Stem Cells – What’s the Hype?

Due to recent national events involving stem cells, LRO is pleased to break down the science for you.

What are Stem Cells?

Stem cells are considered "blank" cells that are capable of developing into many different types of cells found in the human body. They are also capable of dividing and renewing themselves for long periods. Researchers believe that stem cells hold a great deal of promise for medical therapies such as growing replacement cells or whole replacement organs, as well as "patching" organs that don't work properly. Such organs include a spinal cord.

Embryonic Vs. Adult Stem Cells

Researchers are focusing on two types of human stem cells: embryonic stem cells and adult stem cells. Research has been conducted on adult stem cells for more than 40 years, while embryonic stem cells were first extracted in 1998.

Embryonic stem cells are taken from a human embryo a few days after fertilization in a process that destroys the embryo. Adult stem cells are taken from adult tissue, or newborn babies' umbilical cords.

Embryonic stem cells can divide for a year or more in a laboratory without becoming specialized cells, while most adult stem cells can't. One stem cell can produce hundreds of genetically identical stem cells. Stem cell lines consist of cells that have been copied from one original stem cell.

Adult stem cells are also less flexible in giving rise to other types of cells. In most cases, an adult stem cell can only create cells that are found in the same part of the body from which the stem cell was taken. However, research is discovering that adult stem cells may be more flexible than previously thought.

Where Embryonic Stem Cells Come From

Embryonic stem cells come from human embryos created in a laboratory, usually through in-vitro fertilization. First, scientists inject sperm into the egg. A day after the egg is fertilized, it splits into a two-celled embryo. The next day, it splits into four cells, then into eight cells and so on. By the fourth or fifth day after fertilization, the embryo has become a multi-celled ball called a blastocyst. At this point, the embryo is still tiny -- about the size of the dot on an "i" and it can either be implanted into a woman's uterus, frozen for later use or used for research. If the embryo is used for research, scientists remove the stem cells from the inner cell mass of a blastocyst, a process that destroys the embryo. The stem cells are cultivated in a lab and can multiply indefinitely.

Potential Uses of Stem Cells

Although stem cell research is in early stages, scientists say stem cells may someday treat or cure a variety of ailments, including: spinal cord injury, Parkinson's disease, Alzheimer's disease, heart disease, Type 1 diabetes, blood cancers, blood disorders, stroke, burns, osteoarthritis, rheumatoid arthritis and eye diseases.

Source: WTAETV Pittsburgh Channel 4. Distributed by Internet Broadcasting Systems, Inc.

Photo: Credit Children’s Hospital Boston