Tuesday, March 10, 2009
Embryonic Stem Cells and the Future of Transplantation
It is a promise that is already being kept with adult stem cells used for treating patients with immune defects, usually children, or those with some cancers. Sometimes doctors use the patients own stem cells to give the bone marrow a “boost” after intensive chemotherapy for cancer [called autologous transplants.] Or the stem cells of a closely matched donor are used for a leukemia patient to not only restore the bone marrow after aggressive therapy but also to attack any remaining leukemia cells [known as allogeneic transplants.]. And adult stem cells are being used today in research studies of patients who have had heart attacks leaving their heart muscle weakened.
The president has just created an important enablement to further research on stem cells. Yes, it is true that much can be done with adult stem cells but science so far suggests that embryonic stem cells hold promise for much more benefit. It will probably be embryonic stem cells that pave the way for replacing the islet cells of the pancreas with new insulin producing cells to cure diabetes or replace the damaged cells in the brain that are key to Parkinson’s disease. Some strongly feel that it is wrong to use cells form embryos. It is important to remember that these are fertilized eggs that were prepared for couples that could not conceive and so had eggs and sperm placed into a dish with special fluids. Experience has shown that success is better if the doctor implants a few embryos into the woman’s uterus rather than just one. But the doctor may have more than enough embryos and the extras will be discarded if the woman becomes pregnant. I look at it this way. Since the embryos will be destroyed anyway, why not use them for creating stem cells that perhaps many people with diverse diseases might benefit from. It is not dissimilar to transplanting the organs of a person who has died in a car accident rather than burying them in the grave. And there is no issue about “human cloning” – that is just not what is being done or proposed. And the embryo, made up of just a few cells, is disrupted so each cell grows independently. Now the cells can be stimulated to become heart cells, liver cells or what ever might be useful in treating a disease. It will take some years but there will certainly be major advances in how we can repair, restore or replace damaged tissues or organs.
Praise for Dr Schimpff
The craft of science writing requires skills that are arguably the most underestimated and misunderstood in the media world. Dumbing down all too often gets mistaken for clarity. Showmanship frequently masks a poor presentation of scientific issues. Factoids are paraded in lieu of ideas. Answers are marketed at the expense of searching questions. By contrast, Steve Schimpff provides a fine combination of enlightenment and reading satisfaction. As a medical scientist he brings his readers encyclopedic knowledge of his subject. As a teacher and as a medical ambassador to other disciplines he's learned how to explain medical breakthroughs without unnecessary jargon. As an advisor to policymakers he's acquired the knack of cutting directly to the practical effects, showing how advances in medical science affect the big lifestyle and economic questions that concern us all. But Schimpff's greatest strength as a writer is that he's a physician through and through, caring above all for the person. His engaging conversational style, insights and fascinating treasury of cutting-edge information leave both lay readers and medical professionals turning his pages. In his hands the impact of new medical technologies and discoveries becomes an engrossing story about what lies ahead for us in the 21st century: as healthy people, as patients of all ages, as children, as parents, as taxpayers, as both consumers and providers of health services. There can be few greater stories than the adventure of what awaits our minds, bodies, budgets, lifespans and societies as new technologies change our world. Schimpff tells it with passion, vision, sweep, intelligence and an urgency that none of us can ignore.
-- N.J. Slabbert, science writer, co-author of Innovation, The Key to Prosperity: Technology & America's Role in the 21st Century Global Economy (with Aris Melissaratos, director of technology enterprise at the John Hopkins University).