HOLLYWOOD SCIENCE.(Proposition 71 and the debate on embryonic stem cell research)

Addressing a state legislative committee hearing held in San Diego on September 15th, a young research scientist named Hans Keirstead declared, "Maybe every hundred years we have one major milestone in medical research." This was such a moment, he said. The committee, chaired by State Senator Deborah Ortiz, was hearing testimony on Proposition 71, a ballot initiative that would result in the state's investing about three billion dollars in stem-cell research over the next decade. Stem cells are undifferentiated cells that have the capacity to renew and develop into other types of cells. Prompted by research restrictions on embryonic stem cells imposed by the Bush Administration and by threats from its allies in Congress, the initiative constitutes a breathtakingly large debt for California's taxpayers, particularly in light of the state's continuing budgetary crisis and cuts in education, health care, and public safety. According to a Field poll published in August, forty-five per cent of California voters favored the initiative and forty-two per cent opposed it. Keirstead's real audience at this hearing, therefore, was not its presiding officials but the rows and rows of public spectators in the big, packed hearing room and the cameras from a half-dozen TV networks.

Critics of embryonic-stem-cell research often accuse its supporters of promising imminent cures that are at best years away, if feasible at all. Keirstead, whose tanned skin, wavy, sun-streaked hair, and stylish suit hardly suggested a specialist in the study of spinal-cord injuries or days spent in subterranean quarters at the University of California at Irvine with hundreds of caged animals, showed a video in which he attempted to counter such charges. In one scene, a small gray rat struggles to move forward, dragging itself by its front paws. The next scene, Keirstead explained, would show a rat that had suffered the same spinal-cord injury but had received a transplantation of human embryonic cells that had been directed to differentiate into oligodendrocytes, a particular type of brain cell. As Keirstead had told me earlier, the very quality that epitomizes the promise of embryonic stem cells--their amazing plasticity--can also be their great failing ("Just stuff stem cells into a brain lesion with a scar, and the cells will make scar tissue"). He had succeeded, he said, in promoting the differentiation of the stem cells into precisely what he wanted--oligodendrocytes, in high purity. And, in the next clip, the rat appears--walking! Its tail lifted! Keirstead predicted that sometime in 2006 there would be a clinical study involving humans with spinal-cord injuries.

Scientists have studied embryonic stem cells from mice, in culture, for decades, but it was only six years ago that James Thomson, a researcher at the University of Wisconsin, was able to isolate and maintain human embryonic stem cells in a similar way. Some of the hope currently fixed on these cells is based on the far more extensive history of adult stem cells, which are found in fetuses, umbilical-cord blood, children, and adults. Hematopoietic stem cells, for example--the blood-forming cells found mainly in the bone marrow, and discovered about forty years ago--were the first stem cells to be used successfully in blood-disorder and cancer therapies, such as bone-marrow transplants. Some researchers believe they may have the potential for more wide-ranging treatments. But adult stem cells are present only in minute quantities in the body, they are difficult to isolate successfully, and--thus far--it has been nearly impossible to grow them outside the body.

Embryonic stem cells, however, are capable of becoming almost any type of cell or tissue, and they are self-renewing, whether in the body or in the laboratory. They are found in embryos about five days after fertilization, when the embryo becomes a shell called a blastocyst, comprising about two hundred cells; if removed from the blastocyst and placed in a culture dish under the right conditions, these cells become a stem-cell line, which continues to propagate indefinitely in the laboratory, and--scientists believe--can be directed to produce large amounts of tissue. Thus, embryonic stem cells appear to have unique potential to lend themselves to a broad array of disease therapies, creating new healthy tissue to replace damaged or dead tissue, such as pancreatic islet cells for Type 1 diabetes, or various neuronal cells for spinal-cord injuries, A.L.S., and Parkinson's disease.

But the very quality that embodies such promise--the capacity of the stem cells to form any tissue--derives from these cells' representing, if only as a microscopic dot, life's origins. And removing the cells from the blastocyst to create a self-renewing stem line destroys the embryo. The Catholic Church and some other religious institutions, therefore, oppose embryonic-stem-cell research. And in August, 2001, President Bush announced that he would allow federal funding only for research on embryonic-stem-cell lines already cultivated in laboratories, and he prohibited funding for the development of new lines, which would require the destruction of additional embryos.

This fractious conflation of science, religion, and politics had brought a dramatic cast of characters to the San Diego hearing room. The president of the "No on Prop 71" campaign, an emotive physician named Vincent Fortanasce, reviled embryonic-stem-cell research as something that would cause far more disease than it cured, since under certain conditions embryonic stem cells can give rise to tumors. He also swore that its technology would lead inevitably to the cloning of human beings. "This is what we would call a clone-and-kill bill!" he exclaimed. "It will make California the mecca of cloning and irresponsible medicine . . . and keep us in budgetary crisis for twenty-five years!"

Although Fortanasce is a devout Catholic, he did not make a pro-life argument. He and other opponents of Prop 71 emphasize that their coalition includes fiscal conservatives and pro-choice feminists; their lead lobbying group is called Doctors, Patients, and Taxpayers for Fiscal Responsibility. But I had interviewed Dr. Fortanasce a couple of weeks earlier, and he told me, "If you want to know who is organizing this, it is the Catholic Conference. I wouldn't want you to find that out later and feel I'd misled you."