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A.
Virtual Colonoscopy Not Ready for Widespread Use
Narrator: This is Science Today.
New research has found that virtual colonoscopy
– a less invasive screening test for colon cancer
– is not yet ready for widespread use. Dr. Uri Ladabaum
led the University of California, San Francisco
study.
Ladabaum:
Even when the sensitivity and specificity
of the virtual colonoscopy test was comparable to
that of the colonoscopy, the clinical outcomes of
screening with colonoscopy were slightly better,
although comparable. Yet for the two strategies
to be economically comparable, the cost of the virtual
colonoscopy would have to be about two thirds of
the test costs for colonoscopy. The charges for
it tend to be comparable and in some cases, higher.
Narrator:
Ladabaum says since virtual colonoscopy may be best
suited for patients who are at low risk of having
polyps or cancer, high-risk patients should stick
to colonoscopy.
Ladabaum:
Somebody who has a high chance of eventually needing
a conventional colonoscopy anyway, should probably
start out with a conventional colonoscopy from the
start.
Narrator:
For Science Today, I’m Larissa Branin.
B.
A New Generation of MRI Scanners
Narrator:
This is Science Today. There’s a new generation
of MRI scanners referred to as interventional MRI
units. These are used not only for their high quality
imaging to help diagnose disease, but also to facilitate
procedures to treat those diseases. Dr. Phillip Starr,
a professor of neurosurgery at the University of California,
San Francisco, is using interventional MRI to perform
deep brain stimulation surgery, or DBS, to help control
symptoms in patients with Parkinson’s disease.
Starr:
We felt it makes sense to improve DBS surgery by performing
it directly within an MRI scanner, so that we can
use the high quality MR images to see the brain target
to advance the DBS electrode to the target under direct,
continuous visualization with MR imaging.
Narrator:
The procedure is currently being used in clinical
trial.
Starr:
Any new surgical technique is best considered
an investigational technique.
Narrator:
For Science Today, I’m Larissa Branin.
C.The
Health Effects Linked to Damp Buildings
Narrator:
What are the health effects linked to dampness
and mold? This is Science Today. Bill Fisk, head of
the Indoor Environment Department at the Lawrence
Berkeley National Laboratory, says the clear symptoms
are exacerbation of asthma in those who already have
the ailment, as well as other respiratory health symptoms.
Fisk:
Like cough, wheeze, nasal symptoms in ordinary
individuals and when dampness problems or visible
mold are present in buildings, the prevalence of these
outcomes – the fraction of people who have them that
live in buildings with these dampness and mold increases
substantially, for example by fifty percent.
Narrator:
Fisk was part of a national committee reviewing all
the scientific literature on dampness and mold growth
in buildings.
Fisk:
There’s also evidence of some other health
effects associated with dampness and mold, like the
development of asthma as a disease, rather than the
causing of symptoms in individuals, which is quite
a serious outcome, but we decided the evidence isn’t
conclusive there.
Narrator:
For Science Today, I’m Larissa Branin.
D.
Using Synthetic DNA to Treat Colitis
Narrator:
This is Science Today. When it comes to bacterial
compounds in the body, certain organs respond differently
than others. Eyal Raz, a professor of medicine at
the University of California, San Diego, explains
that the spleen for instance is geared to react to
bacteria in a ‘me’ versus ‘you’ fashion.
Raz:
Whereas in the colon, we respond to the bacteria more
in effect that it’s me and you, so there is room for
you, there is room for us. And this type of partnership
is called in biology ‘symbiosis’. Or, especially in
the gut, we call this bacteria commensal.
Narrator:
These bacteria are meant to live with us and not cause
problems because if they did, the consequence of responding
to any bacteria in the gut would be chronic inflammation
of the colon. That’s what happens to those who suffer
from Inflammatory Bowel Disease.
Raz:
So we identified a mechanism by which bacterial
product inhibit the host response towards inflammation
– that you can take bacterial DNA or synthetic DNA
that we make and treat colitis with that. We are preparing
to do clinical trial in the near future.
Narrator:
For Science Today, I’m Larissa Branin.
E.
The Potential of Nerve Growth Factor to Treat Alzheimer’s
Disease
Narrator:
This is Science Today. An experimental gene therapy
trial in which several Alzheimer’s patients had nerve
growth factor directly inserted into their brains
is promising. Dr. Mark Tuszynksi, who led the University
of California, San Diego trial, used PET scans to
track metabolic activity in the brain after treatment.
Tuszynksi:
Normally over the course of Alzheimer’s disease, as
the disease progresses, PET scan activity falls over
time. And in our patients, we saw the opposite sort
of effect. After undergoing the nerve growth factor
gene therapy in fact, PET scan activity increased
in the brain, showing that the cortex of the brain
was more metabolically active.
Narrator:
The researchers also discovered a robust growth response
to the delivered nerve growth factor.
Tuszynski:
This was very important – it established unequivocally
that growth factors delivered to the degenerating
Alzheimer’s disease brain can illicit a growth response
and that degenerating cells in the brain can recognize
and respond to growth factors.
Narrator:
For Science Today, I’m Larissa Branin.
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