3. blind (2).

masochism masochisme the act or instance of gaining pleasure from physical or psychological pain; usually used to denote sexual masochism. Adj.: masochistic. sexual m. m. sexuel a paraphilia in which sexual gratification is derived from being hurt, humiliated, or otherwise made to suffer physically or psychologically.

mass masse 1. a lump or collection of cohering particles. 2. a cohesive mixture to be made into pills. 3. the characteristic of matter that gives it inertia. Symbol m. atomic m. m. atomique atomic weight; used particularly when describing a single isotope of a nuclide. inner cell m. bouton embryonnaire embryoblast. lean body m. m. corporelle maigre that part of the body including all its components except neutral storage lipid; in essence, the fat-free mass of the body. molar m. (M) m. molaire the mass of a molecule in grams (or kilograms) per mole. molecular m. m. moléculaire the mass of a molecule in daltons, derived by addition of the component atomic masses. Its dimensionless equivalent is molecular weight. relative molecular m. m. moléculaire relative technically preferable term for molecular weight. Symbol M_r.

massa massa pl. massae [L.] mass (1).

massage massage [Fr.] systematic therapeutic friction, stroking, or kneading of the body. cardiac m. m. cardiaque intermittent compression of the heart by pressure applied over the sternum (closed cardiac m.) or directly to the heart through an opening in the chest wall (open cardiac m.); done to reinstate and maintain circulation. carotid sinus m. m. du sinus carotidien firm rotatory pressure applied to one side of the neck over the carotid sinus, causing vagal stimulation and used to slow or terminate tachycardia. electrovibratory m., vibratory m. m. électrovibratoire that performed with an electric vibrator.

massasauga massasauga Sistrurus catenatus, a small venomous rattlesnake in the United States and northern Mexico.

masseter masséter see under muscle. Adj.: masseteric.

masseur masseur [Fr.] 1. a man who performs massage. 2. an instrument for performing massage.

masseuse masseuse [Fr.] a woman who performs massage.

MAST MAST acronym for Military Anti-Shock Trousers, inflatable trousers used to induce autotransfusion of blood from the lower to the upper part of the body.

mastadenitis mastadénite mastitis.

Mastadenovirus Mastadenovirus mammalian adenoviruses; a genus of viruses of the family Adenoviridae that infect mammals, causing disease of the gastrointestinal tract, conjunctiva, central nervous system, and urinary tract; many species induce malignancy.

mastalgia mastalgie pain in the breast.

mastatrophy atrophie de la glande mammmaire atrophy of the breast.

mastectomy mastectomie excision of the breast. extended radical m. m. radicale étendue radical mastectomy with removal of the ipsilateral half of the sternum and a portion of ribs two through five with the underlying pleura and the internal mammary lymph nodes. modified radical m. m. radicale modifiée simple mastectomy together with axillary lymphadenectomy, but with preservation of the pectoral muscles. partial m. m. partielle removal of only enough breast tissue to ensure that the margins of the resected surgical specimen are free of tumor. radical m. m. totale élargie amputation of the breast with wide excision of the pectoral muscles and axillary lymph nodes. subcutaneous m. m. sous-cutanée excision of breast tissue with preservation of overlying skin, nipple, and areola so that the breast form may be reconstructed.

mastication mastication chewing; the biting and grinding of food.

masticatory 1. masticateur subserving or pertaining to mastication; affecting the muscles of mastication. 2. masticatoire a remedy to be chewed but not swallowed.

Mastigophora Mastigophora a subphylum of protozoa comprising those having one or more flagella throughout most of their life cycle, and a simple, centrally located nucleus; many are parasitic in both invertebrates and vertebrates, including humans.

mastigophoran mastigophore 1. a protozoan of the subphylum Mastigophora. 2. of or belonging to the subphylum Mastigophora; called also flagellate and mastigote.

mastigote mastigote mastigophoran.

mastitis mastite inflammation of the breast. m. neonatorum m. du nouveau-né any abnormal condition of the breast in the newborn. periductal m. m. périductale inflammation of the tissues about the ducts of the mammary gland. plasma cell m. m. à plasmocytes infiltration of the breast stroma with plasma cells and proliferation of the cells lining the ducts.

mast(o)- mast(o)- word element [Gr.], breast; mastoid process.

mastocyte mastocyte mast cell.

mastocytosis mastocytose an accumulation, local or systemic, of mast cells in the tissues; known as urticaria pigmentosa when widespread in the skin.

mastoid mastoïde 1. breast-shaped. 2. mastoid process. 3. pertaining to the mastoid process.

mastoidalgia mastoïdalgie pain in the mastoid region.

mastoidectomy mastoïdectomie excision of the mastoid cells or the mastoid process.

mastoideocentesis paracentèse des cellules mastoïdiennes paracentesis of the mastoid cells.

mastoiditis mastoïdite inflammation of the mastoid antrum and cells.

mastopathy mastopathie any disease of the mammary gland.

mastopexy mastopexie surgical fixation of a pendulous breast.

mastoplasty mastoplastie mammaplasty.

mastoptosis mastoptose pendulous breasts.

mastosquamous qui se rapporte à la mastoïde et à la squame du temporal. pertaining to the mastoid and squama of the temporal bone.

mastotomy mastotomie surgical incision of a breast.

masturbation masturbation self-stimulation of the genitals for sexual pleasure.

MAT MAT multifocal atrial tachycardia; see chaotic atrial tachycardia, under tachycardia.

matching assortiment 1. comparison and selection of objects having similar or identical characteristics. 2. selection of compatible donors and recipients for transfusion or transplantation. 3. selection of subjects for clinical trials or other studies so that the different groups are similar in selected characteristics. cross m. test croisé crossmatching.

materia matière [L.] matter. m. alba materia alba whitish deposits on the teeth, composed of mucus and epithelial cells containing bacteria and filamentous organisms. m. medica m. médicale pharmacology.

maternal maternel pertaining to the mother.

maternity maternité 1. motherhood. 2. a lyingin hospital.

mating accouplement pairing of individuals of opposite sexes, especially for reproduction. assortative m. croisement assortatif nonrandom mating in which choice of a mate is influenced by phenotype; it is positive if phenotypically similar mates are chosen, and negative if they are dissimilar. nonrandom m. croisement non aléatoire mating in which partner selection is not independent of genotype, such as occurs with assortative mating, inbreeding, or stratification of populations into subgroups. random m. a. aléatoire mating in which partner selection is independent of genotype.

matrix matrice pl. matrices [L.] 1. the intercellular substance of a tissue or the tissue from which a structure develops. 2. groundwork; the base in which or from which a thing develops. 3. a mold or form for casting. 4. a metal or plastic strip used to provide form to a dental restoration. 5. the continuous phase of a composite dental restoration. bone m. m. osseuse the intercellular substance of bone, consisting of collagenous fibers, ground substance, and inorganic salts. cartilage m. m. cartilagineuse the intercellular substance of cartilage, consisting of cells and extracellular fibers embedded in an amorphous ground substance. extracellular m. (ECM) m. extracellulaire any substance produced by cells and excreted to the extracellular space within the tissues, serving as a scaffolding to hold tissues together and helping to determine their characteristics. interterritorial m. m. interterritoriale a paler staining region among the darker territorial matrices. nail m. m. de l ’ongle m. unguis. territorial m. m. territoriale basophilic material around groups of cartilage cells. m. unguis matrix unguis nail bed; also, the proximal part of the nail bed where growth occurs.

matter matière 1. substance; anything that occupies space. 2. pus. gray m. of nervous system substance grise du système nerveux substantia grisea. white m. of nervous system substance blanche du système nerveux substantia alba.

maturation maturation 1. the process of becoming mature. 2. attainment of emotional and intellectual maturity. 3. in biology, a process of cell division during which the number of chromosomes in the germ cells is reduced to one half the number characteristic of the species. 4. suppuration suppuration.

mature 1. mûrir to develop to maturity; to ripen. 2. mature fully developed; ripe.

maxilla maxillaire pl. maxillas, maxillae [L.] the irregularly shaped bone that with its fellow forms the upper jaw; it assists in the formation of the orbit, the nasal cavity, and the palate, and lodges the upper teeth. See Plate 1. Adj.: maxillary.

maxilloethmoidectomy maxillo-ethmoïdectomie excision of the portion of the maxilla surrounding the maxillary sinus and of the cribriform plate and anterior ethmoid cells.

maxillofacial maxillofaciale pertaining to the maxilla and the face.

maxillomandibular maxillomandibulaire pertaining to the upper and lower jaws.

maxillotomy maxillotomie surgical sectioning of the maxilla which allows movement of all or part of the maxilla into the desired position.

maximum maximum pl. maxima [L.] 1. the greatest possible, or actual, effect or quantity. 2. largest; utmost. Adj.: maximal. transport m., tubular m. (T_m) transport maximal (tubulaire) the highest rate (milligrams per minute) at which the renal tubules can transfer a substance either from the tubular luminal fluid to the interstitial fluid or from the interstitial fluid to the tubular luminal fluid, beyond which it may be excreted in the urine.

maze labyrinthe a complicated system of intersecting paths used in intelligence tests and in demonstrating learning in experimental animals.

mazindol mazindol a sympathomimetic amine having amphetamine-like actions; used as an anorectic.

mazopexy mastopexie mastopexy.

mazoplasia mastoplasie degenerative epithelial hyperplasia of the mammary acini.

MB MB [L.] Medicinae Baccalaureus (Bachelor of Medicine).

MC MC [L.] Magister Chirurgiae (Master of Surgery).

MC MC Medical Corps.

MCFA MCFA medium-chain fatty acids.

mcg mcg microgram.

MCH HCM mean corpuscular hemoglobin.

MCHC CCMH mean corpuscular hemoglobin concentration.

mCi mCi millicurie; one thousandth (10^{− 3}) of a curie.

μCi μCi microcurie; one millionth (10^{− 6}) of a curie.

MCP MCP membrane cofactor protein.

MCV VGM mean corpuscular volume.

MD MD [L.] Medicinae Doctor (Doctor of Medicine).

Md Md mendelevium.

MDA MDA methylenedioxyamphetamine.

MDF FDM myocardial depressant factor.

