SARAHLONG:This is Sarah Long.
BOB DOUGHTY:And this is Bob Doughty with Science in the News,a VOA Special English program about recent developments in science.
Today,we tell about scientists who grew nerve cells from special stem cells.
We tell about cancer patients who suffer memory loss from chemotherapy treatments.
And we tell about a rare red panda born in an American zoo.
SARAH LONG:American scientists have found a way to change bone marrow cells into nerve cells like those found in the brain and the spinal cord.
The discovery may lead to safe and successful treatments for nerve injuries and brain disorders.
The work is being done by Ira Black and a team of researchers at the Robert Wood Johnson Medical School in Piscataway,New Jersey.
Doctor Black said he began the research to study how the body's cells,with the same genetic material,become many different kinds of cells.
Some become blood cells.Others become liver cells or brain cells.
Doctor Black wondered how this happened.What caused the cell to change into one kind or another?
He hoped to learn if scientists could make the same kind of changes in cells.
BOB DOUGHTY:Special cells called stem cells are produed in bone marrow,the material inside the large bones of the body.
The stem cells move from the bone marrow to the place where they are needed.
For example,if the body needs liver cells,stem cells travel to the liver.
They become liver cells and do all the work that other liver cells do.
Doctor Black and his team removed stem cells from the bone marrow of rats.
They put the rat stem cells into laboratory dishes and grew many more of them.
Then they added a chemical called beta mercaptoethanol.
Doctor Black had discovered earlier that beta mercaptoethanol had a special effect on cells.
It seemed to block other chemicals that prevented cells from becoming nerve cells.
SARAH LONG:Doctor Black said laboratory stem cells treated with beta mercaptoethanol changed within minutes.
He said they looked exactly like nerve cells
They began growing long,hair-like parts,just as nerve cells do.
The researchers found it was possible to change about eighty percent of the stem cells into nerve cells.
Tests showed that the newly-created nerve cells did all the chemical work that nerve cells usually do.
Doctor Black transplanted the rat nerve cells he had produced in the laboratory into the brains and spinal cords of living rats.
The laboratory nerve cells survived for months in the bodies of the rats.
BOB DOUGHTY:Other scientists praised the discovery.
One was William Greenough,of the Beckman Institute for Advanced Science and Technology at the University of Illinois.
Doctor Greenough said the discovery was an important step toward developing new technologies for the repair of a damaged brain.
He noted that many scientists are working with embryos or animal tissue to try to develop cells to replace damaged human cells.
But the body's defense system often rejects such foreign cells.
That would not be a problem with replacement cells grown from a person's own stem cells.
Scientists say,however,that a huge amount of work must be done before laboratory-produced nerve cells can be used to treat human injury or disease.
The work done by Doctor Black's team is described in the Journal of Neuroscience Research.