transilluminationA procedure that is
sometimes carried out during physical
examination of a lump or swelling. Light
from a small torch is shone on 1 side of
the lump; if it can be seen on the other
side, the lump contains clear fluid.
translocationA rearrangement of the
chromosomesinside a person’s cells; it
is a type of mutation. Sections of chro-
mosomes may be exchanged or the main
parts of 2 chromosomes may be joined.
A translocation may be inherited or ac-
quired as the result of a new mutation.
A translocation often has no obvious
effect, and causes no abnormality. How-
ever, in some cases, it can mean that
some of the affected person’s egg or
sperm cells carry too much or too little
chromosomal material, which may cause
a chromosomal abnormality, such as
Down’ssyndrome, in his or her children.
transmissibleA term meaning capable
of being passed from one person, or
one organism, to another.
transplant surgeryReplacement of a
diseased organ or tissue with a healthy,
living substitute. The organ is usually
taken from a person who has just died.
Some kidneys are transplanted from a
patient’s living relatives (see organ dona-
tion). The results of surgery have also
been improved by testing for histo-
compatibility antigensand tissue-typing.
Rejectionis a major problem. However,
a combination of a corticosteroid drug
and ciclosporinare given in order to
suppress this response.
Every patient who undergoes an organ
transplant operation must take immuno-
suppressant drugsindefinitely. (See also
heart transplant; heart–lung transplant;
liver transplant; kidney transplant.)
transposition of the great vesselsA
serious form of congenital heart disease
in which the aortaand pulmonary artery
are transposed. Open heart surgeryis
needed to correct the defect.
transsexualismA rare disorder in which
a person wishes to live as a member of
the opposite sex. Transsexuals commonly
seek hormonal or surgical treatment to
bring about a physical sex change. A
psychiatric evaluation and a physical
examination are necessary before such
treatment is undertaken.
transvestismAlso called cross-dressing,
a persistent desire by a man to dress in
women’s clothing.
tranylcypromine An antidepressant drug
that belongs to the monoamine-oxidase
inhibitor(MAOI) group and is used main-
ly in patients with severe depression.
trapezius muscleA large, diamond-
shaped muscleextending from the back
of the skull to the lower part of the
spine in the chest and across the width
of the shoulders. It is attached to the
top and back of the shoulderblade and
to the outermost part of the collarbone.
The trapezius helps support the neck and
spine and is involved in moving the arm.
trapped nerveSee nerve, trapped.
traumaA physical injury or severe emo-
tional shock. (See also post-traumatic
stress disorder.)
trauma surgerySee traumatology.
traumatologyEmergency treatment of
patients suffering from acute trauma
(such as severe and/or multiple injuries).
travel immunizationAnyone planning
to travel abroad may need immuniza-
tionsbefore departure. Although few
immunizations are compulsory for inter-
national travel, some are recommended
for the traveller’s protection.
Travel agents and tour operators often
include information about which immu-
nizations may be needed, but travellers
should consult a doctor about individ-
ual requirements. Some vaccines must
be given in 2–3 doses several weeks
apart. Therefore, a doctor should be
consulted at least 2–3 months before
departure. Children under 1 year, and
people with a compromised immune
system or serious underlying disorder
may not be able to have some vacci-
nations, such as those for yellow fever
and tuberculosis (BCG).
traveller’s diarrhoeaA disorder occur-
ring in people who are visiting foreign
countries. Episodes of diarrhoea range
in severity and are due to gastroenteritis.
Attention to hygiene, drinking bottled
water, and avoiding ice in drinks can
prevent a large proportion of episodes.
travel sicknessSee motion sickness.
trazodoneAn antidepressant drugwith
a strong sedative effect that is used to
treat depressionaccompanied by anxietyTRANSILLUMINATION TRAZODONE
T