Death Most Unnecessary
A tiny globe, about the size of a grain of sand, is frozen in a glass straw of liquid nitrogen at minus 320 degrees Fahrenheit. Like flower stems, a dozen or so of these straws are arranged together in a squat aluminum tank that looks like a huge thermos. Several tanks form a row. Rows sometimes fill entire rooms in fertility clinics. Clinics dot the country.
No one can say how many "leftover" human embryos from in-vitro fertilization (IVF) attempts are locked in this climate-controlled limbo, their animation suspended in cryopreservation vats. Best estimate: tens of thousands in America alone, possibly 20,000 more each year, maybe more.
Each embryo-a shimmering soap bubble under the microscope-holds a complete human genome, the seedling of an entirely unique human being that might, given a mother's womb, grow into a child. Each vat of frozen embryos contains a potential playground full of children-boys and girls, redheads, brunettes, blondes, Asian, Caucasian and black. They remain frozen indefinitely. Or they may be doomed to a worse fate.
A powerful body of politicians, scientists and medical-research advocates is campaigning for federally funded researchers to kill living human embryos and harvest their cells for medical experiments. In June, for example, the American Heart Association announced its decision to support embryonic stem-cell research, calling it the "most promising medical and scientific research" in the fight against heart disease and stroke.
Next month, Congress is expected to debate S. 2015, the Stem Cell Research Act of 2000, introduced by Sens. Arlen Specter, R-Pa., and Tom Harkin, D-Iowa. The bill would effectively override current legislation forbidding the National Institutes of Health (NIH) from financing any research "in which a human embryo is harmed or destroyed."
Many of those who support the bill say they do so reluctantly, claiming that such research has the potential to save millions of lives. Yet while it's certainly true that stem cells hold great promise, it's also true that there's no need to sacrifice unborn children to obtain it.
'Illegal, Immoral and unnecessary'
Fueling the demand for experiments on human embryos is the spectacular medical promise of embryonic stem cells, dubbed by one researcher as the "queen of all cells." Theoretically, at least, stem cells hold the potential to cure diseases from diabetes to Parkinson's, to grow tissues and organs for transplants, to repair injuries, and to mend the tatters of old age.
Science magazine called their discovery the "breakthrough of the year" for 1999.
But human embryos are not the only source of stem cells: They are unexpectedly turning up in adult organs, too-in blood, brain and eyes, surprising scientists who've long believed they didn't exist in such places.
And study after study demonstrates that mature stem cells are far more versatile than scientists first believed. Like embryonic stem cells, cells from living adults and from discarded umbilical-cord blood can regenerate themselves and differentiate into other cell types. Both options could revolutionize medicine.
To obtain embryonic stem cells, however, an unborn human must be killed. In light of breakthroughs with cells from other sources, funding embryo harvesting is an endeavor Sen. Sam Brownback, R-Kan., has described as "illegal, immoral and unnecessary." The debate over S. 2015 is bound to hinge, in part at least, on his last point-whether it is necessary when adult stem cells have so much potential.
"That's the $64,000 question," says Eric Meslin, executive director of the National Bioethics Advisory Commission (NBAC).
The stem-cell debate intensified sharply after November 1998, when two privately funded research teams announced they had isolated embryonic stem cells. John Gearhart at Johns Hopkins University extracted the stem cells from cells harvested from the ovaries and testicles of aborted fetuses. Jamie Thomson at the University of Wisconsin, Madison, destroyed 36 living embryos from an in-vitro fertilization clinic to get five embryonic stem-cell lines.
And just what is it that prompts researchers to exploit the unborn with such gold-rush intensity?
A 5-day-old human embryo is a fluid-filled ball with 100-200 stem cells clustered inside at one end, like a mess of peas at the bottom of a pot. Each cell is like a human seed, with the potential to become any cell in the body-a neuron in the brain, say, or a disease-fighting white blood cell, or part of a liver or a kidney.
Researchers are trying to figure out exactly what triggers this transformation. Place a stem cell in one biochemical environment or another and you could yield skin for burn victims or functioning neurons for Alzheimer's patients. Add the right cocktail of growth factors and hormones and you might grow insulin-producing cells for diabetics, or human hearts for transplant.
Theoretically, you could even use stem cells to clone your own "spare parts"-so-called "therapeutic cloning." In that case, doctors would empty the embryonic cell's genetic contents, replace it with a bit of your own DNA (plucked from a skin sample), then tweak it to grow tissue or an organ. Furthermore, the transplant won't trigger an immune reaction when it's put into you, because it's made of you.
