A. Finding Genetic
Clues In Glaucoma
Narrator: This is Science Today. A gene
linked to glaucoma has been found to be activated
by both anti-inflammatory steroids and oxidative
stress. Dr. Jon Polansky, of the University of California,
San Francisco, says this finding sheds new light
on who may develop primary open angle glaucoma,
the most common form of the disease.
Polansky: The gene seems to be giving clues
in some early work we're doing of who's more likely
to develop glaucoma of a more severe kind than have
visual field damage. So we're looking into those
possibilities right now and the area of the gene
is very interesting and seems to be showing that.
So if these tests become available, then it wouldn't
say you're going to get glaucoma, but what it would
do is, it would tell you that you have a much higher
risk and should be followed more closely.
Narrator: And the sooner you find out about
glaucoma, the better.
Polansky: It still is the second leading
cause of blindness even though there's so many drugs
used to treat it. So it would be very good to be
able to identify people early and then use all the
sophisticated tests their ophthalmologists have
for screening for visual field damage.
Narrator: For Science Today, I'm Larissa
Branin.
B. The Link Between Age & The
Effects of Tobacco
Narrator: This is Science Today. Researchers
at the University of California, San Francisco say
there's a crucial link between the age a person
starts smoking and how much DNA damage is present
in their lungs. Epidemiologist John Wiencke explains.
Weincke: Our evidence strongly indicates
that if a person starts smoking very early in life,
before adolescence, the damage that accumulates
persists much longer than if a person starts smoking,
say when they're 20 years or so. It may actually
take many years for it to clear out of the lungs
and of course, once mutations are induced, theoretically,
they're around forever.
Narrator: Many lung cancer patients studied
began smoking before age ten.
Weincke: It's always been controversial
about whether when you start smoking is an independent
risk factor for lung cancer as opposed to how much
you smoke, because people that start smoking very
early in life tend to smoke more cigarettes per
day and they tend to be heavier smokers, so there's
this confounding with age and how much you smoke.
Narrator: For Science Today, I'm Larissa
Branin.
C. The Facts About A Congenital
Heart Defect
Narrator: This is Science Today. Hypoplastic
left heart syndrome is a congenital heart defect
which strikes one in a few thousand babies each
year in this country. According to Dr. Wayne Tworetzky
of the University of California, San Francisco,
no one knows why babies develop this, but the defect
is devastating, since it affects the heart's left
ventricle, which is the main pumping chamber.
Tworetzky: It pumps blood to your brain,
your kidneys, your liver and in this condition either
all or one of the parts of the left side of the
heart are underdeveloped so you either have a small
pumping chamber or ventricle or small, very small
aortic valve, so blood can not flow normally through
the left side of the heart.
Narrator: Twortezky found a prenatal diagnosis
of this defect can increase a newborn's survival
rate, since treatment can begin immediately following
birth.
Tworetzky: In our study, all of the children
had a prenatal diagnosis survived to go home after
the first surgery and in the group that were diagnosed
after birth, about sixty-five percent of them survived.
So there is a large difference.
Narrator: For Science Today, I'm Larissa
Branin.
D. Estrogen & Alzheimers: A Wait
And See Approach
Narrator: This is Science Today. In the
last decade, there's been an explosion of studies
looking into the role estrogen has in Alzheimer's
Disease. Kristine Yaffe, a researcher at the University
of California, San Francisco, says it's pretty clear
estrogen does have an effect in the brain.
Yaffe: There are estrogen receptors throughout
the brain. In particular, in the hippocampus, which
is the area thought to be affected early in Alzheimer's
and very critical in memory in general. And it seems
that in these basic science experiments, that if
you add estrogen - the neurons seem to be healthier.
They sprout more dendritic connections, It seems
overall that this is almost like a protective or
a healthy effect.
Narrator: Still, Yaffe cautions these results
need further study.
Yaffe: It's important to be cautious because
there are side effects associated with estrogen
use that they're not talked about a lot and I think
there are certain expenses of taking the medication
and I think generally speaking, it's better to wait
until the studies are done.
Narrator: For Science Today, I'm Larissa
Branin.
E. The Controversy Over Screening
For Down Syndrome
Narrator: This is Science Today. A new,
early ultrasound screening test for Down Syndrome
has sparked some criticism. The procedure measures
abnormal fluid accumulation in the neck of the fetus,
which is a sign of Down Syndrome. Dr. James Goldberg
of the University of California, San Francisco explains
the potential downsides of the screening test.
Goldberg: We know that many fetuses with
Down Syndrome and other chromosomal abnormalities
are lost spontaneously in utero. So one criticism
has been well, many of those fetuses will be lost
anyway, why screen earlier? Just let nature take
it's course.
Narrator: Goldberg says the same criticism
can also be made for amniocentesis, another screening
method.
Goldberg: One of the things that's important
for people to recognize is that because this is
an earlier test, that they'd have to think about
it earlier in pregnancy. Many women don't go in
for prenatal care >til later now. But this is something
that if you want to take advantage of it, you have
to think about it early enough in gestation to have
that option.
Narrator: For Science Today, I'm Larissa
Branin.
