| direct lytic factors | most abundant proteins in cobra (naja of the elapids) venom; basic polypeptides of 57 to 62 amino acids with four disulfide bonds and a molecular weight of less than 7000; causes skeletal and cardiac muscle contracture, interferes with neuromuscular and ganglionic transmission, depolarises nerve, muscle and blood cell membranes, thus causing haemolysis. Synonym: cobramine a; cobramine b; cobra cytotoxin; gamma toxin; membrane-active polypeptide. (12 Dec 1998) |
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| direct maternal death | Death resulting from obstetric complications of the gestation, labour, or puerperium, and from interventions, omissions, incorrect treatment, or a chain of events caused by any of the above, indirect maternal death, an obstetric death resulting from previously existing disease or from disease developing during pregnancy, labour, or the puerperium; it is not directly due to obstetric causes, but to conditions aggravated by the physiological effects of pregnancy. (05 Mar 2000) |
| direct method for making inlays | In dentistry, an inlay technique in which the wax pattern is made directly in the prepared cavity in the tooth. Synonym: direct technique. (05 Mar 2000) |
| direct nuclear division | <cell biology> An unusual form of nuclear division, in which the nucleus simply constricts, rather like a cell without chromosome condensation or spindle formation. Partitioning of daughter chromosomes is haphazard. Observed in some Protozoa. (18 Nov 1997) |
| direct ophthalmoscope | <instrument> An instrument designed to visualise the interior of the eye, with the instrument relatively close to the subject's eye and the observer viewing an upright magnified image. (05 Mar 2000) |
| direct ophthalmoscopy | Ophthalmoscopy performed with a direct ophthalmoscope. (05 Mar 2000) |
| direct percussion | The striking of the part under examination directly with the finger or a plessor, without the intervention of another finger or plessimeter. Synonym: direct percussion. (05 Mar 2000) |
| direct pulp capping | A procedure for covering and protecting an exposed vital pulp. (05 Mar 2000) |
| direct pyramidal tract | Uncrossed fibres forming a small bundle in the pyramidal tract. See: pyramidal tract. Synonym: tractus corticospinalis anterior, tractus pyramidalis anterior, anterior corticospinal tract, anterior pyramidal fasciculus, direct pyramidal tract, fasciculus corticospinalis anterior, fasciculus pyramidalis anterior, Turck's bundle, Turck's column, Turck's tract. (05 Mar 2000) |
| direct rays | Cosmic ray's in the form in which they first strike the atmosphere, X-ray's generated at the focal spot of the tube. Synonym: direct rays. (05 Mar 2000) |
| direct reacting bilirubin | The fraction of serum bilirubin which has been conjugated with glucuronic acid in the liver cell to form bilirubin diglucuronide; so called because it reacts directly with the Ehrlich diazo reagent; increased levels are found in hepatobiliary diseases, especially of the obstructive variety. Synonym: conjugated bilirubin. (05 Mar 2000) |
| direct resin restoration | A direct restoration made by inserting a plastic mix of auto or light-polymerised resins in a cavity prepared in a tooth. Synonym: direct composite resin restoration. (05 Mar 2000) |
| direct retainer | A clasp or attachment applied to an abutment tooth for the purpose of maintaining a removable appliance in position. (05 Mar 2000) |
| direct retention | Retention obtained in a removable partial denture by the use of attachments or clasps which resist their removal from the abutment teeth. (05 Mar 2000) |
| direct service costs | Costs which are directly identifiable with a particular service. (12 Dec 1998) |