Medical Dictionary

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aspartylglycosamine (as-par′til-gli′ko-sa-men)
Generic term for compounds of asparagine and a 2-amino sugar; e.g., β-aspartyl(acetylglucosamine).

aspartylglycosaminidase (as-par′til-gli′ko-sa-mi-ni-das)
A hydrolytic enzyme that cleaves off l-aspartate from aspartylglycosamines. A deficiency of a. can result in aspartylglycosaminuria.

aspartylglycosaminuria (as-par′til-gli′ko-sa-mi-noor′e-a) [MIM*208400]
A lysosomal disorder due to deficiency of aspartoglucosaminidase, resulting in accumulation of aspartlyglycosamine in the urine and spinal fluid; characterized by symptoms usually in the first few months of life, with recurrent infections and diarrhea; mental retardation, seizures, coarse facial features, and skeletal abnormalities are evident by adolescence. Autosomal recessive inheritance, caused by mutation in the aspartoglucosaminidase gene (AGA) on 4q.

aspect (as′pekt)
1. The manner of appearance; looks. 2. The side of an object that is directed in any designated direction. SYN: norma (1) . [L. aspectus, fr. a-spicio, pp. -spectus, to look at] facial a. [TA] the outline of the skull viewed from in front. SYN: norma facialis [TA] , frontal a.&star, norma frontalis&star, norma anterior. frontal a. facial a.. lateral a. [TA] the profile of the skull; the outline of the skull viewed from either side. SYN: norma lateralis [TA] , norma temporalis. occipital a. [TA] the outline of the skull viewed from behind. SYN: norma occipitalis [TA] , norma posterior. superior a. the outline of the surface of the skull viewed from above. SYN: norma superior [TA] , norma verticalis&star, vertical a.&star. vertical a. superior a..

Asperger
Hans, 20th century Austrian psychiatrist. See A. disorder.

aspergillic acid (as-per-jil′ik)
Produced by Aspergillus flavus; an antibiotic agent moderately active against Gram-positive and Gram-negative bacteria, but toxic to animal tissues.

aspergillin (as-per-jil′in)
A black pigment obtained from various species of Aspergillus; improperly used to designate various antibiotics obtained from Aspergillus.

aspergilloma (as′per-ji-lo′ma)
A ball-like mass of Aspergillis hyphae colonizing an existing cavity in the lung. [aspergillus + -oma, tumor]

aspergillosis (as′per-ji-lo′sis)
The presence of the fungus Aspergillus in the tissues or invading tissue (invasive a.) or colonizing air-containing body cavities. SEE ALSO: aspergilloma. acute invasive a. an aggressive infection, particularly in severely immunocompromised people, which consists of invasion of blood vessels and tissue infarction by Aspergillus fumigatus. The disease often mimics the signs and symptoms of acute bacterial pneumonia. allergic bronchopulmonary a. a disease in which the fungus grows in mucus (evoked by inflammation), which may be expectorated as yellow bronchial casts and cause intermittent bronchial obstruction, with transient infiltrates seen radiographically; asthma is often present, and bronchial wall destruction may eventually result in a proximal form of bronchiectasis. chronic necrotizing a. an indolent but slowly progressive infection of the lungs in patients with underlying lung disease, caused by aspergillus. Most affected patients have a modest depression of the immune system, caused by diseases such as diabetes. disseminated a. a variety of bronchopulmonary a., characterized by a generalized infection of the lung with Aspergillus occurring usually in subjects with defective immune response.

