|Medical Dictionary - Dictionary of Medicine and Human Biology|
Having a small brain.
Abnormal smallness of the brain. SYN: micrencephalia, microencephaly. [micro- + G. enkephalos, brain]
1. Prefixes denoting smallness. 2. (μ) Prefix used in the SI and metric system to signify submultiples of one-millionth (10−6) of such unit. 3. In chemistry, prefix to terms denoting chemical examination, methods, etc. that utilize minimal quantities of the substance to be examined; e.g., a drop or two in place of 1 or more mL. 4. Combining forms meaning microscopic; opposite of macro-, megalo-. [G. mikros, small]
A very small circumscribed collection of leukocytes in solid tissues. Munro m. a microscopic collection of polymorphonuclear leukocytes found in the stratum corneum in psoriasis. SYN: Munro abscess. Pautrier m. a microscopic lesion in the epidermis, seen in mycosis fungoides; it is composed of the same type of atypical mononuclear cells as those that form the infiltrate in the corium. SYN: Pautrier abscess.
A pituitary adenoma less than 10 mm in diameter.
A microaerophilic microorganism.
microaerophil, microaerophile (mi-kro-ar′o-fil, -fil)
1. An aerobic bacterium that requires oxygen, but less than is present in the air, and grows best under modified atmospheric conditions. 2. Relating to such an organism. SYN: microaerophilic, microaerophilous. [micro- + G. aer, air, + philos, fond]
SYN: microaerophil (2) .
SYN: microaerophil (2) .
A suspension in air of particles that are submicronic or, more frequently, from 1–10; μm in diameter.
A slight increase in urinary albumin excretion that can be detected using immunoassays but not using conventional urine protein measurements; an early marker for renal disease in patients with diabetes. [micro- + albuminuria]
Analytic techniques involving unusually small samples.
Anastomosis of minute structures performed under an operating microscope.
Focal dilation of retinal capillaries occurring in diabetes mellitus, retinal vein obstruction, and absolute glaucoma, or of arteriolocapillary junctions in many organs in thrombotic thrombocytopenic purpura.
Radiography of the finer vessels of an organ after the injection of a contrast medium and enlargement of the resulting radiograph. SYN: microarteriography. [micro- + angiography]
SYN: capillaropathy. thrombotic m. thrombosis within small blood vessels, as in thrombotic thrombocytopenic purpura.
SYN: adhesive atelectasis.
A balance designed for use in weighing unusually small samples of materials.
Any very minute organism. As originated, the word was intended as a collective term for the large variety of microorganisms then known in the 19th century; modern usage has retained the original collective meaning but expanded it to include both microscopic and ultramicroscopic organisms (spirochetes, bacteria, rickettsiae, and viruses). These organisms are considered to form a biologically distinctive group, in that the genetic material is not surrounded by a nuclear membrane, and mitosis does not occur during replication. [Fr., fr. G. mikros, small, + bios, life]
Relating to a microbe or to microbes. SYN: microbic, microbiotic (2) .
microbial associates (mi-kro′be-al a-so′she-ats)
SYN: flora (2) .
Destructive to microbes. SYN: microbicide (1) .
1. SYN: microbicidal. 2. An agent destructive to microbes; a germicide; an antiseptic. [microbe + L. caedo, to kill]
Relating to microbiology.
One who specializes in the science of microbiology.
The science concerned with microorganisms, including fungi, protozoa, bacteria, and viruses. [Fr. microbiologie]
1. Short-lived. 2. SYN: microbial.
Infection with microbes. latent m. the presence of pathogenic microorganisms in the body that elicit no symptoms; the condition of a pathogen carrier.
A small, nucleated, red blood cell. [micro- + G. blastos, sprout, germ]
Eyelids with abnormal vertical shortness. SYN: microblepharia, microblepharism. [micro + G. blepharon, eyelid + -ia, condition]
A cytoplasmic organelle, bounded by a single membrane and containing oxidative enzymes. Microbodies include peroxisomes and glyoxysomes.
