Embryonic Stem Cell Research example essay topic

What exactly are stem cells? Stem cells are the mother of all cells in our bodies. They are cells that can develop into many different types of tissue, such as bone, muscle, or brain, and organs of the human body. When a fertilized egg first divides, totipotent stem cells are formed. These totipotent stem cells are cells that can turn into any type of tissue and form a complete organism. It is for this reason that stem cells have been the topic of many medical debates.

In theory, these stem cells can grow into replacements for almost any part of the human body. Scientists think that stem cells will someday provide a cure for diseases such as diabetes, Parkinson's, Alzheimer's, and spinal-cord degeneration. They estimate that over 100 million Americans have diseases that could be affected by research on stem cells. Scientists use the term "stem cell" to describe cells at several stages of development. So where do the stem cells come from?

An egg is fertilized when an egg and sperm join. About five days after fertilization, a hollow ball of around 100 cells will form. This hollow ball is called a blastocyst. The cells on the outside of the blastocyst will develop into the placenta and those on the inside will turn into the embryo.

The cells on the outside of the blastocyst are the totipotent cells. The totipotent stem cell is the most basic cell and has the potential to develop into any kind of cell; it has no preference and can develop into a brain cell, liver cell, etc. The pluripotent cells are the 50 or so inner cells of the blastocyst. They differ from totipotent cells because they can turn into almost all types of tissue, but not an entire organism.

As the embryo develops, the stem cells become multipotent stem cells. These cells can only give rise to specific kinds of tissues. The totipotent and pluripotent stem cells are referred to as embryonic stem cells. Multipotent stem cells are known as adult stem cells. Pluripotent cells are the cells from the inner cell mass of the blastocyst. They can form virtually every type of cell found in the human body.

However, they are unable to form an organism because they are unable to give rise to the placenta and supporting tissues necessary for development in the human uterus. In fact, if the inner cell mass were placed into a woman's uterus, it would not develop into a fetus. One way researchers think that they can isolate pluripotent stem cells is to use somatic cell nuclear transfer (SENT). Researchers using this method will take a normal animal egg cell and remove the nucleus. They will then fuse that egg with a somatic cell. The resulting fused cell is believed to have the potential to develop into a totipotent cell, which can form a blastocyst.

The researchers believe that the inner cells from these blastocysts could be used to develop stem cell lines. Pluripotent stem cells are important to science because they could help us to understand what occurs during human development. They may also help researchers to understand the factors involved in the cellular decision making process that results in cell specialization. Researchers know that turning genes on and off is the key to understanding cell specialization, however, they know little about the decision making genes or what turns them on or off. The difference between a "blank stem cell" and a developing fetus is a series of biochemical reactions that transform stem cells into specific types of body tissue. As an embryo develops, different molecular signals instruct cells to produce proteins that will transform the cell into a particular tissue type.

Scientists are still unsure which proteins are involved in embryonic development. As of August 2001, scientists are still only beginning to understand how exactly the body builds tissues. One of the main purposes of stem cell research is to create cells of different types with specialized functions. In order for scientists to do this, they must first understand what instructs undifferentiated cells to develop into nerve, kidney, heart muscle, or any of the other different types of cells in the human body. In order for stem cells to be used therapeutically, scientists must first learn how to take a generic undifferentiated cell and get it to turn into a specified cell. Much research has been done in this area using brain cells.

It has been discovered that in the nervous system, you can make one type of cell by turning off the ability to make all other possible cell types. Scientists have been able to make interneurons and motor neurons in the spinal cord by turning off transcription of genes for other cell types. The success of making a specific type of cell depends on supplying the right factors, as well as excluding the right repressor's. It was in 1998 that two teams of scientists from different universities first succeeded in growing and replicating stem cells.

One scientist was James A. Thomson, an embryologist at the University of Wisconsin. The other was John D. Gearhart of the Johns Hopkins University School of Medicine in Baltimore, Maryland. Thomson credited his success in part to new nutrient broths that made it easier to grow human embryos up to the five-day mark. It is at the five-day mark that the embryonic stem cells can be taken from the inner part of the blastocyst.

