An Interview with Yuval Levin Scientists largely agree that stem cells may hold a key to the treatment, and even cure, of many serious medical conditions. But while the use of adult stem cells is widely accepted, many religious groups and others oppose stem cell research involving the use and destruction of human embryos. At the same time, many scientists say that embryonic stem cell research is necessary to unlock the promise of stem cell therapies since embryonic stem cells can develop into any cell type in the human body. In lateresearchers in the United States and Japan succeeded in reprogramming adult skin cells to act like embryonic stem cells.
So humble an entity, so hot a potato: The panel recommended ethical guidelines for all future federally funded research on human embryos.
These guidelines helped influence President George W. Stem-cell research has enormous potential value in both medical and commercial terms. Stem cells are the progenitors of all specialized cells in the body. Blood stem cells hematopoietic cells reside in bone marrow and continuously produce a variety of blood and immune system cells.
Mesenchymal stem cells are the source of new bone, cartilage, and connective tissue cells. Neuronal stem cells produce a variety of nervous system tissue, mostly during early embryonic development but, as we are beginning to learn, later in life as well. During early development the precursors to all these more specialized stem cells, sometimes called "pluripotential stem cells" PSCsare found in the inner cell mass of the preimplantation embryo and in certain cell populations of the early fetus.
Stem-cell research took a great leap forward inwhen two independent research groups, led by Dr. John Gearhart of Johns Hopkins University, reported success in growing human stem cells in culture.
Thomson and Gearhart, using different approaches, had isolated these very early precursor cells and spread them out on a feeder layer of mouse cells to produce an immortalized pluripotent human stem cell culture. This resetting Stem cell debate the cells to be cultured indefinitely during repeated cell divisions or passages.
One day, doctors treating a cancer patient with chemotherapy may be able to replace his or her damaged blood or marrow cells with new ones grown from ES cells.
In the future, when better understanding has been gained of the growth factors that induce specific forms of cell differentiation, immortalized PSC lines like these may be induced to produce specific tissue types.
Also on the distant horizon lies the possibility of new cardiac tissue for heart attack victims, replacement blood and marrow cells for those who have undergone chemotherapy or radiation therapy for cancer, new skin tissue for burn victims, bone for those suffering from severe fractures or osteoporosis, and so on.
Closely studied, stem cell lines might give scientists new clues about the growth factors that drive tissue differentiation from the earliest embryonic stage forward.
This would permit new understanding of cellular abnormalities, including cancer, and new ways of steering cell differentiation in desired paths. At the end ofthe journal Science, in a special cover article and editorial, declared pluripotent stem cell research to be the scientific "breakthrough" of the year.
Inthe journal Science declared pluripotent stem cell research the scientific "breakthrough" of the year.
A funding issue Major legal, ethical, and political hurdles stand in the way of these advances. In large part, these obstacles result from the fact that, of the three sources of stem cells, human embryos are the most promising. One source is the "adult," or mature, stem cells that reside in the body from infancy onward.
These cells are "multipotent," meaning they are able to produce a range of related tissues, such as the differing types of blood system cells. A second source is embryonic germ cells that are derived from the primordial reproductive tissues of aborted early fetuses. These are the cells that John Gearhart used in his research.
They are pluripotent, able to give rise to all tissue types, although recent research suggests that their usefulness in cell-replacement therapies might be limited because they have already begun to take on some specific characteristics of their reproductive function.
Finally, there are ES cells, derived from the inner cell mass of blastocyst-stage embryos. These pluripotent cells are the most ubiquitous of all.
Once removed from the blastocyst they lack the outer trophoblast structures for continued embryonic development, but they can theoretically be "nudged" into becoming any cell type found in the human body.
These are the cells that Thomson used in his research. In a trice, the groundbreaking work of James Thomson left and John Gearhart brought the issue of government funding of stem-cell research to the fore. Three issues spurred the debate over whether or not the government should fund stem-cell research.
One concerned the moral status of PSCs themselves. Are they morally protectable entities, or are they more like other disposable tissues gleaned from the human body? A second issue concerned the derivation of PSCs.
Assuming that at least during the earliest phases of research, human embryos produced via in vitro fertilization IVF would be the best source for producing immortalized stem cell lines, could research go forward that depended on the dissection of living human embryos?
Someday researchers may create new ES cells lines using a technique similar to that brought to bear in the birth of Dolly, the famous cloned sheep. Finally, there was the question, still somewhat remote but now looming:The Stem-Cell Debate Part 2 | Back to Part 1 Moral seasoning.
Regarding the second issue I mentioned above - that of derivation of PSCs—presuming that at least initially such stem cells will. Supporting scientists, educators & innovators since , the Academy offers scientific symposia, webinars, career readiness training & youth STEM programs.
I get asked many questions about stem cell therapies, but one of the most common over the years has been about the stem cell treatment cost.
For instance, a reporter might ask, “How much does a stem cell treatment for MS cost?” and a patient might ask me, “How much is a fair cost for a stem cell . The benefits of stem cell research outweigh the cost in terms of embryonic life.
Embryonic stem cells have the capacity to grow indefinitely in a laboratory environment and can differentiate into almost all types of bodily tissue.
At the heart of the stem cell debate is a battle over abortion — but with a twist. Yes, these are cells from embryos. And according to the religious orthodoxy, an embryo is life. The book Stem Cell Research: New Frontiers in Science and Ethics by Nancy E.
is a collection of essays produced at the symposium, titled with the same name.