| 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) |
|---|---|
| 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) |
| heterogenous | <biology> Of or pertaining to heterogenesis; heterogenetic. Source: Websters Dictionary (01 Mar 1998) |
| heterogenous keratoplasty | Corneal transplant with donor material from another species. (05 Mar 2000) |
| heterogenous nuclear RNA | <molecular biology> Originally identified as a class of RNA, found in the nucleus but not the nucleolus, which is rapidly labelled and with a very wide range of sizes, 2-40 kilobases. It represents the primary transcripts of RNA polymerase II and includes precursors of all messenger RNAs from which introns are removed by splicing. (18 Nov 1997) |
| heterogenous vaccine | Vaccine that is not autogenous, but is prepared from the same species of bacterium. (05 Mar 2000) |