Tuesday, July 25, 2006

Deconstructing the Blastocyst

In the past couple of weeks, we've seen and heard a great deal of hand-wringing and emotionally charged rhetoric with regard to the issue of embryonic stem cell research.

Opponents, including President Bush, the Catholic Church, and Fundamentalist Christians, maintain that the human blastocyst--a hollow cluster of about 120 cells at the 5-7 day stage--is a human life, thus the separation and cultivation of these cells for other purposes, even the development of potentially lifesaving stem cell lines, is murder (although in the President's case, it depends on who speaks for him), issues of said blastocysts remaining in cryogenic limbo or simply defrosted and discarded at the IVF clinics' discretion notwithstanding.

Supporters of this important research point to the many potentials of embryonic stem cells, namely, the cultivation of healthy, organ-specific tissue for therapeutic use in all manner of life-threatening illnesses, including diabetes, Alzheimer's disease, and Parkinson's disease.

Missing from most of the media reports is a simple, factual description of that which we are debating: the process of creating stem cells, and the blastocyst itself. To that end, I offer this, from the National Institute of Health's stem cell information page (bolds mine):

Embryonic stem cells, as their name suggests, are derived from embryos. Specifically, embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro—in an in vitro fertilization clinic—and then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman's body.

Bearing in mind that an actual blastocyst is about the size of a pinhead, look at the following enlarged photograph, from the Advanced Fertility Center of Chicago site.

The developing fetus itself is the area marked as "ICM" (inner cell mass). The blastocoel cavity in the center is marked as "C". The trophectoderm cells that will form the placenta surround the cavity - one is marked with a "T".

Notice that this cluster of cells is not entirely made up of the very early stages of a baby; rather, some cells are designated for the formation of the placenta, an amazing and temporary, task-specific, unique-to-female-mammals organ, the functions of which--should successful implantation occur--include receiving nutrients and oxygen from the mother's blood and passing out waste and carbon dioxide. Further, there is no nervous system, no brain, and no heart--only multipurpose cells that might, at some point in the future, differentiate and become the beginnings of these organs and systems.

And that is why scientists consider the blastocyst's cells to be truly Jack-of-all-trades in nature. Given the right circumstances and time, they can become brain cells, pancreas cells, placental cells, and so on.

Here is another fact that is, more often than not, conveniently left out of all those mainstream media stem cell sound-bites to which we're treated: when a blastocyst develops within a woman's body, there is an approximately 40% chance that it will not successfully implant itself into the uterine wall--at the same 5-7 day point when its petri dish counterpart would be utilized for stem cell cultivation--and will therefore not develop into a fetus, but rather, will simply be expelled and a normal menstrual period will follow a couple of weeks thereafter.

According to the President's logic, then, as many as 40% of all sexually-active menstruating women could be party to murder every month.

After weighing the President's statements and drawing upon my own logical processes, I came up with this:

Utilizing a 5-day-old American blastocyst for stem cell lines = murder

Killing a 5-year-old Iraqi child while waging an illegal and immoral war = collateral damage

At this point, would it be stating the obvious to assert that the inhabitant of America's highest office is being utterly ridiculous?

Finally, I will submit this Put Your Own DNA Where Your Mouth Is hypothetical: supposing a loved one of mine were suffering from a disease that could be helped or cured by tissue resulting from embroynic stem cells; would my husband and I donate our own sperm and eggs for in vitro creation of blastocysts to be used for stem cell cultivation?

In a New York minute or a London heartbeat. Whichever is fastest.

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