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Medical Dictionary


Ascaridata (as-ka-rid′a-ta)
SYN: Ascaridida.

Ascaridida (as-ka-rid′i-da)
An order of nematode worms that includes many important human, domestic animal, and fowl parasites such as Ascaris, Ascaridia, Subuluris, Heterakis, and Anisakis. SYN: Ascaridata, Ascarididea, Ascaridorida.

Ascarididae (as-ka-rid′i-de)
A family of large intestinal roundworms that includes the important nematode of humans, Ascaris lumbricoides, the abundant roundworm of swine, Ascaris suum, and the common ascarids of dogs and cats, Toxocara and Toxascaris species. [G. askaris, an intestinal worm]

Ascarididea (as-kar-i-did′e-a)
SYN: Ascaridida.

Ascaridoidea (as-ka-ri-doy′de-a)
Superfamily of stout, 3-lipped intestinal roundworms that includes the family Ascarididae.

ascaridole (as-kar′i-dol)
A major constituent of oil of chenopodium; an anthelmintic.

Ascaridorida (as-kari-dor′i-da)
SYN: Ascaridida.

Ascaris (as′ka-ris)
A genus of large, heavy-bodied roundworms parasitic in the small intestine; abundant in humans and many other vertebrates. [G. askaris, an intestinal worm] A. equorum SYN: Parascaris equorum. A. lumbricoides a large roundworm of humans, one of the commonest human parasites (8–12 inches in length); various symptoms such as restlessness, fever, and sometimes diarrhea are attributed to its presence, but usually it causes no definite symptoms; the similar species, A. suum (or A. lumbricoides suum) is very common in swine, but is not readily transmitted to humans, and vice versa; the types are morphologically and immunologically similar but apparently are host-adapted types, considered distinct species or races.

Ascaroidea (as-ka-roy′de-a)
Former spelling for Ascaridoidea.

ascaron (as-ka-ron)
A toxic peptone present in helminths, especially the ascaridids; symptoms of a. poisoning are similar to those of anaphylactic shock. [G. askaris, an intestinal worm, + hormon, pres. part. of hormao, to excite]

Ascarops strongylina (as′ka-rops stron-ji-li′na)
A small bloodsucking worm found in the stomach of pigs and wild boars in many parts of the world. Larvae of this species develop in coprophagous beetles; worms adhere to the gastric mucosa of the pig, and may cause inflammation and ulceration in heavy infections. [G. askaris, an intestinal worm; strongylos, round]

ascendens (as-sen′denz)
Ascending. Going upward, ascending, toward a higher position. [L.]

ascensus (a-sen′sus)
A moving upward; having an abnormally high position. [L. ascent]

ascertainment (as-ser-tan′ment)
In epidemiological and genetic research, the method by which a person, pedigree, or cluster is brought to the attention of an investigator; has a bearing on the interpretation of segregation ratios, concordance rates, linkage analysis, and other probability features. complete a. method by which all families with at least one affected individual in a population are certain or have an equal chance of being identified by survey or an appropriate random sampling technique. incomplete a. method of locating affected individuals in which probability of locating any specific patient has a known value between 0 and 1. SYN: truncate a.. single a. method of a. of locating affected individuals by hospital or clinic admission or another way in which probability of encountering the same family twice approaches zero; thus, the probability that a family will be ascertained is proportional to the number of affected members. total a. method by which all members of a population at risk of a trait are discerned or equally likely to be contained in a sample thereof. truncate a. SYN: incomplete a..

Aschelminthes (ask-hel-min′thez)
A former phylum of the Metazoa that included the class Nematoda and a disparate assortment of other pseudocelomates, each now accorded separate phylum status; they are nonsegmented, bilaterally symmetric, and cylindric or filiform, with a pseudocele body cavity and rounded or pointed ends; they vary considerably in size, and the male is usually smaller than the female.

Karl W., U.S. ophthalmologist, 1887–1971. See A. aqueous influx phenomenon, A. syndrome.

Bernhard, Austrian gynecologist, 1883–1960. See A. phenomenon, A. reflex, A.-Dagnini reflex.