After reaching the five-day mark, Thomson was able to perfect a biochemical environment in which the stem cells would divide and grow, while remaining in an immature state. Whenever these biochemical conditions are removed, the cells then begin to become specialized kinds of tissues. At one point, Thomson's team had more than 1 trillion stem cells thriving and multiplying in the lab. That was only seven months after they started their experiment. Thomson, because of the ban on stem cell research in the United States at that time, did his work in a room in which not one piece of equipment had been bought with federal funds. Gearhart, unlike Thomson, obtained his stem cells from the developing gonads of aborted fetuses.

He also did his work in a room in which not one piece of equipment had been bought with federal funds. Where do the researchers today get the stem cells? Originally, stem cells derived from human embryos came from frozen embryos created at in-vitro fertilization clinics for sterile couples. However, recently, researchers have created human embryos for the explicit purpose of harvesting them for stem cells. This is the first time that egg and sperm donors have been recruited specifically to produce embryos for stem cell harvesting. The use of embryo stem cells has been the topic of much debate in our country over the last few years.

Some people feel that as soon as an egg is fertilized, a life is formed. These people feel that stem cell research is along the lines of abortion, since embryos are essentially being destroyed for the research. These ethical and moral issues have caused a political battle over the medical use of embryonic stem cells. There is the possibility that some adult cells have treatment potential. There is ongoing adult cell research along side of the embryonic stem cell research.

So far, scientists have obtained stem cells from adult bone marrow, blood cells, and also from adult brain tissue that was surgically removed for the treatment of epilepsy. It has been shown that adult cells previously thought to be committed to the development of one line of specialized cells are actually able to develop into other types of specialized cells. These cells that are obtained from adults are multipotent, as opposed to the pluripotent embryonic stem cells. Like the embryonic stem cells, the adult stem cells may one day be manipulated to generate transplant tissues or even awaken the body's dormant powers of self-repair.

Dennis A. Steindler, a professor of neuroscience and neurosurgery, said "In some ways they may not have the same potential as embryonic stem cells, but once we figure out their molecular genetics, we should be able to coax them into becoming almost anything we want them to be". Scientists have found that mature cells can in fact return to the primitive stem cell state. Another interesting fact is that the assumption that people are born with all of the brain cells they would ever have has been proven untrue. Scientists have discovered that the adult brain has its own population of stem cells that can make other new cells. There goes the "this is your brain on drugs" theory! So why not just use adult stem cells?

Because if attempting to use stem cells from a patient's own body for treatment, the stem cells would first have to be isolated from the patient and then grown in culture in order to obtain adequate quantities for treatment. The problem is that there may not be enough time to grow cells for treatment. Using adult stem cells has its advantages and disadvantages. By using adult stem cells from a patient, it is unlikely that that patient's body would reject the cells.

Also, using adult stem cells instead of embryonic stem cells derived from human embryos may reduce some of the ethical trouble that is circulating. On the other hand, adult stem cells have certain limitations. For example, they have not been isolated for all tissues of the body. Also, adult stem cells are only present in minute quantities and their numbers decrease with age.

So where does the American government stand on stem cell research? In August 2000, the Clinton Administration said that stem cells from frozen embryos destined for destruction at fertility clinics could be used for research. On August 9, 2001, President George W. Bush announced that the federal government would fund embryonic stem cell research. However, that funding is restricted to the 64 existing stem cell lines. Bush stated that the debate is over and said "The statement I laid out is what I think is right for America today".

(Am Med News) On the other hand, private funding in the United States is largely unregulated by the government. In fact, at the time of the isolation of the stem cell in 1998, Ger on Corp., a biotechnology company in Menlo Park, California funded the majority of stem cell research. Some people feel that the president's decisions have caused America to fall behind in the Biomedical research area. For decades, the United States was a world leader in biotechnology. The U.S. conducts more than 90% of the world's biomedical research. Scientists at the University of Wisconsin were the first to isolate human embryonic stem cell in 1998.

However, the U.S. has fallen behind in the area of biotechnology and while the U.S. debates the ethical implications of stem cell research, other countries are forging ahead. Although it was the U.S. that first isolated the stem cell, it is Britain that is home to the leaders in stem cell research. British researchers pioneered much of the early work on mouse embryonic stem cells two decades ago. Former Stanford University electrical engineering professor Jim Clark feels that the United States is forfeiting its leadership to other nations.

