Stem Cell Basics
What are Stem Cells?
Stem cells are cells from which all other cells in the body are created. Not only do they divide into new stem cells in a process of self-regeneration, but stem cells also have the ability to differentiate into special cells that perform very specific duties. For example, stem cells can differentiate into heart cells, bone cells, blood cells, or brain cells. The ability to regenerate and to differentiate makes stem cells unique. It also makes stem cells a prime target for researchers who are interested in how the human body works, develops, and repairs itself.
Stem Cell Potential to Cure Disease
Stem cell research has opened the door to exciting and up-and-coming information about the human physical condition.
•- Researchers study the stem cell development into specialized cells in order to better understand how various diseases and conditions occur.
•- Stem cell researchers try to manipulate stem cell differentiation with the hope of transplanting healthy stem cells into human beings whose cells are damaged or diseased.
•- Researchers use stem cells to test the safety and effectiveness of various medications. If stem cells in the lab react well to new drugs and the drugs have the desired effect, they can potentially be used in humans to cure diseases.
Types of Stem Cells
There are several types of stem cells, each named after their source.
Embryonic stem cells come from very young embryos called blastocysts which contain up to 150 cells. Embryonic stem cells can divide into more stem cells or they can differentiate and become specialized cells in any part of the body. Also known as pluripotent stem cells, versatile embryonic stem cells have the greatest potential for use in human beings.
Adult stem cells are mainly found in the bone marrow, however they are also found in umbilical cords and in children. Unlike embryonic stem cells, adult stem cells are limited in the types of cells they can differentiate into. Until recently, for example, researchers believed that adult stem cells in the bone marrow could only develop into blood cells (red blood cells, white blood cells, and platelets). However new evidence is emerging indicating that adult stem cells may be more versatile than previously thought, and stem cell researchers are currently investigating the full potential of adult stem cells. Research is also underway to determine if scientists can alter the genes in regular adult cells and turn them into stem cells that can be manipulated into behaving like embryonic stem cells.
Amniotic fluid stem cells are located in the sac that surrounds the growing fetus in the uterus. Doctors draw amniotic fluid from pregnant women in a process called amniocentesis in order to test for fetal maturity and for potential abnormalities such as Downs Syndrome. Stem cell researchers are studying amniotic fluid stem cells in order to determine their full potential.
Embryonic Stem Cell Controversy
Since embryonic stem cells are derived from early-stage embryos and since the removal of stem cells destroys the embryos, many pro-life advocates and others who believe that the embryo even at this early stage constitutes a human being claim that the extracting of embryonic stem cells constitutes murder. Conversely, the alternative viewpoint claims that the young embryo is too underdeveloped to be considered a human being. In light of these significant ethical issues, studies exploring the greater range of adult stem cells have become even more urgent and are currently underway.