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Medical Dictionary - Dictionary of Medicine and Human Biology

Medical Dictionary


main (man)
SYN: hand. [Fr.] m. succulente SYN: Marinesco succulent hand.

mainframe (man′fram)
A large digital computer, such as would be used in a hospital for information management. Cf.:mini.

mainstreaming (man′strem-ing)
Providing the least restrictive environment (socially, physically, and educationally) for chronically disabled individuals by introducing them into the natural environment rather than segregating them into homogeneous groups living in sheltered environments under constant supervision.

maintainer (man-ta′ner)
A device utilized to hold or keep teeth in a given position. space m. an orthodontic appliance used to prevent the loss of space or the shifting of teeth following extraction or premature loss of teeth. SYN: space retainer.

maintenance (man′ten-ans)
1. A therapeutic regimen intended to preserve benefit. Cf.:compliance (2) , adherence (2) . 2. The extent to which the patient continues good heath practices without supervision, incorporating them into a general life-style. Cf.:compliance. [M.E., fr O.Fr., fr. Mediev. L. manuteneo, to hold in the hand]

maise oil (maz)
SYN: corn oil.

Jacques H., French anatomist, 1805–1878. See M. band.

Domenico, Italian dermatologist, 1849–1929. See M. granulomas, under granuloma.

major (ma′jor)
Larger or greater in size of two similar structures. [L. comparative of magnus, great]

William Matthew, English actuary, &dag;1892. See M. hypothesis.

mal (mahl)
A disease or disorder. [Fr. fr. L. malum, an evil] m. de la rosa, m. rosso SYN: pellagra. m. del pinto SYN: pinta. m. de Meleda endemic symmetrical keratoderma of the extremities occurring on the island of Meleda off the coast of Dalmatia, in Eastern Europe. m. de mer SYN: seasickness. grand m. (grahn) SYN: generalized tonic-clonic seizure. m. morado (m. mo-ra′do) purplish skin discoloration seen in acute attacks of onchodermatitis caused by Onchocerca volvulus in Central America. [Sp. m., disease, + morado, purple] petit m. (pe-te′) See petit m. seizure. [Fr. small]

Ill, bad; opposite of eu-. Cf.:dys-, caco-. [L. malus, bad]

mala (ma′la)
1. SYN: cheek. 2. SYN: zygomatic bone. [L. cheek bone]

malabsorption (mal-ab-sorp′shun)
Imperfect, inadequate, or otherwise disordered gastrointestinal absorption. congenital selective glucose and galactose m. an inherited disorder in which d-glucose and d-galactose accumulate in the intestinal lumen and exert an osmotic effect; leads to abdominal fullness, abdominal pain, and diarrhea. enterocyte cobalamin m. an inherited disorder of impaired transintestinal transport of cobalamin; symptoms are similar to a vitamin B12 deficiency. fructose m. an inborn error in metabolism in which oral d-fructose is incompletely absorbed; results in abdominal symptoms and diarrhea. hereditary folate m. an inherited disorder in which there is defective transport of folates in intestine and choroid plexus, results in megaloblastic anemia and neurologic abnormalities.

Michele V.G., Italian surgeon, 1744–1816. See M. pyramid, M. space.

malachite green (mal′a-kit) [C.I. 42000]
A dye that has been used as a wound antiseptic, as a treatment of mycotic skin infections, and in biologic staining of tissues and bacteria. [G. malache, a mallow]

malacia (ma-la′she-a)
A softening or loss of consistency and contiguity in any of the organs or tissues. Also used as a combining form in the suffix position. SYN: mollities (2) . SYN: malacosis. [G. malakia, a softness]

malacic (ma-la′sik)
SYN: malacotic.

Soft, softening. [G. malakos, soft; malakia, a softness]

malacoplakia, malakoplakia (mal′a-ko-pla′ke-a, mal′a-ko-pla′ke-a)
Rare lesion in the mucosa of the urinary bladder and other organs, more frequent in women, characterized by numerous mottled yellow and gray soft plaques and nodules that consist of numerous macrophages and calcospherites (Michaelis-Guttmann bodies) that may form around intracellular bacteria, usually Escherichia coli. [malaco- + G. plax, plate, plaque]

malacosis (mal′a-ko′sis)
SYN: malacia.

malacotic (mal′a-kot′ik)
Pertaining to or characterized by malacia. SYN: malacic.

malactic (ma-lak′tik)
SYN: emollient. [G. malaktikos, softening]

maladie (mal′a-de′)
SYN: malady. [Fr.] m. de Roger SYN: Roger disease. [Fr.] m. des jambes (mal′a-de′ de zhamb′) ill-defined disease seen among rice-growers in Louisiana.

