| rosette | <dermatology> A group of organs or other body features, such as leaves or hair, which are clustered and crowned around a common point of attachment. (09 Oct 1997) |
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| rosette formation | The in vitro formation of clusters consisting of a cell (usually a lymphocyte) surrounded by antigenic cells or antigen-bearing particles (usually erythrocytes, which may or may not be coated with antibody or antibody and complement). The rosette-forming cell may be an antibody-forming cell, a memory cell, a T-cell, a cell bearing surface cytophilic antibodies, or a monocyte possessing fc receptors. Rosette formation can be used to identify specific populations of these cells. (12 Dec 1998) |
| rosette-forming cells | T lymphocytes with an affinity for sheep erythrocytes and which, when suspended in serum, bind the uncoated, nonsensitised erythrocytes in a rosette formation. (05 Mar 2000) |
| rosette test | A test for rosette-forming cells (T-lymphocytes) in which these cells and sheep erythrocytes, are incubated and centrifuged lightly, then examined under a microscope for rosette formation or adherence of erythrocytes to T lymphocytes. (05 Mar 2000) |
| chromosome rosette | Right before metaphase, human chromosomes briefly form this single ring structure. (09 Oct 1997) |
| chromosome rosette john jordan | Right before metaphase, human chromosomes briefly form this single ring structure. (09 Oct 1997) |
| EAC rosette | <haematology> Rosettes formed from erythrocytes (E) coated with antibody (A) and complement (C). A test for C3b or C3bi receptors (CR1 or CR3). The rosettes form more easily then E or EA rosettes. See: E rosettes. (16 Mar 2000) |
| EAC rosette assay | <haematology> Rosettes formed from erythrocytes (E) coated with antibody (A) and complement (C). A test for C3b or C3bi receptors (CR1 or CR3). The rosettes form more easily then E or EA rosettes. See: E rosettes. (16 Mar 2000) |
| EA rosette | A test for the presence of Fc receptors. (18 Nov 1997) |
| E rosette | The adherence of erythrocytes to cells. Sheep erythrocytes will adhere spontaneously to human T-cells, forming rosettes. (05 Mar 2000) |
| E-rosette test | A test to identify T lymphocytes by mixing purified blood lymphocytes with serum and sheep erythrocytes; rosettes of erythrocytes form around human T lymphocytes on incubation. (05 Mar 2000) |
| airbrasive technique | A method of grinding, cutting tooth structure, or roughening the natural tooth surface or the surface of a restoration, by means of a device utilizing a gas-impelled jet of fine Al203 particles which, after striking the tooth, are removed by an aspirator. See: microetching technique. (05 Mar 2000) |
| air-gap technique | Chest radiography performed using a space between the subject and film instead of a grid to absorb scattered radiation; usually requires a target-film distance of 10 feet. (05 Mar 2000) |
| aseptic technique | <procedure> A method used by microbiologists and clinicians to keep cultures, sterile instruments and media, and people free of microbial contamination. (09 Oct 1997) |
| atrial-well technique | An obsolete semi-closed surgical technique for repairing atrial septal defects and other cardiac abnormalities. (05 Mar 2000) |