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© 2011, 2012 Health Futures Digest
| Population aging means heart disease could be a growing burden on healthcare systems the world over, but not if stem cell therapies currently in various stages of development are fully validated and become widely accessible. And the breakthroughs keep on coming. “Labs-on-a-chip” are contributing to stem cell therapy research, stable and pure nerve cells (needed for treating neurodegenerative disease) have been created, and a new method for purifying hematopoietic stem cells for transplant into sickle cell patients also has potential for autoimmune disease and some cancers.
The possibility of avoiding the ethical distress of those who oppose the therapeutic use of embryonic stem cells remains alive, most recently with research pointing to a possible way to create human embryonic stem cells from adult cells. However, the Harvard researchers responsible for the discovery caution against using it to support restrictions on other methods of embryonic stem cell research. The same caveat applies to placental cells, another potential alternative to embryonic stem cells for therapy. Even so, as the section on Tissue Engineering shows, adult stem cell-based therapies are much more than mere possibilities. |
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| Heart Therapy and Impact on Healthcare Costs
Source: Advisory Board Daily Briefing (subscription service), October 25: “Seniors’ heart drug regimens becoming more complex and costly.””>Source article In animal studies, adult stem cells harvested from bone marrow or skeletal muscle are able to regenerate muscles and arteries in damaged hearts, and human clinical trials in humans have begun, though no-one knows just how the therapy works. In one pig study presented in 2004, seven of 14 pigs given induced heart attacks almost fully recovered after being injected (directly into the heart) with mesenchymal stem cells extracted from another pig’s bone marrow. The untreated pigs developed congestive heart failure within two months of their heart attack. Six research centers in the US have begun a small human test of this therapy among 48 recent (within 10 days of attack) heart attack victims, but with the mesenchymal stem cells infused into the bloodstream rather than injected into the heart. German scientists meanwhile have already completed two studies of 100 cardiac patients, but their method used stem cells extracted from volunteers’ bone marrow and the cells were injected into the heart. The result was at least 10 percent improvement in cardiac function. European researchers have also recently launched a 300-patient trial using skeletal stem cells harvested from muscle in participants’ legs. Again, the cells will be injected directly into the heart. British researchers have also launched a 700-patient clinical trial using adult stem cells from bone marrow to repair damaged heart muscle. 300 of the patients have heart disease or have suffered a previous heart attack; 200 are patients with dilated cardiomyopathy; and the remaining 200 patients who have recently had a heart attack. Some patients will have stem cells extracted from bone marrow in their hip and injected into the major coronary arteries or directly into the heart. Others will receive injections of growth factor drugs to try to cause stem cells to spill out of their bone marrow and into their blood without the need for harvesting and injection. This study is being funded by a British man who received stem cell injections in his failing heart two years ago in Germany, after being told he had just a couple of months to live. In addition to the obvious clinical benefit to patients, stem cell therapy for heart disease and damage could have significant beneficial impact on the cost of healthcare, given that the cost and complexity of traditional heart drug regimens in elderly patients are increasing rapidly, according to a study by Masoudi et al., published October 10 in the US Annals of Internal Medicine. Using a lab-on-a-chip, researchers at the Whitehead Institute for Biomedical Research have discovered the secrets of pluripotency in human embryonic stem cells — their ability to become any type of cell in the body except a germ cell. The researchers “uncovered a key part of the wiring diagram for these cells and can now see how this is accomplished,” said one. Knowing the wiring diagram means researchers should be able to modify it to facilitate repairs to damaged or diseased cells or to make cells for regenerative medicine. The system (custom arrays) can now be purchased from Agilent Technologies Agilent for $500 to $700 each, and used to find other gene regulators. The sustained growth of pure (non-cancerous) neural stem cells by Scottish and Italian scientists offers hope for the replacement of damaged neural tissue in Alzheimer’s and Parkinson’s sufferers. They will also be used to test the effectiveness of new drugs, and could replace animals in that role. Previous attempts to grow nerve cells have produced contaminated samples that have not been scientifically useful. A method for purifying hematopoietic stem cells removed from the blood to treat sickle cell disease will begin clinical trials in early 2006. The method is intended to increase the safety of stem cell transplantation and broaden the supply of potential donors by eliminating the need to biologically match a recipient to a donor because of the presence of infection-fighting T-cells present with stem cells that are transplanted. The technology could therefore benefit autoimmune disease and certain cancers as well. The use of stem cell transplants has been limited by the risk of the potentially fatal attack of immune cells from the donor on the recipient’s body, known as graft-vs.-host disease. Children with severe cases of sickle cell disease who have a sibling donor with compatible antigens and no genes for the disease are the only ones for whom a transplant has been safe enough to attempt. Regressing to Embryonic State Through Fusion Harvard scientists have created cells similar to human embryonic stem cells by fusing human skin cells with an embryonic stem cell. The method is “inefficient and deeply flawed at this point,” the scientists admit, and — explicitly recognizing that their work could be misused by opponents of embryonic stem cell research — emphasized that it should not deter embryonic stem-cell research that involves embryos, nor diminish support for such research. Like embryonic stem cells, the fused cell is pluripotent (it can turn into any one of many different types of cells), and has the same chemical markers. But the fused cell contained twice the genetic material that cells usually carry. Unless a way can be found to prevent or remove the excess genes, such cells would be too risky for therapeutic use in humans. It also took about 50 million skin cells and 50 million embryonic stem cells to yield just 10 or 20 of the fused hybrid cells, although the latter were stable and could be multiplied in culture. But if the inefficiencies and flaws can ever be eliminated, the method would supply vastly greater quantities of embryonic stem cells and stimulate research. Primitive cells found in the amnion (the outer membrane of the amniotic sac and a part of the placenta) look very similar to ESCs and have been coaxed by researchers at the University of Pittsburgh into becoming a variety of cell types. Placenta are in plentiful supply, with four million children born in the US alone each year. The cells carry the Oct 4 and nanog genes, which so far have only been seen in ESCs. Signs that they may not be true stem cells are that, in tests, they did not form tumors, as a true stem cell would, and did not appear to be immortal. But they were coaxed into forming what looked like heart, nerve, liver, and pancreatic cells. |
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