SCIENCE IN THE NEWS - Cloning in South Korea / Ancient Insec

（单词翻译）

SCIENCE IN THE NEWS - Cloning in South Korea / Ancient Insect / Preeclampsia Research
By

Broadcast: Tuesday, March 09, 2004

(THEME)

VOICE ONE:

This is Science in the News, in VOA Special English. I'm Sarah Long.

VOICE TWO:

And I'm Bob Doughty¹. This week, something new and something old ... the debate over the cloning of human embryos³, and the discovery of the oldest insect ever found.

VOICE ONE:

Plus, some hopeful news from research on a dangerous disorder⁴ of pregnancy⁵.

(THEME)

VOICE TWO:

 
Hwang Woo-suk, center, and Moon Shin-yong talk to Donald Kennedy, editor-in-chief of Science magazine, Feb. 12 at the American Association for the Advancement⁶ of Science meeting in Seattle.
Two doctors in South Korea are in the news a lot these days. They are the first scientists to report success in efforts to create a human embryo² and to remove stem cells from it. Stem cells have the ability to grow into other cells, such as heart, nerve or brain cells. So they might offer new ways to treat disease.

Hwang Woo-suk and Moon Shin-yong are doctors at Seoul National University. Their study was published in February in Science magazine.

Sixteen women took part in the research. They agreed to take fertility drugs for a month. These caused them to produce a large number of eggs. The doctors collected two-hundred-forty-two eggs for their study.

 
Injection of a donor⁷ cell.
They removed the nucleus⁸ from each cell in the eggs. The nucleus contains DNA⁹ material, the complete genetic¹¹ plans for an organism. Then the researchers used electricity to join each egg cell to a different cell taken from the women's ovaries. The ovaries are the organs that produce eggs.

Thirty of the joined cells grew into what are called blastocysts, an early form of an embryo. The doctors say they were able to collect stem cells from twenty of them.

VOICE ONE:

 
Cloned embryo at four-cell stage.
There are many political and moral questions about this work. Lawmakers around the world remain divided over how to supervise cloning research. But scientists, politicians and clergy¹² generally agree that cloning should not be used to copy human beings.

It has been done with animals. In each case, scientists created an embryo and placed it in a female animal to grow. There was Dolly the cloned sheep, for example. This form of science is called reproductive cloning.

But many scientists do support therapeutic¹³ cloning for humans. This is where stem cells are harvested for research on possible treatments for disease. Supporters argue that cloned stem cells could be used for gene¹⁰ therapy or to repair tissue. Researchers say they are still years away from such uses. Yet critics say they fear that human embryos could become just another industrial product.

Some people would ban any form of cloning.

VOICE TWO:

Doctor Hwang says he understands the issues about his research. But he says human embryo cloning must go forward to help people with deadly diseases.

The two doctors are seeking patent ownership rights to the process they developed. They say they also want to protect the cloned human stem cells that grew from their experiments.

Seoul National University will own sixty percent of the patent. Organizations that helped finance the research will own forty percent.

Hwang Woo Suk and Moon Shin Yong say they are not seeking any economic gains in the future. They say their only hope is that one day, their discovery will help solve some incurable¹⁴ disease.

VOICE ONE:

Last week, there was a separate development in the United States. Harvard University announced plans to build a center to grow and study human stem cells. Harvard officials in Cambridge, Massachusetts, say they will pay for the center with private money.

The Bush administration bars the use of federal money for stem cell research. This is because a developing embryo must be destroyed in order to collect the cells. Opponents of such research say this destroys life.

(MUSIC BRIDGE)

VOICE TWO:

Some pregnant women develop a condition called preeclampsia [pre-ee-CLAMP-see-ah]. This causes dangerously high blood pressure. It causes the urine to contain large amounts of protein. And it causes fluid to collect in the hands and feet. Preeclampsia can threaten the life of the mother and her baby. In severe cases, the woman can suffer seizures¹⁵ and die.

Doctors can treat the effects. But the only cure known is giving birth. However, babies born to mothers with preeclampsia may be small for their age. Or they may be born too soon. This puts the baby at risk for a number of problems.

Researchers say preeclampsia affects about five percent of pregnancies¹⁶. It can happen without warning. The cause is unknown. But new findings may help doctors look for signs of preeclampsia before it happens, and do more about it.

VOICE ONE:

A study found that two proteins in the blood may point to the development of preeclampsia. The New England Journal of Medicine published the findings last month. Researchers from the National Institutes of Health and Harvard Medical School did the study.

They studied protein levels in blood taken from one hundred-twenty women who had preeclampsia. The blood had been taken throughout their pregnancies. They compared the findings to the blood of one-hundred-twenty other women who had not developed preeclampsia.

The two groups began their pregnancies with similar levels of the two proteins measured. But the researchers found that changes took place in the women who later developed preeclampsia.

Levels of one protein began to increase about five weeks before the women showed any signs of the condition. Also, levels of the other protein decreased beginning in the thirteenth and sixteenth weeks of their pregnancies.

VOICE TWO:

Doctor Richard Levine of the National Institute of Child Health and Human Development led the study. He notes that the study did not include women who developed pregnancy-related high blood pressure but not preeclampsia. So it is not known if these women have similar changes in their proteins.

But Doctor Levine says the findings do offer the possibility of preventing and treating preeclampsia.

(MUSIC BRIDGE)

VOICE ONE:

Have you heard about the world's oldest insect? Scientists say a small bug¹⁷ found in Scotland is four-hundred-million years. No, it is not still alive. The finding suggests that insects existed on Earth twenty-million years earlier than thought. It also suggests they were among the first living creatures on land.

The insect was first discovered about eighty years ago. But there was little interest until two-thousand-two. Then, two scientists rediscovered it while doing other research. They examined the fossil at the Natural History Museum in London.

The two are David Grimaldi of the American Museum of Natural History in New York and Michael Engel of the University of Kansas. They examined the remains¹⁸ under a powerful microscope. Details of their discovery appear in Nature magazine.

VOICE TWO:

The scientists say the insect was probably just over one-half centimeter long. It may have been about the size of a grain of rice and looked like a small fly. The insect was found in red sandstone called chert. The scientists say the insect probably became trapped in crystals that formed around a hot spring.

They examined parts of the head and body. Mister Grimaldi says the jaws²⁰ proved it was an insect. He says the jaws were very similar to those found only in insects with wings. He says he and Mister Engel became excited at the idea that the insect may have flown.

They did not find any wings. However, Mister Grimaldi says the jaw¹⁹ parts, or mandibles, provide strong evidence that it had them.

VOICE ONE:

Other scientists agree that this is the oldest insect found so far. But not all agree that it flew. The oldest known flying insects -- at least until now -- date back about three-hundred-twenty million years.

Until now, the oldest insect fossils on record were two insects without wings. They are said to be about three-hundred-eighty million years old. They were found in New York State and Canada.

The four-hundred-million-year-old insect is known by the Latin name Rhyniognatha hirsti. Mister Grimaldi says the finding suggests that insects likely developed during the Silurian period. This is the period when evidence shows that plants began to appear on land.

(THEME)

VOICE TWO:

SCIENCE IN THE NEWS, in VOA Special English, was written by Jill Moss²¹, Lawan Davis and Cynthia Kirk, who was also our producer. This is Bob Doughty.

VOICE ONE:

And this is Sarah Long. Listen again next week, when we throw some light on the dark ... dark energy, that is. Scientists say it appears to support a theory that Albert Einstein once proposed, and then rejected.