Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «M»:
Micro-RNA: A tiny piece of RNA, about 21 to 23 bases in length, that binds to matching pieces of messenger RNA to make it double-stranded and decrease the production of the corresponding protein. Micro-RNA's were first discovered in the roundworm C. elegans in the early 1990s and are now known in m...
Microabscess: A tiny abscess. A small accumulation of pus....
Microalbuminuria: 1. Generally, a subtle increase in the urinary excretion of the protein albumin that cannot be detected by a conventional assay. In diabetes, microalbuminuria is an early sign of diabetic kidney disease.
2. Specifically, the excretion of greater than 30 mg and less than 300 mg a da...
Microangiopathy: Angiopathy means disease of
vessels (arteries, veins, and capillaries). There are two
angiopathy: macroangiopathy and microangiopathy. With
and blood clots build up in the
large blood vessels, stick to the vessel walls, and block
Microarray: A tool used to sift through and analyze the information contained within a genome. A microarray consists of different nucleic acid probes that are chemically attached to a substrate, which can be a microchip, a glass slide or a microsphere-sized bead....
Microbe: A very tiny form of life -- microbes include bacteria, fungi, and protozoan parasites -- best visualized under a microscope.
The Microbe is so very small
You cannot make him out at all,
But many sanguine people hope
To see him through a microscope.
(From "The Microbe" by Hilaire Belloc, 19...
Microbicide: An agent that kills microbes, minute forms of life (e.g. bacteria, fungi, and protozoal parasites), some capable of causing human disease.
From microbe + the Latin "caedo," to kill....
Microcephalin: See: Microcephalin 1....
Microcephalin 1: Mutation of this gene is responsible for an autosomal recessive form of primary microcephaly with no other malformations. Microcephalin 1 (MCPH1) is expressed in fetal brain in the developing forebrain and the walls of the lateral ventricles. Cells in this region divide to produce n...
Microcephaly: An abnormally small head due to failure of brain growth. In precise terms, microcephaly is a head circumference that is more than 2 standard deviations below the normal mean for age, sex, race, and gestation. (Some authorities define microcephaly as more than 3 standard deviations belo...
Microchimerism: The presence of two genetically distinct and separately derived populations of cells, one population being at a low concentration, in the same individual or an organ such as the bone marrow. Microchimerism may be due to transfer of cells between mother and fetus or between two twins....
Microcystic corneal dystrophy
dystrophy: A disorder in which the cornea (the normally
clear front window of the eye) shows dots (or microcysts), geographic map-like
lines, and grayish fingerprint lines on examination with a slit-lamp, a device that focuses a high intensity light beam as a slit while the e...
Microcytic: 1. Any abnormally small cell. The opposite is macrocytic, an abnormally large cell.
2. An abnormally small red blood cell. Iron deficiency is a prominent cause of microcytic anemia....
Microdeletion: The loss of a tiny piece of a chromosome, a piece so
small its absence is not apparent on ordinary examination (using a regular light
microscope to look at chromosomes prepared in the usual fashion). The detection
of microdeletions requires special techniques such as high-resolutio...
Microdosimetry: A technique for measuring the microscopic distribution of energy, useful with different types of radiation.
Microdosimetry provides the scientific underpinnings for the measurement of radiation. It is vitally important to both radiation therapy and radiation protection.
The prefix "m...