Does not acknowledge that embryonic stem cells are
unnecessary for medical progress
In their recent paper on stem cell research, the Canadian Institutes of Health Research acknowledges the existence of non-controversial sources of stem cells, including adult tissues, but maintains that they are not as useful as embryonic cells, which are derived from “left-over” embryos created through in vitro fertilization: “Recent evidence that adult stem cells may have broader potency than first thought raises possibilities for reprogramming adults stem cells for tissue-based repair.”
Some experts say that this is pure mythology. British researcher, Dr. Helen Hodges, says adult stem cells may prove safer and more flexible than fetal cells. Some of her work shows adult cells traveling to the area needing repair, whereas fetal stem cells remain where they are injected. Also, because a patient can often “donate” their own adult stem cells for treatment, his immune system won’t reject them. A person treated with embryonic cells has to take drugs for the rest of his life to prevent the rejection of the tissue, says Prof. David Prentice, a professor of life sciences at Indiana State University.
Furthermore, already in 1999, the journal Science reported that adult stem cells were “much more accessible and can develop into a surprisingly broad repertoire of cell types.” Prof. Prentice says that “in the last two years, we’ve gone from thinking that we had a very few stem cells in our bodies to recognizing that many (perhaps most) organs maintain a reservoir of these cells.” He also says that bone marrow and umbilical cord blood are already successfully used clinically, while clinical use of embryonic cells is still years away.
Adult stem cells have shown themselves to be scientifically more successful than embryonic stem cells, he says, both because of the variety of different tissues they can be become and from a manufacturing perspective. The process of turning the stem cells into new tissue is a much shorter and easier process with adult cells, he says, explaining the risk that embryonic cells can be contaminated, causing them to produce tumors.
corSome work has been done indicating the usefulness of cells from the umbilical cord and placenta. In February of this year, Dr. Paul Sanberg from the University of South Florida reported on research that holds out the possibility that umbilical cord cells could be used to help people recover from strokes.
In April of this year, the New Jersey biotech company, Anthrogenesis Corp., reported that it had developed a method to extract a new kind of stem cell from the placenta that it hopes will be as useful in research as embryonic cells.
Sacred Heart University School of Medicine in Italy has set up a stem cell bank so that people can store the blood from their children’s umbilical cord and placental material in case they need it for future treatment. Salvatore Mancuso, director of the Institute of Gynecology of the Catholic University of Rome, discussed the usefulness of such storage at the August 2000 International Congress of the Transplants Society. The practice of stem cell banking is now becoming more and more common.
Researchers have also been able to extract useful adult stem cells from bone marrow, blood and eyes, as well as brain, muscle and skin tissue. They have been able to turn them into fat, bone, cartilage, muscle, blood, nerve and liver cells. Many of the studies so far have been performed on rats and other animals with similar results being anticipated for people, once they are ready to start testing the research on humans.
Deceased individuals have been seen as a possible, though impractical, source of stem cells because, until recently, researchers believed that one could only harvest stem cells from people for up to two hours after they died. Fred H. Gage of the Salk Institute at LaJolla, California, however, reported last year that he has been able to extract useful brain cells from donor cadavers 10 hours to three days after death. He was able to grow them into a number of different nervous system cells.
Last July British researchers reported on work that indicated the potential of generating new liver tissue from a patient’s own bone marrow. The findings, reported in the journal Nature, were made in London by teams from the Imperial Cancer Research Fund, Imperial College School of Medicine, and the Royal Free Hospital.
Then in August, researchers at New Jersey’s University of Medicine and Dentistry and Philadelphia’s MCP Hahnemann University published in the Journal of Neuroscience Research the results of work converting adult bone marrow cells into nerve cells. This research pushed the limits that researchers previously believed would make adult stem cells less beneficial than embryonic cells.
Also in August, Dr. Paul Sanberg from the University of South Florida’s College of Medicine, with other researchers, turned adult stem cells from bone marrow into immature nerve cells which, in turn, may develop into functioning neurons which could be used to help repair damaged brain tissue.
In October, the journal Neuroscience reported on the work of researchers at Italy’s Stem Cell Research Institute and National Neurological Institute. They took stem cells from an adult brain and grew them into skeletal muscle in a laboratory culture and in animals.
Canadian researchers at the McGill University Health Centre have injected bone marrow stem cells directly into the heart, which developed into heart muscle cells. They unveiled their findings last November to the American Heart Association. In March of this year, the journal Medicine reported on successful research at New York Medical College turning adult stem cells into heart cells in mice.
In April of this year, another report from Britain discussed the benefits of adult stem cells for healing brain cells damaged by strokes. The research at the Institute of Psychiatry in London was led by Dr. Helen Hodges and published in the Stroke Journal.
Human fat has now also been identified as a source of useful stem cells. Research by Marc H. Hedrick of the University of California Los Angeles School of Medicine and Adam J. Katz of the University of Pittsburgh School of Medicine was published in April in the journal Tissue Engineering. The researchers turned the fat into healthy cartilage, muscle and bone cells. Jeffrey Gimble of the North Carolina company, Artecel Sciences, has made similar discoveries, but has yet to publish his research.
Other methods being used to try to take advantage of these modern technological advances include the development of drugs for activating natural stem cells within people’s tissues, says Donald P. O’Mathuna, a professor of bioethics and chemistry at Mount Carmel College of Nursing in Columbus, Ohio.
