As noted previously, oligo- and multipotent stem cells
are present in many adult tissues (as opposed to
omnipotent embryonic blastocyst cells**); treatments
for Type I diabetes ("autoimmune") and damaged heart
muscle have been devised using these types of cells.http://my.webmd.com/content/Article/76/90334.htm?printing=true "...The researchers hit on a way to regenerate the insulin-making islets in the pancreas that function in response to blood sugars. "We have found that it is possible to rapidly regrow islets from adult precursor cells, something that many thought could not be done," Faustman says in a news release. "By accomplishing effective, robust, and durable islet regeneration, this discovery opens up an entirely new approach to diabetes treatment." [Pancreatic islet cells are the insulin-secreting ones, which are attacked and destroyed by T-cells in this mouse model.] "...Somehow, their [the diabetic mice in this study] islet cells regenerated themselves. Further study showed that the spleen-cell injections didn't just retrain the animals' immune systems. They did two other things: The spleen cells triggered self-regeneration of islets. Some of the spleen cells themselves became part of the new islets..." While this particular study isn't in PubMed yet, searching with <<pancreas AND "islet cells" AND spleen AND mouse>> yields 67 hits... Damaged heart muscle, once thought to be irreplaceable, has since been shown to have some regenerative potential [I think it was the post-mortem finding of *opposite-gendered* cardiac cells in heart transplant recipients that suggested cardiac stem cells existed somewhere in the body]. Bone marrow and cells extracted from blood (umbilical cord blood is particularly rich in various stem cells) have been used to repair at least some of the damaged myocardium. http://www.nhlbi.nih.gov/new/press/01-06-06.htm "Challenging one of medicine's long-standing beliefs, a team of scientists funded by the National Heart, Lung, and Blood Institute (NHLBI) and the National Institute on Aging (NIA) has found the strongest evidence to date that human heart muscle cells regenerate after a heart attack..."There are preliminary indications that primitive cells like stem cells exist in the human heart. Stem cells may have the ability to develop into the various cardiac cell types and form new healthy functioning myocardium. If we can prove the existence of cardiac stem cells and make these cells migrate to the region of tissue damage, we could conceivably improve the repair of damaged heart muscle and reduce heart failure," says Anversa. "Research on animal models supports this possibility... the Anversa team and a colleague at the NIH reported that adult stem cells isolated from mouse bone and injected into a damaged mouse heart became functioning heart muscle by developing into myocytes and coronary vessels. Moreover, the newly formed tissue partially restored the heart's ability to pump blood..." [This is a 2001 press release.] http://www.msnbc.com/news/991642.asp?0sl=-23 "GERMAN RESEARCHERS showed that cells taken from the bone marrow and washed into the heart soon after heart attack helped patients recover better than patients given standard care...Dr. Ray Gibbons of the Mayo Clinic in Rochester, Minn., said a 6.7 percent improvement could be enough to tip a patient over from questionable survival to long-term survival... "...Dr. Emerson Perin and colleagues at Baylor College of Medicine and the University of Texas Health Science Center in Houston injected a certain type of stem cell called CD34 cells directly into the hearts of heart failure patients. All could later exercise � after being barely able to walk around their homes. �They�re functional and they have their lives back,� Perin said. Five patients who were waiting for heart transplants are now off the transplant list..." [A 2003 report.] This report, from a diagnostic equipment company, goes into a little more detail on how stem cells are extracted from adult blood, as well as discussing another stem cell heart repair trial: http://www.coulter.com/resourcecenter/diagtoday/articles/features/huntermedical.asp?pf=1 Debbi **Many adult stem cells are already partially differentiated, so that one might be able to become a bone or cartilege cell, frex, but not a neuron; some of their "potentiating" genes have been permanently 'turned off.' Of course, with research, it might be possible to 'regressify the cell,' so that it in fact becomes an embryonic stem cell. However, the problem of shortened chromosome ends - which is likely one of the difficulties with animals cloned from adult cells - will have to be rectified. __________________________________ Do you Yahoo!? Protect your identity with Yahoo! Mail AddressGuard http://antispam.yahoo.com/whatsnewfree _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
