送交者: 泰粗 于 March 19, 2002 11:51:28:
⒈明尼苏达那帮研究者正在四处找钱，包括ＮＩＨ。不象是很热门的东西。
⒉记者下面这段话，尤其最后一句，很让人费解，
So far, Steer and his colleagues have discovered that TUDCA easily crosses
the blood-brain barrier, which is key to treating brain diseases. And because
it occurs in extremely small amounts in human gallbladders, the molecule
triggers few, if any, side effects.
那分子在人胆中极少，是人体就需要那么多，而且它活动区域就那么几个器官，其中肯定
没有脑。从这前提，记者愣能推出个把那分子弄到脑子里几乎不会有付作用，是不是有点
跃迁得太厉害了。不是他弱智，就是我糊涂。他弱智的几率更大。
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Posted on Fri, Mar. 15, 2002
Bile of black bears may bring a boon for stroke victims
BY TOM MAJESKI
Pioneer Press
Gall bladders of black bears have been highly prized by the Chinese for the past 500 years. Buyers on the black market have paid up
to $18,000 for a single gall bladder, believing that the bile inside cures everything from headaches and warts to a lack of sexual
prowess.
It turns out the Chinese are on to something.
Researchers at the University of Minnesota have found that a bile acid found in heavy concentrations in black bear gall bladders can
reduce brain damage by more than 50 percent in stroke-impaired laboratory rats.
What's more, the researchers believe the bile molecule, called tauroursodeoxycholic acid, or TUDCA, also may be beneficial in
treating Parkinson's disease, Huntington's disease, Alzheimer's disease, spinal cord injuries and hemorrhagic strokes. "The beauty of
the bile acid is that it doesn't have any side effects,'' and it also is able to cross the blood-brain barrier, said Dr. Clifford Steer, a
professor of medicine, genetics and cell biology and director of the Molecular Gastroenterology Program at the University of
Minnesota Medical School.
While preliminary results from various TUDCA studies are exciting, Steer said he and his colleagues so far have been unsuccessful in
persuading pharmaceutical companies to fund expensive clinical trials involving humans. A major reason for their reluctance, he said,
is that the patent has expired on the molecule, which reduces the likelihood that research investments would translate into attractive
profits. "But with this paper and the Huntington's study coming out, we may get some interest from the private sector,'' Steer said.
"If not, we may go to the (National Institutes of Health) for funding. We are not going to let money stop us from proceeding.''
While the Chinese use bear bile to treat a number of conditions, American doctors so far only use the TUDCA molecule to treat
primary biliary cirrhosis, a liver disease that affects mostly women. The molecule helps control the disease by preserving liver cells.
So far, Steer and his colleagues have discovered that TUDCA easily crosses the blood-brain barrier, which is key to treating brain
diseases. And because it occurs in extremely small amounts in human gallbladders, the molecule triggers few, if any, side effects.
The researchers also have figured out the mechanism that makes the molecule so effective: It protects brain cells by preserving the
integrity of the membrane that surrounds mitochondria, which are tiny, organ-like particles floating inside cells that, when injured,
trigger cell death.
In one of their latest studies, which will be published early next month in the Journal of Cerebral Blood Flow & Metabolism, Steer
and his colleagues mechanically induced strokes in laboratory rats.
An hour after the strokes were induced, the researchers injected some of the rats with TUDCA and the rest with a neutral
substance. Two days later, the rats were tested for neurological deficits. Some rats from both groups were then euthanized and their
brains tested. The rest were euthanized seven days after the study began and their brains also were analyzed.
Among other things, the researchers found that rats treated with TUDCA suffered less serious neurological deficits from their strokes
than those in the control group. They also found that brain damage in treated rats was more than 50 percent less than damage in
untreated rats. What's more, the difference was consistent for the entire seven-day period, indicating the cell protection process was
not just a temporary phenomenon.
"This is the first time anyone has taken a nontoxic bile acid to preserve brain cells after stroke,'' Steer said.
Potential implications from a 50 percent reduction in brain damage are enormous, Steer said. "A 10 percent reduction in damage is
the difference between a patient walking out of the hospital or being pushed out in a wheelchair."
Steer and his colleagues now want to determine how long it takes for cells to die after a stroke so they know how soon the
medication has to be delivered to protect brain cells from injury. "We don't know whether it will work six hours after a stroke. Is
there a gray zone? Probably,'' he said. "Maybe the cell wants to die but the TUDCA gets there to save the day and protects the cell
from the insult.''
The research team's next paper, which probably will be published in the May issue of the journal Cell Transplantation, discusses
TUDCA's impact on Parkinson's disease. "The results are really quite startling — and very positive, of course,'' Steer said.
In that study, Steer's colleague, Dr. Walter Low, a professor of neurosurgery at the university, found that TUDCA-treated
dopamine-producing cells transplanted in the brains of rats had double the survival rate of nontreated cells.
Although the results are preliminary and must undergo a peer-review process before they are published, Low said, "We're very
impressed by the ability of this bile acid to prevent the loss of nerve cells in the brain.''
Steer and his colleague also are submitting a Huntington's study to a medical journal that shows the bile acid protects cells in the
area of the brain decimated by the deadly genetic disease. "I can guarantee you it will generate a lot of excitement because there is
nothing out there'' in the way of treatment, Steer said. The university researchers also are planning to feed TUDCA-laced food to
transgenic Alzheimer and Huntington's mice. "By feeding them this stuff from the get-go, can you see a delay in development of
their disease? If you can, people will be rushing to take these pills," Steer said.
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Tom Majeski, who covers medical news, can be reached at tmajeski@pioneerpress.com or (651) 228-5583.