Make us your home page

Today’s top headlines delivered to you daily.

(View our Privacy Policy)

Stem cells may not help fight off Parkinson's

TAMPA — Fifteen years later, scientists are still learning from a woman who risked her life to be part of a controversial experiment to treat Parkinson's disease with fetal cells implanted in her brain.

The woman died last year, and an autopsy surprised scientists. The transplanted cells showed unmistakable signs of Parkinson's. That means the disease is able to spread inside the brain, migrating from the woman's own cells to the transplanted ones.

It also raises questions about whether stem cell transplants could become the best treatment for Parkinson's, because the disease might spread to affect the new cells.

The study was published online Sunday in the journal Nature Medicine. It's the latest result from a controversial trial with surgeries performed at the University of South Florida by Dr. Thomas Freeman, medical director of the Center of Excellence for Aging and Brain Repair.

"We have learned a lot about Parkinson's itself," Freeman said. "This type of trial is a road map for how to make stem cell therapies, when they become available, even better."

Parkinson's affects part of the brain that controls movement. Brain cells that produce a chemical called dopamine die or don't work properly. People with Parkinson's may have uncontrolled movement, such as trembling, or difficulty moving, with stiffness, slowness and poor balance.

The study transplanted brain cells of aborted fetuses into the brains of Parkinson's patients. The woman in the most recent study was 61 when she underwent surgery in 1993. She had had Parkinson's for 22 years.

After surgery, she had fewer motor control problems and needed less medicine until 2004, when her health again began to decline.

Unlike later patients of Freeman, this woman knew she had surgery. In the later research, Freeman did "sham" surgery on some patients, drilling holes part way into their skulls. He then did real transplants on other patients, but neither they nor their doctors knew which were which.

Some patients improved after the treatment, but some got worse. Overall, it didn't show a benefit. Future research in this area would likely be with stem cells, rather than fetal cells, scientists say. Although embryonic stem cells get the most attention, stem cells come from many places in the body. They can transform themselves into almost any type of cell.

Still, the latest results may help researchers learn more about what causes Parkinson's.

"There's something in the brain of a Parkinson's patient that is chronically there, and that is killing the cells of Parkinson's patients," said Jeffrey H. Kordower, neurological sciences professor at Rush University Medical Center, the study's lead author.

It also shows that genetics has a limited influence on Parkinson's, since the transplanted cells don't share the same genes as the original ones.

The results also argue against another theory. Some scientists have theorized there is one original event that happens to Parkinson's patients, something that kills dopamine-producing brain cells, but doesn't show until years later, as the brain ages and naturally produces less dopamine.

Since the damage seems to keep spreading, that theory seems less likely, Freeman said.

Researchers acknowledged that the results might show limits on stem-cell transplants, if those cells can be damaged.

But Freeman said he thinks stem cell transplants still hold promise for Parkinson's. After all, this patient did well for a decade, he said.

"The possibility exists of a repeat transplant 10 to 12 years later," he said. "Expecting long-term efficacy forever may be overly optimistic. But meaningful benefit for a decade may be realistic."

Lisa Greene can be reached at or at (813) 226-3322.

Stem cells may not help fight off Parkinson's 04/06/08 [Last modified: Wednesday, April 9, 2008 8:32pm]
Photo reprints | Article reprints

© 2017 Tampa Bay Times


Join the discussion: Click to view comments, add yours

  1. Police: Uber driver's gun discharges during fight at Adventure Island in Tampa

    Public Safety

    TAMPA — An Uber driver's gun went off Sunday at Adventure Island during a fight between the driver and two passengers.

  2. Baker cautious on Pride politics


    Rick and Joyce Baker strode down Central Avenue Sunday amid rainbow flags, corporate booths, and blaring music of the St. Pete Pride Festival.

    St. Petersburg mayoral candidate Rick Baker chats Sunday with people at the St. Pete Pride Festival. As mayor, Baker did not sign a Pride parade proclamation, but now he says he would.
  3. Rays' bullpen stars lit up in loss to Orioles

    The Heater

    ST. PETERSBURG — Saturday it was the soft underbelly of the bullpen that let one get away from the Rays, incurring the wrath of the team's faithful followers, who wondered why the high-leverage guys weren't pitching.

    Rays closer Alex Colome, coming in with the score tied in the ninth, allows three runs in his second straight poor outing.
  4. Lightning among early suitors for defenseman Kevin Shattenkirk

    Lightning Strikes

    TAMPA — Lightning general manager Steve Yzerman said he planned to explore free agency for potential needs, which include bolstering his blue line and adding a wing or two.

    Defenseman Kevin Shattenkirk, who can be a free agent Saturday, counts the Lightning among his early suitors.
  5. Senate leaders try to appease members as support for health bill slips


    WASHINGTON — Senate Republican leaders scrambled Sunday to rally support for their health care bill, even as opposition continued to build outside Congress and two Republican senators questioned whether the bill would be approved this week.

    Sen. Rand Paul of Kentucky, speaking to reporters on Capitol Hill on Thursday, is one of the five Republican senators who announced they cannot support the health care bill as drafted.