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Stem cells are one of the most fascinating and controversial areas in biology today

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Stem cells are one of the most fascinating and controversial areas in biology today. Like many expanding fields in scientific inquiry, research on stem cells is raising scientific and ethical questions. Stem cells have three important characteristics that distinguish them from other cells. First, they are unspecialized, that is, they do not have any tissue-specific structures that allow it to perform specialized functions. These unspecialized cells can give rise to specialized cells, including heart muscle cells, blood cells or nerve cells. Second they are capable of dividing and renewing themselves for long periods through cell division called proliferation. In other words, they can replicate many times unlike muscle cells, blood cells and nerve cells which normally do not. These cells are capable of continually reproducing themselves and can renew tissue throughout an individual's life. For example, they can regenerate the lining of a gut, revitalize the skin and produce a whole range of blood cells. A starting population of stem cells can proliferate into millions of cells in a matter of months. ...read more.


It is the unique versatility of the ES and EG cells from the early stage embryo and cadaver fetal tissue that offer scientists the possibility to generate more specialized cells or tissues, which could allow the generation of new cells used to treat injuries or diseases like Alzheimer's, Parkinson's, heart disease and kidney failure. Also, scientists believe these cells could be the means for understanding the earliest stages for human development and important tool in developing life saving drugs and cell replacement therapies to treat disorders caused by early cell death or impairment. Human stem cells can be derived from the following sources: * Human fetal tissue after elective abortion (EG cells) * Human embryos that are created by in vitro fertilization (IVF) and that are no longer needed by couples being treated for infertility (ES cells) * Human embryos that are created by IVF with gamaetes donated for the sole purpose of providing research material (ES cells) ...read more.


Some believe that the embryo has the moral status of a person from the moment of conception, and research that would destroy the embryo is considered wrong and should not take place. Others believe arriving at an ethically acceptable policy ion the arena involves a complex balancing of a number of important ethical issues. For most, the resolution of these ethical issues depends to some degree on the source of the stem cells. The use of cadaver fetal tissue to derive EG stem cells is usually the most accepted. With respect to ES stem cells, most draw an ethical distinction between the two types of embryos. The first referred to as the research embryo, an embryo created through IVF provided solely for research purposes. Many have expressed that the federal government should not fund research that involves creating such embryos. The second type of embryo is created for infertility treatment, but is now intended to be discarded because it is unsuitable or no longer needed for such treatment. The use of these embryos raises fewer ethical questions because it does not alter their final disposition. ?? ?? ?? ?? 1/2 ...read more.

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