Alternatives to Embryo-Destructive Research
Date: April 09, 2007
Time: 9:05am est

As I mentioned in an earlier post , the U.S. Senate is expected to debate and vote on two different bills about stem cell research this week: S.5 , which proposes to broaden federal funding for embryo-destructive stem cell (ESC) research, and S.30 , which seeks to direct federal funding to research on alternative sources of embryonic-like stem cells, alternatives that do not involve the creation, damaging or destruction of human embryos.

The alternatives bill, S.30, provides for innovative research on stem cells, "whether or not they have an embryonic source," as long as obtaining such cells does not involve the creation of embryos for research purposes, or "the destruction or discarding of, or risk of injury to a human embryo or embryos other than those that are naturally dead."

This post is part of short series of posts I am dedicating to explore in greater detail a couple of these alternatives. I've already written about one of these, namely, direct cell reprogramming. Today I want to explore the concept of removing single cells from "naturally dead" embryos obtained from in vitro fertilization (IVF) clinics.

This method was first proposed by Drs. Donald Landry and Howard Zucker (both of Columbia University ) in a paper in the Journal of Clinical Investigation.

Their proposal rests on the scientific possibility of deriving new lines of human embryonic stem cells from just a few cells extracted from these "dead" embryos. The proposal also hinges on the close association of the concept of removing cells from "naturally dead" embryonic human beings, and the concept of organ donation from deceased, fully developed human beings.

But how would we determine whether left-over IVF embryos have, in fact, expired, and how would we distinguish them from those embryos that are simply doomed or already in a process of dying? The Landry/Zucker proposal formulates a notion of embryonic (natural) death drawing on the criteria for assessing death of a developed human. Fully developed human beings are normally considered dead when they have irreversibly lost the capacity for integrated organic body function. The commonly accepted indicator of this loss is "brain death" or the complete cessation of all spontaneous brain activity. And while brain death may come about (marking the consequent loss of a capacity for integrated body function), millions of cells and any number of whole organs remain alive.

Landry and Zucker's proposal is that an embryo is naturally dead when the embryo has irreversibly lost the capacity for integrated cell division , even if some of the individual cells are alive.

Dr. Landry spoke to Senate staff last week as part of a briefing sponsored by the Westechester Institute. He noted in his presentation that current research has shown that no embryo that has been arrested (ceased cell division) for more than 48 hours ever recovered. Concluding that such arrest is irreversible , Landry posited that this marks the threshold for meeting the criteria for natural embryonic death: irreversible loss of integrated organic function, indicated by a 48-hour period of cessation of cell division.

Notwithstanding some ethical concerns that still require further reflection, along with many other Catholic ethicists I am hopeful that those concerns can be allayed, and that the Landry/Zucker proposal will quickly move into the mainstream as an ethically and scientifically viable alternative to embryo-destructive research.

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