SCIENCE IN THE NEWS - Medical Transplants
SCIENCE IN THE NEWS -February 19, 2002: Medical Transplants
By Nancy Steinbach
VOICE ONE:
This is Doug Johnson.
VOICE TWO:
And this is Bob Doughty 1 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 rejection 2 was carried out by the body’s defense 3 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 fungus 4 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 transfusion 5 when a patient
receives blood after an operation or accident. Other tissues that are transplanted include corneas of the eye, skin,
bone marrow 6, bone and blood vessels 7.
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 hip 8 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 donor 9. The one receiving it is the recipient 10.
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 donors 11. 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 diabetes 12, 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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- Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质:脾气倔强,性格刚强。
- The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。
- He decided not to approach her for fear of rejection.他因怕遭拒绝决定不再去找她。
- The rejection plunged her into the dark depths of despair.遭到拒绝使她陷入了绝望的深渊。
- The accused has the right to defense.被告人有权获得辩护。
- The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。
- Mushrooms are a type of fungus.蘑菇是一种真菌。
- This fungus can just be detected by the unaided eye.这种真菌只用肉眼就能检查出。
- She soon came to her senses after a blood transfusion.输血后不久她就苏醒了。
- The doctor kept him alive by a blood transfusion.医生靠输血使他仍然活着。
- It was so cold that he felt frozen to the marrow. 天气太冷了,他感到寒冷刺骨。
- He was tired to the marrow of his bones.他真是累得筋疲力尽了。
- The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
- All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》
- The thigh bone is connected to the hip bone.股骨连着髋骨。
- The new coats blouse gracefully above the hip line.新外套在臀围线上优美地打着褶皱。
- In these cases,the recipient usually takes care of the donor afterwards.在这类情况下,接受捐献者以后通常会照顾捐赠者。
- The Doctor transplanted the donor's heart to Mike's chest cavity.医生将捐赠者的心脏移植进麦克的胸腔。
- Please check that you have a valid email certificate for each recipient. 请检查是否对每个接收者都有有效的电子邮件证书。
- Colombia is the biggest U . S aid recipient in Latin America. 哥伦比亚是美国在拉丁美洲最大的援助对象。