Just FYI, Alzheimer's is not a disease that is likely to be treatable -- at least not for a very long time -- by advances in stem cell research. Parkinson's is a disease where stalled stem cell research has almost certainly slowed progress on a cure.

OK, what population of young women will be providing eggs for the creation of research embryos? Are we willing to mine the bodies of our poorest female citizens in pursuit of (eventually) better babies through IVF?

Every embryo requires a human egg to be extracted from a young, fertile woman. To produce the many thousands of embryos needed for research, scientists will need thousands of young women to undergo the same complex, painful and risky procedure of egg extraction that IVF patients undergo.

On International Women's Day this year in March, women's health advocates held a symposium on the traumatic implications of widespread egg extraction for research. A You Tube video "Trading on the Female Body" (http://youtube.com/watch?v=Fyw3YYejMLg ) summarizes that symposium. One of its most powerful testimonies comes from a woman whose daughter died from Ovarian hyperstimulation syndrome (OHSS) while undergoing egg extraction as an IVF patient.

What will happen when ovarian hyperstimulation moves beyond the comparatively small population of women who do it in hope of having a child, to the wider population of women who will endure the ordeal from economic necessity? Where will scientists obtain the eggs for experimentation?

IVF clinics regularly recruit egg donors from college campuses because eggs from young, fertile, white women are what the mostly-white, mostly well-educated, mostly middle-to-upper class women who want an IVF baby are looking for. Young women see their $5000 "stipend" as a good trade-off for the risk of OHSS and the danger to their own future fertility.

But embryo research, unlike IVF, has no requirements for egg donors to be white, long-legged, cute and collegiate. Research only requires that the donors/vendors be young, fertile and willing to undergo hyperstimulation. It is doubtful that experimental scientists will likewise pay $5000 a try to get donor eggs, especially when the embryo will be killed at, say, 14 days.

So where will researchers find a population of young women happy to donate eggs at a cut-rate price? People on both sides of the issue believe that poor and minority women will be a much-desired target population for the harvesting of eggs. Poverty lowers the threshold for selling a precious resource. That's why paid blood donors are generally from the poorer populations.

If you need thousands of eggs to use and then quickly dispose of, and you can't pay top dollar because you don't have desperate, wealthy couples, you only have scarce research money, where will you court egg donors? It's a no-brainer. You will look for egg donors among the young women who are poorest, most vulnerable, and most willing to undergo the procedure, who don't know much, if anything, about OHSS, and will not ask complex questions about risks vs. benefits..

Are we willing to look at the race and class implications here? Black embryos (lots of them, and cheap) for research, for the eventual benefit of white embryos (fewer and much more expensive) for IVF?

Are we willing to mine the bodies of the poor in order to perfect our lab techniques for the reproductive ambitions of the rich?