MDMA MDMA 3,4-methylenedioxymethamphetamine.

meal repas a portion of food or foods taken at some particular and usually stated or fixed time. test m. r. d ’épreuve a meal containing material given to aid in diagnostic examination of the stomach.

mean moyenne an average; a numerical value that in some sense represents the central value of a set of numbers. arithmetic m. m. arithmétique the sum of n numbers divided by n. geometric m. m. géométrique the nth root of the product of n numbers.

measles rougeole rubeola; a highly contagious viral infection, usually of childhood, involving primarily the respiratory tract and reticuloendothelial tissues, marked by an eruption of discrete, red papules that become confluent, flatten, turn brown, and desquamate. atypical m. r. atypique a form of natural measles infection affecting those who previously received killed measles virus vaccine. German m. rubéole rubella.

measure mesure see tables accompanying weight.

meatitis méatite inflammation of the urinary meatus.

meatoplasty méatoplastie plastic surgery of a meatus.

meatoscopy méatoscopie inspection of a meatus, especially the urinary meatus.

meatotomy méatotomie incision of an acoustic or urinary meatus to enlarge it.

meatus méat pl. meatus [L.] an opening or passage. Adj.: meatal. acoustic m., auditory m. orifice du conduit auditif, m. auditif either of two passages in the ear, one leading to the tympanic membrane (external acoustic m.), and one for passage of nerves and blood vessels (internal acoustic m.). nasal m. m. nasal one of the spaces (inferior, middle, and superior) below the corresponding nasal concha, on either side of the septum. urinary m. m. urinaire the opening of the urethra on the body surface through which urine is discharged.

mebendazole mébendazole an anthelmintic used against trichuriasis, enterobiasis, ascariasis, and hookworm disease.

mecamylamine mécamylamine a ganglionic blocking agent used in the form of the hydrochloride salt as an antihypertensive.

mechanics mécanique the science dealing with the motions of bodies. body m. m. corporelle the application of kinesiology to prevent and correct problems related to posture.

mechanism 1. mécanisme a machine or machinelike structure. 2. mécanisme, processus the manner of combination of parts, processes, etc., which subserve a common function. defense m. m. de defense a usually unconscious mental mechanism by which psychic tension is diminished, e.g., repression, rationalization, etc. escape m. m. d ’evitement in the heart, the mechanism of impulse initiation by lower centers in response to lack of impulse propagation by the sinoatrial node. mental m. processus mental 1. the organization of mental operations. 2. an unconscious and indirect manner of gratifying a repressed desire.

mechanoreceptor mécanorécepteur a receptor that is excited by mechanical pressures or distortions, as those responding to touch and muscular contractions.

mechanosensory mécanosensible pertaining to sensory activation in response to mechanical pressures or distortions.

mechlorethamine méchlorétamine one of the nitrogen mustards, used in the form of the hydrochloride salt as an antineoplastic, particularly in disseminated Hodgkin disease.

meclizine méclizine an antihistamine used as the hydrochloride salt as an antinauseant in motion sickness and to manage vertigo associated with disease affecting the vestibular system.

meclocycline méclocycline a tetracycline antibiotic used topically as m. sulfosalicylate for the treatment of acne vulgaris.

meclofenamate méclofénamate a nonsteroidal antiinflammatory drug used as the sodium salt in the treatment of rheumatic and nonrheumatic inflammatory disorders, pain, dysmenorrhea, hypermenorrhea, and vascular headaches.

meconium méconium dark green mucilaginous material in the intestine of the full-term fetus.

MED MED minimal erythema dose.

media media 1. plural of medium. 2. middle. 3. tunica media vasorum.

medial 1. médial situated toward the median plane or midline of the body or a structure. 2. interne pertaining to the middle layer of structures.

medialis medialis [L.] medial.

median 1. médian situated in the median plane or in the midline of a body or structure. 2. moyenne the value of the middle item of a series when the items are arranged in numerical order. Symbol m.

medianus medianus [L.] median.

mediastinal médiastinal of or pertaining to the mediastinum.

mediastinitis médiastinite inflammation of the mediastinum. fibrosing m., fibrous m. m. fibreuse mediastinal fibrosis.

mediastinography médiastinographie radiography of the mediastinum.

mediastinopericarditis médiastinopéricardite pericarditis with adhesions extending from the pericardium to the mediastinum.

mediastinoscopy médiastinoscopie examination of the mediastinum by means of an endoscope inserted through an anterior midline incision just above the thoracic inlet.

mediastinum médiastin pl. mediastina [L.] 1. a median septum or partition. 2. the mass of tissues and organs separating the two pleural sacs, between the sternum in front and the vertebral column behind, containing the heart and its large vessels, trachea, esophagus, thymus, lymph nodes, and other structures and tissues; it is divided into superior and inferior regions, the latter subdivided into anterior, middle, and posterior parts. m. testis mediastinum testis the partial septum of the testis, formed near its posterior border by a continuation of the tunica albuginea.

mediate médiat indirect; accomplished by means of an intervening medium.

mediate médiatiser to serve as an intermediate agent.

medicable soignable subject to treatment with reasonable expectation of cure.

medical médical pertaining to medicine.

Medicare Medicare a program of the Social Security Administration which provides medical care to the aged.

medicated médicamenteux imbued with a medicinal substance.

medication médication 1. medicine (1). 2. impregnation with a medicine. 3. administration of a medicine or other remedy. ionic m. m. ionique iontophoresis.

medicinal médicinal having healing qualities; pertaining to a medicine.

medicine 1. médicament any drug or remedy. 2. médecine the diagnosis and treatment of disease and the maintenance of health. 3. médecine the treatment of disease by nonsurgical means. alternative m. m. douce see complementary and alternative medicine. aviation m. m. aéronautique that dealing with the physiologic, medical, psychologic, and epidemiologic problems involved in aviation. Chinese herbal m. phytothérapie chinoise a highly complex system of diagnosis and treatment using medicinal herbs, one of the branches of traditional Chinese medicine. Herbs range from the nontoxic and rejuvenating, used to support the body ’s healing system, to highly toxic ones, used to treat disease. clinical m. 1. m. clinique the study of disease by direct examination of the living patient. 2. clinique the last two years of the usual curriculum in a medical college. complementary m., complementary and alternative m. (CAM) m. complémentaire a large and diverse set of systems of diagnosis, treatment, and prevention based on philosophies and techniques other than those used in conventional Western medicine. Such practices may be described as alternative, existing as a body separate from and as a replacement for conventional Western medicine, or complementary, used in addition to conventional Western practice. CAM is characterized by its focus on the whole person as a unique individual, on the energy of the body and its influence on health and disease, on the healing power of nature and the mobilization of the body ’s own resources to heal itself, and on the treatment of the underlying causes, not symptoms, of disease. Many of the techniques used are controversial and have not been validated by controlled studies. emergency m. m. d ’urgence, oxylogie the medical specialty dealing with the acutely ill or injured who require immediate medical treatment. environmental m. m. de l ’environnement that dealing with the effects of the environment on humans, including rapid population growth, water and air pollution, travel, etc. evidence-based m. m. factuelle that in which the physician finds, assesses, and implements methods of diagnosis and treatment on the basis of the best available, current research, their clinical expertise, and the needs and preferences of the patient. See also under practice. experimental m. m. expérimentale the study of diseases based on experimentation in animals. family m. m. familiale see under practice. folk m. m. traditionnelle the use of home remedies and procedures as handed down by tradition. forensic m. m. légale medical jurisprudence. geographic m. m. géographique 1. geomedicine. 2. tropical m. group m. m. de groupe the practice of medicine by a group of physicians, usually representing various specialties, who are associated together for the cooperative diagnosis, treatment, and prevention of disease. herbal m. phytothérapie herbalism. holistic m. m. holistique a system of medicine that considers the human being as an integrated whole or functioning unit. internal m. m. interne that dealing especially with diagnosis and medical treatment of diseases and disorders of internal structures of the body. legal m. m. légale medical jurisprudence. maternal-fetal m. m. maternofœtale a subspecialty of obstetrics concerned with the obstetrical, medical, genetic, and surgical complications of pregnancy and their effects on the mother and fetus. mind-body m. m. corps-esprit a holistic approach to medicine that takes into account the effect of the mind on physical processes, including the effects of psychosocial stressors and conditioning, particularly as they affect the immune system. naturopathic m. m. naturopathique naturopathy. nuclear m. m. nucléaire the branch of medicine concerned with the use of radionuclides in the diagnosis and treatment of disease. occupational m. m. du travail the branch of medicine dealing with the study, prevention, and treatment of workplace-related injuries and occupational diseases. orthomolecular m. m. orthomoléculaire a system for the prevention and treatment of disease based on the theory that each person ’s biochemical environment is genetically determined and individually specific. Therapy involves supplementation with substances naturally present in the body (e.g., vitamins, minerals, trace elements, amino acids) in individually optimized amounts. patent m. médicament breveté a drug or remedy protected by a trademark, available without a prescription; formerly used for quack remedies sold by peddlers. physical m. m. physique physiatry. preclinical m. 1. m. pré-clinique preventive m. 2. pré-clinique the first two years of the usual curriculum in a medical college. preventive m. m. préventive science aimed at preventing disease. proprietary m. spécialité pharmaceutique a remedy whose formula is owned exclusively by the manufacturer and which is marketed usually under a name registered as a trademark. psychosomatic m. m. psychosomatique the study of the interactions between psychological processes and physiological states. rehabilitation m. m. de réadaptation the branch of physiatry concerned with the restoration of form and function after injury or illness. socialized m. m. sociale a system of medical care controlled by the government. space m. m. spatiale the branch of aviation medicine concerned with conditions encountered by humans in space. sports m. m. du sport the branch of medicine concerned with injuries sustained in athletics, including their prevention, diagnosis, and treatment. traditional Chinese m. (TCM) m. traditionnelle chinoise the diverse body of medical theory and practice that has evolved in China, comprising four branches: acupuncture and moxibustion, herbal medicine, qi gong, and tui na. In all of these, the body and mind are considered together as a dynamic system subject to cycles of change and affected by the environment, and emphasis is on supporting the body ’s self-healing ability. Fundamental to TCM are the yin/yang principle and the concept of basic substances that pervade the body: qi, jing, and shen, collectively known as the three treasures, and the blood (a fluid and material manifestation of qi) and body fluids (which moisten and lubricate the body). travel m., travelers’ m. m. des voyages the subspecialty of tropical medicine consisting of the diagnosis and treatment or prevention of diseases of travelers. tropical m. m. tropicale the branch of medicine concerned with diseases of the tropics and subtropics. veterinary m. m. veterinaire the diagnosis and treatment of diseases of animals other than humans.

