| myeloid cell | <haematology, pathology> One of the two classes of marrow derived blood cells, includes megakaryocytes, erythrocyte precursors, mononuclear phagocytes and all the polymorphonuclear granulocytes. That all these are ultimately derived from one stem cell lineage is shown by the occurrence of the Philadelphia chromosome in these, but not lymphoid, cells. most authors tend, however, to restrict the term myeloid to mononuclear phagocytes and granulocytes and commonly distinguish a separate erythroid lineage. (12 May 1997) |
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| acute myeloid leukaemia | <haematology> A rapidly progressing cancer of the blood affecting immature cells of the bone marrow, usually of the white cell population. It is much more common in adults than in children. Symptoms include fatigue, weight loss, fevers, weakness, pallor, bone pains, bleeding gums, nosebleeds, easy bruising, enlarged lymph nodes and joint pains. Treatment includes chemotherapy and/or bone marrow transplant. This leukaemia demonstrates granulocyte differentiation, eosinophilia and Auer rods and is associated with a reciprocal translocation between 8 and 21 (q22;q22), which is the most common translocation in acute myeloid leukaemia and is found more often in younger patients than in older patients. The oncogene involved in this translocation is AML1, which can be detected by Southern blot. Numerical abnormalities, particularly monosomy-7, trisomy-4, trisomy-8, trisomy-21, -Y, monosomy-7 and deletions of the long arms of chromosomes 5 and 7 are quite common in all acute myeloid leukaemia and not restricted to any one FAB classification. Many of these abnormalities are observed at diagnosis and at later stage disease, particularly after chemotherapy. Prognosis is generally more favorable than in FAB-M2 patients showing no translocation, because the latter patients show better remission rates for longer periods of time. Immunophenotyping is useful in diagnosis and expression of one or more of the myeloid antigens CD13, CD14 or CD33 must be detected to make a diagnosis of acute myeloid leukaemia. Acronym: AML Incidence: 2,000 new cases per year in the UK. Origin: Gr. Haima = blood (07 Apr 1998) |
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| agnogenic myeloid metaplasia | A progressive disease of the bone marrow where neoplastic bone marrow stem cells lodge and grow in multiple sites outside the bone marrow. Typically, there is enlargement of the spleen and a gradual replacement of the bone marrow elements by fibrosis (scarring), progressive anaemia and variable changes in the number of white blood cells and platelets. Diagnosis is by bone marrow biopsy. There is no definitive treatment for this disorder that has been shown to affect life span favorably. Origin: Gr. Plassein = to form (27 Sep 1997) |
| chronic myeloid leukaemia | <haematology> A leukaemia which is initially slowly-progressing. There are approximately 650 new cases each year in the UK. It is characterised by the presence of large numbers of abnormal mature granulocytes, circulating in the blood. Synonym: chronic granulocytic leukaemia. Acronym: CML Origin: Gr. Haima = blood (12 Jan 1998) |
| myeloid | Collective term for the nonlymphocyte groups of white blood cells. It includes cells from the granulocyte, monocyte and platelet lineages. (13 Nov 1997) |
| myeloid metaplasia | A progressive disease of the bone marrow where neoplastic bone marrow stem cells lodge and grow in multiple sites outside the bone marrow. Typically, there is enlargement of the spleen and a gradual replacement of the bone marrow elements by fibrosis (scarring), progressive anaemia and variable changes in the number of white blood cells and platelets. Diagnosis is by bone marrow biopsy. There is no definitive treatment for this disorder that has been shown to affect life span favorably. Origin: Gr. Plassein = to form (27 Sep 1997) |
| myeloid sarcoma | <tumour> A malignant tumour of immature myeloid cells, frequently subperiosteal, associated with or preceding granulocytic leukaemia. See: chloroma. Synonym: myeloid sarcoma. (05 Mar 2000) |
| myeloid series | The granulocytic and the erythrocytic series. (05 Mar 2000) |
| myeloid tissue | Bone marrow consisting of the developmental and adult stages of erythrocytes, granulocytes, and megakaryocytes in a stroma of reticular cells and fibres, with sinusoidal vascular channels. (05 Mar 2000) |
| primary myeloid metaplasia | Myeloid metaplasia occurring as the primary condition, often in association with myelofibrosis. Synonym: agnogenic myeloid metaplasia. (05 Mar 2000) |
| secondary myeloid metaplasia | Myeloid metaplasia occurring in individuals with another disease. Synonym: symptomatic myeloid metaplasia. (05 Mar 2000) |
| symptomatic myeloid metaplasia | Myeloid metaplasia occurring in individuals with another disease. Synonym: symptomatic myeloid metaplasia. (05 Mar 2000) |
| leukaemia, myeloid | Form of leukaemia characterised by an uncontrolled proliferation of the myeloid lineage and their precursors in the bone marrow and other sites. (12 Dec 1998) |
| T-cell-rich, B-cell lymphoma | <tumour> A B-cell lymphoma in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. See: adult T-cell lymphoma. (05 Mar 2000) |
| absorption cell | A small glass chamber with parallel sides, in which absorption spectra of solutions can be obtained. (05 Mar 2000) |
| acid cell | One of the cell's of the gastric glands; it lies upon the basement membrane, covered by the chief cell's, and secretes hydrochloric acid that reaches the lumen of the gland through fine intracellular and intercellular canals (canaliculi). Synonym: acid cell, oxyntic cell. (05 Mar 2000) |