Making the most out of leftovers

Written by Sally Sanderson on Wed, 01/14/2009 - 15:44
http://www.mtulode.com/node/441

Taking a closer look at the benefits of embryonic stem cell research
Stem cell research has long been a subject that is intensely interesting and incredibly controversial. The main argument of stem cell research puts the scientific strides that may be made possible with research and application of stem cells against the ethical dilemmas of human embryo destruction.

Stem cells have been deemed so important because they differ from other cells in three major ways. First, stem cells are able to renew themselves by cell division for long periods of time. Secondly, they are unspecialized, and lastly, they are able to differentiate into specialized cells. These specialized cells can include beating cells in the heart as well as insulin producing cells in the pancreas, among others (http://stemcells.nih.gov/info/basics/basics1.asp).

There are two main forms of stem cells: embryonic and adult. These two types differ most noticeably in their differentiation patterns and their origin. Embryonic stem cells originate from embryos (research so far uses mainly mouse or human embryos) that are generated through in vitro fertilization—in a professional clinic—and donated to science with the donor’s permission. It is most important to note that stem cells are not taken from embryos fertilized in a woman’s body. These stem cells are about four to five days old and are found in the blastocyst, a microscopic ball of cells that comes from a zygote (a fertilized egg) and is surrounded by an embryo. Some argue the blastocyst is one of the first stages of human life and should therefore not be used in scientific research.

Embryonic stem cells have the ability of self renewal over long periods of time; this process of replicating is called proliferation. Stem cells are unique in the fact that they can proliferate; nerve, muscle and blood cells lack this ability. It is estimated that after six months of proliferation, the original 30-celled blastocyst is able to form millions of undifferentiated embryonic stem cells.

The reason embryonic stem cells are so interesting can be attributed to the fact that they are able to differentiate into a wide variety of specialized cells. The term differentiate refers to a stem cell’s capacity to change from an unspecialized to a specialized cell. Specialized cells include, but are not limited to, nerve, muscle and heart cells. Being able to understand what triggers differentiation and a method for growing these cells in the laboratory may yield ground breaking results in treating injury or disease that have so far gone untouched by humans.

Adult stem cells differ from embryonic cells in the fact that their origin is unknown, and they often differentiate into the same type of cell found in their tissue of origin. These stem cells are undifferentiated in their tissue or organ and are often found in very small numbers. Their main prerogative is to maintain and repair the tissue they reside in.

There are two main types of adult stem cells: hematopoietic stem cells and bone marrow stromal stem cells. Hematopoietic stem cells give rise to all the different types of blood cells found in the body, while bone marrow stromal cells are found in bone marrow and don’t give rise to blood cells; instead they give rise to bone, cartilage, fat and fibrous connective tissue. Adult stem cells can be found in the brain, bone marrow, peripheral blood, blood vessels, skeletal muscles, skin and liver. Researches are discovering that more adult stem cells exist in the body than originally thought; if these cells can be grown and controlled within laboratories, they may be able to help combat illnesses such as Parkinson’s disease and Type 1 diabetes. They may also help restore cardiac muscle cells after a heart attack. It has been noted that adult blood forming stem cells found in the bone marrow have been used in transplants for over 30 years.

It is important to think about the scientific hurdles we might overcome with the research of stem cells; both embryonic and adult. We may be able to treat diseases and injuries so far untreatable in our world and may be able to change the face of science and medicine. Though research of this topic may step on ethic’s toes, it is my opinion that sacrifices are sometimes made in the name of science and bettering the world overall.

It is also important to realize that embryonic stem cells are not gathered from embryos that have been created in “traditional” terms; that is to say that no embryos removed from a woman’s body through abortion are used; only those that are created in labs for the specific use of in vitro fertilization. Though the blastocysts used in this research are fertilized beginnings of human beings, they are not used to impregnate a woman and are donated with the full and informed consent of a woman. Therefore, these cells would never amount to a human because they lack the tools necessary (a woman’s body) to grow and mature. In that case, is it wrong to use these blastocysts to gain a better understanding of the human body? No clear answer exists and each individual will have a differing opinion. However, a large amount of potential has been stowed in these extraordinary cells and their contribution to future science must not be ignored.