medicolegal médicolégal pertaining to medical jurisprudence.

medicosocial médicosocial having both medical and social aspects.

mediolateral médiolatéral pertaining to the midline and one side.

medionecrosis médionécrose necrosis of the tunica media of a blood vessel.

meditation méditation an intentional and self-regulated focusing of attention, whose purpose is to relax and calm the mind and body. mindfulness m. m. de l ’attention a form in which distracting thoughts and feelings are not ignored but instead acknowledged and observed nonjudgmentally as they arise in order to detach from them and gain insight and awareness. transcendental m. m. transcendentale a technique for attaining a state of physical relaxation and psychological calm by the regular practice of a relaxation procedure that entails the repetition of a mantra to block distracting thoughts.

medium milieu pl. mediums, media [L.] 1. a substance that transmits impulses. 2. culture medium; see under C. 3. a preparation used in treating histologic specimens. active m. m. actif the aggregated atoms, ions, or molecules contained in a laser ’s optical cavity, in which stimulated emission will occur under the proper excitation. clearing m. m. clarifiant a substance to render histologic specimens transparent. contrast m. produit de contraste, milieu de contraste a substance introduced into or around a structure or tissues, being different from the structure or tissues as to absorptivity of x-rays, allowing radiographic visualization. culture m. m. de culture see under C. dioptric media milieux dioptriques refracting media. disperse m., dispersion m., dispersive m. m. de dispersion the continuous phase of a colloid system; the medium in which the particles of the disperse phase are distributed, analogous to the solvent in a true solution. nutrient m. m. nourricier a culture medium to which nutrient materials have been added. radiolucent m. m. radiotransparent a contrast medium that permits passage of x-rays. radiopaque m. m. radio-opaque a contrast medium that blocks passage of x-rays. refracting media milieux réfringents the transparent tissues and fluid in the eye through which light rays pass and by which they are refracted and focused on the retina.

medius medius [L.] situated in the middle.

medroxyprogesterone médroxyprogestérone a progestin used as the acetate ester in treatment of menstrual disorders, in postmenopause hormone replacement therapy, as a test for endogenous estrogen production, as an antineoplastic in the treatment of metastatic endometrial, breast, and renal carcinoma, and as a long-acting contraceptive.

medrysone médrysone a synthetic glucocorticoid used topically in the treatment of corticosteroid-responsive allergic and inflammatory conditions of the eye.

medulla moelle pl. medullae [L.] 1. the innermost part of an organ or structure. 2. medulla m. oblongata. 3. bone marrow. adrenal m., m. of adrenal gland médullosurrénale the inner, reddish brown, soft part of the adrenal gland; it synthesizes, stores, and releases catecholamines. m. of bone m. de l ’os bone marrow. m. oblongata bulbe rachidien that part of the brainstem continuous with the pons above and the spinal cord below. m. ossium m. ossium bone marrow. renal m. médulla rénale the inner part of the kidney substance, composed chiefly of collecting elements, Henle loops, and vasa recta, organized grossly into pyramids. spinal m., m. spinalis m. épinière spinal cord. m. of thymus zone médullaire du thymus the central portion of each lobule of the thymus; it contains many more reticular cells and far fewer lymphocytes than does the surrounding cortex.

medullary médullaire 1. pertaining to a medulla. 2. pertaining to bone marrow. 3. pertaining to the spinal cord.

medullated myélinisé myelinated.

medullization médullisation enlargement of marrow spaces, as in rarefying osteitis.

medulloblast médulloblaste an undifferentiated cell of the embryonic neural tube that may develop into either a neuroblast or spongioblast.

medulloepithelioma médullo-épithéliome a rare type of neuroepithelial tumor, usually in the brain or retina, composed of primitive neuroepithelial cells lining the tubular spaces.

mefenamic acid acide méfénamique a nonsteroidal antiinflammatory drug used to treat or prevent pain, inflammation, dysmenorrhea, and vascular headache.

mefloquine méfloquine an antimalarial effective against chloroquine-resistant strains of Plasmodium falciparum and P. vivax; used as the hydrochloride salt.

mega- méga- word element [Gr.], large; also used in naming units of measurement (symbol M) to designate an amount one million (10⁶) times the size of the unit to which it is joined.

megacalicosis mégacalicose nonobstructive dilatation of the renal calices due to malformation of the renal papillae.

megacaryocyte mégacaryocyte megakaryocyte.

megacolon mégacôlon dilatation and hypertrophy of the colon. acquired m. m. acquis any type associated with chronic constipation but normal ganglion cell innervation. aganglionic m., congenital m. m. congénital Hirschsprung disease; dilatation of one segment of colon due to narrowing and loss of motor function in the next distal segment, which has a congenital lack of myenteric ganglion cells. idiopathic m. m. idiopathique acquired m. toxic m. colectasie that associated with amebic or ulcerative colitis.

megacystis mégacyste an abnormally enlarged urinary bladder.

megaesophagus méga-œsophage see achalasia.

megakaryoblast mégacaryoblaste the earliest cytologically identifiable precursor in the thrombocytic series, which matures to form the promegakaryocyte. Adj.: megakaryoblastic.

megakaryocyte mégacaryocyte the giant cell of bone marrow containing a greatly lobulated nucleus, from which mature blood platelets originate. Adj.: megakaryocytic.

megalgia mégalgie a severe pain.

megal(o)- mégal(o)- word element [Gr.], large; abnormal enlargement.

megaloblast mégaloblaste a large, nucleated, immature progenitor of an abnormal erythrocytic series; the abnormal form corresponding to the normoblast. Adj.: megaloblastic.

megalocephaly mégacéphalie macrocephaly. Adj.: megalocephalic.

megalocheiria chiromégalie, mégalochirie abnormal largeness of the hands.

megalocyte mégalocyte macrocyte.

megalodactyly mégalodactylie excessive size of the fingers or toes. Adj.: megalodactylous.

megalogastria mégagastrie enlargement or abnormally large size of the stomach.

megalokaryocyte mégalocaryocyte megakaryocyte.

megalomania mégalomanie unreasonable conviction of one ’s own extreme greatness, goodness, or power. Adj.: megalomaniac.

megalopenis mégalopénis macropenis.

megalophthalmos mégalophtalmie macrophthalmia.

megalopia mégalopsie macropsia.

megalopodia mégalopodie abnormal largeness of the feet.

megalopsia mégalopsie macropsia.

megaloureter mégalo-uretère megaureter.

megalourethra mégalo-urètre congenital dilation of the urethra, due usually to abnormal development of the corpus spongiosum but occasionally to some abnormality of the corpus cavernosum.

megaureter méga-uretère congenital ureteral dilatation, which may be either primary or secondary to something else.

-megaly -mégalie word element [Gr.], enlargement.

megavitamin mégavitamine a dose of vitamin(s) vastly exceeding the amount recommended for nutritional balance.

megavolt (Mv) mégavolt one million (10⁶) volts.

megavoltage mégavoltage in radiotherapy, voltage greater than 1 megavolt, in contrast to orthovoltage and supervoltage.

megestrol mégestrol a synthetic progestational agent, used as the acetate ester in the palliative treatment of some breast, endometrial, and prostate carcinomas and in the treatment of anorexia, cachexia, and weight loss associated with cancer or AIDS.

meglumine méglumine a crystalline base used in preparing salts of certain acids for use as a radiopaque medium, e.g., diatrizoate m., iothalamate m.

megohm mégohm one million (10⁶) ohms.

megophthalmos buphtalmie hydrophthalmos.

meiosis méiose a special type of cell division occurring in the maturation of germ cells, consisting of two successive cell divisions (meiosis I and meiosis II) without an interval of DNA replication, by means of which diploid germ cells give rise to haploid gametes. Adj.: meiotic.

melagra mélagra muscular pain in the limbs.

melalgia mélalgie pain in the limbs.

melancholia mélancolie former name for depression; curently used to denote severe forms of major depressive disorder. Adj.: melancholic.

melanin mélanine any of several closely related dark pigments of the skin, hair, choroid coat of the eye, substantia nigra, and various tumors, produced by polymerization of oxidation products of tyrosine and dihydroxyphenol compounds.

melanism mélanisme melanosis.

melan(o)- mélan(o)- word element [Gr.], black; melanin.

melanoameloblastoma mélano-améloblastome melanotic neuroectodermal tumor.

melanoblast mélanoblaste a cell that originates from the neural crest and develops into a melanocyte.

melanocyte mélanocyte a type of dendritic clear cell of the stratum basale of the epidermis that synthesizes the enzyme tyrosinase and contains melanosomes that produce melanin and can be later transferred from melanocytes to keratinocytes. Adj.: melanocytic.

melanocytoma mélanocytome a neoplasm or hamartoma composed of melanocytes.

melanoderma mélanodermie abnormally increased melanin in the skin.

melanodermatitis mélanodermite dermatitis with deposit of melanin in the skin.

melanogen mélanogène a colorless chromogen, convertible into melanin, which may occur in the urine in certain diseases.

melanogenesis mélanogenèse the production of melanin.

melanoid mélanoïde 1. resembling melanin. 2. a substance resembling melanin.

melanoleukoderma mélanoleucodermie a mottled appearance of the skin. m. colli m. syphilitique secondaire syphilitic leukoderma about the neck.

