| ataraxic | 1. Having a calming or tranquillising effect. 2. A tranquilliser. Synonym: ataraxic. Origin: G. Ataraktos, calm (05 Mar 2000) |
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| ataunto | Fully rigged, as a vessel; with all sails set; set on end or set right. Origin: F. Autant as much (as possible). Source: Websters Dictionary (01 Mar 1998) |
| atavism | The recurrence, or a tendency to a recurrence, of the original type of a species in the progeny of its varieties; resemblance to remote rather than to near ancestors; reversion to the original form. <biology> The recurrence of any peculiarity or disease of an ancestor in a subsequent generation, after an intermission for a generation or two. "Now and then there occur cases of what physiologists call atavism, or reversion to an ancestral type of character." (J. Fiske) Origin: L. Atavus an ancestor, fr. Avus a grandfather. Source: Websters Dictionary (01 Mar 1998) |
| atavistic | Relating to atavism. (05 Mar 2000) |
| ataxia | <neurology> Failure of muscular coordination, irregularity of muscular action. Origin: Gr. Taxis = order (16 Dec 1997) |
| ataxia cordis | <cardiology> A condition where there is disorganised electrical conduction in the atria, resulting in ineffective pumping of blood into the ventricle. Acronym: AF (02 Jan 1998) |
| ataxia of calves | A specific cerebellar ataxia in the Jersey breed, probably a recessive genetic trait. (05 Mar 2000) |
| ataxia of lambs | Myelination failure seen in ewes on a copper-deficient diet. (05 Mar 2000) |
| ataxia telangiectasia syndrome | ataxia telangiectasia |
| ataxia-telangiectasia | <neurology, oncology> An intriguing autosomal recessive disorder in which a single defective gene produces myriad and protean effects, presents with cerebellar ataxia, telangiectasias in the eyes and skin, immune deficiency and autoimmune phenomena, propensity for lymphoid and other malignancies, excessive sensitivity to ionising radiation, increased serum alpha-fetoprotein concentrations and a tendency for chromosome breakage and translocation. A syndrome characterised by choreoathetosis beginning in childhood, progressive cerebellar ataxia, telangiectasis of conjunctiva and skin, slowly progressive mental deterioration and increasing cerebellar degeneration. There is evidence that heterozygotes show an increased susceptibility to malignancy as well, with breast cancer often cited. The gene was localised by linkage studies to chromosome 11q22-23, and recently cloned, revealing it to be homologous to the PI-3 kinase family so that prenatal diagnosis by RFLP analysis is possible. Other related genes are suspected to exist. Diagnosis in affected patients is made on clinical grounds, by detection of high concentrations of alpha-fetoprotein, and by a specialised cell culture assay for radiosensitivity and atypical radioresistant DNA synthesis. These cell culture methods are also used for prenatal diagnosis. A characteristic autopsy feature of ataxia-telangiectasia is the presence of empty basket cells in the cerebellum which results from degeneration of the previously contained Purkinje cells. Inheritance: autosomal recessive. (16 Dec 1998) |
| ataxiadynamia | Muscular weakness combined with incoordination. (05 Mar 2000) |
| ataxiagram | The recording made by an ataxiagraph. (05 Mar 2000) |
| ataxiagraph | An instrument for measuring the degree and direction of the swaying of the body and head in static ataxia, with the individual's eyes closed. Synonym: ataxiameter. (05 Mar 2000) |
| ataxiameter | An instrument for measuring the degree and direction of the swaying of the body and head in static ataxia, with the individual's eyes closed. Synonym: ataxiameter. (05 Mar 2000) |
| ataxiaphasia | Inability to form connected sentences, although single words may perhaps be used intelligibly. Origin: G. A-priv. + taxis, order, + phasis, an affirmation, speech (05 Mar 2000) |