We Have the Technology
Will the mind-bending potential for medical miracles lead to a run on embryonic stem cells, and thus a run on unborn "donors"? Maybe not. The belief that mature stem cells are fixed in their roles and cannot be cajoled into taking on the business of other tissue is now being turned on its head. In rapid-fire succession, studies from around the world are demonstrating that adult stem cells performing one function in one organ can be triggered to perform other functions in other organs-a breakthrough for cell biologists on the order of turning straw into gold.
For example:
- In Pittsburgh and Montreal, scientists reprogrammed bone-marrow stem cells to make liver.
- Researchers in Baltimore convinced bone-marrow stem cells to produce bone, cartilage and fat cells.
- In Houston, researchers were startled to find adult muscle cells turn to blood.
- University of Minnesota, Minneapolis, hematologist Catherine Verfaillie told Science recently that she has isolated stem cells from the bone marrow of children and adults that are "almost like embryonic stem cells." Verfaillie said she has manipulated them to become brain cells, liver precursors, and heart, skeletal and smooth-muscle cells.
- In a laboratory in Stockholm, Sweden, adult brain cells from mice-stained blue for tracking purposes and injected into chick and mouse embryos-are growing into tell-tale blue heart, liver, muscle, intestine and other tissues.
"We have demonstrated that the potency of these cells was far greater than expected and what seemed to be a fairly restricted cell type can give rise to many different types of cells," Jonas Frisen, the study's lead scientist, told reporters when the research appeared in June. "These recent findings may turn some previous concepts upside down." One of the most amazing demonstrations that adult stem-cell destinies are reversible was reported in January 1999: Canadian and Italian scientists showed that mouse-brain stem cells could turn into blood.
"We think you can use skin stem cells to make other cells," said Angelo Vescovi of the National Neurological Institute in Milan, Italy. By September, scientists in Philadelphia had performed a mirror-image experiment: They showed how blood cells from bone marrow of mice, implanted into newborns, turn into brain matter.
Scientists are also scratching their heads in amazement at the places stem cells are showing up. Just a few years ago, it was believed that adult brains had no regenerative cells. Nowadays, that's like saying the earth is flat. An NIH primer on stem-cell biology, last updated on the government's Web site in May, downplays the advantages of adult stem cells and says they are not likely to be found in some adult organs, including the pancreas. But it's hard to keep on top of the discoveries: In February, a team of scientists at the University of Florida in Gainesville reportedly isolated pancreatic adult stem cells, got them to grow, then transplanted them into diabetic mice,
A better way
The medical implications of such findings are staggering. Researchers in Tokyo reported in the New England Journal of Medicine last year that they had implanted another kind of adult-eye stem cell into legally blind patients for whom no other medical treatment was available. A year later, half of the subjects could see.
While the results are encouraging, many experts say there is a better way. Oxford University's Richard Gardner, who chaired a Royal Society group on therapeutic cloning, says he is not opposed to using human embryos for therapeutic cloning but he thinks that it's "not terribly realistic. . . . This other approach of reprogramming later cells makes sense."
David Prentice, adjunct professor of medical and molecular genetics at Indiana University School of Medicine, agrees. Rather than trying to work "blank slate" embryonic cells up to a highly specialized tissue, Prentice says it's more feasible to start as close to the target cell as possible and work backwards. "There's fewer steps involved with adult cells, and it's less complicated," he says.
Embryonic stem cells' greatest asset-their ability to grow into anything-is also their greatest drawback.
"The problem is trying to control them," Prentice says. "Uncontrolled cell growth is cancer." In this respect, adult cells may be "better behaved," as Verfaillie has described her adult marrow cells, which only seem to grow in response to specific signals.
Prentice says that while embryonic stem-cell research is currently confined to experimental animals, adult stem cells are already used to treat human patients.
Bone marrow, containing a constantly replenished supply of blood- and immune-system stem cells, has been transplanted into patients whose immune systems have been ravaged by cancer therapy for decades. And the "next generation" of stem-cell transplants-using umbilical-cord blood-is well underway.
Miracles in the Making
In fact, stem cells from umbilical-cord blood are already saving lives.
Brandon McElhinney was 13 when he nearly collapsed in pain on his way home from school in Brighton, Colo., in the spring of 1997. His spleen was so enlarged it was bowing his ribs to the breaking point. He was diagnosed with chronic myelogenous leukemia.
The disease progressed rapidly. Brandon underwent intensive chemotherapy and radiation.
Somewhere in New York a baby was born, his umbilical cord cut and clamped, the blood inside siphoned and processed at the New York Blood Center, then shipped to Children's Hospital in Denver. Brandon remembers feeling unimpressed by the small packet of blood hung on his IV dispenser. That's supposed to help me? he thought.
But Brandon's doctor, Roger Giller, director of the hospital's Pediatric Bone Marrow Transplant Program, knew the value of umbilical-cord blood. He's done about 30 such transplants since 1996.