melanoma mélanome a tumor arising from the melanocytic system of the skin and other organs; used alone, it denotes malignant m.. acral-lentiginous m. m. malin des extrémités an irregular, enlarging black macule with a long noninvasive stage, seen chiefly on the palms and soles, the most common type of melanoma in nonwhite persons. amelanotic m. m. achromique an unpigmented malignant melanoma. juvenile m. m. juvénile Spitz nevus. lentigo maligna m. m. sur mélanose de Dubreuilh a cutaneous malignant melanoma arising in the site of a preexisting lentigo maligna, occurring on sun exposed areas, particularly of the face. malignant m. m. malin, nævocarcinome a malignant tumor usually developing from a nevus or lentigo maligna and consisting of black masses of cells with a marked tendency to metastasis. nodular m. m. nodulaire a type of malignant melanoma without a perceptible radial growth phase, usually seen on the head, neck, or trunk as a uniformly pigmented, elevated, discolored, rapidly enlarging nodule that ulcerates. ocular m. m. oculaire malignant melanoma arising from the structures of the eye; it frequently metastasizes, which rapidly causes death. subungual m. m. subunguéal acral-lentiginous melanoma in the nail fold or bed. superficial spreading m. m. superficiel extensif malignant melanoma with a period of radial growth atypical of epidermal melanocytes, which may be followed by invasive growth or may regress; it usually occurs as a small pigmented macule or papule with irregular outline on the lower leg or back. uveal m. m. uvéal ocular melanoma consisting of overgrowth of uveal melanocytes.

melanonychia mélanonychie blackening of the nails by melanin pigmentation.

melanophage mélanophage a histiocyte laden with phagocytosed melanin.

melanoplakia mélanoplakie the formation of melanotic patches on the oral mucosa.

melanosis mélanose melanism; disordered production of melanin, with darkening of the skin. m. coli m. du côlon black or brown discoloration of the mucosa of the colon, due to pigment from cathartics that has leaked into the lamina propria. m. iridis, m. of iris m. de l ’iris abnormal pigmentation of the iris by infiltration of melanoblasts. neurocutaneous m. mélanoblastose neurocutanée giant hairy nevus accompanied by malignant melanomas of the meninges.

melanosome mélanosome any of the granules within the melanocytes that contain tyrosinase and synthesizes melanin; they are transferred from the melanocytes to keratinocytes.

melanotic mélanique 1. pertaining to or characterized by the presence of melanin. 2. characterized by melanosis.

melanuria mélanurie excretion of urine that is darkly stained or turns dark on standing. Adj.: melanuric.

melasma mélasmes sharply demarcated, blotchy, brown macules, usually in a symmetrical distribution on the cheeks and forehead and sometimes the upper lip and neck, often associated with pregnancy or other altered hormonal state.

melatonin mélatonine a catecholamine hormone synthesized and released by the pineal body; in mammals it influences hormone production and in many species regulates seasonal changes such as reproductive pattern and fur color. In humans it is implicated in the regulation of sleep, mood, puberty, and ovarian cycles and it has been tried therapeutically for insomnia, jet lag, and other conditions.

melena melæna the passage of dark stools stained with altered blood.

melioidosis mélioïdose a glanders-like disease of rodents, transmissible to humans, and caused by Pseudomonas pseudomallei.

meloplasty méloplastie plastic surgery of the cheek.

melorheostosis mélorhéostose a form of osteosclerosis, with linear tracks extending through a long bone; see rheostosis.

meloxicam méloxicam a nonsteroidal antiinflammatory drug used in the treatment of osteoarthritis.

melphalan melphalan a cytotoxic alkylating agent derived from mechlorethamine, used as an antineoplastic.

member membre 1. a distinct part of the body. 2. limb.

membra membra [L.] plural of membrum.

membrana membrana [L.] pl. membranae.

membrane membrane a thin layer of tissue that covers a surface, lines a cavity, or divides a space or organ. alveolar-capillary m., alveolocapillary m. m. alvéolocapillaire a thin tissue barrier through which gases are exchanged between the alveolar air and the blood in the pulmonary capillaries. Called also blood-air barrier and blood-gas barrier. alveolodental m. m. alvéolodentaire periodontium. arachnoid m. méninge arachnoïdienne arachnoid (2). atlantooccipital m. m. atlanto-occipitale either of two midline ligamentous structures, one (the anterior) passing from the anterior arch of the atlas to the anterior margin of the foramen magnum, and the other (the posterior) connecting the posterior aspects of the same structures. basement m. m. basale a sheet of amorphous extracellular material upon which the basal surfaces of epithelial cells rest; it is also associated with muscle cells, Schwann cells, fat cells, and capillaries, interposed between the cellular elements and the underlying connective layer. basilar m. of cochlear duct m. basilaire de la cochlée lamina basilaris. Bichat m. m. de Bichat fenestrated m. Bowman m. m. de Bowman a thin layer of cornea between the outer layer of stratified epithelium and the substantia propria. Bruch m. m. de Bruch the inner layer of the choroid, separating it from the pigmentary layer of the retina. Brunn m. épithélium olfactif the epithelium of the olfactory region of the nose. cloacal m. m. cloacale the thin temporary barrier between the embryonic hindgut and the exterior. Corti m. m. de Corti a gelatinous mass resting on the organ of Corti, connected with the hairs of the hair cells. croupous m. fausse membrane de la laryngite diphtérique the false membrane of true croup. cytoplasmic m. m. cytoplasmique plasma m. decidual m ’s, deciduous m ’s caduque, membrane déciduale decidua. Descemet m. m. de Descemet a thin hyaline membrane between the substantia propria and endothelial layer of the cornea. diphtheritic m. fausse membrane de la diphtérie a false membrane characteristic of diphtheria, formed by coagulation necrosis. elastic m. limitante élastique one made up largely of elastic fibers. enamel m. m. de Nasmyth 1. dental cuticle. 2. the inner layer of cells within the enamel organ of the fetal dental germ. epiretinal m. m. épirétinale a pathologic membrane partially covering the surface of the retina, probably originating chiefly from the retinal pigment epithelial and glial cells. extraembryonic m ’s m. extra-embryonnaires those that protect the embryo or fetus and provide for its nutrition, respiration, and excretion; the yolk sac (umbilical vesicle), allantois, amnion, chorion, decidua, and placenta. false m. fausse membrane pseudomembrane. fenestrated m. lame vitrée one of the perforated elastic sheets of the tunica intima and tunica media of arteries. fetal m ’s m. fœtales extraembryonic m ’s. fibroelastic m. of larynx m. fibro-élastique du larynx the fibroelastic layer beneath the mucous coat of the larynx. germinal m. m. germinative blastoderm. glomerular m. m. glomérulaire the membrane covering a glomerular capillary. hemodialyzer m. m. de l ’hémodialyseur the semipermeable membrane that filters the blood in a hemodialyzer, commonly made of cuprophane, cellulose acetate, polyacrylonitrile, or polymethyl methacrylate. hyaline m. m. hyaline 1. a membrane between the outer root sheath and inner fibrous layer of a hair follicle. 2. a layer of eosinophilic hyaline material lining alveoli, alveolar ducts, and bronchioles, found at autopsy in infants who have died of respiratory distress syndrome of the newborn. hyaloid m. m. hyaloïde vitreous m. (1). Jackson m. m. de Jackson a web of adhesions sometimes covering the cecum and causing obstruction of the bowel. limiting m. m. limitante one which constitutes the border of some tissue or structure. medullary m. m. médullaire endosteum. mucous m. muqueuse the membrane lining various canals and cavities of the body. Nasmyth m. m. de Nasmyth dental cuticle. nuclear m. m. nucléaire 1. either of the membranes, inner and outer, comprising the nuclear envelope. 2. nuclear envelope. olfactory m. m. olfactive the olfactory portion of the mucous membrane lining the nasal fossa. ovular m. m. ovulaire vitelline m. peridental m., periodontal m. m. péridentaire periodontal ligament. placental m. m. placentaire the membrane separating the fetal from the maternal blood in the placenta; sometimes inappropriately called the placental barrier. plasma m. m. plasmatique the structure, consisting of a lipid bilayer with embedded proteins, that encloses the cytoplasm of a cell, forming a selectively permeable barrier. postsynaptic m. m. post-synaptique the area of plasma membrane of a postsynaptic cell that is within the synapse and has areas especially adapted for receiving neurotransmitters. presynaptic m. m. présynaptique the area of plasma membrane of a presynaptic axon that is within the synapse and has sites especially adapted for the release of neurotransmitters. pupillary m. m. pupillaire a mesodermal layer attached to the rim or front of the iris during embryonic development. Reissner m. m. de Reissner the thin anterior wall of the cochlear duct, separating it from the scala vestibuli. reticular m., reticulated m. m. réticulée a netlike membrane over the spiral organ of the ear, through which pass the free ends of the outer hair cells. m. of round window m. de la fenêtre ronde secondary tympanic m. Ruysch m., ruyschian m. m. de Ruysch lamina choroidocapillaris. Scarpa m. m. de Scarpa secondary tympanic m. schneiderian m. m. respiratoire de Schneider the mucous membrane lining the nose. secondary tympanic m. t. secondaire the membrane enclosing the fenestra cochlearis. serous m. m. séreuse tunica serosa. Shrapnell m. m. de Shrapnell the thin upper part of the tympanic membrane. suprapleural m. m. suprapleurale the strengthened portion of the endothoracic fascia attached to the inner part of the first rib and the transverse process of the seventh cervical vertebra. synaptic m. m. synaptique the part of the plasma membrane of a neuron that is within a synapse. synovial m. m. synoviale 1. the inner of the two layers of the articular capsule of a synovial joint, composed of loose connective tissue and having a free smooth surface that lines the joint cavity. 2. either of two membranes, superior and inferior, lining the articular capsule of the temporomandibular joint. tectorial m. m. tectoriale Corti m. tympanic m. m. tympanique the thin partition between the external acoustic meatus and the middle ear. undulating m. m. ondulante a protoplasmic membrane running like a fin along the bodies of certain protozoa. unit m. m. unitaire the trilaminar structure of the plasma membrane and other cellular membranes (e.g., nuclear m ’s, mitochondrial m ’s) revealed by the electron microscope. vestibular m. of cochlear duct m. vestibulaire du canal cochléaire the thin anterior wall of the cochlear duct, separating it from the scala tympani. vitelline m. m. vitelline the cytoplasmic, noncellular membrane surrounding an oocyte. vitreous m. m. vitrée 1. a delicate boundary layer investing the vitreous body. 2. Bruch m. 3. Descemet m. 4. hyaline m. (1). yolk m. m. vitelline vitelline m. Zinn m. m. de Zinn ciliary zonule.

membranocartilaginous membranocartilagineux 1. developed in both membrane and cartilage. 2. partly cartilaginous and partly membranous.

membranoid membraniforme resembling a membrane.

membranolysis membranolyse disruption of any membrane.

membranous membraneux pertaining to or of the nature of a membrane.

membrum membrum pl. membra [L.] 1. member. 2. limb.

memory mémoire that faculty by which sensations, impressions, and ideas are stored and recalled. immunologic m. m. immunologique anamnesis; the capacity of the immune system to respond more rapidly and strongly to subsequent antigenic challenge than to the first exposure. remote m. m. des faits anciens memory that is serviceable for events long past, but not able to acquire new recollections. replacement m. m. de substitution the replacing of one memory with another. screen m. souvenir-écran a consciously tolerable memory serving to conceal another memory that might be disturbing or emotionally painful if recalled. short-term m. m. à court terme memory that is lost within a brief period (from a few seconds to a maximum of about 30 minutes) unless reinforced.

