Fetal-cell recipient showing improvements.

Fetal-cell recipient showing improvements

A tiny sample of human fetal cells transplanted into the brain of a man with Parkinson's desease appears to have survived and grown there for at least eight months, significantly reducing his symptoms, European researchers report.

The 49-year-old Swedish man's improvement contrasts with two disappointing attempts by the same researchers, who attribute their latest results to changes in surgical technique. The accomplishment "supports the idea that neural grafting can be developed into an effective therapy in Parkinson's disease," they conclude.

Several U.S. neuroscientists told SCIENCE NEWS that the report -- the most complete analysis of a successful fetal graft to appear in a scientific journal -- still falls short of proving the procedure's ultimate value. But they add that further technical improvements may well lead to more definite successes, which would almost certainly complicate the already heated debate about the ethics of the controversial procedure.

In the Feb. 2 SCIENCE, Olle Lindvall of the University Hospital in Lund, Sweden, Anders Bjorklund and nine others describe the surgery, performed last March. They used 60 microliters of fetal tissue retrieved from four fetuses aborted in the first-trimester. In this latest attempt, the team used a smaller tool to implant the fetal tissue and shortened the interval between tissue retrieval and transplant.

Two months later, the patient showed reduced rigidity, improved motor function and less need for medication, the researchers report. In the months since, he has maintained these improvements. Brain-imaging PET scans performed five months after surgery indicated the fetal cells were alive and producing the neuro-transmitter dopamine, which is in short supply in Parkinson's patients.

However, notes neuroscientist Curt Freed of the University of Colorado Health Sciences Center in Denver, "PET scans are very difficult to interpret, especially with the small changes seen in these transplants." He and others say researchers need even more refined tests to measure survival of grafted cells and to show that any clinical improvement results from those cells. Some experiments in animals have hinted that the trauma of brain surgery itself can spur new growth of dopamine-secreting neurons.

Despite such caveats, the work is "quite exciting," says Irwin Kopin, a neuroscientist whose unprecedented request in 1988 to perform a similar operation at the National Institutes of Health led to a ban on U.S. federal funding for human fetal cell transplants.