| leukocyte | <haematology> White corpuscles in the blood. They are spherical, colourless and nucleated masses involved with host defenses. Normal white blood cell counts are variable with age and sex. Normal adult range is 4, 500 to 11,000 cells per cubic millimetre of blood. Slightly higher counts are seen in children. Elevated counts can be seen in cases of inflammation and infection. See: leucocytes, basophils, coelomocytes, eosinophils, haemocytes, lymphocytes, neutrophils, monocytes. Acronym: WBC (13 Nov 1997) |
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| leukocyte adherence assay test | A test to detect the ability of leukocytes to adhere to bacteria, performed in vitro using nylon fibres to measure adherence. (05 Mar 2000) |
| leukocyte adherence inhibition test | Test for cell-mediated antitumour immunity and related serum blocking factors based on the finding that leukocytes from cancer patients, but not from controls, when mixed in vitro with antigenic extracts of tumours of the same histological type, undergo a diminution in their normal adherence to glass surfaces. Sera from tumour-bearing patients block the lai reaction of their own leukocytes or those of other patients with the same type of tumour. (12 Dec 1998) |
| leukocyte adhesion deficiency | An inherited disorder (autosomal recessive) in which there is a defective CD18 adherence complex that disturbs leukocyte chemotaxis. It is characterised by recurrent bacterial infections and impaired wound healing. (05 Mar 2000) |
| leukocyte-adhesion deficiency syndrome | <syndrome> Rare, autosomal recessive disorder caused by deficiency of the beta 2 integrin receptors (receptors, leukocyte-adhesion) comprising the CD11/CD18 family of glycoproteins. The syndrome is characterised by abnormal adhesion-dependent functions, especially defective tissue emigration of neutrophils, leading to recurrent infection. (12 Dec 1998) |
| leukocyte bactericidal assay test | A test of leukocytes to determine their ability to kill a culture of live bacteria. (05 Mar 2000) |
| leukocyte common antigen | Family of glycoproteins found on most leukocytes and absent from other cell types. These cell surface antigens can comprise up to 10% of the membrane proteins. (05 Mar 2000) |
| leukocyte count | A white blood cell (WBC) count. (12 Dec 1998) |
| leukocyte cream | <haematology> Thin yellow white layer of leucocytes on top of the mass of red cells when whole blood is centrifuged. (18 Nov 1997) |
| leukocyte disorders | Disordered formation of various types of leukocytes or an abnormal accumulation or deficiency of these cells. (12 Dec 1998) |
| leukocyte elastase | <enzyme> An enzyme that catalyses the hydrolysis of proteins, including elastin. It cleaves preferentially bonds at the carboxyl side of ala and val, with greater specificity for ala. Registry number: EC 3.4.21.37 (12 Dec 1998) |
| leukocyte esterase | <enzyme> The presence of leukocyte esterase is indirect evidence for the presence of white blood cells in the urine. The standard urinalysis dip test allows for the quick determination of leukocyte esterase presence via a colour reaction on a urine test strip. A positive test indicates a urinary tract infection. (27 Sep 1997) |
| leukocyte inclusions | Discrete round or oval body's ranging in diameter from just visible to 2 um, which stain sky blue to gray blue with Romanowsky stains, found in neutrophils of patients with infections, burns, trauma, pregnancy, or cancer. Synonym: Dohle inclusions, leukocyte inclusions. (05 Mar 2000) |
| leukocyte interferon | <cytokine> One of the type I interferons produced by peripheral blood leukocytes or lymphoblastoid cells when exposed to live or inactivated virus, double-stranded RNA, or bacterial products. It is the major interferon produced by virus-induced leukocyte cultures and, in addition to its pronounced antiviral activity, causes activation of NK cells. It is used experimentally in the treatment of hairy-cell leukaemia. A number of different subtypes exist that are elaborated by leukocytes in response to viral infection or stimulation with double-stranded RNA; IFN-alpha-2A and -2B are protein products made by recombinant DNA techniques and are used as antineoplastic agents. See: interferon-alpha 2a, interferon-alpha 2b Synonym: leukocyte interferon. Pharmacological action: antineoplastic agent, antiviral agent. (20 Sep 2002) |
| leukocyte migration-inhibitory factors | Protein factor(s) released by sensitised lymphocytes (and possibly other cells) that inhibit the movement of leukocytes, especially polymorphonuclear cells, away from their site of release. Assays for these factors are used as tests for cellular immunity. Two of the common assays are the leukocyte migration capillary tube technique (lmct) and the leukocyte migration agarose technique (lmat). (12 Dec 1998) |