maladjustment (mal-ad-just′ment)
In the mental health professions, an inability to cope with the problems and challenges of everyday living. [mal- + adjust, fr. O.Fr. adjuster, fr. L.L. adjuxto, to put close to, + -ment] social m. m. without manifest psychiatric disorder, as that occasioned by an inability to cope with social situations.

malady (mal′a-de)
A disease or illness. SYN: maladie. [Fr. maladie, illness]

malagma (ma-lag′ma)
A cataplasm or emollient. [G. a poultice]

malaise (ma-laz′)
A feeling of general discomfort or uneasiness, an “out-of-sorts” feeling, often the first indication of an infection or other disease. [Fr. discomfort]

malalignment (mal-a-lin′ment)
Displacement of a tooth or teeth from a normal position in the dental arch.

malar (ma′lar)
Relating to the mala, the cheek or cheek bones.

malaria (ma-lar′e-a)
A disease caused by the presence of the sporozoan Plasmodium in human or other vertebrate red blood cells, usually transmitted to humans by the bite of an infected female mosquito of the genus Anopheles that previously sucked the blood from a person with m.. Human infection begins with the exoerythrocytic cycle in liver parenchyma cells, followed by a series of erythrocytic schizogenous cycles repeated at regular intervals; production of gametocytes in other red cells provides future gametes for another mosquito infection; characterized by episodic severe chills and high fever, prostration, occasionally fatal termination. See tropical diseases, under disease. SEE ALSO: Plasmodium. SYN: jungle fever, marsh fever, paludal fever. [It. malo (fem. mala), bad, + aria, air, referring to the old theory of the miasmatic origin of the disease] acute m. a form of m. that may be intermittent or remittent, consisting of a chill accompanied and followed by fever with its attendant general symptoms and terminating in a sweating stage; the paroxysms, caused by release of merozoites from infected cells, typically recur every 48 hours in tertian (vivax or ovale) m., every 72 hours in quartan (malariae) m., and at indefinite but frequent intervals, usually about 48 hours, in malignant tertian (falciparum) m., but in many cases the periodicity is not well established. airport m. m. inadvertently imported by transport of an infected anopheline mosquito on an airplane. algid m. a form of falciparum m. chiefly involving the gut and other abdominal viscera; gastric algid m. is characterized by persistent vomiting; dysenteric algid m. is characterized by bloody diarrheic stools in which enormous numbers of infected red blood cells are found. autochthonous m. disease acquired by mosquito transmission in an area where m. regularly occurs. benign tertian m. SYN: vivax m.. bilious remittent m. a form of falciparum m. characterized by bilious vomiting, bilious diarrhea, etc. cerebral m. a form of falciparum m. characterized by cerebral involvement, with extreme hyperthermia and headache, and a case fatality rate of about 50%. chronic m. m. that develops after frequently repeated attacks of one of the acute forms, usually falciparum m.; it is characterized by profound anemia, enlargement of the spleen, emaciation, mental depression, sallow complexion, edema of ankles, feeble digestion, and muscular weakness. SYN: limnemia, malarial cachexia. m. comatosa falciparum m. complicated by coma. double tertian m. quotidian m.. dysenteric algid m. algid m.. falciparum m. m. caused by Plasmodium falciparum and characterized by malarial paroxysms of severe form that typically occur every 48 hours with acute cerebral, renal, or gastrointestinal manifestations in severe cases, chiefly caused by the large number of red blood cells affected and the tendency for infected red cells to become sticky and clump, thus blocking capillaries. SEE ALSO: malarial knobs, under knob. SYN: aestivoautumnal fever, falciparum fever, malignant tertian fever, malignant tertian m., pernicious m.. gastric algid m. algid m.. induced m. m. acquired by artificial means, e.g., via blood transfusion, common syringes, or malariotherapy. intermittent m. a malarial fever, usually of the tertian or quartan type, in which there is complete apyrexia, with absence of the other symptoms, in the intervals between the paroxysms. malariae m. a malarial fever with paroxysms that typically recur every 72 hours or every fourth day, reckoning the day of the paroxysm as the first; due to the schizogony and release of merozoites from infected cells, with invasion of new red blood corpuscles by Plasmodium malariae. SYN: quartan fever, quartan m.. malignant tertian m. SYN: falciparum m.. monkey m. SYN: simian m.. nonan m. a malarial fever with paroxysms that occur every ninth day, i.e., every eighth day following the preceding paroxysm, the day of each paroxysm being included in the computation. ovale m., ovale tertian m. m. caused by Plasmodium ovale. pernicious m. SYN: falciparum m.. quartan m. SYN: malariae m.. quotidian m. m. in which the paroxysms occur daily; usually a double tertian m., in which there is an infection by two distinct groups of Plasmodium vivax parasites sporulating alternately every 48 hours, but also may be an infection by the pernicious form of malarial parasite, P. falciparum, combined with P. vivax, or infection by two distinct P. falciparum generations, which mature on different days; also may develop from infection with P. knowlesi. SYN: quotidian fever. relapsing m. renewal of clinical activity at some interval after the primary attack. remittent m. a malarial fever, usually of the severe falciparum type, in which the temperature falls but not to the normal level during the interval between two pronounced paroxysms. simian m. plasmodial infection of monkeys and apes, as with human m., transmitted chiefly by anopheline mosquitoes; a number of Plasmodium species are responsible, with Southeast Asia and Africa being the apparent centers of evolution; among the 20 plasmodial agents described from nonhuman primates, some resemble and induce a malarial infection similar to those caused by the four species of Plasmodium from humans, from which the agents of human m. appear to be derived. SYN: monkey m.. tertian m. SYN: vivax m.. therapeutic m. intentionally induced m., formerly used against neurosyphilis and certain other paralytic diseases. SYN: malariotherapy. vivax m. a malarial fever with paroxysms that typically recur every 48 hours or every other day (every third day, reckoning the day of the paroxysm as the first); the fever is induced by release of merozoites and their invasion of new red blood corpuscles. SYN: benign tertian fever, benign tertian m., tertian fever, tertian m., vivax fever.