MEN NEM multiple endocrine neoplasia.

menacme vie génitale the period of a woman ’s life which is marked by menstrual activity.

menadiol ménadiol a vitamin K analogue; its sodium diphosphate salt is used as a prothrombinogenic vitamin.

menadione ménadione vitamin K₃. 1. a synthetic fat-soluble vitamin that can be converted in the body to active vitamin K. 2. the basic double ring quinone structure that is the parent structure of the related compounds with vitamin K activity, which can be formed by addition of long side chain substituents.

menaquinone ménaquinone vitamin K₂; any of a series of compounds having vitamin K activity and structurally similar to phytonadione (vitamin K₁) but having a different side chain; synthesized by the intestinal flora.

menarche ménarche establishment or beginning of the menstrual function. Adj.: menarcheal.

mendelevium (Md) mendélévium chemical element (see Table of Elements), at. no. 101.

meninges méninges sing. meninx [Gr.] the three membranes covering the brain and spinal cord: dura mater, arachnoid, and pia mater.

meningioma méningiome a benign, slowgrowing tumor of the meninges, usually next to the dura mater, which may invade the skull or cause hyperostosis, and often causes increased intracranial pressure; it is usually subclassified on the basis of anatomic location. angioblastic m. m. angioblastique one containing many blood vessels of various sizes. convexity m ’s m. de la convexité a diverse group of meningiomas located within the sulci of the brain, usually anterior to the rolandic fissure. psammomatous m. m. psammomateux one containing many psammoma bodies.

meningism méningisme the symptoms of meningitis with acute febrile illness or dehydration without infection of the meninges.

meningismus meningismus meningism.

meningitis méningite pl. meningitides [Gr.] inflammation of the meninges. Adj.: meningitic. basilar m. m. basilaire that affecting the meninges at the base of the brain. cerebral m. m. cérébrale inflammation of the membranes of the brain. cerebrospinal m. m. cérébrospinale inflammation of the membranes of the brain and spinal cord. chronic m. m. chronique a variable syndrome of prolonged fever, headache, lethargy, stiff neck, confusion, nausea, and vomiting, with pleocytosis; due to a variety of infectious and noninfectious causes. cryptococcal m. m. cryptococcique cryptococcosis in which the meninges are invaded by Cryptococcus. eosinophilic m. m. à éosinophiles meningitis characterized by an increase in lymphocytes and a high percentage of eosinophils in the cerebrospinal fluid, usually due to Angiostrongylus cantonensis infection. epidemic cerebrospinal m. m. cérébrospinale épidémique meningococcal m. meningococcal m. m. méningococcique an acute infectious, usually epidemic, disease attended by a seropurulent meningitis, due to Neisseria meningitidis, usually with an erythematous, herpetic, or hemorrhagic skin eruption. occlusive m. m. occlusive leptomeningitis of children, with closure of the lateral and median apertures of the fourth ventricle. m. ossificans m. ossifiante ossification of the cerebral meninges. otitic m. m. otogène that secondary to otitis media. spinal m. m. spinale inflammation of the membranes of the spinal cord. tubercular m., tuberculous m. m. tuberculeuse severe meningitis due to Mycobacterium tuberculosis. viral m. m. virale that due to a virus, e.g., coxsackieviruses, mumps virus, or the virus of lymphocytic choriomeningitis, marked by malaise, fever, headache and other aches, nausea, and cerebrospinal fluid pleocytosis (mainly lymphocytic); it usually runs a short uncomplicated course.

mening(o)- méning(o)- word element [Gr.], meninges; membrane.

meningocele méningocèle hernial protrusion of the meninges through a defect in the cranium (cranial m.) or vertebral column (spinal m.).

meningococcemia méningococcémie invasion of the blood by meningococci.

meningococcus méningocoque pl. meningococci an individual organism of Neisseria meningitidis. Adj.: meningococcal, meningococcic.

meningocyte méningocyte a histiocyte of the meninges.

meningoencephalitis méningoencéphalite inflammation of the brain and meninges. toxoplasmic m. m. toxoplasmique meningoencephalitis occurring in toxoplasmosis, with seizures and mental confusion followed by coma; often fatal if untreated.

meningoencephalocele méningoencéphalocèle encephalocele.

meningoencephalopathy méningoencéphalopathie noninflammatory disease of the cerebral meninges and brain.

meningogenic méningé arising in the meninges.

meningomalacia méningomalacie softening of a membrane.

meningomyelitis méningomyélite inflammation of the spinal cord and its membranes.

meningomyeloradiculitis méningomyéloradiculite inflammation of the meninges, spinal cord, and roots of the spinal nerves.

meningo-osteophlebitis méningo-ostéophlébite periostitis with inflammation of the veins of a bone.

meningopathy méningopathie any disease of the meninges.

meningoradicular méningoradiculaire pertaining to the meninges and the cranial or spinal nerve roots.

meningorrhagia méningorragie hemorrhage from cerebral or spinal membranes.

meningosis méningose attachment of bones by membrane.

meninx méninge pl. meninges [Gr.] singular of meninges.

meniscitis méniscite inflammation of a meniscus of the knee joint.

meniscofemoral méniscofémoral pertaining to or connecting the femur and a meniscus.

meniscosynovial méniscosynovial pertaining to a meniscus and the synovial membrane.

meniscus ménisque pl. menisci [L.] something of crescent shape, as the concave or convex surface of a column of liquid in a pipet or buret, or a crescent-shaped cartilage in the knee joint. Adj.: meniscal. tactile m. m. tactile one of the small, cup-shaped nerve endings within the skin (deep epidermis, hair follicles, and hard palate); each is in contact with a single Merkel cell and they function as tactile receptors.

men(o)- mén(o)- word element [Gr.], menstruation.

menometrorrhagia ménométrorragie excessive and prolonged uterine bleeding occurring at irregular, frequent intervals.

menopause ménopause cessation of menstruation. Adj.: menopausal. premature m. m. prématurée cessation of ovulation and menstrual cycles before age 40.

menorrhagia ménorragie hypermenorrhea.

menorrhalgia algoménorrhée dysmenorrhea.

menorrhea ménorrhée 1. the normal discharge of the menses. 2. profuse menstruation. Adj.: menorrheal.

menoschesis ménochèse retention of the menses.

menostaxis polyménorrhée excessively prolonged menstruation.

menotropins ménotropine, gonadotrophine humaine de ménopause a purified preparation of gonadotropins extracted from the urine of postmenopausal women containing folliclestimulating hormone (FSH) and luteinizing hormone (LH); used to treat male hypogonadism, to induce ovulation and pregnancy in certain infertile, anovulatory women, and to stimulate oocyte development and maturation in patients using assisted reproductive technologies.

menses règles the monthly flow of blood from the female genital tract.

menstrual menstruel pertaining to the menses or to menstruation.

menstruation menstruation the cyclic, physiologic discharge through the vagina of blood and muscosal tissues from the nonpregnant uterus; it is under hormonal control and normally recurs usually at approximately four-week intervals, except during pregnancy and lactation, throughout the reproductive period (puberty through menopause). anovular m., anovulatory m. m. anovulaire periodic uterine bleeding without preceding ovulation. infrequent m. spanioménorrhée oligomenorrhea. profuse m. ménorragie hypermenorrhea. retrograde m. m. rétrograde backflow of menstrual fluid, epithelial cells, and debris through the uterine tubes and into the peritoneal cavity. scanty m. hypoménorrhée, oligoménorrhée hypomenorrhea. vicarious m. m. vicariante discharge of blood from an extragenital source at the time menstruation is normally expected.

mensuration mensuration the act or process of measuring.

mental 1. mental pertaining to the mind. 2. mentonnier pertaining to the chin.

menthol menthol an alcohol from various mint oils or produced synthetically; used topically to relieve itching and as an inhalation to treat upper respiratory tract disorders.

mentolabial mentolabial pertaining to the chin and lip.

mentoplasty mentoplastie plastic surgery of the chin; surgical correction of deformities and defects of the chin.

mentum mentum [L.] chin.

