Stem Cells
Stems cells have become a source of hope for treating various diseases affecting the human population today and in the future. Diseases such as cancer and Parkinson's disease, which have puzzled doctors and scientists for many years, may some day be cured by these versatile cells. The knowledge of how stem cells work and their promise to cure diseases is still incomplete as research is in its infancy. It is vital that stem cell research be continued in order to answer these questions and further our application in those people suffering from potentially curable diseases.
Contrary to popular belief, fetuses are not the only source of stem cells used in stem cell research and stem cell transplantation. In fact, these are embryonic stem cells which have not been demonstrated to cure disease at all. Umbilical stem cells are derived from the placenta after the baby has been delivered, so extraction of these cells does not impose on the delivery or pose any threat to the safety of the newborn or the mother. The fact that stem cells can be extracted from the placenta, an element of the delivery process that has traditionally been discarded as biomedical waste, has produced an ethically viable alternative to using fetal tissue that has been aborted or grown in a lab. The placenta is the source of nourishment during pregnancy and once the baby is delivered, as mentioned above, the placenta is usually thrown away. This is still the case at the majority of hospitals in the United States today. University Hospitals of Cleveland is just one of the hospitals in the U.S. that is collecting this blood for stem cell research.
There are two components needed to accomplish this: a person trained to aseptically extract the umbilical cord blood (UCB) and a lab, studying UCB, which is able to process it. The affiliation between University Hospitals of Cleveland and Case Western Reserve University provides both of these components. Kathy Daum-Woods , RN, upon informed consent of the delivering mother, extracts the UCB from the suspended placenta by draining the blood into a sterile collection bag. When not sent to the New York Blood Bank, this bag is then given to Dr. Laughlin's Lab which will process it for the desired cell types within the blood. The processing involves using high-density sugars to create density gradients that settle out the desired cells through a combination of gravitation and centrifugation.
One of the drawbacks of UCB is the limited quantity. It is limited not only by the number of people able to donate UCB, but also by the volume that is obtained per collection. Like the baby itself, the placenta is very small and the average amount of blood recovered from a placenta is about 80-100 ml. A single cord blood collection, when transplanted into a child with a hematological malignancy (cancer of the blood), has been shown to have the ability to give the child an entirely new immune system (cancers of the blood involve a defective immune system). During the course of her work, Dr. Laughlin demonstrated that this could be accomplished in adults as well (New England Journal of Medicine 344 (24): 1815-22, 2001). F urthermore there was no need for the donor and recipient to be related in order for the procedure to be successful. However, there must be a certain number of cells per weight of the patient (1x10 7 MNC/kg) before a transplant can proceed. Research has shown it is possible to expand (multiply the cells through culturing) the number of cells but they tend to lose the properties that make them valuable in the first place (i.e. their ability to differentiate into desired cells). But research done in the Laughlin lab has shown that this loss of stem cell properties can be significantly reduced when they are cultured on a layer of Mesenchymal Stem Cells (MSC) found in the bone marrow and cytokines, which are soluble communication vessels that give instructions to cells. Preliminary studies of using multiple cord blood collections to transplant a single patient have been done but the benefits have yet to be elucidated.
JB
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