Medical Dictionary

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aglossia (a-glos′e-a)
Congenital absence of the tongue. [G. a- priv. + glossa, tongue]

aglossostomia (a-glos-o-sto′me-a)
Congenital absence of the tongue, with a malformed (usually closed) mouth. [G. a- priv. + glossa, tongue, + stoma, mouth]

aglucon (a-gloo′kon)
The portion of a glucoside other than the glucose. [G. a- priv. + glucose + -on]

aglutition (a-gloo-tish′un)
Inability to swallow. SEE ALSO: dysphagia.

aglyca, gen. aglycon (a-gli′kon)

aglycon, aglycone, pl .aglyca (a-gli′kon)
The noncarbohydrate portion of a glycoside ( e.g., digoxigenin). [G. a- priv. + glykys, sweet]

aglycone
See aglycon.

aglycosuria (a-gli-ko-soo′re-a)
Absence of carbohydrate in the urine.

aglycosuric (a-gli-ko-soo′rik)
Relating to aglycosuria.

agmen, pl .agmina (ag′men, ag′min-a)
Obsolete term for aggregation. [L. a multitude] a. peyerianum SYN: aggregated lymphoid nodules of small intestine, under nodule.

agminate, agminated (ag′mi-nat, ag′mi-na-ted)
SYN: aggregated. [L. agmen, a multitude]

agnathia (ag-na′the-a)
Congenital absence of the lower jaw, usually accompanied by approximation of the ears. SEE ALSO: otocephaly, synotia. [G. a- priv. + gnathos, jaw]

agnathous (ag′na-thus)
Relating to agnathia.

agnea (ag-ne′a)
SYN: agnosia. [G. agnoia, want of perception]

agnogenic (ag-no-jen′ik)
SYN: idiopathic. [G. a- priv. + gnosis, knowledge, + genesis, origin]

agnosia (ag-no′ze-a)
Impairment of ability to recognize, or comprehend the meaning of, various sensory stimuli, not attributable to disorders of the primary receptors or general intellect; agnosias are receptive defects caused by lesions in various portions of the cerebrum. SYN: agnea. [G. ignorance; from a- priv. + gnosis, knowledge] auditory a. inability to recognize sounds, words, or music; caused by a lesion of the auditory cortex of the temporal lobe. color a. inability to name or identify specific colors by sight; caused by lesions of the dominant occipital and temporal lobes. finger a. inability to name or recognize individual fingers, of one's own or of other persons; most often caused by lesion of or near the angular gyrus of the dominant hemisphere. gustatory a. inability to classify or identify a tastant, even though the ability to distinguish between or recognize tastants may be normal; may be general, partial, or specific. localization a. inability to recognize the area where the skin is touched. olfactory a. inability to classify or identify an odorant, although the ability to distinguish between or recognize odorants may be normal; may be general, partial, or specific. optic a. SYN: visual a.. position a. failure to recognize the posture of an extremity. tactile a. inability to recognize objects by touch, in the presence of intact cutaneous and proprioceptive hand sensation; caused by a lesion in the contralateral parietal lobe. SYN: astereognosis, stereoagnosis, stereoanesthesia. visual a. inability to recognize objects by sight; usually caused by bilateral parieto-occipital lesions. SYN: optic a.. visual-spatial a. inability to localize objects or to appreciate distance, motion, and spatial relationships; caused by lesion in the occipital lobe. Cf.:simultanagnosia.

-agogue, -agog
Leading, promoting, stimulating; a promoter or stimulant of. [G. agogos, leading forth, fr. ago, to lead]

agomphious (a-gom′-fe-us)
SYN: anodontia.

agomphosis, agomphiasis (ag-om-fo′sis, fi′a-sis)
SYN: anodontia. [G. a- priv. + gomphos, peg, bolt]

agonadal (a-gon′a-dal)
Denoting the absence of gonads.

agonal (ag′on-al)
Relating to the process of dying or the moment of death, so called because of the former erroneous notion that dying is a painful process.

agonist (ag′on-ist)
1. Denoting a muscle in a state of contraction, with reference to its opposing muscle, or antagonist. 2. A drug capable of combining with receptors to initiate drug actions; it possesses affinity and intrinsic activity. [G. agon, a contest]

agony (ag′o-ne)
Intense pain or anguish of body or mind. [G. agon, a struggle, trial]

agoraphobia (ag′or-a-fo′be-a)
A mental disorder characterized by an irrational fear of leaving the familiar setting of home, or venturing into the open, so pervasive that a large number of external life situations are entered into reluctantly or are avoided; often associated with panic attacks. [G. agora, marketplace, + phobos, fear]

agoraphobic (a-gor-a-fo′bik)
Relating to or characteristic of agoraphobia.

