| Weigert-Gram stain | <technique> A stain for bacteria in tissues in which sections are stained in alum-haematoxylin, then in eosin, aniline methyl violet, and Lugol's solution. (05 Mar 2000) |
|---|---|
| half-a-gram stain | <technique> A lab technique used to detect the presence of members from the bacterial family Legionellaceae in samples of sputum. (09 Oct 1997) |
| Stirling's modification of Gram's stain | <technique> A stable aniline-crystal violet stain. (05 Mar 2000) |
| CD4-positive T-lymphocytes | A critical subpopulation of regulatory T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the t4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes, which includes both the helper-inducer (T-lymphocytes, helper-inducer) and suppressor-inducer (T-lymphocytes, suppressor-inducer) T-cells. (12 Dec 1998) |
| CD8-positive T-lymphocytes | A critical subpopulation of regulatory T-lymphocytes involved in MHC class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-lymphocytes, cytotoxic) and suppressor T-lymphocytes (T-lymphocytes, suppressor-effector). (12 Dec 1998) |
| continuous positive airway pressure | A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (05 Mar 2000) |
| continuous positive pressure breathing | Artificial ventilation in which all inspirations are provided by positive pressure applied to the airway. Synonym: continuous positive pressure breathing, continuous positive pressure ventilation, intermittent positive pressure breathing, intermittent positive pressure ventilation. (05 Mar 2000) |
| continuous positive pressure ventilation | Synonym: controlled mechanical ventilation. (05 Mar 2000) |
| positive | Having a value greater than zero, indicating existence or presence of a condition, organism, etc. As chromatin positive or Wassermann positive, characterised by affirmation or cooperation. Origin: L. Positivus (18 Nov 1997) |
| positive accommodation | The increased refractivity of the eye that occurs when shifting from the distance to a near object. (05 Mar 2000) |
| positive afterimage | An afterimage in which the lightness relationship is the same as the original one; if chromatic, it appears in the same colour. (05 Mar 2000) |
| positive afterpotential | A spontaneous or inducible increase in transmembrane potential of a cardiac or nerve cell following the completion of repolarization. In the heart, this usually corresponds to the electrocardiographic U wave. (05 Mar 2000) |
| positive anergy | A reduction of the normal or usual immunologic response resulting from a reaction to a specific allergen. Synonym: specific anergy. (05 Mar 2000) |
| positive control | Mechanism for gene regulation that requires that a regulatory protein must interact with some region of the gene before transcription can be activated. (18 Nov 1997) |
| positive convergence | Inward deviation of the visual axes even when convergence is at rest, as in cases of convergent squint. (05 Mar 2000) |