X-Message-Number: 25074
From: "Basie" <>
Subject: CI and Alcor can use such a device 
Date: Wed, 17 Nov 2004 20:19:21 -0500

Maybe CI and Alcor can use such a device (see below) to improve suspensions.

Basie

BOSTON (Reuters) - Just like a spoon is used to stir sugar into a cup of
tea, high-frequency sound waves may help doctors get rid of deadly blood
clots in the brain, according to a study released on Wednesday.









Researchers reported they were able to increase the efficiency of Genentech
Inc.'s clot dissolver t-PA by 63 percent by bathing the area in front of the
clot with ultrasound while the drug went to work.


In addition, the technique seemed to reduce the likelihood of brain
bleeding, a well-known risk of t-PA therapy.


"We break up clots faster, more efficiently and with less bleeding," said
Andrei Alexandrov, who led the study.


Although t-PA is very effective at dissolving clots, it doesn't work well if
blood isn't flowing. Ultrasound helps by creating turbulence in blood
trapped in front of the clot -- similar to the way a person might use a
spoon to add sugar to a cup of tea, Alexandrov said.


"If you don't stir, the sugar's going to sit there for a long time. But if
you stir, the sugar dissolves very quickly," Alexandrov, of the University
of Texas-Houston, told Reuters.


"In the same way, t-PA cannot get where it's supposed to be because the
fluid in front of the blockage is stagnant. So your ultrasound is like a
harmless spoon, and you can stir from a distance."


If proven effective in further tests, the technique could be used by most
hospitals, which already have ultrasound machines comparable to the ones
used in this study, he said.


However, ultrasound technicians would need a lot more training to locate
clots so that ultrasound probes can be positioned properly during treatment,
Alexandrov said.


The Alexandrov team studied clots in the middle cerebral artery, located on
each side of the head about an inch forward and up from the temple, and
about 5 centimeters (2 inches) below the skin. Clots at that site are
responsible for at least 80 percent of strokes, and 80 percent of the blood
flowing to a hemisphere of the brain flows through that artery.


After two hours, blocked arteries cleared in nearly a third of the 63
patients who got t-PA alone, and nearly half of the other 63, who also got
ultrasound, the researchers reported.


After three months, 42 percent of the ultrasound recipients and 29 percent
who got conventional care were doing well, but the number of patients
checked at the three-month mark was too small to be statistically
significant, which is why further tests are needed, they cautioned.


In a commentary in The New England Journal of Medicine (news - web sites),
where the study appears, Joseph Polak of Tufts School of Medicine in Boston
said the Alexandrov team has introduced "a new and exciting use of
diagnostic ultrasonography."


Clots are also a major problem in the heart, but the Texas researcher said
the technique was not tested there because the arteries in the heart move
too much compared to the brain.


"The brain is easier to target. That's why we made the first stab there," he
said.


A follow-up study, to involve about 550 volunteers, is expected to begin in
a year or two.

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