"It's become a preference now," Giller explains, "because it's a rich source of stem cells and it doesn't require the degree of immunological matching that adult marrow does."
Now 16, Brandon's leukemia has been in remission for three years.
But the holy grail of stem-cell research is not umbilical-cord blood transplants or even embryonic-cell transplants. It is the notion of using resources from within one body to heal another-or itself.
In April, Marina Cavazzana-Calvo and Alain Fischer of Necker Hospital in Paris announced they had done just that. Two babies born with a rare and potentially lethal immune-system disorder that forced them to live in protective tents to prevent infection became the first such patients to live normal lives after gene therapy.
The French team removed bone marrow from the infants, ages 1 month and 11 months. From the samples, they siphoned millions of stem cells, then used genetically altered viruses to deliver those cells healthy copies of the gene the children lacked. Finally, they re-infused the tailor-made stem cells into the children.
Just 15 days later, the new stem cells were detected in the children's blood stream. The babies' chronic diarrhea and skin sores disappeared.
Vaccinations produced a normal antibody response. They've been out of their protective bubbles for a year.
A quantum leap
The most dreaded complications in such procedures are the host rejecting the foreign transplanted tissue, graft versus host disease (in which the transplant assails its new resident), and the potential for introducing a foreign virus. According to William Shearer of Texas Children's Hospital in Houston, these are significant, sometimes fatal, risks.
"Donors always create a problem," Shearer says. "Anytime you can use the patient's own cells, you're leagues ahead. That's what the whole scientific world is chasing."
That's why, if all continues to go well, Shearer says the French gene- therapy experiment represents "a quantum leap into the future." It also represents a quantum leap over the ethical problem of using human embryos for medical progress. But demand for human embryos for experiments is not about to subside. More than 100 advocacy groups have asked the U.S. government to lift the ban on federal funding for human- embryo research. In a May 18 letter urging congressmen to support S. 2015, Superman actor Christopher Reeve, who was paralyzed from the neck down in a 1995 riding accident, wrote, "instead of being treated as so much garbage, [human embryos] can be used to work miracles."
"Thousands of human embryos that have already been frozen could be used," Reeve added. "Alternatively, within a single period of 12 to 18 months, enough new embryos could be harvested . . . to proceed."
"Human embryonic stem cell research holds such hope-such potential for millions of Americans who are sick and in pain," Sen. Specter wrote in a June 13 letter urging colleagues to support his Stem Cell Research Act of 2000. "[I]t is morally wrong for us to prevent or delay our world-class scientists from building on the progress that has been made."
One life for another?
Even if S. 2015 fails, the NIH is expected to issue final guidelines, with backing from the Clinton White House, which would essentially circumvent the existing ban on federal funding for embryonic-cell harvesting.
A group of 70 research scientists, including 67 Nobel Prize winners, called the NIH position "both laudable and forward-thinking" for "protecting the sanctity of life without impeding biomedical research." That seems to be a concession that killing human embryos is dark and troubling, if not outright wrong. Trouble is, they applaud it anyway.
"Life begins at conception," counters ethicist Dianne Irving. "This is not a pro-life position. This is not religious belief. This is objective scientific fact. Every scientist knows this."
Even James Childress, commissioner of President Clinton's National Bioethics Advisory Commission, testified before Congress that his commission "found widespread agreement that human embryos deserve respect as a form of human life." At the very least, Childress added, "this respect means that these sources should not be used unless they are necessary for research." Nevertheless, the NBAC recommended allowing federal funds to be used both to destroy human embryos, and to conduct research on their parts-implicitly recognizing that the distinction is meaningless. This leads us back to the question at the heart of the stem- cell debate: Can one human life be extinguished to help another?
Sen. Brownback argues that S. 2015 "would officially declare for the first time . . . that government may exploit and destroy human life for its own, or somebody else's purposes."
Kevin Fitzgerald, ethicist and assistant professor of medicine at Loyola University Medical Center in Chicago, compares it to such infamous cases as the Tuskegee experiment-in which blacks were denied syphilis treatments-and Nazi experiments on prisoners of war. Will we eventually view experiments on human embryos the same way?
"You can see many instances in history," Fitzgerald says, "where the powerful use the weak to gain certain insight."
"If [embryo scientists] were to offer me an elixir to escape my suffering, I would say no," says Mark Pickup, a disabled-rights activist from Edmonton, Alberta, who has multiple sclerosis. "You don't offer people therapy on the back of somebody else."
The fate of S. 2015 could determine more than the fate of all those human embryos frozen in cryopreservation vats: It will reflect, and to an incalculable degree decide, what kind of civilization we live in.
Celeste McGovern is a freelance writer in British Columbia.
© August 2000, Citizen Magazine, Focus on the Family
This item 3034 digitally provided courtesy of CatholicCulture.org
