A. Proving Tobacco's
Link To Lung Cancer
Narrator: This is Science Today. Researchers
have found new evidence which may prove that an
individual's lung cancer was the direct result of
exposure to tobacco smoke - even secondhand. John
Wiencke, a professor of epidemiology at the University
of California, San Francisco, found tobacco smoke
caused specific mutations in what's called the p53
tumor suppressor gene of lung cells. These genes
are key factors associated with some cases of lung
cancer.
Wiencke: In tobacco smoke related cancers,
there are certain regions of the gene that appear
to be preferentially mutated or disrupted and those
are called hot spots, hot spots for mutation in
the p53 gene.
Narrator: These hot spots may be caused
by the tar in cigarettes which bind to certain parts
of the p53 gene and leave what Wiencke calls Afingerprints@
of tobacco smoke carcinogens.
Wiencke: I think we're on the right track
and these are significant developments but cancer
is a very complicated problem and so we're not going
to have answers about environmental tobacco smoke
overnight.
Narrator: For Science Today, I'm Larissa
Branin.
B. Increasing The Odds of Surviving
A Lethal Heart Defect
Narrator: This is Science Today. Newborns
with a relatively common and lethal heart disorder
called hypoplastic left heart syndrome have better
odds of surviving post-birth surgery if there's
a prenatal diagnosis of the defect. Dr. Wayne Tworetzky
of the University of California, San Francisco says
finding the abnormally small left heart ventricle
during a prenatal ultrasound gives doctors a head
start in treatment after birth.
Tworetzky: The main problem with children
diagnosed after birth is that a small blood vessel
which connects the pulmonary artery and the aorta
normally closes after birth and in these children,
once that vessel closes, they are not getting any
blood flow to their vital organs and they become
extremely ill.
Narrator: This is the first study to show
that prenatal diagnosis of this condition resulted
in an improved outcome.
Twortezky: People have looked at this in
the past and have not seen a difference between
those diagnosed prenatally and postnatally, but
one would expect there to be a difference because
it makes sense that healthier children should do
better in complex surgery.
Narrator: For Science Today, I'm Larissa
Branin.
C. What All Women Should Know
About Down Syndrome
Narrator: This is Science Today. Down Syndrome,
the most common cause of mental retardation, is
most often associated with babies born to mothers
over 35. But Dr. James Goldberg, director of the
Reproductive Genetics Unit at the University of
California, San Francisco, says that's not always
the case.
Goldberg: Eighty percent of Down Syndrome
occur in women that are below the age of 35.
Narrator: There's currently a new ultrasound
procedure available for all women to screen for
Down Syndrome. The new approach measures the tell-tale,
abnormal fluid accumulation in the neck of the fetus
called nuchal translucency. Goldberg says measuring
this indicator of a chromosomal defect is more efficient
than older procedures and can be performed earlier
in pregnancy.
Goldberg: Now for each individual woman,
their risk may be quite small, but what we can do
with this type of approach to screening is give
a woman her individualized risk for Down Syndrome.
So I really believe that all people who want this
information, it should be made available to.
Narrator: For Science Today, I'm Larissa
Branin.
D. The Growing Need For Organ
Donors
Narrator: This is Science Today. Over 50
thousand people in this country need kidney transplants,
yet there's only about 10 thousand organs available
each year. Dr. Flavio Vincenti of the Kidney Transplant
Service at the University of California, San Francisco,
says unfortunately these rates have been pretty
steady.
Vincenti: There is a tremendous need for
organs. For all organs. But clearly there is a tremendous
deficit in the number of kidneys that are required
for patients who have kidney disease that are on
dialysis.
Narrator: Only a minority of kidney transplants
use organs from a living donor. The rest are performed
using organs from cadavers.
Vincenti: We still need an increase in the
number of cadaver organs. That's why there's a great
push and tremendous amount of research in so called
xenograft to obtain organs from genetically engineered
pigs, but that's going to be a few years away at
this point.
Narrator: Right now, researchers are working
to reduce the over immunosuppression and toxicity
of transplant drugs while pushing for more donor
awareness. For Science Today, I'm Larissa Branin.
E. A Space-Age Way To Take Your
Medicine
Narrator: This is Science Today. Miniature
devices the size of a computer chip with microscopic,
heat-activated valves and bubble pumps may become
the drug delivery system of the future. Dorian Liepmann,
a professor of mechanical engineering at the University
of California, Berkeley says this technology of
mixing fluids in channels the size of a human hair,
is called microfluidics.
Liepmann: Microfluidics is just taking off,
I mean there's research being done everywhere for
everything from pathogen detection for protection
against chemical and biological weapons, rapid DNA
processing. We have some ideas about how you can
actually use these things to diagnose diseases very
rapidly.
Narrator: Liepmann envisions using microfluidics
on plastic the size of a credit card. This portable
system would be able to deliver drugs such as insulin
to diabetics or antibiotics to soldiers in the field
-even astronauts in space.
Liepmann: The idea is that if you go up
to the moon or Mars, you can imagine that a first
aid kit or a medical kit would just be a whole set
of credit cards with different dry drugs.
Narrator: For Science Today, I'm Larissa
Branin.
