Stem Cells

Stem cells are found in almost every tissue of our body. Stem cells are very much like embryonic cells in that they can be used to repair many different kinds of tissues because they have not differentiated. Look at what happens when you have an operation, the incision heals. When you break an arm, the bone heals. Blood cells are continually being replaced as is the lining of your intestines. All these repairs use stem cells. Using stem cells should not suffer from the objections raised with using human fetus cells.

There are basically two types of stem cells. The first is a pluripotent stem cell or fertilized egg. (In mice they may be called totipotent stem cells.) During the course of development, this type of stem cell eventually gives rise to all the cells of your body. Pluripotent stem cells can be obtained from the cell mass found inside the blastocyst.

The second cell type is a progenitor cell, these are cells that have already been to committed to develop into tissues such as nerves or skin, but have not yet fully differentiated.

• So why isn't stem cell treatment used routinely in treating diseases?