i wrote this article in 2005. the information about stem cells - what they are - is still valid, although the research data is out of date . i hope it will clarify some of the questions people on this list have been asking.
again, i remind you that this is my understanding of the facts and i have tried not to take sides.
 
hilary blue.
 
p.s. please note 'chromosomes' and 'genetic material' equals DNAHilary Blue wrote:

>
>
>>>
>>> What is all the fuss about?
>>>
>>> There has been much said and written about stem cells in the media,
>>> on Capitol Hill, and in living rooms across the country. Yet it
>>> seems to me that there is much ignorance and even misinformation
>>> being bandied about, sometimes even being touted as gospel truth.
>>> Here is my attempt to make sense out of the issue. 
>>>
>>> To understand stem cells we must first consider where they come
>>> from. Every cell in the human body contains a nucleus which holds
>>> the genetic material, the chromosomes. In regular tissue (somatic 
>>> cells) these chromosomes are double (diploid). The reproductive
>>> cells (eggs and sperm)  have only single chromosomes (haploid). Thus
>>> when a sperm and an egg cell unite in the act of fertilization, the 
>>> fertilized egg  will have double chromosomes with one strand from
>>> the mother and the other from the father.  This fertilized egg cell
>>> divides into two and then four, eight, 16, 32,  64.....      And 
>>> this little group of cells is undifferentiated. Each has the
>>> potential to develop into any  part of the human body, i.e. it is
>>> pluripotent.
>>>
>>> At about this point, the clump of cells forms a hollow ball, known 
>>> as the blastosphere, and it is possible to map out exactly which
>>> cells are going to develop into which tissues. As each organ and
>>> tissue develops in the embryo, and even after birth and into adult 
>>> life, some of the cells remain undifferentiated. These are the
>>> so-called adult stem cells. They retain the ability to develop into
>>> regular tissue cells, but are not as potent as the embryonic cells. 
>>> It seems that, for example, stem cells from the marrow will develop
>>> into blood cells but not into brain cells or pancreas cells.So,
>>> although they offer some promise, they are not as versatile as 
>>> embryonic stem cells.
>>>
>>> The umbilical cord also contains stem cells, and this seems a very
>>> promising area for research, especially when the cord is saved for
>>> the future use of the baby. Should a patient need stem cell
>>> treatment for some future disease; he would have a store of his own
>>> completely compatible cells to call upon.
>>> 
>>> The most successful but most controversial form of stem cell
>>> production is Somatic Cell Nuclear Transfer (SCNT). A cell is taken
>>> from the undifferentiated blastosphere.  Its nucleus is removed and 
>>> replaced with the nucleus from a somatic cell. This can then be
>>> cultured to form a line of stem cells. Unfortunateely, all stem cell
>>> lines weaken over time and thus become less useful, so new lines 
>>> need constantly to be developed. Until now this has been the most
>>> promising source of stem cells for research. The original cell is
>>> taken from a very early stage of embryonic development, the 
>>> blastophere, which can develop into any of the numerous cell types
>>> in the body.
>>>
>>> It must be noted that the source of these embryos is from
>>> fertilization clinics, where many embryos are discarded  and 
>>> incinerated after they are no longer needed by the clients. This
>>> destruction of unwanted embryos is accepted and performed on a
>>> regular basis when a couple has used as many embryos as they want. 
>>> Or they can donate the unwanted embryos to research.
>>
>>
>>
>>> And therein lies the controversy.
>>>
>>> For there are those that say  that using an embryo that has the 
>>> potential for life is destroying that life. And that leads to the
>>> question: when does life begin?. There are those who say it begins
>>> at birth, and those who say it begins at conception, and every stage 
>>> in between. Some say it is the earlieet age at which a fetus will
>>> survive after a premature birth, which is about six months. This is
>>> consistent with Muslim belief and has resulted in Saudi Arabia 
>>> setting up a stem cell research institute  which is attracting
>>> scientists from countries where science is generally regarded as
>>> being more advanced.
>>
>> 
>>
>>> But the viewpoint taken by most stem cell research scientists  is
>>> that the stage at which the embryo begins to differentiate into
>>> distinct organs and other body parts is the point at which sentient 
>>> life begins.A formless cluster of multipurpose cells  becomes a
>>> planned structure, with each part destined for a future definite
>>> purpose.  Until that point,  any embryonic cell could potentially 
>>> develop into a human being; that is essentially what happens in
>>> multiple births. Identical twins are formed from the two cells
>>> created after the first division of the egg cell. This stage, when 
>>> the cells become dedicated to their future role, become presumptive
>>> bone or liver or nerve cells or whatever, occurs on about the 14th
>>> day after conception.
>>
>>
>>
>> But in the meantime, during the past several weeks, a researcher in
>> South Korea, Woo Suk Hwang, has announced the development of a more
>> sophisticated version of SCNT.  He uses a donated egg cell and 
>> replaces its haploid nucleus with a diploid nucleus from one of the
>> patient's own somatic cells. From this he derives stem cells that are
>> completely genetically compatible with the patient and these stem 
>> cells develop into whatever tissue the patient needs. There is no
>> fertilization,  and no embryo. There is no destruction of life. And
>> even if you argue that an egg cell is the fore-runner of a living 
>> being, women have been destroying and casting off egg cells on a
>> monthly basis since the days of Adam and Eve.
>>
>> This brief overview is completely my own point of  view and in no way 
>> reflects the  policies or views of the PFNCA or any board members,
>> employees or members thereof. The information  contained herein is
>> based on my understanding and interpretation of data garnered from 
>> conferences, symposiums and  PAN forums I have attended over the past
>> few years, and from the PIEN Listserv.
>>
>>>
>>>
>>> hilary blue
>>> 
>>
>>
>>
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