Wednesday, December 17, 2008

The Quest for Pluripotency

Mark Johnson of the Milwaukee Sentinel Journal has just published a three-part series on the global quest by stem cell scientists for pluripotent stem cells. The series, "Targeting the Good Cell," appeared in the Sentinel Journal on December 13-16. Based on 90 interviews with leading scientists, this is one of the best pieces of science journalism I have seen.

The story involves the question for the human pluripotent stem cell, which is capable of producing every cell type in the human body. In 1998, scientists achieved this long-sought goal, but did so by taking cells from embryos, something that is objectionable to many. More recently, scientists have found other ways to get cells to be pluripotent, and Johnson tells the tale as if it were the story of a great race.

In telling the story, he reminds us that science is hard work, that scientists are human, that they are motivated (like all of us) by many things, and that the result of their work is anything but predictable at the outset.

Journalism, too, can be hard work, and Johnson has done it well.

Friday, December 12, 2008

Dignitas Personae: Theology and Stem Cell Research

The long-awaited Vatican Instruction, Dignitas Personae, was released today. It is a complex document that will require careful analysis. For instance, compared to Donum Vitae, does Dignitas assert that an embryo is a person from conception, something that Donum avoided asserting? Both agree, of course, that the embryo must be respected morally as a person from conception.

Two points stand out for me on my first reading. They concern Germline Modification and Altered Nuclear Transfer.

Regarding human germline modification, Dignitas is decidedly more negative compared to other recent Vatican statements. According to Dignitas, gene therapy that affects only the patient--"somatic cell gene therapy"--is acceptable. However,

The moral evaluation of germ line cell therapy is different. Whatever genetic modifications are effected on the germ cells of a person will be transmitted to any potential offspring. Because the risks connected to any genetic manipulation are considerable and as yet not fully controllable, in the present state of research, it is not morally permissible to act in a way that may cause possible harm to the resulting progeny. In the hypothesis of gene therapy on the embryo, it needs to be added that this only takes place in the context of in vitro fertilization and thus runs up against all the ethical objections to such procedures. For these reasons, therefore, it must be stated that, in its current state, germ line cell therapy in all its forms is morally illicit.

This rather bleak statement is in clear contrast to a previous Vatican statement entitled "Communion and Stewardship: Human Persons Created in the Image of God," which stated:

Germ line genetic engineering with a therapeutic goal in man would in itself be acceptable were it not for the fact that is it is hard to imagine how this could be achieved without disproportionate risks especially in the first experimental stage, such as the huge loss of embryos and the incidence of mishaps, and without the use of reproductive techniques. A possible alternative would be the use of gene therapy in the stem cells that produce a man’s sperm, whereby he can beget healthy offspring with his own seed by means of the conjugal act.

What is remarkable about the "Communion and Stewardship" text is that the statement actually suggested a way forward for research that could lead to a Vatican-approved approach to human germline modification. What is even more remarkable is that because of recent advances in stem cell research, especially induced pluripotency, research someday may actually achieve success in meeting the previously stated Vatican requirements. Now, however, Dignitas seems to back away from the previous endorsement. For more on this, see my recent book, Design and Destiny, from MIT Press.

The second issue has to do with "Altered Nuclear Transfer" (ANT), a provocative proposal that was seriously debated by the US President's Council on Bioethics. The idea, as championed by Bill Hurlbut, a member of the Council, was to create an "artifact" that might provide embryonic stem cells without being an embryo. The hope of the advocates of ANT was that those who oppose embryo research would see ANT as creating something that was decidely not an embryo and therefore an acceptable object for research. Now the Vatican has raised doubts:

These proposals [explicitly including ANT] have been met with questions of both a scientific and an ethical nature regarding above all the ontological status of the "product” obtained in this way. Until these doubts have been clarified, the statement of the Encyclical Evangelium vitae needs to be kept in mind: “what is at stake is so important that, from the standpoint of moral obligation, the mere probability that a human person is involved would suffice to justify an absolutely clear prohibition of any intervention aimed at killing a human embryo”.

If the Vatican has its doubts, then it's not clear who ANT is meant to placate. Sure, some individuals will say they oppose embryo research but find ANT acceptable. But the big institutional player, the Vatican, has just raised serious doubts and then asserted that doubt means no. As usual, the National Catholic Reporter provides a nice discussion of these issues, including quotes from Hurlbut.

Personally, I have never been a supporter of ANT, but I feel sorry for its advocates, who made the proposal in good faith in hopes that individuals and institutions would see it as a way around the difficult question of the use of the human embryo in research.

Thursday, December 11, 2008

Enhancing Cognition

The journal Nature has just published a helpful Commentary on cognitive enhancement. Henry Greely and his co-authors describe the widespread use of prescription drugs--often traded illegally on campus across the US--to enhance memory and other core cognitive functions.

Among the drugs being used? Ritilan, Adderal, Aricept, and a relative newcomer, modafinil (Provigil). Each of these drugs has a therapeutic use, but many also use them to enhance their performance rather than treat their disease.

Essentially the authors argue that such self-experimentation should be brought out of the shadows of illegality and into the light of "an evidence-based approach to the evalution of the risks and benefits of cognitive enhancement."

In other words, there is nothing intrisically immoral about using such drugs for enhancement, nothing that requires law enforcement, at least. Of course, no one (including soldiers) should be forced to use these drugs, the authors argue. But neither should the drugs be relegated to an illegal market. Those who wish to use them should have access to the best information about the effectiveness and their possible side effects, and they should be able to contribute to that knowledge base without fear of jail.

Enhancing cognition by eduction is something nearly everyone values. Enhancing mental ability by technology--in this case by prescription drugs--is another question. But what's the difference, and does the difference in method make a difference in morality?

Sure, a pharmaceutically-enhanced mind might become smarter, but it's not likely to become more wise or more ethical. So for a long time, there will probably be an enhanced level of wisdom and understanding that is beyond the reach of technology and can only be attained by classical education, meditation, or deeply reflective thought.

On another subject, the Vatican is about to release a new statement on embryo research and stem cell ethics under the title, Dignitas Personae or "The Dignity of Persons." The document itself is embargoed until 6 am eastern time, 12 Dec 08. But the initial buzz is that it is less open than other recent Vatican statements about the possibility of human germline gene therapy and that it is morally apprehensive about "Altered Nuclear Transfer," championed by Bill Hurlbut of Stanford University as a way to derive human pluripotent stem cells without using embryos. We'll see what the document says.