Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «D»:
Domagk, Gerhard: German physician and chemist (1895-1946) who discovered the first sulfa drug, prontosil, which ushered in the era of antibacterial medicine.
For more information, see Prontosil....
Domain: In molecular biology, a discrete portion of a
protein with its own function. The combination of domains in a single protein determines its overall function. (Not to be confused with an Internet domain.) ...
Dominant: A genetic trait is considered dominant if
it is expressed in a person who has only one copy of that gene. (In
genetic terms, a dominant trait is one that is phenotypically
expressed in heterozygotes).
A dominant trait is opposed to a recessive trait which is
expressed only when two cop...
Dominant, autosomal: See: Autosomal dominant....
Donald Fredrickson: See: Fredrickson, Donald....
Donor: The giver of a tissue or organ, for example, of blood or a kidney....
Donor insemination: A procedure in which a fine
catheter (tube) is
through the cervix (the natural opening of the uterus)
into the uterus (the
womb) to deposit a sperm sample from a man other than the
directly into the uterus. The purpose of this procedure is
Donor lymphocyte infusion
Donor lymphocyte infusion: (DLI) A cancer treatment in which lymphocytes from a bone marrow donor are infused into the person who received the original bone marrow transplant. The goal of donor lymphocyte infusion is to induce a remission of the cancer by a process called the graft-versus-tumor (GVT...
Donor, universal: A person who is type O in the ABO blood group system and can donate blood to all recipients....
Dopa: A precursor (forerunner) of dopamine, a key neurotransmitter (messenger) in the brain.
Dopa is used in the treatment of Parkinson disease. Parkinson disease is believed to be related to low levels of dopamine in certain parts of the brain. When dopa is taken by mouth, it crosses through the ...
Dopa-responsive dystonia (DRD)
Dopa-responsive dystonia (DRD): A condition that typically begins in childhood or adolescence with progressive difficulty in walking and, in some cases, spasticity and can be successfully treated with drugs.
is an important variant of DRD. In Segawa dystonia, the symptoms fluctuate ...
Dopamine: An important neurotransmitter (messenger) in the brain.
Dopamine is classified as a catecholamine (a class of molecules that serve as neurotransmitters and hormones). It is a monoamine (a compound containing nitrogen formed from ammonia by replacement of one or more of the hydrogen atoms b...
Doppler ultrasound: A form of ultrasound that can detect and measure blood flow. Doppler ultrasound depends on the Doppler effect, a change in the frequency of a wave resulting here from the motion of a reflector, the red blood cell.
There are several kinds of Doppler ultrasound:
Color Doppler -- ...
Doraphobia: An abnormal and persistent fear of fur. Sufferers of this fear avoid fur-bearing animals such as dogs, cats, foxes, beavers and rabbits because fur is repulsive to them. Perhaps some of these phobics associate fur with childhood stories about "the big bad wolf" and other fur-bearing pred...
Dorian Gray effect
Dorian Gray effect: Sudden aging, an abrupt change from seeming youthfulness to the reality and ravages of age, as can occur naturally or when the effects of plastic surgery and Botox treatments wear off. Named after "The Picture of Dorian Gray" (1890), the novel by Oscar Wilde, in which Dorian giv...