Stem Cells: The Holy Grail of Medical Research

Few scientific issues in recent years have managed to draw as much attention, both scientific and otherwise, than stem cell research. I was first introduced to the term 'stem cells' when I was in high school, and since then, I have had a keen interest in the direction science is taking them. When considering medical research as a whole, stem cells appear to have the makings of a 21st century medical revolution a la discovery of antibiotics . The open-ended nature of stems cells has been recognized by many in the community who see these cells as the golden key for curing and ameliorating many degenerative diseases such as diabetes, Parkinson's, and heart disease, as well as accidental damage such as a spinal cord injury. Clearly, stem cells hold a great deal of promise in medical research and I feel that being more than casually aware of something that will greatly affect health care and my future studies if I chose to pursue medical research in graduate school, is critical. Unfortunately, having not had the occasion to do my own research on the subject, I feel this assignment presents the perfect opportunity (and encouragement) to explore the area.

First isolated in 1998, stem cells are the body's clay, having the potential to become any type of cell. Stem cells are divided into two classes - adult and embryonic. Adult stem cells are found among already differentiated cells of specific tissue and can usually only become one certain type of cell (blood, marrow, liver etc.) Embryonic stem cells are cultured cells obtained from the inner part of a blastocyst - a very early embryo that has divided into about 100 cells. This type of stem cells is particularly controversial because the cells must be extrancted from an embryo. However, to do this the embryo must be destroyed, a process which some believe is tantamount to taking human life.

Nonetheless, embryonic stem cells have a number of remarkable properties, properties which make them very desirable for use in medicinal research. For instance, stem cells can be grown infinitely. Unlike other permanent cell lines which are apt to mutate in later passages, embryonic stem cells remain 'normal' regardless of how long the cell line has been carried out. They also have the ability, under the right conditions, to give rise to all cell types of the body. Despite these advantageous properties, there is one glaring problem that remains in the usage of embryonic cells and that is the body's immune response of rejection. The few stem cell lines that have been established are simply not a viable solution for the entire population. One way to remedy this problem would be through the establishment of a bank that contained hundreds of cell lines. This would increase the chance of a patient finding a match and thus decreasing the chance of an unfavorable immune response. However, the current administration has shown a continued unwillingness to increase our stem cell bank, a move which might prove to be less than smart for a country trying to remain at the forefront of medicinal research.

An apparently convenient solution to this dilemma appeared not long ago in the form of a sheep. In 1997, a lab Edinburgh, Scotland developed a technique which showed that it was indeed possible to reprogram the nucleus of an adult cell. Their novel approach was based on the following:

A unfertilized egg contains a large amount of jelly-like material known as the cytoplasm which contains factors that under normal circumstances reprogram the incoming sperm nucleus such that an embryo is formed. However, these factors are also capable of reprogramming an adult cell's nucleus that can be injected into the egg. By removing the egg's own nucleus and replacing it with one from an adult cell, it is possible for this hybrid cell to become an embryo.

This greatest benefit from this technique is that because the egg is never fertilized, scientists are able to take advantage of these embryonic stem cells without having to worry about ethical issues.

There are, however, other options available that avoid completely the scarlet letter which of embryonic cells. Rather than using stem cells from an embryo - which is both controversial and difficult due to the lack cell lines - scientists have found promise in adult stem cells. Research has determined that adult stem cells found in the body have the potential to differentiate into different types of cells. Researchers at the Louisiana State University tested adult stem cells from bone marrow to provide a therapy for Cystic Fibrosis. They discovered that, if put into the right environment, stem cells from bone marrow could differentiate into airway epithelia - the tissue in the lung that is damaged by Cystic Fibrosis. It is normally very difficult and tedious to isolate adult stem cells within the tissue due to the fact that there is simply not many of them to be found. However, the group at Louisiana made a significant advance in adult-cell separation with the development of their air-liquid-interface coculture method for isolating the stem cells from the bone marrow. This method could facilitate the exploration of bone marrow stem cells for therapy of different lung diseases. However, there are some disadvantages from using these adult stem cells. As stated above, they are often rare and

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