Tuesday, February 05, 2002

Spare Body Parts

As one gets on in years and you use your body, different places, different parts start getting bruised, worn, and start to unravel. At the end of last year, I wrote about the infection I got in my front tooth and gums, and the horrible details that ensued. In order to repair the damage, I had to have the "nerve" removed. Having the "nerve removed" in a dental procedure, involves more than simply removing the nerve cells. In the center of the "tooth pulp", there are, not only nerve cells, but capillaries and lymph nodes as well, and it's through them that the tooth receives nutrition and is protected from microbes. In other words, teeth are "alive." To "extract a nerve" means that you are extracting the entire pulp. So, after the procedure, the tooth no longer receives any nutrients and does not fight against bacteria. And, in time, it is worn down from eating and chewing, becomes dark and discolored, and falls out. In other words, the tooth that I had treated is much like a prisoner sentenced to death some time in a few years. There are "caps" and "crowns" available nowadays, but this, too, is a type of "false tooth." So, if someone were to tell me that my "living tooth" could be brought back to life, I would be overjoyed.

I have also been experiencing some decline in my vision recently. I've been nearsighted since high school, and have been wearing contact lenses for some time now. Nowadays, however, I've begun having problems distinguishing small print--in the newspaper and dictionaries. I've bought a magnifying glass and had a pair of glasses made to help me with this. There's a procedure now where you can correct near-sightedness through laser surgery, but, since the success rate isn't 100%, and because of the exorbitant cost, I'm not interested in doing that. So, if someone were to say that my own eyes could be "regenerated" and vision restored to "as good as new", I'm not sure how long I'd be able to resist the temptation to do something. The same can be said about my thinning head of hair, the elasticity of my skin, my physical strength, memory, and stamina--all of which are far from what they used to be. In other words, the "rejuvenation" of my physical body, and "maintaining youthful performance" are, for me (and probably for most of the readers) an "unreachable dream."

We can look at the development of "spare body parts", beginning with prosthetic hands and legs, as a means of trying to make these dreams attainable. So, there's probably no one who can prevent this, and trying to would not be right. However, sacrificing others in order to realize your own dreams is not right either. If that is the case, then, the question arises as to whether one should take from another in order to receive a spare. The answer to this question may seem quite simple, while, in actuality, it is not. For one thing, the definition of "what is another" differs from person to person. Those who believe that "another" refers to "other people" and does not include "animals", approve of "taking from animals." Then how about "taking from people who are dead?" How about from aborted fetuses? From fertilized eggs? From unfertilized eggs? These are the questions that we who live in these times are confronted with, and, while the answers all differ from person to person, it seems as though technology just keeps going on and on.

In the field of regenerative medicine particularly, there have been one new development after another just in this year. In a previous entry, I mentioned how researchers "tricked" a monkey's egg cells into forming an early embryo--without the use of sperm--that yielded stem cells that then turned into heart, brain and other specialized tissue. According to news reports today, the company responsible for these findings has now said that they have used cells derived from cloned cow embryos to grow kidney-like organs that function, and are now producing urine, and are not rejected when implanted into adult cows. The purpose of this study is not the treatment of cows, but, of course, how it can be used to help humans. Stem cells have been used before to create blood and muscles "tissues", but scientists said that it would be a while before they could create "organs"" With this research, however, we are that much closer to growing personalized, genetically matched organs for transplantation.

In the January 29th edition of the Sankei Shimbun, there was a report on how scientists from Kyoto University's School of Medicine successfully triggered human embryonic stem cells to form human neurons that secrete the crucial chemical, dopamine. The reason for this study is also for eventual use on humans, and has paved the way for use of human stem cells in the treatment of Alzheimers, etc. Moreover, today's Asahi Shimbun ran an article on a surgical procedure performed at Tokai University, in which, using the bone marrow cells from a mouse, blood forming cells in the umbilical cord were caused to multiply and were then transplanted into a woman (a human!) in her 50's who had a malfunctioning bone marrow disorder.

As I've written before, questions of morality come into play when fertilized eggs are destroyed to create stem cells. But procedures have now been developed whereby stem cells and other similar versatile cells can be gained from unfertilized eggs. On the other hand, as in the studies mentioned above, experiments using stem cells to create specialized body parts have been done repeatedly on laboratory animals. So, from now on, it's quite possible that the technology of creating various tissues and organs of the body from the cells of unfertilized egg and bone marrow cells will develop even further. If that happens, we will be able to exchange or replace the parts of our body that have worn down with age with "living parts" created from this technology. If I'm still alive at that time, I may be able to create a new set of teeth, exchange my eyes for "new ones" and replace my old blood vessels.

However, one will undoubtedly have to be prepared to pay a considerable amount of money for this type of treatment. A fraction of people in "developed nations" may be able to do this, but for the overwhelming majority of the people in the world, this would remain an "unreachable dream." And, if the money that it would cost to replace my eyes alone could be used for the people in those countries, we could undoubtedly save dozens--no, hundreds of lives. In this way, when the money that would save one person in a "developed country" could save hundreds in developing nations, I wonder which of the two the conscience of humankind would shout out loud for us to choose?

- MT

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