Stem cell confusion.Byline: The Register-Guard OK, in the world of stem cell stem cell In living organisms, an undifferentiated cell that can produce other cells that eventually make up specialized tissues and organs. There are two major types of stem cells, embryonic and adult. breakthroughs, this one left a lot to be desired. Turns out it isn't the bioethical magic bullet (jargon) magic bullet - (Or "silver bullet" from vampire legends) A term widely used in software engineering for a supposed quick, simple cure for some problem. E.g. "There's no silver bullet for this problem". that allows embryonic stem cells Embryonic stem cells (ES cells) are stem cells derived from the inner cell mass of an early stage embryo known as a blastocyst. Human embryos reach the blastocyst stage 4-5 days post fertilization, at which time they consist of 50-150 cells. ES cells are pluripotent. to be created without harming the host embryo. Not that anyone would have guessed that from Robert Lanza's bold pronouncement in a paper published online Aug. 23 in the prestigious journal Nature. "What we have done, for the first time," Lanza wrote, "is to actually create human embryonic stem cells without destroying the embryo itself." Well, not exactly. In fact, all 16 of the embryos used in Advanced Cell Technology's research were destroyed. That information is contained in Lanza's paper, but Nature's abstract and press release focused narrowly on the principle proven by the research, which critics say overhyped the results. It was the hype that dominated headlines: "Stem cell experiment solves ethical dilemma An ethical dilemma is a situation that will often involve an apparent conflict between moral imperatives, in which to obey one would result in transgressing another. This is also called an ethical paradox ." "Embryos unharmed in research breakthrough." If Lanza's scientists at Advanced Cell Technology had found a way to create new embryonic stem cell lines without destroying the host embryos, it could clear the way for millions of dollars in federal funding for further research. Religious concerns over the destruction of embryos led President Bush to veto a bill authorizing federal funding for embryonic stem cell research. The stem cell debate is complex and can be confusing. There are essentially two types of stem cells stem cells, unspecialized human or animal cells that can produce mature specialized body cells and at the same time replicate themselves. Embryonic stem cells are derived from a blastocyst (the blastula typical of placental mammals; see embryo), which is very young - adult and embryonic em·bry·on·ic or em·bry·on·al adj. Of, relating to, or being an embryo. Embryonic In the life cycle of the round worm, a very early life stage occurring within the uterus of the female round worm. . Both types have the ability to make identical copies of themselves and to divide into other specialized types of cells. Adult stem cells Adult stem cells are undifferentiated cells found throughout the body that divide to replenish dying cells and regenerate damaged tissues. Also known as somatic (from Greek Σωματικóς, of the body , which can be extracted from bone marrow, aren't as versatile as embryonic cells Noun 1. embryonic cell - a cell of an embryo formative cell cell - (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and , which can differentiate into almost any type of cell in the human body. What Lanza actually did was extract 91 cells from 16 embryos in order to create two new stem cell lines A stem cell line is a family of constantly-dividing cells, the product of a single parent group of stem cells. They are obtained from human or animal tissues and can replicate for long periods of time in vitro ("within glass"; or, commonly, "in the lab", in an artificial . A technique already exists - pre-implantation genetic diagnosis, in which a single cell is extracted from an embryo for genetic analysis - which shows that embryos can regularly survive such a procedure. Lanza said it wasn't necessary to prove that process. But Lanza's 2 percent success rate in creating new cell lines, coupled with the loss of 100 percent of the embryos, left many scientists with questions - not about how the research was conducted, but about how it was presented. Lost in the disappointment over the ambiguous breakthrough is the hunger within the scientific community and the American public for substantive embryonic stem cell research. Even opponents of research involving human embryos held their breath, hoping that Lanza had cleared the way for their support. That's why efforts to advance the understanding of embryonic stem cells must continue on all fronts. Whether it comes via a scientific breakthrough or a veto-proof majority in Congress, President Bush must be forced to lift his restrictions on this life-saving research. |
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