| christmas factor assay | A test used to measure the activity of a blood clotting factor IX (Christmas factor). This test may be used to evaluate excessive bleeding. Abnormally low factor IX assays may be seen in the following conditions: congenital deficiency of factor IX, fat malabsorption, heparin administration, cirrhosis, vitamin K deficiency and warfarin administration. (27 Sep 1997) |
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| chrom- | Colour. Origin: G. Chroma (05 Mar 2000) |
| chroma | The relative purity or saturation of a colour, intensity of distinctive hue as related to grayness, one of the three variables of colour. (09 Oct 1997) |
| chromaffin | Giving a brownish yellow reaction with chromic salts; denoting certain cells in the medulla of the adrenal glands and in paraganglia. Synonym: chromaphil, chromatophil, chromophil, chromophile, pheochrome. Origin: chrom-+ L. Affinis, affinity (05 Mar 2000) |
| chromaffin body | A small, roundish body containing chromaffin cells; a number of such bodies may be found retroperitoneally near the aorta and in organs such as the kidney, liver, heart, and gonads. Synonym: chromaffin body. (05 Mar 2000) |
| chromaffin cell | Family of related acidic proteins (400-600 residues) found in many endocrine cell secretory vesicles. Secretogranin 1 = chromogranin B, secretogranin 2 = chromogranin C. (18 Nov 1997) |
| chromaffin cells | Cells that store epinephrine secretory vesicles. During times of stress, the nervous system signals the vesicles to secrete their hormonal content. Their name derives from their ability to stain a brownish colour with chromic salts. Characteristically, they are located in the adrenal medulla and paraganglia (paraganglia, chromaffin) of the sympathetic nervous system. (12 Dec 1998) |
| chromaffin granules | Granules in the adrenal glands and various other organs, which are concerned with the synthesis, storage, metabolism, and secretion of epinephrine and norepinephrine. (12 Dec 1998) |
| chromaffin reaction | Production of a yellow-brown to brown colouration in normal and abnormal cells containing epinephrine and norepinephrine, when fresh tissue slices are placed in a dichromate-chromate mixture overnight; useful for detection of pheochromocytoma (adrenal medulla) and other tumours which produce catecholamines. (05 Mar 2000) |
| chromaffin system | The cells of the body which stain with chromium salts. They occur along the sympathetic nerves, in the adrenal gland, and in various other organs. (12 Dec 1998) |
| chromaffin tissue | Tissue in medulla of adrenal gland containing two populations of cells, one producing adrenaline, the other noradrenaline. The catecholamine is associated with carrier proteins (chromogranins) in membrane vesicles (chromaffin granules). (18 Nov 1997) |
| chromaffin tumour | <tumour> A neoplasm composed of chromaffin cells occurring in the medullae of adrenal glands, the organs of Zuckerkandl, or the paraganglia of the thoracolumbar sympathetic chain; some chromaffinoma's secrete catecholamines. See: pheochromocytoma. Synonym: chromaffin tumour. (05 Mar 2000) |
| chromaffinoma | <tumour> A neoplasm composed of chromaffin cells occurring in the medullae of adrenal glands, the organs of Zuckerkandl, or the paraganglia of the thoracolumbar sympathetic chain; some chromaffinoma's secrete catecholamines. See: pheochromocytoma. Synonym: chromaffin tumour. (05 Mar 2000) |
| chromaffinopathy | Any pathologic condition of chromaffin tissue, as in the medullae of adrenal glands or the organs of Zuckerkandl. Origin: chromaffin + G. Pathos, suffering (05 Mar 2000) |
| chroman | Chromane 3,4-Dihydro-2H-1-benzopyran;fundamental unit of the tocopherols (vitamin E). See: chromanol, chromene, chromenol. (05 Mar 2000) |