malarial (ma-lar′e-al)
Pertaining to or affected with malaria.

malariology (ma-lar-e-ol′o-je)
A study of malaria in all aspects, with particular reference to epidemiology and control.

malariotherapy (ma-lar-e-o-ther′a-pe)
SYN: therapeutic malaria.

malarious (ma-lar′e-us)
Relating to or characterized by the prevalence of malaria.

Louis C., French physiologist, 1842–1910. See Malassezia, M. epithelial rests, under rest.

Malassezia (mal-a-sa′ze-a)
A genus of fungi (family Cryptococcaceae) of low pathogenicity that lack the ability to synthesize medium-chain and long-chain fatty acids and require an exogenous supply of these lipids for growth as can be found in the skin. [L. C. Malassez] M. furfur a fungus species that is normal skin flora but can cause tinea versicolor, folliculitis, or fungemia in patients receiving intravenous lipids. SYN: Pityrosporum orbiculare, Pityrosporum ovale. M. ovalis a species of yeast found in superficial epidermal scales and hair follicles on oily skin, of borderline pathogenicity; may cause seborrheic dermatitis associated with immune deficiency. M. pachydermatis a fungus occasionally isolated from skin lesions of humans and animals; a rare cause of fungemia in patients receiving intravenous lipids.

malassimilation (mal′a-sim-i-la′shun)
Rarely used term for incomplete or faulty assimilation; malabsorption.

malate (mal′at)
A salt or ester of malic acid. m. dehydrogenase an enzyme that catalyzes, through NAD+ or NADP+, the dehydrogenation of m. to oxaloacetate or its decarboxylation to pyruvate and CO2. At least six m. dehydrogenases are known, distinguished by their products, use of NAD+ or NADP+, and specificity of substrate (one acts on d-m., the rest act on l-m.); one is an enzyme in the tricarboxylic acid cycle. SYN: malic acid dehydrogenase, malic dehydrogenase, malic enzyme, pyruvic-malic carboxylase. m. synthase an enzyme catalyzing the reversible condensation of acetyl-CoA with glyoxylate and water to form l-m. and coenzyme A; an enzyme in the glyoxylate cycle. SYN: glyoxylate transacetylase, m.-condensing enzyme.

malathion (mal-a-thi′on, ma-la′thi-on)
An organophosphorous compound used as an insecticide and veterinary ectoparasiticide; considered to be less toxic than parathion.

malaxation (mal′ak-sa′shun)
1. Formation of ingredients into a mass for pills and plasters. 2. A kneading process in massage. [L. malaxo, pp. -atus, to soften]

maldigestion (mal-di-jes′chun)
Imperfect digestion.

