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When a baby is conceived, he begins as a single cell. This cell divides into two cells, which then divide into four, and so on, to eventually produce all the cells in the body. Some of these cells become the baby’s hair, other becomes skin, others become heart muscle, others become blood cells, etc etc. Ultimately there are at least 220 different types of cells to make up all the parts of a complete human being.
Some of your cells continue to divide as long as you are alive, such as hair and skin cells. But even though all these cells came from one original cell, a skin cell cannot give rise to a liver cell nor a brain cell to a blood cell. Somewhere along the line cells become “specialized”. Cells that are capable of giving rise to many different types of cell are called “stem cells”.
A very early embryo is made up almost entirely of stem cells. By the time a baby is born, there are just a relatively small number of stem cells scattered through his body.
In the 1980’s medical researchers got the idea that stem cells might be useful in treating diseases that involved the breakdown of some type of cells in the body. For example, in Parkinson’s Disease, brain cells that produce an important chemical, dopamine, die or cease to function. Researchers hoped that stem cells could be implanted in the patient’s body and caused to grow new brain cells to replace the dead or damaged ones. More ambitious researchers imagined a day when they could grow complete new organs.
One type of stem cell treatment has been successfully used for decades, though doctors didn’t know why it worked because they didn’t know about stem cells: Bone marrow transplants. Bone marrow contains stem cells that produce red blood cells, and it can be transplanted from a healthy person to a sick person and continue to function.
Research was begun using stem cells from mice in the 1980’s. The first research with human stem cells began in 1998. At this stage there are still many unknowns. Researchers today have very little idea what makes a stem cell give rise to one type of specialized cell rather than another. In some experiments the implanted stem cells have turned cancerous, and no one is sure why.
There are two different kinds of stem cells. Stem cells that come from embryos are called “embryonic stem cells”. Stem cells that come from a fully-developed person are called “adult stem cells”. Note that “adult” here means that the cells are adult, not the person, so a new-born baby has “adult stem cells”.
Researchers have been experimenting with both embryonic and adult stem cells.
In some experiments, adult stem cells are taken from the patient himself. Another popular source is umbilical cords.
Most embryonic stem cells for research have been taken from embryos who were declared “surplus” after in vitro fertilization treatments. Couples unable to have a successful pregnancy naturally sometimes have eggs extracted from the woman surgically and fertilized with the man’s sperm in a test tube. Many of the babies conceived this way die quickly because our technology is not as sophisticated as the womb, but a few survive and grow. Of these the healthiest one is implanted into the mother’s womb, where if all goes well it develops normally. If it doesn’t survive, they try again with another embryo. (Sometimes several are implanted at once, and if more than one survives, the extras are aborted.)
But in most procedures, there will be some number of embryos growing in test tubes that are not needed once one of their brothers has “taken” in the womb. So medical researchers have been killing some of these embryos and “harvesting” their stem cells.
It has also been suggested that the bodies of early aborted babies could be used as sources of stem cells.
Adult stem cells have successfully been used to treat 65 different diseases or injuries, ranging from brain cancer to osteoporosis to gangrene. (Note that almost all of these are still in the experimental stage -– don’t expect to get a prescription from your doctor for any of these treatments for many years.) No research using embryonic stem cells has yet resulted in any substantiated positive results. Because of this, by the early 2000’s most private companies had cut off funding for embryonic stem cell research and concentrated their efforts on adult stem cell research. The embryonic stem cell researchers then sought to get tax money to replace the lost private money. Mostly this means federal tax money, though California and Ohio have passed referenda to give billions of dollars of state tax money for such research.
At this time the political debate is entirely about funding. No law has been proposed that would ban any of this research. The only question is whether the government will pay for it or if researchers will have to find private funding.
Embryonic stem cell research raises a serious moral problem: The only way to obtain the cells, whether for research or for treatment, is to kill an innocent baby (embryo).
Defenders of this research reply that these babies are going to be killed anyway, so we may as well get some good out of them. Opponents reply that it is simply wrong to be a party to killing, and the claim that if you don’t murder this person and steal his property, someone else will, or that as you had already decided to murder him he is no worse off for also being robbed, are not moral justifications. Pro-lifers are also concerned that this could become a justification for abortion. If a woman is ambivalent about having an abortion, an argument that she could donate the aborted embryo to medical research and untold numbers of people might benefit could be a deciding factor in her decision.
One of the most commonly-discussed promises of stem cell research is that it may provide a cure for diabetes. In an interesting personal twist for me, the day after I began work on this article my doctor told me I had diabetes. If someone told me that I could be cured at the small price of killing one innocent baby and harvesting some of this tissue, I can’t imagine saying, “Wow, that’s great. Will my insurance cover it?” At this point I certainly haven’t suffered much from it: my pain has mostly been limited to some annoying pin-pricks for blood samples, and I can certainly comprehend that people in serious, unrelenting pain can get desperate. But I certainly hope that I never reach the point where I would be willing to kill someone else to benefit myself.
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