Aspergillus (as-per-jil′us)
A genus of fungi (class Ascomycetes) that contains many species, a number of them with black, brown, or green spores. A few species are pathogenic for humans, avians, and other animals. There are about 300 species in this genus. [Med. L. a sprinkler, fr. L. aspergo, to sprinkle] A. clavatus a fungal species isolated from soil and feces; it yields a carcinogenic mycotoxin known as patulin. A. flavus a fungal species with yellow-green conidia that is found growing on grains; may produce aflatoxin, which is the cause of aflatoxicosis in poultry and cattle, and is carcinogenic for rats and possibly humans; causes invasive aspergillosis in humans and animals. A. fumigatus a fungal species that yields the antibiotics fumigacin and fumigatin, and is the common cause of aspergillosis in humans and birds. A. nidulans a species that causes one form of mycetoma, and occasionally causes aspergillosis in humans and other animals. A. niger a species with black spores, often present in the external auditory meatus but rarely pathogenic; used in the commercial manufacturing of citric and gluconic acids. A. terreus a species that produces the antibiotic citrinin; it has been isolated from otomycosis, especially in Japan and Taiwan, and occasionally causes aspergillosis in humans and animals.

aspermatogenic (a-sper′ma-to-jen′ik, a-sper′)
Failing in the production of spermatozoa. [G. a- priv. + sperma, seed, + -gen, production]

aspermia (a-sper′me-a, a-sper′)
Lack of secretion or expulsion of semen following ejaculation.

aspersion (as-per′zhun)
A form of hydrotherapy in which water of a given temperature is sprinkled on the body. [L. aspersio, a sprinkling]

aspheric (a-sfer′ik)
Denoting a paraboloidal surface, especially of a lens or mirror, that eliminates spherical aberration. [G. a- priv. + sphaira, sphere]

asphygmia (as-fig′me-a)
Temporary absence of pulse. [G. a- priv. + sphygmos, pulse]

asphyxia (as-fik′se-a)
Impaired or absent exchange of oxygen and carbon dioxide on a ventilatory basis; combined hypercapnia and hypoxia or anoxia. [G. a- priv. + sphyzo, to throb] cyanotic a. a. to the point of sufficient destruction of hemoglobin to produce cyanosis. local a. stagnation of the circulation, sometimes resulting in local gangrene, especially of the fingers; one of the symptoms usually associated with Raynaud disease. symmetric a. SYN: Raynaud syndrome. traumatic a. cyanotic a. due to trauma; the extravasation of blood into the skin and conjunctivae, produced by a sudden mechanical increase in venous pressure, analogous to the Rumpel-Leede test; it is common in those who have been hanged, and is seen occasionally in crush injuries. SYN: pressure stasis.

asphyxial (as-fik′se-al)
Relating to asphyxia.

asphyxiant (as-fik′se-ant)
1. Producing asphyxia. SYN: asphyxiating. 2. Anything, especially a gas, that produces asphyxia.

asphyxiate (as-fik′se-at)
To induce asphyxia.

asphyxiating (as-fik′se-at-ing)
SYN: asphyxiant (1) .

asphyxiation (as-fik-se-a′shun)
The production of, or the state of, asphyxia.

Aspiculuris tetraptera (as-pik-u-loo′ris tet-rap′ter-a)
The mouse pinworm, an abundant oxyurid nematode of the mouse cecum or large intestine, along with another common oxyurid pinworm of mice, Syphacia obvelata; it is also found in other rodents, including Rattus. [Pers. espic, fr. L. spica, ear, spike; tetra- + pteron, feather, wing]

aspidin (as-pid′in)
A toxic active principle, C25H32O8, contained in aspidium.

aspidinol (as-pid′i-nol)
An alcohol, C12H16O4, occurring in aspidium.

aspidium (as-pid′e-um)
The rhizomes and stipes of Dryopteris filix-mus (European a. or male fern), or of Dryopteris marginalis (American a. or marginal fern, family Polypodiaceae); used in the treatment of tapeworm infestation, usually in the form of the oleoresin or extract, but because of its potential toxicity, its use is restricted to patients who do not respond to treatment with safer drugs such as dichlorophen, niclosamide, or quinacrine. [G. aspidion, a little shield, dim. of aspis, shield]

aspidosamine (as′pi-do-sam′en)
A strong base, C22H28N2O2, derived from quebracho; a toxic irritant.

