| non-ionic contrast media | <radiology> A class of radiographic contrast media which do not ionise in solution, thereby decreasing effective osmolarity and toxicity. (05 Mar 2000) |
|---|---|
| successive contrast | The visual effect caused by viewing a brightly coloured object and then a gray surface; the latter appears tinged with the complementary colour of the object. Viewing a surface coloured in the complementary colour of the object rather than in gray enhances the colour intensity of the surface. (05 Mar 2000) |
| differential interference contrast | <technique> A mode of contrast generation in microscopy that yields an image with a shadow relief. The relief reflects the gradient of optical path difference. Differential Interference Contrast, which is a form of interferenc microscopy that uses polarizing beam splitters, can be of the Smith or Nomarski type. Acronym: DIC (05 Aug 1998) |
| double contrast enema | After evacuation of a barium enema and injection of air into the rectum, radiographs show fine details of mucosa of the rectum and colon. (05 Mar 2000) |
| iodinated contrast | A substance that contains iodine that can be injected, swallowed or given as an enema for the purpose of diagnostics. Iodinated contrast is radiopaque. This means that conventional X-rays will highlight the course of the contrast in the body. (27 Sep 1997) |
| iodinated contrast material | A substance that contains iodine that can be injected, swallowed or given as an enema for the purpose of diagnostics. Iodinated contrast is radiopaque. This means that conventional X-rays will highlight the course of the contrast in the body. (27 Sep 1997) |
| 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) |
| gram-positive | <microbiology> Bacteria that retain the stain or that are resistant to decolourisation by alcohol during Gram's method of staining. This is a primary characteristic of bacteria whose cell wall is composed of a thick layer of peptidologlycan containing teichoic and lipoteichoic acid complexed to the peptidoglycan. See: gram-negative (06 Oct 1997) |
| gram-positive asporogenous rods | <microbiology> A gram-positive, non-spore-forming group of bacteria comprising organisms that have morphological and physiological characteristics in common. (12 Dec 1998) |
| gram-positive asporogenous rods, irregular | <microbiology> A group of irregular rod-shaped bacteria that stain gram-positive and do not produce endospores. (12 Dec 1998) |
| gram-positive asporogenous rods, regular | <microbiology> A group of regular rod-shaped bacteria that stain gram-positive and do not produce endospores. (12 Dec 1998) |
| gram-positive bacteria | <microbiology> Bacteria which retain the crystal violet stain when treated by gram's method. (12 Dec 1998) |
| gram-positive bacterial infections | <microbiology> Infections caused by bacteria that retain the crystal violet stain (positive) when treated by the gram-staining method. (12 Dec 1998) |
| gram-positive cocci | <microbiology> Coccus-shaped bacteria that retain the crystal violet stain when treated by gram's method. (12 Dec 1998) |