| mitochondrial swelling | Increase in volume of mitochondria due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria. (12 Dec 1998) |
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| disease, mitochondrial | Mutations (changes) in the mitochondrial chromosome are responsible for a number of disorders including an eye disease (Leber's hereditary optic atrophy), a type of epilepsy (called MERRF which stands for Myoclonus Epilepsy with Ragged Red Fibres), and a cause of dementia (called MELAS for Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes). All mitochondrial diseases were entirely enigmatic before it was discovered that they were due to mutations not in regular chromosomes but the mitochondrial chromosome. (12 Dec 1998) |
| DNA, mitochondrial | Double-stranded DNA of mitochondria. In eukaryotes, the mitochondrial genome is circular and codes for ribosomal rnas, transfer rnas, and about 10 proteins. (12 Dec 1998) |
| amalgam matrix | A device used during placement of the amalgam mass within a compound cavity preparation, facilitating proper condensation and contour thereof by providing a confining wall. (05 Mar 2000) |
| bone matrix | The intercellular substance of bone tissue consisting of collagen fibres, ground substance, and inorganic bone salts. (05 Mar 2000) |
| cartilage matrix | The intercellular substance of cartilage consisting of fibres and ground substance. (05 Mar 2000) |
| matrix | Ground substance in which things are embedded or that fills a space (as for example the space within the mitochondrion). most common usage is for a loose meshwork within which cells are embedded (e.g. Extracellular matrix), although it may also be used of filters or absorbent material. (18 Nov 1997) |
| matrix-associated helicase | <enzyme> Component of the pre-mRNA splicing complex; has atpase activity and DNA helicase activity on a partially double-stranded DNA substrate in the 3'-5' direction Registry number: EC 2.7.7.- Synonym: helicase mah (26 Jun 1999) |
| matrix band | A metal or plastic band secured around the crown of a tooth to confine restorative material to be adapted into a prepared cavity. (05 Mar 2000) |
| matrix bands | Devices which provide an artificial temporary wall, or matrix, used in filling a prepared cavity. (12 Dec 1998) |
| matrix calculi | <radiology> Radiolucent, associated with Proteus infection, composition: 2/3 mucoprotein, 1/3 mucopolysaccharide see also: renal calculi (12 Dec 1998) |
| matrix calculus | A yellowish-white to light tan urinary calculus containing calcium salts, with the consistency of putty; composed chiefly of an organic matrix consisting of a mucoprotein and a sulfated mucopolysaccharide, and usually associated with chronic infection. (05 Mar 2000) |
| matrix Gla protein | A calcium binding protein. (05 Mar 2000) |
| matrix mitochondrialis | The substance occupying the space enclosed by the inner membrane of a mitochondrion; it contains enzymes, filaments of DNA, ribosomes, granules, and inclusions of protein crystals, glycogen, and lipid. Synonym: mitochondrial matrix. (05 Mar 2000) |
| matrix processing peptidase | <enzyme> From matrix fraction of rat liver mitochondria; cleaves mitochondrial protein precursors; inhibited by metal chelators and reactived by mn2+; classified as EC 3.4.24.64 Registry number: EC 3.4.24.- Synonym: mitochondrial processing peptidase, mitochondrial processing protease, alpha-mpp, beta-mpp, p-52 protein, rat, p-55 protein, rat, mas1 protein, yeast, mas2 protein, yeast (26 Jun 1999) |