aspidospermine (as′pi-do-sper′men)
An alkaloid, C22H30N2O2, obtained from quebracho, an irritant.

aspirate
1. (as′pi-rat′)To remove by aspiration. 2. (as′pi-rat′)To inhale into the airways foreign particulate material, such as vomitus. 3. (as&prime pi-rit)Foreign body, food, gastric contents, or fluid, including saliva that is inhaled. [L. a-spiro, pp. -atus, to breathe on, give the H sound]

aspiration (as-pi-ra′shun)
1. Removal, by suction, of a gas, fluid, or tissue from a body cavity or organ from unusual accumulations, or from a container. 2. The inspiratory sucking into the airways of fluid or any foreign material, especially gastric contents or food. 3. A surgical technique for cataract, requiring a small corneal incision, severance of the lens capsule, fragmentation of the lens material, and removal with a needle. [L. aspiratio, fr. aspiro, to breathe on] meconium a. intrauterine a. by the fetus of amniotic fluid contaminated by meconium resulting from fetal hypoxic distress.

aspirator (as′pi-ra-ter, -tor)
An apparatus for removing fluid, air, or tissue by aspiration from any of the body cavities; it consists usually of a hollow needle or trocar and cannula, connected by tubing with a container vacuumized by a syringe or reversed air (suction) pump. vacuum a. an instrument for removing the products of conception by suction after cervical dilation. water a. a jet ejector pump operated by water and commonly used as a laboratory suction pump.

aspirin (as′pi-rin)
A widely used analgesic, antipyretic, and anti-inflammatory agent; also used as an antiplatelet agent. SYN: acetylsalicylic acid.

asplenia (a-sple′ne-a)
Congenital or acquired absence of the spleen ( e.g., after surgical removal). functional a. absence of splenic function due to spontaneous infarction of the spleen, as occurs in sickle cell anemia. a. with cardiovascular anomalies SYN: polysplenia.

asplenic (a-splen′ik)
Having no spleen.

asporogenous (as-po-roj′e-nus)
Not producing spores. [G. a- priv. + sporos, seed, + -gen, production]

asporous (as-por′us)
Incapable of producing spores. [G. a- priv. + sporos, seed]

asporulate (as-por′u-lat)
Nonsporeforming.

assay (as′sa, a-sa′)
1. The quantitative or qualitative evaluation of a substance for impurities, toxicity, etc; the results of such an evaluation. 2. To examine; to subject to analysis. 3. Test of purity; trial. [M.E., fr. O.Fr. essaier, fr. L.L. exagium, a weighing] Ames a. SYN: Ames test. biologic a. SYN: biotest. clonogenic a. in vitro culturing of neoplastic cells to test their radiosensitivity or chemosensitivity, and probable clinical efficacy of a therapeutic agent. competitive binding a. general term for an a. in which a substance competes for labeled versus unlabeled ligand; following separation of free and bound ligand, the concentration of unlabeled ligand is inversely proportional to the amount of labeled bound ligand. Values are compared to known standards. SEE ALSO: enzyme-linked immunosorbent a., radioreceptor a., immunoassay, enzyme-multiplied immunoassay technique, radioimmunoassay. SYN: displacement analysis, saturation analysis. complement binding a. SYN: complement fixation. double antibody sandwich a. for antigen; an application of the ELISA method in which material being tested for antigen is added to wells coated with known antibody; the presence of antigen fixed to the antibody coat can be determined either directly, by adding antibody linked to the enzyme of the indicator system, or indirectly, by first adding unlabeled known antibody, the attachment of which to the antigen can be demonstrated by addition of immunoglobulin-specific antibody linked to the enzyme. EAC rosette a. (ro-zet′ as′sa) EAC rosette. enzyme-linked immunosorbent a. (ELISA) an in vitro binding a. in which an enzyme and its substrate (rather than a radioactive substance) serve as the indicator system; in positive tests, the two yield a colored or other easily recognizable substance; tests are made in wells in polystyrene or other material to which immunoglobulins or antigenic preparations readily adsorb; the enzyme is linked to known immunoglobulin (or antigen) and in positive tests remains in the well as part of the antigen-antibody complex available to react with its substrate when added. Grunstein-Hogness a. a procedure for identifying plasmid clones by colony hybridization. hemizona a. (hem′e-zo-na) diagnostic test evaluating the binding capacity of sperm to the zona pellucida. hemolytic plaque a. SYN: Jerne plaque a.. immunochemical a. SYN: immunoassay. immunoradiometric a. an a. that differs from conventional radioimmunoassay in that the compound to be measured combines directly with radioactively labeled antibodies. indirect a. for antibody; an application of the ELISA method in which serum being tested for antibody is added to wells coated with known antigen; presence of antibody bound to the antigen coat can be determined by addition of immunoglobulin-specific antibody to which is linked the enzyme of the indicator system, followed by addition of substrate to the washed aggregate. Jerne plaque a. an a. that enumerates individual antibody-forming cells. SYN: hemolytic plaque a.. Lowry-Folin a. SYN: Lowry protein a.. Lowry protein a. a method for determining protein concentrations using the Folin-Ciocalteu reagent. SYN: Lowry-Folin a.. radioreceptor a. a competitive binding a. in which the binder is a membrane or tissue receptor rather than an antibody. Raji cell radioimmune a. for immune complexes; a procedure by which immune complexes adsorbed from a test serum by a standard preparation of lymphoblastoid (Raji) cells are assayed by the capacity to bind 125I-labeled antibody to immunoglobulin.