Karl Ludwig, German pathologist, 1866–1942. See A. bodies, under body, A. nodules, under nodule, node of A. and Tawara, Rokitansky-A. sinuses, under sinus, A. cell.

ascites (a-si′tez)
Accumulation of serous fluid in the peritoneal cavity. SYN: abdominal dropsy, hydroperitoneum, hydroperitonia. [L. fr. G. askos, a bag, + -ites] a. adiposus SYN: chylous a.. chyliform a. SYN: chylous a.. chylous a., a. chylosus presence in the peritoneal cavity of a milky fluid containing suspended fat, ordinarily caused by an obstruction or injury of the thoracic duct or cisterna. SYN: a. adiposus, chyliform a., chyloperitoneum, fatty a., milky a.. fatty a. SYN: chylous a.. gelatinous a. SYN: pseudomyxoma peritonei. hemorrhagic a. bloody or blood-stained serous fluid, frequently resulting from metastatic carcinoma, in the peritoneal cavity. milky a. SYN: chylous a.. pseudochylous a. presence in the peritoneum of an opalescent or cloudy fluid that does not contain fat.

ascitic (a-sit′ik)
Of or relating to ascites.

ascitogenous (as-i-toj′e-nus)
Producing ascites.

ascocarp (as′ko-karp)
A fungus structure, of varying complexity, which bears asci and ascospores. [G. askos, bag, + karpos, fruit]

ascogenous (as-koj′e-nus)
Denoting ascus-bearing fungus hypha or cell.

ascogonium (as-ko-go′ne-um)
The female cell in an ascomycete that is fertilized by the male cell.

Alberto, Italian serologist, 1877–1957. See A. reaction, A. test.

Ascomycetes (as′ko-mi-se′tez)
A class of fungi characterized by the presence of asci and ascospores. Such fungi have generally two distinct reproductive phases, the sexual or perfect stage and the asexual or imperfect stage. Ajellomyces capsulatum and Ajellomyces dermatitidis are pathogenic members of this class. [G. askos, a bag, + mykes, mushroom]

ascomycetous (as′ko-mi′se-tus)
Fungi related to the Ascomycota.

Ascomycota (as′ko-mi-ko-ta)
A phylum of fungi characterized by the presence of asci and ascospores. Some mycologists have moved the class Ascomycetes to the phylum or division level.

ascorbase (as-kor′bas)
SYN: ascorbate oxidase.

ascorbate (as-kor′bat)
A salt or ester of ascorbic acid. a. oxidase a copper-containing enzyme that catalyzes the oxidation of l-ascorbic acid with O2 to l-dehydroascorbic acid. Some forms of a. oxidase use NADP+ as well. Used as an antitumor enzyme. SYN: ascorbase.

ascorbic acid (as-kor′bik)
Used in preventing scurvy, as a strong reducing agent, and as an antioxidant. SYN: antiscorbutic vitamin, cevitamic acid, vitamin C. [G. a- priv. + Mod.L. scorbutus, scurvy, fr. Germanic]

ascorbyl palmitate (as-kor′bil pal′mi-tat)
Used as a preservative in pharmaceutical preparations.

ascospore (as′ko-spor)
A spore formed within an ascus; the sexual spore of Ascomycetes. [G. askos, bag, + sporos, seed]

In the Bethesda system, acronym for atypical squamous cells of undetermined significance, under cell. SEE ALSO: Bethesda system.

ascus, pl .asci (as′kus, as′i)
The saclike cell of Ascomycetes in which ascospores develop following nuclear fusion and meiosis. [G. askos, bag]

A termination denoting an enzyme, suffixed to the name of the substance (substrate) upon which the enzyme acts; e.g., phosphatase, lipase, proteinase. May also indicate the reaction catalyzed, e.g., decarboxylase, oxidase. Enzymes named before the convention was established generally have an -in ending; e.g., pepsin, ptyalin, trypsin. [Fr. (diast)ase, an amylase that converts starch to maltose, fr. G. diastasis, separation, fr. dia-, through, apart, + stasis, a standing]

asecretory (a-se-kre′to-re)
Without secretion.

Aselli, Asellius, Asellio
Gasparo, Italian anatomist at Cremona, 1581–1626. See A. pancreas.

asepsis (a-sep′sis, a-)
A condition in which living pathogenic organisms are absent; a state of sterility (2). [G. a- priv. + sepsis, putrefaction]

aseptate (a-sep′tat, a-)
In fungi, a term describing absence of cross walls in a hyphal filament or a spore. [G. a- priv. + L. saeptum, a partition]

aseptic (a-sep′tik, a-)
Marked by or relating to asepsis.

asepticism (a-sep′ti-sizm, a-)
The practice of aseptic surgery.

asequence (a-se′kwens)
Lack of normal sequence, specifically, between atrial and ventricular contractions.

asexual (a-seks′u-al)
1. Referring to reproduction without nuclear fusion in an organism. 2. Having no sexual desire or interest. [G. a- priv. + sexual]

Winifred, 20th century hematologist. See A. method.

Joseph G., Czechoslovakian gynecologist, *1889. See A. syndrome.