He feels that because President Bush is restricting stem cell research, the United States will fail to be pioneers. Many people in the scientific community feel that the president's decision will delay the development of cures for diseases for many years. President Bush restricted research to the existing 64 cell lines. However, 48 of the existing 64 stem cell lines reside in labs outside of American borders. Other countries are forging ahead in the area of biotechnology and more specifically, stem cell research.

However, there are some countries that still have a ban on stem cell research. In Germany, research is forbidden on German human embryonic stem cells, but permitted on legally imported cells! Britain allows stem cell research for therapeutic purposes and a publicly funded bank of human embryonic stem cell lines is likely within a year. Israel has no formal laws regarding stem cell research and little public opposition.

In Japan, research is allowed on human embryos left over from fertility treatments, but any human cloning is punishable with 10 years in jail and fines of $90,000. Well, what exactly is the point in all of this research and ethical / governmental debate? It is estimated that over 100,000 Americans die each year from organ failure or tissue loss. One of the main applications for stem cell research is the generation of cells and tissue that could be used for cell therapies. If pluripotent stem cells can be directed to develop into various specialized cells, those cells could possibly be used as replacement cells and tissues to treat a variety of diseases. The stem cells would mainly be used to treat diseases such as Parkinson's disease, Alzheimer's, and diabetes.

In Alzheimer's patients, large masses of brain cells die off and the patient loses the ability to function. Researches have found that by injecting stem cells into the brain, they can replace the dead tissue, which then takes over the functions of the old cells. Also, if those cells could be made to develop into specified organs, a number of problems would be solved. People suffering from diseases that limit the function of their organs face the problem of a limited number of organs available.

If lucky enough to receive an organ, the person then faces the possibility that his body will reject the organ. Researchers hope to one day use organ replacement in place of transplantation. By using an organ developed from the person's own cells, there is no chance of rejection and no need to expose the patient to immune-suppressing drugs. The stem cells could also be used to screen chemicals for effective medicines. Scientists will measure how the cells respond to potential drugs, making it possible to distinguish drugs that will be useful from drugs that will be problematic in human medicine.

Some scientists feel that the first uses for human stem cells will probably be as tissues upon which pharmaceuticals can be tested and toxins assessed. It will also be used to study the earliest stages of embryo development. Studying embryo development could lead to treatments for infertility, as well as a reduction in birth defects. Stem cell research is a hot topic among the scientific community and it is easy to see why. All in all, this research has the potential to revolutionize the practice of medicine and improve the quality and length of life. Citations At Risk: A Golden Opportunity in Biotechnology.

Business Week, (3748): 85, 2001. Burgess, A. ; Nicola, N. Growth Factors and Stem Cells; Academic: New York, 1983; pp 1-18. Cohen, P. ; Young, E. Two Cheers. New Scientist, 171 (2304): 11, 2001. Embryonic Stem Cell Research Fuels Controversy. Health & Medicine Week, Sept.

10, 2001. Ericson, J. et. al. Making One Type of Cell by Turning off all Other Types. web (23 Nov. 2001). Everything you ever wanted to know about stem cells. New Scientist, 167 (2252): 14, Aug. 19, 2000. Joseph, Jennifer.

Growing the Ultimate Cell. web (23 Nov. 2001). Kelley, Melinda. Stem Cell Research: Part I The Basics. Paraplegia News, 54 (5): 26, May 2000.

NIH Fact Sheet on Human Pluripotent Stem Cell Research Guidelines. web (23 Nov. 2001). O'Brien, Ellen. How Stem Cells Build Muscle or Brain or Bone Cells. web (2 Sept. 2001).

Robeznieks, Andis. Federal funding restrictions fuel stem cell research debate. Am. Med. News, 44 (37): 16, Oct. 1, 2001. Thomson, J. Embryonic stem cell lines derived from human blastocysts.

Science, 282: 1145-1147, Nov. 6, 1998. Weiss, Rick. A Crucial Human Cell Isolated, Multiplied. web (21 Nov. 2001). White, Victoria. Adult Stem Cells may be recruited for War on Cancer. web (2 Sept.

2001). Wisconsin scientists culture elusive embryonic stem cells. web (21 Nov. 2001). Wol pert, Lewis. Stem Cells: a problem in asymmetry. J. Cell Sci. Suppl., 10: 1-9, 1988.