| melanosperm | <botany> An alga of any kind that produces blackish spores, or seed dust. The melanosperms include the rockweeds and all kinds of kelp. Melanospermous. Origin: Gr, black + seed. Source: Websters Dictionary (01 Mar 1998) |
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| melanostatin | Inhibits synthesis and release of melanotropin. Synonym: melanotropin release-inhibiting hormone. Origin: melanotropin + G. States, stationary, + -in (05 Mar 2000) |
| melanotic | 1. Pertaining to the presence, normal or pathologic, of melanin. 2. Relating to or characterised by melanosis. (05 Mar 2000) |
| melanotic carcinoma | <tumour> Obsolete term for melanoma. (05 Mar 2000) |
| melanotic freckle | A brown or black mottled, irregularly outlined, slowly enlarging lesion resembling a lentigo in which there are increased numbers of scattered atypical melanocytes in the epidermis, usually occurring on the face of older persons; after many years the dermis may be invaded and the lesion is then termed lentigo maligna melanoma. Synonym: Hutchinson's freckle, melanotic freckle. (05 Mar 2000) |
| melanotic neuroectodermal tumour of infancy | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |
| melanotic pigment | <protein> Pigments largely of animal origin. High molecular weight polymers of indole quinone. Colours include black/brown, yellow, red and violet. Found in feathers, cuttle ink, human skin, hair and eyes and in cellular immune responses and wound healing in arthropods. (18 Nov 1997) |
| melanotic progonoma | A pigmented hairy nevus. (05 Mar 2000) |
| melanotic whitlow | <tumour> A melanoma beginning in the skin at the border of or beneath the nail. Synonym: melanotic whitlow. (05 Mar 2000) |
| melanotonin | See: melatonin. (05 Mar 2000) |
| melanotrichous | Having black hair. Synonym: melanocomous. Origin: melano-+ G. Thrix (trich-), hair (05 Mar 2000) |
| melanotroph | A cell of the intermediate lobe of the hypophysis that produces melanotropin. Origin: melano-+ G. Trophe, nourishment (05 Mar 2000) |
| melanotropin | A polypeptide hormone secreted by the intermediate lobe of the hypophysis in humans (in neurohypophysis in certain other species) which causes dispersion of melanin by melanophores, resulting in darkening of the skin, presumably by promoting melanin synthesis; this effect is readily demonstated in some lower vertebrates, such as frogs and fish; alpha-melanotropin is an N-acetylated peptide with 13 amino acids; beta-melanotropin has 22 amino acids. Synonym: intermedin, melanocyte-stimulating hormone, melanophore-expanding principle. (05 Mar 2000) |
| melanotropin release-inhibiting hormone | Inhibits synthesis and release of melanotropin. Synonym: melanotropin release-inhibiting hormone. Origin: melanotropin + G. States, stationary, + -in (05 Mar 2000) |
| melanotropin-releasing factor | A hexapeptide similar to oxytocin; it stimulates the release of melanotropin. Synonym: melanotropin-releasing factor, melanotropin-releasing hormone. Origin: melanotropin + L. Libero, to free, + -in (05 Mar 2000) |