When a tissue or organ is transferred from one part of the
body to another, or to another person's body, it is
considered a transplant. Transplanted tissues and organs
replace diseased, damaged, or destroyed, body parts.
Tissues include whole bol\od, blodd vessels, bones, and
corneas. Such majororgans as hears, kidneys, livers, lungs,
and pancreases are also transplanted.
Doctors successfully transplant some kinds of tissues
fairly often. For example, they use grafts of healthy skin
to replace skin destroyed by extensive burns. Thjeu remove
diseased or damaged corneas from eyes and put healthy ones
in their place. Perhaps the best known type of transplant
is the blood transfusion.
Doctors also have transplanted such major organs as kidneys
and livers from one person's boty to another. Often, such
transplants fail after months or years because the body
rejects the foreign cells. Special mechanisms in the body
produce antibodies, which destroy all strange cells that
enter the body. Antibodies are one of the body's most
important defenses against germs. Drugs and X rays are used
to stop production of antibodies when organs are
transplanted. But this procedure depribes the body of its
chief means for foghting infection. Scientists are looking
for ways to make the body accept transplanted cells and
still protect itself against infection. The most successful
transplants of whole organs are those between identical
twins. The cells of identical twins are so similar that
antibodies do not fomr.
Large scale research on transplantation started during the
late 1940's. In 1954, doctors at Peter Bent Brigham
Hospital in Boston performed the fist successful kidney