| memory cell | <immunology> Cells of the immune system that do not respond immediately when it first encounters an antigen but facilitates the more rapid secondary response when the antigen is encountered on a subsequent occasion. The long lasting immune memory is humoral and resides in B-cells, although it appears that persistence of the antigen may be essential. T-cell memory is shorter. (14 Oct 1997) |
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| memory T-cell | A T-cell that bears receptors for a specific foreign antigen encountered during a prior infection or vaccination. After an infection or a vaccination, some of the T-cells that participated in the response remain as memory T-cells, which can rapidly mobilize and clone themselves should the same antigen be re-encountered during a second infection at a later time. (09 Oct 1997) |
| chalice cell | 1. <pathology> Cell of the epithelial lining of small intestine that secretes mucus and has a very well developed Golgi apparatus. 2. <zoology> Cell type characteristic of larval lepidopteran midgut, containing a potent H ATPase and thought to be involved in maintenance of ion and pH gradients. (10 Oct 1997) |
| pericapillary cell | <pathology> Cell associated with the walls of small blood vessels: not a smooth muscle cell, nor an endothelial cell. (18 Nov 1997) |
| rhagiocrine cell | Relatively long lived phagocytic cell of mammalian tissues, derived from blood monocyte. Macrophages from different sites have distinctly different properties. Main types are peritoneal and alveolar macrophages, tissue macrophages (histiocytes), Kupffer cells of the liver and osteoclasts. In response to foreign materials may become stimulated or activated. Macrophages play an important role in killing of some bacteria, protozoa and tumour cells, release substances that stimulate other cells of the immune system and are involved in antigen presentation. May further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or Langhans giant cells. (18 Nov 1997) |
| perichondrial cell | <pathology> Cell of the perichondrium, the fibrous connective tissue surrounding cartilage. (18 Nov 1997) |
| Merkel cell tumour | A rare malignant cutaneous tumour seen in sun-exposed skin of elderly patients composed of dermal nodules of small round cells with scanty cytoplasm in a trabecular pattern; the tumour cells contain cytoplasmic dense core granules resembling neurosecretory granules seen in Merkel cells. Synonym: primary neuroendocrine carcinoma of the skin, trabecular carcinoma. (05 Mar 2000) |
| Merkel's tactile cell | A specialised tactile sensory nerve ending in the epidermis, characterised by a terminal cuplike expansion of an intraepidermal axon in contact with the base of a single modified keratinocyte. Synonym: meniscus tactus, Merkel's corpuscle, Merkel's tactile cell, Merkel's tactile disk, tactile disk. (05 Mar 2000) |
| granular cell tumour | Unusual tumour affecting any site of the body, but most often encountered in the head and neck. Considerable debate has surrounded the histogenesis of this neoplasm; however, it is considered to be a myoblastoma of, usually, a benign nature. It affects women more often than men. When it develops beneath the epidermis or mucous membrane, it can lead to proliferation of the squamous cells and mimic squamous cell carcinoma. (12 Dec 1998) |
| mesangial cell | <pathology> Cells found within the glomerular lobules of mammalian kidney, where they serve as structural supports, may regulate blood flow, are phagocytic and may act as accessory cells, presenting antigen in immune responses. (18 Nov 1997) |
| granule cell | Type of neuron found in the cerebellum. (18 Nov 1997) |
| granule cell of connective tissue | <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) |
| granuloma, plasma cell | A slow-growing benign pseudotumour in which plasma cells greatly outnumber the inflammatory cells. (12 Dec 1998) |
| granuloma, plasma cell, orbital | A distinctive, chronic inflammatory reaction in the orbital tissues of the eye, of unknown aetiology, that may closely resemble a neoplasm and often becomes bilateral. Symptoms include exophthalmos and congestion of the lids with oedema. When limitation of ocular motility also occurs, it is sometimes called orbital myositis. (12 Dec 1998) |
| granuloma, plasma cell, pulmonary | A pseudotumour of the lung composed of inflammatory cells and showing complete maturity of fibroblastic components with a striking lack of mitosis. It is also called postinflammatory pseudotumour and pseudoneoplastic pneumonitis. (berardi, r.s. Et al. Inflammatory pseudotumours of the lung. Surg gynecol obstet 156:89-96, jan 83) (12 Dec 1998) |