What is the responsibility of a company sponsoring a clinical trial when one of its participants gets sick? That's the theme of a story in today's Wall Street Journal. As Sarah Rubenstein reports, the family of a woman who took part in a clinical trial of a drug for Parkinson's disease is suing the sponsors and university organizers of the trial. They say the trial -- in which doctors implanted a drug called Spheramine into her brain -- is responsible for the fact that the woman is ''wheelchair-bound and living in a nursing home.''

Rubenstein writes that the case is in a legal void surrounding clinical trials. ''Federal law does not require researchers to compensate participants harmed in such trials,'' she notes. All the law requires is that consent forms say whether participants will get compensation for research-related injuries.

The question of trial sponsor responsibility was also the question that drove my reporting of a story that ran in our January issue about Doug Bergman. In August 2006, Bergman had a needle filled with either saline or his own stem-like cells plunged into his heart. The intervention was part of a Baxter-sponsored phase 2 trial of stem cells for the treatment of myocardial ischemia.

Now Bergman has leukemia. It's entirely unclear whether Bergman's treatment -- which included five days of G-CSF to boost his white cell count, and therefore CD34+ ''stem cell-like'' count -- had anything to do with his cancer. Just as in the case of the woman in the Parkinson's trial, it would be very difficult for Bergman to prove that the trial was responsible for his leukemia.

What puzzled me, though, was that Baxter wouldn't tell him what he'd received in the double-blinded, placebo-controlled study, nor would they give him the frozen cells that were stored in Minneapolis. One of the treatments for the kind of leukemia Bergman has is in fact stem cells. Baxter's own protocol noted several circumstances that would have prompted the release of that information, including hospitalization and medical emergency. Both fit the bill, but Baxter hasn't budged.

When I asked Bergman in October whether he had considered suing, he said he wasn't thinking about it yet, and that he wanted to spend his energy fighting his leukemia. He's still fighting. His leukemia is in remission at this point, according to his oncologist, Ralph Levitt, but he's undergoing what's known as consolidation chemotherapy, with the same drugs he's had before. That chemotherapy, says Levitt, is ''tough,'' and the danger is that blood counts fall dramatically, making Bergman vulnerable to infection and bleeding.

Unfortunately, as Bergman's sister told me this weekend, one of the drugs he was getting to boost his white blood counts -- a cousin of the G-CSF he received during the trial -- was taken off the market last week. It's yet another trial for a man who has volunteered for two clinical trials in less than five years.