Argh...I need a tutorial. I have never liked to another thread so I am just quoting what I had mentioed before. And I don't have the source, but if I remember correctely it a medical magazine of sorts..
Joined: 08 Oct 2004
Location: My Bard's warm and wonderful cottage
Posted: Sun Nov 21, 2004 1:31 am Post: 1029388 -
Thank you for your input to this discussion, Idaho. I do appreciate your views.
I want to point out the differences in stems cells a bit if I may. Einherjar mentioned the differences as well, but I would love to expand on that.
Adult stem cells
Stem cells found in different tissues of the developed, adult organism that remain in an undifferentiated, or unspecialized, state. These stem cells can give rise to specialized cell types of the tissue from which they came, i.e., a heart stem cell can give rise to a functional heart muscle cell, but it is still unclear whether they can give rise to all different cell types of the body.
Umbilical cord stem cells
Hematopoietic stem cells are present in the blood of the umbilical cord during and shortly after delivery. These stem cells are in the blood at the time of delivery, because they move from the liver, where blood-formation takes place during fetal life, to the bone marrow, where blood is made after birth. Umbilical cord stem cells are similar to stem cells that reside in bone marrow, and can be used for the treatment of leukemia, and other diseases of the blood. Efforts are now being undertaken to collect these cells and store them in freezers for later use. However, one problem is that there may not be enough umbilical cord stem cells in any one sample to transplant into an adult.
Embryonic stem cell
Also called ES cells, embryonic stem cells are cells derived from the inner cell mass of developing blastocysts. An ES cell is self-renewing (can replicate itself), pluripotent (can form all cell types found in the body) and theoretically is immortal.
This is, in my opinion, why the Embryonic cells are so vitally important to Therapeutic Stem Cell Research.
What is even more amazing is that now they can create a (blastocyst).....
A very early embryo consisting of approximately 150 cells. The blastocyst is a spherical cell mass produced by cleavage of the zygote (fertilized egg). It contains a fluid-filled cavity, a cluster of cells called the inner cell mass (from which embryonic stem cells are derived) and an outer layer of cells called the trophoblast (that forms the placenta)
....without using sperm for fertilization, but using a woman's own cumulus cells. Researchers used a process called nuclear transfer, which involves removing the nucleus from an egg cell and replacing it with the nucleus of a so-called adult cell -- in this case a cumulus cell.
No sperm, blastocyst created, stem cells retrieved. Where is the moral or ethical issue with this point? Just curious....