MEP PEM maximum expiratory pressure.

mepenzolate mépenzolate a quaternary ammonium compound with anticholinergic and antimuscarinic effects, used in the form of the bromide salt in the treatment of peptic ulcers and disorders characterized by colon hypermotility.

meperidine méripéridine an opioid analgesic, used as the hydrochloride salt as an analgesic and an anesthesia adjunct.

mephentermine méphentermine an adrenergic used as the sulfate salt for its vasopressor effects in the treatment of certain hypotensive states.

mephenytoin méphénytoïne an anticonvulsant used for the control of a variety of epileptic seizures.

mephitic méphitique emitting a foul odor.

mephobarbital méphobarbital, méthylphénobarbital a long-acting barbiturate used as an anticonvulsant.

mepivacaine mépivacaïne a lidocaine analogue used in the form of the hydrochloride salt as a local anesthetic.

meprobamate méprobamate a carbamate derivative with tranquilizing and muscle relaxant actions.

mEq mEq milliequivalent.

meradimate méradimate an absorber of ultraviolet A radiation, used topically as a sunscreen.

meralgia méralgie pain in the thigh. m. paresthetica m. paresthésique paresthesia, pain, and numbness in the outer surface of the thigh due to entrapment of the lateral femoral cutaneous nerve at the inguinal ligament.

mercaptan mercaptan thiol (2).

mercaptopurine (6-MP) mécaptopurine a sulfur-containing purine analogue, used as an antineoplastic and as an immunosuppressant.

mercurial mercuriel 1. pertaining to mercury. 2. a preparation containing mercury.

mercuric mercurique pertaining to mercury as a bivalent element.

mercurous mercureux pertaining to mercury as a monovalent element.

mercury (Hg) mercure chemical element (see Table of Elements), at. no. 80. Acute mercury poisoning, due to ingestion, is marked by severe abdominal pain, vomiting, bloody diarrhea with watery stools, oliguria or anuria, and corrosion and ulceration of the digestive tract; in the chronic form, due to absorption through skin and mucous membranes, inhalation, or ingestion, there is stomatitis, blue line along the gum border, sore hypertrophied gums that bleed easily, loosening of teeth, erethism, ptyalism, tremors, and incoordination.

meridian méridien 1. an imaginary line on the surface of a spherical body, marking the intersection with the surface of a plane passing through its axis. 2. in acupuncture, a system of 20 lines connecting acupoints and regarded as channels through which qi flows.

meridianus meridianus pl. meridiani [L.] meridian.

mer(o)- mér(o)-word element [Gr.], 1. part. 2. thigh.

meroblastic méroblastique partially dividing; undergoing cleavage in which only part of the zygote participates.

merocrine mérocrine discharging only the secretory product and maintaining the secretory cell intact (e.g., salivary glands, pancreas).

merogenesis mérogenèse cleavage of a zygote. Adj.: merogenetic.

meromelia méromélie congenital absence of any part of a limb; cf. amelia.

meromyosin méromyosine a fragment of the myosin molecule isolated by treatment with proteolytic enzyme; there are two types, heavy (H-meromyosin) and light (L-meromyosin).

meropenem méropénem a broad-spectrum antibacterial effective against a wide variety of gram-positive and gram-negative organisms; used in the treatment of intra-abdominal infections and bacterial meningitis.

meropia méropie partial blindness.

merorachischisis mérorachischisis fissure of a part of the vertebral column.

merozoite mérozoïte one of the organisms formed by multiple fission (schizogony) of a sporozoite within the body of the host.

MESA MESA microsurgical epididymal sperm aspiration.

mesalamine mésalamine 5-aminosalicylic acid, an active metabolite of sulfasalazine, used in the prophylaxis and treatment of inflammatory bowel disease.

mesalazine mésalazine mesalamine.

mesangiocapillary mésangiocapillaire pertaining to or affecting the mesangium and the associated capillaries.

mesangium mésangium the thin membrane supporting the capillary loops in renal glomeruli. Adj.: mesangial.

mesaxon mésaxone a pair of parallel membranes marking the line of edge-to-edge contact of Schwann cells encircling an axon.

mescaline mescaline a poisonous alkaloid from the flowering heads (mescal buttons) of a Mexican cactus, Lophophora williamsii; it produces an intoxication with delusions of color and sound.

mesectoderm mésectoderme, ectomésenchyme embryonic migratory cells derived from the neural crest of the head that contribute to the formation of the meninges and become pigment cells.

mesencephalon mésencéphale midbrain. 1. the part of the brain developed from the middle of the three primary vesicles of the embryonic neural tube, comprising the tectum and the cerebral peduncles. 2. the middle of the three primary brain vesicles in the embryo, lying between the prosencephalon and the rhombencephalon. Adj.: mesencephalic.

mesencephalotomy mésencéphalotomie surgical production of lesions in the midbrain, especially for relief of intractable pain.

mesenchyma mesenchyma mesenchyme.

mesenchyme mésenchyme the meshwork of embryonic connective tissue in the mesoderm from which are formed the connective tissues of the body and the blood and lymphatic vessels. Adj.: mesenchymal.

mesenchymoma mésenchymome a mixed mesenchymal tumor composed of two or more cellular elements not commonly associated, exclusive of fibrous tissue.

mesenteric mésentérique pertaining to the mesentery.

mesenteriopexy mésentéropexie fixation or suspension of a torn mesentery.

mesenteriplication mésentériplication shortening of the mesentery by plication.

mesenterium mesenterium [L.] mesentery (1).

mesenteron mesenteron the midgut.

mesentery mésentère 1. the peritoneal fold attaching the small intestine to the posterior body wall. 2. a membranous fold attaching an organ to the body wall.

mesiad en direction du centre toward the middle or center.

mesial mésial nearer the center of the dental arch.

mesially médialement toward the median line.

mesioclusion mésioclusion anteroclusion; malrelation of the dental arches with the mandibular arch anterior to the maxillary arch (prognathism).

mesiodens mésiodens pl. mesiodentes a small supernumerary tooth, occurring singly or paired, generally palatally between the maxillary central incisors.

mesion mésion the plane dividing the body into right and left symmetrical halves.

mesioversion mésioversion displacement of a tooth along the dental arch toward the midline of the face.

mesmerism mesmérisme hypnotism.

mesna mesna a sulfhydryl compound given with urotoxic antineoplastic agents because it inactivates some of their urotoxic metabolites.

mes(o)- més(o)- word element [Gr.], middle.

mesoappendix mésoappendice the peritoneal fold connecting the appendix to the ileum.

mesobilirubinogen mésobilirubinogène a reduced form of bilirubin, formed in the intestine, which on oxidation forms stercobilin.

mesoblast mésoblaste mesoderm, especially in the early, undifferentiated stages.

mesoblastema mésoblastème the cells composing the mesoblast.

mesoblastic mésoblastique pertaining to or derived from the mesoblast.

mesocardia mésocardie congénitale atypical location of the heart, with the apex in the midline of the thorax.

mesocardium mésocarde that part of the embryonic mesentery connecting the heart with the body wall in front and the foregut behind.

mesocecum mésocæcum the occasionally occurring mesentery of the cecum.

mesocolon mésocôlon the peritoneal process attaching the colon to the posterior abdominal wall, and called ascending, descending, etc., according to the portion of colon to which it attaches. Adj.: mesocolic.

mesocolopexy mésocolopexie suspension or fixation of the mesocolon.

mesocortex mésocortex the cortex of the cingulate gyrus, intermediate in form between the allocortex and the isocortex and having five or six layers.

mesoderm mésoderme the middle of the three primary germ layers of the embryo, lying between the ectoderm and endoderm; from it are derived the connective tissue, bone, cartilage, muscle, blood and blood vessels, lymphatics, lymphoid organs, notochord, pleura, pericardium, peritoneum, kidneys, and gonads. Adj.: mesodermal, mesodermic.

mesoduodenum mésoduodénum the mesenteric fold enclosing the duodenum of the early fetus. Adj.: mesoduodenal.

mesoepididymis mésoépididyme a fold of tunica vaginalis testis sometimes connecting the epididymis and testis.

mesogastrium mésogastre the portion of the primitive mesentery which encloses the stomach and from which the greater omentum develops. Adj.: mesogastric.

mesoileum méso-iléon the mesentery of the ileum.

mesojejunum méso-jéjunum the mesentery of the jejunum.

mesomere mésomère 1. a blastomere of size intermediate between a macromere and a micromere. 2. a midzone of the mesoderm between the epimere and hypomere.

mesometrium mésométrium, myomètre the portion of the broad ligament below the mesovarium.

mesomorph mésomorphe an individual having the type of body build in which mesodermal tissues predominate: relative preponderance of muscle, bone, and connective tissue, usually with heavy, hard physique of rectangular outline.

meson méson 1. mesion. 2. a subatomic particle having a rest mass intermediate between the mass of the electron and that of the proton, carrying either a positive, negative, or neutral electric charge.

mesonephric mésonéphrique pertaining to the mesonephros.

mesonephroma mésonéphrome clear cell adenocarcinoma.

mesonephros mésonéphros pl. mesonephroi [Gr.] the excretory organ of the embryo, arising caudad to the pronephric rudiments or the pronephros and using its ducts.

mesophile mésophile an organism which grows best at 20°–55 °C. Adj.: mesophilic.

mesophlebitis mésophlébite inflammation of the middle coat of a vein.

mesophryon point glabellaire, mésophryon the glabella, or its central point.

mesopulmonum ligament pulmonaire the embryonic mesentery enclosing the laterally expanding lung.

mesorchium mésorchium, mésotestis the portion of the primordial mesentery enclosing the fetal testis, represented in the adult by a fold between the testis and epididymis. Adj.: mesorchial.

mesorectum mésorectum the fold of peritoneum connecting the upper portion of the rectum with the sacrum.

mesosalpinx mésosalpinx the portion of the broad ligament above the mesovarium.

mesosigmoid mésosigmoïde the peritoneal fold attaching the sigmoid flexure to the posterior abdominal wall.

mesosigmoidopexy mésosigmoïdopexie fixation of the mesosigmoid for prolapse of the rectum.

mesosome mésosome an invagination of the bacterial cell membrane, forming organelles thought to be the site of cytochrome enzymes and the enzymes of oxidative phosphorylation and the citric acid cycle.

mesosternum mésoternum body of sternum.

mesotendineum mésotendon the connective tissue sheath attaching a tendon to its fibrous sheath.

mesothelioma mésothéliome a tumor derived from mesothelial tissue (peritoneum, pleura, pericardium), occurring in both benign and malignant forms.

mesothelium mésothélium the layer of cells, derived from mesoderm, lining the body cavity of the embryo; in the adult, it forms the simple squamous epithelium that covers all true serous membranes (peritoneum, pericardium, pleura). Adj.: mesothelial.

mesotympanum mésotympanum the portion of the middle ear medial to the tympanic membrane.

mesovarium mésovarium the portion of the broad ligament between the mesometrium and mesosalpinx, which encloses and holds the ovary in place.

messenger messager an information carrier. second m. second messager any of several classes of intracellular signals acting at or situated within the plasma membrane and translating electrical or chemical messages from the environment into cellular responses.

mestranol mestranol an estrogen related to ethinyl estradiol; used in combination with a progestational agent as an oral contraceptive.

mesylate mésylate contraction for methanesulfonate.

