| MELAS | mitochondrial encephalomyopathy-lactic acidosis- and stroke-like symptoms [syndrome] |
|---|---|
| MEM | macrophage electrophoretic mobility; malic enzyme, mitochondrial; minimal essential medium |
| MEP | maximum expiratory pressure; mean effective pressure; mepiridine; mitochondrial encephalopathy; moto... |
| MF | magnetic field; meat free; medium frequency; megafarad; membrane filler; merthiolate-formaldehyde [s... |
| MLG | mesiolingual groove; mitochondrial lipid glycogen |
| bovine mitochondrial endonuclease | <enzyme> Dimer of 29kda peptide; prefers a conserved sequence in the displacement loop region of mitochondrial DNA; nicks double-stranded DNA and fragments single-stranded DNA Registry number: EC 3.1.21.- (26 Jun 1999) |
|---|---|
| mitochondrial | Referring to mitochondria. (12 Dec 1998) |
| mitochondrial chromosome | The DNA component of mitochondria, the chief function of which is synthesis of adenosine triphosphate and the management of cellular energy; the chromosome contains some 16,000 base pairs arranged in a circle. The inheritance is matrilineal, and the mutation rate is unusually high; since each cell contains thousands of copies a mutant form may assume an almost continuous gradation as in a galtonian process. Most of the mutations known have their impact on the respiratory chain. (05 Mar 2000) |
| mitochondrial disease | <disease, neurology> An illnesse, frequently neurological, which can be ascribed to defects in mitochondrial function. If the defect is in the mitochondrial rather than the nuclear genome unusual patterns of inheritance can be observed. (18 Nov 1997) |
| mitochondrial encephalomyopathies | Brain diseases associated with disease of the muscles, accompanied by morphological changes in the muscle mitochondria and their metabolism. The mitochondrial encephalopathies are often multisystemic and vary considerably in age at onset, distribution of weakness, severity, and course. Mitochondrial cytochrome c oxidase deficiency appears to be implicated and often several mitochondrial enzymes are affected in the same patient. The brain lesions can be said to be clinical and morphological expressions of a mitochondrial defect. (12 Dec 1998) |
| mitochondrial gene | A functioning gene located not in the nucleus of a cell but in the mitochondrial chromosome. (05 Mar 2000) |
| mitochondrial inheritance | The inheritance of a trait encoded in the mitochondrial genome. Because of the oddities of mitochondria, mitochondrial inheritance does not obey the classic rules of genetics. Persons with a mitochondrial disease may be male or female but they are always related in the maternal line and no male with the disease can transmit it to his children. (12 Dec 1998) |
| mitochondrial intermediate peptidase | <enzyme> Removes the octapeptide from the amino terminus of the intermediate protein processed from the protein precursor of certain mitochondrial proteins by the mitochondrial processing peptidase; smip from schizophyllum commune; rmip from rat; ymip from saccharomyces cerevisiae Registry number: EC 3.4.24.59 Synonym: mip peptidase, smip peptidase, rmip peptidase, ymip peptidase (26 Jun 1999) |
| mitochondrial matrix | 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) |
| mitochondrial membrane | The double biomembrane surrounding the mitochondrion. (05 Mar 2000) |
| 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) |
| 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) |
| 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) |