An experimental treatment for Parkinson’s disease
seemed to improve symptoms—dramatically so, for one 59-year-old man—without
causing side effects in an early study of a dozen patients. The gene therapy
treatment involved slipping billions of copies of a gene into the brain to calm
overactive brain circuitry. More than half a million Americans have Parkinson’s.
They endure symptoms that include tremors, rigidity in their limbs, slowness of
movement and impaired balance and coordination. Eventually they can become
severely disabled.
The small study focused on testing the
safety of the procedure rather than its effectiveness, and experts cautioned
it’s too soon to draw conclusions about how well it works. But they called the
results promising and said the approach merits further studies. "We still have
quite a bit more testing to do," said Dr. Michael Kaplitt of Weill Cornell
Medical College in New York, an author of the study. Still, "the initial results
are extremely encouraging".
Nathan Klein, a 59-year-old
freelance television producer in Port Washington, N.Y., said the disease left
him "pretty messed up". It weakened his voice, impaired his walking and made his
hand tremble so badly he couldn’t hold a glass of wine without spilling it all.
Klein was the first patient to be treated with Kaplitt’s gene therapy procedure
in 2003, and he said his symptoms gradually subsided afterward. Nowadays, he
said, apart from freezing now and then when he wants to walk, the symptoms are
basically gone. "I’m elated," said Klein, who continues to take his regular
pills for the disease. "It’s unbelievable."
Kaplitt, who has a
financial interest in Neurologix Inc., which paid for the research, noted that
the 12 patients in the study still have Parkinson’s symptoms. The amount of
medication they were already taking for their symptoms didn’t change
significantly in the year after the surgery. Current medicines can control
symptoms, but can’t stop the disease from getting worse over time, and they can
produce troublesome side effects like uncontrollable movement.
Some patients gain relief from a surgical treatment called deep brain
stimulation, in which electrodes are placed in the brain and connected to a
programmable stimulator. Kaplitt’s procedure was aimed at achieving the same
goal as that surgery, calming overactive circuitry in the brain. It gets
overactive because it loses the normal supply of a chemical called GABA. The
gene therapy was designed to make the brain produce more GABA.
For the gene therapy surgery, a tube about the width of a hair was threaded
through a hole about the size of a quarter at the top of the skull. The tube
delivered a dose of a virus engineered to ferry copies of a gene into cells of a
brain region called the subthalamic nucleus. The gene copies enable the cells to
pump out more GABA.The passage is mainly about ______.
