Webster's New World Medical Dictionary

dominant, autosomal
See 
autosomal domi-
nant.
dominant, X-linked
See 
X-linked dominant.
donor
The giver of a tissue or an organ, such as
a blood donor or kidney donor.
donor insemination
See 
artificial insemina-
tion by donor.
dopa-responsive dystonia
A disease character-
ized by progressive difficulty in walking and in some
cases by spasticity. Abbreviated DRD. DRD begins in
childhood or adolescence. It can be successfully
treated with drugs. Segawa dystonia is an important
variant of DRD. Some scientists feel that DRD is not
only rare but also rarely diagnosed because it mim-
ics many of the symptoms of cerebral palsy.
Medications that affect the chemical nerve transmit-
ter dopa can improve symptoms.
dorsal
Pertaining to the back, or posterior, side
of a structure, as opposed to the ventral, or front,
side. Some of the dorsal surfaces of the body are the
back, buttocks, and calves, and the knuckle side of
the hand. See also Appendix B, “Anatomic
Orientation Terms.”
dorsum
The back or posterior side of a structure.
Something that pertains to the dorsum is dorsal.
DOT
Directly observed therapy.
double helix
The structure of DNA, in which two
strands of DNA spiral about each other.
double pneumonia
See 
pneumonia, double.
double-blinded study
A medical study in which
both the subjects participating and the researchers
are uaware of when the experimental medication or
procedure has been given. Double-blinded studies
are often used when initial studies shows particular
promise.
double-jointed
Popular term to describe a joint
that is unusually flexible. Medically, the joint is said
to be hyperflexible, hyperextensible, or hypermo-
bile. People whose fingers are hypermobile have
higher rates of arthritis in the hands. Marked joint
hypermobility is a feature of Ehlers-Danlos syn-
drome. See also 
Ehlers-Danlos syndrome.
douche
Usually, a stream of water applied into
the vagina for cleansing purposes. A douche can use
a solution, such as vinegar and water, rather than
simple water, and it can be directed at any body cav-
ity or part.