Abnormal smallness of the arms. [micro- + G. brachion, arm]
An electric cautery with needle point. [micro- + Ger. Brenner, burner]
Calcifications less than 1 mm in diameter as seen on mammography; often associated with malignant lesions. [micro- + calcification]
Abnormal smallness of the heart. [micro- + G. kardia, heart]
SYN: cytocentrum. [micro- + G. kentron, center]
Having a small head. SYN: microcephalous, nanocephalous, nanocephalic.
Abnormal smallness of the head; applied to a skull with a capacity below 1350 ml. Usually associated with mental retardation. SYN: microcephalia, microcephalism, nanocephalia, nanocephaly. [micro- + G. kephale, head] encephaloclastic m. complex growth disturbances in the brain as a result of regressive changes in fetal life. schizencephalic m. dysgenic process resulting in focal cerebral defects.
microcheilia, microchilia (mi-kro-ki′le-a)
Smallness of the lips. [micro- + G. cheilos, lip]
microcheiria, microchiria (mi-kro-ki′re-a)
Smallness of the hands. [micro- + G. cheir, hand]
The use of chemical procedures involving minute quantities or reactions not visible to the unaided eye. Cf.:macrochemistry.
The presence of donor cells in a graft recipient, or of fetal cells remaining in maternal circulation, which can be detected by molecular methods but not by flow cytometry.
SYN: glucose oxidase.
The application of moving pictures taken through magnifying lenses to the study of an organ or system in motion; e.g., the circulation in living embryos. [micro- + G. kinema, movement, + grapho, to write]
Passage of blood in the smallest vessels, namely arterioles, capillaries, and venules.
A family of bacteria (order Eubacteriales) containing Gram-positive spherical cells which occur singly or in pairs, tetrads, packets, irregular masses, or even chains. Rarely are these organisms motile. Free-living, saprophytic, parasitic, and pathogenic species occur. The type genus is Micrococcus.
Plural of micrococcus.
A genus of bacteria (family Micrococcaceae) containing Gram-positive, spherical cells that occur in irregular masses. Some species are motile or produce motile mutants. These organisms are saprophytic, facultatively parasitic, or parasitic but are not truly pathogenic. The type species is M. luteus. It is the type genus of the family Micrococcaceae. [micro- + G. kokkos, berry] M. conglomeratus a bacterial species found in infections, milk, dairy products, dairy utensils, and water. M. luteus a saphrophytic species found in milk and dairy products and on dust particles, it has caused meningitis in humans; it is the type species of the genus M.. M. varians former name for Kocuria varians.
micrococcus, pl .micrococci (mi′kro-kok′us, -kok′si)
A vernacular term used to refer to any member of the genus M..
Colitis that is not seen by endoscopy, but in which microscopic examination of biopsies shows nonspecific mucosal inflammation.
A small-caliber unused colon, seen in the neonate on radiographic contrast enema; usually a consequence of intestinal atresia or meconium ileus.
A colony of bacteria visible only under a low power microscope.
microconidium, pl .microconidia (mi′kro-ko-nid′e-um, -a)
In fungi, the smaller of two distinctively different-sized types of conidia in a single species, usually single-celled and spherical, ovoid, pyriform, or clavate.
A congenitally small pupil with an inability to dilate. [micro- + G. kore, pupil]
An abnormally small cornea.
microcoulomb (μC) (mi-kro-koo′lom)
One-millionth of a coulomb.
Occurring in minute crystals.
microcurie (μCi) (mi′kro-ku′re)
One-millionth of a curie; a quantity of any radionuclide with 3.7 × 104 disintegrations per second.
A tiny cyst, frequently of such dimensions that a magnifying lens or microscope is required for observation.
A small (5 μm or less) nonnucleated red blood cell. SYN: microerythrocyte. [micro- + G. kytos, cell]
The presence of many microcytes in the circulating blood. SYN: microcytosis. [microcyte + G. haima, blood]
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