Met Met methionine.

met(a)- mét(a)- word element [Gr.], (1) a prefix indicating (a) change; transformation; exchange; (b) after; next; (2) symbol m-, a prefix indicating a 1,3-substituted position in derivatives of benzene; (3) a prefix indicating a polymeric acid anhydride.

meta-analysis méta-analyse a systematic method that takes data from a number of independent studies and integrates them using statistical analysis.

metabasis métabase a change in the manifestations or course of a disease.

metabiosis métabiose dependence of one organism upon another for its existence; commensalism.

metabolism métabolisme 1. the sum of all the physical and chemical processes by which living organized substance is produced and maintained (anabolism), and also the transformation by which energy is made available for the uses of the organism (catabolism). 2. biotransformation. Adj.: metabolic. basal m. m. basal the minimal energy expended to maintain respiration, circulation, peristalsis, muscle tonus, body temperature, glandular activity, and the other vegetative functions of the body.

metabolite métabolite any substance produced by metabolism or by a metabolic process.

metacarpal métacarpien 1. pertaining to the metacarpus. 2. a bone of the metacarpus.

metacarpus métacarpe the part of the hand between the wrist and fingers, its skeleton being five bones (metacarpals) extending from the carpus to the phalanges.

metacentric métacentrique having the centromere near the middle, so that the arms of the chromosome are approximately equal in length.

metacercaria métacercaire pl. metacercariae the encysted resting or maturing stage of a trematode parasite in the tissues of an intermediate host or on vegetation.

metachromasia métachromasie 1. failure to stain true with a given stain. 2. the different coloration of different tissues produced by the same stain. 3. change of color produced by staining.

metachromatic métachromatique staining differently with the same dye; said of tissues in which a dye gives different colors to different elements.

metachromophil métachromatique not staining in the usual manner with a given stain.

metacone métacône the distobuccal cusp of an upper molar tooth.

metaconid métaconide the mesiolingual cusp of a lower molar tooth.

metagaster tube intestinal embryonnaire the permanent intestinal canal of the embryo.

Metagonimus Metagonimus a genus of flukes, including M. yokogawai, parasitic in the small intestine of humans and other mammals in Japan, China, Indonesia, the Balkans, and Israel.

metal métal any element marked by luster, malleability, ductility, and conductivity of electricity and heat and which will ionize positively in solution. Adj.: metallic. alkali m. m. alcalin any of a group of monovalent metals, including lithium, sodium, potassium, rubidium, and cesium. heavy m. m. lourd one with a high specific gravity, usually defined as over 5.0; some cause heavy metal poisoning.

metalloenzyme métallo-enzyme any enzyme containing tightly bound metal atoms, e.g., the cytochromes.

metalloporphyrin métalloporphyrine a combination of a metal with porphyrin, as in heme.

metalloprotein métalloprotéine a protein molecule with a bound metal ion, e.g., hemoglobin.

metallurgy métallurgie the science and art of using metals.

metamere métamère one of a series of homologous segments of the body of an animal. Cf. antimere.

metamorphosis métamorphose change of structure or shape, particularly, transition from one developmental stage to another, as from larva to adult form. Adj.: metamorphic. fatty m. stéatose fatty change.

metamyelocyte métamyélocyte a precursor in the granulocytic series, being a cell intermediate in development between a promyelocyte and the mature, segmented (polymorphonuclear) granular leukocyte, and having a U-shaped nucleus.

metanephric métanéphrique of or pertaining to the metanephros.

metanephrine métanéphrine a metabolite of epinephrine excreted in urine and found in certain tissues.

metanephros métanéphros pl. metanephroi [Gr.] the primordium of the permanent kidney, developing later than and caudad to the mesonephros.

metaphase métaphase the stage of cell division following prometaphase, during which the chromosomes move to the center of the cell and line up to form the equatorial plate.

metaphosphoric acid acide métasphosphorique a polymer of phosphoric acid, used as a reagent for chemical analysis and as a test for albumin in the urine.

metaphyseal métaphysaire pertaining to or of the nature of a metaphysis.

metaphysial métaphysaire metaphyseal.

metaphysis métaphyse pl. metaphyses [Gr.] the wider part at the end of a long bone, adjacent to the epiphyseal disk.

metaplasia métaplasie the change in the type of adult cells in a tissue to a form abnormal for that tissue. Adj.: metaplastic. myeloid m. m. myéloïde a syndrome characterized by myeloid tissue in extramedullary sites with nucleated erythrocytes and immature granulocytes in the circulating blood and extramedullary hematopoiesis in the liver and spleen, as well as anemia and splenomegaly. Both a primary form (agnogenic myeloid m.) and forms secondary to carcinoma, leukemia, leukoerythroblastosis, and tuberculosis are known.

metapneumonic métapneumonique succeeding or following pneumonia.

metaproterenol métaprotérénol a β_2-adrenergic receptor agonist with significant β₁-adrenergic activity, used in the form of the sulfate salt as a bronchodilator.

metapsychology métapsychologie the branch of speculative psychology that deals with the significance of mental processes that are beyond empirical verification.

metaraminol métaraminol a sympathomimetic agent acting mainly as an α-adrenergic agonist but also stimulating the β₁-adrenergic receptors of the heart and having potent vasopressor activity; used as the bitartrate salt in the treatment of certain hypotensive states.

metarubricyte métarubricyte orthochromatic erythroblast.

metastasectomy métastasectomie excision of one or more metastases.

metastasis métastase pl. metastases 1. transfer of disease from one organ or part of the body to another not directly connected with it, due either to transfer of pathogenic microorganisms or to transfer of cells; all malignant tumors are capable of metastasizing. 2. a growth of pathogenic microorganisms or of abnormal cells distant from the site primarily involved by the morbid process. Adj.: metastatic.

metatarsal métatarsien 1. pertaining to the metatarsus. 2. a bone of the metatarsus.

metatarsalgia métatarsalgie pain and tenderness in the metatarsal region.

metatarsus métatarse the part of the foot between the ankle and the toes, its skeleton being the five bones (metatarsals) extending from the tarsus to the phalanges.

metathalamus métathalamus the part of the diencephalon composed of the medial and lateral geniculate bodies; often considered to be part of the thalamus.

metathesis métathèse 1. artificial transfer of a morbid process. 2. a chemical reaction in which an element or radical in one compound exchanges places with another element or radical in another compound.

metatrophic métatrophique utilizing organic matter for food.

metaxalone métaxalone a skeletal muscle relaxant used in the treatment of painful musculoskeletal conditions.

Metazoa Metazoa that division of the animal kingdom embracing the multicellular animals whose cells differentiate to form tissues, i.e., all animals except the Protozoa. Adj.: metazoal, metazoan.

metazoon métazoaire pl. metazoa an individual organism of the Metazoa.

metencephalon métencéphale [Gr.] 1. the anterior part of the rhombencephalon, comprising the cerebellum and pons. 2. the anterior of two brain vesicles formed by specialization of the rhombencephalon in the developing embryo.

meteorotropism météorotropisme response to influence by meteorologic factors noted in certain biological events. Adj.: meteorotropic.

meter mètre 1. the base SI unit of linear measure, approximately equivalent to 39.37 inches. Symbol m. 2. an apparatus to measure the quantity of anything passing through it.

-meter -mètre word element [Gr.], relationship to measurement; instrument for measuring.

metformin metformine an antihyperglycemic agent that potentiates the action of insulin, used in the treatment of type 2 diabetes mellitus.

methacrylate méthacrylate an ester of methacrylic acid, or the resin derived from polymerization of the ester. See also acrylic resins, under resin.

methacrylic acid acide méthacrylique an organic acid that polymerizes easily to form a ceramic-like mass. Its esters, methyl and polymethyl methacrylate, are used in the manufacture of acrylic resins and plastics.

methadone méthadone a synthetic opioid analgesic with actions similar to those of morphine and heroin, and almost equal in potential for addiction; the hydrochloride salt is used as an analgesic and in the management of heroin addiction.

methamphetamine métamphétamine a central nervous system stimulant and pressor substance with actions similar to amphetamine; used as the hydrochloride salt in the treatment of attention-deficit/hyperactivity disorder. Abuse may lead to dependence.

methanal méthanal formaldehyde.

methane méthane an inflammable, explosive gas, CH₄, from decomposition of organic matter.

methanogen méthanogène an anaerobic microorganism that grows in the presence of carbon dioxide and produces methane gas. Methanogens are found in the stomach of cows, in swamp mud, and in other environments in which oxygen is not present.

methanol méthanol methyl alcohol.

methazolamide méthazolamide a carbonic anhydrase inhibitor used as an adjunct to reduce intraocular pressure in the treatment of glaucoma.

methdilazine méthdilazine an antihistamine with anticholinergic and sedative effects, used as the base or the hydrochloride salt as an antipruritic.

methemalbumin méthémalbumine a brownish pigment formed in the blood by the binding of albumin with heme; indicative of intravascular hemolysis.

methemoglobin méthémoglobine a hematogenous pigment formed from hemoglobin by oxidation of the iron atom from the ferrous to the ferric state. A small amount is found in the blood normally, but injury or toxic agents convert a larger proportion of hemoglobin into methemoglobin, which does not function as an oxygen carrier.

methenamine méthénamine an antibacterial used in urinary tract infections; administered as the hippurate and mandelate salts.

methicillin méthicilline a semisynthetic penicillin highly resistant to inactivation by penicillinase; used as the sodium salt.

methimazole méthimazole a thyroid inhibitor used in the treatment of hyperthyroidism.

methionine (Met, M) méthionine a naturally occurring, essential amino acid that furnishes both methyl groups and sulfur necessary for normal metabolism. Labeled with carbon 11, it is used in positron emission tomography for detection of neoplasms.

methocarbamol méthocarbamol a skeletal muscle relaxant used in the treatment of painful musculoskeletal conditions.

method méthode the manner of performing any act or operation; a procedure or technique. dye dilution m. épreuve de dilution d ’un colorant a type of indicator dilution method for assessing flow through the circulatory system, using a dye as an indicator. indicator dilution m. m. de dilution d ’un colorant any of several methods for assessing flow through the circulatory system by injecting a known quantity of an indicator and monitoring its concentration over time at a specific point in the system. Lamaze m. m. de Lamaze a method of preparing for delivery, involving education of the prospective mother in the physiology of pregnancy and parturition as well as in techniques such as breathing exercises and bearing down for the easing of delivery. rhythm m. m. du rythme a method of preventing conception by restricting coitus to the so-called safe period, avoiding the days just before and after the expected time of ovulation. Westergren m. m. de Westergren the most common method for testing the erythrocyte sedimentation rate, measuring the timed fall of the level of red cells after mixing whole blood and sodium citrate anticoagulant-diluent solution. Yuzpe m. m. d ’Yuzpe a regimen for postcoital contraception, consisting of a combination of ethinyl estradiol and norgestrel taken twice, 12 hours apart.

