Stem cell treatment has been a subject of debates since the early 21st What do you think about the current developments in stem cell treatment?
Answers
It is rare that a field of scientific research can both have an enormous potential impact on human health and quality of life and be a fount of new basic research discovery. Stem cell biology is surely one such field, offering hope for curing scourges like diabetes, Parkinson's disease, neurological degeneration, and congenital heart disease, as well as bringing together many disciplines of cell and molecular biology. Five years ago, stem cell biology was an exciting but rather restricted area of science with growing basic science and clinical implications. Currently, the existence of stem cells is a matter of public discussion, with religious, ethical, political, and economic implications. A week does not go by without some new revelation, about either the politics or biology of stem cells in the general press. What has changed? Clearly we know more about the biology of these cells, but the public interest has been driven by their potential in the treatment of disease on the one hand and concerns for the ethical implications of their use on the other. Some of the arguments are semantic and can be resolved by making sure that everyone is using the same terms to discuss the topic. Other concerns are theoretical and religious, such as defining when human life begins, and reflect beliefs and philosophies rather than the facts and data that scientists are restricted to when formulating coherent models. Science relies on facts, and many of the extraordinary claims made about stem cells in the scientific and public domain need to pass the important test of independent verification.
Stem cells are loosely defined as self-renewing progenitor cells that can generate one or more specialized cell type. In vertebrates, stem cells have been traditionally subdivided into two groups. The first group consists only of embryonic stem (ES) cells, which are derived from the inner cell mass of the blastocyst and are capable of generating all differentiated cell types in the body (pluripotent stem cells). ES cells in turn generate the second group, which are called organ- or tissue-specific stem cells (multipotent). Such stem cells generate the cell types comprising a particular tissue in embryos and, in some cases, adults. The prototypic example of this second group is the hematopoietic stem cell, which generates all of the cell types of the blood and immune system. In addition to existing in the blood, there are stem cells that survive throughout life in many other organs of the mammalian body. In some tissues, like the intestine and skin, ongoing cellular turnover provides a rationale for the persistence of stem cells. In other organs, however, such as the brain and heart, stem cells are present, i.e., they can be isolated from these tissues, grown in culture, and then induced to differentiate, either in vitro or after transplantation in vivo. However, it is unclear whether they are actually used by the body to replace diseased or damaged cells.