R., 20th century U.S. physiologist. See A. phenomenon.

asialism (a′syal-izm)
Absence of saliva. [G. a- priv. + sialon saliva + -ism]

asialoglycoprotein (a-si-al′o-gli-ko-pro-ten)
A glycoprotein without a sialic acid moiety; such proteins are recognized by a. receptors and are targeted for degradation.

asitia (a-sish′e-a)
Disgust at the sight or thought of food. [G. a- priv. + sitos, food]

Max, German pathologist, 1865–1940. See A. cell.

Erik., 20th century Swedish pathologist. See Ask-Upmark kidney.

Abbreviation for American Sign Language.

Asn (Asx)
Symbol for asparagine or its mono- or diradical.

asocial (a-so′shul)
Not social; withdrawn from society; indifferent to social rules or customs; e.g., a recluse, a regressed schizophrenic person, a schizoid personality. Cf.:antisocial.

asoma, pl .asomata (a-so′ma, -so′ma-ta)
A fetus with only a rudimentary body. [G. a- priv. + soma, body]

Asp (Asx)
Symbol for aspartic acid or its radical forms.

aspalasoma (as-pal-a-so′ma)
Obsolete term for a malformed fetus with eventration at the lower part of the abdomen, presenting separate openings for intestine, bladder, and sexual organs. [G. aspalax, a mole + soma, body]

asparaginase (as-par′a-ji-nas)
1. An enzyme catalyzing the hydrolysis of l-asparagine to l-aspartic acid and ammonia. 2. The enzyme from Escherichia coli, used in the treatment of acute leukemia and other neoplastic diseases. Erwinia L-a. L-a. from Erwinia bacteria, used in patients who are allergic to Escherichia coli L-a.. SEE ALSO: a..

asparagine (N, Asn) (as-par′a-jin)
NH2COCH2CH(NH3+COO−;the β-amide of aspartic acid, the l-isomer is a nutritionally nonessential amino acid occurring in proteins; a diuretic. a. ligase an acid:ammonia ligase (amide synthetase) forming l-a. and l-glutamate from l-aspartate and l-glutamine, with the concomitant cleavage of ATP to AMP and pyrophosphate. Under nonphysiological conditions, the mammalian enzyme can use ammonia as the nitrogen donor. A. ligase also displays a glutaminase-like activity. SYN: a. synthetase. a. synthetase SYN: a. ligase.

asparaginyl (as-par′a-jin-il)
The aminoacyl radical of asparagine.

Asparagus (as-par′a-gus)
A genus of plants of the family Liliaceae. A. officinalis is an edible vegetable, the rhizome and roots of which, together with the young edible shoots, were used as a diuretic. [L. fr. G. asparagos]

aspartame (as′par-tam)
A low-calorie sweetening agent about 200 times as sweet as sucrose used by persons who must restrict sugar and caloric intake.

aspartase (as-par′tas)
SYN: aspartate ammonia-lyase.

aspartate (as-par′tat)
A salt or ester of aspartic acid. a. aminotransferase (AST) an enzyme catalyzing the reversible transfer of an amine group from l-glutamic acid to oxaloacetic acid, forming α-ketoglutaric acid and l-aspartic acid; a diagnostic aid in viral hepatitis and in myocardial infarction. SYN: a. transaminase, glutamic-aspartic transaminase, glutamic-oxaloacetic transaminase, serum glutamic-oxaloacetic transaminase. a. ammonia-lyase a nonmammalian enzyme catalyzing the conversion of l-aspartic acid to fumaric acid, splitting out ammonia. SYN: aspartase, fumaric aminase. a. carbamoyltransferase an enzyme catalyzing formation of ureidosuccinate (N-carbamoyl-l-a.) and orthophosphate by the transfer of a carbamoyl moiety from carbamoylphosphate to the amino group of l-a.; participates in pyrimidine biosynthesis. a. kinase an enzyme catalyzing the phosphorylation by ATP of l-a. to form 4-phospho-l-a. (β-aspartyl phosphate) and ADP. a. transaminase SYN: a. aminotransferase.

aspartate 1-decarboxylase
SYN: glutamate decarboxylase.

aspartate 4-decarboxylase
Aspartate β-decarboxylase;a carboxy-lyase converting l-aspartate to l-alanine (releasing CO2); it decarboxylates aminomalonate and (in bacteria) removes SO2 from cysteinesulfinate. SEE ALSO: desulfinase.

aspartic acid (Asp) (as-par′tik)
HOOC&cbond;CH2&cbond;CH(NH2)&cbond;COOH;the l-isomer is one of the amino acids occurring naturally in proteins. The d-isomer is found in cell walls of many bacteria.

aspartyl (as-par′til)
The aminoacyl radical of aspartic acid.


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