SCIENCE IN THE NEWS #2123 - DigestBy StaffThis is Bob Doughty.And this is Sarah Long with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about a new drug to treat cancer of the blood. We tell about a new study of the care of young children. And we tell about a lake in Africa that is shrinking.
A new drug appears to produce good results as a treatment for one kind of leukemia or cancer of the blood. In a recent study, the medicine helped patients' blood become normal in fifty-three out of fifty-four cases. Fifty-one of the patients still are doing well after taking the medicine for about one year. Cancer experts say this success rate is very unusual. However, researchers note that it is too early to know how the drug affects patients' survival over long periods of time.
Brian Druker of Oregon Health Sciences University led two studies of the drug. The studies were published in the New England Journal of Medicine.The new drug is called Gleevec. Recent tests show that Gleevec helps people who suffer from chronic myeloid leukemia. There are several different kinds of leukemia. All of them affect the body's production of blood cells. Chronic myeloid leukemia causes the body to produce unhealthy white blood cells. After a period of time, the body produces more unhealthy cells than healthy ones.
The drug works by blocking the action of an enzyme that does not work correctly within the body. The enzyme is said to be defective.
A chromosome lacking several genes causes the enzyme to be produced. The enzyme makes a protein that causes defective white blood cells to be produced uncontrollably. Gleevec appears to stop this process by blocking the action of the defective enzyme.Gleevec also appears to fight different kinds of cancer as well. Some researchers have had good results using the drug against cancer of the stomach and intestines. Glivec is also being tested on some lung cancers and brain cancer. However, scientists say more research is necessary.
Scientists say the drug may be important because it targets the cause of the disease without damaging other cells. They say the drug is also important because the goal of cancer research is to identify the differences between cancer cells and normal cells.
Gleevec is made by the Swiss company Novartis. Novartis has asked the United States Food and Drug Administration to approve Gleevec for treatment of chronic myeloid leukemia. The drug company also permits some people to use the drug now through a special experimental program.
((MUSIC BRIDGE))You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Sarah Long with Bob Doughty in Washington.An American study has linked aggression in children to the amount of time they spend away from their mothers.
The study compared young children who stayed with their mothers to children who were cared for by other people. It found that those who spent long periods away from their mothers were more likely to be aggressive toward other children. They were also more likely to disobey orders.
Study organizers say the findings were true, even when they considered different kinds of child care or the family's financial situation.
The ten-year study is widely considered the most complete investigation yet of child care in the United States. The National Institute of Child Health and Human Development provided financial support for the study. The agency is part of the National Institutes of Health.Child care is a major issue in the United States and other countries. The Children's Defense Fund is a group concerned with improving the quality of child care. It reports that thirteen-million young American children are cared for by someone other than their parents until they are old enough to begin school. Children usually begin school at the age of five or six.
The Children's Defense Fund reports that almost thirty percent of young children are in child care centers. Such centers usually care for thirteen or more children while their parents are at work. About fifteen percent of young boys and girls are cared for by someone in a private home. Five percent stay in their own home with someone other than a parent or family member.
About twenty-five percent of young children stay with a family member. The remaining twenty-four percent are cared for by one or both of their parents.The new study involved more than one-thousand-three-hundred children in ten American cities. The children spent an average of twenty-six hours a week away from their mothers in child care.
Researchers found that seventeen percent of the children who spent more than thirty hours a week in child care showed behavior problems by the time they were ready to start school. Only six percent of those who spent less than ten hours a week in child care had the same problems.
Jay Belsky of the University of London was one of the lead investigators in the study. He said children who spent more than thirty hours a week in child care were more demanding and aggressive. He said they also were more likely to fight with other children, do bad things to other children and talk too much.The study had other interesting findings. The boys and girls who spent more time in child care were found to be more fearful and sad compared to other children. However, these differences disappeared by the time the children were ready to begin school.
There was also good news for boys and girls who spent long periods in child care centers during their early years. The study found they were more likely to have better language skills and better short-term memory.Doctor Belsky warned parents not to overreact to the study's findings. He said the findings do not mean that children in child care are a danger to society. He suggested that parents could increase the time they spend with their children.
Some experts on work and family life question the findings. They say many American mothers have to work. They say child care is the only choice for some families if they want to avoid being poor. Other experts say the study suggests the need to improve the quality of child care in the United States.
((MUSIC BRIDGE))Scientists say there has been a severe decrease in the amount of water in Lake Chad in northern Africa in the last thirty years. They report that nature and humans share equal blame for this loss. In Nineteen-Sixty-Three, the fresh-water lake covered twenty-five-thousand-square kilometers. Now the lake is only about five percent of that size. It measures only about one-thousand-three-hundred square kilometers in the dry season.
Four nations surround Lake Chad. People in Niger, Nigeria, Chad, and Cameroon use it for water and fish.Michael Coe and Jonathan Foley are water experts at the University of Wisconsin in Madison. They reported about Lake Chad in the Journal of Geophysical Research. They say the area has suffered from a lack of heavy rain for more than thirty years. This has forced people to build systems to carry water to dry land. These irrigation systems further decrease the lake.
Mr. Coe says Lake Chad will be only a small body of water in the future. He says people still can get water from the lake to drink and for crops. But he says the lake will no longer provide a healthy environment for fish and plant life.The researchers used a computer to study what caused the water loss. They say major irrigation systems were built in the Nineteen-Eighties. The systems took water from two rivers that flow into Lake Chad. The Chari and Logone rivers carry most of the water that enters the lake.
The study showed the increased irrigation reduced the flow in the two rivers. Climate changes also were responsible for the reduction. Today the flow of the two rivers has been reduced by almost seventy-five percent.
Scientists say the problem is expected to worsen in the coming years as the population and demand for water continue to increase.
This SCIENCE IN THE NEWS program was written by Mario Ritter, George Grow and Jerilyn Watson. It was produced by George Grow. This is Sarah Long.And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.