| chromium radioisotopes | Unstable isotopes of chromium that decay or disintegrate emitting radiation. Cr atoms with atomic weights of 46-49, 51, 55, and 56 are radioactive chromium isotopes. (12 Dec 1998) |
|---|---|
| chromium(VI) reductase | <enzyme> Nad(p)h-dependent enzyme from pseudomonas ambigua reduces cr(vi) to cr(iii) with at least two reaction steps via cr(v) as an intermediate Registry number: EC 1.16.1.- Synonym: cr(vi) reductase (26 Jun 1999) |
| chromo- | See: chrom-. (05 Mar 2000) |
| chromobacterium | A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria occurring in soil and water. Its organisms are generally nonpathogenic, but some species do cause infections of mammals, including humans. (12 Dec 1998) |
| chromobindin | <protein> See annexin. (18 Nov 1997) |
| chromoblast | An embryonic cell with the potentiality of developing into a pigment cell. Origin: chromo-+ G. Blastos, germ (05 Mar 2000) |
| chromoblastomycosis | Scaly papule or warty growth, caused by five fungi, that spreads as a result of satellite lesions affecting the foot or leg. The extremity may become swollen and, at its distal portion, covered with various nodular, tumourous, verrucous lesions that resemble cauliflower. In rare instances, the disease may begin on the hand or wrist and involve the entire upper extremity. (arnold, odom, and james, andrew's diseases of the skin, 8th ed, p362) (12 Dec 1998) |
| chromocenter | <cell biology> The central portion of a cells nucleus that typically contains a glob of heterochromatin. Origin: Gr. Soma = body (09 Oct 1997) |
| chromocentre | Condensed heterochromatic region of a chromosome that stains particularly strongly although in the polytene chromosomes of Drosophila the chromocentre is of under replicated heterochromatin and stains lightly. (18 Nov 1997) |
| chromocystoscopy | Synonym: cystochromoscopy. Origin: chromo-+ G. Kystis, bladder, + skopeo, to view (05 Mar 2000) |
| chromocyte | Any pigmented cell, such as a red blood corpuscle. Origin: chromo-+ G. Kytos, cell (05 Mar 2000) |
| chromogen | 1. A substance, itself without definite colour, that may be transformed into a pigment; denoting especially benzene and its homologues toluene, xylene, quinone, naphthalene, and anthracene, from which the aniline dyes are manufactured. 2. A microorganism that produces pigment. Porter-Silber chromogens, yellow phenylhydrazones formed by the reaction of 17,21-dihydroxy-20-oxosteroids with a phenylhydrazine-ethanol-sulfuric acid reagent; used chiefly to determine plasma cortisol concentrations and the urinary output of 17-hydroxycorticoids. (05 Mar 2000) |
| chromogenesis | Production of colouring matter or pigment. Origin: chromo-+ G. Genesis, production (05 Mar 2000) |
| chromogenic | Producing colour, a chromogenic colony is a pigmented colony. Origin: Gr. Gennan = to produce (09 Oct 1997) |
| chromogenic compounds | Colourless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into coloured compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens). (12 Dec 1998) |