Maldonado-San Jose stain
See under stain.

male (mal)
1. In zoology, denoting the sex to which those belong that produce spermatozoa; an individual of that sex. 2. SYN: masculine. [L. masculus, fr. mas, m.] genetic human m. 1. an individual with a karyotype containing a Y chromosome; 2. an individual whose cell nuclei do not contain Barr sex chromatin bodies, which are normally present in females. Patients with ambiguous sexual development and those with Turner syndrome are classed as genetic males or genetic females according to the absence or presence of Barr bodies even though their sex chromosome complement may suggest otherwise. XX m. a clear m. phenotype in the presence of a 46,XX karyotype; presumably the vital parts of the Y chromosome are located elsewhere in the genome as a result of translocation at least in some of these persons. XXY m. Klinefelter syndrome. XYY m. XYY syndrome.

Achille-Etienne, French surgeon, *1852. See M. catheter.

maleic acid (ma-le′ik)
Butenedioic acid;the cis isomer of fumaric acid; used for preparing maleate salts of antihistaminics and similar drugs. SYN: toxilic acid.

malemission (mal-e-mish′un)
Failure to eject semen from the penis at orgasm. [mal- + L. e-mitto, pp. missus, to send out]

maleruption (mal-e-rup′shun)
Faulty eruption of teeth.

maleylacetoacetate (mal′a-il-as′e-to-as′e-tat)
An intermediate in l-phenylalanine and l-tyrosine catabolism; accumulates in certain inherited disorders of tyrosine metabolism. m. cis,trans-isomerase an enzyme that catalyzes the reversible conversion of m. to 4-fumarylacetoacetate; an enzyme that participates in l-tyrosine catabolism; a deficiency of this enzyme is associated with tyrosinemia type IB.

malformation (mal-for-ma′shun)
Failure of proper or normal development; more specifically, a primary structural defect that results from a localized error of morphogenesis; e.g., cleft lip. Cf.:deformation. Arnold-Chiari m. malformed posterior fossa structures associated with caudad traction and displacement of the rhombencephalon as caused by tethering of the spinal cord; may or may not be accompanied by spina bifida and associated anomalies such as meningomyelocele; this m. is usually multifactorial in inheritance; very weak evidence of autosomal recessive inheritance [MIM*207950]. SYN: Arnold-Chiari deformity, Arnold-Chiari syndrome, cerebellomedullary m. syndrome. cystic adenomatoid m. a rare developmental lung-bud abnormality which results in stillbirth, acute progressive respiratory disease of newborns, or protracted childhood pneumonias; this m. combines features of a hamartoma, dysplastic growth, and tumorous growth. Three types have been described, based chiefly on cyst diameters: Type I: up to 10 cm; Type II: less than 1.2 cm; Type III: less than 0.5 cm. mermaid m. SYN: sirenomelia. Michel m. hypoplasia of the petrous pyramid and aplasia of the inner ear. venous m. SYN: venous angioma.

malfunction (mal-funk′shun)
Disordered, inadequate, or abnormal function.

Joseph F., French surgeon, 1806–1865. See M. amputation, M. fossa, M. hernia, M. luxation, M. triangle.

Albert, 1845–1915. See M. calcifying epithelioma.

malic acid (mal′ik, ma′lik)
Hydroxysuccinic acid;an acid found in apples and various other tart fruits; an intermediate in the tricarboxylic acid cycle, the glyoxylate cycle, and in a shuttle system. SYN: monohydroxysuccinic acid.

malic acid dehydrogenase
SYN: malate dehydrogenase.

malic dehydrogenase
SYN: malate dehydrogenase.

malignancy (ma-lig′nan-se)
The property or condition of being malignant.

malignant (ma-lig′nant)
1. Resistant to treatment;occurring in severe form, and frequently fatal; tending to become worse and leading to an ingravescent course. 2. In reference to a neoplasm, having the property of locally invasive and destructive growth and metastasis. [L. maligno, pres. p. -ans (ant-), to do anything maliciously]

malinger (ma-ling′ger)
To engage in malingering.

malingerer (ma-ling′ger-er)
One who engages in malingering.

malingering (ma-ling′ger-ing)
Feigning illness or disability to escape work, excite sympathy, or gain compensation. [Fr. malingre, poor, weakly]

malinterdigitation (mal′in-ter-dij′i-ta′shun)
Faulty intercuspation of teeth.

Franklin Paine, U.S. anatomist and embryologist, 1862–1917. See M. formula, M. ridges, under ridge, periportal space of M..

malleable (mal′e-a-bl)
Capable of being shaped by being beaten or by pressure; a property of certain metals such as gold and silver. [L. malleus, a hammer]


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