Umbilical cords may provide cells for repairing brains after  strokes
By Daniel Q. Haney, Associated Press, 2/18/2001 16:12
SAN FRANCISCO (AP)

Umbilical cords discarded after birth may offer a vast new source
of repair material for fixing brains damaged by strokes and other ills,
free of the ethical concerns surrounding the use of fetal tissue,
researchers said Sunday.

In animal experiments, at least, cells from umbilical cords
appear to greatly speed recovery after strokes. They work with a
simple infusion into the blood stream without the need for direct
implantation into the brain.

Although many details need to be worked out, Dr. Paul R. Sanberg
of the University of South Florida said he hopes to try the
approach on stroke victims within the next year or two.

Sanberg described the research at a meeting in San Francisco of
the American Association for the Advancement of Science. It was
financed by the state of Florida and Cryo-Cell International Inc.
of Clearwater, Fla.

Many experts believe that primitive tissue called stem cells
will someday be routinely used to make human spare parts. They
might replace tissue damaged by many different diseases, especially
such brain ailments as strokes and Alzheimer's disease. These
generic cells can be nudged to develop into all sorts of
specialized tissue to repopulate every part of the body from head
to toe.

One source of stem cells is aborted fetuses or fertility
clinics' discarded embryos. However, this is especially contentious
since anti-abortion groups oppose fetal and embryonic stem cell
research, and federally funded scientists cannot use stem cells
from these sources.

Sanberg said his research suggests that umbilical cords could be
an excellent source of stem cells without the ethical headaches of
fetal tissue. He noted that 4 million babies are born in the United
States each year, and 99 percent of their cord blood is tossed
away.

He said one or two cords could probably provide enough stem
cells to treat one human stroke victim, if the current approach
proves useful. The cells could be frozen for use when needed.

In experiments so far, his team removed stem cells from cords
and then used retinoic acid and growth hormones to transform them
into immature nerve cells. They then injected 3 million of these
cells into the bloodstreams of rats that had suffered strokes.

In experiments on about 60 rats, the team found that after one
month, those given the cells had recovered about 80 percent from
their strokes, compared with about 20 percent in untreated rats.

Sanberg said the treatment works best when given within 24 hours
of a stroke but still helps up to a week later. Just how the new
cells rewire the damaged parts of the brain is unclear, although
the cells can take on the form of distinctly different types of
brain tissue, and they also appear to prompt damaged cells to
repair themselves.

''They are attracted to the stroke part of the brain more than
the normal brain,'' he said. ''Some signal is being sent that
attracts them.''

Sanberg cautioned that many questions remain, such as whether
the cells should be given in several doses, how many should be
infused, and whether the treatment will require suppression of the
immune system, since the body might otherwise reject the foreign
tissue.

''This is very exciting,'' said Dr. Sandra Chapman of the
University of Texas at Dallas. ''The potential of this will be an
exponential improvement in our chance of treating all sorts of
brain disorders.''

On the Net:
American Association for the Advancement of Science:
http://www.aaas.org/

http://www.boston.com/dailynews/049/nation/Umbilical_cords_may_provide_ceP.shtml

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