| mast cell | <cell biology, immunology> Resident cell of connective tissue that contains many granules rich in histamine and heparan sulphate. Release of histamine from mast cells is responsible for the immediate reddening of the skin in a weal and flare response. Very similar to basophils and possibly derived from the same stem cells. Two types of mast cells are now recognised, those from connective tissue and a distinct set of mucosal mast cells, the activities of the latter are T-cell dependent. (05 Jan 1998) |
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| mast cell leukaemia | A form of granulocytic leukaemia in which there are unusually great numbers of basophilic granulocytes in the tissues and circulating blood; in some instances, the immature and mature basophilic forms may represent from 40 to 80% of the total numbers of white blood cells. Synonym: mast cell leukaemia. (05 Mar 2000) |
| mast leukocyte | A polymorphonuclear leukocyte characterised by many large, coarse, metachromatic granules (dark purple or blue-black when treated with Wright's or similar stains) that usually fill the cytoplasm and may almost mask the nucleus; these leukocyte's are unique in that they usually do not occur in increased numbers as the result of acute infectious disease, and their phagocytic qualities are probably not significant; the granules, which contain heparin and histamine, may degranulate in response to hypersensitivity reactions and can be of significance in general inflammation. Synonym: basocyte, basophilocyte, mast leukocyte. (05 Mar 2000) |
| mastadenitis | <pathology> Inflammation of the mammary gland or breast. (18 Nov 1997) |
| mastadenoma | <tumour> An adenoma of the breast. Origin: masto-+ G. Aden, gland, + -oma, tumour (05 Mar 2000) |
| mastadenovirus | <virology> A genus of adenoviridae that infects mammals including humans and causes a wide range of diseases. The type species is human adenovirus 2 (see adenoviruses, human). (12 Dec 1998) |
| mastalgia | <symptom> General term for breast pain, affecting two thirds of women attending breast clinics. Usually indicates benign problem, often oversensitivity of breast tissue to reproductive hormones. Most women respond to treatment with gamolenic acid (derived from the evening primrose and starflower plants), which takes up to three months to have any effect and may not give relief for more than two years. In more severe cases, synthetic steriods may help. The use of a tailor-made support bra can be of help. (05 Jan 1998) |
| mastatrophy | Mastatrophia Atrophy or wasting of the breasts. Origin: masto-+ atrophy (05 Mar 2000) |
| mastauxe | Hypertrophy of the breast. Origin: masto-+ G. Auxe, increase (05 Mar 2000) |
| mastax | <zoology> The pharynx of a rotifer. It usually contains four horny pieces. The two central ones form the incus, against which the mallei, or lateral ones, work so as to crush the food. The lore of a bird. Origin: NL, fr. Gr. Mouth, jaws. Source: Websters Dictionary (01 Mar 1998) |
| mastectomy | <procedure, surgery> An operation to remove the whole breast. (16 Dec 1997) |
| mastectomy, extended radical | Radical mastectomy with removal of the ipsilateral half of the sternum and a portion of ribs two through five with the underlying pleura and the internal mammary lymph nodes. (12 Dec 1998) |
| mastectomy, modified radical | Total mastectomy with axillary node dissection, but with preservation of the pectoral muscles. (12 Dec 1998) |
| mastectomy, radical | Removal of the breast, pectoral muscles, axillary lymph nodes, and associated skin and subcutaneous tissue. (12 Dec 1998) |
| mastectomy, segmental | Removal of only enough breast tissue to ensure that the margins of the resected surgical specimen are free of tumour. (12 Dec 1998) |