August 04, 2005

Ethics of harvesting cells and tissue from embryos


Slate.com recently had a five-part series on the ethics and science of harvesting cells and organs from embryos. Slate's site is so slow, so I tried to write a summary as briefly as possible.

The cells used for stem cell research are currently harvested from embryos of up to 14 days development. This limit was based upon a number of factors, but the most important factor was that 14 days seems like a conservative limit, yet it was convenient for researcher. Stem cell research is making progress, but scientists have found that it is much easier to culture cells, tissue, or organs that have already differentiated. In other words, you can make a better kidney for a kidney transplant from more mature fetal kidney cells than from stem cells. So, the article asks whether we should push the 14-day limit forward, while at the same time asking whether we were just fooling ourselves with the justification for the 14-day ethical limit.

The principles for defining the time limit were individuality, organization, implantation, and neural development. Individuality is the point at which we can be sure an embryo will not become twins. The author, William Saleton points out that this is fairly meaning meaningless, because destroying an embryo lacking individuality just means that you are destroying an embryo that might actually be two embryos. The next principle, organization means the point at which we can see structure in the developing cells. This is another fuzzy line because finding organization is a question of “what are you looking for?” and “how hard are you looking for it?” The next principle, implantation, is the point at which a normal embryo becomes implanted in the womb. This is used as a principle because embryos lack the potential to become adults until they are implanted into the womb. But this principle is also wanting, because implanted embryos are closer to mature human life, but embryos not yet implanted nonetheless contain the potential for maturity. The last principle, neural development, is that if an embryo cannot think or feel pain, then it is not yet human life.

The article sites a study that proposes “primitive sentience” is not possible until 8-10 weeks. It would be much more convenient for researchers if the ethical line were drawn at this latter stage. And to make it more convincing, we can make the cut-off point coincide with a linguistic division between the terms “embryo” and “fetus.” In short, the author asserts that we will draw the line where it is convenient, which leads to some interesting predictions about the future of this research. The following quotes come from EarlyBird in Slate's forum (the Fray).
We will raise the fetuses without frontal lobes so that there will be no
personality or anything else resembling personhood which might upset their handlers.

Any remaining wincing will be met with vicious political/social opprobrium. "What are you, some Bible thumping freak?! Do you hate cancer patients, the paralyzed and diseased?! Sure, you care about little blobs floating in synthetic amniotic fluid in a lab, but you don't care about quadriplegics!"

The conservatives will scream, but they'll be easily overrun by an aspiritual, aging population trying to stave off pain, disease and
their absorption into Nothingness.

The science is easy; it's the ethics that's the hard part.

I support looking into stem cell research, and I trust other supporters' good intentions. But we've crossed that line where little clumps of humanity are now property which can be destroyed for other,
more matured and organized bits of humanity.


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