| metachromatic leukodystrophy | <radiology> Dysmyelinating disease, autosomal recessive, aryl sulfatase A -- absent from urine and serum, most present by 2 yrs, die at 3-4 yrs, may arise at any age, CT: decreased density of white matter, primarily in centrum semiovale, with or without focal gall bladder defects (!) (12 Dec 1998) |
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| metachromatic stain | <technique> A stain, such as methylene blue, thionin, or azure A, that has the ability to produce different colours with various histological or cytological structures. (05 Mar 2000) |
| metachromatism | 1. Any colour change, whether natural or produced by basic aniline dyes. Synonym: metachromasia. Origin: meta-+ G. Chroma, colour (05 Mar 2000) |
| metachroming | The process of mixing a metal mordant with a dye before applying the dye to a tissue or fabric. (05 Mar 2000) |
| metachromophil | Metachromophile Synonym: metachromatic. Origin: meta-+ G. Chroma, colour, + philos, fond (05 Mar 2000) |
| metachronism | <cell biology> Type of synchrony found in the beating of cilia. A metachronal process is one that happens at a later time and the synchronisation is such that the active stroke of an adjacent cilium is slightly delayed so as to minimise the hydrodynamic interference, coordination is by visco mechanical coupling. Different patterns of metachronal synchronisation are recognised: Symplectic metachronism: the wave of activity in the field passes in the same direction as the active stroke of the individual cilium. Antiplectic metachronism: the opposite is true. In dexioplectic and laeoplectic metachronism the wave of activity in the field is normal to the beat axis. Symplectic and antiplectic metachronism are considered orthoplectic, the other forms as diaplectic. (05 Jan 1998) |
| metachronous | Not synchronous; multiple separate occurrences, such as multiple primary cancers developing at intervals. Origin: meta-+ G. Chronos, time (05 Mar 2000) |
| metachrosis | <biology> The power og changing colour at will by the expansion of special pigment cells, under nerve influence, as seen in many reptiles, fishes, etc. Origin: NL, from Gr. Beyond + a colouring. Source: Websters Dictionary (01 Mar 1998) |
| metacinnabarite | <chemical> Sulphide of mercury in isometric form and black in colour. Origin: Pref. Meta- + cinnabar. Source: Websters Dictionary (01 Mar 1998) |
| metacone | The distobuccal cusp of an upper molar tooth. Origin: meta-+ G. Konos, cone (05 Mar 2000) |
| metaconid | The mesolingual cusp of a lower molar tooth. (05 Mar 2000) |
| metacontrast | Inhibition of the brightness of illumination when an adjacent visual field is illuminated. (05 Mar 2000) |
| metaconule | The distal intermediate cusp of an upper molar tooth. Origin: meta-+ G. Konos, a cone (05 Mar 2000) |
| metacresol | A local antiseptic with a higher germicidal power than phenol and less toxicity to tissues; used in disinfectants and fumigants; its acetate derivative is used as a topical antiseptic and fungicide. Synonym: metacresol. (05 Mar 2000) |
| metacrolein | <chemistry> A polymeric modification of acrolein obtained by heating it with caustic potash. It is a crystalline substance having an aromatic odour. Origin: Pref. Met- + acrolein. Source: Websters Dictionary (01 Mar 1998) |