agouti (ah-gu′te)
SYN: Dasyprocta. [Fr., fr. native Indian]

-agra
Sudden onslaught of acute pain. [G. agra, a hunting, a catching, a trap]

agraffe (a-graf′)
An appliance for clamping together the edges of a wound, used in lieu of sutures. [Fr. agrafe, a hook, clasp]

agrammatica (ag-ra-mat′i-ka)
SYN: agrammatism.

agrammatism (a-gram′a-tizm)
A form of aphasia characterized by an inability to construct a grammatical sentence, and the use of unintelligible or incorrect words; caused by a lesion in the dominant temporal lobe. SYN: agrammatica, agrammatologia, jargon aphasia.

agrammatologia (a-gram′ma-to-lo′je-a)
SYN: agrammatism.

agranulocyte (a-gran′u-lo-sit)
A nongranular leukocyte. [G. a- priv. + L. granulum, granule, + G. kytos, cell]

agranulocytosis (a-gran′u-lo-si-to′sis)
An acute condition characterized by pronounced leukopenia with great reduction in the number of polymorphonuclear leukocytes (frequently less than 500 granulocytes/mm3); infected ulcers are likely to develop in the throat, intestinal tract, and other mucous membranes, as well as in the skin. SYN: agranulocytic angina, angina lymphomatosa, neutropenic angina.

agranuloplastic (a-gran′u-lo-plas′tik)
Capable of forming nongranular cells, and incapable of forming granular cells. [G. a- priv. + L. granulum, granule, + G. plastikos, formative]

agraphia (a-graf′e-a)
Inability to write properly in the absence of abnormalities of the limb; often accompanies aphasia and alexia; caused by lesions in various portions of the cerebrum, especially those in or near the angular gyrus. SYN: graphic aphasia, graphomotor aphasia. [G. a- priv. + grapho, to write] absolute a. a. in which not even unconnected letters can be written. SYN: atactic a., literal a.. acoustic a. inability to write from dictation. amnemonic a. a. in which letters and words can be written, but not connected sentences. atactic a. SYN: absolute a.. constructional a. an aghraphia in which letters and words can be written correctly, but not arranged appropriately on the writing surface. literal a. SYN: absolute a.. motor a. a. due to muscular incoordination. musical a. an inability to write musical notation. verbal a. a. in which single letters can be written, but not words.

agraphic (a-graf′ik)
Relating to or marked by agraphia.

agretope (ag-re′top)
That part of a processed antigen that binds to the major histocompatibility complex molecule.

ague (a′goo)
1. Archaic term for malarial fever. 2. A chill. [Fr. aigu, acute] brass founder's a. SYN: brass founder's fever.

AGUS
Acronym for atypical glandular cells of undetermined significance, under cell. SEE ALSO: Bethesda system.

agyiophobia (aj′e-o-fo′be-a)
A form of agoraphobia characterized by a morbid fear of being in the street. [G. agyia, street, + phobos, fear]

agyria (a-ji′re-a)
Congenital lack or underdevelopment of the convolutional pattern of the cerebral cortex. SYN: lissencephalia, lissencephaly. [G. a- priv. + gyros, circle]

ahaustral (a-hos′tral)
Lacking haustra, smooth; describing the appearance of the colon on radiographs of a barium enema in ulcerative colitis. [G. a- priv. + haustra]

AHF
Abbreviation for antihemophilic factor A.

AHG
Abbreviation for antihemophilic globulin.

aHyl
Symbol for allohydroxylysine.

ahylognosia (a-hi-log-no′se-a)
Inability to recognize differences of density, weight, and coarseness. [G. a- priv. + hyle, matter, + gnosis, recognition]

Aicardi
J. Dennis, 20th century French neurologist. See A. syndrome.

aichmophobia (ik-mo-fo′be-a)
Morbid fear of being touched by the finger or any slender pointed object. [G. aichme, a point, + phobos, fear]

AID
Abbreviation for donor of heterologous (artificial) insemination. programmable hearing a. multichannel hearing a. that can use more than one level-dependent frequency response strategy.

aidoi-, aidoio-
The genitals; corresponds to L. pudend-. [G. aidoia, shameful things, the genitals]