methodology méthodologie the science of method; the science dealing with principles of procedure in research and study.

methohexital méthohexital an ultrashortacting barbiturate; its sodium salt is used as a general anesthetic, a general and local anesthesia adjunct, and a sedative for certain diagnostic procedures in children.

methotrexate méthotrexate a folic acid antagonist used as the base or the sodium salt as an antineoplastic, antipsoriatic, and antiarthritic.

methoxamine méthoxamine an agr;₁-adrenergic agonist, used as the hydrochloride salt as a vasopressor.

methoxsalen méthoxsalen a psoralen that induces melanin production on exposure of the skin to ultraviolet light; used in the treatment of idiopathic vitiligo, mycosis fungoides, and psoriasis.

methoxyflurane méthoxyflurane a highly potent inhalational anesthetic agent.

methsuximide methsuximide an anticonvulsant used in the treatment of seizures in absence epilepsy.

methyclothiazide méthyclothiazide a thiazide diuretic used for treatment of hypertension and edema.

methyl méthyle the chemical group or radical CH₃—. m. methacrylate méthacrylate de méthyle a methyl ester of methacrylic acid, which polymerizes to form polymethyl methacrylate; used in the manufacture of acrylic resins and plastics. m. salicylate salicylate de méthyle a volatile oil with a characteristic wintergreen odor and taste; used as a flavoring agent and as a topical counterirritant for muscle pain.

methylamine méthylamine a flammable, explosive gas used in tanning and organic synthesis and produced naturally in some decaying fish, certain plants, and crude methanol; it is irritating to the eyes.

methylate 1. méthylate a compound of methyl alcohol and a base. 2. méthyler to add a methyl group to a substance.

methylation méthylation addition of one or more methyl groups to a substance. DNA m. m. de l ’ADN the postsynthetic addition of methyl groups to specific sites on DNA molecules; it is involved in gene expression and plays a role in a variety of epigenetic mechanisms.

methylbenzethonium méthylbenzéthonium a disinfectant quaternary compound; applied topically to skin coming in contact with urine, feces, or perspiration, and used in a rinse for diapers and linens of incontinent patients.

methylcellulose méthylcellulose a methyl ester of cellulose; used as a bulk laxative and as a suspending agent for drugs and applied topically to the conjunctiva to protect and lubricate the cornea during certain ophthalmic procedures.

methylcobalamin méthylcobalamine a metabolically active cobalamin derivative synthesized upon ingestion of vitamin B₁₂.

methyldopa méthyldopa a phenylalanine derivative used in the treatment of hypertension.

methyldopate méthyldopate the ethyl ester of methyldopa; its hydrochloride salt is used as an antihypertensive.

methylene méthylène the bivalent hydrocarbon radical —CH₂— or CH₂—.

methylenedioxyamphetamine (MDA) méthylènedioxyamphétamine a hallucinogenic compound chemically related to amphetamine and mescaline; it is widely abused and causes dependence.

3,4-methylenedioxymethamphetamine 3,4-méthylènedioxyamphétamine a compound chemically related to amphetamine and having hallucinogenic properties; it is widely abused. Popularly called Ecstasy.

methylergonovine méthylergonovine an oxytocic, used as the maleate salt to prevent or combat postpartum or postabortion hemorrhage and atony.

methylglucamine méthylglucamine meglumine.

methylmalonic acid acide méthylmalonique a carboxylic acid intermediate in fatty acid metabolism.

methylmalonicacidemia acidémie méthylmalonique 1. an aminoacidopathy characterized by an excess of methylmalonic acid in the blood and urine, with metabolic ketoacidosis, hyperglycinemia, hyperglycinuria, and hyperammonemia, resulting from any of several enzymatic defects. 2. excess of methylmalonic acid in the blood.

methylmalonicaciduria acidurie méthylmalonique 1. excess of methylmalonic acid in the urine. 2. methylmalonicacidemia (1).

methylmethacrylate méthylméthacrylate see under methyl.

methylphenidate méthylphénidate a central stimulant, used in the form of the hydrochloride salt in the treatment of attention-deficit/ hyperactivity disorder in children and narcolepsy.

methylprednisolone méthylprednisolone a synthetic glucocorticoid derived from progesterone, used in replacement therapy for adrenocortical insufficiency and as an antiinflammatory and immunosuppressant; also used as m. acetate and m. sodium succinate.

methyltestosterone méthyltestostérone a synthetic androgenic hormone with actions and uses similar to those of testosterone.

5-methyltetrahydrofolate 5-méthyltétrahydrofolate a derivative of folic acid that is the principal form of folic acid during transport and storage in the body and that also acts as a source of methyl groups for the regeneration of methionine.

methyltransferase méthyltransférase any of a group of enzymes that catalyze the transfer of a methyl group from one compound to another.

methysergide méthysergide a potent serotonin antagonist with direct vasoconstrictor effects, used as the maleate salt in prophylaxis of migraine and cluster headaches.

metipranolol métipranolol a beta-adrenergic blocking agent, used as the hydrochloride salt in the treatment of glaucoma and ocular hypertension.

metmyoglobin metmyoglobine a compound formed from myoglobin by oxidation of the ferrous to the ferric state.

metoclopramide métoclopramide a dopamine receptor antagonist and prokinetic that stimulates gastric motility, used as the hydrochloride salt as an antiemetic, an adjunct in gastrointestinal radiology and intestinal intubation, and in the treatment of gastroparesis and gastroesophageal reflux.

metolazone métolazone a sulfonamide derivative with actions similar to the thiazide diuretics; used in the treatment of hypertension and edema.

metopic métopique frontal (1).

metopion métopion glabella.

metoprolol métoprolol a cardioselective β₁-adrenergic blocking agent used in the form of the succinate and tartrate salts in the treatment of hypertension, chronic angina pectoris, and myocardial infarction.

metoxenous dihétéroxène requiring two hosts for the life cycle; said of parasites.

metra matrice the uterus.

metratrophia atrophie utérine atrophy of the uterus.

metrectopia déviation utérine uterine displacement.

metreurynter métreurynter an inflatable bag for dilating the cervical canal.

metric métrique 1. pertaining to measures or measurement. 2. having the meter as a basis.

metritis métrite inflammation of the uterus.

metrizamide métrizamide a nonionic, watersoluble, iodinated radiographic contrast medium used in myelography and cisternography.

metr(o)- métr(o)- word element [Gr.], uterus.

metronidazole métronidazole an antiprotozoal and antibacterial effective against obligate anaerobes; used as the base or the benzoate or hydrochloride salt. It is also used as a topical treatment for rosacea.

metropathy métropathie hysteropathy.

metroperitonitis métropéritonite inflammation of the peritoneum about the uterus.

metrophlebitis métrophlébite inflammation of the uterine veins.

metroplasty métroplastie plastic surgery on the uterus.

metrorrhagia métrorragie uterine bleeding occurring at irregular intervals, and sometimes of prolonged duration.

metrorrhea métrorrhée a free or abnormal uterine discharge.

metrorrhexis métrorrhexie rupture of the uterus.

metrostaxis métrostaxis slight but persistent uterine bleeding.

metrostenosis métrosténose contraction or stenosis of the uterine cavity.

-metry -métrie word element [Gr.], measurement.

metyrapone métyrapone a synthetic compound that selectively inhibits an enzyme responsible for the biosynthesis of corticosteroids; it is used as a diagnostic aid for determination of hypothalamicopituitary-adrenocortical reserve.

metyrosine métyrosine an inhibitor of the first step in catecholamine synthesis, used to control hypertensive attacks in pheochromocytoma.

MeV MeV megaelectron volt; one million (10⁶) electron volts.

mexiletine mexilétine an antiarrhythmic agent used as the hydrochloride salt in the treatment of ventricular arrhythmias.

mezlocillin mezlocilline a semisynthetic broadspectrum penicillin used as the sodium salt, particularly in the treatment of mixed infections.

μF μF microfarad.

Mg Mg magnesium.

mg mg milligram.

μg μg microgram(on the JCAHO «Do Not Use» List).

MHC CMH major histocompatibility complex.

MHz MHz megahertz; one million (10⁶) hertz.

MI I(D)M myocardial infarction.

mication mouvement rapide a quick motion, such as winking.

miconazole miconazole an imidazoleantifungal agent used as the base or the nitrate salt against tinea and cutaneous or vulvovaginal candidiasis.

micrencephaly microencéphalie abnormal smallness of the brain. Adj.: micrencephalous.

micr(o)- micr(o)- word element [Gr.], small; also used in naming units of measurement (symbol μ) to designate an amount one millionth (10^{− 6}) the size of the unit to which it is joined, e.g., microgram.

microabscess micro-abcès a small, localized collection of pus. Pautrier m. m. de Pautrier one of the well-defined collections of mycosis cells located within the epidermis in T-cell lymphoma and mycosis fungoides.

microadenoma micro-adénome a pituitary adenoma less than 10 mm in diameter.

microaerophilic microaérophile requiring oxygen for growth but at lower concentration than is present in the atmosphere; said of bacteria.

microaggregate microagrégat a microscopic collection of particles, as of platelets, leukocytes, and fibrin, that occurs in stored blood.

microalbuminuria microalbuminurie a very small increase in urinary albumin.

microanalysis microanalyse the chemical analysis of minute quantities of material.

microanatomy microanatomie histology.

microaneurysm microanévrisme a microscopic aneurysm, a characteristic of thrombotic purpura.

microangiopathy microangiopathie angiopathy involving the small blood vessels. Adj.: microangiopathic. thrombotic m. m. thrombotique idiopathique thrombi in arterioles and capillaries, as in thrombotic thrombocytopenic purpura and hemolytic uremic syndrome.

Microbacteriaceae Microbacteriaceae a family of bacteria of the suborder Micrococcineae.

Only gold members can continue reading. Log In or Register to continue

Related

Related posts:

J S H C T P

Stay updated, free articles. Join our Telegram channel

Join

Full access? Get Clinical Tree