Webster's New World Medical Dictionary

testosterone replacement therapy
The prac-
tice of using testosterone to treat conditions in
which the testes produce a deficient amount due to
absence, injury, or disease. Testosterone is available
in oral, IV, and patch forms. As with estrogen
replacement therapy for women, dosing must be
carefully calibrated to gain the greatest benefits
and to minimize unwanted side effects. See also
testosterone.
tetanus
An often fatal infectious disease that is
caused by the bacterium Clostridium tetani, which
usually enters the body through a puncture, a cut,
or an open wound. Tetanus leads to profound
painful spasms of muscles, including “locking” of
the jaw so that the mouth cannot open, and death.
The C. tetani bacteria releases a toxin that affects the
motor nerves, which stimulate the muscles.
Prevention involves immediately cleaning and cov-
ering any open wound and getting a tetanus vacci-
nation. Regular boosters are necessary to ensure
immunity. Unvaccinated people who get puncture
wounds or cuts should get tetanus immunoglobulin
and a series of tetanus shots immediately; those who
have been immunized but are unsure of the date of
their last tetanus shot should get boosters. Also
known as lockjaw.
tetany
A condition that is due usually to low
blood calcium (hypocalcemia) and is characterized
by spasms of the hands and feet, cramps, spasm of
the voice box (larynx), and overactive neurological
reflexes. Tetany is generally considered to result
from very low calcium levels in the blood. However,
tetany can also result from reduction in the ionized
fraction of plasma calcium without marked
hypocalcemia, as is the case in severe alkalosis
(when the blood is highly alkaline).
tetralogy of Fallot
A combination of four heart
defects that are present at birth and account for
about 10 percent of all congenital heart disease:
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