AIDS (adz)
A deficiency of cellular immunity induced by infection with the human immunodeficiency virus (HIV-1) and characterized by opportunistic diseases, including Pneumocystis carinii pneumonia, Kaposi sarcoma, oral hairy leukoplakia, cytomegalovirus disease, tuberculosis, Mycobacterium avium complex (MAC) disease, candidal esophagitis, cryptosporidiosis, isosporiasis, cryptococcosis, non-Hodgkin lymphoma, progressive multifocal leukoencephalopathy (PML), herpes zoster, and lymphoma. HIV is transmitted from person to person in cell-rich body fluids (notably blood and semen) through sexual contact, sharing of contaminated needles (as by IV drug abusers), or other contact with contaminated blood (as in accidental needle sticks among health care workers). The primary targets of HIV are cells with the CD4 surface protein, including principally helper T lymphocytes. Antibody to HIV, which appears in the serum 6 weeks to 6 months after infection, serves as a reliable diagnostic marker but does not bind or inactivate HIV. Gradual decline in the CD4 lymphocyte count, typically occurring over a period of 10–12 years, culminates in loss of ability to resist opportunistic infections; the appearance of one or more of these defines the onset of A.. In some patients, generalized lymphadenopathy, fever, weight loss, dementia, and chronic diarrhea are associated with early stages of the disease. A. is uniformly lethal, most patients dying of one or more opportunistic infections or their complications within 2–5 years of the onset of symptoms. In the U.S., A. is the leading cause of death among men 25–44, and the fourth leading cause among women in the same age group. During the past 5 years, the mortality of the disease and rates of perinatal transmission have declined substantially, as has transmission among homosexual men and intravenous drug users. Meanwhile heterosexual transmission and case rates among blacks and Hispanics have increased. Some 50 million people are estimated to be infected worldwide, with the highest incidence in some Central and East African countries, where as many as 25% of the adult population may be HIV-positive. Besides prophylaxis against opportunistic infection, standard therapy of HIV infection includes use of nucleoside analogs (didanoxine, lamivudine, ribavirin, stavudine, zidovudine), nonnucleoside reverse transcriptase inhibitors (delavirine, efavirenz, nevirapine), and protease inhibitors (crixivan, indinavir, ritonavir, saquinavir). SEE ALSO: human immunodeficiency virus. SYN: acquired immunodeficiency syndrome. [acronym, acquired immunodeficiency syndrome] The development of effective antiretroviral agents (reverse transcriptase inhibitors and protease inhibitors) and of quantitative plasma HIV RNA assays that can monitor progression of disease and response to treatment has shifted the goal of management in A. from prophylaxis and treatment of opportunistic infections to achievement of remission through suppressive therapy. Immune compromise is monitored by serial CD4 counts; viral replication, by plasma HIV RNA assay (viral load). Indications for starting antiretroviral therapy are the appearance of symptoms of opportunistic infection, decline of the CD4 count below 500/mm3, or viral load exceeding 5000 copies/mL. Protease inhibitors have been shown to be highly effective antiretroviral agents, and standard treatment regimens combining 2 reverse transcriptase inhibitors with 1 protease inhibitor (“triple therapy”) have clearly demonstrated superiority over monotherapy. However, these drugs are expensive; in 2000 the annual cost of therapy and monitoring exceeded $10,000. Regimens are often complex, with varying requirements for fasting and timing of doses, and adverse effects and drug interactions are common. Protease inhibitors have been associated with elevation of cholesterol and triglycerides, insulin resistance, and disfiguring lipodystrophy. Strains of HIV resistant to all available protease inhibitors have appeared. The rationale for current A. regimens is an effort to eradicate HIV infection by inhibiting spread of virus to new cells until all infected cells have died. However, no one has ever been cured of A.. A small number of resting CD4 memory cells in treated patients with undetectable plasma HIV RNA levels harbor HIV proviral DNA capable of replication, and these cells may survive for months or years. Macrophages and CNS neurons may serve as an anatomic sanctuary for HIV to which antiretroviral drugs cannot penetrate in adequate concentration. When antiretroviral therapy is initiated early, CD4 helper cell counts rise, CD4 cell activity is preserved, and HIV RNA levels may remain undetectable for long periods. However, in about 50% of patients with advanced disease, even multidrug regimens fail to suppress plasma viral RNA to undetectable levels. Many treatment failures result from poor compliance with multidrug regimens. One-fourth of patients queried admit to allowing themselves occasional “drug holidays.” Failure of one therapeutic regimen often precludes success with others because of the high degree of cross-resistance among antiretroviral drugs. After failure of an initial regimen, genotypic testing can be used to identify mutations in the HIV genome that confer resistance to one or more classes of HIV drugs. In a significant number of patients, opportunistic infections continue despite restoration of CD4 counts, probably because some T-cell subpopulations have been annihilated by HIV infection and are not recoverable even after viral suppression. Hence prophylaxis against opportunistic infections remains an essential component of the management of HIV disease. Moreover, even HIV-infected persons with undetectable viral loads must still be considered infectious. Evolving standards of treatment in HIV disease include aggressive therapy of the acute phase of infection and prophylactic administration of antiretroviral therapy after accidental needlestick or sexual assault. Efforts to develop a vaccine against HIV have been hampered by the unique properties of the virus and the long incubation period of A.. A bivalent vaccine that elicits antibody to the outer shell protein of HIV is in Phase III trials. Many authorities believe that an effective vaccine must also stimulate cell-mediated immunity.

