Re: What are embrionic stem cells?and whats bad about them?

Dear Nicole,
There is nothing bad about embryonic stem (ES) cells, they are likely to be 
extremely useful for the regeneration of tissues and organs in the next few 
years. However, there are major ethical issues regarding ES cells because 
to isolate them requires the destruction of a young (about 3.5 days old) 
embryo. Therefore the argument against isolation of ES cells is that it 
requires the death of a person, and the argument for is that these cells 
are likely to be useful to treat or cure many types of diseases. Both are 
vaild arguments. 

Human ES cells have only recently been isolated (1998) and we are only just 
beginning to understand their biology. Mouse ES cells were isolated in the 
1980's and we know a great deal about these cells. However, human ES cells 
are not the same as mouse ES cells, so a lot of basic research will need to 
be carried out before we can use them effectively. There are, to my 
knowledge, only about 10 human ES cell lines available around the world. 
This is not very many, and at the moment we run the risk of putting all our 
faith in these few cell lines that may ultimately turn out not to be true 
ES cells (we do not know what a human ES cell should be like because they 
haven't been isolated before!). From a scientific point of view we need 
more ES cells to confirm that we have isolated the right cell type. From an 
ethical view that would mean the death of hundreds of people. This is what 
is "bad" about ES cells, both arguments are sound yet ultimately 
uncompromisable.

I hope this helps to answer your question. Only the future knows whether ES 
cells will be bad or not.

Best wishes,
Chris Ward