October 1, 2003
Phone: (504) 865-5714
"In nature, there's an underlying principle of repair," said Eckhard Alt, professor of cardiology. In fact, nature dictates that a body repair itself wounds heal and missing limbs in crabs and salamanders re-grow. This process of self-repair is promulgated by the existence of stem cells.
"Today, we know that stem cells exist and that they contribute to many physiological processes. For my research group, however, the central issue lies in finding the repository wherein those stem cells necessary for self-repair exist," said Alt.
Tulane has committed to pursuing the use of adult autologous stem cellsfrom a patient's own body, sidestepping those issues related to the use of embryonic stem cells.
While the Tulane Center for Gene Therapy is investigating the use of stem cells from adult bone marrow, Alt and his group are pursuing a different avenueboth having the same goal: to treat a number of diseases in hopes of eradicating them or, at least, diminishing their existence.
Alt and his group found that subcutaneous fat tissue contains stem cells that are particularly well-suited to become heart cells. The impetus for this discovery was Alt's theory that generally babies have many fat cells and that these fat cells are what enable muscular and skeletal development as the babies grow.
"While most people try adding extraneous substances such as drugs or hormones to steer cell development, our hypothesis is that the development of a particular cell is dictated by the microenvironment in which that cell develops," he said. "For example, if you take certain stem cells and put them into the heart, the heart becomes the cells' microenvironment and, therefore, dictates the manner in which such cells shall develop."
Alt and his group found that when stem cells that have been harvested from subcutaneous fat tissue are co-cultured with heart cells, within two weeks, the harvested cells become heart cells and start beating. These "new" heart cells could obviate the need for implanted pacemakers and defibrillators. Human trials in Europe next year will test the ability of stem cells to replace heart cells that have died or are damaged after a heart attack.
It is common for such techniques to be tested in Europe long before they make it to the United States. Alt came to Tulane two years ago from Munich, where he was professor of cardiology at the Technical University of Munich and the director of the German Heart Center. He is a pioneer in the field--with well over 150 patents covering varying aspects of cardiology. In fact, virtually every pacemaker or defibrillator on the market today incorporates an idea that came out of his lab. He was attracted to Tulane by a grant from the Brown Foundation and by the caliber of research and spirit of collaboration he found at Tulane.
"Tulane is a university with incredible breadth of experience and knowledge. Such breadth fosters the development of new concepts and ideas," he said." Often, a development in one field can help to solve a problem in another field." For example, Alt said he once attended a pathology conference on asbestos, just out of curiosity. "This was outside of our field of research, but I was interested to learn that iron atoms that contaminate asbestos contribute significantly to the development of lung disease," he said.
"In cardiology, we have experienced the same phenomenon. Stents used in the treatment of cardiac diseases are traditionally made of stainless steel, and my experience has taught me that stainless steel is disastrous as a substance for implantation into the human body."
Stents are little scaffolding devices implanted in an artery to hold it open. But the buildup of scar tissue around the stent can re-narrow the artery. Alt has developed a stent coated with iridium oxide, which reduces scar tissue, and has also experimented with some that have a drug coating. His group has also been collaborating with the biomedical engineering department uptown to develop an implantable impedance monitor to keep tabs on impedance in the lungs of patients who have experienced heart failure.
"The device will warn the patient when his cardiac output decreases. At that time, he might take diuretics or other measures to prevent further damage," Alt said. The ease of collaboration within the university and with other institutions is one of the advantages of doing clinical research in the United States. "The other major advantage is that research money is available on a much larger scale and people seem truly committed to the betterment of mankind," said Alt.
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