I found this article via Nexopia written by a member named Xazer:
Stem cell research is a fairly controversial topic these days, and what sparked my interest was President Bush threatening to veto the U.S. House of Representatives recently passed bill that would expand federally funded research facilities (note: I do NOT want this to become an argument over Bush, the U.S., conservatives or whatnot). What I find ironic is that many people really don’t know much about the properties of stem cells themselves, but instead they debate the issue whether or not that the researchers are “killing” unborn fetuses and other aspects of the research. I’ll try and shed the light on the issue while retaining enough Embryology and Physiology.
First off, when scientists extract stem cells, the developing organism (not necessarily a human) is called a Blastocyst, which is a 3 to 5 day year old embryo. This is a ball of cells approximately 30 to150 in number and is about 0.15mm (150 μm) in diameter (appreciate here the size of it). The reason these cells are so important is that they have the potential to differentiate. Differentiation is where the cells begin to specialize and modify themselves in to various types of cells. You have to keep in mind here that there are over 200 types of cells in your bodies that all perform a specific function (all of your organs are made up of many types and many layers of cells). Scientists can extract, culture, and then induce these cells into various parts of the body where cells either cannot reproduce or have been damaged and altered in some way or where tissue has been damaged.
The “official National Institutes of Health resource for stem cell research” lists the properties of human embryonic stem cells that scientists are trying to discover as,
1. Determining precisely how stem cells remain unspecialized and self renewing for many years; and
2. Identifying the signals that cause stem cells to become specialized cells.
Many medical conditions such as cancer and birth defects are due to abnormal cell differentiation and cell division. Cancer itself has many effects on the human cell, where one is that it causes the specific property of cells contact inhibition to function abnormally. Contact inhibition is where cells are triggered to stop dividing when they maintain physical contact with surrounding cells.
Your body also produces stem cells in its own in differentiated tissue. Their main role is to repair that specific tissue. The main differences between adult stem cells and embryonic stem cells are the number of cells found and the “plasticity” of each type (the different types of cells they can become). Embryonic Stem cells can divide (proliferate) for a long period of time, even for more than a year. Adult Stem cells are rare and cannot differentiate into every type of cell the body has. However, one advantage of adult stem cells would be if a culture could be grown and given to a patient, where the body’s immune system wouldn’t reject it (this is a whole new topic [Immunology] that I won’t get into, but let’s just say that there are many factors involved if a foreign entity is recognized or labeled “self”).
I’m bringing up this topic because not only is this a controversial topic in the U.S. and Canada, but it’s also controversial in many other developed nations. The Attorney General of Brazil, Claudio Fonteles, proposed a law that would outlaw all Embryonic Stem cell research in the nation. He said “the research is a violation of life and unconstitutional” in a petition that O Globo reported Tuesday. Granted that Brazil is a very Roman Catholic country (they have strict laws regarding abortion and “other fetus rights”), you can appreciate that this is a worldwide issue.