| mitochondrial myopathies | Diseases of the muscles characterised by morphologic changes in mitochondria and often associated with excessive lipid accumulation. Muscle biopsies reveal "the presence of overly abundant and large mitochondria (often containing abnormal inclusions and cristae) in many muscle fibres. The terms mitochondrial and lipid storage have been used interchangeably to designate these myopathies, since the enzymes essential for intramuscular lipid metabolism are contained in the mitochondria, and a defect in the latter results in an abnormal accumulation of lipid bodies in muscle fibres." often defects in various oxidative enzymes figure. One type of mitochondrial myopathy is called pleoconial with reference to "a remarkably large number (pleo-) of enlarged mitochondria in the biopsied muscle", another is "called megaconial with reference to giant (mega-) mitochondria in the muscle." (adams and victor: principles of neurology, 2d ed, p980-1) (12 Dec 1998) |
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| mitochondrial oxidative damage endonuclease | <enzyme> An 8-oxog-specific DNA endonuclease from rat liver mitochondria; recognises and incises at 8-oxog and abasic acid sites in duplex DNA Registry number: EC 3.1.25.- Synonym: oxidative damage-specific endonuclease, mtode enzyme (26 Jun 1999) |
| mitochondrial sheath | The spirally arranged mitochondria in the middle piece of a spermatozoon; may control movement of the tail. (05 Mar 2000) |
| 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) |
| mitochondrion | Highly pleiomorphic organelle of eukaryotic cells that varies from short rod like structures present in high number to long branched structures. Contains DNA and mitoribosomes. Has a double membrane and the inner membrane may contain numerous folds (cristae). The inner fluid phase has most of the enzymes of the tricarboxylic acid cycle and some of the urea cycle. The inner membrane contains the components of the electron transport chain. Major function is to regenerate ATP by oxidative phosphorylation (see chemiosmotic theory). (18 Nov 1997) |
| mitogen | A substance which is able to induce mitosis of certain eukaryotic cells. (09 Oct 1997) |
| mitogenesis | <cell biology> The process of stimulating transit through the cell cycle especially as applied to lymphocytes. Concanavalin A is a mitogen for T lymphocytes, the best mitogen for B lymphocytes is Cowan strain Stapylococcus aureus. (18 Nov 1997) |
| mitogenetic | Pertaining to the factor or factors promoting cell mitosis. (05 Mar 2000) |
| mitogenic | Causing mitosis or transformation. (05 Mar 2000) |
| mitogens | Substances that stimulate mitosis and lymphocyte transformation. They include not only substances associated with lectins, but also substances from streptococci (associated with streptolysin s) and from strains of alpha-toxin-producing staphylococci. (12 Dec 1998) |
| mitoguazone | <chemical> 1,1-[(methylethanediylidene)dinitrilo]diguanidine. Antineoplastic agent effective against myelogenous leukaemia in experimental animals. Also acts as an inhibitor of animal s-adenosylmethionine decarboxylase. Pharmacological action: antineoplastic agent, enzyme inhibitors. Chemical name: Hydrazinecarboximidamide, 2,2'-(1-methyl-1,2-ethanediylidene)bis- (12 Dec 1998) |
| mitolactol | <chemical> 1,6-dibromo-1,6-dideoxygalactitol. Alkylating antineoplastic toxic to bone marrow; used in breast cancer, also in combination with other drugs. Pharmacological action: antineoplastic agent, alkylating. Chemical name: Galactitol, 1,6-dibromo-1,6-dideoxy- (12 Dec 1998) |
| mitome | <biology> The denser part of the protoplasm of a cell. Origin: Gr. A thread. Source: Websters Dictionary (01 Mar 1998) |
| mitomycin | Antibiotic produced by Streptomyces caespitosus, variants of which are designated mitomycin A, mitomycin B, etc.; mitomycin C is an antineoplastic agent and a bacteriocide; inhibits DNA synthesis. (05 Mar 2000) |
| mitomycin C | <drug> Aziridine antibiotic isolated from Streptomyces caespitosus. Inhibits DNA synthesis by cross linking the strands. (18 Nov 1997) |