| tumor | 1. <oncology> An abnormal mass of tissue that results from excessive cell division that is uncontrolled and progressive, also called a neoplasm. Tumours perform no useful body function. They may be either benign (not cancerous) or malignant. 2. Swelling, one of the cardinal signs of inflammations, morbid enlargement. Origin: L. Tumere = to swell (12 May 1997) |
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| tumor marker | <investigation, oncology> A substance in the body that usually indicates the presence of cancer. These markers are usually specific to certain types of cancer and are usually found in the blood or other tissue samples. Examples are alphafetoprotein (AFP), human chorionic gonadotropin, and lactate dehydrogenase (LDH). They may be indicators of tumour stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids. (18 Jul 2002) |
| tumor necrosis factor | <cytokine> Originally described as a tumour inhibiting factor in the blood of animals exposed to bacterial lipopolysaccharide or Bacille Calmette-Guerin. Preferentially kills tumour cells in vivo and in vitro, causes necrosis of certain transplanted tumours in mice and inhibits experimental metastases. Human Tumour Necrosis factor alpha is a protein of 157 amino acids and has a wide range of pro inflammatory actions. Usually considered a cytokine. Synonym: cachectin. Acronym: TNF (13 Nov 1997) |
| germ cell | Cell specialised to produce haploid gametes. The germ cell line is often formed very early in embryonic development. (18 Nov 1997) |
| germ cell tumour | A type of brain tumour. (12 Dec 1998) |
| primordial germ cell | The most primitive undifferentiated sex cell, found initially outside the gonad. Synonym: gonocyte. (05 Mar 2000) |
| neoplasms, germ cell and embryonal | Neoplasms composed of primordial germ cells of embryonic gonads or of elements of the germ layers of the embryo. The concept does not refer to neoplasms located in the gonads or present in an embryo or foetus. (12 Dec 1998) |
| mixed cell leukaemia | Term infrequently used as a designation for granulocytic leukaemia, thereby emphasizing the occurrence of different types of cells in the myeloid series (i.e., neutrophilic, eosinophilic, and basophilic granulocytes), in contrast to the comparatively monotonous pattern observed in lymphocytic and monocytic leukaemia. (05 Mar 2000) |
| lymphoma, mixed-cell | Malignant lymphoma characterised by the presence of a mixed population of cells, with the smaller cells resembling lymphocytes and the larger ones histiocytes. It usually presents in a nodular (follicular) pattern, but may evolve into a diffuse pattern. (12 Dec 1998) |
| lymphoma, mixed-cell, diffuse | A heterogeneous group of intermediate-grade lymphomas of mixed cellular composition. Although they have not been extensively studied, it appears that they are predominantly B-cell diseases. (12 Dec 1998) |
| lymphoma, mixed-cell, follicular | A low-grade malignant lymphoma of follicular pattern in which there is no clear preponderance of one cell type (small or large) over another. The large cells, cleaved or noncleaved, are often 2-3 times larger in diameter than normal lymphocytes. (12 Dec 1998) |
| germ | 1. <biology> That which is to develop a new individual; as, the germ of a foetus, of a plant or flower, and the like; the earliest form under which an organism appears. "In the entire process in which a new being originates . Two distinct classes of action participate; namely, the act of generation by which the germ is produced; and the act of development, by which that germ is evolved into the complete organism." (Carpenter) 2. That from which anything springs; origin; first principle; as, the germ of civil liberty. <biology> Disease germ, the theory that living organisms can be produced only by the evolution or development of living germs or seeds. See Biogenesis, and Abiogenesis. As applied to the origin of disease, the theory claims that the zymotic diseases are due to the rapid development and multiplication of various bacteria, the germs or spores of which are either contained in the organism itself, or transferred through the air or water. See Fermentation theory. Origin: F. Germe, fr. L. Germen, germinis, sprout, but, germ. Cf. Germen, Germane. Source: Websters Dictionary (01 Mar 1998) |
| germ cells | The reproductive cells in multicellular organisms. (12 Dec 1998) |
| germ-free animal | An animal which has no microorganisms whatsoever living in or on it. An animal which was born and raised in an isolated environment with no microorganisms in it, such as within a germ-free isolator. (09 Oct 1997) |
| germ-free isolator | A chamber which has absolutely no microorganisms whatsoever living in it, where a germ-free animal can be born and raised. An artificial barrier surrounding a living facility for germ-free animals, which keeps out all microorganisms. (09 Oct 1997) |