Science News Digest
This is Sarah Long. And this is Bob Doughty with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about World AIDS Day. And we tell about scientists who have made genetic copies of human embryos in an effort to treat diseases.
December First was World AIDS Day. World AIDS Day was first observed on December First, Nineteen-Eighty-Eight. It was created during a worldwide conference of health ministers as a way to inform people about the disease.
Twenty years ago, the first cases of the Human Immunodeficiency Virus were identified. H-I-V is the virus that causes AIDS. The United Nations says that the AIDS virus remains one of the greatest health threats the world has ever seen.
Since the disease was discovered, more than sixty-million people have been infected with the virus. The disease is the leading cause of death in southern African countries. It is the fourth leading cause of death worldwide.
The United Nations estimates that more than forty-million people are living with H-I-V and AIDS around the world. That is an increase of about four-million from last year. About one-third of the people infected are between the ages of fifteen and twenty-four. Most of them do not know they have the virus. Millions of other people do not know enough about H-I-V to protect themselves against the virus. Young women are especially at risk.
AIDS is a great human tragedy. U-N officials say about three-million people have died of AIDS around the world this year. The disease also has severe economic effects, especially in poor and developing nations.
African countries have been hardest hit by the disease. They have about seventy-percent of all AIDS cases. More than three-million people in Africa were infected this year. The disease is severely affecting the economy, education systems, health services and farms in many African countries. Were it not for AIDS, life expectancy among Africans would be about sixty-two years instead of forty-seven.
The United Nations recently reported that the disease is now spreading fastest in eastern Europe. Ukraine has been the most severely affected. However, the number of infections in Russia also has greatly increased.
AIDS rates also have risen in Asia and the Middle East. An increase in unsafe sexual activities is leading to higher infection rates in some industrial countries.
However, some countries have reduced the number of AIDS cases. Countries such as Thailand, Brazil and Uganda have led successful treatment and prevention campaigns. These efforts also have reduced the number of babies being born with the virus.
Earlier this year, the United Nations established an international program to finance treatment and prevention efforts. Countries have promised almost two-thousand-million dollars so far. However, U-N Secretary General Kofi Annan has said the program would require at least seven-thousand-million dollars.
Last month, the U-N AIDS organization released its yearly report about World AIDS Day. U-N AIDS was created five years ago to unite international agencies in the fight against the disease. The report calls on countries to quickly put in place effective prevention programs, especially to slow H-I-V among young people. It said providing treatment and care is necessary for the success of any efforts to fight AIDS.
U-N officials say all people should do their part to prevent the spread of H-I-V and AIDS. They also say men must do more to fight the disease because they have more control over its spread.
Peter Piot is the director of U-N AIDS. Doctor Piot says the recent worldwide concern about terrorism has reduced recognition given to AIDS. He says it has been more difficult for his organization to include AIDS in political discussions since the terrorists attacks in the United States three months ago. Doctor Piot says strong national leadership is very important in the fight against AIDS.
You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Sarah Long with Bob Doughty in Washington.
A company in Worcester, Massachusetts, Advanced Cell Technology, has announced it has made the first genetic copies of human embryos.The process of making genetic copies is called cloning.
Cloning involves the creation of an embryo from a single adult cell. Genetic material from the adult cell is joined with an egg cell whose genetic material has been removed. Scientists have used cloning to create animals.
Scientists from Advanced Cell Technology performed the experiment in an effort to create cloned human embryonic stem cells. Embryonic stem cells are unformed cells that can grow into any of the body's tissues or organs. The scientists hope that this new medical technology will be used to replace damaged tissue in people with serious diseases. These include diabetes, cancer and Parkinson's disease.
In August, President Bush approved limited research on stem cells. However, the Bush administration has only permitted research on about sixty groups of existing stem cells. Medical researchers have noted that these groups of stem cells are not useful for treating disease. This is because treatments developed from existing stem cells might be rejected by the bodies of possible patients. Some scientists say the best way to make stem cells for treatment is to grow them from embryos that are clones of the patients.
Michael West is the head of Advanced Cell Technology. Doctor West wants to find a way to avoid biological rejection of stem cell treatments. Researchers for Advanced Cell Technology created experiments to clone human cells. The company published a report about their experiments on an Internet publication called "E-biomed: The Journal of Regenerative Medicine."
The researchers found seven women who agreed to give their egg cells to the project. The women were given chemicals to increase production of eggs. Seventy-one eggs were collected from the women. Some of the eggs, however, were not usable.
Scientists put the egg cells into growth chemicals. Some of the egg cells had their genetic material replaced with cells called cumulus cells. Cumulus cells often attach to eggs in a woman's ovary. The researchers put cumulus cells inside eight egg cells whose genetic material had been removed.
Three of the egg cells began to grow into more cells. Two eggs developed into four cells each. One egg developed into six cells. All three early embryos stopped dividing and died after three days.
The scientists also took genetic material from skin cells collected from other people. They put the genetic material from the skin cells into eleven specially treated egg cells. However, none of those eggs grew into more cells.
Also, the scientists experimented on egg cells that did not receive any new genetic material. Twenty-two eggs were placed in growth chemicals. Of these, six divided into a group of cells with a wall and an empty center. These grew for seven days before they died.
These experiments did not produce stem cells from cloned human embryos because the embryos did not live past the six-cell stage. Usually an embryo must grow to a few hundred cells before it produces stem cells.
Doctor West has said the research on human embryos is designed only to produce embryonic stem cells to treat disease. He has strongly stated that his company has no interest in cloning human beings.
American lawmakers have been preparing legislation that could ban or limit cloning. In July, the House of Representatives approved a bill that would ban all human cloning. However, the Senate has not voted on a cloning bill.
President Bush has said he strongly opposes human cloning. He has said the use of embryos to clone is wrong. However, the debate over cloning human embryos will probably continue for some time.
This SCIENCE IN THE NEWS program was written by Cynthia Kirk and Mario Ritter. It was produced by Nancy Steinbach. This is Bob Doughty. And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.