And perhaps most importantly of all, the UW researchers continue, stem cells "...provide our only window to the earliest stages of human development and, after differentiation, access to more specialized cells that could vastly improve our understanding of the onset of cell-based diseases, and perhaps ways to prevent them."
Among the diseases that may be able to be treated - and even cured - through stem cell research are Parkinson's Disease, Alzheimer's, diabetes, heart disease, stroke, spinal cord injuries, burns, and more. How many people could be helped, even relieved of enormous suffering, through successful stem cell science is unknown, but certainly there are millions who cry out for help.
Medical researchers highly value stem cells because they can develop into many types of human tissue," according to an article in the Washington Post (Babbington, 2004). Stem cells "...hold promise for treating spinal injuries among several other afflictions," Babbington explains. And where the controversy enters into the picture is the fact that some stem cells can be obtained from "adult tissues, but more versatile cells come from human embryos," embryos which are frozen and left over at fertility clinics.
Many researchers currently working on this science use stem cells "from embryos at an early stage of development, about five days after fertilization," Brainard writes. At five days "the embryo numbers only about 200 cells," and all of them are "capable of specializing into all of the cells that make up the body," including such key parts as brain neurons and heart muscle, Brainard explains.)
And so, if using human embryos is so controversial, why not take stem cells from adults? The UW Stem Cell Center answers that question by pointing out that currently, there are indeed a series of approaches in experimental stages "...that utilize mature stem cells (such as blood-forming cells, neuron-forming cells and cartilage-forming cells)." The problem though is that "...because adult cells are already specialized, their potential to regenerate damaged tissue is very limited."
For example: the only thing skin cells will become is skin, and cartilage cells only become more cartilage. "Adults do not have stem cells in many vital organs," the UW explanation continues, "so when those tissues are damaged, scar tissue develops. Only embryonic stem cells, which have the capacity to become any kind of human tissue, have the potential to repair vital organs."
Another shortcoming of adult stem cells is that they do not proliferate in culture like embryonic stem cells do. In fact, "adult stem cells are difficult to grow in the lab and their potential to reproduce diminishes with age." Hence, useful, functioning amounts of adult stem cells may prove to be "difficult to obtain." very recent and positive research result on stem cell science
According to an article in the Washington Post (Weiss, 2004), scientists in Haifa, Israel (Izhak Kehat and Lior Gepstein), working in the Technion-Israel Institute of Technology, have recently made some startling discoveries with reference to stem cells growing into heart muscles. In one of their experiments, the scientists grew masses of stem cells in lab dishes, isolating those stem cells that "were spontaneously developing into heart cells," which they could detect because the stem cells morphing into heart cells "were pulsing in unison, as heart cells are apt to do."
The Israeli researchers then placed a mass of about a million human stem cells (about the size of the head of a pin) into a lab dish with heart cells from rats. At first, the cells of the rat species and of the human species "beat at different rates," but within 24 hours of being in the same lab dish, "the combined masses of cells coordinated their pulsing into a single rhythm."
What does this prove or portend for the use of stem cells? Could stem-driven heart cells assist in setting the pace of a heart in a live animal? To take their experiment a notch further, the team of scientists "threaded a probe into the hearts of 13 pigs," making a tiny burn in the area that regulates the beating of the pig's heart. That burn caused a severe (and permanent) slowing of the pig's hearts, mimicking the rhythm disorder that cause result from a heart attack in a human. Then the scientists "injected about 100,000 of their human embryo-derived heart [stem] cells" into the slowed-down pig's hearts, and soon 11 of the 13 burn-damaged pig's hearts "returned to faster heart rates," according to Weiss's report.
What does this prove? it's just a "proof of principle," said Gepstein, though it's not as though people will be lining up for "biological pacemakers" any time soon.
In a phone interview with an Alzheimer Association staff person named "Elizabeth" (they don't give last names, she said) she was asked if her organization supports stem cell research. "I will read to you the position of our national Board of Directors, which made this official position statement in June, 2004," she said. "In keeping with its mission to eliminate Alzheimer's disease, the Alzheimer's Association opposes any restriction or limitation on human stem cell research, provided that appropriate scientific review, and ethical and oversight guidelines are in place.'"
Babbington, Charles. "Issues Overview: Stem Cell Research." Washington Post, 14 Nov.
Brainard, Jeffery. "Stem-Cell Research Moves Forward." Chronicle of Higher Education (October 2004): 51-6.
Europe Intelligence Wire. "Embryonic Stem Cells Correct Congenital Heart Defect in Mouse Embryos; Can Signal Neighbor Cells to Repair." (October 2004).
Obesity, Fitness & Wellness Week. "First derivation of retinal cells from embryonic stem cells; may treat blindness." October 2004.
O'Donoghue, Keelin, Fisk, Nicholas M. "Potential Applications of Stem Cells: Part 1."
Biologist (2004): 51-3.
Stem Cell Information. "Executive Summary." The Official National Institutes of Health