AIH
Abbreviation for homologous (artificial) insemination.

AILD
Abbreviation for angioimmunoblastic lymphadenopathy with dysproteinemia.

aIle
Abbreviation for alloisoleucine.

ailurophobia (i′loo-ro-fo′be-a, a′lu-)
Morbid fear of or aversion to cats. [G. ailouros, cat, + phobos, fear]

ainhum (i′um)
An acquired slowly progressive painful fibrous constriction that develops in the digitoplantar fold, usually of the little toe, gradually resulting in spontaneous amputation of the toe; most commonly affects black males in the tropics. [fr. Af. (Lagos), to saw]

AIR
Abbreviation for 5-aminoimidazole ribose 5′-phosphate and 5-aminoimidazole ribotide.

air (ar)
1. A mixture of odorless gases found in the atmosphere in the following approximate percentages by volume after water vapor has been removed: oxygen, 20.95; nitrogen, 78.08; argon 0.93; carbon dioxide, 0.03; other gases, 0.01. Formerly used to mean any respiratory gas, regardless of its composition. 2. SYN: ventilate. [G. aer; L. aer] alveolar a. SYN: alveolar gas. complemental a. SYN: inspiratory reserve volume. complementary a. SYN: inspiratory capacity. functional residual a. SYN: functional residual capacity. a. hunger extremely deep ventilation such as occurs in patients with acidosis attempting to increase ventilation of alveoli and exhale more carbon dioxide. SEE ALSO: Kussmaul respiration. liquid a. a. that, by means of intense cold and pressure, has been liquefied. minimal a. the volume of gas that remains in the lungs and cannot be expelled after they have been removed from the body, or after the chest has been opened. reserve a. SYN: expiratory reserve volume. residual a. SYN: residual volume. supplemental a. SYN: expiratory reserve volume. tidal a. SYN: tidal volume. vitiated a. a. containing a reduced percentage of oxygen.

Aird
Robert B., U.S. neurologist, *1903. See Flynn-A. syndrome.

airsickness
A condition resembling seasickness or other forms of motion sickness occurring in airplane or space flight as a result of erratic and continuous stimuli of the inner ear.

airspace (ar′spas)
Pertaining to the portion of the lung distal to the conducting airways or bronchi; alveolar.

airtrapping (ar-trap′ing)
Slow or incomplete emptying of gas from all or part of a lung on expiration; implies obstruction of regional airways or emphysema.

airway (ar′wa)
1. Any part of the respiratory tract through which air passes during breathing. 2. In anesthesia or resuscitation, a device for correcting obstruction to breathing, especially an oropharyngeal and nasopharyngeal a., endotracheal a., or tracheotomy tube. anatomic a. SYN: anatomic dead space. conducting a. the a. from the nasal cavity to a terminal bronchiole. Guedel a. oropharyngeal a. used to ensure a. patency during general anesthesia. lower a. the portion of the respiratory tract that extends from the subglottis to and including the terminal bronchioles. neurogenic a. upper-a. obstruction due to abnormal muscle tone in the upper a.; found in patients with severe developmental delay or brain injury, and especially in those with spastic quadriplegia. respiratory a. that part of the a. where interchange of gases occurs; it includes respiratory bronchioles, alveolar ducts, sacs, and alveoli. upper a. the portion of the respiratory tract that extends from the nares or mouth to and including the larynx.

Ajellomyces capsulatum (ah-je-lo-mi′sez kap-soo-la′tum)
The ascomycetous (perfect, sexual, teleomorph) state of Histoplasma capsulatum. SYN: Emmonsiella capsulata.

Ajellomyces dermatitidis (ah-je-lo-mi′sez der-ma-tit′i-dis)
The perfect (teleomorph) state of the fungus Blastomyces dermatitidis; the (+) and (-) mating types cause disease with equal frequency. This sexual state is placed in the family Gymnoascaceae.

ajmaline (aj′ma-len)
An indole alkaloid from the roots of Rauwolfia serpentina, related to reserpine, serpentine, and yohimbine; has been used for treatment of hypertension and as a tranquilizer or sedative.

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