This is the VOA Special English Health Report.
scientists based in the United States have won the two thousand nine Nobel Prize
for Physiology or Medicine. They are
being honored for their work in the nineteen eighties about the health of cells
and the aging process.
The winners are Elizabeth Blackburn from the University
of California, San Francisco; Jack Szostak from Harvard Medical
School in Massachusetts and Carol Greider from Johns Hopkins
University in Maryland. They will share
the one million four hundred thousand dollar prize.
The scientists' work begins with telomeres. These are like protective coverings on the
ends of chromosomes. Elizabeth Blackburn
compares them to the plastic tips on the ends of shoelaces. She says without telomeres the chromosome and
the genes it holds would come apart.
Telomeres are necessary for a cell to
divide. They also are involved in
directing the number of divisions.
Blackburn and Mister Szostak discovered the special system of genetic
information in the telomeres that protects the chromosomes from ruin. Later, Mizz Blackburn and Mizz Greider
discovered the substance in the body that builds telomeres. The scientists named the enzyme telomerase.
research showed that cells age if telomeres are shortened. But, cell death is delayed if a lot of the
enzyme telomerase is produced.
Toftgard is a Nobel Committee member from Sweden's Karolinska Institute. He says the work of telomeres is important to
the understanding of how genetic material is copied and saved.
RUNE TOFTGARD: "All genes are encoded by DNA and the DNA is
present in the chromosomes in the cell nucleus and telomeres, they are the ends
of the chromosomes and they have an important function to protect the
chromosomes and maintain the integrity of the chromosomes."
telomere research expanded scientific knowledge about diseases and led to possible
new treatments. For example, some
research suggests that cancer cells use telomerase to grow uncontrollably. Some scientists are studying whether drugs
that block the enzyme can help fight cancer.
And that's the VOA Special English Health Report,
written by Caty Weaver. For more health
news, go to voaspecialenglish.com. You can also follow us on Twitter and
YouTube at VOA Learning English. I'm Mario Ritter.