| reverse transcription | <molecular biology> The process of copying information found in RNA into DNA. (09 Oct 1997) |
|---|---|
| reverse transcriptons | An enzyme that converts RNA to DNA. Some viruses have only RNA as their primary genetic material. By converting their RNA genes to DNA with this enzyme, the host cell is 'tricked' into creating new copies of the virus. Useful in genetic engineering to make DNA from mRNA. (14 Nov 1997) |
| reverse Trendelenburg position | Supine position without flexing or extending, in which the head is higher than the feet. (05 Mar 2000) |
| reversed | 1. <botany> Turned side for side, or end for end; changed to the contrary; specifically, sinistrorse or sinistral; as, a reversed, or sinistral, spiral or shell. 2. Annulled and the contrary substituted; as, a reversed judgment or decree. <photography> Reversed positive or negative, a picture corresponding with the original in light and shade, but reversed as to right and left. Source: Websters Dictionary (01 Mar 1998) |
| reversed anaphylaxis | An anaphylactic reaction induced in an animal injected with a specific antigen, which will bind to reactive tissue, and then, after a latent period, with serum from another animal previously sensitised to the identical antigen. Synonym: reversed anaphylaxis. (05 Mar 2000) |
| reversed paradoxical pulse | A pulse in which the amplitude increases with inspiration and decreases with expiration, as observed in some cases of tricuspid insufficiency and during A-V dissociation with sinus arrhythmia. (05 Mar 2000) |
| reversed passive anaphylaxis | An anaphylactic reaction induced in an animal injected with a specific antigen, which will bind to reactive tissue, and then, after a latent period, with serum from another animal previously sensitised to the identical antigen. Synonym: reversed anaphylaxis. (05 Mar 2000) |
| reversed peristalsis | A wave of intestinal contraction in a direction the reverse of normal, by which the contents of the intestine are forced backward. Synonym: antiperistalsis. (05 Mar 2000) |
| reversed phase chromatography | A form of partitionary chromatography in which the stationary phase is more polar than the mobile phase. (05 Mar 2000) |
| reversed Prausnitz-Kustner reaction | The appearance of an urticarial reaction at the site of injection when serum containing reaginic antibody is injected into the skin of a person in whom the allergen is already present. (05 Mar 2000) |
| reversed reciprocal rhythm | A cardiac arrhythmia in which a normal sinus impulse, before reaching the ventricles, is reflected backward to the atria; thus in the electrocardiogram a ventricular complex is sandwiched between a normal sinus P wave and a retrograde P wave; if the dysrhythmia continues, subsequent cycles are similar to those of reciprocating rhythm. (05 Mar 2000) |
| reversed shunt | Right-to-left shunt that had previously been a left-to-right shunt; rarely the opposite. (05 Mar 2000) |
| reversed-field pinch | <radiobiology> A toroidal magnetic confinement scheme which could constitute an alternative to the Tokamak for building a fusion reactor. It is characterised by a magnetic field mostly generated by the plasma itself, with toroidal and poloidal components of comparable intensities, in contrast with the Tokamak where most of the field is toroidal and externally applied. The name of the configuration is given by the fact that the toroidal component of the magnetic field changes sign in the outer region of the plasma. The main attractivness of the Reversed Field Pinch is that, according to presently established scalings, it could reach ignition without the need of auxiliary heating. (09 Oct 1997) |
| reversed-three sign | On an oesophagram of a patient with coarctation of the aorta, the shape of the contrast-filled oesophagus caused by the aortic arch (upper convexity) and post-stenotic dilatation (lower convexity); the cusp of the backwards 3 is at the level of the coarctation itself. (05 Mar 2000) |