assessment
Appraisal. health risk a. (h.r.a.) method of describing an individual's chance of falling ill or dying of a specified condition, based on actuarial calculations that compare chance of acquiring condition with that of general population expressed as expected age at which death or disease will occur, and intended as a way of drawing an individual's attention to the probable health consequences of risk behavior.

Assézat
Jules, French anthropologist, 1832–1876. See A. triangle.

assimilable (a-sim′i-la-bl)
Capable of undergoing assimilation. See assimilation.

assimilation (a-sim-i-la′shun)
1. Incorporation of digested materials from food into the tissues. 2. Amalgamation and modification of newly perceived information and experiences into the existing cognitive structure. [L. as-similo, pp. -atus, to make alike] ammonia a. the utilization of ammonia (or ammonium ions) in the net synthesis of nitrogen-containing molecules, e.g., glutamine synthetase. SYN: ammonia fixation. reproductive a. in sensorimotor theory, an active cognitive process by which past experience is applied to novel situations.

Assmann
Herbert, German internist, 1882–1950. See A. tuberculous infiltrate.

associate
1. (a-so′shi-at)Any item or individual grouped with others by some common factor. 2. (a-so′she-at)To accomplish association. paired associates words, syllables, digits, or other items learned in pairs, so that when one is given, its a. is to be recalled.

association (a-so-se-a′shun)
1. A connection of persons, things, or ideas by some common factor. 2. A functional connection of two ideas, events, or psychologic phenomena established through learning or experience. SEE ALSO: conditioning. 3. Statistical dependence between two or more events, characteristics, or other variables. 4. In medical genetics, a grouping of congenital anomalies found together more frequently than otherwise expected; the use of this term implies that the cause is unknown. [L. as-socio, pp. -sociatus, to join to; ad + socius, companion] CHARGE a. a particular grouping of congenital anomalies found together more frequently than otherwise expected. Affected patients have coloboma of the eye, heart defects (typically tetralogy of Fallot, patent ductus arteriosus, or ventricular or atrial septal defect), atresia of the choanae, renal anomalies and retardation of growth and/or development, genital anomalies in males such as small penis or cryptorchidism, and ear abnormalities or deafness. SYN: CHARGE syndrome. clang a. psychic associations resulting from sounds; often encountered in the manic phase of manic-depressive psychosis. dream associations the memories and emotions mentioned by a patient trying to understand a dream at the request of a psychoanalyst. free a. an investigative psychoanalytic technique in which the patient verbalizes, without reservation or censor, the passing contents of his or her mind; the verbalized conflicts that emerge constitute resistances that are the basis of the psychoanalyst's interpretations. genetic a. the occurrence together in a population, more often than can be readily explained by chance, of two or more traits of which at least one is known to be genetic. independent practice a. (IPA) an a. of independent physicians or small groups of physicians formed for the purpose of contracting with one or more managed health care organizations. Member physicians provide medical services for HMO patients in their own offices and are allowed to maintain private practices. SEE ALSO: managed care, health maintenance organization. loose associations a manifestation of a thought disorder whereby the patient's responses do not relate to the interviewer's questions or one paragraph, sentence, or phrase is not logically connected to those that occur before or after.

