Biology > Human Stem Cells

1. What are human stem cells? How do scientists obtain these cells?

There are two kinds of human stem cells: adult and embryonic stem cells. These human stem cells differ in the number and type of differentiated cells they can become.

Embryonic stem cells are obtained from 3-5 days old embryos, whose cells at this point are identical to each other. These cells later differentiate and become the human organs. Embryonic stem cells can become all cell types of the body. Adult stem cells generally limited to differentiating into different cell types of the tissue of their origin. This is one of the reasons why embryonic stem cells are more valuable to scientists. The other reason is that embryonic stem cells are easy to grow in cultures, making easier to create larger quantities that may be needed for cell replacement therapies. Adult stem cells are difficult to culture, but scientists are working on it. Embryonic stem cells are obtained from embryos that were created through in vitro fertilization. These embryos then donated by the ‘parents’ for scientific purposes. (I don’t know if this is true.)

Adult stem cells can be found in certain organs of adults’, even in the baby teeth. These stem cells are undifferentiated cells found among differentiated cells in a tissue or organ. These cells can renew themselves and differentiate so that they will be the same as the surrounding cell types or tissues. Adult stem cells maintain and repair the tissue in which they’re found. Scientists are now finding stem cells in more organs they originally thought they would. Adult tissues that contain stem cells are: brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin and liver.

How do researchers envision using cloned embryonic stem cells?

There are many ways in which human stem cells can be used. Embryonic stem cell research could provide us with the information of how undifferentiated stem cells become differentiated. This is significant because some of the most serious diseases such as cancer or birth defects are the results of abnormal cell division. Human stem cells can be used to test drugs. New medications can be tested on differentiated stem cells for safety before used on humans. The most important application is to cure diseases by generating cells and tissues used for cell-based therapies. Today organ transplants are commonly used to replace tissues, but unfortunately the number of organ donors is significantly lower than those waiting for those organs. Stem cells offer the possibility of a renewable source of replacement cells and tissues to treat Parkinson’s and Alzheimer’s diseases, spinal cord injury, strokes, burns, heart disease, diabetes, and so forth.

Differentiate between therapeutic cloning and reproductive cloning. Reproductive “cloning merely re-creates the genes of an ancestor, not what he learned or experienced”-says one website. Merely re-creating somebody I don’t think is that simple of an issue. But that’s what reproductive cloning is. It’s also called adult DNA cloning. Until now its intent is to produce a duplicate of an animal. It has been used to clone the famous sheep, Dolly, and other animals. Cloning of humans is illegal in every country. However a few months ago a company said that they successfully cloned a person and the baby is alive and healthy. Nothing was heard from them ever since. Therapeutic cloning is basically developing a human tissue or organ by extracting stem cell from an embryo. The result therefore is not a human, only a replacement organ or a piece of nerve tissue, or quantity of skin.

2. Summarize the current United States policy regarding obtaining and using embryonic stem cells. How do policies of other nations, such as Great Brittan, differ from that of the US? What are the likely consequences of these policy changes

On August 9, 2001, President George Bush announced that he would support limited federal founding for stem cell researches. It was a controversial decision after long months of vacillation. Bush allowed research funding for only those stem cells that already had been extracted from destroyed embryos. He prohibited founding for further destruction of embryos for stem cell research in order to discourage scientists from further destruction of life.

In December 2000, the British government passed a law permitting the cloning of early embryos to provide stem cells for research purposes. It allows the cloning of embryos up to 14 days old for therapeutic purposes and for the development of new treatments. It also established a stem cell bank. I thin that these differences between US and foreign governments have to be eliminated. It will happen either by government regulations, or simply by the exodus of scientist who are interested in these kind of researches.

3. Identify several important moral and ethical issues regarding stem cell research.

I think the reason for all the controversy surrounding stem cell research is that it is obtained from an embryo. An embryo is the first stage of a personhood. Certainly the Church will never agree with this kind of ‘murder’ for the sake of science. Pope John Paul II says stem cell research is the same condemnable act as abortion or euthanasia. President Bush, being a religious person listens to the Pope, and this is why he will not support stem cell research any more than he does now. It means that he forbade the creation of new embryos, or even the future using the ‘available’ embryos from in vitro fertilization for the purpose of stem cell research. I think the moral question is that these embryos are considered as persons or not. And when does life begin. At conception, or just when the embryo reaches a certain age, let’s say 13 or 26 weeks. The Church considers it life from the first moment, therefore it says it’s a murder to kill an embryo. The next question is how ethical it is to create an embryo clearly for research purposes. I think that the creation of a human is just simply an unacceptable idea. To create human parts is another question. It is for the sake of curing and treating life threatening diseases, therefore it is more acceptable to me.

Just think about how many people’s life could be saved as a result of successful stem cell researches. I would certainly support only therapeutic cloning, which is the creation of human organs, or tissues. This is the most ethical way of using stem cells. I think that the creation of other artificial humans or animals is improper. Not even in the name of science. If science helps us to cure diseases, consequently saving millions of lives, than science is desirable. If it results only in the creation of other living organisms just so that a scientist could earn fame, than I think it’s intolerable. What other reason would lead this scientist, if not the belief that he can create something that nobody ever could, believing that hi/she is god. So if I would to advise the government, I would definitely want it to make sure that these researches are highly controlled and restricted by the few institutions. Its purpose can only be researches for therapeutic cloning. I really don’t know how I feel about stem cell research by the way. I mean to use embryos that are created through in vitro fertilization is tolerable. However I think that a lot more embryos would be needed for adequate researches and those could only be ‘manufactured’ by this specific reason. I don’t know whether it’s right or wrong. I think it’s not right, but if I see that by doing this deadly diseases can be cured, then I think it’s the right thing to do. I don’t think I was convincing enough, but I’m not convinced either.

 

 

Sources:

http://stemcells.nih.gov
(This is the governmental National Institute of Health’s website that I found extremely helpful for researching this subject. It provides links to just about everything one would want to find out about the subject. )

http://www.americancatholic.org/News/StemCell/
(This is a website for everybody who follows the catholic religion. In addition to its spiritual content it displays the church’s point of view on certain non-religious subjects such as stem cell research. )

http://www.newscientist.com/news
(This is the website version of the popular New Scientist magazine, with similarly interesting content about the latest scientific researches and their result.)

 

 

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