单项选择题

TEXT D
Last year, when President George W. Bush announced that federal funds could be used to support re search on human embryonic stem cells, he mandated that only those cell lines that existed at the time would qualify for such support. More than a year later it’s becoming increasingly clear that these existing cell lines are inadequate. Unless more are created, the research slowdown may exact a staggering cost in terms of human suffering.
Since this announcement, the U. S National Institutes of Health has tried to stimulate research on the existing cell lines with new funding and efforts to streamline the initially cumbersome process of obtaining approved cells. However, whether there are 60 cell lines, as originally stated, or nine, as now appear to be available to NIH-funded investigators, the number is not adequate. Given the genetic diversity within the population, scientists need access to new cell lines if they are to come up with the most effective cell therapies.
The issue is partly one of safety. In conducting research with human participants, we must minimize risks. The most effective cell line might not be the safest. When developing a new medicine, a large number of molecules must be screened to find a balance between effectiveness and safety. The same is true with cells: In the context of cell therapy, it will be important to minimize unwanted immune reactions and inflammation. This requires selection from a large number of cell lines to obtain the best match.
It’s clear from experiments with animals that stem--cell therapies can reduce human suffering. Parkinsonian mice have been cured with embryonic stem cells that were programmed to become dopamine-secreting, replacement nerve cells. Soon, cells induced to make insulin in tissue cultures will be used in attempts to treat diabetic mice. Similar successes have been achieved in animal models of spinal cord injury, heart failure and other degenerative disorders. We are at a frontier in medicine where tissues will be re stored in ways that were not imaginable just a few years ago. The ethical issues raised by human-embryo research are profound. The human costs of restricting this research must be taken into account as well. The cost in dollars of delaying new stem-cell research is difficult to estimate. It might measure in the hundreds of billions of dollars, especially if one adds the lost productivity of individuals who must leave work to care for victims of degenerative disorders.
A less obvious, but real, cost is the damage to the fabric of America’s extraordinary culture of inquiry and technical development in biomedical science. Our universities and teaching hospitals are unparalleled. We attract the very best students, scientists and physicians from around the world. But these institutions are fragile. Research and education play key roles in attracting the best physicians. A crippled research enterprise might add an unbearable stress with long-lasting effects on the entire system. If revolutionary new therapies are delayed or outlawed, we could be set back for years, if not decades.
To steer clear of controversy, some investigators will redirect their research. Others will emigrate to countries where such research is allowed and encouraged. Some will drop out entirely. The pall cast over the science community could extend far beyond stem-cell research. Many therapies have emerged from collaboration between government-sponsored researchers and private enterprise. Few of these discoveries would have emerged ii, for instance, recombinant DNA research had been outlawed 30 years ago. We face the same type of decision today with limits placed on human embryonic stem cells.
Safeguards will be necessary. But if we do not proceed embracing the values of objective, open, inquiry with complete sharing of methods and results, the field will be left to less rigorous fringe groups here and abroad. Patients and society will suffer.
Which of the following statements about the research is TRUE