associationism (a-so-se-a′shun-izm)
In psychology, the theory that man's understanding of the world occurs through ideas associated with sensory experience rather than through innate ideas.

assortment (a-sort′ment)
In genetics, the relationship between nonallelic genetic traits that are transmitted from parent to child more or less independently in accordance with the degree of linkage between the respective loci. independent a. the pattern of transmission of unlinked loci.

assumption
Belief posited at the outset of an argument as a basis for deduction and inference. Commonly confused with a hypothesis, a conclusion at the end of the argument or an inference based on empirical data.

AST
Abbreviation for aspartate aminotransferase.

astasia (a-sta′ze-a)
Inability, through muscular incoordination, to stand. [G. unsteadiness, from a-priv. + stasis, standing]

astasia-abasia (a-sta′ze-a-a-ba′ze-a)
The inability to either stand or walk in a normal manner; the gait is bizarre and is not suggestive of a specific organic lesion; often the patient sways wildly and nearly falls, but recovers at the last moment; a symptom of hysteria-conversion reaction. SYN: Blocq disease.

astatic (a-stat′ik)
Pertaining to astasia.

astatine (At) (as′ta-ten)
An artificial radioactive element of the halogen series; atomic no. 85, atomic wt. 211. [G. astatos, unstable]

asteatosis (a-ste-a-to′sis)
Diminished or arrested secretion of the sebaceous glands. [G. a- priv. + stear (steat-), fat] a. cutis dry, scaly integument with decrease in sebaceous secretion.

astemizole
An H-1 type histamine-blocking drug with low sedating tendency.

aster (as′ter)
SYN: astrosphere. [Mod. L. fr. G. a., a star] sperm a. sperm-a..

astereognosis (a-ster-og-no′sis)
SYN: tactile agnosia. [G. a- priv. + stereos, solid + gnosis, knowledge]

asterion (as-te′re-on) [TA]
A craniometric point in the region of the posterolateral, or mastoid, fontanel, at the junction of the lambdoid, occipitomastoid and parietomastoid sutures. [G. asterios, starry]

asteriosaponins (a-ster′e-o-sap′o-ninz)
SYN: asteriotoxins.

asteriotoxins (a-ster′e-o-tok′sinz)
Toxic steroids produced by starfish (Asteroidea). SYN: asteriosaponins.

asterixis (as-ter-ik′sis)
Involuntary jerking movements, especially in the hands, best elicited by having the patient extend the arms, dorsiflex the wrists, and spread the fingers; due to arrhythmic lapses of sustained posture; seen primarily with various metabolic and toxic encephalopathies, especially hepatic encephalopathy. SYN: flapping tremor. [G. a- priv. + sterixis, fixed position]

asternal (a-ster′nal)
1. Not related to or connected with the sternum, e.g., a. rib. 2. Without a sternum. [G. a- priv. + sternon, chest]

asternia (a-ster′ne-a)
Congenital absence of the sternum.

Asterococcus
SYN: Mycoplasma. [Mod. L. fr. G. aster, a star, + kokkos, a berry]

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