SCIENCE IN THE NEWS - Medical Transplants

（单词翻译）

SCIENCE IN THE NEWS -February 19, 2002: Medical Transplants

By Nancy Steinbach
VOICE ONE:
This is Doug Johnson.
VOICE TWO:
And this is Bob Doughty¹ with SCIENCE IN THE NEWS, a VOA Special English program about recent

developments in science. Today, we tell about medical transplant operations.
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VOICE ONE:
Doctors perform medical transplant operations to place tissue or organs into the

body of an injured or sick person.

CDC
Medical history experts say the first transplant operation was carried out in Eighteen-Twenty-Three. A German
doctor placed skin from a woman’s leg onto her nose. By Eighteen-Sixty-Three, French scientist Paul Bert
showed that the body rejects tissue transplants from one person to another. Forty years later, German scientist
Carl Jensen found that this rejection² was carried out by the body’s defense³ system attacking the foreign tissue.

VOICE TWO:

Rejection continued to be a problem well into the twentieth century. In Nineteen-Fifty-Eight, French doctor Jean
Dausset discovered a system for tissue matching. This is a way to make sure that the tissue to be transplanted is
as similar as possible to the patient’s own tissue.

In Nineteen-Seventy-Two, Swiss scientist Jean Borel discovered that the drug cyclosporine could stop the body
from rejecting the new organ or tissue. Cyclosporine is a natural product made from a fungus⁴ found in soil.

Cyclosporine was approved for use in the United States in Nineteen-Eighty-Three. Experts say the use of this
drug is the most important reason for the success of transplant operations today.

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VOICE ONE:

Doctors around the world now can save thousands of lives with transplant operations. Each year, more than
twenty-thousand organs are successfully transplanted into patients in the United States alone. These people can
be expected to survive for many years.

At least twenty-one different organs and tissues can be successfully transplanted into the bodies of patients. The
most common organ transplanted is a kidney. A scientific report on transplants said more than twenty-fourthousand
kidney transplants are performed around the world each year. The success rate of these transplants is
very high.

Some kidney transplant patients have survived for more than thirty years. A family member often can provide a
kidney for transplant because people have two kidneys but need only one.

VOICE TWO:

The liver is the only human internal organ that can grow to normal size from a small piece. That is why it is


possible to remove part of a liver from a living person and place it in the body of a person suffering liver failure.
After the operation, both livers will grow to full size. More than seven-thousand liver transplants are performed
around the world each year.

VOICE ONE:

The first successful heart transplant was done in Nineteen-Sixty-Seven by South African doctor Christiaan
Barnard. Many more heart transplant operations have been done since Nineteen-Eighty -Three, when cyclosporine
was approved for use in the United States. About three-thousand heart transplants are performed around the
world each year.

Lung transplants can replace a single diseased lung or both lungs. About one-thousand lung transplants are
performed each year.

Sometimes, lung disease has also damaged the heart, and both organs must be replaced.

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VOICE TWO:

Tissue also can be transplanted. The most common tissue transplant is a blood transfusion⁵ when a patient
receives blood after an operation or accident. Other tissues that are transplanted include corneas of the eye, skin,
bone marrow⁶, bone and blood vessels⁷.

Corneal transplants improve the sight of people whose corneas have been damaged or destroyed by injury or
infection. Corneal transplants have a success rate of more than ninety percent.

Skin transplants reduce the chance of infection in areas of the body that have been burned. These transplants
remain on the body for several weeks, until skin from another part of the patient’s body can be used for a
permanent transplant.

VOICE ONE:

A bone marrow transplant treats people suffering from cancer of the blood and other diseases. Doctors remove
the substance inside the hip⁸ bone of a healthy person and place the bone marrow in a sick person’s body. The
marrow then begins producing healthy blood cells.

Bones can be transplanted, too. Recently, doctors have even transplanted hands and arms onto several patients in
Europe and the United States.

VOICE TWO:

A transplant operation succeeds only if doctors can prevent the body from rejecting the foreign organ or tissue.
This is done with drugs like cyclosporine. The patient also must receive tissue that is similar to his or her own.
The person providing the organ or tissue is known as the donor⁹. The one receiving it is the recipient¹⁰.

Both the donor and recipient must have the same blood type. For some transplants, they also must have some of
the same proteins called H-L-A antigens. H-L-A antigens are found on the outside of cells. Each person has many
different H-L-A antigens. The donor and recipient must have several of the same antigens for the transplant to
have a chance to succeed.

VOICE ONE:

Family members are the best possible organ donors¹¹. Other healthy people also can provide organs. However,
most transplanted organs come from people who have died or are brain dead. People who are brain dead usually
were in a serious accident that injured the head. After the brain dies, doctors keep the other parts of the body alive
with machines.

The family of the accident victim must give permission for transplanting the victim’s organs. Then a local
medical organization makes a computerized search for a person who needs the organ and who has tissue similar


to the victim. Doctors remove the organs from the body and send them to the recipient ’s hospital.

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VOICE TWO:
Animal organs also have been transplanted into people. In Nineteen-Sixty-Three and Nineteen-Sixty-Four,

doctors in the United States placed kidneys from chimpanzees into six people. All the people died from

infections. However, one patient survived for nine months.
Doctors began performing such operations because of the lack of human organs. Those who continue the research
today say they believe there never will be enough human organs for transplant operations.

VOICE ONE:
Many researchers now say pigs are the best animals for transplants. Heart valves from pigs are being used to
replace diseased or damaged heart valves in people. And scientists are continuing research to find ways to use pig

cells to treat several diseases. These include diabetes¹², Parkinson’s disease and Huntington’s disease. Doctors
say animal transplantation could be very useful in countries where human-to-human transplants are not permitted.
However, some medical experts are concerned about the possible dangers of animal transplants. These include

the possibility of releasing a virus like the one that causes the disease AIDS. Medical organizations all over the
world have developed rules about animal transplants. In some nations, animal rights groups strongly protest
transplants of animals to humans.

VOICE TWO:

The United Network for Organ Sharing is the organization in the United States that keeps the national list of
patients needing transplants.
The organization says about seventy-thousand people are waiting for organ transplants in the United States. It

says more than six-thousand people died while waiting for an organ transplant in the United States last year.
Health care workers around the world say organ and tissue transplants save thousands of lives. They urge people

to consider giving permission to use their organs for transplant operations if they should die unexpectedly in an
accident.
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VOICE ONE:
This SCIENCE IN THE NEWS program was written by Nancy Steinbach. This is Doug Johnson.
VOICE TWO:
And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice

of America.

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