From: Science Now
NewHope for Manganese Toxicity
by Greg
Miller
on
9 June
2006,
12:00 AM
Off
target.
In a still from a video shot in 1987, the manganism patient misses the tip of her nose.
In a still from a video shot in 1987, the manganism patient misses the tip of her nose.
Credit:
Wei Zheng
A
chemical cousin of aspirin may help treat neurological problems
caused by exposure to high levels of manganese metal,
according
to a dramatic case study in this month's Journal
of Occupational and Environmental Medicine.
If the results hold up in larger trials, the drug could provide the
first effective treatment for thousands of workers exposed to high
levels of manganese through mining, steel production, and other
occupations.
Neurological
problems associated with high-level manganese exposure have been
noted since the 1800s. Exposed workers often exhibit tremors,
rigidity, and coordination problems strikingly similar to those
observed in Parkinson's disease. (A debate simmers about whether
long-term exposure to low manganese levels can cause similar
problems--see Science,
21 May 2003). Yet Parkinson's drugs such as levodopa have little
effect in people with manganism; the same goes for compounds that
help the body rid itself of manganese.
That's
why the new findings are so promising, says
Wei Zheng of Purdue University in West Lafayette, Indiana. He and
colleagues in Italy and China have followed the case of a Chinese
woman who worked for 19 years at a manganese milling facility. She
was hospitalized several times in the 1980s. In videos taken in 1987,
her movements are unsteady and halting, and she struggles to touch a
finger to the tip of her nose and perform other simple tasks. Then,
over 3 months, she received an experimental treatment of 15
intravenous infusions of para-aminosalicylic acid (PAS), a relative
of aspirin that is used to treat tuberculosis. Nearly all of her
symptoms disappeared and she has remained healthy ever since, Zheng
and colleagues report. "The video speaks for itself," Zheng
says. He adds that he and colleagues have tried PAS in 85 additional
patients in China. The drug seems to help about two-thirds of them,
he says, but so far those results have only appeared in
Chinese-language journals.
It's
not clear how PAS works, Zheng says, but one possibility is that it
sops up manganese and clears the metal from the brain more
effectively than the drugs that have been tried previously. Or it may
have anti-inflammatory properties that protect neurons.
"The
results are very impressive," says Michael Aschner, a
neurotoxicologist at Vanderbilt University in Nashville, Tennessee.
Even so, Aschner cautions that large-scale trials will be needed to
determine whether PAS is an effective treatment for manganism.
Related
sites
·
Zheng's
Web site, with videos of the patient
WEBSITE
INACTIVE
No comments:
Post a Comment